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CDS Technologies leads the fiel stormwater pollution control traps capture the full range of water-borne materials, from sediments to cigarette butts and fast food packaging. In 1998 alone this gold medal performance has been recognised with prestigious industry awards including:

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Banksia Environmental Award

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Australian Technology Award

~ NSW Case Earth Award Thi s performance is a lso the reason our Continuous Deflective Separation units are the first choice of local councils, developers and water authorities across Australia . Winners a t:

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The future Olympic Games site at Homebush

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The Albert Park Grand Prix circuit

~ The Port Melbourne Docklands redevelopment Test results from independently assessed performance trials on some of the 140 CDS installations are available on request. Email us on: info@cdstech.com.au or visit our web site at: http// www.cdstech.com.au for more information on our winning solutions to water pollution . Australia -

VIC/TAS/ SA NSW

QLD New Zealand -

phone

03 02 07 07

5977 0305 9807 7477 3369 365 1 843 8008

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e~DS TECHNOLOGIES

The solution to water pollution


water

Volume 26 No 1 January/February 1999 Journal Australian Water & Wastewater Association

Editorial Board F R Bishop, Chairman B N Anderson, D Deere, P Draayers, W J D ulfer, GA Holder, M Muntisov, P Nadebaum, J D Parker, M Pascoe, A J Priestley, J Rissman, F R oddick, E A Swinton 'l. Water is a refereed journal. T his symbol indicates that a paper has been refereed.

CONTENTS From the Federal President .................... .. ...... .. ........ ........ ........... ..... ............. 2 From the Executive Director ................................................ ........ ..... ............. 4 MY

POINT

OF

VIEW

General Editor

Australian Technology for A Cleaner World .... .... ..... .. ................... .. .... .. ....... 3

Margaret Metz, email: 1mnetz@awwa.asn.au AWWA Federal Office (see postal address below)

I Kiernan AO WATER

Features Editor EA (Bob) Swinton 4 Pleasant View Cres, Wheelers Hill Vic 3150 T eJ/Fax (03) 9560 4752 Email: swintonb@c031.aone.net.au

EA (Bob) Swinton

Branch Correspondents

B Moulds, D How es

ACT - Ian Bergman Tel (02) 6230 1039 Fax (02) 6230 6265 New South Wales - Leonie Huxedurp Tel (02) 9895 5927 Fax (02) 9895 5967 Northern Territory - Mike Lawton Tel (08) 8924 6411 Fax (08) 8924 6410 Queensland - Tom Belgrove T el (07) 3810 7967 Fax (07) 3810 7964 South Australia - Angela Colliver Tel (08) 8227 111 1 Fax (08) 8227 1100 Tasmania - Ed Kleywegt Tel (03) 6238 2841 Fax (036) 234 7109 Victoria - Mike Muntisov T el (03) 9278 2200 Fax (03) 9600 1300 Western Austtalia - Jane Oliver T el (08) 9380 7454 Fax (08) 9388 1908

Advertising & Administration AWW A Federal Office PO Box 388, Artann on NSW 1570 Level 2, 44 Hampden R oad, Artarmon Tel (02) 9413 1288 Fax (02) 941 3 1047 Email: info@awwa.asn.au Advertising: Angela Makris Graphic Design: Elizabeth Wan

e1·

Water (ISSN 0310 · 0367)

is published six times per year: January, March, May, July, September, N ovember by

Australian Water & Wastewater Association Inc ARBN 054 253 066

MP\id

......

Cryptosporldlum... What Next? ... ............................. .... .. ................ ....... ........ 8 •, Lime Crystallisation for Softening Water and Reducing Salinity ....... 11 WASTE MANAGEMENT & POLLUTION CONTROL CRCWMPC Special Feature ...................... ... ........ .. ........ ........... ..... ........ .. ..... 15 The Professional Environmental Research Business: Will It Ever Pay? 16.

D E J Garman Performance and Commercialisation of CRCWMPC Research ...... ......... . 18

L Ridge Membrane Technology .. ........................ ..... ............................ .............. .... .... 20

I Fergus Wastewater Treatment and Water Reuse .... ... .... .. .. .. .. ... ....... .. ................... 22

F H udman The Need to Improve Dewatering Technologies ............ ........ .. ................. 24

S Miller Improved Biological Treatment Processes Through a Better Understanding of the Fundamentals .................... ...................................... 26

J Keller Solid Waste Management .... ... ... ... ... .. .. ... ... .................. .... .. ....... .. ................. 28

R Wainberg Contaminated Site Remediation and Hazardous Waste Treatment ....... 30

R Wainberg Structure of Bacterial Assemblages: Measurement and Application to Process Control ................................................................... ... ...................... 31

J Guan, R Amal, TD Waite Advanced Oxidation Processes and Potential Applications ............... .... 34

A J Feitz, R Aplin , T D Waite

Waste Minimisation and Cleaner Production .......... .. ........ ........... .... ......... 36

R Wainberg

Federal President

Education, Training and Technology Transfer ....... ......... ............. ... ........... 37

Greg Cawston

J Nielsen

Executive Director

WASTEWATER

Chris Davis Australian W ater & Wastewater Association (A WW A) assumes no responsibility for opinions or statements of facts eiqJressed by contributors or advertisers. Editorials do not necessarily represent official AWW A policy. Advertisements are included as an infonn ation service to readers and are reviewed before publication to ensure relevance co the water environment and objectives of AWWA. All material in Water is copyright and should not be reproduced wholly or in part without the written permission of the General Editor.

Subscriptions Water is sent to all members of AWW A as one of the privileges of membership. N on-members can obtain Water on subscription at an annual subscription rate of$50 (surface mail).

·, The Wonder of Worms for Sludge Stabilisation ........... .. ........ .. ............. 38

M Lotzof ENVIRONMENT Impact of Cotton-growing Pesticides on NSW Border Rivers ................... 43

EA (Bob) Swinton BUSINESS ,._ Fine-tuning Community Understanding of the Septic Tank ...... ......... ... 46

B Ridder DEPARTMENTS From the Bottom of the Well ...... .......... .. ....................................................... 4 International Affiliates ............ ..... ............... ....... ........ .... ....... ...... ........ ... ....... 5 Letters to the Editors ........................................................................ .... ......... 7 Meetings ............................................ .......................... ............ ............. ... ..... . 48 OUR COVER: The use of vermiculture to stabilise sewage sludge has been

mooted for the past 50 yea rs. Now the Redland Shire Council in Brisbane is using very large- scale vermiculture to process 400 1113 of mixed sludge per week . Photo courtesy of Mike LotzofofVennitech Pty Limited


FROM

THE

PRESIDENT

Smart Enterprises: Training Is The Key If they want th eir organisations to run at peak pe rformance, Australian employers need to think seriously about training staff at all levels and on an ongoing basis. The Australian Federal Government has invested many millions of dollars to facilitate training people from entry level all the way up to top manageme nt. Smart e nterprises will jump in now, make use of the products and services that have been designed, improve the skills o f all their employees and at the same time e nhance the competitiveness of their organisations. The difficulty which we all face is that of making sense out of the complex, j argon-ridde n world of the training industry. The number of acronyms flying around at a training meeting would rival those in any hightech industry, so it can be very daunting for the uninitiated. Don't be put off though, because opportunities exist to put staff through training, the reby rai sing performance and satisfaction for everyone. To und erstand the way training works, it is important first of all to recognise that the re are two very separate and distinct training worldsthree if you include the school system. Vocational training is aimed at people afte r they leave sc hool and, nowadays, can be delivered partially in school too. It embraces the traditional trades, and includes diplomas. In the language of the new Australian Qualifications Framework (AQF-our first lapse into jargon!), this means AQF levels 2 to 6. The levels are not very well defin ed-they are like regions around the rungs of a ladder rather than the rungs the mselves. T ertiary training, mainly the province of universities, covers AQF levels 5 to 8, i.e. from diplomas and gradua te ce rtificates through to the research pinnacle, the PhD. There is a significant overlap at levels 5 and 6 , which are common to both systems, so it is possible to have a diploma offered in competition by both T AFE and a university. In contrast with historic practice, the aim of current training policies is to allow for 'articulation,' which m eans that anyone who reaches a certain level should be able to improve their skills and move up to almost any higher level. Learning should be continuous and the levels seamless. This is probably a slightly utopian goal, but it will be very beneficial fo r that proportion of the workforce which has the will and application to keep improving. 2

WATER JANUARY/FEBRUARY 1999

The emphasis in training now is on outputs rather than inputs; in other words, on demonstrated competencies as opposed to time spe nt learning some thing. The traditional, time-based apprenticeship is intended to be replaced by a 'new apprenticeship' in which the trainee ca n move at his or he r own pace, mixing on-the-job training with classroom. training. Prior learning will be recognised and muc h of the training can be done at work and not sitting in the actual classroom. To implement this new orde r in the world of training, the Federal Government, through the Australian National Training Authority (ANTAacronym number two), has pumped millions into designing training packages, or structures which set out the competencies required for specific jobs at specific levels, the curriculum structure to deliver th ose competencies and to a lesser extent the resources to support the training organisations which do the teac hing. Althou gh T AFEs are still a major part of the training system, private providers are playing an important role too. A strange schism exists between the so- called vocational training system and the tertiary education system. The n ew, competency-based philosophies have largely been ignored by universities, which continue to focus on inputsstructured courses in specific timesinstead of e mbracing competency concepts. Fortunately, there is some dialogue between these two training worlds, so all is not lost. In reality, of course, neither system is entirely pure in its concepts: the vocational trai ning system still has pockets of very inputbased structure, while competency does come into tertiary training. Wh y burden you with all this background on training? W ell, as I

spelled ou t at the start, training is what will build Australia's competitiveness, so we all need to get into it with a will. Otherwise, we'll be left behi nd in the global race. T o gain from training, we need to ensure that it is appropriate to our needs. T he best way to do that is to keep in touch with the relevant t raining advisory body: in water's case, the N atio nal Utilities and E lectrotechnology Industry Training Advisory Body (NUEITAB-the last acronym, I promise!). This body acts as a conduit for information abou t training trends as well as being our vehicle fo r ge tting our needs heard and attended to. The biggest current risk is that the machinery might grind out courses and structures w hich are not suited to the needs of the water industry. The only way for us to avoid tha t is to be actively involved in all training developments and to make our needs clearly known. Greg Caivston

NewAWWA Members ACT W Bond, F Bouckaert, P Heweston New South Wales M Bates, R Campbell, R Chadwick, M Chapman, P Dahour, H Ellner, A Flinder, K Ford, T Jones, J Keary, S Khan, J Macleod, M Muir, J Prineas, M Rixon , G Rossington, A Spinoulas, Ntsougranis, M Warnecke, G Watson, S West, J Willetts, W Yeomans Queensland T Banks, D Bergade, W Bootle, P Broomhall, C Chidlow, B Cowan, M Crosbie, S Hegedus, R Herd, C Hester, S Hunter, S Koy, P McDonald, B Omundson, S Power, D Robinson, J Swartz, P Tuominen Victoria C Algie, R Ball, M Bethel, T Carroll, D Cecil, A Eglitis, K Evans, N Fisher, B Fu lton, J Giannopou los, K Go, M Gore, M Hindle, G Hocking, M Kozicki, C Leitch , Z Mierzwa, A Ohlsen, N Orr, M Peril, D Pra nanto, D Saunders, P Staiford South Australia S Beaty, T Holland, R Regel , N Rhodes, R Scott-Murphy, D Stevens, V White

Western Australia G Camkin, T Hodgkin, U Morgan, M Murray

Tasmania P Davies, B Hodgson Northern Territory Colin Beard


MY

POINT

OF VIEW

Australian Technology for a Cleaner World I Kiernan AO Ian Kiernan AO i s Chairman of the Cooperative Research Centre for W aste Management and Pollution Control and Chairman ofth e Clean Up Australia and Clean Up the World programs. R ecently he was awarded the top United Nations environment award, the Saskawa Environment Prize. We ail want a cleaner environment. Just ask the 40 million people wh o participated in the Clean Up the World campaign across the globe this year. Both at home and overseas, waterand how we treat it-is increasingly at the top of everyone's agenda. C lean Up the World committees have focused year after year on cleaning up local wa terways , the life-blood of their communities. International commentators even suggest future global conflicts will b e fought over access to fresh and clean water. I believe that the basi c logic of p resen t- day water management is flawed, both from an economic and practical p erspective. We are fighting the natural wa te r cycle, pillaging the aquifers, interrupting natural flows, and polluting one of our most precious resources. But the days of discharging untreated eilluent into the ocean or rivers, while draining our rivers of precious flows, are nu mb ered. We must reuse o ur water. But how can we do this? It is w idely agreed that pollution is economic inefficiency. Industry knows that cleaning up its act will not only make it more efficient, but that i ts efforts in this critical area will lead to a cleaner environment. The future of the world is based on sustainable development, which means integrating best environme ntal practice with best industrial practice. There is w idespread agreement that research makes good sense. Environ mental research makes even be tter sense, as it provides excellent econornic opportunities for business and ensures a sustainable future for our planet. H ere in Australia , cooperative research with industry is the envy o f many other countries. The Cooperative R esearch Centre for Waste Manageand Pollution Control m ent (CR CWMPC) is at the forefront of world environmen tal research. O ver th e years of i ts ope ration the CRCWMP C has increased its profile

within both industry and the public arena to cement the position of research culture in Australian society. But the C RCWMPC hasn't stopped there. It has trail-blazed new paths of internati onal linkages in Asia and E urope through an Environme nt Industry D evelopme n t Network (EID N). Already industry has invested m ore than $4.5 million in new initiatives sponsored by E ID N through government funding for development of the Australian environment industry. It is a heartening experience to be involved with an organisation such as the C R CWMPC, which is committed to providing tool s t hat w ill e nable industry to both manage the environm ent more wisely and generate new industries for Australia. T he CRCWMPC i s tackling the demanding issues of waste and pollution through a n umber of different ch annels. One of the most innovative of its projects is investigating the applications of very large- scale verrniculture (wonns) to convert sewage sludge and waste paper into an organic soil conditioner. An other involves discovering better bacteria to break down sewage in order to help improve the performance of sewage treatment works in Australia and abroad. Many of these ideas are based on very simple science and h ave the potential for widespread, cost-effective application. An example is a project that e ncourages the use of reed beds to remove pollutants from contaminated water. The improvement of the design of manufactured wetlands is another

relatively simple idea that provides a cheap and appropriate technology to remove pollutants and nutrients from wastewater. On the international fron t, th e CRCWMPC proj ect involved in developing a process to remove arsenic from drinking water cheaply and effectively is helping to solve a major international water-quality problem. So we see that the community is demanding bette r environments; the. government is legislating for better environments; and industry is responding. But there are still a few steps to go. The first of these is happening under the auspices of C lean Up Australia. Clean Up is implementing several high profile demonstration projects around the coun try with the aim of setting an example for industry and showing the ben efits that flow from a cleaner enviromn ent. T he CRCWMPC, C lean Up Australia and C lean Up the World all start with a philosophy of waste management w hich recognises that it is a strong partnership between industry, community and government which is going to improve the state of the world's environment. In Australia, C lean Up aims to provide these demonstration projects under the Clean Up Australia 2001 program. Already the first project is complete . The $2.2 million Wastewater Treatmen t and R euse Plant at Sydney's Taronga Zoo has elirn.i.nated a point source of pollution from Sydney H arbour, and reuses water around the Zoo. D emonstration projects like this w ill ultimately show t hat sound environmental management makes good economic sense. But it is not only the demonstration that has to be done. There has to be innovation and research. This is w here the goals of the CRCWMPC and C lean Up dovetail neatly together. It is gratifyi ng to see that the grass roots activities of C lean Up Australia combined w ith th e CRCWMPC's development of Australian technology for a cleaner world are actually going to make a difference. A nd that's good news for all of us, because it means that at this point in our history the prognosis for the health of ou r planet is looking extrem ely good. WATER JANUARY/ FEBRUARY 1999

3-


FROM THE EXECUTIVE DIRECTOR

Good Sports Needed It is interesting to note how the tide of competition ideology is impinging on the water industry. A few years ago every water enterp rise in Australia was owned and operated by e ithe r a statutory agency or a local government body. In the early 80s, a wave of 'reforms' began to sweep in , characterised by endless restructuring and the adoption of n ew buzz words for the way organi sations ope rated and what t hey aimed to achieve. Suddenly, the number of rings before a phone was answered was as important as producing good drinking water or minimising pollution. By the early nineties, a strong current was building, eddying around the whole country and throwing together ideas about competition, globalisation and private sector participation. Conventional wisdom among State governments produced some interesting positions, namely that only international companies had the credentials to operate systems which had been run by locals for the last hundred years or so, and that som e States would not contemplate having an agency fro m another State offering services. This was Australian parochialism at its amazing best. Of course, the truth is that we do have the ability to run water agencies effec tively, either on our own or in partnership with others so that we come up with an optimum result. But we can' t have blinkers on the world. There are innovative people from othe r countries who have learnt and have got ahead of us in a number of areas, bu t conversely we can show that we lead the world in some arenas. Areas where we excel, for instance, are leading-edge BNR technology, asset management strategies and catchment management. We should be building on these strengths, rather than prolo ngi ng the cultural cringe. Given the political and social climate in w hich we have been operating, a move towards globalisation of t he Australian water industry was p erhaps inevitable. But changes have been introduced very rapidly, with the result that local firms have been caught on the back foot and have had to adapt quickly in order to compete in the new market. For the most part, our industry 1s 4

WATER JANUARY/ FEBRUARY 1999

probably better off and more vigorous as a result of these changes, but I do wonder at some asp ects of the b rave new world of the corporate water enterFrom many prise. decades of overcautious, over-staffed and over- e ngineered operations, the n ewly corporatised agencies felt the need to assert their commerciality by focusing almost entirely on the bottom line. T echnical staff were pruned and peripheral, and ' non-core' activities like research were abandoned in favour of aggressive commercial activi ties. At the same time, there was pressure put on water agencies by State gove rn ments w hi ch insisted on sub_stantial dividends and equivalent tax regimes. What seems to have been overlooked in this headlong rush to become 'corporate' is the fac t that successful global businesses do ensure they maintain key staff above minimal levels and do work at being good corp orate citizen s. These are otherwise hard-nosed, commercial companies, with long track records in the cut-throat world of business. They know from many years of experience that th e only real resource most companies have to differentiate themselves from their competition is the intellectual capital they hold in their employees. The pendulum swing of corporate behaviour in our water agencies may have taken them past the real 'corporates' and into risky ground. I feel we need to draw back from those politically correct frontiers and attend to some very basic housekeeping, so that we can rebuild effective, foc used water agencies capable of deliveri ng the services needed in competition with the world's best. The issue is not w hether an organisation is privately or publicly owned and operated, but whether its leadership understa nds its real objectives and applies that understanding w hen it creates the working environment. Australians have a reputation for amazing prowess on the sports field. Let's show the world that our water industry is capable of equal prowess in the corporate sense. And let's learn to play as a team, especially w hen we move out to take on the rest of the world. Chris Davis

From the Bottom of the Well For one hu ndred years we have been searching for a satisfactory system of management for Sydney Water, through seven Royal Commissions and hordes of enquiries and consultants. Why so difficult? To my mind the factors include: • a water authority has the capaci ty to inflict severe political harm on governments and some have lived up to that capacity from time to time • a Minister may value p olitical responses above managerial and technical competence • the public takes water for granted, and is hugely outraged by any problems • water services require long-term planning and there may b e no quick fix available for p roblems that emerge • the public b egrudges t he large amounts of capital required • politicians covet the large and tempting cash fl ows th at ca n b e generated • the complex, multi-disciplinary problems associated with safe water and wastewater services require a perh ap s uniquely skilled management. Crises of confiden ce can be divided into two parts: the 'political' and 'substantive,' or perceptions and reality. The political problem is often solved by sacking somebody, announcing an 'inquiry,' or proposing tougher regulations. This apportions blame, deflects the attack , and more significantly, buys time, so that the crisis is damped down and the su bstantive problems can be calmly addressed. However , it does not solve the real problems, and often results in undesirable collateral damage including tending to make the organisation risk-averse. So w hat might be done? W e could give Sydney Water back to the ratepayers (who have paid for it), with an indep endent board of m anagemen t, elected by and accountable to local government, with an advisory panel of members appointed fo r relevant expertise. We could stop treating authorities as taxing authori ties. We could recognise that there is no substitute for well trained 'water industry managers' able to focus on effectiveness as well as efficiency, and capable of viewin g the water cycle in its totality. They should, of course, be subject to regular technical and financial audits. Does this sound familiar to some of us 'oldies'? Fredda


INTERNATIONAL AFFILIATES \later Environment Federation® P,-eseroh1 &Etllxmci11g the Globa!Water E111Jiro,m1e11t

A special families segment was incorporated into the Water Environment Federation's annual conference for the first time in October last year in Orlando, Florida. Children were encouraged to visit an interactive display on the wate r environment which included a water cycle pinball machine, a m useum of water utility paraphernalia complete with old pumps and laboratory equipment, and an interactive co mpute r game where the player had to identify the source of, say, an oil spill. These 'games' kept the kids entertained and taught them about the water environmen t at the same time. T hey were then encouraged to go on

Kids Go With The Flow at WEFTEC '98 a treasure hunt through the 'Go With the Flow' exhibition, which involved them donning hard hats and following the flow map through the various water treatment phases from the superm arket all the way to the ocean, lake, river or stream. T he map took them to various equipment or service suppliers along the way, where they had to get their map stamped to say they'd been there. When they got to, say, the screenings area, the map took them to a supplier of screen s so that they could see what a screen looked like. At the end of the treasure hunt they received a medal once they'd proved they'd covered the whole treatment flow. T he organisers were surprised at the children's dedication in following the flow-they didn't just take the hat and

run, but actually came back with all the stamps and got the medal. Plans are on the drawing board to mount the family segment again next year. In the United States, water utilities have recognised that it is in their interests to educate the decision-makers of tomorrow about the water cycle in order to ensure that informed decisions are made in the future on water-related projects. H ere in Australia AWWA is making a start on its future decisionm akers by producing a CD-Rom for schools. Hopefully the success of the WEF interactive displays and the treasure hunt are a good indicator of how well the CD- Rom will go herebecause it is along the sam e theme of giving children a greater understanding of the water cycle.

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Now for the big kids. All in all, WEFTEC '98 was a big success, with more than 16,600 registrants turning up to what was a very hot event, in terms of both content and local temperature. At the opening ceremony, J Charles Fox, Assistant Administrator of Water for the US EPA, talked about the large gains made in US water management and thanked WEF for i ts partnership. H e pointed out, however, that there is still much to do, with over 40% of USA waters not meeting swimming and fishing goals.

T he Clean Waters Action Plan aims to: • ensure all 450,000 animal feeding operators follow environmental management plans • develop unifi ed watershed assessments and prioritise improvement work • develop nu trient criteria based on scientific j u stification. T he WEF Board of Directors also met in Orlando and approved the signing of a range of partnering agreements with other associations including the America n Water Works Assoc-

iation, American Consulting Engineers Council, AID IS, American Society of Civil Engineers, and the Water and Wastewater Equipment Manufacturers Association. Aswell, the Water Environment R esearch Foundation (WERF) ou tlined a $35 million research program over the next five years. WERF's vision is: 'Defining the future and conducting the research to meet it.' Outgoing WEF President Dale Jacobson handed over the reins to new President Rhonda E H arris. G Cawston WATER JANUARY/ FEBRUARY 1999


INTERNATIONAL

AFFILIATES

IAWQ Conferences, Western Australia INTERNATIONAL ASSOCIATION ON WATER QUALITY Sludge Management for the 21st Century-A Value-added Renewable Resource Fremantle, Western Australia, 8-10 April 1999 A specialist IAWQ/A WWA confe rence with an emphasis on thermalbased sludge technologies will be held in Fremantle, W estern Australia with the aim of providing sustainable sludge m an agement sys tems for the 21 st Century. The conference, to be held from 8 April to 10 April 1999, will provide an opportunity for sludge practitioners from around the world to exchange information on 'value-adding' sludge m an agem ent system s, emphasising renewable resource options othe r than direct agricultural reuse . The confe rence sessions have been selected to cover all aspects of the sludge man agement cycle. • Thursday 8 April: Sludge prep aration including characterisation , p retreatment, dewatering and drying. T hermal m anagement system s, e.g. gasifica tion, conversion to fuel, product e nd uses.

W estern Australia is definitely the place to be in April/M ay 1999. T wo specialist conferen ces are to be convened by the Australian chapter of the International Association on W ater Quality (IAWQ) and the W estern Australian Bran ch of the Australian W ater and W astewater Association. • Friday 9 April: T h ermal management system s, e.g. combustion/en ergy recovery, vitrification, supe r critical oxidation. Impact assessment, including risk assessm ent, environ mental impacts, cost/benefits and energy conversion. • Saturda y 10 April: Optional morning technical tour to ENERSLUDGE™ plant and the ESD/gas engine plant. We are confident that together with selected keyno te addresses and the technical program, this conferen ce will provide a produ ctive and m emorable experien ce. Trevor Bridle Chairman, Organising Committee

International Conference on Diffuse Pollution Perth, Western Australia, 16-21 May 1999 A specialist IAW Q /AWWA conferen ce is to be conven ed in P erth, W estern Australia, from 16 to 21 May 1999 . The theme of the conference is Solution s-Innovations and the program will focus on non-point source pollution featuring:

• keyn ote addresses by renowned experts from around the world on th e most inn ovative approach es and solu tio ns to diffu se pollution problem s • concurrent sessions of informative, high quali ty pap ers by recognised local and in ternatio nal experts, w ith an emphasis on w orthw hile professional development outcomes fo r delegates • an innovative social program to fac1litate the exchange of information and coop.eration at an informal level. The conference is exp ected to attract more than 200 specialists from 30 countries an d will bring together intern ation al exp erts in the fields of non-point so urce pollu tion estimation, prevention, impact, management and abatement. D etails are available at http://www. environ.wa.gov.au/news/ads/advert.htm. The conference secretariat and Confe rence M anager Dianne M cLeod of Convention Link can be con tacted by email at convlink@wantree.com.au. Dr Robert Humphries Chairman, Organising Committee

Humic Substances Downunder The In ternational Hum..ic Substances Society (IHSS) held its 9th International M eeting (IHSS-9) with the theme of Humic Substances Downunder in Adelaide from 21- 25 September this year. The 230 participants at the conference represented 30 countries, with the four largest representations from Australia (77), Germany (32), Italy (15) and the U SA (17). Seventy- six oral papers and around 150 poster papers were presented. The conferen ce brought together researchers from a wide variety of disciplines who have a common interest in understanding and m anaging natural organi c matter (NOM). Disciplines represented were soil science, environm ental protection, water chemistry, geochemistry, agriculture and soil fertility. The main themes in the scientific sessions w ere Charac terization of Organic Matter, Organic Matter an d Soil Fertility and Plant Grow th, Organic Matter-Metal and Other Interaction s, the Bayer process, W ater 6

WATER JANUARY/ FEBRUARY 1999

Geochemistry, Organi c M atterPesticide Interacti on s, W ate r Treatment, Soil and Sediment Geo chemistry, and N ew D evelopmen ts. In sessio ns on the characterization of organi c m atter, Professor Morris Schnitzer (Germany), Professor Malcolm O ades (Aus tralia) and Dr Michael H ayes (United Kingdom) pointed to a trend aw ay from isolation and fractionation of organic matter towards analysis of whole samples. This move is largely due to a concern that the process of extraction of organic matter from its n atural environment changes the intrinsic characteristics of the individual components and the sample as a w hole, and also that the nature of the resulting isolated sample is dependent on the m ethod used. The move towards whole sample analysis has b een e ncouraged by improvements in analy tical techniques such as heteronuclear and m ulti-dimensional NMR, pyrolysis- CC-MS and related pyrolytic techniques and FTIR/

DRIFT analysis. Professor P H atch er (U SA) , Professor J H edges (U SA) and D r T Eglington (USA) spoke in the sessions on sediment geoch emistry, water geoch emistry and n ew developments in organic matter research, respectively. T heir work highlights how the newer multiple analytical techniques and com puterised data analysis techniqu es have been applied to improving the understanding of the composition and cycling of compon ents of organic matter. The processes involved in C -cycling are being used to develop concepts of the generalised structures of natural organic molecules. This approach to enhancing the understanding of the nature of these compounds is made conside rably easier by the use of recently developed compu ter generated molecular modelling system s allowing a more flexible and more easily m anaged modelling approach. Characterisation of N OM is becoming increasingly important in a wide


INTERNATIONAL variety of disciplines as the nature of NOM is being recognised as significant in the adsorption/interaction with pesticides and formatio n of disinfection byproducts in the water treatment industry. In the session on water treatment, Professor F Frimmel (Germany) highlighted the need make use of recent advances in the techniques of characterising NOM. T his would optimise the methods of NOM removal in water trea tment and mimimise the n eed for c hlorination. Other pape rs in this session addressed specific problems associated with the presence of NOM in the water treatment industry, with presenters coming from the USA, France and Ge rmany as well as Australia. The role of nitrogen- containing compounds is presently being studied not only in the charac terisation of organic matter components but also in research associated with soil fertility, the use of organic wastes as soil ameliorants, and problems associated with the treatability of wate r for drinking

AFFILIATES

The book of abstracts fo r the conference (S20 incl. p os tage) is currently available, and the conference proceedings of selected refereed papers should be available in mid1999. Contact Dr Kaye Spark, Conference Secretary IHSS-9, PMB 3 Salisbury SA 5108, tel. (08) 8259 0349, fax (08) 8259 0228, email ihss9@sawater.sa.gov.au. purposes. Consequently, an interest in nitrogen- containing compounds in organi c matter and N-cycling was apparent in m any of the sessions at the confere nce, as the analytical techniques used and the development of concep ts of c hemical processes overlapped a range of disciplines. As in the sessions on characterisa tion of organic matter, this overlap of interest in N-containing co mp ounds of organic matter from researchers from a variety of scientific disciplines highlighted and reinforced the need for this type of m ulti-discipline scientific conference.

Dr Mich ael Hayes from the Chemistry Department of the U niversity of Birmingham, UK was made an honorary member of the society at the IHSS-9 meeting, in recognition of his work in both founding the society and his contribution to the science of humic substances. A tribute was given by the President of the IHSS, Dr Jim Alberts, Directo r of the Marine Institute at the University of Georgia, Sapelo Island, Georgia, USA at the general meeting of the soci ety in m emory of Dr R on Malcolm, of Colorado, USA, an honorary m ember of the IHSS who died earlier this year. The conference organising committee is grateful for the financial support received from the Grain Research and D evelopme n t Corporation , Horticultural R esearch and D evelopment Corporation , AusAID, the Cooperative R esearch Centre for Water Quality and T reatment, Alcoa Australia, SA Water, U nited Water, the University of Adelaide and CSIRO. Dr Kaye Spark Conference Secretary, IHSS-9

LETTERS TO THE EDITORS Factual Errors In response to Mike Polin's letter in the September/October issue of W ater, I must object to AWW A's editing of m embers' letters/submissions- in particular when what the writer said is misrepresented and printed. I did not call the panel presenting views on the pros and cons of privatisation 'h eavies'- ! called them an 'eminent' panel and I have no problems w ith the views they expressed. However, I did describe some of the speakers at the Melbourne conference in that way, and make no apologies for that. I believe it may have been Water's editor who got it wrong. 1 As Mike Polin pointed out, it was I

Positive Feedback from Sweden On the topic of AWWA's promotion of the Stockholm Junior Water Prize in Australia , I only have one word to say: TERRIFIC! The articles are very good, and of course the placement and coverage overall is wonderful. W e really appreciate the support that you 've given the contest in Australia, and we look forward to continuing. Please let us know how w e may assist you during the coming year. In h er communication with us Angela Makris ' hoped' that your coverage was of the standard of other organisers and supporters, but I must

that asked the question in Sydney as to the benefits that the community could expect if our industry was privatised or sold to private interests. The 'deafening silence' (o r words to that effect) from the panel in response to my qu estion was reported in Crosscurrent by Bill R ees shortly after the event.2 With respect to Mike's 'left field' insinuation that I have a habit of not listening to an answer after I ask a question-this is a rather confrontational sta tem ent by a person w ho sh ould know better and furthermore cannot claim to know anything abou t me except my name. Let me assure colleagues that I was too engrossed in trying to hear an say it is among the best I've seen. If all participants can encourage and develop the Stockholm Ju nior Water Prize as you are (and we will support them in this), then the Junior Water Prize will quickly become known around the world in scientifi c and educational circles, and also in the mainstream. And of co urse this will benefit the students , educators, sponsors and organisers, and, ultimately, the fu ture water envi ronment. Thanks again for the great materials! Anne Lindenb11rg Stockholm ]11nior Water Prize Coordinator Stockholm, Sweden

answer to my question to notice the 'deafening silence' personally. Rein Loo Rein Loo & Associates Consulting Engineers, Water Management, Perth, WA 1. The General Editor of W ater rearranged the text in the interests of readability. If an error was introduced during that process she apologises. However, the edited version was sent to the author for approval and it was his responsibility to check and amend it if necessary. The General and Features Editors of Water reserve the right to edit contributions for scientific and factual accuracy, readability and according to space requirements. 2. In fact, BiU's words were, ' le becam~ apparent that fuU privatisation was regarded as a very sensitive issue and nobody wanted to discuss it!' (Crosscurrent, 17 May 1995, p. 3)-Gen. Ed.

'CRYPTO' CROSSWORD SOLUTION

Mark Biebrick of SA Water received an AWWA tie for sending the first complete, correct crossword.

WATER JANUARY/ FEBRUARY 1999

7


WAYE R

CRYPTOSPORID/UM... WHAT NEXT? EA {Bob) Swinton In October 1998, around 300 delegates attended 'Ciyptosporidium in Water', a conference held in M elbourne by the Water Services Association of Australia (WSAA), the Australian Water and Wastewater Association (AWWA) and the Cooperative R esearch Centre for Water Quality and Treatme nt (CR CWQT ). When first mooted so m e months earlier, the organisers expected about 50 or so 'experts' to attend. However, as a result of the publicity generated by the Sydney Cryptosporidium event, the concern of the water industry in gene ral was reflected in a vastly increased attendance, including a number of people drawn from the management strata. The objec tive of the conference was clearly stated by Dr J o hn Langford , Executive Direc tor of WSAA as being to ac hieve some consensus on wh ere we stand in Australia and in what directions we should advance, both in terms of knowledge and ma nageme n t. Three areas were the subj ect of separate conference streams: parasitology, epidemiology and risk management.

tion w hich resulted in political and legal fallout. Professor O'D onoghue ou tlined the life cycle of C1yptosporidium, which is known to exist in birds, reptiles and fish as well as mammals. H e summarised the transmission routes and said that only one mammalian species, C. parvum, has been associated with disease in humans. Most epidemiological studies have implicated direct h uman- to-human transmission and, to a lesser extent, animal-to-human transmission. To w hat extent animal-to-human transmission of the parasite can flow t hrough the water supply sys tem emerged as perhaps the main theme of thi s conference. Although it is thought that species which infect birds do not infect humans, there is the possibility that wa ter birds can passively transfer oocysts in faecal matter from paddocks into reservoirs. As detection method s improve, the frequen cy of detection increases. H owever, we have no previous data to say w hether there is an increasing trend, partic ularly as the background of Current Knowledge gastroenteritis from food will mask all In fo rmally opening the confere nce, bu t a major waterborne outbreak. Australian awareness is five years Professor Larkins of the National H ealth and M edical Research Council behind that of the UK and U SA, where d rew at tentio n to the necessi ty of the major outbreak in Milwaukee in educating the public about the relation- 1993 stimula ted action. The 1987 ships between health significance and Badenoch R eport in the UK recomcost. In regard to Ciyptosporidium , he mended ri sk assessment and prioritised posed the question o f wh ethe r we responses and there is as yet no standard should aim for zero co unts, safe levels, imposed, though one is proposed. In the USA the SWDR lays down protoo r merely monitor trends. Professor Peter O 'Donoghue of the col for 'boil water alerts' w hich are Department of Parasitology at the instigated qui te frequently in cities University of Queensland spoke from drawing water from surface supplies He posed the qu es tio n , as new the hea rt ab out the Sydney event, asking, Is there really a 'crisis'? H e methods of detection are invented do pointed out that there is a wide differ- we extend our testing frequency, and at ence between detection of contamina- w hat stage do we react? Not en ough is known about the basic biology of the tion and an outbreak of disease. In Sydney, despite the erratic counts parasite, or the real effect on public in the water supply, there had been no health of the low doses which could disease attributed to the water. Yet emanate from inges tion of treated there were recent outbreaks of crypto- water, even with positive counts. sporidiosis in most states of Australia, traced to contaminated public swim- The American Experience ming pools. Bill M ackenzie from the Center for Following the 'boil water alert,' the Disease C ontrol in the USA was m edia had invented a newsworthy involved in the investigations of the 'conspiracy,' so fuelling a panic situa- Milwaukee epidemic. The first human 8

WATER JANUARY/ FEBRUARY 1999

report of cryptosporidiosis was in 1976 in an immuno-compromised patient, followed by diagnoses in international travellers from third-world countries. Since 1984 there have been nine ou tbreaks attri buted to drinking water, yet in all but one instance the water met existing quality standards. Howeve r, in a study of healthy populations, more tha n 50% have antibody evide nce of previous infections. T his suggests that exposure to infection is relatively common. In one survey, 97% of untreated surface wa ter samples con tained the parasite, and filtered water in 67 utilities showed evidence of low levels in 54% of supplies, w ith 21% of these showing mul tiple occurrences. D espite a ' stateof-the-art' treatment plant in Las Vegas, in one year there was a peak of 78 diagnosed cases, after the spring rains, mainly in HIV-positive individua ls. According to Bill, 'C hildren's bottoms are parasitic and bacterial UZis.'* The major spread of infection is by young children using public swimming pools, swimming in rivers, playing in fountains, and also between infa n ts in daycare cen tres, all with peaks in la te summer. There is another age group implicated, the 30-40 years old (possibly the parents of the infected children) . A couple of drugs have been trialled with some success for cryptosporidiosis in infected AIDS patients, giving some stasis of symptoms, though not complete cure. T here is evidence of immunodevelopment after large doses, but this is still susceptible to strain modification . It is extremely difficult to monitor outbreaks, since the incubation period after exposure is 6-7 days, followed by diarrhoea containing thousands of oocysts. Testing of the stools of severely affected patients does not usually occur fo r another 4-10 days, with a further delay in reporting of 3-4 days, i.e. a total of 14-30 days.

UK Experience The theme of how infection spreads was continued by David Casemore of th e P ublic H ealth Laboratories in the UK. Studies commenced in the 1980s,

* An UZI is a high- powered

machine gun


m

WATER

LIME CRYSTALLISATION FOR SOFTENING WATER AND REDUCING SALINITY B Moulds, D Howes Abstract It is proposed to use a lime softening process at a groundwater t reatme nt pla n t being built at Nee rabup near Perth, Weste rn Au stralia. N ee rabup borefield draws water from a coastal aquifer that con tains levels of salinity and hardness in excess of the National H ealth and M edical Research Cou ncil (NH &MRC) drinking water guidelines . The process w ill reduc e the concentra tion of calcium and bicarbonate ions and also the total dissolved solids (TDS) conce ntration. Lime crystallisation is a water softening process which has many potential advantages over conventional softening. Whilst the chemistry of the softening reactio n i s essen tially the same as conventional softening, lime crystallisation empl oys a fl uidised bed reactor to significantly improve the reaction kinetics and produce a pelletised byproduct. As lime crystallisation ha s bee n inc reasingly adopted in Europe for wa ter softening, it was decided to examine the process in d etail. Pilot trials were conducted on water similar to th at expected from the Neerabup borefield. The trials es tablished the technical feasibility of the lime crystallisation process.

Introduction T he Water Corporation of W estern Australia is p resently developing the Neerabup Groundwater Scheme which is located along th e coastal strip about 25 km north of Perth. This scheme is to be developed to its full capacity of 120 ML/day in 1999 (24 GL/annum). The treatment p lant will incorporate a lime soften ing process to reduce water hardness and salinity levels. T he lime crystallisation process was trialled as an alternative to conventional lime softening using clarification. W ater from the Neerabup borefield is expected to have a TDS of about 640

mg/L, whereas th e N H &MRC drinking water guidelines se t an aesthetic guideline of 500 mg/L fo r TDS. Th us, it is required to reduce the TDS by about J50 mg/L. Water having hardness of 60-200 mg/L (as CaCO3) is regarded as good quality. H ardness levels are expected to be about 240 mg/L in the Neerabup borefield. There is therefore a requiremen t to reduce hardness by at least 40 mg/L but not more than 180 mg/L.

T his reaction reduces the hardness. Finally, if additional lime is added, increasing the hydroxide ion conce ntration beyond pH 9.6, the solubility product fo r magnesium hydroxide may be exceeded and magnesium hardness will precipitate as magnesium hydroxide.

Water Softening Using Lime

This reaction is virtually complete at p.H 10.5 bu t in the lime crystallisation process, which is operated at pH values lower than 10.5 , onl y a minor amount of magnesium is likely to be precipitated from the N eera bup water.

H ardness in natural water is caused by the presence of any polyvalent metallic cation. The most p revalent of these species are th e dival ent ca tions of calci um and magnesi um. One method of softening is to add lime and/or soda ash to th e wate r, which eleva tes the pH. Hardness is removed due to the relative insolubilities of calcium carbonate and magnesium hydroxide. The reactions w hich occur w hen Ca(OH )2 (li me) is dosed to hard water as a softening chemical are as follows. Firstly, the hydroxyl ion from the lime reacts w ith dissolved ca rbon dioxide to form first bicarbonate ion , then carbonate ion. If the solubility product of calcium and carbonate is exceeded, calcium carbo nate will precipitate. This reac tion does no t result in any hardness reduction bu t must be taken into accou nt as it may contribute a significant portion of the total lime requi rement.

The lime also reacts with the calcium and bicarbonate ions already present in the water to form insoluble calcium carbonate. Ca(OH) 2(aq) +Ca 2\

aq) +2HCO 3-(aq) -+

2CaCO 3(,) +2H 2O (I)

2Ca(OH)2(aq) + Mg2+(aq) +2HCO 3- (aq) -+ Mg(O H )2(,) +2CaCO 3(,) + 2H 2 O(ll

Lime Crystallisation T he lime crystallisation process takes place in w hat is known as a pelle t reactor. Water is fed into the base of a cylindrical vessel or 'column' that is partially filled with a suitable seed material. T he seed material normally used is sand, which becom es fluidised when subject to the high upflow rate in the column. T his fl uidised bed provides a high specific surface area (- 5000 1112/ 1113) .

Lime (calcium hydroxide) is introduced into the base of the column along with the raw water. The lime reacts to fo rm calcium carbona te. However, the high specific surface area in the fluidised bed favours crystal growth on the sa nd in p reference to spontaneous crys tal formation in solution. The product of the water softening reaction , calcium carbonate, is then deposited onto the sand grains, which grow in size. These larger- sized 'pellets' tend to accu mulate at the bottom of the fl uidised bed. The portion grea ter than 1 111111 diameter is intermittently or contin uously drained from the reactor. Fresh sa nd is added at the top of the column to replace the seed material removed WATER JANUARY/ FEBRUARY 1999

11


WATER when the full-sized pellets are drained. The advantages oflime crys tallisation are that: • it is a high rate process requiring a relatively small area for the plant • the lower control dead-time allows more posi tive control of water quality (at typical loading rates everything hap pens 16 times faster than in the conventional lime clarification process) • the waste products are pellets w hich drain freely as opposed to the voluminous sludge produced in a conventional lime softening clarifier (i.e. pellets are more convenient for transportation and storage) • the pellets are more li kely to be a saleable commodity (in the N etherlands and UK pellets are sold to the agricultural and light industrial sectors).

Pilot Trials A pilot plant was set up to trial the lime c rystall isation process on water similar to that expected from the Neerabup borefield . The pilot trials assessed: • the benefits of aerating the feed water (to reduce the dissolved carbon dioxide concen tration) • possible in terfe rence with pellet fo rmation by phosphate in the grou ndwater • use o f diffe ren t sand types as the feed material • filterability of the effiuent • the filter aids (polyelectrolyte or ferric salts) required. Initially, the trials were conducted using milk-of-lime at a concentration of 2.1 % as CaC0 3 (111/111) (i.e. a suspension of lime containing undissolved calcium hydroxide particles). B ecause various problems were encountered in the pilot plant in batching and handling the milk-of-lim e, most of the remaining trials were conducted using a li me water solution (a saturated solution of calcium hydroxide) . The lime water has a co nce ntration of about 0.21 % as CaC03 (111/111).

Raw bore water was fed direct to the lime crystallisation plant or via a cascade aerator and then pumped in to the pellet reactor. T he effiuent from the pellet reactor was pumped to a pilot filtration plant. Carbon dioxide was dosed after the outlet of this pump to reduce the pH and stabilise the softened water. T his pH was stable across the filter media, indicating that calcium carbonate was not continuing to precipitate within it. Subsequent water analysis showed a Langelier Index of -0.1. For the p ilot trials a bo re from another borefield named GS was chosen with an analysis similar to that expected from th e whole borefield . The respective analyses are summarised in Table 1. T he water used for the p ilot trials had a TDS of 580 mg/L and hardness of 260 mg/ L (as CaC0 3). As discu ssed later, phosphate was dosed to raise GS water from 0.05 mg/1 to levels similar to those expected in the Neerabup borefield.

Results When sufficient lime was added to the bore water to achieve a TDS reduction of 150 mg/L, the corresponding hardness reduction was about 100 mg/L as CaC0 3 , as shown in Figure 1.

Aeration Versus Non-aeration Since li me firstly reacts with any carbon dioxide p resent in the water aeration can reduce the amount of lime required. Calculations based on alkalinity and pH measurements gave an estimate for dissolved carbon dioxide concen tration of 31 mg/L (as CaC0 3) in the raw GS bore water which was reduced to 7 mg/L after aeration. Pilot trial results confirmed that to achieve a reactor effiuent TDS of 450 mg/L (to give sufficient salinity reduction) with this water required a lime dosage of about 260 mg/Las CaC0 3 for raw water but only about 140 mg/L for aerated water. Aeration therefore reduced t he required lime dose by about 120 mg/Las CaC0 3 .

Lmtwate,:Aerationvs. Raw (801fflW')

.

Van Ammers e t al. (1986) noted that withou t pre- aeration crystal growth on the pellets may be disturbed by both the Fe 2+ and PO43- ions which may form FeC0 3 and Ca3 (PO4) 2 . This may result in so tter pellets with a high wate r con tent. Such pellets are more prone to erosion in the p ellet reactor, causing increased carryover. Van Ammers et al. (1986) reported that no problems had been encountered for concentrations of phosphate less than 0.5 mg/ L and iron concentrations less than 3 mg/L. Phosphorus concentrations at the GS bore are 0.05 mg/ L. To assess the effect of phospha te on pellet formation, phosphate was dosed into the GS bore water as shown in Table 1. Pellet formation was not compromised even when total phosphorus concentrations were ra ised to 1.0 mg/L (3.1 mg/Las phosphate) . C hemical analyses were performed on the dosed water (i.e. raw water + p hosphate) and the pellet reactor effi uent. There was about 50% reduction in dissolved and total iron and more than 80% reduction in phosphate. This indicates that iron and phosphate were incorporated into the pellets. The pellets formed had no noticeable difference in appearance and texture from those fo rmed without the addition of phosphate. Therefore, the inclusion of iron and phosphate into the pellets did not produce fluffy pellets. Analysis of the pelle ts showed that the amount of phosphorus in the pellets was directly proportional co th e concentration of phosphorus in the dosed water. Iron was also fo und in the pellets. Iron in the raw water feed to the pilot plant was largely oxidised in the supply pipe. Total iron was abou t 2.5 mg/L, of which dissolved iron was abou t 0.1 mg/L. The expectation of Van Ammers et al. (1986) is that when aeration precedes pellet softening th ere wou ld be no disturbance to crystal growth. Ferrous iron (Fe2+) would oxidise to form iron

Salinity Reduction at G5 bore

Salinity and Hardness Reduction Lmt Oyslll. .l'llon al G5 (garnet -400-200: pr•Nfetlon: 70 mtir)

/~

Phosphate

llliney

,,, n

,oo

"'

100

150 200 2$0 Llml dOH (rrg/1. U C.003)

,oo

,oo

Figure 1 Results of pilot trial : salinity and hardness reduction

12

WATER JAN UARY/ FEBRUARY 1999

"'

100

150 200 2~ Joo l ~ water dos• rate , . u CaC03)

Figure 2 Salinity reduction at the G5 bore

3~

•oo

~$0


WATER phosphate (FePO 4 ) and iron hydroxi de (Fe(OH) 3) whic h incorp orate into the crystal lattice without causing the pellets to be fluffy. As the Fe2+ and PO/ - ion s did not cause pellet formation problems when phosphate was dosed into nonaerated wa ter, it is expec ted that there is eve n less potential for pellet formation problems using aerated water , as these io n s w ould be oxidised.

Seed Materials

Table 1 Water quality data Pa rameter pH Calcium Magnesium Sodium Alkalin ity Chloride Sulfate Total iron Tota l phosphorus TDS Turbidity

Expressed as

mg/L as CaC03 mg/L as CaC03 mg/L as CaC03 mg/L as CaC03 mg/L as CaC03 mg/L as CaC03 mg/L Fe mg/LP mg/L NTU

Neerabup raw water

G5 aerated raw water

G5 bore post-reactor

G5 bore post-CO2

G5 bore post-filtratio n

7.11 190 50 200 200 220 11 2.8 0.5

7.14 225 57

9.51 65 57 163 80 170

7.90 70 57

7.90 70 57 163 90 170 42 0.02

610 1

163 190 170 42 2.55 0.7 * 600 20

42 1.19 0.1 400 35

163 90 170 42 1.19

-

-

410 30

410 <0.2

Trials w e re co n du cted to * after dosing compare the economics of using garne t sand with quartz sand. This analysis was also pe rformed Table 2 Filter configurations theoretically. Garnet and quartz are two Filter B (simila r to Neerabup Groundwater Treatment Plant) Filter A different minerals. Garnet has a 1.0 m of 1.1 mm anthracite coal 1 .0 m of 1.4 mm anthracite coal density of 4 ,100 kg/m3, whereas 0.5 m of 0.6 mm sand 0.5 m of 0.6 mm sand quartz has a density of 2 ,650 kg/m 3 . The densi ty of the sand grains is an important variable in Turbidity of the GS b ore wa ter effec t tha t microc rys tals o f calcium the process because it determines the exte nt to which the sand bed expands varied du e to oxidised iron being stirred carbonate appear in the eilluent of th e whe n water flow s up through it. As up in the supply pipe to the pilot plant. reactor. Due to the small size o f the garne t sand is de nser than quartz, T ypical values of raw water turbidity mi croc1ys tals (0 .45 Âľm, partly <0 .05 smaller grains of garnet sand ca n be used were 20- 30 NTU. Eilluent from the Âľ m) they are not comple tely removed to give the same am ount of bed expan- p ellet reac tor was typ ically 10- 15 by rapid sand filtration . Bo th filte rs exhibited th e behavio ur sion as the less dense bu t larger quartz NTU. The minimum criteria fo r the sand. T he main benefit of the small filter perfo rmance was that the filter of taking a long tim e to ripe n as turbidgrains is that they need to be replaced eilluent have turbidi ty less than 0 .7 ity took many hours to red uce to 1.0 with fresh sa nd less frequently beca use a NTU. Samples fro m the surface of the NTU. The refore, a fi lte r aid was greater volume of calcium carbonate is filter coal were analysed and found to requi red. Trials were conducted using a deposited on them bef'tff they grow to contain hi gh conce ntratio ns of iron n on-ioni c polyelectrolyte (LT20). Filte r their fi nal size. and calcium. T herefore, bo th iron pe rformance was very sensitive to s1nall Garnet sand of diamete r 0 .3 111111 was and calcium carbonate woul d have doses ofLT20. However, it was diffi cult compared to quartz sand of diameter 0.5 contributed to the turbid ity of the pellet to find a dose rate that would give both 111111. The mass of one grain of garne t low turbidity in the fi ltered water and reactor eilluent. sand is less than one grain of quartz sand Crys tallisation can take place by not result in rapid build-up of headloss (garn et grains are about tw ice the either heterogeneous o r homogeneous in the filte r. It was co ncluded that density but one- six th the volume of nucleation, with the physical attribu tes polyelectrolyte was not sui table as a qua rtz grains). As th e garnet grains are of the crystals being determined by the filter aid. smalle r, they have a longer residence type of ctystallisa tion that occurs. Van Dijk and Wilms (1991) report time in the pellet reactor. This results in H eterogen o us nucleation is the that th e mi crocrystals ca n be removed lower costs for fresh garnet sand. Quartz process of crystal growth. The kinetics by dosing acid, coagulation with Fe(III) sand of 0.5 111111 diameter took about 26 of calcium carbonate p recipitation arc (0.5- 1. 0 mg/L) or by slow sa nd filtrahours for the first of the grains to reach basically determined by two variables- tion. Van Eekeren et al. (1994) also 1 111111 size whereas 0.3 111111 ga rnet sand supe rsatu ration an d sp ecific surface comment that mi cro crystals are took about 72 hours. The mass of area . Van Dijk and Wilms (1 991 ) efficiently removed during floe filtragarnet used was only about 30% of the explain that he terogenous nucleation is tion w ith addition of ferric chloride mass of quartz. Graded garnet is also normally the dominant process in the (FeC l , 0.20-0 .25 mg/L). Based on the 3 c heape r in Western Au stralia than pellet reactor whereby crystal grow th expe rie nce in the literature, a trial w as graded quartz. Garne t is clea rly the occurs on the high sp ecific surface area conducted using fe rri c chloride at 1.5 favoured seed material. of th e seeds. However, at a relatively mg/L which successfully reduced the high calcium ca rbo nate sa turation turbidity of th e filter efflu ent (filter B). Lime Crystallisation Using index (SI) o f approximately 2.5, homo- Later in th e run, the dose rate was Lime Water ge neous or spontan eo us nucleation redu ced to 1.0 mg/L. The filter run The pellet reactor eilluent (treated takes place . When milk-o f-lime is time was 40 hours and the run was water) was pumped to a pilot filtration do sed into the pellet reac tor the lime terminated du e to 100% headle ss (4 m ). plant. T wo diffe rent filter media config- particles progressively dissolve as they T here was an even spread of the flocc ulated particles through the depth of th e urations were used in the trials, as move up through the reactor colum n. By co ntrast, li me wa ter when dosed filter bed. From 8 hours till 20 hours outl ined in Table 2. The pilot filtration plant was run at results in a very high SI near the base o f into the filter run, the filtration rate was 15 m/hour with a surge test conducted at the reactor (the high SI occurs becau se 18 m/ hour w hich did no t increase the 18 m/hour to simulate the effect of other the lime is already di ssolved). This can turbidity of the filtered eillue nt. Thus, filters being taken off-line for backwash. favo ur homogen ous n ucleation with the fe rric chloride seems to be an ideal WATER JANUARY/ FEBRUARY 1999

13


WATER flocculant as it only Authors Table 3 Effect of reactor upflow rate on turbidity: milk-of-lime t ria ls requires a low dosage, Barrett Moulds is an Sample Turbidity (NTU) Upflow rate (m/hour) gives long ru n time and enviro nmental e ngineer makes good use of the and Damon Howes is a Aerated raw water 32 entire depth of the filter chemical e ngineer with Pellet reactor effl uent@ pH 9 60 42 bed. the Water Corporation of Pellet reactor effluent @ pH 9 77 43 A run was conducted Western Australia, 629 Pellet reactor effluent @ pH 9 80 48 using 0.3 mg/L of ferric Newcastle Street, Leederchloride. At 15 minutes ville WA 6007. Both into the run the turbidity of the filter and continued to steadily reduce till it authors have a background in water effluent had decreased to 0.3 NTU and reached 0.02 NTU after 10 hours. The treatment. was 0.1 NTU after 40 minutes. As a run was terminated at 29.5 hours for successful filter run was achieved using sake of convenience (i.e. a filter run 0.3 mg/L of ferric chloride, it can be greater than 30 hours was expected). concluded that there is good agreement Turbidity was low throughout th e Survey of Australian Waters between the Neerabup trials and the run and therefore no coagulant was experience of Van Eekeren et al. (1994) required . for Cryptosporidlum and A surge test was conducted at 28.5 w ho quoted dose rates of 0.20-0.25 Giardia mg/L. No attempt was made in the hours before terminating the filter run. A Chapman, D Veal, J Ongerth, M Neerabup trials to optimise the ferric The filtration rate was increased from Faulkner, P Hutton, Urban Water 15 m/hour to 18 m/hour. Turbidity chloride dose. Research Association of Australia responded by increasing to 0.7 NTU Report No. 128, September 1998, Lime Crystallisation Using wi thin 2 minutes and peaked at 3.08 ISBN 1 876088 49 4 NTU after 7 minutes . After 9 minutes, Milk-of-lime In the past few months, there has 2.0 NTU. turbidity had reduced to After the trials using lime water, an been a lot written about protozoan additional trial using milk-of-lime at a Thirty minutes after the surge started parasites, Cryptosporidium and Giardia. concentration of 3.6 % (111/111) as the turbidity was again below 0. 7 NTU. While it is only recently that AustEven though the surge test was well CaCO 3 was n1ade for the pu rposes of ralians have been forced to address comparison. The milk-of-lime was into the run, the filter was able to cope the issues associated with these pararestabilised in half an hour. This and batched using hydrated lime added to sites as a h ealth risk, overseas research de-ionised water. Various upflow rates was a good perforrn.ance, especially and experience has amassed a plethora were trialled to investigate the effects on considering that no filter aid was used. of data on the subject. Quite sensibly, turbidity (see Table 3) . therefore, this publication begins As turbidity did not increase greatly Conclusion with a compre hensive scientific T h e trials co nfirmed t hat lime with upflow rate, there is no advantage review of published reports and in operating th e pellet reactor at a low crystallisation was a suitable technology research findings on the prevalence of upflow rate (i.e. 60 m/hour ra ther than for TDS and hardness reduction for the Cryptosporidium and Giardia in the 80 m/ hour) to reduce filter loading Neerabup Groundwater Scheme. Preenvironment, their potential to be rates. The turbidities are expected to be aeration should b e adopted for th e present in water supplies used by N eerab up plan t because it has the lower for a full-scale pellet reactor. h umans and the associated impacts The pellet reactor eflluent (softened be nefit of signifi ca ntly redu cing the on human health. It is an excellent water) was filtered using filter column B required lime dosage rate. Economic sum mary of the state of knowledge at (1.4 m m coal, 0.6 mm sand) . D uring comparison of garnet and quartz as seed this point and has been prepared by a the filter run, the upflow rate of the material favoured garnet. Filtration was well qualified team of researchers. pellet reactor was 77 m/hour. T his trial required to reduce the turbidity of the Yet the publication uses this literwas run with a target pH of 9 fo r the p ellet reactor effiuent. Ferric chloride ature review as a jumping-off point p ellet reactor efiluent. Carbon dioxide proved to be a highly suitable filter aid. for i ts main focus: a report on an was dosed for pH correction to a pH of Filter loading rates were not signifianalysis, begun in July 1993, of 191 7.4 at the filter inlet. T his pH was stable cantly affected by the upflow rate in the raw water and sediment samples from across the fil te r, indicating that the p ellet reactor (up to loading rates of 100 26 sites around Australia wh ich were water was well buffered at this pH (i.e. m / hou r). Fil te rability o f the p elle t con centrated by flocculation and the pH did not change despite the flow reactor effiuent was better w hen using a analysed by flow cytometry fo r encountering a very high surface area in milk-of-lime suspensi on rather than protozoan parasites. To this reader, the fil ter bed which would promote lime water solu tion. the results appear disappointing. chemical reaction). No filter aid was There was no strong correlation with used . References the occurrence of either parasite and The initial (clean) filter head loss was Van Ammers M , van Dijk J C, Graveland A any water quality parameter, although 10.5% which grad ually inc reased tu rbidity (NTU ) was a minor indicaand Nuhn P A N M (1986) State of the throughout the run. H ead loss was 19% Art of Pellet Softening in the tor. These findings confirm similar Netherlands. Wat. Supply, Vol. 4, at 28.5 hours into the ru n. Head loss difficulties experienced by researchers Amsterdam, pp. 223-235, 1986. reduced evenly through the depth of in the US and UK but the disapthe filter bed. Iron floe could be seen Van DijkJ C and Wilms DA (1991) Water pointment felt by this Australia n Treatment Without Waste Material: team is evident. Nonetheless, the evenly distributed through the entire Fundamentals and State of the Art of depth of the filter coal and the upper report is well worth reading and Pellet Softening. Agua, Vol. 40, N o. 5, part of the filter sand. using as a basis for research on newer, pp 263-280, 1991. Turbidity reduced to 0.7 NTU after Van Eekeren MW M, van PaassenJ AM and more reliable and less error-prone methods of detection and quantification. 12 minutes into the run (which is about Merks CW AM (1994) Improved Milkthe time for the backwash water to be of-lime for Softening of D rinking Water: Dr Diane W iesner displaced from the filter) . At 72 minutes The Answer to the Carry-over Problem. A WWA Bookshop Aqua, Vol. 43, No. 1, pp 1-10, 1994. into the run, turbidity was 0.1 NTU

BOOKS

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WATER JANUARY/FEBRUARY 1999


COOPERATIVE RESEARCH CENTRE FOR WASTE MANAGEMENT AND POLLUTION CONTROL SPECIAL FEATURE ~ V

CRC FOR WASTE MANAGEMENT ANO PoLU JTION CONTROL L1MmID A.CJ-I CWJktlt

The articles in t his special feature of Water provide an overview of the research and development being undertaken by the Cooperative Research Centre for Waste Management and Pollution Control Limited (CRCWMPC) in its four main program areas of: • wastewater treatment and water reuse • solid waste management, including landfill gas production • contaminated sites and hazardous wastes • cleaner production and waste minimisation. New strategic research directions are process intensification; adding value to waste products; and retrofitting of technologies. The research is undertaken to formulate five platforms: • model development • process control • new processes • new chemica ls • new instrumentation. Research and development takes place within the CRCWMPC itself and its 15 member organisations, and in other laboratories with which it has connections. Altogether, the CRCWMPC has eight research nodes throughout Australia and 11 research centres. The CRCWMPC's member organisations have continued as supporters even though they have had considerable changes in their own organisations. The members include five researchers: • University of New South Wales • University of Queensland • University of Western Sydney • ANSTO • CSIRO divisions of Molecular Engineering, Energy Technology and Soil and Water and ten industry partners: • BHP Ltd • Orica Limited • AD I • Brambles Cleanaway • USF Filtration (formerly Memtec) • Waste Services NSW • Sydney Water Corporation • NSW EPA • Public Works and Services, New South Wales • Environment Protection Authority, New South Wa les.

The CRCWMPC was established as a first round Cooperative Research Centre in 1991 and has successfully applied for refunding under its new Chairman Ian Kiernan until 2004. Its turnover is about $8 million a year, of which about 20% is by direct grant from the Commonwea lth under the CRC Program. The CRCWMPC's mission is to: • be the pre-eminent and financially successful national centre of expertise in waste management and pollution control • commit the Centre's collective expertise in waste management and pollution control to research, development, education and commercialisation of innovative approaches to protecting and enhan cing the natural environment and social and economic well-being of Australia. In carrying out its mission the CRCWMPC also incorporates the wider CRC objectives of: • becoming financially self-sustaining within seven years • provid ing appropriate returns to members conducting market• focused quality research capturing benefits of researc h via commercialisation and other means to co ntribute to the well-being of Australia • providing education and training to practitioners in the industry • being recognised as a scientific and technical national and international authority on waste management and pollution control • ensuring cooperation between members in problem solving. Twenty-six projects have been undertaken in the field of water, solids and gaseous waste management in the areas of: • improved design of biological wastewater treatment operations • instrumentation and control • new membrane systems for wastewater treatment • water reuse • wastes from rural industries • site remediation • contaminated site assessment • advanced solid waste management • waste reduction and minimisation • life cycle analysis and impact assessment. These projects are presently undertaken both in Australia and overseas cooperatively with international research organisations. WATER JANUARY/ FEBRUARY 1999

15


CRCWMPC

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THE PROFESSIONAL ENVIRONMENTAL RESEARCH BUSINESS:

WILL IT EVER PAY? DE J Garman Abstract

• new commercial ventures. Additional benefits to CR C members Commercialisati on of researc h is traditionally regarded as a high-risk include: inves tment option. Environmental • maintaining an up-to-date interest in research is seen as being an even higher resea rch and technical activities 111 risk. On the other hand, innovation and specific fields research are being upheld as the way of • outsourcing of research activities • closer linkages with researchers the futu re for industry. • access to a pool of skilled scientists This paper discusses the business basis fo r success of the Cooperative and engineers Research Centre for Waste Management • a commercialisation base which and Pollution Control (CR CWMPC) provides both managerial review and as an investme nt as de te rmined by direct entry to commercial markets. When CRCs were thought of it was a number o f commercial and n oncommercial performance measures. believed that within the proposed seven Examples are provided of a portfolio years of funding they would become mix, spread of risks and management of self-sufficient. That is, they would be risks by the industry partners. able to exist without further support from the Commonwealth. As it turns Risk Management and out, this length of time has proved to be Research Investment insufficient for most CRCs and in What determines w hether invest- particular for the environmental CRCs me nt in environmental research is a that have self- sufficiency as their goal. paying or worthwhile proposition? I So why is this? I believe it is a function believe there are a number of measu res, of a number of facto rs. and I would like to explore these in this In most cases the best chance of brief paper. I will then extend these to getting commercial products to market examine the Cooperative Research is to develop applications from existing Centre (CR C) system to show how well developed research. This was this can provide the correct business neither what the Commonwea lth environment for success. envisaged nor what most of the joint The basic principles for any invest- venture partners in CRCs saw as their ment include: aims. The Commonwealth wanted new • a suitable return for investors industry-related research and edu cation • access to new tec hnologies fo r for PhDs. The industry partners wanted business development solutions for their problems, while the • an ongoing revenue stream or capital researchers wanted new research funds gain. For a sound high-risk investment a and new PhDs. If we look a little further at the spread of investment opportunities is history of resea rch , innovation and also required. The commercially foc used C R Cs are commercialisation, the experts will tell generally able to provide members wi th us that in Australia it takes on average ten years to get a major product from one or more of the following: • return s o n investme nt either in resea rch to commercialisation. It is direct revenue o r return of capital unlikely to take less than seven years • p refe rred access to suitable novel and more likely to ta ke 15 years . technologies generally identified by the Further, the waste management industry is n otoriously conservative in intromembers • savings in operational or investment ducing new technologies. So is there a costs business opportu nity there?

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WATER JANUARY/ FEBRUARY 1999

Environmental ResearchWhat Is the Commercial Strategy? Cooperative R esearch Centres can be divided into two maj or types of research o rganisations. T he first type consists of those whic h are based arou nd one or two major technologies for w hich there will be a number of spin- off applications. Examples of this are the CRC for Eye Research and the CRC for M olecular Engineering an d Technology. Eac h of these has produced a major si ngle technologycontact lens and ion channel sensors respectively. The other mod el is that o f the CRCWMPC, w ith multiple tec hnologi es an d te chnology platforms and possible applications outside the initial environmental applications. An example of this is arsenic oxidation technology. While developed primarily for arsenic wastes, it has applications in water treatment, both high- tech, based around UV reactors, and low-cost systems using sunlight, mining waste processing and acid mine drainage. The environmental field is more likely to provide technology breakthroughs in a number of field s rather than one w ithin one sp ecific technology platform. Indeed, the CRCWMPC has four program areas and over 30 active projec ts. From these there are about 13 technologies on the poi nt c?.[ commercialisation. Of these, five are potentially maj or technologies-with gross revenues in excess of $100 million. So how does this compare with th e initial picture? Paradoxically, the strength of this style of research is, of course, also its weakness. H aving a spread of technologies provides a better chance of success. It spreads the ri sk across a portfolio of projec ts and tec hnology platforms. Indeed , the spread of members makes it more likely that their needs will be met with a variety of technology products. However, its weakness is that it is less likely to produ ce a single maj or produ ct


CRCWMPC that can provide a focus for significant investment in external research investment funds and resou rces. The image of research is now taking on a n ew fa ce. The Myer R eport referred to the CRCs as c hanging resea rch culture. This is indeed what has happened. The Mortimer report proposed a muc h redu ced funding package for CRCs. This was further reviewed in the Mercer report that classified them into a number of levels and types of research. The CRCWMPC is classified as Category 2-commercial with some public good. So are all proj ec ts successfu l commercial ventures? For a start, it is interesting to observe that about one third of all the CRCWMPC's projects have bee n stopped or redire cted. This is more a matter of firm ma nagement rather than poor foc us. The expenditure on th ese has been less than 10% of total funds. But for one project this

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would have been less than 5% of funds. Further, about 40% of all research will not produce a commercial product of sign ificance. These have provided useful information for members and other general knowledge. The balance is regarded as having good commercial potential w ith comm ercial backers identified. What does this m ean in research investment terms? I like to think of the member's funds as high-ri sk venture capital. They have a say in how this capital is spent and the CRCWMPC employs professional research managers to manage the funds for them. In return the aim is to provide m embers with return on their investment that w ill show the funds are well used. With the investment structure used by this C RCWMPC industrial members get leverage of in excess of five times their fund inpu ts, w ith one member valuing its leverage in excess of

Table 1 Technology spread of CRCWMPC Research outcome

Commercial return

Status

Volatile organic chemical (VOC) monitors Floe monitor1

High

Arsenic oxidation technology

Medium

Dewatering technology 2 Prefermenter DSP Model Wetlands Biosensor technology 3 Surepure chemical free high quality water4 Bacterial Cultures, Nitrospira and Phosphorus

High Low Low High High

Under licence and contract negotiations Prototype evaluation and manufacture USEPA minesite demonstration complete Water treatment - demonstration under negotiation Low cost demonstration in Bangladesh Final stages of R&D Commercial package available Private company formed Under development With member for commercialisation

Advanced oxidation technology WWTP control systems

Medium Low

Contaminant biosensor detectors Direct filtration wastewater reuse Anaerobic cont rol system Landfill bioreactors

Medium Low/medium High Low

Sequencing batch reactor Biomass research facility

Low Low

Light emitting bacteria for contaminant detection Ponds design 5

Medium

Medium

Medium

Testing culture stability - N; P to complete - new applications under development New patent applications IP t ransferred to members for development Final stages of R&D Full-scale demonstration Full-scale demonstration - IP position under review New strategy being developed First commercial applications this yea r Sti ll promising-slow development Two projects to finalise in anaerobic t reatment and denitrification

Low

Notes 1. Intellectual property (IP) owned Jointly by UNSW and the CRCWMPC 2. IP owned jointly by CSIRO and the CRCWMPC 3. Base biosensor IP owned by CRC for Molecular Engineering and Technology 4. Development with member organisation 5. IP owned jointly with Meat Industry Research Fund

Ii

~.,

12! R esearch members get leverage of about 2 to 3 on resources invested. The CRCWMPC undertakes to provide each member with a significan t outcome from the research each three years. This will be achieved by the CRCWMPC having a portfolio of projects that will spread the risk and provide the best opportun.ity to give both mone ta1y returns to the CRCWMPC and real returns to the members.

Spreading the Risk-The Portfolio of Investments To achi eve the CRCWMPC's business plan it will need to have a net revenue from investments of about $2 million by 2004. Most of this will come from commercialisation of contract research. This is in addition to any benefits accruing directly to members from the application of the technologies. The prese nt spread of technologies is p resented in Table 1. In an era where industry is being pushed to cut cost while rema.ining competitive, CRCs are seen as having specific advantages not provided by othe r structures or organisations. These include: • leverage on research funds • access to resea rch on preferential basis • outso urced resea rch faciliti es • training for staff • sourcing of skilled staff • con tract research • di rec t inpu ts to a w ide range of research activities. In addition, the Commonwealth's funds of about 20% to 30% of total invested funds provide the glue to keep research members together and help to redu ce the risk of the investment.

Conclusions T h e key elements to having a successful environmenta l R&D program are no different to any other business principles. The risks should be spread over a range of business oppo rtunities with good co mmercial support at all stages. This structure is presently provided by the CRCWMPC. While research may need to be stopped or postponed if commercial viability is not cl ear, the biggest ri sk is not that research will not find solutions. Rather, it is that the technology will never be demonstrated or commercialised due to lack of fu nding at key times in the product life cycle.

Author Dr David E J Garman is Executive Director of the Cooperative R esearch Centre for Waste Managemen t and Pollution Control Limited.

.-.;n

,:,. ·,

·~

• C

WATER JANUARY/FEBRUARY 1999

17


CRCWMPC

SPECIAL

FEATURE

PERFORMANCE AND

COMMERCIALISATION OF CRCWMPC RESEARCH L Ridge There can be no doubt that generation of new research funds for the commercialisation of research is one of the key aims of the Cooperative Research Centre (CRC) program. This has been confirmed by a number of reviews of the program, most recently by the inter- departmental review conducted by Don M ercer (former chief executive of the ANZ Banking Group) and Dr John Stocker (Chief Scientist, Australian Science and Technology Co uncil). A significant numbe r of CRCs have had demonstrated su ccess along the path of conunercialisation of research outcomes. The CRCWMPC has similarly had its successes over the first seven years. It has developed a number of products from a mixture of technology platforms, including: • instrumentation • software or models • p rocess treatment technology • chemicals and reagents

• process control systems. T he products arising from the very different technology platforms has in turn led to different approac hes to commercialisation. By virtue of contributing to the CRCWMP C, members have first right of refusal to commercialise the technologies and this right has been exercised on a number of occasions. Research into the nature of commercialisation reveals that the earlier the marketer of the product being developed is involved in the research, the better the chances of conunercial success. Further, the C RCWMPC undertakes a signi ficant review of all its projects at certain milestones. Funding of the research does not continue past a certain level until a member or third party commercialiser has been found. This approach tries to maximise the research dollars that will ultimately be commercialised. If memb ers decline to take a direct

INTELLECTUAL PROPERTY

uu u u u u

General or public good

Proprietary knowledge

Licence

D 100% Figure 1 Funding of CRCWMPC projects

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WATER JANUARY/ FEBRUARY 1999

Equity

Sale

D Partial

Direct investment

interest in the commercialisation of a particular research project, this does not necessarily mean they are not interested in the commercial outcomes of the product. A third party/non-member of the CRCWMPC is sought to fill this role. A number of options are available as shown in Figure 1.

Joint Venture-Prefermenter Model The single fastest commercial activity occurred with th e preferme nter model develop ed by one of the C R CWMPC's PhD students, Elisabeth von Muench, who completed her PhD studies at the University of Queensland. The model had been previously verified at a member's sewage treatment plant in Sydney. The benefits of changes in operations resulting from t he application of this prefermenter design model have solved a number of operating problems. Within three months of completion, the CRCWMPC form ed a joint venture with a small software company, Science T raveler International (STI) of Bendigo, Victoria. The model was rewritten and made available through the company's website and training has been provided to purchasers of the model.

Licence-lmmoblllsatlon of Arsenic T he CRCWMPC has u ndertaken research into the immobilisation of arsenic since 1993. On completion of the research , a successful demonstration of this technology was funded by


CRCWMPC

SPECIAL

FEATURE

has resulted in the employment of six people, in full- and part- time positions. T h e General Manager of Australia Wetlands is a CRCWMPC PhD student. · of Future expan sion of Aust'Within three months ralia We tlands has been e ncompletion, the CRCWMPC ha nced by a joint venture with t he British company, formed a joint venture...' Oceans Environmental Engineerin g International, the ogy by receipt of a major grant from world 's leader in the application of AusAid backed by the World Bank. industrial wetlands technology. It is The grant is for demonstration of the expected that this joint ven ture technology in Bangladesh. This has a will significantly mcrease market suite of applications, and the costs of opportunities. these applications are highly competiPartial Investment and tive in the marketplace. the US EPA at a si te in Montana where it was applied to mining wastes. T he CRCWMPC received further assistance in the application of the technol-

Licence Direct Investment-Advanced Constructed Wetlands T he CRCWMPC funded signi fica nt researc h in to constru cted we tlands and now operates a w holly owned subsidiary, Australia Wetlan ds Pty Limited, which has now su ccessfully completed its first year of trading. T his direct investment by the CRCWMPC

T he CRC has developed an on-line, real-time monitor for the detection of volatile organic compounds (VOCs). In this case, the CRCWMPC fo und a third party commercialiser wh o in turn fo und a manufacturer for the instrument. We are in th e process of attracting venture capital fundi ng and signing world- wide licence agreements for

the manufacture and distribution of these probes. A number of technologies have been brought to the CRCWMPC for assistance with evaluation, application and potential development and commercialisation. The CRCWMPC holds partial equity interests t hrough the provision of support services to these technologies which complement the CRCWMPC's own technologies.

Conclusion The Cooperative Research Centre for Waste Management and Pollution Control has achieved a n um be r of commercial successes from its research program . It is the C R CWMPC's target to achieve $2,000,000 per annu m in net revenue by 2004 at the e nd of its second grant pe riod. At this stage, tlie CRCWMPC is o n track to achieve that target.

Author Lee Ridge is th e CRCWMPC B usiness Manager.

1999 WATER DEADLINES

Fisher Stewart Environmental and Water Industry Specialists • • • • •

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T he Water j ournal welcomes the submission of papers of 3,000-5,000 words relating to all areas of the water cycle to be published in the water, wastewater, environment and business sections of the journal. T he deadlines for submission of papers to Water during 1999 are: • May/June 22 J an • J uly/Aug 22 Mar • Sept/Oct 21 May 20 Jul • Nov/Dec Please send two hard copies an d one soft copy plus figu res an d graphics to Features Editor Bob Swinton, 4 Pleasant View Crescent, Glen Wave rley Vic 3150, email swintonb@c031.aone.net.au. (Colour photographs to be saved on a Z ip 100MB disk as tiff or EPS Macintosh or T if PC fo rmat, CMYK mode, 600 dpi resolution. Black & white photographs to be 1200 dpi resolution. Otherwise, send transparencies or good quality prints.) Topical, magazine- style stories of up to 2,000 words can be submitted closer to t he publicatio n date by arrangeme nt with Gen eral Editor Margaret Metz, tel. (02) 94 13 1288, PO Box 388, Artarmon NSW 1570, email mmetz@awwa.asn.au. WATER JANUARY/ FEBRUARY 199 9

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CRCWMPC

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MEMBRANE TECHNOLOGY I Fergus The CRCWMPC is at the forefront of membrane technology development and to date has invested more than $8 million in membrane research. The CRCWMPC foresees that innovative membrane technology, with new module design configuratio n s and surface modification, has the potential to dramatically reduce capital and operati ng costs, improve efficiencies, revolutionise the separation of liquids and create new value-added products from waste. The CRCWMPC has made significant progress in the u se of electrical field effects to enhance the separation charac teristics of membranes for a wide range of wastewater applications. A spin-off is the potential application of electroporation, which represen ts one of the most exciting leading-edge deve lopments evolving from th e UNESCO Centre for Memb rane Science research portfolio. It has the potential to not only eliminate membrane fouli ng but could simultaneously achieve 100% disinfection and act as a bacteriacide. The membrane projects in the CRCWMPC wastewater treatment and water reuse researc h program include: • membran e system s for wastewater reuse • self-regenerating ion exc hange membrane technology • compact membrane bioreactor wastewater treatment plants • anti-fouling novel conducting membranes for treating industrial efiluents • high performance m embrane oil coalescer with novel polymer.

Wastewater Reuse A CRCWMPC project entitled M embranes for Wastewater Reuse at South Windsor in Sydney has involved the d evelopment of direct filtration incorporating membrane-based processes for the treatment of raw sewage for reuse up to potable water quality standard and fo r industrial reuse for high quality process water, e.g. boiler feedwater applications. A unique combination of experience within the CRCWMPC has been brought together involvi ng USF Filtration (Windsor) (formerly Memcor Researc,h), UNESCO Centre for M embrane Science and Tec hnology

20

WATER JAN UARY/FEBRUARY 1 999

(UNSW) and NSW Public Works and Services. USF Filtration has the licence to commercialise the outcomes of this research. Simplicity of operation of the principal process avoids the need for secondary treatment. Independent technical review by world-recognised experts concluded that this novel technology development is unique and offers several maj or advantages and significant potential benefits to the wastewater co111111unity. Extensive pilot plant operation has demonstrated that t he screening/ microfiltration/reverse osmosis system is effective in achieving a costeffective techn ology for indu strial process reuse.

Self-regenerating Ion Exchange Technology The CRCWMPC, working with two of its members-the Molecular Science Division of the CSIRO, and USF Filtration (Windsor)-is developing an e nvironmentally friendly water purification system. T he heart of the system involves well established ion exc hange technology for the removal of dissolved ions in the water stream, coupled to conventional reverse osmosis for removal of organics an d the bulk of highly c harged inorganic species. The novelty of the system lies in t he method of regeneration of the exhausted ion exchanger. In conventional systems, the resin is regenerated using alkali and acid solutions, with the attendant problems of storage, handli ng and d1sposal of corrosive materials. In the CRCWMPC sys tem, the exhausted ion exchange resin is regenerated in situ, using a robust and simple benign novel electrochemical regeneration process. The process does not require the use of expensive and easily damaged ion exchange membranes, nor does it require the handling of the resin, which remains in the same module for water scrubbing and resin regeneration. Unlike other electrochemical systems that require stacks of ion exchange membranes, this system is cheap and robust. It tolerates a far wider range of impurities than the existing membrane systems, which may be susceptible to

membrane fouling or damage. It also appears to be amenable to scaling up without complication. The regeneration is efficient, and the waste stream contains only t he salts that have been absorbed onto the resin in the water purifica tion cycle. The system will be incorporated into a unit which can tolerate a wide range of feed waters. It requires only a supply of water and electricity to operate. A provisional patent application has been lodged. USF Filtration instructed the CRCWMP C to cease the pilot research and has u ndertaken to invest iri the prototype development for commercial implementation in 1999.

Compact Membrane Bioreactor D emand in Australia and Asia for cheaper and more effective industrial wastewater treatment systems continues to increase du e to the higher charges for disposal of efflue n t and in some instances the desire fo r reuse of efiluent for process water. The CRCWMPC is involved in a two- year $1.5 million Australia-Korea collaborative resea rch project, Low En ergy Demand M embrane Bioreactor for High Strength Industrial Wastewater. T he Korean counterparts are Sunkyung Engineering and Constru ction Co. Ltd and Hanyang University with funding support from the Korean energy research organisation , RaCER. T he Australian participants are UNESCO Centre for M embrane Science and Technology and USF Filtration (Windsor). The Federal Departme nt of Industry, Science and R esources and the CRCWMPC are providing funding for Australian research on this important demonstration project. The first application identified is brewery wastewater. The proj ect obj ectives are to: • assess and optimise membrane systems capable of integration or retrofitting wi th a wastewater bioreactor with low energy demand • optimise the bioreacto r configuration to achieve h igh biomass content • demonstrate the application of integrated bioreactor/membrane systems to determine optimal operating strategies and economic parameters.


CRCWMPC This project is now at the one-year review milestone which will identify which technology option justifies the investment for the second year prototype demonstration to be undertaken in Korea. The C R CWMPC h as initiated a new proj ect to dem on strate th e patented AEROFILT membrane bioreac to r process. This innovative, compact physico-biological process involves a dual membrane bioreactor system in w hich each membrane module alternates as the filtration uni t and aeration device. This AEROFILT array can be placed inside or external to the bioreactor. The focu s of th e AEROFILT research is the efficient removal of carbon and nitrogen from' high strength industrial waste streams. T he results from the proof of concept stage are en couraging. The CRCWMPC will now review the prototype second stage development of this technology and the potential link of this to the AustraliaKorea project.

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High Performance Membrane Coalesce, The CRCWMPC entered into a joint research project with the Korean International Environmental T echnology Institute (IETI) based at the Pusan National University. Both organisations provided m atched funding for a one- year first stage proof of concept for a unique oil water separation process en compassing a patented CRCWMPC membrane technology and a p atented IETI absorptant chemical. Korea's primary fo cu s i s on the prevention of marine spills, as Korea imports 95% of its energy (oil, coal and nuclear) and is seeking a significantly more efficient and low cost oil removal process. The Australian interes t is focused on the treatment of oily wastewater from petroleu m industry complexes, service stations and industrial manufacturers (e.g. users of cutting oil). Strong interest has been expressed by potential commercialisers and users both i n Australia and South-East Asia w ho are keen to participate and invest

in the second stage, the agreement fo r w hich is now being finalised. The second stage will be foc used on pilot demonstration both in Australia and Korea and possibly in Thailand.

Conclusion The CRCWMPC will continue to invest in novel membrane technology, focusing on new designs and surface modifica tion to dramatically reduce capital costs, improve efficiencies to provide better separation and expand the utilisation of membrane technology. The CRCWMPC is also investigating the use of electrical field effects to achieve disinfection and bacteriocide properties. It is anticipated that there w ill be significant spin-offs into a number of related process applications ou tside tl1e traditional wastewater treatment field.

Author Dr Ian Fergus is th e CRCWMPC Program Manager fo r Wastewater Management and Water R euse.

Anti-fouling Novel Conducting Membranes The CRCWMPC has invested m ore than $3 million in novel conducting membrane research. This membrane research represents an exciting leadingedge technology development evolving from the CRCWMP C M e m brane R esearch Program . It has the potential to revolutionise th e application of membrane separation technology. The objectives of the research are to: • dramatically reduce membrane fouling • significantly increase membrane life • minimise the need for or elimination of pretreatment which for conventional membrane systems represents the most significant capital and operating cost. This technology is based on applying an electric field to the membrane module to: • induce electrophoresis • repel ions from the membrane surface • reduce the formation of the gel layer • change the pH at the membrane surface • improve the efficiency of the cleanmg regime. T he application of anti- fouling membrane technology is not limited to the treatment of waste streams. This could be readily applied to biotechnology, e.g. the separation of proteins, blood, pharmaceutical products, and to the cr;eation of value- added products from waste.

SPECIALISING IN ENVIRONMENTAL SERVICES TO THE WATER INDUSTRY ..,. Water And Wastewater Treatment & R~use ..,. Water Quality Management ..,. Water Resources Development & Hydrology ..,. Hydrogeology ..,. Irrigation & Drainage ..,. Industrial Liquid & Solid Waste Management ..,. Air Pollution Control ..,. Environmental Assessment & Management

CMPS&F ENVIRONMENTAL CONSULTING ENVIRONMENTAL ENGINEERS & SCIENTISTS Otffces throughout Australia and South East Asia

WATER JANUARY/ FEBRUARY 1999

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CRCWMPC

R esearch undertake n by the C R C WMPC in the area of wastew ater treatment and water reuse (Program 1) falls into three broad technology areas: • advanced biological processes, representing 45% of the C R C's investment in Program 1 • novel process con trol systems (15% of the investment) • physico chemical treatment processes (40% of the investment). The research in this technology is being addressed through the associated technology platforms of models, control, chemicals, instrumentation and processes. Investment in these areas is based around global d evelopme nts and research trends in the industry towards: • lowering capital an d ope rating co sts • reducing energy demands • preferring distributed treatment systems • increasing demand for reclamation and reuse • value adding to by-products

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• achieving high er enviro nmen tal standards. The global developme n ts and research trends have set the priority directions (p rocess intensificatio n, adding value to wastes an d retrofitting of technologies) for the C R CWMPC into the n ew millennium. Whilst these priorities currently drive the research direction of the CR CWMPC , the re is a continuing effort to further refine and targe t the overall strategic direction into those areas which w ill provide th e grea tes t commercial benefits w hile maximising the opportunities and substantial knowledge base already resident w ithin the C R C WMPC partners. R ecently effort was put into evaluating Program 1 from the perspective of an alysing the gaps between perceived m arket opportunities and the existing research portfolio within the program. This initial evaluation was undertak en from within the C R CWMPC , looking

out, with a commercial and research aspect. The next step in this process is to further develop this, from the o utside looking in , with a stronger market an d commercial foc us. This evaluation w ill be undertaken under th e auspices of the C R C WMP C by organ isations with market intelligence and a commercial background . T he overall obj ective is to determin e the markets and market n eeds for was tewater treatment and water reuse technologies in order to develop an appropriate research strategy and suite of proj ects. By looking at the issues from a variety of viewpoints an on going strategy sh ould develop w hich is relevan t, flexible and more attuned to the global environment. The evaluation of Program 1 has provided an insight into the relationships be tween the proj ects and the overall direction of the C R CWMPC, as well as providing a higher degree of


CRCWMPC confidence in the relevance of the curren t projects to the overall CRCWMPC objectives. It had the benefit of identifying potential market opportunities and industry applications and also classified the R&D requirements for successful outcomes. The R&D that is required fo r each market opportunity was identified, as were the linkages between the market opportunities where targeted R&D would provide useful outcomes to address the various market opportunities severally. The evaluation saw the following general market opportunities as having the p otential to deliver a commercial benefit to the CR C: • integrated wastewater treatment and/ o r water reuse • organics and/or toxic chemical recovery • treatment of high strength waste (organic and/or inorganic) • biosolids management • high rate separation ofbiosolids and/ or inorganic sludges • retrofi tting and process intensification and management • th e adap tation, integration and simplification of technologies. The remaining task is to re- examine these p erceived opportunities with a greater market and commercial focus and to determine w hat the priorities are, w hether they are appropriate and in which strategic areas the CRCWMP C should develop new research projects. Interestingly enough , one of the more encouraging outcomes from the evaluati on was that the current projects within P rogram 1 are addressing one or m ore of the ma rke t oppo rtunities identified-applied and developmental research. Some 22 projects are currently being undertaken in Program 1 in such areas as biosolids management, risk assessment, novel treatment tech nologies, process control and chemical reclamation and reuse. T he Development and Prototype Demonstration of Electrodewatering Technol ogy for Slu dge is a proj ect which showed considerable promise in th e initial stages, increasing solid content of filter cake from round 20% to over 40%. T his resulted in scaleup to a pilot-scale single- roll belt press. Subsequen t results have also been e ncouraging to the extent that effort is now being placed into developing a conductive dewatering belt in order to fu rther optimise power consum ption and dewatering parameters. T he re are three projects being un dertaken in risk assessment related to human health and verification and

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Research team at the Carlton United Breweries pllot plant

fu rther refinement of a quantitative risk assessment model. One of these projects provided quantification of enteric virus on salad crops irrigated with reclaimed wastewater. In the second project, methods are being developed for pa thogen enumeration in a study into reticulated greywater reuse. T he quantitative risk assessment model is undergoing furthe r verification and modification in the United States and p reparations are under way for collecting data from New South Wales and using this to test and furthe r refine the model in the thfrd proj ect. Some 12 projects are related to novel treatment processes ranging from Covered Anaerobic Lagoon Treatment of Abattoir Wastewater through Advanced Membrane Reactor Inco1porating the Aeration- Filtration Process and Biological Nutrient Removal Retrofitting of an Intermittent Activated Sludge Plant to development of Microbial Cultures to Enhance Activated Sludge Treatment. Projects in these areas are leading towards improved lagoo n t reatment techno logy, anti-fouling membranes, resource recovery and reu se in the textile industry, biofilm bioreactors, improved oil removal using membranes, and the application of biotechnology to provide enhancements to nutrient removal and biologically based analysers (biosensors). There are fou r projects being undertaken related to improving control over wastewater treatment processes. One is

directed at enhancing the perfo rmance of two-stage anaerobic treatment systems. The others are directed towards developing a tool kit to support the design of biological wastewater treatment plants, providing biosensors to enhance process con trol, and optimising and developing a prefermentation model already in the marketplace. One project which falls under the banner of reuse is that of Iron Sludge Reuse. Earlier work carried out under the auspices of the CRCWMPC demon strated t hat alu m could be reclaimed from water treatment sludges and reused in wastewater treatmen t to remove phosphorus. Work currently being undertaken is evaluating whether the operational principles and practices developed for alum slu dges can be readily adapted to iron- based ~udges. Much of the research currently being done o n wastewate r treatmen t and water reuse has built on a solid base of knowledge and k now-how arising from the outcomes of 17 earlier projects which generated eight patents. Ongoing research continues to develo p the CRCWMPC's intellectual property portfolio and th e CRCWMPC is actively pursuing commercial outcomes for thi s intellectual property to provide benefit to the 15 organisations w ho are its members.

Author Dr Frank Hudman is the P roject Research Coordinator for Program 1 of the CRCWMPC.

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l.

some of the excess wa te r is electrodewatering.

Electrodewatering Prototype single roll belt press filter

W aste ac tivated sludge is a byproduct of biological wastewate r trea tment processes. As sewage treatm ent plants convert their secondary wastewater trea tmen t processes from conventional and che mical to extended aeration processes, the amount of waste activated sludge is expected to increase dramatically. As sewage trea tm en t plants increase throughput by redu cing hydraulic re tention times, the quality of this sludge is expected to deteriorate rather than improve. W aste activated sludge is notorious for being difficult to dewater. C onventional dewatering produces cakes with solids conten ts of 10-20 w eight per cent (wt%) . This m eans 80-90wt% of the cake is water that contributes significantly to the co st of reuse, particularly the cost of transport and storage (see Figure 1). These co sts provide an incentive to reduce the amount of wa ter remammg in dewatered ca kes. One e m erging techn ology for rem ovmg

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WATER JANUARY/ FEBRUARY 1999

is

Electrodewa tering an e nhanced

dewatering or solidliquid separation technique (see Figure 2). In this work, electrodewatering is being used to enhance press ure filtration of sludges and involves establishing a d irect-current electric-field across the sludge. Pressure filtration involves two stages: filtration ; followed by expression or compression. In the expression stage, p ressure applied to the sludge fo rces water through the pores or capillaries. In an electric field, the charged solids in a liquid sludge can be attracted to one electrode, a process known as electrophoresis. Once enough liquid has bee n removed to crea te a cake, the dissolved ions in the liquid are attracted to the other electrode in a process known as electroosmosis. The d issolved ion s have water associated with them, as spheres of solvation , m eaning that as the ions m ove, water m oves as well. The current passing through the sludge can also create heat, but this shou ld be avoided to minimise power consumption.

The main types of pressure filters used conventionally to dewater sludges are belt press filters, filter presses and centrifuges. Electrodewatering can be applied to either belt press filters or filter presses. Belt press filters cost less than filte r presses and allow m ore continuou s opera tio n , making them the m ore desirable pressure filter fo r electrodewatering .

Approach to Development The objective of an ongoing research project being undertaken by CSIRO and the CRCW MPC at C SIRO's N orth R yde laboratories is to tran sform electrodewate ring from a laboratory technique into a process dem onstrated on a continuou s multi-roll belt press filte r. T he approac h to developing elec trodewatering on belt press filters has been step-wise, with the concepts initially dem on strated by laboratory testing, followed by retrofitting to a pilo t- scale fil te r press. This wa s relatively straightforward because the filte r material was no t moving. To simplify the next step of demonstrating electrodewatering in a continuous operation with moving filter belts, a single roll prototype was built. The sludge can be put through the prototype to simulate a m ulti-roll belt press filter.

â&#x20AC;˘


CRCWMPC

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Figure 1 Benefits of higher cake solids

Figure 2 Principles of electrodewatering

Figure 3 Dewat ering profile

Figure 4 Prototype power consumption

Results An example of the bench-scale results is shown in Figure 3. The dewatering profile shows that pressu re filtration produced final cake solids o f 25wt%, slightly higher than the cake solids of 18wt% from the plant dewatering device. The electrodewatering final cake solids were significantly higher, reaching 48wt%. Most of the improvement in electrodewatering occurred after the cake solids reached 10wt% , indicating electroosmosis was the dominant electrical e nhancement. Scaling t he bench- scale work up to a pilot-scale filter press demonstrated that the power consumption was lower. Different configurations of applying the electric field have been tested in a batch mode on the prototype. In the most successful configuration, product cake solids of over 40wt% have been repeatedly achieved with three passes around the single dewatering roll. The power consumption required to achieve these high cake solids are acceptable to the end user, but work is co n tinuing to redu ce th e powe r consumption (see Figure 4).

several types of sewage sludges in Brisbane and the Gold Coast have produced cake solids of about 40wt%, demonstrating the wider application of the technology. The prototype is now being reconfigured to allow continuous operation rather than j ust batch operation. The modified prototype is expected to be operating by the end of 1998 and will be used to demonstrate the potential of electrodewateri ng to several inte rested commercial belt press filter manufacturers. It is anticipated that a manufacturer will join the development and take it to the next stage of being applied to a multi-roll belt press filter. Sydney Water currently produces 550 tonnes of biosolids every day and this is expected to double over the next 15 years. At present more than 90% of the biosolids are used in agriculture, forestry, composting and land rehabilitation; and improving the dewatering to 40wt% could reduce the current production to about 275 wet tonnes per day. In an application outside Sydney, electrodewatering is being considered as a means of removing sufficient water to allow the biosolids to be combusted as an energy producing fuel.

Ongoing development

Author

So far the results from the research show that electrodewatering on a belt press filter is thermodynamically and kinetically feasible. W hile the prototype development has focused on one Sydney sludge, laboratory testing on

Dr Sarah Miller is a Senior Research Engineer with CSIRO Energy T echnology and leader of the CRCWMPC project on Electrodewatering of Waste Activated Sewage Sludge.

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CRCWMPC

The Cooperative Research Centre for Waste Management and Pollution Control (CRCWMPC) has a wideranging interest in biological process technologies for both water- and solidsbased poll utants. Its research and development (R&D) work includes fundamental microbial studies, directly releva nt treatment process developments and full-scale demonstrations of novel innovative technologies. Much of the biological R&D work is performed through the Advanced Wastewater Management Centre (AWMC) at The University of Queensland. Here science is combined with engineering to study details of the fundamentals of biological treatment processes. These are then combined with adva nced engineering skills to develop novel treatment concepts and improve current technologies. This is supported by expertise in the physicochemical fields at the University of New South Wales and CSIRO. One major research area is biological nutrient removal (BNR). Recently, the discovery of Nitrospira as the likely bacteria responsible for nitrite oxidation during nitrification has clearly demonstrated the leadin g position of the research group. In the meantime, this discovery has been confirmed by several other research groups around the world. The implications and benefits of this finding are being investigated in relation to the curre nt and possible future operation of nitrification systems. The second main process in BNR-

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enhanced biological phosphorus removal-is the su bject of another exc1tmg research project at the AWMC. Despite the widespread use of this technology in modern wastewater treatment plants, the basic understanding of the microbial processes is still very limited. So fa r, not even the type or group of bacteria performing this unique biological conversion is known. However, the C R CWMPC researche rs are getting very close to solving this mystery as well. They have been able to develop highly specialised cultu res of the relevant bacteria able to remove phosphate from over 30 mg/1 P in the influent to less than 0.1 mg/1 in the effluent of a lab- scale reactor system. This biomass accumulated up to 15% of its total dry mass as phosphorus. These scientific advances are used in conjunction with the engineering exper tise at the AWMC and other CRCWMPC members to increase the p erformance and capacity of existing treatment processes. Furthermore, this fundamental understanding provides valuable information for the development of new, innovative technologies to overcome significant shortcomings of the currently used systems. One such example is the demonstration of a novel sequencing batch reactor (SBR) co n cept at full scale at the Bathurst treatment plant. This project, led by the New South Wales Department of Public Works and Services, is testing the performance and capacity of a modified reactor to compare i t with

the ex1st111g IDEA (inte rmittently decanted extended aeration) system that is used at full scale on the same site and in many other locations wo rldwide. The novel SBR concept aims to provide a complete BNR system to remove both n itrogen and phosphorus in a single tank withou t any baffles or recycles. Previous tests at bench and pilot scale have confirmed the suitability of the technology and this project will assess the performance in a full-scale installation. One in creasing focus of the CRCWMPC in the biological wastewater treatment area is process intensification. This concept has been used in many process industries such as refineries, chemical production and minerals processing to significantly increase the capacity (or throughput) relative to the plant size. In terms of wastewater treatment, this would primarily lead to a decrease in the hydraulic retention time in the reactor system and therefore to smaller tank sizes or higher flow rates through existing plants. Several techniques exist to achieve process intensification. The focus at the moment is on identifying the limiting steps or bottlenecks in existing systems and determining ways to either shift the limiting con straints signifi cantly or eliminate the particular process element completely. The research and development work of the CRCWMPC is currently addressing three main areas of process limitations: â&#x20AC;˘ the concentration of nitrifying bio-


CRCWMPC mass in nitrogen removal plants â&#x20AC;˘ the solids/liquid separation process in activated sludge systems â&#x20AC;˘ the dewatering of the excess sludge or biosolids produced in aerobic biological treatment processes. The first project is trying to increase the fraction of ni trifying biomass in the overall solids concentration in the BNR system. Since nitrifying organisms are among the slowest growing bacteria present in biological wastewater treatment processes, they largely determine the overall plant design. Increasing their fraction in the overall solids con tent in the plant will allow a reduction of the total amount of solids in the system and the overall size of the plant. T heoretical considerations and preliminary results indicate that the desired effect can be achieved but further experimental verificatio n is required. A n other maj or limitation in the existing activated sludge design is the solid/liquid separation in the final stage of the process. This is obviously critical in achieving a high quality effluent and in retaining the required amount of bi omass in the treatment plant. Clarifiers (or settling tanks) are almost exclusively used for this purpose, relying o n the slight density difference between the biomass floes and th e treated water to settle out the biomass under gravity and achieve a clear efflue nt overflow. Based on the very small density difference and the resulting slow settling rates, current design rules require the size of clarifiers to be quite large, typically similar in volume to the actual biological reactor size. C larifie rs have been extensively studied and perform well fo r most of the time, but they certainly suffer regularly from various design and operatio nal proble ms. Ma ny of these problems are related to the need for the bacteria to agglomerate in floes to enable the efficient separation from the effluent. This process is still poorly understood and the excessive growth of filamentous bacteria is observed in many cases to cause 'sludge bulking,' leading to difficulties in sludge settling and ultimately poor effluent quality. CRCWMPC research is trying to tackle this problem in two ways. In one, the use of gravity settling of the biomass is critically assessed and options for its replacement are considered. T h e advances in the development of other solid/liquid separation methods such as membrane filtration, centrifugation or other biomass retenti on systems possib ly offer opportunities as alternatives to the current separation technique. All

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these methods, however, have to perform successfully under the highly demanding operating conditions typically experienced at wastewater treatment plants. The second approach to improve the reliability of the settling process is to gain a mu ch b etter understanding of the underlying principles and the effects of operating parameters on the biomass growth and flocculation processes. This will also help in the improvement of biosolids handling aspects such as digestion and dewatering and will directly link in with other exciting CRCWMPC research work undertaken by CSIRO on electrodewatering of biological and chemical sludges. Bench-scale and pilot-scale trials have confirmed the ability of this technique to more than double the solids content in the fil ter cakes, reaching dry solids concentratio ns of 40-50% (mass basis) on a range of sludges tested . T he p roposition to study flocculation, sedimentation and dewaterability of biological sludges in a combined way is obviously a major challenge to any research team. However , the CRCWMPC has access to leadi ng researchers at the universities of N ew South Wales, Queensland and Western Sydney as well as CSIRO and is therefore planning to approach this task in a truly collaborative way. This will bring together the strong R&D expertise in the physical, chemical and biological fields, all of which are essential in solving one of the great challenges of curren t wastewater treatment processes. Already, a n umber of highly useful techniques are being developed and used in CRCWMPC projects, such as a monitor for floe sizes and shapes, DNA id entification of microorganisms and nuclear magne tic re so nance (NMR) studies of the bou nd water in biological sludges. Another area of strong activity of the CRCWMPC re search program is anae robic biological processes. This includes a diverse range of applications from prefermenters in BNR plants over industrial wastewater treatment to solid waste d egradation i n landfills. The underlying p rocesses, however, are very simila r and this leads to interesting synergies between the different projects. The development of the firs t model of prefermenters was finalised early in 1998 by a CRCWMPC PhD student at T he University of Q u eensland and was made available to the wastewater industry in record time in the form of a commercial software package, DSP, which was released in June 1998. A

tailor-made course has also been conducted and the package is now available on the internet (www.scitrav.com). R esearch on prefermenters is continuing, but with a sligh tly different objective. The focus is on achieving significant process improvements (in line with the process intensification concept) and the control of sulphide generated in these units. The latter is in direct response to a real need identified in the industry, as many of the existing prefermenters show considerable sulphide generation with the potential to create odour problems and even reduced perfo rmance of the BNR process. Control of high- rate anaerobic treatment processes as used in an increasing number of industries (breweries, wineries, food processing, agroprocessing etc.) is another area of expertise in the C R CWMPC. Recent work has produced a novel control strategy which enables a 20-50% reduction of caustic addition (for pH control) on these systems. Given that the annual cost fo r this is often in the order of$100,000-$250 ,000, the possible savings are considerable and will improve the economics of these systems fu rther. Currently, a full-scale installation at a brewery is being implemented. The fundamental biological aspects of anaerobic processes are studied also for their benefit in solid waste treatment. By applying this knowledge to the degradation of organic materials in landfills, it has already been demonstrated that the time to completely break down th e organic waste in landfills can be reduced from years to months. At the same time, this knowledge is also directly applicable to anaerobic sludge digestion and even prefermenters. The key benefi ts of the R&D of the CRCWMPC are the access toâ&#x20AC;˘ collaborative expertise available wi thin t he member organisations and the potential for synergies between the various projects that employ similar or identical process concepts. This enables efficient and effective research progress. T he di rect involvement of 'technology users' among the CRCWMPC members ensures that the research objectives are relevant to the industry and the outcomes ca n be applied to real situations experienced in the day- today operation of environmental protectio n processes.

Author Dr Jurg Keller is the CRCWMPC Queensland Node Director.

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ID WASTE MANAGEMENT RWalnberg

The CRCWMPC research in solid waste managemen t (Program 2) has traditi onally foc used on innovative processes and equipment fo r the treatment or stabi lisation of waste and the conversion of waste materials into value added materials. The treatment processes cover p hysio- chemical and biological processes as well as the application of vermiculture and larviculture to achieve these objectives. There are presently three major projects being undertaken in this program area: advanced bio reacto r landfill design; vernucompost fil tration; and enhanced ferme ntation of municipal solid waste.

Advanced Bioreactor Landfill Design The CRCWMPC's largest solid waste management project is in the area of advanced bioreactor landfill design. This project aims to develop landfill design and operating procedures which enable rapid stabilisation of waste and possible reuse of waste treatment cells. T he market for bioreactor landfill design arises from community expectations that conventional landfills are no longer acceptable as a means of disposal fo r municipal solid waste. This has placed waste managers in the position of encountering increasing resistance to the siting of new landfills and demands for higher operation standards at existing facilities. The value of 'air space' in existing facilities is therefore much enhanced, creating opportunities for improved operation to lengthen the lives oflandfills or to reuse the air space

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WATER JANUARY/FEBRUARY 1999

available. The rapid stabilisation of the waste will also serve to reduce the intergenerational liabili ty inherent 111 co nve n tional landfill p ractices and substantially reduce after-care costs as well as assist with the management of greenhouse gas emissions and energy recovery. Laboratory studies have shown that recirculating leachate grea tly enhances the rate of waste stabilisation. In fact, in a study at the CRCWMP laboratories at The University of Queensland m unicipal waste was fully stabilised in under 90 days. There is a world of difference, however, between laboratory conditions and conditions p revailing in a fullscale landfill and the C R CWMP C's research seeks to apply wha t was observed in the lab to a landfill in a practical way at the Lucas Heigh ts landfill site in Sydney. The project commenced in 1992 and about $2.5 111 has been spent in performing laboratory studies in establishing three full-scale test cells. Six C R CWMPC pa rtne rs are involved: Waste Service, ANSTO, NSW Land and Water Conservation, University of Queensland, NSW EPA and Brambles. Laboratory studies have provided a lot of information regarding the growth rate of nitrifying bacteria in aerated beds, microbiological activities in field leachate, and microbial rate kinetics. The achievements to date have been very encouraging, with the methane composition of the gas from the first test cell exceeding 50% after six months. This indicates that balanced methanogemc conditions have been attained.

The ca rbon dioxide composition peaked at 80% and then fell to less than 50% after six months. The methane to carbon dioxide ratios achieved by the first test cell after 18 months would normally take five years in a conventional landfill. Cored samples obtained from the test cell showed that the waste exposed to recirculated leachate was highly degraded. Tracer studies within the first cell have confirmed the significance and extent of channelling within the bed and this has provided invaluable feedback to improve the bed and leachate distribution design . The experiences gained were applied to the design of the second and third cells, and these were recently constructed and filled with waste material. Because of the long time constants involved in th e landfill process, the project still has some time to rtm , but in the end the CRCWMPC team is confident of developing a full- scale landfill management system which is environmentally sustainable, eco nomically viable and socially acceptable, using process technology that will significantly improve the rate of methanogenic conversion of the degradable fraction of municipal solid waste.

Vermicompost Filtration Vermicompost filtration takes a different approach to landfilling where worm systems are used to break down organic waste materials. Another CRCWMPC proj ect at The Queensland University is aiming to develop a fundamental understanding o f the


CRCWMPC processes involved w he n worms are used to stabilise the solids in sewage and treat the wastewater at the same time. This project is a collaborative two- year activity between the CRCWMP C and D owmu s Technologies, the designer and supplier of the 'Biolytic Filter,' an on-site domestic waste treatment process whic h treats solid organic wastes, greywater and sewage. There has been little research directed at either u nderstanding the principles of verrnicompost filtration systems or developing process guarantees for vermicompost filtra ti on systems. It has been suggested t hat vermicompost beds support a concentrated microbial community which acts in the same way as a biofilm in a trickling filter. The p rofile of the bed changes from fres h organic material dropped on the surface of the bed (e.g., newspapers, food scraps, excreta) to a matrix of vermicasts at the base of the bed. Verrnicasts are the excreta of the worms and consist of sparingly degradable organic material. The substrate fo r . . . worms 1s m1cro-orga111sm s. It is believed that the main effect of

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FEATURE containers will house experime n tal vermicompost beds at different temperatures.

Enhanced Fermentation of Municipal Solid Waste

Worm systems are used to treat sewage In CRCWMPC research

the worms is that they maintain aerated conditions by simply consuming and turning over partially degraded waste and old verrnicasts in their pursuit of . . 1TI1cro-orgamsms. Field trials will be carried out in four 6 m shipping con tainers loca ted at the Fairfield Wastewater Treatment Plant in Brisbane. One container will be used for processing sam ples tha t requ ire immediate analysis. T he other three

The C R CWMPC'S third major solid waste ma nagement p roject involves enhan ced ferme n tation of municipal solid waste (MSW) . The CRCWMPC has constructed a specialised enclosed composting facili ty at Lucas H eights in w hich advanced composting trials can be carried out. The buildi ng is fi tted with a biofilter unit to ensure external odour levels remain well below NSW EPA requirements. In this way it is possible to conduct large- scale experiments under conditions which would no rmally be precluded because of the problems with odour release. The facili ty is available for CR CWMPC and external project use.

Author Dr Ron Wainberg 1s the CRCWMPC Program M anager for Solid Waste Manage:,ment.

AN EXCITING JOINT UNIVERSITIES. POSTGRADUATE PROGRAM IN

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HYDROLOGY AND WATER RESOURCES One-Year Masters Program

A 12-month Joint Universities' Masters Program by coursework and research project leading to a MEng, MSc or MAppSc in Hydrology and Water Resources is offered to both Australian and international students. Applications must be lodged by Friday, 29 January 1999. What is unique about this Program?

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Integration of science and engineering, focusing on real applications. Emphasis on water resources under stress, including arid or tropical lands. Draws on the expertise and collaboration of five research/education institutions. The course is designed to be completed in 12 months. Focus on applications providing knowledge and skills for total water resource management. Water resource managers are among the lecturing staff.

This postgraduate program will be of particular interest to professionals who are working, or planning to work, in the field of water resources management and development in government agencies, conswting firms or academic institutions. Admission to all

courses is in the first semester of the academic year. Graduate Diploma and Graduate Certificate courses are also offered. For application and fee details, please contact Irene Spong, Faculty of Engineering and the Environment, University of South Australia, The Levels Campus,Mawson Lakes 5095, telephone (08) 8302 3207, facsimile (08) 83023540,email irene.spong@unisa.edu.au Web address http:/ /www.scieng.flinders.edu.au/teaching/ Hydrology /Hydrology.htm

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CRCWMPC

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The CRCWMPC Is Investigating the use of photo-oxidation to remove arsenic from groundwater In Bangladesh

In Program 3, the e ReWMPe's stra tegy has been to develop niche technologies for the remediation of contaminated sites or the treatment of hazardous wastes, as well as core capability in environmental monitoring technologies through the development of advan ced instrumentation and control systems The eReWMPe has successfully developed an integrated arsenic removal and immobilisation process which can be used by the mining industry and water treatment authorities. The novel process (which has been patented) u ses ultraviolet light rather than expensive chemicals such as chlorine or hydrogen peroxide (which have their own side effects) to oxidise and remove arsenic from con taminated waters. Under certain condition s, natural sunlight can be used which makes the technology particularly suited to remote locations which lack an established infrastructure. The process was successfully demonstrated to treat acid mi ne water in Montana in 1996 under the USEPA's Mine Waste Technology Program. Further work has extended the application of the photo-oxidation process to the treatment of groundwa ter in neutral/alkaline conditions. At present, the eReWMPe is undertaking a demonstration proj ect in Bangladesh to show how a 'low tech' version of the process can be applied in rural villages to remove arsenic from contaminated tubewell water.

30

WATER JAN UARY/FEBRUARY 1999

O n e of the eReWMPC's most successful projects has resulted in the development of monitors to measure industrial pollutants on-li ne. The research undertook the developmen t and field trial of devices for automatic on-line monitoring and analysis of pollutant species commonly found in contaminated sites, particularly volatile organic compounds (VOes). These p atented instruments employ a diffusion cell to take samples of the voes in soil or ground water direc tly. The samples are automatically fed to a sensor in the field and contaminant concentrations are analysed and available in minutes. T his technique enables site assessment or monitorin g to be completed in a fraction of the time and cost normally encountered using traditional analytical techniques. The probes are in the final stages of commercialisation and their availability o n the market is imminent. Another novel sensor concept under

development is microbiological site assessment technologies. Most natural breakdown of pollu tion depends either directly or indirectly on microbial activity. A eReWMPe proj ect at the University of New South Wales aims to reduce the costs of site assessment and remediation monitoring through the use of a comprehensive microbiological assessment employing repo rter- gene biosensors. The proj ect will develop bacteria which luminesce when in the presence of specific contaminants. In th.is way, cost-effective qualitative (and quantitative) site assessm ents will be able to be made. This suite of detection systems will complement the voe probes. Another novel instrument under development is the floe monitor. A key finding of earlier research in Program 1 has been the applicability of small-angle laser light scattering to the determination of sludge stru cture through measurements of the 'Fractal Index.' A modified commercial laboratory instrument with software developed at th e University of New South Wales has been demonstrated, and this project seeks to develop a dedicated instrument suitable for on-line determination and process control of sludge structure. The business basis for this project rests in both the savings that may be achieved through optimisation of polymer dosing and in the improvement in solid s conte nt that may be achieved through optimisation of polymer dosing. Apart from the obvious savings to b e made through the reduction of polyme r costs, su bstantial savings are to be expected with an increase in biosolids solids content si nce transport costs are tied to the volume of material to be transported.

Author

voe probes are In the final stages of commerclallsatlon

Dr Ron Wainberg i s the eReWMPe Program Manager for Solid Waste Management.


CRCWMPC

SPECIAL

FEATURE

STRUCTURE OF BACTERIAL ASSEMBLAGES: MEASUREMENT AND APPLICATION TO PROCESS CONTROL J Guan, R Amal, T D Waite Introduction Microbial aggrega tes o r 'floes' are generated in alJ wastewa ter treatment processes w hether it be in an activated sludge plant, a sequencing ba tch reactor or a fixed film bioreactor. T he physicochemical characteristics of th ese fl oes will influence many of th e steps involved in treatment inclu ding substrate transfer and utilisatio n, floe fo rmation and break-up , supern atant fil tration , biosol ids thi cke ning via sedimentation and/o r flo tatio n, and biosolids dewatering. O f all the physical

characteristics o f bacte rial aggrega tes, th e most important are probably the floe size distribu tion and floe structure (Li and Ganczarczyk, 1990). In recent years, progress has been mad e with regard to characterisatio n of bacterial floe stru ctu re wit h th e recognitio n t hat such floes exhi bi t m ass fractal prope rties (Ma ndelbrot, 1983; Li and Gancza rczyk, 1989). T hat is, the mass M of these aggregates may be related to their radius of gyration Rg (the sta ndard deviati on of the particles from their ce ntre of mass) by the relationship:

(1 )

For linear, planar and three-dime nsionally com pact objects, the exponen t D will have values of 1, 2 and 3 resp ectively while for po rous aggrega tes (su ch as those typical of colloidal assemblages and those fo und in water and wastewater treatment systems) , D may take a fractional valu e. In such cases, the expone n t (whic h we will , fo r mass fractal obj ects, denote as Dt) is known as the 'fractal dimension' w hich, fo r compact aggregates, has bee n fou nd to

Figure 1 Simulat ed aggregates possessing fractal dimensions of 1.78 (left) and 1.97 (right) (from Bushell, 1998)

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WATER JANUARY/ FEBRUARY 1999

31


CRCWMPC

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FEATURE

thickening, se t tling and have values in the 2.3 to 2.5 Table 1 Effect of cationic polymer addition on size and dewatering ability o f biorange (or higher if 'restructurstructure of activated sludge samples solids. Improvements in soliding' occurs). For 'loose' aggreDigested sludge Waste activated sludge Polymer liquid separation unit process gates, fractal dimensions in the dose(%) Mean diam. D D Mean diam. efficien cies result from th e 1.7-1.8 range are common 2 .26 94.4 0 59.0 2.02 (Lin et al., 1990; Amal et. al., alte ration indu ced in size 189.5 2.00 371.7 2.07 0 .2 and structure of the biosolids 1990; Logan and Wi lkinson, 1.97 1.97 439.8 0.4 405.0 assemblages as a result of 1990). Simulated aggregates of 4 52.4 1.92 461.4 1.89 0.6 fractal dimensions of l. 78 and polymer addition. The change 1.65 1.90 483.7 0.8 488.2 1. 97 illustrating th e d iffe rence in structure of bacterial aggre1.0 479.3 1 .83 489.6 1.75 in structure for aggregates of gates on addition of increasing different fractal dimension are doses of cationic polymer is 1995). This has been achieved in the reflected in an ordered decrease in shown in Figure 1. An additional implication of eq 1 is studies reported here using a Malvern fractal dimension and corresponds to an that the density, p, of mass frac tal Mastersizer/E which enables measure- increasing 'openness' of the aggregates objects is not constant but decreases as ment of forward scattered light as a as added polymer strengthens interparone moves away from a point on the function of scattering angle. The ticle linkages. Typical results of such Mastersizer consists ofa 5 mW H e- Ne behaviour for waste activated sludge and object; i.e. laser (632 .8 n m wavele ngth) beam digested sludge samples are shown in (2) which passes through the sample and is Table l. scattered with scattering intensity as a func tion of angle determined by the size Implications for Wastewater Method of Structure and spatial arrangements of the parti- Treatment Determination cles. An array of 31 photo- sensitive Laboratory and field trials confirm While the fractal dime n sions of detectors is used to collect light that polymer add ition significantly colloidal (sub-micron) aggregates have scattered at angles from 0 .03 ' to 6.25 ' . improves the effectiveness of solid b een determined using small angle For aggregates possessing fractal liquid separation processes as measured neutron and X - ray scattering and structure, it can be shown that: by zone settling velocity (ZSV) and (relatively) large angle 'static' light solids content achievable in centrifugal scatteri ng techniques (Amal et. al, 1990; (3) and filtration dewatering of bacterial Schmidt, 1989; Auvray and Auroy, solids (Guan et al. , 1998). As shown in 1991; Amal et al. , 1994), the more where I is the light scattered at angle Figures 3 and 4, a strong dependence of tedious techniques of image analysis 0 and q, known as the 'wave number,' is these parameters on measured fractal (Ganczarczyk and Zahid, 1992) and a fu nction of both wavelength of the dimension is observed and suggests that settling velocity measurement (Namer incident beam (11.) , scattering angle (0) fractal dimension, which is easily and and Ganczarczyk, 1993) have been used and refractive index (n) of the medium quickly determined, could be a useful for larger floes . These methods are and equal to (41tn/11.)sin(0/2). It is thus parameter for control of polymer dose. time-consuming and, in the case o f possible to determine the fractal dimenThe Cooperative R esearch Centre settlino-~ velocity, require insight into .the sion from the slope of a plot of log I for Waste Management and Pollution non - trivia l issu e of an approp riate versus log q. So-called 'power law' Control (CRCWMPC) is conducting formulation for the drag coefficien t behaviou r for bacte rial aggregates investigations to assess the viability of a Gohnson et al., 1996; Lee et al. , 1996). obtained for digested sludge is shown in 'floe monitor' fo r optimisation of Static light scattering can be applied Figure 2 and is indicative of frac tal polymer dose in belt filter dewatering to particles in the 'post- colloidal' behaviour over the approximately 1 to based on measurement of fractal dimen(micron) size range but the intensity of 30 µm size range (Guan et al., 1998). sion. These investigations are under light scattered at small angles from the way in Queensland where support has incident beam must be measured Gung, Effect of Polymer Addition been p rovided by t he Queensland Synthetic polymers are widely used Advanced Wastewater Treatment in wastewater treatment to improve the T echnologies Scheme, the Gold Coast Digested sludge

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Figure 2 Log I versus log q plot for a digested sludge from St Marys STP in Sydney

32

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WATER JANUARY/ FEBRUARY 1999

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Figure 3 Correspondence between fractal dimension and zone settling veloc ity for waste activated solids

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Figure 4 Correspondence between fractal dimensi on and cake sol ids content achieved by laboratory centrifugation


CRCWMPC City Cou ncil and the CR CWMPC. Related studies o f the possibility of polymer dose control through fractal dime nsion measurement for optimal centrifugal dewa tering ha ve co mme nced in Sydney with suppo rt provided by the C R C WMP C and Sydn ey W ater Corporation .

References Amal R , Gazeau D , Waite TD (1994) Part. Part. Syst. Charact., 11, 3 14- 315. Amal R , R aper J A, W aite T D (1990) J. C o/laid Interface Sci., 140, 158- 168. Auvray L, Auroy P (1991) In N eutron, X-ray and Light Scattering: Introduction to an Investigative Tool for Colloidal and Polym eric System s; Lidner, P.; Z em b, Th ., Eds; North H olland, Amsterdam, pp 199-221. Bu shell G (1998) Frac tal Aggregate s o f Po lyd ispersed Particles, PhD th esis, University of N ew Sou th Wales. GanczarczykJJ , Zahid WM , Li D-H (1992) Wat. R es., 26, 1695- 1699. Guan J, Am al R., W aite T D ('J 998 in press) En viron. Sci. Tcchnol. G uan , J , Waite TD , Amal R , Bustam ante H , Wukasch R (1 99 8) W ater Science and T echnology, 38 (2), 9-15. J ohn son C P, Li X , Logan B (1996) Environ. Sci. T echnol. , 30, 1911- 1918. Ju ng S-J , Am al R , R aper J (1995) Part. Part. Syst. Charact., 12 , 274-278 . Lee DJ , Chen G W , Liao Y C, H sieh C C (1996) Wat. Res., 30, 54 1- 550. Li D , Ganczarczyk J J (1990) Biotcch. Bioeng. 35, 57-65. Li D-H , GanczarczykJJ (1989) Environ. Sci. T ec/11101. 23 , 1385- 1389 Lin M Y, Klein R., Lindsay H M , W eitz DA , Ball R C, Meakin P (1990) J. Colloid Interface Sci. , 137, 263-280. Logan B E , Wi lkinson D B (1990) Limnol. Oceanogr. , 35, 130- 136. Mandelb rot B B (1983) Th e Fractal Geom et1y of Natu re; W H Freeman and Co .: New York. Schm id t P W (1989) In Th e Fractal Approach to Heterogeneous Chemist!}': Sudiices, Colloids, Polym ers; Avnir, D. , Ed .; Wiley: New York, pp 67-79 . Nam er J, Ganczarczyk J J (1993) Wat. Res., 27, 12 85- 1294.

Tap Into A Vital Resource Become a member of the Australian Water and Wastewater Association Dr/Ms/Mr First name ........................... ......... . ....... .......... .............. .................................................... .. Last name ........ .......... .... ..................... .................

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0 Individual ................. ....... .............................................. .......... AU $85 0 Stude nt (enclose proof of full-time status) ...... ......... .. ..... .. .............. AU $26 0 Sustaining ....... ...... .... .. .... .. ...... ..... ..... ........ ... ... ..... ............... .. AU$4 65 PLEASE PHOTOCOPY & RETURN THIS FORM TO: AWNA, PO Box 388, Artarmon NSW 1570 Cost of a loca l call within Australia 1300 36 1 426 Telepho ne: (02) 9413 1288 Facsimile: (02) 9 413 1047 Email: info@awwa .asn.au Internet: http://www.awwa.asn.au

AUSTRALIAN WATER AND WASTEWATER ASSOCIATION

TESTING AND REPAIR OF WATER METERS Our Meter Laboratory is capable of the repair and testing of all types of water meters from 20 to 300 mm

Authors Jing Guan and David Waite are from the Centre fo r Water and Waste T echnology in the School o f C ivil and Environmental Engineering at T h e University of N ew South Wales where M s Guan is undertaking a C R C sponsored PhD and Professor Waite is C en tre Director. Rose Amal is fro m the School of C hemical Engineering and Indu strial C hemistry at The University of New South Wales where sh e is D irector of the Centre for Particle and Cataly~t T echn ologi e~ . Bo th Dr Amal and Professo r Waite are participants in a numbe r of CRCWMP C proj ects and supervisors of a number of CRCWMPCsponsored research studen ts.

ENSURE ACCURATE ACCOUNTABILITY FOR THE WATER IN YOUR PROCESSES Contact: Bernie Regan or Keith Lloyd Tel (08) 9380 7531 Fax (08) 9380 7529 Lemnos Street, Shenton Park W A Postal Address: PO Box 230, Wembley W A 6014 Quality A ssured to

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33


CRCWMPC

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ADVANCED OXIDATION PROCESSES AND POTENTIAL APPLICATIONS A J Feitz, R Aplin, TD Waite Introduction Advanced oxidation processes (AOPs) have the capability to destroy organics in situ and are becoming a favoured water and air treatment alternative for tox ic organic compounds. There are two distinct categories: those that involve h omoge nous reactions which incorporate ozone, hydrogen peroxide and/or UV light; and those that use heterogeneous reactions via photoactive metal oxides such as titanium dioxide. What loosely links these apparently quite diffe rent approaches is their ability to produce the very powerful oxidant, the hydroxyl radical. H ydroxyl radicals are capable of completely mineralising (i .e. degrading to CO?, H ?O and mineral ions) virtually all orga11ic compounds. There are a number of large-scale homogenous AOP plants (without catalysts) in Europe and the US treating highly toxic wastewaters that are highly resistant to biological treatment. Some examples are the ECOCLEAR fixed bed catalytic ozonation plant for the treatment of groundwater contaminated with 1, 1, 1-trichloroethane, ozonation plants for the treatment of textile effiuent and landfill leachate, and the C H EMTOX O 3/ H 2 O 2/UV plant for

treating landfill leachate. In all cases, their application lies in destroying target toxic organics that cannot be treated using biological systems (and actually destroys the target compound unlike scrubbing or adsorption technology). When coupled with biological systems, AOPs can be used to partially degrade biologically 'dead' or non-biodegradable wastewa ters, e.g. tannery and textile wastewaters or landfill leachate. H ere, previously biologically untreatable wastewate rs may be partially oxidised to produce smalle r, less refractory compounds that can be utilised by microorganims in aerobic or anaerobic treatment systems. Biological treatment methods are the least expensive treatment option and partial chemical oxidation increases the BOD/TOC ratio from effectively zero, thereby allowing biodegradation of previously biologically dead waters. Photocatalytic processes are an example of an AOP technology and use a semiconductor (typically TiO2) , and toge ther with surface reactions with adsorbed water and oxygen, generate hydroxyl radicals under UV light (either using a UV lamp or the UV portion of the solar spectrum). The early 1990s saw two engineering- scale solar slurry

type applications developed: one in the USA; and the other in Spain. Although removal rates for toxic compounds were rapid, low photonic efficiencies , catalyst separation problems and the inability to sufficiently work under cloudy conditions plagued both plants. From that work and laboratory studies elucidating important reaction pathways, there has been a shift towards low to nonconcentrating fixed bed photoreactors that can degrade contaminants under cloudy (even raining) conditions. Reactor design for fixed bed reactors is rapidly progressing to a stage where it is virtually as fast as suspended systems without inheriting the separation problems. The present challenge is to maximise light capture, attach highly efficient catalysts to fixed surfaces, and optimise support configurations. Fenton-type reactions are another so-called AOP and use iron (Fe 2+) as a catalyst to dissociate H 2O 2 to generate hydroxyl radicals. Modified photoFenton processes are an extension of Fenton's reaction and greatly increase the production of hydroxyl radicals by incorporating UV light and an organic chelating agent (e.g. oxalate) to increase the solubility of Fe (III), produce faster cycling of Fe (III) to Fe (II) and faster

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0.4

0.6

0.8

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Figure 1 Solar photocatalytic fixed-bed reactor

34

WATER JANUARY/FEBRUARY 1999

Figure 2 Concentration and pH dependence of degradation of textile dye, Reactive Red 235, using ozone


CRCWMPC reaction between Fe (II)- organic complexes and H 20 2. These combined effec ts increase the rate of generation of hydroxyl radicals and grea tly enhance degradation.

Applications and Projects A novel solar pilot scale photocatalytic reactor has been developed by the Centre for Water and Waste Technology at T he University of New South Wales (see Figure 1). Preliminary testing has been completed for this wo rk w hich was su ppo rted through an APAI award and Hunter Water Corporation. The reactor is highly efficien t and achieved rapid 99.3 % remova l of low levels of phenol under m ostly sunny co nditions, photonic efficiencies for 100 mg/L dich.loroacetic acid mineralisation ranged from 2.4-2 .8% (only 40% lower than ideal TiO? susp ension systems), and the reactor has also successfully degraded trace levels of a blue-green algal toxin (microcystin-LR ) from spiked drinking water solutions (1 -3) . Scope now exists to further refine the design and optimise the reactor use for specific applications. The Cooperative R esearch Centre for Waste M anagement and Pollu tion Con trol (CR CWMP C) is providing support to extend t his fundamen tal resea rch and , in collabo ration with NSW Waste Services, is presently investiga ting application of AOP techn ologi es for decontamination of c hlo rinated hydrocarbons at the Lidcombe Aqueous Waste Treatment Plant. Two AOP applications are cu rrently u nder review and include adaptation of the previously developed photocatalytic reactor and a modi fied photo-Fenton process using lightsensitive ferric chelators. Both alternatives will target complete destruction of the chlorinated organics. The IC I UK Oxispec technology will be u sed to benchmark the degradation efficiency of the AOP alternatives to assess commercial application. Textil e wastewaters are typically contaminated with biologically resistant reactive dyes and ozonation is presently the only AOP technology widely used to treat this type of wastewater. Laboratory experiments undertaken at the Centre for Water and Waste Technology (suppo rted by the C R CWMP C) confirm that ozonation is suitable for degrading reactive dyes at low concentrations, particularly at high pH (see Figure 2). However, the researchers are mo re in terested in

SPECIAL

FEATURE

assessing the application of other AOP technologies for decon taminating textile wastewater. Preliminary experiments suggest that Fenton type reactions appear to b e ext remely efficient in degrading textile wastewater (particularly higher dye concen trations) and it is anti cipated that modifi ed p hoto-Fenton reactions wi ll further improve degradation rates.

Conclusion Advanced oxidation process offers the opportunity to completely mineralise non- degradable or biol ogically resistant wastewaters in situ or partially degrade wastewaters to aid conventional biological treatment. The processes are often greatly enhanced by providing UV light, w hic h may be either from a UV lamp or sunlight, and offer a robust and increasingly economically favourable alternative for treatment of wastewaters contaminated with highly toxic organic constituents.

References Feitz A J, Waite TD, Jones G J and Boyden

B H (1998) Photocatalytic Degradation M odel and Solar Pilot Scale Stu dies: Application to Cyanotoxin MicrocystinLR. Chemeca 98: Proceedings of the 26th Australasian C hemical Engineering Conference, 28-30 September 1998, Port Douglas, Institute of Engineers, Australia Publications. Waite T D, Feitz A J and Hug S (1998, in press) Photocatalysed Degradation of Trace Contam_inants in Complex Aqueous Media. In Kinccics and Mechanisms of Reaccions at the Mineral/Water Interface, D L Sparks and T Grund! (Eds.), American C hemical Society. Feitz AJ, Waite T D, Jones G J, Boyden B H and Orr P T (1998, in press) Photocatalytic Degradation of the Bluegreen Algal Toxin Microcystin-LR in a Natural Organic-aqueous Matrix. Environmental Science and Technology.

Authors Andrew Fe ltz, Professor David Waite and Richard Aplln are based at

the Centre for Water and Waste Technology, School of C ivil and Environmental Engineering, University of New South Wales, Sydney.

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CRCWMPC

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FEATURE

WASTE MINIMISATION AND CLEANER PRODUCTION R Wainberg Program 4 of the C R CWMPC Sydney : Total Hazardous Waste is developing a centre of excelGeneration by Manufacturing Sector lence in the techniqu es of life cycle assessment and material flux analysis, as these are seen as funda45000 mental tools fo r evaluating and 40.000 35,000 prioritising the development of 30000 cleaner production technology. ~ 25.000 One of the key activities in the ... 20000 15000 f:1..;~ ' l~_· 1111li •. ,,, 11fi area of waste minimisation is the ., ..· Cf 10 ,000 Australian Waste D atabase. This 5000 I / ,, ! ·•·• ~. • CRCWMPC project, which is 21 ~ ,., . ~!. / , !~ , ~ .-~~~ _;: / / 1991 23 2o1 25 26 . , ... , ,f_ ~/.?_ ..t,i . .,,7 I , 990 funded by Environment Au stralia, 27 28 29 3 1 32 33 34 ASIC Codo 1s central to na tional waste minim.isation strategies becau se i t Figure 1 Tota l hazardous wast e generation documents the waste generated at an Australia- wide level and provides a means of measu ring waste ment and inventory database. T he awareness raising and business trends and the success of minimisation strategies (see Figure 1). It is also a development co mp onent aim s to means of identifying the areas w here develop, through collaboration, a sou nd these strategies should be foc used in scientific basis fo r LCA in Australia. It also aims to ensure that Australia has order to have the greatest effect. The proj ect has established a P C - the LCA capability required to meet based database for the amount and emergi ng inte rnational pressures and comp osition of the urban solid waste realise local opportunities. T he use of stream and fo r manifested hazardous the LCA meth odology m u st occ ur waste genera tion in Australia. It has also against a background of well informed developed an urban solid waste classifi- public and scientifi c debate o n the cation system that is endorsed by the subj ec t. A proposal is presently under Australian and New Zealand Environ- development for the establishment of m ent and Conservation Council 'IMAS' - the Institu te fo r Materials (ANZECC) and a guidance manual for Accountability and Sustainability, urban solid waste cha racterisation. which is seen as the optimal way to Urban solid waste and manifested ensure quality control and accreditation hazardous waste data has been included of practitioners in Australia. The for some major regions from 1990 to C R CWMPC is fos tering establishment 1996 and the information is continuing of this institute and plans to take an to be updated as more data becomes active role in its ac tivities on an equal available. The database is accessible o n basis with other industry and acad emic the Internet at http://www.erin.gov.au/ members. portfolio/epg/env_su st. html The CRCWMP C is also running a Life cycle assessment (LCA) is seen Life Cycle Impact Assessment project by the CRCWMPC as a technique w hich aims to encourage a systematic w hich will become increasingly impor- and scientifically rigorous approach to tant fo r Australia in the near future and environme ntal impact assessme nt, the C RC's activities in this area are within the fram ework of the LCA aimed at ensuring that Australia is well methodology. The life cycle impact positioned to meet the environmental assessment methodology will b e challenges of the 21st century. adapted to Australia n conditions for Aside from external case study chemical stressors and will be advanced researc h proj ects, the C RCWMP C to account for non-chemical stressors presently has three major projects in this particularly with respect to the Asiaarea, covering awareness raising and Pacific region. To date, a linear impact business development, impact assess- assessment for a range of pollutant loads 0

36

WATER JANUARY/FEBRUARY 1999

l

I '/.;

r;;'f.i{/ ;,~9f

has been established for Australian conditions. A linear impact assessm ent m odel for the physical impacts under Australian conditions has also been established. A C D ROM prototype has been developed. Life cycle inventory data aims to develop life cycle inventory (LCI) data sets for selected commodity materials, transportation and energy sources whic h are common to building and packaging applications in Australia . The proj ect will establish aggregated inventory data for the life cycle stages of raw materials extractio n and all unit processes associated wi th commodity material manufacture. Inte rnational databases have b ee n assessed for their relevance to Australian conditions for 11 materials and e nergy and tra nsportation types. Local data valida tion has proceeded by comparison with Australian primary and secondary data sources and expert reviews of six data sets have been conducted. Advanced oxidation technology is a CRCWMPC project in cleaner productio n w hich aims to expand the earlier successful arsenic removal develop m ent in Program 3 through th e development of a suite of advanced oxidation technologies to remove contaminants from water without the u se of large quan ti ties o f ch emical additives. The earlier work resulted in the development of a photo-oxidati on process for th e conversion of dissolved arsenic in to insoluble solids. T he current wo rk aims to broaden this technology in two important ways: the primary focus is oxidisable species other than arsenic, e.g. manganese, selenium and cya nide contaminants; and photoabsorbers will be tested and developed which can operate more effectively in the neutral or alkaline pH range.

Author Dr Ron Wainberg i s the CRCWMPC Program Manager fo r Solid Waste Management.


CRCWMPC

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EDUCATION, TRAINING AND TECHNOLOGY TRANSFER J Nielsen Two objectives of the CRCWMPC are to 'capture the ou tcom es of research through co mmercialisati on and tec hnology transfe r for the be nefit of Australia' and 'provide education and train ing to practitio ners in the enviro nment management industry.' The CR CWMPC has develop ed inn ovati ve education, training and technology tran sfe r pro gram s to fu lfil these objectives .

Education and Training Th e C R C WMP C do es no t run fo rma l edu ca ti on programs fo r students becau se this would be seen as being in competitio n with m embe r u n ive rsities-the U niversities of N ew Sou th W ales, Q u ee nsland and W es te rn Sydney. H oweve r, it d oes provide scholarships for postgradu ate stude nts from member unive rsities to undertake relevant research . Stude nts fu nded by the CRCWMPC are currently undertaking research in all of th e CRC's program areas. T his includes improved and innovative treatment tech no logies for domes tic and industrial wastewaters; textile wastewater trea tment, recycling and resource recove ry; rem oval of arsenic from drinking water; improved sludge dewatering technologies ; a clea ner production management model; solid waste management; and mi crobial ri sk assessment. Much of this research is resulting in patents and awards. For exa mpl e, research undertaken o n a new species o f ni trifying organ ism in wastewater treatment has been recognised by the C RC Secretariat as the seventh most important di scovery made by all Cooperative R esearch C e ntres in Australia. Larger scholarships are provided than are available from governmen t and u niversity sources in recognition of the intellectual property w hi ch stude nts may ge nerate in their researc h . In addition , the C RCWMPC also provides fu nding to scholarship students for cons umables, fieldwork, small items of equipm ent, relocatio n expe n ses fo r study at other universities, production of theses and attendance at conferences, seminars and workshops. In addition to generous sc holarships,

th e C R C WM PC adds value to academic p os tgradu ate program s by providing to students: • t he possibility of study at other universities • in- hou se and exte rnal w o rksh ops and se mi nars fo r th eir professional development • industrial linkages • patenti ng and co mmercialisation o f in tellectual prope rty • acknowledge m e nt o f intellec tu al prope rty and payment if it is commercialised. These benefi ts arc now recognised as adding real valu e to postgrad uate programs and result in grad uates who have signifi cantl y in creased e mployability.

Technology Transfer The C R CWMPC undertakes several typ es of technology transfer ac tivities for th e benefit of th e environ mental management indu stries in Australia and overseas. The main activities include th e Internati onal Win ter Environme n tal Sc hool, the Y oung W ater Scientist o f the Year Award , various w orkshops, and confere nce sponsorship. The In ternational W inter Environme ntal Sch ool (IWES) i s a unique co ntinuing edu ca tion p rogram for e nvironmen tal professionals whi ch is jointly unde1written by the C RCWMPC and T he University of Queensland. ft is designed to keep professionals abreast of the latest environmental management technologies and trend s. The format o f th e School also e ncourages t he exchange of ideas and allows interaction be tween participants on professional and informal levels. The !WES is unique in Australia and ove rseas because of the quality and breadth of courses it offers. It is arguably th e largest and most successful continuing edu cation course for environmental professionals in Australia. O ne of the strengths of the program is the i nteraction within and betwee n disciplines. The School has been held annually most years since 1978 at the Gold Coast, Q ueensland. It bas progressively grown since 1978 from the two initial

courses to around 25 courses, depending on de m and. Cou rses are now o ffered in wastewater treatment and nu nagement, air pollutio n, solid waste man agem en t and environmental management and are taught by national and international experts. More th an 20 0 delegates at te nd the Sch o ol annually and con sistently rate it highly. The IWES program is being expanded i n Australia and wi ll also be o ffered ove rseas in respon se to th e increasing need fo r environmental edu ca tion programs. IWES is now being recogni sed as a uniqu e program overseas and interest is being expressed in offering IWES- type program s in the A sian region and the Middle Eas t. The CRCWMPC held the inaugural Y oung W ate r Scien tist o f the Year Award in 1998 to showcase the quality of students and research from a numbe r o f C RC s. T he judges , prominent prac titio ne rs in th e e nvironme ntal managem ent ind us try, no ted that all prese ntati o ns 'dem onst rated hig h quality research , excellent prese ntation skill s and even m ore impo rtantly , a keen understanding of the relevance o f th eir researc h to indu stry and t h e community.' Th e winner of this pres tigiou s award received $2,000. During th e last year several se minars h ave bee n held in the Phi lippines, Thailand, Vietnam , Singapore, M alaysia and C hina. T he C RCWMPC regularly p rovi des sponsorship to co n fe re nces. R ece nt conferences which have been sponsored include th e 3rd Specialist Conferen ce on B iological Nutrien t R emova l from Wastewaters (BNR3), 2nd Asia-Pacific Confere nce o n Sustainable Energy and Environme ntal T ec hnology, UNEP Inte rnational R egional Conference on Environmental T echnologies i n W as tewa ter Management, the 1998 Enviro nme n tal Engineeri ng R esearch Eve nt and th e Ko rea- Aust ralia 2nd Clean Energy Workshop.

Author Dr Jeppe Nielsen is Education, Trai ning and T echn ology T ran sfer Manager w ith the CRCWMPC.

WATER JANUARY/ FEBRUARY 1999

37


B

---------

Abstract

worm species for the purpose of converting the organic material into - Hamlet, William Shakespeare increased worm biomass and vermicast. Vermicast culture are that it: is the excreta from worms that can be • is po!Jution-free , with no odour or used as a plant growth medium and soil leachate problems conditioner. The biomass of the worms • is cost-competitive themselves has b een sold for bait, • can be installed in the grounds of a animal feed and domestic and small treatment plant, eliminati ng the trans- composting systems. port of raw sludge Worms have an ability to convert a • can be used to process o ther organic wide range of organic material includwastes generated in the region ing sewage sludge provided that the • produces a higher value end product material is presented in an acceptable suitable fo r an unsaturated, expanding form. M any laboratory- scale experimarket. ments have been carried out and many Notwithstanding the scientific sup- small-scale operations exist. However, port fo r the process, to date vermi cul- to date the work on sludge has been ture has remained a cottage industry, seen as too difficult because of the need with very few large-scale facilities to perfect stabilisation techniqu es and processing substantial quantities o f manage contamination, both of w hich organic waste. Much of the fault lies require extensive and exp ensive with the vermiculture indus try w hich research and sampling and analysis. Another barrier to commercial has foc used on the breeding of worms for domestic sales rather than on the implementation has been the high cost business of waste management and of operating traditional on-ground vermicast marketing. To be a viable systems and the commercial risks in alternative, very large- scale vermicul- trying to develop an engineered solution. ture must be proven to be ecologica!Jy and commercially sustainable and Elements of Very Large-Scale capable of being ope rated without Vermiculture subsidy on a competitive basis. T he critical elements of very largeThrough the development of pro- scale vermiculture are : prietary equipment and processes, • preparation o f the sludge before Vermitech Pty Ltd has developed a feeding it to the worms system that can consistently and cost• contro!Jed application of the feed to effectively stabilise a large range of the worm beds organic wastes including sewage sludge. • raised cage bed structures • environmental control systems for Basis of Vermiculture managing moisture, temperature and Vermiculture is the process by w hich wind organic material is fed to a variety of • worm biomass m anagement

A certain convocation of politic worms ...

The use of vermiculture to stabilise sewage sludge and other organic wastes has been mooted for the past 50 years. Considerable work has been done on the sta bilisa tion process and value of the vermicast byproduct. This paper outlines the advantages of vermiculture for processing wastewater and water sludges into a valuable soil conditioner and details the ve rmi culture operation s of Redland Shire Council in Brisba ne, Queensland at a plant which processes 400 m 3 per week of mixed sludge. The Council selected vermiculture over composting and lime stabilisation on the basis of lower cost, superio r process and greater end-product potential.

Key Words Vermiculture, worm farm, vermicast, stabilisation, sewage sludge, waste reduction, recycling

Introduction The driving fo rce behind the introduction of vermiculture and other reuse processes fo r organic wastes is the global recognition o f the need to return these wastes to the soil. W hilst legislation is being enacted to prevent the dumping of organic material to landfill, the costs of this type of disposal are rising. Sim ultaneously, farme rs are becoming more aware of the need to reverse the degradation of their soils. For reuse of sewage sludge, very large- scale vermiculture offers an ecologically and commercially sustainable alternative to composting or lime stabilisation. The advantages of verrni-

38

WASTEWATER

WATER JANUARY/FEBRUARY 1999


WASTEWATER • harvesting of the vermicast • po st-processing of the vermicast for sale • leachate control • sampling and analysis systems for sludge and vermicast • information management systems. T h e system is op erated wi thin a quality co ntrolled environment w here the para mete rs are set by the regulatory authorities, local au thori ties and enduse customers. Sludge from a broad spectrum of sewage and water treatment plan ts is being stabilised and th e end product sold into agriculture in New South Wales, Q ueensland and Victoria. Verm itech 's focus is hi gh value crops, racetracks and golf courses. D ewatered sludge is taken directly fro m the treatment plan t and fed to the wo rm s witho ut t he need for any pre-composting or aging. Systems have been installed on a nu mber of sites, th e largest being the 400 1113 per week facility at R edland in B risbane, Q ueen sland.

Vermlculture at Redland, Brisbane In 1997 R edland Shire Co uncil issued a tender for the disposal o f 250 1113 a week of sludge from fou r sewage plants and one water treatment plan t. The tende r required that the selected system remove and p rocess sludge on a con tinuous basis. T hree types of p rocesses we re co nside red: co m po sting, lime stabilisati on and vermiculture. T he vermiculture system was selected on the basis of lower cost, superio r process and greate r endproduct potential. T he site is licensed by the Queensland D epartment of Envi ronmen t and an In tegrated Environmental M anagement System was prepared as part of the licensing requirements. The install ed system consists of a cen tral worm fa rm on the C leveland sewage treatm ent

• Covered bed-no rain drainage through the bed

Figure 1 Raised cage des ign

Worm Bed Construction The beds are made of galvanised steel fra mes with raised mesh cages which con tai n the worm biomass. The 14 beds, each 3.6 m wide and 70 111 lo ng, are mod ular and can be configu red to any length . At Redland , the total available surface area fo r feeding exceeds 3,000 m 2, giving a capacity of 400 m 3 a week. The additi onal 150 m 3 a week capacity was put in place to enable the worm farm to process stockpiled sludge and take other regio nal wastes. The raised cage system shown in Figu re l is a continuo us flow process: waste is fed to the surface; the worms p rogressive ly stabilise the material; and the fu lly stabilised material is harvested from the base. The design maximises the retentio n of the worm bio mass and eliminates the need to separate the wo rms from the vermicast. It also

l i ~~-· Daily feeding

• Only the feeding zone is kept moist with computer controlled sprays • Bitumen surface with runoff return to wastewater plant

plant, 25 minu tes from Brisbane C BD in a koala habitat and above a creek system that drains i nto the sensitive M orton Bay area. Collection from each of the five treatment plants is by well proven, covered-hook, lift-mounted sludge bi ns. T he worm fa rm is divided into two areas: the worm bed/waste receival area and the ve rmicast storage/postprocessing area. T he worm beds occupy an area of 100 m x 80 111. The su rface is bitumen-sealed and drains to a leachate dam with first flush con trol.

Feeding zone

optimises the environmen t to p romote the development of beneficial bacte ria and fu ngi. T he bed is covered to prevent rain seepage through the bed and the feeding zone is kept to the correct moisture content by computer- controlled sprays. Any runoff to the bitumen surface returns to the wastewater plant if it fails to meet the stringent release condi tions set down by the Q ueensland Department of the Environment. Waste Blending The waste from the five sites is received into a bunded mixing area. Before operations began, sludge was collected from each of the five plan ts and fed to the worms over a six-week period to determine the best sludge blend fo r the worms. It was fou nd that each waste has its own blend requirement. These fo rm ulae are proprietary. The o bjective o f blending is to deod orise and aerate th e waste and adj ust the carbon/ nitrogen balance, p H and salinity. A range of mineral, organic and bacterial addi tives may be mixed depending o n the nature of the waste an d th e state of the worm beds. M ixing has made all sludges worm-accessiblethis includes some 'speciall y aged ' material prepared fo r an odou rf'eatability' t ri al. T h e standard p racti ce o f collection, blending and feeding o n the same day minimises the potential of any odour b uildup.

1 . 0 0 0 .oon.-r---- - - - - - - - - - - - - , 100,00 10,00

D Faecal coliform

1 ,0 0

• E. coli

100 10 R AW

BioVerm harvest

......_ Leachate - . _ drain

TOP

M ID

BASE CAST Gra de A

Note Scale is logarithmic

Figure 2 Progressive st abilisation of sewage

WATER JANUARY/FEBRUARY 1999

39


WASTEWATER To date, the Redland operation has had no contamina nt-based poisoning, although at another plant worm stock has been destroyed by the unintentional adding of caustic sludge fro m a food processi ng plant. Worms seem to be quite resilient to heavy metals contamination (Edwards and Neu hauser, 1998), Dieldrin and PCBs 1.1, 1.2. It is clear that worms do bio-accum ulate heavy metals, but the degree and their value as toxic p urifiers are being researched with a grant from the Queensland Government under the Advanced Waste Water Treatment (AWWT) Scheme.

Feeding Once fuJly populated, the sludge is fed to the worms daily across the entire surface of the worm bed. Controlling the depth of feedi ng is critical to the process . If too much is fed, or if it is fed to o thic kly, there is potential for the material to com post or turn anaerobic, both of wh ich prevent worm activity. It is therefore essential that the quantity fed matches the daily quantity consumed by the worms. Worms eat between one half and their own body weight a day. On this basis, the Redland site is estimated to contain between 80 and 160 tonnes of worm biomass.

Sludge Stabilisation T he gri ndi ng and tumbling action inside the worm gut reduces the sludge p article si ze and exposes a greater surface area to a range of viruscidal enzymes and a host of bacteria. One of the major limitations of on- ground worm fa rms is the high potential fo r the formation of aerob ic zones whic h contaminate the material and promote pathoge n regrowth. T his is avoided in the raised bed design because it maximises the air flow into the bed and facilitates an even distributio n of mixed slu dge. A fter excretion the sludge particles continue to be exposed to an aerobic e nvironment in t he raised cage beds with very high bacterial and fungal populations.

40

WATER JANUARY/ FEBRUARY 1999

Table 1 Grade A standa rds Enteric viruses

< 1 PFU/4 g

Helminth ova

< 1 PFU/4 g (Ascaris

and Taenia spp.) E.coli

< 100 MPN/g

Faecal coliforms

< 1,000 M PN/g

Salmonella

Nil/50g

Stabilisation occurs p rogressively down through the bed. Figure 2 iJlustrates the typical pathogen reductio n profile from raw waste through to stockpile vermicast. T he exact stabilisation mechanism has not been quantified, bu t the empirical results are clear. All vermicast meets stabilisation Grade A requirements set out in the New South Wales Environment Protection Authority Biosolids Guidelines 1997. A rigorous sampling and testi ng regime was established at the R edlan d pla nt to ensure compliance with th e regulatory and contractual requirements (see Table 1). Both the raw sludge and vermicast are tested by NAT Aaccredited laboratories and a range of analyses are done on-site to ensure the waste mix complies with the blend fo rmulation requirements. Samples are taken of each bin of sludge and weekly composites are se n t for analysis. In order to track the source of abno rmal results, ind ividual bin subsamples are kept refrigerated until the composite result is obtained . D ata from sampling is used to predict contamination levels and to assist the Council to trac k the source of contaminants. For example, a dramatic increase in the amou n t of selenium was noted around the time that a new battery reprocessing facility was established in

the shire. The Council is curre ntly investigating practices at this facility. In another incident after a ch romium user advised of an acciden tal discharge into the sewer, sludge from the plant was quarantined and tested. Since no increases above the Grade B inpu t levels were detected, the sludge was processed normally. The vermicast end product 1s sampled and tested followi ng regulatory and contractual requirements. As part of the contract, a detailed Stabilised Sludge Managen1en t Plan governing testing, quaranti ning, blending, labelling and dispatch procedures is followed.

The Vermicast End Product Vermicast is worm excreta and quite diffe rent fro m the original sludge. Vermicast harvested from the base of the bed will have been in the bed fo r more than 80 days. It is free of odour and smells li ke good soil. It is fu lly cast, free of live worms and viable worm eggs. Post- processing co n si sts o f windrow drying under cover, blending fo r quality, and screening to obtain a uniform product. The product is not sterilised or pasteurised, but meets all stabili sation criteria. Final p H is in the range 6.3 to 7.2. C ation exchan ge capacity (CEC) exceeds 30. Vermicast is not sold by specifica tion as a fertili ser but by generic type as a soil conditioner. Vermicast quality will vary according to the food sou rce, productio n process and post-processing practices . Ve rmitech is establishing internal standards for its B ioVe rmâ&#x201E;˘ product to differentiate it from generic vermicasts and to develop product reliability standards for the consumer. Most third party trials on vermicast

Yellow Pages Innovation Award Vermitech has won the Yellow Pages In novation Award held in conjunction with Channel 9's Business Sunday program for its innovative solution for organic waste management that allows councils to substantially reduce or eliminate the cost of waste ma nagement in a com mercially and environmen tally sustainable manner. The $50 ,000 first p rize has been given to the CSIRO and DPI for more research . T he company has also received a $40,000 grant from the Publishers Envi ronmental Network to use vermiculture in the management of newspaper print and glossy magazine waste.


WASTEWATER growth properties have not identified the chemical o r biological composition, food source or method of processing of th e vermicast. Considerable anecdotal information exists, but the lack of co mp rehensive scie ntific research is being addressed. Buckerfie ld and Webster (1998) of CSIR O Land and Water have conducted a broad range of tests. Some resu lts are illustrated in Figure 3. Vermitech has commissioned research by Sydney University, CSIRO, the Departments of Agriculture an d Primary Industry and large commercial growers. All the trials are standardised replicates designed to establish firstly the commercial value ofBioVerm™ to growers of crops in different regions with va1ying soils. Currently, more than 50 trials are under way. Interim results using BioVerm™ for these agricultural trials have demonstrated : • increases 111 the rate of seed emergence • acceleration of root development • rapid advancement of seedlings and earlie r readiness for replanting (lettuce-one week; broccoli, tomato, cabbage and capsicum-two weeks) • plants are hardi er and mo re diseaseresistant • there is a greater uptake of nitrogen beyond the amount contained within the BioVerm™. BioVerm™ has low levels ofN:P:K , a broad ra nge of trace eleme nts, neutral pH , high cation exchange capability and high organic matter and is biologically active, containing live bacteria and fungi. The second stage of the BioVermTM research is to identify the active mecha-

+ Vermicast holds 30% more

12

water than potting mix

10 70

.9

60

50

6

49.4

,o 4

30

20

2

10

0 Primula Poppy Parsley Broad Beans

0

+ 50% increase in grape yields in the Barossa Figure 3 Growth results from 10% vermicast added to potting mix

nisms so that the produ ct quality parameters can be set to maximise the value to the end user. Trials on the role of BioVerm ™ as a pathogen antagonist are also being undertaken. Part of the research is being funded by the AWWT grant from the Queensland Government. R esearch papers will be published once the trials are complete.

Contamination

Vermiculture can be u sed to stabilise any sludge but is more appropriate for processing sludges which meet A or B Grade contamination levels. Whilst they are able to be stabilised , more highly contaminated wastes may resu lt in a level of contamination of th e vermicast which renders the product unsafe for uncontrolled use. Contamination levels can be cont rolled by analysing incoming sludges and blending in 'clean ' organic material to the feed mix to redu ce th e ultimate level. As a soil conditioner, vermicast is applied at relatively low rates- less than a tonne to the hec tare 1s the recommend rate for all but the most degraded soils. The contamination and appli cation control sta n dards vary from State to States. At R edland most contaminants fall within Grade A, reflecting the relatively low industrial ba e. Only copThe vermlcast end product Is sold as a soll conditioner per and zinc push

the vermicast to Grade B. Given the low application rates and the common agricultural use of both these elements, it may be that a new standard for vermicast grading needs to be developed. Results of research carried out by Dr Glen Bany of the Department of Natural Resources in Indooroopilly indicate that the increases in topsoil heavy metal concentrations from an ap plicatio n of BioVerm at 5 wet tonnes/ha are minimal and in most cases would be unli kely to be detected using most analytical techniques. While worms survive and even flou ri sh in con taminated wastes, to date there is insufficient information to determi ne w hat bio-remediation qualities they possess. Even if there is some up take of heavy metals, the degree is n ot quantified. Similarly, there appears to be a decrease in the levels of PCBs and organo- phosphates, but again the data is anecdotal and the method of destru ctio n is not known. Research in this area is being conducted by Vermitech and results will be published in the near future.

The BioVerm™ Market BioVerm™ is being targeted at high va lue h orticulture, viticulture an d seedling propagation. Overseas, more than 150,000 tonnes is used annually on crops such as sugar cane, tobacco, coffee and table grapes. In Australia, BioVerm™ is being marketed as a soil conditioner, not a fertiliser, though in some countries vermicast is seen as a fertiliser. BioVerm™ is recommended to be used in conj unction with standard farm p ractice, or as an additive to seedling and potting mixes for the nursery industry. There is a growing recognition by broad-acre farmers that their soil is being severely degraded and they have been compensating by steadily increas-

WATER JANUARY/ FEBRUARY 1999

41


WASTEWATER coop erative development of very largescale vermiculture operatio ns, the cost of waste disposal can be tu rned into a profit centre .

Conclusion

Galvanised steel frames with raised mesh cages can be configured t o any length

ing the quantity of inorganic fe rtilisers. BioVerm™ is being positioned as one part of the re habi litatio n process, returning soil bacteria and fu ngi on an organic substrate. It is accepted that only a small percen tage of the total fertiliser applied to soil is taken up by plants. The rest is wash ed into rivers, polluting surface and underground water systems, or locked up in soils. Once the impact of vermicast on n u trient uptake is quantified, 'standard' farm practices can be amended to reduce t he amou nt of fertilisers applied. T he annu al fertiliser market in Australia exceeds 2.5 million tonnes, of w hich Vermitech's target is less than 2%. T he impact of the Redland production is negligible. U nlike composts, d ried manures and mulch es, Bi oVerm™ comman ds a price exceeding $250/m3, at the worm fa rm, for bulk sales. The no n-sewagebased vermicast commands a retail premium, selling at $1 per kilo recommended retail price. T he non-sewage p roduct has been certified as organic by the Biological Farmers Associatio n. Because inputs to organic farms must themselves be certified organic, the organic vermicast product commands a premium from consumers.

Comparison of Vermlculture, Lime and Composting Assuming equal operating costs and similar handling and mixing requirements of vermicultu re, lime stabilisation and composting, very large-scale vermiculture has some distinct advantages: • it is odourless • the minimal leachate produced is easily contained. There is even a market for the 'worm wee' leachate (although there is a lack of information on its value and Vermitech does not produce or sell it) • because the process is pollu tion free it can be installed in the precinct of the

42

WATER JANUARY/FEBRUARY 1999

treatment plant, even in urban areas, reducing the cost of sludge transportation • the sludge i s converted into an enhanced product • other o rganic wastes such as dirty paper and cardboard, vegetable and food processing waste, abattoir wastes and green waste can be incorporated into the blend • the end product, vermicast, has no offensive odour and smells like good soil • vermicast is easily transported and can be bagged or shipped in bulk without any negative impact on the product or the environment • vermicast has a high market value • the vermicast market has not been saturated.

Commercial Viability of Very Large-scale Vermlculture Very large- scale vermicultu re is a capital-intensive activity. Development of the technology and the vermicast market has absorbed millions of dollars in research and development and will continue to do so. On a stand-alone basis, a facili ty the size of Redland provides an investment that yields a superior return to most infrastructure proj ects. The rate of return is governed by: • the initial capital investment • t he operating costs o f the worm farm , which will reduce wi th technical innovation • the fee charged to the local council, governed by competitive tender • t he return from the sale of t he BioVermTM_ T he initial capital investment will be in the order of $3 million fo r a facility that p rocesses 20,000 m 3 of waste each year, with site variations impacting on construction costs. From this, about 7,000 m 3 of vermicast will be produced a year at a wholesale value of $1.7 million. This situation provides an opportu ni ty for sludge producers to enter into arrangements whereby, t hrough the

Very large- scale verm icultu re parallels the concentration o f waste p roduction as a result of greater urbanisation and the development of intensive agri culture. T he very la rge system concentrates nature's biological cleaning agents-worms, bacteria and fungi-into a continuous flow process at a scale that is determined by the quantity of waste to be processed. The vermiculture process meets or exceeds all regulatory requirements and p rovides a publicly popular solution to the problem of sludge disposal. The process is cost- effec tive fo r was te producers, allowing them to meet even the most stringe n t waste redu ction targets withou t any increase in costs. T he vermicast end product is superio r to othe r reu se products, providing easy use and greater benefit and value to the agricultural consumer. As a cooperative venture, very largescale vermiculture can turn the cost of waste disposal in to a profi t centre fo r waste authorities.

References BuckerfieldJ C, Webster KA (1998) Wormworked Waste Boosts Grape Yields: Prospects for Vermicompost U se in Vineyards, Aust1~1lian and New Zealand Wine IndustryJournal, 13 : 1, pp. 73-76. Edwards C, Neuhauser E (1998) Earthworms in Waste and Environmental Management, SPB Academic Publishing, Chapters 1-3.

Author Mike Lotzof is th e M anaging Director ofVermitech Pty Limited, 20 Pelican Street, Da rlinghurst NSW 2010. He is a lawyer who has spent most of his life in corporate Australia working with technology and innovation commercialising ideas. (People often tell him that moving from law to worm farming is a step up!)

APOLOGY T hroughout the paper by N W Swain and R A J ago entitled 'Trialling the CDS Screening System on Raw Sewage' published in Water Vol. 25, No. 6 the screen dimensions should have been in micro-metres (µ m). We apologise for the error.


ENVIRONMENT

In J uly 1998 the Land and Water R esources Research and D evelopment Corporation , the Cotton R esearch and D evelopment Corporation and the Murray- D arling Basin Commission held a j oint conference in Canberra to present the fin al results of their $6 million research program on the impact of pesticides on N ew South W ales border rivers between 1993 and D ecember 1997. Some 100 members of th e research gro ups and representatives of the cotton growers attended .

Wa ter Features Editor Bob Swinton h as prepared this report, which is to be read in conjunction w ith a background paper by Schofi eld, Edge and M oran , Minimising the Impact of Pesticides on th e Riverin e Environment, published in the January 1998 issue of the W ater j ournal. Although the research p rogram con centrated on the cotton industry, fo r reason s explained, som e of the findings are relevan t to other impacts of agriculture on our rather delicate rivers and stream s. In summary, there is no doubt that t he improved management practices being adopted by cotton growers in the past six years has reduced the level of endosulfan i n, say, the Namoi River, to about a quarter of the levels observed in 1992. Even so, the median concen tration duri ng the spraying season is fi ve to ten times higher than the limit of 0.01 ug/L set by ANZECC fo r protection of aquatic ecosystems. Although changes in structure of the biota community are observed, the significance of these changes has yet to be quantified. T he most significant effect might well be impairment of the fu nction of the biota which graze on algae. T he cotton industry has p repared a Best Management Practice Ma nual to furt her minimise the leakage , based on the results of the research to date, and this is being promulgated throughou t the industry.

Pesticide Retention and Transport T he prime pesticide used by the cotton industry is endosulfan, and many tonnes are applied during each growing season, December to February, mostly by aircraft sprays. However, o nly a minute proportion finds its way into the streams w hich drain the cottongrowing areas of n orthern New Sou th Wales and southern Queensland. These lead into the 'Border Rivers' (Namoi, Macquarie, Gwydir) which eventually

drain to th e Barwon/Darling l~vers. Although only a mi n ute proportion, the resultant peak concentration in th e local streams is significantly highe r than the EPA limit of 0.01 ug/L, yet their health seems reasonable. Endosulfan is a chlorinated hydrocarbon, but unlike the very persistent DDT and hexach lorbenzene, it has a seven-membered ring which is readily destroyed by a combination of oxidation, hydrolysis and perhaps biodegradation in th e soil. Ivan Kennedy of the University of Sydney has measured the rates of degradation. The initial oxidation product is the sulfate, which is still toxic, but the following diol and other brea kdown products are non- toxic. T he sulfate ca n last for up to four months in soil, but no build- up from year to year has been observed in either paddocks, dams, or streams. The four modes for e ndosulfan transport into the riverine environment are: • drople t d rift onto adjace nt areas • wind- blown dust from paddocks and roads • vaporisation and subsequent re-solution • runoff, both in the water body and sediment. Drift A team from th e Gatton College of The University of Queensland led by Dr Nicholas Woods has investigated drift from aircraft sprays, both from single experimental runs, and from

co mme rcial sprayi ng of ca . 100 ha paddocks. Sampling traps have bee n placed up to 1000 111 from the sprayed area, and traps have also been placed o n rigs above the crop. Laser technology was used to compare the droplet size spectrum of the modern 'ultra low volume' (ULV) sprays (with a spin ning distributor in the discharge of each nozzle) whic h distribute 2-5 L of concentrated solution over a h ectare, with that of 'large droplet placemen t' (LOP) systems, which spray a dilu te solution. T he former generate a wide spectrum of50-150 um droplets, th e latter a narrower range. The researche rs fo und that U LV depo sits 60% of the chemical on the target leaf and 25% on the ground , bu t 14% was ca rried off the paddock as drift, w hich is rapidly attenuated in t he next 500 M. LOP deposits 50% on the leaf, 43% on the ground, and only 7% as drift, which is reduced to 1% at 500 m downwind. Their recommendation is that despite economic disadvantage, LOP sprays should be used close to sensitive areas, such as water channels or streams. Strategies to reduce drift have also been formulated. Dust The un sealed road alo ngside a paddock usually gets a fai r do se of spray, and vehicle movement will stir this up. As well as experime n ts with wi nd tunnels, John Leys' team from the Department of Land an d Water WATER JAN UARY/ FEBRUARY 1999

43


ENVIRONMENT Conse rvation in New South of pollutant, into a river w hich is "fAJm't¥fE.~ Poslicido concentration Wales drove sampling vehicles already running m uch faster due in farm runoff O 1 0 µg/L pell-mell thro ugh the dust plum es to the storm event, summarised in raised by 4WDs driving at 80 k/h, 10.0 Figure 1. The three dimensions relate to flow from the drains, the and also b ehind a c ultivato r 8.0 working a recently sprayed overall flow of the receiving river, 6.0· paddock (at 8 km/h ). and the resultant concentration. Concentration in river ~lg/L 4.0 A typical freshly sprayed road T he envelope is continuous, and surface contained 100 times the 51 Flow in river the point made was that any spot GI/day NOEL, but at the surface tempersample of the concentration in 0.0 ~ ,::-,--,-,-..,_,_ · 75 atures reached in summ er time, th e river could lie anywhere on o 4.s 9.o ,3.s ,a.o 22.s the envelope, depending on the the re was rapid volatilisation. Total Input Flow Dust deposited downwind of the GI/day time of sampling and the time plume contained 1-5 ug/g, but of peak river flow (from relation ] 00.0-2.0 m2.o-•.o o•.o-s.o cis.o-s.o c a.0-10.0 [ upstream) versus the time of the 100 m downwind the peak local input. (This simulation is deposition rate was 34 ug/m 2 for Figure 1 Pot ential pesticide concentratio n increase in river from total irrigated cotton the two days after the spraying. relevant to the impact of any Over a week, off-farm deposition point source, such as a sewe r overflow). averaged 0 .16 ug/m 2/day. If this line for protection of aquatic systems of All these facto rs have been incorpoamount is projected into the volume of O.Ql ug/L. water in a non-flowing river, it transThe dust filters captured only 5-10% rated into two models by CSIRO Land lates to 100 times less than the concen- of the en dosulfan captured by vapour and Wa ter. Michael Raupach outlined trations actually measured at the tim e. adsorption. The study also found that SPREAD , w hich simu lates trans Leys' team 'concluded that dust trans- the alpha and beta isomers in the water port m echanisms, and FATE , which port was relatively insignificant, but fell by 90% in 24 hours due to break- simulates breakdown. SPREAD intecould easily be reduced by management down and revolatilisation. Endosulfan grates the data from the previous invespractices such as limiting vehicle access sulfate was found to be more persistent, tigations into the four pathways and assumes that runoff events are highly for a day afte r a spray, offsetting the but is sequ estered into the sediment. boundary flights, installing windbreaks It was concluded that vapour transfer intermittent, whereas spray and vapour and not cultivating a freshly sprayed could have a significant effect on wate r transport is correlated with p esticide paddock. bodies close to the paddocks, particu- use. FATE applies the dynamics of if spraying is conducted at high chemical breakdown to the resultant larly Vapour bu t that it would not be a decay in concentrations. temperatures, T he vapour pressure of endosulfan is Using the models for prediction, for contribu tor to the riverine significant appreciable, particularly at the high if all spray drift could be cut example, tempera tu res of the growing season. A systems. out, the concentration in Pian Creek study estimated that in 20 weeks some Runoff might be reduced from 0.1-0.15 to 70% of the endosulfan is lost by evapoIn no rmal 1rngat1011 conditions, 0.04 ug/L, and the Namoi to 0.02 ug/L. ration. The active isomers (alpha and run off wa ter from w ell managed Vapour transport can only be reduced beta) are mostly gone in a few hours but paddocks is usually m inor, and is by reduced frequ ency of spraying. the oxidation p roduct, sulfate, is less recycled from a tail-water storage. The volatile. trouble arises when a summer sto rm Impacts on the Environment A project run by th e New South hits the area, and both soil and water is The D epartment of Land and Water Wales D e partment of Agriculture, carried off the paddock. Residues on Conservation in N ew South W ales has reported by Dr Vic Edge, quantified the the soil can be as mu ch as 35 ug/ kg soon conducted surface water monitoring rate of evaporation by placing samplers after spraying, and in one event 10% of over the Border Rivers region on 28 both within the paddock and down- the endosulfan was washed off t he sites on the Macquarie, N amoi and wind of sprayed paddock s (keeping paddock. (That farm has tripled its tail- Gwydir rivers since 199 1, and the them covered u ntil an hour after spray- water storage) . results were summarised by Monika ing). Two types of sampler were used: Bruce Simpson of the Queensland Musc hal and Bruce Cooper. The active carbon filters to capture vapour D epartment of Natural R eso urces program was commenced in response to preced ed by glass fibre filters to trap investigated the export of both h erbi- t he significant effects of broad acre du st; and open trays of water, 5 cm cides and p esticides from furrow irriga- farmi ng on these rivers. (Some results deep. T he trays were located 200, 400, tion, som e more water soluble than are graphed in Figure 7, page 40, of the 800 and 1,000 m beyond the bound- others. He investigated soil erosi on January i ssue of Water). Peak concenfrom various slopes, and the benefit of trations in the Namoi in February 1992 aries, and were sa mpled at intervals. Vaporisation was obviously tempera- retaining a w heat stubble on the land reached 0.20 ug/L (cf ANZECC ture-dependen t. In 40 • C conditions, before planting and irrigation. (This 0 .01 ug/L). T here was a decline to 0 .04 82% of the e ndosulfan on the foliage reduced export from 6 g/ha to 1.5 in 1995, but a sudden increase in 1996 g/ha.). In one large storm (125 111111) just to 0.10 ug/L, related to drought condihad volatilised in the first 24 hours. The concentrations measured in the after a spray, 1,440 tonne of soil was tions . Nonetheless, 60% of samples shallow water trays were. divided by 20 washed from a typical paddock, i.e. 18 taken were w ithin the guidelines, and to simulate those which co uld be kg of endosulfan could theo retically outliers are decreasing. exp ected in water 1 m deep. At 200 m have been exported from the drains into Water concentrations are monitored the p eak concen tration reached 0.018 the river. H owever, most ofit ended up by 'continu ous passive sampler bags' ug/ L two days after sp raying, and in th e tail-water dam, from which it con taining adsorbents, which attempt averaged 0.015 ug/L over five days. At would in best practice management be to integrate the amo unts flowing 1,000 m the p eak was 0.006 ug/L, and recycled onto the paddock. through them. Storm h ydrographs H e prepared a simulation o f the show that it is th e immediate local the average 0.004 ug/L. T hese levels are comparable with the ANZECC guide- effect of export of runoff at, say, 10 ug/L runoff w hich carnes the loads. 44

WATER JANUARY/ FEBRUARY 1999


ENVIRONMENT Sediment cores taken in February 1998 show that 5 out oflS are contaminated. Andrew Brooks, also of the New South Wales Department of Land and Water Conservation, rep orted o n studies on the Border Rivers which demonstrated the impact of agriculture on macroinverteb rate co mmunities. However, the results in the fi eld are not necessarily due solely to pesticides. In a series of ponds with decreasing con centrations, signifi cant effects on individual species were noted at 0.01 ug/L. Far more data are required before definitive limits can be se t. The effects on fi sh and invertebrates were also studied by J ohn C hapman of th e Centre for Ecotoxicity of the N ew South Wales Environment Protec tion Agency, at first using P rofenos, an organophosp hate . A study of the level of acetyl- cholinesterase enzyme(AChE) activity in fish versus the concentration of the pesticide in their li vers showed a sufficiently close correlation for it to be used as a paramete r. Short-te rm exposure to acute levels followed by recovery in clean water showed that recovery took up to ten days. Exposure of carp to sub-acu te levels of 5 ug/L for 28 days redu ced their feeding rate to a quarter, and recovery was minimal. An endemic rnicro-cru stacean (Paryta) was exposed to 0.1 ug/L (ten times the ANZECC guideline) for 24 hours, the n recovery for seven days, followed by

repeti tions simulating the repea tin g spraying necessary for the cotton crop. Although the shrimp regained some of its activity in the recovery period, this was progressively reduced in su bsequent exposures. When 28% of AChE activity was lost, the animal lost 70% of its pe rception of i ts surroundings, and 60% of its ability to grasp its prey. Experiments with e ndosulfan showed similar trends, and the in vestigations included effects of tempe rature, turbidity and sediment load. This th eme was co ntin ued by Ross H yne of the University of Technology, Sydney, who based his studies on the macro-invertebrates may-tly nymphs and caddis fly larvae in eight sites in a 200 km ru n of the Namoi River, five of them in the cotton-growing zone. The latter five sampler bags downsteam of these areas in D ecember 1995 showed pea ks of up to 1,000 ug/L , predominantly the sulfate. H owever, the ratio of sa mple r bag concentration to water co ncen tration has still to be de termined. R esults for 1997-8 were co rrelated with the decrease in count of o nemonth old larvae. H e proposed that such sampler bags could be developed as a regu latory tool, with mon itori ng of th e th e long- term effects of management practices.

Outcomes The cotton industry w ill continu e to

fund research, particularly into assessing the overall co mmunity aspect. W ell aware of the problem , it has prepared a Best Management Practi ces M anu al based o n the interim results. H oweve r, this is to be re-cast in light of comments by growers. T he document has to be some thing which is read and used by individual far mers and not just another piece of lite rature to be filed away. In addition, there has to be some meas ure of compliance or otherwise, perhaps an accreditation sys tem. A 20-page booklet en titled 'The Cotton M odel' summan sing th e findings of th is first holistic approach to the resolu tion of a complex problem, with a view to applyi ng th e results to th e wider irrigation industry, is available on request from the Land and Water R esou rces R esearch and Developme nt Corporation, GPO Box 21 82, Canbe rra A C T 2601.

Reporter E A (Bob) Swinton is the Features Editor of Water. He was a resea rc h scie ntist in CSIRO specialising in desalinatio n, water and wastewater trea tment, and retired in 1987. H e was Chairman of th e Water Edito ria l Committee for some years and is a past Preside nt o f AWWA's Victori a n Branch. In 1994 he was awarded Hon orary Life M e mb ership o f t h e Association.

BOOKS Catchment and Aquatic Ecosystems: Nutrients Ratios, Flow Regulation and Ecosystem Impacts in Rivers Like the Hawkesbury-Nepean Graham P H arris, CSIR O and Cooperative Research Centre for Freshwater Ecology , University of Canberra, P O Box 1, Belconnen ACT 2616 Available from A WWA Bookshop $25. H ave you read any o f Stephen H awkings' work on chaos theory or his A Brief History of Time? Do you have an appreciation of systems chemistry, dynamic equilibria, self o rganising biological systems, transport kinetics? If so, this little publication will seem like a voyage of discovery in th e Australian inland river system rather than the interplanetary cosmos. After a career spent studying rivers, catchment biology, aquatic biota and the impact of Australia' s unpredictable climate, Dr G raham Harris, one of Australia's fo remost re searc he rs in freshwater ecology, has tried to provide an easy-to-understand synopsis of

the curre nt state of knowledge. H e is particularly interested in the impacts and inter- relations hips between nutrients, variable catchment demands and problems of flow regulation. While students of physics, chemistry and enginee ring are trained to collec t information and dissect facts to interpret the unde rlying structu re, ecologists gather fac ts and look fo r relationships betwee n them. Dr H arris is adept at explaining th e complex interplay between sediment and nutrient levels, algal growths and riveri ne flows. Yet he emphasises: 'We are dealing w ith intrinsically and naturally variable systems ... P redictions at any level can only be probabilistic.' (p. 5)

T he fundamentals ofbalance, interrelatedness and the cycling of essential elements through nature underlie the autho r's thinking. The penultimate chapter, Emerging Predictive Models, attempts to borrow from philosophical concep ts of the ever-organising scientist represented by Hawking. The

ecologist in Harris would seem to b e asking: Must every system, i.e. nature, play by rules and behave according to progra mmable mathematics? The implicit refe rence to c haos t heo ry evident in some of the ea rly chapters of the work lurks i n the background. The final chapter provides a brief summary of managem ent strategies and recomm endati ons. It also carries a timely warning for those who seek quick solutions: 'The dynamic approach requires a more sophisticated view of water qualiry than me re concentrations and ratios. Even tho ugh th e ANZECC water quality g uidel ines are couched in terms of concen trations, such measu res are too si mplistic if an swers arc sought to questions like the sign ificance and managemen t of cyanobacterial blooms.'

A good bo ok prese nting a we ll rou nded appreciation of the difficult issu es facing Australian inland water scientists. Dr Diane Wiesner, A WWA Bookshop WATER JANUARY/FEBRUARY 1999

45


m

BUSINESS

FINE-TUNING COMMUNITY UNDERSTANDING OF THE

SEPTIC TANK B Ridder Abstract Septic tanks and other on-site sewage systems are the source of nu merous dilemmas fo r local governmen t authorities. Hobart municipality is blessed with a history and environment that in no way d iminishes the potential fo r such problems . A recent survey undertaken by Hobart City Council confirms suspicions that a reasonable proportion of septic systems are not totally effective, while community understanding of septic processes is low. This paper ou tlines a policy for deali ng with the problem.

Background Hobart City Coun cil governs a relatively small area encompassing the CBD and older suburbs of the southernmost Australian State capital city. From the shores of the Derwent Estuary to the sum mit of M ount Wellington represents an elevation gain of 1270 metres. Steep, dissected topography is the defining feature, bestowing on the city a large proportion of land too steep for development, and a high degree of micro-climatic variability. Sewage reticulation and treatment is managed by the Council, as is the approval and inspection of on-site systems located beyond the reach of sewerage mains. About 370 dwellings are not connected to the sewerage system and, due to topographic limitations, tend to be located in the bushland fringe, at th e back of small valleys and on higher slopes. About 220 of these dwe llings are to be found in the bushland suburb of Fern T ree. The man agement conundrums posed by septic tanks in Fern Tree and a policy designed to deal with them form the basis of this paper.

Site Conditions Fern Tree is located 7 km west of the GPO on the south-west slopes of Mount Wellington at an elevatio n of 420 m . Annual precipitation is about 46

WATER JANUARY/FEBRUARY 1999

A septic tank at Fern Tree too close to a creek

1100 111111, almost dou ble that experienced in the city. The la titude of 42° Sou th gives rise to a low sun angle in w inter and co nsiderable topographic shading, particularly later in the day. Frosts are common, with some patches of ground liable to remain cold and saturated for several months at a time. T he geology of the area is a mixture of Jurassic Dolerite and Permian Sandstone. Both have a propensity to form heavy clays w hich will shrink or swell depending on the moisture content. D evelopment is generally limited to ridgetop s, with the steeper side slopes and narrow gullies densely vegetated with wet schlerophyll eucalyptus forest.

Sewage Disposal Almost all of the dwellings use a dual-purpose 2500 litre septic tank in conjuncti on with absorption trenches. O n average these systems are more than 25 years old. In February 1998 Hobart City Council conducted a survey of the area to determine the level o f the community's understanding of septic system operation and general attitude toward the existing unsewered status of the area. The survey consisted of a questionnaire, with respondents remaining anonymou s. From Fern Tree there was a 56% response rate, wi th only 9% of respondents dissatisfied with nonconnection to the sewerage mains. It is probable that these results are skewed because of: • a desire to retain the existing system and thereby avoid the imposition of a sewerage rate • suspicion that Council could somehow trace the survey responses to their source. D espite the potential for bias, 29% of returned surveys indicated that problems were being experie nced. T hese generally concerned bagginess and odour in the vicinity of absorption trenches. Some comments highlighted

the leakage of efiluent into stormwater drains or from neighbo uring properties. Such proble m s ste m from th e following fairly obvious causes. Site Conditions As descri bed ea rlier, the climate, soil and topography of Fern Tree is not particularly conducive to trouble-free operation of a septic system. For more than six months of the year, much of the area remains cold and wet-increasing the likelihood of soil saturation and microbial inactivity. Infiltration rates in the heavy soils of Fern Tree are low, and the soil depth is fairly shallow, given the steep gradients. Septic System Design For numerous reasons, many existing systems do not co mply with the accepted present-day understanding of good system design. General consen sus as to the most appropriate septic system design for Fern Tree conditio ns h as changed considerably in the last half century. M ore effort is now taken to maximise infiltration, evaporation and the longterm viability of absorption trenches. Over the life of a septic tank, design parameters will also undoubtedly change: the n umber of people using the system may increase; appliances such as dishwashers and spa baths will be installed; trees will grow and cast shade over the tre nches . Althou gh septic systems can be designed to meet the needs of most situations, it would b e virtually unheard of for an owner to have the system professionally modified in response to a change in one of the design parameters. More specific to Hobart, most of the bushland fri nge suburbs were devastated by the 1967 bushfires. During t he subsequent rebuilding program, septic tank applications were often hastily approved . The effort expended to ensure that system design was suitable to cope with the site conditions was cursory.


BUSINESS Modifications As observed by Council Envi ronmental H ealth O fficers, the emergency response by owners to some sort of failu re w ill often involve a backyard modifica tion. H ome- made trenches or redirection of eilluent to somewhere beyond the backyard is not uncommo n , particularly in houses occupied by the same residents for many years. Even a basic unde rstanding of t he prac tical operation of a septic system is rarely in evidence. Maintenance Almost any system, no matter how poorly designed , can fu nction without seriou s health risk if sui tably maintained. T h e recent survey results indicated that about 45% of Fern T ree reside nts, living in the ir houses for more than fi ve years, pu mped ou t their septic tank less frequently than every eight years. Over one-third of these dwelli ngs had three or more occu pants. Given these sorts of practices and the environmental conditions experienced in Fern T ree, it is not surp ri sing that 29% of surveys indicated problems. It is an unfortunate fac t that almost no effort has ever been expended by State agencies or H obart Ci ty Cou ncil on improving comm unity understa nding of the issues related to septic tanks. W ith relatively li ttle effort, awa reness can be increased so that residents can manage their own problems and are able to recognise situations whe n profession al help sh o uld be sought. Prom oting the Council as an organisation co ncerned about co m m unity health that is capable of offering advice rather than simply p erfo rm ing as a regulatory autho rity will decrease the incidence o f problems escalating.

The Legislation and Issues Involved The present situation would seem to warrant some sort of change in Cou ncil policy, perhaps an inspection o f all unsewered dwellings to assess t he extent of the problem. H owever, numerou s obstacles lie in the path of this course of action . Legislative responsibili ty on the issue of septic tan ks includes the following Local Governme n t Ac t 1993 (Tas) which states, 'If a council is satisfied that a nuisance exists, it must serve a n otice.' U nd er the Local Government (Building and Miscellaneous Provision s) Act 1993 (Tas) a nuisance includes 'any waste or stagnant water in, under or near a dwelling-house.' Such wording legally constrains the Council to being a regulator rather than an advi sor. Serving a notice on those residents whose systems are failing yet not creating a nuisance for anyone other

than themselves would result in a co mmuni ty backlas h- heavy- handed tactics on property-related issues are not the sort of approach that a p oli tically astute Council would advocate casually. But it is not only concern at appearing too stern which dissuades Council office rs from carrying o u t a mass inspection. Such an exercise would be extremely resou rce-i ntensive-the Environ me n tal H ealth Officer time required for negotiating j ust one septic tank-related nu isance can extend to weeks. Exam..ining almost 400 properties would take years. U ndertaking such an exercise also raises some fu ndamental questions to w hich most govern ment organisatio ns fi nd it diffic ult to respond : â&#x20AC;˘ how to ensure consistency in th e approach and decisions made by professional officers of varying background, experience and personality â&#x20AC;˘ how to avoid making poor recom-

mendations when technology is conti nually evolving, and environmental facto rs are fo rever changing â&#x20AC;˘ j ust what is the real risk to public well-being anyway? Council officers tend to be j acks- ofall-trades under serious time constraints and attitudes and work practices in a field as dynamic as environmental health va ry con si de rably be tween officers. U nder such conditions, it is difficult fo r Cou ncils to ensure con sistency in all the decisions they make. G iven the problems inhe re nt in the site conditions described above, new technology is usually called u pon to offer sol utions. Such technology has lately been u nder the spotlight- the conce rn about th e effective n ess of aerobic wastewater treatment systems raised at the Watertech conference is one example (Hillier, 1998). Composting toilets have also received criticism and represent a source of ongoing trouble for the T asmani an National Parks and W ildlife Service (Whi te and Crennan, 1992). Whilst these systems have their place, they certainly don't constitute a panacea-all have their advantages and disadvantages. There is always the op tion of connection to the sewerage system, but given the high cost, com munity satisfaction with the existing system and lim ited potential for fu rther population growth in the area, surely this course of action should be taken only as a last

resort. Besides, the key question still remains unanswered-does the degree of risk to public health from potentially faili ng septic tanks i n a suburb surrou nded by bush really j ustify such an expenditure of effort?

Solutions Given that only 9% of survey responses indicated a desire to be connected to sewerage mains and th e fact that no evidence of declining public health has surfaced , H obart C ity Council's Development and Enviro nmental Services Division will focus on com m u nity education and maintena nce advice rathe r than mou nt a regulatory crackdown . Environmental H ealth Officers will con tinue to ta rget p roble m cases. In addition, a water quality monito ri ng p rogram will be initiated for the main creek system below Fern T ree, and the sto rmwa ter drainage system will b e exami ned to assess the potential for subsurface detention of possibly con taminated ru noff. Several survey resp onses indicate th at there exist isolated cases which are serious enough to j ustify fu rther investigation. It has been suggested that up to 50 dwellings be i nspected each year wi th the intenti on of updating Council records as to the status of individual septic systems. O nly those systems in desperate need o f furt he r atten tion would receive it. Otherwise, Council officers would concentrate o n delivering case- specific advice.

Conclusions O n-site sewage systems will probably always constitute a headache for local governmen t authorities, particularly if the commu nity is not aware of how to ensure their system s operate effectively. C ondi tions in Fern Tree are fa r from ideal for trouble- free operation of septic systems, yet there is li ttle j ustifica tio n for the exten sion of sewerage mains into the area. Council officers will work toward improving septic tank performance by placing greater emphasis o n community education and walking a fine li n e between regul atio n an d dispensing advice.

References White S and Crennan L (1992) Compost Toilet Design for Alpine Regions, Department of P arks, Wildlife and H eritage, H obart. Hillier H (1998) Planning for O n-Site Wastewater Treatment Systems, Watertech Conference Proceedings, AWWA, Brisbane.

Author Ben Ridder is an environmental planner with Hobart City Council, GPO Box 503E, Hobart Tas 7001. WATER JANUARY/FEBRUARY 199 9

47


MEETINGS For further in formation abou t the events listed, please con tact A WWA Federal Office. T elephone (02) 9413 1288 Facsimile (02) 9413 1047 OVERSEAS

AWWA CONFERENCES 1999 11-15 April, Adelaide 18th Federal Convention 2000 8-12 April, Sydney 5th National Hazardous & Solid Waste Convention 8-12 April, Sydney WaterTEC H Conference

OZWATER & OZWASTE TRADE EXHIBITION 1999 12-14 April, Adelaide 2000 9-11 April, Sydney

AUSTRALIA

- ¡

1999 17-19 March, Armidale, NSW Environmental Monitoring in Rural Landscapes, CS IRO, N SW Agriculture Email slott@metz.u ne.edu.au 21-25 March, Fremantle, WA Contaminated Site Remediation Conference, Centre for Groundwater Studies Fax (08) 9291 9978 8-10 April, Fremantle, WA Sludge Management for the 21st Century-A Value-Added Renewable Resource, IAWQ, AWWA, Water Corporation, ES! Fax (08) 9310 4997 26 April-2 May, Sydney, NSW World Aquaculture '99-The Annual International Conference and Exposition of the World Aquaculture Society, CRC for Agriculture, DPIE Fax (07) 3832 8245 27- 30 April, Perth, WA Irrigation '99-Water, People and Profit Fax (08) 9257 2099 16-21 May, Perth, WA International Conference on Diffuse Pollution-Solutions? Innovations Fax (08) 9450 2942 5-9 July, Brisbane, Qld WATER 99-25th Hydrology & Water Resources Symposium, Institution of Engineers, Australia Fax (07) 3369 15 12 8-12 November, Sydney, NSW International Congress of Biometeorology & International Conference on Urban Climatology Fax (02) 9262 3135 2000 2- 5 March, Melbourne The International Landcare 2000 Conference: Changing Landscapes, Shaping Futures Fax (03) 9690 7155 11-17 March, Melbourne 10th World Water Congress, IWRA-UNE-AWWA-!E Aust Fax (03) 9682 0288

1999 31 January-3 February, Monterey, USA Conserv 99, AWW A Fax +130 3 794 3951 2- 5 February, Geneva, Switzerland R'99 Recovery R ecycling Re-integration Fax +411 386 4445 11-12 February, Honolulu, Hawaii Hawaii Water Environment Association 21st Annual Conference Fax +808 842 193 7 22-26 February, Auckland, New Zealand Comprehensive Stormwater and Aquatic Ecosystem Management, New Zealand Ministry for the Environment Fax +64 9 360 1242 28 February-3 March 1999, Long Beach, California, USA AWW A Membrane Technology Conference and Exhibition, AWW A, IWSA Fax +1 303 794 3951 23-24 February, Manchester, United Kindom Specialised Conference on Rapid Microbiological Monitoring Methods, IWSA, AISE Fax +44 171 222 7243 26- 28 April, Christchurch, New Zealand Australasian Environmental Engineering Conference-Communications and Community Fax +64 3 379 0460 6-10 J une, Tampere, Finland 6th IAWQ Symposium on Forest Industry Wastewaters, IAWQ Fax +358 3 365 2052 8-12 June, Beijing, China The 6th International Environmental Protection Exh ibition and Conference Fax +61 2 9489 1890 12- 18 June, Toronto, Canada International Congress on Membranes and Membranes Processes Fax +27 12 331 2565 13-18 June, Jerusalem, Israel Environmental C hallenges for the Next Millennium , IWRA, AIDA Email drorg@tavas.co.il 15-18 June, Barcelona, Spain 2nd International Symposium on Anaerobic Digestion of Solid Waste Fax +34919751 180 20-24 June, Chicago, USA AMWWA Annual Conference, AMWWA Fax +1303794 7310 18-24 September, Buenos Aires, Argentina 22nd World Water Congress, IWSA Fax +54 1 325 6029 22- 24 September, Christchurch, NZ Valuing our Environ ment, Dollars and Sense, NZWWA 41st Annual Conference & Expo Fax +64 9 636 1234 9-13 October, New Orleans, Louisiana, USA WEFTEC '99- 72nd Annual Conference and Exposition, WEF Fax +1 703 684 2471 13-15 October, Hong Kong, China International Conference on Urban Pollution Control Technology, The Hong Kong Polytechnic University, WFEO, Hong Kong Inst of Engineers, USAEP Fax +852 2334 6389 17-20 October, N ew York, USA 4th IAWQ Conference on Biofilm Systems Fax +5511 3043 7353 8-12 November, Bangkok, Thailand C ivil and Environmental Engineering Conference-New Frontiers and C halJenges, Asian Institute of Technology Fax +66 2 516 2126

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25

German/Australian Chamber of Commerce & Industry 10 River Sands Tubemakers Water Ultraviolet Technology of Australasia

To obtain a registration brochure please call Secretariat on (02) 9410 1302 or AWW A on (02) 94 13 1288

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35 back cover inside back cover

University of Adelaide

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Water Corporation WA

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Profile for australianwater

Water Journal January - February 1999  

Water Journal January - February 1999