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Editor Bob Swi nton

Editorial Correspondence 4 Pleasant View Crescent Glen Waverley Vic 3150 Tel/Fax (03) 560 4752

AUSTRALIAN WATER &WASTEWATER ASSOCIATION

Advertising Sales & Administration Margaret Bates Tel(02)4131288 Fax (02)4131047 AWW A Federal Office 1st Floor, 76 Hampden Road, Arrarmon PO Box 388, Arrarmon NSW 2064

OUR COVER

Editorial Board

Be Water \Vise .. . It's Worth It is the slogan used by the Queensland Water Resources Commission for a statewide public ed ucation program in demand management. Following a market research program a su ite of educational and com mun ication material was developed during 1992, for use both by local authorit ies and in schools. Our cover is a portion (about one-half) of a large poster wh ich depicts many ways in which water can be saved in the urban community, in an artistic style which appeals to children of up to secondary school age. A paper presented ro rhe Federal Convention described the campaign, and is reprinted within . A similar educational kit was developed during 1992 in ACT, aimed at primary school children (see February Warer). Queensland 's Water Wise campaign was designed to be part of the \Vate,wise 2000 national initiative.

FR Bishop, Chairman MR Chapman, M Muntisov, P Nadebaum P Draayers, J D Parker, AJ Priestley G A Holder, B Lade

Branch Correspondents ACT - Alan \'(lade DELP, PO Box 1119, Tuggeranong 290 1 Tel (06) 207 2350 Fax (06) 207 6084 Q11eensla11d - Lyndsay Chapple SKP, 62 Astor Terrace, Springhill 4004 Tel (07) 835 0222 Fax (07) 832 6335 Netv S0111h Wales - Mitchell Langinestra CMPS&F, PO Box z'O l , Charswood 2057 Tel (02)412 9974 Fax (02)412 9876 1 01¡them Territory - !\'like B11rgess PAW A, GPO Box 1921, Darwin 0800 Tel (089) 82 71 11 Fax (089) 82 7430 S011th Amtralia - Phil Thomas Stare Water Lab, Private Bag Salisbury 5108 Tel (08) 259 0244 Fax (08) 259 0228 Tas111c111 ia - j i111 Stephem E&TS, 340 Elizabeth Sr, Hobart 7000 Tel (002) 31 0656 Fax (002) 34 7334 Victoria - Bill 011/fer 47 Russell Sc, Surrey Hi lls 3127 Tel (03) 890 8757 \'(lestem Australia - Bill Chap111a11 PO Box 356, West Perth 6005 Tel (09) 420 2462 Fax (09) 420 3178

WATER (ISSN 0310-0367) is published six times per year February, April , June, August, Octobet, December by

Australian Water & Wastewater Inc. ARBN 054 253 066 PO Box 388, Artarmon SW 2064

Federal President Barry Sanders

Executive Director Chris Davis Australia Water & \'(/ascewacer Association assumes no responsibility for opinions or statements of faces expressed by contributors or adverrisers and editorials do not necessarily represent the official policy of che organisation. Display and classified advertisements are included as an informational service to readers and are reviewed by che editor before publ icat ion co ensure their relevance to the water environment and co the objecrives of the Association. All material in \'(later is copyright and should nor be reproduced wholly or in part without the written permission of the Editor.

Subscriptions \\'later is sent to all members of the AWW A as one of rhe privileges of membership. Nonmembers can obtain \\'later on subscription at an annual subscription race of 30, rhis includes cost of surface mail postage.

Volume 20, No 3 June 199~

ISSN 03 10-0367

CONTENT! ASSOCIATION NEWS President's Message From the Executive Director From the Branches

MY POINT OF VIEW Every Drop is Precious

5

.

The Honourable Bill Hayden

FEATURES WaterWise Queensland -The Joint Venture

1~

Kerry Jones, Terry Lewis and Ken Aitken Adsorption of Microcystin-LR by Powdered Activated Carbon

25

Cosimo Donati, Mary Drikas, Rob Hayes and Gayle Newcombe Working With the Community - A Community Consultation Program

3C

Gary Sabburg, Michael Simms, Stephanie Paul and Jane West Biological Removal of Manganese From Water by lmmobolized Manganese - Oxidising Bacteria

31!

LI Sly, Vallupa Arunpairojana and DR Dixon

REPORTS 15th Federal Convention

16

Bob Swinton Anaerobic Digestion in Australia

34

Annabelle Duncan Trends in the Disinfection of Sewage Effluent

36

Phil Thomas

DEPARTMENTS Names in the News IAWQ News Meetings Industry News

9 10 41 43

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MANAGEMENT

WATERWISE QUEENSLAND THE JOINT VENTURE

-

-

Kerry Jones, Terry Lewis and Ken Aitken Introduction Emerging Trends. Throug hout the Seate there is a growing recogn ition that the major faccor in achieving acceptable urban warer demand management involves a pay for use pricing sysrem. Warer merer installation programs and pricing structure reform is currently underway rhroughour many communities in Queensland. Ar rhe same time rhar Local Aurhoriries are moving rowards user pays for warer, rhe community as a whole is becoming more environmentally aware co the extent rhar rhis concern for rhe enviro nment ca n lead ro changes in behav iour and changes in arrirudes ro warer conservation. Dealing with the Issue. The DPI Warer Resources, responding co Government direction ro be involved in promotin g demand management, has developed, in associat ion with Local Authorities, a public education campaign called WarerWise Queensland. WaterWise Queensland recog nises rhar investment in ed ucating the general publi c, and our children, in rhe need for responsible usage of water wi ll , undoubtably, result in huge economic, socia l and enviro nm ental dividends in rhe decades co come. The objectives of rhe WaterWise campaign are co: • change the water usage behaviour of rhe Queensland public so rhar urban water consumption is reduced • adopt an appropri ate ly pro-active stance co State government initiatives in rhe area of wise water use, recognisi ng ed ucation as the key • assist Loca l Authori ties ro develop an effective public communication strategy for urban water conservation • reduce rhe cost and duplication of effort required by individual Local Authorities • develop public awareness and agreement to:

- water supply management policies - feas ible and realistic expecrations for a warer supply relevant to their area and - costs associated wirh the provision of these services. • faci litate public commu ni cation which provides facrual information to enable the publ ic co formulate appropriate judge12

menrs, and avoid re-act ive outbursts, or the adoption of incorrect arrirudes based on mis-information. The ca mpai gn wil l ass ist all Local Authori ties co: • defer capi tal expe nditure for new resources; • more effic iently utilise ex isting resources; • minimise any impact on rhe environment; and • promote volunrary warer conserving practices by changing community arrirudes. In some communities, significant progress has already bee n made by Local Aur horir ies. This has included rheir own publi c education programs , regu lat ions on sprinkler resrricrions, mandacory installation of low flow dual flush coilers, and user pays pricing policies co name a few. Recent marker research (Sraddon , April 1992) indicated rhar just over half (56%) rhe State's urban water consumers have a warer merer .installed, wirh 75% of rhese used as a basis for water charg ing (i.e. 42 % of coral). The research also showed rhar 39% of consumers di d not know where their warer comes from or the infrastrucrure involved . Conce rn for the environ ment, awareness of quantity used and excess warer charges were seen as rhe significant reasons for concern which could provide incentives to reduce personal water consumption. This shows how important rhe WarerWise Queensland campaign can be in conserving warer. Wh ile rhe comm unity recognises and accepts a pay-for-use pricing system based on 'excess' warer usage, rhey srill expect some 'free' allowance and needed to be convinced thar a pay for every drop pricing system is necessary. However, rhere appears co be more local 'politica l' concern for rhese pricing issues than wou ld appear justified by the research again showing that WarerWise Queensland is heading in che right direction.

Campaign Strategy WaterWise Qu ee nsland is assoc iated Nationally wi rh : • The Australian Water Resources Council (AW RC) in itiative ca lled WarerWise 2000,and • A warer conservation raring and labelling system from Standards Australia for

water- efficient domestic appliances. Campaign Objectives. The overall objective of rhe WarerWise Queensland campaign is co reduce household warer consumption by up ro 20% in urban centres. We aim co achieve rhis by: • alrering public arri rudes co water was rage • promoting rhe use of water-saving devices • convincing Queensland ers ro acce pt responsibility for their own warer usage and costs • paving rhe way for community acceptance of warer meters • ra ising public awareness of rhe environmental impacts of developi ng additional warer supply systems. When a 20 % reduction in warer use is achieved, a saving of up co $40 mi ll ion per year will flow on co all Queenslanders. It has rhe potential co save another $40 million in cosrs associated wirh deferred capital works . There are environmental benefits which shou ld nor be overlooked. By conserving warer, and deferring rhe need for more development, we can sustain rhe natural habitats of our environment for longer and red uce the associated community impacts. Before deve loping our campaign we undertook research of existing campaigns in orher States and other countries. We quickly realised rhar Queenslanders, wirh rheir own spec ial outdoor living lifesryle, would have habits and arrirudes rhar were different from or hers. So we elected ro conduct our own research. Research. The research was conducted co: • establish existing arrirudes ro warer use in urban environments • rest communication ideas and concepts for potential acceptance and success • provide a benchmark of arr irudes which we could re-measure later ro evaluate the effectiveness of rhe campaign. Existing arrirudes were defined by using focus groups and a Srarewide celephone,survey. Advertising. One of rhe things that was obvious even withou t research was that rhe target audience is absolutely everyone. Everyone consumes water and ro effectively reach them, advertising will be needed. The most successful campaigns in rhe southern Srares used advertising before rhe public relaWATER JUNE 1993


rions campaign was scarred. Ou r adverrising message will be designed rn quickly establish public awareness of: • rhe importance of warer rn Queensland • rhe infrasrrucrure requi red • rhe cosr involved in ge rring warer from rhe source rn a household cap • rh e environm enra l effecrs of was ring warer. Th e avenu es for advenis ing obv iously include relevision , newspapers, billboards, radio, rrade magazines/journals, ere. Options fo r advert ising include relev ision, where rhe inirial telev ision commercial cou ld show dramarically rhe vasr inframucrnre of dams , pipes, pumps and rrearment planes, rn alen users ro rhe huge sum s of money involved and how saving water wil l keep coses down. Hence rhe slogan - 'Be WarerWise, ir's worth ir1' Billboard Advertising. Widespread ourdoor advertising on billboards is also proposed and ir will be effmive if ir is designed ro have high impacr. Newspaper Advertising. In selec red areas separate newspaper adven ising ca mpaig ns will focus on water meters ro explain: • how rhey operate • rhe benefirs ro rhe householder and rhe communiry • why peop le should accepr meters as a reasonable merhod of impl emencing a charging policy Public Relations. As mencioned earlier, public relarions m areg ies will be conducted in conj unction with the initial adverrising. These include: • publications , brochures and videos • media releases to ge nera te ed itori al publicity on television , radio and in newspapers • wid espread rraining of commission and local aurhoriry staff • development of cusrnmised communicarion kits rn suit each local authority • special educational mareri al for schools School Education Package. Children are ou r prime carge r in our efforr rn change arrimdes ro warer use. The marerial for sc hoo ls wi ll cake the form of an ed uca tion package whi ch wi ll include primed marerials and videos suited ro the school curr;iculum . We are formnace ro have the education department, Gold Coasr City and Albert Shire Councils contributing ro chis marerial. Communication Kits. A key element of rhe campaign is ro develop comm unicarion kits for all sponsoring Local Aurhoricies. The kit contains a wide range of primed and audio visual mater ials des igned ro be over- printed wirh cusromised local council logos, names, messages, ere. Ir is envisaged chat marerial will continue ro be developed for chis ki t on an on-going basis. As mentioned earli er, the advertisi ng WATER JUNE 1993

will be supporred by a public relarions componenr. To maxi mise rhe porencial for success, rhe advenising and public relarions components musr be supported by promorions. Promotions. Some high-impacr promorions already planned incl ude: • A mobil e WarerWise display floar • And rh e H20 heroes club for 5 ro 14 year olds .

is being used bteach Local Aurhoriry. Also, it is planned rhar a regular cracking research smdy of rhe campaign will measure communiry arrimdes for comparison wirh rhe result of the benchmark srudy we have jusr complered. All fi ndings from rhe evaluarion wi ll be provided ro sponsoring Loca l Aurhorities.

BE WATERWISE AT HOME

• The WarerWise Queensland campaig n was launched ro the Water Industry on rhe 16 April 1992 by rhe Premi er Mr Wayne Goss . Fo ll owing rh e launch a di splay was held in rhe foye r of th e Primary Indumies building umil the 29 April 1992. • Th ere are curren d y seventy (7 4) Loca l Aurhoricies and Warer Boards parricipacing in WarerWise Queensland. • A Pu blic Commun ica ri on Reso ur ce Kir has bee n sent ro all parri cipar ing Aurhoricies. • Significant secrions currently included in rhe Resource Kir include: group presencarion marerial, display catalogue, media release marerial , ed ucar ional mater ials , posrers, brochures , facr sheets, and sample promorional materials. • Qualirarive and quancicarive research was un derraken by Sraddon Consulring ro dererm ine Queensland accimdes ro warer and warer use. A summary of rhe signifi cant results of chis research is included in rh e Reso ur ce Kir. Sponsoring Lo cal Autlw riri es also received copies of rhe rhree (3) volume research report. • A television advertising campaign, which is seen as crucial ro rhe success of th e overall WarerWise Queensland campaign, has been und ertaken on two occasions ro dare. • A rexr book for senior secondary smdents has been developed. • A WarerWise in the Workplace initiative has been launch ed by rhe Minisrers for Adminisrracive Services (Mr Tom Burns) and Deparr menc of Pri mary Industri es (Mr Ed Casey) ai med ar encouragi ng private industry, inscimtions, government departments and ochers ro use water more efficiently.

Progress To Date WaterWise Highlights.

If water came

in buckets, how many would 1-ou use each day ? ~ ~ --

WATERW ISE 4

A leaflet from the WaterWise Queensland campaign Mobile Float. The mobile floar is intended ro be used in shopping centres and ar field days and is intend ed ro be a selfconcained information cenue. Ir wi ll be equipped wirh videos, education kits and demonsrracions of water-saving devices. H,O Heroes. A spec ial club called H,O Heroes will be aimed at 5-14 year old children who will be encouraged ro moniror rhe amount of water rheir fami lies use ar home. (I will leave ir ro your imagination ro consider the overa ll effec r of th e H,O Heroes on fam ily harmony. Wharever che outcome ar home, we hope H,O Heroes will be seen as environmental heroes.) Ocher promotiona l ac civiri es includ e an annual 'War erWi se Week ' and 's top the drip day'. Evaluation. o communication campaign can be considered successful unless it can be evaluated. Formnacely chis campaign has a built-in evaluarion process. We will be able ro constantly moniror how much water

Market Research Sraddon Consulring Services underrook quancirarive and qualitati ve resea rch on urban Quee nsland attitud es ro water an d water use. Quancirar ive research aim s to provide starisrical information based on measurable responses ro a set quesrionnaire; qualirarive research obcain,5 non- measurable data on opinion and belief th ro ugh interacrive discussion in small groups. Boch the qu ancicarive and qualicarive research focused on the beliefs of urban warer consumers. In terms of rhe positive consumer arrimdes displayed rowards charges, regularion and supply subsidies, rhe research resulrs 13


are sig ni ficant for any Loca l Aut hority reviewing water charging policies. The focus group research was conducted first in March 199 2. Findings were used co help formula te the questionnaire of the telephone survey which was conducted in April 1992.

Qualitative Research on Urban Water Conservation (Focus Groups) Research method: 6 focus groups, 3 male groups, 3 female groups in che age brackets 18-24, 25-44, 44-60 all resident in Southeast Queensland . Research objectives

• To discover knowledge levels of water supply; • To explore attitudes co conservation measures; • To invescigace behaviour in terms of water usage and conservation . Significant findings

• Motivation co conserve water is triggered by: - awareness of amount used , - wish co conserve the environ ment ('no more dams'), - water meters, - restrictions, - excess water charges, and - incentives co install water conservation devices. • Consumers are nor motivated by knowing che cost of supply. Expressing the potential cost saving as either 20% or approximately $40 million/year was nor seen as a significant amount nor as any incentive co save water. • The majority did nor see water supply, water meters or charging poli cies as a poli cical or debaceable issue. • There was an overall preparedness co accept enforced regulation of water usage using pricing policies which charge equitably for the amount used. • Consumers are shocked about how much water they use. They wane co know how co cue down and they want co be cold how they can do chis. • Brochures are needed. They have co be sent co individual householders (nor left on counters in Council offices or similar) and supported by media advertising. • Concern was expressed about di ffere nt administrative systems used throughout South-ease Queensland - 'Why can't we have the same water charges and restrictions for all Local Authority areas'' • Reactions of the survey participants co che campaign logo, literature and advertising were used co develop campaign materials. • Qualitative research revealed char education is needed in the following areas: - ch e quantity of water us ed by an average household; - infrascrucrure needed co supply water (what happens beyond the cap); - measures for conserving water outside 14

the house; - who c_onc rols Qu ee nsland 's water supplies; - who che DPI - Water Resources is and ics role; - a method for helping people perceive volume (e.g. what 600 litres looks like). The above qualitative ed ucation requirements we re supported by che quantitative research findings.

Quantitative Research on Urban Water Conservation (Telephone Surveys) Researc h mer hod: Tel ep hone survey. Sample size: 500. Regional sample size weighted co reflect Queensland urban population distribution Research objectives

• To establish cu rrent levels of aware ness and knowledge of water supply issues. • To determine consumer attitudes co water usage and the potential for usage reducnon. • To establish levels of awareness of consumpti on reduction methods , both currently used and in the furure. • To determine attitudes cowards regulation and charging issues. Significant findings

• Forry percent of urban Queenslanders do not know where their water comes from. Consumer awareness of water sources is higher outside the Brisbane area. • Although a majority of urban residents believe there is currently sufficient water for their needs , only one in five chink there will be enough for che future . • The majority of consumers underestimate how much water is used in and around the home. • Most consumers don't know how much they pay fo r their wa ter or what the charge is based on. • Consumers believe char what they pay in water charges shou ld cover che cost of supply; however, most believe char what they pay does cover these coses. • There is a strong belief char the careful use of water contributes co conserving che environment. • Despite chis positive attitud e co co nserving water, most people ch ink char they already conserve as much as they can; however, chey believe char substanti al savings cou ld be made by ocher consum ers. • Mose co nsum ers are aware of and use some water reducti on method s. Th e popular methods are chose char involve personal control rather than options char involve expense. • The community would be willing ro have water meters installed for charging purposes and would accept restrictions on water usage as long as these chargi ng methods were equitable. • To avoid paying what they consider excess water charges, consumers claim th ey

• • • • • • •

would chang~heir water usage behaviour and cake ocher conservation measures. Quantitative research revealed char education is needed in rhe following areas: the quancicy of water used by the average household; what happens beyond che cap in terms of source and infrastructure; how consumers are charged for their water; how much water coses co supply co homes; what wi ll happen in the future if water use is nor reduced; char water red uction options will pay for themselves in the long run.

Public Communication Resource Kit The Resource Kie currently contains 10 sections , each covering different aspects of WacerWise Queensland. A ring binder has been used co allow additions co be made co existing sections and, because WacerWise is continually deve loping, comp lete new sections may be added in the future. Section 1 and 2 are introd uctory sections explaining the need for urban water conservation and how the WacerWise approach can assist in reducing wacer consumption. How was Water Wise developed, why is it in the form a public education campaign and why should it work 1 The answers co these questions and more are in Section 3 - Marker Research. Before attempting ro change public accicudes, exte nsive marker research was needed co determine what current atti tudes were and what effect planned communication concepts ,,iould have. Section 4 contains a high quality 35 mm sl ide presentation kit plus recommend ed speaker notes and derails of the slides which can be copied as handouts. Ir contai ns virtually everything a presenter would need when giving a group presentation co any audience, whether ic be che general public, community groups such as Rotary, or co raise internal staff awareness . Presentations to primary school children and higher ed ucation groups are currently under development. WacerWise Queensland was launched co the water industry in April 1992. Section 5 explains how rhe techniques applied in char launch can be applied by any Local Auchoricy, and provides relevant sample materials. This section will be updated with special promotional events, and general campaign information shortly. A wide range of materials, available for use in public WacerWise displays, is catalogued and colourfully illustrated in section 6. This material can be hired co supplement exis ting display material. Authorities are encouraged co choose which items suit their needs and order chem by completing the forms char appear in appendix A. Section 7 explains how ro liaise with rhe media co gain widespread pub licity about WacerWise. As well as outlining how ro have the best effect in rhe media it also provides several samples of media re leases, feature WATER JUNE 1993


srnries and face sheers which can be adapted t0 suir che issues concerning any Local Auchori cy. Ir recommends char initial media contacc be made by providing journali ses with a media kit of the above information, and chat regular follow-up will ensure beccer ed irnrial coverage. In sect ion 8 a comprehe nsive li st of videos about the issue of water conservation are itemised , wich rides and bri ef desc riprions. These are available in Queensland and also from ocher Scares. Contact phone numbers for accessing videos are also listed. Changing che water consumption acricudes of rnday's children is the mosc important strategy of che WacerWise campaign. The range of educational material proposed for chi s strategy is covered in sect ion 9. Publications , school activi ties, games and a video are all seen as essential for educating children and teachers. Teacher guidelines are also provided. This material is combined into a Teachers Resource Kie. All education material has been designed in consultation wich the Department of Education in order t0 suit existing school curriculums. A wide range of information material ava ilabl e for promoting Wace rWi se is itemised in section 10. Samples of che icems available are includ ed and drafts of new material being developed are also provided. Items covered include Faces Sheers , brochure outlines , Tec hnical Info Sheets , lin e-arc samples of posters, and ocher promotional icems such as bumper stickers , trivia cards (BBQ ores) and balloons. Information materials provided in chis kic are samples only. Orders can be placed for bulk quantiti es of items incorporating che WacerWise Queensland logo, or they can be customised co also carry individu al Local Auchoricy logos.

Educational Package Education is one of the key objectives of che WacerWise campaign. When che proposal for WacerWise was sent t0 all Local Auchori ties che Gold Coast Cicy and Albert Shire Councils had already started negociacions wich an education consu ltant co develop education materials for cheir region. These Local Authoriti es then offered the education concepts t0 WacerWise as their development contribution. To dace a Teachers Resource Ki c and Water Resource Management and Conservation book for Senior Students have been developed and were trialled in schools during che week commencing 15 June 1992. These educational publications are supplemented with cwo educational posters, 'The WacerWise Cacchmenc ' and 'Th e WacerWise Town'. The education package forms a major component of che Resource Kie. The DPI Water Resources has also with che Education Department co produced a video about water awareness, suited co che schools curriculum. The WacerWise project team, within che WATER JUNE 1993

DPI - Water Resources, formed a revi ew committee t0 edit all che education material produced by consultant, Wee Paper Publi catio ns (Bob Moffat) and by ch e Education Departm ent's nominated video producer Gulliver Productions. The material . produced by ch e co nsultant has exceeded our expectations. Video. The video is designed to fill a void in ch e resource material on water currencly avai lable to Queensland Teacher's, as identified through an Education Department reacher survey conducted in 1991. Ir covers a broader wacer awareness approach and also contains a significant water conservanon component.

Future Directions For Waterwise Queensland • In che fucure, WacerWi se Quee nsland could includ e ch e involvement of che private sector a number of whom have already made unsolicited requests for such involvement. • The 'WacerWise Queensland ' campaign name could be extended to include drinking water quality issues as well as water conservac10n issues. • The WacerWise Queensland campaign could also address rural water conservation issues and broader awareness issues of che value of water as a resource. • Advertising is regarded as a crucial ingredient to che objective of launching the campaign. This is because: - The target audi ence is so large they can only all be reached through che mass media; - Ir will reinforce che messages carried in brochures, displays, newspaper editorials, and videos; - Children 's ed uca tiona l mess.ages learned ac school will be reinforced by ads chey view on television , which -will. also help to influence cheir parents.

Threats To Waterwise Queensland's Success Research has indicated chat the following issues could pose a chreac to che success of che campai g n ob jectives unl ess th ey are addressed: • There is a high level of ignorance of both current personal water charges and current personal usage levels. • There is considerable ignorance of wacer supply coses and how these are met by the community. • The cost to today's community of establishing infrastruccure to meet the needs of furure generations has never been considered. • Many people believe they have adopted sensible water usage habits , and everyone believes that other people are causing the problem and chey could easily reduce wacer consumption. • The community believes that environmental and social equity concerns exist

wich regard a, water supply. The community is aware of ways to reduce consumption and shows a willingness to do so and to accept restrictions, particu larly if it means a reduccion in local and scare government spending.

Concluding Remarks In other Scates and overseas ic has been demonstrated that reduction in water consumption will result in significant financial recurns. In Victoria water conservation techniqu es have been es timat ed by the Melbourne Waterilloard to have resulted in a present day saving of approximately 7 5 million on cap ital works for Melbourn e alone. Queensland as a whole could expect to be at least of this order and probably higher. So remember Be Wac erWise ... Ir 's Worth It.

Authors Kerry Jon es is currently acting Director Water lnd11stry Strategy unit of DP! - Water Resources. Prior to this he was Manager Local Authority Project Services Group. He graduated from the '--- --"--- - - - ' University of ewcastle as a civil engineer and has worked in the public and private sectors of the water indmtry for 20 years. He was the f o11nding member of the \VaterWiseJ2ueensland project.

Terry Lewis is the Public Affairs Manager of DP! - Water Resorwces. He has a Bachelor of Business degree from Queensland's University of Technology and has worked in pub/ic relations, advertising, and promotions in the p11blic and private sectors. He has been with the Water Resources since 1988. He manages the public com1mmication strategies of the WaterWise Queensland campaign and has been involved since its inception.

Ken Aitken ts Executive E_ngineer WaterWise Queensland and Information Systems of the Local A11thority Project Services gr-o11p of [?PI - Water Reso11rces. He graduated from Queensland's University ______, of Technology as a civil engineer and has worked in the public and private sectors of the water indmtry for 15 yean. He manages the technical aspects of Water Wise Queensland. 15


TECHNOLOGY

ADSORPTION OF MICROCYSTIN-LR BY POWDERED ACTIVATED CARBON Cosimo Donati, Mary Drikas, Rob Hayes and Gayle Newcombe 1966 and Carmichael et al, 1985 ) have reported chat blooms of Microcyscis aeruginosa , a common spec ies of cya nobacce ri a (blue-green algae), have been responsible for livestock deaths. Health problems in humans have also been reported (Falconer et al, 1983 and Hawkins et al, 1985). The biological and chem ical properties of cyclic hepcapepcide toxins (microcyscins) produced by Microcyscis aeruginosa have been thoroughly invesciga ced (Runne ga r and Falconer, 1981; Watanabe and Oishi, 1982 and Bores er al, 198 2) . To date , more th an 40 different hepato-toxic microcyscins have been characterised . Microcyscin-LR (Figure 1) is ch e most common microcyscin produced and has been implicated in a number of recent toxic algal blooms. Several methods for removing microcystin-LR from potable waters have been investigated and a sensi tive analytical technique, which is essential for the evaluation of removal techniques, has been developed for chis toxin (Flett and Nicholson, 1991). A number of researchers (Hoffmann, 1976; Keijola er al, 1988; Falconer et al, 1989 and Birnberg et al, 1989) have shown chat conventional water creacmenc techniques such as coagulation, sedimencacion and filtration are not effective for removing mi crocys cins. However, chey showed chat while powdered activated carbon (PAC) afforded some removal of microcyscins and toxicity, granular activated carbon (GAC) was very effective.

This paper won the technology section of the Michael Flynn Award at the 15th Federal Convention.

Summary The adso rpt ion of microcyscin-LR by seven different powdered activated carbons (PACs) was in vestigated. Two wood based carbons, Pi cazine (03 /92) and uchar (07 /92), were clearly che most effeccive microcyscin-LR adsorbents, followed by coal based PACs, Cecarbon (01 /92) and Calgon (04 /92). Coconut and peat moss based carbons, Picacif (02/92), Haycarb (05 /92) and oric (06/92) were the poorest microcyscinLR adsorbents. The excenc of adsorption for each PAC was related to the volume of mesopores (diameters > 2.0 nm) which was dependent on the scarring material. Competitive adsorption with natura l organics in River Murray water significantly reduced the initial race of microcyscin-LR adsorption. There was also a considerable reduction in the maximum level of microcyscin-LR adsorption, the extent of which was dependent on the type of carbon. Under experimental conditions simulating creacmenc plane operations 03/92 was again clearly the most effective microcyscinLR adsorbent.

Introduction Several researchers (Fi tch et al , 1939; Scewarc er al, 1950; McBarron and May,

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/i

(CH~2

Only two water creacmenc planes in Ausrrali, currently use GAC filters because of hi gl produce and capita l coses. The rem aini n! planes use PAC co control the relacivelJ infrequent occurrences of taste and odou: problems. Adsorption from aqueous solutions usini: activated carbon involves concentration of cht adsorbate on the surface of che carbon. As cht process proceeds, the adsorbed material cendi to desorb back into che solution. Eventually equal amounts of adsorbate are being adsorbed and desorbed simultaneously anc che races of adsorption and desorption attain equilibrium when there is no observablt change in the concentration of the adsorbatf on the surface or in solution. The aims of chis srudy were 1; to investigate the race and effect iveness of microcyscin-LR adsorption by various PACs and re relate the removal effectiveness to carbon characteristics, 2; to investigate the effect ol competitive adsorption by dissolved organic matter on the rare and effectiveness of microcysrin-LR adsorption and 3; to determine if the PACs were effective und er simulated rrearmenc plane conditions.

Materials and Methods Powdered Activated Carbon (PAC) Adsorbents. The seven PACs reseed,

which are listed in Table 1, were chosen to represent a cross-section of scarring materials, namely coal, coconut, wood and peat moss. PACs were made up as both 1.0% and 0.05 % w/w suspensions in ultra-pure water (Milli-Q Plus, Millipore) for use in the adsorption experiments. Characterisation of the PACs, Extensive physical data were compiled for these PACs. Iodine and phenol numbers were determined according to AWWA standard procedures (AWWA, 1990). Surface areas were determined by measuring adsorption isotherms of liquid nitrogen at 77K. A Coulter Omnisorp 100 was used for rhe analyses. Prior to each analysis, samples were oucgassed ar 383K for 16h to a residual pressure of less than 10-5 corr. A BET plot

25


Table 1 Product

Producer

Country

Cecarbon Picarif PCO ormal Picazine Calgon Type WPL Astm M325 Norir W20 l uchar SA

Arochem Pica Pica Calgon Haycarb orit Westvaco

USA France France Belgium Sri Lanka coconut Holland USA

Starting Material coal coconut

wood coal

peat moss wood

Ref No 01 /92 02/92 03/92 04/92 Pho 05/92 06/92 07/92

8.7 mg/1 DOC);.was dosed wich 5.0, 25.0, and 50.0 mg/1 of 03/92, 04/92 and 05/92. These nine samples were stirred and subsamples removed after 30 and 60 minute intervals. These subsamples were filtered through a 0.4 5 µm membrane and chen pass ed through Sep-Pak C-18 carcridges co concentrate che coxin. Adsorbed microcyscin-lR was eluted wich methanol and the eluates reduced co 1 ml for HPlC analysis.

Results and Discussion Table 2 PAC

Mesopore Vol (mlJg)

BET Surface Area (m2/g)

Iodine No.

Phenol o.

01/92 02/92 03/92 0 192 05/92 06192 07/92

0. 10 0.02 0.49 0.05 0.03 0.06 0.27

863 99 1 1197 1000 1067 493 1366

688 99 1 964 929 956 590 953

2.7 l.6 4. 1 2.0 l.5 2.3 5.l

(Gregg and Sing, 1982) was constructed and the apparent BET surface area was extracted from the linear region (relative pressure = 0.01-0.10). Allocacion of pore size distribution involved subdividi ng che adsorbed amounc in che range of pressure 0-0.40 and 0.40-0.95 , corresponding broadly co adsorption in micropores (0-2 .0 nm diameter) and mesopores (2-50 nm diameter) respectively. The amount adsorbed was convened co liquid volume by assuming a molar volume of liquid nitrogen of 35 cm3/mol.

with rime were determined by comparison of peak areas with chose of standards. Analysis of Natural Organics.

Absorbance ac 254 nm wavel ength (UV region), which has been shown co be a useful indicacor for the relative levels of dissolved organic carbon in natural waters (Newcombe 1990), was measured wich a Varian DMS-70 UV-Visible speccrophocomecer. Rate Experiments. The rimes required co attain adsorption equilibria were determined using 03/92 and 04/92 in boch MilliQ and natural waters. The 2.8 mg/1 microcystin-lR adsorbate solutions (section 2.2) were dosed at 10 and 30 mg/1 of 03/92 and 04/92 respectively and aliquots removed periodically over a five day period for UV (254 nm) and HPlC analysis. Adsorption Isotherms. The 2.8 mg/1 mi crocys tin -l R adso rbate solution was divided into 7-8 subsamples (9.0 ml) and ::, C, placed in sealable glass vials. These subsam- -E 2.0 ples were dosed with PAC (0.05 % or 1.0% c.i 0 w/w) at levels ranging from 2.5-75.0 mg/1. ()a: One subsample was retained as a control. The .Jc 1.0 coral volume of each subsample (including ~> u the control) was adjusted co 10.0 ml wich 0t; :ii Milli-Q water co give a nominal starting Time (h) microcyscin-lR concencracion of 2.5 mg/1 in Milli-Q ---e--- Rive r each subsample. The subsamples were placed on a flask shaker (Gallenkamp SGl-710) and agicaced Figure 2 at 20° for 72-96 hours, after which an aliquot was removed from each subsample and passed 04/92 RATE EXPERIMENT through a 0.45µm syringe filter. These ,:'. "' aliquots were then analysed by HPlC, as §_ 2.0 u described in section 2.3 , co determine resid0 u ual levels of microcyscin-lR in each subsama: .J .5 1.0 ple (c, µrn/1). The amount of microcystin-lR 1ii > u adsorbed per mg carbon (x/m, µrn /mg) was !'! u calculated and plotted as a fun ction of the :ii 0 ·0 0-1-- -2~0 - -40- ~ ~ 60- -8~0- - - < 100 equilibrium concentration of che mi croTime (h) cystin-lR co produce adsorption isotherms. Milli-a -e--- River

Microcystin-LR Adsorbate. A 2.50 mg/1 standard solution was prepared from commerc ially available micro cysc inlR (Sigma #M5407, 0.5 mg or Calbiochem #47 5815 , 0.5 mg) in Milli-Q water. Similarly, 2.8 mg/1 (nominal) adsorbate solutions were prepared with both Milli-Q and natural wacer for use in the rate and isotherm experiments. River Murray water, collected from che inlet co the Morgan wacer filtration plane in South Australia and filtered through a 0.2 µrn membrane was the natural water used. The dissolved organic carbon (DOC) level of this water varied between 8.0 and 12.0 mg /1. A 50 µg/1 (nominal) solution in River Murray water was also prepared for use in practical application experiments. Analysis of Miaocystin-LR in Water. Microcyscin-lR analyses were carried out by reverse phase, high performance liquid chromacography (HPlC) with phoco-diode array detection at a wavelength of 240 nm . The mobile phase was 27-30% aceconicrile / 0.1 M phosphate buffer (pH 7) ac a flow race of 1 ml/min. The system used was a Waters Associates liquid chromarograph equipped with a model 501 delivery system, a model 991 photo-diode array detector and a Brownl ee ODS 5µrn spheri analytical column, 220 mm x 4.7 mm i.d. MicrocyscinlR concentrations in each aliquot and subsePractical Application Experiments. quently che adsorption of microcyscin-lR A 50 µg /1 adsorbate solution (section 2.2,

26

PAC Characteristics. In addition co iodine number, phenol number and apparent BET surface area, which are commonly used to characterise the perform ance of carbon, pore volume daca was also collected. The physical data is shown in Table 2. Results showed char mesopore volume was dependent on che scarring material. The wood based carbons were highly mesoporous compared wich che coal, coconut and pear moss based carbons. Rate Experiments. Milli-Q Watet: At doses of 10 and 30 mg/1 respectively, both 03/92 and 04/92 showed a rapid initial race of microcys cin-lR adsorption from Milli-Q wacer. Afrer 3h, 03/92 had removed 58% and 04/92 33%. The race of adsorption g radually declined wit h rime until the adsorption equilibri um was reached after approximately 72 hours for both carbons (Figures 2 and 3). River MutTdy Water. Microcyscin-lR adsorbaces prepared in river wacer were also dosed wich 03/92 and 04/92 ac 10 and 30 mg/1 respectively. The initial race of microcyscin-lR upcake for boch carbons was slower chan chat observed in Milli-Q water. After 3h, 03/92 and 04/92 removed 37% and 19% respectively from river water, compared with 58% and 33% from Milli-Q water. This

C:

C:

Figure 3 WATER JUNE 1993


UV ABSORBANCE OF RIVER WATER

I.

"' !::!.

ADSORPTION ISOTHERMS 80 r..- - - : : -:;:_=_:::. _:=_::; _.;= _=,_IF _ =_eaa ________~

;;::::::::::===~ "

o .40

01 /92

60

0 .38

02/92

ci

". 0

E

C:

.c 0 .36

~

.c 0.34

E

0<II

04/92

....._

40

05/92

ci 250

1.2. i

200

)(

<t

06/92

>

::,

ADSORPTION ISOTHERMS 300 ~ - - - - - - - - - - - ~

0. 32

0

20

40 60 Time (h)

- --

80

150 - ' - - - r - - - - - - - - - -- - 0 400 800 1200 1600 C (ug/L) - - 03/92 ---<>- 07/92

100 0

03/92 - e - 04/92

Figure 4

4 00

800 1200 c (ug/L)

1600

Figure 5B

Figure SA

BET SURFACE AR EA

VOLUM E OF MESOPORES

IODINE NUMBER 300

ci 1200

e

ci 0 .4 ::i E

&

. !!

e

; 0 .3 E :,

g

200 800

<t

."

0 .2

u t: :,

!!

~ 0.1

II I

0

2

3

4

5

6

1

7

2

3

PHENOL NUMBER 6.0 - - - - - - - - - - - - - .300

i

~

0

C:

"

ci

0

z

n.

6

100 <t

2.0

a:

...J

~

o.o-~,..__.....,...__,.._....~........,,_.---,o 1

2

3

4 5 PACs

6

:E

7

Figure 9

represents a decrease in the initial uptake of microcyscin-LR of 36% and 42 % for 03/92 and 04/92 respectively. The adsorption equilibrium was reached after approximately 72h for both carbons, as with Milli-Q water (Figures 2 and 3). The UV absorbance (254 nm) of river water decreased significan,l_y over time, indi cating adsorption of natural organics as well as microcyscin-LR. An equilibrium UV level was reached after approximately 72h for both 03/92 and 04/92 (Figure 4), consistent with previous data regarding the rare of adsorption of natural organ ics by activated carbon (Morris, 1991). Competition for adsorption sites on the surface causes a decrease in the level of microcyscin-LR adsorption in river water compared with Milli-Q water. Adsorption Isotherms. Milli-Q Water.

The seven PACs investigated varied widely in their performances. Although all yielded typical monomolecular layer, high affinity type adsorption isotherms (Figures 5A and 5B), the level of microcyscin-LR adsorption varied greatly between PACs and showed a distinct trend. The wood based carbons, 03/92 and 07/92, were clearly the most effecWATER JUNE 1993

200

E

z

0

<II

"

.

,::,

100 <t

)C

I I I• •

200

:E

0

7

0

g

400

C

~

a:

...J

-=C

a

600

:,

0

1

2

3

4

5

6

5 0

7

PACs

Figure 8

COMPETITIVE ADSORPTION

200 c:

4.0

~

C:

0

ci

t

PRACTICAL APPLICATION

320

1.2.

:,

.c:

5

300

800

i

Figure 7

Figure 6

E

4

PACs

PACs

j

-~

1.2.

100 ~

400

ti)

1

1000

ci

240

ci E

~

160

~ .--

03 30mln

:; Cl 40

03 River

.2.

04Mliii-O

~

30

04 30mln

"u

20

04 60mln

u

10

03 60mln

C:

04 River

E

"

03 Mllli-Q

0

E

C:

0

80 o--oo......,_ _ _a----c _ _ _ _ _ __

0

400

800 1200 (ug/L)

a:

-,-,

1600

05 30min

---

...J

05 60mln

9,0

10

C

Figure 10

rive adsorbents , adsorbi ng maxima of 280 and 220 µm /mg carbon respectively, as indicated by plateaus in the adsorption isotherm. PACs 01 /92 and 04/92, both coal based adsorbents, were equally effective, adsorbing 70- 75 µm /mg carbon. Th e lease effec tive adsorbents were che coconut based 02/92 and 05/92, adsorbing 40 and 20 µm /mg carbon and the peat moss based 06/92 which adsorbed 20 µm /mg carbon. The range of maximum microcyscin-LR adsorption leve ls (2 0-28 0 µm /mg carbon) suggests that the PACs reseed are significantly different. Physical data was analysed in order co determine if a correlation could be established between these properties and the extent of microcysrin-LR adsorption. No obvious correlation could be established with either BET surface areas (Figure 7) or iodine numbers (Figure 8), whi ch .suggests chat neither is particularly useful when evaluating the potential of a carbon to adsorb mi crocys cin-LR. While ph eno l numbers (Figure 9) showed a similar trend co the level of microcyscin-LR adsorption a clear correlation was nor evident. Pore volume data showed that all PACs reseed possessed a similar level of pore

20 30 40 PAC Dose (mg/L)

50

Figure 11

volume in che micropore region (0-2.0 nrr diameter). le is therefore unlikely chat ch, wide ranging maximum microcyscin-LF adsorption levels for the PACs are dependen on the micropore volume. An excellent correlation, however, wa: observed between microcyscin-LR adsorprior and total pore volum e for pores with diameters above 2.0 nm (mesopores), as shown ir Figure 6. For example, the wood based PAC! 03/92 and 07/92, which were clearly th< most effective mi crocysti n-LR adsorbents had the largest mesopore volume, 0.49 anc 0.27 ml/g respectively, compared with leveh ranging from 0.10 down to 0.02 mL/g fo1 the less effective PACs. The size and shape of a microcyscin-LR molecule, which is dependent on the overall configuration of the hepto-pepcide ring and side chains, is important when considering the relevance of the above correlation. With the assistance of mo lecular models the diameter of the mol ecu le was es timated at between 1.2 and 2.6 nm, consistent with che correlation between adsorption and mesopore volume. River Murray Water. The adsorption plateaus for 0 3/92 and 04/92 occurred at


approximately 200 and 36 µm /mg carbon respectively (Figure 10), compared with 280 and 75 µm/mg carbon in Milli-Q water. This represents a decrease in adsorption of 29% and 52% respectively. This difference in the decrease of microcys tin-LR adsorption for the two carbons indicates that the effect of competitive adsorption is less for 03/92 than 04/92, presumably because 03/92 is more mesoporous. Practical Application. The extent of adsorption is clearly depe nd ent on th e contact tim e between the adsorbate and adsorbent. The capacity of carbon ro adsorb microcystin-LR is determined at equilibrium, which is typically achieved after 72-96 hours. However, water treatment facil ities which utilise PAC are generally only equipped ro afford short contact times. Therefore, co dete rmin e if th e differences in PAC adsorption would be apparent in the performance of the carbons wi thin a water treatment facility, a natural water (River Murray) containing a realistic concentration of microcys tin-LR (5 0 µm /L) was prepared and treated with a selec tion of carbons (03/92, wood; 04/92, coal and 05 /92 , coconut) for short contact times (30 and 60 mins). The resul ts, which are shown in Figure 11 , indicated that 03/92 effectively reduced the concentration of microcystin-LR from 50 µm /L ro below 1.0 µm /L at a dose of 25 mg/L after 30 mins contact. Ne ither 04/92 nor 05/92 approached 1.0 µm /L, even at doses of 50 mg/L for 60 mins. The 1 µm /L level was based on recent calculations usi ng standard U.S. EPA risk assessment methods (Burch er al., 1993). Clearly, the wood based carbons would display superior microcystin-LR adsorption efficiency under water treatment condi rions as well as laborarory equilibrium conditions.

Conclusions Activated carbons are invariably microporous in nature due essentially ro the raw material properties. The additional presence of th e larger mesopores is less common. Results indicate that the scarring material influences the level of mesoporosity. This study shows that the adsorpt ion of mi cro cys rin-LR is dependent on th e volume of these mesopores , rather than the volume of micropores. For example, the wood based carbons were highly mesoporous and mo st effect iv e wh il e the cocon ut based carbons showed little mesoporosity and were least effective. Surface areas, iodine and phenol numbers alone afford only very specific adsorption information and should not be used as general indicarors of rhe effectiveness of carbons. Although the extent of competition with natural organics will vary depending on the nature of the organics it is anticipated that PACs with large mesopore volume would be rhe most effective microcysrin-LR adsorbents in all natural waters. Th ese res ults are directly transferrabl e to th e effec tive nes s

28

of PAC in water treatment facilities.

Acknowledgments The authors thank Peter Quinlivan (Hope Valley Water Filtration Plant, Soucl1 Australia) for providing io din e and phenol numbers for each PAC.

References American Water Works Associat ion (A WW A). Standard for Powdered Activated Carbon, 8600-90, (1990). Burch M, Jones J , Falconer I R and Craig K (I 993). Techn ical Advisory Group No 3. Cyanobaccerial Toxicity in Technical Advisory Report. MDBC, Canberra. Boces DP, Kruger H and Viljoen CC (1982). Isolation and Characterisation of Four Toxins from che BlueGreen Alga Microcysci n aeruginosa. Toxicon, 20, 945 Carmichael W W, Jones CL A, Mahmood N A and Theiss WC (1985). Algal Toxins and Wacer Based Diseases. CRC Crit Rev Environ Control, 15,275. Falconer I R, Beresford A and Runnegar MT C (1983). Evidence of Liver Damage in Human Populations Exposed co Toxin from a Bloom of che Blue-Green Alga Microcyscis aeruginosa in a Drinki ng Wacer Supply Reservoir. Med J Aust, I , 5 l l. Falconer I R, Runnegar M T C, Buckley T, Huyn V L and Bradshaw P (l 989). Using Accivaced Carbon co Remove Toxicity from Drinking Water Containing Cyanobaccerial Blooms. J AYV\f!A, 81(2), 102. Fitch C P ec al (1939). 'Wace rbloom' as a Cause of Poisoni ng in Domest ic Anim als. Cornell Vet , 24,30 Flecc DJ and icholson BC (1991) Toxic Cyanobacceria in Wacer Supplies: Analytical Techniques. Repo rt N umb er 26 . Urban Water Research Association of Amtralia, Melbourne. Gregg SJ and Sing KS W (1982). Adso1ptio11 Smface Area. and Porosity. Academic Press, London, 2nd Edition. Hawk ins P R ec al (1985). Severe Hepacocox icicy Caused by che Tropical Cyanobacrerium Cylindrospermopsis raciborsk ii [solaced from a Domestic Water Supply Reservoir. J Appl Envir l\licrobiol, 50, 1292 Hi mberg K, Keijola A M, Hiisvirra L, Pyysalo H and Sivonen K (1989). The Effect of Water Treatment Processes on rhe Removal of Heparoroxins from Microcyscis and Osci llacoria Cyanobacceria: A Laboratory Scudy. Wat Res, 23, 979. Hoffmann J R H (1976). Removal of Microcyscis Toxins in Wacer Purification Processes. Water SA, 2,58 Keij ola A M, Himberg K, Esala A L, Sivonen K and Hiisvi rca L (1988). Removal of Cyanobaccerial Toxins in Water Treatment Processes: Laboratory and Pilot-Scale Experiments. Toxicity Assessment: An lnternatio11aljo11rnal, 3,643 . McBarron E J and May V ( 1966). Poisoni ng of Sheep in New Sou th Wales by the Blu e-Gree n Alga Anacystis cyanea. Amt Vet}, 42,449. Morris G (199 1). Granular Acrivaced Carbon: The Variation of Surface Propert ies wich che Adsorption of Nacurally Occu rting Organics. Honours Thesis, University of South Australia. Newcombe G ( 1990). ·Chemical Regeneration of Activated Carbon: Prel iminary Studies Repor t Number 20. Urban Water Research Association of Auscralia, Melbourne. Ru nnegar MT and Falco ner I R (1981). Iso lation, ·Characcerisarion and Pathology of che Toxin from che Blue-Green Alga Microcyscis ae ruginosa. In The

\1(/acer Environmenr;-.:!lgal Toxins and Health. (W W Carmichael, ed), Plenum Press , New York, pp 325 Stewart AG, Barnum DA and Henderson J A (1950). Algal Poisoning in Ontario. Can J Compara ti ve Med, 15 , 197 Watanabe lvf and Oishi S (1982). Toxic Substance from a Natural Bloom of Microcyscis aerug inosa. Appl Environ Microbiol, 43,8 19.

Authors Mary Drikas has been the Senior Che111ist, \\1/ater Treat111ent Section, in the Australian Centre for Water Quality Research since its inception in 1987. She has been employed by the Engineering and Water St1pply Department since 1976, with ten years experience in water treat111ent st11dies. She has a B.Sc (Hons) from Adelaide Univenity and a Post Graduate Dip. in Analytical Chemistry from the University of South Australia. Cosimo Donati has a M.Sc (Organic Che111istry) from the Flinders University of South A11stralia. He is mr;rently a Research Officer in the Water Treatment Section. His previous work includes studies on assimilable organic carbon and coagulation of potable waters.

Gayle Newcombe is a Research Officer. She completed a M.App. Sci from the University of So11th A11stralia in 1988 and has a total of twelve years research experience in colloid and s111face chemistry. She is ettrrently working towards a Ph. D, investigating the s11rface properties of activated carbon in relation to water treatment.

Rob Hayes graduated B.Sc (Hons) fro111 Melbourne, gained his M.App.Sci at SAIT, and his Ph. D at the University of West London. He is a Research Fellow in the Particle and Surface Techno logy LAlr.ta:_.=::c_.,,;.,,,J- Research Group at the University of So11th Australia, working on activated carbon, mineral flotation and wetting processes. WATER JUNE 1993


MANAGEMENT

WORKING WITH THE COMMUNITY - A COMMUNITY CONSULTATION PROGRAM Gary Sabburg, Michael Simms, Stephanie Paul and Jane West T his pap er won th e management section of the Michael Flynn Award at the 15th Federal Convention.

cases, some still have nor come ro terms with exactly what community consultation and community participation involves, nor when the community should get involved and how much of a say they should have.

Summary

Philosophy of Community Consultation/Participation

This paper addresses the viral importance being placed upon the community consultation mechanism by government, local, state or federal, in order to achi eve community support for major project development. It demonstrates that in today 's increasingly complex and volatile world , governments are un li kely to emerge unscathed if they ignore the communi ty expectation to be consulted before hard decisions are taken on sensitive infrastructure issues that impact on community environments. A major case srudy by Maroochy Shire Council in south-east Queensland underlines chis point.

Introduction

Juse

To successfully implement a comm unity consultation program is both rime consuming and complex. Also, it is a lot more than just consulting people. Nor only must there be a genui ne com mitment ro the consultation process, bur also ro listen ing and, where appropriate, to adopting some of the ideas people contribute. Natura ll y, not all suggestions ca n be adopted, bur it is important that the reasons why their ideas have not been accepted (or only partly accepted) must be communicated. This step is viral because it gives the comm unity shared ownership of the outcome. If im pleme nted correc tl y, communit y partic ipation programs can be extre mely effective in achieving widespread support for a project which may otherwise be contentious. While a lengthy process of consultation often is necessary, in the long run it may help ro avoid damaging media reports and aggressive community opposition. Unfortunately, participation in the local planning process can occur roo late, generally well after the real planning directions are set. If it is an issue, then the public may be even more hostile because they haven't been consulted. Community consultation muse be an integral component of plann ing new deve lopments. Adequate attent ion and reso urces should be allocated ro consultation as would be the case with all other aspects of project planning to achieve a successfu l conclusion ro a project.

a few outspoken dissidents is all that it may rake ro easily destroy the credibility of a technically sou nd and financially viable project. Today, most projects which affect the community need ro have the endorsement of that community. Community consultation should not be seen as a com muni cat ions mec hani sm into wh ich government or industry is forced ro participate. Rather, it is a program or process which, in the long term , may save considerable rime and frustration. Also, it can serve as a barometer to moniror the acceptance levels of spec ific issues. Just as important, if publ ic response is positive, the results of such consultation can be used to coun ter balance minority groups' arguments. No longer are co mmuniti es passive. Today's comm unity is far better informed and more vocal. To ensure that gove rnment is Defining the Community. operating responsibly and in the comm u- How Should it be Involved? nity's best interests, people are demand ing What defines a communi ty' Not only more involvement in the decisions that affect must the residents who are affected be conthem. They want ro be involved at the begin- sid ered, bur the var iou s inreresr group s ning of a scheme, to ensure their views are ranging from environmental bodies, business considered before any strategy is set in place. and industry organ isations to residents and Altho ugh gove rnm en t pro jects now the media must also be taken into account . require comm unity co nsultat ion , in many When govern ment decides or is fo rced to

30

involve the community a number of points should be considered . Firstly, the process to be undertaken must be mapped out and objectives clearly defined. Ofrep there is only a series of ad hoc events whic:11, occur as the project reacts to public concern or protests. The process wi ll nor be effective if it is handled by a couple of media releases or a public meeting. Th is approach can leave the situation wide open to abuse. Public meetings are difficult to control and, more often than not, can confuse issues. Usually, there are a couple of people opposing the program who will dominate the floor. Th is gives the im pression char the project is widely opposed. In turn , the media wi ll often report major opposit ion to the plans. Imm ediately, the process has begun negatively and in open and intense conflict. It is then difficult to recover from chis position. Secondly, adequate resources must be allocated. There must be an approp riate investment in people, money and time allocated ro design and undertake the participation program. Whi le considerable funds are generally devoted to the technical studies associated with the program, usually the participation program is underfunded. The program also requires consid erable co mmitm ent in time fro m the techn ica l personnel involved in the project. Lastly, timing. If technical work is seen to be completed and decisions made before the pub li c is in fo rm ed or invited to contribute, it can be extremely difficult ro build trust for further participation. Also, it should be undersrood that undertaki ng a community consu ltation program doesn't mean that the results wanted will be achieved. However, it does help ro make government more considerate of their constituents, and more sensitive to broader issues. It may produce a better result in the eyes of the residents without threatening what was planned overall.

Case Study - Maroochy Shire Council In July 1989, a review of the hydraulic and biological capacity of Eudlo Creek Water Pollution Control Works (WPCW) was conducted. This show ed th at the works was approaching its nominal design capacity of WATER JUN E 1993


50,000 equ ivalent perso ns (EP), and the Maroochy Shire Council resolved co prepare a pl annin g rep ort on aug menta tio n of che project. John Wilson and Partners' report of May, 1990, recommended: • Increasing che capaci cy of che works co 85,000 EP • Deracing the existing standard race activated sludge works capacity ro 42,500 by incorporating nitrogen removal • Constructing a new mod ule of 42,5 00 EP capacicy, and .. • Relocating the created was tewater discharge from Eudlo Creek, a criburary of th e Marooc hy Ri ver, to th e Maroochy River. Generally, the proposed relocation of the discharge was in accordance with a strategy prepared in 1983 by the then Water Quality Council, ro cater for che discharges from an increasing population. The location proposed by the Water Quality Council was the conflu ence of Eudlo Creek with the Maroochy River. The planning report proposed ro construct the pipeline inro the river some 300 m downstream, in a place known locally as the Cod Hole. Thi s was consid ered to be the most environmentally acceptable and techni cally feasible locati on. Th e pl anning repo rt was adop ted by Coun cil and for wa rded ro the Water Resources Commission and the Department of Environm ent and Heri tage fo r approval. Approval was given on 27 September and 30 August 1990 respec tively. Ac the rime, the approval process was the usual method in these situations. John Wi lson and Partners sub se qu entl y comm ence d work on ch e derailed design of the works, incl uding che created wastewater discharge. During derailed survey of the proposed pipeline roure, local res idents became aware of Coun cil 's ac ti vities . Thi s aware ness expanded beyond the local residents, and led ro concern chat Council was intending ro discharge an 'unacceptabl e' wastewater into an area which was extensive ly used fo r prim ary con tact rec rea ti on and fishing. Nat urally people in the community were alarm ed by Council 's plan. The headlines in a local newspaper read: 'As the Cod Hole Tide Goes Out, rhe Stink Go es Up', ' Ri ve r rob e Se wage Dum p', 'Council Reject Sewage Protes t', 'The Raw Faces'. Also, Council received a petition from local res ide nts. In response to rhe growing community concern , Council resolved ro: • Move the discharge location upstream ro the confluence away from the Cod Hole • Engage a consul tant ro confer with th e commun ity ro explain the planning and approval process. The consultant was ro ga uge co mmunity con cern and reco mmend an app ro pri ate stra tegy whic h would meet wi th communi ty acceptance to allow the augmentation of the works to proceed. Turnbull Fox Phillips was commissioned WATER JUN E 1993

by Counc il to und ertake the co nsultat ion process. o one really understood the effort to whi ch the Council went in creating its wastewater. As a resu lt , many ratepaye rs believed char raw sewage was going to be pumped into the Maroochy River. It became an emonve issue. The Con su ltation Program was implemented over a four month period to ed ucate and calk with the comm uni ty about Counci l's proposed plans and to seek chei r reactions, input and comments. Counci l said cliac it was prepared to make changes if requi red and would respond to specific issues raised . This was a Bold New Approach by che Counci l. Never before had it undertaken such consultation on these matters. \Xlascewacer creacm ent is a very complex subject for the comm unity to comprehend. Mos e people si mply don't understand rhe issues , and crying to explai n che issues can cake consid era ble tim e. To avoid chis, th e Maroochy Shi re Council sec out to: • Communi cate the need for improvement and info rm che community of che creacmen c pro cess und ert aken and che processes proposed • Liaise with and analyse the local community's attitudes and concerns and incl ude chem in the decision making process • Add ress any issues raised • Communicate the agreed changes to the community The campaign was broad based to ensure chat all relevant audiences received the key messages. These audiences included: • Councillors and staff • Maroo chy resi dent s li vin g nea r th e Maroochy River • Maroochy community • Action groups • Sporting groups • Res ident groups • Local industry groups • Local and metropolitan media • Community at large The approach placed major emphasis on focus grou ps and spec ial bri efin gs and involved drawing together a presentation on the options available and che coses involved . Eight foc us group meetings were conducted, moderated by an experienced fac ilitator and attended by approx imately 70 people. To achieve thi s participat ion , more than 300 peopl e we re invited by teleph one to participate in the focus group discuss ion s. They were ra nd oml y and geogra phi ca ll y selected from dom es ti c ratepayers, commu nity groups, busi ness and industry. However, only people li ving close to the Marooc hy Ri ver or who used the Ri ver for work or recreation ie. fishermen, wate r sk iers or crui se boar operators were in teres ted in attending. Ar the outse t of eac h mee ting, parti cipants were asked their views on the proposa l. Th ere were a number of parti cipants who were quite negative or scepti cal. A few even accused the Council of 'doing a snow job' .

Michael Fullelove of Maroochy Shire points 011t the location of the outfall, and the mangroves to be protected.

However, the majori ty bad no idea as 1 what the Council was really doing or propo: ing. Therefore it was essential to outline ti· proj ect, cb e opti ons ava il able and cost involved before seeking their opinion. Ac tiend of the eight sessions, after the fac ts we1 presented in a rational and calm way, all pa ticipants were able co make a more informe and sound judgement. In addition to the focus group meeting 15 d1Scussion group meetings were also he] with on e or cwo representat ives of vari oL industry, business, interest and environmer cal groups. In turn , these groups were aske ro report back to their own groups on wh: th e Coun cil was proposing to do and th reas on s wh y. Coun cil encouraged rhe s grou ps co co me back to Coun_cil with an issues or concerns they may ha~e. Five otht discuss ion groups were invited, of whor three declined beca use they di d nor feel was necessary, one cancelled, and one simpl did nor attend. It was esse nti al fo r che Council's Wat( Sup ply and Se werage En g in ee r an d ch Council's Consulting Engineer to be involve in both the focus group and discussion grou meet ings . They prov id ed th e backgroun in fo rma tion and li stened to and disc usse issues raised by the commun ity. The focus group meetings and briefing identified a number of relevant issues. Alsc they helped the Council co understand wh, the attitudes of the wider community wen On ce pe opl e rea li se d th e exte nt of ch prog ram , th e alri; rn ar ives and th e cost: almost all of chose consulted accepted the pre posed plans. However, almost all wanted cl· Council ro pursue created wastewater re-use. Interescingly, the instigators of che pet cion were also invited to a special briefing. A its conclusion they expressed support for cl· Council's approach but were critical chat cl·


Coun cil had nor communi ca red or sought communiry opinion ea rlier. For those wh o wanted more information , to urs of rwo of Council's works were organised. To complete the consu ltation process, a vo lunta ry re spo nse brochure survey was mailed ro every householder in rhe Shire. The objec tive was ro prov ide all hou se hol de rs with an opporrnniry to comment on the propos ed plan s so their arri rn des co ul d be assessed as a guide to the acceptabil ity of the proposed augmentation . Thi s full y ex plained th e Coun ci l's proposed augmentation program and the options available and assoc iated costs. Ir includ ed a rear-off sec ti on on whi ch residents could make comments. They were also invired to relephone rhe Council if rhey preferred. The fe edb ac k by hou se holders was mi nim al. Of rhe 28 ,600 brochu res disrribured onl y 47 responses were received, four by phone and 43 rear-off comm ents fro m rhe brochure. Of those responses 14 rep li ed in support of rhe proposal. Some even thanked rhe Council for providing rhem wi th rh e inform ation or congrarn lared rhe Council on their approach ro rhe issue. Such voluntary responses, while having li mi ted stat istica l va lid ity, do prov ide an opporrn niry for people who did nor attend discussion groups to ai r their views to the Co unci l. Combi ni ng rh e inform ation provision and the research of their arrirndes effectively demonstrated the Council 's com-

mirment to commun ity consulrarion. Th e co mm unity consulta tion process incorporated both quali rarive and qua nti rarive research, and ir is valuable ro reflecr on the benefits of such research. • Firstl y, research is an acri ve, posi tive, and controll able way ro consul t and communi cate in fo rmati on to rhe loca l communi ty and selecred interest groups, • Secondly, ir enables a sensitive issue ro be communicated to the community without direc tl y usi ng the medi a, • Thirdly, ir highlights rhe issues and informarion in wh ich the wider communiry is reall y interesred, and • Finall y, it enabl es rhe co mmuni ca ti ons program ro be very fi nely direcred to rhe very pertinent issue of concern . In rhis particu lar case, ir was an effective way ro exp lain rh e srraregy pro posed by Coun cil and ro seek opini on ra ther th an calling a public meeting. The issue needed robe sensitively hand led and , had publ ic meerings been held , ir is likely rhe Council may have rriggered rwo major reacrions: • First, they wou ld have faced heated and uncontrol led debate.. . and .. • Second , they wou ld have caused wid espread overreacrion to the issue. Info rm ati on provi ded thro ug h thi s method is seen by those researched as being more credible and more obj ec tive , than is direct communication from an organisat ion to those ir wanes to convince. Also, by asking

for their commen~ it recogni ses the im portance of people being consulred . Runni ng in conju nction with rhe overall communications program was a planned and controll ed media program. Med ia play a key role in info rm ing and influencing commu nity op in io ns. Action grou ps also use the med ia ro promore their point of vi ew. Therefore , ir is important ro present all rhe fac ts ro the media ro ensure that they clearl y understand rhe issue. Unfo rtunately, so me of the medi a were off ide in the beg inn ing. So, imm ed iately afte r hold ing rh e foc us g rou ps rh e med ia were invited ro brie mgs so that rhe Council could explain what it was doing. Also, the media were rold rhar copies of th e findings would be made avail abl e to them. The resulr was rhar reporri ng of the iss ue was more balan ced than that which occurred prior ro rhe program commencing. To complete rhe process of consulrari on and ro provide an opportun ity for rhe wider community ro comment or ask quesri ons, an ad verrisemenr was includ ed in rh e loca l newspaper outlining rhe Council's proposals after considering community input. Lastly, to ensure that the Council spoke with one voice Councillors and seni or sraff were fu lly briefed. They were each provided wi th a reference kit containing information on rh e upg rade , poss ible ques tio ns that mig ht ari se, and in for mati on for use in appropriate answers. , Council learned a number of invaluable

You Have Read The Community Consultation, Now The Engineering Outcome Maroochy Shire, Eudlo Creek WWTP Augmentation. Augmentati on fro m 53,000 ep ro 85 ,000 ep wi ll in corporate ni troge n removal by anox ic/ anaero bic bas in s, ro ac hi eve a 10/1 0/ 10 effluent. Fo llowing th e co nsu l ra ti on process, the effluent is to be disinfecred by UV and the discharge to be located in the reg ion of hi ghest flow of th e main Maroochy River, just a kilom etre upstrea m of th e favourite fishing area (Cod Hole), as shown in the plan. Rather than a direct course, the pipeline route avoi ds th e sens iti ve areas of mangroves and seagrass beds and crosses the river by siphon ro a 'beachhead ' on the north bank . As well as the diffusers in the deepest channel of the river, a branch will fac ilitate fu ture re-use in the adjacent agricultural land , an option favoured by the community. Moniroring of baseline conditions will continue, and assessments made of the im pacts of agriculture and seprage, so rh at any shi ft fro m th e base lin e can be determined.

32

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lessons from rhe projecr ir conducred: • Firsrly, tlm the pu blic should be more involved in the decision making process • Secondly, it is important ro disseminare sufficient information so chat rhe publ ic can make an informed decision • Thirdly, Council needs ro be undersranding of people's concern and respecr their opinion; and • Lasrly, consulcarion and com municarion with the communi ry is a never-ending process. So, whar was rhe outcome of chis consulration program) The program highlighted char most participanrs were unaware of rhe excenr of the Council's wastewarer rrear ment processes and re-use programs and ocher iniriatives being underraken. Th e mosr co nsisrenr co mm ent was rhe requesr by many part icipants for Council ro pursue furr her created wastewar er reuse iniriatives. As a resulr of rhe comments made, rhe Council now has an even srronger commitm ent ro pursuing alrernarive re-use opnons. However, rhe real reward for community consulrarion was char rhe majoriry of participants , and also a number of householders, voiced rhei r apprec iarion ar being consulred on rhe issue by rhe Counci l. The Maroochy Shire Counc il has recognised char ro succeed a projecr not on ly needs robe technically sound and financially viable, bur ir muse also be socially acceprable. If rhe

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project does nor have rhe ownership of rhe communiry it can easi ly fai l. Ir is pleasing ro nore chat rhe major local newspaper which ar rhe ourser was exrremely negarive ro rhe proposed di scharge location , subsequenrly pub lished an ed iro ri al which illusrrated irs support. Obviously, rhere will always be conrinuing pockets of opposition ro this rype of issue, bur afrer implemenring chis program the Council is confidenr chat it can proceed knowing ir has wide support from rhe community.

References Sarkissian \Y/ and Perl gur D, with Balla rd E, The Community Participation Handbook, Resources for Pu bl ic Involveme nt in the Planni ng Process. Turnbull , Turnbull Fox Phillips, Speec h on The Geelong and Disrricr Wate r Board commun ications program to rhe Inrernarional Association of Business Communicarors, Hong Kong, Octobe r

1991

Michael Simms is a director ofJohn Wilson and Partners (Q11eensland) Pty Ltd. He is a civil engineer with 13 years experience, some 7 years in the area of wastewater treatment, disposal and re-1/Se. Stephanie Paul is the managing director of T11rnb1tll Fox Phillips ( Qld) and chairman of Worldcom Asia Pacific Region. She has 17 years experience in all ., facets of public relations including community .__J.___- ~ cons11ltation and provides strategic co1m111micatio11s advice to many of A11stralia's leading organisations and ind11Stries.

Authors J ane West is the genera l manager of Turnbull Fox Phillips in Qtteensland. She has a Bachelor of Business and l 3 years experience in all facets of public relations partimlarly media relations and community consultation.

Gary Sab bu rg is Supervising Engineer, Wa ter Supply and Sewerage at Jv!aroochy Shire Council. He is a civil engineer with 19 years experience in the area of water mpply and sewerage design , conw.,__ _ _ . . __ __ , stmction and operations associated with local government in Qtteensland.

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33


TECHNOLOGY

ANAEROBIC DIGESTION IN AUSTRALIA Report by Annabelle Duncan Industrial High-Rate Systems Increasingly stringenr environmenral standards have prompted water aurhori ties to reflect the true cost of waste treatmenr in their trade was te charges and co enforce stricter regu lations regarding rhe quality of industrial effluenr chat they accept. As a result many industries are now seeking economical waste trearmenr technologies that can be installed on-site in order to meet discharge limits. High-rare anaerobic digestion, wirh low energy demands, low sludge production and ability to hand le high strength wasre is an arrractive option for many industries and inreresr in anaerobic technologies has increased in rhe past rwo decades. The currenr issue of rhe IAWQ handbook lists 38 Australian members of the specialist group on anaerobic digestion. Not all have an active inreresr, many are keeping a watching brief for new developmenrs. Several firms are marketing anaerobic reacrors in Australia and there are a number of research groups with an active inreresr in rhe area.

Installations in Australia Th e first fu ll -scale up fl ow anaerobic sludge blanker (UASB) reactor was built in Australia in 1984 ar rhe Bunge plant in Alrona, Vi cro ri a using Gist Brocades (Netherl ands) technology. The planr treats wheat starch wastewater and performs well. Four ocher UASB planrs have since been bui lt in chis counrry by Aquarec-Maxcon under license from Pacques BV ( erherlands). The four planrs rrear pharmaceutical, confecrionary, cann ery and paper mill effluents respec tive ly. Th e co mpany also operates a pilot planr suitable for resting wasre streams for industries conremplaring insrallarion of a UASB (Lawson, 1992). PWT Asia/Pac ifi c has recently signed an exclusive agree ment with Biorhane Inrernarional (Netherlands) co marker rhe Bi or hane UASB high rare reacror in rhe Ausrralasian/Sourh Pacific region. A pilot planr is being consrrucred which wi ll be available for on-site demonstrations. Environm enral Solutions Internacional Led (formerly Campbell Environmenral) have developed and are marketing a hybrid anaerobic reactor under the trade name Hybractor which is suirable for treating medium co high srrengrh wastes from, for example, the 34

food production, brewing and pu lp and paper industries. The reacror consists of a packed section supporting biofilm growth and providing gas/l iquid/solids separation with a suspended sludge bed of anaerobic bacteria below. A skid mounred pi lot planr was rested last year on brewery wastes. Ir gave BOD and COD removals in excess of 80% at a loading of 7 kg COD m3 day l. The reacror was also able to cope with shock loads without detrimental effects (Newland and OH, 1993). The reacror received rhe R&D award at rhe Western Australian In dus try an d Export Awards recen tly and Ausrrade have provided funding for installing a Hybractor planr at a distillery in Indonesia (Anon , 1993)

BHP/CSIRO Research BHP and CSIRO have undertaken a project on anaerobic digestion as part of their Memorandum of Understanding. The main objectives of the project are to idenrify mechanisms associated with process srabiliry/insrabi l i ry, improve understanding of rhe microbial community, improve process efficiency throug h biomass developmenr and rerenrion and establish process design criteria for scale-up of anaerobic reactor systems from laboratory and pilot scale to full sized commercial units. The initial emphasis of rhe project was on rhe baffled anaerobic reactor (BAR) whi ch consists of a rank segmenred inro a series of downflow and upflow chambers by the use of baffles. The reacror is designed so that rhe waste stream is forced to flow sequenrially through each downflow and upflow chamber. Parr of rhe effluenr stream is recyc led . A number of analytical procedures have been used ro monitor rhe performance of rhe reactor including analyses of volatile faery acids, COD, total suspended solids, volatile suspended solids, alkalinity, biogas composition . GC, HPLC and MR techniques have been used to derecr biochemical intermediares which may be indicative of unstable conditions. A rapid technique for characterising rhe biomass in rhe reacror has been employed. The technique is based on fatty acid profi ling of rhe biomass in th e reactor has been employed. The tec hnique is based on fatty acid profiling of rhe biomass and has enabled correlation of cerrain biomarkers wirh periods of instabi lity. The BAR is capable of greater than 95 % reduction of COD ar loading rares

of 40 kg m1 dayl at lab scale. A 2ml pilot model based on a modular design is undergoing trials at present (Dunne, Smith, Mclean, Pilkington and Raper, 1993).

Start-Up Seed Start up of high-rare anaerobic digesrers can be slow and iris often recommended rhar granular sludge from an existing digester be used. This is difficult when there are very few reactors in operation in Australia. The Bunge plant mentioned earlier was seeded with granular sludge imported from rhe Netherlands to encourage rapid starr-up bur this is nor a very satisfactory solution. Hence many research projects have exami ned the effect of different seed mate ri al co get rhe sys tem going. A ream. at Murdoch University in Western Australia, lead by Goen Ho have been examining the start-up of a UAS B, using abattoir stab ilisation pond sludge ro seed be1;ch scale (l.91) reactors which were then fed wirh a synrheric, volatile fatty acid feed. Within 5 weeks COD reductions between 78 and 94 % were obtained ar a load ing of 15kg COD m3 day-1. The concentration of sludge used to seed the reactor had little effect on rhe VFA and COD red uctions. This was attributed co washout of rhe sludge and evenrual retention of about 20 kg VSS m3 of reacror, regardless of the ini rial amount of sludge added (Tenorio and Ho, 1993). In a second project the Murdoch group have been examining rhe removal of grease from wool scouring effl uent. Th e primary purpose of th e project was to degrade rhe derergenr used in emulsifying the wool grease. The work is due for publication shortly.

Rotating Contactors At Melbourne Un iversity, Michael Connor has been working on anaerobic rotating biological conracrors (An RBC). These reacrors are analogous co the aerobic RB C. Studies have been carried our ar laborarory scale, using a synrhetic, glucose based feed and th e performance of rhe reacrors monirored under steady-stare (loading rate 2.4 kg COD m3 dayl) and shock loading (19.2 kg COD m3 dayl) conditions. The digesre rs were operated wirh the discs either fully or only partly submerged. When the discs were WATER JUNE 1993


half submerged, the effective hydraulic reten- rions of lagoons to control odours and to trap tion time was half that when rbe discs were rhe methane produced. A small generator has fully subme rged and yet perfo rm ance was been connected to rake the gas and produce improved . Th is bas been amibuted ro the elecrriciry for rhe operation of some of the ease with which gases (especially hydrogen) aerators in the aerobic ponds. (Gulovsen, er were stripped from the li quid phase (Tseng al, 1992; Russell and Sadler, 1993). and Connor, 1993).

Conclusions

Control of Operation Although ini tial concerns regarding insrability have proved ro be largely unfounded, anaerobic technology is srill relatively slow to catch on in this country. One reason for this has been that operating cosrs can be high, especially cosrs for alkali , and di fficulties can be experienced wirb control. A greater understanding of the control and operation of the process is requi red. University of Queensland and University of SW both have proj ects underw ay on monitor ing and co nt rol of anaerobic digesters. The CRC for Waste Manage ment and Pollution Control ltd is funding a project ar University of Queensland on an anaerobic degrada ti on mod el. In thi s pro jec t , the researchers are aiming to develop a broad control strategy for high rate anaerobic treatment systems. The research is nor unique to any one type of high-rate anaerobic treatment , but should lead to control schemes capable of being used in specific systems. The researchers also hope that they will be able to reduce the ini ti al capi ta l expe nditure of anaerobic digesrers by allowing more intensive process ing and to min imi se operating costs (J urg Keller pers comm ). A fluidised bed is also being used at the University of New South Wales for a stud of control of anaerobic digestion (Fi rzGerald, 1993).

Lagoon Systems Nor all interest is in rhe high rare processes. Many water boards operate anaerobic lagoons for waste water treatment. Gippsland Water treat a mixture of domestic and industri al efflu ent in anae ro bic and aero bi c lagoons. The system rece ives was tes from a draft pulp mill whi ch contai ns organochlorines and appears to ac hi eve grea ter reduction of rb e organochlorines than the aerobic treatment systems traditionally used overseas. The ational Pulp Mills Program is funding a joint project at Gippsland Water and CS IR O Di vis ion of Ch emicals and Polymers to investigate reasons for rhe efficiency. The anaerobic conditions seem to be crucia l to organochlorine degradation , presumably because they fac ili tate reductive dechlorination. Melbourne Water also operate anaerobic lagoons at the Werribee Sewage Treatm ent Complex on the outskirrs of Melbourne. The complex is one of the world 's most extensive farm and lagoon waste water treatment fac ili ti es. Although it was originally built in a remote area, it is now being encroached upon by development. Thus there is a need to reduce odours fro m rhe fac ility. Covers have recently been installed over the anaerobic secWATER JUNE 1993

Al though there are not many high-rare anae robi c digesters cu rrently ope rating in Ausrralia interest is increasi ng and it is to be expected that nor only will research effort in the field increase in the near fu ture, bur we will also see the constructi on of more fullscale plants.

Acknowledgments Thanks to all the Ausrralian members of the IAWQ Speciali st Gro up on An ae robi c Digestion who sent me information regarding thei r interest in the fi eld for inclusion in this article.

References

44 1-448. Gul ovsen T, Hansen P, Hutchison D, Russell J and Scott P, 1992. Odour Minimisation ar \Xferribee. \\1/ater 19: 16-23. Lawson T, I992. The UASB Process. \\1/ater Ocrober. 29-30. 1 ewland M and Oh R, 1993. Energy Efficient High Rare Anaerobic Treatment of Brewery Was tewater. Proceedings of the 15th Federa l Convent ion A \f/\fl A Gold Coast, Apri l 1: 300- 304 Russell J , Sadlier M, 1993 . Design and Consrrucrion of a Synth etic Membrane Cover to a Large Active Sewage Treatment Lagoon. Proceedings of the 15th Federal Convention A\\1/\11/A Gold Coast, Apri l 4: 966-97 1 Tenori o D O and Ho G E, 1993. Sta rt up of UASB Reacror with Concentrated Abanoi r Stabilisati on Pond Sludge. Proceedings of the 15th Federal Conventio11 A\\1/\11/A Gold Coast, April 3: 614-620 Tse ng D \Xf-S , and Connor M A, 1993. An Experi mental Stud y of rhe Anaerobi c Rora ring Biolog ical Contac ro r, and the Implica tion fo r Des ign and Mod elli ng of Anae robi c Diges rers. Proceedings of the 15th Federal Con·ven tion A\\1/\11/A Gold Coast, April 3: 659-664

Anon , 1993 Waste ll-la11age111e11 t and Environment

Author

4 (3) 8.

Dunne DJ, Smith BE, McLean KM, Pilkington H and Raper \XI G C, 1993. Recent Developments in Anaerob ic \Xfas rewarer Treatment Systems. Proceedings of the 15th Federal Convention A\f/\flA Gold Coast, April l: 305-309 FirzGerald PA, 1993. Rapid Monitoring and Control of Anaerobi c Diges tion. Proceedings of the 15th Federal Convention AW'W'A Gold Coast, April 2:

Dr Annabelle Duncan, a member of the CSIRO Water and Wastewater Treatment Group, Division of Chemicals and Polymers, is a microbiologist working on projects for anaerob ic diges tion of food and industry wastes. She is an active member of the IWAQ Specialist Group on Anaerobic Digestion.

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35


SEMINARS

TRENDS IN THE DISINFECTION OF SEWAGE EFFLUENT Report by Phil Thomas A seminar on trends in the disi nfect ion of sewage effl uent was held in Adelaide on 7 December 1992 by rhe Australian Centre for Water Quality Research and rhe SA branch of rhe A\Y/\Y/A. Proceed ings were opened by D j Lane, Director of ACWQR and rhen fo llowed nine presentations on topics incl uding the leg islative siruarion, available options, an operator's viewpoint , current practi ces and research, and monitoring of impacts. The seminar was then rounded off by three industry presenrarions on ultraviolet and membrane fil tration technology. Ian Kirkegaard, Marine Adviser, Dept of Environment and Land Management (SA) , discussed the current legislative position particularly as ir exists in South Australia. The Marine Unit is now iss uing li cences und er rhe Marine Environment Protection Acr for effluent discharges ro sea and whi ch will come into force in March 1993 . Licence conditions indicate char rhe SA \Y/arer Authority (EWSD) will have eight years ro comply with the licence bur with quanrificarion of effluent quality required within rwo years . Targe ts have nor yet been sec and although Australian guidelines for fresh and marine waters have now become available, Stare guidelines will be compatible bur nor necessarily rhe sam e. Pollu tants order of priority as seen by the regulators is nutrients, pathogens, particulates and then chemicals. There is a clear recognition that diffuse sources are at least as important as point sources such as sewage treatment planes. Ian foreshadowed the impact of the EPA which would have integrated sire licences to include all emissions ie water, air and solids. Turning to chlorinated effluents Ian indicated char some data is available on effect of 'fre e chlorin e' on eg estuarin e fish bur a potentially bigger problem exists with chlorinated organics. Data collected during rhe rwo year characterisation period will be made ava ilable to the general pub li c. Severa l general parameters such as AOX shou ld be 36

reseed for bur whole effluent toxicity resting dence had been found to discontinue the use of chlorination . was probably nor requi red. Borvcrn Kracman , Des ign En g ineer, Seminar organiser Cathryn Hamilton, a research officer with AC\Y/QR, then gave a \Y/asrewarer Treatment Unit, EWS, gave an presentation on rhe options available for rhe ins ight inro current disinfection practices di sinfection of sewage effl uents. Chemi cal, in So uth Aust ra li a mos t of which revolve physical and biological rrearments were dis- aro un d eith er lagoo nin g or chlorination. cussed including rhe use of chlorine, ozone, Survey res ults from metropolitan Adelaide chlorine diox ide, bromine chloride and per- bathing waters were presented to illustrate oxygen compounds (eg hydrogen peroxid e). rhe effectiveness of the current disinfection Emphasised were th e va ri ous byproducts program. Cathryn Hamilron then discussed aspects formed from rhe vari ous disinfecranrs avai lab le for use in crea ting se wage effluent s. of dechlorination which is not widely used in Relative coses of rhe various chemical treat- Australia but is used overseas ro reduce ment s were d iscussed. Och er important impacts of,_c hlorine resid uals on rece iving methods include UV irradiat ion and mem- water. Various sulphur compound s such as brane filtration both of which are bei ng seen sulphur dioxide, sodium sulphite and sodium as viable alternatives to rhe traditional use of merasulphice have been used to react with chlorination. Lagoons and constructed wet- chlorine residuals. Use of Granular Activated lands have been effective in markedly reduc- Carbon (GAC) is also a possible creatment ing pathoge ni c bacteri a levels. Discussion bur regeneration is a problem in Australia. Cathryn then discussed current research in ,ensued on a comment made char the toxicity of an effluent char had been chlorinated, then Australia from inform ation obta ined from dechlorinated, was less than chat of the same a recent interstate trip and from published licerarure. \Y/ork is being done particularly on unchlorinaced effluent. Alan Potter, Manager, Tec hnica l Con- ulrravioler irradiation and membrane filrrasultancy Group , Pollution Control Branch, rion with plans for a project on ozonation \Y/acer Board , Sydney gave an operator's per- well advanced. A number of review studies spective of the situation in rhe Sydney Water were mentioned together with chlorinated Board which has th irty six treatment planes byproducts and dechlorination projec ts. of which nineteen have di sinfection facilities, Phil Sutet; Biologist, Scare \Y/ac er th e ochers us ing ocean outfall s. Al an Laboratory, Phil gave an interesting insight explained how the NSW EPA were moving into biological aspecrs, particularly aquatic cowards including microbiological parame- macro inverrebrares, of monitoring receiving ters such as co liforms, viruses and cys ts in screams for rhe effect of discharges, including li ce nce arran ge ments. Chlorin e was still chlorinated sewage efflu ents. Sorensens' widely used to meet public health require- Similarity Ind ex was us ed to compa re ments on the understanding char the risks samples taken above and below discharges at from disinfection byproducts was much less three treatment works . Microtox measurethan when nor using chlorine. As a result of men rs and chlo rine res idu als were also new EPA req uirements, STPs are bein g recorded at eac h sampli'ng location. From upgraded to meet criteria of chlorine residual these comparative studies che major impact less than O.5 mg/L and faecal coliforms less in the screams studied, both temporary and than 200 per mL. In summ ary, Alan indi- perm anent , is from the organic load rather cated rhac alternatives were being inves ri - than from rhe chlorine, although most of the gared bur rhac current practice was to observations were mad e when the screams optimise current practice and char no evi - were behaving as permanent systems , with WATER JUNE 1993


cons id erable flows . Chlorinarion did have a localised effecr ar one of rhe plants. Phil suggesred char rhe impacr of chlorinared effluent may be differenr ar rimes of low flow and fu rnre environm ental legislarion and guidelin es should rake inro considerar ion rhe ephemeral narure of our screams when sening receiving warer srandards. Roger Stokes, Sen ior Parmer, Roger Srokes and Associares gave a disserrarion on design facro rs for effecrive UV disinfecrion. The US EPA Design Manual Muni cipal Wasrewarer Disinfecrion (1986) provided rhe rheorerical basis for chis presentarion rogerher wirh dara produced from several SA plants earlier in 1992. Facrors co be considered when designing or evaluarion UV sysrems include reflon or quarrz rube, dose intensity, residence rim e disrribut ion, turbu lence factor, lamp remperature, lamp life and cleaning rogether wirh various aspens of effl uen t qualiry. Three imporrant factors which were evaluared in rri als recenrly underraken ar merropolitan plants included suspended solids, mixing characre ri sri cs and ultravioler rransmission (filtered) measurements. The UV theme continued in the presenration by Angus McDougall, Manager, Process and Pollu tion Control Pry Ltd , Queensland, who commenced his ralk by revi ew ing the objectives of disinfec rion including a proper Risk Analysis. He mentioned rhe increasing imporran ce of viruses and effl uent reuse. A video then illustrated UV disinfecrion systems parricularly quarrz rube UV and

emphasised rwo problems with chlorination, receiving scream . George Levay, ACWQR, namely OH&S and carcinogenic byproducts. made the observati on chat data on chloriAngus rhen ourlined a number of innovations nated byproducts from Au stralian plants in UV rechnology mainly related ro was lacking. Discussion on chlorinat ion improved operational and mainrenance versus UV contin ued with questions ra ised condirions. Several interesti ng questions from about the source of chlorinated byproducts Bruce Copper, ICI rhen enl ivened proceed- ie industrially sou rced or formed by the chloings as various UV versus chl ori ne argu ments rination process. were discussed. Full proceedings can be obtained for $20 The lasr formal presentation was given by by co nracc ing Ms Cathryn Hamilron on Rhett Butler, Regiona l Manager, Memrec (08) 259 0211 or (08) 226 6428 Fax (08) 259 Ltd , NSW who discussed rhe increasing use 0228 or by writing to AC\XIQR, Pri vare of microfilrrarion in rrearing sewage effluents. Mail Bag, Salisbury SA 5108. Capiral and operating costs were presented A symposium on Disinfection of Potable rogerher with data from rhe Blackhearh plant Water and Effluents: A Re-evalation which has been rnnning for over rwo years . Resulrs indi cared char faeca l col iform reduc- is planned for September 28-29 at the rio n was very good as were ch ose fo r co l- School of Environmen tal Engineering, iph ages. Howeve r, in spire of impressive Griffith University, Brisbane. Contact performances, membrane fi lrrarion is still nor Phil Williams (07) 875 7514. as cheap as ch lorin at ion or UV irradiation merhods. Rherr saw a particular niche marker wirh large scale MF plants where rhe effl uent AWWA BOOKSHOP was co be reused. The quality of effluent was essentially independent of rhe level of faecal Proceedings from the 15th Federal Concoliforms in rhe feed. A discussion panel was then convened vemion April 1993 are available now. The over-200 papers prese nred ar the with Don Bursill, Group Manager Scientific Services EWS as chairperson. Future research Convemion are publ ished in the proceedneeds were discussed wirh lagoon technology ings . Th e pro cee din gs comprise five sti ll very much a viable option. Phi l Surer volumes, 1300 pages. These can be purchased from the AWWA discussed rhe contribution of algae to organic enri chm enr processes togerher wirh rhe Bookshop , PO Box 388, Arcarmon NSW observation that algae from lagoon effluents 2064, eel (02) 413' 1288 fax (02) 413 1047 generally dropped our quickly in freshwater at the cost of$100 plus 10 handling fee.

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TECHNOLOGY

BIOLOGICAL REMOVAL OF MANGANESE FROM WATER BY IMMOBILIZED MANGANESE-OXIDISING BAGTERIA L I Sly, Vu llapa Arunpairojana and D R Dixon Summary A process has been developed for the immobi lisation of manganese-oxidising bacteria on magnetite particles and to use the immobilised ce lls in a continuous recycle fluidised bioreactor (CRFB) for the removal of manganese from water. A model CRFB was operated for 22 weeks with removal rares of greater than 90 % and up to 100% for Mn 1 • concentrations in the range 0.25 to 8.5 mg/I when operated at a residence time of 21 hours. The majority of the manganese in the effl uent was residual Mn 1 • with only low levels of oxidi sed and adsorbed manganese. The bu lk of the oxidised manganese remained attached to the immobilised cells in the fluidised co lumn. The bioreactor approached maximum removal efficie ncy within a week.The CRFB required minimal maintenance, did not clog or bind and therefore did not require backwashing which is a disadvantage with sand fil ters. The pH conditions were criti ca l for manga nese adsorption , oxidation and removal. Optimal conditions were found to be around pH 7.8.

Introduction The presence of manganese in drinking water constitutes a problem for many water authorities both in Australi a (Harr , 1974) and overseas (Bean , 1974, World Health Organisation, 1984) as a cause of manganeserelated 'dirty wa ter' in urban disrributi on systems. Manganese entering the distribution system accumulates as a black manga nese oxide biofilm on pipe surfaces and causes consumer complaints when it sloughs off (Bean, 1974, Harr, 1974, Sly et al. , 1988a, 19886, 1989). The manganese-related 'dirty water' water is aesrhericall y unacceptable and causes economic loss by irreversible staining of washing , equipment , manufactured goods and swimming pools. Most water authorities aim through various water treatment strategies to reduce manganese in drinking water to the WHO and NHMRC recommended level of 0.05 mg/1 (NHMRC, 1980; WHO, 1984). The American Water Works Association goal level is 0.01 mg/I (Bean, 1974). Current water treatment methods for the 38

removal of manganese and iron from water to be self cleaning and wi ll not clog (And rewi suppl ies are destratificarion and oxygenation and Przezdziecki, 1986). of the raw water supply (Queensland DepartSmall, dense, monosized support particle, ment of Local Government , 1986, Wong , have been recommended for aerob ic water 1984) and chemical oxidation at the treat- treatment (Andrews and Przezdziecki, 1986). ment plant followed by filtration (Wong, Small particles are desirable because they givt 1984). Mn 1• is not removed by conventional a higher surface area of biomass and there will water treatment processes such as alum floc- be less transfer resistance. Unlike a packedculation un less an ox idation step is included. bed rhe particle size and densi ry, and the flow The most common oxidant is KMnO4 which velocity in a fluidised-bed are not indepenconverrs Mn 1• to Mn 4• and thi s colloidal pre- dent variables. In the process developed rht cipitate is subseq uently removed by filtra- combination of a dense particle and a strong!} tion. There are pracrical difficulties with this adherent biofilm of manganese-oxid ising bacmethod as the rate and extent of oxidation is teria have beeq exploited in a biotechnologica 1 dependent on factors such as the speciarion of manganese , rhe characteristics of organics present, and fi lter effic iency. These facto rs are often beyond the control of the plant operator. On occasions very little manganese is removed and at worst the concentration may be higher after treatm ent than in the FLUID IZED PAATI CL [ raw water. Convent ional wa ter treatment COlUHN systems usually require extensive mod ification and fine tuning of individual process steps before an adeq uate removal of man• ~ INFLUENT ....+--Yf-L,, ganese is achieved. There exists in nature a variety of microorganisms such as bacteria and fungi which MIXING YESS[L are capable of oxidising manganese (Ghiorse, 1984 , Gregory and Sea ley, 1982). Such organisms are ubiquitous in their distribution , occurring widely in natural so il and Figure 1 water habitats. Some of these organisms are Schematic of the continuom recycle fluidised well adapted to an attached mode of growth bioreactor (CRPB) and have been exploited in biologically active san d fi Iters for the removal of manganese 0.5 . . - - - - - -- -- - - -~ 2 .5 from drinking water (Booudou er al. , 2.0 1985 ,Czekalla er al. , 1985 , Ehrlich, 1980, e o.•, ~ _J, I Moucher et al. , 1985). ,; O.J I\ "' /..,. 1.5 .. The development of a fluidised-bed bioret • \ /" ~ actor offers several advantages over conven0.2 ,o ~rionals and filters. Such reactors rely on the ~ o.o ,.-::;,~-1 =------"10., growt h of immob ili sed cu ltu res on small 0.0 ? 0.0 particl es suspended in a warer column by 0 10 Time ( min) up-flowing water (Andrews and Przezdziecki , 1986). Th is technology offers high surface Figure 2 area to biomass volume ratios and thus higher l111111obilisation of cells on particles in the efficiency for a given volume of reactor. An CRPB de111onstrated by changes in absorbcmce added advantage is that fluidised-beds expand (• ), cells 1111adsorbed (T) and cells to accommodate growing biomass and so rend immobilised ('v).

.

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1

15

WATE R JUNE 199:


Table 1

with medium~tt, remove unadsorbed cells and then filled with medium containing 1 mg/I Mn 2• . The CRFB was initi all y operated in batch mode for four days. The residual Mn 2• was reduced ro zero in 3 days with approximately 90% of resid ual Mn 2• being removed on each successive day (Figure 3). CRFB was challenged with a 5 h pulse of 1 mg/I Mn 2• at a feed rare of 158 ml/h (= 21 h residence rime). The residual Mn 2• rose ro 53 mg/l and rhen fell away ro zero in 3 hours. The CRFB was then operated continuously with a 1 mg/1 Mn 2• feed for 6 days. Th e residual Mn 2• level quickly reached a steady stare level of approximately 71 mg/I, a reduction of 93% ar a residence rime of 21 h.

Removal of Mn 2• by the CRFB operated with a residence time of 21 h Age (months) <l <l <l <l <l

3 4

Input Mn'· (mg/l)

Residual Mn'· (mg/I)

% removal

Removal rare (mgM,d h)

0.2553 0.4820 0.5 142 0.9590 l.9070 0.2545 0.5398 l.0561 l.9620 4.75 10 8.4760 2.0250 l.9730

0 0 0 0 0 65.4 690 l0l.9 137.8 408.8 58 1.0 18!.0 182.0

100 100 100 !00 100 74.3 87.2 90.4 930 91.4 93 l 9l.l 908

398 76.6 80.2 153.4 305 l 28.6 71.6 144. l 280.9 686. l 1247.4 293 2 283.0

process for rhe oxidation and removal of manganese in water treatment. By using a continuous recirculating fluidi sed-bed bioreacror it was possible ro select a particle size and flow velocity with a resultant shear force which would ensure the dominance of the 'railormade' manganese-oxidising biofilm. Ir is envisaged char a continuous recycle fluidi sed-bed bioreacror (CRFB) for the oxidation of Mn 2• will be installed ro rrear the raw water entering the treatment plane. Such a process would operate without the addition of expensive chemi cal oxidants. An additional advantage is that the Mn 4' formed will be fi rmly bound ro organic expolymeric substances either free or on the surface of cells. This material would be more easily removed by alum flocculation and/or fi ltration than chemi cally fo rmed manganese oxide alone. The created water would undergo normal disi nfec r ion by chlorination. Ir shou ld be emphasised char the organ isms involved are harmless aquati c orga nism s and pose no health threat (Famurewa er al. , 1983 ). Ir is also envisaged that rhe process will be suitable for primary treatment of water in small communities, and for the treatment of industrial effluents.

medi um (Tyler and Marshall, 1967) containing 0.0025 % yeast extract. The manganese concentrati on in rhe feed was varied from 0.25 ro8.5 mg/1. Immobilization of Cells. The strain of microorganism used was Pedomicrobium manganicum ACM 3067 isol ated from a water distribution system with a manganesedeposiring biofilm (Sly et al. , 1988a). The cells were immobilised on magnetite particles 212-300mm in diameter which had been treated by eight alternating magnetic fi eld cycles (8AMF) using rhe method of MacRae and Evans (198 3, 1984) . The adsorption of cells ro magnetite particles was studied in jar rests ro model immobilisation in the CRFB. Immobilization of Cells in the CRFB. Immobilisation of cells in the CRFB

(Figure l )closely followed the results of jar res ts which pred icted a loading of 6.8 x l0"cell s on the 1200m l of fluidi sed magnetite in the CRFB. The actual result was 1.6 x 10" which was of the same order and provided a coverage of about 1 cell/104mm 2 . Immobilisat ion occurred rapid ly and was complete in 5 min. (Figure 2). Bioreactor Startup. Immediately after im mobi lisation the CRFB was flushed

Pilot Plant Development

Effect of Mn 2 • Concentration on Manganese Removal. Manganese con-

centration experiments were conducted over a five month period. The removal decreased slightly from an initial 100% ro around 9093% for concentrations between 1 and 8.5 mg/1 Mn 2• with reduced removal rares of 74. 3% and 87.2 % fo r 0. 25 and 0.5 mg/1 Mn 2• respectively (Table 1). Over rhe range of 0. 25 ro 8.5 mg/I Mn 2• there was a linear relationship between manganese concentration and the manganese removal rare . The results showed char the maj or part of the residual manganese was Mn 2• with only low leve ls of ad sorbed Mn 2• and oxidised manganese in the effluent. This indicates char the majority of rhe adsorbed and oxid ised Mn 2• rem ained on the immobilised cells in the column. Effect of pH on Mn 2 • Removal. A se ries oif experi ments were conducted ro study the effect of pH conditions for manganese removal. Under uncontrolled pH conditions with a pH 7feed, the effluent pH was maintained naturally at around pH 7.8. Manga nese removal performance was favo ured by alkaline conditions normally adjusted by rhe metabolic activity of the cells to around pH 7.8. Control of pH at pH 8

1500 , - - - - - - - - - - - - - - - - - - - - - - ~ 1.5

Continuous Recycle Fluidized Bioreactor (CRFB). The mode l CRFB

(Figure 1) consisted of a glass column 60 mm in diamete r and 600 mm hi gh through which medium was pumped into the bottom ro fluidi se 1.2 litres of magnetite particles (2 12-300 mm diameter). The 50% expanded fluidised bed was maintained by recirculati ng a 3.3 litre volume of medium through rhe column and a stirred mixing vessel containing 2.1 litres which was aerated by one Iiere of air per minute. Probes for pH, redox, and dissolved oxygen were included in the vessel and temperature was mainrain ed ar25 °C. Dual sy nchronised peristaltic pumps were used ro circulate the medium at a rare of one litre per minute into and our of the column and mixing vessel. When operating in continuous mode synchronised peristaltic pumps were used to pump in and remove equa l volumes of fresh medium and effluent. The growth medium used was half strength PC WATER JUNE 1993

'-o> ~ ._,..

1000

1.0

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+

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,-..,

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500

0.5

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0

3

6

9

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12

Time (days)

Figure 3

Removal of 1 mg/1 Mn2, (• ) immediately after immobilisation of P manganimm cells by The CRFB operated in batch mode and the response topulses of 1 mg/! Mn 2• ( - ) at a continuous feed of 158 ml/h ( = 21 h residence time). 39


--

500

400 ,-..

2.0

1.6

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"O

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14

16

18

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Age (weeks)

Figure 4

Effect of age on the conversion of 2 mg/I Mn 2• by the CRFB operated at an infl11ent pH of 7 and a residence time of 21 h showing changes in inp11t Mn 2 • ( • ) and effluent levels of total Mn (D ), sol1tble Mn (A), adsorbed Mn (0 ) and MnOx (6 ). resulted in slightly improved Mn 2• and coral Mn removal. Ac pH 8 the ma jority of the effluent manganese was oxid ised, probably as a resu lt of the chemi ca l ox id ati on of the resid ual Mn2 • by NaOH dosi ng for pH control. Control at pH 7.8 reduced the chemical oxidation while only marginally affecting the Mn removal race. Attempts co control the pH at lower values adversely affected manganese oxidation and removal. Effect of Cell Age on Manganese Removal. The results presented in Figure 4

show char the CRFB operated consisten tly over a period of 22 weeks . There was an initial drop in removal race between 1 and 3 months (Table 1) after which the removal race remained between 91% and93 %.

Conclusions The work co dace indicates the porencial of the CRFB for manganese removal from drinking water. There has been insufficient rime ro complete all the developmental work and some further work is being carried our. The major issues being addressed are red uction of the residence rime and improvement of the removal effi ciency. Ir is most likely char che key ro solving these problems will be ro increase the immobilised cell loading on the support particles and co encourage more uniform coloni ,acion and growth. This is being investigated by reducing the particle size which will increase the overall surface area and also reduce abrasive accion by use of lower fluidising flow races. A pilot plane version of che CRFB has been installed at a water creacmene plane co compare removal races with co nve nt ional creacmene and co compare laboratory scale performance wi th char using raw water under real cond itions.

Acknowledgments This research was funded by grams from

40

che Australian Water Research Advisory Council and che CSIR O/Un iversicy of Queensland Collaborative Research Granes Sc heme. We thank Mr Keith Mc Ph ee, Comm ercial Min era ls, for supp lying the magnetite.

References Andrews, G.F. and Przezdziecki, J. (1986). Des ign of fluidised-bed fermence rs. Biotech. Bioeng. 28, 802-810. Bean, E.L (1974). Potable water-quality goals. j oumal American Water Works Association 66, 221 -230. Booudou, J.P. , Kaiser, P. and Phil ipoc, J.M. (1985 ). Elimination de fer ec du manganese: interec des procedes biologiques. \fla terSupply 3, 151-1 55. Czekall a, C. , Mev ius, W. and Hanerc , H. (1985). Quantitative removal of iron and manganese by microorganisms in rapid sand filters (in situ investigations). \flater Supply 3, 111-1 23. Ehrlich, H.L (1980). Different forms of microbial manganese oxidarion and reduction and their environmental significa nce. In Trudinger, P.A. , Walter, M.R. and Ralph , B.J. (eds) Biogeochemistry of Ancient and Modem Environments, p. 327-332 . New York: Springer. Famurewa, 0., Sonntag, H.G. and Hirsch, P. (198 3). Aviru lence of 27 bacteria char are budd ing, proschecace, or boch. lnt.J. Syst, Bacteriol. 33 , 565 -572. Ghiorse, W.C. (1984). Biology of iron-and manganesedeposicing bacteria. Ann. Rev, Microbiol. 38, 515550 Gregory, E. and Sealey, J.T. (I 982). Widespread distribution of ability ro oxidise manganese among freshwater bacteria. Appl. Environ. Microbio l. 44, 509-5 l l. Hare, B.T. (l 974). A compilation of Australian \'(/acer Quality Criteria. A11s /ralia.11 Wate r Resources Council Technical Paper No. 7. Mac Rae, J. C. and Evans, S.K. (1983). Faccors influencing che adsorption of bacteria co magnetite in water and wastewater. \fla.terRes. 17, 27 1-277. Mac Rae, J.C. and Eva ns, S.K. (l 984). Removal of bacteria from water by adsorption co magnetite. Wa ter Res. 18, 1377-1 380. Mouchec, P. , Mag nin , J. , Mazounie, P. , Puill, A. and Fressonnec, B. (1985). Eliminat ion du fer et du

manga nese CO nte.Qt!S cl ans !es eaux soucerrai nes: prob lems classiques, progress rece ncs. Water Supply 3, 137-1 49. acional Health and Medical Research Council and the Australian Wacer Reso urc es Coun cil (l 980). Des irable Quality for Drinking Water in Australia. Australian Government Printing Service, Canberra. Queens land Depa rtment Of Primary Industry (1986). Review of aerac ion/descracificaci on techniques in Au stralian surface water storages. Quee nsland Department of Primary Industry Report. Sl y, L.I ., Arunpairoja na, V. and Hodgki nson, M.C. ( 1988a). Pedomicrobium manganicum from drinking-water discribucion systems with manga neserelated 'dirty water ' problems. Sys /. Appl. Microbiol. 11 , 75-8 Sly, LI. , Hodgk inson, M.C. and Arunpairoj ana, V. (19886). Effect of water velocity on the early development of manganese depositing biofilm in a drink ing-water distribution system. FEMS Microbiology Ecology 53, 175- 186 Sly, L I. , Hodgk inson, M.C. and Arunpairojana, V. (1989). The control of manganese deposition and 'dirty water' in the Gold Coast wacer distri bution system. Proceedings Australian Water and \flastewater Association 13th Federa l Convention, Canb erra, pp 148 -1 5 l. Th e lnscic ucion of Engineers, Canberra, Australia. Tyler, P.A. and Marshall, K.C. (1967). Microbial oxidation of manga nese in hydro-elec tri c pipelines. Antonie van Leeuwenhoek ). Microbiol. Sero/. 33, 171-183 Wong , J.M. (1984). Chlorinacion-fi lcracion for iron and manga nese removal. J ournal American Wa ter Works Association 76, 76-79. World Hea lth Orga ni sati on (1984). Guidelines for Drinking-Water Quality. Volu mes l and 2, Geneva.

Authors Lindsay Sly is a lecturer in the Department of l\ilicrobiology at the University of Q11eens land and Director of the Centre for Bacterial Diversity and Identification. His research intffests are concerned with the discovery and study of environmental bacteria and their application in biofilm bioreactors for water and wastewater treatment. r------,=,,------,

Vullapa Arunpairojana is a research scientist in biotechnology at the Thailand lnsti-tute for Scientific and Technological Research working on waste treatment. She was previously a Senior Research Assistant in the Department of Microbiology at the University of Q11eensland.

David Dixon ts a Senior Principal Research Scientist with the CSIRO Watertek program in the Diyision of Chemical and Polymers. He has a PhD f rom Melbo11rn e University, in colloid and rntface chemistry, and '------~ -- ~ over twenty year's experience in the fields of wate,; wastewate,- and indmtrial effluents. WATER JUNE 1993

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Water Journal June 1993