Waste Management an Overview Prof (Dr) Francis Xavier Kerala Veterinary & Animal Sciences University Mannuthy ,Thrissur,Kerala.India email@example.com. Mob 9447131598
Fragile eco system is a vital concern the world over and any subtle anthropomorphic intervention can initiate ripples of perishable change. Today our Governmentâ€™s priority is to popularize on-site waste management, especially for the biodegradable wastes, so that the flow of waste to the common stream is reduced significantly and it can function with better efficiency. Any person or Institution who honour civil and social rights, naturally think about organic and inorganic waste management to be contained within the existing rules and regulations of the country. In India eight lakh deaths and morbidity costs of up to 3.6% of GDP as per latest research reports ,can be attributed to unclean air and water. The three pillars of sustainable development viz: social justice, environmental integrity and economic development, are entwined on these factors .In any country where there is lackadaisical attitude in waste handling depletion of natural resources, social discontent, and eventual economic breakdown, will happen. Kerala Scenario: Who wastes the most? The social waste concept of Kerala state differs with different districts. The fragmented land holding is the major factor ,More over the 43 rivers also play a role is washing away the pollutants. Social engineering and Technology application are to be considered under this scenario. The social engineering deals with the ethics and efficiency for maintaining environment. In the case of waste management, it is, broadly, the practice of reduce, reuse recover and refuse. The technology application deals with the improvement of assimilative capacity as well as supportive capacity of environment. The bioconversion process is applicable to the organic fraction of wastes, to form compost or to generate biogas such as methane (waste to energy) and residual sludge (manure). Various technologies are available for composting such as aerobic, anaerobic and vermicomposting.The thermal conversion technologies are incineration with or with out heat recovery, pyrolysis and gasification, plasma pyrolysis and pelletization or production of Refuse Derived Fuel (RDF). Eight of the 14 districts in Kerala are disturbed and the daily waste generation with pertinent details are appended: 1. Kannur municipality generates 20 tonnes a day and dumps it at 8 hecters in Chelora village near the city for more than 30 years. 2 Kozhikode corporation generates 150 tonns a day which went to 6.5 hect land at Njeliyanparamb near the cityThe site was used to discard human excreta since it was established in 1930.The plant was built later. Last year, people protested for 65 days, demanding the plantâ€™s upgradation, construction of a leachate collection unit and a landfill to dispose non-biodegradable waste. Municipal corporation now dumps 60-70 tonnes waste
in a day. Meat shops sell waste to agencies in Tamil Nadu. A plastic recycling unit is under construction, even as waste is accumulated on the roadsides 3 Thrissur Corporation has 150 tonnes a day with their Dump yard at Lalur in 10.1 hectaresPeople live close to the century-old disposal site. Three youths died in 1992 after breathing toxic air while cleaning a well. The high court ordered immediate solution. A plant was set up in 2000, but it does not work. In 2010, the LDF government ordered to implement Lalur Model Project for solid waste management. UDF discarded the plan when it came to power in the municipal corporation. Now, corporation secretly burns waste at night. 4 Kottayam Municipality: churns out 30 to 40 tonnes a day with a waste treatment plant at Vadavathoor in Vijayapuram village in 1.4 hectares After years of protests, the municipality built a plant in 2007 along with a private firm. But it converted only a part of the waste into manure. The rest was dumped in the landfill. In 2010, the high courtâ€™s order favoured the firm. Waste is still being sent to the plant with police protection 5 Kollam Corporation produces 100 tonns of waste a day .Dumpyard in Kureepuzha village in 4 hectares mainly handled this waste.The land is near Ashtamudi Lake, an internationally important Ramsar site. After protests, a plant was set up in 2002, but it has not become functional. High Court has ordered that no more waste can be dumped here 6 Kochi Corporation has 120 to 140 tonns of waste generated with a waste treatment plant at Brahmapuram in Kunnathunad panchayat.It is 14.9 hectares. Till 2006, waste was dumped at a landfill near Southern Naval Command in Wellington Island. Naval authorities withdrew permission when a coastguard aircraft suffered bird hit. Corporation started to use a wetland at Brahmapuram it had bought in 1998. A plant was built in 2008, but sank in marshy land. Now, it is recovered and working 7 Alappuzha Municipality comes with 65 tonns waste a day with their dumpyard at Sarvodayapuram in Mararikkulam Thekk villagein 4.6 hectares.The municipality entered into an agreement with private firm Andhra Pradesh Technology Development Centre to build a plant. It could treat only 30 tonnes of waste. The plant worked for a few months, then the firm asked for more money. The municipality decided to run the plant on local expertise. But it cannot treat more than 6 tonnes of waste. The rest is dumped unsegregated in landfills 8 Thalasserry Municipality with 15 to 20 tonnes a day and the handling unit at a dump yard at Punnol Pettippalem near Thalassery cityin 3.2 hectares The century-old dump yard is in a thickly populated area near sea coast. Wells are contaminated, people have skin and respiratory diseases, and fisher folk complain there is less fish to catch. A government primary schoolis close by. Protests intensified two years back, culminating in police action on March 20 this year. Protesters were brutally beaten up. â€˜Emergingâ€™ waste maker Trivandrum Corporation (150 tonns a day!)faces a stiff struggle with their dumping yard residents of Vilappil sala .
Waste management: Identifying appropriate technology feasible for the locality is the main point in waste handling. The usual waste handling methods in our state are : Burial (labour intensive, carelessness attract carnivores)
Incineration (need an incinerator ,costly, labour intensive) Pit disposal (carnivores dig it out, pollute water bodies ) Sanitary land fill (seepage, attract public protest ,carnivores) Traditional Composting (Existing methods not user friendly) Monitoring,Collection,Transporation,Processing,disposal and recycle /reuse are all the points in appropriate technology. â€œAt source treatmentâ€? is basically for Biodegradable waste. Bio-methination and STP are all examples. Collection involves a lot of logistic planning .We have to have a culture where we care for the society. But the segregation at source is an ideal workable plan. Monitoring is identifying the waste management needs and recycling opportunities. But minimizing waste output and a supervision of how that is progressing is a must in an uncivil society. Unsorted non biodegradable waste treatment techniques are also there. Bio-methanation and thermal treatment cannot be compared. Bio-methantion technologies should be evaluated with respect to (a) Pre-sorting methodology, (b) Digester unit utilised , (c) Dewatering of digestate and reuse of water and (d) Methods proposed for the waste water treatment .Thermal waste to energy should be subjected to a preliminary evaluation based on (a) Technical soundness, (b) material and
energy balances, and (c) financial feasibility. The thermal waste to energy technologies that do not produce liquid water are prima-facie uneconomical, on a build-own-operate basis without operational subsidy either as tipping fee or assured inflated energy sale prices. How to plan Composting: Biodegradation is a natural, ongoing biological process that is a common occurrence in both human-made and natural environments. 1. Identify goals of the composting project. 2. Identify the scope of the project and socio cultural impact 3. Get political support for changing the community’s waste management approach. 4. Identify potential sites and environmental factors. 5. Identify potential compost uses and markets. 6. Initiate public information programs. 7. Inventory materials available for composting. 8. Visit successful compost programs. 9. Evaluate alternative composting and associated collection techniques. 10. Finalize arrangements for compost use. 11. Obtain necessary governmental approvals. 12. Prepare final budget and arrange financing. 13. Construct composting facilities and purchase collection equipment. 14. Initiate composting operation and monitor results. The composting option chosen must be compatible with existing processing systems. Communities should consider these factors: • preferences of the community • collection and processing costs • residual waste disposal costs • markets for the quality of compost produced • markets for recyclables • existing collection, processing and disposal systems. The four composting technologies are windrow, aerated static pile, aerobic , and anaerobic composting. Supporting technologies include sorting, screening, and curing. The technologies vary in the method of air supply, temperature control, mixing/turning of the material, and the time required for composting. Their capital and operating costs also vary considerably. Moniter the following: • compost mass temperatures • oxygen concentrations in the compost mass • moisture content • particle size • maturity of the compost • pH • soluble salts • ammonia • organic and volatile materials content.
Microbes: Microorganisms are the key in the composting process. Peak performance by microorganisms requires that their biological, chemical, and physical needs be maintained at ideal levels throughout all stages of composting. Microorganisms such as bacteria, fungi, and actinomycetes play an active role in decomposing the organic materials. As microorganisms begin to decompose the organic material, the carbon in it is converted to by-products like carbon dioxide and water, and a humus end productâ€”compost. Some of the carbon is consumed by the microorganisms to form new microbial cells as they increase their population. Heat is released during the decomposition process. If all conditions are ideal for a given microbial population to perform at its maximum potential, composting will occur rapidly. The composting process, therefore, should cater to the needs of the microorganisms and promote conditions that will lead to rapid stabilization of the organic materials. Microorganisms in the compost process are like microscopic plants: they have more or less the same nutritional needs (nitrogen, phosphorus, potassium, and other trace elements) as the larger plants. There is one important exception, however: compost microorganisms rely on the carbon in organic material as their carbon/energy source instead of carbon dioxide and sunlight, which is used by higher plants. As the more easily degradable forms of carbon are decomposed, a small portion of the carbon is converted to microbial cells, and a significant portion of this carbon is converted to carbon dioxide and lost to the atmosphere. As the composting process progresses, the loss of carbon results in a decrease in weight and volume of the feedstock. The less-easily decomposed forms of carbon will form the matrix for the physical structure of the final productâ€”compost. Chemical environment: Several factors determine the chemical environment for composting, especially: (a) the presence of an adequate carbon (food)/energy source, (b) a balanced amount of nutrients, (c) the correct amount of water, (d) adequate oxygen, (e) appropriate pH, and (f) the absence of toxic constituents that could inhibit microbial activity. Carbon Nitrogen ratio: The ratio of carbon to nitrogen is considered critical in determining the rate of decomposition. Carbon to nitrogen ratios, however, can often be misleading. The ratio must be established on the basis of available carbon rather than total carbon. In general, an initial ratio of 30:1 carbon:nitrogen is considered ideal. Higher ratios tend to retard the process of decomposition, while ratios below 25:1 may result in odor problems. Typically, carbon to nitrogen ratios for green plant waste range from 20 to 80:1, wood chips 400 to 700:1, manure 15 to 20:1, and municipal solid wastes 40 to 100:1. As the composting process proceeds and carbon is lost to the atmosphere, this ratio narrows. Finished compost should have ratios of 15 to 20:1. To lower the carbon:nitrogen ratios, nitrogen-rich materials such as yard trimmings, animal manures, or biosolids are often added. Adding partially decomposed or composted materials (with a lower carbon:nitrogen ratio) as inoculums may also lower the ratio. Attempts to supplement the nitrogen by using commercial fertilizers often create additional problems by modifying salt concentrations in the compost pile, which in turn impedes microbial activity. As temperatures in the compost pile rise and the carbon:nitrogen ratio falls below 25:1, the nitrogen in the fertilizer is lost in a gas form (ammonia) to the atmosphere. This ammonia is also a source of odors.In Kerala the Municipal solid waste (MSW)should have a Carbon Nitrogen ratio between 25 â€“ 50 initially.
Release of ammonia and impeding of biological activity at lower ratios. Nitrogen as a limiting nutrient at higher ratios Moisture: A moisture content of 50 to 60 percent of total weight is considered ideal.55% is optimum for MSW in Kerala. The moisture content should not be great enough, however, to create excessive free flow of water and movement caused by gravity. Excessive moisture and flowing water form leachate, which creates a potential liquid management problem and potential water pollution and odor problems. Excess moisture also impedes oxygen transfer to the microbial cells. Excessive moisture can increase the possibility of anaerobic conditions developing and may lead to rotting and obnoxious odors. A moisture content of 50 to 60 percent of total weight is considered ideal. The moisture content should not be great enough, however, to create excessive free flow of water and movement caused by gravity. Excessive moisture and flowing water form leachate, which creates a potential liquid management problem and potential water pollution and odor problems. Excess moisture also impedes oxygen transfer to the microbial cells. Excessive moisture can increase the possibility of anaerobic conditions developing and may lead to rotting and obnoxious odors. Composting is considered an aerobic process, that is, one requiring oxygen. Anaerobic conditions, those lacking oxygen, can produce offensive odors. While decomposition will occur under both aerobic and anaerobic conditions, aerobic decomposition occurs at a much faster rate. The compost pile should have enough void space to allow free air movement so that oxygen from the atmosphere can enter the pile and the carbon dioxide and other gases emitted can be exhausted to the atmosphere. In some composting operations, air may be mechanically forced into or pulled from the piles to maintain adequate oxygen levels. In other situations, the pile is turned frequently to expose the microbes to the atmosphere and also to create more air spaces by fluffing up the pile. A 10 to 15 percent oxygen concentration is considered adequate, although a concentration as low as 5 percent may be sufficient for leaves. A pH between 6 and 8 is considered optimum. pH affects the amount of nutrients available to the microorganisms, the solubility of heavy metals, and the overall metabolic activity of the microorganisms. While the pH can be adjusted upward by addition of lime or downward with sulfur, such additions are normally not necessary. The composting process itself produces carbon dioxide, which, when combined with water, produces carbonic acid. The carbonic acid could lower the pH of the compost. As the composting process progresses, the final pH varies depending on the specific type of feed stocks used and operating conditions. Particle size: The particle size of the material being composted is critical. As composting progresses, there is a natural process of size reduction. Because smaller particles usually have more surface per unit of weight, they facilitate more microbial activity on their surfaces, which leads to rapid decomposition. However, if all of the particles are ground up, they pack closely together and allow few open spaces for air to circulate. This is especially important when the material being composted has a high moisture content All microorganisms have an optimum temperature range. For composting this range is between 32째 and 60째 C. For each group of organisms, as the temperature increases above the ideal maximum, thermal destruction of cell proteins kills the organisms. Likewise, temperatures below the minimum required for a group of organisms affects the metabolic regulatory machinery of the cells.The Municipal solid waste of Kerala should have a a particle size of 25 to 75 mm for optimum aerobic composting.
Detailing aerobic composting for Municipal solid waste (MSW) in Kerala: MSW characteristics
Sorted organic fraction of MSW, preferable with same rate of decomposition
MSW Particle size
Between 25 – 75 mm for optimum results
Between 25 – 50 initially. Release of ammonia an impeding of biological activity at lower ratios. Nitrogen as a limiting nutrient at higher ratios
Blending & Seeding
Addition of partially decomposed matter (1-5% by weight) reduces composting time.
3m length, 2m width and 1.5m height (optimum)
Every four or five days, until the temperature drops from about 66 – 60oC to about 38oC or less. Alternate days under typical operating conditions
50-55oC for first few days and 55-60oC for the reminder composting period. Biological activity reduces significantly at higher temperature (>66oC)
Maintenance of temperature between 60-70oC for 24 hours
At least 50% of initial oxygen concentration to reach all parts of composting material
7 – 7.5. Not above 8.5 to minimize nitrogen loss in the form of ammonia gas
Not desirable, except in special cases
Degree of decomposition : Area requirement
Determine by COD test or from Respiratory Quotient . ~25 m2 for 1 ton of MSW (only for windrow formation for 21 days composting and maturity yard for 30 stabilization. Area for machinery, packing and storage extra
Post treatment care
Facility for effluent (leachate) recycling and treatment and sanitary landfill of rejects (inert materials, sludge from ETP)
2-4 kg N/ton ; 1-2 kg P/ton ; 1-2 kg K/ton
18-25% of waste input
Residuals for disposal
2-20% sieving overflow (plastic, metal, glass, stones) (Ref: Varma,2007)
Thumburmuzhy Model: “Thumburmuzhy Model” aerobic composting technique(TMACT) developed by Dr Francis Xavier,Professor at Thumburmuzhy Research station of Kerala Veterinary &Animal Sciences University , is a rural, cost effective and eco friendly “Waste Management System” imbibed into the Kerala Agro eco-zone. This Rural technology is a recommended model by the UNDP Climate change community compendium *(2011) , among the four ideal rural technology for farmers of India. This method of composting, which emits very little methane and carbon dioxide, has been adopted by a number of apartment complexes and rural communities in Kerala. The aerobic composting Technology ,the ideal fero-cement Bin and the microbial Consortium developed from cow dung, are the major research achievements .Research in Veterinary University has modified aerobic compost unit with a different layering system to handle rural organic waste, farm waste and dead animal parts which are otherwise wasted and pollutes rivers, roads highways and water bodies. We have designed a cost effective, rural system for livestock farms and rural Kerala. The composting unit which is becoming the darling of decentralised waste management includes a box-like structure with ferro-cement floor, layers of cow dung, carbon source and waste materials are subjected to composting in presence of oxygen. The temperature rises rapidly in the waste to almost 70 degree Celsius and this peak temperature kills pathogens so is a boon to rural health and community health. Waste management is a big problem in most of the farms of the state and hence the waste can be effectively converted into valuable manure by TMACT. The NPK value of “Thumburmuzhy model compost” using home waste is N.1.57%, P-0.049%, K-0.73%. Thumburmuzhy compost model; since it is cost effective can be replicated in rural areas to handle organic waste under Kerala agro climatic conditions. In 90 days time the first crop of manure gets ready. Moreover, livestock/food waste is a rich source of Nitrogen. Research in other places showed that TBC and coliforn count in aerobic compost is minimal. Hence, under public health angle this has to be encouraged. This ideal Rural waste handling technology is not labour intensive.
THUMBURMZHY Model aerobic composting Unit(TMACT)
CCC of UNDP included this in their technology list
Very close to farms TMACT unit will not emit any foul smell
Broiler Waste in Thumburmuzhy model composting no putrifaction
KSE Ltd Factory waste and dry palm leaves(carbon source) in TMACT model
A carcase of 200 kg as a layer in Thumburmuzhy Composting
Dead Birds in Aerobic compost tank of wood
Dead Calf in Thumburmuzhy composting Copyright @ fx