MINIMIZING POLLUTION HAZARDS, APPLICATION OF VERMITECHNOLOGY IN RECYCLING OF ORGANIC WASTE

Ø Vermitechnology is a method of converting all the biodegradable wastes such as farm wastes, kitchen wastes, market wastes, bio-wastes of agro-based industrial wastes, livestock wastes etc. into useful product through the action of earthworms. Through their digestive process, earthworms convert decaying vegetable matter, composted green waste, animal waste and paper into valuable nutritive products for agriculture.

Ø The ideal objectives of vermitechnology are to upgrade the value of the original waste material, produceEarthworms form a major component of the soil system and these organisms have been efficiently ploughing the land for millions of years and assist in the recycling of organic nutrients for the efficient growth of plants.

Ø Compost worms are being used for recycling of organic waste and have the potential to be used in vermitechnology waste conversion systems for industrial or municipal applications. Although many species of earthworms are suitable for waste processing; two species namely Eisenia fetida and Eudrilus eugeniae have mainly been taken into consideration for vermicomposting. Their growth, productivity and ability to transform organic waste as animal dung, agricultural residues, urban washes and sludge have been widely reviewed .

POTENTIAL OF VERMITECHNOLOG

Ø Under present day condition, it becomes very essential to protect environment from further degradation, develop appropriate technologies for use in recycling various organic waste and to harness energy thus minimizing environmental stress. In such a direction, vermitechnology may be an ecofriendly and effective tool in reduction of waste quantities, reuse of waste materials, recovery materials and energy particularly relevant to agricultural production through bioprocessing and bioconversion.

Ø Vermitechnology is an appropriate technique for disposal of biologically decomposable organic waste materials and production of compost of high quality. Vermitechnology improves the composting and utilization process of available organic and inorganic wastes in the natural plant production cycle. Thus, vermis are good biological agents for recovery of vermifertilizer and vermiprotein for wider use in agro- ecosystems, aquaculture and poultr. Vermicomposting has added advantage to abatement of organic pollution by rapid reduction in the bulk density and elimination of foul odour; production of vermifertilizer for the use in agroecosystems and vermiprotein or vermin from waste as feed for poultry, fish, pig and other domestic animals.

Ø Potential benefits of vermitechnology as summarized by Sabine include; reduction of noxious qualities of organic wastes, i.e., elimination of bad odours, elimination/reduction of harmful microorganisms; production of easily handling, high value fertilizer and protein production for food and feed. Certain challenging areas like enhancement of food production, waste recycling and management of solid wastes are targeted promising area of vermitechnology

Ø The process of converting organic waste by earthworm consumption into nutrient- filled humus is

called vermicomposting. Worm castings, the scientific name of worm manure are nature’s finest soil conditioners that are called as “Gardeners Gold” on account of their excellent soil amending value. In natural system, earthworms along with soil microorganisms degrade organic waste materials of soil and thus maintain nutrient flux.

Ø By maintaining suitable temperatures in even the coldest winter months and creating suitable conditions for earthworms to thrive they can process a large amounts of organic material, consuming, digesting and passing almost any decaying organic matter including food waste, leaves and grass, shredded paper or cardboard waste, and chopped straw or hay upgraded material in situ and to obtain a final product free of chemical and biological pollutants

Ø Solid waste management is essential to maintain healthy environment in the nature. There are many problems in the environment concerned with high production and accumulation of large amount of organic wastes. Indiscriminate spreading of these organic wastes can cause soil and water pollution ultimately leads to soil fertility damage and health problems.

Ø These environmental problems can be avoided, if these organic waste materials are pre-porcessed before their disposal into the nature. To process these wastes aerobic biodegradation is must for safe disposal so as to produce good quality processed product. The natural process of breakdown of organic wastes by saprophytic microorganisms can be doubled by using special varieties of earthworms through the process known as Vermitechnology.

Ø Vermitechnology is a combination of both vermiculture and vermicomposting. It is a process of composting organic wastes into valuable organic fertilizer by the action of earthworms. It is an effective, eco- friendly, cheap and easy method for recycling of biodegradable organic wastes using selected species of. It is a cost effective, efficient, safe disposal of all kinds of organic wastes apart from producing very useful product called vermicompost .

Vermiculture

Ø Vermiculture defines the rearing of special types of earthworms such as epigeic and anecic types, which involves multiplication of earthworms stock by providing optimum environmental conditions such as proper moisture, temperature and sufficient food etc. Vermicomposting involves bio-oixdation and stabilization of organic wastes through the interaction between earthworms and microorganisms.

Ø Earthworms play an important role in the fragmentation process and providing substrate so as to increase the surface area for growing micro-organisms.Vermitechnology has become a popular method for the safe disposal and cost effective treatment ofdomestic and agricultural organic wastes, Since, 2010 remarkable work have been published in organic waste management and research on this technology for the transformation of energy rich organic matter into humus like product „vermicompost‟.

Ø Three main ecological groups of earthworms, based on the soil horizons in which the earthworms were commonly found i.e., litter, topsoil and sub soil have been recognized . Epigeic Earthworms have been classified in several ways; perhaps the most useful is based on their behavior and habitat. They developed a classification that divides worms into the following three categories: epigeic, endogeic and anecic.

Ø Epigeic - types live at the surface in freshly decaying plant or animal residues. They do not have permanent burrows. They are phytophagous, very small in size, very active and have regenerative capacity within short period of time, richly pigmented worms. These types of decomposers are used in Vermicomposting. Eg. E.foetida, E.eugenia and P.excavatus

Ø Endogeic – types live underground and eat soil to extract nutrition from degraded organic residues. They have intermediate life cycles with limited regenerative capacity and small to large in body size. They are geophagous. Eg. Octochaetona thurstoni

Ø Anecic – types burrow deep in the soil but come to the surface at night to drag food down in to their permanent burrows deep within the mineral layers of the soil. The body size slightly pigmented at anterior and posterior end. They are phytophagous in nature Eg. Lumbricus terrestris

Vermicompost

Vermicompost is an aerobically degraded organic matter. It is also called as “Black Gold”, it is a granular, aggregate, coated with muco-polysaccharides of microbes and earthworm. The vermicompost contains humified organic matter characterized by high molecular weight and an enzymatically active humic fraction, which stimulates plant germination and growth. The nutrient present in the casts are readily soluble in water and are rich sources of macro and micro nutrients, vitamins, enzymes, antibiotics, growth hormones and immobilized micro flora . Vermicompost is rich in available plant nutrients such as N, P, K, Ca, Mg, S and micronutrients like Fe, Zn, Mn, Cu etc. The Vermicompost has many more plant growth hormones and rich in saprophytic microorganisms.

Vermicomposting Methods

Ø Vermicomposting is the biological degradation and stabilization of organic waste by earthworms and microorganisms to form vermicompost. This is an essential part in organic farming today.

Ø It can be easily prepared, has excellent properties, and is harmless to plants. The earthworms fragment the organic waste substrates, stimulate microbial activity greatly and increase rates of mineralization.

Ø These rapidly convert the waste into humus-like substances with finer structure than thermophilic composts but possessing a greater and more diverse microbial activity.

Ø Vermicompost being a stable fine granular organic matter, when added to clay soil loosens the soil and improves the passage for the entry of air. The mucus associated with the cast being hydroscopic absorbs water and prevents water logging and improves water holding capacity.

Ø The organic carbon in vermicompost releases the nutrients slowly and steadily into the system and enables the plant to absorb these nutrients. The soil enriched with vermincompost provides additional substances that are not found in chemical fertilizers

Ø Vermicomposting offers a solution to tonnes of organic agro-wastes that are being burned by farmers and to recycle and reuse these refuse to promote our agricultural development in more efficient, economical and environmentally friendly manner.

Methods of Vermicomposting

1. Pits below the ground: Pits made for vermicomposting are 1 m deep and 1.5 m wide. The length varies as required.

2.Heaping above the ground

The waste material is spread on a polythene sheet placed on the ground and then covered with cattle dung. The efficacy of pit and heap methods of preparing vermicompost under field conditions was compared . Considering the biodegradation of wastes as the criterion, the heap method of preparing vermicompost was better than the pit method. Earthworm population was high in the heap method, with a 21-fold increase in Eudrilus eugeniae as compared to 17-fold increase in the pit method. Biomass production was also higher in the heap method (46-fold increase) than in the pit method (31-fold). Consequent production of vermicompost was also higher in the heap method (51 kg) than in the pit method (40 kg).

3.Tanks above the ground

Tanks made up of different materials such as normal bricks, hollow bricks, shabaz stones, asbestos sheets and locally available rocks were evaluated for vermicompost preparation. Tanks can be constructed with the dimensions suitable for operations. The tanks with dimensions of 1.5 m (5 feet) width, 4.5 m (15 feet) length and 0.9 m (3 feet) height. The commercial bio-digester contains a partition wall with small holes to facilitate easy movement of earthworms from one tank to the other.

4.Cement rings

Vermicompost can also be prepared above the ground by using cement. The size of the cement ring should be 90 cm in diameter and 30 cm in height. The details of preparing vermicompost by this method have been described in a later section.

5.Commercial model

The commercial model for vermicomposting consists of four chambers enclosed by a wall (1.5 m width, 4.5 m length and 0.9 m height). The walls are made up of different materials such as normal bricks, hollow bricks, shabaz stones, asbestos sheets and locally available rocks. This model contains partition walls with small holes to facilitate easy movement of earthworms from one chamber to another. Providing an outlet at one corner of each chamber with a slight slope facilitates collection of excess water, which is reused later or used as earthworm leachate on crop. The four components of a tank are filled with plant residues one after another. The first chamber is filled layer by layer along with cow dung and then earthworms are released. Then the second chamber is filled layer by layer. Once the contents in the first chamber are processed the earthworms move to chamber 2, which is already filled and ready for earthworms. This facilitates harvesting of decomposed material from the first chamber and also saves labor for harvesting and introducing earthworms. This technology reduces labor cost and saves water as well as time

Wastes utilized in vermitechnology

Ø Earthworms can be fed easily on different forms of non toxic organic waste foods produced in the nature. The common wastes produced by the forests, agriculture and urban areas are mainly abundant organic wastes.They include kitchen wastes, vegetable market wastes, sewage sludge, garden wastes, animal excreta, weeds coir wastes, leaf litter, paper and pulp wastes, feed and fodder wastes and aquatic biomass .

Ø The disposal of these organic wastes in an unscientific manner causes many problems such as fly breeding, pig menace, transmission of pathogens, soil and air pollution, surface and ground water pollution, irritating odour. The lack of awareness, co-operation among people and even shortage of funds by state and central Governments are the main causes of improper disposal of solid waste management especially in urban areas .

Ø The biologically degradable and decomposable organic wastes can be commonly used as composting materials in vermitechnology are

· Animal dung: Cattle, sheep, horse, goat, poultry wastes etc.

· Agricultural wastes: Agri-wastes obtained during and after harvesting and threshing

· Forestry wastes: Wood shavings, peels, saw dust and pulp etc.

· City garbage and leaf litter: Kitchen wastes and leaf litter of street plants and residential areas.

· Paper and cotton industry wastes: Wastes generated from paper and cotton cloth industry

· Biogas slurry: After the recovery of biogas, slurry is used.

· Industrial wastes: Wastes from food processing industries like dal mill, rice mill etc.

Vermiwash

Ø Vermiwash is a liquid that is collected after the passage of water through a column of worm action and is very useful as a foliar spray. It is a collection of excretory products and mucus secretion of earthworms along with micronutrients from the soil organic molecules. These are transported to the leaf, shoots and other parts of the plants in the natural ecosystem.

Ø Vermiwash, if collected properly, is a clear and transparent, pale yellow coloured fluid . Vermiwash, a foliar spray, is a liquid fertilizer collected after the passage of water through a column of worm activation.

Ø It is a collection of excretory and secretory products of earthworms, along with major micronutrients of the soil and soil organic molecules that are useful for plants. Vermiwash seems to possess an inherent property of acting not only as a fertilizer.

Ø It is found to contain a number of enzymes viz. proteases, amylases, urease and phosphatase, soluble plant nutrients, organic acids and mucus of earthworms and microbes.

Ø Role of earthworms in Organic Waste Management

Ø Earthworms not only act in the soil as aerator, grinders, crushers, chemical degrader and biological stimulators. They also secrete many more enzymes namely proteases, lipases, amylases, celluloses and chitinases, which brings about rapid biochemical conversion of the cellulosic and proteinaceous materials of various organic wastes and in fast recycling of available plant materials.

Ø Earthworm create aerobic conditions in the waste materials inhibiting the activity of anaerobic microorganisms, which can cause foul smell. Further, earthworms release coelomic fluid in the decaying organic materials, which have antibacterial properties that kills pathogens in the produced vermicompost [23].

Ø In recent years, disposal of organic wastes from various sources like domestic, agriculture and industrial has caused serious environmental hazards and economic problems. Burning of organic wastes contributes tremendously to environmental pollution thus, leading to polluted air, water and land. This process also releases large amounts of carbon dioxide in the atmosphere, a main contributor to global warming together with dust particles.

Ø Burning also destroys the soil organic matter content, kills the microbial population and affects the physical properties of the soil [24]. It has been demonstrated that earthworms can process household garbage, city refuse, sewage sludge and waste from paper, wood and food industries. In tropical and subtropical conditions Eudrilus eugeniae and Perionyx excavatus are the best vermicomposting earthworms for organic solid waste management [7].

Ø The use of earthworms in composting process decreases the time of stabilisation of the waste and produces an efficient bio-product, i.e., vermicompost. Organic farming system is gaining increased attention for its emphasis on food quality and soil health.

Ø Vermicompost and vermiculture associated with other biological inputs have been actually used to grow vegetables and other crops successfully and have been found to be economical and productive [12,25,26]. In this regard, recycling of organic waste is feasible to produce useful organic manure for agricultural application.

Ø Compost is becoming an important aspect in the quest to increase productivity of food in an environmentally friendly way.Compost is becoming an important aspect in the quest to increase productivity of food in an environmentally friendly way.

Ø Both the sugar and rice industries burn their wastes thereby, contributing tremendously to environmental pollution thus, leading to polluted air, water and land. This process also releases large amounts of carbon dioxide in the atmosphere, a main contributor to global warming together with dust particles.

Ø Burning also destroys the soil organic matter content, kills the microbial population and affects the physical properties of the soil. Therefore organic farming helps to provide many advantages such as; eliminate the use of chemicals in the form of fertilizers/pesticides, recycle and regenerates waste into wealth; improve soil, plant, animal and human health; and creating an eco-friendly, sustainable and economical bio-system models.

Ø Earthworms can consume large quantity of organic wastes rapidly and process them through gizzard and microorganisms so as to excrete vermicasts. Thus, treatment of any non toxic organic wastes by Vermitechnology is not only reduces pollution, eliminating pathogenic diseases but also produces a valuable product immense to agriculture; hence, vermitechnology is called „wealth from wastes‟.

Ø Environmental Hazards are compounded by accumulation of organic waste from different sources like domestic, agricultural and industrial wastes that can be recycled by improvised and simple technologies. Vermicompost could be effectively used for the cultivation of many crops and vegetables, which could be a step towards sustainable organic farming.

Ø All vermiculture technologies – vermicomposting (for solid waste management), vermifiltration (for wastewater treatment), vermiremediation (for land and soil decontamination) and vermiagro production (use of vermicompost for farm production) can be used as most economical and sustainable alternatives to some of the „environmentally unfriendly‟ civil engineering methods to achieve those objectives of development while also significantly reducing waste and pollution and the emission of green house gases (GHG).

Ø Earthworms are truly justifying the beliefs and fulfilling the dreams of Sir Charles Darwin who called them as „unheralded soldiers‟ of mankind and „friends of farmers‟ and said that “there may not be any other creature in world that has played so important a role in the history of life on earth”.

Ø Such technologies in organic waste management would lead to zero waste techno farms without the organic waste being wasted and burned rather then would result in recycling and reutilization of precious organic waste bringing about bioconservation and biovitalization of natural resources

WASTE RECYCLING AND MANAGEMENT

Ø Three possible strategies are available to dispose or reutilize any waste or residue produced by human activities; they are incineration, sanitary landfill and recycling. Disposal of waste by incineration allows energy recovery so that theoretically after the initial supply of fuel, however, disposal is more apparent than actual, because incineration reduces the volume of waste substantially, but not the mass.

Ø Also, the risk of pollution from the emission to the atmosphere cannot be neglected. Landfill is another technology which can appear morefascinating in which wastes are disposed without apparent difficulties in appropriately selected areas and at the end their volume may be utilized to remodel the areas themselves. The first obstacle arises from the relative low availability of suitable land surface.

Ø Another great difficulty is caused by the slow evolution of the landfill caused by the transformation of the disposed materials; landfills undergo slow and continuous bedding along the years, variations of volume, emission of gases to the atmosphere in the short term and leakage of potentially harmful percolates in the medium and long term. Recycling is in general the most difficult practice to face the problem.

Ø For this reason is not popular as one could expect. On the other hand, recycling that prevents the existence of waste itself is the only totally sustainable strategy dealing with the problems of waste.

Ø Recycling transforms any material or complex of materials which actually become wastes if their owner should get rid of them, in useful materials or even commercial products. Recycling of organic residues may give foods, feeds, fertilizers and many other useful materials.

Ø Composting and vermicomposting, like other recycling technologies of wastes avoids the existence of many categories of wastes which are probably the more important from a quantitative point of view. The role of vermicomposting in waste management is to be a productive option for the treatment and disposal of biodegradable waste.

Ø Approximately 60% or more of household waste is of an organic type that could be recycled using vermiculture. Food discards account for 5% to 10% of the overall municipal solid waste stream (exclusive of industrial discards) and offers a huge opportunity for recovery of value from materials otherwise destined for disposal as waste. Governments have committed to reducing the amount of waste going to landfill. There are thus environmental, economic and (increasingly) regulatory reasons for an increase in demand for compost worms.

Ø Such systems require significant investments of capital up front. Their commercial ability depends in part on what payments a producer of waste will pay for this form of waste management, as well as what price can be obtained for the vermicast and associated products that comes out at the end of the process

SOLID WASTE MANAGEMENT

Solid wastes are produced in enormous quantities from industries like breweries, distilleries, sugar industries, food industries, agro-based industries, dairy industries etc. Management of these wastes and their disposal is a major problem. Wastes if not managed scientifically pose a sequel of environmental and health hazards. Considering these wastes as the misplaced resource they can be scientifically managed by biodynamic composting and vermitechnology transforming them into a marketable value added product.

Biodynamic Composting

Ø Biodynamic composting is biological conversion of biodegradable wastes under controlled conditions into a hygienic, humus rich relatively bio-stable product that improves land and fertilizes plants. A set of six special fermented European Herbal Preparations is used in composting to bring in the proper degradation of the waste materials.

Ø These preparations are a source of beneficial microorganisms, which degrade the waste material into very fine humus like manure. The important feature of this composting method is the controlled fermentation/degradation due to the presence of the biodynamic preparations. This results in production of enriched compost with desired specifications and devoid of phytotoxicity. The end product, enriched manure is safe to use in agriculture and horticultural practices.

Ø Biodynamic composting method comprises two phases viz., breakdown phase and build. In the breakdown phase biodegradable wastes are decomposed into smaller particles. Proteins are broken down into amino acids and finally to ammonia, nitrates and free nitrogen.

Ø Similarly, urea, uric acids and other non-protein nitrogen-containing compounds are reduced to form different plant nutrients. The biodynamic preparations contain a balanced consortium of the most favorable breakdown organisms, ammonifers, nitrate formers, cellulose, sugar, and starch digesters in order to bring about the desired results. These biodynamic preparations also work against organisms that cause putrefaction and odour.

Ø In the build-up phase, the biodynamic preparations activate the re-synthesis of simple compounds into complex humic substances. The organisms responsible for transformation to humus are aerobic and facultative aerobic, sporing and non-sporing and nitrogen fixing bacteria of the Azotobacter and Nitrosomonas group. Actinomycetes also play an important role. The development of the humus is evident in colour, changes in the compost, and through qualitative tests such as the 'Circular chromatography' method. Extensive research has developed pragmatic and specific technologies to compost a variety of wastes generated from different agricultural and industrial sources.

Ø The research on the use of biodynamic preparations also reveals that the biodynamic composting method develops higher temperature, matures faster and has higher nitrates than other conventional methods. The biodynamic compost supports the growth of heterotrophic microflora, enhances microbial activity in the soil and increases different types of soil microorganisms.

WASTE WATER MANAGEMENT

Ø Water pollution in surface or groundwater that adversely affect the humans, animals, aquatic biota and the living environment as a whole has become a challenging problem all over the world.

Ø In urban areas, most water borne wastes from households, hotels, hospitals, industries and other such establishments flow through a network of sewage pipes and ultimately reach to open water bodies and nearby lands. Disease-causing agents, traces of various toxic organic and inorganic compounds and radioactive substance present in thewater sources are the major threats to human health.

Ø Economic loses occur when water is too polluted to put in various uses. Hence, there is a pressing need to adopt adequate control measures to treat the waste water before being discharged to water bodies and land areas.

Vermicompost as Biofilter

Keeping the efficiency of drainage system which is the main problem in managing sanitary landfills; failure of leachates collection system is mainly caused by biofouling (formation of insoluble, consolidated deposits and incrustations). vermicompost can act as a buffering material limiting the acid phase and enhancing waste biostabilization. Another possible advantage of using compost as biofilter could be the removal of heavy metals from leachates due to adsorption or complexation phenomena.

Vermi-filter for Sewage Treatment

Ø Water contamination due to industrial activities now is widely recognized as a potential threat to public and the environment. Both industrialized and developing countries are facing serious problems associated with contamination due to toxic and hazardous wastes.

Ø Vermifilter that involves land treatment and vermitechnology has shown its promise in purifying municipal wastewater. The land treatment mechanism includes complex physical, chemical and biological interaction operating together.

Ø During the treatment, sewage sludge so settled are removed and processed through anaerobic digestion or composting. In vermifilter, the surface portion of the vermibed containing worm cast and suitable species of earthworms can enhance the process of bacterial decomposition of organic mater present in the waste water, thereby enhancing the rate of waste conversion to manure.

Ø Some high water consuming ornamental plants can be grown on the vermi bed to minimize the nutrient content of wastewater. Evaluation of characteristics of water from inlet and outlet of vermin-filter bed shows almost 80-90% reduction in nitrate, 60-70% in phosphate and 80% reduction in biochemical oxygen demand. Thus in this method earthworm cast microorganism-soil perform the physical, chemical and biological activities and reduce the inorganic and organic load in water to the acceptable limit.

WASTE MANAGEMENT FOR SUSTAINABLE DEVELOPMENT

Ø Sustainable development has been defined in 1987 in the Report of the World Commission on Environment and Development (The Brundtland Report) as „development, which meets the needs of the present without compromising the ability of future generations to meet their own needs‟. This report identified the characteristics of sustainable development as; the maintenance of the overall quality of life, maintenance of continuing access of natural resources and avoidance of lasting environmental damage.

Ø Vermitechnology represent a valuable opportunity for waste management. Organic materials suitable for such management arise from many industrial processes, such as food production and processing, brewing and paper, leather, wool and textile production. A large proportion of municipal solid waste (MSW) also consists of biodegradable material, which can also be treated biologically. Vermitechnology, therefore, provides a promising tool to treat a significant proportion of both municipal and other solid wastes. It also acts as a pretreatment of solid waste prior to final disposal (Ernst, 1990).

ENVIRONMENTAL BENEFITS

Ø In addition to being a respectable, profitable business, worms are asset for our environment. By consuming organic waste and eating up to their own weight daily, these little creatures offer an alternative to taking all our waste to landfills. This small act will certainly help and promote recycling. Worms eat anything that was once living.

Ø They consume household food waste, cardboard, paper, newspaper, old phone books, composted green waste, vegetables, fruits, paper, coffee grounds, and the paper filter, egg shells and any leftovers go in the garbage, and they have no diseas.

Ø While cutting down the volume of waste going to our landfills and helping Mother Nature, there is also the business side of becoming a worm farmer.

Ø Prevention of soil pollutants and clean up of contaminated soil have become a worldwide environmental priority. Composting has been used to remove pollutant compounds from organic wastes, while generating organic matter for soil directly usable for in-situ bioremediation. Composting food discards aerobically can result in many environmental toxicity benefits by reducing the chemical reactions that occur as food discards break down in landfills and other waste treatment systems.

Ø Composting results in reductions in methane and leachate generation. Methane is a flammable gas that must be managed when generated. Leachate generated in landfills must be treated and disposed of properly. Odors and leachate in solid waste compactors and dumpsters, where health concerns can arises.

Ø Vermitechnology provides a viable option for pre-treatment of different types of environmentally hazardous waste materials before and after their disposal in the following way

Volume reduction

Breakdown into methane and/or carbon dioxide and water can result in decomposition of upto 75% of the organic material on a dry weight basis. On a wet-weight basis, the weight loss is of the order of 50%. As paper, food and garden waste together can produce upto 80% of MSW, the potential for reducing the volume of landfill required for final disposal is considerable.

Stabilization

Since much of the decomposition has occurred during the biological treatment the resulting material is considerably more stable than the original waste. If subsequently landfilled, this material will produce less landfill gas and leachate than the original waste, so alleviating potential problems elsewhere in the waste management system.

Vermicompost as Covering Material

Daily covering of waste is recommended by the current management procedure of sanitary landfilling in order to avoid dispersion of light fraction (paper, plastics) and feeding of animals (rats, birds). Daily covering leads to several disadvantages such as loss of volume for waste disposal and high cost if the material is not available near the facility. Moreover, field experience has shown that the main problems derive from the utilization of low permeability soil as covering material; in this case the landfill is divided into many hydraulically insulated ‘pockets’ where leachates and biogas accumulate. Consequences are: difficulties in draining leachate and biogas, side and surface escape of leachates and biogas.

CONCLUSION

Ø Rapid environmental degradation due to several human activities poses a greater threat to the living environment all over the world. The phenomenon is more pronounced in the developing countries due to the high demographic pressure, growing rural exodus and urbanization.

Ø In recent years, an interest has arisen concerning the possibility of using decomposer organisms, mainly earthworms to process waste materials by clean technologies that minimize environmental pollution.

Ø The potential of vermitechnology in reduction of noxious organic wastes, recycling and management of organic wastes, production of high value fertilizer and protein for food and feed have bas been well established.

Ø In the optic of sustainability policy, the bioremediation of organic wastes is a technology that avoids the existence itself of many categories of wastes transforming them into food, feeds and soil conditioners. The use of bioremediated organic wastes is a primary need more for human society than for agriculture.

Ø The nutrient cycles that occur in the soil and assure the life on our planet are more and more compromised by the human activities. Giving back to soil that comes from soil can be a suitable mean to contrast soil diseases and restore the equilibrium.

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