Agricultural Waste

Agricultural Waste

The kitchen waste such as vegetables, fruits, poultry, meat, wood, leaves, tree branches, paper, cooking oil etc., fall under this category. All these material are biodegradable. However, the biodegradation time for each individual item may vary from one month to a few decades. Material like vegetables, fruits, meat, poultry etc., degrade very fast and wood, branches, paper will take a very long time. Science had mimicked nature and many methods of rapid degradation have been developed.

Normally, organic matter would take approximately 180 days to convert itself into compost through natural microbial reactions. This process is a continuous process and requires high level of oxidation. In the absence of oxygen, gases such as Hydrogen Sulphide evolve leading to unbearable odour in the air. Besides, H₂S is a toxic gas and at lower concentrations, it damages mucus membranes and also will lead to death. Apart from the above, H₂S is a highly flammable gas and sometimes lead to spontaneous combustion of the garbage. The microbial action of natural degradation gives rise to high temperatures inside the garbage often crossing beyond 70⁰C. This temparature aided by the presence of flammable gases leads to spontaneous combustions in garbage landfills. The ensuing smoke and ash particles lead to air pollution also.

Kusters Method

Keeping in view the above, various methods have been developed to convert the  organic matter into a compost quickly. Some of the methods include Vermiculture, bio-composting using lab cultured microbes etc. The older methods such as incineration are discouraged world-wide due to the increased air pollution, dioxins, Furans etc, in the air. Besides, the incinerators can not handle mixed garbage such as the kind we get in India. The methods such as Vermiculture, bio-composting are good. However, even these methods are time taking and the time for composting takes anywhere between 30 to 90 days.

With the garbage being dumped at a rate of 7000 tons per day, waiting for the organic material to get converted into composting is not feasible as more and more material is being dumped on the tract and continuous composting is not possible. Besides, methods like vermi composting requires vast open areas to convert the entire organic matter into garbage and our cities do not have the luxury of such vast spaces available.