Abstract

The increasing waste generation rate, high collection cost and dwindling financial resources are the major problems faced by most of the developing countries for efficient solid waste management. In some cities, the organic waste (market, municipal, household) are dumped indiscriminately or littered on the streets causing environmental deterioration. Biological processes such as composting followed by vermicomposting to convert vegetables waste (as valuable nutrient source) in agriculturally useful organic fertilizer would be of great benefit. Therefore this technique is studied in the present research work. A simple and potentially inexpensive Hydro Based Operating Bioreactor (HBOB) was developed for aeration and turning of plant biomass for efficient aerobic composting process. The composting process was done viz ambient, mesophilic, thermophilic and cooling down stages for a period of two weeks. After cooling stage, the partially decomposed material was used further as bedding for earthworms for vermicomposting. Experiments were conducted to determine the changes in the physicochemical parameters (pH, temperature, moisture content and C/N ratio). The dominant species of microorganisms at different temperatures during entire process of composting and vermicomposting were investigated. Self heating of the ingredients due to microbial activity occurred within the bioreactor at the thermophilic stage of the composting process. The vermicompost developed in the HBOB was found to have comparatively high value of nutrients such as calcium, sodium, magnesium, iron, zinc, manganese and copper which can serve as a natural fertilizer giving high yield of plants. The vermicomposting has proved very effective and efficient for developing compost from vegetable waste.

Key words: Waste management, composting; bioreactor, vegetable waste, earthworms, physico-chemical characterization.