AEROBIC CO-COMPOSTING OF AGRO-INDUSTRIAL AND MUNICIPAL SOLID WASTE

Abstract

A pilot scale experiment was carried out to minimize the problems of municipal waste (such as urban kitchen wastes-KW, tea waste-TW, eggshell-ES) and agroindustrial waste (such as poultry litter-PL, rice husk-RH, and saw dust-SD). Six square shaped bins with dimensions 0.95 m long 0.93 m wide and 0.83 m height (total volume of 0.733 m3 ) were used. The study was carried out in the research field of the Department of Crop Physiology and Ecology, Hajee Mohammad Danesh Science and Technology Dinajpur, Bangladesh. To observe the composting process and assess the compost quality, some physicochemical parameters (temperature, moisture content, electrical conductivity, organic matter, volatile solids, total solid, total organic carbon, total nitrogen, total phosphorus, potassium etc.) were measured at different phases of composting. The duration of composting period was 80-85 days. Physicochemical characteristics of the final product were Carbon and Nitrogen ratio:15.37-18.66%, Germination index: 110.89-137.77%, Total Kjeldahl Nitrogen: 1.38-1.43%, Organic Matter: 37.92-44.426%, Total Organic Carbon: 21.99-25.76%, Electrical Conductivity: 2713-3788 ppm and pH: 7.96-9.09). Municipal wastes were used in higher ratios (KW: RH: TW: PL: ES: SD=50:10:10:10:10:10) produce good quality compost. Moisture also played an important role in temperature evolution during composting. Based on experimental results, the problem of agro-industrial and municipal waste could be minimized by aerobic composting and it can be used in crop production. Nevertheless, composting duration and co-composting materials and their ratios are crucial factors that determine the quality of the final product. A full-scale compost unit could be designed based on the experimental results. Therefore, an urban area consisting of 500-600 families requires about 10-12 m 2 area to compost the entire annual kitchen wastes production.