Biomethanation -A Promising Option For The Treatment Of Kitchen Waste

摘要

The production and disposal of large quantities of organic and biodegradable waste without adequate treatment result in widespread environmental pollution. The present disposal methods of solid wastes like open dumping, sanitary land-filling and composting always trigger primary, secondary and tertiary environmental impacts like ground-water contamination, odor problems and unexpected endemic diseases apart from incurring huge operation and maintenance costs. Wastes from kitchens, which are mainly organic in nature, form an integral part of the domestic wastes. Biological treatment of organic waste can be used to reduce the waste volume. Compared to the aerobic method, the use of anaerobic digesters in processing these waste streams provides greater economic and environmental benefits and advantages. Apart from treating the wastes, the methane produced from the biomethanation process can be used for beneficial purposes. Various disposal options for the putrescible wastes like kitchen wastes were assessed in this paper. Laboratory study was undertaken to assess the feasibility of anaerobic digestion of kitchen waste in terms of waste stabilization efficiency and net energy recovery. Single-stage digestion of kitchen waste was subjected to varying Organic Loading Rates (OLR) ranging from 1.5 kg Volatile Solids (VS) /m~3/day to 5.5 kg VS /m~3/day, with a common Hydraulic Retention Time (HRT) of 15 days. The optimum performance of the system was observed at an OLR of 4.5 kg VS /m~3/day in terms of pollutant removal efficiency and biogas production. The removal rates for Chemical Oxygen demand (COD) was 81% and the maximum production of the methane was 1.3 m~3 of methane/m~3 of the reactor volume per day.