Pilot Plant Study on Combined Treatment of Kitchen Refuse and Domestic Sewage By Anaerobic Digestion

摘要

Poor management of kitchen refuse and similar garbages represent the most serious urban environmental and public health problem. Poor waste management has dire environmental and public health consequences. Public health-wise, the presence of waste in residential areas, markets, roadsides, etc. poses grave health hazards to people, in general, and children in particular. The kitchen refuse from hotels, big hostels and residential colonies can be effectively disposed off by anaerobic digestion. Pilot scale model of 500-litre capacity anaerobic digester was operated using kitchen refuse from the students hostel as a feed stock material. Digester performance was monitored by measuring daily pH and gas production. When the steady state was obtained, it was loaded with 1.08 kg total solids with 18 litres of domestic sewage. On the 17th day the steady state was obtained and it was started with a loading rate of 2.3 kg VS/m~3 of digester volume and the gas production was 0.40 m~3/kg VS/day at an HRT of 25 days. The digester performance was 87% TS reduction, 95% VS reduction, 75% of COD reduction with percentage of methane gas as 75%. The probable volume of biogas would be 6.6 m~3/day if it is completely disposed with 50 kg at the rate of 0.4 m~3/kg VS. This gas could serve 38 persons per day at the rate of 0.227 m~3/person/day.