Abstract
The dependence of CH4 gas production on digester temperatures and volatile solid (VS) loading rates was investigated. Erlenmeyer flasks with a 1×10-3m3 capacity were used as digesters. Liquid fraction, after the solid-liquid separation of dairy cattle manure, were digested by semi continuous operation under the conditions of the temperatures of 20, 30, 35, 40 and 48°C, VS loading rates of 3.0, 6.6, 10.2, 14.8 and 21.9kg-VS·m-3·day-1, and manual shaking of flasks twice a day. CH4 gas production rates were measured by using floating cap type gas holders. The results were as follows;
(a) The dairy cattle manure should be digested at a digester temperature of approximately 40°C.
(b) The liquid fraction was digested better with a higher VS loading rate contrary to conventional values.
