Utilization of Continuous Anaerobic Digesters for Processing Cattle Dung and Cabbage (Brassica oleracea) Waste

Abstract

The purpose of this work is to explore the addition of cabbage (Brassica oleracea) waste interspersed with cattle dung into a continuous anaerobic digester that normally uses cattle dung as a substrate. In this work, a 200-L continuous anaerobic digester was operated to conduct the research. The digester was filled fully with a mixture of cattle dung and water (50%:50%). The digester was then operated by continuously adding a 5-L mixture of cattle dung and water (50%:50%) every day for 1 month. Subsequently, the digester was operated for 1 month with an additional 5-L mixture of cabbage waste and water (50%:50%) for odd-numbered days and a mixture of cattle dung and water (50%:50%) for even-numbered days. The methane composition was higher (in the range of 41–78%) with only the cattle dung in the system. With the addition of cabbage waste, the methane composition became lower (in the range of 20–60%).