Quantitative and qualitative variations of effective parameters on biogas produced from mixed wastes in anaerobic digester: Bench scale

Abstract

Today, biogas production from municipal solid waste as one of the most important sources of energy supply in the world is increasing. In this study, the potential of biogas production from a mixture of cow dung and catering waste was investigated using a continuous flow anaerobic bioreactor with 60 litres at the Bench scale. Operational parameters such as pH, Carbon to Nitrogen ratio (C/N), mixing ratio of restaurant and cow waste in weight percentage (0:100, 50:50, 70:30, and 100:0), total solids (TS) (%5, %10 and %20), temperatures (35, 45 and 55°C) and oxidation-reduction potential (ORP) were evaluated. The results showed that the maximum yield and percent of the biogas produced from cow manure digestion separately was 1003 ml/day and %52.82. Digestion of the catering waste and cow manure as a mixture showed the best mixing ratio, total solid and temperature is 70:30 (w/w), %20 and 55°C respectively and biogas production yield and percent in this conditions was obtained 5430 ml/day and %74.4 respectively. The ORP obtained in this study is -327 millivolt (mv), which indicates the appropriate conditions of the anaerobic process in biogas production and confirmation of methanogenesis.