C / N ratio of the substrate to the impact on biogas generation in food waste and sewage sludge co-digestion

Abstract

The Batch style anaerobic digestion (AD) experiment was used to assessment on a volatile solid (VS) basis the anaerobic biodegradability of food waste (FW), sewage sludge (SS), and then mixtures with ratios of 0:100, 20:80, 40:60, and 60:40 (FW: SS). This paper shows that the anaerobic co-digestion method, mixing ratio of SS with FW, and the (carbon/nitrogen) C / N ratio is a significant issue in the production of biogas. As the FW ratio of the blend with SS improved from 0, 20, 40, and 60 % respectively, the C / N ratio of the mixtures improved from 5.3, 13.6, 21.4, and 32.5. The results show that co-digestion in the digester fed with a combination of 40:60 (FW: SS) achieve improved in the C / N ratio on 21.4 and the highest biogas generation was 98.9 ml/g.