Enhancing the Production of Biogas through Anaerobic Co-Digestion of Commercial and Animal Wastes

With the expansion of commercial centers such as hotels, restaurants, markets, etc., the amount of waste generated by these institutions has become an important challenge in large cities. On the other hand, the application of new biotechnologies to convert biodegradable waste into valuable materials such as biogas and other biofuels is increasing dramatically. The aim of this study was to investigate the potential of biogas production from a mixture of cow dung and restaurant wastes using an anaerobic bioreactor. Operational parameters such as pH, Carbon to Nitrogen ratio (C/N), mixing ratio of restaurant and cow wastes 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 mixing of restaurant and cow wastes showed the best mixing ratio, total solid and temperature were 70:30 (w/w), %20 and 55°C respectively, and biogas production yield and percent was obtained 5430 mL/day and %74.4 respectively. The ORP obtained in this study was -327 millivolt (mv), which indicates the appropriate conditions of the anaerobic process in biogas production and confirmation of methanogenesis.