Effect of Bacterial Agent Addition Ratio on Anaerobic Fermentation of Kitchen Waste

Anaerobic fermentation of kitchen waste was studied under different ratios of bacteria. Results showed that when ratio of bacterial agent to kitchen waste was 2:1, pH change was the most obvious．At 24 hours, the pH decreased to the lowest of 5.2, and at 36 hours, the pH increased to the highest of 6.2．The overall change trend of VFA content and pH change showed the opposite．Cumulative yield of biogas and methane content was always in the highest position, 48.74 L and 70.25%, respectively, and amount of COD showed the opposite trend．An appropriate amount of bacterial agent could promote anaerobic fermentation reaction．If it exceeded a certain amount, it would have an inhibitory effect．In conclusion, when bacterial agent addition ratio was 2:1, anaerobic fermentation efficiency of kitchen waste was high．