Biogas production of food waste with in-situ sulfide control under high organic loading in two-stage anaerobic digestion process: Strategy and response of microbial community

A two-stage anaerobic digestion process utilizing food waste was investigated in this study, without any additive and co-digestion. Solid content, temperature and pH value were key controlling factors for hydrolysis, which results the optimized food waste hydrolysate with COD/VSfood waste of 2.67. Efficient biogas production was maintained in long-term operation (>150 d) without any additive, and methane production yields up to 699.7 mL center dot gVS(-1)center dot d(-1) was achieved under organic loading rate (OLR) of 31.0 gVS center dot d(-1). Methane production can be recovered (70.4 %) after temperature shock within 30 days. This study confirmed the possibility to establish two-stage food waste anaerobic digestion system under high organic load. pH, OLR, and temperature are key factors to maintain stable biogas production, while pH control was performed as a in situ sulfide control technology (75.8 % sulfide reduction). This study provides practical strategies for food waste utilization and decreasing carbon footprint.

Automated summary

This study investigated a two-stage anaerobic digestion process for food waste without any additives and co-digestion. The optimized food waste hydrolysate with COD/VSfood waste of 2.67 was achieved through controlling factors such as solid content, temperature, and pH value. Efficient biogas production was maintained in long-term operation without additives, with methane production yields up to 699.7 mL center dot gVS(-1)center dot d(-1) under an organic loading rate of 31.0 gVS center dot d(-1). Methane production could be recovered by 70.4% after a temperature shock within 30 days. The study confirmed the possibility of establishing a two-stage food waste anaerobic digestion system under high organic load and provided practical strategies for food waste utilization and carbon footprint reduction.