Abstract
Continuous operation treating 100 g·L-1 total solids (TS) simulated food waste was investigated using a novel methane fermentation reactor that enables the agitation of the fermentation liquid without electricity. In this study, the overall performance and reaction attributes of the reactor were evaluated. Under mesophilic condition and at different chemical oxygen demand (CODCr) loading rates (5 to 10 kg·m3·d-1), the reactor achieved 220 days of stable continuous operation. Inside the reactor, the continuous change in the liquid level and the 5 to 16 times self-agitation occurred daily, which was likely responsible for the distribution of organic load near the inlet port of the reactor. The reactor attained 0.72-0.82 m3·g-1-TS biogas production yield and 79.4-85.5% CODCr reduction on average, and a small amount of volatile fatty acid (VFA) was detected in the effluent. These results suggest that the novel reactor investigated is comparable in biogas production yield and CODCr reduction and superior in residual VFA level to the completely stirred tank reactor, in the treatment of same simulated food waste used in a previous study.
