Impact of Food Waste Co-digestion Operational Conditions on Microbial Communities

摘要

Thirteen lab-scale mesophilic digesters were operated for 100 days at an SRT of 15 days and different organic loading rates of 2-4 kgCOD/m~3/day to investigate the effect of food waste (FW) co-digestion on the microbial community. Compared with mono-digestion of municipal sludges, FW co-digesters produced more biogas by 13%. Bacteroidetes and fermentative bacteria were more abundant in FW digesters than municipal sludge digesters while the relative abundance of Clostridium and syntrophs in FW digesters were lower than municipal sludge digesters. The abundant methanogens were Methanosarcina in the FW digesters and Methanosaeta in the municipal sludge digesters. Methane product rate was correlated with Bacteroidetes, Firmicutes, Syntrophs, fermentative/acetogenic bacteria, and aceticlastic methanogens for municipal sludge digesters and Bacteroidetes, Clostridium, and aceticlastic methanogens for FW digesters. The synergism was related to the enhanced activity of hydrolytic bacteria, Clostridium, Syntrophomonas, syntrophs, Methanosarcina, and Methanobacterium.