Depth-resolved microbial community analyses in the anaerobic co-digester of dewatered sewage sludge with food waste.

Abstract This study evaluated the impacts of FW addition on co-digestion in terms of microbial community. Anaerobic co-digestion (AcoD) reactors were conducted at gradually increased addition of food waste (FW) from 0 to 4 kg-VS m −3  d −1 for 220 days. Although no markable acidification was found at an OLR of 4 kg-VS m −3  d −1 , the unhealthy operation was observed in aspect of an inhibited methane yield (185 mL g −1  VS added ), which was restricted by 40% when compared with its peak value. Deterioration of digestion process was timely indicated by the dramatic decrease of archaeal population and microbial biodiversity. Furthermore, the cooperation network showed a considerable number of rare species (