Environmental Pollution ( IF 6.792 ) Pub Date : 2020-11-20 , DOI: 10.1016/j.envpol.2020.116030 Dong Feng; Ao Xia; Qiang Liao; Abdul-Sattar Nizami; Chihe Sun; Yun Huang; Xianqing Zhu; Xun Zhu
The anaerobic digestion of wastewater rich in volatile fatty acids (VFAs) provides a sustainable approach for methane production whilst reducing environmental pollution. However, the anaerobic digestion of VFAs may not be stable during long-term operation under a short hydraulic retention time. In this study, conductive carbon.
cloth was supplemented to investigate the impacts on the anaerobic digestion of VFAs in wastewater sourced from dark fermentation. The results demonstrated that the failure of anaerobic digestion could be avoided when carbon cloth was supplemented. In the stable stage, the methane production rate with carbon cloth supplementation was improved by 200-260%, and the chemical oxygen demand (COD) removal efficiency was significantly enhanced compared with that in the control without carbon cloth. The relative abundance of potential exoelectrogens on the carbon cloth was increased by up to 8-fold compared with that in the suspension. Electrotrophic methanogens on the carbon cloth were enriched by 4.2-17.2% compared with those in the suspension. The genera Ercella and Petrimonas along with the methanogenic archaea Methanosaeta and Methanosarcina on the carbon cloth facilitated direct interspecies electron transfer, thereby enhancing methane production.