Insights into the phenol disinfectant on the methane performance from wastewater by mesophilic anaerobic digestion: Single and two stages analysis

Abstract

In this study, the effect of different phenol disinfectant concentration on wastewater anaerobic digestion was indicated. The results indicated that the cumulative methane production decreased with the increase in the concentration of phenol disinfectant. The difference in the cumulative methane yield from disinfectants at concentrations of 0.04 mL/L, 0.2 mL/L, 0.4 mL/L and 0.8 mL/L was not significant (P ≥ 0.05). However, the disinfectant concentration of 1.6 mL/L and 2.4 mL/L caused a decrease in methane yield by 69.98% (P < 0.05) and 100% (P < 0.05), respectively. The addition of phenol disinfectant led to the accumulation of volatile fatty acids (VFA), affected the secretion of extracellular polymeric substances (EPS) and the construction of anaerobic sludge. With the increase in disinfectant concentration, the activity of acetate kinase and coenzyme F420 were decreased. Furthermore, microbial community analysis indicated that the dominant bacteria were Firmicutes, Chloroflexi, Actinobacteria and Proteobacteria. The addition of disinfectant inhibited the growth of Methanosaeta and Methanobacterium. In addition, the high concentration of the disinfectant inhibited acidification and methanation process during the anaerobic digestion (AD) process and the inhibition was stronger in the methanation stage than in the acidification stage.