Anaerobic digestion of sulphate wastewater mediated by biochar
Chenxi Xu, Yongyu Ding, Jia‐Cheng Liu, Wenwen Huang, Qunpeng Cheng, Guozhi Fan, Juntao Yan, Shunxi Zhang, Guangsen Song, Bo Xiao
Abstract
In this paper, the influences of biochar on the anaerobic digestion of sulphate wastewater, including the COD removal rate, methane yield, intermediate products and the change of microbial community structure, were investigated. The results showed that sulphate could promote the anaerobic digestion with the SO42−/COD ratio increasing from 0 to 0.1, while the activity of MPB was inhibited, which led to the decrease of COD removal rate and methane yield with the SO42−/COD ratio increasing from 0.1 to 2. At 1 g biochar loading, 344.97 mL CH4/gCODremoval was obtained compared with the control group (220.70 CH4/gCODremoval) at 2 of SO42−/COD. Biochar could also reduce the secondary accumulation of NH4+–N and TVFA. Meanwhile, methanogenic microorganisms were selectively enriched especially for methanobacterium, methanosaeta and methanolinea, while the growth of SRB was inhibited with biochar addition.