Role of sulfate in regulating performance and metabolic mechanisms of bioelectrochemical up-flow anaerobic sludge blanket fed with methanolic wastewater

作者：Gao, Yijing; Chen, Bin; Li, Wanjiang; Han, Yule; Liu, Zhaobin; Sun, Yuwei; Zhuo, Guihua; Lu, Xueqin^*; Gadow, Samir Ibrahim; Hu, Weijie; Zhen, Guangyin

来源：JOURNAL OF CLEANER PRODUCTION, 2023, 430: 139714.

DOI：10.1016/j.jclepro.2023.139714

• Anaerobic granular sludge
• Bioelectrocatalysis
• Sulfate-containing methanolic wastewater
• Microbial community evolution

To investigate the impact of sulfate (SO42-) on the performance of bioelectrochemical up-flow anaerobic sludge blanket (BE-UASB), the COD/SO42- ratio of sulfate-containing methanolic wastewater was gradually decreased from 20 to 3. The results showed that BE-UASB maintained higher COD and SO42- removal (i.e., 91% and 70%, respectively) with methane production rate of 278.7 mL/L-reactor/d at COD/SO42- ratio from 10 to 5, ensuring efficient energy recovery. Sulfidogenesis enabled the sludge re-granulation while bioelectrocatalysis further contributed to the growth/proliferation of biomass with interwoven filaments, rods, and spherical microorganisms. 16 S rRNA gene analysis demonstrated that bioelectrocatalysis promoted the diversity of methane-producing archaea (MPA), including Methanomethylovorans, Methanosaeta, Candidatus_Methanofastidiosum, and Methanobacterium. Sulfate-reducing bacteria (SRB), mainly comprising G_norank_f_Syntrophobacteraceae, Desulfomonile, and Syntrophobacter, tended to be enriched on bioelectrodes, which not only eased the competition with MPA but also achieved simultaneous removal of COD and SO42- in synergy with MPA.