Enhancing anaerobic fermentation of waste activated sludge by investigating multiple electrochemical pretreatment conditions: Performance, modeling and microbial dynamics

• Published in: Bioresource technology Vol. 368; p. 128364
• Main Authors: Xi, Shihao, Dong, Xinlei, Lin, Qingshan, Li, Xiang, Ma, Jie, Zan, Feixiang, Biswal, Basanta Kumar, Awasthi, Mukesh Kumar, Wang, Zongping, Chen, Guanghao, Guo, Gang
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2023
• Subjects: Acidogenic fermentation; Current intensity; Electrolyte dosage; Pretreatment time; Volatile fatty acids; Pretreatment time; Acidogenic fermentation; Volatile fatty acids; Current intensity; Electrolyte dosage
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2022.128364

[Display omitted] •Impacts of EPT on anaerobic fermentation of WAS was studied.•EPT considerably enhanced VFAs production by 51.6%.•Rise of VFAs production was related to the reactive chlorine species generation.•Fermentative bacteria included Lactobacillus, Saccharimonadales and Tetrasphaera.•Economic assessment shows practical applicability of EPT technology. Electrochemical pretreatment (EPT) is an efficient technology to improve volatile fatty acids (VFAs) production during anaerobic fermentation of waste activated sludge (WAS). This study investigated the co-effects of different current intensities, electrolyte NaCl dosage and pretreatment time for promoting VFAs production. The results showed that it was considerably enhanced by 51.6 % when EPT was performed at 1.0 A, 1.0 g/L and 60 min, and response surface methodology strategy adjusted the optimal EPT conditions to 1.0 A, 1.2 g/L and 66 min. The potential mechanisms were proposed that EPT at optimal conditions greatly enhanced solubilization and hydrolysis of WAS and selectively inactivated methanogens, causing the enrichment of acidogenic bacteria (i.e., Lactobacillus, Saccharimonadales, Tetrasphaera and Prevotella) due to generated reactive chlorine species. Finally, the economic analysis indicated the promising application potential with the profit of EPT at optimal conditions increasing by 36.0 %.