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

Shihao Xi; Xinlei Dong; Qingshan Lin; Xiang Li; Jie Ma; Feixiang Zan; Basanta Kumar Biswal; Mukesh Kumar Awasthi; Zongping Wang; Guanghao Chen; Gang Guo

doi:10.1016/j.biortech.2022.128364

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

Bioresour Technol. 2023 Jan:368:128364. doi: 10.1016/j.biortech.2022.128364. Epub 2022 Nov 21.

Authors

Affiliations

¹ School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China.
² School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China; Faculty of Resources and Environmental Science, Hubei University, Wuhan 430062, China.
³ Department of Civil & Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China.
⁴ College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China.
⁵ School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China. Electronic address: ceguogang@hust.edu.cn.

PMID: 36423770
DOI: 10.1016/j.biortech.2022.128364

Abstract

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 %.

Keywords: Acidogenic fermentation; Current intensity; Electrolyte dosage; Pretreatment time; Volatile fatty acids.

MeSH terms

Anaerobiosis
Euryarchaeota*
Fermentation
Hydrolysis
Sewage*

Substances

Sewage