Synergistic improvement of short-chain fatty acid production from waste activated sludge via anaerobic fermentation by combined plasma-calcium peroxide process

Nan Jiang; Jinling He; Ai Zhang; Yongquan Zhou; Ming Zheng; Xianbao Xu; Andere Clement Miruka; Xiang Li; Yanan Liu; Gang Xue

doi:10.1016/j.biortech.2022.127754

Synergistic improvement of short-chain fatty acid production from waste activated sludge via anaerobic fermentation by combined plasma-calcium peroxide process

Bioresour Technol. 2022 Oct:361:127754. doi: 10.1016/j.biortech.2022.127754. Epub 2022 Aug 9.

Authors

Nan Jiang¹, Jinling He¹, Ai Zhang², Yongquan Zhou¹, Ming Zheng³, Xianbao Xu¹, Andere Clement Miruka⁴, Xiang Li¹, Yanan Liu¹, Gang Xue¹

Affiliations

¹ College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China.
² College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China; Shanghai institute of pollution control and ecological security, Shanghai 200092, China. Electronic address: aizhang@dhu.edu.cn.
³ Department of Civil & Environmental Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada; Key Laboratory of Organic Compound Pollution Control Engineering, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China.
⁴ College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China; School of Chemistry and Material Science, Technical University of Kenya, Nairobi 52428-00200, Kenya.

PMID: 35952862
DOI: 10.1016/j.biortech.2022.127754

Abstract

In this study, the combination of dielectric barrier discharge plasma (DBD) with calcium peroxide (CaO₂) achieved significant synergistic effects in promoting hydrolysis of waste activated sludge (WAS) and short-chain fatty acid (SCFA) production during anaerobic fermentation. Compared with the control, DBD/CaO₂ pretreatment increased SCFA production by 116 %, acetic acid ratio by 39 %, and sludge reduction by 30 % under the optimal conditions (discharge power = 76.5 W, CaO₂ dosage = 0.05 g/g VSS). Mechanism investigations elucidated that DBD/CaO₂ enhanced the generation of •OH, ¹O₂, and •O₂^-, synergistically promoted decomposing extracellular polymeric substances (EPS), lysing cells, releasing biodegradable substances, and enhancing acetic acid-enriched SCFA accumulation from fermentation. Meanwhile, Illumina MiSeq sequencing analysis revealed that the enrichment of hydrolytic and SCFAs-forming bacteria and the decrease in SCFAs-consuming bacteria by DBD/CaO₂ treatment also contributed. This work provides an effective method to boost the SCFA production from WAS fermentation.

Keywords: Anaerobic fermentation; Calcium peroxide (CaO(2)); Non-thermal plasma; Reactive species; Sludge pretreatment.

MeSH terms

Anaerobiosis
Fatty Acids, Volatile*
Fermentation
Hydrogen-Ion Concentration
Peroxides
Sewage*

Substances

Fatty Acids, Volatile
Peroxides
Sewage
calcium peroxide