An innovative alkaline protease-based pretreatment approach for enhanced short-chain fatty acids production via a short-term anaerobic fermentation of waste activated sludge

Heliang Pang; Xinlei Pan; Lin Li; Junguo He; Yanshi Zheng; Fangshu Qu; Yingqun Ma; Baihui Cui; Jun Nan; Yu Liu

doi:10.1016/j.biortech.2020.123397

An innovative alkaline protease-based pretreatment approach for enhanced short-chain fatty acids production via a short-term anaerobic fermentation of waste activated sludge

Bioresour Technol. 2020 Sep:312:123397. doi: 10.1016/j.biortech.2020.123397. Epub 2020 Apr 18.

Authors

Heliang Pang¹, Xinlei Pan², Lin Li², Junguo He³, Yanshi Zheng², Fangshu Qu⁴, Yingqun Ma⁵, Baihui Cui⁶, Jun Nan², Yu Liu⁷

Affiliations

¹ School of Civil Engineering, Guangzhou University, Guangzhou 510006, PR China; School of Environment, Harbin Institute of Technology, Harbin 150090, PR China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China. Electronic address: 15B927008@hit.edu.cn.
² School of Environment, Harbin Institute of Technology, Harbin 150090, PR China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China.
³ School of Civil Engineering, Guangzhou University, Guangzhou 510006, PR China. Electronic address: junguohe@263.net.
⁴ School of Civil Engineering, Guangzhou University, Guangzhou 510006, PR China.
⁵ Advanced Environmental Biotechnology Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore.
⁶ Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China; Advanced Environmental Biotechnology Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore.
⁷ Advanced Environmental Biotechnology Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.

PMID: 32526667
DOI: 10.1016/j.biortech.2020.123397

Abstract

This study reported a novel pretreatment approach with combination of alkaline protease (AP) and pH 10 for enhancing short-chain fatty acids (SCFAs) production from waste activated sludge (WAS). Through the AP-based pretreatment, WAS flocs were disintegrated with cell lysis, leading to release of biodegradable organic matters. At the external AP dosage of 5%, SCOD of 5363.7 mg/L (SCOD/TCOD = 32.5%) was achievable after 2-h pretreatment. More than 66% of SCOD was composed of proteins and carbohydrates. Considerable SCFAs of 607 mg COD/g VSS was produced over a short-term anaerobic fermentation of 3 days, which was 5.4 times higher than that in the control. Acetic and propionic acids accounted for 74.1% of the SCFAs. The AP-based approach increased endogenous protease and α-glucosidase activities, facilitating biodegradation of dissolved organic matters and SCFAs production. Such approach is promising for WAS disposal and carbon recovery, the produced SCFAs might supply 60% of carbon gap in wastewater.

Keywords: Alkaline protease; Short-chain fatty acids; Short-term anaerobic fermentation; Sludge solubilization; Waste activated sludge.

MeSH terms

Anaerobiosis
Bacterial Proteins
Endopeptidases
Fatty Acids, Volatile*
Fermentation
Hydrogen-Ion Concentration
Sewage*

Substances

Bacterial Proteins
Fatty Acids, Volatile
Sewage
Endopeptidases
alkaline protease