Enhancing methane production from anaerobic digestion of secondary sludge through lignosulfonate addition: Feasibility, mechanisms, and implications

Zhenyao Wang; Xuan Li; Huan Liu; Ting Zhou; Jibin Li; Muhammad Ahmar Siddiqui; Carol Sze Ki Lin; Mohammad Rafe Hatshan; Siyu Huang; Julie M Cairney; Qilin Wang

doi:10.1016/j.biortech.2023.129868

Enhancing methane production from anaerobic digestion of secondary sludge through lignosulfonate addition: Feasibility, mechanisms, and implications

Bioresour Technol. 2023 Dec:390:129868. doi: 10.1016/j.biortech.2023.129868. Epub 2023 Oct 14.

Authors

Affiliations

¹ Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Ultimo, NSW 2007, Australia.
² Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Ultimo, NSW 2007, Australia. Electronic address: Xuan.Li@uts.edu.au.
³ School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China; Department of Civil and Environmental Engineering, Water Technology Center, Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, China.
⁴ School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
⁵ Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia.
⁶ Australian Centre for Microscopy and Microanalysis, The University of Sydney, NSW 2006, Australia.
⁷ Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Ultimo, NSW 2007, Australia. Electronic address: Qilin.Wang@uts.edu.au.

PMID: 37844805
DOI: 10.1016/j.biortech.2023.129868

Abstract

This study explores the feasibility of using lignosulfonate, a byproduct of the pulp and paper industry, to facilitate sludge anaerobic digestion. Biochemical methane potential assays revealed that the maximum methane production was achieved at 60 mg/g volatile solids (VS) lignosulfonate, 22.18 % higher than the control. One substrate model demonstrated that 60 mg/g VS lignosulfonate boosted the hydrolysis rate, biochemical methane potential, and degradation extent of secondary sludge by 19.12 %, 21.87 %, and 21.11 %, respectively, compared to the control. Mechanisms unveiled that lignosulfonate destroyed sludge stability, promoted organic matter release, and enhanced subsequent hydrolysis, acidification, and methanogenesis by up to 31.30 %, 74.42 % and 28.16 %, respectively. Phytotoxicity assays confirmed that lignosulfonate promoted seed germination and root development of lettuce and Chinese cabbage, with seed germination index reaching 170 ± 10 % and 220 ± 22 %, respectively. The findings suggest that lignosulfonate addition offers a sustainable approach to sludge treatment, guiding effective management practices.

Keywords: Biochemical methane potential; Lignosulfonate; One substrate model; Phytotoxicity tests; Secondary sludge.

MeSH terms

Anaerobiosis
Bioreactors
Feasibility Studies
Methane / metabolism
Sewage*
Waste Disposal, Fluid*

Substances

Sewage
lignosulfuric acid
Methane