Effects of quaternary ammonium disinfectants on human pathogenic bacteria in anaerobic sludge digestion: Dose-response and resistance variation

Wan Yang; Yunfei Liang; Shengsen Wang; Chen Cai; Xiaozhi Wang; Xiaohu Dai; Xiang Chen

doi:10.1016/j.biortech.2024.131745

Effects of quaternary ammonium disinfectants on human pathogenic bacteria in anaerobic sludge digestion: Dose-response and resistance variation

Bioresour Technol. 2024 Nov 4:131745. doi: 10.1016/j.biortech.2024.131745. Online ahead of print.

Authors

Wan Yang¹, Yunfei Liang², Shengsen Wang³, Chen Cai⁴, Xiaozhi Wang⁵, Xiaohu Dai⁶, Xiang Chen⁷

Affiliations

¹ College of Environmental Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 225127, China; State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
² College of Environmental Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 225127, China.
³ College of Environmental Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 225127, China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, China. Electronic address: [email protected].
⁴ State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
⁵ College of Environmental Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 225127, China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, China.
⁶ State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China. Electronic address: [email protected].
⁷ YANGTZE Eco-Environment Engineering Research Center, China Three Gorges Corporation, Wuhan 430010, China; National Engineering Research Center of Eco-environment Protection for Yangtze River Economic Belt, Wuhan 430010, China.

PMID: 39505280
DOI: 10.1016/j.biortech.2024.131745

Abstract

Sewage sludge is a critical reservoir for biological pollutants, and its harmless disposal remains a major issue. Quaternary ammonium compounds (QACs) as typical household disinfectants are inevitably concentrated in sewage sludge, and have the potential to affect human pathogenic bacteria (HPBs) that remain poorly understood. This study found that the relative abundance of HPBs in digesters was decreased by 10 - 20 % at low QACs dose, but increased by 238 - 591 % at high QACs dose. Mechanistic analysis revealed that low QACs doses promoted functional hydrolytic/fermentative bacteria and their metabolism by stimulating extracellular polymeric substances secretion and enhancing resistance to QACs. Conversely, high QAC doses decreased microbial biomass and developed QACs and antibiotic resistance of HPBs by increasing cell membrane permeability and triggering oxidative stress, resulting in deteriorating sanitation performance. These findings provide advanced insights into the potential function and hazards of exogenous QACs on the biosafety of digestate.

Keywords: Anaerobic digestion; Biological pollutants; Quaternary ammonium compounds; Resistance genes; Sanitation performance.