Performance and mechanisms of zero valent iron enhancing short-chain fatty acids production during thermophilic anaerobic fermentation of waste activated sludge

Wanqing Ding; Xiumin Fan; Xu Zhou; Ruining Liu; Chuan Chen; Wenbiao Jin; Jing Sun; Xuan Li; Guangming Jiang; Huan Liu

doi:10.1016/j.scitotenv.2023.169025

Performance and mechanisms of zero valent iron enhancing short-chain fatty acids production during thermophilic anaerobic fermentation of waste activated sludge

Sci Total Environ. 2024 Feb 20:912:169025. doi: 10.1016/j.scitotenv.2023.169025. Epub 2023 Dec 4.

Authors

Wanqing Ding¹, Xiumin Fan², Xu Zhou³, Ruining Liu¹, Chuan Chen⁴, Wenbiao Jin¹, Jing Sun⁵, Xuan Li⁶, Guangming Jiang⁷, Huan Liu⁶

Affiliations

¹ State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, Guangdong 518055, China.
² Shenzhen Ecological and Environmental Intelligent Management and Control Center, Shenzhen 518034, China.
³ State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, Guangdong 518055, China. Electronic address: zhouxu@hit.edu.cn.
⁴ State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province 150090, China.
⁵ State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
⁶ Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Ultimo, NSW 2007, Australia.
⁷ School of Civil, Mining and Environmental Engineering, University of Wollongong, NSW 2522, Wollongong, Australia.

PMID: 38056647
DOI: 10.1016/j.scitotenv.2023.169025

Abstract

This work first explored the feasibility and possible mechanisms of zero valent iron (ZVI) pretreatment on the generation of short-chain fatty acids (SCFAs) during thermophilic anaerobic fermentation of waste activated sludge (WAS). Results showed that ZVI enhanced the quantity of SCFAs. On Day 6, the SCFAs production reached 455.84 ± 47.88 mg COD/g VSS at 5 g/L of ZVI addition, which increased by 63.80 % relative to control. The presence of ZVI can effectively promote butyric-based fermentation. ZVI accelerated the destruction of extracellular polymeric substances (EPS) and interior sludge cells, as well as improved biodegradation of soluble organics. Also, ZVI enhanced key enzyme activities (i.e., BK and CoA-), thus promoting degradation rates of acidogenesis (6.30 ± 0.84 mg/(gVSS·h) in glucose) and acetogenesis (74.63 ± 0.29 mg/(gVSS·h) in butyrate). Compared to Fe(III), the contribution of Fe(II) was higher among the decomposition products of ZVI. Besides, ZVI favored Proteobacteria and Actinobacteria, which enhanced acetate formation and organic compounds disassimilation of the process, respectively. The abundance of Tepidiphilus, Thermobrachium and Tepidimicrobium was increased, indicating promoting the system stability of SCFAs production in thermophilic anaerobic fermentation.

Keywords: Short-chain fatty acids; Thermophilic anaerobic fermentation; Waste activated sludge; Zero valent iron.

MeSH terms

Anaerobiosis
Fatty Acids, Volatile
Fermentation
Hydrogen-Ion Concentration
Iron*
Sewage* / microbiology

Substances

Sewage
Iron
Fatty Acids, Volatile