Fate of iron nanoparticles in anammox system: Dissolution, migration and transformation

Xun Weng; Hui-Min Fu; Zheng Mao; Peng Yan; Xiao-Wei Xu; Yu Shen; You-Peng Chen

doi:10.1016/j.jenvman.2023.119323

Fate of iron nanoparticles in anammox system: Dissolution, migration and transformation

J Environ Manage. 2023 Dec 15:348:119323. doi: 10.1016/j.jenvman.2023.119323. Epub 2023 Oct 17.

Authors

Xun Weng¹, Hui-Min Fu², Zheng Mao³, Peng Yan¹, Xiao-Wei Xu¹, Yu Shen⁴, You-Peng Chen⁵

Affiliations

¹ Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing, 400045, China.
² Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing, 400045, China; National Research Base of Intelligent Manufacturing Service, Chongqing Technology and Business University, Chongqing, 400067, China.
³ Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing, 400045, China; Chongqing Institute of Geology and Mineral Resources, Chongqing, 401120, China.
⁴ National Research Base of Intelligent Manufacturing Service, Chongqing Technology and Business University, Chongqing, 400067, China.
⁵ Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing, 400045, China. Electronic address: ypchen@cqu.edu.cn.

PMID: 37852083
DOI: 10.1016/j.jenvman.2023.119323

Abstract

Iron nanoparticles (FeNPs) are commonly used in various industrial processes, leading to their release into the environment and eventual entrance into wastewater treatment plants (WWTPs). FeNPs undergo dissolution, migration, and transformation in WWTPs, which can potentially affect the stable operation of anaerobic ammonia oxidation (anammox) systems and may be discharged with wastewater or biomass. To better understand the fate of FeNPs in anammox systems, exposure experiments were conducted using anammox granular sludges (AnGS) and FeNPs. Results demonstrated that FeNPs released Fe²⁺ upon contact with water, with a portion being bound to functional groups in extracellular polymeric substances (EPS) and the rest entering the bacteria to form highly absorbable substances. A significant amount of FeNPs was observed to cover the surface of AnGS or aggregate and deposit at the bottom of the reactor, eventually converting into Fe₃O₄ and stably existing within the anammox system. The findings of this study clarify the fate of FeNPs in anammox systems and provide important insights into the stable operation of anammox systems under FeNPs exposure.

Keywords: Anaerobic ammonia oxidation (anammox); Anammox granular sludges (AnGS); Extracellular polymeric substances (EPS); Iron form; Iron nanoparticles (FeNPs).

MeSH terms

Anaerobic Ammonia Oxidation*
Bioreactors* / microbiology
Iron
Nitrogen
Oxidation-Reduction
Sewage

Substances

Iron
Nitrogen
Sewage