Magnetite drives self-dechlorination of 4-chlorophenol in anoxic aquatic sediments

Yang Li; Ying Ma; Zisheng Zhao; Xin Wen; Guangkuo Xu; Lin Jiang; Lifen Liu; Yaobin Zhang; Zhiqiang Zhao

doi:10.1016/j.chemosphere.2021.129668

Magnetite drives self-dechlorination of 4-chlorophenol in anoxic aquatic sediments

Chemosphere. 2021 Jun:273:129668. doi: 10.1016/j.chemosphere.2021.129668. Epub 2021 Jan 18.

Authors

Yang Li¹, Ying Ma², Zisheng Zhao³, Xin Wen⁴, Guangkuo Xu⁵, Lin Jiang⁶, Lifen Liu⁷, Yaobin Zhang⁸, Zhiqiang Zhao⁹

Affiliations

¹ School of Ocean Science and Technology, Dalian University of Technology, Panjin, 124221, Liaoning, China. Electronic address: liyang1989@dlut.edu.cn.
² School of Ocean Science and Technology, Dalian University of Technology, Panjin, 124221, Liaoning, China. Electronic address: 1299105487@qq.com.
³ School of Ecology and Environment, Zhengzhou University, Zhengzhou, 450001, Henan, China. Electronic address: zszhao@zzu.edu.cn.
⁴ School of Ocean Science and Technology, Dalian University of Technology, Panjin, 124221, Liaoning, China. Electronic address: 2983698603@qq.com.
⁵ School of Ocean Science and Technology, Dalian University of Technology, Panjin, 124221, Liaoning, China. Electronic address: 2309386700@qq.com.
⁶ School of Ocean Science and Technology, Dalian University of Technology, Panjin, 124221, Liaoning, China. Electronic address: 1220742573@qq.com.
⁷ School of Ocean Science and Technology, Dalian University of Technology, Panjin, 124221, Liaoning, China. Electronic address: lifenliu@dlut.edu.cn.
⁸ Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China. Electronic address: zhangyb@dlut.edu.cn.
⁹ Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China. Electronic address: zhiqiangzhao@dlut.edu.cn.

PMID: 33493817
DOI: 10.1016/j.chemosphere.2021.129668

Abstract

The lack of available electron donors is well known as a major factor limiting the efficiency of microbial dechlorination of 4-chlorophenol (4-CP) in anoxic aquatic sediments. Considering that Fe(III) minerals largely contained in sediments can especially enrich Fe(III)-reducing bacteria and unlock the ring-like intermediates produced by dechlorination of 4-CP via dissimilatory Fe(III) reduction, a strategy of self-dechlorination of 4-CP utilizing its metabolism intermediates such as short-fatty acids (SCFAs) as the endogenous electron donors with magnetite was proposed in this study. The results showed that the removal efficiency of 4-CP increased by 156-203% in magnetite-supplemented biotic groups compared with the magnetite-free biotic group. Liquid chromatography-mass spectrometer (LC-MS) and gas chromatography (GC) revealed the possible metabolic pathway of anoxic 4-CP degradation with magnetite: 4-CP→phenol→cyclohexene-1-carboxylic acid→2-hydroxycyclohexanecarboxylic acid→hexanoic acid/valeric acid→butyric/propionic acids→CO₂. High-throughput sequencing analysis showed that the abundance of functional bacteria, Desulfuromonas, Pseudomonas and Bacillus species, were increased by 1.38-1.97, 1.50-2.04, and 11.60-17.18 folds in magnetite-supplemented biotic groups, compared with the magnetite-free biotic groups. Analysis of Fe²⁺ concentration and cyclic voltammetry (CV) suggested that the potential Fe(III)/Fe(II) transformation occurred and proceeded the anoxic 4-CP degradation continuously.

Keywords: 4-Chlorophenol (4-CP); Anoxic aquatic sediments; Dechlorination; Fe(III)-Reducing bacteria; Magnetite.

MeSH terms

Chlorophenols*
Ferric Compounds
Ferrosoferric Oxide*
Minerals
Oxidation-Reduction

Substances

Chlorophenols
Ferric Compounds
Minerals
4-chlorophenol
Ferrosoferric Oxide