Enhancing anaerobic degradation of phenol to methane via solubilizing Fe(III) oxides for dissimilatory iron reduction with organic chelates

Yang Li; Chongyang Ren; Zisheng Zhao; Qilin Yu; Zhiqiang Zhao; Lifen Liu; Yaobin Zhang; Yujie Feng

doi:10.1016/j.biortech.2019.121858

Enhancing anaerobic degradation of phenol to methane via solubilizing Fe(III) oxides for dissimilatory iron reduction with organic chelates

Bioresour Technol. 2019 Nov:291:121858. doi: 10.1016/j.biortech.2019.121858. Epub 2019 Jul 22.

Authors

Yang Li¹, Chongyang Ren², Zisheng Zhao³, Qilin Yu⁴, Zhiqiang Zhao⁵, Lifen Liu⁶, Yaobin Zhang⁴, Yujie Feng⁷

Affiliations

¹ 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; Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Food and Environment, Dalian University of Technology, Panjin 124221, China.
² School of Environmental Science and Engineering, Shandong University, Jinan 250100, China.
³ School of Water Conservancy and Environment, Zhengzhou University, Kexue Road 100, Zhengzhou 450001, China.
⁴ 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.
⁵ 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.
⁶ Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Food and Environment, Dalian University of Technology, Panjin 124221, China.
⁷ State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.

PMID: 31377515
DOI: 10.1016/j.biortech.2019.121858

Abstract

The improved performances during anaerobic degradation of phenol to methane with Fe(OH)₃ were usually inapparent, due to its lower solubility (unaccessible to dissimilatory iron reduction) and more positive reduction potential of Fe(III)/Fe(II) (unfavorable for enriching Fe(III)-reducing bacteria [IRBs]). In this study, citrate, the organic chelates, were used to solubilize Fe(III) with the aim of improving the phenol degradation and declining the reduction potential of Fe(III)/Fe(II). Results showed that, in the co-occurrence of citrate and Fe(OH)₃, the degradation rates of phenol were about 1.3-fold rapider than that with sole Fe(OH)₃. Analysis of cyclic voltammetry demonstrated that the reduction potential of Fe(III)/Fe(II) in the form of Fe(OH)₃ (-0.41 to -0.28 V vs Ag/AgCl) declined to -0.61 to -0.41 V. As a result, the Fe(III)-reducing genera, such as Petrimonas and Shewanella, which held a great potential of proceeding syntrophic metabolism via direct interspecies electron transfer (DIET), were significantly enriched.

Keywords: Dissimilatory iron reduction; Fe(III) oxides; Fe(III)-reducing bacteria; Phenol degradation; Shewanella.

MeSH terms

Anaerobiosis
Bacteroides / drug effects
Bacteroides / metabolism
Chelating Agents / pharmacology*
Electron Transport
Ferric Compounds / metabolism*
Iron / metabolism*
Methane / metabolism*
Oxidation-Reduction
Phenol / metabolism*
Phenols / metabolism
Shewanella / drug effects
Shewanella / metabolism

Substances

Chelating Agents
Ferric Compounds
Phenols
ferric oxide
Phenol
Iron
Methane