Effects of surface charge, hydrophilicity and hydrophobicity on functional biocathode catalytic efficiency and community structure

Mengyuan Qi; Bin Liang; Rongrong Chen; Xun Sun; Zhiling Li; Xiaodan Ma; Youkang Zhao; Deyong Kong; Jun Wang; Aijie Wang

doi:10.1016/j.chemosphere.2018.03.065

Effects of surface charge, hydrophilicity and hydrophobicity on functional biocathode catalytic efficiency and community structure

Chemosphere. 2018 Jul:202:105-110. doi: 10.1016/j.chemosphere.2018.03.065. Epub 2018 Mar 13.

Authors

Mengyuan Qi¹, Bin Liang², Rongrong Chen³, Xun Sun³, Zhiling Li¹, Xiaodan Ma¹, Youkang Zhao¹, Deyong Kong⁴, Jun Wang³, Aijie Wang⁵

Affiliations

¹ State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China.
² Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China. Electronic address: binliang@rcees.ac.cn.
³ Key Laboratory of Superlight Material and Surface Technology, Ministry of Education, Harbin Engineering Uinversity, 150001, China.
⁴ Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Shenyang Academy of Environmental Sciences, Shenyang, 110167, China.
⁵ State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China; Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China. Electronic address: waj0578@hit.edu.cn.

PMID: 29554502
DOI: 10.1016/j.chemosphere.2018.03.065

Abstract

The bioelectrotransformation efficiency of various organic matters and corresponding electrode biofilm community formation as well as electron transfer efficiency in bioelectrochemical systems (BESs) with different modified electrodes has been extensively studied on the anode side. However, the effects of cathode interface characteristics towards the BESs bioelectrotransformation performance remain poorly understood. In this study, the nitrobenzene-reducing biocathode catalytic efficiency and community structure in response to different modified electrodes (control: hydrophobic and no charge; -SH: hydrophobic and single negative charge; -NH₂: hydrophilic and single positive charge -NH-NH₂: hydrophilic and double positive charges) were investigated. The biocathode transformation efficiency of nitrobenzene (NB) to aniline (AN) (E_NB-AN) was affected by the nature of electrode interface as well as the biocathode community formation and structure. Cathodes with hydrophilic surface and positive charges have performed well in the bioelectrotransformation experiments, and especially made an outstanding performance when inorganic NaHCO₃ was supplied as carbon source and cathode as the sole electron donor. Importantly, the hydrophilic surfaces with positive charges were dominated by the electroactive nitroaromatic reducers (Enterococcus, Desulfovibrio and Klebsiella) with the relative abundance as high as 72.20 ± 1.87% and 74.86 ± 8.71% for -NH₂ and -NH-NH₂ groups respectively. This could explain the higher E_NB-AN in the hydrophilic groups than that of the hydrophobic -SH modified group. This study provides new insights into the effects of electrode interface characteristics on the BESs biocathode performance and offers some suggestions for the future design for the improvement of bioelectroremediation performance.

Keywords: Biocathode community; Bioelectrotransformation; Electroactive nitroaromatic reducers; Hydrophilicity and hydrophobicity; Surface charge.

MeSH terms

Aniline Compounds / chemistry*
Catalysis
Electrodes*
Hydrophobic and Hydrophilic Interactions
Nitrobenzenes / chemistry*

Substances

Aniline Compounds
Nitrobenzenes
nitrobenzene
aniline