Bioelectrochemical decolorization of a reactive diazo dye: Kinetics, optimization with a response surface methodology, and proposed degradation pathway

Hou-Yun Yang; Jing Liu; Yi-Xuan Wang; Chuan-Shu He; Li-Shan Zhang; Yang Mu; Wei-Hua Li

doi:10.1016/j.bioelechem.2019.02.008

Bioelectrochemical decolorization of a reactive diazo dye: Kinetics, optimization with a response surface methodology, and proposed degradation pathway

Bioelectrochemistry. 2019 Aug:128:9-16. doi: 10.1016/j.bioelechem.2019.02.008. Epub 2019 Mar 9.

Authors

Hou-Yun Yang¹, Jing Liu², Yi-Xuan Wang², Chuan-Shu He³, Li-Shan Zhang⁴, Yang Mu², Wei-Hua Li⁵

Affiliations

¹ School of Environment and Energy Engineering, Key Laboratory of Anhui Province of Water Pollution Control and Wastewater Reuse, Anhui Jianzhu University, Hefei, China; CAS Key Laboratory for Urban Pollutant Conversion, Collaborative Innovation Centre of Suzhou Nano Science and Technology, Department of Applied Chemistry, University of Science & Technology of China, Hefei, China.
² CAS Key Laboratory for Urban Pollutant Conversion, Collaborative Innovation Centre of Suzhou Nano Science and Technology, Department of Applied Chemistry, University of Science & Technology of China, Hefei, China.
³ CAS Key Laboratory for Urban Pollutant Conversion, Collaborative Innovation Centre of Suzhou Nano Science and Technology, Department of Applied Chemistry, University of Science & Technology of China, Hefei, China. Electronic address: hcs@mail.ustc.edu.cn.
⁴ College of Environment and Resources, Guangxi Normal University, Guilin, China. Electronic address: lishan_zhang@hotmail.com.
⁵ School of Environment and Energy Engineering, Key Laboratory of Anhui Province of Water Pollution Control and Wastewater Reuse, Anhui Jianzhu University, Hefei, China.

PMID: 30884361
DOI: 10.1016/j.bioelechem.2019.02.008

Abstract

Bioelectrochemical systems (BESs) have shown great potential for azo dye removal. However, comprehensive evaluation of the bioelectrochemical decolorization performance for reactive diazo dyes remains limited, particularly the kinetics and operation parameter optimization. This study evaluated the decolorization of the diazo dye Reactive Black 5 (RB5) in BESs, particularly with regard to kinetics, parameter optimization using response surface methodology (RSM), and the degradation pathway. The results indicated that the pseudo-first-order kinetic rate constant of RB5 decolorization increased from 0.023 ± 0.001 to 0.146 ± 0.008 h^-1 with a decrease in cathode potential from -400 mV to -500 mV. RSM optimization suggested that the linear effects of RB5 concentration, cathode potential and hydraulic retention time (HRT), interaction of RB5 concentration with cathodic HRT, and the quadratic effect of cathodic HRT were most influential on the bioelectrochemical decolorization of RB5. Further, the decolorized RB5 products in the BESs were characterized by ultraviolet-visible spectrophotometry, Fourier-transform infrared spectroscopy, and liquid chromatograph-mass spectrometry. From this, a potential decolorization mechanism is proposed based on cleavage of azo bonds.

Keywords: Bioelectrochemical systems; Decolorization pathway; Diazo dye; Kinetics; Response surface methodology.

MeSH terms

Azo Compounds / chemistry*
Chromatography, Liquid
Color*
Coloring Agents / chemistry*
Electrochemical Techniques / methods*
Electrodes
Feasibility Studies
Kinetics
Microscopy, Electron, Scanning
Naphthalenesulfonates / chemistry
Spectrometry, Mass, Electrospray Ionization
Spectrophotometry, Ultraviolet
Spectroscopy, Fourier Transform Infrared
Tandem Mass Spectrometry

Substances

Azo Compounds
Coloring Agents
Naphthalenesulfonates
Remazol black B