External potential regulated biocathode for enhanced removal of gaseous chlorobenzene in bioelectrchemical system
Autor: | Shihan Zhang, Jingkai Zhao, Zanyun Ying, Jialing Gao, Rui-Jian Peng, Han Chen, Juping You, Jianmeng Chen |
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Rok vydání: | 2020 |
Předmět: |
Environmental Engineering
Health Toxicology and Mutagenesis 0208 environmental biotechnology 02 engineering and technology 010501 environmental sciences Electrochemistry Chlorobenzenes 01 natural sciences Redox Electrolysis Electron transfer chemistry.chemical_compound Microbial electrolysis cell Environmental Chemistry Electrodes 0105 earth and related environmental sciences Catechol Chemistry Public Health Environmental and Occupational Health General Medicine General Chemistry Pollution 020801 environmental engineering Chemical engineering Chlorobenzene Degradation (geology) Gases Oxidation-Reduction Faraday efficiency |
Zdroj: | Chemosphere. 274 |
ISSN: | 1879-1298 |
Popis: | Microbial electrolysis cell (MEC) with a biocathode could provide extra reaction driving force for gaseous chlorobenzene (CB) removal. In this work, external potentials (−0.1 to −0.7 V vs. SHE) were applied to regulate the biocathodic activity. Results showed −0.3 V was the optimum potential, while the removal efficiency, dechlorination efficiency and Coulombic efficiency achieved 94%, 65%, and 89%, respectively. Electrochemical stimulation enriched dechlorination microorganisms (Achromobacter and Gordonia), and significantly improved CB mineralization efficiency, which was twice higher than that without additional potential at 300 mg m−3 inlet concentration. Furthermore, electron transfer between biocathode and microorganisms was mainly through direct electron transfer (DET). A new integrated redox pathway for CB anaerobic degradation was proposed, in which CB was sequentially converted into 2-chlorophenol and 3-chlorocatechol, then dechlorinated to catechol, and finally mineralized into CO2. Overall, this work provided an insight into gaseous CB bioelectrochemical degradation through the potential regulation. |
Databáze: | OpenAIRE |
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