Oxidation of organic contaminant in a self-driven electro/natural maghemite/peroxydisulfate system: Efficiency and mechanism
| Autor: | Weihui Xiong, Suding Yan, Shuya Xing, Shao Yueqi, Rui Guo, Hui Zhang |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Environmental Engineering
Inorganic chemistry Maghemite 02 engineering and technology 010501 environmental sciences engineering.material Photochemistry 01 natural sciences law.invention Catalysis chemistry.chemical_compound X-ray photoelectron spectroscopy law Peroxydisulfate Environmental Chemistry Electron paramagnetic resonance Waste Management and Disposal 0105 earth and related environmental sciences Singlet oxygen 021001 nanoscience & nanotechnology Persulfate Pollution chemistry engineering 0210 nano-technology Energy source |
| Zdroj: | Science of The Total Environment. :1181-1190 |
| ISSN: | 0048-9697 |
| DOI: | 10.1016/j.scitotenv.2017.05.037 |
| Popis: | Electro-assisted iron-mediated persulfate (PS) activation process has been successfully employed to oxidize organic contaminant. However, a majority of iron-based catalysts used for PS activation was synthesized through complicated or demanding procedures and may have potential risks on environment during the preparation process. Herein, natural maghemite (NM) which is abundant on the earth was employed to activate peroxydisulfate (PDS) in an electrolytic cell. The voltage was provided by microbial fuel cell (MFC) instead of external power as reported in the previous studies, so as to establish a self-driven electro/natural maghemite/PDS system (MFC/NM/PDS) for the oxidation of acid orange 7 (AO7). The results showed that above 90% removal efficiency of AO7 was achieved in a wide range of pH (3.0–9.0) after 100 min reaction. Singlet oxygen was identified for the first time during PDS activation and surface bound sulfate radicals served as the dominant active species responsible for AO7 oxidation. The underlying mechanism of AO7 elimination in the MFC/NM/PDS system was elucidated through quenching tests, electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS) techniques. The variation of TOC and cytotoxicity to Escherichia coli was explored. The intermediate products formed were identified using LC-TOF-MS technique and a possible pathway of AO7 degradation was proposed. |
| Databáze: | OpenAIRE |
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