Ultrasound-assisted catalytic reduction of Cr(VI) by an acid mine drainage based nZVI coupling with FeS2 system from aqueous solutions: Performance and mechanism
| Autor: | Fu Xin Dong, Wei Chu, Peng Ran Guo, Zeng Hui Diao, Liu Yan, Jing Yi Liang, Shi Ting Huang, Wei Qian, Wen Xuan Zhang, Zhi Liang Chen |
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| Rok vydání: | 2021 |
| Předmět: |
chemistry.chemical_classification
Reaction mechanism Zerovalent iron Environmental Engineering Aqueous solution Chemistry 0208 environmental biotechnology Selective catalytic reduction 02 engineering and technology General Medicine Human decontamination 010501 environmental sciences Management Monitoring Policy and Law 01 natural sciences 020801 environmental engineering chemistry.chemical_compound Humic acid Reactivity (chemistry) Citric acid Waste Management and Disposal 0105 earth and related environmental sciences Nuclear chemistry |
| Zdroj: | Journal of Environmental Management. 278:111518 |
| ISSN: | 0301-4797 |
| Popis: | Nowadays, nanoscale zero valent iron (nZVI) has been extensively applied for the decontamination of various pollutants, but passivation of nZVI severely affects its reactivity in use. In this study, ultrasound (US)-assisted catalytic reduction of Cr(VI) by an acid mine drainage based nZVI (AMD-nZVI) coupling with FeS2 system was systematically examined. Results show that the presence of FeS2 and US induced a synergistic enhancement of Cr(VI) removal by AMD-nZVI. Nearly 98% of Cr(VI) removal was achieved by AMD-nZVI/FeS2/US process within 60 min under optimal reaction conditions. Several coexisting substances with lower concentration including Pb(II), Ni(II), bisphenol A (BPA) and 2,4-diclorophenol (2,4-DCP) could be effectively removed in simultaneous manner with Cr(VI) removal. The inhibitory order of water matrix species on Cr(VI) removal was NO3− > PO43− > HCO3− > Ca2+ > Mg2+ > Cl−, and a serious suppression effect was induced by humic acid (HA). Addition of ethylene diamine tetra-acetic acid (EDTA) and citric acid (CA) could enhance Cr(VI) removal rate. An enhanced reaction mechanism was proposed, which involved the regeneration of more Fe2+ and H+ by AMD-nZVI/FeS2/US process, leading to the reduction of Cr(VI) by AMD-nZVI and FeS2 into Cr(III) species inculding Cr2O3 and Cr(OH)3. This study well demonstrates that AMD-nZVI/FeS2/US process is considered as a potential candidate for the remediation of Cr(VI) in real wasterwater. |
| Databáze: | OpenAIRE |
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