Influence of [sulfite]/[Fe(VI)] molar ratio on the active oxidants generation in Fe(VI)/sulfite process.
Influence of [sulfite]/[Fe(VI)] molar ratio on the active oxidants generation in Fe(VI)/sulfite process.
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DOI：
10.1016/j.jhazmat.2019.121303
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发表时间：
2020-02
影响因子：
13.6
通讯作者：
Binbin Shao;Hongyu Dong;Liying Feng;Junlian Qiao;Xiaohong Guan
中科院分区：
文献类型：
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作者：
Binbin Shao;Hongyu Dong;Liying Feng;Junlian Qiao;Xiaohong Guan
尽管几个小组已经努力研究 Fe(VI)/亚硫酸盐过程降解微污染物，但其机制还远不清楚，值得进一步研究。在此，系统地研究了亚硫酸盐 (SO32−) 激活的 Fe(VI) 氧化对选定微污染物的降解动力学和机制。 Fe(VI)/亚硫酸盐工艺中恩诺沙星 (ENR) 和苯酚的氧化速率在 pH 6.5 和 8.0 时范围为 0.151 s−1 至 6.18 s−1。与单次添加模式相比，多次添加模式下的亚硫酸盐提高了富电子基团微污染物的降解效率。根据淬火实验和动力学模拟的结果，[SO32−]/[Fe(VI)] 摩尔比为 0.1 至 0.3 时，Fe(V) 被确定为主要活性氧化剂。然而，当 [SO32−]/[Fe(VI)] 摩尔比≥ 0.4 时，Fe(V) 和 SO4 自由基点−/自由基点OH 都会对微污染物氧化做出贡献，并且它们的贡献很大程度上取决于微污染物的性质。在不同亚硫酸盐剂量下，Fe(VI)/亚硫酸盐过程中 ENR 的不同降解产物进一步支持了不同活性氧化剂在不同 [SO32−]/[Fe(VI)] 摩尔比下的贡献。经过Fe(VI)/亚硫酸盐处理后，ENR反应产物对青海弧菌-Q67的毒性显着降低。这项工作的结果可能会促进亚硫酸盐活化Fe(VI)氧化在水处理中的应用。
Although several groups have made efforts to study micropollutants degradation by Fe(VI)/sulfite process, the mechanism is far from clear and warrants further investigation. Herein, the degradation kinetics and mechanism of selected micropollutants by sulfite (SO32−)-activated Fe(VI) oxidation were systematically investigated. The oxidation rates of enrofloxacin (ENR) and phenol in Fe(VI)/sulfite process ranged from 0.151 s−1to 6.18 s−1at pH 6.5 and 8.0. Sulfite applied in multiple-addition mode improved the degradation efficiency of micropollutants with electron-rich moieties compared to the single-addition mode. Based on results of the quenching experiments and kinetic simulation, Fe(V) was identified as the predominant active oxidant at [SO32−]/[Fe(VI)] molar ratio of 0.1 to 0.3. However, both Fe(V) and SO4radical dot−/radical dotOH contributed to micropollutants oxidation at [SO32−]/[Fe(VI)] molar ratio ≥ 0.4 and their contributions were strongly dependent on the properties of micropollutants. The different degradation products of ENR in Fe(VI)/sulfite process at different sulfite dosages further supported the contribution of different active oxidants at different [SO32−]/[Fe(VI)] molar ratios. The toxicity of the reaction products of ENR towardsVibrio qinghaiensissp.-Q67 decreased dramatically after Fe(VI)/sulfite treatment. The results of this work may promote the application of sulfite-activated Fe(VI) oxidation in water treatment.