Further understanding the involvement of Fe(IV) in peroxydisulfate and peroxymonosulfate activation by Fe(II) for oxidative water treatment
Further understanding the involvement of Fe(IV) in peroxydisulfate and peroxymonosulfate activation by Fe(II) for oxidative water treatment
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DOI：
10.1016/j.cej.2019.04.101
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发表时间：
2019-09
影响因子：
15.1
通讯作者：
Zhen Wang;W. Qiu;Su-yan Pang;Yang Zhou;Yuan Gao;Chaoting Guan;Jin Jiang
中科院分区：
文献类型：
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作者：
Zhen Wang;W. Qiu;Su-yan Pang;Yang Zhou;Yuan Gao;Chaoting Guan;Jin Jiang
最近，我们有趣地发现，Fe（II）活化的过二硫酸盐（PDS）过程可以将甲基苯基亚砜（PMSO）氧化为其氧转移产物甲基苯基砜（PMSO 2），这表明在该过程中可能存在铁基中间体（Fe（IV））而不是长期公认的硫酸根（SO 4 radical dot−）。在本工作中，当PMSO被Fe（II）/过一硫酸盐（PMS）体系在pH 3-7范围内处理时，也观察到PMSO 2的形成，并且PMSO 2的产率（即，形成的PMSO 2与损失的PMSO的摩尔比）在酸性条件下定量为约100%，类似于Fe（II）/PDS体系。此外，当PMSO被H218 O中的Fe（II）/PDS和Fe（II）/PMS系统氧化时，来自同位素标记水（H218 O）的18 O成功掺入PMSO 2产物中，这可能是由于Fe（IV）-氧代物种与H218 O的竞争性氧交换。此外，在这两个系统中的Fe（IV）的演变概况预测由Fe（IV）介导的动力学模型，这些结果是在良好的协议与停流分光光度计获得的实验数据。
Very recently, we have interestingly found that the Fe(II)-activated peroxydisulfate (PDS) process can oxidize methyl phenyl sulfoxide (PMSO) to its oxygen transfer product methyl phenyl sulfone (PMSO2), suggesting the possible occurrence of a ferryl intermediate (Fe(IV)) rather than long recognized sulfate radical (SO4radical dot−) in this process. In this work, the formation of PMSO2was also observed when PMSO was treated by the Fe(II)/peroxymonosulfate (PMS) system over the pH range of 3–7, and the yield of PMSO2(i.e., the molar ratio of PMSO2formed to PMSO lost) was quantified to be approximately 100% under acidic conditions, similar to the Fe(II)/PDS system. Moreover,18O from isotope-labeled water (H218O) was successfully incorporated into PMSO2product when PMSO was oxidized by the Fe(II)/PDS and Fe(II)/PMS systems in H218O, likely due to the competitive oxygen exchange of Fe(IV)-oxo species with H218O. Further, Fe(IV) evolution profiles in both systems were predicted by a Fe(IV)-mediated kinetic model, and these results are in good agreement with the experimental data obtained with a stopped-flow spectrophotometer.