Mechanism of unactivated peroxymonosulfate-induced degradation of methyl parathion: Kinetics and transformation pathway.
Mechanism of unactivated peroxymonosulfate-induced degradation of methyl parathion: Kinetics and transformation pathway.
复制标题
未活化的过一硫酸盐诱导甲基对硫磷降解的机制：动力学和转化途径。
DOI：
10.1016/j.chemosphere.2021.131332
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发表时间：
2021-06
期刊：
影响因子：
8.8
通讯作者：
Hu Lisong
中科院分区：
文献类型：
--
作者：
Liao Xiaoping;Cao Jinru;Hu Ying;Zhang Caixiang;Hu Lisong
尽管各种活化的过氧单硫酸盐(PMS)工艺因其高生成各种亲电活性氧物种(如硫酸盐、羟基自由基和单线态氧)而被广泛应用于去除难降解有机物，但人们对非自由基PMS与污染物的反应知之甚少。特别是，关于PMS对有机酯类化合物(如有机磷农药)的反应性的信息相对较少。在这里，我们系统地研究了未活化的PMS诱导的甲基对硫磷的转化，甲基对硫磷是一种顽固的有毒OPP。具体地说，甲基对硫磷的快速降解是直接反应而不是基于亲电自由基氧化的结果。PMS自分解产生的单线态氧(1O2)对甲基对硫磷降解的贡献可以忽略不计。降解速率常数(Kobs)强烈依赖于PMS的负载量和溶液的pH。通过考察沉积物腐植酸、Cl-−和天然水等常见水基质的影响，进一步评价了PMS与甲基对硫磷反应在环境治理中的意义。已鉴定的代谢产物表明，接触PMS会导致甲基对硫磷的水解和氧化。进一步的研究表明，PMS也能够有效地氧化其他典型的有机磷农药，而不需要明确的激活。这项研究为甲基对硫磷与PMS的反应提供了新的见解，表明了OPP污染环境净化的可行性。
Although various activated peroxymonosulfate (PMS) processes have been applied widely for the destruction of recalcitrant organics due to its high generation potential of various electrophiles reactive oxygen species (e.g., sulfate and hydroxyl radicals and singlet oxygen), non-radical-based PMS reactions with pollutants are poorly understood. Especially, relatively little information exists on the reactivity of PMS towards organic ester compounds such an organophosphorus pesticides (OPPs). Herein, we systematically studied the unactivated PMS-induced transformation of methyl parathion, a stubborn and toxic OPP. Specifically, direct reaction rather than electrophile radical-based oxidation was responsible for the rapid degradation of methyl parathion. The contribution of the produced singlet oxygen (1O2) from the self-decomposition of PMS to methyl parathion degradation can be neglected. The degradation rate constant (kobs) was strongly dependent on PMS loading and solution pH. The implication of the PMS reaction with methyl parathion for environment treatment was further evaluated by investigating the effects of common water matrices such as sediment humic acids, Cl−, and natural water. The identified metabolic products revealed that exposure to PMS resulted in hydrolysis and oxidation to methyl parathion. Further study demonstrated that PMS was also capable of effectively oxidizing other typical OPPs without explicit activation. This study provides novel insights into the reaction of methyl parathion with PMS, which indicate feasibility for the decontamination of OPP-contaminated environments.