Removal of sulfachloropyridazine by ferrate(VI): Kinetics, reaction pathways, biodegradation, and toxicity evaluation
Removal of sulfachloropyridazine by ferrate(VI): Kinetics, reaction pathways, biodegradation, and toxicity evaluation
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DOI：
10.1016/j.cej.2019.04.121
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发表时间：
2019-09
影响因子：
15.1
通讯作者：
Xuhui Sun;Mingbao Feng;Shuyu Dong;Y. Qi;Lin Sun;N. Nesnas;V. Sharma
中科院分区：
文献类型：
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作者：
Xuhui Sun;Mingbao Feng;Shuyu Dong;Y. Qi;Lin Sun;N. Nesnas;V. Sharma
磺胺氯哒嗪（SCP）是一种广谱磺胺类抗生素，曾在养牛场和鱼塘的水样中检测到。本文介绍了在酸性至碱性pH范围内，高铁酸盐（VI）（FeO 42 −，FeVI）对SCP的动力学和去除。质子化FeVI物种（HFeO 4 −）的物种特异性速率常数（k，M− 1 s −1）高于FeO 42 −物种。这描述了减少墨水与pH值的增加。确定的有机氧化产物（OP）之间的反应FeVI和SCP建议从磺酰胺基团和SCP的苯胺部分的羟基化的SO2挤出。利用FeVI与SCP摩尔比（2.0-15.0）不同时OP的峰面积和硫酸根离子的形成给出了SCP转化为不同OP的可能机理。在提出的机制中，主要途径涉及单电子转移，导致FeV和自由基阳离子中间体导致SO2挤出。一个次要的次要途径，这不会导致SO2挤出，涉及SCP的苯胺部分的羟基化，这可能是通过氧原子转移步骤发生的。硫酸根离子是由FeVI氧化SO2（或亚硫酸根离子）而形成的，这也可以产生FeV物种。所产生的FeV物种也参与了由FeVI对SCP的整体氧化。进行了有机磷农药的生物降解和毒性试验。在河流沃茨中的处理结果表明，超过90%的SCP被去除的FeVI。
Sulfachloropyridazine (SCP) is a broad-spectrum sulfonamide antibiotic and has been detected in cattle farming and fishpond water samples. This paper presents the kinetics and removal of SCP by ferrate(VI) (FeO42−, FeVI) in the acidic to basic pH range. The species-specific rate constant (k, M−1s−1) of protonated FeVIspecies (HFeO4−) is higher than that of the FeO42−species. This describes the decrease inkwith increase in pH. The identified organic oxidized products (OPs) of reaction between FeVIand SCP suggest an extrusion of SO2from the sulfonamide group and hydroxylation of the aniline moiety of SCP. The peak areas of the OPs at different molar ratios of FeVIto SCP (2.0–15.0) and the formation of sulfate ion are used to give a plausible mechanism for the transformation of SCP to different OPs. In the proposed mechanisms, the major pathway involves a single-electron transfer that leads to FeVand a radical cation intermediate resulting in SO2extrusion. A secondary minor pathway, which does not lead to SO2extrusion, involves the hydroxylation of the aniline moiety of SCP, which likely occurs via an oxygen-atom transfer step. The sulfate ion was formed as a result of SO2(or sulfite ion) oxidation by FeVI, which could also generate the FeVspecies. The generated FeVspecies also participate in the overall oxidation of SCP by FeVI. Biodegradation and toxicity tests of the OPs were performed. Treatment results in river waters demonstrated that more than 90% of SCP was removed by FeVI.