Roles of bromine radicals, HOBr and Br2 in the transformation of flumequine by the UV/chlorine process in the presence of bromide
Roles of bromine radicals, HOBr and Br2 in the transformation of flumequine by the UV/chlorine process in the presence of bromide
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溴自由基、HOBr 和 Br2 在溴化物存在下通过 UV/氯法转化氟甲喹中的作用
DOI：
10.1016/j.cej.2020.125222
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发表时间：
2020-11
影响因子：
15.1
通讯作者：
Jingyun Fang
中科院分区：
文献类型：
--
作者：
Xuewen Zhang;Kaiheng Guo;Yuge Wang;Qingdong Qin;Zhanxiang Yuan;Jia He;Chunyan Chen;Zihao Wu;Jingyun Fang
在溴化物（Br−）存在的情况下，通过UV/氯工艺形成新的反应性物种，例如溴和反应性溴物种（RBS）。在这项研究中，Br−的动力学，产品和通过UV/氯转化氟甲喹（FLU）的途径的影响进行了研究。在pH 7条件下，50 μM Br−使紫外/氯降解FLU的准一级速率常数（k′）提高了2.5倍，生成了HOBr、Br 2、RBS和HO·，它们分别贡献了29.2%，7.8%，57.4%和4.8%的tok′. FLU与HOBr、OBr-、Br 2和Br·反应的二级速率常数（k）分别为115.6 M− 1 s −1（可忽略）、1.5 × 106 M − 1 s − 1和2.4 × 108 M − 1 s −1。在较高的Br−水平和较低的pH值下，Br 2的贡献增强，在pH 6时占k ′的48.2%。在pH 6 ~ 9范围内，总的k ′值下降了97.9%，其中HOBr、Br 2和RBS的k ′值显著下降。溴化产物的形成主要是由于HOBr和Br 2，而RBS和HO·主要促进了Br−在UV/Cl处理过程中的羟基化和酮化。在紫外/氯工艺中，总有机溴（TOBr）的生成量与暗氯化法相当，但前者溴化消毒副产物的生成量要高得多，这进一步表明RBS和HO·促进了小分子产物的生成。此外，在使用Br−的UV/氯过程中，FLU的急性毒性显著降低。这是第一个研究揭示了Br 2和Br·在含Br−水中通过UV/氯过程降解微污染物中的重要作用。
In the presence of bromide (Br−), new reactive species, such as bromine and reactive bromine species (RBS), are formed by the UV/chlorine process. In this study, the effects of Br−on the kinetics, products, and pathways of flumequine (FLU) transformation by the UV/chlorine process were investigated. The pseudo first-order rate constant (k′) for FLU degradation in the UV/chlorine process was enhanced by 2.5 times by 50 μM Br−at pH 7, as HOBr, Br2, RBS and HO•were formed, and they contributed 29.2%, 7.8%, 57.4% and 4.8% tok′, respectively. The second-order rate constants (k) of FLU reacting with HOBr, OBr−, Br2and Br•were determined to be 115.6 M−1s−1, negligible, 1.5 × 106M−1s−1and 2.4 × 108M−1s−1, respectively. The contribution of Br2was enhanced at a higher Br−level and a lower pH, which accounted for 48.2% ofk′ at pH 6. The overallk′value decreased by 97.9% from pH 6 to 9, during whichk′by HOBr, Br2and RBS decreased significantly. The formation of brominated products was mainly attributed to HOBr and Br2, while RBS and HO•primarily promoted hydroxylation and ketonization during UV/chlorine treatment with Br−. The formation of total organic bromine (TOBr) by the UV/chlorine process with Br−was comparable to that during dark chlorination with Br−, while the yield of brominated disinfection byproducts in the former was much higher, further indicating that RBS and HO•promoted the formation of small-molecule products. In addition, the acute toxicity of FLU was significantly reduced during the UV/chlorine process with Br−. This is the first study to reveal the significant roles of Br2and Br•in the degradation of micropollutants by the UV/chlorine process in Br−-containing water.
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影响因子：
9.8
作者：
Feng, Mingbao;Yan, Liqing;Wang, Zunyao
通讯作者：
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影响因子：
15
作者：
EIGEN, M;KUSTIN, K
通讯作者：
KUSTIN, K
影响因子：
9.8
作者：
Rodrigues-Silva, Caio;Maniero, Milena Guedes;Guimaraes, Jose Roberto
通讯作者：
Guimaraes, Jose Roberto
影响因子：
11.4
作者：
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通讯作者：
Roberts, A. Lynn
DOI：
10.1021/j100647a006
发表时间：
1972
期刊：
The Journal of Physical Chemistry
影响因子：
--
作者：
D. Zehavi;J. Rabani
通讯作者：
D. Zehavi;J. Rabani