Ozone oxidation of 2,4,6-TCP in the presence of halide ions: Kinetics, degradation pathways and toxicity evaluation.
Ozone oxidation of 2,4,6-TCP in the presence of halide ions: Kinetics, degradation pathways and toxicity evaluation.
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DOI：
10.1016/j.chemosphere.2021.132343
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发表时间：
2021-09
期刊：
影响因子：
8.8
通讯作者：
Ranyun Xu;H. Ren;Tongtong Chi;Yuhan Zheng;Yawei Xie;Jinping Tian;Lyujun Chen
中科院分区：
文献类型：
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作者：
Ranyun Xu;H. Ren;Tongtong Chi;Yuhan Zheng;Yawei Xie;Jinping Tian;Lyujun Chen
2，4，6-三氯苯酚（2，4，6-TCP）在工业生产中被广泛使用，并可能造成环境污染。卤离子对2，4，6-TCP分解的影响常常被忽视。在O3体系中，溴离子对2，4，6-TCP降解的负面影响大于氯离子，并导致可吸附有机卤素（AOX）的生成。动力学模型表明，各种自由基的浓度在很大程度上取决于溶液的pH值，较强的碱性不仅有助于2，4，6-TCP的矿化，而且抑制卤代副产物的形成。结合中间体鉴定和量子化学计算，提出了2，4，6-TCP在臭氧氧化过程中的降解途径。毒性试验和ECOSAR模拟结果表明，部分2，4，6-TCP降解中间体的急性毒性相对高于其母体化合物。在高浓度的卤素离子下，臭氧处理的溶液显示出比原始2，4，6-TCP溶液更大的毒性。这些结果说明臭氧处理含卤废水可能会造成潜在的生态危害，其应用需要更加谨慎。
2,4,6-Trichlorophenol (2,4,6-TCP) is extensively consumed in industrial production and may cause environmental damages. The effect of halide ions on the decomposition of 2,4,6-TCP has often been overlooked. In this study, the bromide ion was found to have a stronger negative impact on 2,4,6-TCP degradation than chloride ion in the O3system, and led to the formation of adsorbable organic halogens (AOX). Kinetic modeling demonstrated that the concentration of various radicals was largely depended on the solution pH, and stronger basicity not only contributed to the mineralization of 2,4,6-TCP, but also inhibited the formation of halogenated by-products. Combining the intermediate identification and quantum chemical calculation, the degradation pathways of 2,4,6-TCP during ozone oxidation process were proposed. The toxicity test and ECOSAR simulation demonstrated that the acute toxicity of some 2,4,6-TCP degradation intermediates was relatively higher than their parent compound. With high concentrations of halide ions, the ozone-treated solution showed greater toxicity than the originator 2,4,6-TCP solution. These results illustrate that the ozone treatment of the halide-containing wastewater may cause potential ecological hazards and its application needs to be more cautious.