Photo-assisted degradation of 2,4,5-trichlorophenoxyacetic acid by Fe(II)-catalyzed activation of Oxone process: The role of UV irradiation, reaction mechanism and mineralization
Photo-assisted degradation of 2,4,5-trichlorophenoxyacetic acid by Fe(II)-catalyzed activation of Oxone process: The role of UV irradiation, reaction mechanism and mineralization
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DOI：
10.1016/j.apcatb.2012.04.031
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发表时间：
2012-07
影响因子：
22.1
通讯作者：
Y. Wang;W. Chu
中科院分区：
文献类型：
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作者：
Y. Wang;W. Chu
研究了Fe（II）催化紫外光活化过硫酸氢钾（FOU）降解水中2，4，5-三氯苯氧乙酸（2，4，5-T）的可能性，并与Fe（II）/过硫酸氢钾（FO）过程进行了比较。实验结果表明，在引入紫外光照射后，FO过程显着促进。因此，通过比较FO工艺和FOU工艺之间的[Fe（II）]的实时性，深入阐明了UV照射的作用。发现在UV照射的存在下建立了有益的Fe（III）/Fe（II）催化循环，从而导致Fe（II）的加速再生。此外，还检查了在各种[Oxone]和[2，4，5-T]下通过FOU过程的2，4，5-T衰减。利用LC-ESI/MS分析了2，4，5-T在UV、Oxone/UV和FOU作用下的衰变途径。在有或没有自由基（OH和SO 4 −）参与的三个过程中，观察到中间体分布的明显差异。此外，各种过程的效率（即，UV单独，Oxone/UV和FOU）在矿化和Cl−离子积累方面进行了进一步检查。
In this study, the potential of Fe(II)-catalyzed activation of Oxone process with UV irradiation (FOU) for the degradation of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) in aqueous solution was explored and compared with the Fe(II)/Oxone (FO) process. Experimental results show that the FO process was dramatically promoted upon the introduction of UV irradiation. As a result, the role of UV irradiation was elucidated in-depth by comparing the real-time of [Fe(II)] between the FO process and the FOU process. It was found that a beneficial Fe(III)/Fe(II) catalytic cycle is established in the presence of UV irradiation, thereby leading to the accelerated regeneration of Fe(II). Additionally, 2,4,5-T decay by the FOU process under various [Oxone] and [2,4,5-T] was also examined. Furthermore, the decay pathways for the transformation of 2,4,5-T by UV alone, Oxone/UV, and FOU processes were proposed by using LC-ESI/MS analysis. Distinct differences of intermediate distributions were observed among the three processes with or without the involvement of radicals (OH and SO4−). Besides, the efficiencies of various processes (i.e., UV alone, Oxone/UV and FOU) were further examined in terms of mineralization and Cl−ion accumulation.