Model applications and intermediates quantification of atrazine degradation by UV-enhanced fenton process.
Model applications and intermediates quantification of atrazine degradation by UV-enhanced fenton process.
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DOI：
10.1021/jf052572e
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发表时间：
2006-02
影响因子：
6.1
通讯作者：
K. Chan;W. Chu
中科院分区：
文献类型：
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作者：
K. Chan;W. Chu
研究了紫外增强芬顿法（UV-FP）对除草剂阿特拉津（ATZ）的降解。与单独UV（UV辐射）和暗FP（单独芬顿过程）两个单独反应速率的简单组合相比，在该过程中观察到增强的光化学效应。因此，提出了一个基于两个平行反应的光化学模型来预测UV-FP的反应动力学，其中采用了两个速率增强因子，并发现能够成功地描述速率提高。此外，我们还利用液相色谱-电喷雾串联质谱（LC/ESI-MS/MS）技术成功地研究了ATZ衰变的转化途径。在该过程中鉴定了14个中间体。ATZ在UV-FP中的降解主要是烷基氧化、脱烷基和/或脱氯-羟基化。所有检测到的中间体被发现在不同的水平或位置脱烷基。发现脱烷基物质进一步脱氯。氯化产物减少到17%，而脱氯产物保持在73%，并在60 min后进一步腐烂。鉴于总s-三嗪的质量平衡逐渐降低，这表明在UV-FP中ATZ上可能发生环断裂。
Degradation of the herbicide atrazine (ATZ) by the UV-enhanced Fenton process (UV-FP) was investigated. An enhanced photochemical effect was observed in the process compared with the simple combination of the two individual reaction rates of sole-UV (UV radiation) and dark-FP (sole Fenton's process). Accordingly, a photochemical model based on the two parallel reactions was proposed to predict the reaction kinetics of UV-FP, where two rate enhancement factors were adopted and found to be capable of successfully describing the rate improvement. In addition, the transformation pathway of ATZ decay was successfully investigated by using novel technology, liquid chromatography-electrospray tandem mass spectrometry (LC/ESI-MS/MS). Fourteen intermediates were identified in the process. The alkylic oxidation followed by dealkylation and/or dechlorination-hydroxylation was found to be the major pathway of the decay of ATZ in UV-FP. All of the detected intermediates were found to be dealkylated in different levels or positions. The dealkylated species were found to be further dechlorinated. The chlorinated products reduced to 17% of total, whereas the dechlorinated products remained at 73% and were further decayed after 60 min of treatment. In view of the gradual reduction of the mass balance of the total s-triazine, this suggested that a ring cleavage may occur on the ATZ in the UV-FP.