Ultrasonic and photochemical degradation of chlorpropham and 3-chloroaniline in aqueous solution
Ultrasonic and photochemical degradation of chlorpropham and 3-chloroaniline in aqueous solution
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DOI：
10.1016/s0043-1354(97)00477-6
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发表时间：
1998-08-01
期刊：
影响因子：
12.8
通讯作者：
Boule, P
中科院分区：
文献类型：
--
作者：
David, B;Lhote, M;Boule, P
声分解和光解进行了比较转化氯苯胺灵，属于氨基甲酸酯组的系统性除草剂，和3-氯苯胺，氯苯胺灵的降解中经常观察到的主要中间体。在这两种情况下，超声波降解在482 kHz下比在20 kHz下有效得多。氯苯胺灵降解过程中形成的主要声致产物为3-氯苯胺、甲酸、一氧化碳、二氧化碳和氯离子。3-氯苯胺的降解也导致Cl-，CO和CO2，但氯氢醌也被检测到作为中间体。超声波转化过程中涉及两种不同的机理：空化微泡内爆导致的热解和超声分解水形成的羟基自由基的氧化。光解是更具体的：3-氯苯胺最初定量转化为3-氨基苯酚。异裂机制的建议。在第二阶段形成间苯二酚和一些未鉴定的phoro产物。在氯苯胺灵的光转化中涉及相同类型的反应，但反应不是如此特异。在这两种情况下，在254 nm处的光解导致酚类和醌类化合物的完全消失。(C)1998爱思唯尔科技有限公司版权所有。
Sonolysis and photolysis are compared for the transformation of chlorpropham, a systemic herbicide belonging to the carbamate group, and 3-chloroaniline, the main intermediate often observed in the degradation of chlorpropham. In both cases the ultrasonic degradation is much more efficient at 482 kHz than at 20 kHz. The main identified sonoproducts formed in the degradation of chlorpropham are 3-chloroaniline, formic acid, carbon monoxide and dioxide and chloride ions. The degradation of 3-chloroaniline also leads to Cl-, CO and CO2 but chlorohydroquine was also detected as an intermediate. Two different mechanisms are involved in the ultrasonic transformation: pyrolysis resulting from the implosion of cavitation microbubbles and oxidation by hydroxyl radicals formed by sonolysis of water. Photolysis is more specific: 3-chloroaniline is initially quantitatively transformed into 3-aminophenol. A heterolytic mechanism is suggested. Resorcinol and some unidentified phoroproducts are formed in a second stage. The same type of reaction is involved in the photo-transformation of chlorpropham, but the reaction is not so specific. Ln both cases the photolysis at 254 nm leads to a complete disappearance of phenolic and quinonic compounds. (C) 1998 Elsevier Science Ltd. All rights reserved.