Ultrasonic Decomposition of (4-Chloro-2-methyl phenoxy)acetic Acid (MCPA) in Aqueous Solution
Ultrasonic Decomposition of (4-Chloro-2-methyl phenoxy)acetic Acid (MCPA) in Aqueous Solution
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水溶液中 (4-氯-2-甲基苯氧基)乙酸 (MCPA) 的超声波分解
DOI：
10.1252/jcej.36.806
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发表时间：
2003
影响因子：
0.8
通讯作者：
Y. Asakura
中科院分区：
文献类型：
--
作者：
T. Fujita;Erwin P. Ona;Y. Kojima;H. Matsuda;S. Koda;N. Tanahashi;Y. Asakura
在氩气保护下，以500 kHz频率对2-甲基苯氧基-4-氯乙酸（MCPA）水溶液进行超声分解。通过考察超声波降解过程中氯离子、总有机碳（TOC）及副产物的变化，研究了超声波降解MCPA的机理，结果表明：在恒定功率21.4W下，MCPA经180 min超声降解完全，超声降解MCPA符合准一级反应动力学。在360分钟的超声处理后，其大部分氯原子在溶液中矿化。另一方面，它是难以实现完全矿化的碳，和约60%的初始TOC保留在水溶液中360分钟后。基于GC-MS分析，副产物，如4-氯-2-甲基苯酚（CMP），4-氯儿茶酚，甲基氢醌，甲酚，乙酸和甲酸被检测到在水溶液中，其中超声波照射。CMP的浓度增加，在早期的照射达到最大浓度在约60分钟，然后其减少，直到CMP变得无法检测到在180分钟。分解的MCPA通过超声波照射导致乙酸浓度的增加，直到120分钟，之后没有进一步增加被观察到。相反，观察到甲酸浓度仅在超声处理实验期间增加。
Ultrasonic decomposition of (4-Chloro-2-methyl phenoxy)acetic acid (MCPA) in aqueous solution was performed at a frequency of 500 kHz under an argon atmosphere. We investigated the mechanism of ultrasonic degradation of MCPA by observing the decomposition time evolution of MCPA and the behaviors of chloride ion, TOC (total organic carbon), and byproducts formed through the ultrasonic degradation process of MCPA.At a constant power of 21.4 W, MCPA was completely decomposed after 180-min sonication and the ultrasonic decomposition of MCPA followed a pseudo first order reaction kinetics. Much of its chlorine atoms were mineralized in solution after 360-min sonication. On the other hand, it was difficult to achieve complete mineralization of carbon, and about 60% of the initial TOC remained in aqueous solution after 360 min. Based on the GC-MS analysis, byproducts such as 4-chloro-2-methyl phenol (CMP), 4-chlorocathecol, methylhydroquinone, cresol, acetic acid and formic acid were detected in the aqueous solution to which ultrasonic irradiation was applied. The CMP concentration increased during the early period of irradiation reaching a maximum concentration at about 60 min followed by its decrease until CMP became undetectable at 180 min. Decomposition of MCPA by ultrasonic irradiation resulted in the increase in acetic acid concentration until 120 min, after which no further increase was observed. Conversely, formic acid concentration was observed to increase only during the duration of sonication experiment.