Mechanism of degradation of 3,4-dimethylaniline by K2FeO4
YANG Wei-yi1, LI Meng1, ZHANG Qian1, XIANG Wen-qi1,2
1. School of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan 430070, China; 2. Wuhan Municipal Engineering Design and Research Institute Co. Ltd., Wuhan 430023, China
Abstract：The apparent kinetics and reaction mechanism of catalytic oxidation were investigated by using 3,4-dimethylaniline as the target pollutant and potassium ferrate (K2FeO4) as the oxidant. The new equation established for 3,4-dimethylaniline degradation by K2FeO4 was as follows:r=0.0043CA0.486CB1.2479. The reaction order was 1.7334, which conformed to the pseudo-second order kinetic equation. Meanwhile, the intermediate products during the degradation were analyzed through the GC/MS technology. It was presumed that 3,4-dimethylaniline was converted to 2,4-dimethylaniline at first, then the amide & methyl on the benzene ring were oxidized successively before 4-nitroisophthalic acid was formed. Due to decarboxylation, 4-nitroisophthalic acid was oxidized to nitrobenzene and further to a batch of cationic benzenes, and then decomposed into a series of small molecular hydrocarbons by destroying the phenyl structure. In final, these hydrocarbons were degraded into carbon dioxide and water. It was presumed that the control reaction of the oxidation-reduction was a two-steps process:in the first step, the potassium ferrate attacked the side chains on the 3,4-dimethylaniline benzene ring; secondly the ring-opening reaction of the benzene occurred. All in all, this degradation process mainly composed of two kinds of reaction mechanisms:surface complexation and interfacial catalysis.
杨唯艺, 李孟, 张倩, 项文琪. K2FeO4氧化降解3,4－二甲基苯胺的机理研究[J]. 中国环境科学, 2018, 38(5): 1744-1751.
YANG Wei-yi, LI Meng, ZHANG Qian, XIANG Wen-qi. Mechanism of degradation of 3,4-dimethylaniline by K2FeO4. CHINA ENVIRONMENTAL SCIENCECE, 2018, 38(5): 1744-1751.
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