Kinetics of degradation intermediates during ozonization of 2,4-dichlorophenoxyacetic acid
2,4-Dichlorophenoxyacetic acid (2,4-D), a widely used herbicide, was treated by the ozonization technology in the laboratory.During the 2,4-D ozonization, the main categories of intermediates included chloric aromatics, dechlorinated aromatics and organic acids.Some of these intermediates have relatively high toxicity.Therefore, it is crucial to study the kinetics trend of intermediates diversion.Three possible degradation pathways were proposed in this paper.Path Ⅰ was a simple chain pathway.Path Ⅱ was a parallel pathway.Path Ⅲ was a cross pathway, the most complicated pathway.The concentration variations of main intermediates during reaction were analyzed by using these pathways.In addition, three kinetic models of intermediates were derived based on the proposed pathways.The fitting result showed that cross pathway was the best fitted pathway to explain the experimental data of intermediates concentration trend.It was shown that the correlation coefficients of main categories of intermediates were greater than 0.94 in the cross pathway.