Modeling the ozonation of 2,4-dichlorophoxyacetic acid through a kinetic approach

Wei Chu, M. H. Ching

Research output: Journal article publicationJournal articleAcademic researchpeer-review

43 Citations (Scopus)

Abstract

The ozonation of herbicide 2,4-dichlorophoxyacetic acid (2,4-D) was studied and modeled at different initial pH levels and initial concentrations. The degradation rate of 2,4-D was found to increase with the initial pH level and decrease with initial 2,4-D concentration. A two-stage ozonation of 2,4-D was observed, in which the initial stage of ozonation was slightly faster than the second stage due to the higher initial (saturated) ozone concentration; under these circumstances, the direct molecular ozone oxidation was likely to predominate. At the second stage, the indirect radical oxidation became more significant in determining the overall 2,4-D oxidation, and the reaction was more pH-dependent. A mathematic model associated with the analytical solutions consisting of direct and indirect oxidations contributed by the molecular ozone and free radical is proposed. The proposed model is capable of predicting the decay of 2,4-D quantitatively by ozonation at different initial pH levels and initial 2,4-D concentrations.
Original languageEnglish
Pages (from-to)39-46
Number of pages8
JournalWater Research
Volume37
Issue number1
DOIs
Publication statusPublished - 1 Jan 2003

Keywords

  • 2,4-D
  • Herbicide
  • Kinetics
  • Modeling
  • Ozone

ASJC Scopus subject areas

  • Ecological Modelling
  • Water Science and Technology
  • Waste Management and Disposal
  • Pollution

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