Kinetic model and optimization of 2,4-D degradation by anodic Fenton treatment.

Anodic Fenton treatment (AFT) is a new technology derived from chemical Fenton treatment. It has several advantages as compared with classic Fenton treatment and electrochemical Fenton treatment. On the basis of assumptions about a second-order reaction between pesticides and hydroxyl radicals and about AFT technology, a new kinetic model was developed to accurately describe the degradation kinetics of 2,4-D and to quantitatively investigate the effect of operating conditions. 2,4-D (2,4-dichlorophenoxyacetic acid) was employed as a probe in this study to investigate the AFT system. It was found that an increased delivery rate of Fenton reagent increased the degradation rate of 2,4-D, but the efficiency was decreased. The effects of the H2O2:Fe2+ ratio, the temperature, the initial concentration of 2,4-D, and the presence of other organic compounds have also been investigated. Quantitative correlations have been established that allow the use of this technology as a controlled Fenton reaction to determine the reaction rate constants of other compounds with hydroxyl radicals easily and accurately.