Kinetic Model and Optimization of 2,4-D Degradation by Anodic Fenton Treatment

Abstract

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.

AuPd/Fe3O4-based three-dimensional electrochemical system for efficiently catalytic degradation of 1-butyl-3-methylimidazolium hexafluorophosphate

“…As shown in Fig. 4c, the degradation plots versus time appear to have an S shape, which is quite similar to that in the anodic Fenton treatment (AFT) model [33]. The concentration of BMIM suffered a subtle concentration decrease in the beginning and at the end, while a relatively sharp decrease in the middle stage of the degradation proceeding.…”

“…The consensus was that Fe 2+ could also be reproduced through the reduction of Fe(III) by chemically atomic H produced on the active crystal facets of AuPd alloys [34]. In the meantime, Note: K is the substitution of k 1 k 2 lvp v 0 2 ; k 1 k 2 lvpv 0 2 is an integrated parameter in the AFT model [33], which signifies the overall degradation rate in the process.…”

Analytical Methods for Performing Pesticide Degradation Studies in Environmental Samples

“…The times necessary for the disappearance of the pesticide in the presence of Degussa P 25 and Millennium PC 500 were 20 and 80 minutes, respectively, the efficiency of TiO 2 (P 25 ) being the greater. Wang & Lemley, 2001, studied the rate of degradation of the pesticide 2,4-D in natural waters by treatment with Fenton, combined with the photocatalytic degradation of pesticides with TiO 2 . Rapid degradation by the Fenton reaction occurred in the presence of hydrogen peroxide; otherwise, the process was very slow.…”

Optimization and control of Electro-Fenton process by pH inflection points: A case of treating acrylic fiber manufacturing wastewater

“…Moreover, pH variation closely relates to the oxidation of free radicals and the hydrolysis of iron ions, and greatly affects the oxidative efficiency thereafter. For example, the efficiency of EF decreased from 7.4 Â 10 À2 to 2.3 Â 10 À2 min À1 when pH changed from 7.0 to 10.5 [17,18]. Unfortunately, few studies have investigated the relation between the EF efficiency and pH variation to the best of our knowledge; and a strategy to monitor and optimize pH in the EF process has never been reported:…”