A study of kinetic modelling and reaction pathway of 2,4-dichlorophenol transformation by photo-fenton-like oxidation

Chu, Wei; Kwan, C. Y.; Chan, K. H.; Kam, Sit

doi:10.1016/j.jhazmat.2005.01.019

Cited by 66 publications

(31 citation statements)

References 30 publications

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“…Then, and according to (8), the rate constant for the radical reaction k OH can be evaluated by subtracting from the rate constant k O3H the previously calculated value of k O3 . Following this procedure, the values deduced for k OH are listed in Table 4, and when compared to those of k O3 in Table 2, it is concluded that the radical reaction provides a contribution to the total reaction quite similar to that of the direct ozonation reaction.…”

Section: O 3 /H 2 O 2 Systemmentioning

confidence: 99%

“…These systems constitute the so-called ''Advanced Oxidation Processes'' (AOPs), which produce hydroxyl radicals by combining two or more single oxidants (ozone, hydrogen peroxide, and UV radiation), 5,6 as well as the combination of hydrogen peroxide with ferrous ions in the well known Fenton's reagent, 7 or the combination of Fenton's reagent with UV radiation as in the photo-Fenton system. 8 With these considerations in mind, a research program was designed to study the removal of diazinon by single oxidants (UV radiation and ozone separately) and by different AOPs (Fenton's reagent, UV radiation plus hydrogen peroxide, ozone plus hydrogen peroxide and the photo-Fenton system). The objectives of this study were to provide data on the extent of removal obtained, and to determine values of quantum yields and rate constants for the various processes tested, with special emphasis on the evaluation of the rate constant for the direct reaction between diazinon and hydroxyl radicals.…”

Section: Introductionmentioning

confidence: 99%

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Removal of diazinon by various advanced oxidation processes

Real

Benítez

Acero

et al. 2007

J of Chemical Tech & Biotech

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Diazinon is a widely used organophosphorus insecticide that is an important pollutant in aquatic environments. The chemical removal of diazinon has been studied using UV radiation, ozone, Fenton's reagent, UV radiation plus hydrogen peroxide, ozone plus hydrogen peroxide and photo-Fenton as oxidation processes. In the photodegradation process the observed quantum yields had values ranging between 2.42 × 10 −2 and 6.36 × 10 −2 mol E −1 . Similarly, the ozonation reaction gave values for the rate constant ranging between 0.100 and 0.193 min −1 . In the combined systems UV/H 2 O 2 and O 3 /H 2 O 2 the partial contributions to the global oxidation reaction of the direct and radical pathways were deduced. In the Fenton's reagent and photo-Fenton systems, the mechanism of reaction has been partially discussed, and the predominant role of the radical pathway pointed out. Additionally, the rate constant for the reaction between diazinon and the hydroxyl radicals was determined, with the value 8.4 × 10 9 L mol −1 s −1 obtained. A comparison of the different oxidation systems tested under the same operating conditions revealed that UV radiation alone had a moderate oxidation efficiency, which is enhanced in the case of ozone, while the most efficient oxidant is the photo-Fenton system.

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Section: O 3 /H 2 O 2 Systemmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Removal of diazinon by various advanced oxidation processes

Real

Benítez

Acero

et al. 2007

J of Chemical Tech & Biotech

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“…TCE and 2,4-DCP are traditional organic contaminants, which have been researched for their susceptibilities to Fenton degradation [13][14][15][16][17][18], but not on the comparison of biodegradability enhancement by different Fenton reagent types. Fe 0 can effectively reduce (dechlorinate) several chlorinated compounds including TCE and chlorophenols [19][20][21][22].…”

Section: Introductionmentioning

confidence: 99%

Effects of iron type in Fenton reaction on mineralization and biodegradability enhancement of hazardous organic compounds

Khan

Wirojanagud

Sermsai

2009

Journal of Hazardous Materials

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“…Besides that, the abundance, lack of toxicity, and ease of removal from water makes Fe 2+ the most commonly used transition metal for Fenton process applications. 4 Consequently, numerous studies have been carried out by using this oxidant for the treatment of a wide variety of water pollutants, such as atrazine, 5 p-chlorophenol, 6 textile effluents, 7 dichlorophenol, 8 and azo dyes. 9 Phenylurea derivatives are reported to be among the most widely used herbicides in agriculture today.…”

Section: Introductionmentioning

confidence: 99%

Kinetics of phenylurea herbicides oxidation by Fenton and photo‐Fenton processes

Benítez

Real

Acero

et al. 2006

J of Chemical Tech & Biotech

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The chemical oxidation of four selected phenylurea herbicides (linuron, chlortoluron, diuron, and isoproturon) was studied by means of the Fenton system. The influence of the initial concentrations of hydrogen peroxide and ferrous ions, the pH and the type of buffer (perchloric acid/perchlorate, acetic acid/acetate, or phosphoric acid/phosphate) was established according to the degradation levels obtained. In the kinetic study, the general decomposition reaction was divided into two stages with different reaction rates, which was justified by considering the whole reaction mechanism for this system. In this kinetic study, a competition kinetics model, which used p-chlorobenzoic acid as a reference compound, was applied for the evaluation of the rate constants for each reaction between the herbicides and the hydroxyl radical. The proposed values for these rate constants are: 7.5 × 10 9 L mol −1 s −1 for chlortoluron, 5.6 × 10 9 L mol −1 s −1 for linuron, 7.1 × 10 9 L mol −1 s −1 for diuron and 5.7 × 10 9 L mol −1 s −1 for isoproturon. Finally, some experiments with the photo-Fenton system reveal increases in the decomposition levels of the herbicides, due to additional generation reactions of hydroxyl radicals.

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A study of kinetic modelling and reaction pathway of 2,4-dichlorophenol transformation by photo-fenton-like oxidation

Cited by 66 publications

References 30 publications

Removal of diazinon by various advanced oxidation processes

Removal of diazinon by various advanced oxidation processes

Effects of iron type in Fenton reaction on mineralization and biodegradability enhancement of hazardous organic compounds

Kinetics of phenylurea herbicides oxidation by Fenton and photo‐Fenton processes

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