Fenton chemistry encompasses reactions of hydrogen peroxide in the presence of iron to generate highly reactive species such as the hydroxyl radical and possibly others. In this review, the complex mechanisms of Fenton and Fenton-like reactions and the important factors influencing these reactions, from both a fundamental and practical perspective, in applications to water and soil treatment, are discussed. The review covers modified versions including the photoassisted Fenton reaction, use of chelated iron, electro-Fenton reactions, and Fenton reactions using heterogeneous catalysts. Sections are devoted to nonclassical pathways, by-products, kinetics and process modeling, experimental design methodology, soil and aquifer treatment, use of Fenton in combination with other advanced oxidation processes or biodegradation, economic comparison with other advanced oxidation processes, and case studies.

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Advanced Oxidation Processes for Organic Contaminant Destruction Based on the Fenton Reaction and Related Chemistry

Ozonation of drinking water: part I. Oxidation kinetics and product formation.

Combination of Advanced Oxidation Processes and biological treatments for wastewater decontamination—A review

Advanced oxidation processes (AOPs) constitute a promising technology for the treatment of wastewaters containing non-easily removable organic compounds. Chlorophenols (CPs) are a group of special interest due to their high toxicity and low biodegradability. Data concerning the degradation of CPs by means of AOPs reported during the period 1995–2002 are evaluated in this work. Among the AOPs, the following techniques are studied: processes based on hydrogen peroxide (H2O2+UV, Fenton, photo-Fenton and Fenton-like processes), photolysis, photocatalysis and processes based on ozone (O3, O3+UV and O3+catalyst). Half-life times and kinetic constants for CP degradation are reviewed and the different mechanistic degradation pathways are taken into account.

Degradation of chlorophenols by means of advanced oxidation processes: a general review

 Many atmospheric chemicals occur in the gas phase as well as in liquid cloud droplets and aerosol particles Therefore, it is necessary to understand the distribution between the phases According to Henry's law, the equilibrium ratio between the abundances in the gas phase and in the aqueous phase is constant for a dilute solution Henry's law constants of trace gases of potential importance in environmental chemistry have been collected and converted into a uniform format The compilation contains 17 350 values of Henry's law constants for 4632 species, collected from 689 references It is also available at http://wwwhenrys-laworg 

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Compilation of Henry's law constants (version 4.0) for water as solvent

This research describes the heterogeneous catalytic reactions of H2O2 with granular size goethite (α-FeOOH) particles in aqueous solution under various experimental conditions. This is an important reaction for the environment since both H2O2 and iron oxides are common constituents of natural and atmospheric waters. Furthermore, iron oxides function as catalysts in chemical oxidation processes used for treatment of contaminated waters with H2O2. The results of this study demonstrated that the decomposition rate of H2O2 over goethite surface can be described by the second-order kinetic expression −d[H2O2]/dt = k[FeOOH][H2O2], where k = 0.031 M-1 s-1, at pH 7 in the absence of any inorganic or organic chemical species. The apparent reaction rate was dominated by the intrinsic reaction rates on the oxide surfaces rather than the mass transfer rate of H2O2 to the surface. The activation energy of the reaction of H2O2 with the iron oxide surface was determined to be 32.8 kJ/M. The reaction mechanism for the de...

Catalytic Decomposition of Hydrogen Peroxide on Iron Oxide: Kinetics, Mechanism, and Implications

The objective of this study was to investigate the feasibility of using hydrogen peroxide (H 2 O 2 ) as a chemical oxidant for in-situ treatment of contaminated surface soils. The process has been tested in the presence and absence of ferrous sulfate on sand-packed columns, which contained pentachlorophenol (PCP) and trichloroethylene (TCE) as model compounds. Both column and batch studies have demonstrated that H 2 O 2 decomposed readily by interacting with the natural iron content of sand, and additional ferrous salts further enhanced the extent of H 2 O 2 decomposition. As a result, PCP and TCE adsorbed on the sand surface were oxidized effectively and by stoichiometric release of organic bound chlorine as chloride ion

Chemical oxidation of chlorinated organics by hydrogen peroxide in the presence of sand

This paper describes a study of a chemical oxidation process involving simultaneous application of hydrogen peroxide solution and ultraviolet light (H 2 O 2 /UV)for removal of organic pollutants from aqueous solution. The process was investigated experimentally in a continuous-flow stirred tank reactor (CSTR) under various operational conditions, i.e., H 2 O 2 dosage, UV light intensity, and liquid residence time. Synthetic solutions of a model organic compound, n-chlorobutane (BuCI), were oxidized at various pH and in the presence of various amounts of humic material and carbonate/bicarbonate ions in order to examine the effect of water quality on the process efficiency. A kinetic model of the process, which was developed based on H 2 O 2 /UV-induced radical oxidation of organic compounds, was successfully verified in pure water as well as in synthetic solutions.

Chemical oxidation by photolytic decomposition of hydrogen peroxide.

rn Decomposition kinetics of ozone in aqueous solution were studied at 20 \"C and in the pH range 2-10, under both quiescent and dynamic conditions. The data obtained in a batch reactor under quiescent conditions were analyzed by integral, initial-rate, and differential methods. The results indicated that ozone decomposes by a second-order reaction with respect to ozone concentration. The second-order decomposition kinetics determined in the batch reactor was confirmed by using a mathematical model developed for ozone decompgsition in an ozone contact column and the experimental observations under such dynamic conditions. The rate of decomposition was found to be relatively insensitive to pH below 4 and relatively slow under such acidic conditions (kd = 0.27 L/(mol 8)). Above pH 4, the rate is pH dependent with kd = ko[OH-]o*55, where ko is specific to the chemical composition of the aqueous system.

Mirat D. Gurol

Papers

Catalytic Decomposition of Hydrogen Peroxide on Iron Oxide: Kinetics, Mechanism, and Implications

Chemical oxidation of chlorinated organics by hydrogen peroxide in the presence of sand

Chemical oxidation by photolytic decomposition of hydrogen peroxide.

Kinetics of ozone decomposition: a dynamic approach

Oxidation of phenolic compounds by ozone and ozone + u.v. radiation: A comparative study