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.

/pdf/advanced-oxidation-processes-for-organic-contaminant-546ow329vb.pdf

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

2.2. Fenton’s Chemistry 6575 2.2.1. Origins 6575 2.2.2. Fenton Process 6575 2.3. Photo-Fenton Process 6577 3. H2O2 Electrogeneration for Water Treatment 6577 3.1. Fundamentals 6578 3.2. Cathode Materials 6579 3.3. Divided Cells 6580 3.4. Undivided Cells 6583 4. Electro-Fenton (EF) Process 6585 4.1. Origins 6585 4.2. Fundamentals of EF for Water Remediation 6586 4.2.1. Cell Configuration 6586 4.2.2. Cathodic Fe2+ Regeneration 6586 4.2.3. Anodic Generation of Heterogeneous Hydroxyl Radical 6587

Electro-Fenton process and related electrochemical technologies based on Fenton's reaction chemistry

Advanced oxidation processes (AOPs) constitute important, promising, efficient, and environmental-friendly methods developed to principally remove persistent organic pollutants (POPs) from waters and wastewaters. Generally, AOPs are based on the in situ generation of a powerful oxidizing agent, such as hydroxyl radicals (•OH), obtained at a sufficient concentration to effectively decontaminate waters. This critical review presents a precise and overall description of the recent literature (period 1990–2012) concerning the main types of AOPs, based on chemical, photochemical, sonochemical, and electrochemical reactions. The principles, performances, advantages, drawbacks, and applications of these AOPs to the degradation and destruction of POPs in aquatic media and to the treatment of waters and waste waters have been reported and compared.

Advanced Oxidation Processes in Water/Wastewater Treatment: Principles and Applications. A Review

Advanced oxidation processes (AOPs), defined as those technologies that utilize the hydroxyl radical (·OH) for oxidation, have received increasing attention in the research and development of wastewater treatment technologies in the last decades. These processes have been applied successfully for the removal or degradation of toxic pollutants or used as pretreatment to convert recalcitrant pollutants into biodegradable compounds that can then be treated by conventional biological methods. The efficacy of AOPs depends on the generation of reactive free radicals, the most important of which is the hydroxyl radical (·OH). The authors summarize the formation reactions of ·OH and the mechanisms of pollutants degradation. They cover six types of advanced oxidation processes, including radiation, photolysis and photocatalysis, sonolysis, electrochemical oxidation technologies, Fenton-based reactions, and ozone-based processes. Controversial issues in pollutants degradation mechanism were discussed. They review t...

Advanced Oxidation Processes for Wastewater Treatment: Formation of Hydroxyl Radical and Application

The application of strong electric fields in water and organic liquids has been studied for several years, because of its importance in electrical transmission processes and its practical applications in biology, chemistry, and electrochemistry. More recently, liquid-phase electrical discharge reactors have been investigated, and are being developed, for many environmental applications, including drinking water and wastewater treatment, as well as, potentially, for environmentally benign chemical processes. This paper reviews the current status of research on the application of high-voltage electrical discharges for promoting chemical reactions in the aqueous phase, with particular emphasis on applications to water cleaning.

/pdf/electrohydraulic-discharge-and-nonthermal-plasma-for-water-bcogyk507r.pdf

Electrohydraulic Discharge and Nonthermal Plasma for Water Treatment

The average diameter of bubbles generated from the porous plate in aqueous solution of organic substance and in a mixture of polar organic liquid and non-polar liquid were measured at various gas flow rates by taking photographs of bubbles. An addition of organic substance to water or to an organic liquid of opposite polarity reduces the degree of bubble coalescence on and above the plate, and hence the bubble size. As the degree of bubble coalescence and hence the degree of reduction of bubble size depends on da/dc1 of the solution and the diffusivity of the solute, an empirical equation for average bubble diameter is introduced, taking the above two properties into consideration.

Bubbles generated from porous plate in organic solutions and aqueous solutions of organic substances

Experimental study of the initial stage of oil spread on calm water

Entrainment and mass transfer at the density interface in a trough

A novel electrochemical reactor having a vertical stack of perforated graphite plates as bipolar electrodes was investigated by using the electrolysis of sodium bromide. The ratio of Faradaic current to reactor current was explained by an equivalent circuit model which consisted of bypass, sandwiched solution and Faradaic resistances. Energy consumption for bromine production was influenced by liquid flow regime such as continuous flow or trickle flow and by introducing inert gas countercurrently. Effects of flow regimes of liquid and gas on energy consumption were clarified by the changes of Faradaic current efficiency and the ratio of Faradaic current to total reactor current with the electrode potential difference between the two sides of a bipolar plate.

Energy consumption in a novel electrolyzer having a vertical stack of perforated graphite plates as bipolar electrodes

The initial stage of oil spreading on calm water was investigated for one-dimensional flow. Two kinds of experimental methods, instantaneous and constant rate of oil release, were used to investigate the rate of spreading and its dependence on surface contamination. Experimental and theoretical results were compared and some apparent discrepancies, hitherto unreported, are reported here. Also, a modified empirical correlation was obtained to express the spreading rate of oil slicks in the case of instantaneous oil release.

Kozo Koide

Papers

Bubbles generated from porous plate in organic solutions and aqueous solutions of organic substances

Experimental study of the initial stage of oil spread on calm water

Entrainment and mass transfer at the density interface in a trough

Energy consumption in a novel electrolyzer having a vertical stack of perforated graphite plates as bipolar electrodes

A study of the initial stage of oil spreading on calm water through methods of both instantaneous and constant rate of oil release