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

Titanium dioxide in the anatase crystalline form was used as a photocatalyst to generate hydroxyl radicals in a flowthrough water reactor. Experiments were performed on pure cultures of Escherichia coli in dechlorinated tap water and a surface water sample to evaluate the disinfection capabilities of the reactor. In water devoid of significant amounts of inorganic-radical scavengers, rapid cell death was observed with both pure cultures and members of the indigenous flora in a natural water sample.

Inactivation of Escherichia coli by titanium dioxide photocatalytic oxidation.

Solar light induced photocatalytic degradation of Reactive Blue 220 (RB-220) dye with highly efficient Ag@TiO2 core-shell nanoparticles: A comparison with UV photocatalysis

This paper describes the basics of photocatalysis on semiconductors, mainly on TiO2 and the application of photocatalytic processes to water purification from organic matter. The second chapter is devoted to metal cocatalysts introduced in order to improve the photocatalytic action of titania. Finally, a short review of more interesting practical applications of the processes is presented.

Water purification by photocatalysis on semiconductors

Synthesis of yttrium doped nanocrystalline ZnO and its photocatalytic activity in methylene blue degradation

Kinetic Studies in Heterogeneous Photocatalysis. Part 1. Photocatalytic Degradation of Chlorinated Phenols in Aerated Aqueous Solutions Over TiO2 Supported on a Glass Matrix

H. Al-Ekabi

Papers

Kinetic Studies in Heterogeneous Photocatalysis. Part 1. Photocatalytic Degradation of Chlorinated Phenols in Aerated Aqueous Solutions Over TiO2 Supported on a Glass Matrix