Direct And Mediated Anodic Oxidation of Organic Pollutants

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

Over the last decades, research efforts have been made at developing more effective technologies for the remediation of waters containing persistent organic pollutants. Among the various technologies, the so-called electrochemical advanced oxidation processes (EAOPs) have caused increasing interest. These technologies are based on the electrochemical generation of strong oxidants such as hydroxyl radicals ( OH). Here, we present an exhaustive review on the treatment of various synthetic and real wastewaters by five key EAOPs, i.e., anodic oxidation (AO), anodic oxidation with electrogenerated H 2 O 2 (AO-H 2 O 2 ), electro-Fenton (EF), photoelectro-Fenton (PEF) and solar photoelectro-Fenton (SPEF), alone and in combination with other methods like biological treatment, electrocoagulation, coagulation and membrane filtration processes. Fundamentals of each EAOP are also given.

Electrochemical advanced oxidation processes: A review on their application to synthetic and real wastewaters

In recent years, new advanced oxidation processes based on the electrochemical technology, the so-called electrochemical advanced oxidation processes (EAOPs), have been developed for the prevention and remediation of environmental pollution, especially focusing on water streams. These methods are based on the electrochemical generation of a very powerful oxidizing agent, such as the hydroxyl radical (•OH) in solution, which is then able to destroy organics up to their mineralization. EAOPs include heterogeneous processes like anodic oxidation and photoelectrocatalysis methods, in which •OH are generated at the anode surface either electrochemically or photochemically, and homogeneous processes like electro-Fenton, photoelectro-Fenton, and sonoelectrolysis, in which •OH are produced in the bulk solution. This paper presents a general overview of the application of EAOPs on the removal of aqueous organic pollutants, first reviewing the most recent works and then looking to the future. A global perspective on the fundamentals and experimental setups is offered, and laboratory-scale and pilot-scale experiments are examined and discussed.

Electrochemical advanced oxidation processes: today and tomorrow. A review

Traditional physicochemical and biological techniques, as well as advanced oxidation processes (AOPs), are often inadequate, ineffective, or expensive for industrial water reclamation. Within this context, the electrochemical technologies have found a niche where they can become dominant in the near future, especially for the abatement of biorefractory substances. In this critical review, some of the most promising electrochemical tools for the treatment of wastewater contaminated by organic pollutants are discussed in detail with the following goals: (1) to present the fundamental aspects of the selected processes; (2) to discuss the effect of both the main operating parameters and the reactor design on their performance; (3) to critically evaluate their advantages and disadvantages; and (4) to forecast the prospect of their utilization on an applicable scale by identifying the key points to be further investigated. The review is focused on the direct electrochemical oxidation, the indirect electrochemical oxidation mediated by electrogenerated active chlorine, and the coupling between anodic and cathodic processes. The last part of the review is devoted to the critical assessment of the reactors that can be used to put these technologies into practice.

Douglas Waychi Miwa

Papers

Oxidation of the pesticide atrazine at DSA electrodes

Decolorisation of real textile waste using electrochemical techniques: effect of the chloride concentration.

Study of anion adsorption on polycrystalline Pt by electrochemical quartz crystal microbalance

Electrochemical degradation of carbaryl on oxide electrodes.

Electrochemical degradation of the dimethyl phthalate ester on a fluoride-doped Ti/β-PbO2 anode.