In recent years, researchers plunged to find efficient solutions to remove contaminants in water. Electrochemical oxidation methods were studied extensively because of the simple, clean energy and no secondary pollution. The refractory organic pollutants can be converted to biodegradable substances or direct mineralization by electrochemical oxidation method. The present review summarized the progress on electro-chemical oxidation mechanism, the recent development of anode materials, and proposed the research trend in the future. In electro-chemical oxidation mechanism aspect, the direct and indirect approaches are discussed. Some parameters which could impact the direct and indirect processes were considered. Apart from parameters, the dependence of anodic materials on the direct and indirect processes was also discussed. With the progress of anodic materials, carbon electrode, elemental metal electrode and dimensionally stable anode were summarized. All of the anodes were made to prolong the lifespan and improve the catalysis activity by adding the interlayer and adulterating the active components. The removal rates were collected to compare these anodes. For some typical anodes, the life span, the contact angle, the oxygen evolution potential (OEP) and the impedance were also listed. At last, the research trend was proposed. To achieve the commercial application of electrochemical oxidation method, the problems of the cost, the passivation membrane on the anode, and current density should be resolved.
Contents
1 Introduction
2 The mechanism of electro-chemical oxidation of organic pollutants
2.1 Direct electrochemical oxidation on the surface of anode
2.2 Indirect electrochemical oxidation by oxidative intermediates
3 Anodic materials
3.1 Carbon electrode
3.2 Elemental metal electrode
3.3 Dimensionally stable anode (DSA)
4 Summary and prospect