Electrochemical Decomposition and Adsorption for Removal of Organic Pollutants from Water

Water treatment based on electrochemical methods is a powerful means of degrading both biologically and chemically resistant organic compounds. Most organic pollutants can be removed or converted to chemicals of low toxicity using one or more electrochemical processes, including electrochemical oxidation/reduction, electrocoagulation, electroflotation, electrodialysis, and advanced electrochemical oxidation methods. Among the various electrochemical treatments used for organic pollutants, electrochemical adsorption offers a unique water treatment approach in that it utilizes the electrochemical oxidation reactions of target pollutants to obtain clean water via electrochemical polymerization or the formation of highly hydrophobic oxides. In the electrochemical adsorption method, the electrode exhibits dual functions both as a catalyst to promote the electrochemical reaction of the target pollutant and as an adsorbent to accumulate the products of the electrochemical reaction. In this chapter, the electrochemical oxidation of bisphenol A and its derivatives and their treatment with carbon fibers are introduced. In addition, the applications of electrochemical adsorption to other organic pollutants, such as aniline, estrogens, p-nonylphenol, phenol, and chlorinated phenol, are presented. Moreover, recent progress in electrochemical adsorption using various electrode materials such as carbon nanotube-covered polyester yarn, PbO₂, granular carbon, stainless steel, carbon aerogel, and polyaniline is reviewed.