A novel use of nano-ceramic material to remove toxic organic pollutants in water by simultaneous separation and electrochemical oxidation

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Pharmaceuticals and personal care products (PPCPs), and perfluorochemicals (PFCs) as persistent organic pollutants (POPs) in water have raised substantial concern among the public and regulatory agencies recently. Therefore, effective treatment methods for the POPs contaminated water are needed to properly address the concern. Electrochemical oxidation of common PPCPs and PFCs, and simultaneous separation combined with electrochemical oxidation of the PPCPs in water using newly developed nano-ceramic porous electrodes respectively in laboratory batch and continuous experiments were investigated. The water permeable ceramic electrodes with good electrical conductivity were prepared using combustion synthesis method.The sixteen PPCPs were classified into three groups based on their degradations by electrochemical method: (a) easily degradable (Isopropylantipyrine, Diclofenac, Naproxen, Indomethacin, Triclosan and Gemfibrozil), (b) degradable in relatively longer time (Phenacetine, Clarit … More hromycin, Methoxsalen and Carbamazepine) and (c) difficult to degrade (Ibuprofen, Ketoprofen, Phenobarbital, Clofibric acid, Phenytoin and Fenoprofen). Two common PFCs, namely PFOA (Perfluorooctanoic acid) and PFOS (Perfluorooctane sulfonate), which are very resistant to biological and ordinary physicochemical methods, were degraded up to 84% and 99% respectively by the method.Moreover, a novel unit for simultaneous separation and electrochemical oxidation was designed using the nano-ceramic electrodes, and the unit was tested in continuous laboratory experiments for PPCPs removal. The PPCPs were continuously rejected by the system with almost the same efficiencies as observed in batch tests for electrochemical oxidation despite very short retention time for the combined process. About 20% of the PPCPs in feed water were adsorbed onto the porous ceramic medium indicating significance of adsorption on the rejections. The results indicated that the combined treatment method using the new ceramic material is very promising. Less