Treatment of Pharmaceutical Industry Wastewater by PhotoelectroFenton Oxidation

Abstract

The use of Photoelectro-Fenton oxidation to treat real pharmaceutical effluent is an attractiveoption for the elimination of complex and persistent organic contaminants. This advanced oxidation processcombines the electrochemical generation of highly reactive hydroxyl radicals (OH•) with the photochemicaldegradation of by-products, resulting in the efficient removal of pharmaceutical compounds fromwastewater. In the Photoelectro-Fenton process, an appropriate anode material, such as BDD or DSA, isused to generate OH•radicals through the electrochemical oxidation of Fe2+ ions. The addition of a smallamount of Fe2+ and H2O2 facilitates the Fenton reaction, leading to the production of additional OH•radicalsin the solution. The presence of these OH•radicals ensures the effective oxidation of pharmaceuticalpollutants, which are often resistant to conventional wastewater treatment methods. The use of UV orsunlight irradiation further enhances the Photoelectro-Fenton process by promoting thephotodecomposition of intermediate by-products formed during the oxidation process. This simultaneouselectrochemical and photochemical degradation mechanism provides synergistic effects, resulting inenhanced degradation and mineralization of pharmaceutical compounds. Studies have demonstrated thesuccessful application of Photoelectro-Fenton oxidation for the treatment of real pharmaceuticalwastewater, showing significant removal efficiencies for a wide range of pharmaceutical compounds,including antibiotics, analgesics, and hormones. Additionally, the process has been shown to effectivelydegrade recalcitrant by-products and reduce the overall toxicity of the wastewater. However, it is importantto consider factors such as optimal pH, Fe2+ and H2O2 dosages, irradiation intensity, and reaction time toachieve optimal treatment efficiency. Furthermore, the cost-effectiveness and scalability of thePhotoelectro-Fenton process need to be evaluated for its potential implementation in large-scale wastewatertreatment facilities.