Examination and research development of new catalysts for removing pharmaceuticals from water

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The presence of pharmaceuticals and endocrine disrupting compounds (EDCs) in natural waters has raisedincreasing concern due to their frequent appearance and persistence in aquatic ecosystem and the threat tohealth and safety of aquatic life, even at trace concentrations. Conventional water treatment processes areknown to be generally inadequate for the elimination of these persistent contaminants. Studies havedemonstrated that about 64% of EDCs are removed by less than 50% while 9% are not removed at all byconventional biological treatment processes. Therefore, the development of efficient and sustainable removalmethods for these emerging contaminants is essential. TiO2 is the most widely used photocatalyst for removalof organic contaminants from water. However, the higher efficiencies of ZnO compared to TiO2 forelimination of organic contaminant has been reported in several studies. Photocatalytic removal of EDCs byusing zinc oxide photocatalyst (ZnO) is a promising process due to the unique characteristics of thisphotocatalyst such as wide band gap, non-toxicity and low cost. Recently, a considerable effort has been madeto improve the photocatalytic performance of ZnO by doping with elements and narrowing band gap in order tobe activated under visible light irradiation. However, any effort to narrow the band gap of semiconductors leadsto the reduction of redox potential, as well as the efficiencies of elimination and mineralization. As analternative strategy, surface modification is considered for enhancing the efficiency of adsorption andphotocatalytic oxidation in this research. It is expected that surface fluorination of ZnO also enhances thephotocatalytic degradation of emerging contaminants. Through building a partnership with the DaguaTechnology Inc., this research is attempting to synthesize a dual functional hierarchical adsorbent/photocatalystwith high surface area and stability for removing EDCs from water with low energy consumption. For thispurpose, a tubular photoreactor will be designed in this study to perform experiments for elimination andmineralization of sulfamethoxazole as widely detected antibiotic in water, under extremely