Development of an advanced hybrid process coupling TiO2 photocatalysis and zeolite-based adsorption for water and wastewater treatment

We present an advanced hybrid process coupling a fixed-bed photocatalysis reactor with the TiO2 photo-catalyst film coated on microstructured α-Al2O3 hollow fibers (AlHF) under UV exposure, with a second fixed-bed reactor where the zeolite-based adsorbent is fixed onto AlHF support for water and wastewater treatment. The physicochemical properties of both coated films were investigated by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) method, scanning electron microscopy (SEM), and energy dispersive X-ray (EDX). The sequential activity of the dual fixed bed reactor was overall evaluated by examining the degradation of 20 ppm Methylene Blue (MB), 1 ppm Iron and 0.04 ppm Arsenic solution as a general model of a complex aqueous solution containing not only an organic pollutant but also heavy metal and toxic cations. The results show that the proposed hybrid process by coupling two processes together could remove MB, Fe (II), and As (III) effectively, and the removal rates reached nearly 90%, 30%, and 70%, respectively, in 1 hour. These excellent results using the UV-TiO2/zeolite-based adsorbent combined process could be attributed to a synergistic effect between photocatalysis and adsorption process.