Integration of photocatalytic and biological processes for treatment of biorecalcitrant pharmaceuticals

Abstract

The present study facilitated exploring avenues for examining effective solutions to treat pharmaceutical model compounds and simulated effluent. The research primarily focussed on the degradation of pharmaceutical model compounds such as Aspirin, Ibuprofen, Ofloxacin and Atenolol by heterogeneous photocatalysis using various metal doped photocatalyst and its efficacy was compared with P25 TiO2 under optimized conditions. Fe-TiO2 (0.5wt %) photocatalyst was synthesized by solgel method and its efficiency was evaluated in the degradation of the Aspirin (25 ppm).The Brunauer Emmett Teller (BET) surface area of Fe TiO2 was found to be 72 m2/g and it has been observed that Fe-TiO2 resulted in higher degradation (96%) when compared to P25 TiO2 (72%) after 6 h of solar irradiations.Higher activity of Fe doped catalyst was attributed to its higher surface areabecause TiO2 crystallite grain sizes decreased with the increase of Fe contents and the diffuse reflectance spectra of Fe-doped TiO2 nanoparticles displayed a red shift in the band gap transition and the absorbing band edge moved to visible range. Similarly, photocatalytic degradation of Ibuprofen (IBP) was carried out under solar irradiation (30-35W/m2) using two different catalyst viz. Bi-TiO2 and Ni-TiO2synthesized by solgel method with dopant concentration varying from 0.25wt% to 1.0wt% and were characterized using XRD, SEM and UV-reflectance spectroscopy. The rate of solar induced photocatalytic degradation of IBP was observed to be in the order of Bi TiO2gt P25 TiO2gt Ni TiO2 with rate constants as 0.0064, 0.0046 and 0.0043 min-1, respectively.