Photocatalytic Degradation of Pharmaceuticals Wastewater

Abstract

Heterogeneous photocatalysis process has proved its superiority to other conventional methods of wastewater treatments in the presence of biorecalcitrant compounds. In the present study the heterogeneous photocatalytic degradation for the pharmaceutical compound Ornidazole and real wastewater from pharmaceutical industry with TiO2 was assessed. The investigation of % degradation of Ornidazole using TiO2 as a photo catalyst was done. The experiments were conducted in slurry mode and fixed mode. The input parameters which were varied were pH, Ornidazole concentration, TiO2 dose and time. ANN was applied for the modeling of the photocatalytic process. Optimization was performed by using RSM with desirability approach. The experiments were performed at the optimized conditions for slurry mode and fixed mode using TiO2 immobilized on cement beads. At the optimum conditions the % degradation was found to be 77.7% for slurry mode and for fixed bed the % degradation was 76.5% for 360 min. The results showed that the predictions agreed with the experimental results. Kinetic study showed that degradation of ornidazole follows the second order kinetics. The investigation of % COD removal of real pharmaceutical waste water using TiO2 as a photo catalyst was done. The experiments were conducted in slurry mode. The input parameters which were varied were pH, TiO2 dose and time. Optimization was performed by using RSM with desirability approach. The experiments were performed at the optimized condition. At the optimum conditions the % COD removal was found to be 63.7%. The results showed that the predictions agreed with the experimental results. Kinetic study shows that degradation of real wastewater follows the second order kinetics. Bioassay testing was conducted for the treated wastewater. The treated wastewater was found to be non toxic and could be disposed off to the environment safely.