Synergistic degradation of hospital wastewater by solar/TiO2/Fe2+/H2O2 process

Abstract

Combined heterogeneous and homogenous photo-catalytic degradation of hospital wastewater was investigated. Three processes – solar/TiO2/H2O2, solar/Fe2+/H2O2 and solar/TiO2/Fe2+/H2O2 – were evaluated. The solar/TiO2/Fe2+/H2O2 process displayed increased efficiency due to the synergetic effect of homogeneous and heterogeneous photo-catalytic reaction. The combination increased the photo process efficiency by decreasing the reaction time of the separate operations and decreased the cost of treatment. The optimal conditions enabling over 99% reduction of chemical oxygen demand (COD) were pH 7, 0.5 g/L Fe2+, 0.2 g/L TiO2 and 1.35 g/L H2O2. The effluent COD and total suspended solids concentrations were 20 and 30 mg/L, respectively, which met the discharge standard requirements.