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

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.