Photo-Catalytic Degradation of Wastewater from Straw Pulp and Paper Mill by Fe2O3/UV/H2O2

The purpose of this study was to examine the photo catalytic degradation of real effluents from wheat straw pulp and paper mill by nano-Fe₂O₃ catalyst. Four different ferric oxide samples were synthesized by homogeneous precipitation of reflux at different drying and calcination conditions. The most active catalyst was characterized and used as catalyst in photo catalytic degradation process. The effect of key parameters including catalyst dose, solution pH, oxidant concentration were investigated. The results showed UV light alone played a little role in the degradation of wastewater in a short time and the presence of Fe₂O₃ could greatly promote the degradation of wastewater. The degradation of wastewater was favorable at pH 3. Optimum values of catalyst dose and oxidant concentration was found to be 1 g L^-1 and 5⁰/₀₀ (v/v), respectively. Under the optimum condition, the removal rate of COD reached 93.1% under ultraviolet irradiation for 3 h. Satisfactory results suggested the effectiveness of the heterogeneous photo catalytic system of Fe₂C₃UV/H₂O₂ in eliminating COD of paper mill effluent. The COD of effluent was in the range of the acceptable values of the latest China Government standards.