Photo-catalytic Degradation of Wastewater from Straw Pulp and Paper Mill by

The purpose of this study was to examine the photocatalytic 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 photocatalytic 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 5 ‰ (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 photocatalytic system of Fe2O3/UV/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.