Study On The Catalytic Oxidation Of Simulated Wastewater Of High Concentration Organic Substance With Chlorine Dioxide As Oxidant

This paper reports the new technology of catalytic oxidation of simulated wastewater of high concentration organic substance with chlorine dioxide as oxidant. It includes the preparation of catalysts, chlorine dioxide catalytic oxidation high concentration organic wastewater containing naphthol green B and eriochrome black T.Transition metal and its oxide can be used in oxidation-reduction reactions as catalyst. The catalyst was prepared by dipping method by using Cu(NO₃)2, Mn(NO₃)₂, Zn(NO₃)₂ and Fe(NO₃)₃ as dipping solution, silica gel as carrier. The optimum active composition and preparing process was obtained by treating naphthol green B and eriochrome black T wastewater. The experiment indicated that the MnO₂-SiO₂ catalyst had maximum activity at baking temperature 350°C for 2 hours to treat the wastewater containing naphthol green B. Also, (CuO, Fe₂O₃, MnO₂)-SiO₂ catalyst had maximum activity at baking temperature 300°C for 2 hours to treat the wastewater containing eriochrome black T.When the naphthol green B simulated wastewater was treated by chlorine dioxide, the COD removal efficiency and decolor efficiency were 45.3% and 92.5%, respectively, at the condition of wastewater's COD 1533mg/L, the optimum pH value 1.2, the dosage of chlorine dioxide 1500mg/L by reacting 60min. The COD removal efficiency and decolor efficiency were 52.5% and 96.4%, respectively, at the condition of wastewater's COD 1533mg/L, the optimum pH value 1.2, the dosage of chlorine dioxide 1500mg/L, the dosage of TiO₂ 0.25g by reacting 60min. The COD removal efficiency and decolor efficiency were 70.9% and 96.8%, respectively, at the condition of wastewater's COD 1481mg/L, the optimum pH value 1.2, the dosage of chlorine dioxide 1000mg/L, the dosage of MnO₂-SiO₂ 5g by reacting 30min.When the eriochrome black T simulated wastewater was treated by chlorine dioxide, the COD removal efficiency and decolor efficiency were 24.1% and 70.0%, respectively, at the condition of wastewater's COD 2928mg/L, the optimum pH value 1.8, the dosage of chlorine dioxide 1200mg/L by reacting 60min. The COD removal efficiency and decolor efficiency were 33.6% and 53.2%, respectively, at the condition of wastewater's COD 2928mg/L, the optimum pH value 1.8, the dosage of chlorine dioxide 1200mg/L, the dosage of TiO₂ 0.25g by reacting 60min. The COD removal...