Catalytic Oxidation And Spectroscopic Analysis Of Simulated Organic Wastewater By Using Chlorine Dioxide As Oxidant

This paper reports the preparation of catalyst which can be used in the chlorine dioxide catalytic oxidation organic wastewater. It also studys catalytic oxidation and spectroscopic analysis of simulated organic wastewater containing acid chrome blue K and basic fuchsin by using chlorine dioxide as oxidant.Transition metal and its oxide can be used in oxidation-reduction reactions as catalyst. We choosed Fe(NO3)3,Ni(NO3)2,Cu(NO3)2 and Zn(NO3)2 as dipper activated carbon as carrier, preparing catalyst by impregnation method. The results show that the activated carbon-MnO2 catalyst calcinated at 300℃for 4 hours has higher activity in treating the simulated wastewater containing acid chrome blue K, and the carbon-(MnO2-Fe2O3-NiO) catalyst calcinated at 400℃for 3 hours has higher activity in treating the simulated wastewater containing basic fuchsin.The catalyst was used for catalyzing/degrading simulated acid chrome blue K wastewater with chlorine dioxide as oxidant. The CODCr removal efficiency and decolor efficiency by catalytic oxidation were 72.0% and 87.8%, respectively, at the condition of wastewater's CODCr was 2418mg/L, the optimum pH value was 1.2, the dosage of chlorine dioxide was 1200mg/L, the dosage of activated carbon-MnO2 catalyst was 4g by reacting 50min. The CODCr removal efficiency by catalytic oxidation was increased by 42.6% comparing with that of chemical oxidation. The CODCr removal efficiency decreased only 10.5% after the catalyst used 8 times. The IR spectra indicated that the active ingredient of manganese dioxide was linked with activated carbon by a chemical bond, not merely mechanical blending. The benzene ring and naphthalin ring in acid chrome blue K were degradated into quinone and carboxylic acid, and finally changed into carbon dioxide and water during the chemical oxidation or catalytic oxidation by on-line infrared spectrum mechanism analysis.The catalyst was also used for catalyzing/degrading simulated basic fuchsin wastewater with chlorine dioxide as oxidant. The CODCr removal efficiency and decolor efficiency by catalytic oxidation were 42.9% and 70.7%, respectively, at the condition of wastewater's CODCr was 2680mg/L, the optimum pH value was 1.2, the dosage of chlorine dioxide was 1500mg/L. The CODCr removal efficiency by TiO2 catalytic oxidation and the carbon-(MnO2-Fe2O3-NiO) catalytic oxidation were increased by 35.0% and 48.5% comparing with that of chemical oxidation. The CODCr removal efficiency decreased only 2.9% after the catalyst used 9 times. The benzene ring in basic fuchsin was degradated into quinone and carboxylic acid, and finally changed into carbon dioxide and water during the chemical oxidation or catalytic oxidation by on-line infrared spectrum mechanism analysis.This study illuminates that chlorine dioxide catalytic oxidation is an efficient method to treat difficulty degradation organic wasterwater, and it has prospective application.