Abstract:

 The activated carbon-MnO2 catalyst was prepared by the dipping method with activated carbon as the carrier. The catalyst was used for catalyzing／degrading simulated acid chrome blue K wastewater with chlorine dioxide as the  oxidant. The COD removal efficiency and decolor efficiency by catalytic oxidation were 72.0％ and 87.8％, respectively, when the condition of wastewater’s COD was 2418mg／L, the optimum pH value was 1.2, and the dosage of chlorine dioxide was 1200mg／L,  and the dosage of activated carbon-MnO2 catalyst was 4g after  reacting 50min. The COD removal efficiency by catalytic oxidation was increased by 42.6％ compared with that of the chemical oxidation. The COD removal efficiency decreased only 10.5％ after the catalyst was 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 by mechanical blending. The benzene ring and naphthalin ring in the acid chrome blue K were degraded into quinone and carboxylic acid, and finally changed into carbon dioxide and water during  chemical oxidation or catalytic oxidation as shown by on-line infrared spectrum mechanism analysis.
 

Key words: chlorine dioxide, catalytic oxidation, acid chrome blue K, wastewater treatment, on-line infrared spectrum