STUDY ON CATALYTIC OZONATION DEGRADATION OF GUAIACOL WITH CUPRIC OXIDES LOADED ON ACTIVATED CARBON

Catalysts of activated carbon (AC) loaded metal oxides were prepared and characterized by means of surface characterization, XRD and SEM. The prepared catalysts were then used for catalytic ozonation of guaiacol simulated wastewater and the effects of active component, initial pH, loading content and catalyst dosage on guaiacol removal efficiency were investigated. Results showed that the AC and the prepared catalysts loaded with different active components had obvious catalytic activity for the oxidative degradation of guaiacol by ozone and effectively improved the degradation efficiency of chemical oxygen demand (CODcr). The order of catalytic activity was Cu/AC>Ni/AC>Ce/AC>Fe/AC and the highest CODcr removal of 90.21% was achieved in 60 min with Cu/AC as catalyst under conditions of initial pH of 11, loading content of 3% and catalyst dosage of 1.0 g/L. The CODcr removal efficiency was 29.63% and 20.63% higher than that of ozone treatment alone and AC catalytic ozone treatment respectively. Kinetics analysis showed that, during the ozonation process catalyzed by the prepared catalysts, the CODcr - degradation of the guaiacol simulated wastewater approximately conformed to apparent second-order reaction kinetics and the metal oxides loaded on AC effectively improved the reaction rate constant. The tert-butanol (TBA) addition experiments showed that the COD removal decreased significantly when TBA was added, indicating that the CODcr - degradation of the guaiacol simulated wastewater followed the hydroxyl radical reaction mechanism during the catalytic ozonation process. The obvious increases of BOD5 and BOD5/CODcr values of the guaiacol simulated wastewater during catalytic ozonation process indicated enhancement of the biodegradability of the guaiacol simulated wastewater.