Study On The Kinetics In Synergistic Ozonation Of Methylene Blue In The Presence Of Surface Functionalized Activated Carbon

The degradation of Methylene Blue trihydrate (MB) in a bubble column was studied to eliminate the environmental pollutions produced by dye wastewaters. Using ozone oxidation technique, the effects of granular activated carbon (GAC), granular modified activated carbon, pH and hydroxyl radical scavengers on decolorization of MB were investigated, where the possible mechanism of reaction process was analyzed.The four different weight of cerium(Ce) supported on GAC, which are prepared by dipping method, are characterized by XRD, XPS and SEM. CeO2cubic crystal is deposited on GAC. The content of Ce (W/W) is0.12%、0.23%、0.56%and1.12%respectively. At higher Ce on GAC, the surface area and microporous volume on GAC decrease. In pH=2.5buffer system with the dose of Ce/GAC at6g/L, the degradation of MB reaches optimal when0.23%Ce is attached to GAC; at26min, studying TOC removal ration and conductance ration in the four different laden Ce’s Ce/GAC/03systems, there obtains linear correlation between TOC removal ration and conductance ration(R2=-0.99575).In pH=12.7buffer system with the dose of Ce/GAC at6g/L or not, comparable date of degradation with O3,GAC/O3and0.23%Ce/GAC/O3systems, reaction time attains20min,18min,16min respectively when decolorization ration reaches100%, meanwhile, TOC removal ration reaches8.3%,20.3%and28%respectively. Through characterized by BET, the microporous volume and surface area of the new preparation0.23%Ce/GAC (0.5076cc/g^779.278m2/g) increase comparing with original GAC (0.4670cc/g、751.288m2/g), but the used0.23%Ce/GAC decrease (0.3808cc/g,603.344m2/g).It is validated that surface of0.23%Ce/GAC changes during ozonation process.Added HCO3" or tert-butyl alcohol(TBA)? OH radical scavengers in pH=12.7buffer system results in droping the ability for O3. It indicates that there exist? OH in systems. At the same time, compared the rate constants under acidic(pH=2.5), added HCO3-and added TBA conditions, this finding confirms that HCO3" is more stronger than tert-butyl alcohol(TBA). Therefore, it is demonstrated that the power of TBA as scavenger is characterized with limitation.