Catalytic oxidation of highly concentrated real industrial wastewater by integrated ozone and activated carbon

Integration of ozone and granular activated carbon (GAC) was applied to treat highly concentrated real wastewater from chemical industry. The results revealed that the integrated process had more advantages than the individual ozonation and GAC adsorption. The integrated process enhanced COD removal, increased ozone utilization and avoided frequent GAC regeneration. The pH value was found to exert a great effect on COD removal; a positive effect on COD removal was more pronounced at basic conditions than at acidic conditions. Furthermore, there were some differences in reaction mechanisms at different pH conditions, as confirmed by FTIR and SEM analysis. At the acidic conditions, the primary reaction mechanism was adsorption–ozonation regeneration, while at the basic conditions, GAC adsorption ability was restrained, and the primary mechanism was catalytic oxidation.

A comparison among individual ozonation, GAC adsorption and their integration shows the significant synergistic effect occurs in the integrated process at basic pH conditions. No synergistic effect occurs at acid pH conditions. The pH value affects the reaction mechanism. The primary reaction mechanism at acidic conditions is adsorption–ozonation regeneration, while the primary mechanism at basic conditions is catalytic oxidation.Figure optionsDownload as PowerPoint slide