[Study on removal of surfactant by activated carbon catalytic ozonation]

The anionic surfactant sodium dodecyl benzene sulfonate (SDBS) is employed as the target pollutant; the SDBS degradation in the processes of ozone (O3), activated carbon (AC) and activated carbon catalytic ozonation were studied. The impact of natural organic matter (NOMs) on the degradation of SDBS by catalytic ozonation was also investigated. Results show that: SDBS removal by using activated carbon catalytic ozonation is higher than that of using single ozonation or AC adsorption respectively; and the most effective time is the early 20 min when the concentrations of ozone and SDBS are relatively high. In the first 5 min (general hydraulic retention time), SDBS removals of the ozonation and AC adsorption were only about 17% and 12.2%, respectively; while the removal of catalytic ozonation reached 54.2% which was much more than the total removal of single ozonation and single adsorption, which showed significant efficiency of the catalytic ozonation. The mechanism of catalytic ozonation involves more radicals could be generated by ozone with the presence of AC; or much higher concentrations of both ozone and reactant would achieve, which enhances the reaction efficiency. Compared with the raw AC, AC experienced relatively long time and high concentration ozone treatment showed little effects on its decomposition efficiency of SDBS during catalytic ozonation. NOMs in the water samples decreased SDBS removals by catalytic ozonation; but the removals kept high under relatively low NOMs concentrations.