[Oxytetracycline removal in aqueous by two kinds of zeolites with different bore diameter].

5A and 13X, as two kinds of hydrophilic zeolites with different bore diameters, were chosen as adsorption materials for oxytetracycline (OTC) adsorption and desorption in aqueous. The effects of pH value and temperature on OTC adsorption were investigated respectively, and then the adsorption kinetics as well as thermodynamic were calculated to analyze the corresponding adsorption mechanism. The results showed that two zeolites had satisfactory adsorption capacities on OTC and the adsorption processes were well fitted by the single-layer adsorption model. The saturated adsorption were 667 mg/g and 1429 mg/g on 5A and 13X respectively (298K, pH = 7.0). The adsorption property of OTC on 13X was much better than that of 5A at the same temperature. The adsorption kinetics were well described by the secondary kinetic equations and the OTC desorption rates by 5A and 13X were 91% and 95% individually in the desorption processes. The maximum adsorption capacities of two zeolites were in neutral solutions. And the thermodynamic calculations showed that the adsorption of OTC on two zeolites was spontaneous endothermic reaction with the chemical hydrogen bond as dominant.