EFFECT OF Cu2+ TO THE ADSORPTION OF OXYTETRACYCLINE IN SUBALPINE MEADOW SOILS OF PASTORAL AREAS IN ZOIGE PLATEAU

In this study, oxytetracycline (OTC) was used as the target organic pollutant, and the typical soil of Northwest Sichuan Plateau-subalpine meadow soil (SH) was used as the adsorbent. The batch balance experiment method was used to study the adsorption characteristics of OTC on the soil when Cu2+ coexisted, and the results showed that the adsorption was divided into a fast adsorption phase (0-6 h) and a slow adsorption phase (6-36 h), and the adsorption gradually tended to equilibrium after 36 h. Among them, as the initial concentration of OTC increased continuously, the adsorption of OTC also increased, but the adsorption rate showed a decreasing trend. The adsorption of OTC also increased with the increasing initial concentration of OTC, but the adsorption rate showed a decreasing trend. At 25 degrees C, the Freundlich model fitted the experimental data of OTC adsorption isotherm in SH well, indicating that the adsorption was mainly multi-molecular layer adsorption. The adsorption thermodynamic parameters (Delta G(theta), Delta H-theta, Delta S-theta) were less than 0, indicating that the adsorption process is a spontaneous exothermic reaction with gradually decreasing confusion, and the increase of temperature is not favorable to the adsorption of OTC. the presence of Cu2+ increases the adsorption amount and rate of OTC on SH, and The promoting effect increases with increasing Cu2+ concentration.