典型土壤对土霉素的吸附研究

ntibiotics are used extensively in the areas of animal husbandry and aquiculture, and may directly reach the soil environment by the spreading of manure. Batch equilibrium experiments were conducted to study the isothermal adsorption of oxytetracycline (OTC) to two typical agriculture soils from south of China. Influences of pH and ionic strength on sorption of oxytetracycline to soils were also investigated. The results showed that isothermal adsorption of OTC to wushan soil and red soil were separately best described by Freundlich and Langmuir equations; OTC sorption constants for wushan soil and red soil were both decreased with the increasing of pH value, which can be resulted by the different charges of OTC under different pH value; Sorption of OTC to wushan soil was apparently restrained by high ionic strength, while it did not happen to the sorption of red soil, which might be explained by the different sorption mechanisms to these two soils.