Adsorption and Desorption of Tylosin on the Colloidal Fractions of Black Soil

摘要

Adsorption and desorption of tylosin on different colloidal fractions from Black soil were studied. The adsorption isotherms of tylosin conformed to the Langmuir equation. The amount of Tylosin adsorbed followed the order: fine organic clay>fine inorganic clay> coarse organic clay>coarse inorganic clay. Marked decreases in the adsorption of tylosin on soil colloids were observed in the presence of Na+ and Ca2+ ions, and the influence of Ca2+ was stronger than that of Na+. The sorbed tylosin on soil colloids was sequentially desorbed by 10 mmol.L-1 Tris, 100 mmol·L-1 NaCI and 100 mmol·L-1 phosphate solutions at pH 7.0. The percent desorption by Tris and NaCI was 79%～105%, showing that electrostatic interaction played an important role in the adsorption of tylosin by soil colloidal components.