Adsorption Of Difloxacin And Lincomycin Onto Typical Soils

Economy is developing rapidly with a large population in Liaohe Plain, North China Plain and Pearl River Delta, so abuse of antibiotics is serious in these areas resulting environmental risk. This article selects three kinds of adsorbents on behalf of soils in Liaohe Plain, North China Plain and Pearl River Delta, which respectively marked by gss-11, gss-13 and gss-16. Through the study on the adsorption behaviors of two types of antibiotics(difloxacin and lincomycin) in three soils, a theoretical basis for risk assessment of environment and pollution control can be provided. The results from our study indicated that:(1) The adsorption of difloxacin and lincomycin onto three soils conformed to Langmuir isotherm. The mainly adsorption mechanisms of difloxacin were chemical adsorption and electrostatic interaction. Lincomycin adsorption mechanisms were mainly physical adsorption and hydrogen bonding.(2) The p H of solution played a significant role in adsorption and desorption of difloxacin and lincomycin. When p H was close to the p Ka of two antibiotics, their adsorption quantities were almost biggest. With the increasing or decreasing of p H, the adsorption quantity became smaller.(3) Desorption on three soils of difloxacin was obviously hysteretic. Its retardation factor R was large and was not easily migrated. On the other hand, lincomycin was easily desorbed, and retardation factor was about equal to 1, indication easy to migrate in the environment.(4) When two antibiotics existed together, lincomycin promoted adsorption of difloxacin, but inhibited its desorption. Difloxacin occupied the adsorption sites of hydroxy of lincomycin thereby inhibited the adsorption of lincomycin.