College of Environment and Energy, South China University of Technology, Guangzhou 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, China.
Chemosphere. 2013 Nov;93(9):2180-6. doi: 10.1016/j.chemosphere.2013.07.081. Epub 2013 Sep 2.
The equilibrium sorption of tylosin (TYL) on kaolinite and montmorillonite was measured at different solution pH using batch reactor systems. The results showed that all the sorption isotherms were nonlinear and that the nonlinearity decreased as the solution pH increased for a given clay. At a specific aqueous concentration, the single-point sorption distribution coefficient (KD) of TYL decreased rapidly as the solution pH increased. A speciation-dependent sorption model that accounted for the contributions of the cationic and neutral forms of TYL fit the data well, suggesting that the sorption may be dominated by both ion exchange and hydrophobic interactions. The isotherm data also fit well to a dual mode model that quantifies the contributions of a site-limiting Langmuir component (ion exchange) and a non-specific linear partitioning component (hydrophobic interactions). X-ray diffraction analyses revealed that the interlayers of montmorillonite were expanded due to the uptake of TYL. TYL molecules likely form a monolayer surface coverage.
采用间歇反应器系统，在不同溶液 pH 值条件下测定了泰乐菌素（TYL）在高岭石和蒙脱石上的平衡吸附。结果表明，所有吸附等温线均为非线性，对于给定的粘土，随着溶液 pH 值的升高，非线性程度降低。在特定的水相浓度下，TYL 的单点吸附分配系数（KD）随溶液 pH 值的升高而迅速降低。一种基于形态的吸附模型，该模型考虑了 TYL 的阳离子和中性形式的贡献，很好地拟合了数据，表明吸附可能主要由离子交换和疏水相互作用共同控制。等温线数据也很好地符合了一种双模式模型，该模型量化了一个位点限制的 Langmuir 分量（离子交换）和一个非特异性线性分配分量（疏水相互作用）的贡献。X 射线衍射分析表明，由于 TYL 的吸收，蒙脱石的层间被扩展。TYL 分子可能形成单层表面覆盖。
