工业腐殖酸提纯前后对泰乐菌素的吸附特性

The adsorption of tylosin by the industrial humic acid before and after purification

本文采用稀碱法对购买的工业腐殖酸进行了提纯,研究了腐殖酸提纯前后对泰乐菌素的吸附特性,并对其吸附机制进行了初步的探讨.研究结果表明:在对腐殖酸提纯之后,其C、H、O、N、S的含量明显增加,灰分含量显著减小.腐殖酸经提纯后对泰乐菌素的吸附明显增强,在24h可以完全达到吸附平衡,其吸附动力学曲线可以用拉格朗日二级动力学方程和颗粒扩散模型较好的拟合;吸附等温线可以用线性吸附模型和Freundlich吸附模型较好的拟合;且提纯后的腐殖酸对泰乐菌素的吸附随着溶液的p H值和离子强度增加而逐渐减小.综上,推测腐殖酸对泰乐菌素的吸附机制可能以疏水性分配、氢键作用和离子交换作用为主.

In this study the behavior and mechanisms of tylosin sorption on the industrial humic acid, before and after purification with dilute alkali method, were investigated. The results show that the contents of carbon, hydrogen, oxygen, sulphur and nitrogen increased obviously after purification of humic acid. Meanwhile the content of ash decreased remarkably. Importantly, the sorption capacity of the purified humic acid on tylosin increased and the sorption equilibrium could be attained within 24 hours. The pseudo-second-order and the intraparticle diffusion model fitted the sorption kinetics data well. The linear model and Freundlich model were much more suitable for explaining the sorption isotherm. Besides, the sorption on tylosin decreased gradually as the ionic strength and pH of the solutions increased. Generally, hydrophobic interaction, hydrogen bonding interaction and ion exchange interaction could play a main role in the sorption of tylosin on humic acid.