针铁矿与腐殖酸共存于环境中时,会通过一定的相互作用形成有机矿质复合体,这种复合体会对抗生素在环境中的吸附产生一定的影响。研究了针铁矿与腐殖酸的复合物对泰乐菌素的吸附特性。结果表明:针铁矿与腐殖酸的复合是通过化学作用进行结合的;针铁矿与腐殖酸复合之后,其对泰乐菌素的吸附能力明显增强;针铁矿及其与腐殖酸的复合物对泰乐菌素的吸附动力学可以用二级动力学模型和扩散模型较好的拟合,吸附具有明显的非线性,吸附等温线可以用Freundlich模型较好地拟合;针铁矿及其与腐殖酸的复合物对泰乐菌素的吸附受溶液pH值和离子强度的影响,且吸附机制主要以疏水性分配作用、氢键作用、离子交换和表面络合机制为主。
Goethite and humic acid occur simultaneously in the natural environment and form organomineral complexes. These complexes influence the sorption of antibiotics. The sorption characteristics of tylosin on goethite-humic acid complexes were investigated in this study. Results showed that goethite-humic acid complexes were combined by chemical reactions. The sorption capacities of the complexes were higher than that of goethite.The sorption kinetics of tylosin on both goethite and goethite-humic acid complex well fitted the pseudo-secondorder kinetics model and diffusion model. The sorption isotherms exhibited a significant nonlinear trend and the data fitted well with the Freundlich model. Besides,the sorption capacity of tylosin on goethite and its complexes would be different under different conditions of pH and ionic strength of solutions and the sorption mechanisms mainly involved hydrophobic,hydrogen-bond,ion-exchange and inner-sphere complexions.