【作者】 王春红；

【导师】 黄巧云； 梁巍；

【作者基本信息】 华中农业大学 ， 环境科学， 2010， 硕士

【摘要】 采集吉林公主岭的土壤,沉降虹吸法分离小于2μam的土壤胶体,离心分离出0.2-2μm和小于0.2μm的粗细粘粒,取部分粘粒经H202去有机质处理得到四种黑土胶体：0.2-2μm含有机质粘粒、0.2-2μm去有机质粘粒、小于0.2μm含有机质粘粒和小于0.2μm去有机质粘粒。以上述四种黑土胶体、高岭石、针铁矿和蒙脱石为实验材料,研究了大环内酯类抗生素-泰乐菌素在其表面的吸附、解吸特性及吸附前后的官能团变化和吸附过程的热力学特性。主要结果如下：1、土壤细粘粒的吸附量高于粗粘粒,有机质对泰乐菌素的吸附起促进作用,蒙脱石的吸附量远远高于黑土胶体和高岭石、针铁矿。泰乐菌素与蒙脱石之间的亲和力最大,黑土胶体次之,针铁矿最小。2、阳离子对泰乐菌素的吸附起抑制作用,CaCl2比NaCl的抑制作用更强。同时,阳离子对黑土胶体和高岭石、针铁矿的抑制强度大于蒙脱石。3、采用Tris-HCl缓冲液和氯化钠缓冲液连续解吸了土壤胶体和矿物表面吸附的泰乐菌素,结果表明,吸附于黑土胶体表面的泰乐菌素80%结合较松散,可以被解吸剂解吸；蒙脱石的解吸率最低,说明它与泰乐菌素结合最紧密。4、应用傅里叶红外光谱仪对泰乐菌素、黑土胶体和矿物及其复合物的结构进行了分析,发现两者作用后,泰乐菌素的大环内酯类特征峰均有所减小或消失,可能是因为羰基与OH形成了分子间或分子内氢键,导致羰基消失。5、泰乐菌素在黑土胶体和矿物表面的吸附是自发过程。泰乐菌素与黑土胶体、高岭石、针铁矿的吸附过程均为放热反应；而泰乐菌素在蒙脱石上的吸附为吸热反应。6、根据土壤胶体矿物表面抗生素吸附解吸和热力学特性,分析认为泰乐菌素在黑土胶体表面的吸附主要通过静电力的作用；针铁矿表面可能是氢键和范德华力的作用；而泰乐菌素与蒙脱石之间也许是疏水作用。更多还原

【Abstract】 Black soil was sampled from gongzhuling, Jilin province.Soil colloids were obtained through siphon method after dispersion, and separated into coarse clays(0.2-2μm) and fine clays(<0.2μm) by centrifugation. Part of fine and coarse clays were oxidized by H2O2 to remove organic matter. The types of clays were as follows:0.2-2μm organic clay,0.2-2μm inorganic clay,<0.2μm organic clay and<0.2μm inorganic clay. This study investigated the adsorption-desorption, changes in functional groups and thermodynamic characterics of tylosin on soil colloids and minerals.The main results were listed as following:1.The amount of tylosin adsorbed by fine clays was higher than that of coarse clays. Montmorillonite dominates the amount of tylosin adsorption and organic matter also contributes to the tylosin adsorption. Tylosin was adsorbed more tightly on montmorillonite than on Black soil colloids and goethite.2.Ionic species and strength have significant effects on tylosin adsorption on Black soil colloids or minerals.The inhibiting effect of Ca2+ ions was stronger than that of Na+ ions.Meanwhile, the inhibiting effect of cation of soil colloids, kaolinite and goethite was stronger than that of montmorillonite.3.To determine the percentage of various forces involved in tylosin adsorption, tylosin adsorbed by soil colloids and minerals were desorbed by sequential washing with 10 mM Tris-HCl and 100 mM NaCl at pH 7.0.80% of tylosin combined loosely with Black soil colloids which can be desorbed easily; the desorption rate of montmorillonite was the lowest, indicating that it combined with tylosin most closely.4.Fourier transform infrared spectra (FTIR) was employed to investigate the structure characteristics of tylosin, Black soil colloids and minerals as well as their complexes.The results showed that the peaks of macrolide decreased or disappeared after tylosin adsorbed, which may be due to the formation of hydrogen bonds within or between molecules.5.The thermodynamic data of tylosin adsorption on soil colloids and minerals were provided. Tylosin adsorption on Black soil colloids or minerals is a spontaneous process. The adsorption of tylosin on Black soil, kaonite and goethite were exothermic. However, the adsorption of tylosin on montmorillonite was endothermic.6.Tylosin was adsorbed by electrostatic forces on soil colloids; hydrogen bonding and Van der Waals forces played a important role in the adsorption on goethite and the adsorption between tylosin and montmorillonite was a hydrophobic interaction.更多还原