四环素在乌栅土中的吸附与解吸  

Sorption and Desorption of Tetracycline on Wushantu Soil

作　　者：焦少俊[1] 孙兆海[1] 郑寿荣[1] 尹大强[2] 浦海清[1] 陈良燕[1] 

机构地区：[1]南京大学环境学院,污染控制与资源化国家重点实验室,江苏南京210093 [2]同济大学环境科学与工程学院,教育部长江水环境重点实验室,上海200092

出　　处：《农业环境科学学报》2008年第5期1732-1736,共5页Journal of Agro-Environment Science

基　　金：国家自然科学基金(20777055)

摘　　要：采用批平衡实验方法,研究了四环素(TC)在太湖地区乌栅土中的吸附解吸,以及pH和典型二价阳离子Ca2+和Mg2+对TC吸附的影响。结果表明,TC在乌栅土中的吸附可以用线性方程拟合,所得Kd和Koc值分别为419.38L·kg-1和19782.07L·kg-1,Kd和Koc值较高,这表明乌栅土中的TC不易迁移和淋溶,对太湖地区地表水和地下水等饮用水源的影响风险较小。对单次吸附解吸过程的结果采用滞后性指数评价TC的解吸的滞后性,得到滞后性指数为2.58,显示TC在乌栅土中的解吸存在明显的滞后性。TC在乌栅土中的吸附也受pH条件和二价阳离子的明显影响,低pH条件可以明显地促进TC在土壤中的吸附,而高pH条件下,TC吸附受到抑制,并更易于达到最大吸附量。通过对低pH条件TC+离子含量分数的分析表明,TC+离子能明显地增加TC在土壤上的吸附,并且其离子所占比例与分配系数具有良好的相关关系。典型二价阳离子Ca2+和Mg2+的存在也可以明显降低TC在土壤上的吸附。The extensive utilization of antibiotics in agricultural husbandry has led to a worldwide pollution and become the subject of increasing concern. Moreover, tetracycline （TC）is one of the most used antibiotics in China. In this study, sorption and desorption of TC on Wushantu soil, a typical soil in Taihu region, as well as the effects of pH and divalent cations on sorption were evaluated. The results of the batch experiments showed that the sorption and desorption isotherms of TC on Wushantu soil were well fitted the linear model. The distribution coefficient （ Kd ）of TC on the soil was calculated to be 419.38 L·kg^-1, and the carbon normalized distribution coefficient （K∝）went to 19 782.07 L·kg^-1. The high value of Kd and K∝ indicates a little mobility of TC in Wushantu soil and a minor risk to introduce to surface and underground water. The single sorption-desorption, with a calculated index value of 2.58, was indicative of a desorption hysteresis of TC on the soil, which might be attributed to the high affinity of TC on soil. Low solution pH value can significantly promote the TC sorption on soil ; in contrast, sorption is inhibited in high pH. Kd values have a positive correlation with the fraction of TC^＋ species, suggesting the pronounced role of TC^＋ on the sorption of TC. Divalent cations like Mg^2＋ and Ca^2＋ can reduce TC sorption on soil, which might be linked With the adsorption competition and the formation of combinations of TC with Mg^2＋ and Ca^2＋.

关 键 词：四环素 乌栅土 吸附解吸 PH 二价阳离子 

分 类 号：X592[环境科学与工程—环境工程]