膨润土和高岭土对四环素吸附的影响  

Influence of Montmorillonite and Kaolinite on Tetracycline Adsorption

作　　者：武庭瑄[1,2] 周敏[1] 万建新[1] 陈慧[1] 

机构地区：[1]西北师范大学化学化工学院,甘肃兰州730070 [2]太原工业学院环境工程系,山西太原030008

出　　处：《农业环境科学学报》2009年第5期914-918,共5页Journal of Agro-Environment Science

基　　金：甘肃省教育厅科研基金项目(0501-07)

摘　　要：采用批平衡吸附试验,研究了四环素在膨润土和高岭土中的吸附行为。结果显示,膨润土和高岭土对四环素的吸附行为均可用Freudlich等温方程描述,但K(f膨润土)>>K(f高岭土),说明膨润土对四环素吸附能力较高岭土强。随着土壤溶液中离子强度的增加,四环素在两类粘土表面的吸附逐渐减少,表明四环素在粘土表面的吸附是以阳离子交换作用为主。同时,不同阳离子导致四环素在粘土上的吸附存在差异,其影响趋势主要为价态的影响,即价态越高,竞争吸附能力越强:M3(+Al3+)>M2(+Ca2+)>M(+K+)。此外在pH4.5～8.0的范围内,两类粘土对四环素的吸附系数均随着pH的增大而减小。Batch equilibrium experiments were used to reveal tetracycline （TC） adsorption on two different mineral clays-montmorillonite and kaolinite. The experimental results showed that the adsorption isotherms were well described by Freundlieh model. With the great variety of Kf values, tetracycline was adsorbed more strongly on montmorillonite than on kaolinite. In meantime, adsorption of TC on two clays decreased gradually with the increase of natural cation concentrations in solution, suggesting that the sorption process was largely dominated by cation exchange. Moreover, the different cations could result in the apparent difference of TC sorption when cations with higher valencies showed stronger adsorbihy on the surfaces of active sorption sites by the following order： M3^＋（Al^3＋）〉M^2＋（ Ca^2＋）〉M^＋（ K^＋）. In addition, the sorption coefficients of tetracyclineed deereas with the increase of pH values within a range between 4.5 and 8.0.

关 键 词：四环素 膨润土 高岭土 吸附 PH 阳离子 

分 类 号：X592[环境科学与工程—环境工程]