Effects of Soil/Solution Ratios and Cation Types on Adsorption and Desorption of Tetracycline in Soils
Effects of Soil/Solution Ratios and Cation Types on Adsorption and Desorption of Tetracycline in Soils
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土壤/溶液比和阳离子类型对四环素在土壤中吸附和解吸的影响
DOI：
10.2136/sssaj2009.0402
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发表时间：
2010-09-01
影响因子：
2.9
通讯作者：
Xie, Xiujie
中科院分区：
文献类型：
--
作者：
Bao, Yanyu;Zhou, Qixing;Xie, Xiujie
使用间歇平衡实验研究了不同土壤/溶液比例（1:10、1:50 和 1:100）以及不同阳离子类型（CaCl 2 、KCl 和 NaCl）和 H 2 O 下四环素在 Alfisol 和 Ultisol 上的吸附和解吸行为。动力学研究表明，四环素在两种土壤上的吸附是有速率限制的，吸附动力学可以用Elovich方程和指数方程很好地描述。土壤/溶液比例的变化影响 Ultisol 中的相对平衡时间，但初始四环素浓度没有影响。随着土壤/溶液比例从1:50增加到1:10，土壤中的吸附率降低。两种土壤对四环素的吸附和解吸数据可以用Freundlich等温方程描述，所有实验处理下r值>0.952。在所有实验条件下，Ultisol 始终比 Alfisol 具有更强的吸附作用（更高的分配系数 [K d ] 值）。在四环素浓度为 1 或 1.25 mg·L-1 的两种测试土壤中，K d 值随着土壤/溶液比率的增加而降低；然而，四环素浓度为 25 mg·L-1 时，这种趋势并未出现。随着土液比从1:10减小到1:100，吸附等温线由S型曲线变为L型曲线。土壤溶液中阳离子，特别是CaCl 2 的存在，可显着降低土壤对四环素的吸附。阳离子的存在也显着降低了吸附等温线的非线性。
The adsorption and desorption behavior of tetracycline on an Alfisol and an Ultisol was investigated at varying soil/solution ratios (1:10, 1:50, and 1:100) and different cation types (CaCl 2 , KCl, and NaCl) and H 2 O using a batch equilibration experiment. Kinetic studies revealed that the adsorption of tetracycline on the two soils was rate limited, and the adsorption kinetics could be well described by the Elovich equation and exponent equation. Changes in the soil/solution ratio affected the relative equilibration time in the Ultisol, but there was no effect of the initial tetracycline concentration. The adsorption rate in the soils decreased as the soil/solution ratio increased from 1:50 to 1:10. The adsorption and desorption data on tetracycline in the two soils could be described by the Freundlich isotherm equation, with r values >0.952 under all experimental treatments. The Ultisol always had stronger adsorption (higher distribution coefficient [K d ] value) than the Alfisol under all experimental conditions. The K d values decreased with increasing soil/solution ratios in the two tested soils at 1 or 1.25 mg L ―1 of tetracycline; however, this trend did not occur at 25 mg L ―1 of tetracycline. The adsorption isotherm had an S-type curve that changed into an L-type curve with decreasing soil/solution ratios from 1:10 to 1:100. The presence of cations in the soil solution, especially CaCl 2 , can significantly reduce the adsorption of tetracycline in soils. The presence of cations also significantly reduced the nonlinearity of the adsorption isotherms.