磺胺嘧啶和磺胺噻唑在土壤中的吸附行为

ADSORPTION OF SULFADIAZINE AND SULFATHIAZOLE BY SOILS

采用批平衡实验方法研究磺胺嘧啶(SDZ)和磺胺噻唑(STZ)在五种典型土壤及一种泥炭中的吸附行为.结果表明:(1)SDZ和STZ在土壤及泥炭中的吸附量随溶液pH值的升高而减小,与溶液中SDZ和STZ阳离子的含量呈正相关.(2)SDZ和STZ的吸附均可采用Freundlich和Langmuir模型进行拟合,最大吸附量(Qm)的大小依次为:泥炭土>黑土>棕壤≥灰褐土>红壤≥灰漠土.除红壤和灰漠土外,Freundlich吸附系数(Kf)的大小次序和(Qm)基本相同.SDZ和STZ的(Qm)与土壤有机质的含量和土壤粉粒的含量呈显著正相关.因此,SDZ和STZ更容易吸附在有机质的含量比较高的泥炭土和黑土中.

A batch equilibration method was used to reveal the adsorption behavior of sulfadiazine （SDZ） and sulfathiazole（STZ） on five soils and one peat soil. The results showed that the adsorption of SDZ and STZ decreased with an increase in pH of equilibrium solution, and was positively correlated with cationic SDZ and STZ contents in the solution phase. The adsorption isotherms of SDZ and STZ were well described by the Freundlich and Langmuir models. The Qmvalues followed the order peat soil 〉 black soil 〉 brown soil ≥ graybrown soil 〉 red soil≥gray-desert soil. The Freundlich adsorption coefficients （K,） of SDZ and STZ followed the same order except for red soil and gray-desert. Qm values of SDZ and STZ adsorption were significantly positively correlated with the organic matter （OM） and silt contents of the soils. As a result, SDZ and STZ have higher sorption capacity on peat and black soil due to the high OM contents of them.