再生水灌溉区土壤对头孢噻肟的吸附特征

Adsorption characteristics of cefotaxime in reclaimed water irrigated soil

采用批吸附实验法比较了再生水灌溉区汪洋沟流域两种土壤和底泥对头孢噻肟的吸附及其动力学特性,并探讨了土壤与底泥不同pH、阳离子强度及可溶性腐殖酸对头孢噻肟吸附能力的影响。结果表明：汪洋沟段清水灌溉土壤、污水灌溉土壤及底泥均对头孢噻肟有较强的吸附能力,对头孢噻肟的吸附能力从强到弱依次为清水灌溉土壤〉污水灌溉土壤〉底泥。土壤与底泥对头孢噻肟的吸附行为通过等温吸附模型模拟,其中Freundlich方程拟合效果最好。在pH4.0~9.0的范围内,土壤与底泥对头孢噻肟的吸附系数随着pH的增大而减少;随着土壤溶液中阳离子浓度的增加,头孢噻肟的吸附量呈非线性减少趋势;添加可溶性腐殖酸后的土壤对头孢噻肟的吸附能力减弱。

In this paper,the adsorption and dynamic characteristics of two kinds of soils and sediments from reclaimed water irrigated Wangyanggou basin on cefotaxime sodium were compared with batch sorption methods.The influences from pH value,positive ironic strength and soluble humic acid of soils and sediments on the adsorption capacity of cefotaxime sodium were studied. The results showed that both of the soils from fresh water and reclaimed water irrigated area,and sediments in Wangyanggou basin kept strong adsorption on cefotaxime sodium. The adsorption capacity from stronger to weaker was fresh water irrigated soil reclaimed water irrigated soil sediment. The adsorption behavior of soils and sediments on cefotaxime sodium was fitted by some isotherm models,and the Freundlich model was the best one. In the pH range of 4. 0—9. 0,the adsorption coefficients of soils and sediments on cefotaxime sodium decreased with the increase of pH value. As the positive ions increasing in the soil solution,the adsorption capacity on cefotaxime sodium appeared a non-linear downward trend. The adsorption capacity on cefotaxime sodium of soil with adding soluble humic acid became weaker.