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应用批量平衡振荡法研究了非离子表面活性剂Tween60对模拟污染黑龙江黑土中四种有机氯农药狄氏剂、艾氏剂、氯丹和七氯的洗脱效果及影响因素。结果表明,四种农药在黑土中的洗脱去除率随着Tween60浓度的增加而增加,Tween60浓度为4.0 g L-1时对污染黑土的洗脱率达到最高的46.68%~53.31%。在四种有机氯农药共存污染黑土中,Tween60对每种农药的洗脱率与单一污染黑土相比均下降20%左右。Tween60对低浓度农药污染黑土的洗脱效果明显好于高浓度污染黑土,农药浓度为2.0 mg kg-1时的洗脱率可达到80%左右。处理体系中的固液比保持在1∶15时的洗脱率显著高于固液比为1∶5和1∶10时的洗脱率,表明适当提高液相的比例有助于增加洗脱效果。增加洗脱次数可以提高农药污染黑土的洗脱效率,洗脱3次后的农药的去除效果较好。洗脱时间为6 h时即可基本达到洗脱平衡,延长洗脱时间对洗脱率影响不大。
The effects of nonionic surfactants Tween60 on the elution of four organochlorine pesticides dieldrin, aldrin, chlordane and heptachlor from the simulated contaminated black soils in Heilongjiang Province were studied by batch equilibrium method. The results showed that the elution rate of four pesticides in black soil increased with the increase of Tween60 concentration, while that of contaminated black soil reached the highest 46.68% -53.31% when the concentration of Tween60 was 4.0 g L-1. Of the four organochlorine pesticides coexisting contaminated black soil, Tween60 elution rate of each pesticide decreased by about 20% compared with that of single contaminated black soil. Tween60 had a better elution effect on black soil polluted by low concentration pesticides than black soil polluted at high concentration, and the elution rate was about 80% when the pesticide concentration was 2.0 mg kg-1. The elution rate when the solid-liquid ratio in the treatment system was maintained at 1:15 was significantly higher than that at the solid-to-liquid ratio of 1: 5 and 1:10, indicating that appropriately increasing the liquid phase ratio helped to increase the elution effect. Increasing the number of elution can improve the elution efficiency of pesticide-contaminated black soil. After 3 times of elution, the pesticide removal effect is better. When the elution time is 6 h, the elution equilibrium can be basically reached, and prolonging the elution time has little effect on the elution rate.