农药氯氰菊酯对土体基本性质影响的室内试验研究
Effects of pesticide cypermethrin on basic properties of soils based on laboratory test

为了研究有机氯农药对土体基本性质的影响,配制了不同浓度的氯氰菊酯农药污染土试样.对不同龄期的污染土样分别进行了颗粒分析、液塑限、pH值、电阻率测试、扫描电镜(SEM)等试验.结果显示,农药污染土的黏粒组分随农药掺量增加而增大;液限和塑限随污染物浓度增加而增大,塑性指数随浓度增加呈先增大后稳定的趋势;不同龄期试样的pH值随污染物浓度的增加而减小,变化幅度相似;同一龄期污染土的电阻率随农药掺量的增加而减小,在28 d龄期时电阻率最大;SEM试验发现,试样在1~56 d龄期时,孔隙先增大后减小,在28 d龄期时孔隙最大.同时分析了产生这些变化的原因,为有机污染物污染土体的原位测试研究提供了基础.
In order to study the influences of organochlorine pesticides on soil properties, soils contaminated by different concentrations of pesticide cypermethrin were made in the laboratory. Tests including grain size analysis, liquid limit, plastic limit, pH, soil resistivity were conducted on the samples of different pesticide concentrations and different curing time. Results show that clay particles increase with the increase of pesticide concentration. Liquid limit and plastic limit increase with the increase of pesticide concentration, and plastic index increases first and then becomes stable with the increase of pesticide concentration. pH of the contaminated soil at different curing time decrease with the increase of pesticide concentration, the decrease range are similar; Resistivity of contaminated soil at the same curing time decreases with the increase of pesticide concentration, and the peak of resistivity is found at 28 d curing time. Through SEM it is found that the pore size of soil samples increase first and then decrease with the curing time from 1 to 56 d, and reaches its peak at 28 d. Reasons of these results are also analyzed, which provides a foundation for in situ testing of organic contamination soils