不同粒径土壤对氯丹的吸附性能及其急性毒性

Effects of soil particles on their adsorption performance of chloredane and their acute toxicity

以典型有机氯农药氯丹为研究对象,重点研究了不同粒径土壤颗粒对氯丹的吸附特性及其对发光菌急性毒性的影响。研究结果表明,不同粒径的土壤颗粒对氯丹的吸附性能依次为:粘粒(<2μm)≈粉粒(2~20μm)>粗砂(200~2 000μm)>细砂(20~200μm)。Freundlich等温吸附模型的线性相关系数最小为0.84,对不同粒径土壤吸附数据的拟合均优于Langmuir等温吸附模型。对吸附氯丹的吸附数据更符合准一级吸附动力学,其线性相关系数最高达到0.999。四种土壤颗粒浸出液对发光菌毒性的发光抑制率依次为细砂(-21%)≈粗砂(-21%)>粘粒(-13%)>粉粒(-9%),即发光菌的急性毒性与土壤颗粒的吸附性能负相关。

Effects of soil particles on the adsorption performance of chloredane, and the subsequent acute toxicity of the contaminated soil on luminescent bacteria, were studied in this paper.The research results indicate that the adsorption capacity of chloredane by soil particles followed the sequence of clay （〈2 μm） ≈ silt （2~20 μm） 〉 coarse sand （200~2 000 μm） 〉 fine sand （20~200 μm）.It was most reasonable to describe the adsorption behavior using a Freundlich isotherm model, as its minimal linear correlation coefficient （R2） value was 0.84.Analysis of the adsorption dynamics indicated that a pseudo-first-order model fits the experimental data very well, as its maximum linear correlation coefficient （R2） value reached 0.999.The inhibitory rate of acute toxicity from contaminated soil particles on luminescent bacteria was as follows：fine sand （-21%）≈coarse sand （-21%） 〉 silt （-13%） 〉 clay （-9%）, indicating that the acute toxicity to luminescent bacteria was negatively correlated with the adsorption performance of the soil particles.