Rama Krishna K, Philip Ligy
Department of Civil Engineering, Indian Institute of Technology Madras, Chennai 600036, India.
J Hazard Mater. 2008 Dec 30;160(2-3):559-67. doi: 10.1016/j.jhazmat.2008.03.107. Epub 2008 Mar 30.
Adsorption and desorption characteristics of three insecticides on four Indian soils were studied. Insecticides used were representative of organochlorine, organophosphate, and carbomate groups. The order of adsorption of pesticides on soils was: lindane>methyl parathion>carbofuran. Compost soil had shown the maximum adsorption capacity. The order of adsorption capacity of various soils were: compost soil>clayey soil>red soil>sandy soil. Adsorption isotherms were better fitted to Freundlich model and Kf values increased with increase in organic matter content of the soils. Thermodynamic parameters indicated favorable adsorption of all the three pesticides in four different soils. Adsorption was exothermic in nature. Distilled water desorbed 30-60% of adsorbed pesticides whereas; organic solvents were able to affect 50-80% of sorbed pesticides. Clay content and organic matter played a significant role in pesticide adsorption and desorption processes. Hysteresis effect was observed in red, clayey and compost soils. Hysteresis effect increased with increase in organic matter and clay content of the soils.
研究了三种杀虫剂在四种印度土壤上的吸附和解吸特性。所使用的杀虫剂分别代表有机氯、有机磷和氨基甲酸酯类。农药在土壤上的吸附顺序为：林丹>甲基对硫磷>克百威。堆肥土表现出最大的吸附容量。各种土壤的吸附容量顺序为：堆肥土>黏土>红壤>砂土。吸附等温线更符合弗伦德利希模型，且Kf值随土壤有机质含量的增加而增大。热力学参数表明，这三种农药在四种不同土壤中均有良好的吸附。吸附本质上是放热的。蒸馏水可解吸30%-60%的吸附农药，而有机溶剂能够解吸50%-80%的吸附农药。黏粒含量和有机质在农药吸附和解吸过程中起重要作用。在红壤、黏土和堆肥土中观察到滞后效应。滞后效应随土壤有机质和黏粒含量的增加而增强。
