Adsorption Thermodynamics of Carbofuran on Forest and Black Soils

Thermodynamics of adsorption of carbofuran (2, 3-dihydro-2, 2- dimethy 1-7-benzofuranyl methyl carbamate; a systemic non-ionic nematicide) was studied on two different types of Indian soils viz. a forest loam and black silt clay loam at 30° and 60°C. The adsorption isotherms conformed to the Freundlich adsorption model and yielded ‘S’ class isotherms. The amount of carbofuran adsorbed was higher in forest loam soil which also had a lower pH and higher organic matter content as compared to the black silt clay soil. The thermodynamic, parameters such as thermodynamic equilibrium constant K_o, standard free energy Δ T°, enthalpy Δ H° and entropy Δ S° changes for adsorption have been calculated.