Adsorption of Thiram and Dimethoate on Almeria Soils

Abstract

Abstract The adsorption process of thiram and dimethoate on Almería (East‐Andalucía, Spain) soils from aqueous solution at 30 °C has been studied. The adsorption isotherms may be classified as L type of the Giles classification. The K f values (Freundlich equation) vary between 4.81 to 13.73 for fungicide thiram (tetramethylthiuram disulfide) and between 1.06 to 8.95 for insecticide dimethoate [ O,O dimethyl S ‐( N methylcarbamoylmethyl) phosphorodithioate] depending on the soil type. In relation to the correlations between adsorption parameters and soil properties, the adsorption process of thiram seems be conditioned by the soil organic matter content whereas the adsorption of dimethoate is fundamentally conditioned by specific surface area and by cation exchange capacity.