Adsorption of chlorpyrifos on Almería soils

Autor: A. Valverde Garcia, E. Gonzalez Pradas, M. Villafranca Sanchez, M. Socías Viciana
Rok vydání: 1992
Předmět:
Zdroj: Science of The Total Environment. :541-549
ISSN: 0048-9697
DOI: 10.1016/0048-9697(92)90176-s
Popis: The adsorption of the insecticide chlorpyrifos on the eight most representative soils of Almeria Province (Spain) from aqueous solution at 30°C was studied. The adsorption isotherms were derived from batch equilibration experiments. Chlorpyrifos concentrations in the solution phase were determined, after extraction with petroleum ether, by gas liquid chromatography (GLC) with a nitrogen phosphorus detector (NPD) and an electron capture detector (ECD). The adsorption isotherms may be classified as S-type of the Giles classification, and the adsorption constants were calculated with the Freundlich isotherm. Comparisons between adsorption capacities of the soils were done using the X 0.1 values (quantities of chlorpyrifos adsorbed at a actual equilibrium concentration of 0.1 mg · 1 −1 ) calculated from the Freundlich equation. These X 0.1 values ranged from 22.2 up to 71.1 mg · kg −1 . Correlations between X 0.1 values and soil properties show that the adsorption process of chlorpyrifos seems to be conditioned by the electrical conductivity and clay content.
Databáze: OpenAIRE