EQUILIBRIUM ADSORPTION OF ISOPROTURON ON SOIL AND PURE CLAYS

The adsorption of isoproturon on soil and pure clay minerals has been investigated as a means of understanding its mobility in soils. Measur ed adsorption coefficients are correlated with soil and clay mineral p roperties. Soil organic matter controlled the adsorption of isoproturo n at organic carbon contents exceeding 27 g kg(-1), whereas at less th an this threshold, clay mineral surfaces appeared to control adsorptio n. The effect of varying temperature suggests that adsorption of isopr oturon is a physical process. From the comparison of the fits of linea r, Freundlich, and Langmuir adsorption isotherms to the data, the adso rption is best described as a partition process.