Geoscience Reference
In-Depth Information
Fig. 8.33 Adsorption from aqueous solutions of parathion onto montmorillonite saturated with
various cations (Yaron and Saltzman
1978
)
Fig. 8.34 Adsorption of
parathion by attapulgite from
hexane solution, as affected
by initial hydration status of
mineral; RH = relative
humidity (Gerstl and Yaron
1981
)
In a dry attapulgite-parathion-hexane system, parathion molecules compete
effectively with nonpolar hexane molecules for the adsorption sites. In partially
hydrated systems, parathion molecules cannot replace the strongly adsorbed water
molecules, so that parathion adsorption occurs only on water-free surfaces and a
decrease in adsorption per total surface area may be observed. Infrared studies lead
