Sorption of poly(ethylene oxide) to soil: Role of soil mineral composition

Poly(ethylene oxide) impacts on soil physical properties are thought to be a function of its adsorption by the soil material. The objective of the present paper is to evaluate the importance of microchemical surface composition of soil colloids on PEO adsorption. The microchemical surface composition of soil colloids was characterized using scanning electron microscopy (SEM) equipped with energy-dispersive x-ray analysis (EDAX). Results obtained from batch adsorption tests indicate that a correlation between the atomic ratio of Si:(Al+Fe) on soil colloids surface and PEO sorption capacity exist, where those soil colloids with larger value of Si:(Al+Fe) ratio are able to sorb PEO more efficiently. This correlation allows us to predict that the PEO sorption capacity for soil colloids decrease with progressively increasing degrees of soil weathering.