Nanostructured surfaces 

Nanostructure of polyacrylamide adsorption layer on the clay mineral surface in the heavy metal ions presence
Wiśniewska M.1, Fijałkowska G.1, Szewczuk-Karpisz K.2
1 Department of Radiochemistry and Colloid Chemistry, Faculty of Chemistry, Maria Curie-Sklodowska University, M. Curie-Sklodowska sq. 3, 20-031 Lublin, Poland.
e-mail: wisniewska@hektor.umcs.lublin.pl
2 Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, 20-290 Lublin, Poland.

Macromolecular compounds (e.g. anionic and cationic polyacrylamides) are used in agriculture as substances improving soil structure as well as limiting destructive erosion effects. Their presence in the soil environment may influence heavy metal ion mobility, especially when polymer macromolecules are positively or negatively charged [1-3].
In this work, the adsorption layer of polyacrylamides (cationic and anionic ones) on the clay mineral surface (kaolinite and montmorillonite), in the absence and presence of heavy metal ions (chromium(VI) and lead(II)), was described. The adsorbed amount measurements of polymer and metal ions on the solid surface were performed spectrophotometrically, whereas solid surface charge as a function of pH value was determined using a potentiometric titration method. The obtained results allowed to indicate: (1) whether the used polymers enhance the heavy metal ions immobilization, (2) which macromolecular compound increases the ability of heavy metal ion binding of clays more efficiently, (3) if heavy metal presence hinders the polyacrylamide adsorption on the clay mineral surface.

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3.	Mamedov A.J., Wagner L.E., Huang C., Norton L.D., Levy G.J. Polyacrylamide effects on aggregate and structure stability of soils with different clay mineralogy// Soil Sci. Soc. Am. J.-2010-74.-P. 1-12.