Preparation, characterization and physicochemical study of 3-amino propyl trimethoxy silane-modified kaolinite for Pb(II) adsorption

The results show that that modification leads to no significant change in the surface profile or crystallinity by the modification, while a higher amount of Pb(II) (from 5 to 140 mg/L) led to an approximately sevenfold increase of adsorption by modified kaolinite compared to raw kaolinite. FTIR analysis suggests the presence of a chemical interaction on the active surface of modified kaolinite. The adsorption obeys pseudo first-order kinetics and was fit to the Dubinin-Radushkevich isotherm model.