Mining and processing of raw minerals in the central and eastern regions of Ukraine (enterprises of the uranium mining, hydrometallurgical industry, galvanic productions) leads to pollution of a large part of the territories and imbalance of the natural ecosystem. The ecological situation in these industrial regions requires special attention both environmental monitoring and protection of the water basin from toxicants of various nature.

To remove the trace amounts of heavy metal ions and radionuclides from polluted water, the sorption methods are the most effective. Natural clay minerals are widely used in various environmental protection technologies as cheap, accessible and effective sorbents. Considering the tasks and conditions for purification of polluted waters the different methods of surface modification of clay minerals were used.

The surface modification of the montmorillonite by cationic surfactants (hexadecyltrimethylammonium bromide) was aimed at changing the charge of the surface. It is shown that anionic forms of uranium (VI) and chromium (VI) are efficiently sorbed on the positively charged surface of organophilized montmorillonite.

The method of surface modification of montmorillonite by large-sized inorganic cations leads to the formation of two-dimensional zeolite-like materials with an adjustable size of flat micropores and high heat resistance - pillared clays. The highest values of sorption for uranium (VI) were obtained on Ti-Fe pillared clay, for chromium (VI) on Zr-Al pillared clay.

Highly selective sorbents with sorption-reduction properties were obtained by applying nanoscale zero-valent iron powder to montmorillonite surface. The efficiency of chromium (VI) and uranium (VI) purification depends on the mass ratio of zero-valent iron: montmorillonite. The inorganic toxicants (U(VI), Cr(VI)) immobilize on the surface of the sorbent. Subsequently theys degree of oxidation change and the insoluble surface sediments form.