Clay minerals, especially montmorillonite, as well as bentonite minerals with a high content of montmorillonite, have the highest ability to adsorb various organic compounds. In the East Kazakhstan region, the Manyrak deposit has huge deposits of “pink” bentonite clay (BC) with 70% of montmorillonite, extensively studied back in the 70-80-s. Now it is successfully useful in the organo-polymer composition as a mineral filler of polymer composite materials (PCM) and finds the application as domestic sorbents for the group extraction of non-ferrous ions in the purification of industrial sewage and drinking water. This article presents the results of research of creating polymer-clay composite materials based on domestic bentonite clay with improved sorption characteristics. The polymeric matrix of the composites consists of acrylates ‒ polyacrylic and polymethacrylic acids (PAA and PMAA). BC-PAA and BC-PMAA gels were obtained by radical polymerization “in situ” using the intercalation method (and wi thout it). Preliminary intercalation forms more homogeneous and interconnected composite gels. An increase in the content of the clay component and the cross-linking agent in the starting mixture results in a higher cross-linking rate and compaction of the composite gels. The behavior of the swelling of gels under the influence of temperature, pH, ionic strength indicates their polyelectrolyte character with dominant hydrogen bonds and partial hydrophobic interactions (the latter is improved in the case of BC-PMAA). The preparation of composite gels based on local BC and PAA and PMAA expands the range of composite materials and can be used as sorbents for wastewater treatment.

The paper shows the study results of sorption capacities of composite gels based on polyacrylic and polymethacrylic acids with bentonite clay as the mineral filler concerning heavy metal ions (Pb+2, Cu+2, Ni+2, Zn+2, Fe+2, Cd+2). The binding of metal ions to gels occurs through the formation of electrostatic bonds between the charged surface of bentonite clay and ionogenic functional groups of polymers in the composition, as well as the coordination bonds between metal ions and unshared pairs of oxygen electrons in the functional groups of polymers. The gel swelling degree decreases in metal solutions with increasing metals concentration and the content of BC in the composite. The sorption and desorption of heavy metal ions from the polymer-clay composites from model solutions and samples of industrial wastewater from the Kazakhstani metallurgical plants were evaluated. The adjustment of the pH, the temperature of the medium and the clay content in the composite leads to increasing the degree of sorption and achieving regeneration of the used composite gels in certain media. The data obtained testify to the prospects of using these composites as effective sorbents of heavy metals from industrial wastewaters expanding the range of composite materials for wastewater treatment.

The chemically crosslinked gels based on bentonite clay of the Manyrak deposit (East Kazakhstan region) and nonionic polymer polyvinylpyrrolidone were synthesized with using the process of intercalation of the monomer in the aqueous suspension of bentonite. Swelling degree, sorption capacity of the obtained polymer-clay composites to metal cation ions are evaluated. It is shown that with increasing the concentrations of bentonite clay in gels the sorption capacity to metal ions increases significantly.