INVESTIGATION OF THE MECHANISM OF SELECTIVE EXTRACTION OF IONS OF VARIOUS SALTS FROM WATER, USING POLYAMIDE MEMBRANES

The processes of membrane separation and concentration belong to the category of critical technologies for obtaining and processing structural and functional materials for desalination of water. The prospects and advantages of polyamides membranes are determined based on the analysis of the kinetics of membrane separation, the polyamides membrane has resistance to the studied salt solutions. The purpose of this work is to study the features and regularities of the mechanism of selective extraction of salt ions from water by polyamide membranes. Great importance are the methods of water purification in the selective extraction of salt ions from water using polyamide membranes. Methodology. Polyamides have a high selectivity with respect to salts, but the flow of water through them is slightly lower. At a pH range 2.0 – 10 polyamides, they withstand processing temperatures up to 100 0C without significant changes in the porous structure, allow multiple regeneration, and are resistant to most acids, depending on the pH of the medium. Results. According to the results of pilot tests in the extraction of salt ions from water using polyamide membranes, it was found that in the pH region = 6-7, the joint presence of the main charged forms of salt ions is assumed. Conclusion. Thus, based on the results, it follows that the values of the diffusion coefficients of salt ions in membranes with pore radii from 5 to 8 nm at pH =6.5–7.5 are generally comparable for salt ions.