The aim of this study is to select an efficient, inexpensive adsorbent for the removal of synthetic dyes from the wastewater of the textile industry. We used waste products obtained during the regeneration of ion-exchange resins formed from highly saline aqueous solutions of calcium and magnesium that do not require pre-treatment, as well as magnesite minerals that contain traces of impurities, such as Fe, Zn, Co, Cd, Mn. The spectrophotometric characteristics of synthetic organic dyes in wastewater have been studied. The study has shown that in the process of adsorption, synthetic organic dyes are adsorbed by 95–99% in less than 15 minutes. Since synthetic organic dyes have active stretching, the adsorbent particles are not deposited in a dispersed colloidal form in the purified water and particle flotation occurs. To prevent this process, we used the required amount of sprayed activated bentonite with a negative charge, since bentonite causes rapid coagulation of dispersed adsorbent particles and also adsorbs dyes. Experiments have shown that to purify 1 liter of water contaminated with synthetic organic dyes, it is sufficient to use 10–15 ml of salt water obtained during the regeneration of ion-exchange resins or 1.5 g of magnesite, or 1.3 g of dolomite. The developed adsorbent eliminates pollutants by reducing the biological and chemical oxygen demand. These reductions are about ~95%. The adsorption treatment which we offer is effective and inexpensive, since the adsorbent is a mixture obtained from industrial waste and local bentonite

doi.org/10.32737/0005-2531-2022-3-70-74