The paper deals with the modification of clay sorbents in order to improve the efficiency of copper ions extraction from wastewater. The study examined the elemental, mineralogical and phase composition of kaolin and montmorillonite clays. The authors analyzed the sorption capacity of natural sorbents under static conditions before and after modification with hydrochloric acid, sodium chloride and sodium hydroxide. The work also determines the change in the physical and chemical properties of the sorbent after modification. The most optimal modification conditions for the purification of waste-water from copper ions are distinguished.