Sorbents Based on Crown Ethers for Purification of Aqueous Solutions from Metal Ions

The sorption of copper and lead ions by sorbents based on 15-crown-5 and 18-crown-6 esters and their benzosubstituted analogs chemically bonded to porous mineral substrates under the action of gamma radiation is considered. The influence of various parameters on the efficiency of metal sorption from aqueous solutions is studied. The correspondence between the ability of the sorbent to absorb metal ions and the size of the cavity of the crown ether (CE) is shown, which determines the high level of selectivity of such sorbents. Indeed, sorbents based on 18-crown-6 ether have a significantly higher sorption capacity in relation to lead, while 15-crown-5 ether is more effective for the sorption of copper ions. The effect of the radiation dose rate and the time of holding the sorbent in a salt solution on the amount of sorbed metal is studied.