Extraction of Heavy Metal Ions from Water Using the Phosphorylated Carbon Sorbent Based on Natural Raw Material

Abstract

A phosphorylated sorbent exhibiting an enhanced selectivity of Cu²⁺ sorption from aqueous media in the presence of surplus Ca²⁺ was obtained by carbonization of pine sawdust impregnated with (NH₄)₃PO₄ or a mixture of (NH₄)₃PO₄ and CO(NH₂)₂. With an increase of Ca²⁺ concentration to 1 g/dm³, the coefficient of separation using the sorbent phosphorylated in the presence of carbamide increased and reached the level of 19.6 that was three times as much as in the case of sorbent obtained without carbamide. The specific sorption capacity with respect to Cu²⁺ was higher by ~2 mg/g irrespective of the background concentration of Ca²⁺ ions; however, this capacity decreased as the content of the latter increased. The field tests of using the obtained sorbent for extraction of Ni²⁺ and Zn²⁺ at the stage of tertiary treatment of wastewater from the electroplating production facility before the wastewater discharge were carried out.