Sorption of copper(II) ions from aqueous solution by activated carbon BAU-A and coal sorbent MIU-S. The relationship between the structure of sorbents and their sorption properties.

The sorption of copper(II) ions in a wide range of pH by two Russian carbon sorbents BAU-A and MIU-S was studied. Sorbents varied in structure, surface area, pH of the point of zero charge (pH _ZPC ), and graphitization degree. The sorption studies were conducted in batch mode. The removal of copper(II) ions from a solution at pH 4, 5, 6, and 6.7 is described by the classical adsorption isotherms of Freundlich, Langmuir, and Dubinin-Radushkevich. With an increase in pH from 4 to 6.7, the sorption capacity of sorbents increases, from 0.910 to 7.163 mg/g for BAU-A, and from 0.265 to 3.307 mg/g for MIU-S. The relationship between the degree of crystallinity and the sorption properties of sorbents has been established.