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

Abstract

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 (pHZPC), 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. HIGHLIGHTS With an increase in pH from 4 to 6.7, the sorption capacity of BAU-A increases from 0.910 to 7.163 mg/g, and of MIU-S from 0.265 to 3.307 mg/g.; The removal of copper(II) ions is due to simple physical adsorption.; There is a relationship between the degree of crystallinity, and the sorption properties of the sorbents.;

Keywords

• carbon sorbents
• copper(ii) ions
• ir and raman spectra
• langmuir
• sorption