Study of the sorption activity of pharmacophore-containing pectins with respect to cations of cobalt (II)

Abstract

The regularities of sorption to ions of cobalt (II) by native and modified organic pharmacophore (salicylic, antranilic, nicotinic acids) pectins are considered. Modification of pectin by pharmacophore reduces the time to reach equilibrium, depending on the nature of the organic component while maintaining high sorption capacity. The influence of various factors (acidity, temperature, solution/sorbent modulus) on the distribution ions of cobalt (II) in the heterophasic system of the polysaccharide sorbent-aqueous solution was determined. It was found that the optimum pH of the medium for extracting cobalt (II) ions from aqueous solutions, at which the maximum of sorption is reached, is a pH close to neutral. With an increase in the solution/sorbent module from 50 to 1000 l/kg, a decrease in the degree of extraction of Co²⁺ ions by pharmacophore-containing pectins is observed. When studying the effect of temperature on the sorption process, it was found that with increasing temperature, the degree of extraction of cobalt ions with pectin-containing sorbents is markedly reduced. The mechanism of sorption kinetics of metal ions (II) by biosorbents is studied. Sorption process of interaction of metal (II) cations with functional groups of pectin/pharmacophore-containing pectin involves three successive stages of mass transfer of sorbate on biosorbents: external diffusion mass transfer, intradiffusion mass transfer and ion exchange process. The influence of the nature of biosorbents on the thermodynamics of the distribution of cobalt (II) ions is determined. It was found that sorption of Co²⁺ ions by modified pectin sorbents is described by the Langmuir equation.