SORPTION OF CADMIUM, LEAD, AND CHROMIUM (VI) BY CELLULOSIC COMPLEXES OF ARCTIC BROWN ALGAE

Abstract

The purpose of this work is to establish the mechanism of sorption of heavy metal ions (Cd, Pb, and Cr (VI)) by cellulose complexes (CC) of the arctic brown algae Laminaria digitata and Saccharina latissima. These complexes are fibrous mesoporous materials with active sorption centers -COOH, -OH, and -NH2 and a developed surface, which makes them potentially effective preparations for the enterosorption removal of heavy metal ions. The kinetics and thermodynamics of sorption have been studied as well as the influence of the acidity on the sorption capacity. It has been established that the sorption rate is highest during the first minutes of contact between the two phases; the sorption equilibrium is reached by 60 min. According to the sorption enthalpy values, temperature has a positive effect on sorption (endothermic process), with a maximum sorption capacity at 37 °C. Optimal pH of the medium: 5-6 for cadmium and lead, and 2 for chromium (VI), which indicates the possibility of using this material in a wide range of medium acidity, corresponding to the conditions of the human gastrointestinal tract. The results obtained indicate a high prospect of using CC as an effective enterosorbent for health preservation.