Abstract
The paper presents the results of the study of sorption of antimony(III) from aqueous solutions by potassium aluminosilicates obtained from rice straw and husks. The chemical composition, structure and physicochemical characteristics of the obtained biogenic samples were established. The sorption kinetics of Sb(III) ions by potassium aluminosilicates was investigated using diffusion and chemical kinetics models. It is shown that the rate of antimony sorption process on the studied aluminosilicates is limited by the mixed-diffusion process, as well as by the stage of chemical interaction of antimony cations with the sorbent surface. It is shown that in the concentration range of 0.017-0.1 mmol/l the adsorption process of Sb(III) by natural materials is determined by chemical interaction with the surface of samples and obeys the Freundlich model, which indicates the heterogeneity of the sorbent surface. The influence of the solution medium on the sorption of antimony(III) by aluminosilicates has been investigated. It is shown that the adsorbent surface has a positive charge in acidic medium and a negative charge in neutral medium. The sorption activity for all sorbents decreases with increasing pH of the solution. The desorption of Sb(III) depends on the contact time of the sorbent with the solution and on the solution medium, and the desorption is higher in neutral medium. The results show that potassium aluminosilicates obtained from rice straw and husks are promising materials for the removal of antimony(III) from aqueous solutions. These studies allow us to give recommendations on the choice of materials for purification of solutions from Sb(III) ions, expanding the range of currently used natural sorbents based on plant raw materials, as well as to solve an urgent environmental and economic problem - the utilization of rice production waste.
Publisher
Ivanovo State University of Chemistry and Technology