Sorption Of Rare Metal Ions by Ionite Based on Diglycidyl Thiourea and Various Amines

Abstract

The article studies the process of sorption of molybdenum and vanadium ions on anion exchangers obtained on the basis of thiourea, epichlorohydrin and various amines. Various amines (urea, guanidine, melamine, polyethylene polyamine, ethylenediamine, etc.) are used as substances containing ionic groups. The regularities of ion exchange and the main properties of the tested anionites are given, the influence of the pH of the medium and interfering ions in the process of sorption of molybdenum and vanadium ions are studied. For vanadium, the use of empirical partition relations and of an extended Freundlich equation were tested, with promising results. The objective of this paper is to investigate the use of the pH dependent Freundlich model of Gustafsson et al., for describing vanadate(V) sorption to 26 mineral soils (all having less than 12% organic C), and to discuss the possible use of the model for risk assessments. The kinetic curves of the sorption process, the values of the diffusion coefficients for the initial periods of molybdenum sorption are given. In particular, the distribution coefficient of the radiotracers of 99Mo and 131I as homologs of Sg and Ts using the surface modification of chabazite was investigated as liquid-solid system in the present study. The kinetics of molybdenum sorption was carried out under static conditions from an ammonium molybdate solution with a concentration of 1 g/L for molybdenum ions and at pH 4.5–5.  Under the same conditions, molybdenum ions are sorbed much faster by the DGT + M anion exchanger in comparison with AN-2F anion exchangers, in which the diffusion coefficient is much lower. The static exchange capacity (SEC) was determined in industrial solutions in the presence of mineral acids (hydrochloric, sulfuric and nitric), usually contained in them. The obtained kinetic equilibrium parameters of the tested anion exchangers were compared with those of industrial polycondensation anion exchangers, such as AN-2F and AN-1.