The sorption and complex-forming properties of a modified sorbent based on a copolymer of maleic anhydride with methacrylic acid in regard to vanadium (V) were studied and main parameters of metal sorption determined. Sorbent containing fragments of N, N'diphenylguanidine for the selective extraction of vanadium (V) from solutions were proposed. The sorbent was synthesized according to wellknown methods. The optimal conditions for sorption were determined. The sorption was studied under static conditions. In the presented work, a main emphasis was laid on the study into the effect of pH of the medium, time, ionic strength, and metal concentration in a solution on the vanadium sorption. A maximum degree of vanadium extraction by the sorbent was achieved from pH 5 solutions. The influence of the ionic strength of the solution was studied by photometric method. Vanadium (V) was sorbed from solutions containing 0.1-1.4 M KCl. Results of the study showed that a significant decrease in metal sorption was observed in KCl solutions with a concentration of more than 0.6 M. Results of the analysis showed that the sorption equilibrium was achieved in 2 hours. As the concentration of vanadium in the solution increased, its sorption rose as well, and at a concentration of 8•10-3 M it reached maximum: static capacity = 253 mg/g. Also, we researched into possibilities available to determine the conditions for desorption of vanadium (V) with various mineral acids (HClO 4 , H 2 SO 4 , HNO 3 , HCl) after concentration on the proposed sorbent. Analysis results showed that vanadium (V) was quantitatively desorbed by 2 M HNO 3. Multiple uses of the regenerated sorbent for concentration are possible. The degree of extraction of vanadium (V) under optimal conditions exceeded 95%.

A modified sorbent based on copolymer of maleic anhydride with methacrylic acid was proposed for sorption of vanadium (V) concentration. A polymer chelating sorbent with fragments of para-amino salicylic acid was used in the work. Optimal sorption conditions were determined and the dependence of sorption capacity on the acidity of the solution studied. At pH 5, the degree of sorption attains its maximum. The effect of ionic strength on vanadium sorption was studied. Studies have shown that the ionic strength up to 0.6 mol/l does not affect the sorption, after 0.6 mol/l the increase in the ionic strength at the beginning gradually, and then sharply decreases the sorption. The effect of ionic strength on vanadium sorption was studied to show that the ionic strength up to 0.6 mol/l does not affect the sorption, and after 0.6 mol/l the increase in the ionic strength at the beginning gradually, and then sharply decreases the sorption. All further experiments were carried out in the solutions with an ionic strength of 0.6. It was found that as the concentration of vanadium rises in the solution, the amount of sorbed metal increases, and at a concentration of 8.10-3 mol/l it becomes maximum (pH = 5, CV5+ = 8.10-3 mol/l, vtotal = 20 ml, msorb. = 0.03 g, SC = 243 mg/g). The isotherm of vanadium (V) sorption with the synthesized sorbent was constructed. Sorption equilibrium is achieved within 1 hour of contact between the solution and the sorbent. Further growth in the sorption time does not change sorbent’s characteristics. The sorbent extracts vanadium (V) from solutions with a recovery rate of 93%. The effect of different mineral acids (HClO4, H2SO4, HNO3, HCl) of identical concentrations on vanadium (V) desorption from the sorbent was also studied. The results of the analysis showed that the maximum desorption of vanadium (V) occurs in perchlorate acid. The developed method was applied to determine the trace amounts of vanadium in oil sludge with preliminary concentration.