Sorption of Uranium (VI) Ions by a Sorbent Based on a Copolymer of Maleic Anhydride with Styrene Modified by N, N '-diphenylguanidine

摘要

In this paper the results of a study on the extraction and concentration of microquantities of uranium (VI) with a polymeric chelating sorbent with fragments of N, N'diphenylguanidine is discussed. There was studied a static sorption capacity on K+ ions ((SSC = 9.3 mmol / g) and there were determined the ionization constants of ionogenic groups ((pK(1)) over bar =3.97; (pK(2)) over bar =8.47) by potentiometric titration. The optimal conditions of the sorption of elements (pH(opt), sorption time - tau, the influence of ionic strength - mu) were determined by the dependence of the sorption capacity (SC, mg/g) on the parameter being studied; the sorption capacity of the sorbent (SC) was determined from the saturation curve constructed under optimal sorption conditions. The maximum degree of extraction of uranium by sorbents is achieved from solutions with pH 5. Sorption equilibrium is achieved within 2 hours of contact of the solution with the sorbent. With an increase in the concentration of the uranyl ion in the solution, the amount of the sorbed metal increases, and at a concentration of 8.10-3 mol/l, it becomes maximal (pH = 5, = 8.10-3 mol/l, Vgen = 20 ml, msorb. = 0.05 g, SC = 1258 mg/g). Limits of detection (3 sigma, n=20) are 13.9 ng/ml. The effect of various mineral acids(HClO4, H2SO4, HNO3, HCl) with the same concentrations on the desorption of uranium (VI) from the sorbent was studied. The developed technique was applied to determine uranium in oil sludge.