Dual-temperature reactant-less and combined methods for the removal of thiocyanates from solutions on a strong base anion-exchanger
Abstract
The influence of temperature on the ion-exchange sorption of thiocyanate on strong base anionic resin AV-17 from the solution containing the excess of sodium chloride and from mixed chloride-sulfate solution of sodium, magnesium and ammonium is described. It is known that strong base anion exchangers have a high selectivity to the thiocyanate -ion. However, the problem is in the difficulties in choosing the effective, non-toxic and available reagents for desorption (and regeneration of the exchanger ionic form) in the repetitive cycles of ion exchange processing of thiocyanate-containing solutions. A strong temperature effect on the sorption selectivity to SCN-ion, if it is found, would allow to develop the dual-temperature separation and the removal of a target component from multicomponent solutions. Evaluation of the possibility of using such a method is the aim of the presented work. Dynamic break-through curves for the sorption of SCN-on the anion exchanger from the solution containing the 1000-fold exceeding concentration of chloride were obtained at various temperatures. A few cycles of dual-temperature sorption and desorption of thiocyanate from model solutions of different composition was studied. The opportunities for the desorption of SCN-with the use of 1M NaCl solution at ambient and elevated temperatures were also tested. It is shown that for the removal of thiocyanate from the mixed solutions containing chlorides and sulfates, in concentrations comparable with ones of it, the combined method, which blends the dual-temperature separation and reactant desorption is the more effective. The results obtained can be used for the development of methods for purifying thiocyanate-containing wastewaters, for example, in gold-mining industry.
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2.Lodeishchikov V.V., Sait zhurnala «Zolotodobycha» (Irgiredmet), 2012, Sentyabr'. No 166.
3.Danilenko N.V. Diss...kand. khim. nauk. Krasnoyarsk. 2007. 154 p.
4.Ivanov V.A., Timofeevskaya V.D., Gorshkov V.I., Drozdova N.V., J. Radioanalyt. Nucl. Chemistry, 1996, Vol. 208, pp.23-45.
5.Khamizov R.Kh., Ivanov V.A., Madani A.A., React. Funct. Polym,. 2010, Vol. 70, pp. 521-530.
6.Barraque C., Tremillon B., Bull. Soc. Chim. Frans., 1965, No 6, pp.1680-1683.
7.Gregor H.P., Belle J., Marcus R.A., J. Amer.Chem.Soc.,1955, Vol. 7, pp.2713-2719.
8.Fokina O.V., Khamizov R.Kh., Russian Chemical Bulletin., 1994, Vol. 43, No 12, pp. 1965-1971.
9.Khamizov R.Kh., Fokina O.V., Nauka proizvodstvu., 1998, No 2, pp. 20 -25.
10.Nozhov A.M., Kosobryukhova O.M., Khamizov R.Kh. Sorbtsionnye i khromatograficheskie protsessy,. 2003, Vol. 3, No 2, pp. 159-168.
11. Lur’je Yu.Yu., Analiticheskaya khimiya promyshlennykh stochnykh vod, M., Khimiya, 1984, 448 p.
12. Khamizov R.Kh., Ivanov V.A., Tikhonov
N.A. Chapter 5 in Ion Exchange and Solvent Extraction. A series of advances. Vol.20 / A. SenGupta, Ed / CRC Press, Taylor and Francis Group. New York. 2011. pp. 171-231.
