ГеохимияГеохимия0016-7525The Russian Academy of Sciences1781110.31857/S0016-752564101091-1104Research ArticleAdsorption of strontium on manganese oxide (δ-MnO2) at elevated temperatures: experiment and modelingKarasevaO. N.olga@iem.ac.ruIvanovaL. I.olga@iem.ac.ruLakshtanovL. Z.olga@iem.ac.ruD.S. Korzhinskii Institute of Experimental Mineralogy of Russian Academy of Sciences1911201964101091110418112019Copyright © 2019, Russian Academy of Sciences2019<p style="text-align: justify;">Strontium adsorption has been studied by the method of acid-base potentiometric titrations at three different temperatures: 25, 50, 75C. The effect of pH, ionic strength, sorbate/sorbent ratio, and temperature on adsorption was investigated. Experimental data were simulated using two various surface complexation models, with two different electrostatic descriptions of the interface: the constant capacitance model (<em>CCM</em>) and the triple-layer model (<em>TLM</em>). Although the both models used are able to account for the acid-base reactions and surface complexation of strontium on birnessite, we consider that the <em>TLM</em> is more applicable for a description of heterophaseous system <em>H</em><em><sup>+ </sup></em> <em>MnOH</em> <em> Sr</em><em><sup>2+</sup></em>. Under conditions of low ionic strength and negatively charged surface, Sr<sup>2+ </sup>ions compete with the electrolyte ions and form outer-sphere complexes along with inner-sphere complexes. Consequently, using the <em>CCM </em>for description of strontium adsorption data could be mathematically satisfactory, but physically senseless. The equilibrium model proposed here consists of the complexes of inner (MnOHSr<sup>2+</sup>, MnOSr<sup>+</sup>, MnOSrOH<sup>0</sup>) and outer types ([MnO<sup></sup> Sr<sup>2+</sup>]<sup>+</sup>). The corresponding intrinsic equilibrium constants of the formation of these surface complexes were calculated for 25,50, and 75C.</p>sorptionstrontiumbirnessitesurface complexation modelingconstant capacitance modeltriple-layer modelпотенциометрияадсорбциякомплексообразованиебернесситстронциймодель постоянной емкоститрехслойная модель[Ali M.A., Dzombak D.A. (1996) Effects of simple organic acids on sorption of Cu2+ and Ca2+. Geochim. Co. smochim. Acta 60, 291−304.][Appelo C.A.J., Postma D. (1999) A consistent model for surface complexation on birnessite (δ-MnO2) and its application to a column experiment. Geochim.Cosmochim. Acta 63, 3039−3048.][Axe L., Bunker G.B., Anderson P.R., Tyson T.A. (1998) An XAFS analysis of strontium at the hydrous ferric oxide surface. J. Colloid. Interface Sci. 199, 44−52.][Balistrieri L.S., Murray J.W. (1982) The surface chemistry of MnO2 in major ion seawater. Geochim. Cosmochim. Acta 46, 1041−1052.][Belova D.A., Lakshtanov L.Z., Carneiro J.F., Stipp S. (2014) Nickel adsorption on chalk and calcite. J. Contaminant Hydrology 170, 1–9.][Bevara S., Giric P., Acharya S.N., Bhalleraod G., Mishra R.K., Kumar A., Kaushik C.P., Tyagi A.K. (2018) Synthetic Na/K-birnessite for efficient management of Sr(II) from nuclear waste. J. Environ. Chem. Eng. 6, 7200–7213.][Catts J.G., Langmuir D. (1986) Adsorption of Cu, Pb and Zn by MnO2: Applicability of the site binding surface complexation model. Applied Geochemistry 1, 255–264.][Collins C.R., Sherman D.M., Ragnarsdóttir K.V. (1998) The adsorption mechanism of Sr2+ on the surface of goethite. Radiochim. Acta 81, 201–206.][Cowan C.E., Zachara J.M., Resch C.T. (1991) Cadmium adsorption on iron oxides in the presence of alkaline-earth elements. Environ. Sci. Technol. 25, 437−446.][Dzombak D.A., Morel F.M.M. (1990) Surface Complexation Modeling: Hydrous Ferric Oxide. New York: Wiley, 416 p.][Fenter P., Cheng L., Rihs S., Machesky M., Bedzyk M.J., Sturchio N.C. (2000) Electrical double-layer structure at the rutile-water interface as observed in situ with small-period X-ray standing waves J. Colloid. Interface Sci. 225, 154−165.][Freeze R.A., Cherry J.A. (1979) Groundwater. NJ: Prentice-Hall, Englewood Cliffs, 604 p. Fu G., Allen H.E., Cowan C.E. (1991) Adsorption of cadmium and copper by manganese oxide. Soil Scince 152, 72−81.][Ghaly M., El-Dars F.M.S.E., Hegazy M.M., Abdel Rahman R.O. (2016) Evaluation of synthetic Birnessite utilization as a sorbent for cobalt and strontium removal from aqueous solution. Chem. Eng. J. 284, 1373–1385.][Guerin M., Seaman J. (2002) Accounting for diffuse layer ions in triple-layer models. J. Colloid. Interface Sci. 250, 492−495.][Gunneriusson L., Sjberg S. (1993) Surface complexation in the H+-goethite ([alpha]- FeOOH)Hg (II)-chloride system. J. Colloid. Interface Sci. 156, 121−128.][Herbelin A.L., Westall J.C. (1994) FITEQL: A computer program for determination of chemical equilibrium constants from experimental data, Version 3.1. Report 94−01. Dept. of Chemistry, Oregon State Univ. Corvallis, OR, USA.][Karasyova O.N., Ivanova L.I., Lakshtanov L.Z., Lvgren L., Sjberg S. (1998) Complexation of gold(III)-chloride at the surface of hematite. Aquatic geochemistry 4, 215−231.][Karasyova O.N., Ivanova L.I., Lakshtanov L.Z., Lvgren L. (1999) Strontium sorption on hematite at elevated temperatures. J. Colloid. Interface Sci. 220, 419−428.][Karasyova O.N., Lakshtanov L.Z., Ivanova L.I. (2007) The behaviour of strontium and zinc during ageing of Fe(III) hydroxide. Geochim. Cosmochim. Acta 71, A463−A463.][Karaseva O.N., Lakshtanov L.Z., Okhrimenko D.V., Belova D.A., Generosi J., Stipp S. (2018) Biopolymer Control on Calcite Precipitation. Crystal Growth & Design 18, 2972−2985.][Kinniburgh D.G. (1983) The H+/M2+ exchange stoichiometry of calcium and zinc adsorption by ferrihydrite. J. Soil Sci. 34, 759−768.][Kosmulski M. (1997) Standard enthalpies of adsorption of di- and trivalent cations on alumina. J. Colloid. Interface Sci. 192, 215−227.][Lakshtanov L.Z., Stipp S.L.S. (2004) Experimental study of Europium (III) partitioning to calcite. Geochim. Cosmochim. Acta 68, 819−827.][Lakshtanov L.Z., Stipp S.L.S. (2007) Experimental study of nickel(II) interaction with calcite: Adsorption and coprecipitation. Geochim. Cosmochim. Acta 71, 3686−3697.][Lakshtanov L.Z., Okhrimenko D.V., Karaseva O.N., Stipp S. (2018) Limits on calcite and chalk recrystallisation. Crystal Growth & Design 18, 4536−4543.][Loganathan P., Burau R.G., Fuerstenau D.W. (1977) Influence of pH on the sorption of Co2+, Zn2+ and Ca2+ by a hydrous manganese oxide. Soil Sci. Soc. Am. J. 41, 57−62.][Lvgren L., Sjberg S., Schindler P.W. (1990) Acid/Base reactions and AI(III) complexation at the surface of goethite. Geochim. Cosmochim. Acta 54, 1301−1306.][Ltzenkirchen J. (1999) Parameter estimation for the constant capacitance surface complexation model: analysis of parameter interdependencies. J. Colloid. Interface Sci. 210, 384−390.][Ltzenkirchen J. (1999) The Constant capacitance model and variable ionic strength: an evaluation of possible applications and applicability J. Colloid. Interface Sci. 217, 8−18.][Lyklema J., Overbeek J.Th.G. (1961) Electrochemistry of silver iodide the capacity of the double layer at the silver iodide-water interface. J. Colloid. Interface Sci. 16, 595−608.][McKenzie R.M. (1981) The surface charge on manganese dioxides. Aust. J. Soil Res. 19, 41−50.][Murray J.W. (1974) The surface chemistry of hydrous manganese dioxide. J. Colloid. Interface Sci. 46, 357−371.][Machesky M.L., Palmer D.A., Wesolowski D.J. (1994) Hydrogen ion adsorption at the rutile ― water interface to 250°C. Geochim. Cosmochim. Acta 58, 5627−5632.][Machesky M.L., Wesolowski D.J., Palmer D.A., Ichiro-Hayashi K. (1998) Potentiometric titrations of rutile suspensions at 250°C. J. Colloid. Interface Sci. 200, 298−309.][Manceau A., Lanson B., Drits A. (2002) Structure of heavy-metal sorbed birnessite: Part 3. Geochim. Cosmochim. Acta 66, 2639–2663.][Metwally S.S., Ghaly M., El-Sherief E.A. (2017) Physicochemical properties of synthetic nano-birnessite and its enhanced scavenging of Co2+ and Sr2+ ions from aqueous solutions. Mat. Chem. Phys. 193, 63−72.][Nilsson N. (1995) Inner/outer Sphere Complexation of Phosphate and Organic Ligands at the Goethite-Water Interface. Ph.D. dissertation, Umea univ.][O’Day P.A., Newville M., Neuhoff P.S., Sahai N., Carroll S.A. (2000) X-Ray Absorption Spectroscopy of Strontium(II) Coordination. J. Colloid. Interface Sci. 222, 184−197.][Pivovarov S., Lakshtanov L.Z. (2003) Cadmium adsorption on hematite. Geochem. Int. 41, 1013−1027.][Pivovarov S. (2009) Diffuse sorption modeling: Apparent H/Na, or the same, Al/Na exchange on clays. J. Colloid Interface. Sci. 336, 898−901.][Rao R., Laitinen H.A. (1974) Studies of heavy metal adsorption by hydrous iron and manganese oxides. Anal. Chem. 46, 2022−2026.][Righetto L., Azimonti G., Missana T., Bidoglio G. (1995) The Triple Layer Model Revised. Colloids and Surface 95, 141−157.][Schoonen M.A.A. (1994) Calculation of the point of zero charge of metal oxides. Geochim. Cosmochim. Acta 58, 2845−2851.][Stroes-Gascoyne S., Kramer J.R., Snodrass W.J. (1987) Preparation, characterization and aging of δ-MnO2, for use in trace metal speciation studies. Applied Geochemistry 2, 217−226.][Stumm W. (1992) Chemistry of the solid-water interface. New York: Wiley, 428 p.][Sverjensky D.A. (2001) Interpretation and prediction of triple-layer model capacitances and the structure of the oxide– electrolyte–water interface. Geochim. Cosmochim. Acta 65, 3643−3655.][Tamura H., Katayama N., Furuichi R. (1996) Modeling of ion-exchange reactions on metal oxides with the frumkin isotherm. 1. Acid-base and charge characteristics of MnO2, TiO2, Fe3O4r and AI2O3 surfaces and adsorption affinity of alkali metal ions. Environ. Sci. Technol. 30, 1198−1204.][Tewari P.H., Campbell A.B. (1976) Temperature dependence of point of zero charge of cobalt, and nickel oxides and hydroxides. J. Colloid. Interface Sci. 55, 591−600.][Trivedi P., Axe L. (2001) Ni and Zn Sorption to Amorphous versus Crystalline Iron Oxides: Macroscopic Studies. J. Colloid. Interface Sci. 244, 221−229.][Villalobos M., Leckie J.O. (2001) Surface Complexation Modeling and FTIR Study of Carbonate Adsorption to Goethite. J. Colloid. Interface Sci. 235, 15−32.][Zasoski R.J., Burau R.G. (1988) Sorption and sorptive interaction of cadmium and zinc on hydrous manganese oxides. Soil Sci. Soc. Am. J. 52, 81−87.]