Adsorption (2011) 17:967–975 DOI 10.1007/s10450-011-9376-9 Effect of the synthesis temperature of sodium nonatitanate on batch kinetics of strontium-ion adsorption from aqueous solution Aurélie Merceille · Evelyne Weinzaepfel · Yves Barré · Agnès Grandjean Received: 8 March 2011 / Accepted: 12 September 2011 / Published online: 23 September 2011 © Springer Science+Business Media, LLC 2011 Abstract Sodium titanate materials are promising inor- ganic ion exchangers for the adsorption of strontium from aqueous solutions. Sodium nonatitanate exhibits a layered structure consisting of titanate layers and exchangeable sodium ions between the layers. The materials used in this study include samples synthesized by a hydrothermal method at temperatures between 60 °C and 200 °C. Their structure, composition, and morphology were investigated with X-Ray diffraction measurements; thermogravimetric, compositional and surface area analyses, and scanning elec- tron microscopy. The structure, composition, and morphol- ogy depended on the synthesis temperature. Batch kinet- ics experiments for the removal of strontium from aque- ous solutions were performed, and the data were fitted by a pseudo-second-order reaction model and a diffusive model. The strontium extraction capacity also depended on the syn- thesis temperature and exhibited a maximum for samples synthesized at 100 °C. The sorption process occurs in one or two diffusion-controlled steps that also depend on the synthesis temperature. These diffusion-limited steps are the boundary-layer diffusion and intra-particle diffusion in the case of pure nonatitanate synthesized at temperatures lower than 170 °C, and only intra-particle diffusion in the case of nonatitanate synthesized at 200 °C. A. Merceille · E. Weinzaepfel · Y. Barré Service des Procédés de Décontamination et d’Enrobage des déchets, Laboratoire des Procédés Avancés de Décontamination, CEA, Centre de Marcoule, BP17171, 30207 Bagnols sur Cèze, France A. Merceille · E. Weinzaepfel · A. Grandjean ( ) Institut de Chimie Séparative de Marcoule, UMR5257, CEA/CNRS/UMII/ENSCM, Centre de Marcoule, BP17171, 30207 Bagnols-sur-Cèze, France e-mail: agnes.grandjean@cea.fr Keywords Sorption · Kinetics · Ion exchange · Sodium nonatitanate · Strontium removal 1 Introduction The environmental impact of the release of toxic, biologi- cal, and radioactive pollutants from industry is of great sig- nificance for all industrialized societies. As a quick bibli- ographic search reveals, the development of efficient pro- cesses for the purification, e.g., filtration and waste removal, of these industrial effluents has attracted considerable atten- tion. Many water-treatment processes have been described in the literature (Hagg 1998; Kurniawan et al. 2006; Akieh et al. 2008; Crini and Badot 2009). The nuclear industry produces a wide range of liquid ra- dioactive effluents. Compared with wastes from other in- dustries, these wastes have a greater need for treatment to reduce the quantities of contaminants. Co-precipitation was the main process chosen many years ago for the decontami- nation of liquid wastes that cannot be concentrated by evap- oration. This process of decontamination is based on the in situ precipitation of solid particles to selectively entrap and remove one or more of the radioelements. The main co-precipitated radionuclides are 90 Sr, 137 Cs, 106 Ru, 60 Co, and alpha emitters (Pu, Am, etc.) (Hamblin and Ensor 2004; Pacary et al. 2008; Sonar et al. 2009). A selective sorbent is used for each of these species, barium sulfate, for example, is used for the co-precipitation of strontium ions. 90 Sr is one of the major heat producers and biohazards in nuclear wastes. The removal of radioactive strontium is essential for reducing the risk of human exposure to radia- tion and for realizing considerable cost savings through the minimization of the storage-space requirements for nuclear wastes. A long-standing and continuous research effort has