Journal of Chemical and Pharmaceutical Research, 2012, 4(7):3460-3467 Research Article ISSN : 0975-7384 CODEN(USA) : JCPRC5 3460 Elimination of thorium ion by an adsorbent prepared from Moroccan oil shale of Timahdit activated by phosphoric acid M. Elharti 1 , K. Legrouri 1 , E. Khouya 2 , M. Oumam 1 , H. Hannache 1 , S. Fakhi 2 , M. El Bouchti 1 , N. Hanafi 3 , B. Hammouti 4 1 Laboratoire de Recherche Subatomique et Application : Equipe des Matériaux Thermo- Structuraux et Polymères, Université Hassan II-Mohammedia, Faculté des Sciences Ben M’Sik, B. P. 7955, Casablanca, Maroc. 2 Laboratoire de Radiochimie, Université Hassan II- Mohammedia, Faculté des Sciences Ben M’Sik, B. P. 7955, Casablanca, Maroc. 3 Laboratoire de Chimie Organique Catalyse et Environnement, Université Hassan II- Mohammedia, Faculté des Sciences Ben M’Sik, B. P. 7955, Casablanca, Maroc. 4 LCAE-URAC18, Faculté des Sciences, Université Mohammed Premier, BP 4808, Oujda, Morocco. _____________________________________________________________________________________________ ABSTRACT Attention has been focused recently on the production of adsorbents from Moroccan oil shale of by chemical activation with phosphoric acid and its application in wastewaters treatment. The optimal conditions for the preparation were searched and the tests of adsorption of uranium and thorium ions were affected. The best product was obtained by used of the ratio of activated agent/precursor equal 2 and activation of the mixture in air at 300°C during two hours after prepocessing at 120°C in air. Under these conditions the maximal adsorption capacity of methylene blue and specific area (S BET ) of the prepared adsorbent were 502 mg/g and 354 m 2 /g, respectively. A batch mode experiment was used to explore the performances of this adsorbent for the removal of the Th from aqueous solutions prepared from Th(NO 3 ) 4 .5H 2 O. The adsorption parameters for the radioelement ion were determined by application of the Langmuir, Freundlich and Elovich models. Keywords: oil shale, activation, phosphoric acid, adsorption, methylene blue, radionuclide. __________________________________________________________________________________________ INTRODUCTION To satisfy the increasing number of directives referring to the control of environmental radioactivity and its health aspects, numerous treatments of radioactive waste have been developed [1]. Considering the potential risks presented by radionuclides for humans and the environment [2-5], it is necessary to envisage the problem for all nuclear activities. A number of processes for the treatment by natural and synthetic materials [6-8] has been reported, the principal ones being based on the elimination of specific species such as U, Th and Ra by organic, inorganic, or composite (polymer and metallic oxides) adsorbents [9-12]. In this context, the utilization of Moroccan oil shale of Timahdit (layer Y) as a raw material for production of a new adsorbents and the adsorption capacity for Th ion, by these products have been studied. The precursor, referred YH, obtained by elimination of the carbonates in the native rock, was mixed with phosphoric acid and treated in different conditions [13]. The change of microtexture between the precursor and the resulting adsorbents was examined by different analytical methods. The best adsorbent was applied for the removal of the Th ion from aqueous solutions. The curves of kinetics and isotherms adsorption were presented and the adsorption parameters for the radioelement were determined by application of the Langmuir, Freundlich and Elovich models.