[01] Massaï Harouna, Department of Chemistry, Faculty of Science, University of Maroua, Maroua, Cameroon. [02] Constant Tcheka, Department of Chemistry, Faculty of Science, University of Ngaoundéré, Ngaoundéré, Cameroon. [03] Albert Laoh Djongmaila, Department of Chemistry, Faculty of Science, University of Ngaoundéré, Ngaoundéré, Cameroon. [04] Daouda Abia, Department of Chemistry, Faculty of Science, University of Ngaoundéré, Ngaoundéré, Cameroon. [05] Jean Pierre Nguetnkam, Department of Chemistry, Faculty of Science, University of Ngaoundéré, Ngaoundéré, Cameroon. [06] Joseph Ketcha Mbadcam, Department of Inorganic Chemistry, Faculty of Science, Unuiversity of Yaounde I, Yaoundé, Cameroon. [07] Benoît Benguellah Loura, Department of Chemistry, Higher institute of the Sahel, University of Maroua, Physical Chemistry, Maroua, Cameroon. [08] Mohamed Mbarki, Department of Chemistry and Environment, Faculty of Science and Technology, University of Sultan Moulay Slimane, Beni Mellal, Morocco.

The study of the adsorption of heavy metals and the organic molecules by clays is a contribution to the treatment of water. This work primarily concerns the elimination of the ions Mn²⁺, Cu2+ and PO₄3- of synthetic water, by adsorption on modified clay. Some physicochemical parameters of pillared clay were studied such as the pH (6.83), the water content (22.40%), the swelling number (98.83%), the loss on the ignition (4.35%), the density (1.13) and colloidality (95.75%). Following this view, clay materials of Karewa (North Cameroon), specially made up of smectite, have been pillared with polyoxycations of aluminum. Next, some trials of adsorption of metallic ions Cu²⁺, Mn²⁺ and PO43- in aqueous solution mixture were carried out by varying the time of contact, the pH, the initial concentration of ions, C_o and the temperature, T(°C). The kinetics of the reactions indicate that the adsorption of Cu²⁺, Mn²⁺ and PO₄3- ions is rapid and the equilibrium is reached after 8 minutes. The adsorption capacity, Q_e of the clay modified increases with increasing pH up to pH = 7, and reduces when the pH becomes basic. This phenomenon also increases with the increase in the initial concentration of the metallic ions. It was observed that, temperature has a less influence on the retention capacity. The adsorption isotherms are comparable with the Langmuir and Freundlich models. The adsorbed quantities from the monolayer coverage deducted from Langmuir’s model are 21.73 mg/g, 20.62 mg/g and 26.31 mg/g respectively for Cu²⁺, Mn²⁺ and PO₄3- ions. The nature of the retention phenomenon of both ions is exothermic, spontaneous and physical in the range of temperature 298-313K.

Pillared clay, Adsorption, Heavy Metals, Organic Molecules

[01] Rodier, J. Analysis of water: Chemistry, physicochemistry, Bacteriology, Biology, 8 ^3rd edition. Dunod, bets, 1996; 1383 p. [02] Youcef, L., Achour, A. Élimination du cuivre par des procèdes de précipitation chimique et d'adsorption. 2006; pp.59-65. [03] Wandered, E., Reactivity of natural clay surface Study of the adsorption of anion dyes. Thesis of doctorate. University of Strabourg. 2011. [04] Abdelouahab, C, Aït Ammar, H., Obretenov, T., Z., Gaïd, A. Fixing on bentonitic clays of metal ions present in industrial waste water –These of Cd and of Zn, rev. Int. Sci. Water. 1987; 3 (2): 33–40. [05] Benguella B, Benaissa H. Cadmium removal from aqueous solutions by chitin: Kinetic and equilibrium studies. Wat. LMBO. 2002. l36: 2463-2474. [06] Cousin, S., (1980). Contribution to the improvement of the quality of the water intended for the human consumption use of the arg I them during treatments of flocculation decantation. Thesis of Doctorate 32nd cycle, University Paris V, France. [07] Bouanga, F., De Laat, J., Dore. Mode d'élimination de composés organiques polaires par une alumine activée en milieu aqueux. Comparaison avec le charbon actif, Envir. Technol. Lett.1986. 5: 239-254. [08] Canizares, P., Valverde, J. L., SunKou, M. R., Molina, C. B. Synthesis and characterization of PILCs with single and mixed oxide pillars prepared from two different bentonites. A comparative study. Of Microporous and Mesoporous Materials. 1999. 29: 267–281. [09] Bouras O., (2003). Propriétés Absorbantes D’argiles Pontées organophiles: Synthèse et Caractérisation. Thèse de doctorat. Université de Limoges. [10] Li, D., Scala, A. A., Ma, Y. H., 1996. Adsorption 2, 227. [11] Malla, P. B., Yamanaka, S. Unusual water vapor adsorption behavior of montmorillonite pillared with ceramic oxides. Solid State Ionics 1989. 32(33); 354–362. [12] Yamanaka, S., Malla, P. B., Komarneni, S. Water adsorption properties of alumina pillared clay. Journal of Colloid and Interface Science. 1990. 134: 51–58. [13] Sapag, K. 1997. Nuevos catalizadores basados en arcillas pilareadaspar la síntesis de Fischer – Tropsch. PhD thesis, Universidad Autónoma de Madrid, Madrid, Spain. [14] Wang, Y., Gao, B.-Y., Yue, W.-W., Yue, Q.-Y. Adsorption kinetics of nitrate from aqueous solutions onto modified wheat residue. Colloids and Surfaces A: Physico – chemical and Engineering Aspects. 2007. 308: 1–5. [15] Seliem, M. K., Komarneni, S., Byrne, T., Cannon, F., S., Shahien, M., G., Khalil A., Abd El-Gaid, I., M. Removal of perchlorata by synthetic organosilicas and organoclay: Kinetics and isotherm studies. AppliedClayScience. 2013. 71, 21–26. [16] Baidas, S., Gao, B., Meng, X. Perchlorate removal by quaternary amine modified reed. Journal of Hazardous Materials. 2011.189, 54–61. [17] Abollino, O., Aceto, M., Malandrino, M., Sarzanini, C., Mentasli, E. Adsorption of heavy metals on Na-montmorillonite. Effect of pH and organic substance. Water research. 2003; 37: 1619-1627. [18] Kaya, A., Ören, A., H. Adsorption of zinc from aqueous solutions to bentonite. Journal of Hazardous Materials. 2005. 125: 183-189. [19] Ucun et, H., Bayhan, Y., K., Kaya, Y., Cakici, A., Algur O. F., Biosorptionof chromium (VI) from aqueous solution by cone biomass of Pinussylvestris. Bioresour. Technol. 2002. 85: 155-158. [20] Park, D., Yun, Y. S., Park, J. M. Use of dead fungal biomass for the detoxification of hexavalent chromium: screening and kinetics, Process Biochem. 2005. 40: 2559-2565. [21] Zheng H., Donghong L, Yan Z, Shuping L, Zhe L. Sorption isotherm and kinetic modeling of aniline one Cr-bentonite. Newspaper of Hazardous Materials. 2000. 1-7. [22] Djakba R., (2013). Adsorption of the ions Mn2+ and Zn2+ in aqueous solution by decked clays of Boboyo (Area of Cameroun Extreme-North). Memory of master II, Cameroun, University of Ngaoundéré, Faculty of Sciences, Department of Chemistry, 65P. [23] Carmen, 2008. Procédé AD-OX d’élimination de polluants organiques non biodégradables par adsorption puis oxydation catalytique. Thèse de Doctorat l’Institut National Polytechnique de Toulouse. [24] Wang, S., Zhu, Z. H. Characterization and environmental application of an Australian natural zeolite for basic dye removal from aqueous solution. Journal of Hazardous Materials, B. 2006. 136: 946-952. [25] Han, X., Wang, W., Ma, X. Adsrption characteristics of methylene blue onto low cost biomass material lotus leaf. Chemical Engineering Journal. 2011. 171, 1–8. [26] Ncibi, M., C., Mahjoub, B., Seffen, M. Etude de la biosorption du chrome (VI) par une biomasse méditerranéenne: posidonia Oceanica (L.) Delile. Revue des Sciences de l’Eau. 2008. 21, 441-449.