Removal Of Lead In Fixed Bed Using Natural Zeolite Clinoptilolite [remoção De Chumbo Em Coluna De Leito Fixo Utilizando Zeólita Natural Clinoptilolita]

This work investigated the removal of lead ion using natural zeolite clinoptilolite. The study was done using a cylindrical fixed bed column built in acrylic with a height of 13.3 cm and an internal diameter of 1.4 cm. Experimental assays were carried out varying the liquid flow rate from 10 to 50 mL/min to determine the optimum operational conditions which minimizes diffusion resistance. Length of mass transfer zone and column capacity analyzed indicated that the best flow rate was 20 mL/min among the conditions studied. In order to determinate the pH range at which minimized lead precipitation occurs a pH variation study was developed. The minimum amount of precipitation occurred in pH levels from 3.0 to 5.0. Operating conditions for the maximal lead ion removal were determined using the factorial design and response surface techniques. The variables under investigation were lead initial concentration and feeding flow rate. In the range of values studied, only the variable concentration was found significant. The model obtained by surface methodology was statistically significant and predictive with 98.9% of confidence. The zeolite maximal capacity of lead ion removal was predicted by the model at 200.54 mg of Pb/g de zeolite.1428389(2005) Balance mineral Brasileiro, 2001, , http://www.dnpm. gov.br, Disponivel em:, Acesso em: 14 outBreck, D.W., (1974) Zeolite molecular sieves: Structure, chemistry. and use, , New York: John Wiley & Sons, 771 pInglezakis, V.J., Loizidou, M.D., Grigoropoulou, H.P., Equilibrium and kinetic ion studies of Pb2+. Cr3+. Fe3+ and Cu2+ an natural clinoptilolite (2002) Water Research, 36, pp. 2784-2792Ali, A.A.-H., El-Bishtawi, R., Removal of lead ions using zeolite tuff (1997) Journal of chemical technology and biotechnology, 69, pp. 27-34Curkovic, L., Cerjan-Stefanovic, S., Filipan, T., Metal ion exchange by natural and modified zeolites (1997) Water Research, 31 (6), pp. 1379-1382Schiewer, S., Volesky, B., Modelling of the proton-metal ion exchange in biosorption (1995) Environ. Sci. Technol, 29, pp. 3049-3058Blanchard, G., Maunaye, M., Martin, G., Removal of heavy metals from waters bv means of natural zeolites (1984) Water Research, 18 (12), pp. 1501-1507Tantet, J., Removal of sulphur dioxide from flue gases using hydrophobic zeolites (1993), Master Tesis, The University of New Brunswic, CanadaPansini, M., Colella, C., Caputo, D., De'Gennaro, M., Langella, A., Evaluation of phillipsite as cation exchanger in lead removal form water (1996) Microporous Materials, 5, pp. 357-364Geankoplis, C.J., (1993) Transport process and unit operations, , 3rd ed, PTR Prentice Hall, USAMatheickal, J.T., Yu, Q., Biosorption of lead from aqueous solutions by marine algae Ecklonia Radiata (1996) Water Science and Technology, 34 (9), pp. 1-7Zambon, G.A., Remoção de (Pb2+) utilizando zeólita natural clinoptilolita (2003), Dissertação de Mestrado, FEQ/UNICAMP, Campinas, BrasilSag, Y., Kaya, A., Kutzal, T., Biosorption of lead (II)n nickel (II) and copper (II) on Rhizopus Arrhizus from binary and ternary metal mixtures (2000) Separation Science, 35 (16), pp. 2601-2617. , an Technology, vS. J. Gregg e K. S. W. Sing, Adsorption. Surface and Porosity. 2nd. ed. 198