Resumo

ALVARADO IBARRA, Juana et al. Evaluation of the potentality of a Mexican natural chabazite to remove lead from water. Rev. Int. Contam. Ambient [online]. 2013, vol.29, n.2, pp.201-210. ISSN 0188-4999.

The intention of this paper is to present the characterization of a natural zeolite, chabazite-type, from the Mexican reservoir La Palma, at Divisaderos, Sonora, where their potential use as ion exchange material to remove lead in water is assessed. The chabazite was characterized through XRD, ICP-OES, ICP-MS, EDX, BET and TG/TGD. The results indicate the presence of Ba (1930 ppm) and Sr (1220 ppm), which are characteristic of aluminum rich phases. A chabazite modification treatment is proposed by using solutions of NaOH (0.1 M) and NH4NO3 (1 M). The lead removal kinetics both in natural zeolite as in their chemically modified forms was obtained by using the ion exchange process in a batch reactor. The results show how unnecessary natural zeolite homoionization is for the removal of lead, thereby obtaining the equilibrium concentration of unmodified zeolite for plotting the adsorption isotherm, which was adjusted to Langmuir model. The Langmuir isotherm has a good fit of the results at equilibrium (R² = 0.92), which demonstrates that natural zeolites studied, in its natural form, contains exchangeable cations required (Ca⁺², Mg²⁺ and Na⁺) for potentially be used as an adsorbent material/ion exchanger for water treatment impacted by lead.

Palavras-chave : zeolite; ion exchange; heavy metals.

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