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This work describes the preparation of sugarcane bagasse chemically modified with citric acid and evaluated adsorption of Cu(II), Cr(III) and Pb(II) ions from aqueous solutions by sugarcane bagasse in natura and chemically modified. Adsorption analyses in batch system were carried out in function of contact time with the adsorbent and adsorbate concentration. Flame atomic absorption spectrometry was used to determine the ions concentrations. Adsorption experimental data were fitted to Langmuir and Freundlich linear models, and the maximum adsorption capacity was estimated for copper ions in function of modifications. The chemical modifications were confirmed at 1.730 cm−1 peak in infrared spectra, referring to the carboxylate groups. The required time for the adsorption to reach equilibrium was 24 h and the kinetics follows the behavior described by the pseudo-second order equation. Besides, a significant improvement of the ions adsorption has been observed after the bagasse modification, according to Langmuir isotherm linear model, showed maximum adsorption capacities for Cu(II), Pb(II), and Cr(III) ions ranging from 6.87 to 31.53 mg.g-1, 11.63 to 52.63 mg.g-1, and 21.87 to 22,08 mg.g-1, respectively. |
