Avaliação da poatencialidade da perlita natural e expandida na adsorção de metais

摘要

The contamination by metal ions has been occurring for decades through theintroduction of liquid effluent not treated, mainly from industrial activities, rivers and lakes,affecting water quality. For that the effluent can be disposed in water bodies, environmentalstandards require that they be adequately addressed, so that the concentration of metals doesnot exceed the limits of standard conditions of release in the receptor. Several methods forwastewater treatment have been reported in the literature, but many of them are high cost andlow efficiency. The adsorption process has been used as effective for removal of metal ions.This paper presents studies to evaluate the potential of perlite as an adsorbent for removingmetals in model solution. Perlite, in its natural form (NP) and expanded (EP), wascharacterized by X-ray fluorescence, X-ray diffraction, surface area analysis using nitrogenadsorption (BET method), scanning electron microscopy and Fourier transform infraredspectroscopy. The physical characteristic and chemical composition of the material presentedwere appropriate for the study of adsorption. Adsorption experiments by the method of finitebath for model solutions of metal ions Cr3+, Cu2+, Mn2+ and Ni2+ were carried out in order tostudy the effect of pH, mass of the adsorbent and the contact time on removal of ions insolution. The results showed that perlite has good adsorption capacity. The NP has higheradsorption capacity (mg g-1) than the EP. According to the values of the constant ofLangmuir qm (mg g-1), the maximum capacity of the monolayer was obtained and in terms ofproportion of mass, we found the following order experimental adsorption: Cr3+ (2.194 mg g-1) > Ni2+ (0.585 mg g-1) > Mn2+ (0.515 mg g-1) > Cu2+ (0.513 mg g-1) and Cr3+ (1.934 mg g-1)>Ni2+ (0.514 mg g-1) > Cu2+ (0.421 mg g-1) > Mn2+ (0.364 mg g-1) on the NP and EP,respectively. The experimental data were best fitted the Langmuir model compared toFreundlich for Cu2+, Mn2+ and Ni2+. However, for the Cr3+, both models fit the experimentaldata