Abstract

MARTINEZ STAGNARO, Susana Yamila; VOLZONE, Cristina  and  RUEDA, Mónica Luciana. Influence of thermal treatment on bentonite used as adsorbent for Cd, Pb, Zn retention from mono-solute and poly-solute aqueous solutions. Mat. Res. [online]. 2012, vol.15, n.4, pp. 549-553.  Epub July 10, 2012. ISSN 1516-1439.  http://dx.doi.org/10.1590/S1516-14392012005000074.

The retentions of Zn, Cd and Pb cations by one treated bentonite up to 750 °C were analyzed. The retentions were evaluated by using mono-and poly-solute aqueous solutions of such cations. The adsorptions were carried out in batch system at room temperature. The solid/liquid ratio was 2% wt.v^-1. The solids were characterized by X-ray diffraction, thermal and chemical analyses. The Zn cation from mono- or polysolute-solutions was retained in higher amount than Cd and Pb cations in similar solution types by bentonite. The retentions were effective up to 450 °C calcined bentonite, after that, the retention capacity decreased in concordance with dehydroxylation of the structure of clay minerals.

Keywords : adsorption; thermal treatment; clay; heavy metals.