Adsorption study of heavy metals in aqueous solutions aiming at the treatment of contaminated groundwater

Abstract

This study evaluates the application of the vegetal activated carbon (AC), vegetable AC impregnated with Ag and Cu (0.08% m/m) and cationic Supergel^TM SGC650H resin for adsorption of Fe³⁺ and Pb²⁺ ions in closed and batch system. The best adsorption capacities were obtained by using the cationic resin SGC650H, pH 3, temperature of 30 °C and stirring speed of 100 rpm. Thus, the kinetic and equilibrium experiments, in mono- and bicomponent, were performed using SGC650H resin, wherein the kinetic models of pseudo-first and pseudo-second order presented a good fit to the kinetic data, for mono- and bicomponent, respectively. The Langmuir isotherm adequately represented the monocomponent equilibrium data, showing maximum adsorption capacities values of 7.18 and 4.00 meq g⁻¹ for Fe³⁺ and Pb²⁺, respectively. An inhibitory effect between the metal species was verified by fitting the modified extended Langmuir isotherm model to the binary equilibrium data, which allowed to predict changes in the surface affinity to the adsorbent by the metal ions. Based on the observed results, the use of SGC650H resin presents great potential for water treatment systems contaminated with heavy metals.

Keywords:

• Multicomponent adsorption
• heavy metals
• cationic resin
• competitive adsorption

Additional information

Funding

The authors thank to Araucaria Foundation, Coordination for the Improvement of Higher Education Personnel (CAPES) and National Counsel of Technological and Scientific Development (CNPq) by financial support. Purific of Brazil Ltda and Klabin for the adsorbent supply.