Sorption recovery of metal ions from aqueous solution using humus-boehmite complex

Abstract

Humic acid (HA) was immobilized on boehmite (AlOOH) by batch equilibration. Removal of Pb(II), Hg(II) and Cd(II) from aqueous solution was studied using the batch equilibrium method. Experiments were earned out as a function of <i>p</i>H and concentration of metal ions. It was shown that the maximum adsorption of 96.7 % for Pb(II) occurred at an optimum <i>p</i>H

of 5.5 whereas the maximum adsorption of 91.7% for Hg(II) and 80.8% for Cd(II) was observed at <i>p</i>H 6.0. The adsorption of metal ion proceeds predominently by the cation-exchange mechanism. Adsorption isothermal data could be interpreted by the Langmuir and Freundlich isotherm equations. Langmuir and Freundlich constants have been determined . Adsorption experiments were carried out to investigate the competitive effect on the uptake of metal ions from binary mixtures. Sheindorf -Rebhun - Sheintuch (SRS) model was used to study the competitive interactions for the adsorption of Pb-Hg, Pb-Cd and Cd-Hg mixtures by the adsorbent.