Removal of lead from aqueous solutions by adsorption using sphagnum moss peat [articol]

Abstract

In this study, the adsorption experiments were carried out on laboratory scale, to evaluate the adsorption capacity of sphagnum moss peat (Poiana Stampei, Romania) for lead, as a function of several experimental parameters. The aqueous solution influence of various pH, also the initial metal ion concentration, peat dose and contact time was studied in batch experiments. The obtained results indicate that for an initial solution pH = 6.0 (acetate buffer), sphagnum moss peat was effective in removing 98 % of lead, and still increase with the increasing of peat dose. With the increasing of initial lead concentration, the residual Pb(II) content from aqueous solution increase the same, but the removal percent is higher than 95 % only in case of solutions with an initial concentration lower than 350 mg/L. In addition was also observed that the retained lead ions could be easily leaching from sphagnum moss peat using 0.5 N HCl solution. The interferences caused by several ions (Na(I), K(I), Ca(II), Mg(II), Cu(II), Zn(II), Co(II), Ni(II)) which are present in most environmental samples were determined. The validation of this procedure was done by recovery test of lead in tap water and lake water (free of SO4 2-). The results of recovery test showed that the constituents of water samples do not interfere significantly with the lead removal by sphagnum moss peat.