Sorption studies of cadmium and lead ions on hybrid polysaccharide biosorbents

The sorption of lead and cadmium ions on hybrid pectin-based biosorbents containing gellan, carob, and xanthan gum has been studied. The rate constant of the metal ions’ sorption on hybrid P + X beads (analyzed with the two kinetic models: pseudo-first-order and pseudo-second–order models) is at least two times higher than obtained on other pectin-based sorbents. The Langmuir equation fits experimental data better than Freundlich model. A greater equilibrium constant B for lead(II) than cadmium(II) indicates a stronger bond between Pb(II) and pectin-based beads. Prepared hybrid materials are promising biosorbents for heavy metals’ removal from waste waters.