Adsorption behavior of Pb(II) onto xanthated rubber (Hevea brasiliensis) leaf powder

Abstract

A plant waste, rubber (Hevea brasiliensis) leaf powder was modifi ed with carbon disulfi de (xanthation) for the purpose of introducing sulfur groups, and the adsorbent performance in removing Pb(II) ion was evaluated. Pb(II) adsorption was confi rmed by spectroscopic analysis, which involved Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The amount of Pb(II) adsorbed increased with increasing pH, contact time and concentration but slightly decreased with increasing ionic strength. Adsorption equilibrium was achieved in less than 60 min and followed the pseudo-second order model. The isotherm data indicated that Pb(II) adsorption on xanthated rubber leaf (XRL) fi tted well with Langmuir isotherm model. The maximum adsorption capacity computed from the Langmuir isotherm model was 166.7 mg/g. Pb(II) adsorption occurred via ion-exchange and complexation mechanisms.

Mistletoe leaves as a biosorbent for removal of Pb(II) and Cd(II) from aqueous solution

“…The adsorption process strongly followed toward the pseudo-secondorder model, indicating the chemisorption may be rate limiting in the adsorption of mistletoe leaves for Pb(II) and Cd(II). Similar trend has been also observed in the studies of the adsorption of Cd(II) on Terminalia catappa linn leaf powder [50], adsorption of cadmium (II) and lead(II) ions onto Ficus cassia leaves [28], adsorption of copper(II) on dry fruit product [51], and adsorption of Cu(II) on peat [32]. Their data have suggested that the pseudo-second-order model provides the best correlation data for the rate-limiting step that may be sorption or chemical sorption involving valence forces through sharing or exchange of electron between sorbent and sorbate.…”