Kinetic and thermodynamic biosorption of Pb(II) by using a carboxymethyl chitosan-pectin-BADGE-Pb(II)-imprinted ion polymer adsorbent

摘要

Pb(II)-imprinted pectin-carboxymethyl chitosan-BADGE or Pb(II)-CPB was synthesized by mixed pectin (Pec) and carboxymethyl chitosan (CC) and then crosslinked with a crosslinking agent bisphenol A diglycidyl ether (BADGE) to form a stable adsorbent and resistant to acidic media. As a first step, the synthesis was performed by reacting the -OH group among Pec and CC with BADGE to form CPB. The Pb(II) ion was then imprinted with the Pec-CC gel and formed Pb(II)-CPB. Furthermore, the release of Pb(II) ions from the adsorbent was performed using the chelating agent, Na2EDTA. The kinetic and thermodynamic equilibrium of the batch sorption of Pb(II) onto Pb(II)-CPB were investigated. The results of this study showed that the adsorption process of the Pb(II)-CPB adsorbent could be well described by the pseudo-second order model. The thermodynamic biosorbent in adsorption of the Pb(II) ion follows Freundlich isotherm. The adsorption energy of the adsorbent was 15.59 kJ mol-1. This proves that the mechanism process of the adsorbent to Pb(II) ions occurs by physical adsorption. The Pb(II)-CPB adsorbent shows a significantly higher capacity compared to Pec and chitosan. Adsorption capacity of Pb(II)-CPB was 664.44x10-3. The Pb(II)-CPB adsorbent has higher selectivity on Pb2+ ions compared to Pec and CC with the adsorption selectivity order Pb(II)/Zn(II)