US EPA

1786221 

Journal Article 

On the simultaneous adsorption of a reactive dye and hexavalent chromium from aqueous solutions onto grafted chitosan 

Kyzas, GZ; Lazaridis, NK; Kostoglou, M 

2013 

Yes 

Journal of Colloid and Interface Science
ISSN: 0021-9797
EISSN: 1095-7103 

407 

432-441 

English 

23830285 

10.1016/j.jcis.2013.05.052 

WOS:000323470300056 

In the present work, the simultaneous adsorption of Remazol Red 3BS (reactive dye) and Cr(VI) onto chitosan powder grafted with poly(ethylene imine) and cross-linked with epichlorohydrin is experimentally studied. Such a combination of a dye molecule and a heavy metal can be found in real/practical conditions of environmental pollutants' removal, so their mutual interaction on the adsorption efficiencies is very important. The experimental data revealed a competitive type of interaction between the dye molecule and heavy metal ion. An attempt is made to quantitatively describe the data through appropriate isotherms and kinetic equations. The data demonstrated that the common thermodynamic equilibrium is not obtained for the present problem and the final composition of the adsorbed phase depends also on the kinetics. A new scenario of irreversible kinetic-based equilibrium was introduced and examined in detail. None of the scenarios considered here is fully able to cover the whole data, so semi-empirical equations are introduced for their description. It is shown that further development of phenomenological models requires more complicated experimental protocols than simple simultaneous adsorption of the species.