Transport studies for the sorption of copper ions by chitosan

Abstract

The ability of chitosan, prepared from waste prawn shell, to sorb copper (II) ions from aqueous solutions has been studied. Equilibrium studies show that chitosan has a maximum sorption capacity for copper ions of about 40mg/g chitosan. The mass transport characteristics have been investigated by monitoring the kinetics in an agitated batch adsorber. An external mass transfer coefficient and an intraparticle diffusion rate parameter have been determined for a number of system variables including agitation, initial copper ion concentration, chitosan mass, chitosan particle size and solution temperature.

Adsorption of Cu(II) and Cr(VI) ions by chitosan: kinetics and equilibrium studies

“…Transport studies which were conducted by Findon et al (1993) were not able to confirm the actual mechanism of Cu uptake by chitosan, but they considered it likely that the Cu is chelated with the NH 2 and NH groups in the chitosan chain.…”

“…The present method for removal of Cu is to precipitate copper hydroxide by liming. But with this process, residual Cu remains a problem (Findon et al, 1993).…”

“…From the literature it is clear that chitosan can be used to remove numerous trace metals (Cu(II), Pb(II), U(VI), Cr(III), Cr(VI), Ni(II), Cd(II), Zn(II), Co(II), Fe(II), Mn(II), Pt(IV), Ir(III), Pd(II), V(V) and V(IV)) from wastewater. In these studies chitosan has been used in a variety of forms, which include chitosan beads, flakes and membranes (Findon et al, 1993;Deans and Dixon, 1992;Kamiñski and Modrzejewska, 1997;Onsøyen and Skaugrud, 1990;McKay et al, 1989).…”

Kinetic modeling of the biosorption of Cd2+ ions from aqueous solutions onto Eichhornia crassipes roots using potentiometry: low-cost alternative to conventional methods

“…The initial sorption rate (h) was calculated using the following equation: (14) As can be seen from Figure 2d, t/q t varied linearly with time t. The data agreed well with the pseudo-second-order model, and the correlation coefficient for the linear plot was very good. However, the model did not fit the initial stages of the sorption process well, most likely because the roots and Cd 2+ ions were not yet in direct contact.…”

“…The curve obtained here included four separate regions (Figure 2b): an initial curved region (1) followed by two linear regions (2 and 3), and then a plateau (4). Several authors [14][15][16] have reported similar behavior and attributed the different regions of the curve to the sequential stages of solute mass transfer to the adsorbent. In region (1), film diffusion from the bulk solution to the sorbent surface constituted the main process.…”