The adsorption of copper in a packed-bed of chitosan beads: Modeling, multiple adsorption and regeneration

• Published in: Journal of hazardous materials Vol. 167; no. 1; pp. 1242 - 1245
• Main Authors: Osifo, Peter O., Neomagus, Hein W.J.P., Everson, Raymond C., Webster, Athena, vd Gun, Marius A.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.08.2009; Elsevier
• Subjects: Adsorption; Adsorption column; Applied sciences; Chemical engineering; Chitosan - chemistry; Column regeneration; Conservation of Natural Resources - methods; Copper - isolation & purification; Copper adsorption; Cross-linked chitosan beads; Diffusion; Exact sciences and technology; Glutaral; Jasus edwardsii; Microspheres; Pollution; Column regeneration; Copper adsorption; Adsorption column; Cross-linked chitosan beads; Packed bed; Desorption; Raw materials; Modeling; Plug flow; Adsorption; Batchwise; Preparation; Rocks; Diffusion coefficient
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2009.01.109

In this study, exoskeletons of Cape rock lobsters were used as raw material in the preparation of chitin that was successively deacetylated to chitosan flakes. The chitosan flakes were modified into chitosan beads and the beads were cross-linked with glutaraldehyde in order to study copper adsorption and regeneration in a packed-bed column. Five consecutive adsorption and desorption cycles were carried out and a chitosan mass loss of 25% was observed, after the last cycle. Despite the loss of chitosan material, an improved efficiency in the second and third cycles was observed with the adsorbent utilizing 97 and 74% of its adsorbent capacity in the second and third cycles, respectively. The fourth and fifth cycles, however, showed a decreased efficiency, and breakage of the beads was observed after the fifth cycle. In the desorption experiments, 91–99% of the adsorbed copper was regenerated in the first three cycles. It was also observed that the copper can be regenerated at a concentration of about a thousand fold the initial concentration. The first cycle of adsorption could be accurately described with a shrinking core particle model combined with a plug flow column model. The input parameters for this model were determined by batch characterization methods, with as only fitting parameter, the effective diffusion coefficient of copper in the bead.