Biosorption of Silver using Metal-Imprinted Thiourea-Modified Glutaraldehyde-Crosslinked O-Carboxymethyl Chitosan Beads

Authors

  • Meng Zhang Department of Process Engineering, Memorial University of Newfoundland
  • Yan Zhang Department of Process Engineering, Memorial University of Newfoundland
  • Robert Helleur Department of Chemistry, Memorial University of Newfoundland

Abstract

Chitosan, an abundant biopolymer obtained from deacetylation of chitin, has been proved to be a promising biosorbent for metal uptake. Grafting new functional groups on the chitosan backbone was also reported to be efficient in increasing either the sorption capacity or sorption selectivity for the target metal. In this study, silver-imprinted thiourea-modified glutaraldehyde-crosslinked O-carboxymethyl chitosan beads were prepared to selectively adsorb Ag (I) from a bimetallic aqueous solution. The biosorbent was synthesized by using prepared O-carboxymethyl chitosan beads to first absorb Ag (I) ion, then crosslinking with a polymeric Schiff’s base of thiourea/glutaraldehyde. To obtain the best performance sorbent, the degree of carboxymethylation substitution, and the amount of crosslinking agent used were studied. Results indicated the highest selective uptake capacity of Ag (I) occurred when a molar ratio of amino group of chitosan to carboxymethylation agent to crosslinking agent of 6:15:16 is used in the synthesis.

Batch sorption tests were carried out for isotherm and kinetic studies using the sorbent which provides the best selective uptake capacity of Ag (I). All isothermal and kinetic experiments were performed at 25 °C. The maximum uptake of Ag (I) was found to be 137.5 mgg-1 at pH 5.0 with the initial concentration of Ag (I) being 1.75mmolL-1. The sorbent demonstrated extremely good selectivity towards Ag (I) as equal mole of Cu (II) present in the solution was scarcely absorbed over a pH range from 1.0 to 6.0. The experiments also revealed that the biosorption process of Ag (I) fits well with a Langmuir model and Lagergren’s Pseudo-second-order kinetic.

References

. W.S. Wan Ngah, S. Fatinathan. Adsorption of Cu(II) ions in aqueous solution using chitosan beads, chitosan-GLA beads and chitosan-alginate beads. Chemical Engineering Journal. 143(2008): 62-72.

. Jianlong Wang, Can Chen. Chitosan-based biosorbents: Modification and application for biosorption of heavy metals and radionuclides. Bisresource Technology. 2014, in press..

. Guibal Eric. Interactions of metal ions with chitosan-based sorbents: A review. Separation and Purification technology. 38(2004): 43-74.

. N.S. Hon, L.G. Tang. Chelation of chitosan derivatives with zinc ions. I. O,N-carboxymethyl. Journal of Applied Polymer Science. 77(2000): 2246-2253.

. X.G. Chen, H.J. Park. Chemical characteristics of O-carboxymethyl chitosans related to the preparation conditions. Carbohydrate Polymers. 53(2003): 355-359.

. J. Choong, H.H. Wolfgang. Chemical modification of chitosan and equilibrium study for mercury ion removal. Water Research. 37(2003): 4770-4780.

. Lulu Fan, Chuannan Luo, Zhen Lv, Fuguang Lu, Huamin Qiu. Removal of Ag+ from water environment using a novel magnetic thiourea-chitosan imprinted Ag+. Journal of Hazardous Materials. 2011(194): 193-201.

. Feng Tao, Wang Jie, Zhang Fan. Removal of Copper(II) from an aqueous solution with copper(II)-imprinted chitosan microspheres. Journal of Applied Polymer. 2013(128-6): 3631-3638.

. Monier M, Abdel-Latif D.A.. Synthesis and characterization of ionimrinted chelating fibers based on PET for selective removal of Hg2+. Chemical Engineering Journal. 2013(221): 452-460.

. Liu Bingjie, Lv Xin, Wang Dongfeng. Adsorption behavior of As(III) onto chitosan resin with As(III) as template ions. Journal of Applied Polymer. 2012(125-1): 246-253.

. Jiang Guiming, Gao Baojiao, Xu wenmei,. Adsorption behavior and thermodynamics of iminodiacetic acid-type material IDAA-PGMA/SiO2 for heavy metal ions and rare earth ions. ACTA PHYSICO-CHIMICA SINICA. 2011(27-6): 1474-1481.

. Murugesan A, Ravikumar L, Sathyaselvabala V. Removal of Pb(II), Cu(II), Cd(II) ions from aqueous solution using polyazomethineamides: equilibrium and kinetic approach. Desalination. 2011(271): 199-208.

. Chen CHiayun, Yang Chengyu, Chen Arhhwang. Biosorption of Cu(II), Zn(II), Ni(II) and Pb(II) ions by cross-linked metal-imprinted chitosans with epichlorohydrin. Journal of Environmental Management. 2011(92): 796-802.

. Guan Baohong, Ni Weimin, Wu Zhongbiao. Removal of Mn(II), and Zn(II) ions from flue gas desulfurization wastewater with watersoluble chitosan. Separation and Purification Technology. 2008(65): 269-274.

. Jing He, Yangcheng Lu, Guangsheng Luo. Ca(II) imprinted chitosan microsphere: An effective and green adsorbent for the removal of Cu(II), Cd(II), and Pb(II) from aqueous solutions. Chemical Engineering Journal. 244(2014):202-208.

. Varma, A.J., Deshpande, S.V., Kennedy, J.F.. Metal complexation by chitosan and its derivatives: a review. Carbohydrate Polymers. 55(2004): 77-93.

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Published

2014-08-04