Selective Adsorption of Precious Metals on Sulfur-Containing Chitosan Derivatives

Abstract

2-Thienylchitosan and 3-(methylthio)propylchitosan were newly synthesized by crosslinking the corresponding Schiff base derivative before reducing it so that the adsorptive activity was not lowered by the crosslinking. These chitosan derivatives selectively adsorbed gold(III), palladium(II) and platinum(IV) over base metals from hydrochloric acid.

Adsorption Behavior of Cationic and Anionic Species on Chitosan Resins Possessing Amino Acid Moieties

“…Some researchers have applied chitosan to the separation and concentration of trace elements in water samples prior to trace analysis. [5][6][7][8][9][10][11][12][13][14][15][16][17][18] Chitosan as a base material for the development of a chelating resin and an ion-exchange resin is of great interest due to its advantages, such as easy derivatization of its amino group, and being more hydrophilic than synthetic base materials, like polystyrene-divinylbenzene, polyethylene, and polyurethane, which provides a fast sorption kinetic of ionic species in aquatic media. 8 Therefore, novel chitosan resins possessing chelating moieties have been developed by using a cross-linked chitosan resin as a base material.…”

“…In order to develop high-performance chitosan resins prior to the collection and concentration of trace elements in water samples, some researchers have discussed the adsorption ability of cationic species, such as heavy metals and lanthanoids, by modifying of the cross-linked chitosan with chelating moieties, which are the IDA (iminodiacetic acid) group, EDTA (ethylenediaminetetraacetic acid) group, DTPA (diethylenetriaminepentaacetic acid) group, methylthiocarbamoyl group, phenylthiocarbamoyl group, 2-pyridylmethyl group, and 2-thienylmethyl group, and 3-(methylthio) propyl group. [9][10][11][12][13][14] By using the synthesized chitosan resins, the adsorption behavior of 3 -13 kinds of element in aqueous media has been investigated. In order to elucidate their adsorption ability, we must systematically examine the adsorption properties of multi elements under various pH conditions on chitosan resins.…”

Environmental Applications of Chitosan and Its Derivatives

“…Introducing crosslinks to the chitosan structure has successfully enhanced its durability in acidic environments. Crosslinking of chitosan was achieved by using various crosslinking agents, such as glutaraldehyde (GA) , epichlorohydrin (ECH) (Baba et al 1994), ethylene glycol diglycidyl ether (EGDE) (Kamari et al 2009), and hexamethylene diisocyanate (HMDIC) (Choudhari et al 2007) ( Fig. 3; see Table 1 for a list of abbreviations and acronyms used in this paper).…”

In Separation and Purification

“…Beside GA, other crosslinking agents including EPI [206] , ethylene glycol diglycidyl ether (EGDGE), iminodiacetic acid [207] , nitriloacetic acid, and organic diisocyanates [208] have been used to crosslink chitosan adsorbents. For example, chitosan crosslinked with EGDGE, DEGDGE ether, and PEGDGE showed an interesting selectivity for Cu 2+ over Ni 2+ and Co 2+ ions [209 -211] .…”