Chitosan N-benzyl sulfonate derivatives as sorbents for removal of metal ions in an acidic medium
✍ Scribed by M. Weltrowski; B. Martel; M. Morcellet
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 515 KB
- Volume
- 59
- Category
- Article
- ISSN
- 0021-8995
No coin nor oath required. For personal study only.
✦ Synopsis
We synthesized chitosan-based sorhents for the uptake of metal cations in acidic solutions. Chitosan was reacted with 8-formylbenzene sodium sulfonate and 4-formyl-1,3-henzene sodium disulfonate in the presence of NaCNBH3 to yield N-henzyl mono-and disulfonate derivatives of chitosan. IR and NMR spectra confirmed the presence of benzyl sulfonate groups. The degrees of substitution of the monosulfonate chitosan derivatives were in the range of SO%, while those of disulfonate derivatives were about 50%. These sulfonate derivatives of chitosan were tested on the sorption of heavy metals Cd2+, Zn2+, Ni2+, Ph2+, Cu2+, Fe3+, and Cr3+. The sorption capacities for disulfonate compounds were better than for monosulfonate compounds. This phenomenon was attributed to the amphoteric character of the monosulfonate derivatives. T o improve the capacity of adsorption of monosulfonate compounds, the amino groups of these compounds were protected by the henzyloxycarhonyl groups. The protection of amino groups of disulfonate derivatives by benzyloxycarbonyl also improved their sorption capacity. The resulting protected polymers were tested for sorption of heavy metals. Both protected polymers were more efficient than are the parent nonprotected polymers. The synthesized sulfonate derivatives of chitosan are especially adapted to the sorption of heavy metals from the acidic industrial effluents.