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| s a kind of novel adsorption material, collagen fiber immobilized tannin has promised to be an effective adsorbent for removing heavy metal ions from water. In this paper, the mechanism of preparing collagen fiber immobilized tannins was explored and their adsorption behaviors for heavy metal ions were extensively investigated. The results indicated that the formation of the covalent linkage of aldehyde between the nucleophilic sites of tannins and the amino groups of collagen side chains is the reason for solvent extraction resistance and high thermal stability of immobilized tannins. This observation is different from the previous elucidation of collagen-tannin-aldehyde interaction and implies that only condensed tannins, which have rich nucleophilic sites, can be immobilized onto collagen fiber by the described approach. The immobilized condensed tannins were effective in adsorbing Au(III), Th(IV), Cu(II), Pb(II), Cd(II) and Hg(II) from water. For some metal ions, like Au(III) and |
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| Keywords:vegetable tannin, collagen fiber, immobilized tannin, preparation mechanism, heavy metal ions, adsorption, column adsorption, environmental protection |
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