Tannin, an abound natural resource, with multiple structure units, has recently been investigated wide ly as a high-performance adsorbent for the removal of heavy metals from aqueous solution, because tannin has abundant adjacent phenolic hydroxyls chelating with metal ions. The methods of tannin modification including insitu immobilizing, collagen fiber immobilizing, amino-methylating and sulfomethylating were reviewed and discussed in this paper. Finally, the advantages and disadvantages of these modification methods were i...
