Adsorption of heavy metal ions from aqueous solution by tannin based hydrogel

Abstract

Hydrogel based on tannin prepared by the cross-linking reaction of tannin and the copolymer of allyl glycidyl ether with acrylamide was used as sorbent for Pb(II). The data of the adsorption demonstrated fast adsorption property of hydrogel for Pb(II). The ratio of metal ions adsorbed to initial metal ions was over 99 % when the concentration of Pb(II) ion was lower than 0.5 mmol/L. The adsorption isotherms of hydrogel for Pb(II) can be well fitted by the Langmuir equation, the maximum adsorption amount of hydrogels for Pb(II) from Langmuir model were 49.3 mg/g.