Abstract
Characteristics of tannin as an adsorbent for heavy metal ions, such as lead, cadmium, copper and zinc were investigated. The adsorbent used in present study was a gel made and supplied from Mitsubishi Nuclear Fuel Co., Ltd. (MNF). It was found that this gel had ability to adsorb heavy metal ions selectively. The adsorption isotherms were well approximated by Langmuir equation. The maximum adsorption capacity was influenced by some factors, as following: initial pH, kinds of heavy metal ion species and temperature. The adsorption mechanism was performed by ion exchange of heavy metal ion species and functional group in the gel. These results suggest that the gel made from tannin is useful for uptake of heavy metal ions.
