Isamu Kashiki

Adsorption of lead ions on immobilized humic acid

Abstract A fundamental study of the recovery of lead from dilute solution was carried out. Humic acid (HA) was immobilized by calcium alginate gel containing activated carbon powder. To understand the adsorption mechanism of lead on the adsorbent (HA-gel), a model for complexation between divalent metal ions and carboxyl groups on organic polymers was proposed. A general model could be proposed from this work. The results show that the complexation constant of the lead-humic acid system and the number of available sites for complexation of humic acid was not influenced by immobilization. However, the alginate gel used as an immobilizing agent affected the rate of adsorption to a remarkable extent.