Dithiooxamide-Immobilized Microalgal Residue for the Selective Recovery of Pd(II) and Pt(IV)

Abstract

Microalgal residue was chemically modified by immobilizing a functional group of dithiooxamide to prepare a novel type of adsorbent. This adsorbent exhibited high adsorption affinity and selectivity for Pd(II) and Pt(IV) whereas the adsorption of coexisting base metal ions was negligible. From the adsorption isotherms, this adsorbent was found to exhibit remarkably high adsorption capacity. The thermodynamic parameters indicated that the adsorption is governed by an endothermic reaction. The effective separation of Pd(II) and Pt(IV) from Cu(II) was confirmed also by a dynamic adsorption test. The effectiveness of elution of adsorbed Pd(II) and Pt(IV) was 85% and 96%, respectively.

Keywords:

• adsorption
• functional group immobilization
• oil-rich microalgae
• precious metal recovery

ACKNOWLEDGEMENTS

The present work was financially supported by the Ministry of Agriculture, Forestry, and Fisheries, Japan, for the research project on Development of Innovative Total Technologies for Carbon Sequestration, Biomass Production, and Biomass Utilization.