WORLD JOURNAL OF ADVANCE
HEALTHCARE RESEARCH

Hugo J. Marin G., Ramiro Escudero G.*, Rosa E. Pérez S., Roberto Guerra G.

ABSTRACT

The kinetic of biosorption of gold and silver from aqueous media by using a living and dead biomass of fungus Aspergillus niger was investigated. For living biomass the adsorption show recoveries up to 80% and 40% for 1 mg/l of ionic gold and silver, respectively, whereas for 3 mg/l the maximum achieved recovery was near 52% and 70% for gold and silver, respectively. From experiments with dead biomass the cumulative recovery for gold was up to 95% and for silver, the achieved recovery, even in a case was 100%. All the metal recoveries occurred during the first 20 hours of contact. With the experimental data both the isotherm model and the suitable kinetic mechanism, which controls the biosorption phenomenon for this research were established. Most of the experimental results fit the adsorption kinetic model proposed by Elovich (also called the intraparticle diffusion model), suggesting that all the active sites are heterogeneously distributed along the biosorbent. Related to the adsorption isotherms for only dead biomass in contact with a metal in solution, the experimental curves are better described by the model of Langmuir, and by the conjugated model of Freundlich and Langmuir, for gold and silver, respectively.