Influence of the hydration degree on copper removal by Spirulina platensis biomass

In the present work, hydrated biomass of Spirulina platensis has been used for copper removal from aqueous solutions. Biomass has firstly been characterised by potentiometric titration and the overall ionic content evaluated. Copper uptake experiments have been carried out using powdered dry biomass of this cyanobacterium, preliminarily hydrated for increasing time, namely 0, 24, 48, 72 and 96h. Titration experimental data suggest that biomass contains two main acidic groups and total specific negative charge of about 0.4meq/g biomass. The total amount of metal cations released by biomass indicates a metal adsorption capacity of 0.79meq/g. Adsorption tests have evidenced an increase in copper removal capacity of biomass induced by its pre-hydration, likely due to the fact that the contact with water was able to swell up dry biomass so as to expose to the outside a significant number of sites available for adsorption. A hydration time of 48h appears to be the best condition of S. platensis biomass pre-treatment for copper removal. © 2003 SDU. All rights reserved.