CADMIUM UPTAKE BY BIOSORBENT SEAWEEDS - ADSORPTION-ISOTHERMS AND SOMEPROCESS CONDITIONS

Cadmium biosorption was evaluated in 15 samples of heat-inactivated se aweeds collected from the coast of Rio de Janeiro State; Brazil. The c lassical Langmuir and Freundlich sorption models were fitted to the re sults in order to test whether these equations could appropriately des cribe the process of passive biosorption uptake. Depending on the alga l sample and on some assumptions, both models could be applied to this study. The possible ion-exchange mechanism associated with the adsorp tion process was also investigated, as well as the effect of pH on bio sorption and re-use of the different biomasses through several biosorp tion/desorption cycles.