BIOSORPTION AND BIOACCUMULATION OF RARE EARTH ELEMENTS (LANTHANIDES) USING MACROALGAE

Abstract

The potential bioremediation of REEs by macroalgae (P. boryana and G. manilaensis) in batch and continuous fixed bed column was studied. In live seaweed the order of REEs accumulation was LREE (La) > MREE (Ce) > HREE (Yb). Salinity significantly influenced REEs uptake and growth of P. boryana and G. manilaensis, where the highest accumulation of REEs occurred at the lowest salinity (20 psu) for all REEs studied. High DGR inhibition was recorded at salinity of 20 psu, followed by 25 psu and 30 psu. Studies on dried biomass showed that removal efficiency was dependant on pH, rpm, biomass dosage and contact time for both seaweeds. The removal efficiency of La, Ce and Yb increased from pH 2 to pH 5 and increased with increasing biomass dosage for both seaweeds. The longer the contact time, the greater the removal efficiency until the equilibrium state was reached.