Adsorption of heavy metals using magnetically modified alginic acid

To improve efficiency of adsorption process, magnetically modified alginic acid (MMA) was synthesized by means of entrapment method with iron oxide and urethane. MMA had a high uptake capacity of 1.45 mmol/g-dry mass for lead ion at pH 4 and its uptake capacity was higher than that of the commercial ion exachanger (IR-120(+)) and activated carbon. The surface condition and existence of lead ions on the bead was confirmed by the FT-IR, SEM, and EDX instrumental analyses. When 0.6 g of MMA was added to initial heavy metal solution (Pb2+; 300 mg/L, Cd2+; 3 mg/L) removal efficiency of lead and cadmium ions was 100 and 80%, respectively. To increase removal efficiency of heavy metals, step-by-step addition of MMA was applied to heavy metal solution and it increased removal efficiency of heavy metals about 10%. In terms of kinetics, adsorption of heavy metals was almost completed in 10 min. (C) 2006 Elsevier B.V. All rights reserved.