Novel immobilization of alginic acid for heavy metal removal

To apply alginic acid efficiently to wastewater treatment system, it was immobilized by novel polyvinyl alcohol (PVA)-boric acid method using glutaraldehyde to reduce the hydration of the immobilized bead. Since the immobilized alginic acid bead did not swell and has enough mechanical strength, channeling of flow and the increase of pressure drop were not observed through the column operations. In addition, it was also stable under strong acidic (below pH 1.0) and high temperature (above 170degreesC) conditions. The surface condition and existence of lead ions on the bead was confirmed by the SEM and (energy dispersive X-ray spectroscopy) EDX instrument analyses. The PVA-alginic acid bead showed that the breakthrough point emerged around 600 bed volumes and lead ions bound to the immobilized bead were readily desorbed by EDTA solution. Especially, the effect of alkaline metal ion (Ca2+ and Mg2+) on lead ion adsorption capacity was almost negligible. (C) 2002 Elsevier Science B.V. All rights reserved.