Buscano-Ibarra, Sonia Comparative competitive absorption of heavy metals (Cd2+, Cu2+, Pb2+ and Zn2+) in aqueous medium onto chitosan-montmorillionite composite beads Sonia Ibarra-Buscano - Quezon City University of the Philippines Diliman 2009 - xviii, 134p. Master of Science Subjects--Uniform Titles: Chemical Engineering LC Class. No.: T-01549