ION-EXCHANGE EQUILIBRIA OF HEAVY-METALS IN AQUEOUS-SOLUTION ON NEW CHELATING RESINS OF SPOROPOLLENIN

Studies have been conducted on the sorption of several heavy metal ion s Cu(II), Ni(II), Zn(II), Cd(II) and AI(III) from aqueous solutions on the new chelating exchangers of sporopollenin (Lycopodium clavatum) a s a function of pH at several temperatures between 20 and 50 degrees C . The novel metal-ligand exchange resins possessing oxime and carboxyl ic acid side arm functionality were prepared through the reaction of d iaminosporopollenin with dichloroantiglyoxime and bromoacetic acid. Th e sorption of all metals increased considerably in the range of pH 6-1 0 and was observed in sequence as: Cu greater than or equal to Ni > Zn > Cd > Al for carboxylated-diaminoethyl-sporopollenin (DAEC) and Ni g reater than or equal to Cu > Zn > Cd > Al for bis-diaminoethyl-glyoxim e-sporopollenin (bDAEG). The level of pH of the aqueous medium had a l arge influence on the sorption capacity, and the uptake of metals, exc ept Al(III), was found to be 90% or more. The metal-form resins afford ed complete recovery of the sorbed species by acid stripping. Both res ins also showed high stability towards concentrated acids and bases an d retained their high capacity for heavy metals.