HIGHLY SELECTIVE ADSORPTION RESIN, III - SELECTIVE ADSORPTION OF MERCURY(II) ON CHITOSAN DERIVATIVES FROM HYDROCHLORIC-ACID

Crosslinked N-(2-pyridylmethyl)chitosan (PNEC), N-(2-thienylmethyl)chi tosan (TMC), and N-[3-(methylthio)propyl]chitosan(MTPC) were newly syn thesized as adsorbents of mercury(II). The amino group of the active a dsorption site of chitosan was protected by Schiff's base formation pr ior to being crosslinked by 2-(chloromethyl)oxirane. The final chitosa n derivatives were obtained by reducing the imine moiety of the Schiff 's bases with sodium borohydride. The adsorption behavior of metal ion s on the chitosan derivatives was examined from hydrochloric acid usin g a batchwise method. These chitosan derivatives exhibited high select ivities for mercury(II) over base metals in hydrochloric acid. Among t he chitosan derivatives, MTPC especially exhibited high selectivity an d a high loading capacity for mercury(II). The stoichiometric relation s in the adsorption of mercury(II) on PMC and MTPC were clarified from hydrochloric acid.