Surface Cellulose Modification with 2-Aminomethylpyridine for Copper, Cobalt, Nickel and Zinc Removal from Aqueous Solution

Cellulose was first modified with thionyl chloride, followed by reaction with 2-aminomethylpyridine to yield 6-(2'-aminomethylpyridine)-6-deoxycellulose. The resulting chemically-immobilized surface was characterized by elemental analysis, FTIR, C-13 NMR and thermogravimetry. From 0.28% of nitrogen incorporated in the polysaccharide backbone, the amount of 0.10 +/- 0.01 mmol of the proposed molecule was anchored per gram of the chemically modified cellulose. The available basic nitrogen centers attached to the covalent pendant chain bonded to the biopolymer skeleton were investigated for copper, cobalt, nickel and zinc adsorption from aqueous solution at room temperature. The newly synthesized biopolymer gave maximum sorption capacities of 0.100 +/- 0.012, 0.093 +/- 0.021, 0.074 +/- 0.011 and 0.071 +/- 0.019 mmol.g(-1) for copper, cobalt, nickel and zinc cations, respectively, using the batchwise method, whose data was fitted to different sorption models, the best fit being obtained with the Langmuir model. The results suggested the use of this anchored biopolymer for cation removal from the environment.