Synthesis of Chitosan Derivatives and Their Adsorption Properties for Nitrate Anion

Yoshinari BABA*, Kohji OHGUMA†† and Yoshinobu KAWANO

Department of Material Science, Faculty of Engineering, Miyazaki University;Gakuen-kibanadai Nishi 1-1, Miyazaki-shi 889-2192 Japan
†† Chisso Ltd., Co.; Noguchi-machi, Minamata-shi 867-0053 Japan

In order to develop an effective adsorbent for nitrate anion from ground water, four kinds of chitosan derivatives containing the primary amine(CLC), the secondary amine(GCLC), the quaternary ammonium(TMC) and the quaternary ammonium (NTMC) imprinted for nitrate anion were synthesized. These adsorption properties for various anions such as nitrate anion, chloride anion, and sulfate anion were examined by a batchwise method at 303 K. The pH dependencies on the adsorption properties were tested in the adsorption from a single solution containing only nitrate anions. CLC and GCLC exhibited a maximum adsorption of nitrate anions in the pH region of 3--4, while these hardly adsorbed it in the region of pH around 7. On the other hand, the quaternized chitosan derivatives exhibited a high adsorption for nitrate anions even at pH 7, especially, NTMC indicated two times adsorption compared with TMC, owing to a molecularly imprinting effect. This effect has appeared in the adsorption from a solution containing a single solute, while the effect hardly appeared in the adsorption from the mixture solution containing nitrate anion, chloride anion and sulfate anion.

Highly Selective Adsorption Resins. Part 4.

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