Synthesis of chitosan-amino acid conjugates and their use in heavy metal uptake.

Chitosan-amino acid conjugates were prepared by coupling amino acid esters to the carboxyl group of glyoxylic acid-substituted chitosan. The removal of heavy metals (Cu, Ni, Co and Mn) was increased by introduction of amino acids to chitosan, especially for Mn. Heavy metals were almost completely removed by chitosan-amino acid conjugates from solutions at an initial concentration of 100 parts per million.