Herein, Typha angustifolia, a perennial wetland plant abundantly available in China, is employed as an adsorbent material because of its low cost, stable structure and high amino acid and polysaccharide (the compounds with a lot of carboxyl, amino and hydroxyl groups) contents [24].
We adopted a new method for EDTA modi-fication with stoichiometric thionyl chloride (SOCl2) as a carboxyl group activating reagent, which activated only one carboxyl groupin the EDTA and thus increased the amount of carboxyl groups
available for metal adsorption.