The esterification process increases the carboxylic content of the wood fibre surface leading to a corresponding increase in the
sorption of divalent metal ions.
This modified wood pulp had Cu(II) and Pb(II) binding capacities of 24 mg g1 and 83 mg g1, respectively. Through a similar esterification reaction, Marchetti et al. (2000), chemically modified wood pulp using succinic anhydride, in the presence of a
number of catalysts, leading to the introduction of carboxyl groups.
The cadmium(II) binding capacity of the
modified sawdust was directly related to the acid value estimated by titration and could reach uptakes of up to
169 mg g1.