Synthesis and use of esterified sawdusts bearing carboxyl group for removal of cadmium(II) from water

Improvement of the reaction of succinic anhydride with wood meal was studie d in order to prepare low cost materials for the removal of heavy metals. W ithout solvent, the use of 1 equivalent of pyridine or triethylamine/succin ic anhydride was necessary to obtain high grafting efficiencies at 80 degre es C. In the presence of small quantities of 1,2-dichloroethane as swelling agent, only 0.1 equivalent of catalyst was needed to obtain satisfactory r esults. Three more or less modified sawdusts were used after activation wit h NaHCO3 for the removal of cadmium(II) from water. Metal binding capacity was directly connected with the acid value estimated by titration and can r each 200 mg/g. Strongly modified sawdust showed a cadmium binding capacity lower than expected because of diester formation.