A procedure has been developed for determination of cadmium (Cd) species in solid waste leachates employing a cation exchange resin (Chelex 100) in a batch-column-batch sequence. The procedure allows for determination of free divalent Cd (Cd2+), labile Cd complexes, slowly labile Cd complexes and stable Cd complexes. The effects of equilibration time, pH, calcium activity and ratio of sample volume to amount of resin have been examined. The method has been tested on standardized chloride and EDTA solutions containing Cd and on two actual leachates. The Cd species determined in the chloride solutions were in accordance with theoretical calculations of Cd chloride complexes, and Cd in the EDTA solution was identified as stable Cd complexes. The two polluted samples included in the test showed only a small percentage of free divalent Cd and a high degree of labile complexes.
|Publication status||Published - 1989|