ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 29, Number 6
JKCSEZ 29(6)
December 20, 1985 

To predict speciation of copper and cadmium in natural waters, the stability constant of complexes formed between copper or cadmium and natural organic ligands have been determined by the ion selective electrodes at pH 6. The stability constants for copper and cadmium, log K'CuL = 5.80 and log K'CdL = 3.82, were incorporated inot MINEQL computer program and prediction of chemical species of copper and cadmium in a model fresh water system was made by using this computer program. The natural organic ligands form complex with cupric ions at the concentration of 10-6 moles/l and with cadmium ions at the concentration of 10-5 moles/l. This result showed that prediction of chemical species of heavy metals in natural waters was not possible without taking into account the presence of the natural organic ligands.