Abstract:The toxic effect of copper on the growth rate of green algae, Chlorella vulgaris, in copper-fulvic acid-algae system was studied. It was shown that copper of 0.55mg L-1 caused a 50% decrease in the growth rate of algae in the medium without fulvic acid and the addition of fulvic acid inhibited the tixic effect of copper. The relationship among the algae growth rate and the concentrations of copper and fulvic acid was quantitatively described using an integrated equation combining cumulative normal distribut...