Abstract
The inhibition of algal growth is considered to be affected by such factors as algal species, medium composition, culture methods etc.. In this study, the effect of culture conditions on algal growth characteristics and the toxicity of heavy metals to the growth of Chlorella ellipsoidea were evaluated. The algal growth was dependent on the medium composition, the strength of medium (the reciprocal of the dilution rate in the original medium), and the culture methods.
The lower the strength of the medium became, the higher the inhibition rate of cadmium for the algal growth became. Six kinds of heavy metals used in these experiments influenced the growth and the cell volume of C. ellipsoidea and they gave different modes in concentration-effect curves. These curves were well depicted with both the Weibull and the Probit models.
The toxic intensity of heavy metals evaluated from EC50 was in the following order, silver, copper, cadmium, chromium, nickel, and cobalt. The EC10 values obtained from the Weibull model were, however, lower than those obtained from the Probit model.
