Cumulation of Zinc, Cadmium and Mercury on the Alga <i>Scenedesmus obliquus</i>

Abstract

Abstract In batch experiments with the metals labelled with their radionuclides the cumulation of zinc, cadmium and mercury on Scenedesmus obliquus in dependence on the pH‐value is measured, because the original pH‐value of the solution is changed by the algae due to their absorption of hydrogen‐ions. For the uptake of zinc and cadmium the logarithm of the cumulation factor in the range of 2 … 5 is a linear function of the pH‐value in the range of 5 … 9, cumulation increasing with rising pH‐value. In contrast, the mercury cumulation is pH‐independent. If the changed pH‐value is taken into account, the cumulation factors are independent of the metal concentration in the range = 10 −4 mol/l. The degree of cumulation is not changed by the presence of other metals. The cumulation factor is reduced by substances forming negatively charged complexes with the metals.