[Effect and bioaccumulation of heavy metals (Zn, Cd) on Micractinium pusillum ALGA].

Heavy metals (Zn and Cd) effect and their bioaccumulation by a microalga Micractinium pusillum were investigated. Results showed that Cd was more toxic than Zn on Micractinium pusillum. Indeed, inhibitory concentrations of 50% of alga population in 72h (IC(50,72h)) were 0.28 and 0.34 mg l(-1) respectively for Cd and Zn. On the other hand, metal extracted rates from medium solution were more important for Zn than for Cd, essentially for the two first concentrations tested (0.06 and 0.12 mg l(-1)). Furthermore, Zn and Cd extracted proportions were more important for the low concentrations tested and decreased progressively with increasing concentrations applied. This mechanism of extraction corresponds principally to their biosorption by Micractinium pusillum.