Chromium(VI) is more toxic than chromium(III) to freshwater algae: a paradigm to revise? | Le chrome VI plus toxique que le chrome III pour les algues d'eau douce: un paradigme à réviser ?
2010
Vignati, D. | Dominik, J. | Beye, Magatte | Pettine, M. | Ferrari, B. | INSTITUT F.A. FOREL VERSOIX CHE ; Partenaires IRSTEA ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) | CNR IRSA BRUGHERIO ITA ; Partenaires IRSTEA ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) | GIR INC MONTREAL CAN ; Partenaires IRSTEA ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) | CNR Water Research Institute (IRSA) ; National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR) | Milieux aquatiques, écologie et pollutions (UR MALY) ; Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF)
[Departement_IRSTEA]Eaux [TR1_IRSTEA]BELCA
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显示更多 [+] 显示较少 [-]英语. The behavior and toxicity of Cr(III) and Cr(VI) to the green algae Pseudokirchneriella subcapitata and Chlorella kessleri were studied in a standard culture medium (ISO medium) and, for P. subcapitata only, in ultrafiltered natural water enriched with nutrients (modified ISO medium). In all solutions amended with Cr(III), initial chromium concentrations decreased by 60 to 90% over 72 hours (the duration of algal tests) indicating that protocols for testing poorly soluble substances are required to properly evaluate Cr(III) toxicity. After accounting for its behavior in test solutions, chromium(III) was 5 10 times more toxic than Cr(VI) in both media. For P. subcapitata, the average 72h EC50 of Cr(III) in ISO medium was 17.4 ± 4.7 µg/L (n = 9); lower than corresponding hardness-corrected Continuous Concentration Criteria of the US EPA and well within the range of Cr concentrations found in waters impacted by tannery discharges. These results follow from intrinsic chemical properties of Cr(III) in circumneutral solutions, so that the actual toxicity of Cr(III) to aquatic organisms may be generally underestimated.
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