TOXICITY IDENTIFICATION OF METALS: DEVELOPMENT OF TOXICITY IDENTIFICATION FINGERPRINTS

摘要

The ecotoxicological and chemical response of five metals (Cd, Cr, Cu, Ni, and Zn) to selective fractionation techniques was assessed using the organism Daphnia magna. The metals Cu and Zn revealed similar toxicity patterns, showing an increased toxicity when lowering the pH, a marked reduction in toxicity after addition of ethylenediaminetetraacetic acid (EDTA). Similar toxicity reductions were obtained by passing the metal solutions over ion exchangers, activated charcoal, and filtration/solid-phase extraction units at neutral and basic phs. The discrimination between Cu- and Zn-toxicity occurred in the oxidant reduction test, i.e., Zn toxicity was not affected by the addition of Na_2S_2O_3, while Cu toxicity was strongly reduced.