Toxicity of perfluorinated carboxylic acids for aquatic organisms

Toxicity of perfluorinated carboxylic acids with carbon chain C8 to C12 were tested with oligochaeta Tubifex tubifex. Toxicity was evaluated as the exposure time ET50 from onset of damage of the oligochaeta in saturated aqueous solutions. The ET50 fluctuated between 25 and 257 minutes. No statistically significant difference was found among the C8, C9 and C12 acids (ET50 between 143 and 257 minutes with large standard deviation). The acids with carbon chain C10 and C11 induced the effect significantly quicker (25 to 47 minutes). No acute toxicity measured in the three-minute test was observed in any case

Transformation of fly ash from Pb metallurgy in soils

The fly ash from secondary lead metallurgy was placed in two different soils in order to investigate the kinetics of release (in a time horizon of 504 h) and mobility of metals/metalloids in soil water and soil. Uncontaminated soils used for the pot experiment were two: acidified forest soil N and agricultural soil H. An experimental bag containing 0.5 g of fly ash was placed in a pot with 200 g of soil, which was watered using deionised water at the 60 % water holding capacity (WHC) level. Using Rhizon pore water samplers the soil solution was regularly sampled and subsequently analysed. The soil solution analysis was supplemented by the geochemical speciation-solubility modelling using the PHREEQC-2 code and the mineralogical investigation of solid phase. For Cd, Zn and As the release in soil water had similar behaviour in time: during first 96 hours of the experiment their concentration increased up to maximum values and then slowly decreased till the end of experiment. This trend has not been observed for Cu, Pb and Sb, being tightly bound to secondary phases newly formed directly in the fly ash or to soil constituents, or indicating possible resistance to leaching. Weight loss after the experiment for the fly ash was in both soils approximately 60 %, indicating high level of its dissolution...

Toxicity determination of perfluorinated organic acids salts

Department of Analytical ChemistryKatedra analytické chemieFaculty of SciencePřírodovědecká fakult