[Show abstract][Hide abstract] ABSTRACT: Because of their global distribution, environmental persistence and potential risk to human beings and ecosystems, poly- and perfluorinated compounds (PFCs) are of particular concern to scientific and regulatory communities. Despite this concern, data about the physicochemical properties and aquatic toxicity of PFCs are still limited, and there are big debates regarding the actual values of some properties investigated. In order to have a clear overview of the data available, this paper summarizes the data availble for the physicochemical properties and aquatic toxicity of PFCs.
Critical Reviews in Environmental Science and Technology 01/2013; 43(6):598-678. · 3.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Perfluorinated compounds (PFCs) can be detected worldwide in both, soil and water. In order to study the leaching behavior of this heterogeneous group of compounds in soil, flow-through column experiments have been conducted. Ten perfluoro carboxylates and four perfluoro sulfonates ranging from C4 to C14 in chain length, and contaminated sewage sludge, have been used to spike a standard soil. The aqueous column effluent was analyzed using liquid chromatography tandem mass spectrometry (LC-MS/MS) with direct injection. The observed percolation velocity seems to be strongly correlated with the length of the perfluorinated chain. Other factors that additionally contribute to the leaching behavior are the functional group of the PFC, the organic carbon content of the soil and the presence of other adsorbates. A mass balance calculation showed that perfluorobutanoic acid can adsorb strongly to the soil, when no PFC with longer carbon chain are present. Only about 60% of the added perfluorobutanoic acid could be detected in the percolate water. The missing amount started to elute again when longer chain PFC or stearate were added to the soil. Thus it would appear that larger and more lipophilic molecules can displace shorter PFC from their binding sites in the soil. The results of a monitoring study using 32 surface water samples and 150 groundwater samples confirm that the PFC with the highest concentrations in groundwater are the short chain PFC with less than 7 (fluorinated) carbon atoms. The dominating PFC in surface waters are perfluorooctanoic acid and perfluorooctane sulfonic acid.
[Show abstract][Hide abstract] ABSTRACT: The sorption of perfluorinated compounds (PFCs) to soils and sediments determines their fate and distribution in the environment, but there is little consensus regarding distribution coefficients that should be used for assessing the environmental fate of these compounds. Here we reviewed sorption coefficients for PFCs derived from laboratory experiments and compared these values with the gross distribution between the concentrations of PFCs in surface waters and sediments or between wastewater and sewage sludge. Sorption experiments with perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) suggest that their sorption can be described reasonably well as a partitioning-like process with an average logKoc of approximately 2.8 for PFOA and 3.0 for PFOS. However, median concentrations in sediments (PFOA, 0.27ngg(-1); PFOS, 0.54ngg(-1)) or sewage sludge (PFOA, 37ngg(-1); PFOS, 69ngg(-1)) in relation to median concentrations in surface water (PFOA, 3ngl(-1); PFOS, 3ngl(-1)) or wastewater treatment effluent (PFOA, 24ngl(-1); PFOS, 11ngl(-1)), suggest that effective logKoc distribution coefficients for the field situation may be close to 3.7 for PFOA and 4.2 for PFOS. Applying lab-based logKoc distribution coefficients can therefore result in a serious overestimation of PFC concentrations in water and in turn to an underestimation of the residence time of PFOA and PFOS in contaminated soils. Irrespective of the dissipation kinetics, the majority of PFOA and PFOS from contaminated soils will be transported to groundwater and surface water bodies.
Chemosphere 03/2013; · 3.14 Impact Factor
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