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- Campos-Pereira, Hugo, et al.
(författare)
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Effect of pH, surface charge and soil properties on the solid-solution partitioning of perfluoroalkyl substances (PFASs) in a wide range of temperate soils
- 2023
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Ingår i: Chemosphere. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0045-6535 .- 1879-1298. ; 321
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Tidskriftsartikel (refereegranskat)abstract
- The pH-dependent soil-water partitioning of six perfluoroalkyl substances (PFASs) of environmental concern (PFOA, PFDA, PFUnDA, PFHxS, PFOS and FOSA), was investigated for 11 temperate mineral soils and related to soil properties such as organic carbon content (0.2-3%), concentrations of Fe and Al (hydr)oxides, and texture. PFAS sorption was positively related to the perfluorocarbon chain length of the molecule, and inversely related to solution pH for all substances. The negative slope between log Kd and pH became steeper with increasing perfluorocarbon chain length of the PFAS (r2 = 0.75, p <= 0.05). Organic carbon (OC) alone was a poor predictor of the partitioning for all PFASs, except for FOSA (r2 = 0.71), and the OC-normalized PFAS partitioning, as derived from organic soil materials, underestimated PFAS sorption to the soils. Multiple linear regression suggested sorption contributions (p <= 0.05) from OC for perfluorooctane sulfonate (PFOS) and FOSA, and Fe/Al (hydr) oxides for PFOS, FOSA, and perfluorodecanoate (PFDA). FOSA was the only substance under study for which there was a statistically significant correlation between its binding and soil texture (silt + clay). To predict PFAS sorption, the surface net charge of the soil organic matter fraction of all soils was calculated using the Stockholm Humic Model. When calibrated against charge-dependent PFAS sorption to a peat (Oe) material, the derived model significantly underestimated the measured Kd values for 10 out of 11 soils. To conclude, additional
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- de Campos Pereira, Hugo, et al.
(författare)
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Binding of per- and polyfluoroalkyl substances (PFASs) by organic soil materials with different structural composition - Charge- and concentration-dependent sorption behavior
- 2022
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 297
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Tidskriftsartikel (refereegranskat)abstract
- The charge-and concentration-dependent sorption behavior of a range of per-and polyfluoroalkyl substances (PFASs) was studied for three organic soil samples with different organic matter quality, one Spodosol Oe horizon (Mor Oe) and two Sphagnum peats with different degrees of decomposition (Peat Oi and Peat Oe). Sorption to the two peat materials was, on average, four times stronger compared to that onto the Mor Oe material. In particular, longer-chained PFASs were more strongly bound by the two peats as compared to the Mor Oe sample. The combined results of batch sorption experiments and 13C NMR spectroscopy suggested sorption to be positively related to the content of carbohydrates (i.e., O-alkyl carbon). Sorption of all PFAS subclasses was inversely related to the pH value in all soils, with the largest pH effects being observed for perfluoroalkyl carboxylates (PFCAs) with C-10 and C-11 perfluorocarbon chain lengths. Experimentally determined sorption isotherms onto the poorly humified Peat Oi did not deviate significantly from linearity for most substances, while for the Mor Oe horizon, sorption nonlinearity was generally more pronounced. This work should prove useful in assessing PFAS sorption and leaching in organic soil horizons within environmental risk assessment.
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- de Campos Pereira, Hugo
(författare)
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Binding of per- and polyfluoroalkyl substances (PFASs) in soil : effects of solution chemistry, soil properties, and PFAS structure
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The large environmental mobility and persistence of per- and polyfluoroalkyl substances (PFASs) along with confirmed or suspected toxicities make the substances one of the great challenges of our time in the fields of chemical management and environmental risk assessment. In order to risk assess PFAS-contaminated sites, improved quantitative and mechanistic understanding of the partitioning and retention in soil is crucial. The overall aim of this thesis was to improve the understanding of how PFASs are bound to soil and components therein, including soil organic matter (SOM) and iron (hydr)oxides. The focus was on investigating the role of soil/sorbent net charge and solution pH on binding, and the mechanisms that govern this partitioning behavior. The effect of soil/sorbent net charge, solution pH, and solid-phase properties on binding was investigated in batch experiments. The surface net charge of sorbents was quantified by geochemical modeling and ζ-potential measurements. Spectroscopic techniques (X-ray absorption, 13C nuclear magnetic resonance) were employed to increase mechanistic understanding. The driving force for the overall binding of a certain PFAS substance to mineral soils and organic soil horizons was identified as hydrophobic interaction, whereas electrostatic interaction was the main process responsible for the binding onto the positively charged iron (hydr)oxide ferrihydrite. The quality of SOM influenced the binding of PFASs to organic soil materials, in particular that of longer-chained PFASs. Binding of PFASs to soil and to isolated SOM and ferrihydrite was inversely related to solution pH and soil/sorbent net charge, in a manner that suggests that the electronegative fluorine atoms by charge interaction contribute to the binding´s overall pH-/charge-dependency. Extrapolation of organic carbon-normalized binding in organic soil materials to mineral soils underestimated the binding onto the latter, as did an equilibrium partitioning approach based on the surface net charge of SOM. The possible presence of black carbon or other high-affinity binding sites in the mineral soils could not be ruled out, why a component additivity approach (SOM, ferrihydrite) could not be tested properly for these materials. To conclude, this highlights the need for additional experimental binding data that allow the development of more accurate geochemical models with the ability to simulate and predict the binding and leaching of PFASs in the terrestrial environment.
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- de Campos Pereira, Hugo, et al.
(författare)
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The Adsorption of Per- and Polyfluoroalkyl Substances (PFASs) onto Ferrihydrite Is Governed by Surface Charge
- 2020
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 54, s. 15722-15730
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Tidskriftsartikel (refereegranskat)abstract
- An improved quantitative and qualitative understanding of the interaction of per- and polyfluoroalkyl substances (PFASs) and short-range ordered Fe (hydr)oxides is crucial for environmental risk assessment in environments low in natural organic matter. Here, we present data on the pH-dependent sorption behavior of 12 PFASs onto ferrihydrite. The nature of the binding mechanisms was investigated by sulfur K-edge X-ray absorption near-edge structure (XANES) spectroscopy and by phosphate competition experiments. Sulfur K-edge XANES spectroscopy showed that the sulfur atom of the head group of the sulfonated PFASs retained an oxidation state of +V after adsorption. Furthermore, the XANES spectra did not indicate any involvement of inner-sphere surface complexes in the sorption process. Adsorption was inversely related to pH (p < 0.05) for all PFASs (i.e., C-3-C-5 and C-7-C-9 perfluorocarboxylates, C-4, C-6, and C-8 perfluorosulfonates, perfluorooctane sulfonamide, and 6:2 and 8:2 fluorotelomer sulfonates). This was attributed to the pH-dependent charge of the ferrihydrite surface, as reflected in the decrease of surface zeta-potential with increasing pH. The importance of surface charge for PFAS adsorption was further corroborated by the observation that the adsorption of PFASs decreased upon phosphate adsorption in a way that was consistent with the decrease in ferrihydrite zeta-potential. The results show that ferrihydrite can be an important sorbent for PFASs with six or more perfluorinated carbons in acid environments (pH <= 5), particularly when phosphate and other competitors are present in relatively low concentrations.
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- Kattge, Jens, et al.
(författare)
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TRY plant trait database - enhanced coverage and open access
- 2020
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Ingår i: Global Change Biology. - : Wiley-Blackwell. - 1354-1013 .- 1365-2486. ; 26:1, s. 119-188
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Tidskriftsartikel (refereegranskat)abstract
- Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives.
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| 8. |
- Nouhi, Shirin, et al.
(författare)
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Interactions of perfluoroalkyl substances with a phospholipid bilayer studied by neutron reflectometry
- 2018
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier. - 0021-9797 .- 1095-7103. ; 511, s. 474-481
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Tidskriftsartikel (refereegranskat)abstract
- The interactions between perfluoroalkyl substances (PFASs) and a phospholipid bilayer (1,2-dimyristoyl-sn-glycero-3-phosphocholine) were investigated at the molecular level using neutron reflectometry. Representative PFASs with different chain length and functional groups were selected in this study including: perfluorobutane sulfonate (PFBS), perfluorohexanoate (PFHxA), perfluorohexane sulfonate (PFHxS), perfluorononanoate (PFNA), perfluorooctane sulfonate (PFOS), and perfluorooctane sulfonamide (FOSA). All PFASs were found to interact with the bilayer by incorporation, indicating PFAS ability to accumulate once ingested or taken up by organisms. The interactions were observed to increase with chain length and vary with the functional group as SO2NH2" role="presentation">(FOSA) > SO2O−" role="presentation">(PFOS) > COO−(PFNA). The PFAS hydrophobicity, which is strongly correlated with perfluorocarbon chain length, was found to strongly influence the interactions. Longer chain PFASs showed higher tendency to penetrate into the bilayer compared to the short-chain compounds. The incorporated PFASs could for all substances but one (PFNA) be removed from the lipid membrane by gentle rinsing with water (2 mL min−1). Although short-chain PFASs have been suggested to be the potentially less bioaccumulative alternative, we found that in high enough concentrations they can also disturb the bilayer. The roughness and disorder of the bilayer was observed to increase as the concentration of PFASs increased (in particular for the high concentrations of short-chain substances i.e. PFHxA and PFBS), which can be an indication of aggregation of PFASs in the bilayer.
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| 9. |
- Sörengård, Mattias, et al.
(författare)
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Mass loads, source apportionment, and risk estimation of organic micropollutants from hospital and municipal wastewater in recipient catchments
- 2019
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 234, s. 931-941
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the occurrence and sources of organic micropollutants (OMPs) in aquatic environments is essential for environmental risk assessment and adequate interventions to secure good status of aquatic environments. The occurrence and source apportionment of 77 OMPs in the River Fyris catchment (Uppsala, Sweden) were investigated by comparing hospital wastewater, wastewater treatment plant (WWTP) effluent, and surface water. Hospital wastewater was identified as an important source for some classes of OMPs, e.g., antibiotics (number of OMPs (n) = 6) and antidepressants (n = 4), contributing 38% and 31%, respectively, of the mass loads in total WWTP influent. Painkillers (n = 5) and hormones (n = 3), originating mainly from urban Uppsala, contributed 94% and 95%, respectively. WWTP removal efficiency varied from 100% for acetaminophen to <0% for i.e. clindamycin, lamotrigine, bicalutamide, and sucralose. In the recipient River Fyris, the Sigma OMP concentration downstream of the WWTP (738 ng L-1) was more than double that upstream (338 ng demonstrating the high impact of the WWTP on recipient water quality. Surface water risk quotients (RQs) showed a moderate risk of adverse chronic effects (RQ>0.1) for trimethoprim, norsertraline, and metoprolol downstream of the WWTP, and for norsertraline in the recipient river upstream and Lake Ekoln downstream of the WWTP. Recipient metoprolol and trimethoprim, compounds poorly removed in the WWTP, mainly (>90%) originated from wastewater from urban Uppsala, whereas recipient norsertraline originated upstream of the city. No risk compound was apparently sourced from hospital wastewater. (C) 2019 Elsevier Ltd. All rights reserved.
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