| 1. |
- Clark, Andrew G., et al.
(author)
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Evolution of genes and genomes on the Drosophila phylogeny
- 2007
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 450:7167, s. 203-218
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Journal article (peer-reviewed)abstract
- Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species.
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| 2. |
- Franke, Vera, et al.
(author)
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Chemical composition and source analysis of carbonaceous aerosol particles at a mountaintop site in central Sweden
- 2017
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In: Tellus. Series B, Chemical and physical meteorology. - : Stockholm University Press. - 0280-6509 .- 1600-0889. ; 69
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Journal article (peer-reviewed)abstract
- The chemical composition of atmospheric particulate matter at Mt. angstrom reskutan, a mountaintop site in central Sweden, was analysed with a focus on its carbonaceous content. Filter samples taken during the Cloud and Aerosol Experiment at angstrom re (CAEsAR 2014) were analysed by means of a thermo-optical method and ion chromatography. Additionally, the particle light absorption and particle number size distribution measurements for the entire campaign were added to the analysis. Mean airborne concentrations of organic and elemental carbon during CAEsAR 2014 were OC= 0.85 +/- 0.8 mu gm(-3) and EC = 0.06 +/- 0.06 mu gm(-3), respectively. Elemental to organic carbon ratios varied between EC/OC = 0.02 and 0.19. During the study a large wildfire occurred in Vastmanland, Sweden, with the plume reaching our study site. This led to significant increases in OC and EC concentrations (OC = 3.04 +/- 0.03 mu gm(-3) and EC = 0.24 +/- 0.00 mu gm(-3)). The mean mass-specific absorption coefficient observed during the campaign was sigma(BC)(abs) = 9.1 +/- 7.3 m(2)g(-1) (at wavelength lambda= 637 nm). In comparison to similarly remote European sites, Mt. angstrom reskutan experienced significantly lower carbonaceous aerosol loadings with a clear dominance of organic carbon. A mass closure study revealed a missing chemical mass fraction that likely originated from mineral dust. Potential regional source contributions of the carbonaceous aerosol were investigated using modelled air mass back trajectories. This source apportionment pointed to a correlation between high EC concentrations and air originating from continental Europe. Particles rich in organic carbon most often arrived from highly vegetated continental areas. However, marine regions were also a source of these aerosol particles. The source contributions derived during this study were compared to emission inventories of an Earth system model. This comparison highlighted a lack of OC and EC point-sources in the model's emission inventory which could potentially lead to an underestimation of the carbonaceous aerosol reaching Mt. angstrom reskutan in the simulation of this Earth system model.
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| 3. |
- Franke, Vera, et al.
(author)
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Efficient removal of per- and polyfluoroalkyl substances (PFASs) in drinking water treatment: nanofiltration combined with active carbon or anion exchange
- 2019
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In: Environmental science: water research & technology. - : Royal Society of Chemistry (RSC). - 2053-1419 .- 2053-1400. ; 5, s. 1836-1843
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Journal article (peer-reviewed)abstract
- Society's increasing use of chemicals poses a challenge for drinking water producers. Accepted concentrations for per- and polyfluoroalkyl substances (PFASs) in finished water are lower than ever before with new regulations often enacted based on findings made possible by improved analytical techniques and correspondingly justified health concerns. Nanomembrane filtration removes compounds, including PFASs, based primarily on size-exclusion, however, treatment and/or disposal of PFAS laden membrane concentrate remains a challenge. This study combined feedwater nanofiltration with granular activated carbon (GAC) and anion exchange (AIX) for concentrate treatment. Nanofiltration removed PFAS concentrations on average by 99% including some PFASs with molecular weights smaller than the membrane nominal cutoff of 270 Da, indicating membrane rejection mechanisms additional to size-exclusion. Treatment of raw water and concentrate was compared in column tests. AIX showed up to threefold greater half-time of saturation than GAC, however with a higher rate of decreasing efficiency, while GAC removed approximately 20% of incoming PFAS concentrations consistently after treatment of 15 000 bed volumes (BVs). Overall, GAC and AIX removed 2.6-fold and 4.1-fold more PFAS mass per adsorbent volume from the concentrated retentate than from raw water indicating that the combination of nanofiltration with GAC or AIX increases the efficiency of the adsorbent materials in comparison to only using GAC or AIX filters.
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| 4. |
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| 5. |
- Franke, Vera, et al.
(author)
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Removal of per- and polyfluoroalkyl substances (PFASs) from tap water using heterogeneously catalyzed ozonation
- 2019
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In: Environmental science: water research & technology. - : Royal Society of Chemistry (RSC). - 2053-1419 .- 2053-1400. ; 5, s. 1887-1896
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Journal article (peer-reviewed)abstract
- Drinking water is one of the most important human exposure pathways of per- and polyfluoroalkyl substances (PFASs). As conventional water treatment techniques are unable to remove PFASs efficiently, novel treatment methods for the removal of PFASs in water are urgently needed. In the present study advanced oxidation processes (AOPs) based on heterogeneously catalyzed ozonation were evaluated on laboratory- and pilot-scales for their efficiency in removing PFASs from water. Laboratory-scale ozonation experiments were conducted with different combinations of ozone, a catalyst and persulfate and showed the highest efficiency for the treatment combining all three parameters. The method was further evaluated for the treatment of spiked drinking water on the pilot-scale. The concentrations of all 18 analyzed PFASs decreased significantly within three hours of treatment in the pilot-scale set-up. The perfluorocarbon chain length had a dominant influence on the removal efficiency, where CF7 - CF11 PFASs were removed with more than 98% removal efficiency, independent of the functional group, CF12 - CF17 PFASs with 64%, and CF4 - CF6 with 55% on average. As the evaluated ozonation treatment is already commercially available for large scale applications today, it could easily be applied in existing water treatment trains; however, ozonation can create potentially toxic transformation products which needs to be investigated in future research.
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| 6. |
- Franke, Vera, et al.
(author)
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Removal of per- and polyfluoroalkyl substances (PFASs) in a full-scale drinking water treatment plant: Long-term performance of granular activated carbon (GAC) and influence of flow-rate
- 2020
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In: Water Research. - : Elsevier BV. - 0043-1354 .- 1879-2448. ; 182
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Journal article (peer-reviewed)abstract
- Per- and polyfluoroalkyl substances (PFASs) have been ubiquitously detected in drinking water which poses a risk for human exposure. In this study, the treatment efficiency for the removal of 15 PFASs was examined in a full-scale drinking water treatment plant (DWTP) in the City of Uppsala, Sweden, over a period of two years (2015-2017). Removal of the five frequently detected PFASs was influenced by the total operation time of granular activated carbon (GAC) filters, GAC type and surface loading rate. The average removal efficiency of PFASs ranged from 92 to 100% for "young" GAC filters and decreased to 7.0 -100% for "old" GAC filters (up to 357 operation days, 29 300 bed volumes (BV) treated). Flow-rates were adjusted in two full-scale GAC filters of different operational age to examine the removal of PFAS and organic matter depending on GAC operational age and operating flow. The decrease in flow-rate by 10 L s(-1) from 39 to 29 L s(-1) led to an average increase of 14% and 6.5% in total PFAS removal efficiency for an "old" (264 operation days, 21 971 BV treated) and a "young" GAC filter (63 operation days, 5 725 BV treated), respectively. A cost-analysis for various operation scenarios illustrated the dominating effect of treatment goals and costs for GAC regeneration on overall GAC operation costs. The unit costs for GAC filters ranged from 0.08 to 0.10 (sic) M-3 water treated and 0.020-0.025 (sic) M-3 water treated for a treatment goal of 10 ng L-1 and 85 ng L-1, respectively, for Sigma(11)PFAS. Furthermore, it was concluded that prolonging the GAC service life by lowering the flow-rates after reaching the treatment goal could lead to a 26% cost-deduction. The results and methods presented in this study give drinking water providers valuable tools for the operation of a full-scale treatment train for the removal of PFAS in contaminated raw water. (C) 2020 The Authors. Published by Elsevier Ltd.
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| 7. |
- Franke, Vera, et al.
(author)
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The Price of Really Clean Water: Combining Nanofiltration with Granular Activated Carbon and Anion Exchange Resins for the Removal of Per- And Polyfluoralkyl Substances (PFASs) in Drinking Water Production
- 2021
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In: ACS ES&T water. - : American Chemical Society (ACS). - 2690-0637. ; 1, s. 782-795
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Journal article (peer-reviewed)abstract
- The removal of per- and polyfluoroalkyl substances (PFASs) presents a challenge for drinking water providers. Guidelines for PFAS concentrations in final drinking water are regularly updated to ever-decreasing values, and conventional drinking water treatment plants are not designed to remove PFASs. Currently, the most frequently used removal technique, adsorption to granular activated carbon (GAC), is often considered challenging. High-pressure membranes, such as nanofiltration (NF), have been shown to remove PFASs efficiently. However, the creation of a waste stream comprised of at least 10% of the feedwater volume is recognized as a major drawback of this technique. In this study, a NF pilot plant was operated at a drinking water treatment plant in the city of Uppsala, Sweden, for six months. NF removed up to >98% of PFASs and fulfilled other water quality targets, such as the removal of uranium-238, dissolved organic carbon (DOC), and mineral hardness from the raw water. The concentrate from the pilot plant was treated with two different GAC materials and two different anion exchange (AIX) resins in column tests, where the superior performance of AIX over GAC was observed in terms of PFAS removal. PFAS adsorption curves for GAC were found to superimpose each other for the two water types if normalized to the specific throughput of DOC. The application of the freely available PHREEQC model revealed improvement possibilities in terms of resin properties. A cost analysis using the column test results compared GAC filtration to the combination of NF with adsorption materials. Treatment costs were found to be largely dependent on the PFAS drinking water treatment goals and concentrate discharge requirements, which highlight the economic consequences of prevailing guidelines for drinking water and discharge to the environment. The results of this study provide both the scientific community as well as drinking water providers with important insights into the application of NF for PFAS removal during drinking water treatment as well as that mechanistic and economic aspects of NF treatment and the management of the resulting concentrate.
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| 8. |
- Franke, Vera
(author)
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Treatment methods for the removal of per- and polyfluoroalkyl substances (PFASs) from drinking water : optimizing existing and exploring novel treatment techniques
- 2020
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Doctoral thesis (other academic/artistic)abstract
- Worldwide, the demand for safe drinking water is rising. As drinking water sources are increasingly impacted by anthropogenic and environmental changes it is becoming a challenge to produce safe and clean water. The contamination of water with the manmade group of chemical compounds by the name of per- and polyfluoroalkyl substances (PFASs) adds to this challenge. Conventional drinking water treatment is not designed to remove these compounds due to their unique properties and guideline values for allowed concentrations in the final drinking water are low. Thus, there is a need for advanced techniques for the removal of PFASs in drinking water production. During the course of this thesis, existing treatment methods were optimized and novel methods were developed. Filtration through granular activated carbon (GAC) filters, originally implemented in drinking water treatment for the removal of compounds causing odor and taste, was evaluated in a full-scale drinking water treatment plant and conclusions on the cost-effectiveness were gained by adapting flow-rates and describing several operation scenarios (Paper I). The technique of membrane filtration was studied in pilot-scale and different types of adsorption materials were evaluated for the removal of PFASs from raw water directly versus removal from the membrane concentrate. The adsorption materials GAC and anion exchange both performed better with larger ingoing PFAS concentrations. Filtration through specifically designed anion exchange resins can be an option for membrane concentrate management (Paper II and III). Electrochemical oxidation and was shown to degrade PFASs in various water types, including membrane concentrate (Paper IV). Further, the commercially available technique heterogeneously catalysed ozonation was applied in pilot-scale to treat contaminated tap water and was observed to remove certain PFASs efficiently (Paper V). This thesis contributes to an increased knowledge on water treatment techniques for the removal of PFASs, providing new insights into water treatment options to protect human health.
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| 9. |
- Jonsson, Ove, et al.
(author)
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TIMFIE-provtagning för tidsintegrerad haltbestämning av växtskyddsmedel, PFAS, läkemedel och metaller i ytvatten : En pilotstudie
- 2022
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Reports (other academic/artistic)abstract
- TIMFIE (Time Integrating, Micro Flow, In situ Extraction) är en enkel och billig tidsintegrerad provtagningsmetod som här användes för bestämning av ett stort antal organiska ämnen från vitt skilda substansgrupper. Tekniken bygger på kontinuerlig fastfasextraktion i fält under en till två veckor och den efterföljande bestämningen av organiska ämnen är kvantitativ och baseras på helvatten, dvs. med partikelbunden fraktion inkluderad.Förutom organiska ämnen som växtskyddsmedel, PFAS och läkemedel mättes i detta projekt även metallhalter och löst organiskt kol (DOC) i det uppsamlade, filtrerade vattnet. Merparten av de studerade metallerna och DOC påverkades dock negativt av fastfaskolonnerna som används för extraktion av de organiska ämnena. En separat TIMFIE utan kolonner ska därför användas vid bestämning av metaller. En fältstudie med veckovisa TIMFIE-provtagningar i tolv provpunkter fördelade på fem regioner utfördes i samarbete med länsstyrelserna i Gotland, Östergötland och Dalarna samt med en avfallsanläggning i Mälardalen. Totalt analyserades 47 TIMFIE-prover för drygt 200 organiska ämnen och 21 metaller, samt ytterligare 8 TIMFIE-prover endast för metaller.I framtiden kommer två olika TIMFIE-provtagare att användas i studier där både organiska och oorganiska ämnen bestäms. Fortsatt arbete med att även inkludera näringsämnen i det oorganiska analyspaketet pågår och möjligheten att göra dessa bestämningar på ett återskapat helvatten undersöks.
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| 10. |
- Sörengård, Mattias, et al.
(author)
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Losses of poly- and perfluoroalkyl substances to syringe filter materials
- 2020
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In: Journal of Chromatography A. - : Elsevier BV. - 0021-9673 .- 1873-3778. ; 1609
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Journal article (peer-reviewed)abstract
- Syringe filters are used to separate solids from liquids prior to analysis of poly- and perfluoroalkyl substances (PFASs). This is a critical step in sample preparation, as losses of PFASs to the filter material can be significant and lead to underestimation. This study evaluated losses of 21 PFASs in three different matrices (methanol, MilliQ water, and water containing 10 mg L-1 dissolved organic carbon (DOC)) to six different types of syringe filter (0.45 and 0.22 mu m). Regarding sample matrix, the lowest average Sigma(21) PFAS losses were observed in methanol (13%), followed by DOC water (19%) and MilliQ water (26%). Regarding syringe filter material, the lowest average losses of Sigma(21) PFAS in DOC water and MilliQ water were observed for a recycled cellulose filter (average losses 16% and 21%, respectively), while a polypropylene filter had the lowest Sigma(21) PFAS losses in methanol (9%). A smaller polyethersulfone (PES) filter (0.22 mu m, 17 mm empty set) showed significantly (p < 0.05) lower Sigma(21) PFAS losses in DOC water (on average 7.3%) than a larger PES filter (0.45 mu m, 37 mm empty set) (23%). In DOC water, losses to the filter increased by 3.8%, 5.1%, and 8.4% per CF2-moiety for C-3-C-11 perfluoroalkyl carboxylates (PFCAs), perfluoroalkyl sulfonates (PFSAs), and fluorotelomer sulfonic acids (FTSAs), respectively. Comparing different functional groups of PFASs, losses increased as follows: PFCAs < PFSAs < FTSAs < perfluorooctanesulfonamides (FOSAs). Thus, care is needed when including filtration in PFAS analysis, since losses can be significant (up to 100%) depending on the type of syringe filter, target PFAS, and matrix. (C) 2019 Elsevier B.V. All rights reserved.
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