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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Transfert des composés perfluorés des sédiments aux invertébrés benthiques / Transfer of perfluorinated compounds from sediment to benthie invertebrates

Bertin, Delphine 01 December 2014 (has links)
L'accumulation de composés persistants dans le biote constitue des préoccupations écologiques, sanitaires et réglementaires. Parmi ces substances, les composés per- et polyfluorés (PFASs) représentent un cas d'intérêt, en raison de leurs propriétés physico-chimiques particulières. Ces dernières rendent le comportement des PFASs dans l'environnement difficilement prévisibles, les outils actuels n'étant pas adaptés. Bien qu'il soit reconnu que ces composés sont persistants et s'accumulent dans le biote, de nombreuses inconnues subsistent, notamment sur les mécanismes de transferts sédiment–biote et des facteurs qui les contrôlent. Ce travail de thèse aborde le rôle du sédiment dans les processus d'accumulation, et plus particulièrement (a) les voies d'exposition du biote, (b) le rôle de la diversité biologique dans l'accumulation, par l'exposition de deux invertébrés benthiques (Chironomus riparius et gammarus sp.) à du sédiment naturel. La description des cinétiques d'accumulation et d'élimination des PFASs ont mis en évidence la biodisponibilité des composés pour les organismes. Ainsi, un modèle de bioaccumulation en accord avec la croissance des organismes et des particularités des composés a permis d'estimer des constantes d'accumulation et de dépuration (ku et ke). Une représentation conceptuelle du transfert des composés, a permis de comprendre les principales voies de contamination des organismes. D'autre part, la variabilité interspécifique a été évaluée par la comparaison de la bioaccumulation et des voies de transfert des PFASs chez ces deux invertébrés. Ce travail de thèse aura alors permis d'ouvrir de nombreuses questions, notamment celles du rôle du biofilm et de la bioturbation des organismes dans la bioaccumulation et ouvre les perspectives quant à l'étude de la bioamplification / The accumulation of persistent compounds in biota creates environmental, health and regulatory concerns. Among these substances, the poly-fluorinated compounds (PFASs) represents a case of interest due to their specific physicochemical properties. So the PFAs behavior in the environment is difficult to predict as the existing tools are not suitable. Athough it is recognized that these compounds are persistent and accumulate in biota, many knowledge gaps remain, including the mechanisms of sediment-biota transfer and the factors that control them. This thesis examines the role of sediment in the accumulation process, especially (a) exposure routes of biota, (b) role of biodiversity in the accumulation, by exposing two benthic invertebrates (Chironomus riparius and Gammarus sp.) to natural sediment. The description of PFASs kinetics of accumulation and elimination have showed the biodisponibility of the compounds to organisms. Thus, a bioaccumulation model including the organisms growth and the specificity of the compounds was used to estimate the accumulation and depuration rate constants (ku and ke). A conceptual representation of compounds transfer allowed us to understand the major routes for organisms contamination. Moreover, the interspecific variability has been assessed by comparing the PFASs bioaccumulation and transfer pathways for both invertebrates. This thesis have helped to open up many issues, and especially the influence of both biofilm and organism bioturbation onPFASs bioaccumulation. Moreover some new perspectives on the study of biomagnification were opened
2

Microbial binding of per- and polyfluorinated alkyl substances (PFASs) : - Analysis of PFASs in microbes with ultra-performance liquid chromatography – tandem mass spectrometry (UPLC-MS/MS)

Majdak, Karolina January 2018 (has links)
Per- and polyfluorinated alkyl substances (PFASs) belong to a large group of man-made chemicals that pollute the environment. Perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are the most commonly found PFASs. The pollution of PFASs can be caused among others by using of aqueous fire-fighting foams (AFFFs). PFASs are persistent compounds; that can travel long distances and bioaccumulate in biota. There are several exposure routes for PFASs, but the most common are via food and drinking water. A possible way for PFASs to enter the food chain is by adsorption to microbes. In this project, binding of PFASs to three gram-negative bacteria, Eschericha coli, Acidovorax delafieldii and Pseudomonas nitroreducens, was assessed. Microbes were exposed for fluorinated compounds in environmental water samples and a PFAS-11 solution with 11 PFAS substances prepared in the laboratory. The binding seems to be preferential to the most abundant compounds, PFOS, since the second most abundant compound in the samples was PFHxS with concentrations at one third of the PFOS concentration but nonetheless PFHxS was not detected in any of the samples. The binding of mainly one PFAS was identified; PFOS was bound at highest concentrations in E. coli treated with both environmental water sample and a PFAS-11 solution. Low concentrations of FOSA and PFDoDS were identified in E. coli and PFNA in A. delafieldii. Only PFOS was detected in P. nitroreducens. The concentrations of other PFASs were below their respective method detection limits.
3

Problematika perfluorovaných sloučenin ve složkách životního prostředí / Issues of perfluorinated compounds in the environmental compartments

Kalášek, Stanislav January 2008 (has links)
Perfluoroalkylated substencies are priority organics polutants. They are evolved to the environment from many sources. We classify them as new xenobiotics which are present in the environment. There will be described their chemical, physical and environmental properties in theoretical part and there will be described the analytical chemistry of these substancies in varios types of environmental samples. There will be developed metod for their identification and quantification. For this assignment will be use especially chromathografic methods. There will be developed standard operation procedure. The procedure will be verify on real environmental samples.
4

Groundwater Flow and Transport Modelling of PFASs in Åkersberga / Spridningsmodellering av PFAS i Åkersberga

Boonraksasat, Worada January 2019 (has links)
Per- and polyfluoroalkyl substances (PFASs) are a group of man-made organic chemicals that have been commercially used since the 1950s in many consumer products, including impregnated textiles, impregnated paper, nonstick products (e.g., Teflon), cleaning agents, and in firefighting foams. However, PFASs have in recent years received increasing public attention due to their persistence, bioaccumulative potential, and potentially toxic effects on humans and animals. Firefighting training sites have been identified as one of the most important sources for the spread of PFASs in the environment, due to the use of PFAS-containing firefighting foam of type AFFFs (aqueous film forming foams). This has resulted in contamination of both drinking water and groundwater in several municipalities in Sweden. At the former fire station in Åkersberga, AFFFs were handled and used during the fire-training exercises. WSP Environmental Sweden has performed a preliminary investigation on site and elevated levels of PFASs in both soil and groundwater were observed. Since the property is located next to a railroad track, there is a concern that PFASs will spread through the railroad track towards the nearby Åkers canal. The aim of this master’s thesis has therefore been to map the transport of PFASs in groundwater from this former fire station. A groundwater flow model was first constructed in the software program Visual MODFLOW. The groundwater model was then used as a basis for the construction of a transport model with MODPATH and MT3DMS. The transport of four PFAS homologues was modeled; perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), 6:2 Fluorotelomer sulfonate (6:2 FTS), and perfluoropentanoic acid (PFPeA). The result of the groundwater modelling showed that groundwater from the property flows towards the southwest and then further towards Åkers canal. The approximated velocity of a water molecule varied between 270 m/year and 400 m/year. The transport modelling showed that all four PFAS homologues traveled towards Åkers canal via the railroad track and that the short-chain PFAS homologues (6:2 FTS and PFPeA) traveled longer and faster than the long-chain PFAS homologues (PFOS and PFOA). The approximated velocity of the contaminant plume for the concentration 4.5 ·10−5 mg/L was 0.6 m/year for PFOS, 3 m/year for PFOA, 8 m/year for 6:2 FTS, and 16 m/year for PFPeA. / Per- och polyfluorerade alkylsubstanser (PFAS) är en grupp av konstgjorda organiska kemikalier som sedan 1950-talet har kommersiellt använts i många konsumentprodukter, inklusive impregnerade textilier, impregnerat papper, nonstick-produkter (t.ex. Teflon), rengöringsmedel och brandsläckningsskum. PFAS har dock under senare år fått ökad allmän uppmärksamhet på grund av deras persistens, bioackumuleringspotential och potentiella toxiska effekter på människor och djur. Brandövningsplatser har identifierats som en av de största källorna för spridningen av PFAS i miljön, på grund av användningen av PFAS-innehållande brandsläckningsskum av typen AFFF (aqueous film forming foams). Detta har resulterat i förorening av både dricksvatten och grundvatten i flera kommuner i Sverige. På den tidigare brandstationen i Åkersberga har hantering och användning av AFFF ägt rum under släckningsövningarna. WSP Environmental Sverige har utfört förundersökning på plats och förhöjda halter PFAS i både jord och grundvatten observerades. Då fastigheten gränsar mot en banvall, finns det en oro att PFAS ska sprida via banvallen mot den närliggande Åkers kanalen. Syftet med detta examensarbete har därför varit att kartlägga transporten av PFAS i grundvatten från denna tidigare brandstation. En grundvattenflödesmodell konstruerades först i programvaran Visual MODFLOW. Grundvattenmodellen användes sedan som grund för konstruktionen av en transportmodell med MODPATH och MT3DMS. Transporten av fyra PFAS-homologer modellerades; perfluoroktansulfonat (PFOS), perfluorooktansyra (PFOA), 6:2 fluortelomersulfonat (6: 2 FTS) och perfluorpentansyra (PFPeA). Resultatet av grundvattenmodelleringen visade att grundvatten från fastigheten strömmar mot sydväst och sedan vidare mot Åkers kanal. Den approximerade hastigheten hos en vattenmolekyl varierade mellan 270 m/år och 400 m/år. Transportmodelleringen visade att alla fyra PFAS-homologerna spred mot Åkers kanal via banvallen och att de kortkedjiga PFAS-homologerna (6:2 FTS och PFPeA) spred längre och snabbare än de långkedjiga PFAS-homologerna (PFOS och PFOA). Ungefärlig hastighet av föroreningsplymen för koncentration 4.5 ·10−5 mg/L var 0,6 m/år för PFOS, 3 m/år för PFOA, 8 m/år för 6: 2 FTS och 16 m/år för PFPeA.
5

Evaluation of the Removal Efficiency of Perfluoroalkyl Substances in Drinking Water

Englund, Sophie January 2015 (has links)
Per- and polyfluoroalkyl substances (PFASs) are chemicals that have been used for over 50 years. They are both hydrophobic and hydrophilic, which make them useful in a wide range of products, both in the domestic and industrial market. Recently, the global attention on PFASs has increased due to their possible harmful health effects on humans. Furthermore, PFASs have been detected in drinking water sources all over the world. Conventional treatment processes in drinking water treatment plants (DWTPs) are not able to remove PFASs. Therefore, more research is required to find efficient removal techniques for these compounds. The aim of this study was to investigate the removal efficiency of PFASs using two different adsorption techniques, anion exchange (AE) with the resin Purolite A-600, and granular activated carbon (GAC) of type Filtrasorb®400. The experiments were performed in laboratory batch-scale, at Swedish University of Agriculture (SLU), and column tests in pilot-scale, at Bäcklösa DWTP in Uppsala. The PFASs showed a high sorption potential to AE and GAC. However, the removal efficiency differed depending on the perfluorocarbon chain length, functional group, and concentration level. For the AE, in average 92 % of the PFASs were removed in the end of the batch experiments while the average removal efficiency in the column experiment was 86 %. In the batch experiments treated with GAC on average 55 % of the PFASs were removed in the end of the experiments while the column experiment had the average removal efficiency of 86 %. There was an increase in the removal efficiency with increasing perfluorocarbon chain length in the column experiments. However, in the batch experiments, the adsorption of PFASs decreased with an increasing chain length, except for the highest PFAS concentration level (5000 ng L-1) treated with AE and the lowest PFAS concentration level (200 ng L-1) treated with GAC. In the column experiments, the perfluoroalkane sulfonates (PFSAs) were slightly better removed than perfluoroalkyl carboxylates (PFCAs) with an average removal efficiency of 97 % for AE and 91 % for GAC compared to 67 % and 82 % for AE and GAC, respectively. In the batch experiments, there was no clear trend between the removal efficiency and functional group. Overall, the pilot-scale experiments removed the PFASs relatively well even after 42 days (on average, 86 % for both AE and GAC). The lowest removal capacity in the column experiments was seen for the shorter chained PFSAs (in average 46 % for ≤C6 PFCAs using AE and 75 % for ≤C7 PFCAs using GAC). More efficient treatment techniques are needed to minimise the PFAS concentrations in drinking water and the potential human. / Per- och polyfluorerade alkylsubstanser (PFASs) är kemikalier som har används globalt under de senaste 50 åren. Tack vare att de är uppbygda av både en hydrofob och en hydrofil del är de ytaktiva (s.k. surfaktanter) och har ett brett användningsområde, både för industri- och hushållsprodukter. På senare år har dessa ämnen fått uppmärksamhet på grund av att exponering för PFASs har visats kunna medföra hälsorisker. PFASs har upptäckts i dricksvatten på många håll i världen, men flera av de konventionella reningsmetoderna för dricksvatten är inte effektiva för PFASs och därför finns ett behov av mer forskning och kunskap inom vattenberedningsområdet. I denna studie undersöktes reningseffektiviteten för PFASs hos två adsorptionstekniker; i) anjonbyte (AE) med Purolite A-600 och ii) granulerat aktivt kol (GAC) med Filtrasorb®400. Studien utformades så att inverkan av kolkedjans längd, molekylens funktionella grupp samt koncentrationsnivån av PFASs kunde utvärderas. Experimenten utfördes både i liten skala genom försök i bägare på Sveriges lantbruksuniversitet (SLU) och i något större skala i en pilotanläggning med kolonnexperiment på Bäcklösa dricksvattenverk i Uppsala.  Båda reningsmetoderna visade god effekvititet för avlägsnandet av PFASs i dricksvatten. I slutet av bägarexperimenten var i medeltal 92 % och 55 % av PFASs eliminerade för de prover behandlade med AE respektive GAC. Reningseffektivititen för kolonnexperimenten var i medeltal 86 % för båda metoderna. Reningsgraden var beroende av längden på den perfluorerade kolkedjan. I kolonnexperimenten visades att ökad kedjelängd ledde till ökad reningseffektivitet, medan bägarexperimenten visade på motsatt trend, med undantag för prover behandlades med AE och PFAS-koncentration 5000 ng L-1 samt prover behandlade med GAC och PFAS-koncentration 200 ng L-1. Reningseffektiviteten varierade också beroende på funktionell grupp, d.v.s. beroende på om det var en sulfonat eller en karboxylat. I kolonnexperimenten avlägsnades de perfluorerade alkylsulfonaterna (PFSAs) i något högre grad (97 % och 91 %; AE och GAC) än karboxylaterna (PFCAs; 67 % och 82 %; AE och GAC). För bägarexperimenten hittades dock inget tydligt motsvarande samband. Sammanfattningsvis renades PFASs från dricksvattnet i kolonnexperimenten relativt väl även i slutet av experimentent (efter 42 dagar). De sämst renade PFAS ämnena var de med kortare kolkedja. Efter 42 dagar hade PFCAs med kolkedjelängd ≤C6 renats bort med 46 % (AE) och på PFCAs med kolkedjelängd ≤C7 med 75 % (GAC). Behovet av bättre reningsmetoder för dessa PFASs är därför stort.
6

Long-range Transport of Per- and Polyfluorinated Substances to Sweden : The Exposure in Mountain Grazing Reindeers

Johansson, Malin January 2016 (has links)
The aim of this study was to examine if perfluorinated alkylated substances (PFASs) reaches north of Sweden by long-range atmospheric transport. This was done by monitoring the levels of PFASs in reindeer livers at two locations in 2002 and 2010, respectively. The reindeers have lived all of their lives in the mountains and therefore the main source of exposure for PFASs is through air. The samples were extracted and analysed for 24 different PFASs using ultra performance liquid chromatography tandem mass spectrometer (UPLC-MS/MS). The most significant change concerns perfluorooctane sulfonic acid (PFOS) which decreased significantly from 6.1 ng/g at the most northern location (Ammarnäs/Biergenis) in 2002 to 0.87 ng/g 2010. At the other sampling location, Glen, PFOS decreased from 5.0 to 3.2 ng/g during the eight years. Mainly PFOS and longer chain carboxylates were found. The results revealed that the levels of many compounds decreased in time. The location seems to have an impact on the level of perfluorinated compounds present and most likely the distribution of them in the air, since certain PFASs have increased and decreased differently in time between the two locations. Since PFASs are non-volatile, they are believed to be degradation products of volatile compounds such as fluorotelomer alcohols (FTOHs) and perfluoroalkylated sulfonamido alcohols (FOSEs). FTOHs and FOSEs are released, translocated by long-range atmospheric transport and degraded to perfluorinated compounds in organisms or atmosphere.
7

Study on Suspect and Non-Target Screening of Per- and Polyfluoroalkyl Substances (PFASs) by Ion Mobility Mass Spectrometry / イオンモビリティ質量分析によるペルおよびポリフルオロアルキル物質(PFASs)の Suspect and Non-Target Screening に関する研究

Yukioka, Satoru 23 March 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(地球環境学) / 甲第22617号 / 地環博第196号 / 新制||地環||38(附属図書館) / 京都大学大学院地球環境学舎地球環境学専攻 / (主査)教授 藤井 滋穂, 教授 梶井 克純, 准教授 田中 周平 / 学位規則第4条第1項該当 / Doctor of Global Environmental Studies / Kyoto University / DFAM
8

Waste Incineration as a Possible Source of Perfluoroalkyl Acids to the Environment – Method Development and Screening

Sandblom, Oskar January 2014 (has links)
Atmospheric deposition has been suggested to be a major input pathway of perfluoroalkyl acids (PFAAs) to the Baltic Sea catchment area and to the Baltic Sea itself. However, the sources of PFAAs to the atmosphere are not well characterized. In this study we investigated if waste incineration plants in Sweden could be a source of PFAAs to the atmosphere and to the environment in general. Samples of the end products from waste incineration were collected at four different incineration plants. The plants differed in size and technical advancement and were considered to be representative for the majority of waste incineration plants in Sweden. The collected samples were slag from the furnaces, fly ash from the flue gases, “bambergkaka” (a mix of fly ash and sludge from wastewater treatment) as well as condensate and wastewater from the cleaning process of the flue gases. Two methods were developed, one for analysis of PFAAs in solid samples and one for water samples. Method validation showed good performance for both methods in terms of precision and accuracy, despite low recoveries obtained for the method for solid samples. The results from sample analysis revealed that PFAAs were present in all solid samples at concentrations in the low to sub ng/g range and in all but one condensate and wastewater samples at concentrations in the low to sub ng/L range. The quantified concentrations were used to estimate the potential annual discharges of PFAAs from waste incineration plants to the environment. Emission scenarios via landfills, via wastewater treatment plants and to the atmosphere were considered. The main conclusion of this study is that waste incineration in Sweden is not a significant source of PFAAs to the atmosphere or to the environment in general.
9

Rejection Properties of Perfluorohexanoic Acid in Various Aqueous Media by Polyamide and Sulfonated Polyethersulfone Nanofiltration Membranes / ポリアミドおよびスルホン化ポリエーテルスルホン系NF膜による種々の水溶液中のぺルフルオロヘキサン酸の除去特性に関する研究

Zeng, Chenghui 25 September 2017 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第20692号 / 工博第4389号 / 新制||工||1682(附属図書館) / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 田中 宏明, 教授 高岡 昌輝, 教授 藤井 滋穂 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM
10

Analysis of Per- and Polyfluoroalkyl Substances (PFASs) in African Darter (Anhinga rufa) Eggs along Vaal River, South Africa : Comparison of Homologue and Isomer Profiles

Fredriksson, Felicia January 2016 (has links)
Per- and polyfluoroalkyl substances (PFASs) are a group of toxic and persistent organic compounds. Their properties make them extremely resistant and they have been shown to have bioaccumulation and toxic properties in the environment and also to biomagnify in both aquatic and terrestrial food webs. This study has analysed different PFASs in African Darter (Anhinga rufa) eggs from five sites along Vaal River; Orange River, South Africa. Sixteen of 23 analysed PFASs were detected and quantified, and the homologue profiles were studied from all five sites. Total perfluorooctane sulfonic acid (PFOS) (all structural isomers) was the predominated compound of all PFASs, accounting for 88-98% for all sites, with a median concentration range of 58 ng/g ww to 2473 ng/g ww. The second highest concentration was found for perfluorodecanoic acid (PFDA) (1.9-42 ng/g ww), followed by perfluorononanoic acid (PFNA) (1.1-14 ng/g ww) and perfluorohexane sulfonate (PFHxS) (0.68-6.0 ng/g ww). The results showed significantly that the three up-stream sites (Welverdiend, Schoemansdrift and Orkney East) had similar patterns and that eggs from Schoemansdrift had the highest levels of PFASs. This may indicate the same source of origin for these three sites and that Schoemansdrift are closest to the contamination source. The three sites (Welverdiend, Schoemansdrift and Orkney East) with similar pattern is closest to Gauteng, which can be where the emission source is located, because it is an industrial area. Perfluoroalkyl carboxylic acids (PFCAs) and PFOS might originate from different sources and the source for PFCAs could be degradation of fluorotelomer-based precursors. Structural isomer profiles of PFOS showed similar results as the PFAS homologue patterns, which give further indication of the source of origin. The contribution of linear PFOS (L-PFOS) to the total amount of PFOS was between the range of 94 and 97%. Bloemhof had the highest concentration of branched isomers among all sites. The L-PFOS concentrations in Bloemhof were also significantly differ from Schoemansdrift. This indicate two different sources between Bloemhof and the three up-steam sites, or an effect of environmental fractionation.

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