Groundwater contaminated by leachate from historic landfills, closed and typically without liners or leachate-collection systems, can potentially discharge to surrounding surface waters and impair their ecological communities. However, few studies have focused on emerging contaminants (e.g., per- and poly-fluoroalkyl substances (PFAS)), inputs to non-flowing water bodies, and exposure across the various ecological zones. The objective of this study was to better understand the ecological risk posed by a historic landfill plume discharging to a nearby pond, and how the pond’s ecosystem may be affected by potential spatio-temporal variability in contaminant concentrations and contaminant discharge. The site contained an artificial pond 40m west of a historic sanitation landfill and was monitored for ~1 year. Seasonal samples of shallow groundwater analyzed for standard chemistry plus artificial sweeteners and PFAS revealed a large and seasonally stable plume footprint in the pond and relatively constant exposure to the endobenthic zone (within sediments), with some constituents at potentially toxic concentrations. Elevated electrical conductivity measured just above (~1 cm) the sediment bed indicated exposure to the epibenthic zone, with greater exposure associated with higher groundwater fluxes at night, after rain and melt events, and in winter. It is speculated that terrestrial evapotranspiration and pond evaporation play a role in these temporal patterns. Estimated contaminant mass fluxes into the pond using contaminant and temperature-based flux data showed spatial variability within the plume footprint and seasonal patterns. Concentrations in the pond water showed exposure to pelagic organisms was consistent for chloride and saccharin (and likely PFAS), but varied seasonally for nitrate and ammonium, with all at lower concentrations compared to the endobenthic and epibenthic zones. This study revealed significant and variable ecological exposure from a landfill leachate plume discharging to a pond and provides guidance to landfill operators on improved monitoring protocols for such sites. / Thesis / Master of Science (MSc) / Groundwater contaminated by historic landfills, closed and typically without liners or leachate-collection systems, can potentially discharge to surrounding surface waters, threatening their ecological communities. The objective of this study was to better understand the ecological risk posed by a historic landfill plume discharging to a nearby pond, and how this might vary spatially and temporally. The study site contained an artificial pond 40m west of a historic sanitation landfill and was monitored for contaminant concentrations and contaminant discharge for ~1 year. Elevated concentrations of leachate contaminants were relatively steady within the sediments (endobenthic zone) and similar across the contaminant discharge area but varied substantially in space and time (higher at night, after events, in the winter) at the pond bed (epibenthic zone), while the patterns differed by contaminant in the surface water above (pelagic zone). These findings can provide insights into improved monitoring and protection of ecosystems at landfill sites.

Per- och polyfluoroalkylämnen (PFAS) är i enkla termer fluorerade kolväten som har använts i ett flertal produkter på grund av deras unika förmåga att vara vatten- och smutsavstötande, värmetåliga samt skiktbildande. PFAS har släppts ut i naturen på flera olika sätt. En stor bov till det är brandskum beståendes av vattenhaltigt filmbildande skum (AFFF), vilket innehåller PFAS. Stora volymer brandskum har släppts ut vid bränder eller brandövningsplatser. PFAS är mycket svårnedbrytbara och bioackumulerande, vilket betyder att de stannar kvar i miljön lång tid framöver. Eftersom de även har bevisats vara hälsofarliga vid små mycket mängder, har många varianter av PFAS blivit bannlysta, samt att rening av PFAS blivit centralt. Det har gjorts väldigt mycket forskning kring hur man renar PFAS från vatten vid dricksvattenproduktion, men inte lika mycket på hur man sanerar PFAS från mark och grundvatten in situ (på plats), främst eftersom det är svårt på grund av PFAS-kemikaliernas egenskaper. Det är en viktig del för att kunna ta bort PFAS ur naturen, då en stor del av den PFAS som blivit utsläppt, vid exempelvis brandövningsplatser, skapat plymer i jord och grundvatten som fortsätter vara spridningspunkter. Syftet med litteraturstudien är att sammanställa och jämföra utvecklande metoder inom området in situ sanering av PFAS för att se vilka metoder som har potential att stoppa spridningen. / Per- and polyfluoroalkyl substances (PFAS) are, in simple terms, fluorinated hydrocarbons that have been used in many products because of their unique ability to be water- and dirt-repellent, heat-resistant, and film forming. PFAS has been released into the environment in several ways. A major culprit is firefighting foam consisting of aqueous film-forming foam (AFFF), which contains PFAS. Large volumes of firefighting foam have been released during fires or firefighting exercises. PFAS are very persistent and bioaccumulative, meaning they stay in the environment for a long time. Since they have also been proven to be harmful to health at very low concentrations, several varieties of PFAS have been banned, and cleaning up PFAS has become a central issue. There has been a lot of research on how to clean PFAS from water during drinking water production, but not as much on how to remediate PFAS from soil and groundwater in situ (on-site), mainly because it is difficult due to the properties of the PFAS chemicals. This is an important part of removing PFAS from the environment since a large part of the PFAS that has been released, for example at firefighting sites, has created plumes in soil and groundwater that continue to be points of spread. The purpose of the literature study is to compile and compare developing methods in the field of in situ remediation of PFAS to see which methods have the potential to stop the spread.

<p>  </p> <p>Perfluoroalkyl substances (PFAS) are synthetic chemicals that are composed of fluorinated aliphatic chains and are widely used in industrial and consumer products. These chemicals are very stable and persist in the environment. Due to concerns linked with longer chain PFAS, shorter chain chemicals are being used as replacements. There are limited human health data regarding the shorter chain chemicals. In addition, these alternatives are persistent in the environment similar to the longer chain PFAS. The main objective of this dissertation was to assess developmental toxicity of the shorter chain PFAS or shorter chain PFAS with chemical modifications represented by perfluorobutanoic acid (PFBA, C4), perfluorohexanoic acid (PFHxA, C6), perfluorobutane sulfonate (PFBS, C4), and perfluoro-2-proxypropanoic acid (GenX, C6). Overall, the results showed that chain length and functional group are determinants of toxicity of PFAS. All tested PFAS induced one or more developmental adverse outcome, but the effects of each chemical are unique, warranting further studies to address the toxicity of the replacement PFAS. </p>

Per- and polyfluorinated alkyl substances (PFAS) are a group of environmentally harmful chemicals. The group consists of more than 4730 different substances including two of the most famous ones; PFOA and PFOS. PFAS consist of carbon backbones connected to fluorine. They are in general thermally stable and persistent to degradation due to their C-F bonds, which is one of the strongest bonds in chemistry. The use of PFAS is widespread and therefore they can be found in a variety of consumer products, which eventually end up as waste. Household waste and other waste streams are incinerated at waste incineration facilities at (at least) 850° C for two seconds. The aim of this study was to investigate if that temperature is high enough to, at least partly, break down PFAS and to study where in the outflows PFAS ends up. Three different facilities (B2, P4 and P6) for waste incineration where examined, including incoming fuels; household waste, industrial waste, return fuel and sewage sludge. The three facilities included in the study had two types of boilers (grated and circulating fluidized bed) with three different treatment facilities for the flue gas and condensate. Bottom ash, fly ash, end product and condensate were analysed after incineration. A mass balance based on the limited amount of data indicates that at least 86-98 % of the 11 examined PFAS substances are eliminated. The difference between the three facilities are probably due to a difference in temperature and a few problems during the sample week. Another reason might be the variations in PFAS concentrations in incoming fuels. The facility with the lowest elimination percentage also had the lowest PFAS-concentrations in incoming fuels, and some problems during the sample period. The facility with the highest elimination percentage had a more even and higher temperature.

Per- and polyfluoroalkyl substances, PFAS, are a manufactured group of chemicals that have been found to be toxic to humans and the environment. Exposure to PFAS may include birth defects for infants as well as an increased risk of cancer.  Due to PFAS exceptional traits of repelling water and oil, it has commonly been used in products such as cleaning agents, clothing, and coating for furniture. Thus, PFAS reaches the environment through deposition on landfills containing residual as well as industrial waste. Another main source of contamination is aqueous firefighting foam (AFFF) which has led to areas where military and firefighters have been practicing commonly having a high concentration of PFAS in the soil and surrounding environment. PFAS has also been found to accumulate in wastewater treatment plants. It’s partly due to its water repelling traits that PFAS has been spread efficiently over the world and has been detected in remote areas, such as Greenland. Moreover, they are persistent as they don’t naturally degrade, which has led to them being referred to as “forever chemicals”.   As of today, the main products for adsorption of PFAS are activated carbon as well as ion exchange resins, with activated carbon being the most common. The drawbacks with activated carbons are that even though they have high adsorption capacity they are non-selective, meaning that it adsorbs many other particles as well as PFAS. They are also not very effective on short-chained PFAS. Ion exchange resins are considered more selective as well as better at adsorbing short-chain PFAS. Both active carbon and ion exchange resins are expensive and require regeneration, which can only be performed so many times before they have to be disposed of.  The objectives of this master thesis were to test three adsorbents for PFAS, study incineration of PFAS in an environment similar to Swedish incineration plants as well as perform a cost analysis that ranges from production to management of ashes. The adsorbents tested are called Granular peat (float adsorb), Iron peat, and PEI-GTMAC-Pinebark (PG-PB). A batch test was performed with wastewater containing 25 mg/L PFAS on L/S 10 and 100 for the granular peat and iron peat and on L/S 100 and 1 000 for PG-PB. After the batch test, the adsorbents were incinerated at 850°C and 1 100°C, and a TGA analysis was performed in order to detect if fluorine was released during the incineration of the adsorbents.  The adsorbents tested adsorbed considerably less PFAS than the commercially available activated carbon and ion exchange resins. Of the tested adsorbents, PG-PB was the most effective adsorbent followed by iron peat, which adsorbed around half the amount of PFAS compared to PG-PB. Peat adsorbed the least amount, which was around one-third of PG-PB. Metal analysis of the wastewater showed that it contained a considerable amount of sulfur as well as sodium among other metals. As PG-PB has previously been used as an adsorbent for sulfate, the low adsorption capacity for PFAS may be due to competition with other cations for adsorption surface on the adsorbents. However, the concentration of sulfur did not change after the batch test with adsorbents, which means that the reason for the low adsorption capacity is not that sulfur occupies the surface of the adsorbents. Other metals, especially the cations, might have an impact and did change during the batch test with the adsorbents, but due to not enough data, no conclusion could be drawn. During incineration of peat, 42.6 g/kg ash was produced at 850°C and 53.3 g/kg ashes were produced while incinerated at 1100°C. Meanwhile, iron peat produces slightly more ashes with 65 g/kg ashes produced at 850°C and 63.8 g/kg ash produced during incineration at 1100°C. Pine bark was estimated to produce around 7.4 kg/g of ashes based on available literature. No PFAS was detected in the ashes. The gas composition from the TGA suggests that PFAS are emitted as flue gas with water during heating of the adsorbent. However, as incineration plants in Sweden are preheated, no conclusion of the destruction/volatile escapee of PFAS in a real incineration plant can be drawn due to different conditions.

<p dir="ltr">Per- and polyfluoroalkyl substances (PFAS), once considered to be emerging micro-pollutants, are now a very present class of pervasive and persistent micropollutant. Frequently referred to as “forever chemicals”, once they’re in the environment, they do not break down owing to the strength of their network of carbon-fluorine bonds. Their persistence is of particular concern, as they have been shown to have a plethora of negative health effects on living things including low infant birth weights, dyslipidemia, and cancer, to name a few. Due to both their persistence and negative health effects, the ability to rapidly test waters (<i>i.e.,</i> drinking water, river water, lake water, etc.) is of critical importance. The current “gold-standard” method for testing waters is the collection and transport of a sample to a centralized facility where chromatography and mass spectrometric methods can be performed for the separation, identification, and quantification of PFAS; however, this method is not able to be used for real-time analyses and is not sufficient for efficiently informing consumers or remediation efforts. An in-field detection method that is capable of providing real-time analyses is needed.</p><p dir="ltr">Electrochemistry stands well-poised to offer a suite of techniques that can be used for in-field detection. Electrochemistry is cost-effective, easy to perform and analyze, and readily portable; however, it lacks specificity and typically requires an electroactive analyte. These limitations can be overcome through the use of a surface functionalization strategy which adds specificity through the imprinting of the analyte of interest and monitors the change in signal from an alternate mediator molecule. Molecularly imprinted polymers (MIPs) are the chosen surface functionalization strategy that will be used and discussed in this work. While MIPs overcome the specificity and requirement of an electroactive analyte limitations and have been previously demonstrated for the detection of perfluorooctane sulfonate (PFOS), they traditionally require the use of added buffers and one electron mediators, which are not found in natural waters. Thus, to expand MIP-based electrochemical detection to in-field use strategies must be developed and employed to mitigate these concerns.</p><p dir="ltr">This work provides significant strides forward in enabling in-field, MIP-based electro-chemical sensing. We take advantage of ambient dioxygen present in river water to quantify one of the more harmful PFAS molecules, perfluorooctane sulfonate (PFOS), from 0 to 0.5 nM on a MIP-modified carbon substrate. Differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) generated calibration curves for PFOS in river water using oxygen as the mediator. Importantly, we show that electrochemical impedance spectroscopy is superior to voltammetric techniques: like ultramicroelectrodes, this technique can be used in low-conductivity matrices like river water with high reproducibility. Further, impedance provides a PFOS limit of detection of 3.4 pM. We also demonstrate that the common interferents humic acid and chloride do not affect the sensor signal. The use of dioxygen is predicated on the assumption that there will be consistent ambient dioxygen levels in natural waters. This is not always the case in hypoxic groundwater and at high altitudes. To overcome this challenge, and further advance the strategies that will enable in-field electroanalysis of PFAS, we demonstrate that dioxygen can be generated in solution through the hydrolysis of water. The electrogenerated dioxygen can then be used as a mediator for molecularly imprinted polymer (MIP)-based electroanalysis. We demonstrate that calibration curves can be constructed with high precision and sensitivity (LOD > 1 ppt). We also demonstrate the development and use of a universal multiplexer and electrode array, which can enable high throughput, in-field electroanalysis for a wide variety of compounds. In this work, we demonstrate it specifically for detecting PFOS from 0.05 to 0.05 nM and lead at a concentration of 1 nM.</p><p dir="ltr">Additionally, in this work, we lay the groundwork for the future direction of developing a more fundamental understanding of MIPs to be able to fine-tune their selectivity and performance. Preliminary data and experimental approaches are shown for using nanoparticle deposition and visualization, with scanning electrochemical microscopy, to characterize surface reactivity and binding site distribution, functional group studies to better understand what groups and molecular interactions affect the binding of the analyte to the MIP the most, and using cyclic voltammetry to determine the capacitance and resistance of the polymer. Further approaches are outlined to relate the conditions under which the polymer was created to the polymer’s characteristics and then the polymer’s performance. Future improvements to make the in-field use of the multiplexer more efficient are also shown. In total, this work shows the feasibility and nearness of in-field, MIP-based electrochemical detection for PFAS by advancing the strategies and hardware necessary to do so.</p>

Per- and polyfluoroalkyl substances (PFAS) are highly persistent compounds in nature and have been shown to have adverse health effects. Residents in Kallinge, Sweden, were exposed to PFAS through contaminated ground water used for drinking, resulting in the highest globally measured concentrations of PFAS in their blood. While active landfills in Sweden have been well-documented regarding PFAS, thousands inactive landfills in Sweden remain unexamined. This study examines the presence and temporal trends of PFAS in the leachate of one active landfill and the groundwater surrounding 36 closed landfills. Additionally, this study suggests which PFAS compounds should be monitored at landfills and in surrounding groundwater. PFAS concentration in the leachate of the active landfill differed between the snow period and the snow-free period. This may be attributed to differences in landfill treatment, as a chemical treatment is used during the snow period, and biological treatment during the snow-free period. A significant difference between short- and long chained PFAS was found in the active landfill.However, no significant differences were found year-over-year during the 5-year period examined. PFAS were detected in 31 of the 36 investigated inactive landfills, with 6 sites exceeding current guidelines for contamination. Approval of a new proposal would mean that an additional 15 landfills would exceed the guidelines. Typical PFAS analysis currently includes PFAS11, it is however recommended that broader analysis is implemented to comply with future guidelines based on PFAS24. Overall, the results highlight the risk of PFAS-contaminated groundwater spreading from landfills to drinking water sources.

Per- and polyfluoroalkyl substances (PFAS) are a group of highly fluorinated compounds which comprises of more than 4700 substances. A smaller number of those substances is rou-tinely measured, usually the short (C4-C7) and long chain PFAS (&gt;C7). Detection of PFAS in different water matrices including wet precipitation have been done previously in a limited number of studies, including ultra-short chain compounds (C1-C3). Ultra-short chain com-pounds have however not been investigated to a larger extent. In this study, twelve rainwater samples from Råö have been analysed, each representing a composite sample of one month. Long (C8-C18), short as well as ultra-short chain PFAS have been included in the analysis. Long and short chain compounds were analysed with ultra-performance liquid chromatography tan-dem mass spectrometer (UPLC-MS/MS) and ultra-short chain compounds with ultra-perfor-mance convergence chromatography tandem spectrometer (UPCC-MS/MS). Long and short-chain PFAS had a total detectable concentration of 5.1-110 ng/L. A seasonal trend was also studied, which showed a significant difference when performing a Kruskal Wallis test in meas-ured total mean long and short chain PFAS concentration. Dunnet´s test indicated a significant difference between all the seasons. Highest concentrations were measured during summer and lowest during winter. Ultra-short chain compounds analysed by UPCC MS/MS had a total concentration between 16-410 ng/L. No significant difference in total ultra-short PFAS mean concentration could be seen between different seasons using a Kruskal Wallis test. The total PFAS concentration in the rain samples ranged from 28 to 540 ng/L, where ultra-short chain PFAS contributed to 58-92 % of the total concentration. Which makes them an important group to include in future measurements of PFAS in water samples and especially in rainwater sam-ples.

Per- och polyfluorerade alkylsubstanser (PFAS) är en stor grupp industriellt framställda ämnen som fått stor spridning i miljön. På grund av PFAS persistens blir ämnena kvar länge i vår miljö och spridning kan fortgå ifrån förorenade områden under lång tid. Högst halter i miljön i Sverige har noterats i anslutning till brandövningsplatser där man använt brandskum innehållande PFAS-ämnen.De vanligaste källorna till människors exponering för PFAS är via kosten, inklusive dricksvatten. PFAS binder till proteiner i kroppen och ansamlas i blodet och levern samt lungor och njurar. Exponering för förhöjda halter under lång tid har visats ge påverkan på blodfetter, en reducerad födelsevikt samt påverkan på leverceller. Den effekt som noterats vid lägst exponeringsdos är påverkan på immunförsvaret.I januari 2020 skickade Livsmedelsverket ut en enkät till Sveriges kommunala kontrollmyndigheter i syfte att kartlägga halter av PFAS i kommunalt dricksvatten. 261 kommuner av 290 (90 %) besvarade enkäten med uppgifter om 1462 vattenverk. Ett urval gjordes till stora vattenverk, som försörjer fler än 500 personer, vilka omfattade 580 stycken. Totalt 86 kommuner hade analyserat PFAS i dricksvatten från minst ett vattenverk. Detekterbara halter påträffades i dricksvattnet från 74 av samtliga 154 vattenverk där analyser genomförts. I dricksvattnet från 15 vattenverk, vilka tillsammans försörjer cirka 2,2 miljoner människor låg summahalterna av PFAS över 10 ng/l. Den högsta summahalten som uppmättes var 40 ng/l i dricksvattnet från ett vattenverk. Resultaten från denna kartläggning visar på lägre halter i kommunalt dricksvatten jämfört med undersökningar från tidigare år vilket indikerar att åtgärder vidtagits i syfte att sänka PFAS-halterna i dricksvattnet i Sverige. / Per- and polyfluorinated alkyl substances (PFAS) is a large group industrially synthesized compounds being wide spread in the environment. Due to the persistence, the compounds stays in the environment and can further disperse from polluted areas during a long time. The highest levels in the environment in Sweden have been found adjacent to firefighting training facilities using firefighting foam containing PFAS.Humans are exposed to PFAS mainly through food, including drinking water. PFAS binds to proteins in the blood and liver as well as in the lungs and kidney. Exposure during a prolonged time have shown to affect blood lipids, reduce birth weight and affect liver cells. The critical effect observed at the lowest dose is adverse effects on the immune system.In January 2020 the Swedish Food Agency sent out a questionnaire to the municipal control authorities aiming to map levels of PFAS in municipal drinking water. 261 municipalities of 290 (90 %) answered the questionnaire with information including 1462 water works. A selection was made including the larger water works supplying at least 500 persons, resulting in 580 water works. In total, 86 municipalities had analysed PFAS in drinking water from at least one water work. Detectable levels were found in 74 out of 154 water works, where analyses had been performed. In drinking water from 15 water works, supplying approximately 2.2 million people, the sum levels of PFAS exceeded 10 ng/l. The highest sum levels of PFAS in drinking water were 40 ng/l, found in one water work. The results from this survey shows lower levels in municipal drinking water compared to earlier studies, indicating that measures haven been taken aiming to lower the levels of PFAS in drinking water in Sweden.

<p>Perfluoroalkyl substances are synthetic organic chemicals of environmental concern because they have been associated with adverse effects in both human epidemiological studies and standard laboratory animals. In the environment, PFAS occur as mixtures, especially in areas with a history of PFAS application, such as aqueous film forming foam (AFFF) sites. Among the PFAS, perfluorooctanesulfonic acid (PFOS) and perfluorohexanesulfonic acid (PFHxS) are the most common, and occur at the highest concentrations. Thus, amphibian populations at or near AFFF sites are at risk of exposure to known bioaccumulative and persistent chemicals, likely compromising the physiology and body condition of the animals. Here, we exposed northern leopard frogs to environmentally relevant concentrations of 0.5 and 1 ppb PFOS and PFHxS, alone or as a mixture comprised of 0.5 ppb PFOS and 0.5 ppb PFHxS. Univariate analyses showed that in the larval stages, tadpoles exposed to PFAS had significantly reduced scaled mass indexes (SMI’s) relative to the control, and only the organisms exposed to PFHxS 0.5 ppb were significantly larger. Sex did not significantly influence toxicity in the later stages (GS 42 & 46), indicating no sex-related effects. Altered body condition (i.e., fat stores) in the larval stages indicate potential effects to energy balance. There is a need to assess fitness-related effects as amphibians’ transition into the terrestrial environment, and include endpoints such as: reproductive, developmental, immunological, mating, feeding, competition, and survival. Early developmental effects in the larval stages also suggests that earlier developmental endpoints may be of interest. Establishing ecological risk assessments for PFAS are necessary, as they are toxic, persistent, and bioaccumulative.</p>