0 Bachelor thesis in chemistry, 30HP
Analysis of PFAS in ash from incineration facilities
from Sweden
Dennis Wohlin
Supervisor: Anna Kärrman
1 Abstract
Per- and polyfluoroalkyl substances (PFAS) are a group of organohalogens that
bioaccumulate in biota, have toxicological effects and are persistent in the environment. Because of the fluorinated carbon chain, PFASs are present in many household and industrial products. The aim of this study is to investigate if PFASs are residues in ash from
municipality incineration facilities and asses if the ashes can become a source of
environmental pollution. In the method development three different extraction methods were tested (liquid-solid extraction with MeOH, liquid-solid extraction with acetone/hexane and Soxhlet extraction with MeOH) and evaluated by quantification of PFASs and extractable organic fluorine (EOF). The liquid-solid extraction with MeOH was chosen as the extraction method as the target PFASs were extracted from the ash samples while the other methods resulted in lower signals. The EOF had high blank raising questions about the suitability of the method for EOF. The results from analysing ashes from 11 facilities sampled in 2005 indicate that PFASs are occurring more often in fly ash than bottom ash (sum of PFAS 43,1- 950,7 pg/g) however the two samples with the highest detected amount of PFASs (1611 and 7169,5 pg/g) were both bottom ash. The PFASs that were found in the highest concentrations were at low parts per billion in concentration levels. Since the landfill sites around waste facilities are continuously refilled with new ash from the incineration there is a possibility that the landfills could become a source of environmental pollution in the future with continuously leeching from the added ashes.
2 Table of contents
Abstract 1
1. Introduction 3
1.1 Aim and objective 4
2. Method and material 5
2.1 Chemicals 5
2.2 Samples 5
2.3 Sample preparation 7
2.4 Chemical analysis 8
2.5 Quality control 8
3. Result and discussion 9
3.1 Results method development 9
3.2 Results method validation 11
3.3 Bottom and fly ash 13
4. Conclusions 16
5. Acknowledgements 17
6. References 18
Appendix 20
A.1 Native standards, Internal standards, Recovery standards, CAS number, Cone voltage, Collision energy.
A.2 Concentration levels of PFASs in bottom ash, given in pg/g. A.3 Concentration levels of PFASs in fly ash.
3 1.Introduction
Per- and polyfluoroalkyl substances (PFAS) are a group of organohalogens that
bioaccumulate in biota, have toxicological effects and are persistent in the environment [1]. PFASs have all or some of their hydrogen atoms replaced by fluorine atoms, which makes them as compounds very stable and hard to degrade. Because of the fluorinated carbon chain, PFASs become both hydrophobic and oleophobic which means they repel water, fat, and dirt. They are also extremely resistant. These properties have been applied to products like
synthesis chemicals, electronics, printing products, cosmetics, textile and leather treatment, biocides, colour raw material, paper treatment and foam-based fire extinguishing agents [2]. Since 2009 perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) among others, have been restricted in different ways and PFOS is included in the Stockholm
convention Annex B, meaning that production and use is restricted. However nearly 5000 known different types of PFASs exists today and many of them are still frequently used in everyday household products and industrial applications [2].
Burning waste is common practice in Sweden and it is believed that PFASs will be
mineralized during combustion. The complete degradation of PFASs would result in CO2, H2O, and HF. Many waste facilities in Sweden burn their waste at different temperatures depending on the waste [3]. There is no consensus regarding the temperature needed for degradation of PFASs as reports show variations in results. Degradation of PFASs start at around 750o C, however some reported results indicate that to fully degrade PFOS and PFOA a temperature of 1000o C is needed [3]. This becomes a problem as most of the waste is burned at 850o C, making it possible that PFAS residues remains in the gas or ash that is produced from the incineration of waste [2]. The ashes are put on landfills which in term could become a source of environmental pollution from residual PFASs, which are hard to degrade.
The incineration process creates two kinds of ashes, bottom ash and fly ash. The bottom ash is made up of heterogeneous solid material such as metals while the fly ash is collected from the gaseous phase and condensed into a fine powder through air pollution control (APC) systems [4]. Some of the unwanted by-products in waste incinerators are persistent organic pollutants (POPs). Polycyclic aromatic hydrocarbons (PAHs), dioxins and polychlorinated biphenyls (PCBs) are some examples of the unwanted by-products from waste incinerators. As the waste is burned, unwanted by-products forms in either a high temperature pyrosynthesis or a low temperature de novo formation from organic or inorganic compounds in the ash [5]. The
4 possibility and idea to look for PFASs in ash from incineration facilities is fairly new as it is believed that the degradation during incineration is almost complete [3,6,7]. For complete thermal degradation of PFOS of 99,9% the waste is recommended to be burned at 1000oC [3]. There are reports that show the thermal degradation starts already at 500oC, however
fluorinated by-products are then formed which themselves have unwanted properties [3].Reports regarding the matter are scarce but show that the thermal degradation at lower temperature such as 600oC produce products such as the greenhouse gases CF4 and C2F6 [7,8] A total PFAS analysis of combustion products is lacking as well as information if different incineration parameters influence the formation of PFAS residues. Increased knowledge of PFAS emissions is needed given the large number of municipality incinerators, and that incineration presumably is the only option for eliminating PFASs due to the strong carbon-fluorine bond.
A liquid chromatograph tandem mass spectrometer (LC-MS/MS) can be used for the analysis of PFAS in ashes from incineration facilities [9] and other different kinds of solid material for example sediment and soil samples [10]. Usually about 20 different PFASs are targeted during analytical procedures [11,12]. These 20 PFASs tend to be the most commonly found in soil or biota due to being applied to products for a long period of time. When analysing solid materials such as soil or sediment ultrasonication is used to break the interactions between the PFASs and the solid materials to release as much as possible into the solvent. It could
possibly be both non-polar interaction and anionic interactions that bind PFASs to solid materials. By using a Combustion Ion Chromatograph (CIC) the extractable organic fluorine (EOF) can be measured in the samples. Since the CIC measures all EOF in a sample it can be used to compare with the LC-MS results after converting the measured PFASs to fluorine. The strength of the CIC is that it measures all organic fluorine, but that can also be its
weakness as the CIC cannot distinguish the source of fluorine, whether it is inorganic fluoride originating from the sample or any contamination from materials used in the analytical
procedure.
1.1 Aim and objectives
The aim of this project is to investigate if PFASs are residues in ash from incineration facilities and to assess if the ashes can potentially become a source of environmental
pollution. By developing a method that can extract and analyse PFASs from different kind of incinerated waste, and to compare target PFAS with EOF for both bottom ash and fly ash it is
5 possible to assess how much PFAS are residues in the ashes and that possibly can leech out to the environment.
2.Method and materials 2.1 Chemicals
Native standards and labelled standards of PFAS were used for isotope quantification and recovery calculations, all from Wellington Laboratories (see appendix A1). Internal standards were added prior to the extraction and recovery standards were added prior to injection to the instrument.
Methanol HPLC-grade (99,8%) from Fisher Scientific, methanol LCMS-grade (99,9%) from Fisher Scientific, acetic acid from Fisher Scientific, ammonium hydroxide from Fisher Scientific, ammonium acetate from Sigma Aldrich, acetonitrile (HPLC-grade) from Fisher Scientific and isopropanol from Fisher Scientific was used for extraction and LC-MS analysis. The water used during the analysis was laboratory produced MilliQ water (18,2 MΩ).
2.2 Samples
In total 26 samples from fly and bottom ash were taken at 11 waste incineration facilities in March 2005, with additional sample fractions of crude fly ash taken at Händelö P14,
Nynäshamn (here called turn shaft and at Lidköping (here called turn shaft and crude fly). The waste incineration facilities used different kind of fuel and incineration chambers, as can be seen in table 1. The different chambers consist of grate incinerators (GI), circulating fluidized bed boiler (CFBB) and bubbling fluidized bed boiler (BFBB). To get as
representative samples as possible the sample collection was done at four different occasions with different personnel under two days’ time. All the samples were sent to Örebro University in June 2005 where they were stored in the dark in room temperature in polyethylene plastic buckets [13]. All samples were sub-samples from the middle of the plastic bucket for the analytical procedure.
6 Table 1. Description of furnaces and the general percentage of fuel used in the furnaces.
Fuel (%) Söder -tälje Hög-dalen Umeå Lid-köping Kir-una Bra-viken Mälar-dalen Energi Sunds -vall Händel ö P14 Munk-sund Nynäs hamn Type of furnace GI BFB B GI CFBB & GI GI GI BFBB BFB B BFBB BFBB CFBB Peat 33 24 Bark 22 27 70 Stem wood 16 Wood-chips 22 10-15 25 RT-wood chips 50 16 11 100 Well reject 5 DIP*-reject 3 Industrial waste 60 100 40 30-50 50 Fuel crushing pellets 40 DIP* sludge 48 Plastic reject 28 House-hold waste 60 100 30-50 50
*De-inked pulp rejected paper or paper sludge. GI = Grate incineration, CFBB = Circulating fluidized bed boiler, BFBB = Bubbling fluidized bed boiler
7 2.3 Sample preparation
Three extraction methods were tested in the method development: soxhlet using methanol, liquid-solid extraction using acetone and hexane, and liquid-solid extraction using methanol. The different extraction methods cover different polarities and can also assess how hard PFAS bind to the ash [14,15,16]. During the method development, three ash samples (Södertälje, Umeå and Högdalen Fly ash) were used to evaluate the extraction efficiency. IS was spiked before injection for target PFAS analysis, and after splitting the extract to allow for CIC analysis. For the sample analysis using the selected method, 1000 pg of IS was added to the samples before adding the extraction solvent.
For the soxhlet extraction, 250 mL of HPLC-grade MeOH was used to about 1 gram of sample and the extraction ran for 24 hours at a temperature of 60oC before the samples were evaporated and concentrated by using rotary evaporation to 1 mL. MilliQ was added to reduce the MeOH concentration to below 20% before the samples were ultrasonicated and then centrifuged for 15 minutes each. The pH was adjusted with acetic acid to between 4-7 before clean-up.
For the liquid-solid extraction two versions were used. For the first one 4 mL acetone and hexane in a 50:50 combination was added to about 1 gram of sample before it was put on a shake table, ultrasonicated and centrifuged for 15 minutes each. The upper layer was transferred to a new tube and the process was repeated once. The samples were evaporated gently under nitrogen gas until dryness and reconstituted with acetonitrile. Supel QuE Z-Sep sorbent was added to the sample solution before the samples were filtered using pre-washed GHP syringe filters and transferred to LC-vials. The samples were evaporated under nitrogen gas until dryness before 0,5 mL of acetonitrile were added to the LC-vials.
For the second liquid-solid extraction 4 mL MeOH was added to about 1 gram of sample before it was put on a shake table, ultrasonicated and centrifuged for 15 minutes each. The upper layer was transferred to a new tube and the process was repeated once. Nitrogen gas was used to evaporate some of the MeOH so that MilliQ could be added to reduce the MeOH concentration to below 20%. The pH was adjusted with acetic acid to between 4-7 before clean-up.
Solid-phase extraction (SPE) using Weak-anion exchange (WAX) was used for clean-up after both the soxhlet and liquid-solid extraction using MeOH. The SPE-WAX was first
8 mL MilliQ. After the conditioning, the samples were loaded onto the column which was then washed with 4 mL ammonium acetate buffer of pH 4 and 8 mL MilliQ. In the elution step 4 mL MeOH was used for collecting the first fraction and 4 mL 0,1% NH4OH in MeOH for fraction two, the different fractions were collected in separate polypropylene-tubes and evaporated with nitrogen gas down to 0,5 mL and then transferred to LC-vials. The LC-vials used for injection to the instrument was prepared with 1000 pg recovery standard, 195 µL of sample solution and 300 µL of mobile phase.
Duplicate extractions of all ash samples were performed, and the second extraction was used for the extractable organic fluorine (EOF) analysis. The same procedures as described above were used, except that no IS or RS was added for the EOF analysis.
2.4 Chemical analysis
For the separation and quantification of PFASs, an Acquity UPLC coupled to a Xevo TQ-S tandem mass spectrometer (Waters Corporation) was used and operated in electrospray-negative ionization mode. The analytes were injected (10 µL) and separated on a 10 cm BEH C18 UPLC column (Waters Corporation) held at 50oC using water and methanol mobile phases with 2mM ammonium acetate (for gradient see appendix A5). The electrospray capillary voltage was 0,7kV, the source temperature was 150oC, the desolvation temperature was 400oC, the cone gas had a flow of 150 (L/hour), the desolvation gas had a flow of 800 (L/hour), and the collision gas had a flow of 0,20 (mL/min),. Cone voltages and collision energies are found in appendix table A1.
The EOF content was determined using combustion ion chromatography (CIC). The combustion module was from Analytik Jena, Germany, coupled to an absorber module and ion chromatograph from Metrohm, Switzerland. Combustion temperature was 1000–1050 C, which converts all organofluorine compounds into hydrogen fluoride (HF). Injection volume was 100 μL and separation of anions was performed by isocratic elution on an ion exchange column (Metrosep A Supp5–150/4) using carbonate buffer (64 mmol/L sodium carbonate and 20 mmol/L sodium bicarbonate). F¯ concentration was measured by conductivity.
2.5 Quality control
Concentrations were calculated by isotope dilution, each batch of samples were quantified using external standards and an external calibration curve was constructed using a
9 linearity was shown for most of the targeted PFASs with a r2 of >0.99. For limit of detection (LOD) procedural blanks from the liquid-solid extraction with MeOH through-out the study was used and the average value plus three times the standard deviation (mean+3sd) was defined as the LOD. Accuracy and precision were evaluated by performing triplicate spiked samples that was with 5000 pg. The recovery of the IS was monitored for each sample, and two product ions were monitored for each PFAS, except for PFBA and PFPeA. For the CIC measurement, combustion blanks were performed between each sample and a standard control with PFOS was injected on a regular basis. The quantification was done by a 5-point calibration curve using triplicates standards with 50, 100, 200, 500 and 1000 ng F/mL concentration.
3.Results and discussion 3.1 Method development
The results from the target PFAS analysis shows very clearly that using the liquid-solid extraction with MeOH as a solvent was the most efficient way to extract PFASs from the ash samples compared to the liquid-solid extraction method using acetone/hexane and the soxhlet extraction (Figure 1). However, since the three different methods were only used once before determining the method for the rest of the study any errors in the methods that can occur due to human error will influence the choice of method. With the very low soxhlet result
assumption could be made that there is some error in the extraction as the continuous boiling in MeOH should release more PFASs from the ash into the solvent than what is shown in the results. The three samples in the method development had similar concentration levels of the most abundant PFASs. The most abundant PFASs in Södertälje and Umeå were PFBA, PFBS, PFHxA and PFOA while Högdalen were PFBA, PFBS, PFHxA and PFOS. In another study similar pattern could be found regarding the PFASs found in the three fly ash samples using the liquid-solid extraction method [17].
However, the results from the CIC indicates that the liquid-solid method using acetone/hexane as solvents give a higher concentration of extractable F-, compared to the liquid-solid method using MeOH as solvent were the samples had similar concentration as the extraction blank (Figure 2). The soxhlet extraction not only had a poor extraction result for PFAS but the EOF result showed that the extraction blank concentration were 2-3 times as high as the samples. With these results, the liquid-solid extraction using MeOH as solvent was chosen since more target PFASs could be extracted compared to the other methods.
10
Figure 1. A comparison of three different extraction methods, liquid-solid extraction methanol, Soxhlet methanol, and liquid-solid extraction acetone/hexane, and the extracted PFAS >LOD in fly ash from Södertälje, Umeå, and Högdalen.
Figure 2. A comparison of the fluoride (ng/g) in fly ash from three facilities using three different extraction methods.
0 50 100 150 200 250 300 350 400 450 500 Högdalen Liquid-solid MeOH Högdalen Soxhlet Högdalen Liquid-solid A/H Umeå Liquid-solid MeOH Umeå Soxhlet Umeå Liquid-solid A/H Södertälje Liquid-solid MeOH Södertälje Soxhlet Södertälje Liquid-solid A/H
p
g
/g
PFBA PFBS PFHxA PFOS PFOA
0 5 10 15 20 25
Liquid-solid ac/hex Soxhlet Liquid-solid MeOH
C
n
g
F/
g
11 3.2 Method validation
To ensure the accuracy and precision of the method, three replicate ash samples from Högdalen and a procedural blank was spiked with 5000 pg of native standard for analysis. The recovery and relative standard deviation for the 22 spiked PFAS was acceptable and showed good accuracy (recovery 64.4-113%) and precision (RSD 1.9-20%) (see table 2).
A second spiked sample extraction with three replicates was done for the EOF measurement using CIC. The recovery for the method development was between 13%-23% (Figure 3). The result show that the method for the EOF needs to be spiked in a higher amount than the samples for the UPLC as the spiked samples were below the limit of detection for the
instrument thus giving the poor recovery and similar fluoride concentrations as the non-spiked samples.
Figure 3. Shows the recovery of the EOF in the method validation. 0 10 20 30 Recovery ng F/mL
R
ec
ov
er
y
(%)
12 Table 2. Average recovery (%) and relative standard deviation (%) for 22 target PFASs spiked to fly ash.
Compound Average recovery % Relative Standard Deviation %
PFBA 105 8.8 PFPeA 108 12 PFBS 108 11 PFHxA 104 9.5 4:2 FTSA 75.5 1.9 PFHpA 109 13 PFPeS 113 12 PFHxS 110 14 PFOA 100 8.4 PFNA 104 8.4 PFOS 112 8.0 PFDA 107 7.9 PFUnDA 108 10 PFNS 84.3 7.0 PFDS 89.2 9.5 PFDoDA 106 12 PFTrDA 84.4 10 PFDoDS 64.4 20 PFTDA 98.9 6.0 PFHxDA 103 11 6:2 FTSA 80.5 3.6 8:2 FTSA 82.6 7.9
13 3.3 Bottom and fly ash
The results show that many of the PFASs are below the limit of detection in most of the bottom ash and fly ash samples. From the 22 target PFASs in the analysis 15 were quantified above the limit of detection. In the bottom ash samples, the quantification above LOD was only possible in 5 of the 11 different facilities. Target PFASs quantified were between 1-14 in the different samples and the ∑concentration in the samples were between 43,1 pg/g - 7169,5 pg/g (figure 4). In the fly ash samples, the quantification above LOD was possible in all 11 facilities and the target PFASs quantified were between 1-10 with the ∑concentration between 43,1 pg/g – 950,7 pg/g (figure 5). The results indicate that target PFASs are more common in the fly ash rather than the bottom ash. The bottom ash samples consist of heavier materials such as metals compared to the fly ash that is condensed gases that have been cooled down. Because of the temperature needed for PFASs to move into gaseous phase is below the temperature that waste facilities burn to degrade dangerous compounds it makes sense that more PFASs can be found in the fly ash samples.
Figure 4. The concentration (pg/g) and pattern of PFASs measured in bottom ash from Kiruna, Braviken, Södertälje, Högdalen, and Umeå.
0,0 1000,0 2000,0 3000,0 4000,0 5000,0 6000,0 7000,0 8000,0 B Kiruna B Braviken
p
g
/g
PFBA PFPeA PFHxA PFHpA PFOA PFNA PFDA PFUnDA
14
Figure 5. The total amount of PFASs above LOD measured in pg/g from fly ash samples.
The level of PFASs differ between the different waste incineration facilities. The waste facilities have different types of combustion furnaces. Three facilities have the grate
incineration furnace and two of these facilities (Kiruna and Braviken) had the highest PFAS concentrations in bottom ash. This raises questions if the type of furnace and have any impact on the PFASs levels, together with the type of fuel used. Kiruna used 100% household wastes for fuel, Lidköping uses plastic rejects, RT-woodchips, bark, and Braviken uses paper rejects and sludge from its paper production. There is a study indicating differences in the detection of PFAS-concentrations depending on the type of waste [18] yet further studies are needed before a clear conclusion can be made. Since paper often is treated to be resistant towards moisture and water it is possible that this is the reason why PFASs can be found in the ashes from Braviken [19]. For the other facilities it is more complex to get an indication on where the PFASs come from. In the fly ash samples the two different facilities that has the highest amount of PFASs found, have similar composition of the type of fuel they use for their furnaces. Nynäshamn which has the highest concentration of PFASs in fly ash used 100% RT-wood chips for fuel and Lidköping who had the second highest concentration used 50% RT-wood chips, 28% plastic reject and 22% bark. Indicating once again that the type of fuel used impacts the concentration of PFASs in the ash.
0,0 100,0 200,0 300,0 400,0 500,0 600,0 700,0 800,0 900,0 1000,0
p
g
/g
PFBA PFPeA PFHxA PFHpA PFOA PFNA PFDA
15 Lidköping, Nynäshamn and Händelö had multiple sample location during the incineration process that are in the same line in the process and prior to the fly ash sample locations. In the crude fly ash sample from Lidköping, 20 target PFASs were quantified above the LOD with a total concentration of 1268,6 pg/g and in the turn shaft 9 target PFASs were quantified above LOD. For each step in the incineration process more of the larger PFASs become below LOD. It is impossible to make any clear conclusions since the total PFAS concentration for the turn shaft from the other facilities were 7,6 pg/g and 76,9 pg/g (figure 6 and table A4).
Figure 6. Comparison of PFASs during different stages in the incineration process.
In about 70% of the samples PFOA was quantified. It was quantified in almost all the stages during the incineration process regardless of the sample location with only turn shaft
Nynäshamn as the only sample where it was not quantified. It is possible that the PFOA comes from polytetrafluoroethylene (PTFE) also knowns as Teflon. It is possible that PFBA that was found in about 28% of the samples comes from other large PFASs compounds and have been formed as a by-product during the incineration as greenhouse gases as mentioned earlier in the report. Since the samples are from 2005 the restrictions implemented by the Stockholm convention does not apply and the amounts that have been found in ashes from incineration facilities should give some indication on the levels prior to the restrictions.
0 200 400 600 800 1000 1200 1400
F Lidköping Turn shaft Lidköping
Crude fly Lidköping
F Nynäshamn Turn shaft Nynäshamn
F Händelö Turn shaft Händelö
p
g
/g
PFBA PFPeA PFHxA PFHpA PFOA PFNA PFDA PFUnDA
PFTrDA PFTDA PFHxDA PFOcDA PFBS PFHxS PFHpS PFOS
16 PFOS was quantified in eight ash samples at concentrations 26,0-748,3 pg/g (tables A2, A3 and A4). Even if PFOS has been restricted since 2009 it can be found in for example sludge from sewage treatment facilities [20]. It can therefore be possible to find PFOS in waste or waste streams, but to make a clear conclusion more studies are needed, and more recent samples should be included to evaluate the trend after the restrictions were implemented.
Conclusions
The method developed for extracting target PFASs from ash proved accurate and precise, while the method for EOF needs higher concentration levels in the method development to prove accuracy and precision of the method. The level of PFASs found in the different kinds of samples indicate that the method can extract the different compounds present in ash after the incineration. The results also indicate that PFAS with a higher molecular weight may degrade into smaller PFAS due to the incineration treatment. While not presented in this study due to lack of result, the unknown PFAS that should be present in the samples and measured with EOF could also potentially be a source from degradation into PFAS with a smaller molecular weight. Regarding the Swedish waste regulations for PFOS, waste containing PFOS is not allowed to exceed concentrations of 50 mg/kg [21]. The levels that were
quantified in this study were well below those levels. However, since the landfill sites around waste facilities are continuously refilled with new ash from the incineration there is a
possibility that the landfills could become a source of environmental pollution in the future with continuously leeching from the added ashes.
Currently there are no legal problems applying incineration ashes on landfills. However, since there are so few studies regarding PFAS levels in ash there needs to be more studies more on emissions as well as more recent samples. Further method development should take place to be able to analyse all organic fluorine to ensure destruction or irreversible conversion considering the longevity of PFASs. Further in-depth studies comparing the type of furnace and the type of fuel is also needed to make any clear conclusion if this have any effect on the degradation of PFASs during the incineration process.
17 Acknowledgements
I would like to express my gratitude towards my supervisor Anna Kärrman for helping me during this project with her knowledge and her time. I would also like the express my gratitude to Mattias Bäckström for providing knowledge on the samples and the incineration facilities, Mio Skagerkvist and Rudolf Aro for all their help in the laboratory with the instrumental setup and help with solving problems that occurred during the study.
18 References
1. J. C. DeWitt. S. J. Blossom. L. A. Schaider. (2018) Exposure to per-fluoroalkyl and polyfluoroalkyl substances leads to immunotoxicity: epidemiological and
toxicological evidence. Journal of exposure science & environmental epidemiology. 2019 Mar;29(2):148-156.
2. Kemikalieinspektionen. (2015). Förekomst och användning av högfluorerade ämnen och alternativ. Rapport 6/15. ISSN 0284-1185. Artikelnummer: 361 161.
3. Lundin, L., Jansson, S. (2017) Destruction of Persistent Organic Compounds in Combustion systems. Umeå University.
4. Petrlik, J., Ryder, R., Schoevers, A. & havel, M. 2005. After Incineration: The Toxic Ash Problem. IPEN Dioxin, PCBs and Waste Working Group.
5. Hsu, W. T., Liu, M. C., Hung, P. C., Chang, S. H., & Chang, M. B. (2016). PAH emissions from coal combustion and wate incineration. Journal of Hazardous Materials 318 (2016) 32-40.
6. Solo-Gabriele, H. M., Jones, A. S., Lindstrom, A. B., & Lang, J. R. (2020). Waste type, incineration, and aeration are associated with per- and polyfluoroalkyl levels in landfills leachates. Waste Management 107 (2020) 191-200.
7. Fei Wang, Kaimin Shih, Xingwen Lu, Chengshuai Liu (2013) Mineralization
Behavior of Fluorine in Perfluorooctanesulfonate (PFOS) during Thermal Treatment of Lime-Conditioned Sludge. Environmental science & Technology, 47(6), 2621-2627.
8. Taylor, P.H., Yamada, T. (2003) Final Report - Laboratory Scale Thermal
Degradation of PFOS and Related Precursors. University of Dayton Research Institute (UDRI), Environmental Science and Engineering Group, Dayton, OH 45469-0132. 9. Aleksandrov, K. Gehrmann, H-J, Hauser, M, Mätzing, H. Pigeon, D. Stapf, D &
Wexler M. 2019. Waste incineration of Polytetrafluoroethylene (PTFE) to evaluate potential formation of per- and Poly-fluorinated Alkyl Substances (PFAS) in flue gas. Chemosphere 226 (2019) 898-906.
10. Yeung, L. O. De Silva, A. I.H. Loi, E. H. Marvin, C. Taniyasu, S. Yamashita, N. A. Mabury, S. C.G. Muir, D. K.S. Lam, P. (2013). Perfluoroalkyl substances and extractable organic fluorine in surface sediments and cores from Lake Ontario. Environmental International 59, 389-397.
19 11. Boiteux, V., Bach, C., Sagres, V., Hemard, J., Colin, A. and Rosin, C. (2016) Analysis
of 29 per- and polyfluorinated compounds in water, sediment, soil and sludge by liquid chromatography–tandem mass spectrometry. International Journal of Environmental Analytical Chemistry, 96(8), 705-728.
12. Taniyasu, S., Kannan K., Yeung, L., Kwok, K., Lam, P. K. S., and Yamashita, N. (2008) Analysis of trifluoroacetic acid and other short-chain perfluorinated acids (C2-C4) in precipitation by liquid chromatography-tandem mass spectrometry:
Comparison to patterns of long-chain perfluorinated acids (C5-C18). Analytica Chimica Acta, 619(2), 221-230.
13. Bäckström, M. (2006). Lakning av antimon från energiaskor – Totalhalter, lakbarhet samt förslag till åtgärder. Värmeforsk. ISSN 1653-1248.
14. Fredriksson, F., Eriksson, U., Kärrman, A & Yeung, L. (2020). A pilot study of the Fluorinated Ingredient of Scotchgard Products and Their Levels in WWTP Sludge and Landfill Leachate from Sweden. Örebro University.
15. González, P. (2019). Method development for the analysis of PFAS and neutral precursors in active and passive air samplers. Örebro University.
16. Ahrens, L., Nordström, K., Viktor, T., Cousins, A. & Josefsson, S. (2015). Stoclholm Arlanda Airport as a source of per-and polyfluoroalkyl substances to water, sediment and fish. Chemosphere, 129, 33-38.
17. Sandblom, O. (2014). Waste Incineration as a Possible Source of Perfluoroalkyl Acids to the Environment – Method Development and Screening. Stockholm University. 18. Avfall Svergies Utvecklingssatsning. (2018). PFAS På Avfallsanläggningar. Rapport
2018:25. ISSN 1103-4092.
19. Kemikalieinspektionen. (2006). Perfluorinated substances and their uses in Sweden. Report Nr 7/06. ISSN: 0284-1185.
20. Yeung, L., Eriksson, U. & Kärrman, A. (2017). Tidstrend av oidentifierade poly- och perfluorerade alkylämnen i slam från reningsverk i Sverige. Örebro University. 21. Naturvårdsverket Frågor och svar om PFAS och deponier [online]. Available at:
https://www.naturvardsverket.se/Stod-i-miljoarbetet/Vagledningar/Avfall/Deponering-av-avfall-/Fragor-och-svar1/Fragor-och-svar/ [accessed 2020-05-29]
20 Appendix
Table A1. Native standards, Internal standards, Recovery standards, CAS number, Cone voltage, Collision energy & all standards were provided by Wellington laboratories.
Compound Acronym CAS Internal
standard used Recovery standard used Cone voltage Collision energy
Perfluorobutanoic acid PFBA
602-94-8
IS PFBA RS
PFBA
20 11
Perfluoropentanoic acid PFPeA
2706-90-3
IS PFPeA RS PFPeA
20 8
Perfluorohexanoic acid PFHxA
307-24-4 IS PFHxA RS PFHxA 20 9
Perfluoroheptanoic acid PFHpA
375-85-9 IS PFHxA RS PFHxA 20 10
Perfluorooctanoic acid PFOA
335-93-3
IS PFOA RS
PFOA
20 10
Perfluorononanoic acid PFNA
375-95-1
IS PFNA RS
PFNA
20 12
Perfluorodecanoic acid PFDA
335-76-2 IS PFDA RS PFDA 20 11 Perfluoroundecanoic acid PFUnDA 2058-94-8 IS PFUnDA RS PFUnDA 20 12 Perfluorododecanoic acid PFDoDA 307-55-1 IS PFDoDA RS PFUnDA 34 14 Perfluorotridecanoic acid PFTrDA 72629-94-8 IS PFDoDA RS PFUnDA 20 14 Perfluorotetradecanoic acid PFTDA 376-06-7 IS PFTDA RS PFUnDA 20 14 Perfluorohexadecanoic acid PFHxDA 67905-19-5 IS PFHxDA RS PFUnDA 30 15 Perfluorooctadecanoic acid PFODA 16517-11-6 IS PFHxDA RS PFUnDA 36 15
21 Linear perfluoro butanesulfonic acid sulfonate L-PFBS IS PFBS RS PFHxS 20 26 Perfluoropentane sulfonic acid L-PFPeS 2706-91-4 IS PFHxS RS PFHxS 20 26 Perfluorohexanesulfonic acid L-PFHxS 355-46-4 IS PFHxS RS PFHxS 20 30 Perfluoroheptane sulfonic acid L-PFHpS 375-92-8 IS PFOS RS PFOS 20 30 Perfluorooctanesulfonic acid L-PFOS 1763-23-1 IS PFOS RS PFOS 20 38 Perfluorononane sulfonic acid L-PFNS IS PFOS RS PFOS 20 38 Perfluorodecane sulfonic acid L-PFDS 335-77-3 IS PFOS RS PFOS 20 42 Perfluorododecane sulfonic acid L-PFDoDS 79780-39-5 IS PFOS RS PFOS 20 40 4:2 Fluorotelomer sulfonic acid 4:2FTSA IS 6:2 FTSA RS 4:2 FTSA 20 20 6:2 Fluorotelomer sulfonic acid 6:2FTSA IS 6:2 FTSA RS 4:2 FTSA 20 20 8:2 Fluorotelomer sulfonic acid 8:2FTSA IS 8:2 FTSA RS 4:2 FTSA 20 20 Perfluorooctane sulfonamide PFOSA 754-91-6 IS PFOSA RS PFOS 82 30
22 Table A2. Concentration levels of PFASs in bottom ash, given in pg/g.
Compound LOD B Södertälje B Högdalen B Umeå B Lidköping B Kiruna B Braviken B Mälardalen B Sundsvall B Händelö B Munksund
PFBA 42.9 <LOD <LOD <LOD <LOD 153.3 96.8 <LOD <LOD <LOD <LOD
PFPeA 25.0 <LOD <LOD <LOD <LOD 220.6 35.7 <LOD <LOD <LOD <LOD
PFHxA 25.0 <LOD <LOD 49.0 <LOD 662.7 86.3 <LOD <LOD <LOD <LOD
PFHpA 4.1 <LOD <LOD <LOD <LOD 427.9 <LOD <LOD <LOD <LOD <LOD
PFOA 20.0 56.4 43.1 110.8 <LOD 1646.0 467.8 <LOD <LOD <LOD <LOD
PFNA 20.0 <LOD <LOD <LOD <LOD 264.1 23.3 <LOD <LOD <LOD <LOD
PFDA 19.3 27.2 <LOD <LOD <LOD 1248.9 174.8 <LOD <LOD <LOD <LOD
PFUnDA 25.0 <LOD <LOD <LOD <LOD 149.2 <LOD <LOD <LOD <LOD <LOD PFDoDA 10.1 <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD PFTrDA 18.5 <LOD <LOD <LOD <LOD 364.7 64.6 <LOD <LOD <LOD <LOD PFTDA 385.4 <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD PFHxDA 200.0 <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD PFOcDA 500.0 <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD
PFBS 20.0 <LOD <LOD 39.8 <LOD 196.8 59.6 <LOD <LOD <LOD <LOD
PFPeS 0.4 <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD PFHxS 24.0 <LOD <LOD <LOD <LOD 117.8 <LOD <LOD <LOD <LOD <LOD PFHpS 10.2 <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD
PFOS 20.0 <LOD <LOD 33.5 <LOD 748.3 558.0 <LOD <LOD <LOD <LOD
23
PFDoDS 40.5 <LOD <LOD <LOD <LOD <LOD 34.9 <LOD <LOD <LOD <LOD 4:2 FTSA 0.6 <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD 6:2 FTSA 35.8 <LOD <LOD <LOD <LOD 78.3 <LOD <LOD <LOD <LOD <LOD
8:2 FTSA 3.8 <LOD <LOD 17.0 <LOD 891.0 9.4 <LOD <LOD <LOD <LOD
24 Table A3. Concentration levels of PFASs in fly ash, given in pg/g.
Compound LOD F Södertälje F Högdalen F Umeå F Lidköping F Nynäs F Kiruna F Braviken F Mälar-dalen F Sundsvall F Händelö F Munk-sund PFBA 42.9 51.5 <LOD 80.3 <LOD 258.9 93.1 99.1 <LOD <LOD <LOD <LOD PFPeA 25.0 <LOD <LOD <LOD <LOD 59.5 <LOD <LOD <LOD <LOD <LOD <LOD PFHxA 25.0 <LOD <LOD <LOD <LOD 113.6 <LOD <LOD <LOD <LOD <LOD <LOD PFHpA 4.1 <LOD <LOD <LOD <LOD 73.0 <LOD <LOD <LOD <LOD <LOD <LOD
PFOA 20.0 46.1 43.1 <LOD 183.8 224.7 46.7 <LOD 60.5 89.2 46.3 82.6
PFNA 20.0 <LOD <LOD <LOD 212.8 28.7 <LOD <LOD <LOD <LOD <LOD <LOD PFDA 19.3 <LOD <LOD <LOD 37.5 81.6 <LOD <LOD <LOD <LOD <LOD <LOD PFUnDA 25.0 <LOD <LOD <LOD 56.9 <LOD <LOD <LOD <LOD <LOD <LOD <LOD PFDoDA 10.1 <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD PFTrDA 18.5 38.7 <LOD 28.8 <LOD 52.0 <LOD 22.7 <LOD <LOD <LOD <LOD PFTDA 385.4 <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD PFHxDA 200.0 <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD PFOcDA 500.0 <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD PFBS 20.0 <LOD <LOD <LOD <LOD 27.3 <LOD <LOD <LOD <LOD <LOD <LOD PFPeS 0.4 <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD PFHxS 24.0 <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD PFHpS 10.2 <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD
25 PFOS 20.0 <LOD <LOD <LOD 72.0 <LOD <LOD <LOD 27.2 26.0 <LOD <LOD PFNS 2.0 <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD PFDoDS 40.5 <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD 4:2 FTSA 0.6 <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD 6:2 FTSA 35.8 <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD 47.3 <LOD <LOD 8:2 FTSA 3.8 <LOD <LOD <LOD <LOD 31.5 <LOD <LOD <LOD 7.0 10.5 <LOD PFOSA 115.0 <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD <LOD
26 Table A4. Concentration levels of PFASs in turn shaft and crude fly ash, given in pg/g.
Compound LOD Turn shaft Lidköping Turn shaft Nynäshamn Turn shaft Hände§lö P14 Cyklon Lidköping
PFBA 42.9 <LOD <LOD <LOD <LOD
PFPeA 25.0 <LOD <LOD <LOD 18.1
PFHxA 25.0 <LOD <LOD <LOD 43.2
PFHpA 4.1 <LOD <LOD <LOD 20.1
PFOA 20.0 44.0 <LOD 31.3 191.3
PFNA 20.0 14.7 <LOD <LOD 26.9
PFDA 19.3 <LOD <LOD <LOD 69.1
PFUnDA 25.0 <LOD <LOD <LOD 28.0
PFDoDA 10.1 <LOD <LOD <LOD <LOD
PFTrDA 18.5 <LOD <LOD 35.2 114.5
PFTDA 385.4 <LOD <LOD <LOD 171.1
PFHxDA 200.0 <LOD <LOD <LOD 165.2
PFOcDA 500.0 333.7 <LOD <LOD 101.8
PFBS 20.0 <LOD <LOD <LOD 8.2
PFPeS 0.4 <LOD <LOD <LOD <LOD
PFHxS 24.0 5.2 6.6 6.8 7.8
PFHpS 10.2 0.5 1.0 0.4 2.4
PFOS 20.0 29.3 <LOD <LOD 77.8
PFNS 2.0 2.4 <LOD 3.2 11.5
PFDoDS 40.5 <LOD <LOD <LOD 191.8
4:2 FTSA 0.6 <LOD <LOD <LOD 0.9
6:2 FTSA 35.8 80.3 <LOD <LOD <LOD
8:2 FTSA 3.8 8.6 <LOD <LOD 9.2
27 Table A5. The LC gradient and mobile phase composition for both the target and suspect screening analysis. Gradient A% B% Start 99% 1% 1 min 99% 1% 13 min 0% 100% 14 min 0% 100% 17 min 99% 1%
