14 research outputs found
PFAS in the water supply: source water contamination
Water contamination with per- and polyfluoroalkyl substances (PFAS) is a serious problem for water suppliers in many regions. Due to persistence of the substances and a complex distribution mechanism, PFAS can have an adverse impact on water quality. Reported toxicological and health effects, make it very important to minimise the of wildlife and human exposure to PFAS. The exposure path is, however, associated with the most vital resource as water.Mitigation of the PFAS contamination is an extensive challenge that requires a multidisciplinary investigation of the pollution nature and distribution mechanisms in the aquatic environment. Furthermore, since conventional drinking water treatment is insufficient in PFAS removal, development of the treatment alternative is necessary. Not least due to substantial number of contaminated water sources and an increasing worldwide demand on drinking water.Present thesis was built around investigation of the historical source water contamination and human exposure to PFAS at studied locations in Ronneby (primarily) and Luleå in Sweden. Several interconnected studies were conducted regarding present contamination levels, transport and distribution mechanism, contamination and emission history, as well as PFAS treatment alternatives for drinking water.PFAS analysis and assessment of the contamination levels in surface water, groundwater, and sediments were conducted. PFAS occurrence at studied locations was connected to historical use of PFAS containing aqueous film forming foam (PFAS-AFFF). By means of core analysis, accumulation period was studied for the exposed recipient (Lake). Furthermore, influence of the media characteristics (i.e., mineral composition, density, moisture, and organic matter content) on PFAS distribution in sediment was studied and corresponding distribution (partitioning) predictors were estimated. Regarding emission source, profiling of the possible PFAS-AFFF compositions was conducted (based on groundwater analysis), and possible application and emission scenarios were evaluated (based on available fire-training history and related protocols). Investigation of PFAS treatment methods for drinking water was conducted and implementation of ex-situ treatment technique, based on UVC/VUV induced removal, was suggested. The laboratory scale treatment unit was developed and tested in series of experimental trials with PFCAs, PFSAs, FTSAs, and FASAs
PFAS in the Drinking Water Source: Analysis of the Contamination Levels, Origin and Emission Rates
Groundwater contamination caused by the use of the aqueous film-forming foam (AFFF) containing per- and polyfluoroalkyl substances (PFAS) was investigated in southern Sweden. sigma PFAS concentrations in groundwater ranged between 20 and 20,000 ng L-1; PFAS composition was primarily represented by PFOS and PFHxS. The PFAS chain length was suggested to have an impact on the contaminant distribution and transport in the groundwater. PFAS profiling showed that the use of PFSAs- and PFCAs/FTSAs-based PFAS-AFFF can be a contributor to PFAS contamination of the drinking water source (groundwater). PFAS emission was connected to PFAS-AFFF use during the fire-training and fire-fighting equipment tests at the studied location. PFAS emission per individual fire training was (semi-quantitatively) estimated as [1.4 < 11.5 +/- 5.7 < 43.7 kg] (n = 20,000). The annual emission estimates varied as [11 < 401 +/- 233 < 1125 kg yr(-1)] (n = 1005) considering possible [2 < 35 +/- 20 < 96] individual fire-training sessions per year
Impact of the Sediment Organic vs. Mineral Content on Distribution of the Per- and Polyfluoroalkyl Substances (PFAS) in Lake Sediment
Contamination of the water and sediment with per- and polyfluoroalkyl substances (PFAS) was studied for the lake impacted by the release of PFAS-containing aqueous film forming foam (AFFF). PFAS concentrations were analyzed in lake water and sediment core samples. ΣPFAS concentrations were in the range of 95–100 ng L−1 in the lake water and 3.0–61 µg kg−1 dry weight (dw) in sediment core samples, both dominated by perfluorohexane sulfonate, perfluorooctane sulfonate; 6:2 fluortelomer sulfonate was inconsistently present in water and sediment core samples. The sediment–water partitioning coefficients (log Kd) were estimated and ranged 0.6–2.3 L kg−1 for individual perfluoroalkyl carboxylates (PFCAs) and 0.9–5.6 L kg−1 for individual perfluoroalkane sulfonates (PFSAs). The influence of the sediment inorganic content and organic matter on PFAS distribution was investigated. In studied sediments, the mineral content (corresponding to <5% of the bulk media mass) was mainly represented by sulfur, iron and calcium. The PFAS distribution was found strongly connected to the sediment mineral content (i.e., Fe, Pb, Rb and As), whereas the sediment organic carbon content did not to have a direct influence on the PFAS distribution. The aim of this study was to improve our understanding of the PFAS distribution in the natural heterogeneous media
PFAS in the Drinking Water Source: Analysis of the Contamination Levels, Origin and Emission Rates
Groundwater contamination caused by the use of the aqueous film-forming foam (AFFF) containing per- and polyfluoroalkyl substances (PFAS) was investigated in southern Sweden. SPFAS concentrations in groundwater ranged between 20 and 20,000 ng L????1; PFAS composition was primarily represented by PFOS and PFHxS. The PFAS chain length was suggested to have an impact on the contaminant distribution and transport in the groundwater. PFAS profiling showed that the use of PFSAs- and PFCAs/FTSAs-based PFAS-AFFF can be a contributor to PFAS contamination of the drinking water source (groundwater). PFAS emission was connected to PFAS-AFFF use during the fire-training and fire-fighting equipment tests at the studied location. PFAS emission per individual fire training was (semi-quantitatively) estimated as [1.4 < 11.5 5.7 < 43.7 kg] (n = 20,000). The annual emission estimates varied as [11 < 401 233 < 1125 kg yr????1] (n = 1005) considering possible [2 < 35 20 < 96] individual fire-training sessions per year
Impact of the Sediment Organic vs. Mineral Content on Distribution of the Per- and Polyfluoroalkyl Substances (PFAS) in Lake Sediment
Contamination of the water and sediment with per- and polyfluoroalkyl substances (PFAS) was studied for the lake impacted by the release of PFAS-containing aqueous film forming foam (AFFF). PFAS concentrations were analyzed in lake water and sediment core samples. sigma PFAS concentrations were in the range of 95-100 ng L(-1)in the lake water and 3.0-61 mu g kg(-1)dry weight (dw) in sediment core samples, both dominated by perfluorohexane sulfonate, perfluorooctane sulfonate; 6:2 fluortelomer sulfonate was inconsistently present in water and sediment core samples. The sediment-water partitioning coefficients (logK(d)) were estimated and ranged 0.6-2.3 L kg(-1)for individual perfluoroalkyl carboxylates (PFCAs) and 0.9-5.6 L kg(-1)for individual perfluoroalkane sulfonates (PFSAs). The influence of the sediment inorganic content and organic matter on PFAS distribution was investigated. In studied sediments, the mineral content (corresponding to <5% of the bulk media mass) was mainly represented by sulfur, iron and calcium. The PFAS distribution was found strongly connected to the sediment mineral content (i.e., Fe, Pb, Rb and As), whereas the sediment organic carbon content did not to have a direct influence on the PFAS distribution. The aim of this study was to improve our understanding of the PFAS distribution in the natural heterogeneous media
Temporal trends and sediment–water partitioning of per- and polyfluoroalkyl substances (PFAS)in lake sediment
The use of per- and polyfluoroalkyl substances (PFAS)containing aqueous film forming foams (AFFF)at fire training facilities can have an adverse impact on the surrounding environment. The aim of the present study was to study the distribution and temporal trend of 26 PFAS in water and sediment cores for a lake and a pond affected by AFFF release from a fire training facility in Luleå, northern Sweden. In the aqueous phase, maximum ΣPFAS concentration was 1.700 ± 90 ng L −1 . Dominant PFAS groups were perfluoroalkane sulfonates (PFSAs)with 70% of the ΣPFAS, followed by perfluoroalkyl carboxylates (PFCAs, 29%), whereas the contribution of 6:2 fluorotelomer carboxylate (FTSAs)was low (<1%). In the sediment core samples, ΣPFAS concentrations ranged between <1 μg kg −1 dry weight (dw)and 76 μg kg −1 dw, where perfluorooctane sulfonate (PFOS)and perfluorohexane sulfonate (PFHxS)had an average contribution of ∼71% and ∼23% of the ΣPFAS. The sediment core analysis indicated that the PFAS contamination began about 1994 and the highest accumulation rate was observed for the period 2003–2009. The PFAS flux increased from 2.3 μg m −2 yr −1 dw in 1994 to 12 μg m −2 yr −1 dw by 2009. Over the accumulation period 1994–2009, the lake sediment surface received 213 μg m −2 dw for ƩPFAS, where PFOS contributed with 125 μg m −2 yr −1 dw and PFHxS with 65 μg m −2 dw. Results point to that sediment cores collected near PFAS hotspot areas can be used as a contamination record to reconstruct release history
Degradation of 75 organic micropollutants in fresh human urine and water by UV advanced oxidation process
In household wastewater, a large proportion of organic micropollutants (OMPs) load is attributed to human urine. OMPs could pose a risk to human and environmental health when urine collected in source-separating sanitation systems is recycled as crop fertiliser. This study evaluated degradation of 75 OMPs in human urine treated by a UV-based advanced oxidation process. Fresh urine and water samples were spiked with a broad range of OMPs and fed into a photoreactor equipped with a UV lamp (185 and 254 nm) that generated free radicals in situ. Degradation rate constant and the energy required to degrade 90% of all the OMPs in both matrices were determined. At a UV dose of 2060 J m-2, average & sigma;OMP degradation of 99% (& PLUSMN;4%) in water and 55% (& PLUSMN;36%) in fresh urine was achieved. The energy demand for removal of OMPs in water was <1500 J m-2, but for removal of OMPs in urine at least 10-fold more energy was needed. A combination of photolysis and photo-oxidation can explain the degradation of OMPs during UV treatment. Organic substances (e.g. urea, creatinine) likely inhibited degradation of OMPs in urine by competitively absorbing UV-light and scavenging free radicals. There was no reduction in the nitrogen content of urine during treatment. In summary, UV treatment can reduce the load of OMPs to urine recycling sanitation systems
Impact of the Sediment Organic vs. Mineral Content on Distribution of the Per- and Polyfluoroalkyl Substances (PFAS) in Lake Sediment
Contamination of the water and sediment with per- and polyfluoroalkyl substances (PFAS) was studied for the lake impacted by the release of PFAS-containing aqueous film forming foam (AFFF). PFAS concentrations were analyzed in lake water and sediment core samples. ΣPFAS concentrations were in the range of 95-100 ng L-1 in the lake water and 3.0-61 µg kg-1 dry weight (dw) in sediment core samples, both dominated by perfluorohexane sulfonate, perfluorooctane sulfonate; 6:2 fluortelomer sulfonate was inconsistently present in water and sediment core samples. The sediment-water partitioning coefficients (log Kd) were estimated and ranged 0.6-2.3 L kg-1 for individual perfluoroalkyl carboxylates (PFCAs) and 0.9-5.6 L kg-1 for individual perfluoroalkane sulfonates (PFSAs). The influence of the sediment inorganic content and organic matter on PFAS distribution was investigated. In studied sediments, the mineral content (corresponding to <5% of the bulk media mass) was mainly represented by sulfur, iron and calcium. The PFAS distribution was found strongly connected to the sediment mineral content (i.e., Fe, Pb, Rb and As), whereas the sediment organic carbon content did not to have a direct influence on the PFAS distribution. The aim of this study was to improve our understanding of the PFAS distribution in the natural heterogeneous media