Beyond target chemicals: updating the NORMAN prioritisation scheme to support the EU chemicals strategy with semi-quantitative suspect/non-target screening data

Background Prioritisation of chemical pollutants is a major challenge for environmental managers and decision-makers alike, which is essential to help focus the limited resources available for monitoring and mitigation actions on the most relevant chemicals. This study extends the original NORMAN prioritisation scheme beyond target chemicals, presenting the integration of semi-quantitative data from retrospective suspect screening and expansion of existing exposure and risk indicators. The scheme utilises data retrieved automatically from the NORMAN Database System (NDS), including candidate substances for prioritisation, target and suspect screening data, ecotoxicological effect data, physico-chemical data and other properties. Two complementary workflows using target and suspect screening monitoring data are applied to first group the substances into six action categories and then rank the substances using exposure, hazard and risk indicators. The results from the 'target' and 'suspect screening' workflows can then be combined as multiple lines of evidence to support decision-making on regulatory and research actions. Results As a proof-of-concept, the new scheme was applied to a combined dataset of target and suspect screening data. To this end, > 65,000 substances on the NDS, of which 2579 substances supported by target wastewater monitoring data, were retrospectively screened in 84 effluent wastewater samples, totalling > 11 million data points. The final prioritisation results identified 677 substances as high priority for further actions, 7455 as medium priority and 326 with potentially lower priority for actions. Among the remaining substances, ca. 37,000 substances should be considered of medium priority with uncertainty, while it was not possible to conclude for 19,000 substances due to insufficient information from target monitoring and uncertainty in the identification from suspect screening. A high degree of agreement was observed between the categories assigned via target analysis and suspect screening-based prioritisation. Suspect screening was a valuable complementary approach to target analysis, helping to prioritise thousands of substances that are insufficiently investigated in current monitoring programmes. Conclusions This updated prioritisation workflow responds to the increasing use of suspect screening techniques. It can be adapted to different environmental compartments and can support regulatory obligations, including the identification of specific pollutants in river basins and the marine environments, as well as the confirmation of environmental occurrence levels predicted by modelling tools

Drinking water nanofiltration with concentrate foam fractionation-A novel approach for removal of per- and polyfluoroalkyl substances (PFAS)

Per-and polyfluoroalkyl substances (PFAS) are recognized as persistent pollutants that have been found in drinking water sources on a global scale. Semi-permeable membrane treatment processes such as reverse osmosis and nanofiltration (NF) have been shown effective at removing PFAS, however, disposal of PFAS laden concentrate is problematic. Without treatment of the concentrate, PFAS is released into the environment. The present work examined a novel PFAS removal scheme for drinking water using NF filtration with treatment of the resulting NF concentrate via foam fractionation (FF) with and without co-surfactants. The NF-pilot removed 98% of PFAS from AFFF contaminated groundwater producing permeate with 1.4 ng L-1 total PFAS. Using FF resulted in EPFAS removal efficiency of 90% from the NF concentrate and with improved removal of 94% with addition of cationic co-surfactant. The resulting foamate composed approximately 2% of the NF feedwater volume and contained greater than 3000 ng L-1 PFAS or 41 times greater than the NF feedwater. Addition of the cationic co-surfactant to the FF process resulted in increased removal efficiency of the shorter chain PFAS, specifically 37% for PFPeA, 9% for PFHxA, and 34% for PFBS thus attaining 59%, 99% and 96% removal efficiency, respectively. PFOA, PFPeS, PFHxS, PFOS each attained 99% FF removal with or without co-surfactant addition

Use of lignocellulosic substrate colonized by oyster mushroom (Pleurotus ostreatus) for removal of organic micropollutants from water

Efficient removal techniques are urgently needed to remove organic micropollutants (OMPs) from wastewater, in order to protect water resources. In this study, laccase activity of mushroom substrate colonized by Pleurotus ostreatus was evaluated as a novel wastewater treatment method for removal of OMPs, including diclofenac, bicalutamide, lamotrigine, and metformin at environmentally relevant concentrations. Laccase activity of the colonized mushroom substrate was found to be highest, 0.8 enzyme activity (U)/g mushroom substrate wet weight, immediately before initiation of fruiting body formation. The selected OMPs were treated for 5 min with suspensions of mushroom substrate with laccase activity of approximately 50 U/L. Removal of all OMPs was significant, with the highest removal for diclofenac of 90% compared with a control with uncolonized mushroom substrate. To our knowledge, direct use of colonized mushroom substrate in removing diclofenac from water has not been reported previously. Removal efficiency of bicalutamide, lamotrigine, and metformin was 43%, 73%, and 59%, respectively. This demonstrates potential for using mushroom substrate colonized by P. ostreatus for removal of OMPs from wastewater

Foam fractionation removal of multiple per- and polyfluoroalkyl substances from landfill leachate

Per- and polyfluoroalkyl substances (PFAS) are a common contaminant inmunicipal landfill leachate and are recognized as a pollutant on global scale.The present work examined foam fractionation (FF) in batch and continuousmodes as an appropriate treatment technique for PFAS removal for the landfillleachate and found stable removal efficiency of greater than 90% for PFOA(C7), PFOS (C8), PFHxS (C6), and PFHpA (C6) and 6:2 FTSA (C6). For otherPFAS such as PFNA (C8), PFPeS (C4), PFHxA (C5), PFHpS (C7), and PFBS(C4), a less stable removal between 80% and 50% was achieved while between50% and 20% removal was observed for EtFOSAA (C8), PFBA (C3), PFDA (C9),FOSA (C8), PFPeA (C4), and MeFOSAA (C8). Increased air flowrate, additionof iron (III) oxide (Fe+3) coagulant, conductivity, and greater untreated leach-ate PFAS concentration were factors resulting in increased removal efficiencyfor the majority of PFAS

A novel method for extraction, clean-up and analysis of per- and polyfluoroalkyl substances (PFAS) in different plant matrices using LC-MS/MS

Per- and polyfluoroalkyl substances (PFAS) are chemicals of concern due to their persistence, bioaccumulation, and toxic properties. PFAS accumulation in plants poses a risk of human and animal exposure due to consumption of the affected plants, but also allows plants to be used in remediation of PFAS-contaminated soils and groundwater. Therefore, effective extraction, cleanup, and analytical methods for measuring PFAS concentrations in plants are fundamental for research on animal and environmental health. PFAS analysis in plant matrices is complex, due to high matrix interference, and scarcity of methods for analyzing different classes of PFAS. In this study, a simple sample preparation method for PFAS analysis in various plant tissues (leaves, needles, twigs, stems, roots from 10 different species) was developed and validated. Instrumental analysis was performed using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The method was optimized considering six different extraction conditions and three different cleanup techniques. Methanol as extraction solvent, combined with 1 g ENVI carb cartridges, showed best performance among all extraction conditions and cleanup techniques tested. Method validation showed good recovery (90–120%), high within-day and between-day precision (−1 dry weight (dw)) for different plant matrices. In tests of the method on soil and different plant tissues of silver birch (Betula pendula) and Norway spruce (Picea abies) at a PFAS-contaminated site, 16 of 24 target PFAS were detected in plants and 17 in soil. ƩPFAS concentration in soil was 43 ng g−1 dw. PFAS distribution in silver birch tissues ranged from 7.1 ng g−1 dw in roots to 64 ng g−1 dw in leaves, and in Norway spruce from 14 ng g−1 dw in roots to 16 ng g−1 dw in needles. This novel method for PFAS analysis in plants can be valuable in future monitoring, process understanding, remediation, and risk assessments

Thermal desorption as a high removal remediation technique for soils contaminated with per- and polyfluoroalkyl substances (PFASs)

Soils contaminated with per- and polyfluoroalkyl substances (PFASs) are an important source for impacting drinking water delivery systems and surface water bodies world-wide, posing an urgent risk to human health and environmental quality. However, few treatment techniques have been tested for PFAS-contaminated soil hotspots. This study investigated the possibility of thermal desorption as a possible technique to remediate soils contaminated with multiple PFASs. Two fortified soils ( n-ary sumation (9)PFAS approximate to 4 mg kg(-1)) and one field-contaminated soil ( n-ary sumation (9)PFAS approximate to 0.025 mg kg(-1)) were subjected to a 75-min thermal treatment at temperatures ranging from 150 to 550 degrees C. Soil concentrations of PFASs showed a significant decrease at 350 degrees C, with the n-ary sumation (9)PFAS concentration decreasing by, on average, 43% and 79% in the fortified and field contaminated soils, respectively. At 450 degrees C, >99% of PFASs were removed from the fortified soils, while at 550 degrees C the fraction removed ranged between 71 and 99% for the field contaminated soil. In the field contaminated soil, PFAS classes with functional groups of sulfonates (PFSAs) and sulfonamides (FOSAs) showed higher removal than the perfluoroalkyl carboxylates (PFCAs). Thus thermal desorption has the potential to remove a wide variety of PFASs from soil, although more studies are needed to investigate the cost-effectiveness, creation of transformation products, and air-phase vacuum filtration techniques

Suspect screening and total oxidizable precursor (TOP) assay as tools for characterization of per- and polyfluoroalkyl substance (PFAS)-contaminated groundwater and treated landfill leachate

Landfill facilities are a major source of release of per- and polyfluoroalkyl substances (PFAS) to the surrounding environment. In this study, landfill leachate treated in a conventional wastewater treatment plant and PFAScontaminated groundwater were subjected to suspect screening analysis and semi-quantification using total oxidizable precursor (TOP) assay and liquid chromatography coupled to high-resolution mass spectrometry (LCHRMS). TOP assays yielded expected results for legacy PFAS and their precursors, but showed no discernible evidence of degradation of perfluoroethylcyclohexane sulfonic acid. TOP assays also produced significant evidence of presence of precursors in both treated landfill leachate and groundwater, but the majority of precursors had probably degraded into legacy PFAS after many years in the landfill. Suspect screening identified a total of 28 PF AS, of which six were not included in the targeted method and were identified with confidence level (CL) ≥3. Semi-quantification of these six compounds showed very low concentrations, indicating that they are not as great a concern as the target PFAS

Environmental distribution of per- and polyfluoroalkyl substances (PFAS) on Svalbard: Local sources and long-range transport to the Arctic

The environmental distribution of per- and polyfluoroalkyl substances (PFAS) in water, snow, sediment and soil samples taken along the west coast of Spitsbergen in the Svalbard archipelago, Norwegian Arctic, was determined. The contribution of potential local primary sources (wastewater, firefighting training site at Svalbard airport, landfill) to PFAS concentrations and long-range transport (atmosphere, ocean currents) were then compared, based on measured PFAS levels and composition profiles. In remote coastal and inland areas of Spitsbergen, meltwater had the highest mean ΣPFAS concentration (6.5 ± 1.3 ng L−1), followed by surface snow (2.5 ± 1.7 ng L−1), freshwater (2.3 ± 1.1 ng L−1), seawater (1.05 ± 0.64 ng L−1), lake sediments (0.084 ± 0.038 ng g−1 dry weight (dw)) and marine sediments (−1 dw, median 0.015 ng g−1 dw). Perfluoroalkyl sulfonates (PFSA) and 6:2 fluorotelomer sulfonate (FTSA) were predominant in water and soil samples influenced by local sources, while perfluoroalkyl carboxylates (PFCA) were predominant in water and sediment from remote coastal and inland areas of Svalbard. The PFAS composition profiles observed in remote areas indicated that atmospheric transport and oxidation of volatile precursors is an important source of PFCA on Svalbard. Shorter-chain PFAS such as perfluorobutanoate (PFBA) were the predominant PFAS in freshwater, reflecting replacement of C8-chained PFAS with shorter-chained compounds. The comparatively high PFAS (especially PFBA) concentration in meltwater indicated that melting of snow and ice during the Arctic spring is an important diffuse local PFAS source. This source may become even more important with climate warming-induced melting of Arctic glaciers and ice sheets. Further studies of mobilisation and transport of PFAS in the Arctic region are needed to confirm this trend

Electrokinetic remediation for removal of per- and polyfluoroalkyl substances (PFASs) from contaminated soil

Uncontrolled use and disposal of per-and polyfluoroalkyl substances (PFASs) in recent decades has resulted in extensive soil and groundwater contamination, necessitating counteraction. Electrokinetic remediation (EKR) offers a promising approach to in-situ soil remediation. Two novel modifications to conventional EKR were tested for the first time in a laboratory-scale study, to explore the capacity of EKR for PFAS removal. The first modi-fication was a two-compartment setup designed for PFAS extraction from soil to an electrolyte-filled chamber. The second was a single-compartment setup designed to transport and confine contaminants in a chamber filled with granular activated carbon (GAC), thus, combining extraction with stabilisation. Electromigration varied for individual compounds, based mainly on perfluorocarbon chain length and functional group. The results indicated up to 89% concentration and extraction of n-ary sumation PFASs for the two-compartment setup, with removal efficiency reaching 99% for individual PFASs with C <= 6. Removed PFASs were concentrated adjacent to the anode at the anion exchange membrane, while short-chain compounds were extracted in the anolyte. The single-compartment setup achieved 75% extraction and accumulation of n-ary sumation PFASs in GAC. This demonstrates, for the first time, good effectiveness of coupling EKR with AC stabilisation for PFAS removal from soil. Perfluorocarbon chain length was a dominant factor affecting treatment efficiency in both setups, with very high removal rates for short-chain PFASs