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Release of persistent and potentially toxic per- and polyfluoroalkyl substances (PFAS) and other halogenated compounds into the aqueous environment is an emerging issue and advanced treatment methods are needed for their removal from contaminated water. Destructive treatment methods for PFAS exist, but there is a risk of incomplete degradation, resulting in creation of transformation products during treatment. This study assessed the potential of electrochemical oxidation (EO) for destruction of PFAS and other halogenated compounds, and their transformation products. Suspect and non-target screening were used to explore the chemical space of these samples and identify compounds present before and after the treatment, including transformation products. In total, 21 PFAS classes and 53 individual PFAS were identified using suspect and non-target screening, with confidence level (CL) 3d or higher. Two new classes of PFAS (FASHN and MeOH-FASA) were discovered for the first time. Suspect screening of PFAS revealed that hydro-substituted and ether PFAS could be formed during EO. A total of 12 chlorinated and two brominated compounds were also detected and confirmed with CL 1-3, with six compounds determined to be transformation products. Formation of ammonium oxidation byproducts was hypothesized as being responsible for most identified transformation products formed during EO., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Per- and polyfluoroalkyl substances (PFAS) are widespread pollutants that can influence microorganisms. To unveil the effects of PFAS in natural microecosystems, a study that focused on the bacterial, fungal, and microeukaryotic communities around the PFAS point source was conducted in China. A total of 255 specific taxa were significantly different between the upstream and downstream samples, 54 of which were directly correlated with PFAS concentration. Stenotrophomonas (99.2 %), Ralstonia (90.7 %), Phoma (21.9 %), and Alternaria (97.6 %) were the dominant genera in sediment samples from the downstream communities. In addition, most of the dominant taxa were significantly correlated with PFAS concentration. Furthermore, the type of microorganism (bacteria, fungi, and microeukaryotes) and habitat (sediment or pelagic) also influence the microbial community responses to PFAS exposure. Pelagic microorganisms featured more PFAS-correlated biomarker taxa (36 pelagic microeukaryotic biomarkers and 8 pelagic bacteria biomarkers) than the sediments (9 sediment fungi biomarkers and 5 sediment bacteria biomarker). In general, around the factory, the microbial community was more variable in pelagic, summer, and microeukaryotic conditions than in other types. Attention needs to be paid to these variables in the future effect of PFAS on microorganisms., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Persistent, mobile, and toxic (PMT) substances have recently garnered increased attention by environmental researchers, the water sector and environmental protection agencies. In this study, acute and chronic species sensitivity distributions (SSDs) were retrieved from literature data for previously quantified contaminants of emerging concern (CECs) in Swedish surface waters (n = 92) and risk quotients (RQ) were calculated. To better understand the characteristics of the detected CECs in non-urban lake sites (n = 71), these compounds were checked against established criteria for potentially toxic PMs (PM(T)s) and occurrence in the aquatic environment, respectively. For the CECs with missing SSDs (n = 15 [acute], n = 41 [chronic]), ecotoxicity data were extracted for eight taxonomic groups, and if data were sufficient (n ≥ 3), SSDs were derived. The retrieved and newly developed SSDs were then used in an environmental hazard assessment (EHA) in the investigated Swedish rivers and lakes. In the rivers, 8 CECs had RQ> 1 in at least one location, and 20 CECs posed a moderate risk (0.01 < RQ < 1). In total, 21 of the 71 detected substances had already been identified as PM(T)/vPvM substances. Our study shows the importance of studying field data at large spatial scale to reveal potential environmental hazards far from source areas., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Concerns about environmental contamination by organic micropollutants (OMPs) are increasing, due to their potential bioaccumulative and toxic properties. This study evaluated the risk posed by OMPs to aquatic ecosystems in Swedish freshwaters. The assessment was based on measured environmental concentrations (MEC) of OMPs in surface waters upstream and downstream of Swedish wastewater treatment plants (WWTPs). A novel optimised risk quotient (RQ f ) was used to identify potential high-risk substances in the aquatic environment. A secondary objective was to assess the impact of WWTP effluent on aquatic ecosystems using a novel impact factor (I) based on the risk quotient (RQ). Among the 126 substances investigated, four compounds (metformin, N,N-dimethyltetradecylamine, oxazepam, and venlafaxine) were identified as likely to pose a risk to aquatic ecosystems in Swedish surface waters (RQ f >1), and five compounds (clindamycin, gemfibrozil, sertraline, o-desmethylvenlafaxine, and diclofenac) were identified as posing a moderate risk to aquatic ecosystems ( 0.1 f <1). WWTP effluent appeared to pose an environmental risk for all recipient sites, but the impact of calculated RQ was site-specific. These results can be used by authorities to prioritise OMPs and contaminated hotspots, in order to decrease negative impacts on aquatic ecosystems. SYNOPSIS: A novel optimised risk assessment approach for identification of high-concern organic micropollutants in aquatic environments., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Environmental monitoring studies based on target analysis capture only a small fraction of contaminants of emerging concern (CECs) and miss pollutants potentially harmful to wildlife. Environmental specimen banks, with their archived samples, provide opportunities to identify new CECs by temporal trend analysis and non-target screening. In this study, archived white-tailed sea eagle (Haliaeetus albicilla) muscle tissue was analysed by non-targeted high-resolution mass spectrometry. Univariate statistical tests (Mann-Kendall and Spearman rank) for temporal trend analysis were applied as prioritisation methods. A workflow for non-target data was developed and validated using an artificial time series spiked at five levels with gradient concentrations of selected CECs (n = 243). Pooled eagle muscle tissues collected 1965-2017 were then investigated with an eight-point time series using the validated screening workflow. Following peak detection, peak alignment, and blank subtraction, 14 409 features were considered for statistical analysis. Prioritisation by time-trend analysis detected 207 features with increasing trends. Following unequivocal molecular formula assignment to prioritised features and further elucidation with MetFrag and EU Massbank, 13 compounds were tentatively identified, of which four were of anthropogenic origin. These results show that it is possible to prioritise new CECs in archived biological samples using univariate statistical approaches., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Remediation of soil contaminated with per- and polyfluoroalkyl substances (PFAS) is critical due to the high persistence and mobility of these compounds. In this study, stabilization and solidification (S/S) treatment was evaluated at pilot-scale using 6 tons of soil contaminated with PFAS-containing aqueous film-forming foam. At pilot-scale, long-term PFAS removal over 6 years of precipitation (simulated using irrigation) in leachate from non-treated contaminated reference soil and S/S-treated soil with 15 % binder and 0.2 % GAC was compared. PFAS removal rate from leachate, corresponding to reduction in leaching potential after 6 years, was >97 % for four dominant PFASs (perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorohexanesulfonic acid (PFHxS) and perfluorooctanesulfonic acid (PFOS)), but low (3%) for short-chain perfluoropentanoic acid (PFPeA). During the pilot-scale experiment, PFAS sorption strength (i.e., soil-water partitioning coefficient (K d )) increased 2- to 40-fold for both reference and S/S-treated soil, to much higher levels than in laboratory-scale tests. However, PFAS behavior in pilot-scale and laboratory-scale tests was generally well-correlated (p < 0.001), which will help in future S/S recipe optimization. In addition, seven PFASs were tentatively identified using an automated suspect screening approach. Among these, perfluorohexanesulfonamide and 3:2 fluorotelomer alcohol were tentatively identified and the latter had low removal rates from leachate (<12 %) in S/S treatment., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

To date, there is no analytical approach available that allows the full identification and characterization of highly complex disinfection by-product (DBP) mixtures. This study aimed at investigating the chemodiversity of drinking water halogenated DBPs using diverse analytical tools: measurement of adsorbable organic halogen (AOX) and mass spectrometry (MS)-based target and non-target analytical workflows. Water was sampled before and after chemical disinfection (chlorine or chloramine) at four drinking water treatment plants in Sweden. The target analysis had the highest sensitivity, although it could only partially explain the AOX formed in the disinfected waters. Non-target Fourier transform ion cyclotron resonance (FT-ICR) MS analysis indicated that only up to 19 Cl and/or Br-CHO formulae were common to all disinfected waters. Unexpectedly, a high diversity of halogenated DBPs (presumed halogenated polyphenolic and highly unsaturated compounds) was found in chloraminated surface water, comparable to that found in chlorinated surface water. Overall, up to 86 DBPs (including isobaric species) were tentatively identified using liquid chromatography (LC)-Orbitrap MS. Although further work is needed to confirm their identity and assess their relevance in terms of toxicity, they can be used to design suspect lists to improve the characterization of disinfected water halogenated mixtures., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Wastewater treatment plants (WWTPs) are known point sources of contaminants of emerging concern (CECs) to the aquatic environment, but current knowledge is mostly limited to well-known chemical structures. In this study, we sought to identify unknown CECs polluting the aquatic environment through a novel suspect screening approach for organohalogens, i.e. organic halogenated molecules often toxic and resistant to transformation and characterised as persistent organic pollutants (POPs). Surface water samples were collected with passive samplers in the Fyris River catchment (Uppsala, Sweden), analysed using liquid chromatography high-resolution mass spectrometry (LC-HRMS) and screened for organohalogens using a suspect screening approach based on market data obtained from a regulatory authority. Thirteen suspects from very different application areas were confirmed or tentatively identified with high confidence, including seven previously unknown structures (diflufenican, chlorzoxazone, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, 2,4-disulfamyl-5-trifluoromethylaniline, 5-amino-2-chlorotoluene-4-sulfonic acid, perfluoropentane-1-sufonic acid, (2-chlorophenyl)(hydroxy)methanesulfonic acid). Spatiotemporal occurrence patterns were detected, which helped to understand the usage pattern of the chemicals and pinpoint potential pollution sources, e.g. specific WWTPs in the catchment. Several of the newly identified structures had virtually no information publicly available and were detected years after their last registered use, which highlights the knowledge gaps and concerns about POPs., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Remediation methods for soils contaminated with poly- and perfluoroalkyl substances (PFASs) are urgently needed to protect the surrounding environment and drinking water source areas from pollution. In this study, the stabilization and solidification (S/S) technique was tested on aged PFAS-contaminated soil that were artificially spiked with 14 PFAS. To further reduce leaching of PFASs in S/S-treated soil, seven different additives were tested at 2% concentration: powdered activated carbon (PAC), Rembind®, pulverized zeolite, chitosan, hydrotalcite, bentonite, and calcium chloride. Standardized leaching tests on S/S-treated soil revealed that leaching of 13 out of 14 target PFASs (excluding perfluorobutane sulfonate (PFBA)) was reduced by, on average, 70% and 94% by adding PAC and Rembind®. Longer-chained PFASs such as perfluorooctane sulfonate (PFOS), which is considered persistent, bioaccumulative and toxic, were stabilized by 99.9% in all S/S treatments when PAC or Rembind® was used as an additive. The S/S stabilization efficiency depended on PFAS perfluorocarbon chain length and functional group, e.g., it increased on average by 11-15 % per CF 3 -moeity and was on average 49% higher for the perfluorosulfonates (PFSAs) than the perfluorocarboxylates (PFCAs). Overall, the S/S treatment with active carbon-based additives showed excellent performance in reducing leaching of PFASs, without marked loss of physical matrix stability., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The aim of this study was to calibrate and apply polar organic chemical integrative samplers (POCIS) to examine 26 per- and polyfluoroalkyl substances (PFASs) in a drinking water treatment plant (DWTP). As a first step, the sampling rates (R s ) of 14 PFASs were determined in a laboratory calibration study for POCIS-WAX (weak-anion exchange) and POCIS-HLB (hydrophilic-lipophilic balance) (each with a surface area per mass of sorbent ratio of 227 cm 2  g -1 ). While most PFASs were still in the linear uptake phase during the 28-day calibration study, R s ranged from 0.003 to 0.10 L d -1 for POCIS-WAX and 0.00052 to 0.13 for POCIS-HLB. It is important to note that POCIS-WAX had higher R s for short-chain perfluoroalkyl carboxylates (PFCAs) with a perfluorocarbon chain length of C 3 -C 6 and perfluorobutane sulfonate (PFBS) compared with POCIS-HLB. Furthermore, R s was significantly positively correlated with the sorbent-water partition coefficient (K pw ) for POCIS-WAX and POCIS-HLB (p < 0.0001). Use of POCIS-WAX and POCIS-HLB in the DWTP showed good agreement with composite water sampling. No removal of PFASs was observed in the full-scale DWTP. Overall, this is the first study of PFAS monitoring in a DWTP using two types of POCIS. The results demonstrate high suitability for future applications., (Copyright © 2018 Elsevier B.V. All rights reserved.)

A comprehensive screening of micropollutants was performed in wastewaters from on-site sewage treatment facilities (OSSFs) and urban wastewater treatment plants (WWTPs) in Sweden. A suspect screening approach, using high resolution mass spectrometry, was developed and used in combination with target analysis. With this strategy, a total number of 79 micropollutants were successfully identified, which belong to the groups of per- and polyfluoroalkyl substances (PFASs), pesticides, phosphorus-containing flame retardants (PFRs) and pharmaceuticals and personal care products (PPCPs). Results from this screening indicate that concentrations of micropollutants are similar in influents and effluents of OSSFs and WWTPs, respectively. Removal efficiencies of micropollutants were assessed in the OSSFs and compared with those observed in WWTPs. In general, removal of PFASs and PFRs was higher in package treatment OSSFs, which are based on biological treatments, while removal of PPCPs was more efficient in soil bed OSSFs. A novel comprehensive prioritization strategy was then developed to identify OSSF specific chemicals of environmental relevance. The strategy was based on the compound concentrations in the wastewater, removal efficiency, frequency of detection in OSSFs and on in silico based data for toxicity, persistency and bioaccumulation potential., (Copyright © 2016 Elsevier B.V. All rights reserved.)