We investigated perfluorinated carboxylic acids (PFCAs) with 7-14 carbon atoms (C7-C14) in the Yodo River system in 2013. C7-C11 were detected at most sampling sites. The range and median of total PFCAs (ΣPFCAs) concentrations were 1.0-89.7 and 11.2 ng L(-1), respectively. The dominant component was C8 (average for all samples=53.3±8.8%), followed by C7 (19.2±6.7%) and C9 (17.6±7.1%). The levels of C8 were confirmed to decrease greatly over the last 10 years. We assessed the fluxes in C7-C11 discharged from the basin based on the concentrations in river water and river flow rate. The flux of discharged ΣPFCAs was 237.0 g d(-1) at the most downriver point of the assessment areas. Considering the variability in flow rate due to precipitation, the annual ΣPFCAs flux was estimated to be 86.5-173.4 kg y(-1). Identification and quantification of PFCAs sources is difficult because the strength of the sources changes with time, and available information is quite limited. Further monitoring and investigation are necessary to understand sources of PFCAs, as well as their potential for human exposure.
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http://dx.doi.org/10.1016/j.chemosphere.2015.05.060 | DOI Listing |
Sci Total Environ
January 2025
US Geological Survey, New England Water Science Center, Northborough, MA, USA.
Groundwater-dependent ecosystems in areas with industrial land use are at risk of exposure to a PFAS chemicals. We investigated one such system with several known PFAS source areas, where high and low permeability sediments (glacial) coupled with groundwater-lake and groundwater/surface-water interactions created complex 'source to seep' dynamics. Using heat-tracing and chemical methods, numerous preferential groundwater discharge zones were identified and sampled across the upper Quashnet River stream-wetland system in Mashpee, MA, USA, downgradient of Joint Base Cape Cod (JBCC).
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Université Paris-Saclay, CNRS, Institut de Chimie Moléculaire et des Matériaux d'Orsay, Orsay, 91400, France.
To efficiently capture, activate, and transform small molecules, metalloenzymes have evolved to integrate a well-organized pocket around the active metal center. Within this cavity, second coordination sphere functionalities are precisely positioned to optimize the rate, selectivity, and energy cost of catalytic reactions. Inspired by this strategy, an artificial distal pocket defined by a preorganized 3D strap is introduced on an iron-porphyrin catalyst (sc-Fe) for the CO-to-CO electrocatalytic reduction.
View Article and Find Full Text PDFEnviron Res
January 2025
Institute of Food Safety, Animal Health and Environment "BIOR", Lejupes iela 3, Riga, LV-1076, Latvia.
This study was performed to evaluate the occurrence of perfluorinated substances (PFAS) in European perch (Perca fluviatilis) samples from Latvian freshwater bodies. Twenty-nine samples of perch tissue homogenates were analyzed on the content of PFAS representing different sampling sites to cover all territory of Latvia evenly. The total PFAS concentrations (∑) ranged from 0.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States.
Radical-radical reaction channels are important in the pyrolysis and oxidation chemistry of perfluoroalkyl substances (PFAS). In particular, unimolecular dissociation reactions within unbranched -perfluoroalkyl chains, and their corresponding reverse barrierless association reactions, are expected to be significant contributors to the gas-phase thermal decomposition of families of species such as perfluorinated carboxylic acids and perfluorinated sulfonic acids. Unfortunately, experimental data for these reactions are scarce and uncertain.
View Article and Find Full Text PDFACS Nano
January 2025
Key Laboratory of Materials Chemistry for Energy Conversion and Storage of Ministry of Education (HUST), Hubei Key Laboratory of Materials Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China.
Bicontinuous microparticles have advanced transport, mechanical, and electrochemical properties and show promising applications in energy storage, catalysis, and other fields. However, it remains a great challenge to fabricate bicontinuous microparticles of block copolymers (BCPs) by controlling the microphase separation due to the extremely narrow region of a bicontinuous structure in the phase diagram. Here, we demonstrate a strategy to balance the phase separation of BCPs and fluorinated additives at different length scales in emulsion droplets, providing a large window to access bicontinuous microparticles.
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