1
|
Arshadi M, Garza-Rubalcava U, Guedes A, Cápiro NL, Pennell KD, Christ J, Abriola LM. Modeling 1-D aqueous film forming foam transport through the vadose zone under realistic site and release conditions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 919:170566. [PMID: 38331271 DOI: 10.1016/j.scitotenv.2024.170566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 01/12/2024] [Accepted: 01/28/2024] [Indexed: 02/10/2024]
Abstract
Aqueous film forming foams (AFFFs) have been used to extinguish fires since the 1960s, leading to widespread subsurface contamination by per- and polyfluoroalkyl substances (PFAS), an essential component of AFFF. This study presents 1-D simulations of PFAS migration in the vadose zone resulting from AFFF releases. Simulation scenarios used soil profiles from three US Air Force (USAF) installations, encompassing a range of climatic conditions and hydrogeologic environments. A three-component mixture, representative of major constituents of AFFF, facilitated the exploration of competitive and synergistic effects of co-constituents on PFAS migration. To accurately capture unsaturated transport of PFAS in porous media, the model considers (1) surfactant-induced flow, (2) non-linear sorption to the solid phase, (3) competitive accumulation at the air-water interface, and (4) the moisture-dependence of the air-water interfacial area. Defined PFAS releases were consistent with fire training exercises, emergency responses, and accidental spills of record. Simulation results illustrate the importance of hydrogeologic, climatic, geochemical, and AFFF release conditions on PFAS transport and retention. Comparison of field observations and model simulations for Ellsworth AFB indicate that much of the PFOA and PFOS mass is associated with the air-water interface and the solid phase, which limits their migration potential in the vadose zone. Results also show that rates of migration in the aqueous phase are largely controlled by hydrogeologic properties, including recharge rates and hydraulic conductivity. AFFF spill scenarios varying in volume, concentration, and frequency reveal the importance of release characteristics in determining rates of PFAS migration and concentration peaks. Variability is attributed to non-linear sorption processes, where, contrary to simple linear partitioning formulations, transport is strongly affected by the concentration of PFAS species. Simulations also demonstrate the importance of modeling the AFFF as a mixture since competitive interfacial accumulation effects are shown to enhance the mobility of less surface-active PFAS compounds.
Collapse
Affiliation(s)
- Masoud Arshadi
- Department of Civil and Environmental Engineering, Tufts University, Medford, MA 02155, United States
| | | | - Ana Guedes
- Department of Civil and Environmental Engineering, Tufts University, Medford, MA 02155, United States
| | - Natalie L Cápiro
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, United States
| | - Kurt D Pennell
- School of Engineering, Brown University, Providence, RI 02912, United States
| | - John Christ
- S&B Christ Consulting, Las Vegas, NV 89134, United States
| | - Linda M Abriola
- School of Engineering, Brown University, Providence, RI 02912, United States.
| |
Collapse
|
2
|
Bierbaum T, Hansen SK, Poudel B, Haslauer C. Investigating rate-limited sorption, sorption to air-water interfaces, and colloid-facilitated transport during PFAS leaching. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:121529-121547. [PMID: 37957494 PMCID: PMC10724089 DOI: 10.1007/s11356-023-30811-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 10/28/2023] [Indexed: 11/15/2023]
Abstract
Various sorption processes affect leaching of per- and polyfluoroalkyl substances (PFAS) such as PFOA and PFOS. The objectives of this study are to (1) compare rate-limited leaching in column and lysimeter experiments, (2) investigate the relevance of sorption to air-water interfaces (AWI), and (3) examine colloid-facilitated transport as a process explaining early experimental breakthrough. A continuum model (CM) with two-domain sorption is used to simulate equilibrium and rate-limited sorption. A random walk particle tracking (PT) model was developed and applied to analyze complex leaching characteristics. Results show that sorption parameters derived from column experiments underestimate long-term PFOA leaching in lysimeter experiments due to early depletion, suggesting that transformation of precursors contributes to the observed long-term leaching in the lysimeters (approximately 0.003 µg/kg/d PFOA). Both models demonstrate that sorption to AWI is the dominant retention mechanism for PFOS in lysimeter experiments, with retardation due to AWI being 3 (CM) to 3.7 (PT) times higher than retardation due to solid phase sorption. Notably, despite a simplified conception of AWI sorption, the PT results are closer to the observations. The PT simulations demonstrate possible colloid-facilitated transport at early time; however, results using substance-specific varying transport parameters align better with the observations, which should be equal if colloid-facilitated transport without additional kinetics is the sole mechanism affecting early breakthrough. Possibly, rate-limited sorption to AWI is relevant during the early stages of the lysimeter experiment. Our findings demonstrate that rate-limited sorption is less relevant for long-term leaching under field conditions compared to transformation of precursors and that sorption to AWI can be the dominant retention mechanism on contaminated sites. Moreover, they highlight the potential of random walk particle tracking as a practical alternative to continuum models for estimating the relative contributions of various retention mechanisms.
Collapse
Affiliation(s)
- Thomas Bierbaum
- Research Facility for Subsurface Remediation (VEGAS), University of Stuttgart, Institute for Modelling Environmental Systems (IWS), Pfaffenwaldring 61, 70569, Stuttgart, Germany.
| | - Scott K Hansen
- Ben-Gurion University of the Negev, Zuckerberg Institute for Water Research, 8499000, Midreshet Ben-Gurion, Israel
| | - Bikash Poudel
- Research Facility for Subsurface Remediation (VEGAS), University of Stuttgart, Institute for Modelling Environmental Systems (IWS), Pfaffenwaldring 61, 70569, Stuttgart, Germany
| | - Claus Haslauer
- Research Facility for Subsurface Remediation (VEGAS), University of Stuttgart, Institute for Modelling Environmental Systems (IWS), Pfaffenwaldring 61, 70569, Stuttgart, Germany
| |
Collapse
|
3
|
Burgess RM, Kane Driscoll S, Bejarano AC, Davis CW, Hermens JLM, Redman AD, Jonker MTO. A Review of Mechanistic Models for Predicting Adverse Effects in Sediment Toxicity Testing. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2023. [PMID: 37975556 DOI: 10.1002/etc.5789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 10/15/2023] [Accepted: 11/12/2023] [Indexed: 11/19/2023]
Abstract
Since recognizing the importance of bioavailability for understanding the toxicity of chemicals in sediments, mechanistic modeling has advanced over the last 40 years by building better tools for estimating exposure and making predictions of probable adverse effects. Our review provides an up-to-date survey of the status of mechanistic modeling in contaminated sediment toxicity assessments. Relative to exposure, advances have been most substantial for non-ionic organic contaminants (NOCs) and divalent cationic metals, with several equilibrium partitioning-based (Eq-P) models having been developed. This has included the use of Abraham equations to estimate partition coefficients for environmental media. As a result of the complexity of their partitioning behavior, progress has been less substantial for ionic/polar organic contaminants. When the EqP-based estimates of exposure and bioavailability are combined with water-only effects measurements, predictions of sediment toxicity can be successfully made for NOCs and selected metals. Both species sensitivity distributions and toxicokinetic and toxicodynamic models are increasingly being applied to better predict contaminated sediment toxicity. Furthermore, for some classes of contaminants, such as polycyclic aromatic hydrocarbons, adverse effects can be modeled as mixtures, making the models useful in real-world applications, where contaminants seldomly occur individually. Despite the impressive advances in the development and application of mechanistic models to predict sediment toxicity, several critical research needs remain to be addressed. These needs and others represent the next frontier in the continuing development and application of mechanistic models for informing environmental scientists, managers, and decisions makers of the risks associated with contaminated sediments. Environ Toxicol Chem 2023;00:1-17. © 2023 SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.
Collapse
Affiliation(s)
- Robert M Burgess
- Office of Research and Development/Center for Environmental Measurement and Modeling/Atlantic Coastal Environmental Sciences Division, US Environmental Protection Agency, Narragansett, Rhode Island, USA
| | | | | | | | - Joop L M Hermens
- Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands
| | - Aaron D Redman
- ExxonMobil Biomedical Sciences, Annandale, New Jersey, USA
| | - Michiel T O Jonker
- Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands
| |
Collapse
|
4
|
Brusseau ML, Guo B. Revising the EPA Dilution-Attenuation Soil Screening Model for PFAS. JOURNAL OF HAZARDOUS MATERIALS LETTERS 2023; 4:100077. [PMID: 37990738 PMCID: PMC10662647 DOI: 10.1016/j.hazl.2023.100077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2023]
Abstract
Per and polyfluoroalkyl substances (PFAS) have been shown to be ubiquitous in the environment, and one issue of critical concern is the leaching of PFAS from soil to groundwater. The risk posed by contaminants present in soil is often assessed in terms of the anticipated impact to groundwater through the determination of soil screening levels (SSLs). The U.S. Environmental Protection Agency (EPA) established a soil screening model for determining SSLs. However, the model does not consider the unique retention properties of PFAS and, consequently, the SSLs established with the model may not represent the actual levels that are protective of groundwater quality. The objective of this work is to revise the standard EPA SSL model to reflect the unique properties and associated retention behavior of PFAS. Specifically, the distribution parameter used to convert soil porewater concentrations to soil concentrations is revised to account for adsorption at the air-water interface. Example calculations conducted for PFOS and PFOA illustrate the contrasting SSLs obtained with the revised and standard models. A comparison of distribution parameters calculated for a series of PFAS of different chain length shows that the significance of air-water interfacial adsorption can vary greatly as a function of the specific PFAS. Therefore, the difference between SSLs calculated with the revised versus standard models will vary as a function of the specific PFAS, with greater differences typically observed for longer-chain PFAS. It is anticipated that this revised model will be useful for developing improved SSLs that can be used to enhance site investigations and management for PFAS-impacted sites.
Collapse
Affiliation(s)
- Mark L. Brusseau
- Environmental Science Department, The University of Arizona, Tucson, AZ 85721
- Hydrology and Atmospheric Sciences Department, The University of Arizona, Tucson, AZ 85721
| | - Bo Guo
- Hydrology and Atmospheric Sciences Department, The University of Arizona, Tucson, AZ 85721
| |
Collapse
|
5
|
Bierbaum T, Klaas N, Braun J, Nürenberg G, Lange FT, Haslauer C. Immobilization of per- and polyfluoroalkyl substances (PFAS): Comparison of leaching behavior by three different leaching tests. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 876:162588. [PMID: 36871732 DOI: 10.1016/j.scitotenv.2023.162588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 02/26/2023] [Accepted: 02/27/2023] [Indexed: 06/18/2023]
Abstract
The evaluation of PFAS immobilization performance in laboratory experiments, especially the long-term stability, is a challenge. To contribute to the development of adequate experimental procedures, the impact of experimental conditions on the leaching behavior was studied. Three experiments on different scales were compared: batch, saturated column, and variably saturated laboratory lysimeter experiments. The Infinite Sink (IS) test - a batch test with repeated sampling - was applied for PFAS for the first time. Soil from an agricultural field amended with paper-fiber biosolids polluted with various perfluoroalkyl acids (PFAAs; 655 μg/kg ∑18PFAAs) and polyfluorinated precursors (1.4 mg/kg ∑18precursors) was used as the primary material (N-1). Two types of PFAS immobilization agents were tested: treatment with activated carbon-based additives (soil mixtures: R-1 and R-2), and solidification with cement and bentonite (R-3). In all experiments, a chain-length dependent immobilization efficacy is observed. In R-3, the leaching of short-chain PFAAs was enhanced relative to N-1. In column and lysimeter experiments with R-1 and R-2, delayed breakthrough of short-chain PFAAs (C4) occurred (> 90 days; in column experiments at liquid-to-solid ratio (LS) > 30 L/kg) with similar temporal leaching rates suggesting that leaching in these cases was a kinetically controlled process. Observed differences between column and lysimeter experiments may be attributed to varying saturation conditions. In IS experiments, PFAS desorption from N-1, R-1, and R-2 is higher than in the column experiments (N-1: +44 %; R-1: +280 %; R-2: +162 %), desorption of short-chain PFAS occurred predominantly in the initial phase (< 14 days). Our findings demonstrate that sufficient operating times are essential in percolation experiments, e.g., in column experiments >100 days and LS > 30 L/kg. IS experiments may provide a faster estimate for nonpermanent immobilization. The comparison of experimental data from various experiments is beneficial to evaluate PFAS immobilization and to interpret leaching characteristics.
Collapse
Affiliation(s)
- Thomas Bierbaum
- University of Stuttgart, Institute for Modelling Hydraulic and Environmental Systems (IWS), Research Facility for Subsurface Remediation (VEGAS), Pfaffenwaldring 61, 70597 Stuttgart, Germany.
| | - Norbert Klaas
- University of Stuttgart, Institute for Modelling Hydraulic and Environmental Systems (IWS), Research Facility for Subsurface Remediation (VEGAS), Pfaffenwaldring 61, 70597 Stuttgart, Germany
| | - Jürgen Braun
- University of Stuttgart, Institute for Modelling Hydraulic and Environmental Systems (IWS), Research Facility for Subsurface Remediation (VEGAS), Pfaffenwaldring 61, 70597 Stuttgart, Germany
| | - Gudrun Nürenberg
- TZW: DVGW-Technologiezentrum Wasser (German Water Centre), Karlsruher Straße 84, 76139 Karlsruhe, Germany
| | - Frank Thomas Lange
- TZW: DVGW-Technologiezentrum Wasser (German Water Centre), Karlsruher Straße 84, 76139 Karlsruhe, Germany
| | - Claus Haslauer
- University of Stuttgart, Institute for Modelling Hydraulic and Environmental Systems (IWS), Research Facility for Subsurface Remediation (VEGAS), Pfaffenwaldring 61, 70597 Stuttgart, Germany
| |
Collapse
|
6
|
Lv L, Liu B, Zhang B, Yu Y, Gao L, Ding L. A systematic review on distribution, sources and sorption of perfluoroalkyl acids (PFAAs) in soil and their plant uptake. ENVIRONMENTAL RESEARCH 2023; 231:116156. [PMID: 37196690 DOI: 10.1016/j.envres.2023.116156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 04/29/2023] [Accepted: 05/13/2023] [Indexed: 05/19/2023]
Abstract
Perfluoroalkyl acids (PFAAs) are ubiquitous in environment, which have attracted increasing concerns in recent years. This study collected the data on PFAAs concentrations in 1042 soil samples from 15 countries and comprehensively reviewed the spatial distribution, sources, sorption mechanisms of PFAAs in soil and their plant uptake. PFAAs are widely detected in soils from many countries worldwide and their distribution is related to the emission of the fluorine-containing organic industry. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are found to be the predominant PFAAs in soil. Industrial emission is the main source of PFAAs contributing 49.9% of the total concentrations of PFAAs (Ʃ PFAAs) in soil, followed by activated sludge treated by wastewater treatment plants (WWTPs) (19.9%) and irrigation of effluents from WWTPs, usage of aqueous film-forming foam (AFFFs) and leaching of leachate from landfill (30.2%). The adsorption of PFAAs by soil is mainly influenced by soil pH, ionic strength, soil organic matter and minerals. The concentrations of perfluoroalkyl carboxylic acids (PFCAs) in soil are negatively correlated with the length of carbon chain, log Kow, and log Koc. The carbon chain lengths of PFAAs are negatively correlated with the root-soil concentration factors (RCFs) and shoot-soil concentration factors (SCFs). The uptake of PFAAs by plant is influenced by physicochemical properties of PFAAs, plant physiology and soil environment. Further studies should be conducted to make up the inadequacy of existing knowledge on the behavior and fate of PFAAs in soil-plant system.
Collapse
Affiliation(s)
- Linyang Lv
- College of Chemistry, Changchun Normal University, Changchun, 130032, China
| | - Baolin Liu
- College of Chemistry, Changchun Normal University, Changchun, 130032, China.
| | - Bimi Zhang
- Food and Drug Engineering Institute, Jilin Province Economic Management Cadre College, Changchun, 130012, China
| | - Yong Yu
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China
| | - Lei Gao
- College of Chemistry, Changchun Normal University, Changchun, 130032, China
| | - Lingjie Ding
- College of Chemistry, Changchun Normal University, Changchun, 130032, China
| |
Collapse
|
7
|
Huang YR, Liu SS, Zi JX, Cheng SM, Li J, Ying GG, Chen CE. In Situ Insight into the Availability and Desorption Kinetics of Per- and Polyfluoroalkyl Substances in Soils with Diffusive Gradients in Thin Films. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:7809-7817. [PMID: 37155686 DOI: 10.1021/acs.est.2c09348] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The physicochemical exchange dynamics between the solid and solution phases of per- and polyfluoroalkyl substances (PFAS) in soils needs to be better understood. This study employed an in situ tool, diffusive gradients in thin films (DGT), to understand the distribution and exchange kinetics of five typical PFAS in four soils. Results show a nonlinear relationship between the PFAS masses in DGT and time, implying that PFAS were partially supplied by the solid phase in all of the soils. A dynamic model DGT-induced fluxes in soils/sediments (DIFS) was used to interpret the results and derive the distribution coefficients for the labile fraction (Kdl), response time (tc), and adsorption/desorption rates (k1 and k-1). The larger labile pool size (indicated by Kdl) for the longer chain PFAS implies their higher potential availability. The shorter chain PFAS tend to have a larger tc and relatively smaller k-1, implying that the release of these PFAS in soils might be kinetically limited but not for more hydrophobic compounds, such as perfluorooctanesulfonic acid (PFOS), although soil properties might play an important role. Kdl ultimately controls the PFAS availability in soils, while the PFAS release from soils might be kinetically constrained (which may also hold for biota uptake), particularly for more hydrophilic PFAS.
Collapse
Affiliation(s)
- Yue-Rui Huang
- Environmental Research Institute/School of Environment, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, Guangdong 510006, People's Republic of China
| | - Si-Si Liu
- Environmental Research Institute/School of Environment, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, Guangdong 510006, People's Republic of China
| | - Jin-Xin Zi
- Environmental Research Institute/School of Environment, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, Guangdong 510006, People's Republic of China
| | - Sheng-Ming Cheng
- Environmental Research Institute/School of Environment, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, Guangdong 510006, People's Republic of China
| | - Jun Li
- State Key Laboratory of Organic Geochemistry and Guangdong Province Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, Guangdong 510640, People's Republic of China
| | - Guang-Guo Ying
- Environmental Research Institute/School of Environment, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, Guangdong 510006, People's Republic of China
| | - Chang-Er Chen
- Environmental Research Institute/School of Environment, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, Guangdong 510006, People's Republic of China
| |
Collapse
|
8
|
Jahn KL, Lincoln SA, Freeman KH, Saffer DM. Preferential Retention and Transport of Perfluorooctanesulfonic Acid in a Dolomite Aquifer. GROUND WATER 2023; 61:318-329. [PMID: 36103019 DOI: 10.1111/gwat.13255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 08/31/2022] [Accepted: 09/03/2022] [Indexed: 05/14/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) can represent a significant human health risk if present in aquifers used as a drinking water source. Accurate assessment of PFAS exposure risks requires an improved understanding of field-scale PFAS transport in groundwater. Activities at a former firefighter training site in University Park, Pennsylvania introduced perfluorooctanesulfonic acid (PFOS) to the underlying dolomite aquifer. Groundwater sampling from 2015 to 2018 delineated a PFOS plume with two concentration maxima located approximately 20 and approximately 220 m downgradient of the training site, separated by a zone of lower concentrations. We use a combination of analytical and numerical models, informed by independent measurements of aquifer porosity, hydraulic conductivity, and organic carbon content, to interpret the field observations. Our analysis demonstrates that preferential retention and transport resulting from simple heterogeneity in bedrock sorption, as caused by organic carbon (OC) content variability, provides a plausible explanation for plume separation. Dissolved PFOS partitions strongly to organic solids (high Koc ), so even a small OC (<1 wt%) significantly retards PFOS transport, whereas zones with little to no OC allow for transport rates that approximate those of a conservative solute. Our work highlights an important consideration for modeling the groundwater transport of PFOS, and other compounds with high Koc . In aquifers with discrete layers of varying OC, models using a uniform site-average OC will underestimate transport distances, thereby misrepresenting exposure risks for downgradient communities.
Collapse
Affiliation(s)
- Kalle L Jahn
- USGS New York Water Science Center, Troy, NY, USA
| | - Sara A Lincoln
- Department of Geosciences, The Pennsylvania State University, University Park, PA
- Akima Systems Engineering, Herndon, VA
| | - Katherine H Freeman
- Department of Geosciences, The Pennsylvania State University, University Park, PA
| | - Demian M Saffer
- Institute for Geophysics, Department of Geological Sciences, University of Texas at Austin, Austin, TX
| |
Collapse
|
9
|
Wanzek T, Stults JF, Johnson MG, Field JA, Kleber M. Role of Mineral-Organic Interactions in PFAS Retention by AFFF-Impacted Soil. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:5231-5242. [PMID: 36947878 PMCID: PMC10764056 DOI: 10.1021/acs.est.2c08806] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
A comprehensive, generalized approach to predict the retention of per- and polyfluoroalkyl substances (PFAS) from aqueous film-forming foam (AFFF) by a soil matrix as a function of PFAS molecular and soil physiochemical properties was developed. An AFFF with 34 major PFAS (12 anions and 22 zwitterions) was added to uncontaminated soil in one-dimensional saturated column experiments and PFAS mass retained was measured. PFAS mass retention was described using an exhaustive statistical approach to generate a poly-parameter quantitative structure-property relationship (ppQSPR). The relevant predictive properties were PFAS molar mass, mass fluorine, number of nitrogens in the PFAS molecule, poorly crystalline Fe oxides, organic carbon, and specific (BET-N2) surface area. The retention of anionic PFAS was nearly independent of soil properties and largely a function of molecular hydrophobicity, with the size of the fluorinated side chain as the main predictor. Retention of nitrogen-containing zwitterionic PFAS was related to poorly crystalline metal oxides and organic carbon content. Knowledge of the extent to which a suite of PFAS may respond to variations in soil matrix properties, as developed here, paves the way for the development of reactive transport algorithms with the ability to capture PFAS dynamics in source zones over extended time frames.
Collapse
Affiliation(s)
- Thomas Wanzek
- Department of Crop and Soil Science, Oregon State University, Corvallis, Oregon 97331, United States
| | - John F. Stults
- Department Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado, 80401, United States
| | - Mark G. Johnson
- U.S. Environmental Protection Agency, Center for Public Health and Environmental Assessment, Pacific Ecological Systems Division, Corvallis, Oregon 97333, United States
| | - Jennifer A. Field
- Department Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon 97331, United States
| | - Markus Kleber
- Department of Crop and Soil Science, Oregon State University, Corvallis, Oregon 97331, United States
| |
Collapse
|
10
|
Abou-Khalil C, Kewalramani J, Zhang Z, Sarkar D, Abrams S, Boufadel MC. Effect of clay content on the mobilization efficiency of per- and polyfluoroalkyl substances (PFAS) from soils by electrokinetics and hydraulic flushing. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 322:121160. [PMID: 36716947 DOI: 10.1016/j.envpol.2023.121160] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 01/15/2023] [Accepted: 01/26/2023] [Indexed: 06/18/2023]
Abstract
The need for the efficient remediation of soils impacted by per- and polyfluoroalkyl substances (PFAS) is substantially growing because of the notable upsurge in societal and regulatory awareness of this class of chemicals. To remediate PFAS-contaminated soils using mobilization approaches, the choice of appropriate techniques highly depends on the soil's composition, particularly the clay content, which significantly affects the soil's permeability. Here, we investigated the PFAS mobilization efficiency from soils with different clay contents by using two techniques: electrokinetic (EK) remediation and hydraulic flushing. Artificial kaolinite was added to a loamy sand soil to prepare four soil blends with clay contents of 5, 25, 50, and 75%, each contaminated with perfluorooctanoic acid (PFOA) and perfulorooctanesulfonic acid (PFOA) at 10,000 μg/kg. EK remediation was conducted by applying a low voltage (30 V) with a current of 100 mA, and hydraulic flushing was carried out by applying a hydraulic gradient (HG) with a slope of 6.7%. Results show that, with a 14-day treatment duration, the EK-mobilization efficiency was enhanced substantially with the increase of clay content (removal of PFOS increased from 20% at 5% clay to 80% at 75% clay), most likely due to the increase of electroosmotic flow due to the higher content of particles having a zeta potential (i.e., clay). For HG, increasing the clay content significantly suppressed the mobilization of PFAS (removal of PFOS decreased from 40% at 5% clay to 10% at 75% clay) due to a notable decrease in the soil's permeability. Based on the results, applying hydraulic flushing and washing techniques for mobilizing PFAS would be appropriate when treating permeable soils with a maximum clay content of about 25%; otherwise, other suitable mobilization techniques such as EKs should be considered.
Collapse
Affiliation(s)
- Charbel Abou-Khalil
- Center for Natural Resources, Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA
| | - Jitendra Kewalramani
- Center for Natural Resources, Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA
| | - Zhiming Zhang
- Department of Civil, Environmental and Ocean Engineering, Stevens Institute of Technology, Hoboken, NJ 07030, USA
| | - Dibyendu Sarkar
- Department of Civil, Environmental and Ocean Engineering, Stevens Institute of Technology, Hoboken, NJ 07030, USA
| | - Stewart Abrams
- Langan Engineering and Environmental Services, Inc., 300 Kimball Dr., Parsippany, NJ 07054, USA
| | - Michel C Boufadel
- Center for Natural Resources, Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA.
| |
Collapse
|
11
|
Campos-Pereira H, Kleja DB, Ahrens L, Enell A, Kikuchi J, Pettersson M, Gustafsson JP. Effect of pH, surface charge and soil properties on the solid-solution partitioning of perfluoroalkyl substances (PFASs) in a wide range of temperate soils. CHEMOSPHERE 2023; 321:138133. [PMID: 36791815 DOI: 10.1016/j.chemosphere.2023.138133] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 02/09/2023] [Accepted: 02/10/2023] [Indexed: 06/18/2023]
Abstract
The pH-dependent soil-water partitioning of six perfluoroalkyl substances (PFASs) of environmental concern (PFOA, PFDA, PFUnDA, PFHxS, PFOS and FOSA), was investigated for 11 temperate mineral soils and related to soil properties such as organic carbon content (0.2-3%), concentrations of Fe and Al (hydr)oxides, and texture. PFAS sorption was positively related to the perfluorocarbon chain length of the molecule, and inversely related to solution pH for all substances. The negative slope between log Kd and pH became steeper with increasing perfluorocarbon chain length of the PFAS (r2 = 0.75, p ≤ 0.05). Organic carbon (OC) alone was a poor predictor of the partitioning for all PFASs, except for FOSA (r2 = 0.71), and the OC-normalized PFAS partitioning, as derived from organic soil materials, underestimated PFAS sorption to the soils. Multiple linear regression suggested sorption contributions (p ≤ 0.05) from OC for perfluorooctane sulfonate (PFOS) and FOSA, and Fe/Al (hydr)oxides for PFOS, FOSA, and perfluorodecanoate (PFDA). FOSA was the only substance under study for which there was a statistically significant correlation between its binding and soil texture (silt + clay). To predict PFAS sorption, the surface net charge of the soil organic matter fraction of all soils was calculated using the Stockholm Humic Model. When calibrated against charge-dependent PFAS sorption to a peat (Oe) material, the derived model significantly underestimated the measured Kd values for 10 out of 11 soils. To conclude, additional sorbents, possibly including silicate minerals, contribute to the binding of PFASs in soil. More research is needed to develop geochemical models that can accurately predict PFAS sorption in soils.
Collapse
Affiliation(s)
- Hugo Campos-Pereira
- Department of Soil and Environment, Swedish University of Agricultural Sciences (SLU), Box 7014, SE-750 07, Uppsala, Sweden
| | - Dan B Kleja
- Department of Soil and Environment, Swedish University of Agricultural Sciences (SLU), Box 7014, SE-750 07, Uppsala, Sweden; Swedish Geotechnical Institute (SGI), SE-581 93, Linköping, Sweden
| | - Lutz Ahrens
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences (SLU), Box 7050, SE-750 07, Uppsala, Sweden
| | - Anja Enell
- Swedish Geotechnical Institute (SGI), SE-581 93, Linköping, Sweden
| | - Johannes Kikuchi
- Swedish Geotechnical Institute (SGI), SE-581 93, Linköping, Sweden; Department of Thematic Studies, Linköping University, SE-581 83, Linköping, Sweden
| | | | - Jon Petter Gustafsson
- Department of Soil and Environment, Swedish University of Agricultural Sciences (SLU), Box 7014, SE-750 07, Uppsala, Sweden.
| |
Collapse
|
12
|
Krahn KM, Cornelissen G, Castro G, Arp HPH, Asimakopoulos AG, Wolf R, Holmstad R, Zimmerman AR, Sørmo E. Sewage sludge biochars as effective PFAS-sorbents. JOURNAL OF HAZARDOUS MATERIALS 2023; 445:130449. [PMID: 36459882 DOI: 10.1016/j.jhazmat.2022.130449] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/24/2022] [Accepted: 11/18/2022] [Indexed: 06/17/2023]
Abstract
The use of sewage sludge to produce biochar-based sorbents for per- and polyfluoroalkyl substances (PFAS) removal from water and soil may be an economically and environmentally sustainable waste management option. This study compared the sorption of six perfluorinated carboxylic acids (PFCAs) by two sewage sludge biochars (SSBCs) and one wood chip biochar (WCBC), dry pyrolyzed at 700 °C. Batch sorption tests were conducted by adding individual PFCAs and a PFCA-mixture to pure biochars and mixtures of biochar and a sandy soil (1.3% TOC). PFAS-sorption to the SSBCs exhibited log-linear biochar-water distribution coefficients (log Kd), comparable to those previously reported for commercial activated carbons (e.g., 5.73 ± 0.02 for perfluorooctanoic acid at 1 µg/L). The strong sorption of PFCAs was attributed to the SSBCs relatively high pore volumes in the pore size range that can accommodate these compounds. Sorption was attenuated by the presence of soil (by factors 3-10), by the presence of a mixture of PFCAs (by factors of 6-532) and by both together (by factors of 8-6581), indicating strongly competitive sorption between PFCA-congeners, and less severe sorption attenuation by soil organic matter. These findings could enable sustainable value chains for SSBs in soil remediation and water filtration solutions.
Collapse
Affiliation(s)
- Katinka M Krahn
- Norwegian Geotechnical Institute (NGI), 0484 Oslo, Norway; Norwegian University of Life Sciences (NMBU), 1430 Ås, Norway; Lindum AS, 3036 Drammen, Norway
| | - Gerard Cornelissen
- Norwegian Geotechnical Institute (NGI), 0484 Oslo, Norway; Norwegian University of Life Sciences (NMBU), 1430 Ås, Norway
| | - Gabriela Castro
- Norwegian University of Science and Technology (NTNU), 7024 Trondheim, Norway
| | - Hans Peter H Arp
- Norwegian Geotechnical Institute (NGI), 0484 Oslo, Norway; Norwegian University of Science and Technology (NTNU), 7024 Trondheim, Norway
| | | | - Raoul Wolf
- Norwegian Geotechnical Institute (NGI), 0484 Oslo, Norway
| | | | | | - Erlend Sørmo
- Norwegian Geotechnical Institute (NGI), 0484 Oslo, Norway; Norwegian University of Life Sciences (NMBU), 1430 Ås, Norway
| |
Collapse
|
13
|
Using a batch test to derive sorption data of fluoroquinolone antibiotics in humic acids. MethodsX 2023; 10:102109. [PMID: 36970026 PMCID: PMC10033734 DOI: 10.1016/j.mex.2023.102109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 03/03/2023] [Indexed: 03/14/2023] Open
Abstract
Fluoroquinolone antibiotics (FQs) are of concern due to their disrupting effects on environmental bacterial communities. Evaluating FQ sorption by soil components is important to understand their interaction with soils and to address their environmental (bio)availability. However, data in soil organic components, especially humic acids, are scarce. Batch experiments following OECD guidelines are suitable for testing the sorption of pollutants in solid matrices. Here, we applied this methodology, with specific changes in the experimental setup, to derive sorption data and to identify the factors affecting sorption of four common FQs in seven humic acids with contrasting properties. The effect of shaking time, pH, calcium concentration in solution and dissolved organic carbon (DOC) content on the quantification of the solid-liquid distribution coefficient (Kd) of norfloxacin in three reference humic acids was evaluated. Sorption reversibility and sorption analogy of four FQs were additionally assessed in these three reference materials, whereas the effect of initial norfloxacin concentration was evaluated in the overall set of seven humic acids. Sorption was fast, strong, non-linear, irreversible and affected by changes in the pH and calcium levels in solution. The bell-shaped sorption trend at varying pH values confirmed the key role of FQ speciation in sorption and the high Kd values indicated a positive effect of soil organic matter components on FQ sorption in bulk soils at environmentally relevant pH values.•Relevant factors affecting sorption of pollutants in environmental matrices must be considered to derive Kd values with low variability and high representativeness.•In this article we modify the experimental conditions of standard batch tests to identify the factors that affect the sorption of FQs in humic acids.•The methodological approach followed can be extrapolated to the evaluation of other combinations of pollutant and environmental matrix.
Collapse
|
14
|
Sadia M, Nollen I, Helmus R, ter Laak TL, Béen F, Praetorius A, van Wezel AP. Occurrence, Fate, and Related Health Risks of PFAS in Raw and Produced Drinking Water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:3062-3074. [PMID: 36779784 PMCID: PMC9979608 DOI: 10.1021/acs.est.2c06015] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 01/31/2023] [Accepted: 01/31/2023] [Indexed: 06/01/2023]
Abstract
This study investigates human exposure to per- and polyfluoroalkyl substances (PFAS) via drinking water and evaluates human health risks. An analytical method for 56 target PFAS, including ultrashort-chain (C2-C3) and branched isomers, was developed. The limit of detection (LOD) ranged from 0.009 to 0.1 ng/L, except for trifluoroacetic-acid and perfluoropropanoic-acid with higher LODs of 35 and 0.24 ng/L, respectively. The method was applied to raw and produced drinking water from 18 Dutch locations, including groundwater or surface water as source, and applied various treatment processes. Ultrashort-chain (300 to 1100 ng/L) followed by the group of perfluoroalkyl-carboxylic-acids (PFCA, ≥C4) (0.4 to 95.1 ng/L) were dominant. PFCA and perfluoroalkyl-sulfonic-acid (≥C4), including precursors, showed significantly higher levels in drinking water produced from surface water. However, no significant difference was found for ultrashort PFAS, indicating the need for groundwater protection. Negative removal of PFAS occasionally observed for advanced treatment indicates desorption and/or degradation of precursors. The proportion of branched isomers was higher in raw and produced drinking water as compared to industrial production. Drinking water produced from surface water, except for a few locations, exceed non-binding provisional guideline values proposed; however, all produced drinking waters met the recent soon-to-be binding drinking-water-directive requirements.
Collapse
Affiliation(s)
- Mohammad Sadia
- Institute
for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE Amsterdam, The Netherlands
| | - Ingeborg Nollen
- Institute
for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE Amsterdam, The Netherlands
| | - Rick Helmus
- Institute
for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE Amsterdam, The Netherlands
| | - Thomas L. ter Laak
- Institute
for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE Amsterdam, The Netherlands
- KWR
Water Research Institute, P.O. Box 1072, 3430 BB Nieuwegein, The Netherlands
| | - Frederic Béen
- KWR
Water Research Institute, P.O. Box 1072, 3430 BB Nieuwegein, The Netherlands
| | - Antonia Praetorius
- Institute
for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE Amsterdam, The Netherlands
| | - Annemarie P. van Wezel
- Institute
for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE Amsterdam, The Netherlands
| |
Collapse
|
15
|
Gnesda WR, Draxler EF, Tinjum J, Zahasky C. Adsorption of PFAAs in the Vadose Zone and Implications for Long-Term Groundwater Contamination. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:16748-16758. [PMID: 36395358 DOI: 10.1021/acs.est.2c03962] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Perfluoroalkyl acids (PFAAs) are persistent environmental contaminants that sorb to air-water and solid interfaces throughout the vadose zone. These sorption processes lead to decadal leaching of PFAS from the source zones to groundwater systems. While these processes are increasingly well understood, critical gaps exist in describing the vertically variable adsorption in the presence of vadose zone heterogeneity and methods for efficiently upscaling the laboratory observations to predict field-scale PFAA transport and retardation. In this work, we build upon fundamental theories and scalable relationships to define a semi-analytical framework for synthesizing and upscaling PFAA adsorption in heterogeneous vadose zone systems. Solid-phase and air-water interfacial adsorption are quantified mechanistically for several PFAAs and then applied to a contaminated site in Northern Wisconsin. The results highlight the dominance of air-water and organic carbon solid-phase adsorption processes in the vadose zone. Strong sorption heterogeneity─driven by depth-dependent adsorption mechanisms─produces complex spatially variable retardation profiles. We develop vadose zone retardation potentials to quantify this field-scale heterogeneity and propose vertical integration methods to upscale spatially resolved information for transport modeling. This work highlights the importance of accounting for multiscale and multiprocess heterogeneity for accurately describing and predicting the long-term fate and transport of PFAAs in the subsurface.
Collapse
Affiliation(s)
- William R Gnesda
- Department of Geoscience, University of Wisconsin─Madison, Madison, Wisconsin53715, United States
| | - Elliot F Draxler
- Department of Civil and Environmental Engineering, University of Wisconsin─Madison, Madison, Wisconsin53715, United States
| | - James Tinjum
- Department of Civil and Environmental Engineering, University of Wisconsin─Madison, Madison, Wisconsin53715, United States
| | - Christopher Zahasky
- Department of Geoscience, University of Wisconsin─Madison, Madison, Wisconsin53715, United States
| |
Collapse
|
16
|
Sviridov AV, Maltsev GI, Timofeev KL. Adsorption of Metal Ions on Aluminosilicates. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2022. [DOI: 10.1134/s0036024422120263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
17
|
Mroczko O, Preisendanz HE, Wilson C, Mashtare ML, Elliott HA, Veith TL, Soder KJ, Watson JE. Spatiotemporal patterns of PFAS in water and crop tissue at a beneficial wastewater reuse site in central Pennsylvania. JOURNAL OF ENVIRONMENTAL QUALITY 2022; 51:1282-1297. [PMID: 36070520 PMCID: PMC9828414 DOI: 10.1002/jeq2.20408] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 08/09/2022] [Indexed: 06/15/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are a collective name for thousands of synthetic compounds produced to enhance consumer and industrial products since the 1940s. They do not easily degrade, and some are known to pose serious ecological and human health concerns at trace concentrations (ng L-1 levels). Per- and polyfluoroalkyl substances persist in treated wastewater and are inadvertently introduced into the environment when treated wastewater is reused as an irrigation source. The Pennsylvania State University (PSU) has been spray-irrigating its wastewater at a 2.45 km2 mixed-use agricultural and forested site known as the "Living Filter" since the 1960s. To understand the spatiotemporal patterns of 20 PFAS at the Living Filter, water samples were collected bimonthly from fall 2019 through winter 2021 from the PSU's wastewater effluent and from each of the site's 13 monitoring wells. Crop tissue was collected at the time of harvest to assess PFAS presence in corn silage and tall fescue grown at the study site. Total measured PFAS concentrations in the monitoring wells ranged from nondectable to 155 ng L-1 , with concentrations increasing with the direction of groundwater flow. Concentrations within each well exhibited little temporal variability across sampling events, with mixed relationships between PFAS and groundwater elevation observed between wells. Further, >84% of the PFAS present in livestock feed crops were short-chain compounds, with PFAS consumed annually by livestock fed crops harvested from the site estimated to be 2.46-7.67 mg animal-1 yr-1 . This research provides insight into the potential impacts of long-term beneficial reuse of treated wastewater on groundwater and crop tissue quality.
Collapse
Affiliation(s)
- Olivia Mroczko
- Dep. of Agricultural and Biological EngineeringThe Pennsylvania State Univ.University ParkPA16802USA
| | - Heather E. Preisendanz
- Dep. of Agricultural and Biological EngineeringThe Pennsylvania State Univ.University ParkPA16802USA
- Institute for Sustainable Agricultural, Food, and Environmental ScienceThe Pennsylvania State Univ.University ParkPA16802USA
| | - Christopher Wilson
- Dep. of Agricultural and Biological EngineeringThe Pennsylvania State Univ.University ParkPA16802USA
| | - Michael L. Mashtare
- Dep. of Agricultural and Biological EngineeringThe Pennsylvania State Univ.University ParkPA16802USA
| | - Herschel A. Elliott
- Dep. of Agricultural and Biological EngineeringThe Pennsylvania State Univ.University ParkPA16802USA
| | - Tamie L. Veith
- USDA‐ARS Pasture Systems and Watershed Management Research UnitUniversity ParkPA16802USA
| | - Kathy J. Soder
- USDA‐ARS Pasture Systems and Watershed Management Research UnitUniversity ParkPA16802USA
| | - John E. Watson
- Dep. of Ecosystem Science and ManagementThe Pennsylvania State Univ.University ParkPA16802USA
| |
Collapse
|
18
|
Liu Y, Bahar MM, Samarasinghe SVAC, Qi F, Carles S, Richmond WR, Dong Z, Naidu R. Ecological risk assessment for perfluorohexanesulfonic acid (PFHxS) in soil using species sensitivity distribution (SSD) approach. JOURNAL OF HAZARDOUS MATERIALS 2022; 439:129667. [PMID: 36104899 DOI: 10.1016/j.jhazmat.2022.129667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 07/09/2022] [Accepted: 07/20/2022] [Indexed: 06/15/2023]
Abstract
Perfluorohexanesulfonic acid (PFHxS) is one of the persistent organic pollutants that has been recommended to be listed in Annex A of the Stockholm Convention. It has gained increasing attention in recent years due to its toxic effects. The guideline values of PFHxS are commonly associated with PFOS in various countries and regulatory agencies. In this study, multispecies bioassays were conducted to determine the ecological toxic effects of PFHxS, including plants, soil invertebrates, and soil microorganisms, which indicated the EC10/NOEC values ranged from 2.9 to 250 mg/kg. Where possible, logistic models were used to calculate the EC30 values for various endpoints. The species sensitivity distributions were employed to estimate the ecological investigation levels for PFHxS contamination in soils using toxicity results from literature and this study. The calculation using EC10/NOEC values from both literature and this study indicated a most conservative HC5 as 1.0 mg/kg (hazardous concentration for 5 % of the species being impacted). However, utilisation of EC30 values derived from this study resulted in a much higher HC5 for PFHxS in contaminated soils (13.0 mg/kg) which is at the higher end of the existing guideline values for PFOS for protecting ecological systems. The results obtained in this study can be useful in risk assessment processes to minimize any uncertainty using combined values with PFOS.
Collapse
Affiliation(s)
- Yanju Liu
- Global Centre for Environmental Remediation, College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW 2308, Australia; CRC for Contamination Assessment and Remediation of the Environment (CRC CARE), Callaghan, NSW 2308, Australia.
| | - Md Mezbaul Bahar
- Global Centre for Environmental Remediation, College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW 2308, Australia; CRC for Contamination Assessment and Remediation of the Environment (CRC CARE), Callaghan, NSW 2308, Australia.
| | - S V A Chamila Samarasinghe
- Global Centre for Environmental Remediation, College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW 2308, Australia; CRC for Contamination Assessment and Remediation of the Environment (CRC CARE), Callaghan, NSW 2308, Australia.
| | - Fangjie Qi
- Global Centre for Environmental Remediation, College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW 2308, Australia; CRC for Contamination Assessment and Remediation of the Environment (CRC CARE), Callaghan, NSW 2308, Australia.
| | | | - William R Richmond
- Department of Water and Environmental Regulation, Government of Western Australia, 8 Davidson Terrace, Joondalup WA 6027, Australia.
| | - Zhaomin Dong
- School of Space and Environment, Beihang University, Beijging 100191, China.
| | - Ravi Naidu
- Global Centre for Environmental Remediation, College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW 2308, Australia; CRC for Contamination Assessment and Remediation of the Environment (CRC CARE), Callaghan, NSW 2308, Australia.
| |
Collapse
|
19
|
Weidemann E, Lämmer R, Stahl T, Göckener B, Bücking M, Breuer J, Kowalczyk J, Just H, Boeddinghaus RS, Gassmann M. Leaching and Transformation of Perfluoroalkyl Acids and Polyfluoroalkyl Phosphate Diesters in Unsaturated Soil Column Studies. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2022; 41:2065-2077. [PMID: 35751449 DOI: 10.1002/etc.5417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 05/01/2022] [Accepted: 06/24/2022] [Indexed: 06/15/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are environmentally ubiquitous, anthropogenic substances with adverse effects on organisms, which shows the need to study their environmental fate and leaching behavior. In the present soil columns study, the leaching behavior and fate of nontransformable and transformable (precursors) were investigated. Ten nontransformable PFAS in two different soils, two precursors and two field soils, which were already contaminated with a mixture of PFAS, and two uncontaminated controls, were set up for a time span of 2 years. At the end of the study, the molecular balance could not be closed for nontransformable PFAS. This effect was positively correlated to the fluorinated carbon chain length. The precursors, which were both polyfluoroalkyl phosphate diesters (diPAP), had different transformation products and transformation rates, with a higher rate for 6:2 diPAP than 8:2 diPAP. After 2 years, amounts of diPAP were still found in the soil with no significant vertical movement, showing high adsorption to soils. Transformation products were estimated to be simultaneously formed. They were predominantly found in the percolation water; the amounts left in soil were negligible. Up to half of the initial precursor amounts could not be balanced and were considered missing amounts. The results of contaminated field soil experiments showed the challenge to estimate PFAS leaching without knowing all occurring precursors and complex transformation dynamics. For this purpose, it was shown that a broad examination of contaminated soil with different analytical methods can help with qualitative estimations of leaching risks. For a better quantitative estimation, analytical determination of more PFAS and a quantification of the missing amounts are needed. Environ Toxicol Chem 2022;41:2065-2077. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
Collapse
Affiliation(s)
- Eva Weidemann
- Department of Hydrology and Substance Balance, University of Kassel, Kassel, Germany
| | - René Lämmer
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Schmallenberg, Germany
| | - Thorsten Stahl
- Chemical and Veterinary Analytical Institute Münsterland-Emscher-Lippe, Münster, Germany
| | - Bernd Göckener
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Schmallenberg, Germany
| | - Mark Bücking
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Schmallenberg, Germany
- School of Chemistry, Monash University, Clayton, Victoria, Australia
| | - Jörn Breuer
- Center for Agricultural Technology Augustenberg (LTZ), Karlsruhe, Germany
| | | | - Hildegard Just
- German Federal Institute for Risk Assessment, Berlin, Germany
| | | | - Matthias Gassmann
- Department of Hydrology and Substance Balance, University of Kassel, Kassel, Germany
| |
Collapse
|
20
|
Fabregat-Palau J, Vidal M, Rigol A. Examining sorption of perfluoroalkyl substances (PFAS) in biochars and other carbon-rich materials. CHEMOSPHERE 2022; 302:134733. [PMID: 35500630 DOI: 10.1016/j.chemosphere.2022.134733] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 04/21/2022] [Accepted: 04/22/2022] [Indexed: 06/14/2023]
Abstract
The use of carbon-rich sorbents to remove and/or immobilize perfluoroalkyl substances (PFAS) in contaminated environmental scenarios is attracting increasing interest. The identification of key sorbent properties responsible for PFAS sorption and the development of models that can predict the distribution coefficients (Kd) for PFAS sorption in these materials are crucial in the screening of candidate materials for environmental remediation. In this study, sorption kinetics, sorption isotherms, and the effects of pH, calcium concentration and dissolved organic carbon (DOC) content on PFAS sorption were evaluated in four representative carbon-rich materials: two biochars with contrasting properties, a compost, and charcoal fines rejected by the metallurgical industry. Subsequently, the sorption of seven PFAS with numbers of fluorinated carbons ranging from 4 to 11 was evaluated in a total of ten carbon-rich materials, including activated carbons, so as to build up a Kd prediction model. The sorption of PFAS increased with greater fluorinated chain length, suggesting that hydrophobic interactions play a major role in sorption and electrostatic interactions a minor one. These results were confirmed by a principal component analysis, which revealed that the CORG/O molar ratio and the specific surface area of the material were the two main sorbent properties affecting PFAS sorption. Furthermore, the DOC content in solution had a negative effect on PFAS sorption. Using this information, a simple Kd prediction model applicable to a wide range of materials and PFAS was developed, using only a few easily-derived physicochemical properties of sorbent (CORG/O molar ratio and SSA) and PFAS (number of CF2), and was externally validated with data gathered from the literature.
Collapse
Affiliation(s)
- Joel Fabregat-Palau
- Department of Chemical Engineering and Analytical Chemistry, University of Barcelona, Martí i Franquès 1-11, 08028, Barcelona, Spain
| | - Miquel Vidal
- Department of Chemical Engineering and Analytical Chemistry, University of Barcelona, Martí i Franquès 1-11, 08028, Barcelona, Spain
| | - Anna Rigol
- Department of Chemical Engineering and Analytical Chemistry, University of Barcelona, Martí i Franquès 1-11, 08028, Barcelona, Spain.
| |
Collapse
|
21
|
Liu Z, Xu C, Johnson AC, Sun X, Wang M, Xiong J, Chen C, Wan X, Ding X, Ding M. Exploring the source, migration and environmental risk of perfluoroalkyl acids and novel alternatives in groundwater beneath fluorochemical industries along the Yangtze River, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 827:154413. [PMID: 35276179 DOI: 10.1016/j.scitotenv.2022.154413] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 02/14/2022] [Accepted: 03/05/2022] [Indexed: 06/14/2023]
Abstract
The widely used legacy perfluoroalkyl acids (PFAAs) with serious environmental hazards are gradually restricted and being replaced by novel alternatives. Here, for an efficient control of emerging environmental risks in groundwater, we systematically studied the source apportionment, spatial attenuation, composition change and risk zoning of 12 PFAAs and five novel alternatives within a region of ~200 km2 around a mega fluorochemical industrial park (FIP) along the Yangtze River, and in-depth explored potential association between groundwater and soil pollution as well as influencing factors on contaminant migration and risk distribution in the aquifer. Short-chain PFAAs and novel alternatives together accounted for over 70% in groundwater, revealing their prevalence in replacing legacy perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). Novel alternatives for PFOA were mainly hexafluoropropylene oxide dimer acid (GenX) and hexafluoropropylene oxide trimer acid (HFPO-TA), while those for PFOS were 6:2 chlorinated polyfluorinated ether sulfonic acid (6:2 Cl-PFESA) and 6:2 fluorotelomer sulfonic acid (6:2 FTS). PFAAs (maximum total: 1339 ng/L) and novel alternatives (maximum total: 208 ng/L) in groundwater were mostly derived from the FIP, and exhibited an exponentially decreasing trend with increasing distance. Compared with those in groundwater, more diverse sources of PFAAs and novel alternatives in surface soil were identified. The transport of these chemicals may be retarded by clayed surface soils with high organic matter contents. High aquifer permeability could generally promote the dilution and migration of PFAAs and novel alternatives in groundwater, as well as reduce the differences in their spatial distribution. Shorter-chain components with smaller molecules and higher hydrophilicity exhibited greater migration capacities in the aquifer. In addition, different levels of health risk from PFOS and PFOA were zoned based on drinking groundwater, and high risks tended to be distributed in areas with relatively poor aquifer water yield due to higher pollutant accumulation.
Collapse
Affiliation(s)
- Zhaoyang Liu
- State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
| | - Chang Xu
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Andrew C Johnson
- Centre for Ecology & Hydrology, Maclean Building, Crowmarsh Gifford Wallingford, Oxon OX 10 8BB, UK
| | - Xiaoyan Sun
- Jiangxi Engineering and Technology Research Center for Ecological Remediation of Heavy Metal Pollution, Institute of Microbe, Jiangxi Academy of Sciences, Nanchang 330096, China
| | - Mingxia Wang
- State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Juan Xiong
- State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Chang Chen
- State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Xiang Wan
- Hubei Geological Survey, Wuhan 430034, China
| | - Xiaoyan Ding
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Muyang Ding
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| |
Collapse
|
22
|
Loganathan N, Wilson AK. Adsorption, Structure, and Dynamics of Short- and Long-Chain PFAS Molecules in Kaolinite: Molecular-Level Insights. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:8043-8052. [PMID: 35543620 DOI: 10.1021/acs.est.2c01054] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The ubiquitous presence of poly- and perfluoroalkyl substances (PFAS) in different natural settings poses a serious threat to environmental and human health. Soils and sediments represent one of the important exposure pathways of PFAS for humans and animals. With increasing bioaccumulation and mobility, it is extremely important to understand the interactions of PFAS molecules with the dominant constituents of soils such as clay minerals. This study reports for the first time the fundamental molecular-level insights into the adsorption, interfacial structure, and dynamics of short- and long-chain PFAS molecules at the water-saturated mesopores of kaolinite clay using classical molecular dynamics (MD) simulations. At environmental conditions, all the PFAS molecules are exclusively adsorbed near the hydroxyl surface of the kaolinite, irrespective of the terminal functional groups and metal cations. The interfacial adsorption structures and coordination environments of PFAS are strongly dependent on the nature of the functional groups and their hydrophobic chain length. The formation of large, aggregated clusters of long-chain PFAS at the hydroxyl surface of kaolinite is responsible for their restricted dynamics in comparison to short-chain PFAS molecules. Such comprehensive knowledge of PFAS at the clay mineral interface is critical to developing novel site-specific degradation and mitigation strategies.
Collapse
Affiliation(s)
- Narasimhan Loganathan
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Angela K Wilson
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| |
Collapse
|
23
|
Zhang Y, Cornelissen G, Silvani L, Zivanovic V, Smebye AB, Sørmo E, Thune G, Okkenhaug G. Industrial byproducts for the soil stabilization of trace elements and per- and polyfluorinated alkyl substances (PFASs). THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 820:153188. [PMID: 35051478 DOI: 10.1016/j.scitotenv.2022.153188] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 01/05/2022] [Accepted: 01/12/2022] [Indexed: 06/14/2023]
Abstract
The present work was the first exploration of the use of industrial byproducts from iron and titanium processing as sorbents for the stabilization of soil contamination. The main aim was to test slag waste and iron-rich charred fossil coal ("Fe-char"), as sorbents for per- and polyfluorinated alkyl substances (PFASs), as well as lead (Pb) and antimony (Sb), in four soils from a firefighting training area (PFASs) and a shooting range (Pb and Sb). Adding slag (10-20%) to shooting range soils decreased the leaching of Pb and Sb up to 50-90%. Fe-char amendment to these soils resulted in a moderate reduction in Sb leaching (20-70%) and a slightly stronger effect on Pb (40-50%). The sorption is most likely explained by the presence of Fe oxyhydroxides. These are present in the highest concentrations in the slag, probably resulting in more effective metal binding to the slag than to the Fe-char. Fe-char but not slag proved to be a strong sorbent for PFASs (reducing PFAS leaching from the soil by up to 99.7%) in soil containing low total organic carbon (TOC; 1.2%) but not in high-TOC soil (34%). The sorption coefficient KD for Fe-char was high, in the range of 104.3 to 106.5 L/kg at 1 ng/L in the low-TOC soil. The KD value increased with increasing perfluorocarbon chain length, exceeding PFAS sorption to biochar in the low ng/L concentration range. This result indicates that the mechanism behind the strong PFAS sorption to Fe-char was mainly van der Waals dispersive interactions between the hydrophobic PFAS-chain and the aromatic π-electron systems on nanopore walls within the Fe-char matrix. Overall, this study indicates that industrial byproducts can provide sustainable and cost-effective materials for soil remediation. However, the sorbent needs to be tailored to the type of soil and type of contamination.
Collapse
Affiliation(s)
- Yaxin Zhang
- College of Environmental Science and Engineering, Hunan University, Lushan Gate, Lushan South Road, Yuelu District, Changsha 100084, China; Norwegian University of Life Sciences (NMBU), Faculty of Environmental Sciences and Natural Resource Management, PB 5003 NMBU, Ås 1432, Norway
| | - Gerard Cornelissen
- Norwegian University of Life Sciences (NMBU), Faculty of Environmental Sciences and Natural Resource Management, PB 5003 NMBU, Ås 1432, Norway; Norwegian Geotechnical Institute (NGI), Department of Environmental Engineering, PB 3930 Ullevaal Stadion, 0806 Oslo, Norway
| | - Ludovica Silvani
- Norwegian Geotechnical Institute (NGI), Department of Environmental Engineering, PB 3930 Ullevaal Stadion, 0806 Oslo, Norway
| | - Valentina Zivanovic
- Norwegian University of Life Sciences (NMBU), Faculty of Environmental Sciences and Natural Resource Management, PB 5003 NMBU, Ås 1432, Norway
| | - Andreas Botnen Smebye
- Norwegian Geotechnical Institute (NGI), Department of Environmental Engineering, PB 3930 Ullevaal Stadion, 0806 Oslo, Norway
| | - Erlend Sørmo
- Norwegian University of Life Sciences (NMBU), Faculty of Environmental Sciences and Natural Resource Management, PB 5003 NMBU, Ås 1432, Norway; Norwegian Geotechnical Institute (NGI), Department of Environmental Engineering, PB 3930 Ullevaal Stadion, 0806 Oslo, Norway
| | - Gorm Thune
- Lindum AS, Lerpeveien 155, Drammen, Norway
| | - Gudny Okkenhaug
- Norwegian University of Life Sciences (NMBU), Faculty of Environmental Sciences and Natural Resource Management, PB 5003 NMBU, Ås 1432, Norway; Norwegian Geotechnical Institute (NGI), Department of Environmental Engineering, PB 3930 Ullevaal Stadion, 0806 Oslo, Norway.
| |
Collapse
|
24
|
MacInnis J, De Silva AO, Lehnherr I, Muir DCG, St Pierre KA, St Louis VL, Spencer C. Investigation of perfluoroalkyl substances in proglacial rivers and permafrost seep in a high Arctic watershed. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2022; 24:42-51. [PMID: 34908076 DOI: 10.1039/d1em00349f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
We measured perfluoroalkyl substances (PFAS) in proglacial rivers and along a non-glacial freshwater continuum to investigate the role of snow and ice melting in their transport and fate within the Lake Hazen watershed (82° N). PFAS concentrations in glacial rivers were higher than those in surface waters of Lake Hazen, suggesting melting glacial ice increased PFAS concentrations in the lake. Stream water derived from subsurface soils along a non-glacial (permafrost thaw and snowmelt) freshwater continuum was a source of PFAS to Lake Hazen. Lower concentrations were found downstream of a meadow wetland relative to upstream locations along the continuum, suggesting PFAS partitioning into vegetation and soil as water flowed downstream towards Lake Hazen. Our estimations indicate that total PFAS inputs from glacial rivers and snowmelt were 1.6 kg (78%) and 0.44 kg (22%), respectively, into Lake Hazen, totalling 2.04 kg, and the output of PFAS from Lake Hazen was 0.64 kg. A positive net annual change of 1.4 kg indicates PFAS had notable residence times and/or net storage in Lake Hazen.
Collapse
Affiliation(s)
- John MacInnis
- Department of Chemistry, Memorial University, St. John's, NL A1B 3X7, Canada.
| | - Amila O De Silva
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, ON L7S 1A1, Canada.
| | - Igor Lehnherr
- Department of Geography, Geomatics and Environment, University of Toronto, Mississauga, ON L5L 1C6, Canada.
| | - Derek C G Muir
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, ON L7S 1A1, Canada.
| | - Kyra A St Pierre
- Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
| | - Vincent L St Louis
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada.
| | - Christine Spencer
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, ON L7S 1A1, Canada.
| |
Collapse
|