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Shahrokhi R, Rahman A, Hubbe MA, Park J. Aminated clay-polymer composite as soil amendment for stabilizing the short- and long-chain per- and poly-fluoroalkyl substances in contaminated soil. JOURNAL OF HAZARDOUS MATERIALS 2024; 472:134470. [PMID: 38714051 DOI: 10.1016/j.jhazmat.2024.134470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Revised: 04/14/2024] [Accepted: 04/27/2024] [Indexed: 05/09/2024]
Abstract
Soils contaminated with per- and poly- fluoroalkyl substances (PFAS) require immediate remediation to protect the surrounding environment and human health. A novel animated clay-polymer composite was developed by applying polyethyleneimine (PEI) solution onto a montmorillonite clay-chitosan polymer composite. The resulting product, PEI-modified montmorillonite chitosan beads (MMTCBs) were characterized as an adsorptive soil amendment for immobilizing PFAS contaminants. The MMTCBs exhibited good efficiency to adsorb the PFAS, showing adsorption capacities of 12.2, 16.7, 18.5, and 20.8 mg g-1 for PFBA, PFBS, PFOA, and PFOS, respectively, which were higher than those obtained by granular activated carbon (GAC) (i.e., an adsorbent used as a reference). Column leaching tests demonstrated that amending soil with 10% MMTCBs resulted in a substantial decrease in the leaching of PFOA, PFOS, PFBA, and PFBS by 90%, 100%, 64%, and 68%, respectively. These reductions were comparable to the values obtained for GAC-modified soil, particularly for long-chain PFAS. Incorporating MMTCBs into the soil not only preserved the structural integrity of the soil matrix but also enhanced its shear strength (kPa). Conversely, adding GAC to the soil resulted in a reduction of the soil's mechanical properties.
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Affiliation(s)
- Rahim Shahrokhi
- Department of Civil and Environmental Engineering, Seoul National University, Seoul, South Korea.
| | - Aneesu Rahman
- Department of Civil and Environmental Engineering, Seoul National University, Seoul, South Korea
| | - Martin A Hubbe
- Department of Forest Biomaterials, North Carolina State University, NC, United States
| | - Junboum Park
- Department of Civil and Environmental Engineering, Seoul National University, Seoul, South Korea; Institute of Construction and Environmental Engineering, Seoul National University, Seoul, South Korea.
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2
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Trzcinski AP, Harada KH. Comparison of perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and perfluorobutane sulfonate (PFBS) removal in a combined adsorption and electrochemical oxidation process. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 927:172184. [PMID: 38575007 DOI: 10.1016/j.scitotenv.2024.172184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 03/08/2024] [Accepted: 04/01/2024] [Indexed: 04/06/2024]
Abstract
This study focused on three of the most studied PFAS molecules, namely perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and perfluorobutane sulfonate (PFBS). They were compared in terms of their adsorption capacity onto graphite intercalated compound (GIC), a low surface area, highly conductive and cheap adsorbent. The adsorption on GIC followed a pseudo second order kinetics and the maximum adsorption capacity using Langmuir was 53.9 μg/g for PFOS, 22.3 μg/g for PFOA and 0.985 μg/g for PFBS due to electrostatic attraction and hydrophobic interactions. GIC was added into an electrochemical oxidation reactor and >100 μg/L PFOS was found to be fully degraded (<10 ng/L) leaving degradation by-products such as PFHpS, PFHxS, PFPeS, PFBS, PFOA, PFHxA and PFBA below 100 ng/L after 5 cycles of adsorption onto GIC for 20 min followed by regeneration at 28 mA/cm2 for 10 min. PFBS was completely removed due to degradation by aqueous electrons on GIC flakes. Up to 98 % PFOA was removed by the process after 3 cycles of adsorption onto GIC for 20 min followed by regeneration at 25 mA/cm2 for 10 min. When PFBS was spiked individually, only 17 % was removed due to poor adsorption on GIC. There was a drop of 3-40 % by treating PFOS, PFOA and smaller sulfonates in a real water matrix under the same electrochemical conditions (20 mA/cm2), but PFOS and PFOA removal percentage were 95 and 68 % after 20 min at 20 mA/cm2.
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Affiliation(s)
- Antoine P Trzcinski
- School of Agriculture and Environmental Science, University of Southern Queensland, West Street, 4350, Queensland, Australia.
| | - Kouji H Harada
- Department of health and environmental sciences, Graduate school of Medicine, Kyoto University, Kyoto 606-8501, Japan
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3
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Goranov AI, Sørmo E, Hagemann N, Cornelissen G, Zimmerman AR, Hatcher PG. Using the benzenepolycarboxylic acid (BPCA) method to assess activated biochars and their PFAS sorption abilities. CHEMOSPHERE 2024; 355:141750. [PMID: 38522671 DOI: 10.1016/j.chemosphere.2024.141750] [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: 09/13/2023] [Revised: 02/05/2024] [Accepted: 03/16/2024] [Indexed: 03/26/2024]
Abstract
Activated carbon (AC) has important industrial and environmental applications as it has excellent abilities to sorb contaminants such as per- and polyfluoroalkyl substances (PFAS). Current research aims to develop activated biochars (AB) from renewable biomass to replace AC that is produced from fossil feedstock. Both AC and AB are primarily comprised of condensed aromatic carbon (ConAC), the component that is the focus of this study. ConAC is characterized to determine its relationship with biochar activation conditions and PFAS sorption, which are understudied at present. Benzenepolycarboxylic acid (BPCA) markers for ConAC were quantified in steam-activated biochars (AB-Steam) and carbon dioxide-activated biochars (AB-CO2) prepared from waste timber at different temperatures (800, 850, 900 °C) and molar ratios of feedstock-carbon:steam (0.50 - 1.25). A non-activated biochar was also included as a reference. ConAC relative to total organic carbon content was higher in AB-Steam than in AB-CO2 (92 ± 2 % vs. 81 ± 11%). The ratio of benzenehexa- (B6CA) to benzenepentacarboxylic (B5CA) acids revealed that AB-Steam also had larger ConAC clusters than AB-CO2. These findings provide novel evidence that steam activation is more effective than CO2 activation in creating ConAC. To assess how ConAC impacts AB sorption abilities, AB-Steam were used to remediate PFAS from contaminated soils. The observed strong correlations between ConAC content and sorption of long-chain PFAS suggest the importance of hydrophobic interactions between PFAS tails and ConAC. Poor correlations for short-chain PFAS, on the other hand, indicated the existence of electrostatic repulsion interactions between PFAS head groups and ConAC. Collectively, these results explain the great ability of AB-Steam to sorb PFAS from contaminated soils (up to 100% remediation). More broadly, this work demonstrates that the BPCA method can be a valuable tool to assess the quality of biochars and other carbonaceous sorbents in relation to their production conditions or contaminant sorption abilities.
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Affiliation(s)
- Aleksandar I Goranov
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, VA, USA.
| | - Erlend Sørmo
- Department of Environmental Chemistry, Norwegian Geotechnical Institute (NGI), Oslo, Norway; Faculty of Environmental Science and Natural Resource Management (MINA), University of Life Sciences (NMBU), Ås, Norway
| | - Nikolas Hagemann
- Agroscope, Reckenholz, Switzerland; Ithaka Institute for Carbon Strategies, Arbaz, Switzerland and Goldbach, Germany
| | - Gerard Cornelissen
- Department of Environmental Chemistry, Norwegian Geotechnical Institute (NGI), Oslo, Norway; Faculty of Environmental Science and Natural Resource Management (MINA), University of Life Sciences (NMBU), Ås, Norway
| | - Andrew R Zimmerman
- Department of Geological Sciences, University of Florida, Gainesville, FL, USA
| | - Patrick G Hatcher
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, VA, USA.
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4
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Wang M, Rivenbark KJ, Nikkhah H, Beykal B, Phillips TD. In vitro and in vivo remediation of per- and polyfluoroalkyl substances by processed and amended clays and activated carbon in soil. APPLIED SOIL ECOLOGY : A SECTION OF AGRICULTURE, ECOSYSTEMS & ENVIRONMENT 2024; 196:105285. [PMID: 38463139 PMCID: PMC10919550 DOI: 10.1016/j.apsoil.2024.105285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Remediation methods for soil contaminated with poly- and perfluoroalkyl substances (PFAS) are needed to prevent their leaching into drinking water sources and to protect living organisms in the surrounding environment. In this study, the efficacy of processed and amended clays and carbons as soil amendments to sequester PFAS and prevent leaching was assessed using PFAS-contaminated soil and validated using sensitive ecotoxicological bioassays. Four different soil matrices including quartz sand, clay loam soil, garden soil, and compost were spiked with 4 PFAS congeners (PFOA, PFOS, GenX, and PFBS) at 0.01-0.2 μg/mL and subjected to a 3-step extraction method to quantify the leachability of PFAS from each matrix. The multistep extraction method showed that PFAS leaching from soil was aligned with the total carbon content in soil, and the recovery was dependent on concentration of the PFAS. To prevent the leaching of PFAS, several sorbents including activated carbon (AC), calcium montmorillonite (CM), acid processed montmorillonite (APM), and organoclays modified with carnitine, choline, and chlorophyll were added to the four soil matrices at 0.5-4 % w/w, and PFAS was extracted using the LEAF method. Total PFAS bioavailability was reduced by 58-97 % by all sorbents in a dose-dependent manner, with AC being the most efficient sorbent with a reduction of 73-97 %. The water leachates and soil were tested for toxicity using an aquatic plant (Lemna minor) and a soil nematode (Caenorhabditis elegans), respectively, to validate the reduction in PFAS bioavailability. Growth parameters in both ecotoxicological models showed a dose-dependent reduction in toxicity with value-added growth promotion from the organoclays due to added nutrients. The kinetic studies at varying time intervals and varying pHs simulating acidic rain, fresh water, and brackish water suggested a stable sorption of PFAS on all sorbents that fit the pseudo-second-order for up to 21 days. Contaminated soil with higher than 0.1 μg/mL PFAS may require reapplication of soil amendments every 21 days. Overall, AC showed the highest sorption percentage of total PFAS from in vitro studies, while organoclays delivered higher protection in ecotoxicological models (in vivo). This study suggests that in situ immobilization with soil amendments can reduce PFAS leachates and their bioavailability to surrounding organisms. A combination of sorbents may facilitate the most effective remediation of complex soil matrices containing mixtures of PFAS and prevent leaching and uptake into plants.
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Affiliation(s)
- Meichen Wang
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA
- Interdisciplinary Faculty of Toxicology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Kelly J Rivenbark
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA
- Interdisciplinary Faculty of Toxicology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Hasan Nikkhah
- Department of Chemical and Biomolecular Engineering, University of Connecticut, Storrs, CT 06269, USA
- Center for Clean Energy Engineering, University of Connecticut, Storrs, CT 06269, USA
| | - Burcu Beykal
- Department of Chemical and Biomolecular Engineering, University of Connecticut, Storrs, CT 06269, USA
- Center for Clean Energy Engineering, University of Connecticut, Storrs, CT 06269, USA
| | - Timothy D Phillips
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA
- Interdisciplinary Faculty of Toxicology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA
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Rodgers TFM, Spraakman S, Wang Y, Johannessen C, Scholes RC, Giang A. Bioretention Design Modifications Increase the Simulated Capture of Hydrophobic and Hydrophilic Trace Organic Compounds. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:5500-5511. [PMID: 38483320 DOI: 10.1021/acs.est.3c10375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/27/2024]
Abstract
Stormwater rapidly moves trace organic contaminants (TrOCs) from the built environment to the aquatic environment. Bioretention cells reduce loadings of some TrOCs, but they struggle with hydrophilic compounds. Herein, we assessed the potential to enhance TrOC removal via changes in bioretention system design by simulating the fate of seven high-priority stormwater TrOCs (e.g., PFOA, 6PPD-quinone, PAHs) with log KOC values between -1.5 and 6.74 in a bioretention cell. We evaluated eight design and management interventions for three illustrative use cases representing a highway, a residential area, and an airport. We suggest two metrics of performance: mass advected to the sewer network, which poses an acute risk to aquatic ecosystems, and total mass advected from the system, which poses a longer-term risk for persistent compounds. The optimized designs for each use case reduced effluent loadings of all but the most polar compound (PFOA) to <5% of influent mass. Our results suggest that having the largest possible system area allowed bioretention systems to provide benefits during larger events, which improved performance for all compounds. To improve performance for the most hydrophilic TrOCs, an amendment like biochar was necessary; field-scale research is needed to confirm this result. Our results showed that changing the design of bioretention systems can allow them to effectively capture TrOCs with a wide range of physicochemical properties, protecting human health and aquatic species from chemical impacts.
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Affiliation(s)
- Timothy F M Rodgers
- Institute of Resources, Environment and Sustainability, University of British Columbia, Vancouver, British Columbia V6T1Z4, Canada
- Department of Civil Engineering, University of British Columbia, Vancouver, British Columbia V6T1Z4, Canada
| | - Sylvie Spraakman
- Green Infrastructure Design Team, City of Vancouver Engineering Services, Vancouver, British Columbia V5Z0B4, Canada
| | - Yanru Wang
- Department of Civil Engineering, University of British Columbia, Vancouver, British Columbia V6T1Z4, Canada
| | - Cassandra Johannessen
- Department of Chemistry and Biochemistry, Concordia University, Montreal, Quebec H4B1R6, Canada
| | - Rachel C Scholes
- Department of Civil Engineering, University of British Columbia, Vancouver, British Columbia V6T1Z4, Canada
| | - Amanda Giang
- Institute of Resources, Environment and Sustainability, University of British Columbia, Vancouver, British Columbia V6T1Z4, Canada
- Department of Mechanical Engineering, University of British Columbia, Vancouver, British Columbia V6T1Z4, Canada
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6
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Zhou P, Gu Q, Zhou S, Cui X. A novel montmorillonite clay-cetylpyridinium chloride material for reducing PFAS leachability and bioavailability from soils. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133402. [PMID: 38183937 DOI: 10.1016/j.jhazmat.2023.133402] [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: 09/20/2023] [Revised: 12/23/2023] [Accepted: 12/27/2023] [Indexed: 01/08/2024]
Abstract
Soils contaminated by per- and polyfluoroalkyl substances (PFAS) present a significant threat to both ecological and human health. Extensive research efforts are currently underway to develop effective strategies for immobilizing these chemicals in soils. In this study, calcium montmorillonite was modified with cetylpyridinium chloride (CPC-CM) to enhance its electrostatic and hydrophobic interactions with PFAS. CPC-CM exhibited high adsorption for perfluorooctanoate acid (PFOA), perfluorooctane sulfonate (PFOS) and 8:2 fluorotelomer sulfonic acids (8:2 FTSA) across initial concentrations of 50-1000 μg/L, outperforming both the parent CM and L-carnitine modified CM. Soil leaching tests demonstrated the superior immobilization capabilities of the CPC-CM, maintaining an average PFAS leaching rate below 7% after 120-day incubation. In the context of human exposure scenarios, the in vitro bioaccessibility and in vivo bioavailability of PFAS in soils were measured by gastrointestinal extraction and mouse assay. CPC-CM treatment effectively reduced the bioaccessibility (by up to 84%) and bioavailability (by up to 76%) of PFAS in soils. Furthermore, the safety and efficacy of CPC-CM were evaluated using enteric microorganisms of mice. CPC-CM treatment mitigated PFAS-induced changes in the abundance of Bacteroidetes and Firmicutes, thereby reducing PFAS-induced health risks for humans. Overall, CPC-CM synthesized in this study demonstrated superior adsorption performance and application safety, offering a highly promising approach for remediating PFAS-contaminated soil.
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Affiliation(s)
- Pengfei Zhou
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, People's Republic of China
| | - Qian Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, People's Republic of China
| | - Shuo Zhou
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, People's Republic of China
| | - Xinyi Cui
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, People's Republic of China.
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7
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Bui TH, Zuverza-Mena N, Dimkpa CO, Nason SL, Thomas S, White JC. PFAS remediation in soil: An evaluation of carbon-based materials for contaminant sequestration. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 344:123335. [PMID: 38211874 PMCID: PMC10922530 DOI: 10.1016/j.envpol.2024.123335] [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: 08/04/2023] [Revised: 12/19/2023] [Accepted: 01/08/2024] [Indexed: 01/13/2024]
Abstract
The presence of per- and poly-fluoroalkyl substances (PFAS) in soils is a global concern as these emerging contaminants are highly resistant to degradation and cause adverse effects on human and environmental health at very low concentrations. Sequestering PFAS in soils using carbon-based materials is a low-cost and effective strategy to minimize pollutant bioavailability and exposure, and may offer potential long-term remediation of PFAS in the environment. This paper provides a comprehensive evaluation of current insights on sequestration of PFAS in soil using carbon-based sorbents. Hydrophobic effects originating from fluorinated carbon (C-F) backbone "tail" and electrostatic interactions deriving from functional groups on the molecules' "head" are the two driving forces governing PFAS sorption. Consequently, varying C-F chain lengths and polar functional groups significantly alter PFAS availability and leachability. Furthermore, matrix parameters such as soil organic matter, inorganic minerals, and pH significantly impact PFAS sequestration by sorbent amendments. Materials such as activated carbon, biochar, carbon nanotubes, and their composites are the primary C-based materials used for PFAS adsorption. Importantly, modifying the carbon structural and surface chemistry is essential for increasing the active sorption sites and for strengthening interactions with PFAS. This review evaluates current literature, identifies knowledge gaps in current remediation technologies and addresses future strategies on the sequestration of PFAS in contaminated soil using sustainable novel C-based sorbents.
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Affiliation(s)
- Trung Huu Bui
- The Connecticut Agricultural Experiment Station, 123 Huntington Street, New Haven, CT, 06511, USA
| | - Nubia Zuverza-Mena
- The Connecticut Agricultural Experiment Station, 123 Huntington Street, New Haven, CT, 06511, USA
| | - Christian O Dimkpa
- The Connecticut Agricultural Experiment Station, 123 Huntington Street, New Haven, CT, 06511, USA
| | - Sara L Nason
- The Connecticut Agricultural Experiment Station, 123 Huntington Street, New Haven, CT, 06511, USA
| | - Sara Thomas
- The Connecticut Agricultural Experiment Station, 123 Huntington Street, New Haven, CT, 06511, USA
| | - Jason C White
- The Connecticut Agricultural Experiment Station, 123 Huntington Street, New Haven, CT, 06511, USA.
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8
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Trzcinski AP, Harada K. Combined adsorption and electrochemical oxidation of perfluorooctanoic acid (PFOA) using graphite intercalated compound. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:19946-19960. [PMID: 38367112 PMCID: PMC10927886 DOI: 10.1007/s11356-024-32449-0] [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: 11/28/2023] [Accepted: 02/08/2024] [Indexed: 02/19/2024]
Abstract
Perfluorooctanoic acid (PFOA) is a bioaccumulative synthetic chemical containing strong C-F bonds and is one of the most common per- and polyfluoroalkyl substances (PFAS) detected in the environment. Graphite intercalated compound (GIC) flakes were used to adsorb and degrade PFOA through electrochemical oxidation. The adsorption followed the Langmuir model with a loading capacity of 2.6 µg PFOA g-1 GIC and a second-order kinetics (3.354 g µg-1 min-1). 99.4% of PFOA was removed by the process with a half-life of 15 min. When PFOA molecules broke down, they released various by-products, such as short-chain perfluoro carboxylic acids like PFHpA, PFHxA, and PFBA. This breakdown indicates the cleavage of the perfluorocarbon chain and the release of CF2 units, suggesting a transformation or degradation of the original compound into these smaller acids. Shorter-chain perfluorinated compounds had slower degradation rates compared to longer-chain ones. Combining these two methods (adsorption and in situ electrochemical oxidation) was found to be advantageous because adsorption can initially concentrate the PFOA molecules, making it easier for the electrochemical process to target and degrade them. The electrochemical process can potentially break down or transform the PFAS compounds into less harmful substances through oxidation or other reactions.
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Affiliation(s)
- Antoine P Trzcinski
- School of Agriculture and Environmental Science, University of Southern Queensland, West Street, Queensland, 4350, Australia.
| | - Kouji Harada
- Department of Health and Environmental Sciences, Graduate School of Medicine, Kyoto University, Kyoto, 606-8501, Japan
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9
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Cerlanek A, Liu Y, Robey N, Timshina AS, Bowden JA, Townsend TG. Assessing construction and demolition wood-derived biochar for in-situ per- and polyfluoroalkyl substance (PFAS) removal from landfill leachate. WASTE MANAGEMENT (NEW YORK, N.Y.) 2024; 174:382-389. [PMID: 38101234 DOI: 10.1016/j.wasman.2023.12.017] [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: 10/30/2023] [Revised: 12/04/2023] [Accepted: 12/08/2023] [Indexed: 12/17/2023]
Abstract
With regulations for per-and polyfluoroalkyl substances (PFAS) impending, the abundance of these chemicals of emerging concern in municipal solid waste (MSW) landfill leachate increasingly challenges landfill operators to seek on-site leachate pre-treatment options. This two-staged study explores the potential reuse of biochar derived from construction and demolition debris (CDD) wood as an in-situ PFAS sorbent for application within MSW landfill leachate collection systems. Batch leaching tests were first used to examine the feasibility of capturing PFAS from landfill leachate using two sources of CDD-wood-derived biochar. Then, columns were used to test the in-situ sorption capabilities of the same biochars under simulated landfill conditions. All leachates were characterized for pH, chemical oxygen demand, ammonia-nitrogen, and 92 PFAS. Seventeen PFAS were detected in the batch leaching experiment, and nine PFAS were detected in column leachates. In the batch leaching scenario, Biochar 1 achieved a maximum of 29% PFAS reduction compared to controls. Columns containing Biochar 1 generated leachates with PFAS concentrations 50% to 80% higher than those in control columns for the duration of the experiment. Columns containing Biochar 2 generated leachates with PFAS concentrations 44% less than controls in week 1 and similar concentrations in weeks 2, 3, and 4. In this study, PFAS removal from landfill leachate using biochar derived from CDD wood was not significant. Further research on biochar derived from CDD wood is needed before it can be recommended as an in-situ landfill leachate pre-treatment method.
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Affiliation(s)
- Allison Cerlanek
- University of Florida, Department of Environmental Engineering Sciences, College of Engineering, Gainesville, FL 32611, USA
| | - Yalan Liu
- Florida Atlantic University, Department of Civil, Environmental and Geomatics Engineering, Boca Raton, FL 33431, USA
| | - Nicole Robey
- Innovative Technical Solutions, Gainesville, FL 32606, USA
| | - Alina S Timshina
- University of Florida, Department of Environmental Engineering Sciences, College of Engineering, Gainesville, FL 32611, USA
| | - John A Bowden
- University of Florida, Department of Environmental Engineering Sciences, College of Engineering, Gainesville, FL 32611, USA; University of Florida, Center for Environmental and Human Toxicology & Department of Physiological Sciences, College of Veterinary Medicine, Gainesville, FL 32611, USA
| | - Timothy G Townsend
- University of Florida, Department of Environmental Engineering Sciences, College of Engineering, Gainesville, FL 32611, USA.
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10
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Shahrokhi R, Park J. Enhanced removal of short- and long-chain per- and poly-fluoroalkyl substances from aqueous phase using crushed grafted chitosan beads: Performance and mechanisms. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 340:122836. [PMID: 37925012 DOI: 10.1016/j.envpol.2023.122836] [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: 08/01/2023] [Revised: 10/23/2023] [Accepted: 10/29/2023] [Indexed: 11/06/2023]
Abstract
The widespread use of per- and poly-fluoroalkyl substances (PFASs), environmentally persistent halogenated hydrocarbons, in various industrial and commercial applications has caused significant concerns owing to their contamination of soil and groundwater. Chitosan is a biopolymer substance with abundant amine and hydroxyl functional groups, making it a good candidate for adsorption of PFASs. This study aimed to increase chitosan's adsorption capacity by grafting additional amine functional groups on its surface for the removal of long- and short-chain PFASs from an aqueous phase. Two types of chitosan-based sorbents were developed: crushed chitosan beads (CBs) and polyethyleneimine-grafted CBs (GCBs). Batch adsorption tests assessed the adsorption capacities of the sorbents in terms of the sorption kinetics, isotherms, selectivity, and reusability. Based on the results, the GCBs had significant potential for adsorbing PFASs. These capacities were significantly higher than those demonstrated by the CBs. The sorption kinetics data revealed that the GCBs had a fast sorption rate. Furthermore, the GCBs demonstrated a high adsorption affinity, with log Kd values ranging from 1.5 to 2.5 for PFASs at environmentally relevant concentrations (1000 ng L-1). They also demonstrated excellent selectivity sorption for these compounds, even in the presence of other organic and inorganic pollutants.
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Affiliation(s)
- Rahim Shahrokhi
- Department of Civil and Environmental Engineering, Seoul National University, South Korea
| | - Junboum Park
- Department of Civil and Environmental Engineering, Seoul National University, South Korea; Institute of Construction and Environmental Engineering, Seoul National University, South Korea.
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11
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Cai W, Navarro DA, Du J, Srivastava P, Cao Z, Ying G, Kookana RS. Effect of heavy metal co-contaminants on the sorption of thirteen anionic per- and poly-fluoroalkyl substances (PFAS) in soils. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 905:167188. [PMID: 37734606 DOI: 10.1016/j.scitotenv.2023.167188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Revised: 09/13/2023] [Accepted: 09/16/2023] [Indexed: 09/23/2023]
Abstract
Understanding the sorption behavior of per- and poly-fluoroalkyl substances (PFAS) in soils are essential for assessing their mobility and risk in the environment. Heavy metals often coexist with PFAS depending on the source and history of contamination. In this study, we investigated the effect of heavy metal co-contaminants (Pb2+, Cu2+ and Zn2+) on the sorption of 13 anionic PFAS with different perfluorocarbon chain length (C3-C9) in two soils with different properties. Results revealed that Pb2+, Cu2+ and Zn2+ had little effect on the sorption of most short-chain compounds, while the presence of these heavy metals enhanced the sorption of long-chain PFAS in two soils. The distribution coefficients (Kd) of several long-chain PFAS linearly increased with increasing concentrations of heavy metal, especially in the presence of Pb2+ (ΔKd/Δ [Pb2+] > 3 for PFOS and PFNA vs <1 for PFPeS and PFHxS). While several mechanisms may have contributed to the enhancement of sorption of PFAS, the heavy metals most likely contributed through enhanced hydrophobic interactions of PFAS by neutralizing the negative charge of adsorption surfaces in soils and thus making it more favorable for their partitioning onto the solid phase. Moreover, the increase in the concentrations of heavy metals led to a decrease in the pH of the system and promoted sorption of long-chain compounds, especially in soil with lower organic carbon content. Overall, this study provides evidence that the presence of co-existing heavy metal cations in soils can significantly enhance the sorption of long-chain PFAS onto soil, thereby potentially limiting their mobility in the environment.
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Affiliation(s)
- Wenwen Cai
- School of Environment, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, International Joint Laboratory on Key Techniques in Water Treatment, Henan Normal University, Xinxiang 453007, China; State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Divina A Navarro
- CSIRO Environment, Locked Bag 2, Glen Osmond, 5064, Australia; School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, Locked Bag 1, Glen Osmond 5064, Australia.
| | - Jun Du
- CSIRO Environment, Locked Bag 2, Glen Osmond, 5064, Australia
| | | | - Zhiguo Cao
- School of Environment, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, International Joint Laboratory on Key Techniques in Water Treatment, Henan Normal University, Xinxiang 453007, China
| | - Guangguo Ying
- School of Environment, South China Normal University, Guangzhou 510006, China
| | - Rai S Kookana
- CSIRO Environment, Locked Bag 2, Glen Osmond, 5064, Australia; School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, Locked Bag 1, Glen Osmond 5064, Australia
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12
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Bresnahan CG, Schutt TC, Shukla MK. Exploration of functionalizing graphene and the subsequent impact on PFAS adsorption capabilities via molecular dynamics. CHEMOSPHERE 2023; 345:140462. [PMID: 37866495 DOI: 10.1016/j.chemosphere.2023.140462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 10/13/2023] [Accepted: 10/14/2023] [Indexed: 10/24/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are extremely stable compounds due to their strong C-F bonds. They are used in water and stain proof coatings, aqueous film forming foams for fire suppression, cosmetics, paints, adhesives, etc. PFAS have been found in soils and waterways around the world due to their widespread usage and recalcitrance to degradation. Development of selective adsorbent materials is necessary to effectively capture a vast family of PFAS structures in order to remediate PFAS contamination in the environment. The work herein is focused on extracting design principles from molecular dynamics simulations of PFAS with functionalized graphene materials. Simulations examined how PFBA, PFOA, and PFOS interact with graphene, graphene oxide, nitrogen group-functionalized graphene oxide, partially fluorinated graphene flakes, and fully fluorinated flakes. Five flakes were used in each simulation to examine how interactions between flakes may lead to competitive interactions with respect to PFAS or formation of pores. Our study revealed that both the clustering mechanisms of the flakes and functional groups on the flake play a role in PFAS adsorption. The most effective functionalizations for PFAS adsorption are as follows: pristine graphene ≈ fully fluorinated > graphene oxide ≈ partially fluorinated > amine and amide functionalized graphene oxide flake. Long chain PFAS and sulfonate PFAS had higher propensity to adsorb to the materials compared to short chain PFAS and carboxylic head groups.
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Affiliation(s)
- Caitlin G Bresnahan
- US Army Corps of Engineers, Engineer Research and Development Center, Environmental Laboratory, Vicksburg, MS 39180, United States.
| | - Timothy C Schutt
- US Army Corps of Engineers, Engineer Research and Development Center, Environmental Laboratory, Vicksburg, MS 39180, United States
| | - Manoj K Shukla
- US Army Corps of Engineers, Engineer Research and Development Center, Environmental Laboratory, Vicksburg, MS 39180, United States.
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13
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Ganbat N, Hamdi FM, Ibrar I, Altaee A, Alsaka L, Samal AK, Zhou J, Hawari AH. Iron slag permeable reactive barrier for PFOA removal by the electrokinetic process. JOURNAL OF HAZARDOUS MATERIALS 2023; 460:132360. [PMID: 37657326 DOI: 10.1016/j.jhazmat.2023.132360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 08/14/2023] [Accepted: 08/20/2023] [Indexed: 09/03/2023]
Abstract
The efficacy of the Standalone Electrokinetic (EK) process in soil PFAS removal is negligible, primarily due to the intersecting mechanisms of electromigration and electroosmosis transportation. Consequently, the redistribution of PFAS across the soil matrix occurs, hampering effective remediation efforts. Permeable reactive barrier (PRB) has been used to capture contaminants and extract them at the end of the EK process. This study conducted laboratory-scale tests to evaluate the feasibility of the iron slag PRB enhanced-EK process in conjunction with Sodium Cholate (NaC) biosurfactant as a cost-effective and sustainable method for removing PFOA from the soil. A 2 cm iron slag-based PRB with a pH of 9.5, obtained from the steel-making industry, was strategically embedded in the middle of the EK reactors to capture PFOA within the soil. The main component of the slag, iron oxide, exhibited significant adsorption capacity for PFOA contamination. The laboratory-scale tests were conducted over two weeks, revealing a PFOA removal rate of more than 79% in the slag/activated carbon PRB-EK test with NaC enhancement and 70% PFOA removal in the slag/activated carbon PRB-EK without NaC. By extending the duration of the slag/AC PRB-EK test with NaC enhancement to three weeks, the PFOA removal rate increased to 94.09%, with the slag/AC PRB capturing over 87% of the initial PFOA concentration of 10 mg/L. The specific energy required for soil decontamination by the EK process was determined to be 0.15 kWh/kg. The outcomes of this study confirm the feasibility of utilizing iron slag waste in the EK process to capture PFOA contaminants, offering a sustainable approach to soil decontamination. Combining iron slag PRB and NaC biosurfactant provides a cost-effective and environmentally friendly method for efficient PFOA removal from soil.
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Affiliation(s)
- Namuun Ganbat
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, Australia
| | - Faris M Hamdi
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, Australia
| | - Ibrar Ibrar
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, Australia
| | - Ali Altaee
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, Australia.
| | - Lilyan Alsaka
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, Australia
| | - Akshaya K Samal
- Centre for Nano and Material Sciences, Jain University, Ramanagara, Bangalore 562 112, Karnataka, India
| | - John Zhou
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, Australia
| | - Alaa H Hawari
- Department of Civil and Architectural Engineering, College of Engineering, Qatar University, PO Box 2713, Doha, Qatar
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14
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Wang Y, Ji Y, Li K, Huang Q. Foam fractionation and electrochemical oxidation for the treatment of per- and polyfluoroalkyl substances (PFAS) in environmental water samples. CHEMOSPHERE 2023; 339:139615. [PMID: 37499808 DOI: 10.1016/j.chemosphere.2023.139615] [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: 05/06/2023] [Revised: 07/20/2023] [Accepted: 07/21/2023] [Indexed: 07/29/2023]
Abstract
Treatment of waters contaminated by per- and polyfluoroalkyl substances (PFAS) in large volumes remains a challenge to date. Treatment trains comprising separation and destruction technologies are promising to manage PFAS contamination. Foam fractionation (FF) and electrochemical oxidation (EO) are two cost-effective technologies for PFAS separation and destruction, respectively. This work systematically explored the performance of a treatment train of FF followed by EO (FF-EO) for treating PFAS in environmental water samples. For each treatment step, the dependence of the treatment performance on operational factors and other variables were analyzed statistically. The statistical analysis revealed PFAS enrichment and removal depend significantly on PFAS carbon chain length, solution conductivity, and PFAS concentration. Whether FF-EO treatment costs less energy than direct EO without FF mainly relies upon PFAS carbon chain length and TOC content in the sample. Both correlations were found to be linear. For all environmental water samples in this study, FF-EO is more energy-efficient than EO alone.
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Affiliation(s)
- Yifei Wang
- Department of Crop and Soil Sciences, University of Georgia, Griffin, GA, 30223, USA
| | - Yuqing Ji
- Department of Crop and Soil Sciences, University of Georgia, Griffin, GA, 30223, USA
| | - Ke Li
- College of Engineering, University of Georgia, Athens, GA, 30602, USA
| | - Qingguo Huang
- Department of Crop and Soil Sciences, University of Georgia, Griffin, GA, 30223, USA.
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15
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Mohona TM, Ye Z, Dai N, Nalam PC. Adsorption behavior of long-chain perfluoroalkyl substances on hydrophobic surface: A combined molecular characterization and simulation study. WATER RESEARCH 2023; 239:120074. [PMID: 37207455 DOI: 10.1016/j.watres.2023.120074] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 05/06/2023] [Accepted: 05/11/2023] [Indexed: 05/21/2023]
Abstract
Hydrophobic interaction is a prevalent sorption mechanism of poly- and perfluoroalkyl substances (PFAS) in natural and engineered environments. In this study, we combined quartz crystal microbalance with dissipation (QCM-D), atomic force microscope (AFM) with force mapping, and molecular dynamics (MD) simulation to probe the molecular behavior of PFAS at the hydrophobic interface. On a CH3-terminated self-assembled monolayer (SAM), perfluorononanoic acid (PFNA) showed ∼2-fold higher adsorption than perfluorooctane sulfonate (PFOS) that has the same fluorocarbon tail length but a different head group. Kinetic modeling using the linearized Avrami model suggests that the PFNA/PFOS-surface interaction mechanisms can evolve over time. This is confirmed by AFM force-distance measurements, which shows that while the adsorbed PFNA/PFOS molecules mostly lay flat, a portion of them formed aggregates/hierarchical structures of 1-10 nm in size after lateral diffusion on surface. PFOS showed a higher affinity to aggregate than PFNA. Association with air nanobubbles is observed for PFOS but not PFNA. MD simulations further showed that PFNA has a greater tendency than PFOS to have its tail inserted into the hydrophobic SAM, which can enhance adsorption but limit lateral diffusion, consistent with the relative behavior of PFNA/PFOS in QCM and AFM experiments. This integrative QCM-AFM-MD study reveals that the interfacial behavior of PFAS molecules can be heterogeneous even on a relatively homogeneous surface.
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Affiliation(s)
- Tashfia M Mohona
- Department of Civil, Structural and Environmental Engineering, University at Buffalo, Buffalo, NY, USA; Department of Materials Design and Innovation, University at Buffalo, Buffalo, NY, USA
| | - Zhijiang Ye
- Department of Mechanical and Manufacturing Engineering, Miami University, Oxford, OH, USA
| | - Ning Dai
- Department of Civil, Structural and Environmental Engineering, University at Buffalo, Buffalo, NY, USA.
| | - Prathima C Nalam
- Department of Materials Design and Innovation, University at Buffalo, Buffalo, NY, USA.
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16
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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.
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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
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17
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Qian S, Zhou X, Fu Y, Song B, Yan H, Chen Z, Sun Q, Ye H, Qin L, Lai C. Biochar-compost as a new option for soil improvement: Application in various problem soils. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 870:162024. [PMID: 36740069 DOI: 10.1016/j.scitotenv.2023.162024] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 01/09/2023] [Accepted: 01/31/2023] [Indexed: 06/18/2023]
Abstract
Due to the synergistic effects of biochar and compost/composting, the combined application of biochar and compost (biochar-compost) has been recognized as a highly promising and efficient method of soil improvement. However, the willingness to apply biochar-compost for soil improvement is still low compared to the use of biochar or compost alone. This paper collects data on the application of biochar-compost in several problem soils that are well-known and extensively investigated by agronomists and scientists, and summarizes the effects of biochar-compost application in common problem soils. These typical problem soils are classified based on three different characteristics: climatic zones, abiotic stresses, and contaminants. The improvement effect of biochar-compost in different soils is assessed and directions for further research and suggestions for application are made. Generally, biochar-compost mitigates the high mineralization rate of soil organic matter, phosphorus deficiency and aluminum toxicity, and significantly improves crop yields in most tropical soils. Biochar-compost can help to achieve long-term sustainable management of temperate agricultural soils by sequestering carbon and improving soil physicochemical properties. Biochar-compost has shown positive performance in the remediation of both dry and saline soils by reducing the threat of soil water scarcity or high salinity and improving the consequent deterioration of soil conditions. By combining different mechanisms of biochar and compost to immobilize or remove contaminants, biochar-compost tends to perform better than biochar or compost alone in soils contaminated with heavy metals (HMs) or organic pollutants (OPs). This review aims to improve the practicality and acceptability of biochar-compost and to promote its application in soil. Additionally, the prospects, challenges and future directions for the application of biochar-compost in problem soil improvement were foreseen.
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Affiliation(s)
- Shixian Qian
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China
| | - Xuerong Zhou
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China
| | - Yukui Fu
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China
| | - Biao Song
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China
| | - Huchuan Yan
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China
| | - Zhexin Chen
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China
| | - Qian Sun
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China
| | - Haoyang Ye
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China
| | - Lei Qin
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China.
| | - Cui Lai
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China.
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18
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Chang PH, Mukhopadhyay R, Zhong B, Yang QY, Zhou S, Tzou YM, Sarkar B. Synthesis and characterization of PCN-222 metal organic framework and its application for removing perfluorooctane sulfonate from water. J Colloid Interface Sci 2023; 636:459-469. [PMID: 36641821 DOI: 10.1016/j.jcis.2023.01.032] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 12/09/2022] [Accepted: 01/06/2023] [Indexed: 01/09/2023]
Abstract
Poly- and perfluoro alkyl substances (PFAS) are a group of man-made, notoriously persistent, and highly toxic contaminants in the environment reported worldwide. Many adsorbents including granular activated carbon, graphene, biochar, zeolites, and clay minerals have been tested for PFAS removal from water, but most of these materials suffer from high cost and/or poor removal performance. Here, we synthesized, characterized, and examined the efficiency of PCN-222(Fe), a new porous metal organic framework (MOF) with high water stability, for adsorptive removal of a frequently occurring PFAS, perfluorooctane sulfonate (PFOS), from water. The adsorption isotherm and kinetic studies revealed high PFOS adsorption capacity of PCN-222 (2257 mg/g), with rapid PFOS removal rate (within 30 min). The structure of PCN-222 was unaffected in water in the pH range of 2-10 but disintegrated and lost its PFOS removal ability at pH > 10. The PFOS adsorption on PCN-222 was an endothermic reaction. Electrostatic attraction was a dominant mechanism for PFOS adsorption at < 1694 mg/g PFOS concentration, while hydrophobic interaction accompanied with hydrogen-bonding was responsible at ≥ 1694 mg/g PFOS concentration. The interlayer morphology of PCN-222 did not change due to increasing PFOS loading. The findings of this study demonstrated superior features of PCN-222 over other conventional adsorbents for its potential application in removing PFOS from contaminated water to reduce PFOS transfer from water to living organisms.
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Affiliation(s)
- Po-Hsiang Chang
- College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China
| | - Raj Mukhopadhyay
- Division of Irrigation and Drainage Engineering, ICAR-Central Soil Salinity Research Institute, Karnal 132001, Haryana, India
| | - Bo Zhong
- Shaanxi Provincial Land Engineering Construction Group Co. Ltd., Xi'an, Shaanxi 710075, China
| | - Qing-Yuan Yang
- School of Chemical Engineering and Technology, Xi'an Jiaotong University, 28 Xianning West Road, Xi'an, Shaanxi 710049, PR China
| | - Shungui Zhou
- College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China
| | - Yu-Min Tzou
- Department of Soil and Environmental Sciences, National Chung Hsing University, 145 Xingda Rd., Taichung 40227, Taiwan.
| | - Binoy Sarkar
- Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095, Australia.
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19
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Navarro DA, Kabiri S, Ho J, Bowles KC, Davis G, McLaughlin MJ, Kookana RS. Stabilisation of PFAS in soils: Long-term effectiveness of carbon-based soil amendments. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 323:121249. [PMID: 36764376 DOI: 10.1016/j.envpol.2023.121249] [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: 12/19/2022] [Revised: 01/27/2023] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
Immobilisation/stabilisation is one of the most developed and studied approaches for treating soils contaminated with per- and poly-fluoroalkyl substances (PFAS). However, its application has been inhibited by insufficient understanding of the effectiveness of added soil sorbents over time. Herein, we present results on the effectiveness of select carbon-based sorbents, over 4 years (longevity) and multiple laboratory leaching conditions (durability). Standard batch leaching tests simulating aggressive, worst-case scenario conditions for leaching (i.e., shaking for 24-48 h at high liquid/solid ratios) were employed to test longevity and durability of stabilisation in clay-loam and sandy-loam soils historically contaminated with PFAS (2 and 14 mg/kg ∑28 PFAS). The different sorbents, which were applied at 1-6% (w/w), reduced leaching of PFAS from the soils to varying degrees. Among the 5 sorbents tested, initial assessments completed 1 week after treatment revealed that 2 powdered activated carbon (PAC) sorbents and 1 biochar were able to reduce leaching of PFAS in the soil by at least 95%. Four years after treatment, the performance of the PAC sorbents did not significantly change, whilst colloidal AC improved and was able to reduce leaching of PFAS by at least 94%. The AC-treated soils also appeared to be durable and achieved at least 95% reduction in PFAS leaching under repetitive leaching events (5 times extraction) and with minimal effect of pH (pH 4-10.5). In contrast, the biochars were affected by aging and were at least 22% less effective in reducing PFAS leaching across a range of leaching conditions. Sorbent performance was generally consistent with the sorbent's physical and chemical characteristics. Overall, the AC sorbents used in this study appeared to be better than the biochars in stabilising PFAS in the long term.
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Affiliation(s)
- Divina A Navarro
- CSIRO Environment, PMB 2, Glen Osmond, SA, 5064, Australia; School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, PMB1, Glen Osmond, South Australia, 5064, Australia.
| | - Shervin Kabiri
- School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, PMB1, Glen Osmond, South Australia, 5064, Australia
| | - Jonathan Ho
- AECOM Australia Pty Ltd, Sydney, NSW, 2000, Australia
| | - Karl C Bowles
- RPS AAP Consulting Pty Ltd, 420 George Street, Sydney, NSW, 2000, Australia; Queensland Alliance for Environmental Health Sciences, The University of Queensland, level 4/20 Cornwall St, Woolloongabba, QLD, 4102, Australia
| | - Greg Davis
- CSIRO Environment, 147 Underwood Avenue, Floreat, Western Australia, 6014, Australia
| | - Mike J McLaughlin
- School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, PMB1, Glen Osmond, South Australia, 5064, Australia
| | - Rai S Kookana
- CSIRO Environment, PMB 2, Glen Osmond, SA, 5064, Australia; School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, PMB1, Glen Osmond, South Australia, 5064, Australia
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20
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Adu O, Ma X, Sharma VK. Bioavailability, phytotoxicity and plant uptake of per-and polyfluoroalkyl substances (PFAS): A review. JOURNAL OF HAZARDOUS MATERIALS 2023; 447:130805. [PMID: 36669401 DOI: 10.1016/j.jhazmat.2023.130805] [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: 12/03/2022] [Revised: 01/12/2023] [Accepted: 01/14/2023] [Indexed: 06/17/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are a group of legacy and emerging contaminants containing at least one aliphatic perfluorocarbon moiety. They display rapid and extensive transport in the environment due to their generally high water-solubility and weak adsorption onto soil particles. Because of their widespread presence in the environment and known toxicity, PFAS has become a serious threat to the ecosystem and public health. Plants are an essential component of the ecosystem and their uptake and accumulation of PFAS affect the fate and transport of PFAS in the ecosystem and has strong implications for human health. It is therefore imperative to investigate the interactions of plants with PFAS. This review presents a detailed discussion on the mechanisms of the bioavailability and plant uptake of PFAS, and essential factors affecting these processes. The phytotoxic effects of PFAS at physiological, biochemical, and molecular level were also carefully reviewed. At the end, key research gaps were identified, and future research needs were proposed.
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Affiliation(s)
- Olatunbosun Adu
- Department of Water Management and Hydrological Science, Texas A&M University, College Station, TX 77843, USA; Program for the Environment and Sustainability, Department of Environmental and Occupational Health, School of Public Health, Texas A&M University, 212 Adriance Lab Rd., 1266 TAMU, College Station, TX 77843, USA
| | - Xingmao Ma
- Department of Civil and Environmental Engineering, Texas A&M University, College Station, TX 77843, USA.
| | - Virender K Sharma
- Program for the Environment and Sustainability, Department of Environmental and Occupational Health, School of Public Health, Texas A&M University, 212 Adriance Lab Rd., 1266 TAMU, College Station, TX 77843, USA.
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21
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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.
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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
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22
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Li YF, Fang T, Lee YC, Liu YJ, Hu CY, Lo SL. Cationic surfactants influencing the enhancement of energy efficiency for perfluorooctanoic acid (PFOA) removal in the electrocoagulation-flotation (ECF) system. CHEMOSPHERE 2023; 318:137932. [PMID: 36690258 DOI: 10.1016/j.chemosphere.2023.137932] [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: 09/07/2022] [Revised: 12/24/2022] [Accepted: 01/19/2023] [Indexed: 06/17/2023]
Abstract
From an environmental perspective, approaching sustainability requires a fundamental conceptual shift from the wastewater treatment process toward integrated treatment systems that consider efficient and effective utilization. This study aims to investigate the effects of different surfactants on the removal of perfluorooctanoic acid (PFOA). We used cationic surfactants as both frothers and collectors in the electrocoagulation-flotation (ECF) method to improve the removal efficiency of PFOA. The results showed that, under a monopolar aluminum electrode and with an initial PFOA concentration of 0.25 mM, the ECF method with decyl-trimethyl-ammonium bromide (DTAB) was able to remove over 98% of PFOA within 10 min. Cationic surfactants with a similar linear alkyl chain shape to PFOA, but a longer chain length, are more effective at removing PFOA through the ECF process. The removal mechanism is thought to involve co-precipitation with aluminum hydroxides through Al-F bonding, co-flotation with cationic surfactants, and mixed micelle formation with cationic surfactants. The optimal conditions were tested in both synthetic and realistic wastewater matrices and produced similar results. It has the potential for real wastewater application. The energy yield (G50) of ECF with 5 mM DTAB is 497 g·kWh-1, superior to other treatments, and is an extremely energy-effective method for separating PFOA from wastewater.
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Affiliation(s)
- Yueh-Feng Li
- Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chuo-Shan Rd., Taipei, 10673, Taiwan
| | - Ting Fang
- Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chuo-Shan Rd., Taipei, 10673, Taiwan
| | - Yu-Chi Lee
- Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chuo-Shan Rd., Taipei, 10673, Taiwan
| | - Yu-Jung Liu
- Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chuo-Shan Rd., Taipei, 10673, Taiwan
| | - Ching-Yao Hu
- School of Public Health, Taipei Medical University, 250 Wu-Xing Street, Taipei, 11031, Taiwan.
| | - Shang-Lien Lo
- Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chuo-Shan Rd., Taipei, 10673, Taiwan; Water Innovation, Low Carbon and Environmental Sustainability Research Center, National Taiwan University, Taipei, 10617, Taiwan.
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23
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Zhang W, Wellington TE, Liang Y. Effect of two sorbents on the distribution and transformation of N-ethyl perfluorooctane sulfonamido acetic acid (N-EtFOSAA) in soil-soybean systems. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 318:120941. [PMID: 36566675 DOI: 10.1016/j.envpol.2022.120941] [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: 10/28/2022] [Revised: 12/12/2022] [Accepted: 12/22/2022] [Indexed: 06/17/2023]
Abstract
The broad application of perfluoroalkyl acid (PFAA) precursors has led to their occurrence in soil, resulting in potential uptake and bioaccumulation in plants. In this study, we investigated the effect of powdered activated carbon (PAC) and montmorillonite on the distribution and transformation of a perfluorooctanesulfonic acid (PFOS) precursor, N-ethyl perfluorooctane sulfonamido acetic acid (N-EtFOSAA), in soil-plant systems. The results showed that N-EtFOSAA at 300 μg/kg was taken up by soybean roots and shoots together with its transformation products (i.e., perfluorooctane sulfonamide (PFOSA), PFOS), while decreasing the biomass of shoots and roots by 47.63% and 61.16%, respectively. PAC amendment significantly reduced the water leachable and methanol extractable N-EtFOSAA and its transformation products in soil. In the presence of soybean and after 60 days, 73.5% of the initially spiked N-EtFOSAA became non-extractable bound residues. Compared to the spiked controls, the PAC addition also decreased the total plant uptake of N-EtFOSAA by 94.96%. In contrast, montmorillonite showed limited stabilization performance for N-EtFOSAA and its transformation products and was ineffective to lower their bioavailability. Overall, the combination of PAC and soybean was found to be effective in immobilizing N-EtFOSAA in soil.
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Affiliation(s)
- Weilan Zhang
- Department of Environmental and Sustainable Engineering, University at Albany, State University of New York, Albany, NY, 12222, USA.
| | - Tamia E Wellington
- Department of Environmental and Sustainable Engineering, University at Albany, State University of New York, Albany, NY, 12222, USA
| | - Yanna Liang
- Department of Environmental and Sustainable Engineering, University at Albany, State University of New York, Albany, NY, 12222, USA
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24
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Preparation and photocatalytic performance of a magnetically recyclable ZnFeO@TiO@AgO p-n/Z-type tandem heterojunction photocatalyst: Degradation pathway and mechanism. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.130604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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25
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Contrastive study on organic contaminated soils remediated using dielectric barrier discharge (DBD) plasma. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.122576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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26
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Brunhoferova H, Venditti S, Hansen J. Characterization of unconventional sand-based substrates for adsorption of micropollutants in nature-based systems. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 318:115593. [PMID: 35772272 DOI: 10.1016/j.jenvman.2022.115593] [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: 01/04/2022] [Revised: 06/17/2022] [Accepted: 06/18/2022] [Indexed: 06/15/2023]
Abstract
The focus of this study is the characterization of unconventional sand-based substrates used in our previous project EmiSûre, (Interreg Greater Region (German federal states Rhineland-Palatinate and Saarland, the Grand Duchy of Luxembourg, regions Wallonia and Lorraine from Belgium and France, respectively), 2017-2021). The project aimed to develop and test alternative, nature-based technologies for the elimination of micropollutants (MPs) from municipal wastewater. For the characterization, two approaches were chosen. In the first approach, adsorption kinetics with a single compound allowed a perception of the adsorption capacity of the studied substrates compared to conventional substrates (granular activated carbons). This knowledge was completed by the second approach: an implementation of the studied substrates in packed-bed columns, which treated a mixture of 27 MPs in tap water for 10 months. Additionally, all three substrates (bentonite sand, sand with 15% activated biochar and sand with 15% zeolite) were characterized for physical and chemical properties, and the microbial potential of the activated and non-activated biochar was examined. From the studies, it is clear that the sand with an admixture of activated biochar is the most efficient sorbent in terms of single compound adsorption in batch (dye) and adsorption of 27 MPs on packed-bed columns. In contrast to the two other substrates, it shows long-term stable removal efficiencies. In the packed-bed columns, 18 out of 27 compounds were removed on average with high efficiency (80-99%), which is impressive, if we consider the variety of the compounds examined (pharmaceuticals, herbicides, pesticides, etc.) and their removal in conventional treatments. Additionally, adsorption models were created for the experimental data of all compounds adsorbed on the substrate with an admixture of activated biochar resulting in the best fit with the combined Langmuir-Freundlich model. These satisfying results suggest the application of the sand-based substrate with an admixture of activated biochar for further research and possibly upscale installations with the aim to offer and prove a reasonable and efficient alternative for MPs elimination from municipal wastewater.
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Affiliation(s)
- Hana Brunhoferova
- Chair for Urban Water Management, Department of Engineering, University of Luxembourg, Campus Kirchberg, 6, rue Coudenhove-Kalergi, L-1359, Luxembourg.
| | - Silvia Venditti
- Chair for Urban Water Management, Department of Engineering, University of Luxembourg, Campus Kirchberg, 6, rue Coudenhove-Kalergi, L-1359, Luxembourg
| | - Joachim Hansen
- Chair for Urban Water Management, Department of Engineering, University of Luxembourg, Campus Kirchberg, 6, rue Coudenhove-Kalergi, L-1359, Luxembourg
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27
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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: 16] [Impact Index Per Article: 8.0] [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.
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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.
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28
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Zhang W, Liang Y. Changing bioavailability of per- and polyfluoroalkyl substances (PFAS) to plant in biosolids amended soil through stabilization or mobilization. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 308:119724. [PMID: 35809706 DOI: 10.1016/j.envpol.2022.119724] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 06/28/2022] [Accepted: 07/03/2022] [Indexed: 06/15/2023]
Abstract
Biosolids containing per- and polyfluoroalkyl substances (PFAS) could contaminate the receiving environments once they are land applied. In this study, we evaluated the feasibility of controlling the bioavailability of PFAS in biosolids to timothy-grass through stabilization or mobilization approaches. Stabilization was accomplished by adding a sorbent (i.e. granular activated carbon (GAC), RemBind, biochar) to biosolids, while mobilization was achieved by adding a surfactant, sodium dodecyl sulphate (SDS), to biosolids. The results showed that the ΣPFAS concentration in grass shoots grown in biosolids amended soil treated by GAC or RemBind at 2% was only 2.77% and 3.35% of the ΣPFAS concentration detected in shoots grown in biosolids amended soil without a sorbent, respectively, indicating the effectiveness of GAC and RemBind for stabilizing PFAS and reduce their bioavailability. On the other hand, mobilization by adding SDS to biosolids at a dose range of 10-100 mg/kg significantly increased the plant uptake of ΣPFAS by 15.48%-108.57%. Thus, mobilization by adding SDS could be a valuable approach for enhancing the PFAS removal if phytoremediation is applied. Moreover, higher rate of PFAS uptake took place after grass cutting was observed in this study. Thus, proper mowing and regrowth of timothy-grass could lead to efficient and cost-effective removal of PFAS from biosolids amended soil through phytoremediation and leave the site clean to be used for other purposes.
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Affiliation(s)
- Weilan Zhang
- Department of Environmental and Sustainable Engineering, University at Albany, State University of New York, Albany, NY, 12222, USA.
| | - Yanna Liang
- Department of Environmental and Sustainable Engineering, University at Albany, State University of New York, Albany, NY, 12222, USA
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29
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Zhu Q, Qian J, Huang S, Li Q, Guo L, Zeng J, Zhang W, Cao X, Yang J. Occurrence, distribution, and input pathways of per- and polyfluoroalkyl substances in soils near different sources in Shanghai. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 308:119620. [PMID: 35709920 DOI: 10.1016/j.envpol.2022.119620] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 06/08/2022] [Accepted: 06/12/2022] [Indexed: 06/15/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are complex emerging pollutants that are widely distributed in soils. The compositions of PFAS vary according to the emission sources. However, the soil distributions of PFAS from different sources are still poorly understood. In this study, the concentrations and compositions of 18 PFAS in soils close to potential sources (industrial areas, airports, landfills, fire stations and agricultural areas) were investigated in Shanghai. The total PFAS concentrations varied from 0.64 to 294 μg kg-1d.w.. Among the sites, the highest PFAS concentration was found near the fire station (average = 57.9 μg kg-1d.w.), followed by the industrial area (average = 8.53 μg kg-1d.w.). The detection frequencies of the 18 PFAS ranged from 47.5% to 100%. Perfluorooctanoic acid (PFOA) and perfluoroheptanoic acid (PFHpA) were detected in all samples. The detection frequencies of PFAS near the fire station were higher than those near other sources. The PFAS in soils were mainly composed of short-chain perfluoroalkyl carboxylic acids (C ≤ 8). Elevated concentrations of long-chain perfluoroalkyl carboxylic acids (C > 12) were found in industrial area. Principal component analysis revealed that long-chain PFAS had different factor loadings compared to short-chain PFAS. With the exception of agricultural soils, the correlations between individual PFAS were more positive than negative. Strong positive correlations were found within three groups of perfluoroalkyl carboxylic acids (C5-C7, C9-C12, and C14-C18), suggesting their similar inputs and transportation pathways. The PFAS in soils around the fire station were likely directly emitted from a point source. In contrast, the PFAS in soils near the other sites had multiple input pathways, including both direct emission and precursor degradation.
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Affiliation(s)
- Qinghe Zhu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China; State Environmental Protection Engineering Center for Urban Soil Contamination Control and Remediation, Shanghai Academy of Environmental Sciences, Shanghai, 200233, China
| | - Jiahao Qian
- State Environmental Protection Engineering Center for Urban Soil Contamination Control and Remediation, Shanghai Academy of Environmental Sciences, Shanghai, 200233, China; State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Shenfa Huang
- State Environmental Protection Engineering Center for Urban Soil Contamination Control and Remediation, Shanghai Academy of Environmental Sciences, Shanghai, 200233, China
| | - Qingqing Li
- State Environmental Protection Engineering Center for Urban Soil Contamination Control and Remediation, Shanghai Academy of Environmental Sciences, Shanghai, 200233, China
| | - Lin Guo
- State Environmental Protection Engineering Center for Urban Soil Contamination Control and Remediation, Shanghai Academy of Environmental Sciences, Shanghai, 200233, China
| | - Jun Zeng
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Wei Zhang
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Xinde Cao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Jie Yang
- State Environmental Protection Engineering Center for Urban Soil Contamination Control and Remediation, Shanghai Academy of Environmental Sciences, Shanghai, 200233, China.
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30
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Ambaye TG, Vaccari M, Prasad S, Rtimi S. Recent progress and challenges on the removal of per- and poly-fluoroalkyl substances (PFAS) from contaminated soil and water. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:58405-58428. [PMID: 35754080 DOI: 10.1007/s11356-022-21513-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 06/12/2022] [Indexed: 06/15/2023]
Abstract
Currently, due to an increase in urbanization and industrialization around the world, a large volume of per- and poly-fluoroalkyl substances (PFAS) containing materials such as aqueous film-forming foam (AFFF), protective coatings, landfill leachates, and wastewater are produced. Most of the polluted wastewaters are left untreated and discharged into the environment, which causes high environmental risks, a threat to human beings, and hampered socioeconomic growth. Developing sustainable alternatives for removing PFAS from contaminated soil and water has attracted more attention from policymakers and scientists worldwide under various conditions. This paper reviews the recent emerging technologies for the degradation or sorption of PFAS to treat contaminated soil and water. It highlights the mechanisms involved in removing these persistent contaminants at a molecular level. Recent advances in developing nanostructured and advanced reduction remediation materials, challenges, and perspectives in the future are also discussed. Among the variety of nanomaterials, modified nano-sized iron oxides are the best sorbents materials due to their specific surface area and photogenerated holes and appear extremely promising in the remediation of PFAS from contaminated soil and water.
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Affiliation(s)
- Teklit Gebregiorgis Ambaye
- Department of Civil, Environmental, Architectural Engineering and Mathematics, University of Brescia, Via Branze 43, 25123, Brescia, Italy
| | - Mentore Vaccari
- Department of Civil, Environmental, Architectural Engineering and Mathematics, University of Brescia, Via Branze 43, 25123, Brescia, Italy
| | - Shiv Prasad
- Division of Environment Science, ICAR-Indian Agricultural Research Institute New Delhi, New Delhi, 110012, India
| | - Sami Rtimi
- Global Institute for Water, Environment and Health, CH-1201, Geneva, Switzerland.
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31
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Melo TM, Schauerte M, Bluhm A, Slaný M, Paller M, Bolan N, Bosch J, Fritzsche A, Rinklebe J. Ecotoxicological effects of per- and polyfluoroalkyl substances (PFAS) and of a new PFAS adsorbing organoclay to immobilize PFAS in soils on earthworms and plants. JOURNAL OF HAZARDOUS MATERIALS 2022; 433:128771. [PMID: 35366444 DOI: 10.1016/j.jhazmat.2022.128771] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 03/07/2022] [Accepted: 03/21/2022] [Indexed: 06/14/2023]
Abstract
A novel adsorptive organoclay (Intraplex A®) was developed for the in situ immobilization of per- and polyfluoroalkyl substances (PFAS) in the vadose zone. We provide the first evaluation of the effects of Intraplex A® on earthworms and plants in a PFAS-contaminated soil. Ecotoxicological tests were carried out on control soil with and without Intraplex A® (C + I and C, respectively) and PFAS-contaminated soil with and without Intraplex A® (PFAS + I and PFAS, respectively). We investigated the acute ecotoxicological effects of PFAS and Intraplex A® on the growth, reproduction and survival of earthworms (Eisenia fetida) and on plant growth (oat - Avena sativa and turnip - Brassica rapa L. silvestris). Earthworm lethality was 7.6 lower in PFAS + I than in PFAS soil. Earthworms avoided 100% C + I and PFAS + I soils, and reduced earthworms' reproduction was observed in both these soils. For both plant species, the PFAS + I soil yielded less fresh and dry shoot biomass than the PFAS soil, while root growth remained unaffected (all tests: p < 0.05). Soils with Intraplex A® had some negative effects on plants and earthworms, which must be balanced with its benefits as an in situ PFAS adsorbent.
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Affiliation(s)
- Tatiane Medeiros Melo
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water and Waste-Management, Laboratory of Soil and Groundwater Management, Pauluskirchstraße 7, Wuppertal 42285, Germany.
| | - Marina Schauerte
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water and Waste-Management, Laboratory of Soil and Groundwater Management, Pauluskirchstraße 7, Wuppertal 42285, Germany.
| | - Annika Bluhm
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water and Waste-Management, Laboratory of Soil and Groundwater Management, Pauluskirchstraße 7, Wuppertal 42285, Germany.
| | - Michal Slaný
- Institue of Inorgnanic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, Bratislava 845 36, Slovakia; Institute of Construction and Architecture, Slovak Academy of Sciences, Dúbravská cesta 9, Bratislava 845 03, Slovakia.
| | - Michael Paller
- Aquatic Biology Consultants, Inc., 35 Bungalow Ct., Aiken, SC 29803, USA.
| | - Nanthi Bolan
- UWA School of Agriculture and Environment, The UWA Institute of Agriculture, M079, Perth, WA 6009, Australia.
| | - Julian Bosch
- Intrapore GmbH, Katernberger Str. 107, Essen 45327, Germany.
| | | | - Jörg Rinklebe
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water and Waste-Management, Laboratory of Soil and Groundwater Management, Pauluskirchstraße 7, Wuppertal 42285, Germany; Department of Environment, Energy and Geoinformatics, Sejong University, 98 Gunja-Dong, Guangjin-Gu, Seoul, Republic of Korea.
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32
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Ji P, Zhu F, Zhou J, Ma J, Wang H, Xu G. Synthesis of superparamagnetic MnFe 2O 4/mSiO 2 nanomaterial for degradation of perfluorooctanoic acid by activated persulfate. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:37071-37083. [PMID: 35031993 DOI: 10.1007/s11356-021-17782-y] [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] [Received: 07/07/2021] [Accepted: 11/23/2021] [Indexed: 06/14/2023]
Abstract
In this paper, magnetic MnFe2O4/mSiO2 nanocomposites were successfully synthesized, and the activation performance of the materials for persulfate was evaluated by the degradation efficiency of perfluorooctanoic acid. The structure of the catalyst was proved to be a core-shell structure by several characterization methods. The mesoporous silicon coating can effectively avoid the agglomeration of MnFe2O4 and at the same time increase the contact area with the reactants. A comparison of different catalyst addition conditions demonstrates that MnFe2O4/mSiO2 can effectively activate the persulfate. The optimal reaction conditions were investigated by several key influencing factors. It was experimentally demonstrated that about 90% of PFOA (10 mg·L-1) could be decomposed under the conditions of 0.4 g·L-1 MnFe2O4/mSiO2 and PS, pH 5.68, and 25 °C within 4 h; the defluorination rate reached 58.33%. In addition, the cyclability and stability tests demonstrated that MnFe2O4/mSiO2 is a stable material that can be recycled. Furthermore, XPS characterization and radical scavenging experiments demonstrated that sulfate radicals (SO4·-) and hydroxyl radicals (OH) play a major role in the reaction of MnFe2O4/mSiO2 activated PS. Subsequently, the degradation products were detected by high-performance liquid chromatography tandem triple quadrupole mass spectrometry, indicating that the degradation of PFOA is a gradual process of defluorination and decarbonization in the presence of free radicals. Finally, the metal leaching rate is tested to prove that the material meets environmental requirements while reacting efficiently. In conclusion, this study shows that MnFe2O4/mSiO2 is an easily recoverable and highly efficient and stable material that has great potential for PS activation to treat organic pollutants in water.
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Affiliation(s)
- Pengfei Ji
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, People's Republic of China
- Key Laboratory of Organic Compound Pollution Control Engineering, Ministry of Education, Shanghai, 200444, People's Republic of China
| | - Feng Zhu
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, People's Republic of China
| | - Jiamin Zhou
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, People's Republic of China
| | - Jintao Ma
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, People's Republic of China
| | - Hongyong Wang
- Institute of Applied Radiation of Shanghai, Shanghai University, Shanghai, 200444, People's Republic of China.
| | - Gang Xu
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, People's Republic of China.
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Cai W, Navarro DA, Du J, Ying G, Yang B, McLaughlin MJ, Kookana RS. Increasing ionic strength and valency of cations enhance sorption through hydrophobic interactions of PFAS with soil surfaces. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 817:152975. [PMID: 35026264 DOI: 10.1016/j.scitotenv.2022.152975] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/20/2021] [Accepted: 01/04/2022] [Indexed: 06/14/2023]
Abstract
The effect of soluble cations on sorption in soils of a range of anionic PFAS is not well studied. We investigated the role of three common cations (Na+, Ca2+, and Mg2+) at varying solution concentrations on the sorption coefficients (Kd) of 18 anionic PFAS in two contrasting soils. The effective charge of the soil suspension (Zeta potential) became less negative as the concentration of these cations increased in the soil solutions. Perfluorinated compounds showed greater sorption than polyfluorinated compounds, with sulfonates of comparable chain lengths showing higher sorption than the carboxylates. We observed that the Kd values of several PFAS in the two soils were positively correlated with the concentration of cations in solution, especially in the presence of polyvalent cations (Ca2+and Mg2+). The changes in sorption with cation concentration were more prominent for long-chain PFAS, with C > 10 PFAS being completely removed from solution at higher cation concentrations. The emerging PFAS (replacement compounds GenX and ADONA) showed negligible or little sorption (Kd < 0.6 L/kg). While several mechanisms contribute towards sorption of PFAS in the presence of cations, we conclude that the primary effect of cations is through screening of negative charges on head groups of PFAS and reorientation of molecules at the interface between organic matter surfaces and soil solution as well as charge neutralisation at soil solid surface. Screening of negative charges allows for greater hydrophobic interaction between hydrophobic tails of PFAS and soil surfaces resulting in greater sorption. Increasing cation concentrations in soil solutions could thus reduce mobility of PFAS through a soil profile.
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Affiliation(s)
- Wenwen Cai
- School of Environment, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Normal University, Xinxiang 453007, China; State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; CSIRO Land and Water, Locked Bag 2, Glen Osmond 5064, Australia
| | - Divina A Navarro
- CSIRO Land and Water, Locked Bag 2, Glen Osmond 5064, Australia; University of Adelaide, Waite Campus, Locked Bag 1, Glen Osmond 5064, Australia.
| | - Jun Du
- CSIRO Land and Water, Locked Bag 2, Glen Osmond 5064, Australia
| | - Guangguo Ying
- School of Environment, South China Normal University, Guangzhou 510006, China
| | - Bin Yang
- School of Environment, South China Normal University, Guangzhou 510006, China
| | - Mike J McLaughlin
- University of Adelaide, Waite Campus, Locked Bag 1, Glen Osmond 5064, Australia
| | - Rai S Kookana
- CSIRO Land and Water, Locked Bag 2, Glen Osmond 5064, Australia; University of Adelaide, Waite Campus, Locked Bag 1, Glen Osmond 5064, Australia
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Hearon SE, Orr AA, Moyer H, Wang M, Tamamis P, Phillips TD. Montmorillonite clay-based sorbents decrease the bioavailability of per- and polyfluoroalkyl substances (PFAS) from soil and their translocation to plants. ENVIRONMENTAL RESEARCH 2022; 205:112433. [PMID: 34875259 PMCID: PMC8760172 DOI: 10.1016/j.envres.2021.112433] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 10/06/2021] [Accepted: 11/23/2021] [Indexed: 05/23/2023]
Abstract
Consumption of food and water contaminated with per- and polyfluoroalkyl substances (PFAS) presents a significant risk for human exposure. There is limited data on high affinity sorbents that can be used to reduce the bioavailability of PFAS from soil and translocation to plants and garden produce. To address this need, montmorillonite clay was amended with the nutrients carnitine and choline to increase the hydrophobicity of the sorbent and the interlayer spacing. In this study, the binding of PFOA (perfluorooctanoic acid) and PFOS (perfluorooctanesulfonic acid) to parent and amended clays was characterized. Isothermal analyses were conducted at pH 7 and ambient temperature to simulate environmentally-relevant conditions. The data for all tested sorbents fit the Langmuir model indicating saturable binding sites with high capacities and affinities under neutral conditions. Amended montmorillonite clays had increased capacities for PFOA and PFOS (0.51-0.71 mol kg-1) compared to the parent clay (0.37-0.49 mol kg-1). Molecular dynamics (MD) simulations suggested that hydrophobic and electrostatic interactions at the terminal fluorinated carbon chains of PFAS compounds were major modes of surface interaction. The safety and efficacy of the clays were confirmed in a living organism (Lemna minor), where clays (at 0.1% inclusion) allowed for increased growth compared to PFOA and PFOS controls (p ≤ 0.01). Importantly, soil studies showed that 2% sorbent inclusion could significantly reduce PFAS bioavailability from soil (up to 74%). Studies in plants demonstrated that inclusion of 2% sorbent significantly reduced PFAS residues in cucumber plants (p ≤ 0.05). These results suggest that nutrient-amended clays could be included in soil to decrease PFAS bioavailability and translocation of PFAS to plants.
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Affiliation(s)
- Sara E Hearon
- Veterinary Integrative Biosciences Department, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77845, USA
| | - Asuka A Orr
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, 77843, USA
| | - Haley Moyer
- Veterinary Integrative Biosciences Department, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77845, USA
| | - Meichen Wang
- Veterinary Integrative Biosciences Department, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77845, USA
| | - Phanourios Tamamis
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, 77843, USA; Department of Materials Science and Engineering, Texas A&M University, College Station, TX, 77843, USA
| | - Timothy D Phillips
- Veterinary Integrative Biosciences Department, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77845, USA.
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Yang M, Zhang X, Yang Y, Liu Q, Nghiem LD, Guo W, Ngo HH. Effective destruction of perfluorooctanoic acid by zero-valent iron laden biochar obtained from carbothermal reduction: Experimental and simulation study. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 805:150326. [PMID: 34543795 DOI: 10.1016/j.scitotenv.2021.150326] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 08/17/2021] [Accepted: 09/09/2021] [Indexed: 06/13/2023]
Abstract
This study investigated the degradation of perfluorooctanoic acid (PFOA) on zerovalent iron-laden biochar (BC-ZVI) prepared by carbothermal reduction. Results show that over 99% PFOA can be removed by BC-ZVI in hydrothermal conditions under 240 °C within 6 h. The maximum defluorination rate of 63.2% was achieved after 192 h, and this outcome was significantly better than biochar (BC) and zero-valent iron (ZVI) alone. The short-chain perfluorinated compounds (PFCs) and perfluoroheptanal were detected in the liquid phase after degradation, suggesting that the degradation of PFOAs by BC-ZVI followed the Kobel decarboxylation process. XRD and SEM-EDS analyses strongly suggested that carbothermal reduction could avoid the agglomeration of ZVI loaded onto biochar, which helped make the PFOA degradation more efficient. The frontier molecular orbital theory calculated by density functional theory revealed there were two possibilities for ZVI loading on BC (edged or internal loading), while the edge loaded ZVI had a greater tendency to provide electrons for the defluorination of PFOA than internally loaded ZVI.
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Affiliation(s)
- Min Yang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Xiaolei Zhang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Yicheng Yang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Qiang Liu
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China.
| | - Long D Nghiem
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NWS 2007, Australia
| | - Wenshan Guo
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NWS 2007, Australia
| | - Huu Hao Ngo
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NWS 2007, Australia.
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Liu G, Stewart BA, Yuan K, Ling S, Zhang M, Wang G, Lin K. Comprehensive adsorption behavior and mechanism of PFOA and PFCs in various subsurface systems in China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 794:148463. [PMID: 34198087 DOI: 10.1016/j.scitotenv.2021.148463] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 06/07/2021] [Accepted: 06/10/2021] [Indexed: 06/13/2023]
Abstract
The adsorption-desorption performance of perfluorooctanoic acid (PFOA), one of the environmentally persistent pollutants which is refractory to degrade in soil, was investigated and reported. The adsorption-desorption process of PFOA was firstly conducted using different fractions (sand, coarse silt and fine silt) of soil collected from Shanghai, China. More than 50% of PFOA (2.0 mg/L) could be adsorbed by soils while only less than 10% of which could be desorbed once contamination occurs. The kinetics and particle diffusion rates of PFOA in different fractions of soil were calculated and analyzed in detail. Apart from this, the retention of short-chained PFCs, which can be generated as degradation products of PFOA, were also measured. In single solute systems, the adsorption of pollutants in soils dramatically increased as the chain length of PFCs grew longer. Similarly, in mixed solutions, preferential adsorption of longer-chained PFCs over shorter chains in soils were sited, attributable to the stronger hydrophobicity of the pollutants. However, the desorption of them performed in reverse, where the desorption rates of longer-chained PFCs were far lower than those of shorter ones. Furthermore, influencing factors including pH, temperature and co-existing matters were studied during the adsorption process. After comprehending the adsorption behavior of PFOA in soil fractions, the situation of the adsorption of PFOA in various soils chosen from nine provinces in China was investigated and compared. There was an obvious discrepancy, whether it be from the rate or the amount of adsorption of PFOA (approximately 10%), in the nine different soils. Finally, a multiple linear regressive equation was employed to sort influencing parameters which are prone to affect the adsorption of PFOA in soils, the contribution of these are provided in order of relevance. These results demonstrate the adsorption performance and behavior of PFOA and PFCs in different soils, which can be utilized as a scientific reference for maximizing remediation of PFOA polluted sites in the future.
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Affiliation(s)
- Guanhong Liu
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of resource and environmental engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Brittney Ashley Stewart
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of resource and environmental engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Kai Yuan
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of resource and environmental engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Siyuan Ling
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of resource and environmental engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Meng Zhang
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of resource and environmental engineering, East China University of Science and Technology, Shanghai 200237, China.
| | - Guangju Wang
- School of Science, The Hong Kong University of Science and Technology, China
| | - Kuangfei Lin
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of resource and environmental engineering, East China University of Science and Technology, Shanghai 200237, China.
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Natural and engineered clays and clay minerals for the removal of poly- and perfluoroalkyl substances from water: State-of-the-art and future perspectives. Adv Colloid Interface Sci 2021; 297:102537. [PMID: 34624725 DOI: 10.1016/j.cis.2021.102537] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 09/25/2021] [Accepted: 09/27/2021] [Indexed: 12/13/2022]
Abstract
Poly- and perfluoroalkyl substances (PFAS) present globally in drinking-, waste-, and groundwater sources are contaminants of emerging concern due to their long-term environmental persistence and toxicity to organisms, including humans. Here we review PFAS occurrence, behavior, and toxicity in various water sources, and critically discuss their removal via mineral adsorbents, including natural aluminosilicate clay minerals, oxidic clays (Al, Fe, and Si oxides), organoclay minerals, and clay-polymer and clay‑carbon (biochar and graphene oxide) composite materials. Among the many remediation technologies, such as reverse osmosis, adsorption, advanced oxidation and biologically active processes, adsorption is the most suitable for PFAS removal in aquatic systems. Treatment strategies using clay minerals and oxidic clays are inexpensive, eco-friendly, and efficient for bulk PFAS removal due to their high surface areas, porosity, and high loading capacity. A comparison of partition coefficient values calculated from extracted data in published literature indicate that organically-modified clay minerals are the best-performing adsorbent for PFAS removal. In this review, we scrutinize the corresponding plausible mechanisms, factors, and challenges affecting the PFAS removal processes, demonstrating that modified clay minerals (e.g., surfactant, amine), including some commercially available products (e.g., FLUORO-SORB®, RemBind®, matCARE™), show good efficacy in PFAS remediation in contaminated media under field conditions. Finally, we propose future research to focus on the challenges of using clay-based adsorbents for PFAS removal from contaminated water due to the regeneration and safe-disposal of spent clay adsorbents is still a major issue, whilst enhancing the PFAS removal efficiency should be an ongoing scientific effort.
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Bräunig J, Baduel C, Barnes CM, Mueller JF. Sorbent assisted immobilisation of perfluoroalkyl acids in soils - effect on leaching and bioavailability. JOURNAL OF HAZARDOUS MATERIALS 2021; 412:125171. [PMID: 33529830 DOI: 10.1016/j.jhazmat.2021.125171] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 12/27/2020] [Accepted: 01/15/2021] [Indexed: 05/22/2023]
Abstract
Contamination of soils and groundwater with perfluoroalkyl acids (PFAAs) is widespread due to their use in aqueous film-forming foams (AFFF). In this study the effectiveness of RemBind®, a sorbent containing activated carbon and aluminium oxyhydroxides was tested, as a tool to reduce the leaching and bioavailability of 12 PFAAs in soils, by amending contaminated soils with 5-30% (by weight) of the sorbents. Batch tests were used to determine the leaching of PFAAs. Their bioavailability to earthworms and wheat grass was assessed in greenhouse microcosms. Leaching and bioavailability of PFOS was reduced by up to 99.9%, at most sorbent application rates. Lowest reduction of leaching was found for shorter perfluoroalkyl chain length chemicals. The specific formulation of RemBind®, which is available in a basic and superior formulation, as well as the application rate were parameters for increasing effectiveness of the treatment. Furthermore, differences in leaching as well as bioavailability were seen depending on the perfluoroalkyl chain length. A preliminary assessment of the long-term stability of the treatment, assessed after a three-year curing period, suggested that the sorbent continued to be effective in reducing PFAAs in leachates, thus showing the potential of this sorbent to hinder further environmental contamination.
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Affiliation(s)
- Jennifer Bräunig
- Queensland Alliance for Environmental Health Sciences, The University of Queensland, 20 Cornwall Street, Woolloongabba, 4102 QLD, Australia.
| | - Christine Baduel
- Queensland Alliance for Environmental Health Sciences, The University of Queensland, 20 Cornwall Street, Woolloongabba, 4102 QLD, Australia
| | - Craig M Barnes
- Airservices Australia, 25 Constitution Avenue, Canberra ACT 2601, Australia
| | - Jochen F Mueller
- Queensland Alliance for Environmental Health Sciences, The University of Queensland, 20 Cornwall Street, Woolloongabba, 4102 QLD, Australia
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Lee DY, Choi GH, Megson D, Oh KY, Choi IW, Seo DC, Kim JH. Effect of soil organic matter on the plant uptake of perfluorooctanoic acid (PFOA) and perfluorooctanesulphonic acid (PFOS) in lettuce on granular activated carbon-applied soil. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2021; 43:2193-2202. [PMID: 33411166 DOI: 10.1007/s10653-020-00793-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Accepted: 12/08/2020] [Indexed: 06/12/2023]
Abstract
The presence of perfluorooctanoic acid (PFOA) and perfluorooctanesulphonic acid (PFOS) in crops is an important consideration for food safety. The soil organic matter (SOM) content may affect the adsorption potential of PFOA and PFOS in water and soil and their subsequent uptake in crops. To better understand these dynamics, the adsorption and uptake of PFOA and PFOS in lettuce were investigated using granular activated carbon (GAC)-treated soils with varying SOM content. The adsorption potential of GAC was investigated, with maximum adsorption capacities for PFOA and PFOS calculated to be 9.091 mg g-1 and 27.778 mg g-1, respectively. These values decreased to 5.208 mg g-1 and 17.241 mg g-1, respectively, after the addition of 0.04 wt% humic acid. The average plant uptake factor (PUF) in low and high perfluoroalkyl and polyfluoroalkyl acid (PFAA)-contaminated soils with 4.0 wt% SOM was restricted to 0.353 for PFOA and 0.108 for PFOS. The PUFs were approximately two times lower than those for soil with 2.6 wt% SOM. Addition of 1 wt% GAC to the soil successfully reduced the PUF by up to 99.4%, with values of 0.006 (PFOA) and 0.005 (PFOS) in 2.6 wt% SOM-treated soil and 0.079 (PFOA) and 0.023 (PFOS) in 4.0 wt% SOM-treated soil. Although the PUF in the GAC-treated soil was drastically decreased, the PUF of the soil with 4.0 wt% SOM was at least four times higher than that with 2.6 wt% SOM. Therefore, SOM content is an important consideration in the remediation of PFOA- and PFOS-contaminated farmland soil using carbonaceous adsorbent.
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Affiliation(s)
- Deuk-Yeong Lee
- Department of Agricultural Chemistry, Institutes of Agriculture and Life Science (IALS), Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Geun-Hyoung Choi
- Chemical Safety Division, National Institute of Agricultural Sciences, RDA, Wanju, 55365, Republic of Korea
| | - David Megson
- Ecology and Environment Research Centre, Manchester Metropolitan University, Manchester, M15GD, UK
| | - Kyeong-Yeol Oh
- Department of Agricultural Chemistry, Institutes of Agriculture and Life Science (IALS), Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Ik-Won Choi
- Water Environmental Engineering Research Division, National Institute of Environmental Research, Environmental Research Complex, Incheon, 22689, Republic of Korea
| | - Dong-Cheol Seo
- Department of Agricultural Chemistry, Institutes of Agriculture and Life Science (IALS), Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Jin-Hyo Kim
- Department of Agricultural Chemistry, Institutes of Agriculture and Life Science (IALS), Gyeongsang National University, Jinju, 52828, Republic of Korea.
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Sørmo E, Silvani L, Bjerkli N, Hagemann N, Zimmerman AR, Hale SE, Hansen CB, Hartnik T, Cornelissen G. Stabilization of PFAS-contaminated soil with activated biochar. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 763:144034. [PMID: 33360959 DOI: 10.1016/j.scitotenv.2020.144034] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 11/16/2020] [Accepted: 11/18/2020] [Indexed: 06/12/2023]
Abstract
Biochars are considered potential sustainable sorbents to reduce the leaching of per- and polyfluoroalkyl substances (PFAS) from contaminated soils. However, biochar characteristics must probably be optimized to achieve useful sorption capacity. In the present work, eight waste timber biochars were produced, including biochars activated to different degrees, at different temperatures, and using both steam and CO2. In laboratory batch experiments, the eight biochars were amended to soil samples from two different horizons, with low and high total organic carbon (TOC, 1.6% and 34.2%, respectively), of a heavily PFAS-contaminated soil (1200-3800 μg kg-1 PFAStot), at varying doses (0, 0.1, 0.5, 1.0 and 5.0%). With a 5% amendment to the low-TOC soil, all eight biochars resulted in strongly reduced leachate PFAS concentrations (by 98-100%). At the same amendment dose in the high-TOC soil, leachate concentration reductions were more modest (23-100%). This was likely due to a strong PFAS-sorption to the high-TOC soil itself, as well as biochar pore clogging in the presence of abundant organic matter, resulting in fewer sorption sites available to PFAS. Reduction in PFAS leaching was proportional to the degree of activation and activation temperature. Thus, lower amendment doses of activated biochars were needed to reduce PFAS leaching to the same level as with the non-activated biochar. Activation however, came at a tradeoff with biochar yield. Furthermore, the adsorption ability of these biochars increased proportionally with PFAS-fluorocarbon chain length, demonstrating the role of hydrophobic interactions in reduction of PFAS leaching. Development of internal surface area and porosity was proposed as the main factor causing the improved performance of activated biochars. This study shows that woody residues such as waste timber can be used to produce effective sorbents for the remediation of PFAS-contaminated soil. It also highlights the desirability of sorbate and matrix-specific optimization of biochar production.
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Affiliation(s)
- Erlend Sørmo
- Department of Environmental Chemistry, Norwegian Geotechnical Institute (NGI), Oslo, Norway; Faculty of Environmental Science and Natural Resource Management (MINA), University of Life Sciences (NMBU), Ås, Norway.
| | - Ludovica Silvani
- Department of Environmental Chemistry, Norwegian Geotechnical Institute (NGI), Oslo, Norway
| | - Nora Bjerkli
- Faculty of Environmental Science and Natural Resource Management (MINA), University of Life Sciences (NMBU), Ås, Norway
| | - Nikolas Hagemann
- Agroscope, Reckenholz, Switzerland; Ithaka Institute for Carbon Strategies, Arbaz, Switzerland and Freiburg, Germany
| | - Andrew R Zimmerman
- Department of Geological Sciences, University of Florida, Gainesville, FL, USA
| | - Sarah E Hale
- Department of Environmental Chemistry, Norwegian Geotechnical Institute (NGI), Oslo, Norway
| | - Caroline B Hansen
- Department of Environmental Chemistry, Norwegian Geotechnical Institute (NGI), Oslo, Norway
| | | | - Gerard Cornelissen
- Department of Environmental Chemistry, Norwegian Geotechnical Institute (NGI), Oslo, Norway; Faculty of Environmental Science and Natural Resource Management (MINA), University of Life Sciences (NMBU), Ås, Norway
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Sima MW, Jaffé PR. A critical review of modeling Poly- and Perfluoroalkyl Substances (PFAS) in the soil-water environment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 757:143793. [PMID: 33303199 DOI: 10.1016/j.scitotenv.2020.143793] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 10/26/2020] [Accepted: 10/30/2020] [Indexed: 06/12/2023]
Abstract
Due to their health effects and the recalcitrant nature of their CF bonds, Poly- and Perfluoroalkyl Substances (PFAS) are widely investigated for their distribution, remediation, and toxicology in ecosystems. However, very few studies have focused on modeling PFAS in the soil-water environment. In this review, we summarized the recent development in PFAS modeling for various chemical, physical, and biological processes, including sorption, volatilization, degradation, bioaccumulation, and transport. PFAS sorption is kinetic in nature with sorption equilibrium commonly quantified by either a linear, the Freundlich, or the Langmuir isotherms. Volatilization of PFAS depends on carbon chain length and ionization status and has been simulated by a two-layer diffusion process across the air water interface. First-order kinetics is commonly used for physical, chemical, and biological degradation processes. Uptake by plants and other biota can be passive and/or active. As surfactants, PFAS have a tendency to be sorbed or concentrated on air-water or non-aqueous phase liquid (NAPL)-water interfaces, where the same three isotherms for soil sorption are adopted. PFAS transport in the soil-water environment is simulated by solving the convection-dispersion equation (CDE) that is coupled to PFAS sorption, phase transfer, as well as physical, chemical, and biological transformations. As the physicochemical properties and concentration vary greatly among the potentially thousands of PFAS species in the environment, systematic efforts are needed to identify models and model parameters to simulate their fate, transport, and response to remediation techniques. Since many process formulations are empirical in nature, mechanistic approaches are needed to further the understanding of PFAS-soil-water-plant interactions so that the model parameters are less site dependent and more predictive in simulating PFAS remediation efficiency.
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Affiliation(s)
- Matthew W Sima
- Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Peter R Jaffé
- Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ 08544, USA.
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Zheng T, Li J, Liu C. Improvement of α-amylase to the metabolism adaptions of soil bacteria against PFOS exposure. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 208:111770. [PMID: 33396088 DOI: 10.1016/j.ecoenv.2020.111770] [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: 09/18/2020] [Revised: 11/10/2020] [Accepted: 12/05/2020] [Indexed: 06/12/2023]
Abstract
Toxicity of perfluoroalkyl substances (PFASs) in soils towards bacteria shows an impact on its ecosystem function. This study aims to obtain insight into the effect of hydrolase (e.g. α-amylase) in soil on metabolism adaptions of bacteria (e.g. Bacillus substilis) against PFOS exposure. Results show that exogenous α-amylase alleviates PFOS toxicity to bacteria growth, disturbance to membrane permeability and stimulation to reactive oxygen species (ROS) production. The mechanisms were owing to that α-amylase strongly influences the strategies of metabolism adaptions of bacteria against PFOS stress. In details, α-amylase prompts bacteria to regulate the secretion of extracellular polymeric substances (EPSs) and the production of metabolic signal (acetic acid), which leads to changes in the physicochemical properties (hydrophilicity, surface charge) of the bacterial surface and the inactivation of the interaction with PFOS, thereby reducing the PFOS toxicity. Molecular simulations show that PFOS combines with Srt A at Gly 53 and Trp 171, which may induce the increase of permeability and changes of surface characteristics. Meanwhile, α-amylase competes with Srt A to bind PFOS at Arg 125 and Lys 176. This competition changes the physicochemical characteristics of PFOS and its bioavailability, further improving the metabolism adaptions of bacteria against PFOS. Altogether, this work provides direct evidences about α-amylase buffering effect of PFOS and demonstrates that the presence of α-amylase affects the essential but complex metabolic response in bacteria triggered by PFOS.
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Affiliation(s)
- Tongtong Zheng
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, China-America CRC for Environment & Health of Shandong Province, School of Environmental Science and Engineering, Shandong University, 72# Jimo Binhai Road, Qingdao, Shandong 266237, PR China
| | - Jie Li
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, China-America CRC for Environment & Health of Shandong Province, School of Environmental Science and Engineering, Shandong University, 72# Jimo Binhai Road, Qingdao, Shandong 266237, PR China
| | - Chunguang Liu
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, China-America CRC for Environment & Health of Shandong Province, School of Environmental Science and Engineering, Shandong University, 72# Jimo Binhai Road, Qingdao, Shandong 266237, PR China; Guangzhou Key Laboratory of Environmental Exposure and Health, School of Environment, Jinan University, PR China.
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Ahmed MB, Johir MAH, McLaughlan R, Nguyen LN, Xu B, Nghiem LD. Per- and polyfluoroalkyl substances in soil and sediments: Occurrence, fate, remediation and future outlook. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 748:141251. [PMID: 32805564 DOI: 10.1016/j.scitotenv.2020.141251] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 07/19/2020] [Accepted: 07/24/2020] [Indexed: 06/11/2023]
Abstract
Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are contaminants of great concern due to their wide-spread occurrence and persistence in the environments (i.e., in water, soil and sediment) and potential toxicology even at very low concentration. The main focus of this review is on the PFASs in soil and sediments. More specifically, this review systematically examines the occurrence and toxicological effects with associated risks, fate (i.e., PFASs adsorption by soil and sediment, transportation and transformation, and bioaccumulation), and remediation practices of PFASs in soil and sediment. Various models and equations such as fugacity-based multimedia fate and hydrodynamic models are used to study the fate, transport, and transformation of PFASs. Among different remediation practices, sorption is the dominant process for the removal of PFASs from soil and sediments. Results also indicate that PFASs adsorption onto activated carbon decrease with the increase of carbon chain length in the PFASs. The longer-chain PFASs have larger partition coefficient values than shorter-chained PFASs. Sorption of PFASs to soil and sediments are mainly governed by different electrostatic interactions, hydrogen bonds formation, hydrophobic interactions, organic content in soil and sediments, and ligand exchange. Other technology such as thermal treatment might be potential in the removal of PAFSs, but need further study to elucidate a conclusion. Finally, the associated challenges and future outlook have been included.
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Affiliation(s)
- M B Ahmed
- School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007, Australia; School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
| | - M A H Johir
- School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007, Australia.
| | - Robert McLaughlan
- School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007, Australia
| | - Luong N Nguyen
- School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007, Australia
| | - Bentuo Xu
- School of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Long D Nghiem
- School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007, Australia
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Effect of Biochar and Hydrochar on Forms of Aluminium in an Acidic Soil. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10217843] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Biochars and hydrochars have a significant effect on soil properties linked to fertility or to carbon cycling and have been proposed as an amendment to increase soil productivity, particularly in acidic soils. Phytotoxic forms of aluminium (Al) are relatively abundant in acidic soils and, for a long period of time, liming has been used to correct this. Ca(OH)2, a pig manure (PM) and two biochars and two hydrochars prepared from pig manure were studied for their effects on Al fractions. Biochars were prepared at 450 °C (BPC450) and 600 °C (BPC600) and hydrochars were obtained using a pig manure solution (ratio 30:70) that was heated at 200 °C (HPC200) and 240 °C (HPC240). A treatment with an amount of Ca(OH)2 necessary to increase soil pH to the same pH value as the average in the treatments BPC450, BPC600, HPC200, HPC240 and PM was used for comparison. The fractionation of Al was studied, with the liming treatment allowing the differentiation between changes in fractionation driven by pH changes from other mechanisms. In relation to the control, all soil amendments presented high capacity of controlling toxic Al, similar to a traditional liming product (Ca(OH)2) and decreased the exchangeable Al extracted by NH4Cl. Both types of materials (biochars and hydrochars) lead to the formation of an increased number of organo-aluminium complexes (OAC). Biochars lead to the formation of OAC of low to medium stability, while hydrochars promoted the formation of OAC of high stability.
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