1
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Wang J, Tran LN, Mendoza J, Chen K, Tian L, Zhao Y, Liu J, Lin YH. Thermal transformations of perfluorooctanoic acid (PFOA): Mechanisms, volatile organofluorine emissions, and implications to thermal regeneration of granular activated carbon. JOURNAL OF HAZARDOUS MATERIALS 2024; 479:135737. [PMID: 39259991 DOI: 10.1016/j.jhazmat.2024.135737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2024] [Revised: 08/22/2024] [Accepted: 09/02/2024] [Indexed: 09/13/2024]
Abstract
Thermal treatment is effective for the removal of perfluorooctanoic acid (PFOA). However, how temperatures, heating methods, and granular activated carbon (GAC) influence pyrolysis of PFOA, and emission risks are not fully understood. We studied thermal behaviors of PFOA at various conditions and analyzed gaseous products using real-time detection technologies and gas chromatography-mass spectrometry (GC-MS). The thermal decomposition of PFOA is surface-mediated. On the surface of quartz, PFOA decomposed into perfluoro-1-heptene and perfluoro-2-heptene, while on GAC, it tended to decompose into 1 H-perfluoroheptane (C7HF15). Neutral PFOA started evaporating around 100 ℃ without decomposition in ramp heating. During pyrolysis, when PFOA was pre-adsorbed onto GAC, it was mineralized into SiF4 and produced more than 45 volatile organic fluorine (VOF) byproducts, including perfluorocarbons (PFCs) and hydrofluorocarbons (HFCs). The VOF products were longer-chain (hydro)fluorocarbons (C4-C7) at low temperatures (< 500 ℃) and became shorter-chain (C1-C4) at higher temperatures (> 600 ℃). PFOA transformations include decarboxylation, VOF desorption, further organofluorine decomposition and mineralization in ramp heating of PFOA-laden GAC. Decarboxylation initiates at 120 ℃, but other processes require higher temperatures (>200 ℃). These results offer valuable information regarding the thermal regeneration of PFAS-laden GAC and further VOF control with the afterburner or thermal oxidizer.
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Affiliation(s)
- Junli Wang
- Department of Environmental Sciences, University of California, Riverside, CA 92521, United States
| | - Lillian N Tran
- Environmental Toxicology Graduate Program, University of California, Riverside, CA 92521, United States
| | - Jose Mendoza
- Department of Environmental Sciences, University of California, Riverside, CA 92521, United States
| | - Kunpeng Chen
- Department of Environmental Sciences, University of California, Riverside, CA 92521, United States
| | - Linhui Tian
- Department of Environmental Sciences, University of California, Riverside, CA 92521, United States
| | - Yuwei Zhao
- Biotechnology Development and Applications Group, APTIM, 17 Princess Rd., Lawrenceville, NJ 08648, United States
| | - Jinyong Liu
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, United States
| | - Ying-Hsuan Lin
- Department of Environmental Sciences, University of California, Riverside, CA 92521, United States; Environmental Toxicology Graduate Program, University of California, Riverside, CA 92521, United States.
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2
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Meservey A, Külaots I, Bryant JD, Gray C, Wahl J, Manz KE, Pennell KD. Adsorption of per- and polyfluoroalkyl substances on biochar derived from municipal sewage sludge. CHEMOSPHERE 2024; 365:143331. [PMID: 39278324 DOI: 10.1016/j.chemosphere.2024.143331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2024] [Revised: 09/06/2024] [Accepted: 09/10/2024] [Indexed: 09/18/2024]
Abstract
Granular activated carbon (GAC) and ion exchange resin (IXR) are widely used as adsorbents to remove PFAS from drinking water sources and effluent waste streams. However, the high cost associated with GAC and IXR generation has motivated the development of less expensive adsorbents for treatment of PFAS-impacted water. Thus, the objective of this research was to create an economically viable and sustainable PFAS adsorbent from sewage sludge. Stepwise pyrolysis at temperatures from 300 °C to 1000 °C yielded biochars whose specific surface area (SSA) and porosity increased from 41 to 148 m2/g, and from 0.062 to 0.193 cm3/g, respectively. On a per organic char basis, the SSA of the biochar was as high as 1183 m2/g, which is comparable to commercially-available activated carbons. The adsorption of perfluorooctane sulfonic acid (PFOS) on sludge biochar increased with increasing pyrolysis temperature, which was positively correlated with increasing porosity and SSA. When 1000 °C processed biochar was tested with a mixture of eight PFAS, preferential adsorption of longer carbon chain-length species was observed, indicating the importance of PFAS hydrophobic interactions with the biochar and the availability of a wide range of mesopores. The adsorption of each PFAS was dependent upon both chain length and head group, with longer chain-length species exhibiting greater adsorption than shorter chain-length species, along with greater adsorption of species with sulfonic acid head groups compared to their chain length counterparts with carboxylic acid head groups. These findings demonstrate that biochar derived from municipal solid waste can serve as a cost-effective and sustainable adsorbent for the removal of PFOS and PFAS mixtures from source waters. The circular economy benefits and waste reduction potential associated with the use of sewage sludge-derived biochar supports the development of a viable sludge-derived biochar for the removal of PFAS from water.
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Affiliation(s)
- Alexis Meservey
- School of Engineering, Brown University, Providence, RI, 02912, United States
| | - Indrek Külaots
- School of Engineering, Brown University, Providence, RI, 02912, United States
| | - J Daniel Bryant
- Woodard & Curran, 50 Millstone Road, Building 400, East Windsor, NJ, 08520, United States
| | - Chloe Gray
- School of Engineering, Brown University, Providence, RI, 02912, United States
| | - Julia Wahl
- Woodard & Curran, 47 Pleasant Street, Northampton, MA, 01060, United States
| | - Katherine E Manz
- School of Engineering, Brown University, Providence, RI, 02912, United States; Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI, 48109, United States
| | - Kurt D Pennell
- School of Engineering, Brown University, Providence, RI, 02912, United States.
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3
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Santiago-Cruz HA, Lou Z, Xu J, Sullivan RC, Bowers BB, Molé RA, Zhang W, Li J, Yuan JS, Dai SY, Lowry GV. Carbon Adsorbent Properties Impact Hydrated Electron Activity and Perfluorocarboxylic Acid (PFCA) Destruction. ACS ES&T ENGINEERING 2024; 4:2220-2233. [PMID: 39296420 PMCID: PMC11406532 DOI: 10.1021/acsestengg.4c00211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 07/15/2024] [Accepted: 07/19/2024] [Indexed: 09/21/2024]
Abstract
Carbon-based adsorbents used to remove recalcitrant water contaminants, including perfluoroalkyl substances (PFAS), are often regenerated using energy-intensive treatments that can form harmful byproducts. We explore mechanisms for sorbent regeneration using hydrated electrons (eaq -) from sulfite ultraviolet photolysis (UV/sulfite) in water. We studied the UV/sulfite treatment on three carbon-based sorbents with varying material properties: granular activated carbon (GAC), carbon nanotubes (CNTs), and polyethylenimine-modified lignin (lignin). Reaction rates and defluorination of dissolved and adsorbed model perfluorocarboxylic acids (PFCAs), perfluorooctanoic acid (PFOA) and perfluorobutanoic acid (PFBA), were measured. Monochloroacetic acid (MCAA) was employed to empirically quantify eaq - formation rates in heterogeneous suspensions. Results show that dissolved PFCAs react rapidly compared to adsorbed ones. Carbon particles in solution decreased aqueous reaction rates by inducing light attenuation, eaq - scavenging, and sulfite consumption. The magnitude of these effects depended on adsorbent properties and surface chemistry. GAC lowered PFOA destruction due to strong adsorption. CNT and lignin suspensions decreased eaq - formation rates by attenuating light. Lignin showed high eaq - quenching, likely due to its oxygenated functional groups. These results indicate that desorbing PFAS and separating the adsorbent before initiating PFAS degradation reactions will be the best engineering approach for adsorbent regeneration using UV/sulfite.
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Affiliation(s)
- Hosea A Santiago-Cruz
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Zimo Lou
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
- Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jiang Xu
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Ryan C Sullivan
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15217, United States
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15217, United States
| | - Bailey B Bowers
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15217, United States
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, Ohio 44074, United States
| | - Rachel A Molé
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Wan Zhang
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843, United States
| | - Jinghao Li
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843, United States
- Department of Energy, Environmental, and Chemical Engineering, McKelvey School of Engineering, Washington University in St. Louis, St. Louis, Missouri 63130-4899, United States
| | - Joshua S Yuan
- Department of Energy, Environmental, and Chemical Engineering, McKelvey School of Engineering, Washington University in St. Louis, St. Louis, Missouri 63130-4899, United States
| | - Susie Y Dai
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843, United States
| | - Gregory V Lowry
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
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4
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Kim HH, Koster van Groos PG, Zhao Y, Pham ALT. Removal of PFAS by hydrotalcite: Adsorption mechanisms, effect of adsorbent aging, and thermal regeneration. WATER RESEARCH 2024; 260:121925. [PMID: 38901316 DOI: 10.1016/j.watres.2024.121925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 05/17/2024] [Accepted: 06/10/2024] [Indexed: 06/22/2024]
Abstract
Layered double hydroxides (LDH) have been shown to be effective adsorbents, but their utility for the treatment of per- and polyfluoroalkyl substances (PFAS) in water has not been fully explored. In this study, the adsorption of 9 PFAS on hydrotalcite (HT), a type of LDH, was investigated using reaction solutions with environmentally relevant PFAS concentrations. The adsorption of individual PFAS by HT depended upon a range of factors, including the temperature used to pre-treat (i.e., calcine) the HT, aging conditions, and the presence of anions in the solution. HT calcined near 400 °C most effectively adsorbed PFAS, but its ability to adsorb PFAS was sensitive to storage conditions. The adsorption of CO2 and moisture from air, which likely resulted in the re-intercalation of CO32- into the interlayer regions of HT, was observed to reduce PFAS adsorption and may explain performance loss over time. The adsorption trend among 9 PFAS and the influence on this process by Cl-, NO3-, SO42-, and CO32- indicated that adsorption occurred via a combination of ion exchange, electrostatic attraction, and hydrophobic interactions, although the relative importance of each mechanism deserves further investigation. During this study, we also demonstrated for the first time that HT can be thermally regenerated at 400 °C without affecting its ability to adsorb PFOS and PFBA. Overall, our results suggest that HT may serve as an effective alternative for PFAS treatment.
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Affiliation(s)
- Hak-Hyeon Kim
- Department of Civil and Environmental Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Paul G Koster van Groos
- Biotechnology Development and Applications Group, APTIM, 17 Princess Road, Lawrenceville, New Jersey 08648, United States
| | - Yuwei Zhao
- Biotechnology Development and Applications Group, APTIM, 17 Princess Road, Lawrenceville, New Jersey 08648, United States
| | - Anh Le-Tuan Pham
- Department of Civil and Environmental Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
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5
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Chen S, Li B, Zhao R, Zhang B, Zhang Y, Chen J, Sun J, Ma X. Natural mineral and industrial solid waste-based adsorbent for perfluorooctanoic acid and perfluorooctane sulfonate removal from surface water: Advances and prospects. CHEMOSPHERE 2024; 362:142662. [PMID: 38936483 DOI: 10.1016/j.chemosphere.2024.142662] [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: 04/17/2024] [Revised: 06/14/2024] [Accepted: 06/18/2024] [Indexed: 06/29/2024]
Abstract
PER: and polyfluorinated alkyl substances, especially perfluorooctanoic acid and perfluorooctane sulfonic acid (PFOX), have attracted considerable attention lately because of their widespread occurrence in aquatic environment and potential biological toxicity to animals and human beings. The development of economical, efficient, and engineerable adsorbents for removing PFOX in water has become one of the research focuses. This review summarized the recent progress on natural mineral and industrial solid based adsorbent (NM&ISW-A) and removal mechanisms concerning PFOX onto NM&ISW-A, as well as proposed the current challenges and future perspectives of using NM&ISW-A for PFOX removal in water. Kaolinite and montmorillonite are usually used as model clay minerals for PFOX removal, and have been proved to adsorb PFOX by ligand exchange and electrostatic attraction. Fe-based minerals, such as goethite, magnetite, and hematite, have better PFOX adsorption capacity than clay minerals. The adsorbent prepared from industrial solid waste by high temperature roasting has great potential application prospects. Fabricating nanomaterials, amination modification, surfactant modification, fluorination modification, developing versatile composites, and designing special porous structure are beneficial to improve the adsorption performance of PFOX onto NM&ISW-A by enhancing the specific surface area, positive charge, and hydrophobicity. Electrostatic interaction, hydrophobic interaction, hydrogen bond, ligand and ion exchange, and self-aggregation (formation of micelle or hemimicelle) are the main adsorption mechanisms of PFOX by NM&ISW-A. Among them, electrostatic and hydrophobic interactions play a considerable role in the removal of PFOX by NM&ISW-A. Therefore, NM&ISW-A with electrostatic functionalities and considerable hydrophobic segments enables rapid, efficient, and high-capacity removal of PFOX. The future directions of NM&ISW-A for PFOX removal include the preparation and regeneration of engineerable NM&ISW-A, the development of coupling technology for PFOX removal based on NM&ISW-A, the in-depth research on adsorption mechanism of PFOX by NM&ISW-A, as well as the development of NM&ISW-A for PFOX alternatives removal. This review paper would be helpful the comprehensive understanding of NM&ISW-A potential for PFOX removal and the PFOX removal mechanisms, and identifies the gaps for future research and development.
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Affiliation(s)
- Siyuan Chen
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China
| | - Benhang Li
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China.
| | - Ruining Zhao
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China
| | - Boxuan Zhang
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China
| | - Yuqing Zhang
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China
| | - Jiale Chen
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China
| | - Jiahe Sun
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China
| | - Xiaodong Ma
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China.
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6
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Weitz K, Kantner D, Kessler A, Key H, Larson J, Bodnar W, Parvathikar S, Davis L, Robey N, Taylor P, De la Cruz F, Tolaymat T, Weber N, Linak W, Krug J, Phelps L. Review of per- and poly-fluoroalkyl treatment in combustion-based thermal waste systems in the United States. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 932:172658. [PMID: 38657813 DOI: 10.1016/j.scitotenv.2024.172658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 04/19/2024] [Accepted: 04/19/2024] [Indexed: 04/26/2024]
Abstract
Per- and poly-fluoroalkyl substances (PFAS) are a class of synthetic chemicals known for their widespread presence and environmental persistence. Carbon-fluorine (C-F) bonds are major components among PFAS and among the strongest organic bonds, thus destroying PFAS may present significant challenge. Thermal treatment such as incineration is an effective and approved method for destroying many halogenated organic chemicals. Here, we present the results of existing studies and testing at combustion-based thermal treatment facilities and summarize what is known regarding PFAS destruction and mineralization at such units. Available results suggest the temperature and residence times reached by some thermal treatment systems are generally favorable to the destruction of PFAS, but the possibility for PFAS or fluorinated organic byproducts to escape destruction and adequate mineralization and be released into the air cannot be ruled out. Few studies have been conducted at full-scale operating facilities, and none to date have attempted to characterize possible fluorinated organic products of incomplete combustion (PICs). Further, the ability of existing air pollution control (APC) systems, designed primarily for particulate and acid gas control, to reduce PFAS air emissions has not been determined. These data gaps remain primarily due to the previous lack of available methods to characterize PFAS destruction and PIC concentrations in facility air emissions. However, newly developed stack testing methods offer an improved understanding of the extent to which thermal waste treatment technologies successfully destroy and mineralize PFAS in these waste streams.
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Affiliation(s)
- Keith Weitz
- RTI International, Research Triangle Park, NC, USA
| | | | | | - Haley Key
- RTI International, Research Triangle Park, NC, USA
| | - Judd Larson
- RTI International, Research Triangle Park, NC, USA
| | - Wanda Bodnar
- RTI International, Research Triangle Park, NC, USA
| | | | - Lynn Davis
- RTI International, Research Triangle Park, NC, USA
| | - Nicole Robey
- Innovative Technical Solutions, Gainesville, FL, USA
| | | | - Florentino De la Cruz
- College of Computing, Engineering and Construction, University of North Florida, Jacksonville, FL, USA
| | - Thabet Tolaymat
- Center for Environmental Solutions and Emergency Management, Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, OH, USA
| | - Nathan Weber
- Oak Ridge Institute for Science and Education, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - William Linak
- Center for Environmental Measurement and Modeling, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Jonathan Krug
- Center for Environmental Measurement and Modeling, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Lara Phelps
- Center for Environmental Measurement and Modeling, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA.
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7
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Hou Y, Mayer BK. The impact of PAC-loaded polymer membrane thickness on chloroform removal and comparison of solvent and thermal membrane regeneration methods. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2024; 96:e11081. [PMID: 39023047 DOI: 10.1002/wer.11081] [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: 04/16/2024] [Revised: 06/08/2024] [Accepted: 06/29/2024] [Indexed: 07/20/2024]
Abstract
Powdered activated carbon (PAC) has better adsorption performance than granular activated carbon (GAC) and is widely used in water purification. In most cases, PAC is dosed into water directly, then precipitated as sludge, and landfilled. In this study, PAC was mixed with a polymer and dissolved in dimethylformamide (DMF) solvent to form a PAC-loaded membrane, which was then tested for chloroform removal. The chloroform adsorption capacity of the PAC membrane increased with increasing membrane thickness because of higher carbon loading. However, regardless of membrane thickness, the flux of the PAC membranes was similar since flux resistance predominantly occurred at the top dense polymer surface. This dense surface can be removed by sandpaper polishing, where the adsorption capacity of the polished PAC membranes was 20% higher than the unpolished membranes because of more even distribution of feed water on the polished surface. Removal of the dense surface via polishing increased the flux by 97% to 130%, exceeding the flux of typical household carbon block filters. Using DMF to regenerate the membrane recovered 48% to 66% of the initial adsorption capacity. Thermal regeneration of the exhausted PAC membrane at 250°C was more effective than DMF regeneration (both in terms of cost and performance), with 83% to 94% PAC membrane regeneration efficiency over four regeneration recycles. After four thermal regeneration cycles, flux increased by 300% and the membrane became brittle because of thermal aging of the polymer, indicating that a total of 6 h of regeneration time (equivalent to three cycles in this study) was the limit for effective PAC membrane performance. PRACTITIONER POINTS: Powdered activated carbon was immobilized on a membrane to remove chloroform from water. Thicker membranes increased adsorption capacity but did not impact flux. Flux and capacity increased using polishing to remove the dense polymer surface and more evenly distribute flow across the membrane. Thermal regeneration of the membrane at 250°C was effective for up to three cycles and outperformed solvent-based regeneration. PAC-loaded filters are relevant for applications such as household carbon block filtration.
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Affiliation(s)
- Yizhi Hou
- Department of Civil, Construction and Environmental Engineering, Marquette University, Milwaukee, Wisconsin, USA
- A.O. Smith Corporation Technology Center, Milwaukee, Wisconsin, USA
| | - Brooke K Mayer
- Department of Civil, Construction and Environmental Engineering, Marquette University, Milwaukee, Wisconsin, USA
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8
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Abou-Khalil C, Chernysheva L, Miller A, Abarca-Perez A, Peaslee G, Herckes P, Westerhoff P, Doudrick K. Enhancing the Thermal Mineralization of Perfluorooctanesulfonate on Granular Activated Carbon Using Alkali and Alkaline-Earth Metal Additives. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:11162-11174. [PMID: 38857410 DOI: 10.1021/acs.est.3c09795] [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: 06/12/2024]
Abstract
Thermal treatment has emerged as a promising approach for either the end-of-life treatment or regeneration of granular activated carbon (GAC) contaminated with per- and polyfluoroalkyl substances (PFAS). However, its effectiveness has been limited by the requirement for high temperatures, the generation of products of incomplete destruction, and the necessity to scrub HF in the flue gas. This study investigates the use of common alkali and alkaline-earth metal additives to enhance the mineralization of perfluorooctanesulfonate (PFOS) adsorbed onto GAC. When treated at 800 °C without an additive, only 49% of PFOS was mineralized to HF. All additives tested demonstrated improved mineralization, and Ca(OH)2 had the best performance, achieving a mineralization efficiency of 98% in air or N2. Its ability to increase the reaction rate and shift the byproduct selectivity suggests that its role may be catalytic. Moreover, additives reduced HF in the flue gas by instead reacting with the additive to form inorganic fluorine (e.g., CaF2) in the starting waste material. A hypothesized reaction mechanism is proposed that involves the electron transfer from O2- defect sites of CaO to intermediates formed during the thermal decomposition of PFOS. These findings advocate for the use of additives in the thermal treatment of GAC for disposal or reuse, with the potential to reduce operating costs and mitigate the environmental impact associated with incinerating PFAS-laden wastes.
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Affiliation(s)
- Charbel Abou-Khalil
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Liliya Chernysheva
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Anthony Miller
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Angela Abarca-Perez
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Graham Peaslee
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Pierre Herckes
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Paul Westerhoff
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85287, United States
| | - Kyle Doudrick
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United States
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9
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Vakili M, Cagnetta G, Deng S, Wang W, Gholami Z, Gholami F, Dastyar W, Mojiri A, Blaney L. Regeneration of exhausted adsorbents after PFAS adsorption: A critical review. JOURNAL OF HAZARDOUS MATERIALS 2024; 471:134429. [PMID: 38691929 DOI: 10.1016/j.jhazmat.2024.134429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Revised: 03/26/2024] [Accepted: 04/24/2024] [Indexed: 05/03/2024]
Abstract
The adsorption process efficiently removes per- and polyfluoroalkyl substances (PFAS) from water, but managing exhausted adsorbents presents notable environmental and economic challenges. Conventional disposal methods, such as incineration, may reintroduce PFAS into the environment. Therefore, advanced regeneration techniques are imperative to prevent leaching during disposal and enhance sustainability and cost-effectiveness. This review critically evaluates thermal and chemical regeneration approaches for PFAS-laden adsorbents, elucidating their operational mechanisms, the influence of water quality parameters, and their inherent advantages and limitations. Thermal regeneration achieves notable desorption efficiencies, reaching up to 99% for activated carbon. However, it requires significant energy input and risks compromising the adsorbent's structural integrity, resulting in considerable mass loss (10-20%). In contrast, chemical regeneration presents a diverse efficiency landscape across different regenerants, including water, acidic/basic, salt, solvent, and multi-component solutions. Multi-component solutions demonstrate superior efficiency (>90%) compared to solvent-based solutions (12.50%), which, in turn, outperform salt (2.34%), acidic/basic (1.17%), and water (0.40%) regenerants. This hierarchical effectiveness underscores the nuanced nature of chemical regeneration, significantly influenced by factors such as regenerant composition, the molecular structure of PFAS, and the presence of organic co-contaminants. Exploring the conditional efficacy of thermal and chemical regeneration methods underscores the imperative of strategic selection based on specific types of PFAS and material properties. By emphasizing the limitations and potential of particular regeneration schemes and advocating for future research directions, such as exploring persulfate activation treatments, this review aims to catalyze the development of more effective regeneration processes. The ultimate goal is to ensure water quality and public health protection through environmentally sound solutions for PFAS remediation efforts.
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Affiliation(s)
| | - Giovanni Cagnetta
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 610031, China.
| | - Shubo Deng
- State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Wei Wang
- State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xi'ning, Qinghai Province 810016, China
| | - Zahra Gholami
- ORLEN UniCRE, a.s, Revoluční 1521/84, 400 01 Ústí nad Labem, Czech Republic
| | - Fatemeh Gholami
- Department of Mathematics, Physics, and Technology, Faculty of Education, University of West Bohemia, Klatovská 51, Plzeň 301 00, Czech Republic
| | - Wafa Dastyar
- Chemical, Environmental, and Materials Engineering Department, McArthur Engineering Building, University of Miami, Coral Gables, FL 33124, USA
| | - Amin Mojiri
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287-3005, USA
| | - Lee Blaney
- University of Maryland Baltimore County, Department of Chemical, Biochemical, and Environmental Engineering, Baltimore, MD 21250, USA
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10
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Ersan G, Gaber MS, Perreault F, Garcia-Segura S. Comparative study on electro-regeneration of antibiotic-laden activated carbons in reverse osmosis concentrate. WATER RESEARCH 2024; 255:121528. [PMID: 38555781 DOI: 10.1016/j.watres.2024.121528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 03/20/2024] [Accepted: 03/25/2024] [Indexed: 04/02/2024]
Abstract
Electro-regeneration is emerging as a new technique to regenerate spent carbon adsorbents through an electrochemical process. In this study, sequential adsorption and electro-regeneration of ciprofloxacin (CIP)-laden carbon were investigated using both pristine and iron (Fe)-doped F400 activated carbon in distilled, deionized (DI) water and reverse osmosis (RO) concentrate water. The impact of reactor flow rate and sequential adsorption/electro-regeneration cycles on the regeneration efficiency were also evaluated. The results indicate that the breakthrough points for both adsorbents in DI water, where 100 % of the CIP molecules were adsorbed, occurred at around 7,800 bed volumes (BVs). Conversely, electro-regeneration for both adsorbents, where 94 % of the CIP molecules were desorbed, took place at 380 BVs. The main distinction between the two activated carbons lies in the initial range of BVs (<400 BVs).Fe doping on F400 appears to enhance its surface selectivity for CIP uptake, which can easily diffuse into the meso/macropore regions of Fe-doped F400. In contrast, pristine F400, being highly microporous, necessitated more contact time to fill its high-energy sites, resulting in a higher affinity for CIP adsorption. Over the four sequential adsorption/electro-regeneration cycles in DI water, a similar regeneration efficiency was observed at 190 BVs. As the flow rate increased from 2 to 6 mL/min, the CIP uptake on pristine F400 decreased in DI water, calculating 138, 74 and 57 mg/g for flow rates of 2, 4, and 6 mL/min, respectively. When the RO concentrate water was compared with DI water, the pristine F400 quickly reached saturation due to pore blockage caused by organic matter in RO concentrate. During electro-regeneration, up to 100 % of adsorbed CIP molecules were desorbed at around 120 BVs in RO concentrate, which is 3X faster than DI water. The effectiveness of this technology can be enhanced by implementing continuous flow systems, thereby improving the overall efficiency of CIP removal in RO concentrate.
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Affiliation(s)
- Gamze Ersan
- School of Sustainable Engineering and The Built Environment, Arizona State University, Tempe, AZ 85287-5306, USA.
| | - Mohamed S Gaber
- School of Sustainable Engineering and The Built Environment, Arizona State University, Tempe, AZ 85287-5306, USA; Chemistry Department, Faculty of Science, Helwan University, Ain Helwan, Helwan 11795, Cairo, Egypt
| | - François Perreault
- School of Sustainable Engineering and The Built Environment, Arizona State University, Tempe, AZ 85287-5306, USA; Department of Chemistry, University of Quebec in Montreal, CP 8888, Succ. Centre-Ville, Montreal, QC, H3C 3P8, Canada
| | - Sergi Garcia-Segura
- School of Sustainable Engineering and The Built Environment, Arizona State University, Tempe, AZ 85287-5306, USA.
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11
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Zhao Y, Koster van Groos PG, Thakur N, Fuller ME, Soto A, Hatzinger PB. Formation of volatile chlorinated and brominated products during low temperature thermal decomposition of the representative PFAS perfluorohexane sulfonate (PFHxS) in the presence of NaCl and NaBr. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 348:123782. [PMID: 38484959 DOI: 10.1016/j.envpol.2024.123782] [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: 12/20/2023] [Revised: 02/26/2024] [Accepted: 03/11/2024] [Indexed: 04/07/2024]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are synthetic organofluorine compounds known for their chemical and physical stability as well as their wide range of uses. Some PFAS are widely distributed in the environment, leading to concerns related to both environmental and human health. High temperature thermal treatment (i.e., incineration) has been utilized for PFAS treatment, but this requires significant infrastructure and energy, prompting interest in lower temperature approaches that may still lead to efficient destruction. Lower treatment temperatures, however, increase the potential for incomplete PFAS mineralization and formation of volatile organofluorine (VOF) products. Herein, we report the formation of novel VOF products that include chlorinated and brominated compounds during the thermal treatment of potassium perfluorohexane sulfonate (PFHxS), a representative perfluoroalkyl acid (PFAA). By comparing the gas chromatography-mass spectrometry (GC-MS) results of known VOF stocks to evolved VOF during thermal treatment of PFAS, the formation of perfluorohexyl chloride and perfluorohexyl bromide was observed when PFHxS was heated at temperatures between 275 and 475 °C in the presence of NaCl and NaBr, respectively. To our knowledge, this is the first report of chlorinated or brominated VOF products during thermal treatment of a PFAA. These findings suggest that a range of mixed halogenated VOF may form during thermal treatment of PFAS at relatively low temperature (e.g., 500 °C) and that these can be a function of salts present in the matrix.
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Affiliation(s)
- Yuwei Zhao
- Biotechnology Development and Applications Group, APTIM, 17 Princess Rd. Lawrenceville, NJ, 08648, USA.
| | - Paul G Koster van Groos
- Biotechnology Development and Applications Group, APTIM, 17 Princess Rd. Lawrenceville, NJ, 08648, USA
| | - Nikita Thakur
- Biotechnology Development and Applications Group, APTIM, 17 Princess Rd. Lawrenceville, NJ, 08648, USA
| | - Mark E Fuller
- Biotechnology Development and Applications Group, APTIM, 17 Princess Rd. Lawrenceville, NJ, 08648, USA
| | - Anthony Soto
- Biotechnology Development and Applications Group, APTIM, 17 Princess Rd. Lawrenceville, NJ, 08648, USA
| | - Paul B Hatzinger
- Biotechnology Development and Applications Group, APTIM, 17 Princess Rd. Lawrenceville, NJ, 08648, USA
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12
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Londhe K, Lee CS, Grdanovska S, Smolinski R, Hamdan N, McDonough C, Cooper C, Venkatesan AK. Application of electron beam technology to decompose per- and polyfluoroalkyl substances in water. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 348:123770. [PMID: 38493862 DOI: 10.1016/j.envpol.2024.123770] [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: 01/04/2024] [Accepted: 03/10/2024] [Indexed: 03/19/2024]
Abstract
The widespread detection of per- and polyfluoroalkyl substances (PFAS) in environmental compartments across the globe has raised several health concerns. Destructive technologies that aim to transform these recalcitrant PFAS into less toxic, more manageable products, are gaining impetus to address this problem. In this study, a 9 MeV electron beam accelerator was utilized to treat a suite of PFAS (perfluoroalkyl carboxylates: PFCAs, perfluoroalkyl sulfonates, and 6:2 fluorotelomer sulfonate: FTS) at environmentally relevant levels in water under different operating and water quality conditions. Although perfluorooctanoic acid and perfluorooctane sulfonic acid showed >90% degradation at <500 kGy dose at optimized conditions, a fluoride mass balance revealed that complete defluorination occurred only at/or near 1000 kGy. Non-target and suspect screening revealed additional degradation pathways differing from previously reported mechanisms. Treatment of PFAS mixtures in deionized water and groundwater matrices showed that FTS was preferentially degraded (∼90%), followed by partial degradation of long-chain PFAS (∼15-60%) and a simultaneous increase of short-chain PFAS (up to 20%) with increasing doses. The increase was much higher (up to 3.5X) in groundwaters compared to deionized water due to the presence of PFAS precursors as confirmed by total oxidizable precursor (TOP) assay. TOP assay of e-beam treated samples did not show any increase in PFCAs, confirming that e-beam was effective in also degrading precursors. This study provides an improved understanding of the mechanism of PFAS degradation and revealed that short-chain PFAS are more resistant to defluorination and their levels and regulation in the environment will determine the operating conditions of e-beam and other PFAS treatment technologies.
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Affiliation(s)
- Kaushik Londhe
- Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ, 07102, USA; New York State Center for Clean Water Technology, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Cheng-Shiuan Lee
- Research Center for Environmental Changes, Academia Sinica, Taipei, 115, Taiwan
| | | | - Rachel Smolinski
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | - Noor Hamdan
- Department of Environmental Health and Engineering, Johns Hopkins University, MD, 21205, USA
| | - Carrie McDonough
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | - Charles Cooper
- Fermi National Accelerator Laboratory, Batavia, IL, 60510, USA
| | - Arjun K Venkatesan
- Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ, 07102, USA; New York State Center for Clean Water Technology, Stony Brook University, Stony Brook, NY, 11794, USA.
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13
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Sun R, Babalol S, Ni R, Dolatabad AA, Cao J, Xiao F. Efficient and fast remediation of soil contaminated by per- and polyfluoroalkyl substances (PFAS) by high-frequency heating. JOURNAL OF HAZARDOUS MATERIALS 2024; 463:132660. [PMID: 37898088 DOI: 10.1016/j.jhazmat.2023.132660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 08/17/2023] [Accepted: 09/26/2023] [Indexed: 10/30/2023]
Abstract
This study presents a novel thermal technology (high-frequency heating, HFH) for the decontamination of soil containing per- and polyfluoroalkyl substances (PFAS) and aqueous film-forming foams (AFFFs). Ultra-fast degradation of short-chain PFAS, long-chain homologs, precursors, legacy PFAS, emerging PFAS was achieved in a matter of minutes. The concentrations of PFAS and the soil type had a negligible impact on degradation efficiency, possibly due to the ultra-fast degradation rate overwhelming potential differences. Under the current HFH experiment setup, we achieved near-complete degradation (e.g., >99.9%) after 1 min for perfluoroalkyl carboxylic acids and perfluoroalkyl ether carboxylic acids and 2 min for perfluoroalkanesulfonic acids. Polyfluoroalkyl precursors in AFFFs were found to degrade completely within 1 min of HFH; no residual cationic, zwitterionic, anionic, or non-ionic intermediate products were detected following the treatment. The gaseous byproducts were considered. Most of gaseous organofluorine products of PFAS at low-and-moderate temperatures disappeared when temperatures reached 890 °C, which is in the temperature zone of HFH. For the first time, we demonstrated minimal loss of PFAS in water during the boiling process, indicating a low risk of PFAS entering the atmosphere with the water vapor. The findings highlight HFH its potential as a promising remediation tool for PFAS-contaminated soils.
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Affiliation(s)
- Runze Sun
- Department of Civil and Environmental Engineering, The University of Missouri, Columbia, MO 65211, USA
| | - Samuel Babalol
- Department of Civil and Environmental Engineering, The University of Missouri, Columbia, MO 65211, USA
| | - Ruichong Ni
- Department of Petroleum Engineering, University of North Dakota, 243 Centennial Drive Stop 8155, Grand Forks, ND 58202, USA
| | - Alireza Arhami Dolatabad
- Department of Civil and Environmental Engineering, The University of Missouri, Columbia, MO 65211, USA
| | - Jiefei Cao
- Department of Civil and Environmental Engineering, The University of Missouri, Columbia, MO 65211, USA
| | - Feng Xiao
- Department of Civil and Environmental Engineering, The University of Missouri, Columbia, MO 65211, USA.
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14
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Wang D, Xin S, Dong Y, Sun Z, Li X, Wang Q, Liu G, Liu Y, Xin Y. Heat and carbon co-activated persulfate to regenerate gentamicin-laden activated carbon: Performance, mechanism, and safety assessment. CHEMOSPHERE 2024; 349:140960. [PMID: 38104734 DOI: 10.1016/j.chemosphere.2023.140960] [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: 09/03/2023] [Revised: 12/07/2023] [Accepted: 12/12/2023] [Indexed: 12/19/2023]
Abstract
Activated carbon enriched with high concentrations of gentamicin (ACG) was generated in the production process of gentamicin. Inappropriate handling methods for ACG not only squanders carbon resource, but also seriously hinders achieving global carbon neutrality and hazardous to human health. In the present work, thermal and carbon co-activated persulfate method (TC-PS) was developed to regenerate ACG with degrading gentamicin. The results showed that ACG was effectively regenerated by TC-PS, restoring the adsorption performance for gentamicin. When the treatment temperature was 80 °C, the persulfate dosage was 20 mM and the initial pH was 3.0, the degradation efficiency of gentamicin reached 100%. The HO• and SO4•- were the major reactive species for gentamicin degradation. The possible degradation routes of gentamicin were proposed and the safety assessment indicated that the produced intermediates during the regeneration process of ACG by TC-PS have insignificant impact on the biological and ecological environment.
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Affiliation(s)
- Dong Wang
- Qingdao Engineering Research Center for Rural Environment, College of Resources and Environment, Qingdao Agricultural University, Qingdao, 266109, China
| | - Shuaishuai Xin
- Qingdao Engineering Research Center for Rural Environment, College of Resources and Environment, Qingdao Agricultural University, Qingdao, 266109, China.
| | - Yanan Dong
- Qingdao Engineering Research Center for Rural Environment, College of Resources and Environment, Qingdao Agricultural University, Qingdao, 266109, China
| | - Zhihao Sun
- Qingdao Engineering Research Center for Rural Environment, College of Resources and Environment, Qingdao Agricultural University, Qingdao, 266109, China
| | - Xiaofen Li
- Qingdao Engineering Research Center for Rural Environment, College of Resources and Environment, Qingdao Agricultural University, Qingdao, 266109, China
| | - Qianwen Wang
- Qingdao Engineering Research Center for Rural Environment, College of Resources and Environment, Qingdao Agricultural University, Qingdao, 266109, China
| | - Guocheng Liu
- Qingdao Engineering Research Center for Rural Environment, College of Resources and Environment, Qingdao Agricultural University, Qingdao, 266109, China
| | - Yucan Liu
- School of Civil Engineering, Yantai University, Yantai, 264005, China
| | - Yanjun Xin
- Qingdao Engineering Research Center for Rural Environment, College of Resources and Environment, Qingdao Agricultural University, Qingdao, 266109, China.
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15
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Lauwers A, Vercammen J, De Vos D. Adsorption of PFAS by All-Silica Zeolite β: Insights into the Effect of the Water Matrix, Regeneration of the Material, and Continuous PFAS Adsorption. ACS APPLIED MATERIALS & INTERFACES 2023. [PMID: 37932926 DOI: 10.1021/acsami.3c12321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are man-made organic compounds ubiquitously present in the environment. Due to their persistency and bioaccumulative nature, and because of increasingly stringent regulations of PFAS, their removal from the environment is necessary. Our initial study identified all-silica zeolite β as an alternative adsorbent with a high selectivity, affinity, and capacity for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) removal. Here, we study the influence of the PFAS chain length on the affinity and capacity of a novel material, all-silica zeolite β, showing that the *BEA zeolite is an ideal sorbent for the removal of PFAS with 8 carbons. The solution pH and the addition of cations or natural organic substances to the water matrix have minimal influence on PFOA/PFOS removal with the zeolite. Next, regeneration of a PFOS-loaded zeolite was assessed; besides thermal, solvent-driven regeneration of the zeolite is also possible, using well-selected combinations of non-noxious solvents. Lastly, continuous adsorption experiments show that zeolite can be used for larger-scale applications.
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Affiliation(s)
- Aline Lauwers
- Centre for Membrane Separations, Adsorption, Catalysis and Spectroscopy for Sustainable Solutions (cMACS), KU Leuven, Celestijnenlaan 200F, Leuven 3001, Belgium
| | - Jannick Vercammen
- Centre for Membrane Separations, Adsorption, Catalysis and Spectroscopy for Sustainable Solutions (cMACS), KU Leuven, Celestijnenlaan 200F, Leuven 3001, Belgium
| | - Dirk De Vos
- Centre for Membrane Separations, Adsorption, Catalysis and Spectroscopy for Sustainable Solutions (cMACS), KU Leuven, Celestijnenlaan 200F, Leuven 3001, Belgium
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16
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Sánchez-Yepes A, Santos A, Rosas JM, Rodríguez-Mirasol J, Cordero T, Lorenzo D. Sustainable reuse of toxic spent granular activated carbon by heterogeneous fenton reaction intensified by temperature changes. CHEMOSPHERE 2023; 341:140047. [PMID: 37660800 DOI: 10.1016/j.chemosphere.2023.140047] [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: 03/23/2023] [Revised: 07/20/2023] [Accepted: 08/31/2023] [Indexed: 09/05/2023]
Abstract
A common strategy for removing highly toxic organic compounds, such as chlorinated organic compounds, is their adsorption on granular activated carbon. Spent granular activated carbon results in a toxic residue to manage; therefore, the regeneration and reuse of granular activated carbon on the site would be advisable. This work studies the regeneration of a granular activated carbon saturated in 1,2,4-trichlorobenzene, chosen as the model chlorinated organic compounds, by heterogeneous Fenton, where iron was previously immobilised on the granular activated carbon surface. This methodology avoids the addition of iron to the aqueous phase at concentrations above the allowable limits and the need for acidification. Three successive cycles of adsorption-regeneration were carried out batchwise (5 gGAC·L-1) with a granular activated carbon saturated with 300 mg124-TCB·gGAC-1. The recovery of the adsorption capacity after regeneration was studied with H2O2 (166 mM, 1.5 the stoichiometric dosage), at different concentrations adsorbed with iron adsorbed concentrations (0-12 mgFe·gGAC-1) and temperatures (20-80 °C). Stable recovery of the adsorption capacity values of 65% were obtained at 180 min with 12 mgFe·gGAC-1 and 60 °C. The porosity and surface chemistry of the adsorbent remained very similar after different adsorption-regeneration cycles without iron leaching into the aqueous phase. The oxidant consumption was close to the stoichiometric value for the mineralization of 1,2,4-trichlorobenzene, with a low unproductive consumption of H2O2 with granular activated carbon. In addition, no aromatic or chlorinated by-products were detected in the aqueous solution obtained in the regeneration process. The negligible toxicity of the aqueous phase with the Microtox bioassay confirmed the absence of toxic oxidation by-products.
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Affiliation(s)
- Andrés Sánchez-Yepes
- Chemical Engineering and Materials Department, Complutense University of Madrid, Spain
| | - Aurora Santos
- Chemical Engineering and Materials Department, Complutense University of Madrid, Spain
| | - Juana M Rosas
- Universidad de Málaga, Andalucia Tech., Departamento de Ingeniería Química, Campus de Teatinos S/n, 29010, Málaga, Spain
| | - José Rodríguez-Mirasol
- Universidad de Málaga, Andalucia Tech., Departamento de Ingeniería Química, Campus de Teatinos S/n, 29010, Málaga, Spain
| | - Tomás Cordero
- Universidad de Málaga, Andalucia Tech., Departamento de Ingeniería Química, Campus de Teatinos S/n, 29010, Málaga, Spain
| | - David Lorenzo
- Chemical Engineering and Materials Department, Complutense University of Madrid, Spain.
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17
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Deng J, Han J, Hou C, Zhang Y, Fang Y, Du W, Li M, Yuan Y, Tang C, Hu X. Efficient removal of per- and polyfluoroalkyl substances from biochar composites: Cyclic adsorption and spent regenerant degradation. CHEMOSPHERE 2023; 341:140051. [PMID: 37660789 DOI: 10.1016/j.chemosphere.2023.140051] [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: 06/23/2023] [Revised: 08/17/2023] [Accepted: 09/01/2023] [Indexed: 09/05/2023]
Abstract
In order to solve the problem of efficient desorption of per- and polyfluoroalkyl substances (PFAS) and regeneration of adsorbents, a novel biochar composite was prepared based on the quaternary ammonium groups and hydrophobicity of sulfobetaine polymer, which can be used for the efficient removal of various PFASs and has great regeneration ability. Through adsorption, regeneration and degradation experiment, the comprehensive effect of the novel biochar composite on the whole process of removal of PFAS was systematically investigated. The results showed that the maximum adsorption capacity of PFOS, PFOA, PFBS, and PFBA reached 634 mg/g, 536 mg/g, 301 mg/g and 264 mg/g, respectively. The adsorption process involved hydrophobicity, electrostatic, pore diffusion and complexation. The NaI + NaOH solution was used at 50 °C to achieve efficient regeneration of the adsorbent, which can be recycled more than 4 times. When the vacuum-ultraviolet (VUV)/sulfite reduction system was used for deep degradation of the regenerated solution, the effect of hydrated electrons on PFAS was enhanced due to the inclusion of NaI and NaOH in the regeneration reagent, resulting in an increase in the degradation efficiency (89.1%-99.9%) and defluorination efficiency (63.3%-84.1%). Based on the performance of BC-P(SB-co-AM) and the treatment efficiency of PFAS, the design idea of the whole process treatment technology of PFAS proposed in this work is expected to hold great promise in environmental applications. This work provides a novel idea and system for the efficient adsorption removal and desorption of PFAS, and subsequent deep degradation.
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Affiliation(s)
- Jiaqin Deng
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China; State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha, 410004, China.
| | - Jianing Han
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China
| | - Changlan Hou
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, China
| | - Yanru Zhang
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha, 410004, China
| | - Ying Fang
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, China
| | - WanXuan Du
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China
| | - Meifang Li
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China
| | - Yuan Yuan
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China
| | - Chunfang Tang
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China
| | - Xinjiang Hu
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China.
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Chiang SYD, Saba M, Leighton M, Ballenghien D, Hatler D, Gal J, Deshusses MA. Supercritical water oxidation for the destruction of spent media wastes generated from PFAS treatment. JOURNAL OF HAZARDOUS MATERIALS 2023; 460:132264. [PMID: 37633016 DOI: 10.1016/j.jhazmat.2023.132264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 08/02/2023] [Accepted: 08/08/2023] [Indexed: 08/28/2023]
Abstract
Granular activated carbon (GAC) and anion exchange resin (AIX) have been successfully demonstrated to remove per- and polyfluoroalkyl substances (PFAS) from contaminated water and wastewater. These treatment technologies, when applied for PFAS removal, generate spent media loaded with a high mass of PFAS requiring further treatment and disposal. This project is the first study on the use of supercritical water oxidation (SCWO) to destroy both the spent media and the PFAS adsorbed onto it. One sample of spent GAC and one sample of spent AIX were collected from full-scale groundwater remediation systems treating PFAS. A second spent AIX sample was collected from a mobile PFAS treatment unit. The total PFAS concentrations reported in the GAC, AIX and second AIX feedstock slurries were 0.21 mg/kg, 1.3 mg/kg and 0.9 mg/kg, respectively. Each feedstock was processed separately in a one (1) wet metric ton per day tubular reactor SCWO system. The study demonstrated that SCWO is a very effective PFAS destruction technology for spent GAC and AIX, derived from water remediation systems treating PFAS. The spent media were completely mineralized to water, carbon dioxide (CO2) and a negligible amount of residual minerals. Total target PFAS compound concentrations in the SCWO system effluents after treating spent GAC, AIX and second AIX feedstocks were 548, 77 and 796 ng/L, respectively. The results indicated that the percentage elimination of perfluorocarboxylic acids (PFCAs) was better than that of perfluosulfonic acids (PFSAs) and long-chain PFAS elimination was better than short-chain PFAS.
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Affiliation(s)
- Sheau-Yun Dora Chiang
- WSP USA, Environmental Remediation and PFAS Innovation, Earth & Environment, 1075 Big Shanty Rd NW #100, Kennesaw, GA 30144, USA.
| | - Matthew Saba
- 374Water Inc., 3710 Shanon R. #51877, Durham, NC 27717, USA; Duke University, Department of Civil and Environmental Engineering, Box 90287, Durham, NC 27708, USA
| | - Macon Leighton
- 374Water Inc., 3710 Shanon R. #51877, Durham, NC 27717, USA; Duke University, Department of Civil and Environmental Engineering, Box 90287, Durham, NC 27708, USA
| | | | - Douglas Hatler
- 374Water Inc., 3710 Shanon R. #51877, Durham, NC 27717, USA
| | - Justin Gal
- WSP USA, Environmental Remediation and PFAS Innovation, Earth & Environment, 1075 Big Shanty Rd NW #100, Kennesaw, GA 30144, USA
| | - Marc A Deshusses
- 374Water Inc., 3710 Shanon R. #51877, Durham, NC 27717, USA; Duke University, Department of Civil and Environmental Engineering, Box 90287, Durham, NC 27708, USA
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19
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Zhang Y, Thomas A, Apul O, Venkatesan AK. Coexisting ions and long-chain per- and polyfluoroalkyl substances (PFAS) inhibit the adsorption of short-chain PFAS by granular activated carbon. JOURNAL OF HAZARDOUS MATERIALS 2023; 460:132378. [PMID: 37643572 DOI: 10.1016/j.jhazmat.2023.132378] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 07/27/2023] [Accepted: 08/22/2023] [Indexed: 08/31/2023]
Abstract
We assessed the competitive adsorption between long-chain and short-chain PFAS and the impact of coexisting ions to understand the mechanisms leading to the early breakthrough of short-chain PFAS from granular activated carbon (GAC) filters. Three pairs of short-chain and long-chain PFAS representing different functional groups were studied using GAC (Filtrasorb 400) in batch systems. In bisolute systems, the presence of long-chain PFAS decreased the adsorption of short-chain PFAS by 30-50% compared to their single solute adsorption capacity (0.22-0.31 mmol/g). In contrast to the partial decrease observed in bisolute systems, the addition of long-chain PFAS to GAC pre-equilibrated with short-chain PFAS completely desorbed all short-chain PFAS from GAC. This suggested that the outermost adsorption sites on GAC were preferentially occupied by short-chain PFAS in the absence of competition but were prone to displacement by long-chain PFAS. The presence of inorganic/organic ions inhibited the adsorption of short-chain PFAS (up to 60%) but had little to no impact on long-chain PFAS, with the inhibitory trend inversely correlated with Kow values. Study results indicated that the displacement of short-chain PFAS by long-chain PFAS and charge neutralization are important mechanisms contributing to the early breakthrough of short-chain PFAS from GAC systems.
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Affiliation(s)
- Yi Zhang
- New York State Center for Clean Water Technology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Amanda Thomas
- New York State Center for Clean Water Technology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Onur Apul
- Department of Civil and Environmental Engineering, University of Maine, Orono, ME 04469, USA
| | - Arjun K Venkatesan
- New York State Center for Clean Water Technology, Stony Brook University, Stony Brook, NY 11794, USA; Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA.
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Xiao F, Challa Sasi P, Alinezhad A, Sun R, Abdulmalik Ali M. Thermal Phase Transition and Rapid Degradation of Forever Chemicals (PFAS) in Spent Media Using Induction Heating. ACS ES&T ENGINEERING 2023; 3:1370-1380. [PMID: 37705671 PMCID: PMC10497035 DOI: 10.1021/acsestengg.3c00114] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Revised: 04/13/2023] [Accepted: 04/17/2023] [Indexed: 09/15/2023]
Abstract
In this study, we have developed an innovative thermal degradation strategy for treating per- and polyfluoroalkyl substance (PFAS)-containing solid materials. Our strategy satisfies three criteria: the ability to achieve near-complete degradation of PFASs within a short timescale, nonselectivity, and low energy cost. In our method, a metallic reactor containing a PFAS-laden sample was subjected to electromagnetic induction that prompted a rapid temperature rise of the reactor via the Joule heating effect. We demonstrated that subjecting PFASs (0.001-12 μmol) to induction heating for a brief duration (e.g., <40 s) resulted in substantial degradation (>90%) of these compounds, including recalcitrant short-chain PFASs and perfluoroalkyl sulfonic acids. This finding prompted us to conduct a detailed study of the thermal phase transitions of PFASs using thermogravimetric analysis and differential scanning calorimetry (DSC). We identified at least two endothermic DSC peaks for anionic, cationic, and zwitterionic PFASs, signifying the melting and evaporation of the melted PFASs. Melting and evaporation points of many PFASs were reported for the first time. Our data suggest that the rate-limiting step in PFAS thermal degradation is linked with phase transitions (e.g., evaporation) occurring on different time scales. When PFASs are rapidly heated to temperatures similar to those produced during induction heating, the evaporation of melted PFAS slows down, allowing for the degradation of the melted PFAS.
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Affiliation(s)
- Feng Xiao
- Department of Civil and Environmental Engineering, University of Missouri, Columbia, Missouri 65211, United States
| | - Pavankumar Challa Sasi
- Department of Civil
Engineering, University of North Dakota, 243 Centennial Drive Stop 8115, Grand Forks, North Dakota 58202, United States
- EA Engineering, Science, and Technology, Inc., Hunt Valley, Maryland 21031, United States
| | - Ali Alinezhad
- Department of Civil and Environmental Engineering, University of Missouri, Columbia, Missouri 65211, United States
| | - Runze Sun
- Department of Civil and Environmental Engineering, University of Missouri, Columbia, Missouri 65211, United States
| | - Mansurat Abdulmalik Ali
- Department of Civil
Engineering, University of North Dakota, 243 Centennial Drive Stop 8115, Grand Forks, North Dakota 58202, United States
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21
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Apul O, Howell C, Hatinoglu MD. Per- and polyfluoroalkyl substances (PFAS) at the interface of biological and environmental systems. Biointerphases 2023; 18:050201. [PMID: 37800992 DOI: 10.1116/6.0003104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 09/13/2023] [Indexed: 10/07/2023] Open
Affiliation(s)
- Onur Apul
- Department of Civil and Environmental Engineering, University of Maine, Orono, Maine 04473
| | - Caitlin Howell
- Department of Chemical and Biomedical Engineering, University of Maine, Orono, Maine 04473
| | - M Dilara Hatinoglu
- Department of Civil and Environmental Engineering, University of Maine, Orono, Maine 04473
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22
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Shittu AR, Iwaloye OF, Ojewole AE, Rabiu AG, Amechi MO, Herve OF. The effects of per- and polyfluoroalkyl substances on environmental and human microorganisms and their potential for bioremediation. Arh Hig Rada Toksikol 2023; 74:167-178. [PMID: 37791672 PMCID: PMC10549896 DOI: 10.2478/aiht-2023-74-3708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 01/01/2023] [Accepted: 08/01/2023] [Indexed: 10/05/2023] Open
Abstract
Utilised in a variety of consumer products, per- and polyfluoroalkyl substances (PFAS) are major environmental contaminants that accumulate in living organisms due to their highly hydrophobic, lipophobic, heat-resistant, and non-biodegradable properties. This review summarizes their effects on microbial populations in soils, aquatic and biogeochemical systems, and the human microbiome. Specific microbes are insensitive to and even thrive with PFAS contamination, such as Escherichia coli and the Proteobacteria in soil and aquatic environments, while some bacterial species, such as Actinobacteria and Chloroflexi, are sensitive and drop in population. Some bacterial species, in turn, have shown success in PFAS bioremediation, such as Acidimicrobium sp. and Pseudomonas parafulva.
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Affiliation(s)
- Adenike R. Shittu
- Bowling Green State University College of Arts and Sciences, Department of Biological Sciences, Bowling Green, OH, USA
| | - Opeoluwa F. Iwaloye
- Bowling Green State University College of Arts and Sciences, Department of Biological Sciences, Bowling Green, OH, USA
| | - Akinloye E. Ojewole
- Southern Illinois University, Department of Environmental Sciences, Edwardsville, IL, USA
| | - Akeem G. Rabiu
- University of Ibadan, Department of Microbiology, Ibadan, Nigeria
| | - Miracle O. Amechi
- University of Louisville, Department of Chemistry, Louisville, KY, USA
| | - Ouambo F. Herve
- Chantal Biya International Reference Centre, Laboratory of Vaccinology, Yaounde, Cameroon
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23
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Shi Y, Mu H, You J, Han C, Cheng H, Wang J, Hu H, Ren H. Confined water-encapsulated activated carbon for capturing short-chain perfluoroalkyl and polyfluoroalkyl substances from drinking water. Proc Natl Acad Sci U S A 2023; 120:e2219179120. [PMID: 37364117 PMCID: PMC10318985 DOI: 10.1073/pnas.2219179120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 04/18/2023] [Indexed: 06/28/2023] Open
Abstract
The global ecological crisis of perfluoroalkyl and polyfluoroalkyl substances (PFASs) in drinking water has gradually shifted from long-chain to short-chain PFASs; however, the widespread established PFAS adsorption technology cannot cope with the impact of such hydrophilic pollutants given the inherent defects of solid-liquid mass transfer. Herein, we describe a reagent-free and low-cost strategy to reduce the energy state of short-chain PFASs in hydrophobic nanopores by employing an in situ constructed confined water structure in activated carbon (AC). Through direct (driving force) and indirect (assisted slip) effects, the confined water introduced a dual-drive mode in the confined water-encapsulated activated carbon (CW-AC) and completely eliminated the mass transfer barrier (3.27 to 5.66 kcal/mol), which caused the CW-AC to exhibit the highest adsorption capacity for various short-chain PFASs (C-F number: 3-6) among parent AC and other adsorbents reported. Meanwhile, benefiting from the chain length- and functional group-dependent confined water-binding pattern, the affinity of the CW-AC surpassed the traditional hydrophobicity dominance and shifted toward hydrophilic short-chain PFASs that easily escaped treatment. Importantly, the ability of CW-AC functionality to directly transfer to existing adsorption devices was verified, which could treat 21,000 bed volumes of environment-related high-load (~350 ng/L short-chain PFAS each) real drinking water to below the World Health Organization's standard. Overall, our results provide a green and cost-effective in situ upgrade scheme for existing adsorption devices to address the short-chain PFAS crisis.
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Affiliation(s)
- Yuanji Shi
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing210023, Jiangsu, PR China
| | - Hongxin Mu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing210023, Jiangsu, PR China
| | - Jiaqian You
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing210023, Jiangsu, PR China
| | - Chenglong Han
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing210023, Jiangsu, PR China
| | - Huazai Cheng
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing210023, Jiangsu, PR China
| | - Jinfeng Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing210023, Jiangsu, PR China
| | - Haidong Hu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing210023, Jiangsu, PR China
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing210023, Jiangsu, PR China
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24
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Alinezhad A, Shao H, Litvanova K, Sun R, Kubatova A, Zhang W, Li Y, Xiao F. Mechanistic Investigations of Thermal Decomposition of Perfluoroalkyl Ether Carboxylic Acids and Short-Chain Perfluoroalkyl Carboxylic Acids. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:8796-8807. [PMID: 37195265 PMCID: PMC10269594 DOI: 10.1021/acs.est.3c00294] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 04/27/2023] [Accepted: 05/03/2023] [Indexed: 05/18/2023]
Abstract
In this study, we investigated the thermal decomposition mechanisms of perfluoroalkyl ether carboxylic acids (PFECAs) and short-chain perfluoroalkyl carboxylic acids (PFCAs) that have been manufactured as replacements for phased-out per- and polyfluoroalkyl substances (PFAS). C-C, C-F, C-O, O-H, and C═C bond dissociation energies were calculated at the M06-2X/Def2-TZVP level of theory. The α-C and carboxyl-C bond dissociation energy of PFECAs declines with increasing chain length and the attachment of an electron-withdrawing trifluoromethyl (-CF3) group to the α-C. Experimental and computational results show that the thermal transformation of hexafluoropropylene oxide dimer acid to trifluoroacetic acid (TFA) occurs due to the preferential cleavage of the C-O ether bond close to the carboxyl group. This pathway produces precursors of perfluoropropionic acid (PFPeA) and TFA and is supplemented by a minor pathway (CF3CF2CF2OCFCF3COOH → CF3CF2CF2· + ·OCFCF3COOH) through which perfluorobutanoic acid (PFBA) is formed. The weakest C-C bond in PFPeA and PFBA is the one connecting the α-C and the β-C. The results support (1) the C-C scission in the perfluorinated backbone as an effective PFCA thermal decomposition mechanism and (2) the thermal recombination of radicals through which intermediates are formed. Additionally, we detected a few novel thermal decomposition products of studied PFAS.
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Affiliation(s)
- Ali Alinezhad
- Department
of Civil and Environmental Engineering, The University of Missouri, Columbia, Missouri 65211, United States
| | - Heng Shao
- Key
Laboratory of Water and Sediment Sciences of Ministry of Education,
State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, People’s Republic of China
| | - Katerina Litvanova
- Department
of Chemistry, The University of North Dakota, Grand Forks, North Dakota 58202, United States
| | - Runze Sun
- Department
of Civil and Environmental Engineering, The University of Missouri, Columbia, Missouri 65211, United States
| | - Alena Kubatova
- Department
of Chemistry, The University of North Dakota, Grand Forks, North Dakota 58202, United States
| | - Wen Zhang
- John
A. Reif, Jr. Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102, United States
| | - Yang Li
- Key
Laboratory of Water and Sediment Sciences of Ministry of Education,
State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, People’s Republic of China
| | - Feng Xiao
- Department
of Civil and Environmental Engineering, The University of Missouri, Columbia, Missouri 65211, United States
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25
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Wang J, Song M, Abusallout I, Hanigan D. Thermal Decomposition of Two Gaseous Perfluorocarboxylic Acids: Products and Mechanisms. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:6179-6187. [PMID: 37018767 DOI: 10.1021/acs.est.2c08210] [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: 06/19/2023]
Abstract
The thermal decomposition products and mechanisms of per- and polyfluoroalkyl substances (PFASs) are poorly understood despite the use of thermal treatment to remediate PFAS-contaminated media. To identify the thermal decomposition products and mechanisms of perfluorocarboxylic acids (PFCAs), gaseous perfluoropropionic acid (PFPrA) and perfluorobutyric acid (PFBA) were decomposed in nitrogen and oxygen at temperatures from 200 to 780 °C. In nitrogen (i.e., pyrolysis), the primary products of PFPrA were CF2═CF2, CF3CF2H, and CF3COF. CF3CF═CF2 was the dominant product of PFBA. These products are produced by HF elimination (detected as low as 200 °C). CF4 and C2F6 were observed from both PFCAs, suggesting formation of perfluorocarbon radical intermediates. Pyrolysis products were highly thermally stable, resulting in poor defluorination. In oxygen (i.e., combustion), the primary product of both PFPrA and PFBA below 400 °C was COF2, but the primary product was SiF4 above 600 °C due to reactions with the quartz reactor. Oxygen facilitated thermal defluorination by reacting with PFCAs and with pyrolysis products (i.e., fluoroolefins and fluorocarbon radicals). Platinum improved combustion of PFCAs to COF2 at temperatures as low as 200 °C, while quartz promoted the combustion of PFCAs into SiF4 at higher temperatures (>600 °C), highlighting the importance of surface reactions that are not typically incorporated into computational approaches.
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Affiliation(s)
- Junli Wang
- Department of Civil and Environmental Engineering, University of Nevada, Reno, Nevada 89557-0258, United States
- Department of Environmental Science, University of California, Riverside, California 92521, United States
| | - Mingrui Song
- Department of Civil and Environmental Engineering, University of Nevada, Reno, Nevada 89557-0258, United States
| | - Ibrahim Abusallout
- Department of Civil and Environmental Engineering, University of Nevada, Reno, Nevada 89557-0258, United States
- CDM Smith, 75 State Street, Suite 701, Boston, Massachusetts 02109, United States
- Fraunhofer USA, Inc., Center Midwest, Division for Coatings and Diamonds Technologies, East Lansing, Michigan 48824, United States
| | - David Hanigan
- Department of Civil and Environmental Engineering, University of Nevada, Reno, Nevada 89557-0258, United States
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26
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Aumeier BM, Georgi A, Saeidi N, Sigmund G. Is sorption technology fit for the removal of persistent and mobile organic contaminants from water? THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 880:163343. [PMID: 37030383 DOI: 10.1016/j.scitotenv.2023.163343] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 03/21/2023] [Accepted: 04/03/2023] [Indexed: 04/15/2023]
Abstract
Persistent, Mobile, and Toxic (PMT) and very persistent and very mobile (vPvM) substances are a growing threat to water security and safety. Many of these substances are distinctively different from other more traditional contaminants in terms of their charge, polarity, and aromaticity. This results in distinctively different sorption affinities towards traditional sorbents such as activated carbon. Additionally, an increasing awareness on the environmental impact and carbon footprint of sorption technologies puts some of the more energy-intensive practices in water treatment into question. Commonly used approaches may thus need to be readjusted to become fit for purpose to remove some of the more challenging PMT and vPvM substances, including for example short chained per- and polyfluoroalkyl substances (PFAS). We here critically review the interactions that drive sorption of organic compounds to activated carbon and related sorbent materials and identify opportunities and limitations of tailoring activated carbon for PMT and vPvM removal. Other less traditional sorbent materials, including ion exchange resins, modified cyclodextrins, zeolites and metal-organic frameworks are then discussed for potential alternative or complementary use in water treatment scenarios. Sorbent regeneration approaches are evaluated in terms of their potential, considering reusability, potential for on-site regeneration, and potential for local production. In this context, we also discuss the benefits of coupling sorption to destructive technologies or to other separation technologies. Finally, we sketch out possible future trends in the evolution of sorption technologies for PMT and vPvM removal from water.
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Affiliation(s)
- Benedikt M Aumeier
- RWTH Aachen University, Institute of Environmental Engineering, Mies-van-der-Rohe-Strasse 1, 52074 Aachen, Germany.
| | - Anett Georgi
- Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Engineering, 04318 Leipzig, Germany
| | - Navid Saeidi
- Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Engineering, 04318 Leipzig, Germany
| | - Gabriel Sigmund
- Department of Environmental Geosciences, Centre for Microbiology and Environmental Systems Science, University of Vienna, 1090 Wien, Austria; Environmental Technology, Wageningen University & Research, P.O. Box 17, 6700 AA Wageningen, the Netherlands.
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27
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Ersan G, Cerrón-Calle GA, Ersan MS, Garcia-Segura S. Opportunities for in situ electro-regeneration of organic contaminant-laden carbonaceous adsorbents. WATER RESEARCH 2023; 232:119718. [PMID: 36774755 DOI: 10.1016/j.watres.2023.119718] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 12/19/2022] [Accepted: 02/04/2023] [Indexed: 06/18/2023]
Abstract
Adsorptive separation technologies have proven to be effective on organic contaminant removal in aqueous water. However, the breakthrough of contaminants is inevitable and can be at relatively low bed volumes, which makes the regeneration of spent adsorbents an urgent need. Electrochemically induced regeneration processes are given special attention and may provide ease of operation through in situ regeneration avoiding (i) removal and transport adsorbents, and (ii) avoiding use of hazardous chemicals (i.e., organic solvents, acids, or bases). Therefore, this review article critically evaluates the fundamental aspects of in situ electro-regeneration for spent carbons, and later discusses specific examples related to the treatment of emerging contaminants (such as per- and polyfluoroalkyl substances or PFAS). The fundamental concepts of electrochemically driven processes are comprehensively defined and addressed in terms of (i) adsorbent characteristics, (ii) contaminant properties, (iii) adsorption/regeneration driving operational parameters and conditions, and (iv) the competitive effects of water matrices. Additionally, future research needs and challenges to enhance understanding of in situ electro-regeneration applications for organic contaminants (specifically PFAS)-laden adsorbents are identified and outlined as a future key perspective.
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Affiliation(s)
- Gamze Ersan
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287-5306, United States.
| | - Gabriel Antonio Cerrón-Calle
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287-5306, United States
| | - Mahmut S Ersan
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287-5306, United States
| | - Sergi Garcia-Segura
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287-5306, United States.
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28
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Zhang T, Zuo S. Drying enables multiple reuses of activated carbon without regeneration. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:45097-45111. [PMID: 36701054 DOI: 10.1007/s11356-023-25481-z] [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] [Accepted: 01/18/2023] [Indexed: 06/17/2023]
Abstract
Traditional regeneration of activated carbon is usually carried out by high-temperature oxidation in industrial processes, which reduces the quality and performance of the adsorbent, thereby increasing costs and damaging the environment. In this study, a simple drying process is proposed to enable reuse of spent activated carbon. The feasibility and merits of this method were evaluated in batch and continuous adsorption modes using dyes as adsorbates. The batch adsorption results showed that the activated carbon could be reused seven times after a simple drying process, because it led to full occupancy of the activated carbon pores by adsorbate molecules. The cumulative adsorption capacities of the activated carbon were as high as 1005.3 mg/g for methyl orange (MO) and 954.8 mg/g for methylene blue (MB). Continuous adsorption experiments in a fixed-bed column demonstrated that the activated carbon column could be reused more than three times after simply drying. Moreover, dye molecules adsorbed by the activated carbon were not leached by the stream of dye solution during reuse. This drying method exhibits three main merits for reuse of activated carbon, including (1) remarkably reduced consumption of fresh activated carbon to 51.5% or below, (2) significantly increased recovery of high-value adsorbate from the liquid phase, and (3) potential integration of multiple steps for industrial adsorption processes.
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Affiliation(s)
- Tao Zhang
- College of Chemical Engineering, International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing, 210037, China
| | - Songlin Zuo
- College of Chemical Engineering, International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing, 210037, China.
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29
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Yu H, Chen H, Fang B, Sun H. Sorptive removal of per- and polyfluoroalkyl substances from aqueous solution: Enhanced sorption, challenges and perspectives. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 861:160647. [PMID: 36460105 DOI: 10.1016/j.scitotenv.2022.160647] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 11/25/2022] [Accepted: 11/28/2022] [Indexed: 06/17/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs) have garnered attention globally given their ubiquitous occurrence, toxicity, bioaccumulative potential, and environmental persistence. Sorption is widely used to remove PFASs given its simplicity and cost-effectiveness. This article reviews recently fabricated sorbents, including carbon materials, minerals, polymers, and composite materials. The characteristics and interactions of the sorbents with PFASs are discussed to better understand sorptive processes. Various sorbents have exhibited high removal rates for legacy perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). Novel polymers with special design better remove long- and short-chain PFASs than other sorbents. Although hydrophobic and electrostatic interactions mainly drive the sorption of anionic, cationic, and zwitterionic PFASs, enhancing PFAS sorption on designed sorbents has mainly depended on improving electrostatic interactions. Pearson correlation analysis showed that PFOS sorption capacity of sorbents is positively correlated with their specific surface area. Newly discovered pathways, including the air-water interfacial adsorption, F-F fluorophilic interactions, and (hemi) micelle formation, can enhance PFAS sorption to a certain extent. In addition to PFOA and PFOS, the sorption of emerging PFASs, including aqueous film-forming foam-relevant PFASs, constitutes a new research direction. The functionalization methods for enhancing PFAS sorption and challenges of PFAS sorption are also discussed to provide scope for future research. The discussions herein may contribute to developing efficient sorption technologies to remove PFASs.
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Affiliation(s)
- Hao Yu
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Hao Chen
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Bo Fang
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Hongwen Sun
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
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30
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Hatinoglu MD, Perreault F, Apul OG. Modified linear solvation energy relationships for adsorption of perfluorocarboxylic acids by polystyrene microplastics. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 860:160524. [PMID: 36574542 DOI: 10.1016/j.scitotenv.2022.160524] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 11/09/2022] [Accepted: 11/23/2022] [Indexed: 06/17/2023]
Abstract
Microplastics (MPs) could act as vectors of organic pollutants such as per- and polyfluoroalkyl substances (PFAS). Therefore, understanding adsorptive interactions are essential steps towards unraveling the fate of PFAS in the natural waters where MPs are ubiquitous. Linear solvation energy relationships (LSER)-based predictive models are utilitarian tools to delineate the complexity of adsorption interactions. However, commonly studied PFAS are in their ionic forms at environmentally relevant conditions and LSER modeling parameters do not account for their ionization. This study aims to develop the first LSER model for the adsorption of PFAS by MPs using a subset of ionizable perfluoroalkyl carboxylic acids (PFCA). The adsorption of twelve PFCAs by polystyrene (PS) MPs was used for model training. The study provided mechanistic insights regarding the impacts of PFCA chain length, PS oxidation state, and water chemistry. Results show that the polarizability and hydrophobicity of anionic PFCA are the most significant contributors to their adsorption by MPs. In contrast, van der Waals interactions between PFCA and water significantly decrease PFCA binding affinity. Overall, LSER is demonstrated as a promising approach for predicting the adsorption of ionizable PFAS by MPs after the correction of Abraham's solute descriptors to account for their ionization.
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Affiliation(s)
- M Dilara Hatinoglu
- Department of Civil and Environmental Engineering, University of Maine, Orono, ME 04469, USA
| | - François Perreault
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85281, USA
| | - Onur G Apul
- Department of Civil and Environmental Engineering, University of Maine, Orono, ME 04469, USA.
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31
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Zhang J, Gao L, Bergmann D, Bulatovic T, Surapaneni A, Gray S. Review of influence of critical operation conditions on by-product/intermediate formation during thermal destruction of PFAS in solid/biosolids. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 854:158796. [PMID: 36115408 DOI: 10.1016/j.scitotenv.2022.158796] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 09/11/2022] [Accepted: 09/12/2022] [Indexed: 06/15/2023]
Abstract
Poly- and perfluoroalkyl substances (PFAS) are a large group of synthetic organofluorine compounds. Over 4700 PFAS compounds have been produced and used in our daily life since the 1940s. PFAS have received considerable interest because of their toxicity, environmental persistence, bioaccumulation and wide existence in the environment. Various treatment methods have been developed to overcome these issues. Thermal treatment such as combustion and pyrolysis/gasification have been employed to treat PFAS contaminated solids and soils. However, short-chain PFAS and/or volatile organic fluorine is produced and emitted via exhaust gas during the thermal treatment. Combustion can achieve complete mineralisation of PFAS at large scale operation using temperatures >1000 °C. Pyrolysis has been used in treatment of biosolids and has demonstrated that it could remove PFAS completely from the generated biochar by evaporation and degradation. Although pyrolysis partially degrades PFAS to short-chain fluorine containing organics in the syngas, it could not efficiently mineralise PFAS. Combustion of PFAS containing syngas at 1000 °C can achieve complete mineralisation of PFAS. Furthermore, the by-product of mineralisation, HF, should also be monitored due to its low regulated atmospheric discharge values. Alkali scrubbing is normally required to lower the HF concentration in the exhaust gas to acceptable discharge concentrations.
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Affiliation(s)
- Jianhua Zhang
- Institute for Sustainable Industries and Liveable Cities, Victoria University, Melbourne, VIC 8001, Australia.
| | - Li Gao
- Institute for Sustainable Industries and Liveable Cities, Victoria University, Melbourne, VIC 8001, Australia; South East Water Corporation, PO Box 2268, Seaford, Victoria 3198, Australia
| | - David Bergmann
- South East Water Corporation, PO Box 2268, Seaford, Victoria 3198, Australia
| | - Tamara Bulatovic
- South East Water Corporation, PO Box 2268, Seaford, Victoria 3198, Australia
| | - Aravind Surapaneni
- South East Water Corporation, PO Box 2268, Seaford, Victoria 3198, Australia
| | - Stephen Gray
- Institute for Sustainable Industries and Liveable Cities, Victoria University, Melbourne, VIC 8001, Australia
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Zhang M, Zhao X, Zhao D, Soong TY, Tian S. Poly- and Perfluoroalkyl Substances (PFAS) in Landfills: Occurrence, Transformation and Treatment. WASTE MANAGEMENT (NEW YORK, N.Y.) 2023; 155:162-178. [PMID: 36379166 DOI: 10.1016/j.wasman.2022.10.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 10/21/2022] [Accepted: 10/24/2022] [Indexed: 06/16/2023]
Abstract
Landfills have served as the final repository for > 50 % municipal solid wastes in the United States. Because of their widespread uses and persistence in the environment, per- and polyfluoroalkyl substances (PFAS) (>4000 on the global market) are ubiquitously present in everyday consumer, commercial and industrial products, and have been widely detected in both closed (tens ng/L) and active (thousands to ten thousands ng/L) landfills due to disposal of PFAS-containing materials. Along with the decomposition of wastes in-place, PFAS can be transformed and released from the wastes into leachate and landfill gas. Consequently, it is critical to understand the occurrence and transformation of PFAS in landfills and the effectiveness of landfills, as a disposal alternative, for long-term containment of PFAS. This article presents a state-of-the-art review on the occurrence and transformation of PFAS in landfills, and possible effect of PFAS on the integrity of modern liner systems. Based on the data published from 10 countries (250 + landfills), C4-C7 perfluoroalkyl carboxylic acids were found predominant in the untreated landfill leachate and neutral PFAS, primarily fluorotelomer alcohols, in landfill air. The effectiveness and limitations of the conventional leachate treatment technologies and emerging technologies were also evaluated to address PFAS released into the leachate. Among conventional technologies, reverse osmosis (RO) may achieve a high removal efficiency of 90-100 % based on full-scale data, which, however, is vulnerable to the organic fouling and requires additional disposal of the concentrate. Implications of these knowledge on PFAS management at landfills are discussed and major knowledge gaps are identified.
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Affiliation(s)
- Man Zhang
- CTI and Associates, Inc., 34705 W 12 Mile Rd Suite 230, Farmington Hills, MI 48331, USA.
| | - Xianda Zhao
- CTI and Associates, Inc., 34705 W 12 Mile Rd Suite 230, Farmington Hills, MI 48331, USA
| | - Dongye Zhao
- Environmental Engineering Program, Department of Civil & Environmental Engineering, Auburn University, Auburn AL 36849, USA; Department of Civil, Construction and Environmental Engineering, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USA.
| | - Te-Yang Soong
- CTI and Associates, Inc., 34705 W 12 Mile Rd Suite 230, Farmington Hills, MI 48331, USA
| | - Shuting Tian
- Environmental Engineering Program, Department of Civil & Environmental Engineering, Auburn University, Auburn AL 36849, USA; Institute of Environmental Science, Taiyuan University of Science and Technology, Taiyuan, Shanxi 030024, China
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Tan X, Dewapriya P, Prasad P, Chang Y, Huang X, Wang Y, Gong X, Hopkins TE, Fu C, Thomas KV, Peng H, Whittaker AK, Zhang C. Efficient Removal of Perfluorinated Chemicals from Contaminated Water Sources Using Magnetic Fluorinated Polymer Sorbents. Angew Chem Int Ed Engl 2022; 61:e202213071. [PMID: 36225164 PMCID: PMC10946870 DOI: 10.1002/anie.202213071] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Indexed: 11/07/2022]
Abstract
Efficient removal of per- and polyfluoroalkyl substances (PFAS) from contaminated waters is urgently needed to safeguard public and environmental health. In this work, novel magnetic fluorinated polymer sorbents were designed to allow efficient capture of PFAS and fast magnetic recovery of the sorbed material. The new sorbent has superior PFAS removal efficiency compared with the commercially available activated carbon and ion-exchange resins. The removal of the ammonium salt of hexafluoropropylene oxide dimer acid (GenX) reaches >99 % within 30 s, and the estimated sorption capacity was 219 mg g-1 based on the Langmuir model. Robust and efficient regeneration of the magnetic polymer sorbent was confirmed by the repeated sorption and desorption of GenX over four cycles. The sorption of multiple PFAS in two real contaminated water matrices at an environmentally relevant concentration (1 ppb) shows >95 % removal for the majority of PFAS tested in this study.
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Affiliation(s)
- Xiao Tan
- Australian Institute for Bioengineering and NanotechnologyThe University of QueenslandCorner College and Cooper Rds (Bldg 75)BrisbaneQueensland4072Australia
| | - Pradeep Dewapriya
- Queensland Alliance for Environmental Health SciencesThe University of Queensland, Level 420 Cornwall StreetWoolloongabbaQueensland4102Australia
| | - Pritesh Prasad
- Queensland Alliance for Environmental Health SciencesThe University of Queensland, Level 420 Cornwall StreetWoolloongabbaQueensland4102Australia
| | - Yixin Chang
- Australian Institute for Bioengineering and NanotechnologyThe University of QueenslandCorner College and Cooper Rds (Bldg 75)BrisbaneQueensland4072Australia
| | - Xumin Huang
- Australian Institute for Bioengineering and NanotechnologyThe University of QueenslandCorner College and Cooper Rds (Bldg 75)BrisbaneQueensland4072Australia
| | - Yiqing Wang
- Australian Institute for Bioengineering and NanotechnologyThe University of QueenslandCorner College and Cooper Rds (Bldg 75)BrisbaneQueensland4072Australia
| | - Xiaokai Gong
- Australian Institute for Bioengineering and NanotechnologyThe University of QueenslandCorner College and Cooper Rds (Bldg 75)BrisbaneQueensland4072Australia
| | - Timothy E. Hopkins
- The Chemours Company, Chemours Discovery Hub201 Discovery BoulevardNewarkDE 19713USA
| | - Changkui Fu
- Australian Institute for Bioengineering and NanotechnologyThe University of QueenslandCorner College and Cooper Rds (Bldg 75)BrisbaneQueensland4072Australia
| | - Kevin V. Thomas
- Queensland Alliance for Environmental Health SciencesThe University of Queensland, Level 420 Cornwall StreetWoolloongabbaQueensland4102Australia
| | - Hui Peng
- Australian Institute for Bioengineering and NanotechnologyThe University of QueenslandCorner College and Cooper Rds (Bldg 75)BrisbaneQueensland4072Australia
| | - Andrew K. Whittaker
- Australian Institute for Bioengineering and NanotechnologyThe University of QueenslandCorner College and Cooper Rds (Bldg 75)BrisbaneQueensland4072Australia
| | - Cheng Zhang
- Australian Institute for Bioengineering and NanotechnologyThe University of QueenslandCorner College and Cooper Rds (Bldg 75)BrisbaneQueensland4072Australia
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34
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Venkatesan AK, Lee CS, Gobler CJ. Hydroxyl-radical based advanced oxidation processes can increase perfluoroalkyl substances beyond drinking water standards: Results from a pilot study. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 847:157577. [PMID: 35882318 DOI: 10.1016/j.scitotenv.2022.157577] [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: 05/12/2022] [Revised: 07/05/2022] [Accepted: 07/19/2022] [Indexed: 06/15/2023]
Abstract
Advanced oxidation processes (AOPs) are popular technologies employed across the U.S. for wastewater reclamation and drinking water treatment of recalcitrant chemicals. Although there is consensus about the ineffectiveness of AOPs to treat perfluoroalkyl substances (PFASs; not polyfluoro compounds by definition here), there is a lack of field data demonstrating their impact on the transformation of unknown PFAS precursors during groundwater treatment. In this study, the fate of PFASs in seven pilot-scale AOPs, including four different technologies (UV/H2O2, UV/Cl2, UV/TiO2, and O3/H2O2), was assessed at four drinking water systems across New York State (NYS), USA. Seven of 18 PFASs were detected in the influent at concentrations ranging from below method detection to 64 ng/L. Across all systems, all detected PFASs showed an increase in concentration after treatment presumably due to unknown precursor transformation with specific increases for perfluorobutane sulfonate (PFBS), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorohexane sulfonate (PFHxS), perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), and perfluorononanoic acid (PFNA) averaging 405 (range: 0 - 1220) %, 1.0 (-7 - 9) %, 3.8 (0 - 9.5) %, 3.3 (-11 - 13) %, 14 (0 - 48) %, 13 (3 - 25) %, and 2 (0 - 5.2) %, respectively. The increase in PFAS concentration was dependent on UV and oxidant dose, further confirming that transformation reactions were occurring due to AOPs similar to a total oxidizable precursor assay. At one of the sites, PFOA levels exceeded the current NYS drinking water standard of 10 ng/L after, but not before treatment, highlighting the importance of considering the potential impact of AOP on treated water quality when designing treatment systems for regulatory compliance. The increase in PFAS concentration in the AOP systems positively correlated (r = 0.91) with nitrate levels in groundwater, suggesting that onsite septic discharges may be an important source of PFAS contamination in these unsewered study areas. Results from this pilot-scale demonstration reveal that hydroxyl radical-based AOPs, although ineffective in treating PFASs, can help to reveal the true extent of PFAS contamination in source waters.
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Affiliation(s)
- Arjun K Venkatesan
- New York State Center for Clean Water Technology, Stony Brook University, Stony Brook, NY 11794, USA; School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA.
| | - Cheng-Shiuan Lee
- New York State Center for Clean Water Technology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Christopher J Gobler
- New York State Center for Clean Water Technology, Stony Brook University, Stony Brook, NY 11794, USA; School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA
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35
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Falyouna O, Maamoun I, Ghosh S, Malloum A, Othmani A, Eljamal O, Amen TW, Oroke A, Bornman C, Ahmadi S, Hadi Dehghani M, Hossein Mahvi A, Nasseri S, Tyagi I, Suhas, Reddy Koduru J. Sustainable Technologies for the Removal of Chloramphenicol from Pharmaceutical Industries Effluent: A critical review. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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36
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Veciana M, Bräunig J, Farhat A, Pype ML, Freguia S, Carvalho G, Keller J, Ledezma P. Electrochemical oxidation processes for PFAS removal from contaminated water and wastewater: fundamentals, gaps and opportunities towards practical implementation. JOURNAL OF HAZARDOUS MATERIALS 2022; 434:128886. [PMID: 35436757 DOI: 10.1016/j.jhazmat.2022.128886] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 03/20/2022] [Accepted: 04/07/2022] [Indexed: 05/27/2023]
Abstract
Electrochemical oxidation (EO) is emerging as one of the most promising methods for the degradation of recalcitrant per- and poly-fluoroalkyl substances (PFASs) in water and wastewater, as these compounds cannot be effectively treated with conventional bio- or chemical approaches. This review examines the state of the art of EO for PFASs destruction, and comprehensively compares operating parameters and treatment performance indicators for both synthetic and real contaminated water and wastewater media. The evaluation shows the need to use environmentally-relevant media to properly quantify the effectiveness/efficiency of EO for PFASs treatment. Additionally, there is currently a lack of quantification of sorption losses, resulting in a likely over-estimation of process' efficiencies. Furthermore, the majority of experimental results to date indicate that short-chain PFASs are the most challenging and need to be prioritized as environmental regulations become more stringent. Finally, and with a perspective towards practical implementation, several operational strategies are proposed, including processes combining up-concentration followed by EO destruction.
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Affiliation(s)
- Mersabel Veciana
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane QLD 4072, Australia.
| | - Jennifer Bräunig
- Queensland Alliance for Environmental Health Sciences, The University of Queensland, Brisbane QLD 4102, Australia
| | - Ali Farhat
- GHD Pty Ltd, Brisbane QLD 4000, Australia
| | - Marie-Laure Pype
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane QLD 4072, Australia
| | - Stefano Freguia
- Department of Chemical Engineering, The University of Melbourne, Parkville VIC 3010, Australia
| | - Gilda Carvalho
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane QLD 4072, Australia
| | - Jürg Keller
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane QLD 4072, Australia
| | - Pablo Ledezma
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane QLD 4072, Australia.
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37
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Das S, Ronen A. A Review on Removal and Destruction of Per- and Polyfluoroalkyl Substances (PFAS) by Novel Membranes. MEMBRANES 2022; 12:662. [PMID: 35877866 PMCID: PMC9325267 DOI: 10.3390/membranes12070662] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 06/20/2022] [Accepted: 06/22/2022] [Indexed: 02/01/2023]
Abstract
Per- and Polyfluoroalkyl Substances (PFAS) are anthropogenic chemicals consisting of thousands of individual species. PFAS consists of a fully or partly fluorinated carbon-fluorine bond, which is hard to break and requires a high amount of energy (536 kJ/mole). Resulting from their unique hydrophobic/oleophobic nature and their chemical and mechanical stability, they are highly resistant to thermal, chemical, and biological degradation. PFAS have been used extensively worldwide since the 1940s in various products such as non-stick household items, food-packaging, cosmetics, electronics, and firefighting foams. Exposure to PFAS may lead to health issues such as hormonal imbalances, a compromised immune system, cancer, fertility disorders, and adverse effects on fetal growth and learning ability in children. To date, very few novel membrane approaches have been reported effective in removing and destroying PFAS. Therefore, this article provides a critical review of PFAS treatment and removal approaches by membrane separation systems. We discuss recently reported novel and effective membrane techniques for PFAS separation and include a detailed discussion of parameters affecting PFAS membrane separation and destruction. Moreover, an estimation of cost analysis is also included for each treatment technology. Additionally, since the PFAS treatment technology is still growing, we have incorporated several future directions for efficient PFAS treatment.
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Affiliation(s)
| | - Avner Ronen
- Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus 84990, Israel;
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38
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Baskar AV, Bolan N, Hoang SA, Sooriyakumar P, Kumar M, Singh L, Jasemizad T, Padhye LP, Singh G, Vinu A, Sarkar B, Kirkham MB, Rinklebe J, Wang S, Wang H, Balasubramanian R, Siddique KHM. Recovery, regeneration and sustainable management of spent adsorbents from wastewater treatment streams: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 822:153555. [PMID: 35104528 DOI: 10.1016/j.scitotenv.2022.153555] [Citation(s) in RCA: 83] [Impact Index Per Article: 41.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 01/26/2022] [Accepted: 01/26/2022] [Indexed: 04/15/2023]
Abstract
Adsorption is the most widely adopted, effective, and reliable treatment process for the removal of inorganic and organic contaminants from wastewater. One of the major issues with the adsorption-treatment process for the removal of contaminants from wastewater streams is the recovery and sustainable management of spent adsorbents. This review focuses on the effectiveness of emerging adsorbents and how the spent adsorbents could be recovered, regenerated, and further managed through reuse or safe disposal. The critical analysis of both conventional and emerging adsorbents on organic and inorganic contaminants in wastewater systems are evaluated. The various recovery and regeneration techniques of spent adsorbents including magnetic separation, filtration, thermal desorption and decomposition, chemical desorption, supercritical fluid desorption, advanced oxidation process and microbial assisted adsorbent regeneration are discussed in detail. The current challenges for the recovery and regeneration of adsorbents and the methodologies used for solving those problems are covered. The spent adsorbents are managed through regeneration for reuse (such as soil amendment, capacitor, catalyst/catalyst support) or safe disposal involving incineration and landfilling. Sustainable management of spent adsorbents, including processes involved in the recovery and regeneration of adsorbents for reuse, is examined in the context of resource recovery and circular economy. Finally, the review ends with the current drawbacks in the recovery and management of the spent adsorbents and the future directions for the economic and environmental feasibility of the system for industrial-scale application.
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Affiliation(s)
- Arun V Baskar
- The Global Innovative Centre for Advanced Nanomaterials, College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Nanthi Bolan
- School of Agriculture and Environment, The University of Western Australia, Perth, WA 6001, Australia; The UWA Institute of Agriculture, The University of Western Australia, Perth, WA 6001, Australia
| | - Son A Hoang
- The Global Innovative Centre for Advanced Nanomaterials, College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW 2308, Australia; Division of Urban Infrastructural Engineering, Mientrung University of Civil Engineering, Phu Yen 56000, Viet Nam
| | - Prasanthi Sooriyakumar
- The Global Innovative Centre for Advanced Nanomaterials, College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Manish Kumar
- CSIR-National Environmental Engineering Research Institute (CSIR-NEERI), Nehru Marg, Nagpur 440020, Maharashtra, India
| | - Lal Singh
- CSIR-National Environmental Engineering Research Institute (CSIR-NEERI), Nehru Marg, Nagpur 440020, Maharashtra, India
| | - Tahereh Jasemizad
- Department of Civil and Environmental Engineering, Faculty of Engineering, The University of Auckland, Auckland 1010, New Zealand
| | - Lokesh P Padhye
- Department of Civil and Environmental Engineering, Faculty of Engineering, The University of Auckland, Auckland 1010, New Zealand
| | - Gurwinder Singh
- The Global Innovative Centre for Advanced Nanomaterials, College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Ajayan Vinu
- The Global Innovative Centre for Advanced Nanomaterials, College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Binoy Sarkar
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom
| | - M B Kirkham
- Department of Agronomy, Kansas State University, Manhattan, KS, USA
| | - Jörg Rinklebe
- University of Wuppertal, Germany, Faculty of Architecture und Civil Engineering, Institute of Soil Engineering, Waste- and Water Science, Laboratory of Soil- and Groundwater-Management, Germany; Department of Environment, Energy and Geoinformatics, Sejong University, Seoul, Republic of Korea.
| | - Shengsen Wang
- College of Environmental Science and Engineering, Yangzhou University, Yangzhou 225127, Jiangsu, People's Republic of China
| | - Hailong Wang
- Biochar Engineering Technology Research Center of Guangdong Province, School of Environmental and Chemical Engineering, Foshan University, Foshan, Guangdong 528000, People's Republic of China; Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, Zhejiang A&F University, Hangzhou, Zhejiang 311300, People's Republic of China
| | | | - Kadambot H M Siddique
- The UWA Institute of Agriculture, The University of Western Australia, Perth, WA 6001, Australia
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39
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Zhu C, Xue C, Huang M, Zhu F, Fang G, Wang D, Liu S, Chen N, Wu S, Zhou D. Rapid As(III) oxidation mediated by activated carbons: Reactive species vs. direct oxidation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 822:153536. [PMID: 35104530 DOI: 10.1016/j.scitotenv.2022.153536] [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: 12/04/2021] [Revised: 01/25/2022] [Accepted: 01/26/2022] [Indexed: 06/14/2023]
Abstract
Activated carbon (AC) is widely used in pollutant removal, due to its adsorption capacity, conductivity and catalytic performance. However, few studies focus on the redox activity of AC and its role in pollutant transformation. In this study, we found that AC could efficiently mediate the oxidation of As(III) and the process of As(III) oxidation was pH and oxygen concentration dependent. In general, the presence of O2 promoted As(III) oxidation at pH 3.0-9.5. Acidic and alkaline conditions favored As(III) oxidation regardless of whether there was oxygen, but the mechanisms involved were quite different when there was oxygen. At pH 3.0, reactive species (H2O2 and ·OH) were generated and accounted for As(III) oxidation; at pH 9.5, As(III) was directly oxidized by O2 (electron transfer from As(III) to O2 mediated by carbon matrix) under aerobic conditions. Pre-oxidation and cyclic experiments results indicated the ability of AC to oxidize As(III) at pH 9.5 was sustainable and recyclable. This study provided a new insight in pollutant oxidation by AC in the environment.
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Affiliation(s)
- Changyin Zhu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Chenyan Xue
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Mingquan Huang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Fengxiao Zhu
- School of Environment, Nanjing Normal University, Nanjing 210023, PR China
| | - Guodong Fang
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China
| | - Dixiang Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Shaochong Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Ning Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Song Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Dongmei Zhou
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
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40
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Wang J, Lin Z, He X, Song M, Westerhoff P, Doudrick K, Hanigan D. Critical Review of Thermal Decomposition of Per- and Polyfluoroalkyl Substances: Mechanisms and Implications for Thermal Treatment Processes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:5355-5370. [PMID: 35446563 DOI: 10.1021/acs.est.2c02251] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs) are fluorinated organic chemicals that are concerning due to their environmental persistence and adverse human and ecological effects. Remediation of environmental PFAS contamination and their presence in consumer products have led to the production of solid and liquid waste streams containing high concentrations of PFASs, which require efficient and cost-effective treatment solutions. PFASs are challenging to defluorinate by conventional and advanced destructive treatment processes, and physical separation processes produce waste streams (e.g., membrane concentrate, spent activated carbon) requiring further post-treatment. Incineration and other thermal treatment processes are widely available, but their use in managing PFAS-containing wastes remains poorly understood. Under specific operating conditions, thermal treatment is expected to mineralize PFASs, but the degradation mechanisms and pathways are unknown. In this review, we critically evaluate the thermal decomposition mechanisms, pathways, and byproducts of PFASs that are crucial to the design and operation of thermal treatment processes. We highlight the analytical capabilities and challenges and identify research gaps which limit the current understanding of safely applying thermal treatment to destroy PFASs as a viable end-of-life treatment process.
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Affiliation(s)
- Junli Wang
- Department of Civil and Environmental Engineering, University of Nevada, Reno, Nevada 89557-0258, United States
| | - Zunhui Lin
- Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85287-3005, United States
| | - Xuexiang He
- Department of Civil and Environmental Engineering, University of Nevada, Reno, Nevada 89557-0258, United States
| | - Mingrui Song
- Department of Civil and Environmental Engineering, University of Nevada, Reno, Nevada 89557-0258, United States
| | - Paul Westerhoff
- Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85287-3005, United States
| | - Kyle Doudrick
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - David Hanigan
- Department of Civil and Environmental Engineering, University of Nevada, Reno, Nevada 89557-0258, United States
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41
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Weber NH, Delva CS, Stockenhuber SP, Grimison CC, Lucas JA, Mackie JC, Stockenhuber M, Kennedy EM. Modeling and Experimental Study on the Thermal Decomposition of Perfluorooctanesulfonic Acid (PFOS) in an α-Alumina Reactor. Ind Eng Chem Res 2022. [DOI: 10.1021/acs.iecr.2c00339] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nathan H. Weber
- Discipline of Chemical Engineering, School of Engineering, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - Cameron S. Delva
- Discipline of Chemical Engineering, School of Engineering, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - Sebastian P. Stockenhuber
- Discipline of Chemical Engineering, School of Engineering, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | | | - John A. Lucas
- Discipline of Chemical Engineering, School of Engineering, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - John C. Mackie
- Discipline of Chemical Engineering, School of Engineering, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - Michael Stockenhuber
- Discipline of Chemical Engineering, School of Engineering, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - Eric M. Kennedy
- Discipline of Chemical Engineering, School of Engineering, University of Newcastle, Callaghan, New South Wales 2308, Australia
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42
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Adsorption of perfluorooctanoic acid from water by pH-modulated Brönsted acid and base sites in mesoporous hafnium oxide ceramics. iScience 2022; 25:104138. [PMID: 35402881 PMCID: PMC8987376 DOI: 10.1016/j.isci.2022.104138] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 02/24/2022] [Accepted: 03/18/2022] [Indexed: 02/04/2023] Open
Abstract
Per- and polyfluoroalkyl substances (PFAS) are increasingly appearing in drinking water sources globally. Our work focuses specifically on the adsorption of the legacy perfluorooctanoic acid (PFOA) using mesoporous hafnium oxide (MHO) ceramic synthesized via a sol-gel process. Experiments were performed at varying pH to determine the effect of surface charge on adsorption capacity of PFOA by MHO, and to postulate adsorption behavior. At pH 2.3, the adsorption capacity of PFOA on MHO was 20.9 mg/g, whereas at a higher pH of 6.3, it was much lower at 9.2 mg/g. This was due to increased coulombic attractions at lower pH between the positively charged conjugate acid active sites on MHO surface and negatively charged deprotonated PFOA anion in solution. After adsorption, the solid MHO was regenerated via calcination, reducing the amount of toxic solid waste to be disposed since the adsorbent is regenerated, and the PFOA is completely removed. The adsorption capacity of PFOA by MHO was determined to be 20.9 mg/g at pH 2.3 As pH increased, the adsorption capacity of MHO decreased due to Coulombic repulsions MHO could be regenerated via calcination to limit the amount of toxic waste produced
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43
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Assessment of Reed Grasses (Phragmites australis) Performance in PFAS Removal from Water: A Phytoremediation Pilot Plant Study. WATER 2022. [DOI: 10.3390/w14060946] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs) have multiple emission sources, from industrial to domestic, and their high persistence and mobility help them to spread in all the networks of watercourses. Diffuse pollution of these compounds can be potentially mitigated by the application of green infrastructures, which are a pillar of the EU Green Deal. In this context, a phytoremediation pilot plant was realised and supplied by a contaminated well-located in Lonigo (Veneto Region, Italy) where surface and groundwaters were significantly impacted by perfluoroalkyl acids (PFAAs) discharges from a fluorochemical factory. The investigation involved the detection of perfluorobutanoic acid (PFBA), perfluorooctanoic acid (PFOA), perfluorobutanesulfonic acid (PFBS) and perfluorooctanesulfonic acid (PFOS) inside the inlet and outlet waters of the phytoremediation pilot plant as well as in reed grasses grown into its main tank. The obtained results demonstrate that the pilot plant is able to reduce up to 50% of considered PFAAs in terms of mass flow without an evident dependence on physico-chemical characteristics of these contaminants. Moreover, PFAAs were found in the exposed reed grasses at concentrations up to 13 ng g−1 ww. A positive correlation between PFAA concentration in plants and exposure time was also observed. In conclusion, this paper highlights the potential efficiency of phytodepuration in PFAS removal and recommends improving the knowledge about its application in constructed wetlands as a highly sustainable choice in wastewater remediation.
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Liu Z, Chen Z, Gao J, Yu Y, Men Y, Gu C, Liu J. Accelerated Degradation of Perfluorosulfonates and Perfluorocarboxylates by UV/Sulfite + Iodide: Reaction Mechanisms and System Efficiencies. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:3699-3709. [PMID: 35226468 PMCID: PMC9481055 DOI: 10.1021/acs.est.1c07608] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The addition of iodide (I-) in the UV/sulfite system (UV/S) significantly accelerated the reductive degradation of perfluorosulfonates (PFSAs, CnF2n+1SO3-) and perfluorocarboxylates (PFCAs, CnF2n+1COO-). Using the highly recalcitrant perfluorobutane sulfonate (C4F9SO3-) as a probe, we optimized the UV/sulfite + iodide system (UV/S + I) to degrade n = 1-7 PFCAs and n = 4, 6, 8 PFSAs. In general, the kinetics of per- and polyfluoroalkyl substance (PFAS) decay, defluorination, and transformation product formations in UV/S + I were up to three times faster than those in UV/S. Both systems achieve a similar maximum defluorination. The enhanced reaction rates and optimized photoreactor settings lowered the EE/O for PFCA degradation below 1.5 kW h m-3. The relatively high quantum yield of eaq- from I- made the availability of hydrated electrons (eaq-) in UV/S + I and UV/I two times greater than that in UV/S. Meanwhile, the rapid scavenging of reactive iodine species by SO32- made the lifetime of eaq- in UV/S + I eight times longer than that in UV/I. The addition of I- also substantially enhanced SO32- utilization in treating concentrated PFAS. The optimized UV/S + I system achieved >99.7% removal of most PFSAs and PFCAs and >90% overall defluorination in a synthetic solution of concentrated PFAS mixtures and NaCl. We extended the discussion over molecular transformation mechanisms, development of PFAS degradation technologies, and the fate of iodine species.
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Affiliation(s)
- Zekun Liu
- Department
of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Zhanghao Chen
- State
Key Laboratory of Pollution Control and Resource Reuse, School of
the Environment, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Jinyu Gao
- Department
of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Yaochun Yu
- Department
of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
- Department
of Civil & Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Yujie Men
- Department
of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
- Department
of Civil & Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Cheng Gu
- State
Key Laboratory of Pollution Control and Resource Reuse, School of
the Environment, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Jinyong Liu
- Department
of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
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Wackett LP. Nothing lasts forever: understanding microbial biodegradation of polyfluorinated compounds and perfluorinated alkyl substances. Microb Biotechnol 2022; 15:773-792. [PMID: 34570953 PMCID: PMC8913905 DOI: 10.1111/1751-7915.13928] [Citation(s) in RCA: 50] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/12/2021] [Accepted: 09/13/2021] [Indexed: 12/20/2022] Open
Abstract
Poly- and perfluorinated chemicals, including perfluorinated alkyl substances (PFAS), are pervasive in today's society, with a negative impact on human and ecosystem health continually emerging. These chemicals are now subject to strict government regulations, leading to costly environmental remediation efforts. Commercial polyfluorinated compounds have been called 'forever chemicals' due to their strong resistance to biological and chemical degradation. Environmental cleanup by bioremediation is not considered practical currently. Implementation of bioremediation will require uncovering and understanding the rare microbial successes in degrading these compounds. This review discusses the underlying reasons why microbial degradation of heavily fluorinated compounds is rare. Fluorinated and chlorinated compounds are very different with respect to chemistry and microbial physiology. Moreover, the end product of biodegradation, fluoride, is much more toxic than chloride. It is imperative to understand these limitations, and elucidate physiological mechanisms of defluorination, in order to better discover, study, and engineer bacteria that can efficiently degrade polyfluorinated compounds.
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Affiliation(s)
- Lawrence P. Wackett
- Department of Biochemistry, Molecular Biology and BiophysicsUniversity of MinnesotaSt. PaulMN55108USA
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Dastgheib SA, Mock J, Ilangovan T, Patterson C. Thermogravimetric Studies for the Incineration of an Anion Exchange Resin Laden with Short- or Long-Chain PFAS Compounds Containing Carboxylic or Sulfonic Acid Functionalities in the Presence or Absence of Calcium Oxide. Ind Eng Chem Res 2021. [DOI: 10.1021/acs.iecr.1c03537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Seyed A. Dastgheib
- Illinois State Geological Survey, Prairie Research Institute, University of Illinois, Champaign, Illinois 61820, United States
| | - Justin Mock
- Illinois State Geological Survey, Prairie Research Institute, University of Illinois, Champaign, Illinois 61820, United States
| | - Tina Ilangovan
- Illinois State Geological Survey, Prairie Research Institute, University of Illinois, Champaign, Illinois 61820, United States
| | - Craig Patterson
- U.S. Environmental Protection Agency, Center for Environmental Solutions and Emergency Response, Cincinnati, Ohio 45268, United States
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