1
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Dai C, Li K, Liu Y, Teng B, Chen Q, Jin X, Xu D, Hong R. Unveiling the directional dynamics: Hydrated electron driven defluorination in PFOA⁻ and PFOS⁻ through ab Initio molecular dynamics and quantum chemistry. WATER RESEARCH 2025; 280:123486. [PMID: 40101503 DOI: 10.1016/j.watres.2025.123486] [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: 11/12/2024] [Revised: 03/04/2025] [Accepted: 03/11/2025] [Indexed: 03/20/2025]
Abstract
Hydrated electrons (e-(aq)) are recognized for their potent reducing capabilities, making them significant in environmental engineering, particularly in the degradation of persistent pollutants like perfluoroalkyl compounds (PFCs). This study investigates the influence of attack direction of e-(aq) on the degradation mechanisms of PFCs, addressing a critical gap in understanding due to experimental limitations. Utilizing ab initio molecular dynamics and quantum chemical calculations, we systematically simulated the attack direction of e-(aq) on PFCs, focusing on the formation of anionic radicals and their excited-state reactivity. Our results indicate that the attack direction is pivotal for C-F bond cleavage: e-(aq) targeting the carboxyl end promotes effective bond cleavage, while approaches from the carbon-fluorine chain are hindered by molecular orbital shielding effects. Furthermore, we demonstrate that employing micellar systems to maintain PFCs in an unsolvated anionic state significantly reduces excitation energy, enhances red-shifted absorption, and increases excitation probability. Importantly, the excited-state electronic structure of PFCs closely mirrors that of their anionic radicals. These findings provide a novel strategy for improving the degradation of PFCs, thereby advancing treatment processes for persistent environmental pollutants and contributing to the broader understanding of water quality management.
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Affiliation(s)
- Chencheng Dai
- School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu 241000, Anhui Province, PR China
| | - Kaixin Li
- School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu 241000, Anhui Province, PR China
| | - Yazi Liu
- School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu 241000, Anhui Province, PR China
| | - BoChen Teng
- Zhejiang Zhonghuan Detection CO., LTD, Wenzhou 325003, Zhejiang Province, PR China
| | - Qi Chen
- School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu 241000, Anhui Province, PR China
| | - Xin Jin
- School of the Environment, Nanjing Normal University, Nanjing 210093, PR China
| | - Dayong Xu
- School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu 241000, Anhui Province, PR China.
| | - Ran Hong
- School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu 241000, Anhui Province, PR China; National local joint engineering laboratory to functional adsorption material technology for the environmental protection, Jiangsu, Suzhou, 215123, China.
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2
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Song C, Zhao Y, Liu Z, Zhang Y, Lai J, Tan C, Song M. Plasma-Generated Free Electrons Induced Perfluorooctanoic Acid Efficient Degradation at the Gas-Liquid Interface. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2025; 59:9332-9343. [PMID: 40172041 DOI: 10.1021/acs.est.5c02062] [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: 04/04/2025]
Abstract
Low-temperature plasma, generating both reductive electrons and diverse oxidative species, has demonstrated considerable potential for the degradation of perfluorooctanoic acid (PFOA). However, limited understanding of electron propagation mechanisms during discharge has led previous research to focus on hydrated electrons (eaq-) while neglecting free electrons (e-). In this study, a consistent and modeled dielectric barrier discharge (DBD) plasma was employed to degrade PFOA. Contribution analysis indicated that reactions driven by e- were dominant, with substantial contributions from hydroxyl radical (•OH)-mediated oxidation. By integrating a kinetic model with a streamer solver, a basic discharge unit model was developed. Simulation of e- streamer propagation identified a high-intensity response electric field formed by the e- memory effect, with a peak strength of 1.816 × 106 V/m. This electric field facilitated a secondary acceleration of e-, allowing e- to penetrate the surface water layer and directly attack PFOA via chain-shortening mechanisms. The delocalized state of e- restricted degradation primarily to the gas-liquid interface, minimizing interference from the surrounding medium. This study highlights the previously overlooked role of e- and provides essential theoretical insights for the plasma-based treatment of PFOA-contaminated water.
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Affiliation(s)
- Chengye Song
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, China
| | - Yan Zhao
- Anhui Provincial Academy of Eco-Environmental Science Research, Hefei 230071, China
| | - Zonghao Liu
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, China
| | - Yueqing Zhang
- Key Laboratory of Pesticide Environmental Assessment and Pollution Control, Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, China
| | - Jiahao Lai
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, China
| | - Chaoqun Tan
- School of Civil Engineering, Southeast University, Nanjing 210096, China
| | - Min Song
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, China
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3
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Junker AL, Juve JMA, Bai L, Qvist Christensen CS, Ahrens L, Cousins IT, Ateia M, Wei Z. Best Practices for Experimental Design, Testing, and Reporting of Aqueous PFAS-Degrading Technologies. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2025; 59:8939-8950. [PMID: 40312980 DOI: 10.1021/acs.est.4c08571] [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: 05/03/2025]
Abstract
Increased awareness of pervasive per- and polyfluoroalkyl substances (PFAS) contamination and the need for zero-pollution treatment solutions necessitate the scientific and engineering community to respond urgently and systematically. Existing approaches lack reproducible and standardized methods to report the technological treatment capabilities. Consequently, it is difficult to compare innovations and accurately assess their potential. In this Perspective, we shed light on hurdles encountered in the lab-scale research and development of aqueous PFAS destruction technologies with a focus on chemical methods and offer recommendations for overcoming them. Best practices are provided for developing robust PFAS laboratory protocols covering crucial aspects such as experimental planning, sample storage and analysis, and waste management. Further, we present five criteria to standardize reporting on performance and advances in PFAS degrading technologies: 1) scope, 2) defluorination efficiency, 3) relative energy consumption, 4) material stability, and 5) unit process considerations. Through the dissemination of these insights, we aim to foster progress in the development of highly effective treatment solutions.
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Affiliation(s)
- Allyson Leigh Junker
- Centre for Water Technology (WATEC) & Department of Biological and Chemical Engineering, Aarhus University, Ole Worms Alle 3, DK-8000 Aarhus C, Denmark
| | - Jan-Max Arana Juve
- Centre for Water Technology (WATEC) & Department of Biological and Chemical Engineering, Aarhus University, Ole Worms Alle 3, DK-8000 Aarhus C, Denmark
| | - Lu Bai
- Centre for Water Technology (WATEC) & Department of Biological and Chemical Engineering, Aarhus University, Ole Worms Alle 3, DK-8000 Aarhus C, Denmark
| | - Charlotte Skjold Qvist Christensen
- Centre for Water Technology (WATEC) & Department of Biological and Chemical Engineering, Aarhus University, Ole Worms Alle 3, DK-8000 Aarhus C, Denmark
| | - Lutz Ahrens
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences (SLU), Box 7050, 75007, Uppsala, Sweden
| | - Ian T Cousins
- Department for Environmental Science, Stockholm University, 106 91 Stockholm, Sweden
| | - Mohamed Ateia
- Center for Environmental Solutions & Emergency Response, U.S. Environmental Protection Agency, Cincinnati, Ohio 45268, United States
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005-1827, United States
| | - Zongsu Wei
- Centre for Water Technology (WATEC) & Department of Biological and Chemical Engineering, Aarhus University, Ole Worms Alle 3, DK-8000 Aarhus C, Denmark
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4
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Verma PK, Nayak SK, Bhardwaj K, Yamijala SSRKC. Realizing Direct Hot-Electron Transfer from Metal Nanoparticles to Per- and Polyfluoroalkyl Substances. J Phys Chem Lett 2025; 16:4536-4546. [PMID: 40305111 DOI: 10.1021/acs.jpclett.5c00373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2025]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are a group of forever synthetic chemicals. They are widely utilized in industries and household appliances because of their remarkable stability and distinctive oil- and water-repellent properties. Despite their broad applications, unfortunately, PFAS are hazardous to all forms of life, including humans. In recent years, the environmental persistence of PFAS has raised significant interest in degrading these substances. However, the strong C-F bonds in these chemicals pose several challenges to their degradation. Plasmons of noble metal nanoparticles (NPs) offer many exciting applications, including photocatalytic reactions. However, an atomistic understanding of plasmon-driven processes remains elusive. In this work, using the real-time time-dependent density functional theory, we have studied the real-time formation of plasmons, hot-carrier generation, and subsequent direct hot-carrier transfer from metal NPs to the PFAS. Our simulations show that there is an apparent direct hot-electron transfer from NPs to PFAS. Moreover, using Ehrenfest dynamics simulations, we demonstrated that the transferred hot electrons can efficiently degrade PFAS without requiring any external thermal bath. Thus, our work provides an atomistic picture of plasmon-induced direct hot-carrier transfer from NPs to PFAS and the efficient degradation of PFAS. We strongly believe that this work generates the impetus to utilize plasmonic NPs to mitigate PFAS.
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Affiliation(s)
- P K Verma
- Center for Atomistic Modelling and Materials Design, Indian Institute of Technology Madras, Chennai 600036, India
| | - Samir Kumar Nayak
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
| | - Khushboo Bhardwaj
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
| | - Sharma S R K C Yamijala
- Center for Atomistic Modelling and Materials Design, Indian Institute of Technology Madras, Chennai 600036, India
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
- Center for Molecular Materials and Functions, Indian Institute of Technology Madras, Chennai 600036, India
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5
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Wang X, Qiu L, Chen Z, Chen H, Wang J, Zhang Y, Xu Y, Kong D, Zhang M, Gu C. New Insights into the Reductive Destruction of Per- and Polyfluoroalkyl Substances in Hydrated Electron-Based Systems. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2025; 59:5786-5795. [PMID: 40080663 DOI: 10.1021/acs.est.4c08548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/15/2025]
Abstract
Per- and polyfluoroalkyl substances (PFAS) make up a class of highly toxic and persistent chemicals that have been widely detected in different environmental matrices. Recently, various hydrated electron-based techniques have been developed to destroy these compounds. However, the molecular mechanisms controlled by different hydrated electron photosensitizers are still unclear. Herein, we investigated the PFAS transformation processes in different hydrated electron-based systems, i.e., UV/Na2SO3, UV/indole, and UV/3-indoleacetic acid (IAA), using different perfluorocarboxylic acids (PFCA) as model compounds. By monitoring the production and decay of hydrated electrons, molecular interactions, and the generated intermediates, we systematically revealed the structure-property-performance mechanism of different systems. In the UV/Na2SO3 system, the disordered attack of hydrated electrons induced rapid destruction for either long or short-chain PFCA. However, the lower hydrated electron efficiency limited the final defluorination ratio. In the UV/indole system, the interaction between indole and PFCA promoted the directed transfer of hydrated electrons, resulting in a significantly higher destruction efficiency for long-chain PFCA than for short-chain PFCA. However, the self-quenching of hydrated electrons in the UV/IAA system led to the ineffective decomposition for all PFCA. This study provides mechanistic insights into the hydrated electron-induced PFAS decomposition processes, which would expand the designing strategies for improving PFAS destruction efficiency.
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Affiliation(s)
- Xinhao Wang
- State Key Laboratory of Water Pollution Control and Green Resource Recycling, Nanjing University, Nanjing 210023, P. R. China
| | - Longlong Qiu
- State Key Laboratory of Water Pollution Control and Green Resource Recycling, Nanjing University, Nanjing 210023, P. R. China
| | - Zhanghao Chen
- State Key Laboratory of Water Pollution Control and Green Resource Recycling, Nanjing University, Nanjing 210023, P. R. China
- Quanzhou Institute for Environmental Protection Industry, Nanjing University, Quanzhou 362000, P. R. China
| | - Hanyang Chen
- State Key Laboratory of Water Pollution Control and Green Resource Recycling, Nanjing University, Nanjing 210023, P. R. China
| | - Jiabao Wang
- State Key Laboratory of Water Pollution Control and Green Resource Recycling, Nanjing University, Nanjing 210023, P. R. China
| | - Yueqing Zhang
- Key Laboratory of Pesticide Environmental Assessment and Pollution Control, Nanjing Institute of Environmental Sciences, Ministry of Environment and Ecology of China, Nanjing 210042, China
| | - Yichen Xu
- State Key Laboratory of Water Pollution Control and Green Resource Recycling, Nanjing University, Nanjing 210023, P. R. China
| | - Deyang Kong
- Key Laboratory of Pesticide Environmental Assessment and Pollution Control, Nanjing Institute of Environmental Sciences, Ministry of Environment and Ecology of China, Nanjing 210042, China
| | - Ming Zhang
- State Key Laboratory of Water Pollution Control and Green Resource Recycling, Nanjing University, Nanjing 210023, P. R. China
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, P. R. China
| | - Cheng Gu
- State Key Laboratory of Water Pollution Control and Green Resource Recycling, Nanjing University, Nanjing 210023, P. R. China
- Quanzhou Institute for Environmental Protection Industry, Nanjing University, Quanzhou 362000, P. R. China
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6
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Luo X, Zheng W, Li Q, Ma H, Chen R, Liu X, Feng C. Hydrated Electrons Trigger the Breakdown of Recalcitrant Cyanuric Acid in Wastewater. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2025; 59:5327-5336. [PMID: 40033772 DOI: 10.1021/acs.est.4c11652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/05/2025]
Abstract
Cyanuric acid (CA), a triazine-ring compound commonly used as a stabilizer for free chlorine to enhance disinfection, often persists in wastewater for the production of chlorinated cyanurates (Cl-CAs), posing challenges for treatment. This study demonstrates that conventional advanced oxidation processes (UV/H2O2 and UV/peroxydisulfate) are ineffective in degrading CA, while the UV/sulfite system successfully achieves its breakdown. Hydrated electrons (eaq-) were identified as the primary reactive species responsible for cleaving the stable triazine ring, with minimal contributions from SO3•- and H•. The pH value influences both the activity of eaq- and the degradability of CA by altering its structure; lower pH increases the electron-deficient regions in dihydrogen CA, enhancing its susceptibility to nucleophilic attack by eaq-. The high concentrations of Cl- can inhibit CA removal, likely due to the formation of reactive chlorine species that react with sulfite and suppress eaq- production. Effective CA degradation was also demonstrated in real wastewater, highlighting the UV/sulfite system as a sustainable solution for water treatment. These findings offer valuable insights into CA transformation and present effective approaches for eliminating emerging contaminants in the context of the extensive use of disinfectants.
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Affiliation(s)
- Xin Luo
- The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Wenxiao Zheng
- The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Qiaoxin Li
- The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Huanxin Ma
- The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Rundong Chen
- The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Xueming Liu
- The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Chunhua Feng
- The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
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7
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Sharkas K, Wong BM. Defluorination Mechanisms and Real-Time Dynamics of Per- and Polyfluoroalkyl Substances on Electrified Surfaces. ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS 2025; 12:230-236. [PMID: 39957785 PMCID: PMC11823447 DOI: 10.1021/acs.estlett.4c01130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2024] [Revised: 01/23/2025] [Accepted: 01/24/2025] [Indexed: 02/18/2025]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants found in groundwater sources and a wide variety of consumer products. In recent years, electrochemical approaches for the degradation of these harmful contaminants have garnered a significant amount of attention due to their efficiency and chemical-free modular nature. However, these electrochemical processes occur in open, highly non-equilibrium systems, and a detailed understanding of PFAS degradation mechanisms in these promising technologies is still in its infancy. To shed mechanistic insight into these complex processes, we present the first constant-electrode potential (CEP) quantum calculations of PFAS degradation on electrified surfaces. These advanced CEP calculations provide new mechanistic details about the intricate electronic processes that occur during PFAS degradation in the presence of an electrochemical bias, which cannot be gleaned from conventional density functional theory calculations. We complement our CEP calculations with large-scale ab initio molecular dynamics simulations in the presence of an electrochemical bias to provide time scales for PFAS degradation on electrified surfaces. Taken together, our CEP-based quantum calculations provide critical reaction mechanisms for PFAS degradation in open electrochemical systems, which can be used to prescreen candidate material surfaces and optimal electrochemical conditions for remediating PFAS and other environmental contaminants.
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Affiliation(s)
- Kamal Sharkas
- Department of Chemistry,
Department of Physics & Astronomy, and Materials Science &
Engineering Program, University of California—Riverside, Riverside, California 92521, United States
| | - Bryan M. Wong
- Department of Chemistry,
Department of Physics & Astronomy, and Materials Science &
Engineering Program, University of California—Riverside, Riverside, California 92521, United States
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8
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Qi Y, Yang Y, Yu X, Wu S, Wang W, Yu Q, Wang C, Liang Y, Sun H. Unveiling the Contribution of Hydrogen Radicals to Per- and Polyfluoroalkyl Substances (PFASs) Defluorination: Applicability and Degradation Mechanisms. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2025; 59:1875-1886. [PMID: 39800992 DOI: 10.1021/acs.est.4c10411] [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: 01/29/2025]
Abstract
At present, the defluorination of per- and polyfluoroalkyl substances (PFASs), including perfluoroether compounds as substitutes of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate, is limited by the effective active species produced during the oxidation-reduction process. The contribution of the hydrogen radical (•H) as a companion active substance in the photoreduction and electrocatalytic degradation of PFASs has been neglected. Herein, we demonstrate that perfluorocarboxylic acids and perfluoroether compounds such as PFOA and hexafluoropropylene oxide dimer acid (GenX) underwent near-complete photodegradation and effective defluorination by continuously generating •H through perfluoroalkyl radical activation of water under UV irradiation without any reagents and catalysts. Importantly, the initial dissolved oxygen, H+, and impurities in surface water scarcely inhibited the defluorination of the PFASs. The difference in the defluorination mechanism between PFOA and GenX under the action of •H was elucidated by combining theoretical calculations with targeted and nontargeted analysis methods. The investigation of the photodegradation of different PFASs indicates that perfluoroether compounds were not easily photodegraded via reduction of •H compared with other compounds, whereas polyfluorinated compounds in which some F atoms were replaced with Cl were more prone to elimination. However, the UV/•H system was ineffective against perfluorosulfonic acids. This study provides an unprecedented perspective for further development of the removal technology of PFASs and the design of alternative PFASs that are easy to eliminate.
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Affiliation(s)
- Yuwen Qi
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, PR China
| | - Yinbo Yang
- School of Chemical Engineering and Technology, Tianjin University, Tianjin 300354, PR China
| | - Xue Yu
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, PR China
| | - Sai Wu
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, PR China
| | - Weicheng Wang
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, PR China
| | - Qin Yu
- Liaoning Jinhua Xinda Ecological Environment Technology Co., Ltd., Panjin 124000, PR China
| | - Cuiping Wang
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, PR China
| | - Yanna Liang
- Department of Environmental and Sustainable Engineering, University at Albany, SUNY, Albany, New York 12222, United States
| | - Hongwen Sun
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, PR China
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9
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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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10
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Fu K, Huang J, Luo F, Fang Z, Yu D, Zhang X, Wang D, Xing M, Luo J. Understanding the Selective Removal of Perfluoroalkyl and Polyfluoroalkyl Substances via Fluorine-Fluorine Interactions: A Critical Review. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024. [PMID: 39264176 DOI: 10.1021/acs.est.4c06519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/13/2024]
Abstract
As regulatory standards for per- and polyfluoroalkyl substances (PFAS) become increasingly stringent, innovative water treatment technologies are urgently demanded for effective PFAS removal. Reported sorbents often exhibit limited affinity for PFAS and are frequently hindered by competitive background substances. Recently, fluorinated sorbents (abbreviated as fluorosorbents) have emerged as a potent solution by leveraging fluorine-fluorine (F···F) interactions to enhance selectivity and efficiency in PFAS removal. This review delves into the designs and applications of fluorosorbents, emphasizing how F···F interactions improve PFAS binding affinity. Specifically, the existence of F···F interactions results in removal efficiencies orders of magnitude higher than other counterpart sorbents, particularly under competitive conditions. Furthermore, we provide a detailed analysis of the fundamental principles underlying F···F interactions and elucidate their synergistic effects with other sorption forces, which contribute to the enhanced efficacy and selectivity. Subsequently, we examine various fluorosorbents and their synthesis and fluorination techniques, underscore the importance of accurately characterizing F···F interactions through advanced analytical methods, and emphasize the significance of this interaction in developing selective sorbents. Finally, we discuss challenges and opportunities associated with employing advanced techniques to guide the design of selective sorbents and advocate for further research in the development of sustainable and cost-effective treatment technologies leveraging F···F interactions.
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Affiliation(s)
- Kaixing Fu
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Jinjing Huang
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Fang Luo
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Zhuoya Fang
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Deyou Yu
- Engineering Research Center for Eco-Dyeing and Finishing of Textiles (Ministry of Education), Zhejiang Sci-Tech University, Hangzhou 310018, P. R. China
| | - Xiaolin Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, P. R. China
| | - Dawei Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, P. R. China
| | - Mingyang Xing
- School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Jinming Luo
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
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11
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Wang F, Xiang L, Sze-Yin Leung K, Elsner M, Zhang Y, Guo Y, Pan B, Sun H, An T, Ying G, Brooks BW, Hou D, Helbling DE, Sun J, Qiu H, Vogel TM, Zhang W, Gao Y, Simpson MJ, Luo Y, Chang SX, Su G, Wong BM, Fu TM, Zhu D, Jobst KJ, Ge C, Coulon F, Harindintwali JD, Zeng X, Wang H, Fu Y, Wei Z, Lohmann R, Chen C, Song Y, Sanchez-Cid C, Wang Y, El-Naggar A, Yao Y, Huang Y, Cheuk-Fung Law J, Gu C, Shen H, Gao Y, Qin C, Li H, Zhang T, Corcoll N, Liu M, Alessi DS, Li H, Brandt KK, Pico Y, Gu C, Guo J, Su J, Corvini P, Ye M, Rocha-Santos T, He H, Yang Y, Tong M, Zhang W, Suanon F, Brahushi F, Wang Z, Hashsham SA, Virta M, Yuan Q, Jiang G, Tremblay LA, Bu Q, Wu J, Peijnenburg W, Topp E, Cao X, Jiang X, Zheng M, Zhang T, Luo Y, Zhu L, Li X, Barceló D, Chen J, Xing B, Amelung W, Cai Z, Naidu R, Shen Q, Pawliszyn J, Zhu YG, Schaeffer A, Rillig MC, Wu F, Yu G, Tiedje JM. Emerging contaminants: A One Health perspective. Innovation (N Y) 2024; 5:100612. [PMID: 38756954 PMCID: PMC11096751 DOI: 10.1016/j.xinn.2024.100612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 03/10/2024] [Indexed: 05/18/2024] Open
Abstract
Environmental pollution is escalating due to rapid global development that often prioritizes human needs over planetary health. Despite global efforts to mitigate legacy pollutants, the continuous introduction of new substances remains a major threat to both people and the planet. In response, global initiatives are focusing on risk assessment and regulation of emerging contaminants, as demonstrated by the ongoing efforts to establish the UN's Intergovernmental Science-Policy Panel on Chemicals, Waste, and Pollution Prevention. This review identifies the sources and impacts of emerging contaminants on planetary health, emphasizing the importance of adopting a One Health approach. Strategies for monitoring and addressing these pollutants are discussed, underscoring the need for robust and socially equitable environmental policies at both regional and international levels. Urgent actions are needed to transition toward sustainable pollution management practices to safeguard our planet for future generations.
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Affiliation(s)
- Fang Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Leilei Xiang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kelvin Sze-Yin Leung
- Department of Chemistry, Hong Kong Baptist University, Hong Kong, China
- HKBU Institute of Research and Continuing Education, Shenzhen Virtual University Park, Shenzhen, China
| | - Martin Elsner
- Technical University of Munich, TUM School of Natural Sciences, Institute of Hydrochemistry, 85748 Garching, Germany
| | - Ying Zhang
- School of Resources & Environment, Northeast Agricultural University, Harbin 150030, China
| | - Yuming Guo
- Climate, Air Quality Research Unit, School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia
| | - Bo Pan
- Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming 650500, China
| | - Hongwen Sun
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Taicheng An
- Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Guangguo Ying
- Ministry of Education Key Laboratory of Environmental Theoretical Chemistry, South China Normal University, Guangzhou, Guangdong 510006, China
| | - Bryan W. Brooks
- Department of Environmental Science, Baylor University, Waco, TX, USA
- Center for Reservoir and Aquatic Systems Research (CRASR), Baylor University, Waco, TX, USA
| | - Deyi Hou
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Damian E. Helbling
- School of Civil and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Jianqiang Sun
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, Zhejiang University of Technology, Hangzhou 310014, China
| | - Hao Qiu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Timothy M. Vogel
- Laboratoire d’Ecologie Microbienne, Universite Claude Bernard Lyon 1, UMR CNRS 5557, UMR INRAE 1418, VetAgro Sup, 69622 Villeurbanne, France
| | - Wei Zhang
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824, USA
| | - Yanzheng Gao
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Weigang Road 1, Nanjing 210095, China
| | - Myrna J. Simpson
- Environmental NMR Centre and Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4, Canada
| | - Yi Luo
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, China
| | - Scott X. Chang
- Department of Renewable Resources, University of Alberta, 442 Earth Sciences Building, Edmonton, AB T6G 2E3, Canada
| | - Guanyong Su
- Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Bryan M. Wong
- Materials Science & Engineering Program, Department of Chemistry, and Department of Physics & Astronomy, University of California-Riverside, Riverside, CA, USA
| | - Tzung-May Fu
- Shenzhen Key Laboratory of Precision Measurement and Early Warning Technology for Urban Environmental Health Risks, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Dong Zhu
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Karl J. Jobst
- Department of Chemistry, Memorial University of Newfoundland, 45 Arctic Avenue, St. John’s, NL A1C 5S7, Canada
| | - Chengjun Ge
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, School of Ecological and Environmental Sciences, Hainan University, Haikou 570228, China
| | - Frederic Coulon
- School of Water, Energy and Environment, Cranfield University, Cranfield MK43 0AL, UK
| | - Jean Damascene Harindintwali
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiankui Zeng
- Key Laboratory of Surficial Geochemistry, Ministry of Education, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China
| | - Haijun Wang
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming 650504, China
| | - Yuhao Fu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhong Wei
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Rainer Lohmann
- Graduate School of Oceanography, University of Rhode Island, Narragansett, RI, USA
| | - Changer Chen
- Ministry of Education Key Laboratory of Environmental Theoretical Chemistry, South China Normal University, Guangzhou, Guangdong 510006, China
| | - Yang Song
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Concepcion Sanchez-Cid
- Environmental Microbial Genomics, UMR 5005 Laboratoire Ampère, CNRS, École Centrale de Lyon, Université de Lyon, Écully, France
| | - Yu Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ali El-Naggar
- Department of Renewable Resources, University of Alberta, 442 Earth Sciences Building, Edmonton, AB T6G 2E3, Canada
- Department of Soil Sciences, Faculty of Agriculture, Ain Shams University, Cairo 11241, Egypt
| | - Yiming Yao
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Yanran Huang
- Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hong Kong, China
| | | | - Chenggang Gu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Huizhong Shen
- Shenzhen Key Laboratory of Precision Measurement and Early Warning Technology for Urban Environmental Health Risks, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Yanpeng Gao
- Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Chao Qin
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Weigang Road 1, Nanjing 210095, China
| | - Hao Li
- Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming 650500, China
| | - Tong Zhang
- Environmental Microbiome Engineering and Biotechnology Laboratory, Center for Environmental Engineering Research, Department of Civil Engineering, The University of Hong Kong, Hong Kong, China
| | - Natàlia Corcoll
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Min Liu
- Key Laboratory of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200241, China
| | - Daniel S. Alessi
- Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, AB T6G 2E3, Canada
| | - Hui Li
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824, USA
| | - Kristian K. Brandt
- Section for Microbial Ecology and Biotechnology, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
- Sino-Danish Center (SDC), Beijing, China
| | - Yolanda Pico
- Food and Environmental Safety Research Group of the University of Valencia (SAMA-UV), Desertification Research Centre - CIDE (CSIC-UV-GV), Road CV-315 km 10.7, 46113 Moncada, Valencia, Spain
| | - Cheng Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, China
| | - Jianhua Guo
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Jianqiang Su
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Philippe Corvini
- School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, 4132 Muttenz, Switzerland
| | - Mao Ye
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Teresa Rocha-Santos
- Centre for Environmental and Marine Studies (CESAM) & Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Huan He
- Jiangsu Engineering Laboratory of Water and Soil Eco-remediation, School of Environment, Nanjing Normal University, Nanjing 210023, China
| | - Yi Yang
- Key Laboratory of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200241, China
| | - Meiping Tong
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Weina Zhang
- Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Fidèle Suanon
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
- Laboratory of Physical Chemistry, Materials and Molecular Modeling (LCP3M), University of Abomey-Calavi, Republic of Benin, Cotonou 01 BP 526, Benin
| | - Ferdi Brahushi
- Department of Environment and Natural Resources, Agricultural University of Tirana, 1029 Tirana, Albania
| | - Zhenyu Wang
- Institute of Environmental Processes and Pollution Control, and School of Environment & Ecology, Jiangnan University, Wuxi 214122, China
| | - Syed A. Hashsham
- Center for Microbial Ecology, Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, USA
- Department of Civil and Environmental Engineering, Michigan State University, East Lansing, MI 48824, USA
| | - Marko Virta
- Department of Microbiology, University of Helsinki, 00010 Helsinki, Finland
| | - Qingbin Yuan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, China
| | - Gaofei Jiang
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Louis A. Tremblay
- School of Biological Sciences, University of Auckland, Auckland, Aotearoa 1142, New Zealand
| | - Qingwei Bu
- School of Chemical & Environmental Engineering, China University of Mining & Technology - Beijing, Beijing 100083, China
| | - Jichun Wu
- Key Laboratory of Surficial Geochemistry, Ministry of Education, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China
| | - Willie Peijnenburg
- National Institute of Public Health and the Environment, Center for the Safety of Substances and Products, 3720 BA Bilthoven, The Netherlands
- Leiden University, Center for Environmental Studies, Leiden, the Netherlands
| | - Edward Topp
- Agroecology Mixed Research Unit, INRAE, 17 rue Sully, 21065 Dijon Cedex, France
| | - Xinde Cao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xin Jiang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Minghui Zheng
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Taolin Zhang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Yongming Luo
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lizhong Zhu
- Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Xiangdong Li
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Damià Barceló
- Chemistry and Physics Department, University of Almeria, 04120 Almeria, Spain
| | - Jianmin Chen
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Baoshan Xing
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, USA
| | - Wulf Amelung
- Institute of Crop Science and Resource Conservation (INRES), Soil Science and Soil Ecology, University of Bonn, 53115 Bonn, Germany
- Agrosphere Institute (IBG-3), Forschungszentrum Jülich GmbH, 52428 Jülich, Germany
| | - Zongwei Cai
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong, China
| | - Ravi Naidu
- Global Centre for Environmental Remediation (GCER), The University of Newcastle (UON), Newcastle, NSW 2308, Australia
- Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), The University of Newcastle (UON), Newcastle, NSW 2308, Australia
| | - Qirong Shen
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Janusz Pawliszyn
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Yong-guan Zhu
- University of Chinese Academy of Sciences, Beijing 100049, China
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Andreas Schaeffer
- Institute for Environmental Research, RWTH Aachen University, 52074 Aachen, Germany
| | - Matthias C. Rillig
- Institute of Biology, Freie Universität Berlin, Berlin, Germany
- Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, Germany
| | - Fengchang Wu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Gang Yu
- Advanced Interdisciplinary Institute of Environment and Ecology, Beijing Normal University, Zhuhai, China
| | - James M. Tiedje
- Center for Microbial Ecology, Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, USA
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Xue Y, Sun W, Shi W, Huang CH, Santoro D. Prehydrated Electrons Activated by Continuous Electron Transfer Stemmed from Peracetic Acid Homolysis Mediated by Diamond Surface Defects for Enhanced PFOA Destruction. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:11152-11161. [PMID: 38867504 DOI: 10.1021/acs.est.4c02020] [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: 06/14/2024]
Abstract
Research on the use of peracetic acid (PAA) activated by nonmetal solid catalysts for the removal of dissolved refractory organic compounds has gained attention recently due to its improved efficiency and suitability for advanced water treatment (AWT). Among these catalysts, nanocarbon (NC) stands out as an exceptional example. In the NC-based peroxide AWT studies, the focus on the mechanism involving multimedia coordination on the NC surface (reactive species (RS) path, electron reduction non-RS pathway, and singlet oxygen non-RS path) has been confined to the one-step electron reaction, leaving the mechanisms of multichannel or continuous electron transfer paths unexplored. Moreover, there are very few studies that have identified the nonfree radical pathway initiated by electron transfer within PAA AWT. In this study, the complete decomposition (kobs = 0.1995) and significant defluorination of perfluorooctanoic acid (PFOA, deF% = 72%) through PAA/NC has been confirmed. Through the use of multiple electrochemical monitors and the exploration of current diffusion effects, the process of electron reception and conduction stimulated by PAA activation was examined, leading to the discovery of the dynamic process from the PAA molecule → NC solid surface → target object. The vital role of prehydrated electrons (epre-) before the entry of resolvable electrons into the aqueous phase was also detailed. To the best of our knowledge, this is the first instance of identifying the nonradical mechanism of continuous electron transfer in PAA-based AWT, which deviates from the previously identified mechanisms of singlet oxygen, single-electron, or double-electron single-path transfer. The pathway, along with the strong reducibility of epre- initiated by this pathway, has been proven to be essential in reducing the need for catalysts and chemicals in AWT.
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Affiliation(s)
- Yanei Xue
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Wenjun Sun
- School of Environment, Tsinghua University, Beijing 100084, China
- Department of Chemical and Biochemical Engineering, Western University, London, Ontario N6A 5B9, Canada
| | - Wenxin Shi
- School of Environmental and Ecology, Chongqing University, Chongqing 400044, China
| | - Ching-Hua Huang
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Domenico Santoro
- USP Technologies, 3020 Gore Road, London, Ontario N5 V4T7, Canada
- Department of Chemical and Biochemical Engineering, Western University, London, Ontario N6A 5B9, Canada
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13
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Jiang Z, Denisov S, Adjei D, Mostafavi M, Ma J. Overlooked Activation Role of Sulfite in Accelerating Hydrated Electron Treatment of Perfluorosulfonates. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:9427-9435. [PMID: 38747404 DOI: 10.1021/acs.est.4c01444] [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: 05/29/2024]
Abstract
Photoexcitation of sulfite (SO32-) is often used to generate hydrated electrons (eaq-) in processes to degrade perfluoroalkyl and polyfluoroalkyl substances (PFASs). Conventional consensus discourages the utilization of SO32- concentrations exceeding 10 mM for effective defluorination. This has hindered our understanding of SO32- chemistry beyond its electron photogeneration properties. In contrast, the radiation-chemical study presented here, directly producing eaq- through water radiolysis, suggests that SO32- plays a previously overlooked activation role in the defluorination. Quantitative 60Co gamma irradiation experiments indicate that the increased SO32- concentration from 0.1 to 1 M enhances the defluorination rate by a remarkable 15-fold, especially for short-chain perfluoroalkyl sulfonate (PFSA). Furthermore, during the treatment of long-chain PFSA (C8F17-SO3-) with a higher concentration of SO32-, the intermediates of C8H17-SO3- and C3F7-COO- were observed, which are absent without SO32-. These observations highlight that a higher concentration of SO32- facilitates both reaction pathways: chain shortening and H/F exchange. Pulse radiolysis measurements show that elevated SO32- concentrations accelerate the bimolecular reaction between eaq- and PFSA by 2 orders of magnitude. 19F NMR measurements and theoretical simulations reveal the noncovalent interactions between SO32- and F atoms, which exceptionally reduce the C-F bond dissociation energy by nearly 40%. As a result, our study offers a more effective strategy for degrading highly persistent PFSA contaminants.
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Affiliation(s)
- Zhiwen Jiang
- School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026, China
- Institute de Chimie Physique, UMR8000 CNRS/Université Paris-Saclay, Orsay 91405, France
| | - Sergey Denisov
- Institute de Chimie Physique, UMR8000 CNRS/Université Paris-Saclay, Orsay 91405, France
| | - Daniel Adjei
- Institute de Chimie Physique, UMR8000 CNRS/Université Paris-Saclay, Orsay 91405, France
| | - Mehran Mostafavi
- Institute de Chimie Physique, UMR8000 CNRS/Université Paris-Saclay, Orsay 91405, France
| | - Jun Ma
- School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026, China
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14
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Wang Y, Zhang J, Zhang W, Yao J, Liu J, He H, Gu C, Gao G, Jin X. Electrostatic Field in Contact-Electro-Catalysis Driven C-F Bond Cleavage of Perfluoroalkyl Substances. Angew Chem Int Ed Engl 2024; 63:e202402440. [PMID: 38426574 DOI: 10.1002/anie.202402440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 02/26/2024] [Accepted: 02/29/2024] [Indexed: 03/02/2024]
Abstract
Perfluoroalkyl substances (PFASs) are persistent and toxic to human health. It is demanding for high-efficient and green technologies to remove PFASs from water. In this study, a novel PFAS treatment technology was developed, utilizing polytetrafluoroethylene (PTFE) particles (1-5 μm) as the catalyst and a low frequency ultrasound (US, 40 kHz, 0.3 W/cm2) for activation. Remarkably, this system can induce near-complete defluorination for different structured PFASs. The underlying mechanism relies on contact electrification between PTFE and water, which induces cumulative electrons on PTFE surface, and creates a high surface voltage (tens of volts). Such high surface voltage can generate abundant reactive oxygen species (ROS, i.e., O2⋅-, HO⋅, etc.) and a strong interfacial electrostatic field (IEF of 109~1010 V/m). Consequently, the strong IEF significantly activates PFAS molecules and reduces the energy barrier of O2⋅- nucleophilic reaction. Simultaneously, the co-existence of surface electrons (PTFE*(e-)) and HO⋅ enables synergetic reduction and oxidation of PFAS and its intermediates, leading to enhanced and thorough defluorination. The US/PTFE method shows compelling advantages of low energy consumption, zero chemical input, and few harmful intermediates. It offers a new and promising solution for effectively treating the PFAS-contaminated drinking water.
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Affiliation(s)
- Yanfeng Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China
- School of Life and Environmental Sciences, Shaoxing University, Huancheng Road 508, Shaoxing, 312000, China
| | - Jing Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China
- Suzhou High School Of Jiangsu Province, Renmin Road 699, Suzhou, 215007, China
| | - Wenkai Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China
| | - Jiaming Yao
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China
| | - Jinyong Liu
- Department of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Huan He
- School of Environment, Nanjing, Normal University, Nanjing, 210023, China
| | - Cheng Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China
| | - Guandao Gao
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China
- Chongqing Innovation Research Institute of Nanjing University, Chongqing, 401121, China
| | - Xin Jin
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China
- School of Environment, Nanjing, Normal University, Nanjing, 210023, China
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15
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Chen B, Xu J, Zhu L. Controllable chemical redox reactions to couple microbial degradation for organic contaminated sites remediation: A review. J Environ Sci (China) 2024; 139:428-445. [PMID: 38105066 DOI: 10.1016/j.jes.2023.06.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 06/09/2023] [Accepted: 06/10/2023] [Indexed: 12/19/2023]
Abstract
Global environmental concern over organic contaminated sites has been progressively conspicuous during the process of urbanization and industrial restructuring. While traditional physical or chemical remediation technologies may significantly destroy the soil structure and function, coupling moderate chemical degradation with microbial remediation becomes a potential way for the green, economic, and efficient remediation of contaminated sites. Hence, this work systematically elucidates why and how to couple chemical technology with microbial remediation, mainly focused on the controllable redox reactions of organic contaminants. The rational design of materials structure, selective generation of reactive oxygen species, and estimation of degradation pathway are described for chemical oxidation. Meanwhile, current progress on efficient and selective reductions of organic contaminants (i.e., dechlorination, defluorination, -NO2 reduction) is introduced. Combined with the microbial remediation of contaminated sites, several consideration factors of how to couple chemical and microbial remediation are proposed based on both fundamental and practical points of view. This review will advance the understanding and development of chemical-microbial coupled remediation for organic contaminated sites.
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Affiliation(s)
- Bin Chen
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Agriculture & Forest University, Lin'an 311300, China
| | - Jiang Xu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Zhejiang University, Hangzhou 310058, China.
| | - Lizhong Zhu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Zhejiang University, Hangzhou 310058, China
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16
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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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17
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Nayak SK, Yamijala SSRKC. Computing accurate bond dissociation energies of emerging per- and polyfluoroalkyl substances: Achieving chemical accuracy using connectivity-based hierarchy schemes. JOURNAL OF HAZARDOUS MATERIALS 2024; 468:133804. [PMID: 38377911 DOI: 10.1016/j.jhazmat.2024.133804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 02/06/2024] [Accepted: 02/14/2024] [Indexed: 02/22/2024]
Abstract
Understanding the bond dissociation energies (BDEs) of per- and polyfluoroalkyl substances (PFAS) helps in devising their efficient degradation pathways. However, there is only limited experimental data on the PFAS BDEs, and there are uncertainties associated with the BDEs computed using density functional theory. Although quantum chemical methods like the G4 composite method can provide highly accurate BDEs (< 1 kcal mol-1), they are limited to small system sizes. To address DFT's accuracy limitations and G4's system size constraints, we examined the connectivity-based hierarchy (CBH) scheme and found that it can provide BDEs that are reasonably close to the G4 accuracy while retaining the computational efficiency of DFT. To further improve the accuracy, we modified the CBH scheme and demonstrated that BDEs calculated using it have a mean-absolute deviation of 0.7 kcal mol-1 from G4 BDEs. To validate the reliability of this new scheme, we computed the ground state free energies of seven PFAS compounds and BDEs for 44 C-C and C-F bonds at the G4 level of theory. Our results suggest that the modified CBH scheme can accurately compute the BDEs of both small and large PFAS at near G4 level accuracy, offering promise for more effective PFAS degradation strategies.
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Affiliation(s)
- Samir Kumar Nayak
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036 India; Centre for Atomistic Modelling and Materials Design, Indian Institute of Technology Madras, Chennai 600036, India
| | - Sharma S R K C Yamijala
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036 India; Centre for Atomistic Modelling and Materials Design, Indian Institute of Technology Madras, Chennai 600036, India; Centre for Molecular Materials and Functions, Indian Institute of Technology Madras, Chennai 600036, India; Centre for Quantum Information, Communication, and Computing, Indian Institute of Technology Madras, Chennai 600036, India.
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18
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Amador CK, Vyas S, Strathmann TJ. Kinetic Model for Predicting Perfluoroalkyl Acid Degradation During UV-Sulfite Treatment. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:6425-6434. [PMID: 38554136 DOI: 10.1021/acs.est.3c10584] [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: 04/01/2024]
Abstract
Hydrated electron (eaq-) treatment processes show great potential in remediating recalcitrant water contaminants, including perfluoroalkyl and polyfluoroalkyl substances (PFAS). However, treatment efficacy depends upon many factors relating to source water composition, UV light source characteristics, and contaminant reactivity. Here, we provide critical insights into the complex roles of solution parameters on contaminant abatement through application of a UV-sulfite kinetic model that incorporates first-principles information on eaq- photogeneration and reactivity. The model accurately predicts decay profiles of short-chain perfluoroalkyl acids (PFAAs) during UV-sulfite treatment and facilitates quantitative interpretation of the effects of changing solution composition on PFAS degradation rates. Model results also confirm that the enhanced degradation of PFAAs observed under highly alkaline pH conditions results from changes in speciation of nontarget eaq- scavengers. Reverse application of the model to UV-sulfite data collected for longer chain PFAAs enabled estimation of bimolecular rate constants (k2, M-1 s-1), providing an alternative to laser flash photolysis (LFP) measurements that are not feasible due to the water solubility limitations of these compounds. The proposed model links the disparate means of investigating eaq- processes, namely, UV photolysis and LFP, and provides a framework to estimate UV-sulfite treatment efficacy of PFAS in diverse water sources.
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Affiliation(s)
- Camille K Amador
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
- Department of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Shubham Vyas
- Department of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Timothy J Strathmann
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
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19
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Xia D, Zhang H, Ju Y, Xie HB, Su L, Ma F, Jiang J, Chen J, Francisco JS. Spontaneous Degradation of the "Forever Chemicals" Perfluoroalkyl and Polyfluoroalkyl Substances (PFASs) on Water Droplet Surfaces. J Am Chem Soc 2024. [PMID: 38584396 DOI: 10.1021/jacs.4c00435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Because of their innate chemical stability, the ubiquitous perfluoroalkyl and polyfluoroalkyl substances (PFASs) have been dubbed "forever chemicals" and have attracted considerable attention. However, their stability under environmental conditions has not been widely verified. Herein, perfluorooctanoic acid (PFOA), a widely used and detected PFAS, was found to be spontaneously degraded in aqueous microdroplets under room temperature and atmospheric pressure conditions. This unexpected fast degradation occurred via a unique multicycle redox reaction of PFOA with interfacial reactive species on the droplet surface. Similar degradation was observed for other PFASs. This study extends the current understanding of the environmental fate and chemistry of PFASs and provides insight into aid in the development of effective methods for removing PFASs.
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Affiliation(s)
- Deming Xia
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), Dalian Key Laboratory on Chemicals Risk Control and Pollution Prevention Technology, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
- Department of Earth and Environmental Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6316, United States
| | - Hong Zhang
- School of Marin Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong 264209, China
| | - Yun Ju
- School of Marin Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong 264209, China
| | - Hong-Bin Xie
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), Dalian Key Laboratory on Chemicals Risk Control and Pollution Prevention Technology, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Lihao Su
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), Dalian Key Laboratory on Chemicals Risk Control and Pollution Prevention Technology, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Fangfang Ma
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), Dalian Key Laboratory on Chemicals Risk Control and Pollution Prevention Technology, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Jie Jiang
- School of Marin Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong 264209, China
| | - Jingwen Chen
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), Dalian Key Laboratory on Chemicals Risk Control and Pollution Prevention Technology, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Joseph S Francisco
- Department of Earth and Environmental Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6316, United States
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20
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Chu C, Ma LL, Alawi H, Ma W, Zhu Y, Sun J, Lu Y, Xue Y, Chen G. Mechanistic exploration of polytetrafluoroethylene thermal plasma gasification through multiscale simulation coupled with experimental validation. Nat Commun 2024; 15:1654. [PMID: 38395949 PMCID: PMC10891128 DOI: 10.1038/s41467-024-45077-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 01/15/2024] [Indexed: 02/25/2024] Open
Abstract
The ever-growing quantities of persistent Polytetrafluoroethylene (PTFE) wastes, along with consequential ecological and human health concerns, stimulate the need for alternative PTFE disposal method. The central research challenge lies in elucidating the decomposition mechanism of PTFE during high-temperature waste treatment. Here, we propose the PTFE microscopic thermal decomposition pathways by integrating plasma gasification experiments with multi-scale simulations strategies. Molecular dynamic simulations reveal a pyrolysis-oxidation & chain-shortening-deep defluorination (POCD) degradation pathway in an oxygen atmosphere, and an F abstraction-hydrolysis-deep defluorination (FHD) pathway in a steam atmosphere. Density functional theory computations demonstrate the vital roles of 1O2 and ·H radicals in the scission of PTFE carbon skeleton, validating the proposed pathways. Experimental results confirm the simulation results and show that up to 80.12% of gaseous fluorine can be recovered through plasma gasification within 5 min, under the optimized operating conditions determined through response surface methodology.
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Affiliation(s)
- Chu Chu
- School of Environmental Science and Engineering, Tianjin University/Tianjin Key Lab of Biomass/Wastes Utilization, Tianjin, 300072, China
| | - Long Long Ma
- School of Energy &Environment, Key Lab Energy Thermal Conversion & Control, Southeast University, Nanjing, 210096, China
| | - Hyder Alawi
- School of Environmental Science and Engineering, Tianjin University/Tianjin Key Lab of Biomass/Wastes Utilization, Tianjin, 300072, China
| | - Wenchao Ma
- School of Environmental Science and Engineering, Tianjin University/Tianjin Key Lab of Biomass/Wastes Utilization, Tianjin, 300072, China.
| | - YiFei Zhu
- School of Electrical Engineering, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Junhao Sun
- Postdoctoral Programme, Guosen Securities, Shenzhen, 518001, China
| | - Yao Lu
- School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin, 300401, China
| | - Yixian Xue
- School of Environmental Science and Engineering, Tianjin University/Tianjin Key Lab of Biomass/Wastes Utilization, Tianjin, 300072, China
| | - Guanyi Chen
- School of Environmental Science and Engineering, Tianjin University/Tianjin Key Lab of Biomass/Wastes Utilization, Tianjin, 300072, China
- School of Ecology and Environment, Tibet University, Lhasa, 850012, Tibet, China
- School of Mechanical Engineering, Tianjin University of Commerce, Tianjin, 300314, China
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21
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Chen Z, Dong R, Wang X, Huang L, Qiu L, Zhang M, Mi N, Xu M, He H, Gu C. Efficient Decomposition of Perfluoroalkyl Substances by Low Concentration Indole: New Insights into the Molecular Mechanisms. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024. [PMID: 38329941 DOI: 10.1021/acs.est.3c08453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2024]
Abstract
Perfluoroalkyl substances (PFAS) are a class of persistent organic pollutants known as "forever chemicals". Currently, the hydrated electron-based advanced reduction process (ARP) holds promise for the elimination of PFAS. However, the efficiency of ARP is often challenged by an oxygen-rich environment, resulting in the consumption of hydrated electron source materials in exchange for the high PFAS decomposition efficiency. Herein, we developed a ternary system constructed by indole and isopropyl alcohol (IPA), and the addition of IPA significantly enhanced the PFOA degradation and defluorination efficiency in the presence of low-concentration indole (<0.4 mM). Meanwhile, opposite results were obtained with a higher amount of indole (>0.4 mM). Further exploring the molecular mechanism of the reaction system, the addition of IPA played two roles. On one hand, IPA built an anaerobic reaction atmosphere and improved the yield and utilization efficiency of hydrated electrons with a low concentration of indole. On the other hand, IPA suppressed the attraction between indole and PFOA, thus reducing the hydrated electron transfer efficiency, especially with more indole. In general, the indole/PFAS/IPA system significantly improved the PFAS destruction efficiency with a small amount of hydrated electron donors, which provided new insights for development of simple and efficient techniques for the treatment of PFAS-contaminated wastewater.
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Affiliation(s)
- Zhanghao Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, P. R. China
| | - Ruochen Dong
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, P. R. China
| | - Xinhao Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, P. R. China
| | - Liuqing Huang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, P. R. China
| | - Longlong Qiu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, P. R. China
| | - Ming Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, P. R. China
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, P. R. China
| | - Na Mi
- Ministry of Ecology and Environment, Nanjing Institute of Environmental Science, Nanjing 210042, P. R. China
| | - Min Xu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, P. R. China
| | - Huan He
- School of Environment, Nanjing Normal University, Nanjing 210023, P. R. China
| | - Cheng Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, P. R. China
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22
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Sopena Moros A, Li S, Li K, Doumy G, Southworth SH, Otolski C, Schaller RD, Kumagai Y, Rubensson JE, Simon M, Dakovski G, Kunnus K, Robinson JS, Hampton CY, Hoffman DJ, Koralek J, Loh ZH, Santra R, Inhester L, Young L. Tracking Cavity Formation in Electron Solvation: Insights from X-ray Spectroscopy and Theory. J Am Chem Soc 2024; 146:3262-3269. [PMID: 38270463 PMCID: PMC10859959 DOI: 10.1021/jacs.3c11857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2024]
Abstract
We present time-resolved X-ray absorption spectra of ionized liquid water and demonstrate that OH radicals, H3O+ ions, and solvated electrons all leave distinct X-ray-spectroscopic signatures. Particularly, this allows us to characterize the electron solvation process through a tool that focuses on the electronic response of oxygen atoms in the immediate vicinity of a solvated electron. Our experimental results, supported by ab initio calculations, confirm the formation of a cavity in which the solvated electron is trapped. We show that the solvation dynamics are governed by the magnitude of the random structural fluctuations present in water. As a consequence, the solvation time is highly sensitive to temperature and to the specific way the electron is injected into water.
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Affiliation(s)
- Arturo Sopena Moros
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, Hamburg 22607, Germany
| | - Shuai Li
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Kai Li
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Department of Physics and James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States
| | - Gilles Doumy
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Stephen H Southworth
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Christopher Otolski
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Richard D Schaller
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinous 60439, United States
- Department of Chemistry, Northwestern University, 2145 N. Sheridan Rd., Evanston, Illinois 60208, United States
| | - Yoshiaki Kumagai
- Department of Applied Physics, Tokyo University of Agriculture and Technology, Tokyo 184-8588, Japan
| | - Jan-Erik Rubensson
- Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala SE-75120, Sweden
| | - Marc Simon
- Laboratoire de Chimie Physique-Matière et Rayonnement, LCPMR, Sorbonne Université, CNRS, Paris F-75005, France
| | | | | | | | | | | | - Jake Koralek
- LCLS, SLAC, Menlo Park, California 94025, United States
| | - Zhi-Heng Loh
- School of Chemistry, Chemical Engineering and Biotechnology, and School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Robin Santra
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, Hamburg 22607, Germany
- Department of Physics, Universität Hamburg, Notkestraße 9, Hamburg 22607, Germany
| | - Ludger Inhester
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, Hamburg 22607, Germany
| | - Linda Young
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Department of Physics and James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States
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23
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Park J, Bandstra JZ, Tratnyek PG, Harvey OR, Bae JS, Lee G. Modeling the Role in pH on Contaminant Sequestration by Zerovalent Metals: Chromate Reduction by Zerovalent Magnesium. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:2564-2573. [PMID: 38278139 DOI: 10.1021/acs.est.3c08367] [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: 01/28/2024]
Abstract
The role of pH in sequestration of Cr(VI) by zerovalent magnesium (ZVMg) was characterized by global fitting of a kinetic model to time-series data from unbuffered batch experiments with varying initial pH values. At initial pH values ranging from 2.0 to 6.8, ZVMg (0.5 g/L) completely reduced Cr(VI) (18.1 μM) within 24 h, during which time pH rapidly increased to a plateau value of ∼10. Time-series correlation analysis of the pH and aqueous Cr(VI), Cr(III), and Mg(II) concentration data suggested that these conditions are controlled by combinations of reactions (involving Mg0 oxidative dissolution and Cr(VI) sequestration) that evolve over the time course of each experiment. Since this is also likely to occur during any engineering applications of ZVMg for remediation, we developed a kinetic model for dynamic pH changes coupled with ZVMg corrosion processes. Using this model, the synchronous changes in Cr(VI) and Mg(II) concentrations were fully predicted based on the Langmuir-Hinshelwood kinetics and transition-state theory, respectively. The reactivity of ZVMg was different in two pH regimes that were pH-dependent at pH < 4 and pH-independent at the higher pH. This contrasting pH effect could be ascribed to the shift of the primary oxidant of ZVMg from H+ to H2O at the lower and higher pH regimes, respectively.
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Affiliation(s)
- Jaeseon Park
- Department of Earth System Sciences, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Joel Z Bandstra
- Department of Mathematics, Engineering, and Computer Science, Saint Francis University, P.O. Box 600, Loretto, Pennsylvania 15940, United States
| | - Paul G Tratnyek
- OHSU-PSU School of Public Health, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, United States
| | - Omar R Harvey
- Department of Geological Sciences, Texas Christian University, Fort Worth, Texas 76129, United States
| | - Jong-Seong Bae
- Division of High-Technology Materials Research, Busan Center, Korea Basic Science Institute, 30 Gwahaksandan 1-ro 60, Gangseo-gu, Busan 618-230, Republic of Korea
| | - Giehyeon Lee
- Department of Earth System Sciences, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea
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24
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McTaggart M, Malardier-Jugroot C. The role of helicity in PFAS resistance to degradation: DFT simulation of electron capture and defluorination. Phys Chem Chem Phys 2024; 26:4692-4701. [PMID: 38251935 DOI: 10.1039/d3cp04973f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
Defluorination of perfluorinated alkyl substances (PFASs) via the direct capture of excess electrons poses a promising path to environmental decontamination. Herein we show that quantum-chemical model optimization methods can be adapted to simulate the changes to molecular geometry that result from electron capture. These reaction pathways demonstrate that the introduction of an additional electron causes a loss of the helical arrangement along linear carbon tail chains. Regaining helicity is sufficiently favourable to enable fluoride release in C7-C10 PFAS chains; shorter chains are enthalpically hindered from degradation while the additional charge is stabilized on longer chains by the greater entropy their flexibility permits. These results suggest that reductive PFAS treatment processes could be made more effective under high pressure or confined conditions.
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Affiliation(s)
- Matt McTaggart
- Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, Ontario, Canada.
| | - Cécile Malardier-Jugroot
- Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, Ontario, Canada.
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25
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Juve JMA, Donoso Reece JA, Wong MS, Wei Z, Ateia M. Photocatalysts for chemical-free PFOA degradation - What we know and where we go from here? JOURNAL OF HAZARDOUS MATERIALS 2024; 462:132651. [PMID: 37827098 DOI: 10.1016/j.jhazmat.2023.132651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 08/11/2023] [Accepted: 09/26/2023] [Indexed: 10/14/2023]
Abstract
Perfluorooctanoic acid (PFOA) is a toxic and recalcitrant perfluoroalkyl substance commonly detected in the environment. Its low concentration challenges the development of effective degradation techniques, which demands intensive chemical and energy consumption. The recent stringent health advisories and the upgrowth and advances in photocatalytic technologies claim the need to evaluate and compare the state-of-the-art. Among these systems, chemical-free photocatalysis emerges as a cost-effective and sustainable solution for PFOA degradation and potentially other perfluorinated carboxylic acids. This review (I) classifies the state-of-the-art of chemical-free photocatalysts for PFOA degradation in families of materials (Ti, Fe, In, Ga, Bi, Si, and BN), (II) describes the evolution of catalysts, identifies and discusses the strategies to enhance their performance, (III) proposes a simplified cost evaluation tool for simple techno-economical analysis of the materials; (IV) compares the features of the catalysts expanding the classic degradation focus to other essential parameters, and (V) identifies current research gaps and future research opportunities to enhance the photocatalyst performance. We aim that this critical review will assist researchers and practitioners to develop rational photocatalyst designs and identify research gaps for green and effective PFAS degradation.
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Affiliation(s)
- Jan-Max Arana Juve
- Centre for Water Technology (WATEC) & Department of Biological and Chemical Engineering, Aarhus University, Universitetsbyen 36, 8000 Aarhus C, Denmark; Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | - Juan A Donoso Reece
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | - Michael S Wong
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | - Zongsu Wei
- Centre for Water Technology (WATEC) & Department of Biological and Chemical Engineering, Aarhus University, Universitetsbyen 36, 8000 Aarhus C, Denmark.
| | - Mohamed Ateia
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA; Center for Environmental Solutions & Emergency Response, US Environmental Protection Agency, Cincinnati, OH, USA.
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26
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Biswas S, Wong BM. Beyond Conventional Density Functional Theory: Advanced Quantum Dynamical Methods for Understanding Degradation of Per- and Polyfluoroalkyl Substances. ACS ES&T ENGINEERING 2024; 4:96-104. [PMID: 38229882 PMCID: PMC10788865 DOI: 10.1021/acsestengg.3c00216] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 08/18/2023] [Accepted: 08/21/2023] [Indexed: 01/18/2024]
Abstract
Computational chemistry methods, such as density functional theory (DFT), have now become more common in environmental research, particularly for simulating the degradation of per- and polyfluoroalkyl substances (PFAS). However, the vast majority of PFAS computational studies have focused on conventional DFT approaches that only probe static, time-independent properties of PFAS near stationary points on the potential energy surface. To demonstrate the rich mechanistic information that can be obtained from time-dependent quantum dynamics calculations, we highlight recent studies using these advanced techniques for probing PFAS systems. We briefly discuss recent applications ranging from ab initio molecular dynamics to DFT-based metadynamics and real-time time-dependent DFT for probing PFAS degradation in various reactive environments. These quantum dynamical approaches provide critical mechanistic information that cannot be gleaned from conventional DFT calculations. We conclude with a perspective of promising research directions and recommend that these advanced quantum dynamics simulations be more widely used by the environmental research community to directly probe PFAS degradation dynamics and other environmental processes.
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Affiliation(s)
- Sohag Biswas
- Materials Science & Engineering
Program, Department of Chemistry, and Department of Physics &
Astronomy, University of California-Riverside, Riverside, California 92521, United States
| | - Bryan M. Wong
- Materials Science & Engineering
Program, Department of Chemistry, and Department of Physics &
Astronomy, University of California-Riverside, Riverside, California 92521, United States
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27
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Marciesky M, Aga DS, Bradley IM, Aich N, Ng C. Mechanisms and Opportunities for Rational In Silico Design of Enzymes to Degrade Per- and Polyfluoroalkyl Substances (PFAS). J Chem Inf Model 2023; 63:7299-7319. [PMID: 37981739 PMCID: PMC10716909 DOI: 10.1021/acs.jcim.3c01303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/17/2023] [Accepted: 10/18/2023] [Indexed: 11/21/2023]
Abstract
Per and polyfluoroalkyl substances (PFAS) present a unique challenge to remediation techniques because their strong carbon-fluorine bonds make them difficult to degrade. This review explores the use of in silico enzymatic design as a potential PFAS degradation technique. The scope of the enzymes included is based on currently known PFAS degradation techniques, including chemical redox systems that have been studied for perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) defluorination, such as those that incorporate hydrated electrons, sulfate, peroxide, and metal catalysts. Bioremediation techniques are also discussed, namely the laccase and horseradish peroxidase systems. The redox potential of known reactants and enzymatic radicals/metal-complexes are then considered and compared to potential enzymes for degrading PFAS. The molecular structure and reaction cycle of prospective enzymes are explored. Current knowledge and techniques of enzyme design, particularly radical-generating enzymes, and application are also discussed. Finally, potential routes for bioengineering enzymes to enable or enhance PFAS remediation are considered as well as the future outlook for computational exploration of enzymatic in situ bioremediation routes for these highly persistent and globally distributed contaminants.
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Affiliation(s)
- Melissa Marciesky
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, United States
| | - Diana S Aga
- Department of Chemistry, State University of New York at Buffalo, Buffalo, New York 14260, United States
| | - Ian M Bradley
- Department of Civil, Structural, and Environmental Engineering, State University of New York at Buffalo, Buffalo, New York 14228, United States
- Research and Education in Energy, Environmental and Water (RENEW) Institute, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Nirupam Aich
- Department of Civil and Environmental Engineering, University of Nebraska─Lincoln, Lincoln, Nebraska 68588-0531, United States
| | - Carla Ng
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, United States
- Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
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28
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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: 3.0] [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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29
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Kumar R, Dada TK, Whelan A, Cannon P, Sheehan M, Reeves L, Antunes E. Microbial and thermal treatment techniques for degradation of PFAS in biosolids: A focus on degradation mechanisms and pathways. JOURNAL OF HAZARDOUS MATERIALS 2023; 452:131212. [PMID: 36934630 DOI: 10.1016/j.jhazmat.2023.131212] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/09/2023] [Accepted: 03/13/2023] [Indexed: 05/03/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are persistent organic chemicals detected in biosolids worldwide, which have become a significant concern for biosolids applications due to their increasing environmental risks. Hence, it is pivotal to understand the magnitude of PFAS contamination in biosolids and implement effective technologies to reduce their contamination and prevent hazardous aftermaths. Thermal techniques such as pyrolysis, incineration and gasification, and biodegradation have been regarded as impactful solutions to degrade PFAS and transform biosolids into value-added products like biochar. These techniques can mineralize PFAS compounds under specific operating parameters, which can lead to unique degradation mechanisms and pathways. Understanding PFAS degradation mechanisms can pave the way to design the technology and to optimize the process conditions. Therefore, in this review, we aim to review and compare PFAS degradation mechanisms in thermal treatment like pyrolysis, incineration, gasification, smouldering combustion, hydrothermal liquefaction (HTL), and biodegradation. For instance, in biodegradation of perfluorooctane sulfonic acid (PFOS), firstly C-S bond cleavage occurs which is followed by hydroxylation, decarboxylation and defluorination reactions to form perfluoroheptanoic acid. In HTL, PFOS degradation is carried through OH-catalyzed series of nucleophilic substitution and decarboxylation reactions. In contrast, thermal PFOS degradation involves a three-step random-chain scission pathway. The first step includes C-S bond cleavage, followed by defluorination of perfluoroalkyl radical, and radical chain propagation reactions. Finally, the termination of chain propagation reactions produces very short-fluorinated units. We also highlighted important policies and strategies employed worldwide to curb PFAS contamination in biosolids.
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Affiliation(s)
- Ravinder Kumar
- College of Science & Engineering, James Cook University, Townsville, QLD 4811, Australia
| | - Tewodros Kassa Dada
- College of Science & Engineering, James Cook University, Townsville, QLD 4811, Australia
| | - Anna Whelan
- College of Science & Engineering, James Cook University, Townsville, QLD 4811, Australia; Townsville City Council, Wastewater Operations, Townsville, QLD 4810, Australia
| | | | - Madoc Sheehan
- College of Science & Engineering, James Cook University, Townsville, QLD 4811, Australia
| | - Louise Reeves
- Queensland Water Directorate, Brisbane, QLD 4009, Australia
| | - Elsa Antunes
- College of Science & Engineering, James Cook University, Townsville, QLD 4811, Australia.
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Wang Y, Xiao Y, Wang Y, Lin Q, Zhu Y, Ni Z, Qiu R. Electroreductive Defluorination of Unsaturated PFAS by a Quaternary Ammonium Surfactant-Modified Cathode via Direct Cathodic Reduction. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:7578-7589. [PMID: 37116179 DOI: 10.1021/acs.est.2c08182] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Remediation of per- and polyfluoroalkyl substances (PFAS) in groundwater remains a technological challenge due to the trace concentrations of PFAS and the strength of their C-F bonds. This study investigated an electroreductive system with a quaternary ammonium surfactant-modified cathode for degrading (E)-perfluoro(4-methylpent-2-enoic acid) (PFMeUPA) at a low cathodic potential. A removal efficiency of 99.81% and defluorination efficiency of 78.67% were achieved under -1.6 V (vs Ag/AgCl) at the cathode modified by octadecyltrimethylammonium bromide (OTAB). The overall degradation procedure started with the adsorption of PFMeUPA onto the modified cathode. This adsorption process was promoted by hydrophobic and electrostatic interactions between the surfactants and PFMeUPA, of which the binding percentage, binding mode, and binding energy were determined via molecular dynamics (MD) simulations and density functional theory (DFT) calculations. The step-wise degradation pathway of PFMeUPA, including reductive defluorination and hydrogenation, was derived. Meanwhile, C-F bond breaking with direct electron transfer only was achieved for the first time in this study, which also showed that the C═C bond structure of PFAS facilitates the C-F cleavage. Overall, this study highlights the crucial role of quaternary ammonium surfactants in electron transfer and electrocatalytic activities in the electroreductive system and provides insights into novel remediation approaches on PFAS-contaminated groundwater.
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Affiliation(s)
- Yue Wang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
| | - Ye Xiao
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
| | - Yafei Wang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
| | - Qingqi Lin
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Yanping Zhu
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Zhuobiao Ni
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Rongliang Qiu
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
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31
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Yan B, Liu J. Molecular framework for designing Fluoroclay with enhanced affinity for per- and polyfluoroalkyl substances. WATER RESEARCH X 2023; 19:100175. [PMID: 36950253 PMCID: PMC10026042 DOI: 10.1016/j.wroa.2023.100175] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 03/07/2023] [Accepted: 03/08/2023] [Indexed: 06/18/2023]
Abstract
Motivated by the need for enhancing sorbent affinity for per- and polyfluoroalkyl substances (PFAS), we demonstrate the possibility of rationally designing clay-based material (FluoroClay) with a pre-selected intercalant and predicting sorbent performance using all-atom molecular dynamics simulation coupled with density functional theory-based computation. Perfluorohexyldodecane quaternary ammonium (F6H12A) as the selected intercalant revealed significant enhancement in adsorption affinity for hard-to-remove compounds, including perfluorobutane sulfonate (PFBS) and polyfluoroalkylethers (GenX and ADONA). The adsorption is thermodynamically entropy-driven and dominated by the hydrophobic effect. The incorporation of fluorine atoms into clay intercalants gave rise to a hydrophobic and fluorophilic "cavity" structure for targeted PFAS. The self-assembly of intercalant-PFAS under the negative electric field of clay sheets created a unique configuration that significantly enlarged the contact surface area between PFAS and F6H12A and was quantitatively driven by their intermolecular interactions, e.g., CF chain-CH chain, CF chain-CF chain, and charge-CH chain interactions. Collectively, our work demonstrated a new approach to select fluorinated functionality for designing a new adsorbent and estimating its performance via molecular simulation. It also provided an in-depth understanding of the underlying fundamental physics and chemistry in the adsorption of PFAS, suggesting a new strategy for PFAS removal, particularly for short-chain PFAS and new chemical alternatives.
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Affiliation(s)
- Bei Yan
- Department of Civil Engineering, McGill University, 817 Sherbrooke Street West, Montreal, Quebec H3A 0C3, Canada
| | - Jinxia Liu
- Department of Civil Engineering, McGill University, 817 Sherbrooke Street West, Montreal, Quebec H3A 0C3, Canada
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32
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Biswas S, Wong BM. Degradation of Perfluorooctanoic Acid on Aluminum Oxide Surfaces: New Mechanisms from Ab Initio Molecular Dynamics Simulations. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:6695-6702. [PMID: 37018510 PMCID: PMC10134488 DOI: 10.1021/acs.est.3c00948] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 03/24/2023] [Accepted: 03/27/2023] [Indexed: 06/19/2023]
Abstract
Perfluorooctanoic acid (PFOA) is a part of a large group of anthropogenic, persistent, and bioaccumulative contaminants known as per- and polyfluoroalkyl substances (PFAS) that can be harmful to human health. In this work, we present the first ab initio molecular dynamics (AIMD) study of temperature-dependent degradation dynamics of PFOA on (100) and (110) surfaces of γ-Al2O3. Our results show that PFOA degradation does not occur on the pristine (100) surface, even when carried out at high temperatures. However, introducing an oxygen vacancy on the (100) surface facilitates an ultrafast (<100 fs) defluorination of C-F bonds in PFOA. We also examined degradation dynamics on the (110) surface and found that PFOA interacts strongly with Al(III) centers on the surface of γ-Al2O3, resulting in a stepwise breaking of C-F, C-C, and C-COO bonds. Most importantly, at the end of the degradation process, strong Al-F bonds are formed on the mineralized γ-Al2O3 surface, which prevents further dissociation of fluorine into the surrounding environment. Taken together, our AIMD simulations provide critical reaction mechanisms at a quantum level of detail and highlight the importance of temperature effects, defects, and surface facets for PFOA degradation on reactive surfaces, which have not been systematically explored or analyzed.
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33
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Li K, Chen Z, Jin X, Tian H, Song Z, Zhang Q, Xu D, Hong R. Theoretical investigation of Aryl/Alkyl halide reduction with hydrated electrons from energy and AIMD aspects. J Mol Model 2023; 29:142. [PMID: 37061582 DOI: 10.1007/s00894-023-05553-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 04/10/2023] [Indexed: 04/17/2023]
Abstract
CONTEXT In this study, the reactions of hydrated electron (e-(aq)) with alkyl and aryl halides were simulated with an ab initial molecular dynamics (AIMD) method to reveal the underlying mechanism. An original protocol was developed for preparing the proper initial wavefunction guess of AIMD, in which a single electron was curled in a tetrahedral cavity of four water molecules. Our results show that the stability of e-(aq) increases with the hydrogen bond grid integrity. The organic halides prefer to react with e-(aq) in neutral or alkaline environment, while they are more likely to react with hydrogen radical (the product of e-(aq) and proton) under acidic conditions. The reaction between fluorobenzene/fluoromethane and hydrogen radical is considered as the least favorable reaction due to the highest reaction barriers. The bond dissociation energy (BDE) suggested that the cleavage of the carbon-halogen bond of their anion radical might be a thermodynamically favorable reaction. AIMD results indicated that the LUMO or higher orbitals were the e-(aq) migration destination. The transplanted electron enhanced carbon-halogen bond vibration intensively, leading to bond cleavage. The solvation process of the departing halogen anions was observed in both fluorobenzene and fluoromethane AIMD simulation, indicating that it might have a significant effect on enthalpy. Side reactions and byproducts obtained during the AIMD simulation suggested the complexity of the e-(aq) reactions and further investigation was needed to fully understand the reaction mechanisms. This study provided theoretical insight into the pollutant environmental fate and constructed a methodological foundation for AIMD simulation of analogous free radical reactions. METHODS The theoretical calculation was conducted on the combination of Gaussian16 and ORCA5.0.3 software packages. The initial geometries, as well as the wavefunction initial guesses, were obtained at PBE0/ma-def2-TZVP/IEFPCM-water level in Gaussian16 unless otherwise stated. AIMD simulations were performed at the same level in ORCA. Wavefunction analysis was carried out with Multiwfn. The details methods were described in the section "Computational details" section.
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Affiliation(s)
- Kaixin Li
- School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu, 241000, Anhui Province, People's Republic of China
| | - Zhanghao Chen
- School of the Environment, Nanjing University, Nanjing, 210093, People's Republic of China
- State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing, 210093, People's Republic of China
| | - Xin Jin
- School of the Environment, Nanjing University, Nanjing, 210093, People's Republic of China
- State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing, 210093, People's Republic of China
| | - Haoting Tian
- School of Environmental science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China
| | - Zhenxia Song
- School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu, 241000, Anhui Province, People's Republic of China
| | - Qingyun Zhang
- School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu, 241000, Anhui Province, People's Republic of China
| | - Dayong Xu
- School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu, 241000, Anhui Province, People's Republic of China
| | - Ran Hong
- School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu, 241000, Anhui Province, People's Republic of China.
- State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing, 210093, People's Republic of China.
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Morrison AL, Strezov V, Niven RK, Taylor MP, Wilson SP, Wang J, Burns DJ, Murphy PJC. Impact of Salinity and Temperature on Removal of PFAS Species from Water by Aeration in the Absence of Additional Surfactants: A Novel Application of Green Chemistry Using Adsorptive Bubble Fractionation. Ind Eng Chem Res 2023. [DOI: 10.1021/acs.iecr.3c00150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
Affiliation(s)
- Anthony L. Morrison
- School of Natural Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Vladimir Strezov
- School of Natural Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Robert K. Niven
- School of Engineering and Information Technology, The University of New South Wales at Canberra, Canberra, Australian Capital Territory 2610, Australia
| | - Mark P. Taylor
- School of Natural Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, New South Wales 2109, Australia
- EPA Science, Centre for Applied Sciences, Environment Protection Authority Victoria, Ernest Jones Drive, Macleod, Melbourne, Victoria 3085, Australia
| | - Scott P. Wilson
- School of Natural Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Jianlong Wang
- School of Engineering and Information Technology, The University of New South Wales at Canberra, Canberra, Australian Capital Territory 2610, Australia
| | - David J. Burns
- EPOC Enviro, 48-50/7 Narabang Way, Belrose, New South Wales 2085, Australia
| | - Peter J. C. Murphy
- EPOC Enviro, 48-50/7 Narabang Way, Belrose, New South Wales 2085, Australia
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35
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Marquínez-Marquínez AN, Loor-Molina NS, Quiroz-Fernández LS, Maddela NR, Luque R, Rodríguez-Díaz JM. Recent advances in the remediation of perfluoroalkylated and polyfluoroalkylated contaminated sites. ENVIRONMENTAL RESEARCH 2023; 219:115152. [PMID: 36572331 DOI: 10.1016/j.envres.2022.115152] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 11/30/2022] [Accepted: 12/22/2022] [Indexed: 06/17/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs) are compounds used since 1940 in various formulations in the industrial and consumer sectors due to their high chemical and thermal stability. In recent years, PFASs have caused global concern due to their presence in different water and soil matrices, which threatens the environment and human health. These compounds have been reported to be linked to the development of serious human diseases, including but not limited to cancer. For this reason, PFASs have been considered as persistent organic compounds (COPs) and contaminants of emerging concern (CECs). Therefore, this work aims to present the advances in remediation of PFASs-contaminated soil and water by addressing the current literature. The performance and characteristics of each technique were addressed deeply in this work. The reviewed literature found that PFASs elimination studies in soil and water were carried out at a laboratory and pilot-scale in some cases. It was found that ball milling, chemical oxidation and thermal desorption are the most efficient techniques for the removal of PFASs in soils, however, phyto-microbial remediation is under study, which claims to be a promising technique. For the remediation of PFASs-contaminated water, the processes of electrocoagulation, membrane filtration, ozofractionation, catalysis, oxidation reactions - reduction, thermolysis and destructive treatments with plasma have presented the best results. It is noteworthy that hybrid treatments have also proved to be efficient techniques in the removal of these contaminants from soil and water matrices. Therefore, the improvisation and implication of existing techniques on a field-scale are greatly warranted to corroborate the yields obtained on a pilot- and laboratory-scale.
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Affiliation(s)
- Angelo Noe Marquínez-Marquínez
- Departamento de Procesos Químicos, Facultad de Ciencias Matemáticas, Físicas y Químicas, Universidad Técnica de Manabí, Portoviejo, Ecuador; Laboratorio de Análisis Químicos y Biotecnológicos, Instituto de Investigación, Universidad Técnica de Manabí, S/N, Avenida Urbina y Che Guevara, Portoviejo, 130104, Ecuador.
| | - Nikolt Stephanie Loor-Molina
- Departamento de Procesos Químicos, Facultad de Ciencias Matemáticas, Físicas y Químicas, Universidad Técnica de Manabí, Portoviejo, Ecuador; Laboratorio de Análisis Químicos y Biotecnológicos, Instituto de Investigación, Universidad Técnica de Manabí, S/N, Avenida Urbina y Che Guevara, Portoviejo, 130104, Ecuador.
| | | | - Naga Raju Maddela
- Departamento de Ciencias Biológicas, Facultad de Ciencias de La Salud, Universidad Técnica de Manabí, Portoviejo, 130105, Ecuador.
| | - Rafael Luque
- Departamento de Química Orgánica, Universidad de Cordoba, Edificio Marie Curie (C-3), Ctra Nnal IV-A, Km 396, E14014, Cordoba, Spain; Universidad ECOTEC, Km. 13.5 Samborondón, Samborondón, EC092302, Ecuador
| | - Joan Manuel Rodríguez-Díaz
- Departamento de Procesos Químicos, Facultad de Ciencias Matemáticas, Físicas y Químicas, Universidad Técnica de Manabí, Portoviejo, Ecuador; Laboratorio de Análisis Químicos y Biotecnológicos, Instituto de Investigación, Universidad Técnica de Manabí, S/N, Avenida Urbina y Che Guevara, Portoviejo, 130104, Ecuador.
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Amador CK, Van Hoomissen DJ, Liu J, Strathmann TJ, Vyas S. Ultra-short chain fluorocarboxylates exhibit wide ranging reactivity with hydrated electrons. CHEMOSPHERE 2023; 311:136918. [PMID: 36306966 DOI: 10.1016/j.chemosphere.2022.136918] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 10/14/2022] [Accepted: 10/15/2022] [Indexed: 06/16/2023]
Abstract
Recent reports demonstrate that technologies generating hydrated electrons (eaq-; e.g., UV-sulfite) are a promising strategy for destruction of per- and polyfluoroalkyl substances, but fundamental rate constants are lacking. This work examines the kinetics and mechanisms of eaq- reactions with ultra-short chain (C2-C4) fluorocarboxylates using experimental and theoretical approaches. Laser flash photolysis (LFP) was used to measure bimolecular rate constants (k2; M-1 s-1) for eaq- reactions with thirteen per-, and for the first time, polyfluorinated carboxylate structures. The measured k2 values varied widely from 5.26 × 106 to 1.30 × 108 M-1s-1, a large range considering the minor structural changes among the target compounds. Molecular descriptors calculated using density functional theory did not reveal correlation between k2 values and individual descriptors when considering the whole dataset, however, semiquantitative correlation manifests when grouping by similar possible initial reduction event such as electron attachment at the α-carbon versus β- or γ-carbons along the backbone. From this, it is postulated that fluorocarboxylate reduction by eaq- occurs via divergent mechanisms with the possibility of non-degradative pathways being prominent. These mechanistic insights provide rationale for contradictory trends between LFP-derived k2 values and apparent degradation rates recently reported in UV-sulfite constant irradiation treatment experiments.
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Affiliation(s)
- Camille K Amador
- Department of Chemistry, Colorado School of Mines, Golden, CO, 80401, USA; Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO, 80401, USA
| | | | - Jiaoqin Liu
- Department of Chemistry, Colorado School of Mines, Golden, CO, 80401, USA; Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO, 80401, USA
| | - Timothy J Strathmann
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO, 80401, USA.
| | - Shubham Vyas
- Department of Chemistry, Colorado School of Mines, Golden, CO, 80401, USA.
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Jenness GR, Koval AM, Etz BD, Shukla MK. Atomistic insights into the hydrodefluorination of PFAS using silylium catalysts. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2022; 24:2085-2099. [PMID: 36165287 DOI: 10.1039/d2em00291d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Fluorochemicals are a persistent environmental contaminant that require specialized techniques for degradation and capture. In particular, recent attention on per- and poly-fluoroalkyl substances (PFAS) has led to numerous explorations of different techniques for degrading the super-strong C-F bonds found in these fluorochemicals. In this study, we investigated the hydrodefluorination mechanism using silylium-carborane salts for the degradation of PFAS at the density functional theory (DFT) level. We find that the degradation process involves both a cationic silylium (Et3Si+) and a hydridic silylium (Et3SiH) to facilitate the defluorination and hydride-addition events. Additionally, the role of carborane ([HCB11H5F6]-) is to force unoccupied anti-bonding orbitals to be partially occupied, weakening the C-F bond. We also show that changing the substituents on carborane from fluorine to other halogens weakens the C-F bond even further, with iodic carborane ([HCB11H5I6]-) having the greatest weakening effect. Moreover, our calculations reveal why the C-F bonds are resistant to degradation, and how the silylium-carborane chemistry is able to chemically transform these bonds into C-H bonds. We believe that our results are further applicable to other halocarbons, and can be used to treat either our existing stocks of these chemicals or to treat concentrated solutions following filtration and capture.
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Affiliation(s)
- Glen R Jenness
- Environmental Laboratory, US Army Engineer Research and Development Center, 3909 Halls Ferry Road, Vicksburg 39180, Mississippi, USA.
| | - Ashlyn M Koval
- Oak Ridge Institute for Science and Education (ORISE), 1299 Bethel Valley Rd, Oak Ridge 37830, Tennessee, USA
| | - Brian D Etz
- Oak Ridge Institute for Science and Education (ORISE), 1299 Bethel Valley Rd, Oak Ridge 37830, Tennessee, USA
| | - Manoj K Shukla
- Environmental Laboratory, US Army Engineer Research and Development Center, 3909 Halls Ferry Road, Vicksburg 39180, Mississippi, USA.
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Liu F, Guan X, Xiao F. Photodegradation of per- and polyfluoroalkyl substances in water: A review of fundamentals and applications. JOURNAL OF HAZARDOUS MATERIALS 2022; 439:129580. [PMID: 35905606 DOI: 10.1016/j.jhazmat.2022.129580] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 07/05/2022] [Accepted: 07/09/2022] [Indexed: 06/15/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are persistent, mobile, and toxic chemicals that are hazardous to human health and the environment. Several countries, including the United States, plan to set an enforceable maximum contamination level for certain PFAS compounds in drinking water sources. Among the available treatment options, photocatalytic treatment is promising for PFAS degradation and mineralization in the aqueous solution. In this review, recent advances in the abatement of PFAS from water using photo-oxidation and photo-reduction are systematically reviewed. Degradation mechanisms of PFAS by photo-oxidation involving the holes (hvb+) and oxidative radicals and photo-reduction using the electrons (ecb-) and hydrated electrons (eaq-) are integrated. The recent development of innovative heterogeneous photocatalysts and photolysis systems for enhanced degradation of PFAS is highlighted. Photodegradation mechanisms of alternative compounds, such as hexafluoropropylene oxide dimer acid (GenX) and chlorinated polyfluorinated ether sulfonate (F-53B), are also critically evaluated. This paper concludes by identifying major knowledge gaps and some of the challenges that lie ahead in the scalability and adaptability issues of photocatalysis for natural water treatment. Development made in photocatalysts design and system optimization forges a path toward sustainable treatment of PFAS-contaminated water through photodegradation technologies.
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Affiliation(s)
- Fuqiang Liu
- School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Xiaohong Guan
- School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China.
| | - Feng Xiao
- Department of Civil Engineering, University of North Dakota, 243 Centennial Drive Stop 8115, Grand Forks, ND 58202, United States.
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