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Xu D, Ding W, Gong X, Tan X, Li H, Li F, Zhang M, Huang Y, Su Y, Cheng HM. Graphene oxide with 1-nm-thick adlayer for efficient and near-instant removal of per- and polyfluoroalkyl substances. Natl Sci Rev 2025; 12:nwaf092. [PMID: 40196394 PMCID: PMC11974386 DOI: 10.1093/nsr/nwaf092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2025] [Revised: 02/25/2025] [Accepted: 03/06/2025] [Indexed: 04/09/2025] Open
Abstract
The environmental occurrence of anthropogenic chemicals-especially persistent micropollutants of per- and polyfluoroalkyl substances (PFAS)-raises pressing concerns for global drinking-water safety. Adsorption is an effective technology for removing PFAS but is limited by unsatisfactory adsorption capacity and efficiency. We report a strategy to attach polyamine adlayers to graphene oxide (GO) nanosheets that produces highly charged and monodispersed 2D adsorbents of a GO nanosheet sandwiched between two 1-nm-thick polyamine adlayers. This adsorbent has a high adsorption capacity for PFAS of ∼3070 mg/g-tens of times greater than that of GO and commercial activated carbon. It also provides almost instant adsorption of a variety of PFAS and reaches 57%-95% of its equilibrium capacity in a minute and removes ∼100% of PFAS from contaminated water sources within a few minutes, transforming real-life PFAS-contaminated water into safe drinking water. Experiment and theory show that the planar nature of the 2D adsorbent combined with its abundant surface adsorption sites that electrostatically attract the polar groups of the PFAS, and hydrogen bonding and hydrophobic-hydrophobic interactions with their non-polar groups, account for its ultra-high adsorption capacity and rapid removal efficiency. We also show that regeneration of the adsorbents removes the adsorbed PFAS and allows subsequent destruction, demonstrating a closed-loop treatment solution for micropollutant contamination.
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Affiliation(s)
- Dingxin Xu
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Wenhui Ding
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Xinyu Gong
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Xianjun Tan
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Hang Li
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Fei Li
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Mingrui Zhang
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Yuxiong Huang
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Yang Su
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Hui-Ming Cheng
- Shenzhen Key Laboratory of Energy Materials for Carbon Neutrality, Institute of Technology for Carbon Neutrality, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
- Faculty of Materials Science and Energy Engineering, Shenzhen Institute of Advanced Technology, Shenzhen 518055, China
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
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2
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Liu X, Shu Y, Pan Y, Zeng G, Zhang M, Zhu C, Xu Y, Wan A, Wang M, Han Q, Liu B, Wang Z. Electrochemical destruction of PFAS at low oxidation potential enabled by CeO 2 electrodes utilizing adsorption and activation strategies. JOURNAL OF HAZARDOUS MATERIALS 2025; 486:137043. [PMID: 39754874 DOI: 10.1016/j.jhazmat.2024.137043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2024] [Revised: 11/22/2024] [Accepted: 12/29/2024] [Indexed: 01/06/2025]
Abstract
The persistence and ecological impact of per- and poly-fluoroalkyl substances (PFAS) in water sources necessitate effective and energy-efficient treatment solutions. This study introduces a novel approach using cerium dioxide (CeO2) electrodes enhanced with oxygen vacancy (Ov) to catalyze the defluorination of PFAS. By leveraging the unique affinity between cerium and fluorine-containing species, our approach enables adsorptive preconcentration and catalytic degradation at low oxidation potentials (1.37 V vs. SHE). Demonstrating high removal and defluorination efficiencies of perfluorooctanoic acid (PFOA) at 94.0 % and 73.0 %, respectively, our approach also proves effective in the environmental matrix. It minimizes the impacts of co-existing natural organic matter and chloride ions, crucial benefits of operating at lower oxidation potentials. The role of Ov in CeO2 is validated by both experimental results and density functional theory modeling, demonstrating that these sites can activate the C-F bond and substantially reduce the energy barriers for defluorination. Consequently, our CeO2-based method not only achieves defluorination efficiencies comparable to more energy-intensive techniques but does so while requiring less than 0.62 kWh/m3 per order. This positions our approach as a promising, cost-effective alternative for the remediation of PFAS-contaminated waters, emphasizing its relevance and effectiveness in environmental remediation scenarios.
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Affiliation(s)
- Xun Liu
- School of Environment, Harbin Institute of Technology, Harbin 150086, PR China; School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China
| | - Yufei Shu
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China
| | - Yu Pan
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China
| | - Guoshen Zeng
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, PR China
| | - Meng Zhang
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China
| | - Chaoqun Zhu
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China
| | - Youmei Xu
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China
| | - Aling Wan
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China
| | - Mengxia Wang
- School of Environment, Harbin Institute of Technology, Harbin 150086, PR China; School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China
| | - Qi Han
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China
| | - Bei Liu
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China
| | - Zhongying Wang
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China; Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, Southern University of Science and Technology, Shenzhen 518055, PR China.
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3
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Liang Y, Wang A, Liang S, Sun K, Xie R, Zheng C, Zhang S, Tang C, Cheng D, Wang J, Huang Q, Lin H. Durable Ti 4O 7 Heterojunction Composite Membrane Encapsulating N-Doped Graphene Nanosheets for Efficient Electro-Oxidation of GenX and Other PFAS in Fluorochemical Wastewater. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2025; 59:4745-4755. [PMID: 40008448 DOI: 10.1021/acs.est.4c09423] [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: 02/27/2025]
Abstract
Rational interfacial engineering design of an electrocatalyst, such as a heterojunction structure, can effectively enhance its catalytic activity. This study aims to address a critical challenge associated with the use of carbon material@Ti4O7 heterojunction composite electrodes for wastewater treatment─electrode stability over long-term operation. Herein, we report a highly stabilized interfacial engineering strategy, i.e., the use of conductive inorganic CeO2 as a "cement" to firmly encapsulate N-doped graphene oxide nanosheets (N-GS) on the Ti4O7 surface. The defect-rich N-GS encapsulated on the Ti4O7 surface significantly enhances interfacial charge transfer. This enhancement results in the N-GS/CeO2@Ti4O7 heterojunction composite electrode exhibiting excellent efficiency in the electro-oxidation of hexafluoropropylene oxide dimer acid (HFPO-DA or GenX). Furthermore, a flow-through N-GS/CeO2@Ti4O7 reactive electrochemical membrane system effectively mineralizes other 35 PFASs in a real fluorochemical wastewater sample, achieving a high defluorination rate of 70-90% and exhibiting better performance in PFAS destruction and energy efficiency compared to the UV/KI-SO32- process. Results of this study enhance our understanding of the electrochemical oxidation of PFAS and offer valuable insight into the design of stabilized Ti4O7 heterojunction composites. These findings are instrumental in advancing the development of effective treatments for PFAS-contaminated environments.
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Affiliation(s)
- Yiyang Liang
- Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan 523808, PR China
- College of Eco-Environment and Architectural Engineering, Dongguan University of Technology, Dongguan 523808, PR China
| | - Anqi Wang
- Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan 523808, PR China
- College of Eco-Environment and Architectural Engineering, Dongguan University of Technology, Dongguan 523808, PR China
| | - Shangtao Liang
- College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences, University of Georgia, Griffin, Georgia 30223, United States
| | - Kai Sun
- College of Resources and Environment, Anhui Agricultural University, Hefei 230036, PR China
| | - Ruzhen Xie
- College of Architecture and Environment, Sichuan University, Chengdu 610065, PR China
| | - Chuanen Zheng
- Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan 523808, PR China
- College of Eco-Environment and Architectural Engineering, Dongguan University of Technology, Dongguan 523808, PR China
| | - Sihan Zhang
- College of Eco-Environment and Architectural Engineering, Dongguan University of Technology, Dongguan 523808, PR China
| | - Caiming Tang
- Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan 523808, PR China
- College of Eco-Environment and Architectural Engineering, Dongguan University of Technology, Dongguan 523808, PR China
| | - Dengmiao Cheng
- Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan 523808, PR China
- College of Eco-Environment and Architectural Engineering, Dongguan University of Technology, Dongguan 523808, PR China
| | - Jinxia Wang
- Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan 523808, PR China
- College of Eco-Environment and Architectural Engineering, Dongguan University of Technology, Dongguan 523808, PR China
| | - Qingguo Huang
- College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences, University of Georgia, Griffin, Georgia 30223, United States
| | - Hui Lin
- Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan 523808, PR China
- College of Eco-Environment and Architectural Engineering, Dongguan University of Technology, Dongguan 523808, PR China
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4
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Zeidabadi FA, Abbasi P, Esfahani EB, Mohseni M. Integrating kinetic modeling and experimental insights: PFAS electrochemical degradation in concentrated streams with a focus on organic and inorganic effects. JOURNAL OF HAZARDOUS MATERIALS 2025; 484:136624. [PMID: 39637779 DOI: 10.1016/j.jhazmat.2024.136624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2024] [Revised: 11/07/2024] [Accepted: 11/20/2024] [Indexed: 12/07/2024]
Abstract
This study investigated the impact of organic and inorganic constituents on electrochemical degradation of per- and poly-fluoroalkyl substances (PFAS) in a sulfate-based brine from regeneration of spent ion exchange (IX) resin. The system's performance was assessed in the presence of natural organic matter (NOM) and common inorganic constituents: chloride, nitrate, and bicarbonate. Results revealed distinct outcomes based on constituent type, concentration, and specific PFAS variant. NOM hindered PFAS decomposition, especially for more hydrophobic compounds. Chloride reduced degradation and defluorination efficiencies through competitive interactions with PFAS for the anode's active sites and scavenging effects on SO4•- and •OH. Nitrate and bicarbonate minimally impacted degradation but significantly reduced defluorination. Investigating the electrochemical process in real brine solutions showed higher efficiency and lower electrical energy consumption when methanol was distilled, as methanol scavenges reactive radicals and competes for active anode sites. A kinetic model was also developed to determine the direct electron transfer (DET) and mass transfer coefficients for the species present, considering both surface and bulk solution interactions. The model predicted mass transfer (mol m-2 s-1) and DET (m2 mol-1 s-1) coefficients of 6:2 FTCA, PFOA, GenX, and PFBA to be (5.0 ×10-10, 3.7 ×1011), (1.0 ×10-9, 8.0 ×108), (6.0 ×10-8, 7.5 ×108), and (6.2 ×10-8, 4.2 ×108), respectively.
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Affiliation(s)
- Fatemeh Asadi Zeidabadi
- Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, Canada
| | - Pezhman Abbasi
- Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, Canada
| | - Ehsan Banayan Esfahani
- Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, Canada
| | - Madjid Mohseni
- Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, Canada.
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5
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Sabba F, Kassar C, Zeng T, Mallick SP, Downing L, McNamara P. PFAS in landfill leachate: Practical considerations for treatment and characterization. JOURNAL OF HAZARDOUS MATERIALS 2025; 481:136685. [PMID: 39674787 DOI: 10.1016/j.jhazmat.2024.136685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2024] [Revised: 11/22/2024] [Accepted: 11/25/2024] [Indexed: 12/16/2024]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are widely used in consumer products and are particularly high in landfill leachate. The practice of sending leachate to wastewater treatment plants (WWTPs) is an issue for utilities that have biosolids land application limits based on PFAS concentrations. Moreover, landfills may face their own effluent limit guidelines for PFAS. The purpose of this review is to understand the most appropriate treatment technology combinations for mitigating PFAS in landfill leachate. The first objective is to understand the unique chemical characteristics of landfill leachate. The second objective is to establish the role and importance of known and emerging analytical techniques for PFAS characterization in leachate, including quantification of precursor compounds. Next, an overview of technologies that concentrate PFAS and technologies that destroy PFAS is provided, including fundamental background content and key operating parameters. Finally, practical considerations for PFAS treatment technologies are reviewed, and recommendations for PFAS treatment trains are described. Both pros and cons of treatment trains are noted. In summary, the complex matrix of leachate requires a separation treatment step first, such as foam fractionation, for example, to concentrate the PFAS into a lower-volume stream. Then, a degradation treatment step can be applied to the concentrated PFAS stream.
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Affiliation(s)
- Fabrizio Sabba
- Black & Veatch, 11401 Lamar Ave, Overland Park, KS 66211, United States; Department of Civil and Environmental Engineering, Syracuse University, Syracuse, NY 13244, United States.
| | - Christian Kassar
- Black & Veatch, 11401 Lamar Ave, Overland Park, KS 66211, United States
| | - Teng Zeng
- Department of Civil and Environmental Engineering, Syracuse University, Syracuse, NY 13244, United States
| | - Synthia P Mallick
- Black & Veatch, 11401 Lamar Ave, Overland Park, KS 66211, United States
| | - Leon Downing
- Black & Veatch, 11401 Lamar Ave, Overland Park, KS 66211, United States
| | - Patrick McNamara
- Black & Veatch, 11401 Lamar Ave, Overland Park, KS 66211, United States; Department of Civil, Construction, and Environmental Engineering, Marquette University, Milwaukee, WI 53233, United States
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6
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Dong F, Zhu J, Lou J, Chen Z, He Z, Song S, Zhu L, Crittenden JC. Unveiling the Mechanism and Kinetics of Pollutant Attenuation by Free Radicals Triggered from Goethite in Water Distribution Systems. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:12664-12673. [PMID: 38953777 DOI: 10.1021/acs.est.4c04022] [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: 07/04/2024]
Abstract
Investigating the fate of persistent organic pollutants in water distribution systems (WDSs) is of great significance for preventing human health risks. The role of iron corrosion scales in the migration and transformation of organics in such systems remains unclear. Herein, we determined that hydroxyl (•OH), chlorine, and chlorine oxide radicals are generated by Fenton-like reactions due to the coexistence of oxygen vacancy-related Fe(II) on goethite (a major constituent of iron corrosion scales) and hypochlorous acid (HClO, the main reactive chlorine species of residual chlorine at pH ∼ 7.0). •OH contributed mostly to the decomposition of atrazine (ATZ, model compound) more than other radicals, producing a series of relatively low-toxicity small molecular intermediates. A simplified kinetic model consisting of mass transfer of ATZ and HClO, •OH generation, and ATZ oxidation by •OH on the goethite surface was developed to simulate iron corrosion scale-triggered residual chlorine oxidation of organic compounds in a WDS. The model was validated by comparing the fitting results to the experimental data. Moreover, the model was comprehensively applicable to cases in which various inorganic ions (Ca2+, Na+, HCO3-, and SO42-) and natural organic matter were present. With further optimization, the model may be employed to predict the migration and accumulation of persistent organic pollutants under real environmental conditions in the WDSs.
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Affiliation(s)
- Feilong Dong
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, Peoples Republic of China
| | - Jiani Zhu
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, Peoples Republic of China
| | - Jinxiu Lou
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, Peoples Republic of China
| | - Zefang Chen
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Zhiqiao He
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, Peoples Republic of China
| | - Shuang Song
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, Peoples Republic of China
| | - Lizhong Zhu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, Peoples Republic of China
| | - John C Crittenden
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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Calvillo Solís JJ, Sandoval-Pauker C, Bai D, Yin S, Senftle TP, Villagrán D. Electrochemical Reduction of Perfluorooctanoic Acid (PFOA): An Experimental and Theoretical Approach. J Am Chem Soc 2024; 146:10687-10698. [PMID: 38578843 DOI: 10.1021/jacs.4c00443] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2024]
Abstract
Perfluorooctanoic acid (PFOA) is an artificial chemical of global concern due to its high environmental persistence and potential human health risk. Electrochemical methods are promising technologies for water treatment because they are efficient, cheap, and scalable. The electrochemical reduction of PFOA is one of the current methodologies. This process leads to defluorination of the carbon chain to hydrogenated products. Here, we describe a mechanistic study of the electrochemical reduction of PFOA in gold electrodes. By using linear sweep voltammetry (LSV), an E0' of -1.80 V vs Ag/AgCl was estimated. Using a scan rate diagnosis, we determined an electron-transfer coefficient (αexp) of 0.37, corresponding to a concerted mechanism. The strong adsorption of PFOA into the gold surface is confirmed by the Langmuir-like isotherm in the absence (KA = 1.89 × 1012 cm3 mol-1) and presence of a negative potential (KA = 3.94 × 107 cm3 mol-1, at -1.40 V vs Ag/AgCl). Based on Marcus-Hush's theory, calculations show a solvent reorganization energy (λ0) of 0.9 eV, suggesting a large electrostatic repulsion between the perfluorinated chain and water. The estimated free energy of the transition state of the electron transfer (ΔG‡ = 2.42 eV) suggests that it is thermodynamically the reaction-limiting step. 19F - 1H NMR, UV-vis, and mass spectrometry studies confirm the displacement of fluorine atoms by hydrogen. Density functional theory (DFT) calculations also support the concerted mechanism for the reductive defluorination of PFOA, in agreement with the experimental values.
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Affiliation(s)
- Jonathan J Calvillo Solís
- Department of Chemistry and Biochemistry, The University of Texas at El Paso, El Paso, Texas 79968, United States
- Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment (NEWT), El Paso, Texas 79968, United States
| | - Christian Sandoval-Pauker
- Department of Chemistry and Biochemistry, The University of Texas at El Paso, El Paso, Texas 79968, United States
- Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment (NEWT), El Paso, Texas 79968, United States
| | - David Bai
- Department of Chemistry and Biochemistry, The University of Texas at El Paso, El Paso, Texas 79968, United States
- Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment (NEWT), El Paso, Texas 79968, United States
| | - Sheng Yin
- Department of Chemistry and Biochemistry, The University of Texas at El Paso, El Paso, Texas 79968, United States
- Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment (NEWT), El Paso, Texas 79968, United States
| | - Thomas P Senftle
- Department of Chemical and Biomolecular Engineering, Rice University, 6100 Main Street, Houston, Texas 770052, United States
- Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment (NEWT), El Paso, Texas 79968, United States
| | - Dino Villagrán
- Department of Chemistry and Biochemistry, The University of Texas at El Paso, El Paso, Texas 79968, United States
- Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment (NEWT), El Paso, Texas 79968, United States
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8
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Teng X, Qi Y, Guo R, Zhang S, Wei J, Ajarem JS, Maodaa S, Allam AA, Wang Z, Qu R. Enhanced electrochemical degradation of perfluorooctanoic acid by ligand-bridged Pt II at Pt anodes. JOURNAL OF HAZARDOUS MATERIALS 2024; 464:133008. [PMID: 37984143 DOI: 10.1016/j.jhazmat.2023.133008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 11/01/2023] [Accepted: 11/12/2023] [Indexed: 11/22/2023]
Abstract
A new mechanism for the electro-oxidation (EO) degradation of perfluorooctanoic acid (PFOA) by Pt anode was reported. Using bridge-based ligand anions (SCN-, Cl- and N3-) as electrolytes, the degradation effect of PFOA by Pt-EO system was significant. Characterization of the Pt anode, the detection and addition of dissolved platinum ions, and the comparison of Pt with DSA anodes determined that the Pt- ligand complexes resulting from the specific binding of anodically dissolved PtII with ligand ions and C7F15COO- ((C7F15-COO)PtII-L3, L = SCN-, Cl- and N3-) on the electrode surface played a decisive role in the degradation of PFOA. Density functional theory (DFT) calculations showed that inside (C7F15-COO)PtII-L3 complexes, the electron density of the perfluorocarbon chain (including the F atom) compensated toward the carboxyl group and electrons in the PFOA ion transferred to the PtII-Cl3. Moreover, the (C7F15-COO)PtII-Cl3, as a whole, was calculated to migrate electrons toward the Pt anode, leading to the formation of PFOA radical (C7F15-COO•). Finally, with the detection of a series of short chain homologues, the CF2-unzipping degradation pathway of PFOA was proposed. The newly developed Pt-EO system is not affected by water quality conditions and can directly degrade alcohol eluent of PFOA, which has great potential for treating industrial wastewater contaminated with PFOA.
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Affiliation(s)
- Xiaolei Teng
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Yumeng Qi
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Ruixue Guo
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Shengnan Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Junyan Wei
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Jamaan S Ajarem
- Department of Zoology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Saleh Maodaa
- Department of Zoology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Ahmed A Allam
- Department of Zoology, Faculty of Science, Beni-suef University, Beni-suef 65211, Egypt
| | - Zunyao Wang
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Ruijuan Qu
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
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9
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Ling C, Li M, Li H, Liu X, Zhan G, Sun H, Liang C, Li Y, Zhou B, Zhao J, Zhang L. Symmetry dependent activation and reactivity of peroxysulfates on FeS 2(001) surface. Sci Bull (Beijing) 2024; 69:154-158. [PMID: 37957067 DOI: 10.1016/j.scib.2023.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 08/19/2023] [Accepted: 10/23/2023] [Indexed: 11/15/2023]
Affiliation(s)
- Cancan Ling
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China; Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, Central China Normal University, Wuhan 430079, China
| | - Meiqi Li
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, Central China Normal University, Wuhan 430079, China
| | - Hao Li
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
| | - Xiufan Liu
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, Central China Normal University, Wuhan 430079, China
| | - Guangming Zhan
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China; Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, Central China Normal University, Wuhan 430079, China
| | - Hongwei Sun
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, Central China Normal University, Wuhan 430079, China
| | - Chuan Liang
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, Central China Normal University, Wuhan 430079, China
| | - Yaling Li
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, Central China Normal University, Wuhan 430079, China
| | - Bing Zhou
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, Central China Normal University, Wuhan 430079, China
| | - Jincai Zhao
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, Central China Normal University, Wuhan 430079, China
| | - Lizhi Zhang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China; Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, Central China Normal University, Wuhan 430079, China.
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Xin X, Kim J, Ashley DC, Huang CH. Degradation and Defluorination of Per- and Polyfluoroalkyl Substances by Direct Photolysis at 222 nm. ACS ES&T WATER 2023; 3:2776-2785. [PMID: 37588805 PMCID: PMC10425954 DOI: 10.1021/acsestwater.3c00274] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 06/15/2023] [Accepted: 06/20/2023] [Indexed: 08/18/2023]
Abstract
The susceptibility of 19 representative per- and polyfluoroalkyl substances (PFAS) to direct photolysis and defluorination under far-UVC 222 nm irradiation was investigated. Enhanced photolysis occurred for perfluorocarboxylic acids (PFCAs), fluorotelomer unsaturated carboxylic acids (FTUCAs), and GenX, compared to that at conventional 254 nm irradiation on a similar fluence basis, while other PFAS showed minimal decay. For degradable PFAS, up to 81% of parent compound decay (photolysis rate constant (k222 nm) = 8.19-34.76 L·Einstein-1; quantum yield (Φ222 nm) = 0.031-0.158) and up to 31% of defluorination were achieved within 4 h, and the major transformation products were shorter-chain PFCAs. Solution pH, dissolved oxygen, carbonate, phosphate, chloride, and humic acids had mild impacts, while nitrate significantly affected PFAS photolysis/defluorination at 222 nm. Decarboxylation is a crucial step of photolytic decay. The slower degradation of short-chain PFCAs than long-chain ones is related to molar absorptivity and may also be influenced by chain-length dependent structural factors, such as differences in pKa, conformation, and perfluoroalkyl radical stability. Meanwhile, theoretical calculations indicated that the widely proposed HF elimination from the alcohol intermediate (CnF2n+1OH) of PFCA is an unlikely degradation pathway due to high activation barriers. These new findings are useful for further development of far-UVC technology for PFAS in water treatment.
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Affiliation(s)
- Xiaoyue Xin
- School
of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Juhee Kim
- School
of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Daniel C. Ashley
- Department
of Chemistry and Biochemistry, Spelman College, Atlanta, Georgia 30314, United States
| | - Ching-Hua Huang
- School
of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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Ma Q, Gao J, Moussa B, Young J, Zhao M, Zhang W. Electrosorption, Desorption, and Oxidation of Perfluoroalkyl Carboxylic Acids (PFCAs) via MXene-Based Electrocatalytic Membranes. ACS APPLIED MATERIALS & INTERFACES 2023. [PMID: 37294711 DOI: 10.1021/acsami.3c03991] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
MXenes exhibit excellent conductivity, tunable surface chemistry, and high surface area. Particularly, the surface reactivity of MXenes strongly depends on surface exposed atoms or terminated groups. This study examines three types of MXenes with oxygen, fluorine, and chlorine as respective terminal atoms and evaluates their electrosorption, desorption, and oxidative properties. Two perfluorocarboxylic acids (PFCAs), perfluorobutanoic acid (PFBA) and perfluorooctanoic acid (PFOA) are used as model persistent micropollutants for the tests. The experimental results reveal that O-terminated MXene achieves a significantly higher adsorption capacity of 215.9 mg·g-1 and an oxidation rate constant of 3.9 × 10-2 min-1 for PFOA compared to those with F and Cl terminations. Electrochemical oxidation of the two PFCAs (1 ppm) with an applied potential of +6 V in a 0.1 M Na2SO4 solution yields >99% removal in 3 h. Moreover, PFOA degrades about 20% faster than PFBA on O-terminated MXene. The density functional theory (DFT) calculations reveal that the O-terminated MXene surface yielded the highest PFOA and PFBA adsorption energy and the most favorable degradation pathway, suggesting the high potential of MXenes as highly reactive and adsorptive electrocatalysts for environmental remediation.
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Affiliation(s)
- Qingquan Ma
- Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102, United States
| | - Jianan Gao
- Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102, United States
| | - Botamina Moussa
- Department of Chemical & Materials Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102, United States
| | - Joshua Young
- Department of Chemical & Materials Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102, United States
| | - Mengqiang Zhao
- Department of Chemical & Materials Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102, United States
| | - Wen Zhang
- Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102, United States
- Department of Chemical & Materials Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102, United States
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