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Antonopoulou M, Spyrou A, Tzamaria A, Efthimiou I, Triantafyllidis V. Current state of knowledge of environmental occurrence, toxic effects, and advanced treatment of PFOS and PFOA. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 913:169332. [PMID: 38123090 DOI: 10.1016/j.scitotenv.2023.169332] [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: 09/23/2023] [Revised: 12/11/2023] [Accepted: 12/11/2023] [Indexed: 12/23/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are anthropogenic synthetic compounds, with high chemical and thermal stability and a persistent, stable and bioaccumulative nature that renders them a potential hazard for the environment, its organisms, and humans alike. Perfluorooctane sulfonic acid (PFOS) and Perfluorooctanoic acid (PFOA) are the most well-known substances of this category and even though they are phased out from production they are still highly detectable in several environmental matrices. As a result, they have been spread globally in water sources, soil and biota exerting toxic and detrimental effects. Therefore, up and coming technologies, namely advanced oxidation processes (AOPs) and advanced reduction processes (ARPs) are being tested for their implementation in the degradation of these pollutants. Thus, the present review compiles the current knowledge on the occurrence of PFOS and PFOA in the environment, the various toxic effects they have induced in different organisms as well as the ability of AOPs and ARPs to diminish and/or eliminate them from the environment.
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Affiliation(s)
- Maria Antonopoulou
- Department of Sustainable Agriculture, University of Patras, 30131 Agrinio, Greece.
| | - Alexandra Spyrou
- Department of Sustainable Agriculture, University of Patras, 30131 Agrinio, Greece
| | - Anna Tzamaria
- Department of Sustainable Agriculture, University of Patras, 30131 Agrinio, Greece
| | - Ioanna Efthimiou
- Department of Biology, Section of Genetics Cell Biology and Development, University of Patras, 26500 Patras, Greece
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Zheng J, Zhang S. Subnanoscale spatially confined heterogeneous Fenton reaction enables mineralization of perfluorooctanoic acid. WATER RESEARCH 2023; 246:120696. [PMID: 37806126 DOI: 10.1016/j.watres.2023.120696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 08/22/2023] [Accepted: 10/03/2023] [Indexed: 10/10/2023]
Abstract
Superoxide radical (•O2-) is capable of degrading perfluorinated compounds that are persistent in nature and cannot be removed by biological or advanced oxidation treatments, but the inherent drawback is the negligible reactivity of •O2-in aqueous phases due to the hydration effect. Here, we explored an innovative way to make use of •O2- by modulating a partial hydration state through spatial confinement control. We demonstrated this idea by conducting heterogeneous Fenton reaction with layered iron oxychloride (FeOCl) catalyst, wherein •O2-radicals produced and confined within the catalyst structure (interlayer spacing of 7.92 Å) showed defluorination effect dealing with perfluorooctanoic acid (PFOA) as model compound. The defluorination combined with advanced oxidation achieved mineralization. Mechanism study revealed that the confinement frustrated the hydration shell of •O2-with coordination number reduced from 3.3 (for bulk phase) to 1.89, and thereby changed its orbital electron properties and enhanced the nucleophilic ability. We further demonstrated a compact FeOCl membrane reactor with highly efficient degradation of PFOA (kobs up to 1.2 min-1) and cost-effective mineralization (2 × 10-6 $ per mgC), operated under ultrafiltration reaction mode. Our findings highlight the great interest of developing spatial confinement technology to modulate •O2--based reactions, as well as the feasibility of combining confinement catalyst structures with heterogeneous Fenton reaction to achieve the mineralization treatment goal.
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Affiliation(s)
- Jianfeng Zheng
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin, 300384 PR China
| | - Shuo Zhang
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tongyan Road 38, Tianjin, 300350 PR China.
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3
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Liang J, Guo L, Xiang B, Wang X, Tang J, Liu Y. Research Updates on the Mechanism and Influencing Factors of the Photocatalytic Degradation of Perfluorooctanoic Acid (PFOA) in Water Environments. Molecules 2023; 28:molecules28114489. [PMID: 37298966 DOI: 10.3390/molecules28114489] [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: 03/30/2023] [Revised: 05/27/2023] [Accepted: 05/29/2023] [Indexed: 06/12/2023] Open
Abstract
Perfluorooctanoic acid is ubiquitous in water bodies and is detrimental to the health of organisms. Effectively removing perfluorooctanoic acid (PFOA), a persistent organic pollutant, has been a hot topic around the world. With traditional physical, chemical, and biological methods, it is difficult to effectively and completely remove PFOA, the costs are high, and it is easy to cause secondary pollution. There are difficulties in applying some technologies. Therefore, more efficient and green degradation technologies have been sought. Photochemical degradation has been shown to be a low-cost, efficient, and sustainable technique for PFOA removal from water. Photocatalytic degradation technology offers great potential and prospects for the efficient degradation of PFOA. Most studies on PFOA have been conducted under ideal laboratory conditions at concentrations that are higher than those detected in real wastewater. This paper summarizes the research status of the photo-oxidative degradation of PFOA, and it summarizes the mechanism and kinetics of PFOA degradation in different systems, as well as the influence of key factors on the photo-oxidative degradation and defluoridation process, such as system pH, photocatalyst concentration, etc. PFOA photodegradation technology's existing problems and future work directions are also presented. This review provides a useful reference for future research on PFOA pollution control technology.
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Affiliation(s)
- Jie Liang
- School of Environmental Science and Engineering, Liaoning Technical University, 47 Zhonghua Road, Xihe District, Fuxin 123000, China
| | - Lingling Guo
- Microbial Research Institute of Liaoning Province, Chaoyang 122000, China
| | - Biao Xiang
- School of Environmental Science and Engineering, Liaoning Technical University, 47 Zhonghua Road, Xihe District, Fuxin 123000, China
| | - Xueyi Wang
- School of Environmental Science and Engineering, Liaoning Technical University, 47 Zhonghua Road, Xihe District, Fuxin 123000, China
| | - Jiaxi Tang
- School of Environmental Science and Engineering, Liaoning Technical University, 47 Zhonghua Road, Xihe District, Fuxin 123000, China
| | - Yue Liu
- School of Environmental Science and Engineering, Liaoning Technical University, 47 Zhonghua Road, Xihe District, Fuxin 123000, China
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Luo Y, Khoshyan A, Al Amin M, Nolan A, Robinson F, Fenstermacher J, Niu J, Megharaj M, Naidu R, Fang C. Ultrasound-enhanced Magnéli phase Ti 4O 7 anodic oxidation of per- and polyfluoroalkyl substances (PFAS) towards remediation of aqueous film forming foams (AFFF). THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 862:160836. [PMID: 36521599 DOI: 10.1016/j.scitotenv.2022.160836] [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: 09/21/2022] [Revised: 12/05/2022] [Accepted: 12/06/2022] [Indexed: 06/17/2023]
Abstract
Per-and polyfluoroalkyl substances (PFAS) remediation is still a challenge. In this study, we propose a hybrid system that combines electrochemical treatment with ultrasound irradiation, aiming for an enhanced degradation of PFAS. Equipped with a titanium suboxide (Ti4O7) anode, the electrochemical cell is able to remove perfluorooctanoic acid (PFOA) effectively. Under the optimal conditions (50 mA/cm2 current density, 0.15 M Na2SO4 supporting electrolyte, and stainless steel/Ti4O7/stainless steel electrode configuration with a gap of ∼10 mm), the electrochemical process achieves ∼100 % PFOA removal and 43 % defluorination after 6 h. Applying ultrasound irradiation (130 kHz) alone offers a limited PFOA removal, with 33 % PFOA removal and 5.5 % defluorination. When the electrochemical process is combined with ultrasound irradiation, we observe a significant improvement in the remediation performance, with ∼100 % PFOA removal and 63.5 % defluorination, higher than the sum of 48.5 % (43 % achieved by the electrochemical process, plus 5.5 % by the ultrasound irradiation), implying synergistic removal/oxidation effects. The hybrid system also consistently shows the synergistic defluorination during degradation of other PFAS and the PFAS constituents in aqueous film forming foam (AFFF). We attribute the synergistic effect to an activated/cleaned electrode surface, improved mass transfer, and enhanced production of radicals.
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Affiliation(s)
- Yunlong Luo
- Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, Callaghan, NSW 2308, Australia
| | - Ashkan Khoshyan
- Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan, NSW 2308, Australia
| | - Md Al Amin
- Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan, NSW 2308, Australia
| | - Annette Nolan
- Ramboll Australia, The Junction, NSW 2291, Australia
| | | | | | - Junfeng Niu
- Suzhou institute of North China Electric Power University, Jiangsu 215000, PR China
| | - Mallavarapu Megharaj
- Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, Callaghan, NSW 2308, Australia
| | - Ravi Naidu
- Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, Callaghan, NSW 2308, Australia
| | - Cheng Fang
- Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, Callaghan, NSW 2308, Australia.
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Zhang D, Li Y, Dong L, Chen X, Guan Y, Liu W, Wang Z. Efficient degradation of PFOA in water by persulfate-assisted and UV-activated electrocoagulation technique using Fe foam electrode. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2022.141296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Dickman RA, Aga DS. A review of recent studies on toxicity, sequestration, and degradation of per- and polyfluoroalkyl substances (PFAS). JOURNAL OF HAZARDOUS MATERIALS 2022; 436:129120. [PMID: 35643010 DOI: 10.1016/j.jhazmat.2022.129120] [Citation(s) in RCA: 59] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 05/04/2022] [Accepted: 05/07/2022] [Indexed: 05/27/2023]
Abstract
The fate, effects, and treatment of per- and polyfluoroalkyl substances (PFAS), an anthropogenic class of chemicals used in industrial and commercial production, are topics of great interest in recent research and news cycles. This interest stems from the ubiquity of PFAS in the global environment as well as their significant toxicological effects in humans and wildlife. Research on toxicity, sequestration, removal, and degradation of PFAS has grown rapidly, leading to a flood of valuable knowledge that can get swamped out in the perpetual rise in the number of publications. Selected papers from the Journal of Hazardous Materials between January 2018 and May 2022 on the toxicity, sequestration, and degradation of PFAS are reviewed in this article and made available as open-access publications for one year, in order to facilitate the distribution of critical knowledge surrounding PFAS. This review discusses routes of toxicity as observed in mammalian and cellular models, and the observed human health effects in exposed communities. Studies that evaluate of toxicity through in-silico approaches are highlighted in this paper. Removal of PFAS through modified carbon sorbents, nanoparticles, and anion exchange materials are discussed while comparing treatment efficiencies for different classes of PFAS. Finally, various biotic and abiotic degradation techniques, and the pathways and mechanisms involved are reviewed to provide a better understanding on the removal efficiencies and cost effectiveness of existing treatment strategies.
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Affiliation(s)
- Rebecca A Dickman
- Department of Chemistry, The State University of New York at Buffalo, Buffalo, NY 14260, United States
| | - Diana S Aga
- Department of Chemistry, The State University of New York at Buffalo, Buffalo, NY 14260, United States.
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7
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Performance Optimization and Toxicity Effects of the Electrochemical Oxidation of Octogen. Catalysts 2022. [DOI: 10.3390/catal12080815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Octogen (HMX) is widely used as a high explosive and constituent in plastic explosives, nuclear devices, and rocket fuel. The direct discharge of wastewater generated during HMX production threatens the environment. In this study, we used the electrochemical oxidation (EO) method with a PbO2-based anode to treat HMX wastewater and investigated its degradation performance, mechanism, and toxicity evolution under different conditions. The results showed that HMX treated by EO could achieve a removal efficiency of 81.2% within 180 min at a current density of 70 mA/cm2, Na2SO4 concentration of 0.25 mol/L, interelectrode distance of 1.0 cm, and pH of 5.0. The degradation followed pseudo-first-order kinetics (R2 > 0.93). The degradation pathways of HMX in the EO system have been proposed, including cathode reduction and indirect oxidation by •OH radicals. The molecular toxicity level (expressed as the transcriptional effect level index) of HMX wastewater first increased to 1.81 and then decreased to a non-toxic level during the degradation process. Protein and oxidative stress were the dominant stress categories, possibly because of the intermediates that evolved during HMX degradation. This study provides new insights into the electrochemical degradation mechanisms and molecular-level toxicity evolution during HMX degradation. It also serves as initial evidence for the potential of the EO-enabled method as an alternative for explosive wastewater treatment with high removal performance, low cost, and low environmental impact.
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Chen Y, Ma H, Zhu J, Gu Y, Liu T. New insights into ferric iron-facilitated UV 254 photolytic defluorination of perfluorooctanoic acid (PFOA): Combined experimental and theoretical study. JOURNAL OF HAZARDOUS MATERIALS 2022; 434:128865. [PMID: 35405606 DOI: 10.1016/j.jhazmat.2022.128865] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 03/14/2022] [Accepted: 04/02/2022] [Indexed: 06/14/2023]
Abstract
UV/Fe3+-facilitated PFOA defluorination was often reported and recognized to proceed through a "ligand-to-metal charge transfer (LMCT)" mechanism in the literatures. Sufficient Fe3+ supply is important for sustaining the LMCT reaction pathway. In this study, an interesting "excessive defluorination" was observed, even the continuous Fe3+ supply was cut off, implying a parallel mechanism strengthening PFOA defluorination. Based the results of intermediate products detection, 19F NMR analysis, and exploration of electron density alternation, transition energy evolution, and bonds characteristics, remarkable electron density perturbation in [PFOA-Fe]2+ was revealed. This effect was triggered by the complexation between PFOA anion and Fe3+, diminishing electron shielding on the perfluorinated carbon chain. Hence, the dissociation energy of C-C bonds was reduced by maximally 53% (C4-C5). Once attacked by high-flux UV254 photons, the perfluorinated carbon chain underwent scission, and subsequent defluorination was achieved via hydrolysis reactions. This parallel mechanism cooperated with the LMCT mechanism, leading to the observed "excessive defluorination." The degree of UV/Fe3+-synergized PFOA defluorination depended on UV254 photon flux and Fe3+ dosage. High UV254 intensity guaranteed fast defluorination kinetics. A [Fe3+]/[PFOA] molar ratio near 1 showed the best UV/Fe3+ synergic effect on PFOA defluorination.
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Affiliation(s)
- Yihua Chen
- Harbin Institute of Technology (Shenzhen), Shenzhen 518055, PR China
| | - Hang Ma
- Harbin Institute of Technology (Shenzhen), Shenzhen 518055, PR China
| | - Jiaxin Zhu
- Harbin Institute of Technology (Shenzhen), Shenzhen 518055, PR China
| | - Yurong Gu
- Shenzhen Polytechnic, Shenzhen 518055, PR China
| | - Tongzhou Liu
- Harbin Institute of Technology (Shenzhen), Shenzhen 518055, PR China.
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Leung SCE, Shukla P, Chen D, Eftekhari E, An H, Zare F, Ghasemi N, Zhang D, Nguyen NT, Li Q. Emerging technologies for PFOS/PFOA degradation and removal: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 827:153669. [PMID: 35217058 DOI: 10.1016/j.scitotenv.2022.153669] [Citation(s) in RCA: 58] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 01/31/2022] [Accepted: 01/31/2022] [Indexed: 05/20/2023]
Abstract
Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are highly recalcitrant anthropogenic chemicals that are ubiquitously present in the environment and are harmful to humans. Typical water and wastewater treatment processes (coagulation, flocculation, sedimentation, and filtration) are proven to be largely ineffective, while adsorption with granular activated carbon (GAC) has been the chief option to capture them from aqueous sources followed by incineration. However, this process is time-consuming, and produces additional solid waste and air pollution. Treatment methods for PFOS and PFOA generally follow two routes: (1) removal from source and reduce the risk; (2) degradation. Emerging technologies focusing on degradation are critically reviewed in this contribution. Various processes such as bioremediation, electrocoagulation, foam fractionation, sonolysis, photocatalysis, mechanochemical, electrochemical degradation, beams of electron and plasma have been developed and studied in the past decade to address PFAS crisis. The underlying mechanisms of these PFAS degradation methods have been categorized. Two main challenges have been identified, namely complexity in large scale operation and the release of toxic byproducts. Based on the literature survey, we have provided a strength-weakness-opportunity-threat (SWOT) analysis and quantitative rating on their efficiency, environmental impact and technology readiness.
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Affiliation(s)
- Shui Cheung Edgar Leung
- Queensland Micro- and Nanotechnology Centre, Griffith University, Brisbane, QLD 4111, Australia; School of Engineering and Built Environment, Griffith University, Brisbane, QLD 4111, Australia
| | - Pradeep Shukla
- Queensland Alliance for Environmental Health Sciences, Department of Chemical Engineering, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Dechao Chen
- Queensland Micro- and Nanotechnology Centre, Griffith University, Brisbane, QLD 4111, Australia
| | - Ehsan Eftekhari
- School of Engineering and Built Environment, Griffith University, Brisbane, QLD 4111, Australia; Golder Associates Pty Ltd, Level 4, 45 Francis Street, Northbridge, Western Australia 6003, Australia
| | - Hongjie An
- Queensland Micro- and Nanotechnology Centre, Griffith University, Brisbane, QLD 4111, Australia
| | - Firuz Zare
- School of Electrical Engineering and Robotics, Faculty of Engineering, Queensland University of Technology, Garden Point, QLD 4000, Australia
| | - Negareh Ghasemi
- School of Information Technology and Electrical Engineering, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Dongke Zhang
- Centre for Energy (M473), The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Nam-Trung Nguyen
- Queensland Micro- and Nanotechnology Centre, Griffith University, Brisbane, QLD 4111, Australia
| | - Qin Li
- Queensland Micro- and Nanotechnology Centre, Griffith University, Brisbane, QLD 4111, Australia; School of Engineering and Built Environment, Griffith University, Brisbane, QLD 4111, Australia.
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10
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Ma Q, Yan C, Lv W, Mei Y, Peng H, Du J, Zheng B, Guo Y. Coexisting Chloride Ion for Boosting the Photoelectrocatalytic Degradation Efficiency of Organic Dyes. Catal Letters 2022. [DOI: 10.1007/s10562-022-03978-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
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11
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Yang JS, Lai WWP, Lin AYC. New insight into PFOS transformation pathways and the associated competitive inhibition with other perfluoroalkyl acids via photoelectrochemical processes using GOTiO 2 film photoelectrodes. WATER RESEARCH 2021; 207:117805. [PMID: 34736002 DOI: 10.1016/j.watres.2021.117805] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 10/18/2021] [Accepted: 10/21/2021] [Indexed: 06/13/2023]
Abstract
The global distribution and environmental persistence of perfluoroalkyl acids (PFAAs) has been considered a critical environmental concern. In this work, we successfully fabricated a graphene oxide-titanium dioxide (GOTiO2) photoelectrode for perfluorooctane sulfonate (PFOS) degradation in a photoelectrochemical (PEC) system. The results reveal that a 5 wt.% GOTiO2 anode possesses the optimal PEC performance, with a band gap (Eg) of 2.42 eV, specific surface area (SBET) of 72.6 m2 g-1 and specific capacitance (Cs) of 4.63 mF cm-2. In the PEC system, PFOS can be efficiently removed within 4 h of reaction time, with a pseudo-first-order rate constant of 0.0124 min-1, under the optimized conditions of current density = 20 mA cm-2, electrode distance = 5 mm, solution pH = 5.64, [PFOS]0= 0.5 µM and NaClO4 electrolyte concentration = 50 mM. The electron transfer pathway, hydroxyl radicals and superoxide radicals are all responsible for PFOS decomposition/transformation. New degradation pathways were identified; a total of 25 PFOS byproducts are reported in this work; and perfluoroalkane sulfonates (PFSAs), perfluorinated aldehydes (PFALs) and hydrofluorocarbons (HFCs) were identified for the first time. PFOS degradation involves the desulfonation pathway as the first step, followed by oxidation and subsequent defluorination, decarboxylation, decarbonylation, sulfonation, defluorination and hydroxylation. The results from this work also show that the reactivity of PFAAs is related to their carbon chain length, with shorter-chain PFAAs exhibiting a lower degradation rate. In a PFAA mixture, a decline in the degradation rate was observed for the shorter-chain-length PFAAs, suggesting stronger competitive inhibition and indicating stronger environmental recalcitrance during the treatment process. Novelty statement: Although many efforts have been made to identify perfluorooctane sulfonate (PFOS) degradation byproducts, previous studies were only able to identify byproducts that are related to perfluorinated carboxylic acids (PFCAs). This is the first study to elucidate the new PFOS degradation pathway; furthermore, this is the first report to identify byproducts containing sulfonate groups (perfluoroalkane sulfonates, PFSAs), aldehyde groups (perfluorinated aldehydes, PFALs), and hydrofluorocarbons (HFCs). This study further systematically explores how perfluoroalkyl acid (PFAA) degradation may be affected in the mixture system: shorter-chain-length PFAAs suffer stronger competitive inhibition in the photoelectrochemical (PEC) system. By utilizing the graphene oxide-titanium dioxide (GOTiO2) photoelectrode fabricated in this work, PFOS can be successfully decomposed during the PEC process for the first time.
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Affiliation(s)
- Jheng-Sian Yang
- Graduate Institute of Environmental Engineering, National Taiwan University, Taipei 106, Taiwan, ROC
| | - Webber Wei-Po Lai
- Department of Environmental Science and Engineering, Tunghai University, Taichung 407, Taiwan, ROC
| | - Angela Yu-Chen Lin
- Graduate Institute of Environmental Engineering, National Taiwan University, Taipei 106, Taiwan, ROC.
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12
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Verma S, Varma RS, Nadagouda MN. Remediation and mineralization processes for per- and polyfluoroalkyl substances (PFAS) in water: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 794:148987. [PMID: 34426018 DOI: 10.1016/j.scitotenv.2021.148987] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 07/06/2021] [Accepted: 07/07/2021] [Indexed: 06/13/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are synthetic organic molecules used to manufacture various consumer and industrials products. In PFAS, the CF bond is stable, which renders these compounds chemically stable and prevents their breakdown. Several PFAS treatment processes such as adsorption, photolysis and photocatalysis, bioremediation, sonolysis, electrochemical oxidation, etc., have been explored and are being developed. The present review article has critically summarized degradative technologies and provides in-depth knowledge of photodegradation, electrochemical degradation, chemical oxidation, and reduction mineralization mechanism. Also, novel non-degradative technologies, including nano-adsorbents, natural and surface-modified clay minerals/zeolites, calixarene-based polymers, and molecularly imprinted polymers and adsorbents derived from biomaterials are discussed in detail. Of these novel approaches photocatalysis combined with membrane filtration or electrochemical oxidation via a treatment train approach shows promising results in removing PFAS in natural waters. The photocatalytic mineralization mechanism of PFOA is discussed, leading to recommendations for future research on novel remediation strategies for removing PFAS from water.
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Affiliation(s)
- Sanny Verma
- Pegasus Technical Services, Inc., 46 E. Hollister Street, Cincinnati, OH 45219, USA
| | - Rajender S Varma
- Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute, Palacký University in Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Mallikarjuna N Nadagouda
- Department of Mechanical and Materials Engineering, Wright State University, Dayton, OH 45435, USA.
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13
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Deng Y, Liang Z, Lu X, Chen D, Li Z, Wang F. The degradation mechanisms of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) by different chemical methods: A critical review. CHEMOSPHERE 2021; 283:131168. [PMID: 34182635 DOI: 10.1016/j.chemosphere.2021.131168] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 06/04/2021] [Accepted: 06/08/2021] [Indexed: 06/13/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs) are a class of artificial compounds comprised of a perfluoroalkyl main chain and a terminal functional group. With them being applied in a wide range of applications, PFASs have drawn increasing regulatory attention and research interests on their reductions and treatments due to their harmful effects on environment and human beings. Among numerous studies, chemical treatments (e.g., photochemical, electrochemical, and thermal technologies) have been proved to be important methods to degradation PFASs. However, the pathways and mechanisms for the degradation of PFASs through these chemical methods still have not been well documented. This article therefore provides a comprehensive review on the degradation mechanisms of two important PFASs (perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS)) with photochemical, electrochemical and thermal methods. Different decomposition mechanisms of PFOA and PFOS are reviewed and discussed. Overall, the degradation pathways of PFASs are associated closely with their head groups and chain lengths, and H/F exchange and chain shortening were found to be predominant degradation mechanisms. The clear study on the degradation mechanisms of PFOA and PFOS should be very useful for the complete degradation or mineralization of PFASs in the future.
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Affiliation(s)
- Yun Deng
- School of Environment, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, 510632, China
| | - Zhihong Liang
- The Pearl River Water Resources Research Institute, Guangzhou, Guangdong, 510611, China
| | - Xingwen Lu
- School of Environmental Science and Engineering and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, China
| | - Da Chen
- School of Environment, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, 510632, China
| | - Zhe Li
- School of Engineering and Materials Science, Faculty of Science and Engineering, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Fei Wang
- School of Environment, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, 510632, China.
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High performance of electrosprayed graphene oxide/TiO2/Ce-TiO2 photoanodes for photoelectrocatalytic inactivation of S. aureus. Electrochim Acta 2021. [DOI: 10.1016/j.electacta.2021.139203] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Fang X, Gan L, Wang L, Gong H, Xu L, Wu Y, Lu H, Han S, Cui J, Xia C. Enhanced degradation of bisphenol A by mixed ZIF derived CoZn oxide encapsulated N-doped carbon via peroxymonosulfate activation: The importance of N doping amount. JOURNAL OF HAZARDOUS MATERIALS 2021; 419:126363. [PMID: 34174625 DOI: 10.1016/j.jhazmat.2021.126363] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/21/2021] [Accepted: 06/07/2021] [Indexed: 05/28/2023]
Abstract
In this study, mixed metal cobalt zinc oxide embedded nitrogen enriched porous carbon composites (CoZnO-PC) were prepared via pyrolyzing polyvinylpyrrolidone (PVP) encapsulated Co, Zn-bimetal centered zeolitic imidazolate frameworks (ZIF). The prepared composites were then used to activate peroxymonosulfate (PMS) for bisphenol A (BPA) removal in water. When mole ratio of Co/Zn was 2/1, the resulted Co2Zn1O-PC possessed spinel structure with prominent degradation capability, in which the introduction of Zn accelerated the PMS activation performance of Co through establishing bimetal synergistic interactions. Both radical and non-radical activation pathways were existed in the Co2Zn1O-PC/PMS system, in which Co2Zn1O dominated the radical pathway whereas PC dominated the non-radical way. Since PVP contained abundant nitrogen atoms and could form strong coordination interactions with the ZIF precursor, the introduction of PVP in the ZIF precursor prevented pore collapsing during pyrolysis process, as well as enhancing the nitrogen content in the pyrolzed composites, which significantly promoted the generation of singlet oxygen. With combined pathways, the Co2Zn1O-PC/PMS system showed a wide pH application range with promising mineralization rate. Meanwhile, the spinel-structured Co2Zn1O-PC was magnetically separable with desirable recyclability. This study presents a novel composite with remarkable performance for the removal of refractory organic pollutants in municipal wastewater.
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Affiliation(s)
- Xingyu Fang
- College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, 210037 Jiangsu, People's Republic of China
| | - Lu Gan
- College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, 210037 Jiangsu, People's Republic of China.
| | - Linjie Wang
- College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, 210037 Jiangsu, People's Republic of China
| | - Han Gong
- College of Marine Sciences, South China Agricultural University, Guangzhou, 510642 Guangdong, People's Republic of China
| | - Lijie Xu
- College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037 Jiangsu, People's Republic of China
| | - Ying Wu
- College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, 210037 Jiangsu, People's Republic of China
| | - Haiqin Lu
- College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, 210037 Jiangsu, People's Republic of China
| | - Shuguang Han
- College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, 210037 Jiangsu, People's Republic of China
| | - Juqing Cui
- College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, 210037 Jiangsu, People's Republic of China
| | - Changlei Xia
- College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, 210037 Jiangsu, People's Republic of China
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16
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Divyapriya G, Singh S, Martínez-Huitle CA, Scaria J, Karim AV, Nidheesh PV. Treatment of real wastewater by photoelectrochemical methods: An overview. CHEMOSPHERE 2021; 276:130188. [PMID: 33743419 DOI: 10.1016/j.chemosphere.2021.130188] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 02/24/2021] [Accepted: 03/03/2021] [Indexed: 06/12/2023]
Abstract
An inadequate and inefficient performance ability of conventional methods to remove persistent organic pollutants urges the need of alternative or complementary advanced wastewater treatments methods to ensure the safer reuse of reclaimed water. Photoelectrochemical methods are emerging as promising options among other advanced oxidation processes because of the higher treatment efficiency achieved due to the synergistic effects of combined photochemical and electrolysis reactions. Synergistic effects of integrated photochemical, electrochemical and photoelectrochemical processes not only increase the hydroxyl radical production; an enhancement on the mineralization ability through various side reactions is also achieved. In this review, fundamental reaction mechanisms of different photoelectrochemical methods including photoelectrocatalysis, photo/solar electro-Fenton, photo anodic oxidation, photoelectroperoxone and photocatalytic fuel cell are discussed. Various integrated photochemical, electrochemical and photoelectrochemical processes and their synergistic effects are elaborated. Different reactor configurations along with the positioning of electrodes, photocatalysts and light source of the individual/combined photoelectrochemical treatment systems are discussed. Modified photoanode and cathode materials used in the photoelectrochemical reactors and their performance ability is presented. Photoelectrochemical treatment of real wastewater such as landfill leachate, oil mill, pharmaceutical, textile, and tannery wastewater are reviewed. Hydrogen production efficiency in the photoelectrochemical process is further elaborated. Cost and energy involved in these processes are briefed, but the applicability of photocatalytic fuel cells to reduce the electrical dependence is also summarised. Finally, the use of photoelectrochemical approaches as an alternative for treating soil washing effluents is currently discussed.
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Affiliation(s)
- G Divyapriya
- Virginia Polytechnic Institute and State University, USA
| | - Seema Singh
- Omvati Devi Degree College, Bhalaswagaj, Haridwar, India
| | - Carlos A Martínez-Huitle
- Institute of Chemistry, Federal University of Rio Grande do Norte, Lagoa Nova, CEP 59078-970, Natal, RN, Brazil.
| | - Jaimy Scaria
- CSIR-National Environmental Engineering Research Institute, Nagpur, Maharashtra, India
| | - Ansaf V Karim
- Environmental Science and Engineering Department, Indian Institute of Technology, Bombay, India
| | - P V Nidheesh
- CSIR-National Environmental Engineering Research Institute, Nagpur, Maharashtra, India.
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17
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Xu B, Liu S, Zhou JL, Zheng C, Weifeng J, Chen B, Zhang T, Qiu W. PFAS and their substitutes in groundwater: Occurrence, transformation and remediation. JOURNAL OF HAZARDOUS MATERIALS 2021; 412:125159. [PMID: 33951855 DOI: 10.1016/j.jhazmat.2021.125159] [Citation(s) in RCA: 86] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/29/2020] [Accepted: 01/13/2021] [Indexed: 05/27/2023]
Abstract
Poly- and perfluoroalkyl substances (PFAS) are increasingly investigated due to their global occurrence and potential human health risk. The ban on PFOA and PFOS has led to the use of novel substitutes such as GenX, F-53B and OBS. This paper reviews the studies on the occurrence, transformation and remediation of major PFAS i.e. PFOA, PFNA, PFBA, PFOS, PFHxS, PFBS and the three substitutes in groundwater. The data indicated that PFOA, PFBA, PFOS and PFBS were present at high concentrations up to 21,200 ng L-1 while GenX and F-53B were found up to 30,000 ng L-1 and 0.18-0.59 ng L-1, respectively. PFAS in groundwater are from direct sources e.g. surface water and soil. PFAS remediation methods based on membrane, redox, sorption, electrochemical and photocatalysis are analyzed. Overall, photocatalysis is considered to be an ideal technology with low cost and high degradation efficacy for PFAS removal. Photocatalysis could be combined with electrochemical or membrane filtration to become more advantageous. GenX, F-53B and OBS in groundwater treatment by UV/sulfite system and electrochemical oxidation proved effective. The review identified gaps such as the immobilization and recycling of materials in groundwater treatment, and recommended visible light photocatalysis for future studies.
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Affiliation(s)
- Bentuo Xu
- National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, School of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Shuai Liu
- Research Institute of Poyang Lake, Jiangxi Academy of Sciences, Nanchang 330012, China
| | - John L Zhou
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW 2007, Australia
| | - Chunmiao Zheng
- Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Jin Weifeng
- National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, School of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Bei Chen
- Fisheries Research Institute of Fujian, Xiamen 361013, China
| | - Ting Zhang
- Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Wenhui Qiu
- Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
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18
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Zheng Z, Ng YH, Tang Y, Li Y, Chen W, Wang J, Li X, Li L. Visible-light-driven photoelectrocatalytic activation of chloride by nanoporous MoS 2@BiVO 4 photoanode for enhanced degradation of bisphenol A. CHEMOSPHERE 2021; 263:128279. [PMID: 33297223 DOI: 10.1016/j.chemosphere.2020.128279] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 08/24/2020] [Accepted: 09/04/2020] [Indexed: 06/12/2023]
Abstract
The massive emission of bisphenol A (BPA) has imposed adverse effects on both ecosystems and human health. Herein, nanoporous MoS2@BiVO4 photoanodes were fabricated on fluorine-doped tin oxide (FTO) substrates for photoelectrocatalytic degradation of BPA. The photocurrent density of the optimized photoanode (MoS2-3@BiVO4) was 5.4 times as that of BiVO4 photoanode at 1.5 V vs. Ag/AgCl under visible light illumination, which was ascribed to the reduced recombination of photogenerated charge carriers of the well-designed hybrid structure. 10 ppm of BPA could be completely degraded in 75 min by MoS2-3@BiVO4 photoanode, with a bias of 1.5 V vs. Ag/AgCl and 100 mM of NaCl as the supporting electrolyte. The electron paramagnetic resonance (EPR) and free radicals scavenging experiments confirmed that chlorine oxide radical (•ClO) played a dominant role in the degradation of BPA. 14 intermediates were detected and identified during photoelectrocatalytic degradation of BPA by MoS2-3@BiVO4 photoanode and 3 pathways were proposed based on the above intermediates. The hybrid film exhibited high stability and reusability, and promising application potential in photoelectrocatalytic degradation of organic pollutants in aqueous solution.
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Affiliation(s)
- Zexiao Zheng
- School of Environment, South China Normal University; Guangdong Provincial Engineering Technology Research Center for Drinking Water Safety; Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, Guangzhou, 510006, China; Department of Civil & Environmental Engineering, Hong Kong University of Science & Technology, Hong Kong, China
| | - Yun Hau Ng
- School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China
| | - Yiming Tang
- School of Environment, South China Normal University; Guangdong Provincial Engineering Technology Research Center for Drinking Water Safety; Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, Guangzhou, 510006, China; School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
| | - Yaping Li
- School of Environment, South China Normal University; Guangdong Provincial Engineering Technology Research Center for Drinking Water Safety; Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, Guangzhou, 510006, China
| | - Weirui Chen
- School of Environment, South China Normal University; Guangdong Provincial Engineering Technology Research Center for Drinking Water Safety; Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, Guangzhou, 510006, China
| | - Jing Wang
- School of Environment, South China Normal University; Guangdong Provincial Engineering Technology Research Center for Drinking Water Safety; Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, Guangzhou, 510006, China
| | - Xukai Li
- School of Environment, South China Normal University; Guangdong Provincial Engineering Technology Research Center for Drinking Water Safety; Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, Guangzhou, 510006, China
| | - Laisheng Li
- School of Environment, South China Normal University; Guangdong Provincial Engineering Technology Research Center for Drinking Water Safety; Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, Guangzhou, 510006, China.
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