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Wang Q, Zhang G, Zhang C, Xu F, Zhang Y, Fu W, Liu J, Li J. Enhanced Mineralization of Organic Pollutants through Atomic Hydrogen-Mediated Alternative Transformation Pathways. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:11185-11192. [PMID: 38869092 DOI: 10.1021/acs.est.4c02545] [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
Electrocatalytic hydrogen atom-hydroxyl radical (H*-·OH) redox system is a promising approach for contaminant removal and mineralization. However, its working mechanism, especially the effect of H*, remains unclear, hindering its practical application. Herein, we constructed an electrochemical reactor equipped with our self-made Pd-loaded Ti/TiO2 nanotube cathode and a commercial boron-doped diamond anode. After fulfilling the electrode characterization and free radical detection, we employed coumarin and 7-azido-4-methylcoumarin as probes to confirm the participation of H* in the transformation of organic compounds. A comprehensive study on the degradation kinetics, reaction, and mineralization mechanisms using benzoic acid (BA) and 4-chlorophenol (4-CP) as model compounds was further conducted. The rate constants and total organic carbon removal of BA and 4-CP in the redox system increased compared with those of the individual oxidation and reduction processes. Theoretical calculations demonstrate that H* opens up alternative pathways for BA and 4-CP ring cleavage, forming quinones as reactive intermediates. Furthermore, H* facilitates the mineralization of the typical intermediates, maleic acid and fumaric acid, through C=C bond addition and H-abstraction from the 1,1-diol structure. The presence of H* provides alternative pathways for pollutant transformation, consequently reducing the treatment duration.
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Affiliation(s)
- Qiancheng Wang
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
- Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Gong Zhang
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Chao Zhang
- College of Environment and Resources, Guangxi Normal University, Guilin 541004, China
| | - Fu Xu
- Suzhou Suwater Environment Science Technology Co., LTD., Suzhou 215011, China
| | - Yixiang Zhang
- Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Wenjie Fu
- College of Environment and Resources, Guangxi Normal University, Guilin 541004, China
| | - Jianyun Liu
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
| | - Jinghong Li
- Department of Chemistry, Tsinghua University, Beijing 100084, China
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2
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Zeng Y, Dai Y, Yin L, Huang J, Hoffmann MR. Rethinking alternatives to fluorinated pops in aqueous environment and corresponding destructive treatment strategies. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174200. [PMID: 38936705 DOI: 10.1016/j.scitotenv.2024.174200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Revised: 05/25/2024] [Accepted: 06/20/2024] [Indexed: 06/29/2024]
Abstract
Alternatives are being developed to replace fluorinated persistent organic pollutants (POPs) listed in the Stockholm Convention, bypass environmental regulations, and overcome environmental risks. However, the extensive usage of fluorinated POPs alternatives has revealed potential risks such as high exposure levels, long-range transport properties, and physiological toxicity. Therefore, it is imperative to rethink the alternatives and their treatment technologies. This review aims to consider the existing destructive technologies for completely eliminating fluorinated POPs alternatives from the earth based on the updated classification and risks overview. Herein, the types of common alternatives were renewed and categorized, and their risks to the environment and organisms were concluded. The efficiency, effectiveness, energy utilization, sustainability, and cost of various degradation technologies in the treatment of fluorinated POPs alternatives were reviewed and evaluated. Meanwhile, the reaction mechanisms of different fluorinated POPs alternatives are systematically generalized, and the correlation between the structure of alternatives and the degradation characteristics was discussed, providing mechanistic insights for their removal from the environment. Overall, the review supplies a theoretical foundation and reference for the control and treatment of fluorinated POPs alternatives pollution.
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Affiliation(s)
- Yuxin Zeng
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China.
| | - Yunrong Dai
- School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing 100083, PR China.
| | - Lifeng Yin
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China.
| | - Jun Huang
- State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control (BKLEOC), School of Environment, POPs Research Center, Tsinghua University, Beijing 100084, PR China.
| | - Michael R Hoffmann
- Department of Environmental Science & Engineering, California Institute of Technology, Pasadena, CA 91125, United States.
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Trzcinski AP, Harada KH. Comparison of perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and perfluorobutane sulfonate (PFBS) removal in a combined adsorption and electrochemical oxidation process. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 927:172184. [PMID: 38575007 DOI: 10.1016/j.scitotenv.2024.172184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 03/08/2024] [Accepted: 04/01/2024] [Indexed: 04/06/2024]
Abstract
This study focused on three of the most studied PFAS molecules, namely perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and perfluorobutane sulfonate (PFBS). They were compared in terms of their adsorption capacity onto graphite intercalated compound (GIC), a low surface area, highly conductive and cheap adsorbent. The adsorption on GIC followed a pseudo second order kinetics and the maximum adsorption capacity using Langmuir was 53.9 μg/g for PFOS, 22.3 μg/g for PFOA and 0.985 μg/g for PFBS due to electrostatic attraction and hydrophobic interactions. GIC was added into an electrochemical oxidation reactor and >100 μg/L PFOS was found to be fully degraded (<10 ng/L) leaving degradation by-products such as PFHpS, PFHxS, PFPeS, PFBS, PFOA, PFHxA and PFBA below 100 ng/L after 5 cycles of adsorption onto GIC for 20 min followed by regeneration at 28 mA/cm2 for 10 min. PFBS was completely removed due to degradation by aqueous electrons on GIC flakes. Up to 98 % PFOA was removed by the process after 3 cycles of adsorption onto GIC for 20 min followed by regeneration at 25 mA/cm2 for 10 min. When PFBS was spiked individually, only 17 % was removed due to poor adsorption on GIC. There was a drop of 3-40 % by treating PFOS, PFOA and smaller sulfonates in a real water matrix under the same electrochemical conditions (20 mA/cm2), but PFOS and PFOA removal percentage were 95 and 68 % after 20 min at 20 mA/cm2.
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Affiliation(s)
- Antoine P Trzcinski
- School of Agriculture and Environmental Science, University of Southern Queensland, West Street, 4350, Queensland, Australia.
| | - Kouji H Harada
- Department of health and environmental sciences, Graduate school of Medicine, Kyoto University, Kyoto 606-8501, Japan
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Zeidabadi FA, Esfahani EB, McBeath ST, Mohseni M. Managing PFAS exhausted Ion-exchange resins through effective regeneration/electrochemical process. WATER RESEARCH 2024; 255:121529. [PMID: 38554630 DOI: 10.1016/j.watres.2024.121529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 03/03/2024] [Accepted: 03/25/2024] [Indexed: 04/02/2024]
Abstract
This study proposes an integrated approach that combines ion-exchange (IX) and electrochemical technologies to tackle problems associated with PFAS contamination. Our investigation centers on evaluating the recovery and efficiency of IX/electrochemical systems in the presence of five different salts, spanning dosages from 0.1 % to 8 %. The outcomes reveal a slight superiority for NaCl within the regeneration system, with sulfate and bicarbonate also showing comparable efficacy. Notably, the introduction of chloride ion (Cl-) into the electrochemical system results in substantial generation of undesirable chlorate (ClO3-) and perchlorate (ClO4-) by-products, accounting for ∼18 % and ∼81 % of the consumed Cl-, respectively. Several agents, including H2O2, KI, and Na2S2O3, exhibited effective mitigation of ClO3- and ClO4- formation. However, only H2O2 demonstrated a favorable influence on the degradation and defluorination of PFOA. The addition of 0.8 M H2O2 resulted in the near-complete removal of ClO3- and ClO4-, accompanied by 1.3 and 2.2-fold enhancements in the degradation and defluorination of PFOA, respectively. Furthermore, a comparative analysis of different salts in the electrochemical system reveals that Cl- and OH- ions exhibit slower performance, possibly due to competitive interactions with PFOA on the anode's reactive sites. In contrast, sulfate and bicarbonate salts consistently demonstrate robust decomposition efficiencies. Despite the notable enhancement in IX regeneration efficacy facilitated by the presence of methanol, particularly for PFAS-specific resins, this enhancement comes at the cost of reduced electrochemical decomposition of all PFAS. The average decay rate ratio of all PFAS in the presence of 50 % methanol, compared to its absence, falls within the range of 0.11-0.39. In conclusion, the use of 1 % Na2SO4 salt stands out as a favorable option for the integrated IX/electrochemical process. This choice not only eliminates the need to introduce an additional chemical (e.g., H2O2) into the wastewater stream, but also ensures both satisfactory regeneration recovery and efficiency in the decomposition process through electrochemical treatment.
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Affiliation(s)
- Fatemeh Asadi Zeidabadi
- 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
| | - Sean T McBeath
- Department of Civil and Environmental Engineering, University of Massachusetts Amherst, Amherst, MA 01003, United States
| | - Madjid Mohseni
- Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, Canada.
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Hübner U, Spahr S, Lutze H, Wieland A, Rüting S, Gernjak W, Wenk J. Advanced oxidation processes for water and wastewater treatment - Guidance for systematic future research. Heliyon 2024; 10:e30402. [PMID: 38726145 PMCID: PMC11079112 DOI: 10.1016/j.heliyon.2024.e30402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 04/23/2024] [Accepted: 04/25/2024] [Indexed: 05/12/2024] Open
Abstract
Advanced oxidation processes (AOPs) are a growing research field with a large variety of different process variants and materials being tested at laboratory scale. However, despite extensive research in recent years and decades, many variants have not been transitioned to pilot- and full-scale operation. One major concern are the inconsistent experimental approaches applied across different studies that impede identification, comparison, and upscaling of the most promising AOPs. The aim of this tutorial review is to streamline future studies on the development of new solutions and materials for advanced oxidation by providing guidance for comparable and scalable oxidation experiments. We discuss recent developments in catalytic, ozone-based, radiation-driven, and other AOPs, and outline future perspectives and research needs. Since standardized experimental procedures are not available for most AOPs, we propose basic rules and key parameters for lab-scale evaluation of new AOPs including selection of suitable probe compounds and scavengers for the measurement of (major) reactive species. A two-phase approach to assess new AOP concepts is proposed, consisting of (i) basic research and proof-of-concept (technology readiness levels (TRL) 1-3), followed by (ii) process development in the intended water matrix including a cost comparison with an established process, applying comparable and scalable parameters such as UV fluence or ozone consumption (TRL 3-5). Subsequent demonstration of the new process (TRL 6-7) is briefly discussed, too. Finally, we highlight important research tools for a thorough mechanistic process evaluation and risk assessment including screening for transformation products that should be based on chemical logic and combined with complementary tools (mass balance, chemical calculations).
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Affiliation(s)
- Uwe Hübner
- Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 3, 85748, Garching, Germany
- Xylem Services GmbH, Boschstraße 4-14, 32051, Herford, Germany
| | - Stephanie Spahr
- Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Müggelseedamm 301, 12587, Berlin, Germany
| | - Holger Lutze
- Department of Civil and Environmental Engineering, Institute IWAR, Chair of Environmental Analytics and Pollutants, Technical University of Darmstadt, Franziska-Braun-Straße 7, 64287, Darmstadt, Germany
- IWW Water Centre, Moritzstraße 26, 45476, Mülheim an der Ruhr, Germany
- Centre for Water and Environmental Research (ZWU), Universitätsstraße 5, 45141, Essen, Germany
| | - Arne Wieland
- Xylem Services GmbH, Boschstraße 4-14, 32051, Herford, Germany
| | - Steffen Rüting
- Xylem Services GmbH, Boschstraße 4-14, 32051, Herford, Germany
| | - Wolfgang Gernjak
- Catalan Institute for Water Research (ICRA), 17003, Girona, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), 08010, Barcelona, Spain
| | - Jannis Wenk
- University of Bath, Department of Chemical Engineering and Water Innovation & Research Centre (WIRC@Bath), Bath, BA2 7AY, United Kingdom
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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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7
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Asadi Zeidabadi F, Banayan Esfahani E, Moreira R, McBeath ST, Foster J, Mohseni M. Structural dependence of PFAS oxidation in a boron doped diamond-electrochemical system. ENVIRONMENTAL RESEARCH 2024; 246:118103. [PMID: 38181849 DOI: 10.1016/j.envres.2024.118103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 12/11/2023] [Accepted: 01/02/2024] [Indexed: 01/07/2024]
Abstract
Driven by long-term persistence and adverse health impacts of legacy perfluorooctanoic acid (PFOA), production has shifted towards shorter chain analogs (C4, perfluorobutanoic acid (PFBA)) or fluorinated alternatives such as hexafluoropropylene oxide dimer acid (HFPO-DA, known as GenX) and 6:2 fluorotelomer carboxylic acid (6:2 FTCA). Yet, a thorough understanding of treatment processes for these alternatives is limited. Herein, we conducted a comprehensive study using an electrochemical approach with a boron doped diamond anode in Na2SO4 electrolyte for the remediation of PFOA common alternatives, i.e., PFBA, GenX, and 6:2 FTCA. The degradability, fluorine recovery, transformation pathway, and contributions from electro-synthesized radicals were investigated. The results indicated the significance of chain length and structure, with shorter chains being harder to break down (PFBA (65.6 ± 5.0%) < GenX (84.9 ± 3.3%) < PFOA (97.9 ± 0.1%) < 6:2 FTCA (99.4 ± 0.0%) within 120 min of electrolysis). The same by-products were observed during the oxidation of both low and high concentrations of parent PFAS (2 and 20 mg L-1), indicating that the fundamental mechanism of PFAS degradation remained consistent. Nevertheless, the ratio of these by-products to the parent PFAS concentration varied which primarily arises from the more rapid PFAS decomposition at lower dosages. For all experiments, the main mechanism of PFAS oxidation was initiated by direct electron transfer at the anode surface. Sulfate radical (SO4•-) also contributed to the oxidation of all PFAS, while hydroxyl radical (•OH) only played a role in the decomposition of 6:2 FTCA. Total fluorine recovery of PFBA, GenX, and 6:2 FTCA were 96.5%, 94.0%, and 76.4% within 240 min. The more complex transformation pathway of 6:2 FTCA could explain its lower fluorine recovery. Detailed decomposition pathways for each PFAS were also proposed through identifying the generated intermediates and fluorine recovery. The proposed pathways were also assessed using 19F Nuclear Magnetic Resonance (NMR) spectroscopy.
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Affiliation(s)
- Fatemeh Asadi Zeidabadi
- 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
| | - Raphaell Moreira
- Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, Canada
| | - Sean T McBeath
- Department of Civil and Environmental Engineering, University of Massachusetts Amherst, Amherst, MA, 01002, United States
| | - Johan Foster
- 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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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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Yadav M, Osonga FJ, Sadik OA. Unveiling nano-empowered catalytic mechanisms for PFAS sensing, removal and destruction in water. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169279. [PMID: 38123092 DOI: 10.1016/j.scitotenv.2023.169279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 11/14/2023] [Accepted: 12/09/2023] [Indexed: 12/23/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are organofluorine compounds used to manufacture various industrial and consumer goods. Due to their excellent physical and thermal stability ascribed to the strong CF bond, these are ubiquitously present globally and difficult to remediate. Extensive toxicological and epidemiological studies have confirmed these substances to cause adverse health effects. With the increasing literature on the environmental impact of PFAS, the regulations and research have also expanded. Researchers worldwide are working on the detection and remediation of PFAS. Many methods have been developed for their sensing, removal, and destruction. Amongst these methods, nanotechnology has emerged as a sustainable and affordable solution due to its tunable surface properties, high sorption capacities, and excellent reactivities. This review comprehensively discusses the recently developed nanoengineered materials used for detecting, sequestering, and destroying PFAS from aqueous matrices. Innovative designs of nanocomposites and their efficiency for the sensing, removal, and degradation of these persistent pollutants are reviewed, and key insights are analyzed. The mechanistic details and evidence available to support the cleavage of the CF bond during the treatment of PFAS in water are critically examined. Moreover, it highlights the challenges during PFAS quantification and analysis, including the analysis of intermediates in transitioning nanotechnologies from the laboratory to the field.
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Affiliation(s)
- Manavi Yadav
- Department of Chemistry and Environmental Sciences, New Jersey Institutes of Technology (NJIT), United States of America
| | - Francis J Osonga
- Department of Chemistry and Environmental Sciences, New Jersey Institutes of Technology (NJIT), United States of America
| | - Omowunmi A Sadik
- Department of Chemistry and Environmental Sciences, New Jersey Institutes of Technology (NJIT), United States of America.
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10
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Mostefaoui N, Oturan N, Bouafia SC, Hien SA, Gibert-Vilas M, Lesage G, Pechaud Y, Tassin B, Oturan M, Trellu C. Integration of electrochemical processes in a treatment system for landfill leachates based on a membrane bioreactor. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:168841. [PMID: 38036133 DOI: 10.1016/j.scitotenv.2023.168841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 11/16/2023] [Accepted: 11/22/2023] [Indexed: 12/02/2023]
Abstract
The use of electrocoagulation (EC) and anodic oxidation (AO) processes was studied for improving a treatment system for landfill leachates based on a membrane bioreactor (MBR) and a nanofiltration step. The main limitation of the current full-scale system is related to the partial removal of organic compounds that leads to operation of the nanofiltration unit with a highly concentrated feed solution. Application of the EC before the MBR participated in partial removal of the organic load (40 %) with limited energy consumption (2.8 kWh m-3) but with additional production of iron hydroxide sludge. Only AO allowed for non-selective removal of organic compounds. As a standalone process, AO would require a sharp increase of the energy consumption (116 kWh for 81 % removal of total organic carbon). But using lower electric charge and combining AO with EC and MBR processes would allow for achieving high overall removal yields with limited energy consumption. For example, the overall removal yield of total organic carbon was 65 % by application of AO after EC, with an energy consumption of 21 kWh m-3. Results also showed that such treatment strategy might allow for a significant increase of the biodegradability of the effluent before treatment by the MBR. The MBR might then be dedicated to the removal of the residual organic load as well as to the removal of the nitrogen load. The data obtained in this study also showed that the lower electric charge required for integrating AO in a coupled process would allow for strongly decreasing the formation of undesired by-products such as ClO3- and ClO4-.
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Affiliation(s)
- Nabil Mostefaoui
- Université Gustave Eiffel, Laboratoire Géomatériaux et Environnement EA 4508, 77454 Marne-la-Vallée, Cedex 2, France; Laboratory of Reaction Engineering, Faculty of Mechanical Engineering and Process Engineering USTHB, BP 32, El-Allia, Bab-Ezzouar, Algiers 16111, Algeria
| | - Nihal Oturan
- Université Gustave Eiffel, Laboratoire Géomatériaux et Environnement EA 4508, 77454 Marne-la-Vallée, Cedex 2, France
| | - Souad Chergui Bouafia
- Laboratory of Reaction Engineering, Faculty of Mechanical Engineering and Process Engineering USTHB, BP 32, El-Allia, Bab-Ezzouar, Algiers 16111, Algeria
| | - Sié Alain Hien
- Université Gustave Eiffel, Laboratoire Géomatériaux et Environnement EA 4508, 77454 Marne-la-Vallée, Cedex 2, France; Laboratoire des Procédés Industriels, de Synthèse de l'Environnement et des Energies Nouvelles (LAPISEN), Institut National Polytechnique Houphouët-Boigny, BP 1313, Yamoussoukro, Côte d'Ivoire
| | - Màxim Gibert-Vilas
- Université Gustave Eiffel, Laboratoire Géomatériaux et Environnement EA 4508, 77454 Marne-la-Vallée, Cedex 2, France
| | - Geoffroy Lesage
- Institut Européen des Membranes, IEM, UMR 5635, Centre National de la Recherche Scientifique (CNRS), University Montpellier, ENSCM, Place Eugène Bataillon, 34095 Montpellier, France
| | - Yoan Pechaud
- Université Gustave Eiffel, Laboratoire Géomatériaux et Environnement EA 4508, 77454 Marne-la-Vallée, Cedex 2, France
| | - Bruno Tassin
- Laboratoire Eau Environnement et Systèmes Urbains, LEESU, Ecole des Ponts, Université Paris-Est Créteil, 61 avenue du Général de Gaulle, 94010 Créteil Cedex, France
| | - Mehmet Oturan
- Université Gustave Eiffel, Laboratoire Géomatériaux et Environnement EA 4508, 77454 Marne-la-Vallée, Cedex 2, France
| | - Clément Trellu
- Université Gustave Eiffel, Laboratoire Géomatériaux et Environnement EA 4508, 77454 Marne-la-Vallée, Cedex 2, France.
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11
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Hamid N, Junaid M, Sultan M, Yoganandham ST, Chuan OM. The untold story of PFAS alternatives: Insights into the occurrence, ecotoxicological impacts, and removal strategies in the aquatic environment. WATER RESEARCH 2024; 250:121044. [PMID: 38154338 DOI: 10.1016/j.watres.2023.121044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 12/17/2023] [Accepted: 12/18/2023] [Indexed: 12/30/2023]
Abstract
Due to increasing regulations on the production and consumption of legacy per- and polyfluoroalkyl substances (PFAS), the global use of PFAS substitutes increased tremendously, posing serious environmental risks owing to their bioaccumulation, toxicity, and lack of removal strategies. This review summarized the spatial distribution of alternative PFAS and their ecological risks in global freshwater and marine ecosystems. Further, toxicological effects of novel PFAS in various freshwater and marine species were highlighted. Moreover, degradation mechanisms for alternative PFAS removal from aquatic environments were compared and discussed. The spatial distribution showed that 6:2 chlorinated polyfluorinated ether sulfonate (6:2 CI-PFAES, also known as F-53B) was the most dominant emerging PFAS found in freshwater. Additionally, the highest levels of PFBS and PFBA were observed in marine waters (West Pacific Ocean). Moreover, short-chain PFAS exhibited higher concentrations than long-chain congeners. The ecological risk quotients (RQs) for phytoplankton were relatively higher >1 than invertebrates, indicating a higher risk for freshwater phytoplankton species. Similarly, in marine water, the majority of PFAS substitutes exhibited negligible risk for invertebrates and fish, and posed elevated risks for phytoplanktons. Reviewed studies showed that alternative PFAS undergo bioaccumulation and cause deleterious effects such as oxidative stress, hepatoxicity, neurotoxicity, histopathological alterations, behavioral and growth abnormalities, reproductive toxicity and metabolism defects in freshwater and marine species. Regarding PFAS treatment methods, photodegradation, photocatalysis, and adsorption showed promising degradation approaches with efficiencies as high as 90%. Finally, research gaps and future perspectives for alternative PFAS toxicological implications and their removal were offered.
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Affiliation(s)
- Naima Hamid
- Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia; Ocean Pollution and Ecotoxicology (OPEC) Research Group, Universiti Malaysia Terengganu, Malaysia.
| | - Muhammad Junaid
- College of Marine Sciences, South China Agricultural University, Guangzhou 510641, China.
| | - Marriya Sultan
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing School, University of Chinese Academy of Sciences, Chongqing 400714, China
| | - Suman Thodhal Yoganandham
- Department of Environmental Engineering, Changwon National University, Changwon, 51140, Republic of Korea
| | - Ong Meng Chuan
- Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia; Ocean Pollution and Ecotoxicology (OPEC) Research Group, Universiti Malaysia Terengganu, Malaysia
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12
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Vatankhah H, Anderson RH, Ghosh R, Willey J, Leeson A. A review of innovative approaches for onsite management of PFAS-impacted investigation derived waste. WATER RESEARCH 2023; 247:120769. [PMID: 37931356 DOI: 10.1016/j.watres.2023.120769] [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: 09/10/2023] [Revised: 10/19/2023] [Accepted: 10/20/2023] [Indexed: 11/08/2023]
Abstract
The historic use of aqueous film-forming foam (AFFF) has led to widespread detection of per- and polyfluoroalkyl substance (PFAS) in groundwater, soils, sediments, drinking water, wastewater, and receiving aquatic systems throughout the United States (U.S.). Prior to any remediation activities, in order to identify the PFAS-impacted source zones and select the optimum management approach, extensive site investigations need to be conducted. These site investigations have resulted in the generation of considerable amount of investigation-derived waste (IDW) which predominantly consists of well purging water and drill fluid, equipment washing residue, soil, drill cuttings, and residues from the destruction of asphalt and concrete surfaces. IDW is often impacted by varying levels of PFAS which poses a substantial challenge concerning disposal to prevent potential mobilization of PFAS, logistical complexities, and increasing requirement for storage as a result of accumulation of the associated wastes. The distinct features of IDW involve the intermittent generation of waste, substantial volume of waste produced, and the critical demand for onsite management. This article critically focuses on innovative technologies and approaches employed for onsite treatment and management of PFAS-impacted IDW. The overall objective of this study centers on developing and deploying end-of-life treatment technology systems capable of facilitating unrestricted disposal, discharge, and/or IDW reuse on-site, thereby reducing spatial footprints and mobilization time.
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Affiliation(s)
- Hooman Vatankhah
- Strategic Environmental Research and Development Program and the Environmental Security Technology Certification Program, Arlington, VA, USA; Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA; Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO, USA.
| | | | | | | | - Andrea Leeson
- Strategic Environmental Research and Development Program and the Environmental Security Technology Certification Program, Arlington, VA, USA
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13
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Li Z, Lu Y, Chen T, He A, Huang Y, Li L, Pan W, Li J, Zhu N, Wang Y, Jiang G. Generation Mechanism of Perfluorohexanesulfonic Acid from Polyfluoroalkyl Sulfonamide Derivatives During Chloramination in Drinking Water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:18462-18472. [PMID: 36633968 DOI: 10.1021/acs.est.2c07881] [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: 06/17/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs), including perfluorohexanesulfonic acid (PFHxS), as emerging persistent organic pollutants widely detected in drinking water, have drawn increasing concern. The PFHxS contamination of drinking water always results from direct and indirect sources, especially the secondary generations through environmental transformations of precursors. However, the mechanism of the transformation of precursors to PFHXS during the drinking water treatment processes remains unclear. Herein, the potential precursors and formation mechanisms of PFHxS were explored during drinking water disinfection. Simultaneously, the factors affecting PFHxS generation were also examined. This study found PFHxS could be generated from polyfluoroalkyl sulfonamide derivatives during chlorination and chloramination. The fate and yield of PFHxS varied from different precursors and disinfection processes. In particular, monochloramine more favorably formed PFHxS. Several perfluoroalkyl oxidation products and decarboxylation intermediates were detected and identified in the chloraminated samples using Fourier-transform ion cyclotron resonance mass spectrometry. Combined with density functional theory calculations, the results indicated that the indirect oxidation via the attack of the nitrogen atom in sulfonamide groups might be the dominant pathway for generating PFHxS during chloramination, and the process could be highly affected by the monochloramine dose, pH, and temperature. This study provides important evidence of the secondary formation of PFHxS during drinking water disinfection and scientific support for chemical management of PFHxS and PFHxS-related compounds.
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Affiliation(s)
- Zhigang Li
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou310024, China
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
- University of Chinese Academy of Science, Beijing100049, China
| | - Yao Lu
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou310024, China
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
- University of Chinese Academy of Science, Beijing100049, China
| | - Tianyu Chen
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
- University of Chinese Academy of Science, Beijing100049, China
| | - Anen He
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
- University of Chinese Academy of Science, Beijing100049, China
| | - Ying Huang
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou310024, China
- University of Chinese Academy of Science, Beijing100049, China
| | - Lingxiangyu Li
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou310024, China
- University of Chinese Academy of Science, Beijing100049, China
| | - Wenxiao Pan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
- University of Chinese Academy of Science, Beijing100049, China
| | - Juan Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
- University of Chinese Academy of Science, Beijing100049, China
| | - Nali Zhu
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou310024, China
- University of Chinese Academy of Science, Beijing100049, China
| | - Yawei Wang
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou310024, China
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
- University of Chinese Academy of Science, Beijing100049, China
| | - Guibin Jiang
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou310024, China
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
- University of Chinese Academy of Science, Beijing100049, China
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14
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Wilsey MK, Taseska T, Meng Z, Yu W, Müller AM. Advanced electrocatalytic redox processes for environmental remediation of halogenated organic water pollutants. Chem Commun (Camb) 2023; 59:11895-11922. [PMID: 37740361 DOI: 10.1039/d3cc03176d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/24/2023]
Abstract
Halogenated organic compounds are widespread, and decades of heavy use have resulted in global bioaccumulation and contamination of the environment, including water sources. Here, we introduce the most common halogenated organic water pollutants, their classification by type of halogen (fluorine, chlorine, or bromine), important policies and regulations, main applications, and environmental and human health risks. Remediation techniques are outlined with particular emphasis on carbon-halogen bond strengths. Aqueous advanced redox processes are discussed, highlighting mechanistic details, including electrochemical oxidations and reductions of the water-oxygen system, and thermodynamic potentials, protonation states, and lifetimes of radicals and reactive oxygen species in aqueous electrolytes at different pH conditions. The state of the art of aqueous advanced redox processes for brominated, chlorinated, and fluorinated organic compounds is presented, along with reported mechanisms for aqueous destruction of select PFAS (per- and polyfluoroalkyl substances). Future research directions for aqueous electrocatalytic destruction of organohalogens are identified, emphasizing the crucial need for developing a quantitative mechanistic understanding of degradation pathways, the improvement of analytical detection methods for organohalogens and transient species during advanced redox processes, and the development of new catalysts and processes that are globally scalable.
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Affiliation(s)
- Madeleine K Wilsey
- Materials Science Program, University of Rochester, Rochester, New York 14627, USA.
| | - Teona Taseska
- Department of Chemical Engineering, University of Rochester, Rochester, New York 14627, USA
| | - Ziyi Meng
- Materials Science Program, University of Rochester, Rochester, New York 14627, USA.
| | - Wanqing Yu
- Department of Chemical Engineering, University of Rochester, Rochester, New York 14627, USA
| | - Astrid M Müller
- Materials Science Program, University of Rochester, Rochester, New York 14627, USA.
- Department of Chemical Engineering, University of Rochester, Rochester, New York 14627, USA
- Department of Chemistry, University of Rochester, Rochester, New York 14627, USA
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15
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Wang Y, Ji Y, Li K, Huang Q. Foam fractionation and electrochemical oxidation for the treatment of per- and polyfluoroalkyl substances (PFAS) in environmental water samples. CHEMOSPHERE 2023; 339:139615. [PMID: 37499808 DOI: 10.1016/j.chemosphere.2023.139615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 07/20/2023] [Accepted: 07/21/2023] [Indexed: 07/29/2023]
Abstract
Treatment of waters contaminated by per- and polyfluoroalkyl substances (PFAS) in large volumes remains a challenge to date. Treatment trains comprising separation and destruction technologies are promising to manage PFAS contamination. Foam fractionation (FF) and electrochemical oxidation (EO) are two cost-effective technologies for PFAS separation and destruction, respectively. This work systematically explored the performance of a treatment train of FF followed by EO (FF-EO) for treating PFAS in environmental water samples. For each treatment step, the dependence of the treatment performance on operational factors and other variables were analyzed statistically. The statistical analysis revealed PFAS enrichment and removal depend significantly on PFAS carbon chain length, solution conductivity, and PFAS concentration. Whether FF-EO treatment costs less energy than direct EO without FF mainly relies upon PFAS carbon chain length and TOC content in the sample. Both correlations were found to be linear. For all environmental water samples in this study, FF-EO is more energy-efficient than EO alone.
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Affiliation(s)
- Yifei Wang
- Department of Crop and Soil Sciences, University of Georgia, Griffin, GA, 30223, USA
| | - Yuqing Ji
- Department of Crop and Soil Sciences, University of Georgia, Griffin, GA, 30223, USA
| | - Ke Li
- College of Engineering, University of Georgia, Athens, GA, 30602, USA
| | - Qingguo Huang
- Department of Crop and Soil Sciences, University of Georgia, Griffin, GA, 30223, USA.
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16
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Duinslaeger N, Doni A, Radjenovic J. Impact of supporting electrolyte on electrochemical performance of borophene-functionalized graphene sponge anode and degradation of per- and polyfluoroalkyl substances (PFAS). WATER RESEARCH 2023; 242:120232. [PMID: 37352674 DOI: 10.1016/j.watres.2023.120232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 06/13/2023] [Accepted: 06/14/2023] [Indexed: 06/25/2023]
Abstract
Graphene sponge anode functionalized with two-dimensional (2D) boron, i.e., borophene, was applied for electrochemical oxidation of C4-C8 per- and polyfluoroalkyl substances (PFASs). Borophene-doped graphene sponge outperformed boron-doped graphene sponge anode in terms of PFASs removal efficiencies and their electrochemical degradation; whereas at the boron-doped graphene sponge anode up to 35% of the removed PFASs was recovered after the current was switched off, the switch to a 2D boron enabled further degradation of the electrosorbed PFASs. Borophene-doped graphene sponge anode achieved 32-77% removal of C4-C8 PFASs in one-pass flow-through mode from a 10 mM phosphate buffer at 230 A m-2 of anodic current density. Higher molarity phosphate buffer (100 mM) resulted in lower PFASs removal efficiencies (11-60%) due to the higher resistance of the graphene sponge electrode in the presence of phosphate ions, as demonstrated by the electrochemical impedance spectroscopy (EIS) analyses. Electro-oxidation of PFASs was more efficient in landfill leachate despite its high organic loading, with up to 95% and 75% removal obtained for perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), versus 77% and 57% removal in the 10 mM phosphate buffer, respectively. Defluorination efficiencies as determined relative to the electrooxidized fraction of PFASs indicated up to 69% and 82% of defluorination of PFOS and PFOA in 10 mM phosphate buffer, which was decreased to 16 and 29% defluorination, respectively, for higher buffer molarity (100 mM) due to the worsened electrochemical performance of the sponge. In landfill leachate, relative defluorination efficiencies of PFOS and PFOA were 33% and 45%, respectively, indicating the inhibiting effect of complex organic and inorganic matrix of landfill leachate on the C-F bond breakage. This study demonstrates that electrochemical degradation of PFASs is possible to achieve in complex and brackish streams using a low-cost graphene sponge anode, without forming toxic chlorinated byproducts even in the presence of >7 g L-1 of chloride.
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Affiliation(s)
- Nick Duinslaeger
- Catalan Institute for Water Research (ICRA-CERCA), Emili Grahit 101, Girona 17003, Spain; University of Girona, Plaça de Sant Domènec, 3, 17004 Girona, Spain
| | - Ariadni Doni
- Catalan Institute for Water Research (ICRA-CERCA), Emili Grahit 101, Girona 17003, Spain; Aristotle University of Thessaloniki, Thessaloniki 541, 24, Greece
| | - Jelena Radjenovic
- Catalan Institute for Water Research (ICRA-CERCA), Emili Grahit 101, Girona 17003, Spain; Catalan Institution for Research and Advanced Studies (ICREA), Passeig Lluís Companys 23, Barcelona 08010, Spain.
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17
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Wang Z, Anand D, He Z. Phosphorus Recovery from Whole Digestate through Electrochemical Leaching and Precipitation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023. [PMID: 37364242 DOI: 10.1021/acs.est.3c02843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
Phosphorus (P) recovery from biosolids can play an important role in a circular economy. Herein, an electrochemical phosphorus recovery cell (EPRC) was proposed and examined to recover P from municipal whole digestate via simultaneous leaching and precipitation. The anode of the EPRC released P as aqueous PO43--P through acidification, achieving the highest leaching efficiency of 93.3% under a current density of 30 A m-2. When the leached P solution was treated in the cathode, native metals including Ca and Fe facilitated electrochemically mediated PO43--P precipitation (EMP) and precipitated ∼99% of the leached P in the cathode chamber. Around 54.3-78.7% of total P existed in two harvestable forms: suspended solids in the cathode effluent and immobilized P in the cathode chamber. The solid products contained 28.42-33.51% of P2O5, comparable to the high-grade phosphate rock. Higher current densities reduced cathode scaling and resulted in a lower content of heavy metals in the solid products. An acidic solution was reused three times and effectively maintained cathode performance during a 42-cycle operation, achieving a consistent P recovery efficiency of nearly 80%. Those results have demonstrated the feasibility of the EPRC for recovering P from P-rich solid wastes.
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Affiliation(s)
- Zixuan Wang
- Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Daran Anand
- Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Zhen He
- Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
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18
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Najafinejad MS, Chianese S, Fenti A, Iovino P, Musmarra D. Application of Electrochemical Oxidation for Water and Wastewater Treatment: An Overview. Molecules 2023; 28:molecules28104208. [PMID: 37241948 DOI: 10.3390/molecules28104208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 05/15/2023] [Accepted: 05/18/2023] [Indexed: 05/28/2023] Open
Abstract
In recent years, the discharge of various emerging pollutants, chemicals, and dyes in water and wastewater has represented one of the prominent human problems. Since water pollution is directly related to human health, highly resistant and emerging compounds in aquatic environments will pose many potential risks to the health of all living beings. Therefore, water pollution is a very acute problem that has constantly increased in recent years with the expansion of various industries. Consequently, choosing efficient and innovative wastewater treatment methods to remove contaminants is crucial. Among advanced oxidation processes, electrochemical oxidation (EO) is the most common and effective method for removing persistent pollutants from municipal and industrial wastewater. However, despite the great progress in using EO to treat real wastewater, there are still many gaps. This is due to the lack of comprehensive information on the operating parameters which affect the process and its operating costs. In this paper, among various scientific articles, the impact of operational parameters on the EO performances, a comparison between different electrochemical reactor configurations, and a report on general mechanisms of electrochemical oxidation of organic pollutants have been reported. Moreover, an evaluation of cost analysis and energy consumption requirements have also been discussed. Finally, the combination process between EO and photocatalysis (PC), called photoelectrocatalysis (PEC), has been discussed and reviewed briefly. This article shows that there is a direct relationship between important operating parameters with the amount of costs and the final removal efficiency of emerging pollutants. Optimal operating conditions can be achieved by paying special attention to reactor design, which can lead to higher efficiency and more efficient treatment. The rapid development of EO for removing emerging pollutants from impacted water and its combination with other green methods can result in more efficient approaches to face the pressing water pollution challenge. PEC proved to be a promising pollutants degradation technology, in which renewable energy sources can be adopted as a primer to perform an environmentally friendly water treatment.
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Affiliation(s)
| | - Simeone Chianese
- Department of Engineering, University of Campania "Luigi Vanvitelli", Via Roma 29, 81031 Aversa, Italy
| | - Angelo Fenti
- Department of Engineering, University of Campania "Luigi Vanvitelli", Via Roma 29, 81031 Aversa, Italy
| | - Pasquale Iovino
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania "Luigi Vanvitelli", Via Vivaldi 43, 81100 Caserta, Italy
| | - Dino Musmarra
- Department of Engineering, University of Campania "Luigi Vanvitelli", Via Roma 29, 81031 Aversa, Italy
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19
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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: 0] [Impact Index Per Article: 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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20
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Smith SJ, Lauria M, Ahrens L, McCleaf P, Hollman P, Bjälkefur Seroka S, Hamers T, Arp HPH, Wiberg K. Electrochemical Oxidation for Treatment of PFAS in Contaminated Water and Fractionated Foam-A Pilot-Scale Study. ACS ES&T WATER 2023; 3:1201-1211. [PMID: 37090120 PMCID: PMC10111409 DOI: 10.1021/acsestwater.2c00660] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 03/02/2023] [Accepted: 03/03/2023] [Indexed: 05/03/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are persistent synthetic contaminants that are present globally in water and are exceptionally difficult to remove during conventional water treatment processes. Here, we demonstrate a practical treatment train that combines foam fractionation to concentrate PFAS from groundwater and landfill leachate, followed by an electrochemical oxidation (EO) step to degrade the PFAS. The study combined an up-scaled experimental approach with thorough characterization strategies, including target analysis, PFAS sum parameters, and toxicity testing. Additionally, the EO kinetics were successfully reproduced by a newly developed coupled numerical model. The mean total PFAS degradation over the designed treatment train reached 50%, with long- and short-chain PFAS degrading up to 86 and 31%, respectively. The treatment resulted in a decrease in the toxic potency of the water, as assessed by transthyretin binding and bacterial bioluminescence bioassays. Moreover, the extractable organofluorine concentration of the water decreased by up to 44%. Together, these findings provide an improved understanding of a promising and practical approach for on-site remediation of PFAS-contaminated water.
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Affiliation(s)
- Sanne J. Smith
- Department
of Aquatic Sciences and Assessment, Swedish
University of Agricultural Sciences (SLU), P.O. Box 7050, SE-750 07 Uppsala, Sweden
| | - Melanie Lauria
- Department
of Environmental Science, Stockholm University, Svante Arrhenius Väg 8, 10691 Stockholm, Sweden
| | - Lutz Ahrens
- Department
of Aquatic Sciences and Assessment, Swedish
University of Agricultural Sciences (SLU), P.O. Box 7050, SE-750 07 Uppsala, Sweden
| | - Philip McCleaf
- Uppsala
Water and Waste AB, P.O. Box 1444, SE-751 44 Uppsala, Sweden
| | | | | | - Timo Hamers
- Amsterdam
Institute for Life and Environment (A-LIFE), Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | - Hans Peter H. Arp
- Norwegian
Geotechnical Institute (NGI), P.O. Box
3930, Ullevål Stadion, NO-0806 Oslo, Norway
- Department
of Chemistry, Norwegian University of Science
and Technology (NTNU), NO-7491 Trondheim, Norway
| | - Karin Wiberg
- Department
of Aquatic Sciences and Assessment, Swedish
University of Agricultural Sciences (SLU), P.O. Box 7050, SE-750 07 Uppsala, Sweden
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21
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Aumeier BM, Georgi A, Saeidi N, Sigmund G. Is sorption technology fit for the removal of persistent and mobile organic contaminants from water? THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 880:163343. [PMID: 37030383 DOI: 10.1016/j.scitotenv.2023.163343] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 03/21/2023] [Accepted: 04/03/2023] [Indexed: 04/15/2023]
Abstract
Persistent, Mobile, and Toxic (PMT) and very persistent and very mobile (vPvM) substances are a growing threat to water security and safety. Many of these substances are distinctively different from other more traditional contaminants in terms of their charge, polarity, and aromaticity. This results in distinctively different sorption affinities towards traditional sorbents such as activated carbon. Additionally, an increasing awareness on the environmental impact and carbon footprint of sorption technologies puts some of the more energy-intensive practices in water treatment into question. Commonly used approaches may thus need to be readjusted to become fit for purpose to remove some of the more challenging PMT and vPvM substances, including for example short chained per- and polyfluoroalkyl substances (PFAS). We here critically review the interactions that drive sorption of organic compounds to activated carbon and related sorbent materials and identify opportunities and limitations of tailoring activated carbon for PMT and vPvM removal. Other less traditional sorbent materials, including ion exchange resins, modified cyclodextrins, zeolites and metal-organic frameworks are then discussed for potential alternative or complementary use in water treatment scenarios. Sorbent regeneration approaches are evaluated in terms of their potential, considering reusability, potential for on-site regeneration, and potential for local production. In this context, we also discuss the benefits of coupling sorption to destructive technologies or to other separation technologies. Finally, we sketch out possible future trends in the evolution of sorption technologies for PMT and vPvM removal from water.
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Affiliation(s)
- Benedikt M Aumeier
- RWTH Aachen University, Institute of Environmental Engineering, Mies-van-der-Rohe-Strasse 1, 52074 Aachen, Germany.
| | - Anett Georgi
- Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Engineering, 04318 Leipzig, Germany
| | - Navid Saeidi
- Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Engineering, 04318 Leipzig, Germany
| | - Gabriel Sigmund
- Department of Environmental Geosciences, Centre for Microbiology and Environmental Systems Science, University of Vienna, 1090 Wien, Austria; Environmental Technology, Wageningen University & Research, P.O. Box 17, 6700 AA Wageningen, the Netherlands.
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22
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Mirabediny M, Sun J, Yu TT, Åkermark B, Das B, Kumar N. Effective PFAS degradation by electrochemical oxidation methods-recent progress and requirement. CHEMOSPHERE 2023; 321:138109. [PMID: 36787844 DOI: 10.1016/j.chemosphere.2023.138109] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 02/02/2023] [Accepted: 02/08/2023] [Indexed: 06/18/2023]
Abstract
The presence of per- and poly-fluoroalkyl substances (PFASs) in water is of global concern due to their high stability and toxicity even at very low concentrations. There are several technologies for the remediation of PFASs, but most of them are inadequate either due to limited effectiveness, high cost, or production of a large amount of sludge. Electrochemical oxidation (EO) technology shows great potential for large-scale application in the degradation of PFASs due to its simple procedure, low loading of chemicals, and least amount of waste. Here, we have reviewed the recent progress in EO methods for PFAS degradation, focusing on the last 10 years, to explore an efficient, cost-effective, and environmentally benign remediation technology. The effects of important parameters (e.g., anode material, current density, solution pH, electrolyte, plate distance, and electrical connector type) are summarized and evaluated. Also, the energy consumption, the consequence of different PFASs functional groups, and water matrices are discussed to provide an insight that is pivotal for developing new EO materials and technologies. The proposed degradation pathways of shorter-chain PFAS by-products during EO of PFAS are also discussed.
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Affiliation(s)
- Maryam Mirabediny
- School of Chemistry, University of New South Wales (UNSW) Sydney, Sydney, 2052, Australia
| | - Jun Sun
- School of Chemistry, University of New South Wales (UNSW) Sydney, Sydney, 2052, Australia
| | - Tsz Tin Yu
- School of Chemistry, University of New South Wales (UNSW) Sydney, Sydney, 2052, Australia
| | - Björn Åkermark
- Department of Organic Chemistry, Arrhenius Laboratory Stockholm University, Svante Arrhenius väg 16C, 10691, Stockholm, Sweden
| | - Biswanath Das
- Department of Organic Chemistry, Arrhenius Laboratory Stockholm University, Svante Arrhenius väg 16C, 10691, Stockholm, Sweden.
| | - Naresh Kumar
- School of Chemistry, University of New South Wales (UNSW) Sydney, Sydney, 2052, Australia.
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23
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Deng Y, Wang F, Liu L, Chen D, Guo Y, Li Z. High density polyethylene (HDPE) and thermoplastic polyurethane (TPU) wristbands as personal passive samplers monitoring per- and polyfluoroalkyl substances (PFASs) exposure to postgraduate students. JOURNAL OF HAZARDOUS MATERIALS 2023; 446:130652. [PMID: 36603420 DOI: 10.1016/j.jhazmat.2022.130652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/30/2022] [Accepted: 12/20/2022] [Indexed: 06/17/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs) present adverse effects for human health, which result in strong needs for reliable tools monitoring personal exposure to PFASs. This study manufactured two wristbands of high density polyethylene (HDPE) and thermoplastic polyurethane (TPU), and used the wristbands to monitor PFASs personal exposure. The analytical method was developed to measure 32 PFASs in the paired HDPE and TPU wristbands worn by 60 postgraduates. Twenty-nine of 32 PFASs were detected and hexafluoropropylene oxide dimer acid (HFPO-DA) was predominant individual PFASs with median concentrations of 337 and 554 pg/g for HDPE and TPU wristbands respectively. The gender and grade of students had moderate effects on PFASs distribution in the wristbands. Higher PFASs levels were determined in the two wristbands worn by the male students compared to the females, and the greatest PFASs concentration was observed in the wristbands worn by the first-year postgraduates, follow by second- and third-year postgraduates. Additionally, significant correlations between paired HDPE and TPU wristbands were observed for perfluorobutanoic acid (PFBA), perfluorohexane sulfonic acid (PFHxS), perfluoroheptane sulfonic acid (PFHpS), perfluorooctane sulfonic acid (PFOS), and HFPO-DA. These results suggest that HDPE and TPU wristbands can be used as effective tools for monitoring personal PFAS exposure.
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Affiliation(s)
- Yun Deng
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 510632, China
| | - Fei Wang
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 510632, China.
| | - Liangying Liu
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 510632, China
| | - Da Chen
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 510632, China
| | - Ying Guo
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, 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
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24
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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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25
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Sivagami K, Sharma P, Karim AV, Mohanakrishna G, Karthika S, Divyapriya G, Saravanathamizhan R, Kumar AN. Electrochemical-based approaches for the treatment of forever chemicals: Removal of perfluoroalkyl and polyfluoroalkyl substances (PFAS) from wastewater. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 861:160440. [PMID: 36436638 DOI: 10.1016/j.scitotenv.2022.160440] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 11/19/2022] [Accepted: 11/19/2022] [Indexed: 06/16/2023]
Abstract
Electrochemical based approaches for the treatment of recalcitrant water borne pollutants are known to exhibit superior function in terms of efficiency and rate of treatment. Considering the stability of Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are designated as forever chemicals, which generating from various industrial activities. PFAS are contaminating the environment in small concentrations, yet exhibit severe environmental and health impacts. Electro-oxidation (EO) is a recent development that treats PFAS, in which different reactive species generates at anode due to oxidative reaction and reductive reactions at the cathode. Compared to water and wastewater treatment methods those being implemented, electrochemical approaches demonstrate superior function against PFAS. EO completely mineralizes (almost 100 %) non-biodegradable organic matter and eliminate some of the inorganic species, which proven as a robust and versatile technology. Electrode materials, electrolyte concentration pH and the current density applying for electrochemical processes determine the treatment efficiency. EO along with electrocoagulation (EC) treats PFAS along with other pollutants from variety of industries showed highest degradation of 7.69 mmol/g of PFAS. Integrated approach with other processes was found to exhibit improved efficiency in treating PFAS using several electrodes boron-doped diamond (BDD), zinc, titanium and lead based with efficiency the range of 64 to 97 %.
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Affiliation(s)
- K Sivagami
- Industrial Ecology Research Group, School of Chemical Engineering, Vellore Institute of Technology, Vellore, India.
| | - Pranshu Sharma
- Industrial Ecology Research Group, School of Chemical Engineering, Vellore Institute of Technology, Vellore, India
| | - Ansaf V Karim
- Environmental Science and Engineering, Indian Institute of Technology, Bombay, Powai, Mumbai, India
| | - Gunda Mohanakrishna
- School of Advanced Sciences, KLE Technological University, Hubli 580031, India.
| | - S Karthika
- Industrial Ecology Research Group, School of Chemical Engineering, Vellore Institute of Technology, Vellore, India
| | - G Divyapriya
- Swiss Government Excellence Postdoctoral Scholar, Multi-Scale Robotics Lab (MSRL), Swiss Federal Institute of Technology (ETH) Zurich, Switzerland
| | - R Saravanathamizhan
- Department of Chemical Engineering, A.C. College of Technology, Anna University, India
| | - A Naresh Kumar
- Department of Environmental Science and Technology, University of Maryland, College Park, MD 20742, USA
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26
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Fang Y, Meng P, Schaefer C, Knappe DRU. Removal and destruction of perfluoroalkyl ether carboxylic acids (PFECAs) in an anion exchange resin and electrochemical oxidation treatment train. WATER RESEARCH 2023; 230:119522. [PMID: 36577256 DOI: 10.1016/j.watres.2022.119522] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 11/18/2022] [Accepted: 12/18/2022] [Indexed: 06/17/2023]
Abstract
Perfluoroalkyl ether carboxylic acids (PFECAs) are a group of emerging recalcitrant contaminants that are being developed to replace legacy per- and polyfluoroalkyl substances (PFAS) in industrial applications and that are generated as by-products in fluoropolymer manufacturing. Here, we report on the removal and destruction of four structurally different PFECAs using an integrated anion exchange resin (AER) and electrochemical oxidation (ECO) treatment train. Results from this work illustrated that (1) flow-through columns packed with PFAS-selective AERs are highly effective for the removal of PFECAs and (2) PFECA affinity is strongly correlated with their hydrophobic features. Regeneration of the spent resin columns revealed that high percentage (e.g., 80%) of organic cosolvent is necessary for achieving 60-100% PFECA release, and regeneration efficiency was higher for a macroporous resin than a gel-type resin. Treatment of spent regenerants showed (1) >99.99% methanol removal was achieved by distillation, (2) >99.999% conversion of the four studied PFECAs was achieved during the ECO treatment of the still bottoms after 24 hours with an energy per order of magnitude of PFECA removal (EE/O) <1.03 kWh/m3 of total groundwater treated, and (3) >85% of the organic fluorine was recovered as inorganic fluoride. Trifluoroacetic acid (TFA), perfluoropropionic acid (PFPrA), and perfluoro-2-methoxyacetic acid (PFMOAA) were confirmed via high-resolution mass spectrometry as transformation products (TPs) in the treated still bottoms, and two distinctive degradation schemes and four reaction pathways are proposed for the four PFECAs. Lastly, dissolved organic matter (DOM) inhibited uptake, regeneration, and oxidation of PFECAs throughout the treatment train, suggesting pretreatment steps targeting DOM removal can enhance the system's treatment efficiency. Results from this work provide guidelines for developing effective separation-concentration-destruction treatment trains and meaningful insights for achieving PFECA destruction in impacted aquatic systems.
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Affiliation(s)
- Yida Fang
- CDM Smith, 14432 SE Eastgate Way, #100, Bellevue, Washington 98007, United States.
| | - Pingping Meng
- North Carolina State University, 915 Partners Way, Raleigh, North Carolina 27695, United States
| | - Charles Schaefer
- CDM Smith, 110 Fieldcrest Avenue, #8, Edison, New Jersey 08837, United States
| | - Detlef R U Knappe
- North Carolina State University, 915 Partners Way, Raleigh, North Carolina 27695, United States
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27
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Yang N, Yang S, Ma Q, Beltran C, Guan Y, Morsey M, Brown E, Fernando S, Holsen TM, Zhang W, Yang Y. Solvent-Free Nonthermal Destruction of PFAS Chemicals and PFAS in Sediment by Piezoelectric Ball Milling. ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS 2023; 10:198-203. [PMID: 37034438 PMCID: PMC10074478 DOI: 10.1021/acs.estlett.2c00902] [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: 12/02/2022] [Revised: 01/03/2023] [Accepted: 01/04/2023] [Indexed: 06/19/2023]
Abstract
Studies on the destruction of solid per- and polyfluoroalkyl substances (PFAS) chemicals and PFAS-laden solid wastes significantly lag behind the urgent social demand. There is a great need to develop novel treatment processes that can destroy nonaqueous PFAS at ambient temperatures and pressures. In this study, we develop a piezoelectric-material-assisted ball milling (PZM-BM) process built on the principle that ball collisions during milling can activate PZMs to generate ∼kV potentials for PFAS destruction in the absence of solvents. Using boron nitride (BN), a typical PZM, as an example, we successfully demonstrate the complete destruction and near-quantitative (∼100%) defluorination of solid PFOS and perfluorooctanoic acid (PFOA) after a 2 h treatment. This process was also used to treat PFAS-contaminated sediment. Approximately 80% of 21 targeted PFAS were destroyed after 6 h of treatment. The reaction mechanisms were determined to be a combination of piezo-electrochemical oxidation of PFAS and fluorination of BN. The PZM-BM process demonstrates many potential advantages, as the degradation of diverse PFAS is independent of functional group and chain configurations and does not require caustic chemicals, heating, or pressurization. This pioneering study lays the groundwork for optimizing PZM-BM to treat various PFAS-laden solid wastes.
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Affiliation(s)
- Nanyang Yang
- Department
of Civil and Environmental Engineering, Clarkson University, Potsdam, New York13699, United States
| | - Shasha Yang
- Department
of Civil and Environmental Engineering, Clarkson University, Potsdam, New York13699, United States
- Institute
for a Sustainable Environment, Clarkson
University, Potsdam, New York13699, United States
| | - Qingquan Ma
- John
A. Reif, Jr. Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, New Jersey07102, United States
| | - Claudia Beltran
- Department
of Civil and Environmental Engineering, Clarkson University, Potsdam, New York13699, United States
| | - Yunqiao Guan
- Department
of Civil and Environmental Engineering, Clarkson University, Potsdam, New York13699, United States
| | - Madison Morsey
- Department
of Chemistry and Biomolecular Science, Clarkson
University, Potsdam, New York13699, United States
| | - Elizabeth Brown
- Department
of Civil and Environmental Engineering, Clarkson University, Potsdam, New York13699, United States
| | - Sujan Fernando
- Department
of Civil and Environmental Engineering, Clarkson University, Potsdam, New York13699, United States
| | - Thomas M. Holsen
- Department
of Civil and Environmental Engineering, Clarkson University, Potsdam, New York13699, United States
| | - Wen Zhang
- John
A. Reif, Jr. Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, New Jersey07102, United States
| | - Yang Yang
- Department
of Civil and Environmental Engineering, Clarkson University, Potsdam, New York13699, United States
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28
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Li Z, Luo ZM, Huang Y, Wang JW, Ouyang G. Recent trends in degradation strategies of PFOA/PFOS substitutes. CHEMOSPHERE 2023; 315:137653. [PMID: 36581124 DOI: 10.1016/j.chemosphere.2022.137653] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/21/2022] [Accepted: 12/23/2022] [Indexed: 06/17/2023]
Abstract
The global elimination and restriction of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), respectively, have urged manufacturers to shift production to their substitutes which still pose threat to the environment with their bioaccumulation, toxicity and migration issues. In this context, efficient technologies and systematic mechanistic studies on the degradation of PFOA/PFOS substitutes are highly desirable. In this review, we summarize the progress in degrading PFOA/PFOS substitutes, including four kinds of mainstream methods. The pros and cons of the present technologies are analyzed, which renders the discussion of future prospects on rational optimizations. Additional discussion is made on the differences in the degradation of various kinds of substitutes, which is compared to the PFOA/PFOS and derives designing principles for more degradable F-containing compounds.
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Affiliation(s)
- Zizi Li
- KLGHEI of Environment and Energy Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China
| | - Zhi-Mei Luo
- KLGHEI of Environment and Energy Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China
| | - Yanjun Huang
- KLGHEI of Environment and Energy Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China
| | - Jia-Wei Wang
- KLGHEI of Environment and Energy Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China.
| | - Gangfeng Ouyang
- KLGHEI of Environment and Energy Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China.
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29
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Asadi Zeidabadi F, Banayan Esfahani E, McBeath ST, Dubrawski KL, Mohseni M. Electrochemical degradation of PFOA and its common alternatives: Assessment of key parameters, roles of active species, and transformation pathway. CHEMOSPHERE 2023; 315:137743. [PMID: 36608884 DOI: 10.1016/j.chemosphere.2023.137743] [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: 11/07/2022] [Revised: 12/24/2022] [Accepted: 01/02/2023] [Indexed: 06/17/2023]
Abstract
This study investigates an electrochemical approach for the treatment of water polluted with per- and poly-fluoroalkyl substances (PFAS), looking at the impact of different variables, contributions from generated radicals, and degradability of different structures of PFAS. Results obtained from a central composite design (CCD) showed the importance of mass transfer, related to the stirring speed, and the amount of charge passed through the electrodes, related to the current density on decomposition rate of PFOA. The CCD informed optimized operating conditions which we then used to study the impact of solution conditions. Acidic condition, high temperature, and low initial concentration of PFOA accelerated the degradation kinetic, while DO had a negligible effect. The impact of electrolyte concentration depended on the initial concentration of PFOA. At low initial PFOA dosage (0.2 mg L-1), the rate constant increased considerably from 0.079 ± 0.001 to 0.259 ± 0.019 min-1 when sulfate increased from 0.1% to 10%, likely due to the production of SO4•-. However, at higher initial PFOA dosage (20 mg L-1), the rate constant decreased slightly from 0.019 ± 0.001 to 0.015 ± 0.000 min-1, possibly due to the occupation of active anode sites by excess amount of sulfate. SO4•- and •OH played important roles in decomposition and defluorination of PFOA, respectively. PFOA oxidation was initiated by one electron transfer to the anode or SO4•-, undergoing Kolbe decarboxylation where yielded perfluoroalkyl radical followed three reaction pathways with •OH, O2 and/or H2O. PFAS electrooxidation depended on the chemical structures where the decomposition rate constants (min-1) were in the order of 6:2 FTCA (0.031) > PFOA (0.019) > GenX (0.013) > PFBA (0.008). PFBA with a shorter chain length and GenX with -CF3 branching had slower decomposition than PFOA. While presence of C-H bonds makes 6:2 FTCA susceptible to the attack of •OH accelerating its decomposition kinetic. Conducting experiments in mixed solution of all studied PFAS and in natural water showed that the co-presence of PFAS and other water constituents (organic and inorganic matters) had adverse effects on PFAS decomposition efficiency.
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Affiliation(s)
- Fatemeh Asadi Zeidabadi
- 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
| | - Sean T McBeath
- Department of Civil and Environmental Engineering, University of Massachusetts Amherst, Amherst, MA 01002, United States
| | - Kristian L Dubrawski
- Department of Civil Engineering, University of Victoria, Victoria, BC, V8P 5C2, Canada
| | - Madjid Mohseni
- Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, Canada.
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30
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Zhang M, Zhao X, Zhao D, Soong TY, Tian S. Poly- and Perfluoroalkyl Substances (PFAS) in Landfills: Occurrence, Transformation and Treatment. WASTE MANAGEMENT (NEW YORK, N.Y.) 2023; 155:162-178. [PMID: 36379166 DOI: 10.1016/j.wasman.2022.10.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 10/21/2022] [Accepted: 10/24/2022] [Indexed: 06/16/2023]
Abstract
Landfills have served as the final repository for > 50 % municipal solid wastes in the United States. Because of their widespread uses and persistence in the environment, per- and polyfluoroalkyl substances (PFAS) (>4000 on the global market) are ubiquitously present in everyday consumer, commercial and industrial products, and have been widely detected in both closed (tens ng/L) and active (thousands to ten thousands ng/L) landfills due to disposal of PFAS-containing materials. Along with the decomposition of wastes in-place, PFAS can be transformed and released from the wastes into leachate and landfill gas. Consequently, it is critical to understand the occurrence and transformation of PFAS in landfills and the effectiveness of landfills, as a disposal alternative, for long-term containment of PFAS. This article presents a state-of-the-art review on the occurrence and transformation of PFAS in landfills, and possible effect of PFAS on the integrity of modern liner systems. Based on the data published from 10 countries (250 + landfills), C4-C7 perfluoroalkyl carboxylic acids were found predominant in the untreated landfill leachate and neutral PFAS, primarily fluorotelomer alcohols, in landfill air. The effectiveness and limitations of the conventional leachate treatment technologies and emerging technologies were also evaluated to address PFAS released into the leachate. Among conventional technologies, reverse osmosis (RO) may achieve a high removal efficiency of 90-100 % based on full-scale data, which, however, is vulnerable to the organic fouling and requires additional disposal of the concentrate. Implications of these knowledge on PFAS management at landfills are discussed and major knowledge gaps are identified.
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Affiliation(s)
- Man Zhang
- CTI and Associates, Inc., 34705 W 12 Mile Rd Suite 230, Farmington Hills, MI 48331, USA.
| | - Xianda Zhao
- CTI and Associates, Inc., 34705 W 12 Mile Rd Suite 230, Farmington Hills, MI 48331, USA
| | - Dongye Zhao
- Environmental Engineering Program, Department of Civil & Environmental Engineering, Auburn University, Auburn AL 36849, USA; Department of Civil, Construction and Environmental Engineering, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USA.
| | - Te-Yang Soong
- CTI and Associates, Inc., 34705 W 12 Mile Rd Suite 230, Farmington Hills, MI 48331, USA
| | - Shuting Tian
- Environmental Engineering Program, Department of Civil & Environmental Engineering, Auburn University, Auburn AL 36849, USA; Institute of Environmental Science, Taiyuan University of Science and Technology, Taiyuan, Shanxi 030024, China
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31
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New Magnetically Assembled Electrode Consisting of Magnetic Activated Carbon Particles and Ti/Sb-SnO2 for a More Flexible and Cost-Effective Electrochemical Oxidation Wastewater Treatment. Catalysts 2022. [DOI: 10.3390/catal13010007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Magnetic activated carbon particles (Fe3O4/active carbon composites) as auxiliary electrodes (AEs) were fixed on the surface of Ti/Sb-SnO2 foil by a NdFeB magnet to form a new magnetically assembled electrode (MAE). Characterizations including cyclic voltammetry, Tafel analysis, and electrochemical impedance spectroscopy were carried out. The electrochemical oxidation performances of the new MAE towards different simulated wastewaters (azo dye acid red G, phenol, and lignosulfonate) were also studied. Series of the electrochemical properties of MAE were found to be varied with the loading amounts of AEs. The electrochemical area as well as the number of active sites increased significantly with the AEs loading, and the charge transfer was also facilitated by these AEs. Target pollutants’ removal of all simulated wastewaters were found to be enhanced when loading appropriate amounts of AEs. The accumulation of intermediate products was also determined by the AEs loading amount. This new MAE may provide a landscape of a more cost-effective and flexible electrochemical oxidation wastewater treatment (EOWT).
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Meegoda JN, Bezerra de Souza B, Casarini MM, Kewalramani JA. A Review of PFAS Destruction Technologies. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph192416397. [PMID: 36554276 PMCID: PMC9778349 DOI: 10.3390/ijerph192416397] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/19/2022] [Accepted: 12/02/2022] [Indexed: 05/13/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs) are a family of highly toxic emerging contaminants that have caught the attention of both the public and private sectors due to their adverse health impacts on society. The scientific community has been laboriously working on two fronts: (1) adapting already existing and effective technologies in destroying organic contaminants for PFAS remediation and (2) developing new technologies to remediate PFAS. A common characteristic in both areas is the separation/removal of PFASs from other contaminants or media, followed by destruction. The widely adopted separation technologies can remove PFASs from being in contact with humans; however, they remain in the environment and continue to pose health risks. On the other hand, the destructive technologies discussed here can effectively destroy PFAS compounds and fully address society's urgent need to remediate this harmful family of chemical compounds. This review reports and compare widely accepted as well as emerging PFAS destruction technologies. Some of the technologies presented in this review are still under development at the lab scale, while others have already been tested in the field.
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Investigating the reactivity of TiOx and BDD anodes for electro-oxidation of organic pollutants by experimental and modeling approaches. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2022.141513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Wang Y, Li L, Huang Q. Electrooxidation of per- and polyfluoroalkyl substances in chloride-containing water on surface-fluorinated Ti 4O 7 anodes: Mitigation and elimination of chlorate and perchlorate formation. CHEMOSPHERE 2022; 307:135877. [PMID: 35931258 DOI: 10.1016/j.chemosphere.2022.135877] [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: 06/16/2022] [Revised: 07/24/2022] [Accepted: 07/26/2022] [Indexed: 06/15/2023]
Abstract
Electrooxidation (EO) has been shown effective in degrading per- and polyfluoroalkyl substances (PFASs) in water, but concurrent formation of chlorate and perchlorate in the presence of chloride is of concern due to their toxicity. This study examined EO treatment of three representative PFASs, perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and 6:2 fluorotelomer sulfonate (6:2 FTS), in chloride-containing solutions on pristine and surface-fluorinated Ti4O7 anodes having different percentage of surface fluorination. The experiment results indicate that surface fluorination of Ti4O7 anodes slightly inhibited PFAS degradation, while significantly decreased the formation of chlorate and perchlorate. Further studies with spectroscopic and electrochemical characterizations and density functional theory (DFT) computation reveal the mechanisms of the impact on EO performance by anode fluorination. In particular, chlorate and perchlorate formation were fully inhibited when fluorinated Ti4O7 anode was used in reactive electrochemical membrane (REM) under a proper anodic potential range (<3.0 V vs Standard Hydrogen Electrode), resulting from slower intermediate reaction steps and short residence time of the REM system. The results of this study provide a basis for design and optimization of modified Ti4O7 anodes for efficient EO treatment of PFAS while limiting chlorate and perchlorate formation.
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Affiliation(s)
- Yaye Wang
- College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences, University of Georgia, Griffin, GA, 30223, United States
| | - Lei Li
- College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences, University of Georgia, Griffin, GA, 30223, United States
| | - Qingguo Huang
- College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences, University of Georgia, Griffin, GA, 30223, United States.
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Chen Z, Wang X, Feng H, Chen S, Niu J, Di G, Kujawski D, Crittenden JC. Electrochemical Advanced Oxidation of Perfluorooctanoic Acid: Mechanisms and Process Optimization with Kinetic Modeling. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:14409-14417. [PMID: 36173643 DOI: 10.1021/acs.est.2c02906] [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] [Indexed: 06/16/2023]
Abstract
Electrochemical advanced oxidation processes (EAOPs) are promising technologies for perfluorooctanoic acid (PFOA) degradation, but the mechanisms and preferred pathways for PFOA mineralization remain unknown. Herein, we proposed a plausible primary pathway for electrochemical PFOA mineralization using density functional theory (DFT) simulations and experiments. We neglected the unique effects of the anode surface and treated anodes as electron sinks only to acquire a general pathway. This was the essential first step toward fully revealing the primary pathway applicable to all anodes. Systematically exploring the roles of valence band holes (h+), hydroxyl radicals (HO•), and H2O, we found that h+, whose contribution was previously underestimated, dominated PFOA mineralization. Notably, the primary pathway did not generate short-chain perfluoroalkyl carboxylic acids (PFCAs), which were previously thought to be the main degradation intermediates, but generated other polyfluorinated alkyl substances (PFASs) that were rapidly degraded upon formation. Also, we developed a simplified kinetic model, which considered all of the main processes (mass transfer with electromigration included, surface adsorption/desorption, and oxidation on the anode surface), to simulate PFOA degradation in EAOPs. Our model can predict PFOA concentration profiles under various current densities, initial PFOA concentrations, and flow velocities.
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Affiliation(s)
- Zefang Chen
- Brook Byers Institute of Sustainable Systems, School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30308, United States
| | - Xiaojun Wang
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, P. R. China
| | - Hualiang Feng
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, P. R. China
| | - Shaohua Chen
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, P. R. China
| | - Junfeng Niu
- College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, P. R. China
| | - Guanglan Di
- School of Resources and Environment, Anhui Agricultural University, Hefei 230036, P. R. China
| | - David Kujawski
- Refinery Water Engineering & Associates, Hydrocarbon Processing Water & Waste Technology, Inc., 15634 Wallisville Road, Houston, Texas 77042, United States
| | - John C Crittenden
- Brook Byers Institute of Sustainable Systems, School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30308, United States
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Li H, Liu G, Zhou B, Deng Z, Wang Y, Ma L, Yu Z, Zhou K, Wei Q. Periodic porous 3D boron-doped diamond electrode for enhanced perfluorooctanoic acid degradation. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.121556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Li C, Wang Y, Wang Y, Wang Z, Huang Q. Electrochemical oxidation combined with UV irradiation for synergistic removal of perfluorooctane sulfonate (PFOS) in water. JOURNAL OF HAZARDOUS MATERIALS 2022; 436:129091. [PMID: 35569375 DOI: 10.1016/j.jhazmat.2022.129091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 04/25/2022] [Accepted: 05/04/2022] [Indexed: 06/15/2023]
Abstract
The effect of electrochemical degradation on Magnéli phase Ti4O7 anode combined with UV irradiation on the removal of PFOS was systematically evaluated in the present study. A synergistic effect of electrolysis and UV irradiation rather than a simple additive effect for PFOS degradation was demonstrated experimentally and theoretically. The short wavelength irradiation within 400 nm is the main contribution to enhance the electrochemical degradation of PFOS, while the initial pH of the solution has little effect on the PFOS degradation. The increase of current density accelerates the removal of PFOS either by electrolysis treatment or the joint process. The time-dependent density functional theory (TD-DFT) calculation indicates that the synergistic effect of the electrolysis and UV irradiation is most likely due to the involvement of the excited PFOS induced under UV irradiation in the electrochemical reaction. This study provides the first mechanistic explanation for the electrochemical degradation of PFOS enhanced by UV irradiation.
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Affiliation(s)
- Chenguang Li
- Key Laboratory of Marine Environment and Ecology, Ministry of Education, College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, PR China; College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences, University of Georgia, Griffin, GA 30223, United States; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, Nanjing 210023, PR China
| | - Yifei Wang
- College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences, University of Georgia, Griffin, GA 30223, United States
| | - Yaye Wang
- College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences, University of Georgia, Griffin, GA 30223, United States
| | - Zunyao Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, Nanjing 210023, PR China
| | - Qingguo Huang
- College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences, University of Georgia, Griffin, GA 30223, United States.
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Veciana M, Bräunig J, Farhat A, Pype ML, Freguia S, Carvalho G, Keller J, Ledezma P. Electrochemical oxidation processes for PFAS removal from contaminated water and wastewater: fundamentals, gaps and opportunities towards practical implementation. JOURNAL OF HAZARDOUS MATERIALS 2022; 434:128886. [PMID: 35436757 DOI: 10.1016/j.jhazmat.2022.128886] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 03/20/2022] [Accepted: 04/07/2022] [Indexed: 05/27/2023]
Abstract
Electrochemical oxidation (EO) is emerging as one of the most promising methods for the degradation of recalcitrant per- and poly-fluoroalkyl substances (PFASs) in water and wastewater, as these compounds cannot be effectively treated with conventional bio- or chemical approaches. This review examines the state of the art of EO for PFASs destruction, and comprehensively compares operating parameters and treatment performance indicators for both synthetic and real contaminated water and wastewater media. The evaluation shows the need to use environmentally-relevant media to properly quantify the effectiveness/efficiency of EO for PFASs treatment. Additionally, there is currently a lack of quantification of sorption losses, resulting in a likely over-estimation of process' efficiencies. Furthermore, the majority of experimental results to date indicate that short-chain PFASs are the most challenging and need to be prioritized as environmental regulations become more stringent. Finally, and with a perspective towards practical implementation, several operational strategies are proposed, including processes combining up-concentration followed by EO destruction.
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Affiliation(s)
- Mersabel Veciana
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane QLD 4072, Australia.
| | - Jennifer Bräunig
- Queensland Alliance for Environmental Health Sciences, The University of Queensland, Brisbane QLD 4102, Australia
| | - Ali Farhat
- GHD Pty Ltd, Brisbane QLD 4000, Australia
| | - Marie-Laure Pype
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane QLD 4072, Australia
| | - Stefano Freguia
- Department of Chemical Engineering, The University of Melbourne, Parkville VIC 3010, Australia
| | - Gilda Carvalho
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane QLD 4072, Australia
| | - Jürg Keller
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane QLD 4072, Australia
| | - Pablo Ledezma
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane QLD 4072, Australia.
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Xu H, Chen R, Liang S, Lei Z, Zheng W, Yan Z, Cao J, Wei C, Feng C. Minimizing toxic chlorinated byproducts during electrochemical oxidation of Ni-EDTA: Importance of active chlorine-triggered Fe(II) transition to Fe(IV). WATER RESEARCH 2022; 219:118548. [PMID: 35561618 DOI: 10.1016/j.watres.2022.118548] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 04/14/2022] [Accepted: 05/02/2022] [Indexed: 06/15/2023]
Abstract
The formation of chlorinated byproducts represents a significant threat to the quality of the effluent treated using electrochemical advanced oxidation processes (EAOPs), thus spurring investigation into alleviating their production. This study presents a new strategy to minimize the release of chlorinated intermediates during the electrochemical oxidation of Ni-EDTA by establishing a dual mixed metal oxide (MMO)/Fe anode system. The results indicate that the dual-anode system achieved a substantially higher rate (0.141 min-1) of Ni-EDTA destruction and accordingly allowed a more pronounced removal of aqueous Ni (from 39.85 to 0.63 mg L-1) after alkaline precipitation, compared with its single MMO anode (0.017 min-1 of Ni-EDTA removal, with 14.38 mg L-1 Ni remaining) and single Fe anode (insignificant Ni-EDTA removal, with 38.37 mg L-1 Ni remaining) counterparts. Compared to reactive chlorine species (RCS) produced from the single MMO anode system, Fe(IV) was in situ generated from the dual-anode system and was predominantly responsible for the attenuation of chlorinated byproducts and thus the decrease in the acute toxicity of the treated solution (evaluated using luminescent bacteria). The Fe(IV)-dominated dual-anode system also exhibited superior performance in removing multiple pollutants (including organic ligands, Ni, and phosphite) in the real electroless plating effluent. The findings suggest that the strategy for Fe(II) transition to Fe(IV) by active chlorine paves a new avenue for yielding less chlorinated products with lower toxicity when EAOPs are used to treat chloride-containing organic wastewater.
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Affiliation(s)
- Haolin Xu
- 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, PR 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, PR China
| | - Sheng Liang
- 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, PR China
| | - Zhenchao Lei
- 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, PR 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, PR China
| | - Zhang Yan
- 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, PR China
| | - Jianxin Cao
- 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, PR China
| | - Chaohai Wei
- 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, PR 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, PR China.
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Wang S, Pei S, Zhang J, Huang J, You S. Flow-through electrochemical removal of benzotriazole by electroactive ceramic membrane. WATER RESEARCH 2022; 218:118454. [PMID: 35447419 DOI: 10.1016/j.watres.2022.118454] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 03/19/2022] [Accepted: 04/11/2022] [Indexed: 06/14/2023]
Abstract
Benzotriazole (BTA) is a widely used anticorrosive additive that is of endurance, bioaccumulation and toxicity, and BTA industrial wastewater treatment remains a challenge. This study reports efficient electrochemical removal of BTA by titanium oxide (TiSO) electroactive ceramic membrane (ECM), indicated by 98.1% removal at current density of 20 mA∙cm-2 and permeate flux of 692 LHM under cathode-to-anode flow pattern (1 h). Electrochemical analysis demonstrated the pH-dependent formation of anti-corrosive BTA film on the TiSO anode, which was responsible for improved BTA removal for cathode-to-anode (CA) flow pattern compared with that for anode-to-cathode (AC). The modelling results showed the CA flow pattern to be more favourable for BTA oxidation mediated by electro-generated •OH by preventing the formation of deactivation film via creating an alkaline boundary layer at the anode/electrolyte interface. Intermediates and essential active sites were identified by using experimental analysis and theoretical density functional theory (DFT) calculations, thereby the most likely degradation pathways were underlined. Toxicity analysis revealed remarkable decrease in oral rat LD50 values and bioaccumulation factor during electrochemical degradation of BTA. This study provides a proof-in-concept demonstration of effective removal for anti-corrosive emerging pollutants by TiSO-ECM under flow-through pattern.
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Affiliation(s)
- Shengli Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
| | - Shuzhao Pei
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
| | - Jinna Zhang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
| | - Junqiang Huang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
| | - Shijie You
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, P. R. China.
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Ferrari F, Pijuan M, Molenaar S, Duinslaeger N, Sleutels T, Kuntke P, Radjenovic J. Ammonia recovery from anaerobic digester centrate using onsite pilot scale bipolar membrane electrodialysis coupled to membrane stripping. WATER RESEARCH 2022; 218:118504. [PMID: 35525033 DOI: 10.1016/j.watres.2022.118504] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 04/20/2022] [Accepted: 04/21/2022] [Indexed: 06/14/2023]
Abstract
Ammonia recovery from centrate of an anaerobic digester was investigated using an onsite bipolar-electrodialysis (BP-ED) pilot scale plant coupled to two liquid/liquid membrane contactor (LLMC) modules. To investigate the process performance and robustness, the pilot plant was operated at varying current densities, load ratio (current to nitrogen loading), and in continuous and intermittent current (Donnan) mode. A higher load ratio led to higher total ammonium nitrogen (TAN, sum of ammonia and ammonium) removal efficiency, whereas the increase in the applied current did not have a significant impact the TAN removal efficiency. Continuous current application resulted in the higher TAN removal compared with the Donnan dialysis mode. The lowest specific energy consumption of 6.3 kWh kgN-1 was recorded in the Donnan mode, with the load ratio of 1.4, at 200 L h-1 flowrate and current density of 75 A m-2. Lower energy demand observed in the Donnan mode was likely due to the lower scaling and fouling of the ion exchange membranes. Nevertheless, scaling and fouling limited the operation of the BP-ED stack in all operational modes, which had to be interrupted by the daily cleaning procedures. The LLMC module enabled a highly selective recovery of ammonia as ammonium sulfate ((NH4)2SO4), with the concentration of ammonia ranging from 19 to 33 gN L-1. However, the analysis of per- and polyfluoroalkyl substances (PFASs) in the obtained (NH4)2SO4 product revealed the presence of 212-253 ng L-1 of 6:2 fluorotelomer sulfonate (FTS), a common substitute of legacy PFAS. Given the very low concentrations of 6:2 FTS (i.e., < 2 ng L-1) encountered in the concentrated stream, 6:2 FTS was likely released from the Teflon-based components in the sulfuric acid dosage line. Thus, careful selection of the pilot plant tubing, pumps and other components is required to avoid any risks associated with the PFAS presence and ensure safe use of the final product as fertilizer.
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Affiliation(s)
- Federico Ferrari
- Catalan Institute for Water Research (ICRA), Emili Grahit 101, 17003 Girona, Spain; University of Girona, 17003 Girona, Spain
| | - Maite Pijuan
- Catalan Institute for Water Research (ICRA), Emili Grahit 101, 17003 Girona, Spain; University of Girona, 17003 Girona, Spain
| | - Sam Molenaar
- W&F Technologies, Noordhaven 88a, 4761 DC Zevenbergen, the Netherlands
| | - Nick Duinslaeger
- Catalan Institute for Water Research (ICRA), Emili Grahit 101, 17003 Girona, Spain; University of Girona, 17003 Girona, Spain
| | - Tom Sleutels
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden; P.O. Box 1113, 8900 CC Leeuwarden, the Netherlands
| | - Philipp Kuntke
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden; P.O. Box 1113, 8900 CC Leeuwarden, the Netherlands; Environmental Technology, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen; P.O. Box 17, 6700 AA Wageningen, the Netherlands.
| | - Jelena Radjenovic
- Catalan Institute for Water Research (ICRA), Emili Grahit 101, 17003 Girona, Spain; Catalan Institution for Research and Advanced Studies (ICREA), Passeig Lluís Companys 23, 08010 Barcelona, Spain.
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A Review on Removal and Destruction of Per- and Polyfluoroalkyl Substances (PFAS) by Novel Membranes. MEMBRANES 2022; 12:membranes12070662. [PMID: 35877866 PMCID: PMC9325267 DOI: 10.3390/membranes12070662] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 06/20/2022] [Accepted: 06/22/2022] [Indexed: 02/01/2023]
Abstract
Per- and Polyfluoroalkyl Substances (PFAS) are anthropogenic chemicals consisting of thousands of individual species. PFAS consists of a fully or partly fluorinated carbon–fluorine bond, which is hard to break and requires a high amount of energy (536 kJ/mole). Resulting from their unique hydrophobic/oleophobic nature and their chemical and mechanical stability, they are highly resistant to thermal, chemical, and biological degradation. PFAS have been used extensively worldwide since the 1940s in various products such as non-stick household items, food-packaging, cosmetics, electronics, and firefighting foams. Exposure to PFAS may lead to health issues such as hormonal imbalances, a compromised immune system, cancer, fertility disorders, and adverse effects on fetal growth and learning ability in children. To date, very few novel membrane approaches have been reported effective in removing and destroying PFAS. Therefore, this article provides a critical review of PFAS treatment and removal approaches by membrane separation systems. We discuss recently reported novel and effective membrane techniques for PFAS separation and include a detailed discussion of parameters affecting PFAS membrane separation and destruction. Moreover, an estimation of cost analysis is also included for each treatment technology. Additionally, since the PFAS treatment technology is still growing, we have incorporated several future directions for efficient PFAS treatment.
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Wen Y, Rentería-Gómez Á, Day GS, Smith MF, Yan TH, Ozdemir ROK, Gutierrez O, Sharma VK, Ma X, Zhou HC. Integrated Photocatalytic Reduction and Oxidation of Perfluorooctanoic Acid by Metal-Organic Frameworks: Key Insights into the Degradation Mechanisms. J Am Chem Soc 2022; 144:11840-11850. [PMID: 35732040 DOI: 10.1021/jacs.2c04341] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The high porosity and tunability of metal-organic frameworks (MOFs) have made them an appealing group of materials for environmental applications. However, their potential in the photocatalytic degradation of per- and polyfluoroalkyl substances (PFAS) has been rarely investigated. Hereby, we demonstrate that over 98.9% of perfluorooctanoic acid (PFOA) was degraded by MIL-125-NH2, a titanium-based MOF, in 24 h under Hg-lamp irradiation. The MOF maintained its structural integrity and porosity after three cycles, as indicated by its crystal structure, surface area, and pore size distribution. Based on the experimental results and density functional theory (DFT) calculations, a detailed reaction mechanism of the chain-shortening and H/F exchange pathways in hydrated electron (eaq-)-induced PFOA degradation were revealed. Significantly, we proposed that the coordinated contribution of eaq- and hydroxyl radical (•OH) is vital for chain-shortening, highlighting the importance of an integrated system capable of both reduction and oxidation for efficient PFAS degradation in water. Our results shed light on the development of effective and sustainable technologies for PFAS breakdown in the environment.
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Affiliation(s)
- Yinghao Wen
- Department of Civil and Environmental Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Ángel Rentería-Gómez
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Gregory S Day
- Framergy Inc., 800 Raymond Stotzer Pkwy, College Station, Texas 77945, United States
| | - Mallory F Smith
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Tian-Hao Yan
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Ray Osman K Ozdemir
- Framergy Inc., 800 Raymond Stotzer Pkwy, College Station, Texas 77945, United States
| | - Osvaldo Gutierrez
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Virender K Sharma
- Program for the Environment and Sustainability, Department of Environmental and Occupational Health, Texas A&M University, College Station, Texas 77843, United States
| | - Xingmao Ma
- Department of Civil and Environmental Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Hong-Cai Zhou
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States.,Department of Materials Science and Engineering, Texas A&M University, College Station, Texas 77843, United States
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Xie J, Zhang C, Waite TD. Hydroxyl radicals in anodic oxidation systems: generation, identification and quantification. WATER RESEARCH 2022; 217:118425. [PMID: 35429884 DOI: 10.1016/j.watres.2022.118425] [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: 01/29/2022] [Revised: 03/17/2022] [Accepted: 04/05/2022] [Indexed: 06/14/2023]
Abstract
Anodic oxidation has emerged as a promising treatment technology for the removal of a broad range of organic pollutants from wastewaters. Hydroxyl radicals are the primary species generated in anodic oxidation systems to oxidize organics. In this review, the methods of identifying hydroxyl radicals and the existing debates and misunderstandings regarding the validity of experimental results are discussed. Consideration is given to the methods of quantification of hydroxyl radicals in anodic oxidation systems with particular attention to approaches used to compare the electrochemical performance of different anodes. In addition, we describe recent progress in understanding the mechanisms of hydroxyl radical generation at the surface of most commonly used anodes and the utilization of hydroxyl radical in typical electrochemical reactors. This review shows that the key challenges facing anodic oxidation technology are related to i) the elimination of mistakes in identifying hydroxyl radicals, ii) the establishment of an effective hydroxyl radical quantification method, iii) the development of cost effective anode materials with high corrosion resistance and high electrochemical activity and iv) the optimization of electrochemical reactor design to maximise the utilization efficiency of hydroxyl radicals.
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Affiliation(s)
- Jiangzhou Xie
- UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052, Australia
| | - Changyong Zhang
- UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052, Australia; CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei, 230026, China
| | - T David Waite
- UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052, Australia; UNSW Centre for Transformational Environmental Technologies, Yixing, Jiangsu Province, 214206, P.R. China.
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Xie J, Zhang C, David Waite T. Integrated flow anodic oxidation and ultrafiltration system for continuous defluorination of perfluorooctanoic acid (PFOA). WATER RESEARCH 2022; 216:118319. [PMID: 35339051 DOI: 10.1016/j.watres.2022.118319] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 02/14/2022] [Accepted: 03/15/2022] [Indexed: 06/14/2023]
Abstract
While flow anodic oxidation systems can efficiently generate hydroxyl radicals (·OH) and significantly enhance direct electron transfer (DET) processes that result in the oxidation of target contaminants via the charge percolating network of flow anode particles, challenges remain in constructing a flow anodic oxidation system that can be operated continuously with stable performance. Here we incorporate an ultrafiltration (UF) membrane module into the flow anodic oxidation system and achieve the continuous defluorination of perfluorooctanoic acid (PFOA) for 12 days with high efficiency (94.1%) and reasonable energy consumption (38.1 Wh mg-1) compared to other advanced oxidation processes by using a mixture of conducting TixO2x-1 and Pd/CNT particles as the flow anode. The results indicate that DET, ·OH mediated oxidation and adsorption processes play critical roles in the degradation of PFOA during the flow anodic oxidation processes. The synergistic effect of the TixO2x-1 and Pd/CNT particles enhances the defluorination efficiency by 3.2 times at 4.5 V vs Ag/AgCl compared to the control experiment (no flow anode particles present) and promotes the release of F- into solution while other intermediate products remain adsorbed to the surface of the Pd/CNT particles. Although the Pd/CNT particles were oxidized after the long-term operation, no obvious Pd ion leakage into solution was observed. Results of this study support the feasibility of continuous operation of a flow anode/UF system with stable performance and pave the way for the translation of this advanced oxidation technology to practical application.
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Affiliation(s)
- Jiangzhou Xie
- UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052, Australia.
| | - Changyong Zhang
- UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052, Australia.
| | - T David Waite
- UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052, Australia; UNSW Centre for Transformational Environmental Technologies, Yixing, Jiangsu Province 214206, P R China.
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Ren L, Ma J, Chen M, Qiao Y, Dai R, Li X, Wang Z. Recent advances in electrocatalytic membrane for the removal of micropollutants from water and wastewater. iScience 2022; 25:104342. [PMID: 35602955 PMCID: PMC9117875 DOI: 10.1016/j.isci.2022.104342] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The increasing occurrence of micropollutants in water and wastewater threatens human health and ecological security. Electrocatalytic membrane (EM), a new hybrid water treatment platform that integrates membrane separation with electrochemical technologies, has attracted extensive attention in the removal of micropollutants from water and wastewater in the past decade. Here, we systematically review the recent advances of EM for micropollutant removal from water and wastewater. The mechanisms of the EM for micropollutant removal are first introduced. Afterwards, the related membrane materials and operating conditions of the EM are summarized and analyzed. Lastly, the challenges and future prospects of the EM in research and applications are also discussed, aiming at a more efficient removal of micropollutants from water and wastewater.
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Affiliation(s)
- Lehui Ren
- State Key Laboratory of Pollution Control and Resource Reuse, Advanced Membrane Technology Center of Tongji University, Shanghai Institute of Pollution Control and Ecological Security, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Jinxing Ma
- Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, PR China
| | - Mei Chen
- College of Environmental Science and Engineering, Nankai University, Tianjin 300350, PR China
| | - Yiwen Qiao
- State Key Laboratory of Pollution Control and Resource Reuse, Advanced Membrane Technology Center of Tongji University, Shanghai Institute of Pollution Control and Ecological Security, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Ruobin Dai
- State Key Laboratory of Pollution Control and Resource Reuse, Advanced Membrane Technology Center of Tongji University, Shanghai Institute of Pollution Control and Ecological Security, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Xuesong Li
- State Key Laboratory of Pollution Control and Resource Reuse, Advanced Membrane Technology Center of Tongji University, Shanghai Institute of Pollution Control and Ecological Security, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Zhiwei Wang
- State Key Laboratory of Pollution Control and Resource Reuse, Advanced Membrane Technology Center of Tongji University, Shanghai Institute of Pollution Control and Ecological Security, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
- Corresponding author
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Liu G, Feng C, Shao P. Degradation of Perfluorooctanoic Acid with Hydrated Electron by a Heterogeneous Catalytic System. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:6223-6231. [PMID: 34941262 DOI: 10.1021/acs.est.1c06793] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Hydrated electron (eaq-)-induced reduction protocols have bright prospects for the decomposition of recalcitrant organic pollutants. However, traditional eaq- production involves homogeneous sulfite photolysis, which has a pH-dependent reaction activity and might have potential secondary pollution risks. In this study, a heterogeneous UV/diamond catalytic system was proposed to decompose of a typical persistent organic pollutant, perfluorooctanoic acid (PFOA). In contrast to the rate constant of the advanced reduction process (ARP) of a UV/SO32-, the kobs of PFOA decomposition in the UV/diamond system showed only minor pH dependence, ranging from 0.01823 ± 0.0014 min-1 to 0.02208 ± 0.0013 min-1 (pH 2 to pH 11). As suggested by the electron affinity (EA) and electron configuration of the diamond catalyst, the diamond catalyst yields facile energetic photogenerated electron emission into water without a high energy barrier after photoexcitation, thus inducing eaq- production. The impact of radical scavengers, electron spin resonance (ESR), and transient absorption (TA) measurements verified the formation of eaq- in the UV/diamond system. The investigation of diamond for ejection of energetic photoelectrons into a water matrix represents a new paradigm for ARPs and would facilitate future applications of heterogeneous catalytic processes for efficient recalcitrant pollutant removal by eaq-.
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Affiliation(s)
- Guoshuai Liu
- School of Environmental and Civil Engineering, Jiangsu Key Laboratory of Anaerobic Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Cuijie Feng
- Department of Civil and Environmental Engineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | - Penghui Shao
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle and National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resource Utilization, Nanchang Hangkong University, Nanchang 330063, China
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Metz J, Javed H, Mathieu J, Long M, Alvarez PJJ. Comment on "Mechanistic Understanding of Superoxide Radical-Mediated Degradation of Perfluorocarboxylic Acids". ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:5287-5288. [PMID: 35311262 DOI: 10.1021/acs.est.2c00400] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Affiliation(s)
- Jordin Metz
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
- Nanosystems Engineering Research Center for Nanotechnology Enabled Water Treatment (NEWT), Rice University, Houston, Texas 77005, United States
| | - Hassan Javed
- GSI Environmental, Inc., Houston, Texas 77098, United States
| | - Jacques Mathieu
- Department of Civil and Environmental Engineering, Rice University, Houston, Texas 77005, United States
- Sentinel Environmental LLC, Houston, Texas 77082, United States
| | - Mingce Long
- School of Environmental Science and Engineering, Key Laboratory of Thin Film and Microfabrication Technology (Ministry of Education), Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Pedro J J Alvarez
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
- Nanosystems Engineering Research Center for Nanotechnology Enabled Water Treatment (NEWT), Rice University, Houston, Texas 77005, United States
- Department of Civil and Environmental Engineering, Rice University, Houston, Texas 77005, United States
- Department of Materials Science and Nanoengineering, Rice University, Houston, Texas 77005, United States
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
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Duinslaeger N, Radjenovic J. Electrochemical degradation of per- and polyfluoroalkyl substances (PFAS) using low-cost graphene sponge electrodes. WATER RESEARCH 2022; 213:118148. [PMID: 35151089 DOI: 10.1016/j.watres.2022.118148] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 01/03/2022] [Accepted: 01/31/2022] [Indexed: 06/14/2023]
Abstract
Boron-doped, graphene sponge anode was synthesized and applied for the electrochemical oxidation of C4-C8 per- and polyfluoroalkyl substances (PFASs). Removal efficiencies, obtained in low conductivity electrolyte (1 mS cm-1) and one-pass flow-through mode, were in the range 16.7-67% at 230 A m-2 of anodic current density, and with the energy consumption of 10.1 ± 0.7 kWh m-3. Their removal was attributed to electrosorption (7.4-35%), and electrooxidation (9.3-32%). Defluorination efficiencies of C4-C8 perfluoroalkyl sulfonates and acids were 8-24% due to a fraction of PFAS being electrosorbed only at the anode surface. Yet, the recovery of fluoride was 74-87% relative to the electrooxidized fraction, suggesting that once the degradation of the PFAS is initiated, the C-F bond cleavage is very efficient. The nearly stoichiometric sulfate recoveries obtained for perfluoroalkyl sulfonates (91%-98%) relative to the electrooxidized fraction demonstrated an efficient cleavage of the sulfonate head-group. Adsorbable organic fluoride (AOF) analysis showed that the remaining partially defluorinated byproducts are electrosorbed at the graphene sponge anode during current application and are released into the solution after the current is switched off. This proof-of-concept study demonstrated that the developed graphene sponge anode is capable of C-F bond cleavage and defluorination of PFAS. Given that the graphene sponge anode is electrochemically inert towards chloride and does not form any chlorate and perchlorate even in brackish solutions, the developed material may unlock the electrochemical degradation of PFAS complex wastewaters and brines.
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Affiliation(s)
- Nick Duinslaeger
- Catalan Institute for Water Research (ICRA), Emili Grahit 101, 17003 Girona, Spain; University of Girona, Girona, Spain
| | - Jelena Radjenovic
- Catalan Institute for Water Research (ICRA), Emili Grahit 101, 17003 Girona, Spain; Catalan Institution for Research and Advanced Studies (ICREA), Passeig Lluís Companys 23, 08010 Barcelona, Spain.
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Assessment of Reed Grasses (Phragmites australis) Performance in PFAS Removal from Water: A Phytoremediation Pilot Plant Study. WATER 2022. [DOI: 10.3390/w14060946] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs) have multiple emission sources, from industrial to domestic, and their high persistence and mobility help them to spread in all the networks of watercourses. Diffuse pollution of these compounds can be potentially mitigated by the application of green infrastructures, which are a pillar of the EU Green Deal. In this context, a phytoremediation pilot plant was realised and supplied by a contaminated well-located in Lonigo (Veneto Region, Italy) where surface and groundwaters were significantly impacted by perfluoroalkyl acids (PFAAs) discharges from a fluorochemical factory. The investigation involved the detection of perfluorobutanoic acid (PFBA), perfluorooctanoic acid (PFOA), perfluorobutanesulfonic acid (PFBS) and perfluorooctanesulfonic acid (PFOS) inside the inlet and outlet waters of the phytoremediation pilot plant as well as in reed grasses grown into its main tank. The obtained results demonstrate that the pilot plant is able to reduce up to 50% of considered PFAAs in terms of mass flow without an evident dependence on physico-chemical characteristics of these contaminants. Moreover, PFAAs were found in the exposed reed grasses at concentrations up to 13 ng g−1 ww. A positive correlation between PFAA concentration in plants and exposure time was also observed. In conclusion, this paper highlights the potential efficiency of phytodepuration in PFAS removal and recommends improving the knowledge about its application in constructed wetlands as a highly sustainable choice in wastewater remediation.
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