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Vakili M, Cagnetta G, Deng S, Wang W, Gholami Z, Gholami F, Dastyar W, Mojiri A, Blaney L. Regeneration of exhausted adsorbents after PFAS adsorption: A critical review. J Hazard Mater 2024; 471:134429. [PMID: 38691929 DOI: 10.1016/j.jhazmat.2024.134429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Revised: 03/26/2024] [Accepted: 04/24/2024] [Indexed: 05/03/2024]
Abstract
The adsorption process efficiently removes per- and polyfluoroalkyl substances (PFAS) from water, but managing exhausted adsorbents presents notable environmental and economic challenges. Conventional disposal methods, such as incineration, may reintroduce PFAS into the environment. Therefore, advanced regeneration techniques are imperative to prevent leaching during disposal and enhance sustainability and cost-effectiveness. This review critically evaluates thermal and chemical regeneration approaches for PFAS-laden adsorbents, elucidating their operational mechanisms, the influence of water quality parameters, and their inherent advantages and limitations. Thermal regeneration achieves notable desorption efficiencies, reaching up to 99% for activated carbon. However, it requires significant energy input and risks compromising the adsorbent's structural integrity, resulting in considerable mass loss (10-20%). In contrast, chemical regeneration presents a diverse efficiency landscape across different regenerants, including water, acidic/basic, salt, solvent, and multi-component solutions. Multi-component solutions demonstrate superior efficiency (>90%) compared to solvent-based solutions (12.50%), which, in turn, outperform salt (2.34%), acidic/basic (1.17%), and water (0.40%) regenerants. This hierarchical effectiveness underscores the nuanced nature of chemical regeneration, significantly influenced by factors such as regenerant composition, the molecular structure of PFAS, and the presence of organic co-contaminants. Exploring the conditional efficacy of thermal and chemical regeneration methods underscores the imperative of strategic selection based on specific types of PFAS and material properties. By emphasizing the limitations and potential of particular regeneration schemes and advocating for future research directions, such as exploring persulfate activation treatments, this review aims to catalyze the development of more effective regeneration processes. The ultimate goal is to ensure water quality and public health protection through environmentally sound solutions for PFAS remediation efforts.
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Affiliation(s)
| | - Giovanni Cagnetta
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 610031, China.
| | - Shubo Deng
- State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Wei Wang
- State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xi'ning, Qinghai Province 810016, China
| | - Zahra Gholami
- ORLEN UniCRE, a.s, Revoluční 1521/84, 400 01 Ústí nad Labem, Czech Republic
| | - Fatemeh Gholami
- Department of Mathematics, Physics, and Technology, Faculty of Education, University of West Bohemia, Klatovská 51, Plzeň 301 00, Czech Republic
| | - Wafa Dastyar
- Chemical, Environmental, and Materials Engineering Department, McArthur Engineering Building, University of Miami, Coral Gables, FL 33124, USA
| | - Amin Mojiri
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287-3005, USA
| | - Lee Blaney
- University of Maryland Baltimore County, Department of Chemical, Biochemical, and Environmental Engineering, Baltimore, MD 21250, USA
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2
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Behnami A, Pourakbar M, Ayyar ASR, Lee JW, Gagnon G, Zoroufchi Benis K. Treatment of aqueous per- and poly-fluoroalkyl substances: A review of biochar adsorbent preparation methods. Chemosphere 2024; 357:142088. [PMID: 38643842 DOI: 10.1016/j.chemosphere.2024.142088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 03/25/2024] [Accepted: 04/18/2024] [Indexed: 04/23/2024]
Abstract
Per- and poly-fluoroalkyl substances (PFAS) are synthetic chemicals widely used in everyday products, causing elevated concentrations in drinking water and posing a global challenge. While adsorption methods are commonly employed for PFAS removal, the substantial cost and environmental footprint of commercial adsorbents highlight the need for more cost-effective alternatives. Additionally, existing adsorbents exhibit limited effectiveness, particularly against diverse PFAS types, such as short-chain PFAS, necessitating modifications to enhance adsorption capacity. Biochar can be considered a cost-effective and eco-friendly alternative to conventional adsorbents. With abundant feedstocks and favorable physicochemical properties, biochar shows significant potential to be applied as an adsorbent for removing contaminants from water. Despite its effectiveness in adsorbing different inorganic and organic contaminants from water environments, some factors restrict its effective application for PFAS adsorption. These factors are related to the biochar properties, and characteristics of PFAS, as well as water chemistry. Therefore, some modifications have been introduced to overcome these limitations and improve biochar's adsorption capacity. This review explores the preparation conditions, including the pyrolysis process, activation, and modification techniques applied to biochar to enhance its adsorption capacity for different types of PFAS. It addresses critical questions about the adsorption performance of biochar and its composites, mechanisms governing PFAS adsorption, challenges, and future perspectives in this field. The surge in research on biochar for PFAS adsorption indicates a growing interest, making this timely review a valuable resource for future research and an in-depth exploration of biochar's potential in PFAS remediation.
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Affiliation(s)
- Ali Behnami
- Department of Environmental Health Engineering, Iran University of Medical Sciences, Tehran, Iran; Department of Environmental Health Engineering, Maragheh University of Medical Sciences, Maragheh, Iran
| | - Mojtaba Pourakbar
- Department of Environmental Health Engineering, Maragheh University of Medical Sciences, Maragheh, Iran; Health and Environment Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Ji-Woong Lee
- Department of Chemistry, Nano-Science Centre, University of Copenhagen, Copenhagen, Denmark; Novo Nordisk CO2 Research Center, Aarhus, Denmark
| | - Graham Gagnon
- Centre for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, Halifax, NS, Canada
| | - Khaled Zoroufchi Benis
- Department of Process Engineering and Applied Science, Dalhousie University, Halifax, NS, Canada.
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3
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Liu B, Liu YL, Sun M. Remove legacy perfluoroalkyl acids and emerging per- and polyfluoroalkyl ether acids by single-use and regenerable anion exchange resins: Rapid small-scale column tests and model fits. Water Res 2024; 257:121661. [PMID: 38677109 DOI: 10.1016/j.watres.2024.121661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 04/19/2024] [Accepted: 04/21/2024] [Indexed: 04/29/2024]
Abstract
Rapid small-scale column tests (RSSCT) are used to study the removal of per- and polyfluoroalkyl substances (PFAS) for drinking water treatment by ion exchange. Breakthroughs of 15 emerging per- and perfluoroalkyl ether acids and six legacy perfluoroalkyl acid analogs are studied using a single-use PFAS-selective anion exchange resin (AER1) and a regenerable, generic anion exchange resin (AER2). The Bohart-Adams model was used to describe and predict breakthrough, with the modeled results reasonably aligned with RSSCT results in most cases, enabling shorter RSSCT duration for future applications. AER1 exhibited high uptake capacity with no breakthrough for 11 of the 21 tested PFAS during the 144,175 BV continuous operation, allowing compliance with the new National Primary Drinking Water Regulation in many application scenarios. AER2 exhibited much faster breakthroughs for most PFAS and is not a promising option for drinking water treatment. However, the summed PFAS capacity via model fit and total PFAS adsorbed via measurement were only <0.01 % of both resin capacities at full breakthrough, suggesting PFAS could only occupy a tiny portion of the ion exchange sites even for the PFAS-selective AER1. Ether group insertion in the PFAS group leads to later breakthrough, and linear isomers were better captured by the resins than the branched isomers. Overall, PFAS uptake capacity increases and kinetics decrease when the PFAS molecular volume increases. Regeneration using 10 % NaCl solutions partially released PFAS from AER2 but not from AER1, with more short-chain PFAS released than long-chain ones. Ether group insertion decreased the PFAS recoveries during the regeneration of AER2. The regenerated resins showed much faster breakthroughs than the pristine resins, making them unfavorable for drinking water treatment applications. Adsorption displacement of short-chain PFAS by long-chain PFAS was observed in pristine AER1, and post-regeneration leaching occurred for both resins, both phenomena making the resins a possible PFAS source in long-term use.
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Affiliation(s)
- Bingchuan Liu
- Department of Civil and Environmental Engineering, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA.
| | - Yen-Ling Liu
- Department of Civil and Environmental Engineering, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
| | - Mei Sun
- Department of Civil and Environmental Engineering, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
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4
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Rekik H, Arab H, Pichon L, El Khakani MA, Drogui P. Per-and polyfluoroalkyl (PFAS) eternal pollutants: Sources, environmental impacts and treatment processes. Chemosphere 2024; 358:142044. [PMID: 38648982 DOI: 10.1016/j.chemosphere.2024.142044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 04/03/2024] [Accepted: 04/04/2024] [Indexed: 04/25/2024]
Abstract
Per- and polyfluoroalkyl substances (PFAS) have become a growing environmental concern due to their tangible impacts on human health. However, due to the large number of PFAS compounds and the analytical difficulty to identify all of them, there are still some knowledge gaps not only on their impact on human health, but also on how to manage them and achieve their effective degradation. PFAS compounds originate from man-made chemicals that are resistant to degradation because of the presence of the strong carbon-fluorine bonds in their chemical structure. This review consists of two parts. In the first part, the environmental effects of fluorinated compound contamination in water are covered with the objective to highlight how their presence in the environment adversely impacts the human health. In the second part, the focus is put on the different techniques available for the degradation and/or separation of PFAS compounds in different types of waters. Examples of removal/treatment of PFAS present in either surface or ground water are presented.
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Affiliation(s)
- Hela Rekik
- Institut National de la Recherche Scientifique (INRS) - Centre Eau Terre Environnement (ETE), 490 Rue de la Couronne, Québec (QC), G1K 9A9, Canada
| | - Hamed Arab
- Institut National de la Recherche Scientifique (INRS) - Centre Eau Terre Environnement (ETE), 490 Rue de la Couronne, Québec (QC), G1K 9A9, Canada
| | - Loick Pichon
- Institut National de la Recherche Scientifique, Centre Énergie, Matériaux et Télécommunications, 1650, Blvd, Lionel-Boulet, Varennes, QC, J3X-1P7, Canada
| | - My Ali El Khakani
- Institut National de la Recherche Scientifique, Centre Énergie, Matériaux et Télécommunications, 1650, Blvd, Lionel-Boulet, Varennes, QC, J3X-1P7, Canada
| | - Patrick Drogui
- Institut National de la Recherche Scientifique (INRS) - Centre Eau Terre Environnement (ETE), 490 Rue de la Couronne, Québec (QC), G1K 9A9, Canada.
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5
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Darmawan YA, Goto T, Yanagishima T, Fuji T, Kudo T. Mid-Infrared Optical Force Chromatography of Microspheres Containing Siloxane Bonds. J Phys Chem Lett 2023; 14:7306-7312. [PMID: 37561048 DOI: 10.1021/acs.jpclett.3c01679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
Recent interest in particle sorting using optical forces has grown due to its ability to separate micro- and nanomaterials based on their optical properties. Here, we present a mid-infrared optical force manipulation technique that enables precise sorting of microspheres based on their molecular vibrational properties using a mid-infrared quantum cascade laser. Utilizing the optical pushing force driven by a 9.3 μm mid-infrared evanescent field generated on a prism through total internal reflection, a variety of microspheres, including those composed of Si-O-Si bonds, can be separated in accordance with their absorbance values at 9.3 μm. The experimental results are in good agreement with the optical force calculations using finite-difference time-domain simulation. Thus, each microsphere's displacement and velocity can be predicted from the absorbance value; conversely, the optical properties (e.g., absorbance and complex refractive index in the mid-infrared region) of individual microspheres can be estimated by monitoring their velocity.
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Affiliation(s)
- Yoshua Albert Darmawan
- Laser Science Laboratory, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku-ku, Nagoya 468-8511, Japan
| | - Takuma Goto
- Laser Science Laboratory, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku-ku, Nagoya 468-8511, Japan
| | - Taiki Yanagishima
- Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Takao Fuji
- Laser Science Laboratory, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku-ku, Nagoya 468-8511, Japan
| | - Tetsuhiro Kudo
- Laser Science Laboratory, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku-ku, Nagoya 468-8511, Japan
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6
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Tajdini B, Vatankhah H, Murray CC, Liethen A, Bellona C. Impact of effluent organic matter on perfluoroalkyl acid removal from wastewater effluent by granular activated carbon and alternative adsorbents. Water Res 2023; 241:120105. [PMID: 37270948 DOI: 10.1016/j.watres.2023.120105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 05/19/2023] [Accepted: 05/20/2023] [Indexed: 06/06/2023]
Abstract
Occurrence of perfluoroalkyl acids (PFAAs) in wastewater effluent coupled with increasingly stringent regulations has increased the need for more effective sorption-based PFAA treatment approaches. This study investigated the impact of ozone (O3)- biologically active filtration (BAF) as integral components of non-reverse osmosis (RO)-based potable reuse treatment trains and as a potential pretreatment option to improve adsorptive PFAA removal from wastewater effluent by nonselective (e.g., granular activated carbon (GAC) and selective (e.g., anionic exchange resins (AER) and surface-modified clay (SMC)) adsorbents. For nonselective GAC, O3 and BAF resulted in similar PFAA removal improvements, while BAF alone performed better than O3 for AER and SMC. O3-BAF in tandem resulted in the highest PFAA removal performance improvement among pretreatments investigated for selective and nonselective adsorbents. Side by side evaluation of the dissolved organic carbon (DOC) breakthrough curves and size exclusion chromatography (SEC) for each pretreatment scenario suggested that despite the higher affinity of selective adsorbents towards PFAAs, the competition between PFAA and effluent organic matter (EfOM) (molecular weights (MWs): 100-1000 Da) negatively impacts the performance of these adsorbents. The SEC results also demonstrated that transformation of hydrophobic EfOM to more hydrophilic molecules during O3 and biotransformation of EfOM during BAF were the dominant mechanisms responsible for alleviating the competition between PFAA and EfOM, resulting in PFAA removal improvement.
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Affiliation(s)
- Bahareh Tajdini
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO, USA
| | - Hooman Vatankhah
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO, USA; Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - Conner C Murray
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO, USA; Hazen and Sawyer, Lakewood, CO, USA
| | - Alexander Liethen
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO, USA
| | - Christopher Bellona
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO, USA.
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7
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Murray CC, Safulko A, Vatankhah H, Liu CJ, Tajdini B, Marshall RE, Bellona C. PFAS adsorbent selection: The role of adsorbent use rate, water quality, and cost. J Hazard Mater 2023; 454:131481. [PMID: 37146339 DOI: 10.1016/j.jhazmat.2023.131481] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 04/20/2023] [Accepted: 04/22/2023] [Indexed: 05/07/2023]
Abstract
Per- and polyfluoroalkyl substance (PFAS) contamination in aqueous matrices has intensified the search for PFAS adsorbents with elevated capacity, selectivity, and cost effectiveness. A novel surface modified organoclay (SMC) adsorbent was evaluated for PFAS removal performance in parallel with granular activated carbon (GAC) and ion exchange resin (IX) for the treatment of five distinct PFAS impaired waters including groundwater, landfill leachate, membrane concentrate and wastewater effluent. Rapid small scale column tests (RSSCTs) and breakthrough modeling were coupled to provide insight on adsorbent performance and cost for multiple PFAS and water types. IX exhibited the best performance with respect to adsorbent use rates in treatment of all tested waters. IX was nearly four times more effective than GAC and two times more effective than SMC in the treatment of PFOA from water types excluding groundwater. Employed modeling strengthened the comparison of adsorbent performance and water quality to infer adsorption feasibility. Further, evaluation of adsorption was extended beyond PFAS breakthrough with the inclusion of unit adsorbent cost as a decision metric influencing adsorbent selection. An analysis of levelized media cost indicated treatment of landfill leachate and membrane concentrate was at least three times more expensive than groundwaters or wastewaters evaluated.
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Affiliation(s)
- Conner C Murray
- Department of Civil and Environmental Engineering, Colorado School of Mines, 1500 Illinois St, Golden, CO 80401, USA; Hazen and Sawyer, Lakewood, CO 80228, USA
| | - Andrew Safulko
- Department of Civil and Environmental Engineering, Colorado School of Mines, 1500 Illinois St, Golden, CO 80401, USA; Brown and Caldwell, Lakewood, CO 80401, USA
| | - Hooman Vatankhah
- Department of Civil and Environmental Engineering, Colorado School of Mines, 1500 Illinois St, Golden, CO 80401, USA
| | - Charlie J Liu
- Kennedy Jenks Consultants, San Francisco, CA 94107, USA
| | - Bahareh Tajdini
- Department of Civil and Environmental Engineering, Colorado School of Mines, 1500 Illinois St, Golden, CO 80401, USA
| | | | - Christopher Bellona
- Department of Civil and Environmental Engineering, Colorado School of Mines, 1500 Illinois St, Golden, CO 80401, USA.
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8
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Tan HM, Pan CG, Yin C, Yu K. Insights into the Understanding of Adsorption Behaviors of Legacy and Emerging Per- and Polyfluoroalkyl Substances (PFASs) on Various Anion-Exchange Resins. Toxics 2023; 11:161. [PMID: 36851036 PMCID: PMC9961606 DOI: 10.3390/toxics11020161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 02/06/2023] [Accepted: 02/06/2023] [Indexed: 06/18/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs) have received extensive attention due to their various harmful effects. In this study, the adsorptive removal of 10 legacy and emerging PFASs by four anion-exchange resins (including gel and macroreticular resins) were systematically investigated. Our results showed that the capacities of resins absorbing PFASs were ranked in the following order: gel strong base HPR4700 (297~300 μg/g) ≈ macroreticular strong base S6368 (294~300 μg/g) ≈ macroreticular weak base A111S (289~300 μg/g) > gel weak base WA10 (233~297 μg/g). Adsorption kinetic results indicated that the adsorption process might involve chemical and Henry regime adsorption or reaction control. Intraparticle diffusion was probably the major removal step. Co-existing fulvic acid (0.5, 1, 5 mg/L) and inorganic anions (5 mg/L of sulfate, carbonate, bicarbonate) would hinder the PFAS removal by resins with WA10 showing the highest inhibition rate of 17% and 71%, respectively. The adsorption capacities of PFBA decreased from 233 μg/g to 194 μg/g, and from 233 μg/g to 67 μg/g in the presence of fulvic acid and inorganic anions, respectively. PFASs were more easily removed by HPR4700, S6368, and A111S under neutral and alkaline environment. Moreover, WA10 was not able to remove PFASs under an alkaline medium. This study offered theoretical support for removing PFASs from aqueous phases with various resins.
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Affiliation(s)
- Hong-Ming Tan
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, School of Marine Sciences, Guangxi University, Nanning 530004, China
- School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China
| | - Chang-Gui Pan
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, School of Marine Sciences, Guangxi University, Nanning 530004, China
- Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai 519000, China
| | - Chao Yin
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, School of Marine Sciences, Guangxi University, Nanning 530004, China
| | - Kefu Yu
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, School of Marine Sciences, Guangxi University, Nanning 530004, China
- School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China
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9
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Ellis AC, Liu CJ, Fang Y, Boyer TH, Schaefer CE, Higgins CP, Strathmann TJ. Pilot study comparison of regenerable and emerging single-use anion exchange resins for treatment of groundwater contaminated by per- and polyfluoroalkyl substances (PFASs). Water Res 2022; 223:119019. [PMID: 36049246 DOI: 10.1016/j.watres.2022.119019] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 07/19/2022] [Accepted: 08/22/2022] [Indexed: 06/15/2023]
Abstract
This study reports the results of an 8-month pilot study comparing both regenerable and emerging single-use anion exchange resins (AERs) for treatment of per- and polyfluoroalkyl substances (PFASs) at a source zone impacted by historical use of aqueous film-forming foam (AFFF). Two regenerable (Purolite A860 and A520E) and three single-use (Purolite PFA694E, Calgon CalRes 2301, and Dowex PSR2+) AERs were tested in parallel, collecting effluent samples after treatment for 30-sec and 2-min total empty bed contact time (EBCT). Results demonstrate that single-use AERs significantly outperform regenerable resins, particularly for treatment of long-chain perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs). No detectable concentrations of ≥C7 PFCAs or PFSAs were observed within 150,000 bed volumes (BVs) after treatment with the single-use resins (2-min EBCT). Analysis of effluent samples following 30-sec EBCT treatment shows that even the shortest-chain PFSAs do not reach 50% breakthrough within the first 350,000 BVs, though differences in removal of short-chain PFCAs was less dramatic. The regenerable polyacrylic A860 resin performed very poorly compared to all polystyrene resins, with >90% breakthrough of all PFASs occurring within 10,000 BVs. The greater affinity of polystyrene resins is attributed to increased hydrophobic interactions in addition to electrostatic ion exchange. Analysis of breakthrough profiles reveals empirical correlation with ion exchange affinity coefficients (logKex) measured in batch experiments. Postmortem analysis of PFASs extracted from spent resins revealed chromatographic elution behavior and competition among PFASs for adsorption to the resins. PFSAs and long-chain PFCAs were preferentially adsorbed to earlier sections in the AER columns, whereas short-chain PFCAs were competitively displaced towards the later sections of the columns and into the effluent, consistent with effluent concentrations of the latter structures exceeding influent values. These results provide insights into the mechanisms that govern PFAS adsorption to AERs in real multisolute groundwater matrices and support findings from other diverse sites regarding PFAS affinity, elution behavior, and competition for exchange sites.
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Affiliation(s)
- Anderson C Ellis
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Charlie J Liu
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado 80401, United States; Kennedy Jenks Consultants, San Francisco, California 94118, United States
| | - Yida Fang
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado 80401, United States; CDM Smith, Bellevue, Washington 98807, United States
| | - Treavor H Boyer
- School of Sustainable Engineering and the Built Environment (SSEBE), Arizona State University (ASU), Tempe, Arizona 85287, United States
| | | | - Christopher P Higgins
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Timothy J Strathmann
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado 80401, United States.
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10
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Wang Y, Warner M, Li K, Hawkins GL, Huang Q. Assessing explicit models of per- and polyfluoroalkyl substances adsorption on anion exchange resins by rapid small-scale column tests. Chemosphere 2022; 300:134547. [PMID: 35405197 DOI: 10.1016/j.chemosphere.2022.134547] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/31/2022] [Accepted: 04/05/2022] [Indexed: 06/14/2023]
Abstract
Managing per- and polyfluoroalkyl substance (PFAS) contamination has gained worldwide attention due to their ubiquitous occurrence in water systems. Anion exchange resins (AERs) have been proven effective in removing both long-chain and short-chain PFASs. In this study, an explicit model was developed to describe the breakthrough behavior of an individual PFAS as a single solute onto anion exchange resin in a column filtration process. The model was further modified to predict the breakthrough curve of co-existing PFASs on AER in multi-solute systems by incorporating a separation factor describing the competitive adsorption and a blockage factor describing the loss of adsorption sites. Rapid small-scale column tests (RSSCTs) were performed with six AERs of various properties and three model PFASs in both single- and multi-solutes systems. The breakthrough behaviors of RSSCTs for both single- and multi-solute systems were found adequately described by the models developed in this study. The experiments and accompanied model simulations reveal some important relationships between the AER performance and the properties of both the AERs and the PFASs.
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Affiliation(s)
- Yifei Wang
- Department of Crop and Soil Sciences, University of Georgia, Griffin, GA, 30223, USA
| | - Max Warner
- 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
| | - Gary L Hawkins
- Department of Crop and Soil Sciences, 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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11
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Zhu Y, Ji H, He K, Blaney L, Xu T, Zhao D. Photocatalytic degradation of GenX in water using a new adsorptive photocatalyst. Water Res 2022; 220:118650. [PMID: 35640506 DOI: 10.1016/j.watres.2022.118650] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 05/19/2022] [Accepted: 05/21/2022] [Indexed: 06/15/2023]
Abstract
GenX, the ammonium salt of hexafluoropropylene oxide dimer acid, has been used as a replacement for perfluorooctanoic acid. Due to its widespread uses, GenX has been detected in waters around the world amid growing concerns about its persistence and adverse health effects. As relevant regulations are rapidly evolving, new technologies are needed to cost-effectively remove and degrade GenX. In this study, we developed an adsorptive photocatalyst by depositing a small amount (3 wt.%) of bismuth (Bi) onto activated-carbon supported titanate nanotubes, Bi/TNTs@AC, and tested the material for adsorption and subsequent solid-phase photodegradation of GenX. Bi/TNTs@AC at 1 g/L was able to adsorb GenX (100 µg/L, pH 7.0) within 1 h, and then degrade 70.0% and mineralize 42.7% of pre-sorbed GenX under UV (254 nm) in 4 h. The efficient degradation also regenerated the material, allowing for repeated uses without chemical regeneration. Material characterizations revealed that the active components of Bi/TNTs@AC included activated carbon, anatase, and Bi nanoparticles with a metallic Bi core and an amorphous Bi2O3 shell. Electron paramagnetic resonance spin-trapping, UV-vis diffuse reflectance spectrometry, and photoluminescence analyses indicated the superior photoactivity of Bi/TNTs@AC was attributed to enhanced light harvesting and generation of charge carriers due to the UV-induced surface plasmon resonance effect, which was enabled by the metallic Bi nanoparticles. •OH radicals and photogenerated holes (h+) were responsible for degradation of GenX. Based on the analysis of degradation byproducts and density functional theory calculations, photocatalytic degradation of GenX started with cleavage of the carboxyl group and/or ether group by •OH, h+, and/or eaq-, and the resulting intermediates were transformed into shorter-chain fluorochemicals following the stepwise defluorination mechanism. Bi/TNTs@AC holds the potential for more cost-effective degradation of GenX and other per- and polyfluorinated alkyl substances.
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Affiliation(s)
- Yangmo Zhu
- Department of Civil & Environmental Engineering, Auburn University, Auburn, AL 36849, USA
| | - Haodong Ji
- School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Ke He
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, MD 21250, USA
| | - Lee Blaney
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, MD 21250, USA
| | - Tianyuan Xu
- School of Resource and Geosciences, China University of Mining and Technology, Xuzhou, Jiangsu 221116, China.
| | - Dongye Zhao
- Department of Civil & Environmental Engineering, Auburn University, Auburn, AL 36849, USA.
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12
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Rahman MF, Anderson WB, Peldszus S, Huck PM. Ion-Exchange Treatment of Perfluorinated Carboxylic Acids in Water: Comparison of Polystyrenic and Polyacrylic Resin Structures and Impact of Sulfate on Their Performance. ACS ES T Water 2022; 2:1195-1205. [PMID: 35846407 PMCID: PMC9274775 DOI: 10.1021/acsestwater.1c00501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The removal of three perfluorinated carboxylic acids (PFCAs)-PFHpA, PFOA, and PFNA-in ultrapure and river water was evaluated using two anion-exchange resins-previously unreported macroporous polystyrenic A-500P and a more widely studied macroporous polyacrylic A-860. Both resins had similar properties, allowing direct comparison of PFCA removal performance between the two resin structures/matrices. This study also presents a new gas chromatography-mass spectrometry (GC/MS) method developed for PFCA analysis in water. In ultrapure water, A-500P exhibited higher removal capacity and faster removal compared to A-860, suggesting greater effectiveness of the polystyrenic structure compared to the polyacrylic structure. In the Grand River water, the target PFCAs were well removed by A-500P but not A-860. However, both resins achieved similarly high overall reductions of dissolved organic carbon (∼75%), suggesting, later confirmed in ultrapure water experiments, that inorganic anions (sulfate particularly) were the dominant competitors for the A-860 resin. The uncharged styrenic and acrylic beads (base materials) of the two tested resins were unable to remove PFOA, implying that the dominant removal mechanism involves charge interactions between the negatively charged PFCA and the positively charged anion-exchange functional groups.
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Affiliation(s)
- M. Feisal Rahman
- Department
of Civil and Environmental Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
- Living
Deltas Hub, Dept. of Geography and Environmental Sciences, Northumbria University, Newcastle-upon-Tyne, NE1 8ST, United Kingdom
| | - William B. Anderson
- Department
of Civil and Environmental Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - Sigrid Peldszus
- Department
of Civil and Environmental Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - Peter M. Huck
- Department
of Civil and Environmental Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
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13
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Dixit F, Munoz G, Mirzaei M, Barbeau B, Liu J, Duy SV, Sauvé S, Kandasubramanian B, Mohseni M. Removal of Zwitterionic PFAS by MXenes: Comparisons with Anionic, Nonionic, and PFAS-Specific Resins. Environ Sci Technol 2022; 56:6212-6222. [PMID: 35533009 DOI: 10.1021/acs.est.1c03780] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Zwitterionic per- and polyfluoroalkyl substances are increasingly detected in aquatic environments. The magnitude of their concentration and increased frequency of detection worldwide raise questions on their presence in drinking water and associated health risk. Scientific knowledge on the identification of treatment technologies to effectively capture such zwitterionic PFAS from contaminated water sources remains largely unknown. In this study, we investigated the application of anionic organic scavenger ion exchange (IX) resins (A860), nonionic IX resins (XAD 4 and XAD 7), PFAS-specific resins (A694 and A592), and Ti3C2 MXenes (novel two-dimensional metal carbides) for the removal of select fluorotelomer zwitterionic PFAS from natural waters. The cumulative removal of zwitterionic PFAS at pH ∼ 7 follows the order: Ti3C2 MXenes > A694 > A592 > A860 > XAD 4 ∼ XAD 7. Ti3C2 MXenes were able to capture >75% of the total influent zwitterionic PFAS and the performance remained consistent in natural and synthetic water. Ti3C2 MXenes also exhibited efficient regeneration (>90% recovery) with 0.4 M Na2SO3 solution, while the regeneration efficacy of other IX resins generally remained below 20%. Treatment with ∼180 J/cm2 UV dosage in the 0.4 M Na2SO3 regenerant brine solution yielded >99.9% reduction in the zwitterionic PFAS concentration indicating that UV-sulfite systems exhibit promising potential for the treatment of zwitterionic PFAS concentrates.
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Affiliation(s)
- Fuhar Dixit
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Gabriel Munoz
- Department of Chemistry, Université de Montréal, Montreal, Quebec H3C 3J7, Canada
| | - Mahboubeh Mirzaei
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Benoit Barbeau
- Department of Civil, Geological and Mining Engineering, Ecole Polytechnique Montreal, Montreal, Quebec H3C 3A7, Canada
| | - Jinxia Liu
- Department of Civil Engineering, McGill University, Montréal, Quebec H3A 0G4, Canada
| | - Sung Vo Duy
- Department of Chemistry, Université de Montréal, Montreal, Quebec H3C 3J7, Canada
| | - Sébastien Sauvé
- Department of Chemistry, Université de Montréal, Montreal, Quebec H3C 3J7, Canada
| | - Balasubramanian Kandasubramanian
- Nano Surface Texturing Lab, Department of Metallurgical and Materials Engineering, Defence Institute of Advanced Technology (DU), 411025 Pune, India
| | - Madjid Mohseni
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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14
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Kazwini T, Yadav S, Ibrar I, Al-Juboori RA, Singh L, Ganbat N, Karbassiyazdi E, Samal AK, Subbiah S, Altaee A. Updated review on emerging technologies for PFAS contaminated water treatment. Chem Eng Res Des 2022. [DOI: 10.1016/j.cherd.2022.04.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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15
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Dixit F, Zimmermann K, Dutta R, Prakash NJ, Barbeau B, Mohseni M, Kandasubramanian B. Application of MXenes for water treatment and energy-efficient desalination: A review. J Hazard Mater 2022; 423:127050. [PMID: 34534806 DOI: 10.1016/j.jhazmat.2021.127050] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 08/24/2021] [Accepted: 08/26/2021] [Indexed: 06/13/2023]
Abstract
MXenes are a new type of two-dimensional (2D) material which are rapidly gaining traction for a range of environmental, chemical and medical applications. MXenes and MXene-composites exhibit high surface area, superlative chemical stability, thermal conductivity, hydrophilicity and are environmentally compatible. Consequently, MXenes have been successfully employed for hydrogen storage, semiconductor manufacture and lithium ion batteries. In recent years, MXenes have been utilized in numerous environmental applications for treating contaminated surface waters, ground and industrial/ municipal wastewaters and for desalination, often outperforming conventional materials in each field. MXene-composites can adsorb multiple organic and inorganic contaminants, and undergo Faradaic capacitive deionization (CDI) when utilized for electrochemical applications. This approach allows for a significant decrease in the energy demand by overcoming the concentration polarization limitation of conventional CDI electrodes, offering a solution for low-energy desalination of brackish waters. This article presents a state-of-the-art review on water treatment and desalination applications of MXenes and MXene-composites. An investigation into the kinetics and isotherms is presented, as well as the impact of water constituents and operating conditions are also discussed. The applications of MXenes for CDI, pervaporation desalination and solar thermal desalination are also examined based on the reviewed literature. The effects of the water composition and operational protocols on the regeneration efficacy and long-term usage are also highlighted.
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Affiliation(s)
- Fuhar Dixit
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, Canada
| | - Karl Zimmermann
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, Canada
| | - Rahul Dutta
- Department of Civil Engineering, University of British Columbia, Vancouver, Canada
| | - Niranjana Jaya Prakash
- Nano Surface Texturing Lab, Department of Metallurgical and Materials Engineering, Defence Institute of Advanced Technology (DU), Pune, India
| | - Benoit Barbeau
- Department of Civil, Geological and Mining Engineering, Polytechnique Montreal, Quebec, Canada
| | - Madjid Mohseni
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, Canada.
| | - Balasubramanian Kandasubramanian
- Nano Surface Texturing Lab, Department of Metallurgical and Materials Engineering, Defence Institute of Advanced Technology (DU), Pune, India.
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16
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Liu C, Chu J, Cápiro NL, Fortner JD, Pennell KD. In-situ sequestration of perfluoroalkyl substances using polymer-stabilized ion exchange resin. J Hazard Mater 2022; 422:126960. [PMID: 34449348 DOI: 10.1016/j.jhazmat.2021.126960] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 08/16/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
Remediation of groundwater impacted by per- and polyfluoroalkyl substances (PFAS) is challenging due to the strength of the carbon-fluorine bond and the need to achieve nanogram per liter drinking water targets. Previous studies have shown that ion exchange resins can serve as effective sorbents for the removal of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) in conventional water treatment systems. The objectives of this study were to evaluate the in situ delivery and PFAS sorption capacity of a polymer-stabilized ion exchange resin (S-IXR) consisting of Amberlite® IRA910 beads and Pluronic® F-127 in a quartz sand. At concentrations below 100 µg/L, individual and mixed PFAS adsorption on resin beads exhibited linear isotherms with no apparent competitive effects. However, at concentrations up to 100 mg/L, PFAS adsorption isotherms were non-linear and a mixture of six PFAS exhibited strong competitive effects. In columns packed with 40-50 mesh Ottawa sand, injection of the S-IXR suspension created a uniform sorptive zone that increased PFOA or PFOS retention by more than five orders-of-magnitude compared to untreated control columns. Multi-solute column studies revealed earlier breakthrough of shorter-chain length PFAS, which was consistent with the mixed PFAS adsorption data. These findings indicate that injectable ion exchange resins could provide an effective in situ remediation strategy for PFAS-impacted groundwater plumes.
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Affiliation(s)
- Chen Liu
- School of Engineering, Brown University, Providence, RI 02912, United States
| | - Jenna Chu
- School of Engineering, Brown University, Providence, RI 02912, United States
| | - Natalie L Cápiro
- Department of Civil and Environmental Engineering, Auburn University, Auburn, AL 36830, United States
| | - John D Fortner
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT 06520, United States
| | - Kurt D Pennell
- School of Engineering, Brown University, Providence, RI 02912, United States.
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17
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Wang Y, Darling SB, Chen J. Selectivity of Per- and Polyfluoroalkyl Substance Sensors and Sorbents in Water. ACS Appl Mater Interfaces 2021; 13:60789-60814. [PMID: 34911297 PMCID: PMC8719322 DOI: 10.1021/acsami.1c16517] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 11/29/2021] [Indexed: 05/26/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are a large group of engineered chemicals that have been widely used in industrial production. PFAS have drawn increasing attention due to their frequent occurrence in the aquatic environment and their toxicity to animals and humans. Developing effective and efficient detection and remediation methods for PFAS in aquatic systems is critical to mitigate ongoing exposure and promote water reuse. Adsorption-based removal is the most common method for PFAS remediation since it avoids hazardous byproducts; in situ sensing technology is a promising approach for PFAS monitoring due to its fast response, easy operation, and portability. This review summarizes current materials and devices that have been demonstrated for PFAS adsorption and sensing. Selectivity, the key factor underlying both sensor and sorbent performance, is discussed by exploring the interactions between PFAS and various probes. Examples of selective probes will be presented and classified by fluorinated groups, cationic groups, and cavitary groups, and their synergistic effects will also be analyzed. This review aims to provide guidance and implication for future material design toward more selective and effective PFAS sensors and sorbents.
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Affiliation(s)
- Yuqin Wang
- Chemical
Sciences and Engineering Division and Center for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Advanced
Materials for Energy-Water Systems Energy Frontier Research Center, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Pritzker
School of Molecular Engineering, University
of Chicago, Chicago, Illinois 60637, United States
| | - Seth B. Darling
- Chemical
Sciences and Engineering Division and Center for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Advanced
Materials for Energy-Water Systems Energy Frontier Research Center, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Pritzker
School of Molecular Engineering, University
of Chicago, Chicago, Illinois 60637, United States
| | - Junhong Chen
- Chemical
Sciences and Engineering Division and Center for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Pritzker
School of Molecular Engineering, University
of Chicago, Chicago, Illinois 60637, United States
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18
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Liu YL, Sun M. Ion exchange removal and resin regeneration to treat per- and polyfluoroalkyl ether acids and other emerging PFAS in drinking water. Water Res 2021; 207:117781. [PMID: 34731662 DOI: 10.1016/j.watres.2021.117781] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 10/12/2021] [Accepted: 10/13/2021] [Indexed: 05/27/2023]
Abstract
Ion exchange (IX) is a promising technology to remove legacy anionic per- and polyfluoroalkyl substances (PFAS) from water. As increasing numbers of per- and polyfluoroalkyl ether acids (PFEA) and other emerging PFAS were detected in the environment, it is necessary to understand how well IX resins remove these emerging PFAS for drinking water treatment. In this study, nine commercially available IX resins were tested to treat a drinking water source spiked with 40 legacy and emerging PFAS at 600 ng/L, including PFEA, perfluoroalkyl carboxylic and sulfonic acids, fluorotelomer sulfonic acids, perfluoroalkane sulfonamides, perfluoroalkane sulfonamidoacetic acids, and zwitterionic species. With limited contact time (15 min), PFAS properties such as the fluorinated chain length, charge, and functional groups all affected PFAS adsorption to resins. However, the impact of PFAS properties on PFAS removal became less pronounced when the contact time increased beyond 2 h, while the resin polymer matrix became the critical factor for PFAS removal. All five tested polystyrene-divinylbenzene (PS-DVB) resins achieved more than 90% removal in 24 h of 35 PFAS compounds, while polymethacrylate and polyacrylic resins achieved >90% removal for less than half of the compounds. Regenerating PS-DVB resin was investigated using different salt species, regenerant pH, brine concentrations, and methanol contents. Sodium chloride and ammonium chloride were found the best brines for regenerating the tested resins. Increasing brine concentrations enhanced the regeneration efficiency, especially for short-chain PFAS. Using simple salt regenerants, up to 94% of selected short-chain PFAS was released from resins designed for general water treatment, but no meaningful regeneration was achieved for long-chain PFAS or PFAS-specific resins when the organic solvent content was less than 20%.
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Affiliation(s)
- Yen-Ling Liu
- Department of Civil and Environmental Engineering, University of North Carolina at Charlotte, Charlotte, NC, 28223, United States
| | - Mei Sun
- Department of Civil and Environmental Engineering, University of North Carolina at Charlotte, Charlotte, NC, 28223, United States.
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19
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Teymourian T, Teymoorian T, Kowsari E, Ramakrishna S. A review of emerging PFAS contaminants: sources, fate, health risks, and a comprehensive assortment of recent sorbents for PFAS treatment by evaluating their mechanism. Res Chem Intermed 2021; 47:4879-914. [DOI: 10.1007/s11164-021-04603-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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20
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Liu Z, Haddad M, Sauvé S, Barbeau B. Alleviating the burden of ion exchange brine in water treatment: From operational strategies to brine management. Water Res 2021; 205:117728. [PMID: 34619606 DOI: 10.1016/j.watres.2021.117728] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 07/21/2021] [Accepted: 09/26/2021] [Indexed: 06/13/2023]
Abstract
Ion exchange (IX) using synthetic resins is a cost-efficient technology to cope with a wide range of contaminants in water treatment. However, implementing IX processes is constrained by the regeneration of IX resins that generates a highly concentrated brine (i.e., IX brine), the disposal of which is costly and detrimental to ecosystems. In an effort to make the application of IX resins more sustainable in water treatment, substantial research has been conducted on the optimization of IX resins operation and the management of IX brine. The present review critically evaluates the literature surrounding IX operational strategies and IX brine management which can be used to limit the negative impacts arising from IX brine. To this end, we first analyzed the physicochemical characteristics of brines from the regeneration of IX resins. Then, we critically evaluated IX operational strategies that facilitate brine management, including resin selection, contactor selection, operational modes, and regeneration strategies. Furthermore, we analyzed IX brine management strategies, including brine reuse and brine disposal (without or with treatment). Finally, a novel workflow for the IX water treatment plant design that integrates IX operational strategies and IX brine management is proposed, thereby highlighting the areas that make IX technology more sustainable for water treatment.
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Affiliation(s)
- Zhen Liu
- Department of Chemistry, Université de Montréal, Montréal, QC H2V 0B3, Canada; NSERC-Industrial Chair on Drinking Water, Department of Civil, Mining and Geological Engineering, Polytechnique Montréal, Montréal, QC H3T 1J4, Canada.
| | - Maryam Haddad
- Department of Chemical Engineering, California State University, Long Beach, CA 90840, United States.
| | - Sébastien Sauvé
- Department of Chemistry, Université de Montréal, Montréal, QC H2V 0B3, Canada.
| | - Benoit Barbeau
- NSERC-Industrial Chair on Drinking Water, Department of Civil, Mining and Geological Engineering, Polytechnique Montréal, Montréal, QC H3T 1J4, Canada.
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21
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Heidari H, Abbas T, Ok YS, Tsang DCW, Bhatnagar A, Khan E. GenX is not always a better fluorinated organic compound than PFOA: A critical review on aqueous phase treatability by adsorption and its associated cost. Water Res 2021; 205:117683. [PMID: 34607087 DOI: 10.1016/j.watres.2021.117683] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 09/14/2021] [Accepted: 09/17/2021] [Indexed: 06/13/2023]
Abstract
Hexafluoropropylene oxide dimer acid (GenX) has been marketed as a substitute for perfluorooctanoic acid (PFOA) to reduce environmental and health risks. GenX and PFOA have been detected in various natural water sources, and adsorption is recognized as a typical treatment process for PFOA removal. In this paper, comparisons of GenX and PFOA adsorption are evaluated, including adsorption potential, adsorption mechanisms, and associated costs. A detailed literature review suggests that anion-exchange resins are more effective in removing GenX than activated carbon. GenX removal efficiency through activated carbon (30%) is lower than that of PFOA (80-95%), while GenX and PFOA removal efficiencies by anion exchange resins are similar (99%). Unconventional adsorbents, such as ionic fluorogels and covalent organic frameworks can effectively remove GenX from water. The review reveals that GenX adsorption is more challenging, requiring almost 4 times the treatment cost of its predecessor, PFOA. Annual operation and maintenance costs for GenX adsorption (initial concentration of GenX and PFOA = 0.2 µg.L-1) by GAC for treating 10,000 m3 per day is almost US$1,000,000 per year, but only around US$240,000 per year for PFOA. Desorption of GenX in the presence of PFOA highlights GenX's inferior treatability by adsorption. It is believed that GenX is a more environmentally friendly compound than PFOA, but this environmental friendliness comes with the price.
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Affiliation(s)
- Hamed Heidari
- Civil and Environmental Engineering and Construction Department, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - Tauqeer Abbas
- Civil and Environmental Engineering and Construction Department, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - Yong Sik Ok
- Korea Biochar Research Center, APRU Sustainable Waste Management Program & Division of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea
| | - Daniel C W Tsang
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Amit Bhatnagar
- Department of Separation Science, LUT School of Engineering Science, LUT University, Sammonkatu 12, FI-50130, Mikkeli, Finland
| | - Eakalak Khan
- Civil and Environmental Engineering and Construction Department, University of Nevada, Las Vegas, Las Vegas, NV, United States.
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22
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Boyer TH, Fang Y, Ellis A, Dietz R, Choi YJ, Schaefer CE, Higgins CP, Strathmann TJ. Anion exchange resin removal of per- and polyfluoroalkyl substances (PFAS) from impacted water: A critical review. Water Res 2021; 200:117244. [PMID: 34089925 DOI: 10.1016/j.watres.2021.117244] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 05/06/2021] [Accepted: 05/08/2021] [Indexed: 05/27/2023]
Abstract
A key gap in the literature on the treatment of per- and polyfluoroalkyl substances (PFAS) in impacted water is the absence of a review article dedicated to anion exchange resin (AER) treatment. This gap is important because previous research has consistently shown adsorption by AER to be one of the most effective treatment processes for PFAS removal from impacted water, and AER is one of the most commonly deployed technologies in the field. Given the scope of the previous review articles on PFAS removal by various adsorbent types, the sections on AER do not explore the full depth of PFAS and AER interactions nor cover the breadth of AER testing conditions. Accordingly, the goal of this paper was to critically review the available peer-reviewed literature on PFAS removal from water by AER. The specific objectives of the review were to synthesize the previous literature results on (1) batch adsorption behavior, (2) impact of water chemistry conditions, (3) continuous-flow adsorption, (4) adsorption modeling, (5) regeneration, and (6) weak-base AER. Following from critical review of the literature, the future research priorities discussed include: (i) improving the underlying science that governs PFAS-resin interactions, (ii) improving methods for resin regeneration and management of PFAS-contaminated concentrate streams, and (iii) comparative life cycle environmental and economic analyses for ion exchange treatment systems relative to competing technologies.
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Affiliation(s)
- Treavor H Boyer
- School of Sustainable Engineering and the Built Environment (SSEBE), Arizona State University (ASU), Tempe, Arizona, 85287, United States
| | - Yida Fang
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado, 80401, United States
| | - Anderson Ellis
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado, 80401, United States
| | - Rebecca Dietz
- School of Sustainable Engineering and the Built Environment (SSEBE), Arizona State University (ASU), Tempe, Arizona, 85287, United States
| | - Youn Jeong Choi
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado, 80401, United States
| | | | - Christopher P Higgins
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado, 80401, United States
| | - Timothy J Strathmann
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado, 80401, United States
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