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de Souza BB, Meegoda J. Insights into PFAS environmental fate through computational chemistry: A review. Sci Total Environ 2024; 926:171738. [PMID: 38494023 DOI: 10.1016/j.scitotenv.2024.171738] [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: 12/17/2023] [Revised: 02/28/2024] [Accepted: 03/14/2024] [Indexed: 03/19/2024]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are widely used chemicals that exhibit exceptional chemical and thermal stability. However, their resistance to degradation has led to their widespread environmental contamination. PFAS also negatively affect the environment and other organisms, highlighting the need for effective remediation methods to mitigate their presence and prevent further contamination. Computational chemistry methods, such as Density Functional Theory (DFT) and Molecular Dynamics (MD) offer valuable tools for studying PFAS and simulating their interactions with other molecules. This review explores how computational chemistry methods contribute to understanding and tackling PFAS in the environment. PFAS have been extensively studied using DFT and MD, each method offering unique advantages and computational limitations. MD simulates large macromolecules systems however it lacks the ability model chemical reactions, while DFT provides molecular insights however at a high computational cost. The integration of DFT with MD shows promise in predicting PFAS behavior in different environments. This work summarizes reported studies on PFAS compounds, focusing on adsorption, destruction, and bioaccumulation, highlighting contributions of computational methods while discussing the need for continued research. The findings emphasize the importance of computational chemistry in addressing PFAS contamination, guiding risk assessments, and informing future research and innovations in this field.
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Affiliation(s)
- Bruno Bezerra de Souza
- John A. Reif, Jr. Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA
| | - Jay Meegoda
- John A. Reif, Jr. Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA.
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We ACE, Stickland AD, Clarke BO, Freguia S. The role of suspended biomass in PFAS enrichment in wastewater treatment foams. Water Res 2024; 254:121349. [PMID: 38401288 DOI: 10.1016/j.watres.2024.121349] [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: 12/18/2023] [Revised: 02/08/2024] [Accepted: 02/20/2024] [Indexed: 02/26/2024]
Abstract
Foaming in aerated bioreactors at wastewater treatment plants (WWTPs) has been identified as an operational issue for decades. However, the affinity of per- and polyfluoroalkyl substances (PFAS) for air-liquid interfaces suggests that foam harvesting has the potential to become a sustainable method for PFAS removal from sewage. Aerated bioreactors' foams are considered three-phase systems, comprising air, aqueous and solid components, the latter consisting of activated sludge biomass. To achieve a comprehensive understanding of the capability of aerated bioreactors' foams to enrich PFAS, we analysed PFAS concentrations from WWTPs in both the solid and aqueous phases of the collapsed foams (foamate) and underlying bulk mixed liquors. Our findings show that PFAS enrichment occurs not only in the aqueous phase but also in the solid phase of the foamate. This suggests that previous field studies that only analysed the aqueous phase may have underestimated the capability of the aerated bioreactors' foams to enrich PFAS. Fractions of PFOA and PFOS sorbed to the solid phase of the foamate can be as high as 60 % and 95 %, respectively. Our findings highlight the importance of implementing effective foamate management strategies that consider both the aqueous and solid phases.
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Affiliation(s)
- Angel Chyi En We
- Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria, 3010, Australia; Australian Laboratory for Emerging Contaminants, School of Chemistry, The University of Melbourne, Victoria, 3010, Australia
| | - Anthony D Stickland
- Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Bradley O Clarke
- Australian Laboratory for Emerging Contaminants, School of Chemistry, The University of Melbourne, Victoria, 3010, Australia
| | - Stefano Freguia
- Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria, 3010, Australia.
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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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