1
|
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.
Collapse
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
| |
Collapse
|
2
|
Trzcinski AP, Harada K. Combined adsorption and electrochemical oxidation of perfluorooctanoic acid (PFOA) using graphite intercalated compound. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:19946-19960. [PMID: 38367112 DOI: 10.1007/s11356-024-32449-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 02/08/2024] [Indexed: 02/19/2024]
Abstract
Perfluorooctanoic acid (PFOA) is a bioaccumulative synthetic chemical containing strong C-F bonds and is one of the most common per- and polyfluoroalkyl substances (PFAS) detected in the environment. Graphite intercalated compound (GIC) flakes were used to adsorb and degrade PFOA through electrochemical oxidation. The adsorption followed the Langmuir model with a loading capacity of 2.6 µg PFOA g-1 GIC and a second-order kinetics (3.354 g µg-1 min-1). 99.4% of PFOA was removed by the process with a half-life of 15 min. When PFOA molecules broke down, they released various by-products, such as short-chain perfluoro carboxylic acids like PFHpA, PFHxA, and PFBA. This breakdown indicates the cleavage of the perfluorocarbon chain and the release of CF2 units, suggesting a transformation or degradation of the original compound into these smaller acids. Shorter-chain perfluorinated compounds had slower degradation rates compared to longer-chain ones. Combining these two methods (adsorption and in situ electrochemical oxidation) was found to be advantageous because adsorption can initially concentrate the PFOA molecules, making it easier for the electrochemical process to target and degrade them. The electrochemical process can potentially break down or transform the PFAS compounds into less harmful substances through oxidation or other reactions.
Collapse
Affiliation(s)
- Antoine P Trzcinski
- School of Agriculture and Environmental Science, University of Southern Queensland, West Street, Queensland, 4350, Australia.
| | - Kouji Harada
- Department of Health and Environmental Sciences, Graduate School of Medicine, Kyoto University, Kyoto, 606-8501, Japan
| |
Collapse
|
3
|
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.
Collapse
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
| | | |
Collapse
|
4
|
Ersan MS, Wang B, Wong MS, Westerhoff P. Advanced oxidation processes may transform unknown PFAS in groundwater into known products. CHEMOSPHERE 2024; 349:140865. [PMID: 38048829 DOI: 10.1016/j.chemosphere.2023.140865] [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: 08/12/2023] [Revised: 11/28/2023] [Accepted: 11/29/2023] [Indexed: 12/06/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are a group of fluorinated organic contaminants classified as persistent in the aquatic environment. Early studies using targeted analysis approaches to evaluate the degradation of PFAS by advanced oxidation processes (AOP) in real water matrices may have been misinterpreted due to the presence of undetected or unknown PFAS in these matrices. The aims of the present study were to (1) screen selected commercially available AOPs (UV, UV + H2O2, O3/H2O2) and UV photocatalysis in a pilot system using commercially used and novel photocatalysts (TiO2, boron nitride [BN]) for removing PFAS contaminants and (2) evaluate their role on the conversion of non-detected/unknown to known PFAS compounds in real groundwater used as drinking water supplies. Results indicated that, while AOPs have the potential to achieve removal of the EPA method 533 target PFAS compounds (PFDA [100%], PFNA [100%], PFOA [85-94%], PFOS [25-100%], PFHxS [3-100%], PFPeS [100%], PFBS [100%]), AOPs transformed non-detected/unknown longer-chain PFAS compounds to detectable shorter-chain ones under very high-dose AOP operating conditions, leading to an increase in ∑PFAS concentration ranging from 95% to 340%. As emerging PFAS treatment processes transition from lab-scale investigations of target PFAS to pilot testing of real water matrices, studies will need to consider impact of the presence of non-target long-chain PFAS to transform into targeted PFAS compounds. A promising approach to address the potential risks and unforeseen consequences could involve an increased reliance on adsorbable organic fluorine (AOF) analysis before and after advanced oxidation process (AOP) treatment.
Collapse
Affiliation(s)
- Mahmut S Ersan
- Department of Civil Engineering, University of North Dakota, Grand Forks, ND, 58202, USA; School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ, 85287-5306, USA; Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, Arizona State University, USA.
| | - Bo Wang
- Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, Arizona State University, USA; Department of Chemical and Biomolecular Engineering, Department of Environmental Engineering, Department of Chemistry, and Department of Materials Science and NanoEngineering, Rice University, Houston, TX, 77005, USA
| | - Michael S Wong
- Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, Arizona State University, USA; Department of Chemical and Biomolecular Engineering, Department of Environmental Engineering, Department of Chemistry, and Department of Materials Science and NanoEngineering, Rice University, Houston, TX, 77005, USA
| | - Paul Westerhoff
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ, 85287-5306, USA; Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, Arizona State University, USA
| |
Collapse
|
5
|
Tolaymat T, Robey N, Krause M, Larson J, Weitz K, Parvathikar S, Phelps L, Linak W, Burden S, Speth T, Krug J. A critical review of perfluoroalkyl and polyfluoroalkyl substances (PFAS) landfill disposal in the United States. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 905:167185. [PMID: 37734620 PMCID: PMC10842600 DOI: 10.1016/j.scitotenv.2023.167185] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 09/15/2023] [Accepted: 09/16/2023] [Indexed: 09/23/2023]
Abstract
Landfills manage materials containing per- and polyfluoroalkyl substances (PFAS) from municipal solid waste (MSW) and other waste streams. This manuscript summarizes state and federal initiatives and critically reviews peer-reviewed literature to define best practices for managing these wastes and identify data gaps to guide future research. The objective is to inform stakeholders about waste-derived PFAS disposed of in landfills, PFAS emissions, and the potential for related environmental impacts. Furthermore, this document highlights data gaps and uncertainties concerning the fate of PFAS during landfill disposal. Most studies on this topic measured PFAS in liquid landfill effluent (leachate); comparatively fewer have attempted to estimate PFAS loading in landfills or other effluent streams such as landfill gas (LFG). In all media, the reported total PFAS heavily depends on waste types and the number of PFAS included in the analytical method. Early studies which only measured a small number of PFAS, predominantly perfluoroalkyl acids (PFAAs), likely report a significant underestimation of total PFAS. Major findings include relationships between PFAS effluent and landfill conditions - biodegradable waste increases PFAS transformation and leaching. Based on the results of multiple studies, it is estimated that 84% of PFAS loading to MSW landfills (7.2 T total) remains in the waste mass, while 5% leaves via LFG and 11% via leachate on an annual basis. The environmental impact of landfill-derived PFAS has been well-documented. Additional research is needed on PFAS in landfilled construction and demolition debris, hazardous, and industrial waste in the US.
Collapse
Affiliation(s)
- Thabet Tolaymat
- The Center for Environmental Solutions and Emergency Management, Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, OH, USA.
| | - Nicole Robey
- Innovative Technical Solutions, Gainesville, FL, USA
| | - Max Krause
- The Center for Environmental Solutions and Emergency Management, Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, OH, USA
| | - Judd Larson
- RTI International, Research Triangle Park, NC, USA
| | - Keith Weitz
- RTI International, Research Triangle Park, NC, USA
| | | | - Lara Phelps
- The Center for Environmental Measurements and Modeling, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - William Linak
- The Center for Environmental Measurements and Modeling, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Susan Burden
- Office of Science Advisor, Policy and Engagement, Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC, USA
| | - Tom Speth
- The Center for Environmental Solutions and Emergency Management, Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, OH, USA
| | - Jonathan Krug
- The Center for Environmental Measurements and Modeling, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| |
Collapse
|
6
|
Marciesky M, Aga DS, Bradley IM, Aich N, Ng C. Mechanisms and Opportunities for Rational In Silico Design of Enzymes to Degrade Per- and Polyfluoroalkyl Substances (PFAS). J Chem Inf Model 2023; 63:7299-7319. [PMID: 37981739 PMCID: PMC10716909 DOI: 10.1021/acs.jcim.3c01303] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/17/2023] [Accepted: 10/18/2023] [Indexed: 11/21/2023]
Abstract
Per and polyfluoroalkyl substances (PFAS) present a unique challenge to remediation techniques because their strong carbon-fluorine bonds make them difficult to degrade. This review explores the use of in silico enzymatic design as a potential PFAS degradation technique. The scope of the enzymes included is based on currently known PFAS degradation techniques, including chemical redox systems that have been studied for perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) defluorination, such as those that incorporate hydrated electrons, sulfate, peroxide, and metal catalysts. Bioremediation techniques are also discussed, namely the laccase and horseradish peroxidase systems. The redox potential of known reactants and enzymatic radicals/metal-complexes are then considered and compared to potential enzymes for degrading PFAS. The molecular structure and reaction cycle of prospective enzymes are explored. Current knowledge and techniques of enzyme design, particularly radical-generating enzymes, and application are also discussed. Finally, potential routes for bioengineering enzymes to enable or enhance PFAS remediation are considered as well as the future outlook for computational exploration of enzymatic in situ bioremediation routes for these highly persistent and globally distributed contaminants.
Collapse
Affiliation(s)
- Melissa Marciesky
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, United States
| | - Diana S Aga
- Department of Chemistry, State University of New York at Buffalo, Buffalo, New York 14260, United States
| | - Ian M Bradley
- Department of Civil, Structural, and Environmental Engineering, State University of New York at Buffalo, Buffalo, New York 14228, United States
- Research and Education in Energy, Environmental and Water (RENEW) Institute, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Nirupam Aich
- Department of Civil and Environmental Engineering, University of Nebraska─Lincoln, Lincoln, Nebraska 68588-0531, United States
| | - Carla Ng
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, United States
- Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| |
Collapse
|
7
|
Mojiri A, Zhou JL, Ozaki N, KarimiDermani B, Razmi E, Kasmuri N. Occurrence of per- and polyfluoroalkyl substances in aquatic environments and their removal by advanced oxidation processes. CHEMOSPHERE 2023; 330:138666. [PMID: 37068615 DOI: 10.1016/j.chemosphere.2023.138666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 03/15/2023] [Accepted: 04/10/2023] [Indexed: 05/14/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS), one of the main categories of emerging contaminants, are a family of fluorinated organic compounds of anthropogenic origin. PFAS can endanger the environment and human health because of their wide application in industries, long-term persistence, unique properties, and bioaccumulation potential. This study sought to explain the accumulation of different PFAS in water bodies. In aquatic environments, PFAS concentrations range extensively from <0.03 (groundwater; Melbourne, Australia) to 51,000 ng/L (Groundwater, Sweden). Additionally, bioaccumulation of PFAS in fish and water biota has been stated to range from 0.2 (Burbot, Lake Vättern, Sweden) to 13,900 ng/g (Bluegill samples, U.S.). Recently, studies have focused on PFAS removal from aqueous solutions; one promising technique is advanced oxidation processes (AOPs), including microwaves, ultrasound, ozonation, photocatalysis, UV, electrochemical oxidation, the Fenton process, and hydrogen peroxide-based and sulfate radical-based systems. The removal efficiency of PFAS ranges from 3% (for MW) to 100% for UV/sulfate radical as a hybrid reactor. Therefore, a hybrid reactor can be used to efficiently degrade and remove PFAS. Developing novel, efficient, cost-effective, and sustainable AOPs for PFAS degradation in water treatment systems is a critical area of research.
Collapse
Affiliation(s)
- Amin Mojiri
- Department of Civil and Environmental Engineering, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashihiroshima, 739-8527, Hiroshima, Japan.
| | - John L Zhou
- School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW, 2007, Australia
| | - Noriatsu Ozaki
- Department of Civil and Environmental Engineering, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashihiroshima, 739-8527, Hiroshima, Japan
| | - Bahareh KarimiDermani
- Department of Geological Sciences, Hydrogeology, University of Alabama, Tuscaloosa, AL, 35487, USA
| | - Elham Razmi
- Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran
| | - Norhafezah Kasmuri
- School of Civil Engineering, College of Engineering, Universiti Teknologi MARA (UiTM), Shah Alam, 40450, Selangor, Malaysia
| |
Collapse
|
8
|
Cardoso IMF, Pinto da Silva L, Esteves da Silva JCG. Nanomaterial-Based Advanced Oxidation/Reduction Processes for the Degradation of PFAS. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:nano13101668. [PMID: 37242085 DOI: 10.3390/nano13101668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 05/11/2023] [Accepted: 05/16/2023] [Indexed: 05/28/2023]
Abstract
This review focuses on a critical analysis of nanocatalysts for advanced reductive processes (ARPs) and oxidation processes (AOPs) designed for the degradation of poly/perfluoroalkyl substances (PFAS) in water. Ozone, ultraviolet and photocatalyzed ARPs and/or AOPs are the basic treatment technologies. Besides the review of the nanomaterials with greater potential as catalysts for advanced processes of PFAS in water, the perspectives for their future development, considering sustainability, are discussed. Moreover, a brief analysis of the current state of the art of ARPs and AOPs for the treatment of PFAS in water is presented.
Collapse
Affiliation(s)
- Inês M F Cardoso
- Chemistry Research Unit (CIQUP), Institute of Molecular Sciences (IMS), Department of Geosciences, Environment and Territorial Planning, Faculty of Sciences, University of Porto (FCUP), Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - Luís Pinto da Silva
- Chemistry Research Unit (CIQUP), Institute of Molecular Sciences (IMS), Department of Geosciences, Environment and Territorial Planning, Faculty of Sciences, University of Porto (FCUP), Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - Joaquim C G Esteves da Silva
- Chemistry Research Unit (CIQUP), Institute of Molecular Sciences (IMS), Department of Geosciences, Environment and Territorial Planning, Faculty of Sciences, University of Porto (FCUP), Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| |
Collapse
|
9
|
Lashuk B, Pineda M, AbuBakr S, Boffito D, Yargeau V. Application of photocatalytic ozonation with a WO 3/TiO 2 catalyst for PFAS removal under UVA/visible light. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 843:157006. [PMID: 35779716 DOI: 10.1016/j.scitotenv.2022.157006] [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: 04/11/2022] [Revised: 06/08/2022] [Accepted: 06/23/2022] [Indexed: 06/15/2023]
Abstract
This research evaluates photocatalytic ozonation for removing 5 PFAS (PFOA/PFHxS/PFBS/6:2 FTS/GenX) from water using a WO3/TiO2 catalyst under UVA-visible radiation. Four catalysts of varying WO3 content (0/1/3/5 wt%) were synthesized by sol-gel and characterized by XRD, TEM, STEM-EDS, HAADF-STEM, adsorption/desorption N2 isotherms, and DRS-UV-vis. 5 wt% WO3/TiO2 was the optimal composition based on physicochemical properties and photocatalytic activity tests with methylene blue. PFAS degradation showed that photocatalytic ozonation inefficiently degraded PFAS with WO3/TiO2 under UVA-visible light after 4 h (ΣPFAS removal 16 %, [range 4 %-26 %]). Photocatalysis had comparable removal to photocatalytic ozonation, photolysis and ozone photolysis showed lower removal, and ozonation had no effect. Microtox analysis showed the initial acute toxicity was no longer detectable after photocatalysis and photocatalytic ozonation treatment. Low PFAS removals under tested conditions require that future work evaluate different catalysts or treatment conditions, while disparities between tested PFAS removals demonstrate the need to evaluate multiple compounds. ENVIRONMENTAL IMPLICATION: The research presented in this manuscript involves the preparation and characterization of WO3/TiO2 catalysts used, for the first time, to remove multiple PFAS in water via photocatalytic ozonation. This manuscript supports the development of a catalytic process for the elimination of hard to degrade environmental pollutants, provides new knowledge on aspects of photocatalytic processes, and provides insights on environmental pollution abatement.
Collapse
Affiliation(s)
- Brent Lashuk
- Department of Chemical Engineering, McGill University, 3610 Rue University, Montréal, QC H3A 0C5, Canada
| | - Marco Pineda
- Department of Chemical Engineering, McGill University, 3610 Rue University, Montréal, QC H3A 0C5, Canada
| | - Salma AbuBakr
- Department of Chemical Engineering, McGill University, 3610 Rue University, Montréal, QC H3A 0C5, Canada
| | - Daria Boffito
- Department of Chemical Engineering, Polytechnique Montréal, 2500 Chemin de Polytechnique, Montréal, QC H3T 1J4, Canada; Canada Research Chair in Engineering Process Intensification and Catalysis (EPIC), Department of Chemical Engineering, Polytechnique Montréal, 2500 Chemin de Polytechnique, Montréal, QC H3T 1J4, Canada
| | - Viviane Yargeau
- Department of Chemical Engineering, McGill University, 3610 Rue University, Montréal, QC H3A 0C5, Canada.
| |
Collapse
|
10
|
Wang M, Cai Y, Zhou B, Yuan R, Chen Z, Chen H. Removal of PFASs from water by carbon-based composite photocatalysis with adsorption and catalytic properties: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 836:155652. [PMID: 35508243 DOI: 10.1016/j.scitotenv.2022.155652] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 04/24/2022] [Accepted: 04/28/2022] [Indexed: 05/27/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs) are a class of persistent organic pollutants widely distributed in aquatic environments. The adsorption and photocatalytic methods have been widely used to remove PFASs in water because of their respective advantages. Still, they have apparent defects when used alone. Therefore, the adsorption and photocatalytic technologies are combined through suitable preparation methods, and the excellent properties of the two are used to synergize the treatment of organic pollutants. This strategy of "concentrating" pollutants and then degrading them in a centralized manner plays an essential role in removing trace PFASs. Nevertheless, a review focusing on this kind of adsorption photocatalyst system is lacking. This review will fill this gap and provide a reference for developing a carbon-based composite photocatalyst. Firstly, different carbon-based composite photocatalysts are reviewed in detail, focusing on the differences in various composite materials' excellent adsorption and catalytic properties. Secondly, the factors influencing the removal effect of carbon-based composite photocatalysts are discussed. Thirdly, the removal mechanism of carbon-based composite photocatalysts is summarized in detail. The removal process involves two steps: adsorption and photodegradation. The adsorption process involves multiple cooperative adsorption mechanisms, and photocatalytic degradation includes oxidative and reductive degradation. Fourthly, the comparison of adsorption-photocatalysis with common treatment techniques (including removal rate, range of adaptation, cost, and the possibility of expanding application) is summarized. Finally, the prospects of carbon-based composite photocatalysts for repairing PFASs are given by evaluating the performance of different composites.
Collapse
Affiliation(s)
- Mingran Wang
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Yanping Cai
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Beihai Zhou
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Rongfang Yuan
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Zhongbing Chen
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 16500 Prague, Czech Republic
| | - Huilun Chen
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China.
| |
Collapse
|
11
|
Kaiser AM, Saracevic E, Schaar HP, Weiss S, Hornek-Gausterer R. Ozone as oxidizing agent for the total oxidizable precursor (TOP) assay and as a preceding step for activated carbon treatments concerning per- and polyfluoroalkyl substance removal. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 300:113692. [PMID: 34509127 DOI: 10.1016/j.jenvman.2021.113692] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 09/03/2021] [Accepted: 09/03/2021] [Indexed: 06/13/2023]
Abstract
Several thousands of highly persistent per- and polyfluoroalkyl substances (PFAS) exist and it is therefore challenging to analytically determine a larger spectrum of these compounds simultaneously in one sample. It is even more difficult to efficiently remove mobile PFAS in wastewater treatment plants (WWTPs) to protect the receiving waters. The total oxidizable precursor (TOP) assay is an approach that enables the detection of the total PFAS content in a sample via oxidation of precursors, followed by subsequent analysis of the perfluoroalkyl acid (PFAA) concentration before and after oxidative processes. Activated carbon combined with a preceding ozonation step is considered a promising tool for the removal of micropollutants but considering PFAS removal efficiencies in effluents for this process combination more information is required. The focus of the study was to implement and assess the TOP assay with ozone as oxidizing agent to estimate the total PFAS content in a WWTP effluent. Additionally, granular activated carbon (GAC) and powdered activated carbon (PAC) with a preceding ozonation step was tested for the removal efficiencies for 22 PFAS. For the TOP assay the obtained accordance in molarity using spiked tap water as quality control was 95.2% (15 mg O3/L) and 99.1% (6 mg O3/L). Applying the TOP assay, an estimated total PFAS content of 840 ng/L was determined in the respective effluent, which was 91.1% higher than obtained by target PFAS analysis, implying the presence of unknown precursors not included in common monitoring. While all treatment techniques that included ozone or a preceding ozonation step solely transformed precursors and long-chain perfluoroalkyl acids (PFAA, i.e., >C9) to shorter congeners, PAC was the only tested water treatment application that was able to remove 19.3% of the total PFAS molarity.
Collapse
Affiliation(s)
| | - Ernis Saracevic
- TU Wien, Institute for Water Quality and Resource Management, Karlsplatz 12/226-1, Vienna, Austria
| | - Heidemarie Paula Schaar
- TU Wien, Institute for Water Quality and Resource Management, Karlsplatz 12/226-1, Vienna, Austria
| | - Stefan Weiss
- Environment Agency Austria, Spittelauer Lände 5, A-1090, Vienna, Austria
| | | |
Collapse
|
12
|
He H, Li Y, Shen R, Shim H, Zeng Y, Zhao S, Lu Q, Mai B, Wang S. Environmental occurrence and remediation of emerging organohalides: A review. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 290:118060. [PMID: 34479159 DOI: 10.1016/j.envpol.2021.118060] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 08/02/2021] [Accepted: 08/25/2021] [Indexed: 06/13/2023]
Abstract
As replacements for "old" organohalides, such as polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs), "new" organohalides have been developed, including decabromodiphenyl ethane (DBDPE), short-chain chlorinated paraffins (SCCPs), and perfluorobutyrate (PFBA). In the past decade, these emerging organohalides (EOHs) have been extensively produced as industrial and consumer products, resulting in their widespread environmental distribution. This review comprehensively summarizes the environmental occurrence and remediation methods for typical EOHs. Based on the data collected from 2015 to 2021, these EOHs are widespread in both abiotic (e.g., dust, air, soil, sediment, and water) and biotic (e.g., bird, fish, and human serum) matrices. A significant positive correlation was found between the estimated annual production amounts of EOHs and their environmental contamination levels, suggesting the prohibition of both production and usage of EOHs as a critical pollution-source control strategy. The strengths and weaknesses, as well as the future prospects of up-to-date remediation techniques, such as photodegradation, chemical oxidation, and biodegradation, are critically discussed. Of these remediation techniques, microbial reductive dehalogenation represents a promising in situ remediation method for removal of EOHs, such as perfluoroalkyl and polyfluoroalkyl substances (PFASs) and halogenated flame retardants (HFRs).
Collapse
Affiliation(s)
- Haozheng He
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou, 510006, China
| | - Yiyang Li
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou, 510006, China
| | - Rui Shen
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou, 510006, China
| | - Hojae Shim
- Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau SAR, 999078, China
| | - Yanhong Zeng
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
| | - Siyan Zhao
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Qihong Lu
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou, 510006, China; State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.
| | - Bixian Mai
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
| | - Shanquan Wang
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou, 510006, China
| |
Collapse
|
13
|
Yang JS, Lai WWP, Lin AYC. New insight into PFOS transformation pathways and the associated competitive inhibition with other perfluoroalkyl acids via photoelectrochemical processes using GOTiO 2 film photoelectrodes. WATER RESEARCH 2021; 207:117805. [PMID: 34736002 DOI: 10.1016/j.watres.2021.117805] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 10/18/2021] [Accepted: 10/21/2021] [Indexed: 06/13/2023]
Abstract
The global distribution and environmental persistence of perfluoroalkyl acids (PFAAs) has been considered a critical environmental concern. In this work, we successfully fabricated a graphene oxide-titanium dioxide (GOTiO2) photoelectrode for perfluorooctane sulfonate (PFOS) degradation in a photoelectrochemical (PEC) system. The results reveal that a 5 wt.% GOTiO2 anode possesses the optimal PEC performance, with a band gap (Eg) of 2.42 eV, specific surface area (SBET) of 72.6 m2 g-1 and specific capacitance (Cs) of 4.63 mF cm-2. In the PEC system, PFOS can be efficiently removed within 4 h of reaction time, with a pseudo-first-order rate constant of 0.0124 min-1, under the optimized conditions of current density = 20 mA cm-2, electrode distance = 5 mm, solution pH = 5.64, [PFOS]0= 0.5 µM and NaClO4 electrolyte concentration = 50 mM. The electron transfer pathway, hydroxyl radicals and superoxide radicals are all responsible for PFOS decomposition/transformation. New degradation pathways were identified; a total of 25 PFOS byproducts are reported in this work; and perfluoroalkane sulfonates (PFSAs), perfluorinated aldehydes (PFALs) and hydrofluorocarbons (HFCs) were identified for the first time. PFOS degradation involves the desulfonation pathway as the first step, followed by oxidation and subsequent defluorination, decarboxylation, decarbonylation, sulfonation, defluorination and hydroxylation. The results from this work also show that the reactivity of PFAAs is related to their carbon chain length, with shorter-chain PFAAs exhibiting a lower degradation rate. In a PFAA mixture, a decline in the degradation rate was observed for the shorter-chain-length PFAAs, suggesting stronger competitive inhibition and indicating stronger environmental recalcitrance during the treatment process. Novelty statement: Although many efforts have been made to identify perfluorooctane sulfonate (PFOS) degradation byproducts, previous studies were only able to identify byproducts that are related to perfluorinated carboxylic acids (PFCAs). This is the first study to elucidate the new PFOS degradation pathway; furthermore, this is the first report to identify byproducts containing sulfonate groups (perfluoroalkane sulfonates, PFSAs), aldehyde groups (perfluorinated aldehydes, PFALs), and hydrofluorocarbons (HFCs). This study further systematically explores how perfluoroalkyl acid (PFAA) degradation may be affected in the mixture system: shorter-chain-length PFAAs suffer stronger competitive inhibition in the photoelectrochemical (PEC) system. By utilizing the graphene oxide-titanium dioxide (GOTiO2) photoelectrode fabricated in this work, PFOS can be successfully decomposed during the PEC process for the first time.
Collapse
Affiliation(s)
- Jheng-Sian Yang
- Graduate Institute of Environmental Engineering, National Taiwan University, Taipei 106, Taiwan, ROC
| | - Webber Wei-Po Lai
- Department of Environmental Science and Engineering, Tunghai University, Taichung 407, Taiwan, ROC
| | - Angela Yu-Chen Lin
- Graduate Institute of Environmental Engineering, National Taiwan University, Taipei 106, Taiwan, ROC.
| |
Collapse
|
14
|
Verma S, Varma RS, Nadagouda MN. Remediation and mineralization processes for per- and polyfluoroalkyl substances (PFAS) in water: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 794:148987. [PMID: 34426018 DOI: 10.1016/j.scitotenv.2021.148987] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 07/06/2021] [Accepted: 07/07/2021] [Indexed: 06/13/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are synthetic organic molecules used to manufacture various consumer and industrials products. In PFAS, the CF bond is stable, which renders these compounds chemically stable and prevents their breakdown. Several PFAS treatment processes such as adsorption, photolysis and photocatalysis, bioremediation, sonolysis, electrochemical oxidation, etc., have been explored and are being developed. The present review article has critically summarized degradative technologies and provides in-depth knowledge of photodegradation, electrochemical degradation, chemical oxidation, and reduction mineralization mechanism. Also, novel non-degradative technologies, including nano-adsorbents, natural and surface-modified clay minerals/zeolites, calixarene-based polymers, and molecularly imprinted polymers and adsorbents derived from biomaterials are discussed in detail. Of these novel approaches photocatalysis combined with membrane filtration or electrochemical oxidation via a treatment train approach shows promising results in removing PFAS in natural waters. The photocatalytic mineralization mechanism of PFOA is discussed, leading to recommendations for future research on novel remediation strategies for removing PFAS from water.
Collapse
Affiliation(s)
- Sanny Verma
- Pegasus Technical Services, Inc., 46 E. Hollister Street, Cincinnati, OH 45219, USA
| | - Rajender S Varma
- Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute, Palacký University in Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Mallikarjuna N Nadagouda
- Department of Mechanical and Materials Engineering, Wright State University, Dayton, OH 45435, USA.
| |
Collapse
|
15
|
Alameddine M, Siraki A, Tonoyan L, Gamal El-Din M. Treatment of a mixture of pharmaceuticals, herbicides and perfluorinated compounds by powdered activated carbon and ozone: Synergy, catalysis and insights into non-free OH contingent mechanisms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 777:146138. [PMID: 33689896 DOI: 10.1016/j.scitotenv.2021.146138] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 02/05/2021] [Accepted: 02/22/2021] [Indexed: 06/12/2023]
Abstract
Powdered activated carbon (PAC) is a strong adsorbent also capable of catalyzing ozonation processes. Ozone (O3) and PAC were simultaneously applied to treat a mixture of 17 micropollutants (MPs) at low concentrations, including 13 compounds that were studied for the first time by simultaneous addition of O3 and PAC system. Synergy and catalysis improved the removals and specific degradation rates of MPs in the first minute of the treatment. Radical probing experiments showed that scavenging hydroxyl radicals (OH) did not have a significant impact on the removals, while scavenging other reactive oxygen species was more influential. A detailed study by electron paramagnetic resonance spectroscopy ascertained that the decomposition of ozone in presence of PAC at neutral pH did not boost the generation of free OH. Instead, adsorbed OH was likely produced as PAC-HO along with other oxidizing species resulting from adsorbed singlet oxygen and superoxide radicals.
Collapse
Affiliation(s)
- Mirna Alameddine
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Arno Siraki
- Faculty of Pharmacy and Pharmaceutical Sciences(,) University of Alberta, Edmonton, Alberta T6G 2H5, Canada
| | - Lusine Tonoyan
- Faculty of Pharmacy and Pharmaceutical Sciences(,) University of Alberta, Edmonton, Alberta T6G 2H5, Canada
| | - Mohamed Gamal El-Din
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada.
| |
Collapse
|
16
|
Guan Z, Guo Y, Li S, Feng S, Deng Y, Ou X, Ren J, Sun S, Liang J. Decomplexation of heterogeneous catalytic ozonation assisted with heavy metal chelation for advanced treatment of coordination complexes of Ni. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 732:139223. [PMID: 32438144 DOI: 10.1016/j.scitotenv.2020.139223] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 04/28/2020] [Accepted: 05/03/2020] [Indexed: 06/11/2023]
Abstract
Following the conventional physicochemical treatment of electroless nickel (Ni) plating wastewater (ENPW) in electroplating wastewater treatment plants, highly stable and recalcitrant coordination complexes of Ni (CCN) still remain. This results in various technical problems, leading to the treatment difficulty, poor wastewater biochemistry, and failure to meet effluent standards. Therefore, an efficient decomplexation system involving heterogeneous catalytic ozonation assisted with heavy metal chelation (O3/SAO3II-MDCR) was proposed in this study for the advanced treatment of CCN. The catalyst SAO3II was characterized by various methods, which revealed the mechanism of catalytic ozonation. Hydroxyl radicals (OH) and other reactive oxygen species (ROS) groups were detected, proving that catalytic ozonation was a complicated reaction process and also a foundation process of the entire system. These ROS are vital for decomplexation via heterogeneous catalytic ozonation of the system. During the catalytic decomplexation process via ozonation, CCN first underwent gradual decomposition from a highly stable macromolecular state to a volatile micromolecular state (or even completely mineralized state). Then Ni was chelated to form an insoluble and stable chelate via competitive coordination. The optimum conditions for the O3/SAO3II-MDCR system were determined by single factor static experiments. After treatment with the O3/SAO3II-MDCR system, the effluent concentration of total Ni was found to be <0.1 mg L-1, exhibiting a removal rate of up to 95.6% and achieving effective removal of total Ni from ENPW and stably meeting the discharge standard. O3/SAO3II-MDCR system can easily and hopefully be extended to practical engineering applications.
Collapse
Affiliation(s)
- Zhijie Guan
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Yanping Guo
- Guangdong Province Solid Waste Recycling and Heavy Metal Pollution Control Engineering Technology Research Center, Guangdong Polytechnic of Environmental Protection Engineering, Foshan 528216, China
| | - Shoupeng Li
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Shaoqing Feng
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Yanghong Deng
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Xuelian Ou
- Guangdong Province Solid Waste Recycling and Heavy Metal Pollution Control Engineering Technology Research Center, Guangdong Polytechnic of Environmental Protection Engineering, Foshan 528216, China
| | - Jie Ren
- Guangdong Province Solid Waste Recycling and Heavy Metal Pollution Control Engineering Technology Research Center, Guangdong Polytechnic of Environmental Protection Engineering, Foshan 528216, China
| | - Shuiyu Sun
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangdong Province Solid Waste Recycling and Heavy Metal Pollution Control Engineering Technology Research Center, Guangdong Polytechnic of Environmental Protection Engineering, Foshan 528216, China.
| | - Jialin Liang
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| |
Collapse
|
17
|
Yang JS, Lai WWP, Panchangam SC, Lin AYC. Photoelectrochemical degradation of perfluorooctanoic acid (PFOA) with GOP25/FTO anodes: Intermediates and reaction pathways. JOURNAL OF HAZARDOUS MATERIALS 2020; 391:122247. [PMID: 32062347 DOI: 10.1016/j.jhazmat.2020.122247] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 02/03/2020] [Accepted: 02/04/2020] [Indexed: 06/10/2023]
Abstract
Perfluorooctanoic acid (PFOA) have been widely studied due to their persistence, bioaccumulation and possible toxic effects. In this work, we investigated a photoelectrochemical (PEC) system consisting of a graphene oxide-titanium dioxide (GOP25) anode coated on fluorine-doped tin oxide (FTO) glass for removal of PFOA in an aquatic environment. The GOP25/FTO anode was fabricated and well characterized. Nearly complete decomposition of 0.5 mg/L PFOA was achieved after 4 h of PEC treatment with an initial pH of 5.3 and a current density of 16.7 mA cm-2. The presence of graphene oxide (GO) on the TiO2 anode could enhance its electrochemical performance, thereby leading to increased decomposition efficiency. A total of 18 PFOA transformation products, including short-chain perfluoroalkyl acids, are reported in this work, and 13 products were observed for the first time. Four possible routes of PFOA decomposition, namely, decarboxylation followed by oxidation, defluorination, hydroxylation and Cl atom substitution, were determined. The presence of chlorinated byproducts in the system indicated that reactive chlorine species contributed to PFOA degradation.
Collapse
Affiliation(s)
- Jheng-Sian Yang
- Graduate Institute of Environmental Engineering, National Taiwan University, Taipei, 106, Taiwan, ROC
| | - Webber Wei-Po Lai
- Graduate Institute of Environmental Engineering, National Taiwan University, Taipei, 106, Taiwan, ROC
| | - Sri Chandana Panchangam
- Graduate Institute of Environmental Engineering, National Taiwan University, Taipei, 106, Taiwan, ROC; Annamacharya Institute of Technology and Sciences, Rajampeta, 516126, Kadapa, A.P., India.
| | - Angela Yu-Chen Lin
- Graduate Institute of Environmental Engineering, National Taiwan University, Taipei, 106, Taiwan, ROC.
| |
Collapse
|
18
|
Li P, Zhi D, Zhang X, Zhu H, Li Z, Peng Y, He Y, Luo L, Rong X, Zhou Y. Research progress on the removal of hazardous perfluorochemicals: A review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 250:109488. [PMID: 31499465 DOI: 10.1016/j.jenvman.2019.109488] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 08/21/2019] [Accepted: 08/27/2019] [Indexed: 05/27/2023]
Abstract
Perfluorinated substances are global and ubiquitous pollutants. The persistent organic pollution of perfluorochemicals (PFCs) have drawn attentions worldwide. In view of the current need for sustainable development, many researchers began to study the remediation techniques for PFCs. Due to its unique hydrophobic and oil-phobic characteristics, the requirements for the PFCs removal process are different, so that their remediation techniques are still under continuous exploration. Hence, this review summarized the removal behaviors of various PFCs on different materials which supply a good foundation for future investigations in this field. It is evident from previous literature that every remediation techniques for PFCs has its own advantages. Among various currently evaluated removal methods, adsorption seems to be one of the most commonly used and recognized techniques for PFCs pollution control. Other innovative and promising techniques, such as physical and/or chemical methods, have also been tested for their effectiveness in removing perfluorinated compounds.
Collapse
Affiliation(s)
- Peipei Li
- Hunan International Scientific and Technological Cooperation Base of Agricultural Typical Pollution Remediation and Wetland Protection, College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, China
| | - Dan Zhi
- Hunan International Scientific and Technological Cooperation Base of Agricultural Typical Pollution Remediation and Wetland Protection, College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, China
| | - Xiaoxiao Zhang
- State Key Laboratory of Urban Water Resources and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, PR China
| | - Hongmei Zhu
- Hunan International Scientific and Technological Cooperation Base of Agricultural Typical Pollution Remediation and Wetland Protection, College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, China.
| | - Zhiyong Li
- Hunan International Scientific and Technological Cooperation Base of Agricultural Typical Pollution Remediation and Wetland Protection, College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, China
| | - Yutao Peng
- College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China
| | - Yangzhou He
- Hunan International Scientific and Technological Cooperation Base of Agricultural Typical Pollution Remediation and Wetland Protection, College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, China
| | - Lin Luo
- Hunan International Scientific and Technological Cooperation Base of Agricultural Typical Pollution Remediation and Wetland Protection, College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, China
| | - Xiangmin Rong
- Hunan International Scientific and Technological Cooperation Base of Agricultural Typical Pollution Remediation and Wetland Protection, College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, China
| | - Yaoyu Zhou
- Hunan International Scientific and Technological Cooperation Base of Agricultural Typical Pollution Remediation and Wetland Protection, College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, China.
| |
Collapse
|
19
|
Wei Z, Li P, Hassan M, Wang P, Xu C, Ren LF, He Y. Employing a novel O 3/H 2O 2 + BiPO 4/UV synergy technique to deal with thiourea-containing photovoltaic wastewater. RSC Adv 2018; 9:450-459. [PMID: 35521572 PMCID: PMC9059259 DOI: 10.1039/c8ra08085b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Accepted: 11/23/2018] [Indexed: 11/21/2022] Open
Abstract
Photovoltaic wastewater contains a large amount of thiourea that cannot be directly treated by biological methods because of its biotoxicity. In this study, a novel O3/H2O2 + BiPO4/UV synergy technique was used as a pre-treatment process to degrade thiourea. The effects of H2O2 and catalyst loading were investigated, and the transformation pathway of thiourea was predicted based on the intermediates detected by UPLC-Vion-IMS-QToF. The synergy technique degraded 89.14% thiourea within only 30 min, and complete degradation occurred after 150 min. The TOC removal of O3/H2O2 + BiPO4/UV was 1.8, 1.5, and 1.9 times that of O3/H2O2 and BiPO4/UV/H2O2 single processes and O3/H2O2 + UV process, respectively, which was due to the synergy between H2O2 residues and BiPO4. In addition, thiourea was mainly degraded by ·OH into thiourea dioxide and melamine (polymerized by other intermediates) and then further degraded into biuret and methyl carbamate by the holes of BiPO4, followed by complete mineralization into H2O and CO2. These results confirm that the O3/H2O2 + BiPO4/UV synergy technique is a promising option for the degradation of thiourea. Photovoltaic wastewater contains a large amount of thiourea that cannot be directly treated by biological methods because of its biotoxicity.![]()
Collapse
Affiliation(s)
- Zhikai Wei
- School of Environmental Science and Engineering, Shanghai Jiao Tong University 800 Dongchuan Road 200240 Shanghai PR China +86 21-54744008
| | - Peng Li
- School of Environmental Science and Engineering, Shanghai Jiao Tong University 800 Dongchuan Road 200240 Shanghai PR China +86 21-54744008
| | - Muhammad Hassan
- School of Environmental Science and Engineering, Shanghai Jiao Tong University 800 Dongchuan Road 200240 Shanghai PR China +86 21-54744008
| | - Pu Wang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University 800 Dongchuan Road 200240 Shanghai PR China +86 21-54744008
| | - Cong Xu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University 800 Dongchuan Road 200240 Shanghai PR China +86 21-54744008
| | - Long-Fei Ren
- School of Environmental Science and Engineering, Shanghai Jiao Tong University 800 Dongchuan Road 200240 Shanghai PR China +86 21-54744008
| | - Yiliang He
- School of Environmental Science and Engineering, Shanghai Jiao Tong University 800 Dongchuan Road 200240 Shanghai PR China +86 21-54744008
| |
Collapse
|
20
|
Sun Y, Angelotti B, Brooks M, Dowbiggin B, Evans PJ, Devins B, Wang ZW. A pilot-scale investigation of disinfection by-product precursors and trace organic removal mechanisms in ozone-biologically activated carbon treatment for potable reuse. CHEMOSPHERE 2018; 210:539-549. [PMID: 30029146 DOI: 10.1016/j.chemosphere.2018.06.162] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 06/26/2018] [Accepted: 06/27/2018] [Indexed: 06/08/2023]
Abstract
Although granular activated carbon (GAC) has been broadly applied in ozone-biologically activated carbon filtration (O3/BAC) systems for potable reuse of municipal wastewater, the mechanisms of various pollutant removal remain largely unknown as the regenerated GAC develops microbial populations resulting in biofiltration but loses significant adsorption capacity as it becomes spent GAC. Therefore, pilot-scale parallel performance comparisons of spent and regenerated GAC, along with a range of pre-oxidant ozone doses, were used to shed light on the mechanisms responsible for the removal of various types of treatment byproduct precursors and trace organic compounds. It was confirmed from this pilot-study that ozone alone can effectively degrade chlorinated trihalomethane (THM) and haloacetic acid (HAA) precursors, chloramine-reactive N-nitrosodimethylamine (NDMA) precursors, and 29 PPCPs. In contrast, biodegradation by microbial population on spent or regenerated GAC can remove NDMA and 22 PPCPs, while the adsorption by regenerated GAC can remove chlorinated THM and HAA precursors, PFAS, flame retardants, and 27 PPCPs. The results of this pilot study are intended to provide those interested in potable reuse with an example of the simultaneous removal capabilities and mechanisms that can be anticipated for treating a complex mixture of organics present in real municipal wastewater effluent.
Collapse
Affiliation(s)
- Yewei Sun
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA
| | - Bob Angelotti
- Upper Occoquan Service Authority, Centreville, VA, USA.
| | - Matt Brooks
- Upper Occoquan Service Authority, Centreville, VA, USA
| | | | | | | | - Zhi-Wu Wang
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA.
| |
Collapse
|
21
|
Kim TH, Yu S, Choi Y, Jeong TY, Kim SD. Profiling the decomposition products of perfluorooctane sulfonate (PFOS) irradiated using an electron beam. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 631-632:1295-1303. [PMID: 29727953 DOI: 10.1016/j.scitotenv.2018.03.055] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 02/11/2018] [Accepted: 03/05/2018] [Indexed: 05/07/2023]
Abstract
Perfluorooctane sulfonate (PFOS) has been found in wastewater treatment plants (WWTPs) and in surface water as a result of domestic uses of textiles, electronics, and surfactants. The detection of PFOS in the aqueous environment has been linked to hazardous biological effects including estrogenicity and genotoxicity. To provide an alternative to conventional processes, one of the radical-based advanced oxidation and reduction processes being tested for treatment of refractory compounds in water, involves the use of an electron beam. Therefore, the aims of this study were to investigate the degradation efficiency of PFOS (100mg/L) by electron beam, to evaluate the predicted toxicity of the radiolysis products using the ECOSAR model, and to identify the radiolytic products of PFOS. As a result of using the ECOSAR model, the toxicity levels of by-products after electron beam treatment were reduced by decreasing the carbon-chain number of PFOS. The molecular structures of the radiolytic products were elucidated using authentic standards via liquid chromatography and tandem mass spectrometry, and by the interpretation of MS2 fragmentation patterns of each product using liquid chromatography with quadrupole time of-flight mass spectrometry (LC-QTOF-MS). In total, ten radiolytic products were confirmed by LC-MS/MS, HPLC, and IC data matching with commercial standards. The two radiolytic substances produced during irradiation with an electron beam were predicted by LC-QTOF-MS. This study led to an understanding of the role of electron beams in the transformation of parent compounds and to the decomposition products created when an electron beam is applied to treat perfluorinated compounds.
Collapse
Affiliation(s)
- Tae-Hun Kim
- Industry and Environment Research Division, Korea Atomic Energy Research Institute, Republic of Korea
| | - Seungho Yu
- Industry and Environment Research Division, Korea Atomic Energy Research Institute, Republic of Korea
| | - Yeowool Choi
- School of Earth Science and Environmental Engineering, Gwangju Institute of Science and Technology, Republic of Korea
| | - Tae-Yong Jeong
- Department of Physical and Environmental Science, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario M1C1A4, Canada
| | - Sang Don Kim
- School of Earth Science and Environmental Engineering, Gwangju Institute of Science and Technology, Republic of Korea.
| |
Collapse
|
22
|
Dombrowski PM, Kakarla P, Caldicott W, Chin Y, Sadeghi V, Bogdan D, Barajas-Rodriguez F, Chiang SYD. Technology review and evaluation of different chemical oxidation conditions on treatability of PFAS. ACTA ACUST UNITED AC 2018. [DOI: 10.1002/rem.21555] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | - Yan Chin
- Senior Project Manager at ISOTEC Inc
| | | | | | | | | |
Collapse
|
23
|
A survey of analytical methods employed for monitoring of Advanced Oxidation/Reduction Processes for decomposition of selected perfluorinated environmental pollutants. Talanta 2018; 177:122-141. [DOI: 10.1016/j.talanta.2017.09.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 08/30/2017] [Accepted: 09/01/2017] [Indexed: 02/05/2023]
|
24
|
Wang L, Sun L, Yu Z, Hou Y, Peng Z, Yang F, Chen Y, Huang J. Synergetic decomposition performance and mechanism of perfluorooctanoic acid in dielectric barrier discharge plasma system with Fe3O4@SiO2-BiOBr magnetic photocatalyst. MOLECULAR CATALYSIS 2017. [DOI: 10.1016/j.mcat.2017.08.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
25
|
Zhang S, Quan X, Zheng JF, Wang D. Probing the interphase "HO zone" originated by carbon nanotube during catalytic ozonation. WATER RESEARCH 2017; 122:86-95. [PMID: 28595124 DOI: 10.1016/j.watres.2017.05.063] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 05/27/2017] [Accepted: 05/28/2017] [Indexed: 06/07/2023]
Abstract
Carbon nanotube (CNT) is an attractive metal-free catalyst that can be explored in combination with ozone treatment. Using fluorescence microscopy image analysis, we investigated the production of hydroxyl radicals (HO) within the solid-liquid interphase for CNT-mediated catalytic ozonation. The visualized results suggest that HO was vastly generated via catalysis and accumulated within a surface region of the CNT (we defined this region as the interphase "HO zone"). In this region, using 7-hydroxycoumarin as a HO marker, the radical abundance was at least 1000 times higher than that in the aqueous bulk phase. Owing to the observed inhomogeneity of HO, the CNT/ozone system effectively decomposed perfluorooctane sulfonate that was fairly resistant to non-catalytic ozonation, and the decomposition kinetics was not much inhibited by tert-butanol as bulk-phase HO scavenger due to the remaining "HO zone" at surface region available for reaction. A longevity trial revealed the sustained formation of the interphase "HO zone" and strongly indicated that the graphitic structure may optimize the density of surface active sites responsible for the proliferation and local concentration of HO. CNT, with good catalytic efficiency, longevity and stability, is anticipated as the basis of future nanomaterials able to promote HO exposure in ozone treatment for advanced oxidation process.
Collapse
Affiliation(s)
- Shuo Zhang
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian 116024, China; Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China.
| | - Xie Quan
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian 116024, China
| | - Jian-Feng Zheng
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China
| | - Dong Wang
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian 116024, China
| |
Collapse
|
26
|
Zhuo Q, Xiang Q, Yi H, Zhang Z, Yang B, Cui K, Bing X, Xu Z, Liang X, Guo Q, Yang R. Electrochemical oxidation of PFOA in aqueous solution using highly hydrophobic modified PbO 2 electrodes. J Electroanal Chem (Lausanne) 2017. [DOI: 10.1016/j.jelechem.2017.07.018] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
27
|
Eberle D, Ball R, Boving TB. Impact of ISCO Treatment on PFAA Co-Contaminants at a Former Fire Training Area. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:5127-5136. [PMID: 28391685 DOI: 10.1021/acs.est.6b06591] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The effects of an in situ chemical oxidation (ISCO) treatment aimed predominantly at remediation of chlorinated volatile organic compounds (cVOCs) and perfluoroalkyl acids (PFAAs) co-contaminants were investigated. Soil and groundwater samples were collected before and after an ISCO pilot-scale field test of a peroxone activated persulfate (OxyZone) technology. Statistically significant decreases in PFAA groundwater concentrations were observed in post-treatment samples. Reductions in PFAA aqueous phase concentrations were also supported by decreases in soil concentrations. Importantly, there was no evidence for increased aqueous PFAA concentrations due to mobilization from soil or conversion of precursors into PFAAs. As indicated by chloride data from inside and outside the treatment zone, displacement and/or dilution could not explain the observed decrease in PFAA concentration. Also, relatively constant pH values, due to using a buffered oxidant solution, did not support increased PFAA removal via soil sorption. Overall, the use of peroxone activated persulfate to treat cVOCs had no discernible negative impacts on PFAA co-contaminants at the Site. Rather, the data suggest that PFAA concentrations decreased due to ISCO treatment.
Collapse
Affiliation(s)
- Dylan Eberle
- Department of Geosciences, University of Rhode Island , Kingston, Rhode Island 02881 United States
| | - Raymond Ball
- EnChem Engineering Inc. , Newton, Massachusetts 02458 United States
| | - Thomas B Boving
- Department of Geosciences, University of Rhode Island , Kingston, Rhode Island 02881 United States
- Department of Civil and Environmental Engineering, University of Rhode Island , Kingston, Rhode Island 02881 United States
| |
Collapse
|
28
|
Wu D, Lu G, Zhang R, Lin Q, Yao J, Shen X, Wang W. Effective degradation of diatrizoate by electro-peroxone process using ferrite/carbon nanotubes based gas diffusion cathode. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.03.196] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
29
|
Zhang T, Pan G, Zhou Q. Temperature effect on photolysis decomposing of perfluorooctanoic acid. J Environ Sci (China) 2016; 42:126-133. [PMID: 27090703 DOI: 10.1016/j.jes.2015.05.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 05/07/2015] [Accepted: 05/11/2015] [Indexed: 06/05/2023]
Abstract
Perfluorooctanoic acid (PFOA) is recalcitrant to degrade and mineralize. Here, the effect of temperature on the photolytic decomposition of PFOA was investigated. The decomposition of PFOA was enhanced from 34% to 99% in 60 min of exposure when the temperature was increased from 25 to 85°C under UV light (201-600 nm). The limited degree of decomposition at 25°C was due to low quantum yield, which was increased by a factor of 12 at 85°C. Under the imposed conditions, the defluorination ratio increased from 8% at 25°C to 50% at 85°C in 60 min. Production of perfluorinated carboxylic acids (PFCAs, C7-C5), PFCAs (C4-C3) and TFA (trifluoroacetic acid, C2) accelerated and attained a maximum within 30 to 90 min at 85°C. However, these reactions did not occur at 25°C despite extended irradiation to 180 min. PFOA was decomposed in a step-wise process by surrendering one CF2 unit. In each cyclical process, increased temperature enhanced the quantum yields of irradiation and reactions between water molecules and intermediates radicals. The energy consumption for removing each μmol of PFOA was reduced from 82.5 kJ at 25°C to 10.9 kJ at 85°C using photolysis. Photolysis coupled with heat achieved high rates of PFOA degradation and defluorination.
Collapse
Affiliation(s)
- Tiliang Zhang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Gang Pan
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Qin Zhou
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| |
Collapse
|
30
|
Yang B, Jiang C, Yu G, Zhuo Q, Deng S, Wu J, Zhang H. Highly efficient electrochemical degradation of perfluorooctanoic acid (PFOA) by F-doped Ti/SnO2 electrode. JOURNAL OF HAZARDOUS MATERIALS 2015; 299:417-424. [PMID: 26183235 DOI: 10.1016/j.jhazmat.2015.06.033] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 05/22/2015] [Accepted: 06/18/2015] [Indexed: 06/04/2023]
Abstract
The novel F-doped Ti/SnO2 electrode prepared by SnF4 as the single-source precursor was used for electrochemical degradation of aqueous perfluorooctanoic acid (PFOA). Higher oxidation reactivity and significantly longer service life were achieved for Ti/SnO2-F electrode than Ti/SnO2-X (X=Cl, Br, I, or Sb) electrode, which could decomposed over 99% of PFOA (50 mL of 100 mg L(-1)) within 30-min electrolysis. The property of Ti/SnO2-F electrode and its electrooxidation mechanism were investigated by XRD, SEM-EDX, EIS, LSV, and interfacial resistance measurements. We propose that the similar ionic radii of F and O as well as strong electronegativity of F caused its electrochemical stability with high oxygen evolution potential (OEP) and smooth surface to generate weakly adsorbed OH. The preparation conditions of electrode were also optimized including F doping amount, calcination temperature, and dip coating times, which revealed the formation process of electrode. Additionally, the major mineralization product, F(-), and low concentration of shorter chain perfluorocarboxylic acids (PFCAs) were detected in solution. So the reaction pathway of PFOA electrooxidation was proposed by intermediate analysis. These results demonstrate that Ti/SnO2-F electrode is promising for highly efficient treatment of PFOA in wastewater.
Collapse
Affiliation(s)
- Bo Yang
- Department of Environmental Engineering, College of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen 518060, PR China; School of Environment, POPs Research Center, Tsinghua University, Beijing 100084, PR China.
| | - Chaojin Jiang
- Department of Environmental Engineering, College of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen 518060, PR China
| | - Gang Yu
- School of Environment, POPs Research Center, Tsinghua University, Beijing 100084, PR China.
| | - Qiongfang Zhuo
- South China Institute of Environmental Sciences, The Ministry of Environment Protection, Guangzhou 510655, PR China
| | - Shubo Deng
- School of Environment, POPs Research Center, Tsinghua University, Beijing 100084, PR China
| | - Jinhua Wu
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China
| | - Hong Zhang
- Department of Environmental Engineering, College of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen 518060, PR China
| |
Collapse
|
31
|
Li YM, Zhang FS. Characterization of a cetyltrimethyl ammonium bromide-modified sorbent for removal of perfluorooctane sulphonate from water. ENVIRONMENTAL TECHNOLOGY 2014; 35:2556-2568. [PMID: 25145211 DOI: 10.1080/09593330.2014.912253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
This study was carried out to develop a cost-effective and practicable sorbent for application in abrupt perfluorooctane sulphonate (PFOS) pollution accidents. The main merit of this work was that a waste material, namely construction and demolition (C&D) waste, was employed as a raw base material for the sorbent synthesis. The waste material underwent alkaline fusion-hydrothermal synthesis and a cationic surfactant cetyltrimethyl ammonium bromide (CTAB) modification process to form a CTAB-modified sorbent (CMCDSS). Experimental results showed that PFOS concentrations and solution pH had significant effect on the PFOS sorption on construction and demolition waste synthesized sorbent (CDSS) and CMCDSS (using 0.2CMCDSS as representative). PFOS could be effectively and rapidly adsorbed on CMCDSS, and sorption equilibrium was achieved within 2.5 h. The sorption amounts of PFOS on CMCDSSs enhanced along with the increase in CTAB loading amounts. Moreover, the CMCDSS can be applied effectively under acidic condition at pH 2-6 and various removal mechanisms were clarified at different sorption conditions. Accordingly, this work developed a novel and applicable material for dealing with abrupt environmental PFOS contamination accidents.
Collapse
|
32
|
Yang X, Huang J, Zhang K, Yu G, Deng S, Wang B. Stability of 6:2 fluorotelomer sulfonate in advanced oxidation processes: degradation kinetics and pathway. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2014; 21:4634-4642. [PMID: 24352540 DOI: 10.1007/s11356-013-2389-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 11/20/2013] [Indexed: 06/03/2023]
Abstract
Perfluorooctane sulfonate (PFOS), a widely used mist suppressant in hard chrome electroplating industry, has been listed in the Stockholm Convention for global ban. 6:2 Fluorotelomer sulfonate (6:2 FTS) acid and salts have been adopted as alternative products in the market, but no data about their abiotic degradation has been reported. In the present study, the degradability of 6:2 FTS potassium salt (6:2 FTS-K) was evaluated under various advanced oxidation processes, including ultraviolet (UV) irradiation, UV with hydrogen peroxide (H2O2), alkaline ozonation (O3, pH = 11), peroxone (O3/H2O2), and Fenton reagent oxidation (Fe(2+)/H2O2). UV/H2O2 was found to be the most effective approach, where the degradation of 6:2 FTS-K followed the pseudo-first-order kinetics. The intermediates were mainly shorter chain perfluoroalkyl carboxylic acid (C7 to C2), while sulfate (SO4 (2-)) and fluoride (F(-)) were found to be the final products. The high yields of SO4 (2-) and F(-) indicate that 6:2 FTS-K can be nearly completely desulfonated and defluorinated under UV/H2O2 condition. The degradation should firstly begin with the substitution of hydrogen atom by hydroxyl radicals, followed by desulfonation, carboxylation, and sequential "flake off" of CF2 unit. Compared with PFOS which is inert in most advanced oxidation processes, 6:2 FTS-K is more degradable as the alternative.
Collapse
Affiliation(s)
- Xiaoling Yang
- State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), School of Environment, POPs Research Center, Tsinghua University, Beijing, 100084, People's Republic of China
| | | | | | | | | | | |
Collapse
|
33
|
Defluorination of aqueous perfluorooctanesulfonate by activated persulfate oxidation. PLoS One 2013; 8:e74877. [PMID: 24116016 PMCID: PMC3792066 DOI: 10.1371/journal.pone.0074877] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 08/09/2013] [Indexed: 11/24/2022] Open
Abstract
Activated persulfate oxidation technologies based on sulfate radicals were first evaluated for defluorination of aqueous perfluorooctanesulfonate (PFOS). The influences of catalytic method, time, pH and K2S2O8 amounts on PFOS defluorination were investigated. The intermediate products during PFOS defluorination were detected by using LC/MS/MS. The results showed that the S2O82− had weak effect on the defluorination of PFOS, while the PFOS was oxidatively defluorinated by sulfate radicals in water. The defluorination efficiency of PFOS under various treatment was followed the order: HT (hydrothermal)/K2S2O8 > UV (ultraviolet)/K2S2O8 > Fe2+/K2S2O8 > US (ultrasound)/K2S2O8. Low pH was favorable for the PFOS defluorination with sulfate radicals. Increase in the amount of S2O82− had positive effect on PFOS defluorination. However, further increase in amounts of S2O82− caused insignificant improvement in PFOS defluorination due to elimination of sulfate radicals under high concentration of S2O82−. CF3(CF2)nCOOH (n = 0–6) were detected as intermediates during PFOS defluorination. Sulfate radicals oxidation and hydrolysis were the main mechanisms involved in defluorination process of PFOS.
Collapse
|