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Awoyemi OS, Luo Y, Niu J, Naidu R, Fang C. Ultrasonic degradation of per-and polyfluoroalkyl substances (PFAS), aqueous film-forming foam (AFFF) and foam fractionate (FF). CHEMOSPHERE 2024; 360:142420. [PMID: 38795914 DOI: 10.1016/j.chemosphere.2024.142420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 05/20/2024] [Accepted: 05/22/2024] [Indexed: 05/28/2024]
Abstract
The ubiquitousness of per- and polyfluoroalkyl substances (PFAS) is a big concern and PFAS remediation is urgently needed such as via degradation. While previous studies have explored ultrasonic degradation of PFAS, work evaluating the operational parameters is rare, especially concerning real wastes such as aqueous film-forming foam (AFFF) and foam fractionate (FF). This study investigates the key operational parameters affecting the degradation efficiency of PFAS, encompassing ultrasonication frequency (580-1144 kHz), power intensity (125-187.5 W), initial concentration (0.08-40 ppm), treatment duration (0.5-3 h), sample volume (100-500 mL), and PFAS structure (perfluorooctanoic acid or PFOA; perfluorooctane sulfonate or PFOS; 6:2 fluorotelomer sulfonate or 6:2 FTS). The defluorination kinetics is different from the removal/degradation kinetics due to the generation of degradation intermediates, suggesting the complex degradation mechanism, which should be evaluated to close the mass balance effectively. Notably, the optimised ultrasonic system achieves ∼125%/∼115% defluorination in AFFF/FF example wastes (compared to ∼65%/∼97% removal) despite their complex composition and the involvement of total oxidizable precursor (TOP) assay. In the meantime, a few new PFAS are detected in the post-treatments, including perfluorohexane sulfonic acid (PFHxS) and 10:2 fluorotelomer sulfonate (10:2 FTS) in the AFFF, and perfluorooctane sulfonamide (FOSA) and 8:2 fluorotelomer sulfonate (8:2 FTS) in the FF, again suggesting the complex degradation mechanism. Overall, ultrasonication is effective to degrade PFAS real example wastes, advancing its potential for scale-up applications.
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Affiliation(s)
- Olalekan Simon Awoyemi
- Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan, NSW, 2308, Australia; CRC for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Yunlong Luo
- Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Junfeng Niu
- College of Environmental Science and Engineering, North China Electric Power University, Beijing, 102206, China
| | - Ravi Naidu
- Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan, NSW, 2308, Australia; CRC for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Cheng Fang
- Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan, NSW, 2308, Australia; CRC for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, Callaghan, NSW, 2308, Australia.
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2
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Zhan M, Wu L, Xu X, Wang J, Shan Y, Yin Y, Jiao W, Giesy JP. Synergetic degradation of perfluorooctanoic acid (PFOA) in soil using electrical resistance heating induced persulfate activation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 900:165497. [PMID: 37451438 DOI: 10.1016/j.scitotenv.2023.165497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/29/2023] [Accepted: 07/10/2023] [Indexed: 07/18/2023]
Abstract
Due to wastes from production of fluorinated materials and use of aqueous fire-fighting foams (AFFF), soils contaminated with perfluorooctanoic acid (PFOA) is of concern. However, current PFOA-contaminated soil disposal techniques have relatively low degradation efficiencies and are not suitable for on-site remediation. In this study, an electrical resistance heating (ERH) device and a box experimental device were used to study whether ERH induced persulfate activation (ERH/PS) could degrade PFOA in the soil. The results indicated that single ERH and single PS addition could not effectively degrade PFOA (with approximately 0.3 % and 3.9 % degradation after 9 h, respectively), while the degradation efficiency of PFOA with coupled ERH/PS could reach 87.3 % after 9 h of reaction. Moreover, effects of PS content, heating temperature, and soil organic matter on the degradation of PFOA were explored. During the ERH/PS process, PFOA was gradually transformed into short chain perfluorinated compounds and finally mineralized to fluoride ions. Finally, using a box experimental device, PS was effectively transported to the target contaminated area through electrokinetic (EK)-assisted delivery. After activating PS through ERH, the degradation rate of PFOA could reach 95.5 %. This is a novel study demonstrating the feasibility of ERH induced PS activation to degrade PFOA in soil, which provides a potential on-site strategy for remediation of PFOA-contaminated soil.
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Affiliation(s)
- Mingxiu Zhan
- College of Metrology and Measurement Engineering, China Jiliang University, Hangzhou 310018, Zhejiang, China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Liutao Wu
- College of Metrology and Measurement Engineering, China Jiliang University, Hangzhou 310018, Zhejiang, China
| | - Xu Xu
- College of Metrology and Measurement Engineering, China Jiliang University, Hangzhou 310018, Zhejiang, China
| | - Jinqing Wang
- College of Metrology and Measurement Engineering, China Jiliang University, Hangzhou 310018, Zhejiang, China.
| | - Yongping Shan
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yongguang Yin
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Wentao Jiao
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - John P Giesy
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada; Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK, Canada; Department of Integrative Biology, Michigan State University, East Lansing, MI, USA; Department of Environmental Sciences, Baylor University, Waco, TX, USA
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3
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Luo Y, Khoshyan A, Al Amin M, Nolan A, Robinson F, Fenstermacher J, Niu J, Megharaj M, Naidu R, Fang C. Ultrasound-enhanced Magnéli phase Ti 4O 7 anodic oxidation of per- and polyfluoroalkyl substances (PFAS) towards remediation of aqueous film forming foams (AFFF). THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 862:160836. [PMID: 36521599 DOI: 10.1016/j.scitotenv.2022.160836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 12/05/2022] [Accepted: 12/06/2022] [Indexed: 06/17/2023]
Abstract
Per-and polyfluoroalkyl substances (PFAS) remediation is still a challenge. In this study, we propose a hybrid system that combines electrochemical treatment with ultrasound irradiation, aiming for an enhanced degradation of PFAS. Equipped with a titanium suboxide (Ti4O7) anode, the electrochemical cell is able to remove perfluorooctanoic acid (PFOA) effectively. Under the optimal conditions (50 mA/cm2 current density, 0.15 M Na2SO4 supporting electrolyte, and stainless steel/Ti4O7/stainless steel electrode configuration with a gap of ∼10 mm), the electrochemical process achieves ∼100 % PFOA removal and 43 % defluorination after 6 h. Applying ultrasound irradiation (130 kHz) alone offers a limited PFOA removal, with 33 % PFOA removal and 5.5 % defluorination. When the electrochemical process is combined with ultrasound irradiation, we observe a significant improvement in the remediation performance, with ∼100 % PFOA removal and 63.5 % defluorination, higher than the sum of 48.5 % (43 % achieved by the electrochemical process, plus 5.5 % by the ultrasound irradiation), implying synergistic removal/oxidation effects. The hybrid system also consistently shows the synergistic defluorination during degradation of other PFAS and the PFAS constituents in aqueous film forming foam (AFFF). We attribute the synergistic effect to an activated/cleaned electrode surface, improved mass transfer, and enhanced production of radicals.
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Affiliation(s)
- Yunlong Luo
- Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, Callaghan, NSW 2308, Australia
| | - Ashkan Khoshyan
- Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan, NSW 2308, Australia
| | - Md Al Amin
- Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan, NSW 2308, Australia
| | - Annette Nolan
- Ramboll Australia, The Junction, NSW 2291, Australia
| | | | | | - Junfeng Niu
- Suzhou institute of North China Electric Power University, Jiangsu 215000, PR China
| | - Mallavarapu Megharaj
- Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, Callaghan, NSW 2308, Australia
| | - Ravi Naidu
- Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, Callaghan, NSW 2308, Australia
| | - Cheng Fang
- Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, Callaghan, NSW 2308, Australia.
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4
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Al Amin M, Luo Y, Nolan A, Mallavarapu M, Naidu R, Fang C. Thermal kinetics of PFAS and precursors in soil: Experiment and surface simulation in temperature-time plane. CHEMOSPHERE 2023; 318:138012. [PMID: 36720409 DOI: 10.1016/j.chemosphere.2023.138012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 01/16/2023] [Accepted: 01/27/2023] [Indexed: 06/18/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are chemically and thermally stable due to the presence of carbon-fluorine (C-F) bond in their molecular structures, hence have been previously formulated as firefighting ingredients. During the firefighting process, however, owing to the high temperature, PFAS can be potentially degraded, particularly for PFAS precursors that contain non-C-F bonds, which is studied herein by exposing PFAS-contaminated soil in a muffle furnace oven. Different temperatures and time intervals are applied to the real soil sample to mimic the firing process and to evaluate the degradation and conversion of PFAS. This thermal treatment can not only degrade precursors (e.g. 6:2 fluorotelomer sulphonate), but also degrade perfluoroalkyl carboxylates (PFCA, e.g. perfluorooctanoic acid PFOA) and perfluoroalkyl sulfonates (PFSA, e.g. perfluorooctane sulfonate PFOS). The concentration dependence of the PFAS on temperature and time is fitted using a 2D Gaussian surface to simulate the complex thermal kinetic, and to compare with the traditional approach such as thermogravimetric analysis (TGA) (1D dependence on temperature only). The 2D simulation can directly visualise the thermal kinetic of individual or sum PFAS in the complex temperature-time plane, which depends on the sample background and particularly on the coexist PFAS precursors. Overall, this study provides a simple approach to monitor and optimise the thermal treatment of the PFAS-contaminated soil.
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Affiliation(s)
- Md Al Amin
- Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan NSW, 2308, Australia
| | - Yunlong Luo
- Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan NSW, 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, Callaghan NSW, 2308, Australia
| | - Annette Nolan
- Ramboll Australia, The Junction, NSW, 2291, Australia
| | - Megharaj Mallavarapu
- Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan NSW, 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, Callaghan NSW, 2308, Australia
| | - Ravi Naidu
- Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan NSW, 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, Callaghan NSW, 2308, Australia
| | - Cheng Fang
- Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan NSW, 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, Callaghan NSW, 2308, Australia.
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5
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Fang Y, Meng P, Schaefer C, Knappe DRU. Removal and destruction of perfluoroalkyl ether carboxylic acids (PFECAs) in an anion exchange resin and electrochemical oxidation treatment train. WATER RESEARCH 2023; 230:119522. [PMID: 36577256 DOI: 10.1016/j.watres.2022.119522] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 11/18/2022] [Accepted: 12/18/2022] [Indexed: 06/17/2023]
Abstract
Perfluoroalkyl ether carboxylic acids (PFECAs) are a group of emerging recalcitrant contaminants that are being developed to replace legacy per- and polyfluoroalkyl substances (PFAS) in industrial applications and that are generated as by-products in fluoropolymer manufacturing. Here, we report on the removal and destruction of four structurally different PFECAs using an integrated anion exchange resin (AER) and electrochemical oxidation (ECO) treatment train. Results from this work illustrated that (1) flow-through columns packed with PFAS-selective AERs are highly effective for the removal of PFECAs and (2) PFECA affinity is strongly correlated with their hydrophobic features. Regeneration of the spent resin columns revealed that high percentage (e.g., 80%) of organic cosolvent is necessary for achieving 60-100% PFECA release, and regeneration efficiency was higher for a macroporous resin than a gel-type resin. Treatment of spent regenerants showed (1) >99.99% methanol removal was achieved by distillation, (2) >99.999% conversion of the four studied PFECAs was achieved during the ECO treatment of the still bottoms after 24 hours with an energy per order of magnitude of PFECA removal (EE/O) <1.03 kWh/m3 of total groundwater treated, and (3) >85% of the organic fluorine was recovered as inorganic fluoride. Trifluoroacetic acid (TFA), perfluoropropionic acid (PFPrA), and perfluoro-2-methoxyacetic acid (PFMOAA) were confirmed via high-resolution mass spectrometry as transformation products (TPs) in the treated still bottoms, and two distinctive degradation schemes and four reaction pathways are proposed for the four PFECAs. Lastly, dissolved organic matter (DOM) inhibited uptake, regeneration, and oxidation of PFECAs throughout the treatment train, suggesting pretreatment steps targeting DOM removal can enhance the system's treatment efficiency. Results from this work provide guidelines for developing effective separation-concentration-destruction treatment trains and meaningful insights for achieving PFECA destruction in impacted aquatic systems.
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Affiliation(s)
- Yida Fang
- CDM Smith, 14432 SE Eastgate Way, #100, Bellevue, Washington 98007, United States.
| | - Pingping Meng
- North Carolina State University, 915 Partners Way, Raleigh, North Carolina 27695, United States
| | - Charles Schaefer
- CDM Smith, 110 Fieldcrest Avenue, #8, Edison, New Jersey 08837, United States
| | - Detlef R U Knappe
- North Carolina State University, 915 Partners Way, Raleigh, North Carolina 27695, United States
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6
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Saawarn B, Mahanty B, Hait S, Hussain S. Sources, occurrence, and treatment techniques of per- and polyfluoroalkyl substances in aqueous matrices: A comprehensive review. ENVIRONMENTAL RESEARCH 2022; 214:114004. [PMID: 35970375 DOI: 10.1016/j.envres.2022.114004] [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: 04/15/2022] [Revised: 07/04/2022] [Accepted: 07/25/2022] [Indexed: 06/15/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS), a class of synthetic organic pollutants, have prompted concerns about their global prevalence and possible health effects. This review consolidates the most recent data on different aspects of PFAS, such as their occurrence, and prominent sources. The current literature analysis of PFAS occurrence suggests significant variation in their concentration ranging from 0.025 to 1.2 × 108 ng/L in wastewater, 0.01 to 8.9 × 105 ng/L in surface water, and <0.01 to 1.3 × 104 ng/L in groundwater globally. Since conventional treatment techniques are inadequate in remediating PFAS, innovative treatment approaches based on their removal or mineralization mechanism have been comprehensively reviewed. Advanced treatment technologies have shown degradation or removal of PFAS to be around 6 and > 99.9% in different aqueous matrices. However, due to significant drawbacks in their applicability in wastewater treatment plants (WWTPs), a novel treatment train approach has emerged as an effective alternative. This approach synergistically integrates multiple remediation techniques while addressing the impediments of individual treatments. Furthermore, nanofiltration (NF270) combined with electrochemical degradation has been demonstrated to be the most efficient (>98%) treatment train approach in PFAS remediation. If implemented in WWTPs, nanofiltration followed by adsorption using activated carbon is also a viable method for PFAS removal.
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Affiliation(s)
- Bhavini Saawarn
- Department of Civil and Environmental Engineering, Indian Institute of Technology Patna, Bihar, 801 106, India
| | - Byomkesh Mahanty
- Department of Civil and Environmental Engineering, Indian Institute of Technology Patna, Bihar, 801 106, India
| | - Subrata Hait
- Department of Civil and Environmental Engineering, Indian Institute of Technology Patna, Bihar, 801 106, India.
| | - Sahid Hussain
- Department of Chemistry, Indian Institute of Technology Patna, Bihar, 801 106, India
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7
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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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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8
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Hou J, Li G, Liu M, Chen L, Yao Y, Fallgren PH, Jin S. Electrochemical destruction and mobilization of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) in saturated soil. CHEMOSPHERE 2022; 287:132205. [PMID: 34563764 DOI: 10.1016/j.chemosphere.2021.132205] [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: 06/03/2021] [Revised: 08/23/2021] [Accepted: 09/06/2021] [Indexed: 06/13/2023]
Abstract
Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have attracted attention due to their widespread distribution, recalcitrance, and substantial toxicity. In this work, high concentrations of PFOA and PFOS were degraded and mobilized through electrochemical treatments in a simulated source zone of saturated soil. Under a low constant voltage and direct current of 24 V and 467-690 mA, approximately 51.7% and 33% of PFOA and PFOS were degraded, respectively. Additionally, a total defluorination mass balance of 44.7% and 23% were detected for PFOA and PFOS, respectively, which indicates that the removal of PFOA and PFOS occurs through its destruction. Substantial electromigration causes the destruction and mobilization of solid PFOA and PFOS to shift into the water phase. Although electrochemical oxidation of PFAS (per- and polyfluoroalkyl substances) were previously reported and studied, this study is one of the few that focus on simultaneous desorption, mobilization, and destruction of PFAS in saturated soil containing a low-intensity electrical field.
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Affiliation(s)
- Jie Hou
- State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin, PR China; Department of Civil Engineering, Tianjin University, Tianjin, 300072, PR China
| | - Guoao Li
- Beijing Key Laboratory of Water Resources and Environmental Engineering, China University of Geosciences (Beijing), Beijing, 100083, PR China; MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 10083, PR China
| | - Mingrui Liu
- State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin, PR China; Department of Civil Engineering, Tianjin University, Tianjin, 300072, PR China
| | - Liang Chen
- State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin, PR China; Department of Civil Engineering, Tianjin University, Tianjin, 300072, PR China.
| | - Ye Yao
- State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin, PR China; Department of Civil Engineering, Tianjin University, Tianjin, 300072, PR China
| | - Paul H Fallgren
- Advanced Environmental Technologies LLC, Fort Collins, CO, 80525, USA
| | - Song Jin
- Advanced Environmental Technologies LLC, Fort Collins, CO, 80525, USA; Department of Civil and Architectural Engineering, University of Wyoming, Laramie, WY, 82071, USA
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9
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Román Santiago A, Baldaguez Medina P, Su X. Electrochemical remediation of perfluoroalkyl substances from water. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2021.139635] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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10
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Zhou C, Wang Y, Tang S, Wang Y, Yu H, Niu J. Insights into the electrochemical degradation of triclosan from human urine: Kinetics, mechanism and toxicity. CHEMOSPHERE 2021; 264:128598. [PMID: 33068970 DOI: 10.1016/j.chemosphere.2020.128598] [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: 09/08/2020] [Revised: 10/05/2020] [Accepted: 10/07/2020] [Indexed: 06/11/2023]
Abstract
Electrochemical degradation of triclosan in human urine was firstly studied by using Ti/SnO2-Sb/PbO2 anode doped with rare-earth elements. The results indicated that the Ti/SnO2-Sb/Gd-PbO2 anode demonstrated the best performance with the degradation rate constants being 0.095 min-1 in fresh urine and 0.045 min-1 in hydrolyzed urine at a current density of 10 mA cm-2. The electrochemical degradation was improved in the presence of phosphate and chloride, while the degradation was obviously inhibited by urea, bicarbonate and ammonia. Degradation mechanism mainly involved ether-bond cleavage, hydroxylation, cyclization, dehydrogenation and carboxylation. Quantitative structure-activity relationship model showed that ecological risks of cyclization products to fish, daphnid and green algae was higher than the parent compound, implying that the potential risks to aquatic organism should not be ignored before triclosan mineralized completely. Energy consumption for 90% triclosan degradation ranged from 4.5 to 47.8 Wh L-1, and the consumption increased along with the hydrolysis of urine. The results indicate that electrochemical oxidation is a feasible and energy-saving technique to effectively remove triclosan from human urine.
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Affiliation(s)
- Chengzhi Zhou
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan, 523808, China
| | - Yanping Wang
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan, 523808, China
| | - Shaoyu Tang
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan, 523808, China
| | - Ya Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Haiying Yu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China
| | - Junfeng Niu
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan, 523808, China.
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11
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Senevirathna STMLD, Mahinroosta R, Li M, KrishnaPillai K. In situ soil flushing to remediate confined soil contaminated with PFOS- an innovative solution for emerging environmental issue. CHEMOSPHERE 2021; 262:127606. [PMID: 32805650 DOI: 10.1016/j.chemosphere.2020.127606] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 06/29/2020] [Accepted: 07/02/2020] [Indexed: 06/11/2023]
Abstract
PerFluoroOctane Sulfonate (PFOS), is a toxic anthropogenic chemical that has been produced and gradually released into the environment for the past seven decades. An accurate audit of global PFOS contamination and contaminated sites are yet to be published. The available technologies to remediate PFOS contaminated soil are limited and often basic strategies such as temporary soil containment are adopted as immediate measures to manage the contaminated sites. In this study, the in situ soil flushing technique is assessed for its capacity to remediate soil contaminated with PFOS. A complete treatment process with several operation units was proposed such as solvent flushing, ground water pumping, solvent recovery and water treatment for PFOS. Potential solvents were identified and it was observed that more than 98% PFOS removal could be attained by flushing with five bed volumes of 50% ethanol. In addition, the study investigated thirteen commercially available filter materials and identified PFA694E, K6362, MP 62, Amberlite IRA 67 and Dowexoptopore V493 as suitable to eliminate PFOS with competitive PFOS adsorption characteristics. The proposed method can be recommended to remediate PFOS in recognised contaminated soils, such as those at defence sites. Furthermore, a contaminated site with favourable characteristics to implement the suggested method was identified in Australia and described in this paper.
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Affiliation(s)
- S T M L D Senevirathna
- CSU Engineering, Faculty of Business, Justice and Behavioural Sciences, Charles Sturt University, Panorama Avenue, Bathurst, NSW, Australia; Institute of Land, Water, and Society, Charles Sturt University, Australia.
| | - Reza Mahinroosta
- CSU Engineering, Faculty of Business, Justice and Behavioural Sciences, Charles Sturt University, Panorama Avenue, Bathurst, NSW, Australia; Institute of Land, Water, and Society, Charles Sturt University, Australia
| | - Miao Li
- CSU Engineering, Faculty of Business, Justice and Behavioural Sciences, Charles Sturt University, Panorama Avenue, Bathurst, NSW, Australia; Institute of Land, Water, and Society, Charles Sturt University, Australia
| | - Karthika KrishnaPillai
- CSU Engineering, Faculty of Business, Justice and Behavioural Sciences, Charles Sturt University, Panorama Avenue, Bathurst, NSW, Australia; Institute of Land, Water, and Society, Charles Sturt University, Australia
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12
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Shi H, Wang Y, Li C, Pierce R, Gao S, Huang Q. Degradation of Perfluorooctanesulfonate by Reactive Electrochemical Membrane Composed of Magnéli Phase Titanium Suboxide. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:14528-14537. [PMID: 31730354 DOI: 10.1021/acs.est.9b04148] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
This study investigated the degradation of perfluorooctanesulfonate (PFOS) in a reactive electrochemical membrane (REM) system in which a porous Magnéli phase titanium suboxide ceramic membrane served simultaneously as the anode and the membrane. Near complete removal (98.30 ± 0.51%) of PFOS was achieved under a cross-flow filtration mode at the anodic potential of 3.15 V vs standard hydrogen electrode (SHE). PFOS removal efficiency during the REM operation is much greater than that of the batch operation mode under the same anodic potential. A systematic reaction rate analysis in combination with electrochemical characterizations quantitatively elucidated the enhancement of PFOS removal in REM operation in relation to the increased electroactive surface area and improved interphase mass transfer. PFOS appeared to undergo rapid mineralization to CO2 and F-, with only trace levels of short-chain perfluorocarboxylic acids (PFCAs, C4-C8) identified as intermediate products. Density functional theory (DFT) simulations and experiments involving free radical scavengers indicated that PFOS degradation was initiated by direct electron transfer (DET) on anode to yield PFOS free radicals (PFOS•), which further react with hydroxyl radicals that were generated by water oxidation and adsorbed on the anode surface (•OHads). The attack of •OHads is essential to PFOS degradation, because, otherwise, PFOS• may react with water and revert to PFOS.
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Affiliation(s)
- Huanhuan Shi
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment , Nanjing University , Nanjing 210023 , P.R. China
- College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences , University of Georgia , Griffin , Georgia 30223 , United States
| | - Yaye Wang
- College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences , University of Georgia , Griffin , Georgia 30223 , United States
| | - Chenguang Li
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment , Nanjing University , Nanjing 210023 , P.R. China
- College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences , University of Georgia , Griffin , Georgia 30223 , United States
| | - Randall Pierce
- College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences , University of Georgia , Griffin , Georgia 30223 , United States
| | - Shixiang Gao
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment , Nanjing University , Nanjing 210023 , P.R. China
| | - Qingguo Huang
- College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences , University of Georgia , Griffin , Georgia 30223 , United States
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13
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Xu L, Ma X, Niu J, Chen J, Zhou C. Removal of trace naproxen from aqueous solution using a laboratory-scale reactive flow-through membrane electrode. JOURNAL OF HAZARDOUS MATERIALS 2019; 379:120692. [PMID: 31255850 DOI: 10.1016/j.jhazmat.2019.05.085] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 04/02/2019] [Accepted: 05/26/2019] [Indexed: 06/09/2023]
Abstract
The kinetics and mechanisms of naproxen (NPX) degradation with the concentration of 20-200 μg/L were investigated by using reactive flow-through membrane anode. The electrochemical degradation of NPX followed pseudo-first-order reaction kinetics. The kinetic rate constant (k) of 0.649 min-1 and energy consumption (EEO) of 0.744 Wh/L were found under optimal conditions with the initial NPX concentration of 50 μg/L. Higher current density benefited •OH production and NPX degradation. Faster rotational speed of pump and lower pH were in favor of electrochemical degradation of NPX, in which k and EEO were 3.9 and 0.27 times when rotational speed was increased from 100 to 600 rpm, and 4.9 and 0.21 times when pH was decreased from 11.0 to 3.0, respectively. The degradation efficiency and energy consumption were both maintained at a narrow range when the initial concentration of NPX was changed from 20 to 200 μg/L, and even under the addition of humic acid (1.0-10.0 mg/L). The major degradation pathways of NPX were demethylation and decarboxylation, followed with the further ring cleavage reactions. The flow-through membrane electrode is proved to be effective for the elimination of trace NPX from aqueous solution.
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Affiliation(s)
- Lei Xu
- Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan 523808, China
| | - Xiao Ma
- Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan 523808, China
| | - Junfeng Niu
- Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan 523808, China.
| | - Jie Chen
- Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan 523808, China
| | - Chengzhi Zhou
- Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan 523808, China
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14
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Zhou C, Wang Y, Chen J, Niu J. Electrochemical degradation of sunscreen agent benzophenone-3 and its metabolite by Ti/SnO 2-Sb/Ce-PbO 2 anode: Kinetics, mechanism, toxicity and energy consumption. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 688:75-82. [PMID: 31229830 DOI: 10.1016/j.scitotenv.2019.06.197] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 06/09/2019] [Accepted: 06/12/2019] [Indexed: 06/09/2023]
Abstract
Electrochemical degradation of sunscreen agent benzophenone-3 (BP-3) and its metabolite 4-hydroxybenzophenone (4-OH-BP) was investigated by using a Ti/SnO2-Sb/Ce-PbO2 anode. Results showed that the degradation of BP-3 and 4-OH-BP followed pseudo-first-order kinetics, and the rate constants were 0.083 and 0.113 min-1 at a current density of 25 mA cm-2, respectively. The electrochemical degradation of BP-3 and 4-OH-BP was efficient over a wide range of pH values, and the degradation was obviously accelerated in the presence of Cl-. Degradation intermediates were identified during the electrochemical process, and the degradation pathways, mainly including hydroxylation, carbonyl group broken from aromatic ring, benzene ring opening and carboxylation, were proposed. Quantitative structure-activity relationship model indicated that the potential risks of BP-3 and 4-OH-BP to fish, daphnia and green algae were decreased with the increase of reaction time. The energy consumption for the degradation of 90% BP-3 and 4-OH-BP was 3.3-62.1 and 3.6-79.5 Wh L-1, respectively. The results illustrate that the electrochemical technique with Ti/SnO2-Sb/Ce-PbO2 anode is expected to be an effective way for removing BP-3 and its metabolite 4-OH-BP from wastewater.
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Affiliation(s)
- Chengzhi Zhou
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan 523808, PR China
| | - Yanping Wang
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan 523808, PR China
| | - Jie Chen
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan 523808, PR China
| | - Junfeng Niu
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan 523808, PR China.
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15
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Zhou C, Wang Y, Chen J, Xu L, Huang H, Niu J. High-efficiency electrochemical degradation of antiviral drug abacavir using a penetration flux porous Ti/SnO 2-Sb anode. CHEMOSPHERE 2019; 225:304-310. [PMID: 30877924 DOI: 10.1016/j.chemosphere.2019.03.036] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 03/06/2019] [Accepted: 03/07/2019] [Indexed: 05/07/2023]
Abstract
Electrochemical degradation of antiviral drug abacavir was investigated by using a penetration flux porous Ti/SnO2-Sb anode prepared by sol-gel method. The effects of applied current density, initial pH, and inorganic anions on the degradation kinetics were systematically studied. Degradation efficiency more than 97% was performed in only 10 min at a current density of 0.2 mA cm-2. The corresponding degradation rate constant and the lowest electrical energy per order were calculated to be 0.36 min-1 and 6.5 mWh L-1, respectively. Extending the reaction duration to 5 h, 53.3% of TOC removal was observed. The results indicated that effective degradation of abacavir appeared in the penetration flux porous Ti/SnO2-Sb anode with a very low energy consumption. Furthermore, the electrochemical intermediate products and the reaction site during abacavir degradation were detected and recognized. The quantitative structure-activity relationship model revealed that the potential risks of abacavir to the aquatic organism, such as fish, greatly decreased after flowing through the penetration flux porous Ti/SnO2-Sb anode.
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Affiliation(s)
- Chengzhi Zhou
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan, 523808, China
| | - Yanping Wang
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan, 523808, China
| | - Jie Chen
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan, 523808, China
| | - Lei Xu
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan, 523808, China
| | - Haiming Huang
- School of Environment and Civil Engineering, Dongguan University of Technology, Dongguan, 523808, China
| | - Junfeng Niu
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan, 523808, China.
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