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Hamdi FM, Ganbat N, Altaee A, Samal AK, Ibrar I, Zhou JL, Sharif AO. Hybrid and enhanced electrokinetic system for soil remediation from heavy metals and organic matter. J Environ Sci (China) 2025; 147:424-450. [PMID: 39003060 DOI: 10.1016/j.jes.2023.11.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 11/07/2023] [Accepted: 11/08/2023] [Indexed: 07/15/2024]
Abstract
The electrokinetic (EK) process has been proposed for soil decontamination from heavy metals and organic matter. The advantages of the EK process include the low operating energy, suitability for fine-grained soil decontamination, and no need for excavation. During the last three decades, enhanced and hybrid EK systems were developed and tested for improving the efficiency of contaminants removal from soils. Chemically enhanced-EK processes exhibited excellent efficiency in removing contaminants by controlling the soil pH or the chemical reaction of contaminants. EK hybrid systems were tested to overcome environmental hurdles or technical drawbacks of decontamination technologies. Hybridization of the EK process with phytoremediation, bioremediation, or reactive filter media (RFM) improved the remediation process performance by capturing contaminants or facilitating biological agents' movement in the soil. Also, EK process coupling with solar energy was proposed to treat off-grid contaminated soils or reduce the EK energy requirements. This study reviews recent advancements in the enhancement and hybrid EK systems for soil remediation and the type of contaminants targeted by the process. The study also covered the impact of operating parameters, imperfect pollution separation, and differences in the physicochemical characteristics and microstructure of soil/sediment on the EK performance. Finally, a comparison between various remediation processes was presented to highlight the pros and cons of these technologies.
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Affiliation(s)
- Faris M Hamdi
- Centre for Green Technology, School of Civil and Environmental Engineering, The University of Technology Sydney, 15 Broadway, NSW 2007, Australia; Department of Civil Engineering, Jazan University, Jazan 82822, Saudi Arabia
| | - Namuun Ganbat
- Centre for Green Technology, School of Civil and Environmental Engineering, The University of Technology Sydney, 15 Broadway, NSW 2007, Australia
| | - Ali Altaee
- Centre for Green Technology, School of Civil and Environmental Engineering, The University of Technology Sydney, 15 Broadway, NSW 2007, Australia.
| | - Akshaya K Samal
- Centre for Nano and Material Sciences, Jain University, Ramanagara, Bangalore, Karnataka 562 112, India
| | - Ibrar Ibrar
- Centre for Green Technology, School of Civil and Environmental Engineering, The University of Technology Sydney, 15 Broadway, NSW 2007, Australia
| | - John L Zhou
- Centre for Green Technology, School of Civil and Environmental Engineering, The University of Technology Sydney, 15 Broadway, NSW 2007, Australia
| | - Adel O Sharif
- School of Mechanical Sciences, Faculty of Engineering and Physical Sciences, University of Surrey, Australia
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Soltanian M, Gitipour S, Baghdadi M, Rtimi S. PFOA-contaminated soil remediation: a comprehensive review. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:49985-50011. [PMID: 39088169 DOI: 10.1007/s11356-024-34516-y] [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: 01/17/2024] [Accepted: 07/23/2024] [Indexed: 08/02/2024]
Abstract
Soil and groundwater contamination has been raised as a concern due to the capability of posing a risk to human health and ecology, especially in facing highly toxic and emerging pollutants. Because of the prevalent usage of perfluorooctanoic acid (PFOA), in industrial and production processes, and subsequently the extent of sites contaminated with these pollutants, cleaning up PFOA polluted sites is paramount. This research provides a review of remediation approaches that have been used, and nine remediation techniques were reviewed under physical, chemical, and biological approaches categorization. As the pollutant specifications, environmental implications, and adverse ecological effects of remediation procedures should be considered in the analysis and evaluation of remediation approaches, unlike previous research that considered a couple of PFAS pollutants and generally dealt with technical issues, in this study, the benefits, drawbacks, and possible environmental and ecological adverse effects of PFOA-contaminated site remediation also were discussed. In the end, in addition to providing sufficient and applicable understanding by comprehensively considering all aspects and field-scale challenges and obstacles, knowledge gaps have been found and discussed.
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Affiliation(s)
- Mehdi Soltanian
- School of Civil and Environmental Engineering, Faculty of engineering and IT, University of Technology Sydney, Sydney, Australia
| | - Saeid Gitipour
- Faculty of Environment, College of Engineering, University of Tehran, Tehran, Iran
| | - Majid Baghdadi
- Faculty of Environment, College of Engineering, University of Tehran, Tehran, Iran
| | - Sami Rtimi
- Global Institute for Water Environment and Health, 1201, Geneva, Switzerland.
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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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Ganbat N, Hamdi FM, Ibrar I, Altaee A, Alsaka L, Samal AK, Zhou J, Hawari AH. Iron slag permeable reactive barrier for PFOA removal by the electrokinetic process. JOURNAL OF HAZARDOUS MATERIALS 2023; 460:132360. [PMID: 37657326 DOI: 10.1016/j.jhazmat.2023.132360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 08/14/2023] [Accepted: 08/20/2023] [Indexed: 09/03/2023]
Abstract
The efficacy of the Standalone Electrokinetic (EK) process in soil PFAS removal is negligible, primarily due to the intersecting mechanisms of electromigration and electroosmosis transportation. Consequently, the redistribution of PFAS across the soil matrix occurs, hampering effective remediation efforts. Permeable reactive barrier (PRB) has been used to capture contaminants and extract them at the end of the EK process. This study conducted laboratory-scale tests to evaluate the feasibility of the iron slag PRB enhanced-EK process in conjunction with Sodium Cholate (NaC) biosurfactant as a cost-effective and sustainable method for removing PFOA from the soil. A 2 cm iron slag-based PRB with a pH of 9.5, obtained from the steel-making industry, was strategically embedded in the middle of the EK reactors to capture PFOA within the soil. The main component of the slag, iron oxide, exhibited significant adsorption capacity for PFOA contamination. The laboratory-scale tests were conducted over two weeks, revealing a PFOA removal rate of more than 79% in the slag/activated carbon PRB-EK test with NaC enhancement and 70% PFOA removal in the slag/activated carbon PRB-EK without NaC. By extending the duration of the slag/AC PRB-EK test with NaC enhancement to three weeks, the PFOA removal rate increased to 94.09%, with the slag/AC PRB capturing over 87% of the initial PFOA concentration of 10 mg/L. The specific energy required for soil decontamination by the EK process was determined to be 0.15 kWh/kg. The outcomes of this study confirm the feasibility of utilizing iron slag waste in the EK process to capture PFOA contaminants, offering a sustainable approach to soil decontamination. Combining iron slag PRB and NaC biosurfactant provides a cost-effective and environmentally friendly method for efficient PFOA removal from soil.
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Affiliation(s)
- Namuun Ganbat
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, Australia
| | - Faris M Hamdi
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, Australia
| | - Ibrar Ibrar
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, Australia
| | - Ali Altaee
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, Australia.
| | - Lilyan Alsaka
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, Australia
| | - Akshaya K Samal
- Centre for Nano and Material Sciences, Jain University, Ramanagara, Bangalore 562 112, Karnataka, India
| | - John Zhou
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, Australia
| | - Alaa H Hawari
- Department of Civil and Architectural Engineering, College of Engineering, Qatar University, PO Box 2713, Doha, Qatar
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Abou-Khalil C, Kewalramani J, Zhang Z, Sarkar D, Abrams S, Boufadel MC. Effect of clay content on the mobilization efficiency of per- and polyfluoroalkyl substances (PFAS) from soils by electrokinetics and hydraulic flushing. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 322:121160. [PMID: 36716947 DOI: 10.1016/j.envpol.2023.121160] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 01/15/2023] [Accepted: 01/26/2023] [Indexed: 06/18/2023]
Abstract
The need for the efficient remediation of soils impacted by per- and polyfluoroalkyl substances (PFAS) is substantially growing because of the notable upsurge in societal and regulatory awareness of this class of chemicals. To remediate PFAS-contaminated soils using mobilization approaches, the choice of appropriate techniques highly depends on the soil's composition, particularly the clay content, which significantly affects the soil's permeability. Here, we investigated the PFAS mobilization efficiency from soils with different clay contents by using two techniques: electrokinetic (EK) remediation and hydraulic flushing. Artificial kaolinite was added to a loamy sand soil to prepare four soil blends with clay contents of 5, 25, 50, and 75%, each contaminated with perfluorooctanoic acid (PFOA) and perfulorooctanesulfonic acid (PFOA) at 10,000 μg/kg. EK remediation was conducted by applying a low voltage (30 V) with a current of 100 mA, and hydraulic flushing was carried out by applying a hydraulic gradient (HG) with a slope of 6.7%. Results show that, with a 14-day treatment duration, the EK-mobilization efficiency was enhanced substantially with the increase of clay content (removal of PFOS increased from 20% at 5% clay to 80% at 75% clay), most likely due to the increase of electroosmotic flow due to the higher content of particles having a zeta potential (i.e., clay). For HG, increasing the clay content significantly suppressed the mobilization of PFAS (removal of PFOS decreased from 40% at 5% clay to 10% at 75% clay) due to a notable decrease in the soil's permeability. Based on the results, applying hydraulic flushing and washing techniques for mobilizing PFAS would be appropriate when treating permeable soils with a maximum clay content of about 25%; otherwise, other suitable mobilization techniques such as EKs should be considered.
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Affiliation(s)
- Charbel Abou-Khalil
- Center for Natural Resources, Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA
| | - Jitendra Kewalramani
- Center for Natural Resources, Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA
| | - Zhiming Zhang
- Department of Civil, Environmental and Ocean Engineering, Stevens Institute of Technology, Hoboken, NJ 07030, USA
| | - Dibyendu Sarkar
- Department of Civil, Environmental and Ocean Engineering, Stevens Institute of Technology, Hoboken, NJ 07030, USA
| | - Stewart Abrams
- Langan Engineering and Environmental Services, Inc., 300 Kimball Dr., Parsippany, NJ 07054, USA
| | - Michel C Boufadel
- Center for Natural Resources, Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA.
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Contrastive study on organic contaminated soils remediated using dielectric barrier discharge (DBD) plasma. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.122576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Niarchos G, Ahrens L, Kleja DB, Fagerlund F. Per- and polyfluoroalkyl substance (PFAS) retention by colloidal activated carbon (CAC) using dynamic column experiments. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 308:119667. [PMID: 35750303 DOI: 10.1016/j.envpol.2022.119667] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 06/16/2022] [Accepted: 06/18/2022] [Indexed: 06/15/2023]
Abstract
Developing effective remediation methods for per- and polyfluoroalkyl substance (PFAS)-contaminated soils is a substantial step towards counteracting their widespread occurrence and protecting our ecosystems and drinking water sources. Stabilisation of PFAS in the subsurface using colloidal activated carbon (CAC) is an innovative, yet promising technique, requiring better understanding. In this study, dynamic soil column tests were used to assess the retardation of 10 classical perfluoroalkyl acids (PFAAs) (C5-C11 perfluoroalkyl carboxylic acids (PFCAs) and C4, C6, C8 perfluoroalkane sulfonates (PFSAs)) as well as two alternative PFAS (6:2 and 8:2 fluorotelomer sulfonates) using CAC at 0.03% w/w, to investigate the fate and transport of PFAS under CAC treatment applications. Results showed high retardation rates for long-chain PFAS and eight times higher retardation for the CAC-treated soil compared to the non-treated reference soil for the ∑PFAS. Replacement of shorter chain perfluorocarboxylic acids (PFCAs), such as perfluoropentanoic acid (PFPeA), by longer chained PFAS was observed, indicating competition effects. Partitioning coefficients (Kd values) were calculated for the CAC fraction at ∼103-105 L kg-1 for individual PFAS, while there was a significant positive correlation (p < 0.05) between perfluorocarbon chain length and Kd. Mass balance calculations showed 37% retention of ∑PFAS in treated soil columns after completion of the experiments and 99.7% higher retention rates than the reference soil. Redistribution and elution of CAC were noticed and quantified through organic carbon analysis, which showed a 23% loss of carbon during the experiments. These findings are a step towards better understanding the extent of CAC's potential for remediation of PFAS-contaminated soil and groundwater and the limitations of its applications.
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Affiliation(s)
- Georgios Niarchos
- Department of Earth Sciences, Uppsala University, P.O. Box 256, SE-751 05, Uppsala, Sweden.
| | - Lutz Ahrens
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences (SLU), P.O. Box 7050, SE-750 07, Uppsala, Sweden
| | - Dan Berggren Kleja
- Department of Soil and Environment, Swedish University of Agricultural Sciences (SLU), P. O. Box 7090, SE-750 07, Uppsala, Sweden
| | - Fritjof Fagerlund
- Department of Earth Sciences, Uppsala University, P.O. Box 256, SE-751 05, Uppsala, Sweden
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Ferrari F, Pijuan M, Molenaar S, Duinslaeger N, Sleutels T, Kuntke P, Radjenovic J. Ammonia recovery from anaerobic digester centrate using onsite pilot scale bipolar membrane electrodialysis coupled to membrane stripping. WATER RESEARCH 2022; 218:118504. [PMID: 35525033 DOI: 10.1016/j.watres.2022.118504] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 04/20/2022] [Accepted: 04/21/2022] [Indexed: 06/14/2023]
Abstract
Ammonia recovery from centrate of an anaerobic digester was investigated using an onsite bipolar-electrodialysis (BP-ED) pilot scale plant coupled to two liquid/liquid membrane contactor (LLMC) modules. To investigate the process performance and robustness, the pilot plant was operated at varying current densities, load ratio (current to nitrogen loading), and in continuous and intermittent current (Donnan) mode. A higher load ratio led to higher total ammonium nitrogen (TAN, sum of ammonia and ammonium) removal efficiency, whereas the increase in the applied current did not have a significant impact the TAN removal efficiency. Continuous current application resulted in the higher TAN removal compared with the Donnan dialysis mode. The lowest specific energy consumption of 6.3 kWh kgN-1 was recorded in the Donnan mode, with the load ratio of 1.4, at 200 L h-1 flowrate and current density of 75 A m-2. Lower energy demand observed in the Donnan mode was likely due to the lower scaling and fouling of the ion exchange membranes. Nevertheless, scaling and fouling limited the operation of the BP-ED stack in all operational modes, which had to be interrupted by the daily cleaning procedures. The LLMC module enabled a highly selective recovery of ammonia as ammonium sulfate ((NH4)2SO4), with the concentration of ammonia ranging from 19 to 33 gN L-1. However, the analysis of per- and polyfluoroalkyl substances (PFASs) in the obtained (NH4)2SO4 product revealed the presence of 212-253 ng L-1 of 6:2 fluorotelomer sulfonate (FTS), a common substitute of legacy PFAS. Given the very low concentrations of 6:2 FTS (i.e., < 2 ng L-1) encountered in the concentrated stream, 6:2 FTS was likely released from the Teflon-based components in the sulfuric acid dosage line. Thus, careful selection of the pilot plant tubing, pumps and other components is required to avoid any risks associated with the PFAS presence and ensure safe use of the final product as fertilizer.
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Affiliation(s)
- Federico Ferrari
- Catalan Institute for Water Research (ICRA), Emili Grahit 101, 17003 Girona, Spain; University of Girona, 17003 Girona, Spain
| | - Maite Pijuan
- Catalan Institute for Water Research (ICRA), Emili Grahit 101, 17003 Girona, Spain; University of Girona, 17003 Girona, Spain
| | - Sam Molenaar
- W&F Technologies, Noordhaven 88a, 4761 DC Zevenbergen, the Netherlands
| | - Nick Duinslaeger
- Catalan Institute for Water Research (ICRA), Emili Grahit 101, 17003 Girona, Spain; University of Girona, 17003 Girona, Spain
| | - Tom Sleutels
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden; P.O. Box 1113, 8900 CC Leeuwarden, the Netherlands
| | - Philipp Kuntke
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden; P.O. Box 1113, 8900 CC Leeuwarden, the Netherlands; Environmental Technology, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen; P.O. Box 17, 6700 AA Wageningen, the Netherlands.
| | - Jelena Radjenovic
- Catalan Institute for Water Research (ICRA), Emili Grahit 101, 17003 Girona, Spain; Catalan Institution for Research and Advanced Studies (ICREA), Passeig Lluís Companys 23, 08010 Barcelona, Spain.
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Mixed Contaminants: Occurrence, Interactions, Toxicity, Detection, and Remediation. Molecules 2022; 27:molecules27082577. [PMID: 35458775 PMCID: PMC9029723 DOI: 10.3390/molecules27082577] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 04/13/2022] [Accepted: 04/14/2022] [Indexed: 12/18/2022] Open
Abstract
The ever-increasing rate of pollution has attracted considerable interest in research. Several anthropogenic activities have diminished soil, air, and water quality and have led to complex chemical pollutants. This review aims to provide a clear idea about the latest and most prevalent pollutants such as heavy metals, PAHs, pesticides, hydrocarbons, and pharmaceuticals—their occurrence in various complex mixtures and how several environmental factors influence their interaction. The mechanism adopted by these contaminants to form the complex mixtures leading to the rise of a new class of contaminants, and thus resulting in severe threats to human health and the environment, has also been exhibited. Additionally, this review provides an in-depth idea of various in vivo, in vitro, and trending biomarkers used for risk assessment and identifies the occurrence of mixed contaminants even at very minute concentrations. Much importance has been given to remediation technologies to understand our current position in handling these contaminants and how the technologies can be improved. This paper aims to create awareness among readers about the most ubiquitous contaminants and how simple ways can be adopted to tackle the same.
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Cleaning up Forever Chemicals in Construction: Informing Industry Change. SUSTAINABILITY 2022. [DOI: 10.3390/su14052854] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Per- and polyfluorinated alkyl substance (PFAS) contamination has been found in the construction spoil of many major projects, and there is growing concern about the health and environmental implications of these “forever” chemicals. In a context where construction and tunneling have experienced substantial growth, Australia and other countries are still developing their PFAS management. This study used convergent interviews to surface the key common issues that are associated with the management of PFAS contamination in the construction industry. The construction industry appears stuck in their ways and extremely financially driven. Regulation is not working because of poor enforcement and policing from the Environmental Protection Agency (EPA). The EPA could look to employ individuals with more construction industry experience in order to become a strong regulator in the industry, as well as to streamlining decision-making processes, while maintaining quality. To speed up changes in the management of PFASs within the construction industry, large organizations could be targeted by the relevant sustainability rating scheme, and there could be further use of the alliance models to research, develop, and implement PFAS treatment methods.
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11
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Niarchos G, Sörengård M, Fagerlund F, Ahrens L. Electrokinetic remediation for removal of per- and polyfluoroalkyl substances (PFASs) from contaminated soil. CHEMOSPHERE 2022; 291:133041. [PMID: 34826446 DOI: 10.1016/j.chemosphere.2021.133041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 11/16/2021] [Accepted: 11/20/2021] [Indexed: 06/13/2023]
Abstract
Uncontrolled use and disposal of per- and polyfluoroalkyl substances (PFASs) in recent decades has resulted in extensive soil and groundwater contamination, necessitating counteraction. Electrokinetic remediation (EKR) offers a promising approach to in-situ soil remediation. Two novel modifications to conventional EKR were tested for the first time in a laboratory-scale study, to explore the capacity of EKR for PFAS removal. The first modification was a two-compartment setup designed for PFAS extraction from soil to an electrolyte-filled chamber. The second was a single-compartment setup designed to transport and confine contaminants in a chamber filled with granular activated carbon (GAC), thus, combining extraction with stabilisation. Electromigration varied for individual compounds, based mainly on perfluorocarbon chain length and functional group. The results indicated up to 89% concentration and extraction of ∑PFASs for the two-compartment setup, with removal efficiency reaching 99% for individual PFASs with C ≤ 6. Removed PFASs were concentrated adjacent to the anode at the anion exchange membrane, while short-chain compounds were extracted in the anolyte. The single-compartment setup achieved 75% extraction and accumulation of ∑PFASs in GAC. This demonstrates, for the first time, good effectiveness of coupling EKR with AC stabilisation for PFAS removal from soil. Perfluorocarbon chain length was a dominant factor affecting treatment efficiency in both setups, with very high removal rates for short-chain PFASs.
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Affiliation(s)
- Georgios Niarchos
- Uppsala University, Department of Earth Sciences, Uppsala University, P.O. Box 256, SE-751 05, Uppsala, Sweden.
| | - Mattias Sörengård
- Swedish University of Agricultural Sciences, Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences (SLU), P.O. Box 7050, SE-750 07, Uppsala, Sweden.
| | - Fritjof Fagerlund
- Uppsala University, Department of Earth Sciences, Uppsala University, P.O. Box 256, SE-751 05, Uppsala, Sweden.
| | - Lutz Ahrens
- Swedish University of Agricultural Sciences, Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences (SLU), P.O. Box 7050, SE-750 07, Uppsala, Sweden.
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12
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Sörengård M, Gago-Ferrero P, B Kleja D, Ahrens L. Laboratory-scale and pilot-scale stabilization and solidification (S/S) remediation of soil contaminated with per- and polyfluoroalkyl substances (PFASs). JOURNAL OF HAZARDOUS MATERIALS 2021; 402:123453. [PMID: 32707463 DOI: 10.1016/j.jhazmat.2020.123453] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 06/18/2020] [Accepted: 07/08/2020] [Indexed: 05/22/2023]
Abstract
Remediation of soil contaminated with per- and polyfluoroalkyl substances (PFAS) is critical due to the high persistence and mobility of these compounds. In this study, stabilization and solidification (S/S) treatment was evaluated at pilot-scale using 6 tons of soil contaminated with PFAS-containing aqueous film-forming foam. At pilot-scale, long-term PFAS removal over 6 years of precipitation (simulated using irrigation) in leachate from non-treated contaminated reference soil and S/S-treated soil with 15 % binder and 0.2 % GAC was compared. PFAS removal rate from leachate, corresponding to reduction in leaching potential after 6 years, was >97 % for four dominant PFASs (perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorohexanesulfonic acid (PFHxS) and perfluorooctanesulfonic acid (PFOS)), but low (3%) for short-chain perfluoropentanoic acid (PFPeA). During the pilot-scale experiment, PFAS sorption strength (i.e., soil-water partitioning coefficient (Kd)) increased 2- to 40-fold for both reference and S/S-treated soil, to much higher levels than in laboratory-scale tests. However, PFAS behavior in pilot-scale and laboratory-scale tests was generally well-correlated (p < 0.001), which will help in future S/S recipe optimization. In addition, seven PFASs were tentatively identified using an automated suspect screening approach. Among these, perfluorohexanesulfonamide and 3:2 fluorotelomer alcohol were tentatively identified and the latter had low removal rates from leachate (<12 %) in S/S treatment.
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Affiliation(s)
- Mattias Sörengård
- Department of Aquatic Science and Assessment, Swedish University of Agricultural Sciences, Uppsala, 750 07, Sweden.
| | - Pablo Gago-Ferrero
- Catalan Institute for Water Research (ICRA), Carrer Emili Grahit 101, 17003, Girona, Spain
| | - Dan B Kleja
- Swedish Geotechnical Institute (SGI), SE-581 93, Linköping, Sweden; Department of Soil and Environment, Swedish University of Agricultural Sciences, Box 7014, Uppsala, Sweden
| | - Lutz Ahrens
- Department of Aquatic Science and Assessment, Swedish University of Agricultural Sciences, Uppsala, 750 07, Sweden
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13
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Ahmed MB, Johir MAH, McLaughlan R, Nguyen LN, Xu B, Nghiem LD. Per- and polyfluoroalkyl substances in soil and sediments: Occurrence, fate, remediation and future outlook. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 748:141251. [PMID: 32805564 DOI: 10.1016/j.scitotenv.2020.141251] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 07/19/2020] [Accepted: 07/24/2020] [Indexed: 06/11/2023]
Abstract
Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are contaminants of great concern due to their wide-spread occurrence and persistence in the environments (i.e., in water, soil and sediment) and potential toxicology even at very low concentration. The main focus of this review is on the PFASs in soil and sediments. More specifically, this review systematically examines the occurrence and toxicological effects with associated risks, fate (i.e., PFASs adsorption by soil and sediment, transportation and transformation, and bioaccumulation), and remediation practices of PFASs in soil and sediment. Various models and equations such as fugacity-based multimedia fate and hydrodynamic models are used to study the fate, transport, and transformation of PFASs. Among different remediation practices, sorption is the dominant process for the removal of PFASs from soil and sediments. Results also indicate that PFASs adsorption onto activated carbon decrease with the increase of carbon chain length in the PFASs. The longer-chain PFASs have larger partition coefficient values than shorter-chained PFASs. Sorption of PFASs to soil and sediments are mainly governed by different electrostatic interactions, hydrogen bonds formation, hydrophobic interactions, organic content in soil and sediments, and ligand exchange. Other technology such as thermal treatment might be potential in the removal of PAFSs, but need further study to elucidate a conclusion. Finally, the associated challenges and future outlook have been included.
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Affiliation(s)
- M B Ahmed
- School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007, Australia; School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
| | - M A H Johir
- School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007, Australia.
| | - Robert McLaughlan
- School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007, Australia
| | - Luong N Nguyen
- School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007, Australia
| | - Bentuo Xu
- School of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Long D Nghiem
- School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007, Australia
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14
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Duchesne AL, Brown JK, Patch DJ, Major D, Weber KP, Gerhard JI. Remediation of PFAS-Contaminated Soil and Granular Activated Carbon by Smoldering Combustion. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:12631-12640. [PMID: 32822535 DOI: 10.1021/acs.est.0c03058] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
This study explored smoldering combustion for remediating polyfluoroalkyl substance (PFAS)-impacted granular activated carbon (GAC) and PFAS-contaminated soil. GAC, both fresh and PFAS-loaded, was employed as the supplemental fuel supporting smoldering in mixtures with sand (≈175 mg PFAS/kg GAC-sand), with PFAS-spiked, laboratory-constructed soil (≈4 mg PFAS/kg soil), and with a PFAS-impacted field soil (≈0.2 mg PFAS/kg soil). The fate of PFAS and fluorine was quantified with soil and emission analyses, including targeted PFAS and suspect screening as well as hydrogen fluoride and total fluorine. Results demonstrated that exceeding 35 g GAC/kg soil resulted in self-sustained smoldering with temperatures exceeding 900 °C. Post-treatment PFAS concentrations of the treated soil were near (2 experiments) or below (7 experiments) detection limits (0.0004 mg/kg). Further, 44% of the initial PFAS on GAC underwent full destruction, compared to 16% of the PFAS on soil. Less than 1% of the initial PFAS contamination on GAC or soil was emitted as PFAS in the quantifiable analytical suite. Results suggest that the rest were emitted as altered, shorter-chain PFAS and volatile fluorinated compounds, which were scrubbed effectively with GAC. Total organic fluorine analysis proved useful for PFAS-loaded GAC in sand; however, analyzing soils suffered from interference from non-PFAS. Overall, this study demonstrated that smoldering has significant potential as an effective remediation technique for PFAS-impacted soils and PFAS-laden GAC.
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Affiliation(s)
- Alexandra L Duchesne
- University of Western Ontario, Spencer Engineering Building, London, Ontario N6A 5B9, Canada
| | - Joshua K Brown
- University of Western Ontario, Spencer Engineering Building, London, Ontario N6A 5B9, Canada
| | - David J Patch
- Royal Military College of Canada, Kingston, Ontario K7K 7B4, Canada
| | - David Major
- Savron, 130 Stone Rd. W, Guelph, Ontario N1G 3Z2, Canada
| | - Kela P Weber
- Royal Military College of Canada, Kingston, Ontario K7K 7B4, Canada
| | - Jason I Gerhard
- University of Western Ontario, Spencer Engineering Building, London, Ontario N6A 5B9, Canada
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15
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Sörengård M, Lindh AS, Ahrens L. Thermal desorption as a high removal remediation technique for soils contaminated with per- and polyfluoroalkyl substances (PFASs). PLoS One 2020; 15:e0234476. [PMID: 32584848 PMCID: PMC7316335 DOI: 10.1371/journal.pone.0234476] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 05/26/2020] [Indexed: 01/10/2023] Open
Abstract
Soils contaminated with per- and polyfluoroalkyl substances (PFASs) are an important source for impacting drinking water delivery systems and surface water bodies world-wide, posing an urgent risk to human health and environmental quality. However, few treatment techniques have been tested for PFAS-contaminated soil hotspots. This study investigated the possibility of thermal desorption as a possible technique to remediate soils contaminated with multiple PFASs. Two fortified soils (∑9PFAS ≈ 4 mg kg-1) and one field-contaminated soil (∑9PFAS ≈ 0.025 mg kg-1) were subjected to a 75-min thermal treatment at temperatures ranging from 150 to 550°C. Soil concentrations of PFASs showed a significant decrease at 350°C, with the ∑9PFAS concentration decreasing by, on average, 43% and 79% in the fortified and field contaminated soils, respectively. At 450°C, >99% of PFASs were removed from the fortified soils, while at 550°C the fraction removed ranged between 71 and 99% for the field contaminated soil. In the field contaminated soil, PFAS classes with functional groups of sulfonates (PFSAs) and sulfonamides (FOSAs) showed higher removal than the perfluoroalkyl carboxylates (PFCAs). Thus thermal desorption has the potential to remove a wide variety of PFASs from soil, although more studies are needed to investigate the cost-effectiveness, creation of transformation products, and air-phase vacuum filtration techniques.
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Affiliation(s)
- M. Sörengård
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
- * E-mail:
| | - A-S. Lindh
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
| | - L. Ahrens
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
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16
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Zhan J, Zhang A, Héroux P, Guo Y, Sun Z, Li Z, Zhao J, Liu Y. Remediation of perfluorooctanoic acid (PFOA) polluted soil using pulsed corona discharge plasma. JOURNAL OF HAZARDOUS MATERIALS 2020; 387:121688. [PMID: 31776082 DOI: 10.1016/j.jhazmat.2019.121688] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 11/08/2019] [Accepted: 11/11/2019] [Indexed: 06/10/2023]
Abstract
Perfluorooctanoic acid (PFOA) from contaminated soil accumulates in higher organisms, and causes health risks to humans. In this research, 71 % of the PFOA was degraded, of which 51 % was decomposed into short chain by-products, 19 % mineralized, and 1 % volatilized with 30 kV of voltage, 50 Hz of discharge frequency, 1 % of soil moisture, 300 ppm of PFOA concentration and 6.3 of soil pH using pulsed positive discharge plasma. From a series of experiments, electrons were identified as the dominant active means of PFOA degradation. The decomposition by-products were analyzed by LC-MS. The results indicated that PFOA was decomposed into small by-products including perfluoroheptanoic acid (PFHpA), perfluorohexanoic acid (PFHxA), perfluoropentanoic acid (PFPeA), perfluorobutyric acid (PFBA), pentafluoropropionic acid (PFPrA) and trifluoroacetic acid (TFA). Moreover, in plasma treated soil, the concentration of ammonia nitrogen increased from less than 10 ppm-462 ppm, and the average dry weight of lettuce was 1.6 mg higher than that in natural soil. Additionally, Planctomycetes and Nitrospirae increased after treatment, indicating that plasma technology promotes the process of nitrogen cycle. Thus, PFOA polluted soil could be remediated using this pulse corona plasma technology, and simultaneously improve the fertility of soil without chemical injections.
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Affiliation(s)
- Jiaxun Zhan
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Ai Zhang
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
| | - Paul Héroux
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Canada
| | - Ying Guo
- Department of Applied Physics, College of Science, Donghua University, Shanghai 201620, China
| | - Zhuyu Sun
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
| | - Zhenyu Li
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
| | - Jingyi Zhao
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
| | - Yanan Liu
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
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17
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Sörengård M, Franke V, Tröger R, Ahrens L. Losses of poly- and perfluoroalkyl substances to syringe filter materials. J Chromatogr A 2019; 1609:460430. [PMID: 31445806 DOI: 10.1016/j.chroma.2019.460430] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 07/30/2019] [Accepted: 08/05/2019] [Indexed: 11/28/2022]
Abstract
Syringe filters are used to separate solids from liquids prior to analysis of poly- and perfluoroalkyl substances (PFASs). This is a critical step in sample preparation, as losses of PFASs to the filter material can be significant and lead to underestimation. This study evaluated losses of 21 PFASs in three different matrices (methanol, MilliQ water, and water containing 10 mg L-1 dissolved organic carbon (DOC)) to six different types of syringe filter (0.45 and 0.22 μm). Regarding sample matrix, the lowest average ∑21PFAS losses were observed in methanol (13%), followed by DOC water (19%) and MilliQ water (26%). Regarding syringe filter material, the lowest average losses of ∑21PFAS in DOC water and MilliQ water were observed for a recycled cellulose filter (average losses 16% and 21%, respectively), while a polypropylene filter had the lowest ∑21PFAS losses in methanol (9%). A smaller polyethersulfone (PES) filter (0.22 μm, 17 mm Ø) showed significantly (p < 0.05) lower ∑21PFAS losses in DOC water (on average 7.3%) than a larger PES filter (0.45 μm, 37 mm Ø) (23%). In DOC water, losses to the filter increased by 3.8%, 5.1%, and 8.4% per CF2-moiety for C3-C11 perfluoroalkyl carboxylates (PFCAs), perfluoroalkyl sulfonates (PFSAs), and fluorotelomer sulfonic acids (FTSAs), respectively. Comparing different functional groups of PFASs, losses increased as follows: PFCAs < PFSAs < FTSAs < perfluorooctanesulfonamides (FOSAs). Thus, care is needed when including filtration in PFAS analysis, since losses can be significant (up to 100%) depending on the type of syringe filter, target PFAS, and matrix.
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Affiliation(s)
- Mattias Sörengård
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, P. O. Box 7050, SE-750 07 Uppsala, Sweden.
| | - Vera Franke
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, P. O. Box 7050, SE-750 07 Uppsala, Sweden
| | - Rikard Tröger
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, P. O. Box 7050, SE-750 07 Uppsala, Sweden
| | - Lutz Ahrens
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, P. O. Box 7050, SE-750 07 Uppsala, Sweden
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