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Mineo S. Groundwater and soil contamination by LNAPL: State of the art and future challenges. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 874:162394. [PMID: 36858232 DOI: 10.1016/j.scitotenv.2023.162394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 02/05/2023] [Accepted: 02/18/2023] [Indexed: 06/18/2023]
Abstract
Contamination by Light Non-Aqueous Phase Liquids (LNAPL) represents a challenge due to the difficulties encountered in its underground assessment and recovery. The major risks arising from subsoil LNAPL accumulation face human health and environment, gaining a social relevance also in the frame of a continuously changing climate. This paper reports on a literature review about the underground contamination by LNAPL, with the aims of providing a categorization of the aspects involved in this topic, analyzing the current state of the art, underlying potential lacks and future perspectives. The review was focused on papers published in the 2012-2022 time-interval, in journals indexed in Scopus and WoS databases, by querying "LNAPL" within article title, abstract and/or key words. 245 papers were collected and classified according to three "key approaches" -namely laboratory activity, field based-data studies and mathematical simulations- and subordinate "key themes", so to allow summarizing and commenting the main aspects based on the application setting, content and scope. Results show that there is a wide experience on plume dynamics and evolution, detection and monitoring through direct and indirect surveys, oil recovery and natural attenuation processes. Few cues of innovations were found regarding both the use of new materials and/or specific field configuration for remediation, and the application of new techniques for plume detection. Some limitations were found in the common oversimplification of the polluted media in laboratory or mathematical models, where the contamination is set within homogeneous porous environments, and in the low number of studies focused on rock masses, where the discontinuous hydraulic behavior complicates the address and modeling of the issue. This paper represents a reference for a quick update on the addressed topic, along with a starting point to develop new ideas and cues for the advance in one of the greatest environmental banes of the current century.
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Affiliation(s)
- S Mineo
- University of Catania, Department of Biological, Geological and Environmental Sciences, Corso Italia 57, Catania 95123, Italy.
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2
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Davoodi SM, Miri S, Brar SK, Martel R. Formulation of synthetic bacteria consortia for enzymatic biodegradation of polyaromatic hydrocarbons contaminated soil: soil column study. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023:10.1007/s11356-023-27233-5. [PMID: 37178293 DOI: 10.1007/s11356-023-27233-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 04/22/2023] [Indexed: 05/15/2023]
Abstract
As an efficient method to remove contaminants from highly polluted sites, enzyme biodegradation addresses unresolved issues such as bioremediation inefficiency. In this study, the key enzymes involved in PAH degradation were brought together from different arctic strains for the biodegradation of highly contaminated soil. These enzymes were produced via a multi-culture of psychrophilic Pseudomonas and Rhodococcus strains. As a result of biosurfactant production, the removal of pyrene was sufficiently prompted by Alcanivorax borkumensis. The key enzymes (e.g., naphthalene dioxygenase, pyrene dioxygenase, catechol-2,3 dioxygenase, 1-hydroxy-2-naphthoate hydroxylase, protocatechuic acid 3,4-dioxygenase) obtained via multi-culture were characterized by tandem LC-MS/MS and kinetic studies. To simulate in situ application of produced enzyme solutions, pyrene- and dilbit-contaminated soil was bioremediated in soil columns and flask tests by injecting enzyme cocktails from the most promising consortia. The enzyme cocktail contained about 35.2 U/mg protein pyrene dioxygenase, 61.4 U/mg protein naphthalene dioxygenase, 56.5 U/mg protein catechol-2,3-dioxygenase, 6.1 U/mg protein 1-hydroxy-2-naphthoate hydroxylase, and 33.5 U/mg protein protocatechuic acid (P3,4D) 3,4-dioxygenase enzymes. It was found that after 6 weeks, the average pyrene removal values showed that the enzyme solution could be effective in the soil column system (80-85% degradation of pyrene).
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Affiliation(s)
- Seyyed Mohammadreza Davoodi
- Department of Civil Engineering, Lassonde School of Engineering, York University, North York, Toronto, ON, M3J 1P3, Canada
| | - Saba Miri
- Department of Civil Engineering, Lassonde School of Engineering, York University, North York, Toronto, ON, M3J 1P3, Canada
| | - Satinder Kaur Brar
- Department of Civil Engineering, Lassonde School of Engineering, York University, North York, Toronto, ON, M3J 1P3, Canada.
| | - Richard Martel
- INRS-ETE, Université du Québec, 490, Rue de La Couronne, Québec, G1K 9A9, Canada
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Ramsburg CA, Baniahmad P, Muller KA, Robinson AD. Emulsion-based recovery of a multicomponent petroleum hydrocarbon NAPL using nonionic surfactant formulations. JOURNAL OF CONTAMINANT HYDROLOGY 2023; 255:104144. [PMID: 36791614 DOI: 10.1016/j.jconhyd.2023.104144] [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: 11/06/2022] [Revised: 01/27/2023] [Accepted: 01/29/2023] [Indexed: 06/18/2023]
Abstract
Surfactants can aid subsurface remediation through three primary mechanisms - solubilization, mobilization and/or emulsification. Among these mechanisms, emulsification in porous media is generally not well studied or well understood; particularly in the context of treating sources containing multicomponent NAPL. The objective of this research was to elucidate the processes responsible for recovery of a multicomponent hydrocarbon NAPL when surfactant solutions are introduced within a porous medium to promote the formation of kinetically-stable oil-in-water emulsions. Emulsifier formulations considered here were selected to offer similar performance characteristics while relying on different families of non-ionic surfactants - nonylphenol ethoxylates or alcohol ethoxylates - for emulsification. The families of surfactants have particular environment relevance, as alcohol ethoxylates are often used where replacement of nonylphenol content is necessary. Results from batch and column studies suggest performance of the two formulations was similar. With both, a synergistic combination of emulsification and mobilization led to recovery of a synthetic gasoline NAPL. The relative contribution of solubilization to the recovery was found to be minor. Moreover, the physical processes associated with emulsification and mobilization acted to limit the amount of preferential recovery (or fractionation) of the multicomponent NAPL.
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Affiliation(s)
- C Andrew Ramsburg
- Department of Civil and Environmental Engineering, Tufts University, 200 College Avenue, Room 204 Anderson Hall, Medford, MA 02155, USA.
| | - Parnian Baniahmad
- Department of Civil and Environmental Engineering, Tufts University, 200 College Avenue, Room 204 Anderson Hall, Medford, MA 02155, USA
| | - Katherine A Muller
- Department of Civil and Environmental Engineering, Tufts University, 200 College Avenue, Room 204 Anderson Hall, Medford, MA 02155, USA
| | - Andrew D Robinson
- Department of Civil and Environmental Engineering, Tufts University, 200 College Avenue, Room 204 Anderson Hall, Medford, MA 02155, USA
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Vaidyanathan VK, Rathankumar AK, Senthil Kumar P, Rangasamy G, Saikia K, Rajendran DS, Venkataraman S, Varjani S. Utilization of surface-active compounds derived from biosolids to remediate polycyclic aromatic hydrocarbons contaminated sediment soil. ENVIRONMENTAL RESEARCH 2022; 215:114180. [PMID: 36057335 DOI: 10.1016/j.envres.2022.114180] [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: 05/26/2022] [Revised: 08/03/2022] [Accepted: 08/19/2022] [Indexed: 06/15/2023]
Abstract
In the present study, surface-active compounds (SAC) were extracted from biosolids using an alkaline treatment process. They were tested for their remediation efficiency of crude oil-contaminated sediment soil and was compared with Triton x-100. The SAC exhibited a similar soil washing efficiency to that of the commercial Triton x-100, and under the optimized soil washing parameters, SAC exhibited a maximum of 91% total polycyclic aromatic hydrocarbons removal. Further, on analysing the toxicity of the soil residue after washing, it was observed that SAC from biosolids washed soil exhibited an average of 1.5-fold lesser toxicity compared to that of Triton x-100 on different test models-earthworm, a monocot, and dicot plants. The analysis of the key soil parameters revealed that the commercial surfactant reduced the soil organic matter and porosity by an average of 1.3-fold compared to SAC. Further, the ability of surfactants to induce toxicity was confirmed by the adsorption of the surfactants on the surface of the soil particles which was in the order of Triton x-100 > SAC. Thus, this study suggests that SAC can be applied as an effective bioremediation approach for contaminated soil for a greener and sustainable ecosystem.
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Affiliation(s)
- Vinoth Kumar Vaidyanathan
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, Tamil Nadu, 603 203, India.
| | - Abiram Karanam Rathankumar
- Department of Biotechnology, Faculty of Engineering, Karpagam Academy of Higher Education, Coimbatore, Tamil Nadu, 641021, India
| | - P Senthil Kumar
- Department of Chemical Engineering, Sri Sivasubramaniya Nadar College of Engineering, Kalavakkam, 603 110, Chennai, India; Centre of Excellence in Water Research (CEWAR), Sri Sivasubramaniya Nadar College of Engineering, Kalavakkam, 603 110, Chennai, India.
| | - Gayathri Rangasamy
- University Centre for Research and Development & Department of Civil Engineering, Chandigarh University, Gharuan, Mohali, Punjab, 140413, India
| | - Kongkona Saikia
- Department of Biochemistry, FASCM, Karpagam Academy of Higher Education, Coimbatore, Tamil Nadu, 641021, India
| | - Devi Sri Rajendran
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, Tamil Nadu, 603 203, India
| | - Swethaa Venkataraman
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, Tamil Nadu, 603 203, India
| | - Sunita Varjani
- Gujarat Pollution Control Board, Gandhinagar, Gujarat 382 010, India.
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Miri S, Davoodi SM, Robert T, Brar SK, Martel R, Rouissi T. Enzymatic biodegradation of highly p-xylene contaminated soil using cold-active enzymes: A soil column study. JOURNAL OF HAZARDOUS MATERIALS 2022; 423:127099. [PMID: 34523486 DOI: 10.1016/j.jhazmat.2021.127099] [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: 06/25/2021] [Revised: 08/24/2021] [Accepted: 08/29/2021] [Indexed: 06/13/2023]
Abstract
Enzymatic bioremediation is a sustainable and environment-friendly method for the clean-up of contaminated soil and water. In the present study, enzymatic bioremediation was designed using cold-active enzymes (psychrozymes) which catalyze oxidation steps of p-xylene biodegradation in highly contaminated soil (initial concentration of 13,000 mg/kg). The enzymes were obtained via co-culture of two psychrophilic Pseudomonas strains and characterized by kinetic studies and tandem LC-MS/MS. To mimic in situ application of enzyme mixture, bioremediation of p-xylene contaminated soil was carried out in soil column (140 mL) tests with the injection (3 pore volume) of different concentrations of enzyme cocktails (X, X/5, and X/10). Enzyme cocktail in X concentration contained about 10 U/mL of xylene monooxygenase (XMO) and 20 U/mL of catechol 2, 3 dioxygenases (C2,3D). X/5 and X/10 correspond to 5x and 10x dilution of enzyme cocktail respectively. The results showed that around 92-94% p-xylene removal was achieved in the treated soil column with enzyme concentration X, X/5 after second enzyme injection. While the p-xylene removal rate obtained by X/10 concentration of enzyme was less than 30% and near to untreated soil column (22.2%). The analysis of microbial diversity and biotoxicity assay (root elongation and seed germination) confirmed the advantage of using enzymes as a green and environmentally friendly approach for decontamination of pollutants with minimal or even positive effects on microbial community and also enrichment of soil after treatment.
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Affiliation(s)
- Saba Miri
- Department of Civil Engineering, Lassonde School of Engineering, York University, North York, Toronto, Ontario M3J 1P3, Canada; INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec G1K 9A9, Canada.
| | - Seyyed Mohammadreza Davoodi
- Department of Civil Engineering, Lassonde School of Engineering, York University, North York, Toronto, Ontario M3J 1P3, Canada; INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec G1K 9A9, Canada.
| | - Thomas Robert
- INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec G1K 9A9, Canada.
| | - Satinder Kaur Brar
- Department of Civil Engineering, Lassonde School of Engineering, York University, North York, Toronto, Ontario M3J 1P3, Canada; INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec G1K 9A9, Canada.
| | - Richard Martel
- INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec G1K 9A9, Canada.
| | - Tarek Rouissi
- INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec G1K 9A9, Canada.
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Liu JW, Wei KH, Xu SW, Cui J, Ma J, Xiao XL, Xi BD, He XS. Surfactant-enhanced remediation of oil-contaminated soil and groundwater: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 756:144142. [PMID: 33302075 DOI: 10.1016/j.scitotenv.2020.144142] [Citation(s) in RCA: 82] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 11/13/2020] [Accepted: 11/24/2020] [Indexed: 05/16/2023]
Abstract
Oil leakage, which is inevitable in the process of extraction, processing, transportation and storage, seriously undermines the soil and groundwater environment. Surfactants can facilitate the migration and solution of oil contaminants from nonaqueous phase liquid (NAPL) or solid phase to water by reducing the (air/water) surface tension, (oil/water) interfacial tension and micellar solubilization. They can effectively enhance the hydrodynamic driven remediation technologies by improving the contact efficiency of contaminants and liquid remediation agents or microorganism, and have been widely used to enhance the remediation of oil-contaminated sites. This paper summarizes the characteristics of different types of surfactants such as nonionic, anionic, biological and mixed surfactants, their enhancements to the remediation of oil-contaminated soil and groundwater, and examines the factors influencing surfactant performance. The causes of tailing and rebound effects and the role of surfactants in suppressing them are also discussed. Laboratory researches and actual site remediation practices have shown that various types of surfactants offer diverse options. Biosurfactants and mixed surfactants are superior and worth attention among the surfactants. Using surfactant foams, adding shear-thinning polymers, and combining surfactants with in-situ chemical oxidation are effective ways to resolve tailing and rebound effects. The adsorption of surfactants on soils and aquifer sediments decreases remediation efficiency and may cause secondary pollution, Therefore the adsorption loss should be noticed and minimized.
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Affiliation(s)
- Jian-Wu Liu
- Shandong Provincial Key Laboratory of Oilfield Produced Water Treatment and Environmental Pollution Control, SINOPEC Petroleum Engineering Corporation, Dongying 257026, China
| | - Kun-Hao Wei
- State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Shao-Wei Xu
- Shengli Oilfield Company, SINOPEC, Dongying 257026, China
| | - Jun Cui
- State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Jie Ma
- State Key Laboratory of Heavy Oil Processing, Beijing Key Lab of Oil & Gas Pollution Control, China University of Petroleum-Beijing, Beijing 102249, China
| | - Xiao-Long Xiao
- Shandong Provincial Key Laboratory of Oilfield Produced Water Treatment and Environmental Pollution Control, SINOPEC Petroleum Engineering Corporation, Dongying 257026, China
| | - Bei-Dou Xi
- State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Xiao-Song He
- State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
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Li X, Wu B, Zhang Q, Liu Y, Wang J, Xu D, Li F, Ma F, Gu Q. Effects of soil properties on the remediation of diesel-contaminated soil by Triton X-100-aided washing. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:23323-23330. [PMID: 32337673 DOI: 10.1007/s11356-020-08781-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 04/06/2020] [Indexed: 06/11/2023]
Abstract
Although nonionic surfactant is widely used for petroleum-contaminated soil washing, there is no definite conclusion on the main soil factors which determine the removal of petroleum hydrocarbons from the soil. In this study, the influences of soil properties on Triton X-100-aided soil washing were investigated using 12 soils in China. The sorption characteristic of Triton X-100 on soils was described as well. The sorption isotherms of Triton X-100 on 12 typical soils were fitted to the Langmuir adsorption model, and the maximum sorption amount of Triton X-100 (Qmax) varied from 1.54 to 15.15 mg/g. The removal rates of diesel for 12 soils were well fitted to the modified Michaelis-Menten equation, and the maximum removal rate of diesel (φmax) ranged from 62.92 to 90.36%. The correlation analysis indicated that the φmax is significantly correlated with the Qmax. The soil factors affecting diesel removal from soils followed the order of sand content > cation exchange capacity (CEC) > organic matter (OM) content > silt and clay content > SSA >> pH. The prediction model based on CEC, silt content, and pH explained 83.1% of variance of diesel removal from soils. This study will have important implication for successfully remediating organic-contaminated soil using nonionic surfactant-based soil washing.
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Affiliation(s)
- Xiaodong Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China
| | - Bin Wu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Qian Zhang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Yuqin Liu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China
| | - Jiaqi Wang
- School of Chemical and Environmental Engineering, China University of Mining & Technology, Beijing, 100083, China
| | - Duanping Xu
- College of Environmental Science and Engineering, Liaoning Technical University, Fuxin, 123000, China
| | - Fasheng Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Fujun Ma
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
| | - Qingbao Gu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China.
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Qi S, Luo J, O'Connor D, Wang Y, Hou D. A numerical model to optimize LNAPL remediation by multi-phase extraction. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 718:137309. [PMID: 32087590 DOI: 10.1016/j.scitotenv.2020.137309] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 02/08/2020] [Accepted: 02/13/2020] [Indexed: 06/10/2023]
Abstract
Light non-aqueous phase liquid (LNAPL) contaminated sites pose a risk to human health and the natural environment. Multi-phase extraction (MPE) is one of the most widely used technologies to remediate these sites. Thus, it is important to optimize MPE systems to improve their effectiveness and cost-efficiency. In this study, we developed a numerical model to optimize LNAPL mass removal by MPE, in which the aquifer domain was simplified as a cylinder with a single MPE extraction well located at the center. A dual-pump extraction system was applied to the model, which involved vacuum enhanced recovery to remove volatilized gaseous phase contaminants and a submerged pump to remove NAPL and contaminants in groundwater. After the model was validated with field data, the results showed that the contaminant extraction rate varied with the LNAPL thickness and submerged pump position. For benzene selected as the contaminant of concern, greater LNAPL extraction rates were achieved when the initial LNAPL thickness was large (>1.5 m) or in aquifers of high permeability (>2.45 × 10-10 m2). Importantly, it was discovered that in highly permeable coarse sand and gravel, the submerged pump ought to be placed within the LNAPL layer, whereas the pump should be placed below the water-NAPL interface in fine to medium sand aquifers. It was also found that an optimal liquid pumping rates exist, beyond which contaminant mass removal rates do not increase. Furthermore, it was found that in aquifers contaminated with thin LNAPL layers, mass transfer modelling that assumes equilibrium between the phases may greatly overestimate the accumulated mass of contaminants removed and, therefore, non-equilibrium modelling should be adopted. Finally, a cost analysis was carried out to compare the costs of remediating a contaminated site with MPE and by an alternative chemical oxidation approach. The MPE technology was found to be more cost effective when the initial thickness of LNAPL was relatively thin. In summary, the numerical model developed in this study is a useful tool for optimizing MPE system design.
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Affiliation(s)
- Shengqi Qi
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Jian Luo
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0355, United States
| | - David O'Connor
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Yidong Wang
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Deyi Hou
- School of Environment, Tsinghua University, Beijing 100084, China.
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Bouzid I, Maire J, Fatin-Rouge N. Comparative assessment of a foam-based oxidative treatment of hydrocarbon-contaminated unsaturated and anisotropic soils. CHEMOSPHERE 2019; 233:667-676. [PMID: 31195271 DOI: 10.1016/j.chemosphere.2019.05.295] [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: 03/27/2019] [Revised: 05/28/2019] [Accepted: 05/31/2019] [Indexed: 06/09/2023]
Abstract
In situ delivery of liquid reagents in vadose zone is limited by soil anisotropy and gravity. The enhanced delivery of persulfate (PS) as oxidant, using a new foam-based method (F-PS) was compared at bench-scale to traditional water-based (W-PS) and surfactant solution-based (S-PS) deliveries. The goal was to distribute PS uniformly in coal tar-contaminated unsaturated and anisotropic soils, both in terms of permeability and contamination. Water was the less efficiently delivered fluid because of the hydrophobicity of the contaminated soils. Surfactant enhanced PS-distribution into contaminated zones by reducing interfacial tension and inverting soil wettability. Regardless of coal tar contamination contrasts (0 vs. 5 and 1 vs. 10 g kg soil-1) or strong permeability contrasts, PS-solution injection after foam injection led to the most uniform reagents delivery. While PS-concentration varied more than 5-times between zones using W-PS and S-PS methods, it varied less than 1.6-times when the F-PS one was used. Finally, despite unfavorable conditions, the foam-based method did not show any detrimental effect regarding the oxidation of hydrocarbons compared to the W-PS and S-PS methods carried out in ideal conditions. Moreover, hydrocarbon degradation rates were slightly higher when using F-PS than S-PS due to a lower surfactant content in the targeted zone.
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Affiliation(s)
- Iheb Bouzid
- Université de Bourgogne Franche-Comté - Besançon, Institut UTINAM - UMR CNRS 6213, 16, Route de Gray, 25030, Besançon, France
| | - Julien Maire
- Université de Bourgogne Franche-Comté - Besançon, Institut UTINAM - UMR CNRS 6213, 16, Route de Gray, 25030, Besançon, France
| | - Nicolas Fatin-Rouge
- Université de Bourgogne Franche-Comté - Besançon, Institut UTINAM - UMR CNRS 6213, 16, Route de Gray, 25030, Besançon, France.
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