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Acharya A, Jeppu G, Raju Girish C, Prabhu B. Development of a Multicomponent Adsorption Isotherm Equation and Its Validation by Modeling. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:17862-17878. [PMID: 37997228 PMCID: PMC10720473 DOI: 10.1021/acs.langmuir.3c02496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 11/08/2023] [Accepted: 11/13/2023] [Indexed: 11/25/2023]
Abstract
Researchers have made significant efforts over the past few decades to understand adsorption by developing various simple adsorption isotherm models. However, though many contaminants usually occur as multicomponent mixtures in nature, multicomponent adsorption isotherms have received limited attention and remain an area of inadequate research. We have presented here in a new multicomponent adsorption isotherm model, named the Jeppu Amrutha Manipal Multicomponent (JAMM) isotherm, that can alleviate this problem. We first developed the JAMM multicomponent isotherm using our experimental data sets of arsenic and fluoride competitive adsorption on activated carbon. We then tested the JAMM multicomponent isotherm for a case study of cadmium and zinc competitive adsorption. Next, we further assessed the JAMM isotherm using another competitive adsorption case study of copper and chromium. Through extensive validation studies and error analysis, the JAMM isotherm was able to demonstrate its efficacy in predicting the adsorption behavior in several multicomponent adsorption systems accurately. The main advantage of JAMM isotherm over other multicomponent isotherms is that it utilizes and leverages the single-component adsorption parameters to simulate multicomponent isotherms. The proposed JAMM analytical isotherm model furthermore incorporates the interaction between the components, a mole fraction parameter, and a heterogeneity index, providing a more comprehensive modeling framework for multicomponent adsorption. The mole fraction term was introduced for the distribution of adsorption sites based on the relative number of molecules of each component. An additional term for interaction coefficient was introduced for the representation of interactions. During the validation of JAMM with three experimental case studies with negligible, small, and high competition systems of adsorbates, impressive predictions were exhibited, with the average normalized absolute percentage error as 6.05% and average R2 as 0.86, highlighting the model's robustness, versatility, and reliability. We propose that the new JAMM isotherm modeling framework might profoundly help in chemical engineering, environmental engineering, and materials science applications by providing a potent tool for analyzing and predicting multicomponent adsorption systems.
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Affiliation(s)
- Amrutha Acharya
- Department of Chemical Engineering, Manipal Institute of Technology (MIT), Manipal Academy
of Higher Education (MAHE), Manipal 576104, Karnataka, India
| | - Gautham Jeppu
- Department of Chemical Engineering, Manipal Institute of Technology (MIT), Manipal Academy
of Higher Education (MAHE), Manipal 576104, Karnataka, India
| | - Chikmagalur Raju Girish
- Department of Chemical Engineering, Manipal Institute of Technology (MIT), Manipal Academy
of Higher Education (MAHE), Manipal 576104, Karnataka, India
| | - Balakrishna Prabhu
- Department of Chemical Engineering, Manipal Institute of Technology (MIT), Manipal Academy
of Higher Education (MAHE), Manipal 576104, Karnataka, India
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Illy VD, Cohen GJV, Verardo E, Höhener P, Guiserix N, Atteia O. Chlorinated solvents source identification by nonlinear optimization method. ENVIRONMENTAL MONITORING AND ASSESSMENT 2023; 195:531. [PMID: 37004632 DOI: 10.1007/s10661-023-11107-x] [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: 05/15/2022] [Accepted: 03/09/2023] [Indexed: 06/19/2023]
Abstract
In this work, chloride ions were used as conservative tracers and supplemented with conservative amounts of chloroethenes (PCE, TCE, Cis-DCE, 1,1-DCE), chloroethanes (1,1,1-TCA, 1,1-DCA), and the carbon isotope ratios of certain compounds, the most representative on the sites studied, which is a novelty compared to the optimization methods developed in the scientific literature so far. A location of the potential missing sources is then proposed in view of the balances of the calculated mixing fractions. A test of the influence of measurement errors on the results shows that the uncertainties in the calculation of the mixture fractions are less than 11%, indicating that the source identification method developed is a robust tool for identifying sources of chlorinated solvents in groundwater.
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Affiliation(s)
- Valeureux D Illy
- EA 4592, Géoressources Et Environnement, Bordeaux INP, Université Bordeaux Montaigne, 1 Avenue Dr Schweitzer, 33400, Talence, France.
- 1 Allée du Golf, Renault SAS, 78 280, Guyancourt, France.
| | - Gregory J V Cohen
- EA 4592, Géoressources Et Environnement, Bordeaux INP, Université Bordeaux Montaigne, 1 Avenue Dr Schweitzer, 33400, Talence, France
| | - Elicia Verardo
- EA 4592, Géoressources Et Environnement, Bordeaux INP, Université Bordeaux Montaigne, 1 Avenue Dr Schweitzer, 33400, Talence, France
| | - Patrick Höhener
- Laboratoire de Chimie Environnementale-UMR 7376, Aix-Marseille Université-CNRS, 3 Place Victor Hugo - Case 29, 13331, Marseille Cedex 3, France
| | | | - Olivier Atteia
- EA 4592, Géoressources Et Environnement, Bordeaux INP, Université Bordeaux Montaigne, 1 Avenue Dr Schweitzer, 33400, Talence, France
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Valletti N, Budroni MA, Albanese P, Marchettini N, Sanchez-Dominguez M, Lagzi I, Rossi F. Hydrodynamically-enhanced transfer of dense non-aqueous phase liquids into an aqueous reservoir. WATER RESEARCH 2023; 231:119608. [PMID: 36709564 DOI: 10.1016/j.watres.2023.119608] [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: 09/30/2022] [Revised: 01/09/2023] [Accepted: 01/12/2023] [Indexed: 06/18/2023]
Abstract
The use of surfactants represents a viable strategy to boost the removal yield of Dense Non-Aqueous Phase Liquids (DNAPLs) from groundwater and to shorten the operational timing of the remediation process. Surfactants, in general, help in reducing the interfacial tension at the DNAPL/water interface and enhance the solubility of the pollutant in the water phase through the formation of dispersed systems, such as micelles and emulsions. In this paper, we show that a suitable choice of a surfactant, in this case belonging to the bio-degradable class of ethoxylated alcohols, allows for the formation of hydrodynamic interfacial instabilities that further enhances the dissolution rate of the organic pollutant into the water phase. In a stratified configuration (denser organic phase at the bottom and lighter water phase on top), the instabilities appear as upward-pointing fingers that originate from the inversion of the local density at the interface. This inversion stems from the synergetic coupling of two effects promoted by the ethoxylated surfactant: i) the enhanced co-solubility of the DNAPL into the water (and viceversa), and (ii) the differential diffusion of the DNAPL and the surfactant in the aqueous phase. By dissolving into the DNAPL, the surfactant also reduces locally the surface tension at the liquid-liquid interface, thereby inducing transversal Marangoni flows. In our work, we carefully evaluated the effects of the concentration of different surfactants (two different ethoxylated alcohols, sodium dodecylsulphate, cetyltrimethyl ammonium bromide, N-tetradecyl-N, N-dimethylamine oxide and bis(2-ethylhexyl) sulfosuccinate sodium salt) on the onset of the instabilities in 3 different DNAPLs/water stratifications, namely chloroform, trichloroethylene and tetrachloroethylene, with a special emphasis on the trichloroethylene/water system. By means of a theoretical model and nonlinear simulations, supported by surface tension, density and diffusivity measurements, we could provide a solid explanation to the observed phenomena and we found that the type of the dispersed system, the solubility of the DNAPL into the water phase, the solubility of the surfactant in the organic phase, as well as the relative diffusion and density of the surfactant and the DNAPL in the aqueous phase, are all key parameters for the onset of the instabilities. These results can be exploited in the most common remediation techniques.
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Affiliation(s)
- Nadia Valletti
- Department of Earth, Environmental and Physical Sciences, University of Siena, Pian dei Mantellini 44, 53100 Siena, Italy
| | - Marcello A Budroni
- Department of Chemical, Physical, Mathematical and Natural Sciences, University of Sassari, Via Vienna 2, 07100 Sassari, Italy
| | - Paola Albanese
- Department of Earth, Environmental and Physical Sciences, University of Siena, Pian dei Mantellini 44, 53100 Siena, Italy
| | - Nadia Marchettini
- Department of Earth, Environmental and Physical Sciences, University of Siena, Pian dei Mantellini 44, 53100 Siena, Italy
| | - Margarita Sanchez-Dominguez
- Grupo de Quimica Coloidal e Interfacial Aplicada a Nanomateriales y Formulaciones, Centro de Investigacion en Materiales Avanzados, S.C. (CIMAV), Unidad Monterrey, Alianza Norte 202, Parque de Investigacion e Innovacion Tecnologica, Apodaca 66628, Mexico
| | - Istvan Lagzi
- Department of Physics, Institute of Physics, Budapest University of Technology and Economics, Muegyetem rkp. 3., H-1111 Budapest, Hungary; ELKH-BME Condensed Matter Research Group, Budapest University of Technology and Economics, Muegyetem rkp. 3., H-1111 Budapest, Hungary
| | - Federico Rossi
- Department of Earth, Environmental and Physical Sciences, University of Siena, Pian dei Mantellini 44, 53100 Siena, Italy.
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Ibrahim SI, Yadav PK, Dwiandani A, Liedl R, Dietrich P. An approach for quantification of the heterogeneity of DNAPL source zone geometries. JOURNAL OF CONTAMINANT HYDROLOGY 2022; 251:104096. [PMID: 36308863 DOI: 10.1016/j.jconhyd.2022.104096] [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: 09/30/2021] [Revised: 09/22/2022] [Accepted: 10/06/2022] [Indexed: 06/16/2023]
Abstract
Many studies have investigated the migration and entrapment processes of source zones from dense non-aqueous phase liquid (DNAPL) contamination under different conditions. However, the characterization of occupying area by source zone (or source shape) in water-saturated aquifers is still rudimentarily considered. In this study, we demonstrated this issue (1) by providing a brief review of existing approaches for source shape consideration, (2) by proposing an approach with simple shape parameters based on the non-uniformity of source widths, and (3) by providing exemplary applications of our proposed approach on shapes already published in previous research works. Our literature review suggested that the source zone in mathematical approaches is generally characterized as simple geometrical shapes (arbitrary lines or rectangles) or system-defined parameters that contrast to complex and discontinuous shapes observed in the real world. But the characterization of such complex shapes is still not possible with acceptable efforts. Therefore, we proposed an approach to parameterize the source shape by considering the variation of width and midpoints over the depth of the entire source zone and formulate four parameters based on population statistics (mean, standard deviation). To illustrate the suitability of our approach, we applied it to the results of lab experiments, and by analyzing these complex shapes, we highlighted the potential for improving the characterization techniques of non-uniformity of the source zones.
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Affiliation(s)
- Sharif Ibne Ibrahim
- Helmholtz Centre for Environmental Research - UFZ, Department of Monitoring and Exploration Technologies, Permoserstr. 15, 04318 Leipzig, Germany; Technische Universität Dresden, Department of Hydrosciences, Institute of Groundwater Management, Bergstr. 66, 01069 Dresden, Germany.
| | - Prabhas Kumar Yadav
- Technische Universität Dresden, Department of Hydrosciences, Institute of Groundwater Management, Bergstr. 66, 01069 Dresden, Germany
| | - Amalia Dwiandani
- Technische Universität Dresden, Department of Hydrosciences, Institute of Groundwater Management, Bergstr. 66, 01069 Dresden, Germany
| | - Rudolf Liedl
- Technische Universität Dresden, Department of Hydrosciences, Institute of Groundwater Management, Bergstr. 66, 01069 Dresden, Germany
| | - Peter Dietrich
- Helmholtz Centre for Environmental Research - UFZ, Department of Monitoring and Exploration Technologies, Permoserstr. 15, 04318 Leipzig, Germany; Center for Applied Geoscience (ZAG), University of Tübingen, Hölderlinstr. 12, 72074 Tübingen, Germany
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Stewart LD, Chambon JC, Widdowson MA, Kavanaugh MC. Upscaled modeling of complex DNAPL dissolution. JOURNAL OF CONTAMINANT HYDROLOGY 2022; 244:103920. [PMID: 34798507 DOI: 10.1016/j.jconhyd.2021.103920] [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: 06/01/2021] [Revised: 09/20/2021] [Accepted: 11/06/2021] [Indexed: 06/13/2023]
Abstract
A straightforward, upscaled DNAPL mass dissolution model is developed using relatively simple input consisting of characteristic dimensions and saturations of a DNAPL accumulation. Multiple accumulations are aggregated into a single source zone volume. Physically, the dissolution process is a combination of flow through the mass (advective component) and flow around the mass (dispersive component). The contribution of each component is based on initial characteristic length scales and the average initial saturation. Changes over time with the depletion of mass are captured with a changing relative permeability and a power law relationship for the fraction of initial mass remaining. The utility of the upscaled process model is demonstrated with data from three studies: numerical simulation of multiple pools, two-dimensional test cell experiments with mixed architecture and with heterogeneous soil, and a controlled field study of multicomponent DNAPL release and depletion. Use of the model successfully reproduced the observed multistage mass discharge in each study and illuminated the governing processes. The power law exponent was relatively constant for the various conditions and relative permeability changes were integral to the success. The numerical and experimental studies were run to complete mass depletion which the upscaled model matched. The input parameters are minimal and are found in typical DNAPL source zone characterization data.
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Affiliation(s)
- Lloyd D Stewart
- Praxis Environmental Technologies, Inc., 1440 Rollins Road, Burlingame, CA 94010, United States.
| | - Julie C Chambon
- Geosyntec Consultants, Inc., 1111 Broadway Street 6th Floor, Oakland, CA 94607, United States
| | - Mark A Widdowson
- The Charles E. Via, Jr. Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24061-0105, United States
| | - Michael C Kavanaugh
- Geosyntec Consultants, Inc., 1111 Broadway Street 6th Floor, Oakland, CA 94607, United States
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Engelmann C, Sookhak Lari K, Schmidt L, Werth CJ, Walther M. Towards predicting DNAPL source zone formation to improve plume assessment: Using robust laboratory and numerical experiments to evaluate the relevance of retention curve characteristics. JOURNAL OF HAZARDOUS MATERIALS 2021; 407:124741. [PMID: 33352423 DOI: 10.1016/j.jhazmat.2020.124741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 11/13/2020] [Accepted: 11/29/2020] [Indexed: 06/12/2023]
Abstract
We conducted multiple laboratory trials in a robust and repeatable experimental layout to study dense non-aqueous phase liquid (DNAPL) source zone formation. We extended an image processing and analysis framework to derive DNAPL saturation distributions from reflective optical imaging data, with volume balance deviations < 5.07%. We used a multiphase flow model to simulate source zone formation in a Monte Carlo approach, where the parameter space was defined by the variation of retention curve parameters. Integral and geometric measures were used to characterize the source zones and implemented into a multi-criteria objective function. The latter showed good agreement between observation data and simulation results for effective DNAPL saturation values > 0.04, especially for early stages of DNAPL migration. The common hypothesis that parameters defining the DNAPL-water retention curves are constant over time was not confirmed. Once DNAPL pooling started, the optimal fit in the parameter space was significantly different compared to the earlier DNAPL migration stages. We suspect more complex processes (e.g., capillary hysteresis, adsorption) to become relevant during pool formation. Our results reveal deficits in the grayscale-DNAPL saturation relationship definition and laboratory estimation of DNAPL-water retention curve parameters to overcome current limitations to describe DNAPL source zone formation.
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Affiliation(s)
- Christian Engelmann
- Faculty of Environmental Sciences, Institute of Groundwater Management, Technische Universität Dresden, Bergstraße 66, 01069 Dresden, Germany; Department Environmental Informatics, Helmholtz-Centre for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig, Germany; CSIRO Land and Water, Private Bag No. 5, Wembley, WA 6913, Australia.
| | - Kaveh Sookhak Lari
- CSIRO Land and Water, Private Bag No. 5, Wembley, WA 6913, Australia; School of Engineering, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA 6027, Australia
| | - Luisa Schmidt
- Faculty of Environmental Sciences, Institute of Groundwater Management, Technische Universität Dresden, Bergstraße 66, 01069 Dresden, Germany; Faculty of Environmental Sciences, Institute Photogrammetry and Remote Sensing, Juniorprofessorship in Environmental Remote Sensing, Technische Universität Dresden, Helmholtzstraße 10, 01069 Dresden, Germany; Department Monitoring and Exploration Technologies, Helmholtz-Centre for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig, Germany
| | - Charles J Werth
- Department of Civil, Architectural and Environmental Engineering, Bettie Margaret Smith Chair in Environmental Health Engineering, University of Texas at Austin, Texas, United States
| | - Marc Walther
- Faculty of Environmental Sciences, Institute of Groundwater Management, Technische Universität Dresden, Bergstraße 66, 01069 Dresden, Germany; Department Environmental Informatics, Helmholtz-Centre for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig, Germany
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Colombano S, Davarzani H, van Hullebusch ED, Huguenot D, Guyonnet D, Deparis J, Lion F, Ignatiadis I. Comparison of thermal and chemical enhanced recovery of DNAPL in saturated porous media: 2D tank pumping experiments and two-phase flow modelling. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 760:143958. [PMID: 33341615 DOI: 10.1016/j.scitotenv.2020.143958] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 10/28/2020] [Accepted: 11/13/2020] [Indexed: 06/12/2023]
Abstract
Pumping experiments were performed in a 2D tank in order to estimate the recovery yield of pure heavy chlorinated organic compounds (DNAPL; dense non-aqueous phase liquids) by varying different parameters: permeability of the saturated zone, pumping flow rates, addition of surfactant and heating. Surfactant was added to decrease capillary forces involved in the entrapment of DNAPL in porous media while temperature was increased to reduce DNAPL viscosity (and hence increase its mobility). Chemical enhancement was performed with the addition of Sodium Dodecyl Benzene Sulfonate (SDBS) (at its Critical Micelle Concentration, to avoid DNAPL dissolution) and thermal enhancement was performed at 50 °C (to avoid DNAPL volatilization). The experiments were monitored with photography allowing, on the basis of image interpretation, to convert optical densities (OD) into water saturations (Sw). Image interpretations were compared with modelling results. The two-phase flow modelling was performed with the pressure-pressure formulation using capillary pressure and relative permeability functions based on the van Genuchten-Mualem equations. Measured volumes of DNAPL recovered as well as the displacement of the DNAPL-water interface (radius and height of the cone of depression) are consistent with the modelling results. Furthermore, chemical enhancement results in a significant increase in the recovery rates of DNAPL. The observed improvement in the recovery of DNAPL with chemical enhancement is due to the fact that: (i) the residual saturation inside the cone of depression is lower and (ii) the cone of depression radius and height increase. Thermal enhancement had no beneficial effect on DNAPL recovery rate or yield. This study shows that it is possible to accurately determine water and DNAPL saturations by image interpretation during pumping tests in a 2D tank in the laboratory. For field-scale applications, the two-phase flow model allows to determine remediation yields as well as the volumes of the cone of depression according to the different operating conditions.
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Affiliation(s)
| | | | - E D van Hullebusch
- Université de Paris, Institut de Physique du Globe de Paris, CNRS, F-75005 Paris, France
| | - D Huguenot
- Laboratoire Géomatériaux et Environnement, Université Gustave-Eiffel, France
| | | | - J Deparis
- BRGM (French Geological Survey), France
| | - F Lion
- BRGM (French Geological Survey), France
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Guo Z, Russo AE, DiFilippo EL, Zhang Z, Zheng C, Brusseau ML. Mathematical modeling of organic liquid dissolution in heterogeneous source zones. JOURNAL OF CONTAMINANT HYDROLOGY 2020; 235:103716. [PMID: 32977295 PMCID: PMC7704655 DOI: 10.1016/j.jconhyd.2020.103716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 09/13/2020] [Accepted: 09/14/2020] [Indexed: 06/11/2023]
Abstract
A simple one-dimensional heterogeneous-source model was used to simulate dissolution of organic liquid that was non-uniformly distributed in physically heterogeneous porous media. The permeability field was depicted as a pseudo-homogeneous medium. The source zone was discretized into multiple domains representing different organic-liquid configurations and hydraulic accessibilities, each with a different representative upscaled mass transfer rate coefficient that is temporally variable. This simplified approach represents a system where minimal information is available regarding system heterogeneities. All factors that influence dissolution were incorporated into the calibrated mass transfer terms. The mass transfer terms were calibrated for each zone separately. The one-dimensional, heterogeneous-source model adequately simulated the multi-stage dissolution behavior observed for column-scale systems that were packed with different natural soils, as well as for flow-cell systems wherein the source zone consisted of both a residual zone and pool. The results indicate that the model adequately simulated the presence of multiple organic-liquid zones in porous media with different configurations and hydraulic accessibilities, which accounts for the non-ideal dissolution behavior observed. The calibrated mass transfer terms for each source type were consistent with those obtained for systems that contained only one of either source type.
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Affiliation(s)
- Zhilin Guo
- State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
| | - Ann E Russo
- Environmental Science, University of Arizona, 429 Shantz Building, Tucson, AZ 85721, United States
| | - Erica L DiFilippo
- Hydrology and Atmospheric Sciences, University of Arizona, John W. Harshbarger Building, Tucson, AZ 85721, United States
| | - Zhihui Zhang
- Environmental Science, University of Arizona, 429 Shantz Building, Tucson, AZ 85721, United States
| | - Chunmiao Zheng
- State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Mark L Brusseau
- Environmental Science, University of Arizona, 429 Shantz Building, Tucson, AZ 85721, United States; Hydrology and Atmospheric Sciences, University of Arizona, John W. Harshbarger Building, Tucson, AZ 85721, United States.
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9
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Injection of Zerovalent Iron Gels for Aquifer Nanoremediation: Lab Experiments and Modeling. WATER 2020. [DOI: 10.3390/w12030826] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
One of the main technical problems faced during field-scale injections of iron microparticles (mZVI) for groundwater nanoremediation is related to their poor colloidal stability and mobility in porous media. In this study, a shear-thinning gel, composed of a mixture of two environmentally friendly biopolymers, i.e., guar gum and xanthan gum, was employed to overcome these limitations. The slurry rheology and particle mobility were characterized by column transport tests. Then, a radial transport experiment was performed to mimic the particle delivery in more realistic conditions. The gel, even at a low polymeric content (1.75 g/L), proved effective in enhancing the mobility of high concentrated mZVI suspensions (20 g/L) in field-like conditions. The high radius of influence (73 cm) and homogeneous iron distribution were achieved by maintaining a low injection overpressure (<0.4 bar). Based only on the information derived from column tests, the MNMs 2018 software (Micro- and Nanoparticle transport, filtration, and clogging Model-Suite) was able to predict the particle distribution and pressure build-up measured in the radial domain. Experimental and simulated results showed good agreement, thus proving that a simplified experimental-modeling procedure based on 1D column tests could be used to effectively upscale the slurry behavior to more representative scales, e.g., radial domains.
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10
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Khasi S, Ramezanzadeh M, Ghazanfari MH. Experimentally based pore network modeling of NAPL dissolution process in heterogeneous porous media. JOURNAL OF CONTAMINANT HYDROLOGY 2020; 228:103565. [PMID: 31718908 DOI: 10.1016/j.jconhyd.2019.103565] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 10/15/2019] [Accepted: 10/31/2019] [Indexed: 06/10/2023]
Abstract
Practical designs of non-aqueous phase liquids (NAPLs) remediation strategies require reliable modeling of interphase mass transfer to predict the retraction of NAPL during processes such as dissolution. In this work, the dissolution process of NAPL during two-phase flow in heterogeneous porous media is studied using pore-network modeling and micromodel experiments. A new physical-experimental approach is proposed to enhance the prediction of the dissolution process during modeling of interphase mass transfer. In this regard, the normalized average resident solute concentration is evaluated for describing the dissolution process at pore-level. To incorporate the effect of medium heterogeneities, a new experimental factor is considered for enhancing corner diffusion modeling. In addition, capillary desaturation curves (CDCs) are predicted during hydraulic flow modeling to estimate initial residual NAPL saturation. The developed network model can predict residual NAPL saturations and mass transfer rate coefficient for a NAPL-water system at different injection rates and fluid saturations. The evaluated mass transfer rate coefficients using the proposed physical-experimental approach show a significant improvement compared to either mechanistic or empirical methods. The proposed approach in this study can be attractive for possible applications in commercial simulators of contaminant transport in porous media.
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Affiliation(s)
- Saeid Khasi
- Chemical and Petroleum Engineering Department, Sharif University of Technology, Tehran, Iran
| | - Mehdi Ramezanzadeh
- Chemical and Petroleum Engineering Department, Sharif University of Technology, Tehran, Iran
| | - Mohammad H Ghazanfari
- Chemical and Petroleum Engineering Department, Sharif University of Technology, Tehran, Iran.
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Ramezanzadeh M, Khasi S, Fatemi M, Ghazanfari MH. Remediation of trapped DNAPL enhanced by SDS surfactant and silica nanoparticles in heterogeneous porous media: experimental data and empirical models. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:2658-2669. [PMID: 31836978 DOI: 10.1007/s11356-019-07194-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 11/27/2019] [Indexed: 06/10/2023]
Abstract
The remediation of nonaqueous phase liquids (NAPLs) enhanced by surfactant and nanoparticles (NP) has been investigated in numerous studies. However, the role of NP-assisted surfactants in the dissolution process is still not well discussed. Besides, there is a lack of empirical dissolution models considering the effects of initial residual saturation Strap, NAPL distribution, and surfactant concentration in NAPL-aqueous phase systems. In this work, micromodel experiments are conducted to quantify mass transfer coefficients for different injected aqueous phases including deionized water, SDS surfactant solutions, and NP-assisted solutions with different levels of concentrations and flow rates. Observations reveal that silica nanoparticles (SNP) can significantly enhance interphase mass transfer, while SDS surfactant reduces the mass transfer coefficient. In addition, Strap and intrinsic interfacial area ai, as an indicator of dense nonaqueous phase liquids (DNAPL) distribution, influence the interphase mass transfer. The ai is also independent of DNAPL saturation SNAPL except for SNAPL < 7% when ganglia breakup occurs. Based on these observations, new empirical dissolution models are proposed in the presence and the absence of SDS surfactant and SNP in which ai, Strap, and surfactant concentrations are introduced as new parameters. The evaluated mass transfer rate coefficients using the proposed models show a significant improvement compared to available empirical models. The finding of this study might be attractive for application in field-scale simulations of surfactant-enhanced aquifer remediation (SEAR) and NP-assisted methods.
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Affiliation(s)
- Mehdi Ramezanzadeh
- Chemical and Petroleum Engineering Department, Sharif University of Technology, Azadi Ave, Tehran, Iran
| | - Saeid Khasi
- Chemical and Petroleum Engineering Department, Sharif University of Technology, Azadi Ave, Tehran, Iran
| | - Mobeen Fatemi
- Chemical and Petroleum Engineering Department, Sharif University of Technology, Azadi Ave, Tehran, Iran
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Soil flushing pilot test in a landfill polluted with liquid organic wastes from lindane production. Heliyon 2019; 5:e02875. [PMID: 31768444 PMCID: PMC6872847 DOI: 10.1016/j.heliyon.2019.e02875] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 10/20/2019] [Accepted: 11/14/2019] [Indexed: 11/22/2022] Open
Abstract
Sites contaminated by Dense Non-Aqueous Liquid Phases (DNAPLs) containing chlorinated compounds are a ubiquitous problem caused by spills or the dumping of wastes with no concern for the environment. Their migration by gravity through the subsurface and their accumulation far below ground level make in-situ treatments the most appropriate remediation technologies. In this work, an aqueous solution containing a non-ionic and biodegradable surfactant was injected in the Sardas alluvial layer contaminated at some points with DNAPL (formed by a mixture of more than 28 chlorinated compounds) from lindane production. A volume of 5.28 m3 of an aqueous surfactant emulsion (13 g L-1) was injected at 14.5 m b g.l in the permeable layer (gravel-sand), at a flow rate of 0.6 m3 h-1 and the groundwater was monitored within a test cell (3.5 m radius) built ad hoc. The flow of the injected fluids in the subsurface was also evaluated using a conservative tracer, bromide (130 mg L-1), added to the surfactant solution. Concentration of contaminants, chloride, bromide and surfactant, surface tension and conductivity were measured at the injection point and at three monitoring points over time. High radial dispersion was noticed resulting in high dilution of the injected fluids. The surfactant was not adsorbed in the soil during the injection time, the adsorption of the surfactant took place in the meantime (15 h) between its injection and the groundwater (GW) extraction. The concentration of chlorinated compounds dissolved from the soil in the surfactant aqueous phase when equilibrium was reached (about 850 mg L-1) is related to the moderate average contamination of the soil in the test cell (about 1230 mg kg-1). In contrast, the extraction of the free DNAPL in the altered marls layer was highly enhanced due to the addition of the surfactant. Finally, it was found that the surfactant and the contamination did not migrate from the capture zone.
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Quantification of Uncertainties from Image Processing and Analysis in Laboratory-Scale DNAPL Release Studies Evaluated by Reflective Optical Imaging. WATER 2019. [DOI: 10.3390/w11112274] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Subsurface DNAPL (dense non-aqueous phase liquid) contamination from (un-) intentional spilling typically leads to severe environmental hazards. A large number of studies have demonstrated the relevance of DNAPL source zone geometry for the determination of contaminant plume propagation in groundwater. Optical imaging represents a promising non-invasive method for identifying DNAPL saturation without disturbing multiphase flow dynamics. However, workflow and image analysis methodologies have not been sufficiently developed or described for general application to related experimental efforts. For example, the choice of dye(s) used for phase colorization affects image processing and can bias final estimations of DNAPL saturations. In this study, we perform a series of DNAPL migration and entrapment studies in transparent tanks that are filled with three different types of porous media. Different dyes are used and raw images are acquired. Subsequently, these are used to evaluate a suite of image processing and analysis approaches, which are organized into a workflow. Our approach allows for us to identify key image processing and analysis steps that introduce the most error. Applicable dye configurations led to uncertainties of up to 41% depending on the selection of processing steps. Based on these findings, it was possible to delineate a flexible framework for image processing and analysis that has the potential for transfer and application in other tank experiment setups.
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Luciano A, Mancini G, Torretta V, Viotti P. An empirical model for the evaluation of the dissolution rate from a DNAPL-contaminated area. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:33992-34004. [PMID: 30280338 DOI: 10.1007/s11356-018-3193-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 09/11/2018] [Indexed: 06/08/2023]
Abstract
This paper investigates dynamic variation in the morphologic distribution of dense non-aqueous phase liquids (DNAPLs), which take into account the coupled mass transfer. Experiments were carried out in a 2D tank representing a reconstructed aquifer model. DNAPL dissolution rates were investigated over a wide range of DNAPL saturations, several source configurations, and different hydraulic conditions. Morphometric indexes are presented that take into consideration further factors affecting the dissolution process. Local information regarding transport parameters related to the characteristics of the medium was obtained through a neural network and an optimization algorithm applied to experimental tracer tests. The history of DNAPL source architecture, in terms of saturation, indentation grade, and orientation, was determined by image analysis. Dissolved concentrations were registered and mass transfer rate coefficients were obtained for a wide range of source-zone configurations. A statistical analysis was performed to develop a constitutive equation that is descriptive of the mass transfer rate as a function of source-zone metric characteristics. A new empirical dissolution model using the proposed morphometric parameters is presented and compared with other models. The mass transfer correlation reported incorporates morphometric parameters and considers the complex and variable architecture of non-miscible contaminants. The proposed correlation can be used for an initial assessment of non-aqueous phase liquid (NAPL) dissolution rates over a wide range of saturation (residual and non-residual) conditions and different aqueous phase velocities within the NAPL source zone.
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Affiliation(s)
- Antonella Luciano
- Department for Sustainability, ENEA-Italian National Agency for the New Technologies, Energy and Sustainable Economic Development-Casaccia Research Centre, Via Anguillarese 301, I 00123, Rome, Italy.
| | - Giuseppe Mancini
- Department of Electrıcal Electronıc and Computer Engıneerıng, University of Catania, Viale Andrea Doria 6, I 95125, Catania, Italy
| | - Vincenzo Torretta
- Department of Theoretical and Applied Sciences, University of Insubria, via GB Vico 46, I-21100, Varese, Italy
| | - Paolo Viotti
- Department of Civil, Construction and Environmental Engineering (DICEA), Sapienza University of Rome, Via Eudossiana 18, I-00184, Rome, Italy
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