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Falciglia PP, Gagliano E, Scandura P, Bianco C, Tosco T, Sethi R, Varvaro G, Agostinelli E, Bongiorno C, Russo A, Romano S, Malandrino G, Roccaro P, Vagliasindi FG. Physico-magnetic properties and dynamics of magnetite (Fe3O4) nanoparticles (MNPs) under the effect of permanent magnetic fields in contaminated water treatment applications. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.121342] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Maamoun I, Bensaida K, Eljamal R, Falyouna O, Tanaka K, Tosco T, Sugihara Y, Eljamal O. Rapid and efficient chromium (VI) removal from aqueous solutions using nickel hydroxide nanoplates (nNiHs). J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119216] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Beryani A, Bianco C, Casasso A, Sethi R, Tosco T. Exploring the potential of graphene oxide nanosheets for porous media decontamination from cationic dyes. J Hazard Mater 2022; 424:127468. [PMID: 34688001 DOI: 10.1016/j.jhazmat.2021.127468] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/15/2021] [Accepted: 10/06/2021] [Indexed: 06/13/2023]
Abstract
Graphene oxide (GO) nanosheets, often embedded in nano-composites, have been studied as promising materials for waste water purification, in particular to adsorb heavy metals and cationic organic contaminants. However, a broader range of potential applications of GO is still unexplored. This work investigated the potential applicability of GO for enhanced in-situ soil washing of secondary sources of groundwater contamination (i.e. the controlled recirculation of a washing GO suspension via injection/extraction wells). The laboratory study aimed at quantifying the capability of GO to effectively remove adsorbed methylene blue (MB) from contaminated sand. The tests were conducted in simplified conditions (synthetic groundwater at NaCl concentration of 20 mM, silica sand) to better highlight the key mechanisms under study. The results indicated a maximum sorption capacity of 1.6 mgMB/mgGO in moderately alkaline conditions. Even though the adsorption of MB onto GO slightly reduced the GO mobility in the porous medium, a breakthrough higher than 95% was obtained for MB/GO mass ratios up to 0.5. This suggests that a very high recovery of the injected particles should be also expected in the field.
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Affiliation(s)
- Ali Beryani
- Department of Environmental, Land and Infrastructure Engineering (DIATI), Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy)
| | - Carlo Bianco
- Department of Environmental, Land and Infrastructure Engineering (DIATI), Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy)
| | - Alessandro Casasso
- Department of Environmental, Land and Infrastructure Engineering (DIATI), Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy)
| | - Rajandrea Sethi
- Department of Environmental, Land and Infrastructure Engineering (DIATI), Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy)
| | - Tiziana Tosco
- Department of Environmental, Land and Infrastructure Engineering (DIATI), Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy).
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Granetto M, Serpella L, Fogliatto S, Re L, Bianco C, Vidotto F, Tosco T. Natural clay and biopolymer-based nanopesticides to control the environmental spread of a soluble herbicide. Sci Total Environ 2022; 806:151199. [PMID: 34699829 DOI: 10.1016/j.scitotenv.2021.151199] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 09/16/2021] [Accepted: 10/20/2021] [Indexed: 06/13/2023]
Abstract
In this work a novel nano-formulation is proposed to control leaching and volatilization of a broadly used herbicide, dicamba. Dicamba is subject to significant leaching in soils, due to its marked solubility, and to significant volatilization and vapor drift, with consequent risks for operators and neighbouring crops. Natural, biocompatible, low-cost materials were employed to control its dispersion in the environment: among four tested candidate carriers, a nanosized natural clay (namely, K10 montmorillonite) was selected to adsorb the pesticide, and carboxymethyl cellulose (CMC), a food-grade biodegradable polymer, was employed as a coating agent. The synthesis approach is based on direct adsorption at ambient temperature and pressure, with a subsequent particle coating to increase suspension stability and control pesticide release. The nano-formulation showed a controlled release when diluted to field-relevant concentrations: in tap water, the uncoated K10 released approximately 45% of the total loaded dicamba, and the percentage reduced to less than 30% with coating. CMC also contributed to significantly reduce dicamba losses due to volatilization from treated soils (e.g., in medium sand, 9.3% of dicamba was lost in 24 h from the commercial product, 15.1% from the uncoated nanoformulation, and only 4.5% from the coated one). Moreover, the coated nanoformulation showed a dramatic decrease in mobility in porous media (when injected in a 11.6 cm sand-packed column, 99.3% of the commercial formulation was eluted, compared to 88.4% of the uncoated nanoformulation and only 24.5% of the coated one). Greenhouse tests indicated that the clay-based nanoformulation does not hinder the dicamba efficacy toward target weeds, even though differences were observed depending on the treated species. Despite the small (lab and greenhouse) scale of the tests, these preliminary results suggest a good efficacy of the proposed nanoformulation in controlling the environmental spreading of dicamba, without hindering efficacy toward target species.
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Affiliation(s)
- Monica Granetto
- Department of Environmental, Land and Infrastructure Engineering (DIATI), Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Luca Serpella
- Department of Environmental, Land and Infrastructure Engineering (DIATI), Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Silvia Fogliatto
- Department of Agricultural, Forest and Food Sciences (DISAFA), University of Torino, Largo Paolo Braccini 2, 10095 Grugliasco, TO, Italy
| | - Lucia Re
- Department of Environmental, Land and Infrastructure Engineering (DIATI), Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Carlo Bianco
- Department of Environmental, Land and Infrastructure Engineering (DIATI), Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Francesco Vidotto
- Department of Agricultural, Forest and Food Sciences (DISAFA), University of Torino, Largo Paolo Braccini 2, 10095 Grugliasco, TO, Italy
| | - Tiziana Tosco
- Department of Environmental, Land and Infrastructure Engineering (DIATI), Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy.
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Bueno V, Bosi A, Tosco T, Ghoshal S. Mobility of solid and porous hollow SiO 2 nanoparticles in saturated porous media: Impacts of surface and particle structure. J Colloid Interface Sci 2021; 606:480-490. [PMID: 34399364 DOI: 10.1016/j.jcis.2021.07.142] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 07/22/2021] [Accepted: 07/28/2021] [Indexed: 01/05/2023]
Abstract
Silica nanoparticles (SiO2 NPs) are of increasing interest in nano-enabled agriculture, particularly as nanocarriers for the targeted delivery of agrochemicals. Their direct application in agricultural soils may lead to the release of SiO2 NPs in the environment. Although some studies have investigated transport of solid SiO2 NPs in porous media, there is a knowledge gap on how different SiO2 NP structures incorporating significant porosities can affect the mobility of such particles under different conditions. Herein, we investigated the effect of pH and ionic strength (IS) on the transport of two distinct structures of SiO2 NPs, namely solid SiO2 NPs (SSNs) and porous hollow SiO2 NPs (PHSNs), of comparable sizes (~200 nm). Decreasing pH and increasing ionic strength reduced the mobility of PHSNs in sand-packed columns more significantly than for SSNs. The deposition of PHSNs was approximately 3 times greater than that of SSNs at pH 4.5 and IS 100 mM. The results are non-intuitive given that PHSNs have a lower density and the same chemical composition of SSNs but can be explained by the greater surface roughness and ten-fold greater specific surface area of PHSNs, and their impacts on van der Waals and electrostatic interaction energies.
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Affiliation(s)
- Vinicius Bueno
- Department of Civil Engineering, McGill University, Montreal, Quebec H3A 0C3, Canada
| | - Alessandro Bosi
- Department of Environment, Land and Infrastructure Engineering (DIATI), Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Tiziana Tosco
- Department of Environment, Land and Infrastructure Engineering (DIATI), Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Subhasis Ghoshal
- Department of Civil Engineering, McGill University, Montreal, Quebec H3A 0C3, Canada.
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Mohammadian S, Krok B, Fritzsche A, Bianco C, Tosco T, Cagigal E, Mata B, Gonzalez V, Diez-Ortiz M, Ramos V, Montalvo D, Smolders E, Sethi R, Meckenstock RU. Field-scale demonstration of in situ immobilization of heavy metals by injecting iron oxide nanoparticle adsorption barriers in groundwater. J Contam Hydrol 2021; 237:103741. [PMID: 33341658 DOI: 10.1016/j.jconhyd.2020.103741] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 10/11/2020] [Accepted: 11/15/2020] [Indexed: 06/12/2023]
Abstract
Remediation of heavy metal-contaminated aquifers is a challenging process because they cannot be degraded by microorganisms. Together with the usually limited effectiveness of technologies applied today for treatment of heavy metal contaminated groundwater, this creates a need for new remediation technologies. We therefore developed a new treatment, in which permeable adsorption barriers are established in situ in aquifers by the injection of colloidal iron oxides. These adsorption barriers aim at the immobilization of heavy metals in aquifers groundwater, which was assessed in a large-scale field study in a brownfield site. Colloidal iron oxide (goethite) nanoparticles were used to install an in situ adsorption barrier in a very heterogeneous, contaminated aquifer of a brownfield in Asturias, Spain. The groundwater contained high concentrations of heavy metals with up to 25 mg/L zinc, 1.3 mg/L lead, 40 mg/L copper, 0.1 mg/L nickel and other minor heavy metal pollutants below 1 mg/L. High amounts of zinc (>900 mg/kg), lead (>2000 mg/kg), nickel (>190 mg/kg) were also present in the sediment. Ca. 1500 kg of goethite nanoparticles of 461 ± 266 nm diameter were injected at low pressure (< 0.6 bar) into the aquifer through nine screened injection wells. For each injection well, a radius of influence of at least 2.5 m was achieved within 8 h, creating an in situ barrier of 22 × 3 × 9 m. Despite the extremely high heavy metal contamination and the strong heterogeneity of the aquifer, successful immobilization of contaminants was observed in the tested area. The contaminant concentrations were strongly reduced immediately after the injection and the abatement of the heavy metals continued for a total post-injection monitoring period of 189 days. The iron oxide particles were found to adsorb heavy metals even at pH-values between 4 and 6, where low adsorption would have been expected. The study demonstrated the applicability of iron oxide nanoparticles for installing adsorption barriers for containment of heavy metals in contaminated groundwater under real conditions.
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Affiliation(s)
- Sadjad Mohammadian
- Environmental Microbiology and Biotechnology, University Duisburg-Essen, Universitätstr. 5, 45141 Essen, Germany
| | - Beate Krok
- Environmental Microbiology and Biotechnology, University Duisburg-Essen, Universitätstr. 5, 45141 Essen, Germany
| | - Andreas Fritzsche
- Institute of Geosciences, Friedrich Schiller University Jena, Burgweg 11, 07749 Jena, Germany
| | - Carlo Bianco
- Department of Environmental, Land and Infrastructure Engineering, Politecnico di Torino, Corso Duca degli Abruzzi, 24, 10129 Turin, Italy
| | - Tiziana Tosco
- Department of Environmental, Land and Infrastructure Engineering, Politecnico di Torino, Corso Duca degli Abruzzi, 24, 10129 Turin, Italy
| | - Ekain Cagigal
- TECNALIA, Basque Research and Technology Alliance (BRTA), Parque Científico y Tecnológico de Bizkaia, Astondo bidea, Edificio 700, 48160 Derio (Bizkaia), Spain
| | - Bruno Mata
- Geoplano Consultores, S.A, Zona Industrial de Casais da Serra, Lote 10, 2665-305 Mafra, Portugal
| | - Veronica Gonzalez
- LEITAT Technological Center, Carrer de Pallars, 179-185, 08005 Barcelona, Spain
| | - Maria Diez-Ortiz
- LEITAT Technological Center, Carrer de Pallars, 179-185, 08005 Barcelona, Spain
| | - Vanesa Ramos
- Knowledge Innovation Market - KIM, Carrer de Pallars, 179-185, 08005 Barcelona, Spain
| | - Daniela Montalvo
- Division of Soil and Water Management, KU Leuven, Kasteelpark Arenberg 20, 3001 Leuven, Belgium
| | - Erik Smolders
- Division of Soil and Water Management, KU Leuven, Kasteelpark Arenberg 20, 3001 Leuven, Belgium
| | - Rajandrea Sethi
- Department of Environmental, Land and Infrastructure Engineering, Politecnico di Torino, Corso Duca degli Abruzzi, 24, 10129 Turin, Italy
| | - Rainer U Meckenstock
- Environmental Microbiology and Biotechnology, University Duisburg-Essen, Universitätstr. 5, 45141 Essen, Germany.
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Beryani A, Alavi Moghaddam MR, Tosco T, Bianco C, Hosseini SM, Kowsari E, Sethi R. Key factors affecting graphene oxide transport in saturated porous media. Sci Total Environ 2020; 698:134224. [PMID: 31493572 DOI: 10.1016/j.scitotenv.2019.134224] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 07/05/2019] [Accepted: 08/31/2019] [Indexed: 06/10/2023]
Abstract
This study focuses on the transport in porous media of graphene oxide nanoparticles (GONP) under conditions similar to those applied in the generation of in-situ reactive zones for groundwater remediation (i.e. GO concentration of few tens of mg/l, stable suspension in alkaline solution). The experimental tests evaluated the influence on GO transport of three key factors, namely particle size (300-1200 nm), concentration (10-50 mg/L), and sand size (coarse to fine). Three sources of GONP were considered (two commercial and one synthesized in the laboratory). Particles were stably dispersed in water at pH 8.5 and showed a good mobility in the porous medium under all experimental conditions: after injection of 5 pore volumes and flushing, the highest recovery was around 90%, the lowest around 30% (only for largest particles in fine sand). The particle size was by far the most impacting parameter, with increasing mobility with decreasing size, even if sand size and particle concentration were also relevant. The source of GONP showed a minor impact on the mobility. The transport test data were successfully modeled using the advection-dispersion-deposition equations typically applied for spherical colloids. Experimental and modeling results suggested that GONP, under the explored conditions, are retained due to both blocking and straining, the latter being relevant only for large particles and/or fine sand. The findings of this study play a key role in the development of an in-situ groundwater remediation technology based on the injection of GONP for contaminant degradation or sorption. Despite their peculiar shape, GONP behavior in porous media is comparable with spherical colloids, which have been more studied by far. In particular, the possibility of modeling GONP transport using existing models ensures that they can be applied also for the design of field-scale injections of GONP, similarly to other particles already used in nanoremediation.
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Affiliation(s)
- Ali Beryani
- Civil & Environmental Engineering Department (CEE), Amirkabir University of Technology (Tehran Polytechnic), Hafez Ave., 424, 15875-4413 Tehran, Iran
| | - Mohammad Reza Alavi Moghaddam
- Civil & Environmental Engineering Department (CEE), Amirkabir University of Technology (Tehran Polytechnic), Hafez Ave., 424, 15875-4413 Tehran, Iran.
| | - Tiziana Tosco
- Department of Environmental, Land and Infrastructure Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24. 10129 Torino, Italy
| | - Carlo Bianco
- Department of Environmental, Land and Infrastructure Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24. 10129 Torino, Italy
| | - Seiyed Mossa Hosseini
- Physical Geography Department, University of Tehran, 16th Azar St., Enghelab Sq, 14155-6465 Tehran, Iran
| | - Elaheh Kowsari
- Department of Chemistry, Amirkabir University of Technology (Tehran Polytechnic), Hafez Ave., 424, 15875-4413 Tehran, Iran
| | - Rajandrea Sethi
- Department of Environmental, Land and Infrastructure Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24. 10129 Torino, Italy
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Tosco T, Sethi R. Human health risk assessment for nanoparticle-contaminated aquifer systems. Environ Pollut 2018; 239:242-252. [PMID: 29656248 DOI: 10.1016/j.envpol.2018.03.041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 03/08/2018] [Accepted: 03/13/2018] [Indexed: 06/08/2023]
Abstract
Nanosized particles (NPs), such as TiO2, Silver, graphene NPs, nanoscale zero-valent iron, carbon nanotubes, etc., are increasingly used in industrial processes, and releases at production plants and from landfills are likely scenarios for the next years. As a consequence, appropriate procedures and tools to quantify the risks for human health associated to these releases are needed. The tiered approach of the standard ASTM procedure (ASTM-E2081-00) is today the most applied for human health risk assessment at sites contaminated by chemical substances, but it cannot be directly applied to nanoparticles: NP transport along migration pathways follows mechanisms significantly different from those of chemicals; moreover, also toxicity indicators (namely, reference dose and slope factor) are NP-specific. In this work a risk assessment approach modified for NPs is proposed, with a specific application at Tier 2 to migration in groundwater. The standard ASTM equations are modified to include NP-specific transport mechanisms. NPs in natural environments are typically characterized by a heterogeneous set of NPs having different size, shape, coating, etc. (all properties having a significant impact on both mobility and toxicity). To take into account this heterogeneity, the proposed approach divides the NP population into classes, each having specific transport and toxicity properties, and simulates them as independent species. The approach is finally applied to a test case simulating the release of heterogeneous Silver NPs from a landfill. The results show that taking into account the size-dependent mobility of the particles provides a more accurate result compared to the direct application of the standard ASTM procedure. In particular, the latter tends to underestimate the overall toxic risk associated to the nP release.
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Affiliation(s)
- Tiziana Tosco
- DIATI - Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture - Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129, Torino, Italy
| | - Rajandrea Sethi
- DIATI - Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture - Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129, Torino, Italy.
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Crevacore E, Tosco T, Sethi R, Boccardo G, Marchisio DL. Recirculation zones induce non-Fickian transport in three-dimensional periodic porous media. Phys Rev E 2016; 94:053118. [PMID: 27967112 DOI: 10.1103/physreve.94.053118] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Indexed: 06/06/2023]
Abstract
In this work, the influence of pore space geometry on solute transport in porous media is investigated performing computational fluid dynamics pore-scale simulations of fluid flow and solute transport. The three-dimensional periodic domains are obtained from three different pore structure configurations, namely, face-centered-cubic (fcc), body-centered-cubic (bcc), and sphere-in-cube (sic) arrangements of spherical grains. Although transport simulations are performed with media having the same grain size and the same porosity (in fcc and bcc configurations), the resulting breakthrough curves present noteworthy differences, such as enhanced tailing. The cause of such differences is ascribed to the presence of recirculation zones, even at low Reynolds numbers. Various methods to readily identify recirculation zones and quantify their magnitude using pore-scale data are proposed. The information gained from this analysis is then used to define macroscale models able to provide an appropriate description of the observed anomalous transport. A mass transfer model is applied to estimate relevant macroscale parameters (hydrodynamic dispersion above all) and their spatial variation in the medium; a functional relation describing the spatial variation of such macroscale parameters is then proposed.
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Affiliation(s)
- Eleonora Crevacore
- Department of Environment, Land and Infrastructures, Politecnico di Torino, 10129 Torino, Italy
| | - Tiziana Tosco
- Department of Environment, Land and Infrastructures, Politecnico di Torino, 10129 Torino, Italy
| | - Rajandrea Sethi
- Department of Environment, Land and Infrastructures, Politecnico di Torino, 10129 Torino, Italy
| | - Gianluca Boccardo
- Department of Applied Science and Technology, Politecnico di Torino, 10129 Torino, Italy
| | - Daniele L Marchisio
- Department of Applied Science and Technology, Politecnico di Torino, 10129 Torino, Italy
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Bianco C, Tosco T, Sethi R. A 3-dimensional micro- and nanoparticle transport and filtration model (MNM3D) applied to the migration of carbon-based nanomaterials in porous media. J Contam Hydrol 2016; 193:10-20. [PMID: 27607520 DOI: 10.1016/j.jconhyd.2016.08.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 08/13/2016] [Accepted: 08/18/2016] [Indexed: 06/06/2023]
Abstract
Engineered nanoparticles (NPs) in the environment can act both as contaminants, when they are unintentionally released, and as remediation agents when injected on purpose at contaminated sites. In this work two carbon-based NPs are considered, namely CARBO-IRON®, a new material developed for contaminated site remediation, and single layer graphene oxide (SLGO), a potential contaminant of the next future. Understanding and modeling the transport and deposition of such NPs in aquifer systems is a key aspect in both cases, and numerical models capable to simulate NP transport in groundwater in complex 3D scenarios are necessary. To this aim, this work proposes a modeling approach based on modified advection-dispersion-deposition equations accounting for the coupled influence of flow velocity and ionic strength on particle transport. A new modeling tool (MNM3D - Micro and Nanoparticle transport Model in 3D geometries) is presented for the simulation of NPs injection and transport in 3D scenarios. MNM3D is the result of the integration of the numerical code MNMs (Micro and Nanoparticle transport, filtration and clogging Model - Suite) in the well-known transport model RT3D (Clement et al., 1998). The injection in field-like conditions of CARBO-IRON® (20g/l) amended by CMC (4g/l) in a 2D vertical tank (0.7×1.0×0.12m) was simulated using MNM3D, and compared to experimental results under the same conditions. Column transport tests of SLGO at a concentration (10mg/l) representative of a possible spill of SLGO-containing waste water were performed at different values of ionic strength (0.1 to 35mM), evidencing a strong dependence of SLGO transport on IS, and a reversible blocking deposition. The experimental data were fitted using the numerical code MNMs and the ionic strength-dependent transport was up-scaled for a full scale 3D simulation of SLGO release and long-term transport in a heterogeneous aquifer. MNM3D showed to potentially represent a valid tool for the prediction of the long-term behavior of engineered nanoparticles released in the environment (e.g. from landfills), and the preliminary design of in situ aquifer remediation through injection of suspensions of reactive NPs.
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Affiliation(s)
- Carlo Bianco
- Politecnico di Torino, DIATI, C.so Duca degli Abruzzi 24, 10129 Torino, Italy.
| | - Tiziana Tosco
- Politecnico di Torino, DIATI, C.so Duca degli Abruzzi 24, 10129 Torino, Italy.
| | - Rajandrea Sethi
- Politecnico di Torino, DIATI, C.so Duca degli Abruzzi 24, 10129 Torino, Italy.
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Luna M, Gastone F, Tosco T, Sethi R, Velimirovic M, Gemoets J, Muyshondt R, Sapion H, Klaas N, Bastiaens L. Pressure-controlled injection of guar gum stabilized microscale zerovalent iron for groundwater remediation. J Contam Hydrol 2015; 181:46-58. [PMID: 25971233 DOI: 10.1016/j.jconhyd.2015.04.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 04/15/2015] [Accepted: 04/19/2015] [Indexed: 06/04/2023]
Abstract
The paper reports a pilot injection test of microsized zerovalent iron (mZVI) dispersed in a guar gum shear thinning solution. The test was performed in the framework of the EU research project AQUAREHAB in a site in Belgium contaminated by chlorinated aliphatic hydrocarbons (CAHs). The field application was aimed to overcome those critical aspects which hinder mZVI field injection, mainly due to the colloidal instability of ZVI-based suspensions. The iron slurry properties (iron particles size and concentration, polymeric stabilizer type and concentration, slurry viscosity) were designed in the laboratory based on several tests (reactivity tests towards contaminants, sedimentation tests and rheological measurements). The particles were delivered into the aquifer through an injection well specifically designed for controlled-pressure delivery (approximately 10 bars). The well characteristics and the critical pressure of the aquifer (i.e. the injection pressure above which fracturing occurs) were assessed via two innovative injection step rate tests, one performed with water and the other one with guar gum. Based on laboratory and field preliminary tests, a flow regime at the threshold between permeation and preferential flow was selected for mZVI delivery, as a compromise between the desired homogeneous distribution of the mZVI around the injection point (ensured by permeation flow) and the fast and effective injection of the slurry (guaranteed by high discharge rates and injection pressure, resulting in the generation of preferential flow paths). A monitoring setup was designed and installed for the real-time monitoring of relevant parameters during injection, and for a fast determination of the spatial mZVI distribution after injection via non-invasive magnetic susceptibility measurements.
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Affiliation(s)
- M Luna
- Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture-Politecnico di Torino, corso Duca degli Abruzzi 24, 10129 Torino, Italy
| | - F Gastone
- Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture-Politecnico di Torino, corso Duca degli Abruzzi 24, 10129 Torino, Italy
| | - T Tosco
- Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture-Politecnico di Torino, corso Duca degli Abruzzi 24, 10129 Torino, Italy
| | - R Sethi
- Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture-Politecnico di Torino, corso Duca degli Abruzzi 24, 10129 Torino, Italy.
| | - M Velimirovic
- VITO, Boeretang 200, 2400 Mol, Belgium; Department of Environmental Geosciences, University of Wien, Althanstrasse 14, 1090 Wien, Austria
| | - J Gemoets
- VITO, Boeretang 200, 2400 Mol, Belgium
| | | | - H Sapion
- SAPION, Oude Bevelsesteenweg 51, 2560 Nijlen, Belgium
| | - N Klaas
- VEGAS, University of Stuttgart, Pfaffenwaldring 61, 70569 Stuttgart, Germany
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Hosseini SM, Tosco T. Integrating NZVI and carbon substrates in a non-pumping reactive wells array for the remediation of a nitrate contaminated aquifer. J Contam Hydrol 2015; 179:182-195. [PMID: 26142547 DOI: 10.1016/j.jconhyd.2015.06.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Revised: 05/19/2015] [Accepted: 06/22/2015] [Indexed: 06/04/2023]
Abstract
The work explores the efficacy of a biochemical remediation of a nitrate-contaminated aquifer by a combination of nanoscale zero-valent iron (NZVI) and bacteria supported by carbon substrates. Nitrate removal was first assessed in batch tests, and then in a laboratory bench-scale aquifer model (60cm length×40cm width×50cm height), in which a background flow was maintained. Water and natural sandy material of a stratified aquifer were used in the tests to enhance the reliability of the results. An array of non-pumping-reactive wells (NPRWs) filled with NZVI (d50=50nm, and SSA=22.5m(2)/g) mixed with carbon substrates (beech sawdust and maize cobs) was installed in the bench-scale aquifer model to intercept the flow and remove nitrate (NO3(-) conc.=105mg/l). The NPRW array was preferred to a continuous permeable reactive barrier (PRB) since wells can be drilled at greater depths compared to PRBs. The optimal well diameter, spacing among the NPRWs and number of wells in the bench-scale model were designed based on flow simulations using the semi-analytical particle tracking (advection) model, PMPATH. An optimal configuration of four wells, 35mm diameter, and capture width of 1.8 times the well diameter was obtained for a hydraulic conductivity contrast between reactive materials in the wells and aquifer media (KPM/Kaq=16.5). To avoid excessive proximity between wells, the system was designed so that the capture of the contaminated water was not complete, and several sequential arrays of wells were preferred. To simulate the performance of the array, the water that passed through the bench-scale NPRW system was re-circulated to the aquifer inlet, and a nitrate degradation below the limit target concentration (10mg/l) was obtained after 13days (corresponding to 13 arrays of wells in the field). The results of this study demonstrated that using the NZVI-mixed-carbon substrates in the NPRW system has a great potential for in-situ nitrate reduction in contaminated groundwater. This NPRW system can be considered a promising and viable technology in deep aquifers.
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Affiliation(s)
- Seiyed Mossa Hosseini
- Natural Geography Department, University of Tehran, Tehran, P.O. Box: 14155-6465, Iran.
| | - Tiziana Tosco
- Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture, Politecnico di Torino, Torino, Italy
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Flores Orozco A, Velimirovic M, Tosco T, Kemna A, Sapion H, Klaas N, Sethi R, Bastiaens L. Monitoring the injection of microscale zerovalent iron particles for groundwater remediation by means of complex electrical conductivity imaging. Environ Sci Technol 2015; 49:5593-5600. [PMID: 25884287 DOI: 10.1021/acs.est.5b00208] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The injection of microscale zerovalent iron (mZVI) particles for groundwater remediation has received much interest in recent years. However, to date, monitoring of mZVI particle injection is based on chemical analysis of groundwater and soil samples and thus might be limited in its spatiotemporal resolution. To overcome this deficiency, in this study, we investigate the application of complex electrical conductivity imaging, a geophysical method, to monitor the high-pressure injection of mZVI in a field-scale application. The resulting electrical images revealed an increase in the induced electrical polarization (∼20%), upon delivery of ZVI into the targeted area, due to the accumulation of metallic surfaces at which the polarization takes place. Furthermore, larger changes (>50%) occurred in shallow sediments, a few meters away from the injection, suggesting the migration of particles through preferential flowpaths. Correlation of the electrical response and geochemical data, in particular the analysis of recovered cores from drilling after the injection, confirmed the migration of particles (and stabilizing solution) to shallow areas through fractures formed during the injection. Hence, our results demonstrate the suitability of the complex conductivity imaging method to monitor the transport of mZVI during subsurface amendment in quasi real-time.
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Affiliation(s)
- Adrián Flores Orozco
- †Geophysics Research Group, Vienna University of Technology, Gusshausstraße 27-29, E120-3, 1040 Vienna, Austria
| | - Milica Velimirovic
- ‡Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol, Belgium
- §Department of Environmental Geosciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Tiziana Tosco
- ⊥DIATI-Dipartimento di Ingegneria del Territorio, dell'Ambiente e delle Infrastrutture, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Andreas Kemna
- ¶Department of Geophysics, Steinmann Institute, University of Bonn, Meckenheimer Allee 176, 53115 Bonn, Germany
| | - Hans Sapion
- ∥SAPION, Oude Bevelsesteenweg 51, 2560 Nijlen, Belgium
| | - Norbert Klaas
- #VEGAS, University of Stuttgart, Pfaffenwaldring 61, 70569 Stuttgart, Germany
| | - Rajandrea Sethi
- ⊥DIATI-Dipartimento di Ingegneria del Territorio, dell'Ambiente e delle Infrastrutture, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Leen Bastiaens
- ‡Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol, Belgium
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Gastone F, Tosco T, Sethi R. Guar gum solutions for improved delivery of iron particles in porous media (part 1): porous medium rheology and guar gum-induced clogging. J Contam Hydrol 2014; 166:23-33. [PMID: 25065767 DOI: 10.1016/j.jconhyd.2014.06.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 06/26/2014] [Accepted: 06/27/2014] [Indexed: 06/03/2023]
Abstract
The present work is the first part of a comprehensive study on the use of guar gum to improve delivery of microscale zero-valent iron particles in contaminated aquifers. Guar gum solutions exhibit peculiar shear thinning properties, with high viscosity in static conditions and lower viscosity in dynamic conditions: this is beneficial both for the storage of MZVI dispersions, and also for the injection in porous media. In the present paper, the processes associated with guar gum injection in porous media are studied performing single-step and multi-step filtration tests in sand-packed columns. The experimental results of single-step tests performed by injecting guar gum solutions prepared at several concentrations and applying different dissolution procedures evidenced that the presence of residual undissolved polymeric particles in the guar gum solution may have a relevant negative impact on the permeability of the porous medium, resulting in evident clogging. The most effective preparation procedure which minimizes the presence of residual particles is dissolution in warm water (60°C) followed by centrifugation (procedure T60C). The multi-step tests (i.e. injection of guar gum at constant concentration with a step increase of flow velocity), performed at three polymer concentrations (1.5, 3 and 4g/l) provided information on the rheological properties of guar gum solutions when flowing through a porous medium at variable discharge rates, which mimic the injection in radial geometry. An experimental protocol was defined for the rheological characterization of the fluids in porous media, and empirical relationships were derived for the quantification of rheological properties and clogging with variable injection rate. These relationships will be implemented in the second companion paper (Part II) in a radial transport model for the simulation of large-scale injection of MZVI-guar gum slurries.
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Affiliation(s)
- Francesca Gastone
- DIATI - Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Tiziana Tosco
- DIATI - Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Rajandrea Sethi
- DIATI - Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy.
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Tosco T, Gastone F, Sethi R. Guar gum solutions for improved delivery of iron particles in porous media (part 2): iron transport tests and modeling in radial geometry. J Contam Hydrol 2014; 166:34-51. [PMID: 25063698 DOI: 10.1016/j.jconhyd.2014.06.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 06/26/2014] [Accepted: 06/27/2014] [Indexed: 06/03/2023]
Abstract
In the present work column transport tests were performed in order to study the mobility of guar-gum suspensions of microscale zero-valent iron particles (MZVI) in porous media. The results were analyzed with the purpose of implementing a radial model for the design of full scale interventions. The transport tests were performed using several concentrations of shear thinning guar gum solutions as stabilizer (1.5, 3 and 4g/l) and applying different flow rates (Darcy velocity in the range 1·10(-4) to 2·10(-3)m/s), representative of different distances from the injection point in the radial domain. Empirical relationships, expressing the dependence of the deposition and release parameters on the flow velocity, were derived by inverse fitting of the column transport tests using a modified version of E-MNM1D (Tosco and Sethi, 2010) and the user interface MNMs (www.polito.it/groundwater/software). They were used to develop a comprehensive transport model of MZVI suspensions in radial coordinates, called E-MNM1R, which takes into account the non Newtonian (shear thinning) rheological properties of the dispersant fluid and the porous medium clogging associated with filtration and sedimentation in the porous medium of both MZVI and guar gum residual undissolved particles. The radial model was run in forward mode to simulate the injection of MZVI dispersed in guar gum in conditions similar to those applied in the column transport tests. In a second stage, we demonstrated how the model can be used as a valid tool for the design and the optimization of a full scale intervention. The simulation results indicated that several concurrent aspects are to be taken into account for the design of a successful delivery of MZVI/guar gum slurries via permeation injection, and a compromise is necessary between maximizing the radius of influence of the injection and minimizing the injection pressure, to guarantee a sufficiently homogeneous distribution of the particles around the injection point and to prevent preferential flow paths.
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Affiliation(s)
- Tiziana Tosco
- DIATI - Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture - Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Francesca Gastone
- DIATI - Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture - Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Rajandrea Sethi
- DIATI - Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture - Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy.
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Velimirovic M, Tosco T, Uyttebroek M, Luna M, Gastone F, De Boer C, Klaas N, Sapion H, Eisenmann H, Larsson PO, Braun J, Sethi R, Bastiaens L. Field assessment of guar gum stabilized microscale zerovalent iron particles for in-situ remediation of 1,1,1-trichloroethane. J Contam Hydrol 2014; 164:88-99. [PMID: 24963597 DOI: 10.1016/j.jconhyd.2014.05.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Revised: 05/26/2014] [Accepted: 05/27/2014] [Indexed: 06/03/2023]
Abstract
A pilot injection test with guar gum stabilized microscale zerovalent iron (mZVI) particles was performed at test site V (Belgium) where different chlorinated aliphatic hydrocarbons (CAHs) were present as pollutants in the subsurface. One hundred kilograms of 56μm-diameter mZVI (~70gL(-1)) was suspended in 1.5m(3) of guar gum (~7gL(-1)) solution and injected into the test area. In order to deliver the guar gum stabilized mZVI slurry, one direct push bottom-up injection (Geoprobe) was performed with injections at 5 depths between 10.5 and 8.5m bgs. The direct push technique was preferred above others (e.g. injection at low flow rate via screened wells) because of the limited hydraulic conductivity of the aquifer, and to the large size of the mZVI particles. A final heterogeneous distribution of the mZVI in the porous medium was observed explicable by preferential flow paths created during the high pressure injection. The maximum observed delivery distance was 2.5m. A significant decrease in 1,1,1-TCA concentrations was observed in close vicinity of spots where the highest concentration of mZVI was observed. Carbon stable isotope analysis (CSIA) yielded information on the success of the abiotic degradation of 1,1,1-TCA and indicated a heterogeneous spatio-temporal pattern of degradation. Finally, the obtained results show that mZVI slurries stabilized by guar gum can be prepared at pilot scale and directly injected into low permeable aquifers, indicating a significant removal of 1,1,1-TCA.
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Affiliation(s)
- Milica Velimirovic
- VITO, Boeretang 200, 2400 Mol, Belgium; University of Antwerp, Department of Bio-Engineering, Groenenborgerlaan 171, 2020 Antwerp, Belgium; Department of Environmental Geosciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria.
| | - Tiziana Tosco
- Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture - Politecnico di Torino, corso Duca degli Abruzzi 24, 10129 Torino, Italy.
| | | | - Michela Luna
- Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture - Politecnico di Torino, corso Duca degli Abruzzi 24, 10129 Torino, Italy.
| | - Francesca Gastone
- Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture - Politecnico di Torino, corso Duca degli Abruzzi 24, 10129 Torino, Italy.
| | - Cjestmir De Boer
- VEGAS, University of Stuttgart, Pfaffenwaldring 61, 70569 Stuttgart, Germany; Department of Civil and Environmental Engineering, Western University, 1151 Richmond Street, London, ON, N6A 5B9 Canada.
| | - Norbert Klaas
- VEGAS, University of Stuttgart, Pfaffenwaldring 61, 70569 Stuttgart, Germany.
| | - Hans Sapion
- SAPION, Oude Bevelsesteenweg 51, 2560 Nijlen, Belgium.
| | | | | | - Juergen Braun
- VEGAS, University of Stuttgart, Pfaffenwaldring 61, 70569 Stuttgart, Germany.
| | - Rajandrea Sethi
- Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture - Politecnico di Torino, corso Duca degli Abruzzi 24, 10129 Torino, Italy.
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Icardi M, Boccardo G, Marchisio DL, Tosco T, Sethi R. Pore-scale simulation of fluid flow and solute dispersion in three-dimensional porous media. Phys Rev E Stat Nonlin Soft Matter Phys 2014; 90:013032. [PMID: 25122394 DOI: 10.1103/physreve.90.013032] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Indexed: 05/15/2023]
Abstract
In the present work fluid flow and solute transport through porous media are described by solving the governing equations at the pore scale with finite-volume discretization. Instead of solving the simplified Stokes equation (very often employed in this context) the full Navier-Stokes equation is used here. The realistic three-dimensional porous medium is created in this work by packing together, with standard ballistic physics, irregular and polydisperse objects. Emphasis is placed on numerical issues related to mesh generation and spatial discretization, which play an important role in determining the final accuracy of the finite-volume scheme and are often overlooked. The simulations performed are then analyzed in terms of velocity distributions and dispersion rates in a wider range of operating conditions, when compared with other works carried out by solving the Stokes equation. Results show that dispersion within the analyzed porous medium is adequately described by classical power laws obtained by analytic homogenization. Eventually the validity of Fickian diffusion to treat dispersion in porous media is also assessed.
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Affiliation(s)
- Matteo Icardi
- Division of Computer, Electrical and Mathematical Science and Engineering, King Abdullah University of Science and Technology, 23955-6900, Thuwal, Saudi Arabia and Institute for Computational Engineering and Sciences, University of Texas at Austin, 78712-0027, Austin, Texas, USA
| | - Gianluca Boccardo
- Department of Applied Science and Technology, Politecnico di Torino, 10129 Torino, Italy
| | - Daniele L Marchisio
- Department of Applied Science and Technology, Politecnico di Torino, 10129 Torino, Italy
| | - Tiziana Tosco
- Department of Environment, Land and Infrastructures, Politecnico di Torino, 10129 Torino, Italy
| | - Rajandrea Sethi
- Department of Environment, Land and Infrastructures, Politecnico di Torino, 10129 Torino, Italy
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Gastone F, Tosco T, Sethi R. Green stabilization of microscale iron particles using guar gum: Bulk rheology, sedimentation rate and enzymatic degradation. J Colloid Interface Sci 2014; 421:33-43. [DOI: 10.1016/j.jcis.2014.01.021] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 01/10/2014] [Accepted: 01/16/2014] [Indexed: 11/28/2022]
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Hosseini SM, Tosco T. Transport and retention of high concentrated nano-Fe/Cu particles through highly flow-rated packed sand column. Water Res 2013; 47:326-338. [PMID: 23141767 DOI: 10.1016/j.watres.2012.10.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Revised: 10/02/2012] [Accepted: 10/04/2012] [Indexed: 06/01/2023]
Abstract
The design of an efficient field-scale remediation based on the use of nanoscale zero valent iron (NZVI) requires an accurate assessment of the mobility of such particles in saturated porous media, both during injection in the subsurface (short-term mobility) and later (long-term mobility). In this study, the mobility of highly concentrated dispersions of bimetallic Fe/Cu nanoparticles (d(50) = 70 ± 5 nm) in sand-packed columns (0.5 m length and 0.025 m inner diameter) was studied. In particular, the influence of flow rate (V = 5 × 10(-4), 1 × 10(-3), 2 × 10(-3) m/s) and injected particle concentrations (2, 5, 8, 12 g/l) was addressed. Breakthrough curves and water pressure drop along the column, averaged effective porosity and final distribution of retained particles along the column were measured. Experimental results evidenced a good mobility of the Fe/Cu particles, with significant breakthrough in all explored experimental conditions of flow rate and C(0), without requiring the addition of any stabilizing agent. Clogging phenomenon of the column and also the pore pressure variation during injection period are strongly affected by injected concentration. Clogging due to deposition of particles following a ripening dynamics was observed in particular for C(0) = 8 and 12 g/l. The experimental data were modeled using the E-MNM1D software. The study has implications for field injection of bimetallic nanoparticles, suggesting that particular care is to be devoted when selecting injection concentration, to avoid porous medium clogging and control the radius of influence.
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Tosco T, Bosch J, Meckenstock RU, Sethi R. Transport of ferrihydrite nanoparticles in saturated porous media: role of ionic strength and flow rate. Environ Sci Technol 2012; 46:4008-4015. [PMID: 22356610 DOI: 10.1021/es202643c] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The use of nanoscale ferrihydrite particles, which are known to effectively enhance microbial degradation of a wide range of contaminants, represents a promising technology for in situ remediation of contaminated aquifers. Thanks to their small size, ferrihydrite nanoparticles can be dispersed in water and directly injected into the subsurface to create reactive zones where contaminant biodegradation is promoted. Field applications would require a detailed knowledge of ferrihydrite transport mechanisms in the subsurface, but such studies are lacking in the literature. The present study is intended to fill this gap, focusing in particular on the influence of flow rate and ionic strength on particle mobility. Column tests were performed under constant or transient ionic strength, including injection of ferrihydrite colloidal dispersions, followed by flushing with particle-free electrolyte solutions. Particle mobility was greatly affected by the salt concentration, and particle retention was almost irreversible under typical salt content in groundwater. Experimental results indicate that, for usual ionic strength in European aquifers (2 to 5 mM), under natural flow condition ferrihydrite nanoparticles are likely to be transported for 5 to 30 m. For higher ionic strength, corresponding to contaminated aquifers, (e.g., 10 mM) the travel distance decreases to few meters. A simple relationship is proposed for the estimation of travel distance with changing flow rate and ionic strength. For future applications to aquifer remediation, ionic strength and injection rate can be used as tuning parameters to control ferrihydrite mobility in the subsurface and therefore the radius of influence during field injections.
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Affiliation(s)
- Tiziana Tosco
- Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture, Politecnico di Torino, Torino, Italy
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Tosco T, Sethi R. Transport of non-newtonian suspensions of highly concentrated micro- and nanoscale iron particles in porous media: a modeling approach. Environ Sci Technol 2010; 44:9062-9068. [PMID: 21058641 DOI: 10.1021/es100868n] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The use of zerovalent iron micro- and nanoparticles (MZVI and NZVI) for groundwater remediation is hindered by colloidal instability, causing aggregation (for NZVI) and sedimentation (for MZVI) of the particles. Transportability of MZVI and NZVI in porous media was previously shown to be significantly increased if viscous shear-thinning fluids (xanthan gum solutions) are used as carrier fluids. In this work, a novel modeling approach is proposed and applied for the simulation of 1D flow and transport of highly concentrated (20 g/L) non-newtonian suspensions of MZVI and NZVI, amended with xanthan gum (3 g/L). The coupled model is able to simulate the flow of a shear thinning fluid including the variable apparent viscosity arising from changes in xanthan and suspended iron particle concentrations. The transport of iron particles is modeled using a dual-site approach accounting for straining and physicochemical deposition/release phenomena. A general formulation for reversible deposition is herein proposed, that includes all commonly applied dynamics (linear attachment, blocking, ripening). Clogging of the porous medium due to deposition of iron particles is modeled by tying porosity and permeability to deposited iron particles. The numerical model proved to adequately fit the transport tests conducted using both MZVI and NZVI and can develop into a powerful tool for the design and the implementation of full scale zerovalent iron applications.
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Affiliation(s)
- Tiziana Tosco
- Dipartimento di Ingegneria del Territorio, dell'Ambiente e delle Geotecnologie, Politecnico di Torino, Corso Duca degli Abruzzi, 24, 10129 Torino, Italy
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Tosco T, Tiraferri A, Sethi R. Ionic strength dependent transport of microparticles in saturated porous media: modeling mobilization and immobilization phenomena under transient chemical conditions. Environ Sci Technol 2009; 43:4425-4431. [PMID: 19603657 DOI: 10.1021/es900245d] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This study investigates ionic strength dependent deposition and release of microparticles in saturated porous media. Controlled micrometer-sized particle deposition experiments were conducted, followed by stepwise modifications in porewater chemistry to induce retained particle mobilization. A transient dual site transport model was tested against deposition and release, systematically addressing the effect of variations in solution ionic strength by coupling the equations for colloid transport with that for solute transport. The attachment and detachment coefficients of the model equations were explicitly tied to the salt concentration through proposed empirical functions, derived from experimental and theoretical considerations. Two regimes of attachment (and detachment) were hypothesized, showing favorable behavior beyond modeled values of a critical deposition concentration (and critical release concentration). Blocking phenomena were accounted for as well. This work shows how the intimate inclusion of salt concentration in a unique model equation system is able to describe both deposition and release behaviors of the particles under transient chemical conditions.
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Affiliation(s)
- Tiziana Tosco
- DITAG - Dipartimento di Ingegneria del Territorio, Ambiente e Geotecnologie, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
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