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Ma Y, You W, Yang Z, Ren Z, Jing Q. In-depth understanding of transport behavior of sulfided nano zerovalent iron/reduced graphene oxide@guar gum slurry: Stability and mobility. J Environ Sci (China) 2024; 144:1-14. [PMID: 38802222 DOI: 10.1016/j.jes.2023.08.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 08/27/2023] [Accepted: 08/28/2023] [Indexed: 05/29/2024]
Abstract
Nanoscale zero-valent iron (NZVI), which has the advantages of small particle size, large specific surface area, and high reactivity, is often injected into contaminated aquifers in the form of slurry. However, the prone to passivation and agglomeration as well as poor stability and mobility of NZVI limit the further application of this technology in fields. Therefore, sulfided NZVI loaded on reduced graphene oxide (S-NZVI/rGO) and guar gum (GG) with shear-thinning properties as stabilizers were used to synthesize S-NZVI/rGO@GG slurries. SEM, TEM, and FT-IR confirmed that the dispersion and anti-passivation of NZVI were optimized in the coupled system. The stability and mobility of the slurry were improved by increasing the GG concentration, enhancing the pH, and decreasing the ionic strength and the presence of Ca2+ ions, respectively. A modified advection-dispersion equation (ADE) was used to simulate the transport experiments considering the strain and physicochemical deposition/release. Meanwhile, colloidal filtration theory (CFT) demonstrated that Brownian motion plays a dominant role in the migration of S-NZVI/rGO@GG slurry, and the maximum migration distance can be increased by appropriately increasing the injection rate. Extended-Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory showed that the excellent stability and migration of S-NZVI/rGO@GG slurry mainly came from the GG spatial forces. This study has important implications for the field injection of S-NZVI/rGO@GG slurry. According to the injection parameters, the injection range of S-NZVI/rGO@GG slurry is effectively controlled, which lays the foundation for the promotion of application in actual fields.
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Affiliation(s)
- Yuheng Ma
- Faculty of Architecture, Civil and Transportation Engineering, Beijing University of Technology, Beijing 100124, China
| | - Wenhui You
- Faculty of Architecture, Civil and Transportation Engineering, Beijing University of Technology, Beijing 100124, China
| | - Zijiang Yang
- Faculty of Architecture, Civil and Transportation Engineering, Beijing University of Technology, Beijing 100124, China
| | - Zhongyu Ren
- Faculty of Architecture, Civil and Transportation Engineering, Beijing University of Technology, Beijing 100124, China
| | - Qi Jing
- Faculty of Architecture, Civil and Transportation Engineering, Beijing University of Technology, Beijing 100124, China.
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Han P, Xie J, Qin X, Yang X, Zhao Y. Experimental study on in situ remediation of Cr(VI) contaminated groundwater by sulfidated micron zero valent iron stabilized with xanthan gum. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 828:154422. [PMID: 35276162 DOI: 10.1016/j.scitotenv.2022.154422] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 03/02/2022] [Accepted: 03/05/2022] [Indexed: 06/14/2023]
Abstract
Micron zero valent iron (mZVI) was an underground remediation material, which had great application potential to replace nano zero valent iron (nZVI) from the perspective of economic and health benefits. However, mZVI was highly prone to gravitational settling, which limited its wide application for in situ remediation of contaminated groundwater. This paper was devoted to develop an efficient and economical groundwater remediation material based on mZVI, which should possess excellent stability, reactivity, and transportability. Thereby xanthan gum (XG) stabilized and Na2S2O4 sulfidated mZVI (XG-S-mZVI) was synthesized and characterized with SEM, XRD, XPS, and FTIR techniques. In terms of stability, the adsorbed XG and the dispersed XG worked together to resist the sedimentation of S-mZVI. In terms of reactivity, sulfidation enhanced the electron transfer rate and electron selectivity of XG-S-mZVI, thereby improved the reactivity of XG-S-mZVI. The hexavalent chromium (Cr(VI)) removal rate constant by XG-S-mZVI was determined to be 832.4 times than bare mZVI. In terms of transportability, the transportability of XG-S-mZVI was greatly improved (~80 cm in coarse sand and ~50 cm in medium sand). Straining was the main mechanism of XG-S-mZVI retention in porous media. XG-S-mZVI in situ reactive zone (XG-S-mZVI-IRZ) was only suitable to the media with a grain size larger than 0.25 mm. This study could provide theoretical support and guidance for the implementation of IRZ technology based on mZVI.
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Affiliation(s)
- Peiling Han
- Key Laboratory of Groundwater Resources and Environment of Ministry of Education, College of New Energy and Environment, Jilin University, Changchun 130021, China; Jilin Provincial Key Laboratory of Water Resources and Environment, College of New Energy and Environment, Jilin University, Changchun 130021, China; National and Local Joint Engineering Laboratory for Petrochemical Contaminated Site Control and Remediation Technology, Jilin University, Changchun 130021, China
| | - Jiayin Xie
- Key Laboratory of Groundwater Resources and Environment of Ministry of Education, College of New Energy and Environment, Jilin University, Changchun 130021, China; Jilin Provincial Key Laboratory of Water Resources and Environment, College of New Energy and Environment, Jilin University, Changchun 130021, China; National and Local Joint Engineering Laboratory for Petrochemical Contaminated Site Control and Remediation Technology, Jilin University, Changchun 130021, China
| | - Xueming Qin
- Key Laboratory of Groundwater Resources and Environment of Ministry of Education, College of New Energy and Environment, Jilin University, Changchun 130021, China; Jilin Provincial Key Laboratory of Water Resources and Environment, College of New Energy and Environment, Jilin University, Changchun 130021, China; National and Local Joint Engineering Laboratory for Petrochemical Contaminated Site Control and Remediation Technology, Jilin University, Changchun 130021, China
| | - Xinru Yang
- Key Laboratory of Groundwater Resources and Environment of Ministry of Education, College of New Energy and Environment, Jilin University, Changchun 130021, China; Jilin Provincial Key Laboratory of Water Resources and Environment, College of New Energy and Environment, Jilin University, Changchun 130021, China; National and Local Joint Engineering Laboratory for Petrochemical Contaminated Site Control and Remediation Technology, Jilin University, Changchun 130021, China
| | - Yongsheng Zhao
- Key Laboratory of Groundwater Resources and Environment of Ministry of Education, College of New Energy and Environment, Jilin University, Changchun 130021, China; Jilin Provincial Key Laboratory of Water Resources and Environment, College of New Energy and Environment, Jilin University, Changchun 130021, China; National and Local Joint Engineering Laboratory for Petrochemical Contaminated Site Control and Remediation Technology, Jilin University, Changchun 130021, China.
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Lu H, Dong J, Xi B, Cai P, Xia T, Zhang M. Transport and retention of porous silicon-coated zero-valent iron in saturated porous media. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 276:116700. [PMID: 33621736 DOI: 10.1016/j.envpol.2021.116700] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 01/26/2021] [Accepted: 02/05/2021] [Indexed: 06/12/2023]
Abstract
Porous silicon-coated zero-valent iron (Fe0@p-SiO2) is a promising material for in-situ contaminated groundwater remediation. However, investigations of factors that affect the transport of Fe0@p-SiO2 remain incomplete. In the present study, Fe0@p-SiO2 composites were prepared by a SiO2-coated technology, and a series of column experiments were conducted to examine the effects of media size, ionic strength, and injection velocity and concentration on retention and transport in saturated porous media. Results showed that the obtained Fe0@p-SiO2 is a core-shell composite with zero-valent iron as the core and porous silicon as the shell. Media size, injection velocity, Fe0 concentration, and ionic strength had a significant impact on the transport of Fe0@p-SiO2. Fe0@p-SiO2 effluent concentrations decreased with a smaller media size. Increasing initial particle concentration and ionic strength led to a decrease in particle transport. High particle retention was observed near the middle of the column, especially with high injection concentration. That was also observable in the condition of lower injection velocity or finer media. The results indicated that two transport behaviors during particles transport, which were "agglomeration-straining" and "detachment-re-migration". Moreover, the dominated mechanisms for Fe0@p-SiO2 transport and retention in saturated porous media are hydrodynamic dispersion and interception. Given the results, in practical engineering applications, proper injection velocity and concentration should be selected depending on the pollution status of groundwater and the geochemical environment to ensure an effective in-situ reaction zone.
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Affiliation(s)
- Haojie Lu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China; Key Lab of Groundwater Resources and Environment Ministry of Education, Jilin University, Changchun, 130026, PR China; State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China
| | - Jun Dong
- Key Lab of Groundwater Resources and Environment Ministry of Education, Jilin University, Changchun, 130026, PR China.
| | - Beidou Xi
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China; State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China
| | - Peiyao Cai
- Key Lab of Groundwater Resources and Environment Ministry of Education, Jilin University, Changchun, 130026, PR China
| | - Tian Xia
- Key Lab of Groundwater Resources and Environment Ministry of Education, Jilin University, Changchun, 130026, PR China
| | - Mengyue Zhang
- Key Lab of Groundwater Resources and Environment Ministry of Education, Jilin University, Changchun, 130026, PR China
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Mondal A, Dubey BK, Arora M, Mumford K. Porous media transport of iron nanoparticles for site remediation application: A review of lab scale column study, transport modelling and field-scale application. JOURNAL OF HAZARDOUS MATERIALS 2021; 403:123443. [PMID: 32798796 DOI: 10.1016/j.jhazmat.2020.123443] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 07/02/2020] [Accepted: 07/07/2020] [Indexed: 06/11/2023]
Abstract
Injection of surface modified zero valent iron nanoparticles for in situ remediation of soil, contaminated with an array of pollutants has attracted great attention due to the high reactivity of zero valent iron towards a broad range of contaminants, its cost effectiveness, minimal physical disruption and low toxicity. The effectiveness of this technology relies on the stability and mobility of injected iron nanoparticles. Hence the development of a modelling tool capable of predicting nZVI transport is indispensable. This review provides state of the art knowledge on the mobility of iron nanoparticles in porous media, mechanisms involved in subsurface retention of nZVI based on continuum models and field scale application. Special attention is given to the identification of the influential parameters controlling the transport potential of iron nanoparticles and the available numerical models for the simulation of laboratory scale transport data.
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Affiliation(s)
- Abhisek Mondal
- Department of Infrastructure Engineering, The University of Melbourne, Melbourne, Australia; Department of Civil Engineering, Indian Institute of Technology Kharagpur, Kharagpur, India
| | - Brajesh Kumar Dubey
- Department of Civil Engineering, Indian Institute of Technology Kharagpur, Kharagpur, India
| | - Meenakshi Arora
- Department of Infrastructure Engineering, The University of Melbourne, Melbourne, Australia
| | - Kathryn Mumford
- Department of Chemical Engineering, The University of Melbourne, Melbourne, Australia.
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Bouzid I, Maire J, Laurent F, Broquaire M, Fatin-Rouge N. Controlled treatment of a high velocity anisotropic aquifer model contaminated by hexachlorocyclohexanes. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 268:115678. [PMID: 33007599 DOI: 10.1016/j.envpol.2020.115678] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 09/02/2020] [Accepted: 09/14/2020] [Indexed: 06/11/2023]
Abstract
Xanthan gels were assessed to control the reductive dechlorination of hexachlorocyclohexanes (HCHs) and trichlorobenzenes (TCBs) in a strong permeability contrast and high velocity sedimentary aquifer. An alkaline degradation was selected because of the low cost of NaOH and Ca(OH)2. The rheology of alkaline xanthan gels and their ability to deliver alkalinity homogeneously, while maintaining the latter, were studied. Whereas the xanthan gels behaved like non-Newtonian shear-thinning fluids, alkalinity and Ca(OH)2 microparticles had detrimental effects, yet, the latter decreased with the shear-rate. Breakthrough curves for the NaOH and Ca(OH)2 in xanthan solutions, carried out in the lowest permeability soil (9.9 μm2), demonstrated the excellent transmission of alkalinity, while moderate pressure gradients were applied. Injection velocities ranging from 1.8 to 3.8 m h-1 are anticipated in the field, given the permeability range from 9.9 to 848.7 μm2. Despite a permeability contrast of 8.7 in an anisotropic aquifer model, the NaOH and the Ca(OH)2 both in xanthan gels spread only 5- and 7-times faster in the higher permeability zone, demonstrating that the delivery was enhanced. Moreover, the alkaline gels which were injected into a high permeability layer under lateral water flow, showed a persistent blocking effect and longevity (timescale of weeks), in contrast to the alkaline solution in absence of xanthan. Kinetics of alkaline dechlorination carried out on the historically contaminated soil, using the Ca(OH)2 suspension in xanthan solution, showed that HCHs were converted in TCBs by dehydrodechlorination, whereas the latter were then degraded by reductive hydrogenolysis. Degradation kinetics were achieved within 30 h for the major and most reactive fraction of HCHs.
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Affiliation(s)
- Iheb Bouzid
- Université de Bourgogne Franche-Comté-Besançon, Institut UTINAM-UMR CNRS 6213, 16, Route de Gray, 25030, Besançon, France
| | - Julien Maire
- Université de Bourgogne Franche-Comté-Besançon, Institut UTINAM-UMR CNRS 6213, 16, Route de Gray, 25030, Besançon, France
| | - Fabien Laurent
- SOLVAY, Centre de Recherche et Innovation de Lyon, DRP-ERA, 85 Rue des Frères Perret, 69192, Saint Fons, France
| | - Mathias Broquaire
- SOLVAY, Direction Réhabilitation Environnement, Parc Everest, 54 Rue Marcel Dassault, 69740, Genas, France
| | - Nicolas Fatin-Rouge
- Université de Bourgogne Franche-Comté-Besançon, Institut UTINAM-UMR CNRS 6213, 16, Route de Gray, 25030, Besançon, France.
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Gong L, Lv N, Qi J, Qiu X, Gu Y, He F. Effects of non-reducible dissolved solutes on reductive dechlorination of trichloroethylene by ball milled zero valent irons. JOURNAL OF HAZARDOUS MATERIALS 2020; 396:122620. [PMID: 32315940 DOI: 10.1016/j.jhazmat.2020.122620] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 03/24/2020] [Accepted: 03/30/2020] [Indexed: 06/11/2023]
Abstract
Non-reducible solution anions have been well recognized to affect reactivity of ZVI in dechlorinating chlorinated hydrocarbons. However, their effects and corresponding functional mechanisms on electron efficiency (εe) of ZVI remain unclear. In this study, mechanochemically modified microscale sulfidated and unsulfidated ZVI particles (i.e., S-mZVIbm and mZVIbm) and trichloroethylene (TCE) were used as model particles and contaminant to explore such effects. PO43- as a corrosion promoter enhanced initial dechlorination rate by both particles. However, its passivating role as a surface complex agent became significant at the later stage of dechlorination by mZVIbm, while sulfidation alleviated this effect without inhibition of dechlorination. Compared with enhancing dechlorination, PO43- promoted hydrogen evolution reaction (HER) to a higher extent, decreasing εe for both particles by 17-73 %. HCO3- negligibly affected dechlorination by both particles, while elevated HER. Thus, HCO3- [5 mM] decreased εe for S-mZVIbm and mZVIbm by 1.9 % and 22 %. Different from PO43- and HCO3-, Cl- and SO42- showed no significant effects on dechlorination, HER, and therefore εe for both particles. These results imply that even though some co-existing anions (i.e., PO43- and HCO3-) acting as corrosion promoters could improve the dechlorination by ZVIs, they would lead to decreased εe and shortened particle reactive lifetime.
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Affiliation(s)
- Li Gong
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Neng Lv
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Jianlong Qi
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Xiaojiang Qiu
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Yawei Gu
- School of Environmental Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong Province, 250353, PR China
| | - Feng He
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, PR China.
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A Large-Scale 3D Study on Transport of Humic Acid-Coated Goethite Nanoparticles for Aquifer Remediation. WATER 2020. [DOI: 10.3390/w12041207] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Humic acid-coated goethite nanoparticles (HA-GoeNPs) have been recently proposed as an effective reagent for the in situ nanoremediation of contaminated aquifers. However, the effective dosage of these particles has been studied only at laboratory scale to date. This study investigates the possibility of using HA-GoeNPs in remediation of real field sites by mimicking the injection and transport of HA-GoeNPs under realistic conditions. To this purpose, a three-dimensional (3D) transport experiment was conducted in a large-scale container representing a heterogeneous unconfined aquifer. Monitoring data, including particle size distribution, total iron (Fetot) content and turbidity measurements, revealed a good subsurface mobility of the HA-GoeNP suspension, especially within the higher permeability zones. A radius of influence of 2 m was achieved, proving that HA-GoeNPs delivery is feasible for aquifer restoration. A flow and transport model of the container was built using the numerical code Micro and Nanoparticle transport Model in 3D geometries (MNM3D) to predict the particle behavior during the experiment. The agreement between modeling and experimental results validated the capability of the model to reproduce the HA-GoeNP transport in a 3D heterogeneous aquifer. Such result confirms MNM3D as a valuable tool to support the design of field-scale applications of goethite-based nanoremediation.
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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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Ren L, Dong J, Chi Z, Li Y, Zhao Y, E J. Rheology modification of reduced graphene oxide based nanoscale zero valent iron (nZVI/rGO) using xanthan gum (XG): Stability and transport in saturated porous media. Colloids Surf A Physicochem Eng Asp 2019. [DOI: 10.1016/j.colsurfa.2018.11.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Li Q, Prigiobbe V. Modeling Nanoparticle Transport in Porous Media in the Presence of a Foam. Transp Porous Media 2019. [DOI: 10.1007/s11242-019-01235-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Tsakiroglou CD, Sikinioti-Lock A, Terzi K, Theodoropoulou M. A numerical model to simulate the NAPL source zone remediation by injecting zero-valent iron nanoparticles. Chem Eng Sci 2018. [DOI: 10.1016/j.ces.2018.07.037] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Tosco T, Sethi R. Human health risk assessment for nanoparticle-contaminated aquifer systems. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 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] [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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14
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Guar gum and its composites as potential materials for diverse applications: A review. Carbohydr Polym 2018; 199:534-545. [PMID: 30143160 DOI: 10.1016/j.carbpol.2018.07.053] [Citation(s) in RCA: 182] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 05/02/2018] [Accepted: 07/16/2018] [Indexed: 11/22/2022]
Abstract
Naturally occurring polymers are currently of prime importance among which polysaccharides occupies superior position due to their easy availability, eco- friendly and non-toxic nature. Guar gum, one of the naturally occurring polymer, is a galactomannan acquired by ground endosperm of Cyamopsis tetragonolobus or Cyamopsis psoraloides. It belongs to the family leguminosae. Presence of large number of hydroxyl groups increases its H- bonding ability when dissolved in water that enhance the viscosity and gelling properties of the guar gum solution. Based upon these properties, guar gum is used in several industries such as textile, food, petrochemical, mining and paper for varied applications. It is used as suspending, emulsifying, gelling and stabilising agent in the conventional dosage forms. Last few decades have marked the increase in development of various composites of guar gum that have intrinsic utilization in various fields. Immobilization of guar gum with the others not only enhances its properties but also enriches its utilization in numerous fields for diverse applications such as water purification, drug delivery, pharmaceutical, cosmetic and food industries, etc. Guar gum derivatives are found to have therapeutic importance in certain physiological disorders also. In this review article, we have summarized various possible composites of guar gum and their most probable applications in different fields.
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Corsi I, Winther-Nielsen M, Sethi R, Punta C, Della Torre C, Libralato G, Lofrano G, Sabatini L, Aiello M, Fiordi L, Cinuzzi F, Caneschi A, Pellegrini D, Buttino I. Ecofriendly nanotechnologies and nanomaterials for environmental applications: Key issue and consensus recommendations for sustainable and ecosafe nanoremediation. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 154:237-244. [PMID: 29476973 DOI: 10.1016/j.ecoenv.2018.02.037] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 02/02/2018] [Accepted: 02/12/2018] [Indexed: 05/23/2023]
Abstract
The use of engineered nanomaterials (ENMs) for environmental remediation, known as nanoremediation, represents a challenging and innovative solution, ensuring a quick and efficient removal of pollutants from contaminated sites. Although the growing interest in nanotechnological solutions for pollution remediation, with significant economic investment worldwide, environmental and human risk assessment associated with the use of ENMs is still a matter of debate and nanoremediation is seen yet as an emerging technology. Innovative nanotechnologies applied to water and soil remediation suffer for a proper environmental impact scenario which is limiting the development of specific regulatory measures and the exploitation at European level. The present paper summarizes the findings from the workshop: "Ecofriendly Nanotechnology: state of the art, future perspectives and ecotoxicological evaluation of nanoremediation applied to contaminated sediments and soils" convened during the Biannual ECOtoxicology Meeting 2016 (BECOME) held in Livorno (Italy). Several topics have been discussed and, starting from current state of the art of nanoremediation, which represents a breakthrough in pollution control, the following recommendations have been proposed: (i) ecosafety has to be a priority feature of ENMs intended for nanoremediation; ii) predictive safety assessment of ENMs for environmental remediation is mandatory; (iii) greener, sustainable and innovative nano-structured materials should be further supported; (iii) those ENMs that meet the highest standards of environmental safety will support industrial competitiveness, innovation and sustainability. The workshop aims to favour environmental safety and industrial competitiveness by providing tools and modus operandi for the valorization of public and private investments.
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Affiliation(s)
- I Corsi
- Department of Physical, Earth and Environmental Sciences, University of Siena, via Mattioli, 4-53100 Siena, Italy.
| | - M Winther-Nielsen
- Department of Environment and Toxicology, DHI, Agern Allé 5, 2970 Hoersholm, Denmark
| | - R Sethi
- Department of Environment, Land and Infrastructure Engineering (DIATI), Politecnico di Torino, Italy
| | - C Punta
- Department of Chemistry, Materials, and Chemical Engineering "G. Natta", Politecnico di Milano and RU INSTM, Via Mancinelli 7, 20131 Milano, Italy
| | - C Della Torre
- Department of Bioscience, University of Milano, via Celoria 26, 20133 Milano, Italy
| | - G Libralato
- Department of Biology, University of Naples Federico II, via Cinthia ed. 7, 80126 Naples, Italy
| | - G Lofrano
- Department of Chemical and Biology "A. Zambelli", University of Salerno, via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy
| | - L Sabatini
- Regional Technological District for Advanced Materials, c/o ASEV SpA (management entity), via delle Fiascaie 12, 50053 Empoli, FI, Italy
| | - M Aiello
- Acque Industriali SRL, Via Molise, 1, 56025 Pontedera, PI, Italy
| | - L Fiordi
- Acque Industriali SRL, Via Molise, 1, 56025 Pontedera, PI, Italy
| | - F Cinuzzi
- LABROMARE SRL, Via dell'Artigianato 69, 57121 Livorno, Italy
| | - A Caneschi
- Department of Chemistry & RU INSTM at the University of Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy
| | - D Pellegrini
- Institute for Environmental Protection and Research (ISPRA), Piazzale dei marmi 12, 57013 Livorno, Italy
| | - I Buttino
- Institute for Environmental Protection and Research (ISPRA), Piazzale dei marmi 12, 57013 Livorno, Italy.
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16
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Babakhani P, Bridge J, Doong RA, Phenrat T. Continuum-based models and concepts for the transport of nanoparticles in saturated porous media: A state-of-the-science review. Adv Colloid Interface Sci 2017. [PMID: 28641812 DOI: 10.1016/j.cis.2017.06.002] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Environmental applications of nanoparticles (NP) increasingly result in widespread NP distribution within porous media where they are subject to various concurrent transport mechanisms including irreversible deposition, attachment/detachment (equilibrium or kinetic), agglomeration, physical straining, site-blocking, ripening, and size exclusion. Fundamental research in NP transport is typically conducted at small scale, and theoretical mechanistic modeling of particle transport in porous media faces challenges when considering the simultaneous effects of transport mechanisms. Continuum modeling approaches, in contrast, are scalable across various scales ranging from column experiments to aquifer. They have also been able to successfully describe the simultaneous occurrence of various transport mechanisms of NP in porous media such as blocking/straining or agglomeration/deposition/detachment. However, the diversity of model equations developed by different authors and the lack of effective approaches for their validation present obstacles to the successful robust application of these models for describing or predicting NP transport phenomena. This review aims to describe consistently all the important NP transport mechanisms along with their representative mathematical continuum models as found in the current scientific literature. Detailed characterizations of each transport phenomenon in regards to their manifestation in the column experiment outcomes, i.e., breakthrough curve (BTC) and residual concentration profile (RCP), are presented to facilitate future interpretations of BTCs and RCPs. The review highlights two NP transport mechanisms, agglomeration and size exclusion, which are potentially of great importance in controlling the fate and transport of NP in the subsurface media yet have been widely neglected in many existing modeling studies. A critical limitation of the continuum modeling approach is the number of parameters used upon application to larger scales and when a series of transport mechanisms are involved. We investigate the use of simplifying assumptions, such as the equilibrium assumption, in modeling the attachment/detachment mechanisms within a continuum modelling framework. While acknowledging criticisms about the use of this assumption for NP deposition on a mechanistic (process) basis, we found that its use as a description of dynamic deposition behavior in a continuum model yields broadly similar results to those arising from a kinetic model. Furthermore, we show that in two dimensional (2-D) continuum models the modeling efficiency based on the Akaike information criterion (AIC) is enhanced for equilibrium vs kinetic with no significant reduction in model performance. This is because fewer parameters are needed for the equilibrium model compared to the kinetic model. Two major transport regimes are identified in the transport of NP within porous media. The first regime is characterized by higher particle-surface attachment affinity than particle-particle attachment affinity, and operative transport mechanisms of physicochemical filtration, blocking, and physical retention. The second regime is characterized by the domination of particle-particle attachment tendency over particle-surface affinity. In this regime although physicochemical filtration as well as straining may still be operative, ripening is predominant together with agglomeration and further subsequent retention. In both regimes careful assessment of NP fate and transport is necessary since certain combinations of concurrent transport phenomena leading to large migration distances are possible in either case.
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17
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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. JOURNAL OF CONTAMINANT HYDROLOGY 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] [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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18
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Velimirovic M, Schmid D, Wagner S, Micić V, von der Kammer F, Hofmann T. Agar agar-stabilized milled zerovalent iron particles for in situ groundwater remediation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 563-564:713-23. [PMID: 26596889 DOI: 10.1016/j.scitotenv.2015.11.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 10/29/2015] [Accepted: 11/02/2015] [Indexed: 05/09/2023]
Abstract
Submicron-scale milled zerovalent iron (milled ZVI) particles produced by grinding macroscopic raw materials could provide a cost-effective alternative to nanoscale zerovalent iron (nZVI) particles for in situ degradation of chlorinated aliphatic hydrocarbons in groundwater. However, the aggregation and settling of bare milled ZVI particles from suspension presents a significant obstacle to their in situ application for groundwater remediation. In our investigations we reduced the rapid aggregation and settling rate of bare milled ZVI particles from suspension by stabilization with a "green" agar agar polymer. The transport potential of stabilized milled ZVI particle suspensions in a diverse array of natural heterogeneous porous media was evaluated in a series of well-controlled laboratory column experiments. The impact of agar agar on trichloroethene (TCE) removal by milled ZVI particles was assessed in laboratory-scale batch reactors. The use of agar agar significantly enhanced the transport of milled ZVI particles in all of the investigated porous media. Reactivity tests showed that the agar agar-stabilized milled ZVI particles were reactive towards TCE, but that their reactivity was an order of magnitude less than that of bare, non-stabilized milled ZVI particles. Our results suggest that milled ZVI particles could be used as an alternative to nZVI particles as their potential for emplacement into contaminated zone, their reactivity, and expected longevity are beneficial for in situ groundwater remediation.
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Affiliation(s)
- Milica Velimirovic
- Department of Environmental Geosciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Doris Schmid
- Department of Environmental Geosciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Stephan Wagner
- Department of Environmental Geosciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Vesna Micić
- Department of Environmental Geosciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Frank von der Kammer
- Department of Environmental Geosciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Thilo Hofmann
- Department of Environmental Geosciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria.
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19
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Tsakiroglou C, Terzi K, Sikinioti-Lock A, Hajdu K, Aggelopoulos C. Assessing the capacity of zero valent iron nanofluids to remediate NAPL-polluted porous media. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 563-564:866-878. [PMID: 26875604 DOI: 10.1016/j.scitotenv.2016.02.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Revised: 02/01/2016] [Accepted: 02/02/2016] [Indexed: 06/05/2023]
Abstract
A variety of aqueous suspensions (nanofluids) of zero-valent nano-particles (nZVI) are prepared by wet chemistry techniques, their stability and longevity is evaluated by physic-chemical methods of characterization, and their reactivity toward the dechlorination of per-chloro-ethylene (PCE) is examined with tests in batch reactors. For assessing the mobility, longevity and reactivity of nZVI suspensions (nanofluids), under flow-through conditions, visualization multiphase flow and transport tests are performed on a glass-etched pore network. The nZVI breakthrough curves are constructed by measuring the transient variation of the iron concentration in the effluent with atomic absorption spectroscopy. The capacity of nZVI to remediate the bulk phase of PCE is quantified by detecting the mass loss rate of PCE ganglia trapped in glass-etched pore networks during the continuous injection of nZVI suspension or pure water. The nZVI injection in porous media is simulated as an advection- dispersion process by accounting for the attachment/detachment of nanoparticles on the pore-walls, and describing the kinetics of PCE dissolution and reaction by 1st order equations. Visualization experiments reveal that the gradual elimination of PCE ganglia by the injected nZVI is associated with the preferential "erosion" of the upstream interfacial regions. The step controlling the overall process kinetics might be either (i) the enhanced PCE dissolution or (ii) the direct reaction of bulk PCE with the nZVI deposited upon the ganglia interfaces. Inverse modeling of the experiments under the simplifying assumption of one active mechanism indicates that the estimated kinetic coefficients are increasing functions of the flow rate.
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Affiliation(s)
- Christos Tsakiroglou
- Foundation for Research and Technology Hellas-Institute of Chemical Engineering Sciences, Stadiou street, Platani, 26504 Patras, Greece.
| | - Katerina Terzi
- Foundation for Research and Technology Hellas-Institute of Chemical Engineering Sciences, Stadiou street, Platani, 26504 Patras, Greece; Department of Chemical Engineering, University of Patras, 26504 Patras, Greece
| | - Alexandra Sikinioti-Lock
- Foundation for Research and Technology Hellas-Institute of Chemical Engineering Sciences, Stadiou street, Platani, 26504 Patras, Greece; Department of Chemical Engineering, University of Patras, 26504 Patras, Greece
| | - Kata Hajdu
- Foundation for Research and Technology Hellas-Institute of Chemical Engineering Sciences, Stadiou street, Platani, 26504 Patras, Greece
| | - Christos Aggelopoulos
- Foundation for Research and Technology Hellas-Institute of Chemical Engineering Sciences, Stadiou street, Platani, 26504 Patras, Greece
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20
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Xin J, Tang F, Zheng X, Shao H, Kolditz O. Transport and retention of xanthan gum-stabilized microscale zero-valent iron particles in saturated porous media. WATER RESEARCH 2016; 88:199-206. [PMID: 26497937 DOI: 10.1016/j.watres.2015.10.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 09/25/2015] [Accepted: 10/02/2015] [Indexed: 06/05/2023]
Abstract
Microscale zero valent iron (mZVI) is a promising material for in-situ contaminated groundwater remediation. However, its usefulness has been usually inhibited by mZVI particles' low mobility in saturated porous media for sedimentation and deposition. In our study, laboratory experiments, including sedimentation studies, rheological measurements and transport tests, were conducted to investigate the feasibility of xanthan gum (XG) being used as a coating agent for mZVI particle stabilization. In addition, the effects of XG concentration, flow rate, grain diameter and water chemistry on XG-coated mZVI (XG-mZVI) particle mobility were explored by analyzing its breakthrough curves and retention profiles. It was demonstrated that XG worked efficiently to enhance the suspension stability and mobility of mZVI particles through the porous media as a shear thinning fluid, especially at a higher concentration level (3 g/L). The results of the column study showed that the mobility of XG-mZVI particles increased with an increasing flow rate and larger grain diameter. At the highest flow rate (2.30 × 10(-3) m/s) within the coarsest porous media (0.8-1.2 mm), 86.52% of the XG-mZVI flowed through the column. At the lowest flow rate (0.97 × 10(-4) m/s) within the finest porous media (0.3-0.6 mm), the retention was dramatically strengthened, with only 48.22% of the particles flowing through the column. The XG-mZVI particles appeared to be easily trapped at the beginning of the column especially at a low flow rate. In terms of two representative water chemistry parameters (ion strength and pH value), no significant influence on XG-mZVI particle mobility was observed. The experimental results suggested that straining was the primary mechanism of XG-mZVI retention under saturated condition. Given the above results, the specific site-related conditions should be taken into consideration for the design of a successful delivery system to achieve a compromise between maximizing the radius of influence of the injection and minimizing the injection pressure.
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Affiliation(s)
- Jia Xin
- Key Lab of Marine Environmental Science and Ecology, Ministry of Education, College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Fenglin Tang
- Key Lab of Marine Environmental Science and Ecology, Ministry of Education, College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Xilai Zheng
- Key Lab of Marine Environmental Science and Ecology, Ministry of Education, College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
| | - Haibing Shao
- Helmholtz Center for Environmental Research UFZ/TU Dresden, Leipzig 034202, Germany
| | - Olaf Kolditz
- Helmholtz Center for Environmental Research UFZ/TU Dresden, Leipzig 034202, Germany
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21
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Tiraferri A, Borkovec M. Probing effects of polymer adsorption in colloidal particle suspensions by light scattering as relevant for the aquatic environment: An overview. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 535:131-140. [PMID: 25434471 DOI: 10.1016/j.scitotenv.2014.11.063] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 11/19/2014] [Accepted: 11/19/2014] [Indexed: 06/04/2023]
Abstract
Modification of particle surfaces by adsorption of polymers is a process that governs particle behavior in aqueous environmental systems. The present article briefly reviews the current understanding of the adsorption mechanisms and the properties of the resulting layers, and it discusses two environmentally relevant cases of particle modification by polymers. In particular, the discussion focuses on the usefulness of methods based on light scattering to probe such adsorbed layers together with the resulting properties of the particle suspensions, and it highlights advantages and disadvantages of these techniques. Measurement of the electrophoretic mobility allows to follow the development of the adsorption layer and to characterize the charge of the modified particles. At saturation, the surface charge is governed by the charge of the adsorbed film. Dynamic light scattering provides information on the film thickness and on the behavior of the modified suspensions. The charge and the structure of the adsorbed layer influence the stability of the particles, as well as the applicability of the classical theory of Derjaguin, Landau, Verwey, and Overbeek (DLVO). This fundamental knowledge is presented in the light of environmental systems and its significance for applied systems is underlined. In particular, the article discusses two examples of environmental processes involving adsorption of polymers, namely, the modification of particles by natural adsorption of humic substances and the tailoring of surface properties of iron-based particles used to remediate contaminated aquifers.
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Affiliation(s)
- Alberto Tiraferri
- Department of Inorganic and Analytical Chemistry, University of Geneva, Sciences II, Quai Ernest-Ansermet 30, 1205 Geneva, Switzerland.
| | - Michal Borkovec
- Department of Inorganic and Analytical Chemistry, University of Geneva, Sciences II, Quai Ernest-Ansermet 30, 1205 Geneva, Switzerland
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22
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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. JOURNAL OF CONTAMINANT HYDROLOGY 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] [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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23
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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. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:5593-5600. [PMID: 25884287 DOI: 10.1021/acs.est.5b00208] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [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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