Locations (click on image for detailed information)
 M.Sc. in Utrecht, The Netherlands |
 Ph.D. in Stuttgart, Germany |
 Postdoc in London, Ontario, Canada |
 Scientist in Utrecht, The Netherlands |
My scientific external pages
Citations (click here to open/close all at once)
| Author | Title | Year | Journal/Proceedings | Reftype | DOI/URL |
|---|---|---|---|---|---|
| de Boer, C.V. | Transport of nano sized zero valent iron colloids during injection into the subsurface | 2012 | School: University of Stuttgart | phdthesis | URL |
| Abstract: One of the recent In-Situ groundwater remediation techniques under development uses reactive zero valent iron (ZVI) to turn highly toxic chlorinated hydrocarbons (CHCs) into harmless compounds. CHCs are non miscible and characterized by a low solubility which determines their slow dissolution (over decades or centuries) into groundwater, forming plumes that can target drinking water wells, rivers and lakes. Injection of nano sized zero valent iron (nZVI) suspension into the subsurface could target the contaminants directly in the source zone. The high reactivity of nZVI together with the injection into the source fastens the depletion of the contaminant and interrupts the plume generation. The presented work focused on the transport of nZVI during the injection. To make quantitative descriptions of transport possible, an effective detection technique was developed. Exact concentrations of nZVI inside the porous medium was measured through changes in susceptibility detected with electromagnetic induction sensors. Mobility tests with different suspension concentrations were performed in a 1-D horizontally orientated two meter long column. Continuous concentration measurements were performed over the whole length of the column. In a near field scale container experiment a confined aquifer with a radial flow field over a radius of almost two meters was simulated. Different injection rates and pumping techniques were tested inside this experimental set up. A discretization method to represent all effects of a radial flow field using sets of columns was developed. The method could be verified successfully by comparing the concentration profiles to the results obtained from the container experiments. A mathematical model, developed by starting from the classic colloid filtration theory and by considering the transport of primary colloids and aggregates separately, was able to be fitted on the 1-D results. After implementation in a numerical solver, the model was furthermore capable of providing a very good fit on the results of the radial geometry tests while using exclusively the fitted parameters obtained from the 1-D tests. Throughout the work a better understanding of the transport of nZVI during the injection was developed. It was demonstrated that transport of nZVI without modification was possible over a distance of two meters in both 1-D and radial geometry flow fields. An extrapolation of the work for field application was furthermore described. By applying the methods developed in this work the necessary suspension concentration, the volume of suspension and the injection rate could be determined in advance. The presented work showed promising results and could be a sound scientific basis for further investigations and case studies on nZVI based remediation. | |||||
BibTeX:
@phdthesis{deboer_2012,
author = {Cjestmir Volkert de Boer},
title = {Transport of nano sized zero valent iron colloids during injection into the subsurface},
school = {University of Stuttgart},
year = {2012},
url = {http://elib.uni-stuttgart.de/opus/volltexte/2013/8214}
}
|
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| Li, H., De Boer, C., Buchau, A., Klaas, N., Rucker, W. and Hermes, H. | Development of an inductive concentration measurement sensor of nano sized zero valent iron | 2012 | International Multi-Conference on Systems, Signals and Devices, SSD 2012 - Summary Proceedings | conference | DOI URL |
| Abstract: The injection of colloidal nano sized zero valent iron (nZVI) into a contaminated aquifer is a promising new in-situ groundwater remediation technique. An inductive sensor is presented to directly detect and measure the concentration of nZVI in the subsurface. The method is based on the inductive measurement of magnetic material properties of nZVI within an alternating magnetic field. The change of magnetic flux density generated by one coil is determined by measuring an induced voltage in a second coil. Numerical simulations with the finite element software COMSOL Multiphysics were performed to optimize the sensor design. Furthermore, these components were used to analyze the possible measuring range, taking into account the accuracy of the measuring device to be used. Since the susceptibility of nZVI in the aquifer is very small, it is necessary to use a background measurement to improve the sensitivity of the measurement system. Finally, the measuring concept was experimentally verified. © 2012 IEEE. | |||||
BibTeX:
@conference{Li++_2012,
author = {Li, H.a and De Boer, C.V.b and Buchau, A.a and Klaas, N.b and Rucker, W.M.a and Hermes, H.c},
title = {Development of an inductive concentration measurement sensor of nano sized zero valent iron},
journal = {International Multi-Conference on Systems, Signals and Devices, SSD 2012 - Summary Proceedings},
year = {2012},
note = {cited By (since 1996) 0; Conference of 9th International Multi-Conference on Systems, Signals and Devices, SSD 2012; Conference Date: 20 March 2012 through 23 March 2012; Conference Code: 89934},
url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84861615189&partnerID=40&md5=54abe6b7eb227bae910cc2715f7e2381},
doi = {http://dx.doi.org/10.1109/SSD.2012.6198042}
}
|
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| Buchau, A., Rucker, W., de Boer, C. & Klaas, N. | Inductive detection and concentration measurement of nano sized zero valent iron in the subsurface [BibTeX] |
2010 | IET Science, Measurement & Technology Vol. 4(6), pp. 289-297 |
article | DOI |
BibTeX:
@article{buchau2010,
author = {A. Buchau and W.M. Rucker and C.V. de Boer and N. Klaas},
title = {Inductive detection and concentration measurement of nano sized zero valent iron in the subsurface},
journal = {IET Science, Measurement & Technology},
publisher = {IET},
year = {2010},
volume = {4},
number = {6},
pages = {289-297},
doi = {http://dx.doi.org/10.1049/iet-smt.2009.0116}
}
|
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| de Boer, C., Klaas, N. & Braun, J. | Anwendung nanoskaliger Eisenkolloide zur In-Situ-Sanierung anthropogener CKW-Kontaminationen im Untergrund | 2009 | (VEG 36) | techreport | |
| Abstract: Im Rahmen dieses Vorhabens konnte die Sanierung von CKW-Kontaminationen im Grundwasser mit Nanoeisen einen großen Schritt voran- und einem routinemäßigen Einsatz im Feld deutlich nähergebracht werden. Es wurde eine Messtechnik entwickelt, die es erlaubt, eine Injektion von Eisensuspensionen kontinuierlich zu überwachen und so die Eisenausbreitung zeitlich zu verfolgen. Diese Technik wurde in einem dreidimensionalen Großversuch erstmals erfolgreich eingesetzt. In diesem Großversuch konnte in Kooperation mit der Firma Alenco, Stuttgart, erstmals in einem dreidimensionalen Aufbau mit radialsymmetrischem Strömungsfeld gezeigt werden, dass es möglich ist, eine Ausbreitungsdistanz des Nanoeisens von 2 m zu erreichen. Diese Ausbreitung konnte dank der speziellen Konzeption des Aufbaus sowohl visuell, mittels der entwickelten Messtechnik als auch über spätere Laboranalysen verfolgt und dokumentiert werden. Auch bezüglich der Reaktivität der Kolloide mit den Schadstoffen konnten wesentliche, neue Erkenntnisse gewonnen werden. Insbesondere war die starke Abhängigkeit der (gewünschten) Reaktion der Schadstoffe mit dem Eisen vom pH-Wert bislang nur unzureichend untersucht. Es wurde im Projektverlauf auch eine Methode entwickelt, die (unerwünschte) anaerobe Korrosion als Konkurrenzreaktion zu vermindern, zugunsten des Abbaus der Schadstoffe. | |||||
BibTeX:
@techreport{deboer++_2009a,
author = {de Boer, C.V. and Klaas, N. and J. Braun},
title = {Anwendung nanoskaliger Eisenkolloide zur In-Situ-Sanierung anthropogener CKW-Kontaminationen im Untergrund},
year = {2009},
number = {VEG 36}
}
|
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| de Boer, C., Klaas, N. & Braun, J. | Machbarkeitsstudie zum Einsatz von Eisenkolloiden zur Sanierung von CKW-Kontaminationen (Fahnensanierung) [BibTeX] |
2007 | (VEG 21) | techreport | |
BibTeX:
@techreport{deboer++_2007b,
author = {de Boer, C.V. and Klaas, N. and J. Braun},
title = {Machbarkeitsstudie zum Einsatz von Eisenkolloiden zur Sanierung von CKW-Kontaminationen (Fahnensanierung)},
year = {2007},
number = {VEG 21}
}
|
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| de Boer, Cjestmir, V. | Characteristics and Mobility of Zero-Valent Nano-Iron in Porous Media | 2007 | School: University of Utrecht | mastersthesis | |
| Abstract: Aquifers contaminated with chlorinated solvents promises to be very effectively remediated with reactive nano-iron. The large specific surface of nano-iron results in extremely fast reaction rates. Due to the small size, the particles are thought of to be able to be injected into the aquifer and reach the contaminants through simple injection wells. So far, very little is known about the exact transport capacity of nano-iron. In the literature the claims toward this differ greatly. In this research project, systematic experiments were conducted to get a better understanding of the mobility and characteristics of nano-iron. It was shown that the transport distance of nano-iron particles was affected by the age (and with that the aggregation stage) of the particles, by the discharge and the concentration of the suspension during injection, by the grain size distribution, as well as the permeability and heterogeneity of the porous media. There was no significant change in the retardation of nano-iron at different velocities. Apart from the experiments, a technology to accurately and non-destructively measure the concentration distribution of nano-iron in a column was developed. | |||||
BibTeX:
@mastersthesis{deboer_2007,
author = {de Boer, Cjestmir, V.},
title = {Characteristics and Mobility of Zero-Valent Nano-Iron in Porous Media},
school = {University of Utrecht},
year = {2007}
}
|
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Created by JabRef on 01/08/2012.
| Author | Title | Year | Journal/Proceedings | Reftype | DOI/URL |
|---|---|---|---|---|---|
| Estrella, D. | Transport of Nano-Sized Zero-Valent Iron in Porous Media: Transformation of 2D Container Experiments into 1D Column Experiments. [BibTeX] |
2011 | School: Institut für Wasserbau, Universität Stuttgart | mastersthesis | |
BibTeX:
@mastersthesis{esterlla_2011a,
author = {Estrella, David},
title = {Transport of Nano-Sized Zero-Valent Iron in Porous Media: Transformation of 2D Container Experiments into 1D Column Experiments.},
school = {Institut für Wasserbau, Universität Stuttgart},
year = {2011}
}
|
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| Estrella, D. | Experimental and Numerical Approximation Methods for Zero-Valent Iron Transport around Injection Wells | 2011 | School: Institut für Wasserbau, Universität Stuttgart | mastersthesis | |
| Abstract: Zero valent iron (ZVI) colloids have received much attention as a tool for remediation of many groundwater contaminants including chlorinated hydrocarbons. In the past, permeable reactive barriers (PRBs) containing ZVI have been used for plume treatment, but because PRBs only target the plume, rather than completely remediating the contamination, recent research has focused on the direct injection of nano-scale ZVI (nZVI) into the source zone of contaminations. Although the technology is promising, it is still uncertain that suficient spreading of nZVI can be achieved at the required radius through injection. Signifficant research has been performed to characterize nano- and micro-scale ZVI transport in porous media both by experimental and numerical means, however very little research has been done into the behavior of ZVI colloids in a radial system. The transport of nZVI colloids in porous media has been experimentally investigated in the Research Facility for Subsurface Remediation at the University of Stuttgart using two different approaches: one characterizing transport in one dimension using columns filled with fully saturated sand and another using a near field scale 60deg. wedge radial injection experiment. The purpose of these 2D experiments was to prove that 2m of ZVI transport could be achieved. Though successful and effective, these experiments are time consuming and impractical for screening tests. During this study, two methods were developed to approximate ZVI distribution around an injection well using column experiments. The first was achieved by discretizing the radial system into segments and applying the appropriate boundary conditions in order to approximate the ZVI distribution in columns representing the discretized sections. The second method transfers fitting parameters from a 1D numerical model of column experiments to a 3D radial model which simulates the transport around an injection well. |
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BibTeX:
@mastersthesis{esterlla_2011b,
author = {Estrella, David},
title = {Experimental and Numerical Approximation Methods for Zero-Valent Iron Transport around Injection Wells},
school = {Institut für Wasserbau, Universität Stuttgart},
year = {2011}
}
|
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| Baarsma, R. | Modeling the Transport of Nano-Sized Zero-Valent Iron in an Aquifer . | 2010 | School: University of Utrecht, Utrecht, The Netherlands | mastersthesis | |
| Abstract: Nano-sized zero-valent iron (NZVI) is very potent in remediating a large range of soil contaminants. The nano-particles can move through an aquifer easily while having a high reactivity due to their large specific surface area. At the University of Stuttgart, an experiment was carried out to research the movement of NZVI through an aquifer in a radial flow field. To increase understanding of the underlying processes, a model had to be created that simulates the experiment. For the presented work, a model was created to simulate the transport of NZVI in a radial flow field using the advection-dispersion relation. The model was created using COMSOL Multiphysics. | |||||
BibTeX:
@mastersthesis{baarsma_2010,
author = {Baarsma, Rein},
title = {Modeling the Transport of Nano-Sized Zero-Valent Iron in an Aquifer .},
school = {University of Utrecht, Utrecht, The Netherlands},
year = {2010}
}
|
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| Bartels, W.-B. | Transport of Nano-Sized Zero-Valent Iron Particles in an Aquifer | 2010 | School: University of Utrecht, Utrecht, The Netherlands | mastersthesis | |
| Abstract: Background: Recently a new technique in groundwater remediation is getting more attention. Instead of the more common pump and treat or PRB treatments, this technique is all about injecting remediation particles directly in the contaminated zone. Often, nano-sized zero-valent iron particles (NZVI-particles) are used for injection. Experimental set-up: Results: |
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BibTeX:
@mastersthesis{bartels_2010,
author = {Bartels, Willem-Bart},
title = {Transport of Nano-Sized Zero-Valent Iron Particles in an Aquifer},
school = {University of Utrecht, Utrecht, The Netherlands},
year = {2010}
}
|
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| Xu, W. | Ermittlung der Transporteigenschaften von reaktiven Nano-Eisen-Partikel mittels horizontaler Säulenversuche [BibTeX] |
2009 | School: Institut für Wasserbau, Universität Stuttgart | mastersthesis | |
BibTeX:
@mastersthesis{xu_2009,
author = {Xu, Weining},
title = {Ermittlung der Transporteigenschaften von reaktiven Nano-Eisen-Partikel mittels horizontaler Säulenversuche},
school = {Institut für Wasserbau, Universität Stuttgart},
year = {2009}
}
|
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| Steiert, S. | Reaktivität und Langzeitstabilität von nullwertigem Nano-Eisen bei der Sanierung von CKW-Schadensfällen in Grundwasserleitern | 2008 | School: Versuchseinrichtung zur Grundwasser- und Altlastensanierung VEGAS Institut für Wasserbau |
mastersthesis | |
| Abstract: In den letzten Jahren werden für die Sanierung von Schadensfällen in Grundwasserleitern mit leichtflüchtigen chlorierten Kohlenwasserstoffen (LCKW) immer öfter reaktive Wände eingesetzt. Dabei hat sich der Einsatz von elementarem Eisen als Reduktionsmittel bereits bewährt. Eine mögliche neue Variante der Errichtung einer reaktiven Wand ist die Injektion von elementarem Eisen in Form von Nano-Partikel als wässrige Suspension. Das reaktive Eisen wird dabei durch Injektion in Brunnen mit der Suspension im Porenraum des Bodens verteilt und bildet so eine injizierte, reaktive Zone, die in der Lage ist, eine Schadstofffahne abzureinigen. Ziel dieser Arbeit war die Reaktivität und Langzeitstabilität von nullwertigen Nano-Eisen-Partikeln bei der Sanierung von LCKW-kontaminiertem Wasser im Labormaßstab anhand des Modellkontaminanten Tetrachlorethen (PCE) zu untersuchen. Sowohl in Batchversuchen unter idealen Bedingungen als auch in Säulenversuchen bei der Durchströmung eines simulierten, natürlichen Grundwasserleites konnte gezeigt werden, dass es möglich ist PCE mit Nano-Eisen-Partikeln (RNIP) abzubauen. In Batchversuchen wurde zunächst der Einfluss der Vorbehandlungen Gefriertrocknen und Dispergieren sowie der Einfluss der Konzentration der Eisenpartikel auf die Reaktivität ermittelt. Dabei konnte kein Einfluss der Vorbehandlungen Gefriertrocknen und Dispergieren auf die Reaktivität nachgewiesen werden. Es wurde aber gezeigt, dass bei einer Sanierung aufgrund von anaerober Korrosion ein gewisser stöchiometrischer Überschuss an elementarem Eisen im Vergleich zum Schadstoff notwendig ist. Die bei dieser Arbeit in Batchversuchen ermittelte spezifische Abbaukonstante war deutlich geringer als in der Literatur angegebene Werte. Bezüglich der Langzeitstabilität konnte in dieser Arbeit nachgewiesen werden, dass RNIP in Batchversuchen in der Lage ist über einen Zeitraum von mehr als 100 Tagen PCE abzubauen. In Säulenversuchen hingegen wurde eine massive Wasserstoffbildung beobachtet und es zeigte sich, dass die untersuchten Nano-Eisen-Partikel aufgrund von anaerober Korrosion in durchströmten Systemen mit neutralem pH-Wert nicht langzeitstabil sind. In weiteren Säulenversuchen konnte jedoch die anaerobe Korrosion und die damit verbundene Wasserstoffbildung durch die Zugabe von Weißkalkhydrat zur Nano-Eisen-Suspension vor der Injektion deutlich reduziert werden. | |||||
| Review: Steiert, Stefan | |||||
BibTeX:
@mastersthesis{steiert2008,
author = {Steiert, Stefan},
title = {Reaktivität und Langzeitstabilität von nullwertigem Nano-Eisen bei der Sanierung von CKW-Schadensfällen in Grundwasserleitern},
school = {Versuchseinrichtung zur Grundwasser- und Altlastensanierung VEGAS |
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Created by JabRef on 01/08/2012.
| Author | Title | Year | Journal/Proceedings | Reftype | DOI/URL |
|---|---|---|---|---|---|
| de Boer, C.V., Sharma, P. & OĆarroll, D.M. | Transport of Multi-walled Carbon Nanotubes in Partially Saturated Porous Media [BibTeX] |
2013 | Environmental Nanotechnology, Novel Approaches to Meet Global Challenges, Gordon Research Conferences, June 2-7, Stowe, VT, USA | conference | |
BibTeX:
@conference{deboer++_2013a,
author = {Cjestmir V. de Boer and Prabhakar Sharma and Denis M. OĆarroll},
title = {Transport of Multi-walled Carbon Nanotubes in Partially Saturated Porous Media},
booktitle = {Environmental Nanotechnology, Novel Approaches to Meet Global Challenges, Gordon Research Conferences, June 2-7, Stowe, VT, USA},
year = {2013}
}
|
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| de Boer, C. | Charakteristika und Mobilität von nullwertigem Nano-Eisen in porösen Medien | 2009 | Altlastensymposium 2009 | inproceedings | |
| Abstract: Im Rahmen der vorliegenden Arbeit wurde eine Methodik entwickelt, mit der es möglich ist, das Ausbreitungsverhalten von Kolloidsuspensionen systematisch zu untersuchen. Dazu wurden die einzelnen Parameter, die einen möglichen Einfluss auf das Transportverhalten haben isoliert und in einer eindimensionalen Anordnung untersucht. Durch die Entwicklung einer Methode zur Eisenbestimmung mit einem modifizierten Metall-Suchgerät konnten die Grundlagen gelegt werden für eine quantitative Beschreibung der Einflussfaktoren. In dieser Arbeit wurde der Transport von Nano-Eisen-Partikeln eingehend betrachtet. Es gelang dabei, in ersten Messreihen die wesentlichen Einflussfaktoren auf die Mobilität von Nano-Eisen-Partikeln zu identifizieren. Dabei wurden einerseits die Vorbehandlung bzw. Modifikation der Nano-Eisen-Partikel zur Verhinderung der Agglomeration und andererseits die Konzentration der Nano-Eisen-Suspension als Hauptfaktoren ermittelt. Die Reaktivität im Hinblick auf die Abbaufähigkeit von CKWs wurde nicht weiter untersucht. Vor einer Feldanwendung dieser Technologie muss jedoch auch die Reaktivität detailliert untersucht werden. | |||||
BibTeX:
@inproceedings{deboer_2009,
author = {de Boer, C.V.},
title = {Charakteristika und Mobilität von nullwertigem Nano-Eisen in porösen Medien},
booktitle = {Altlastensymposium 2009},
year = {2009},
note = {Invited lecture}
}
|
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| de Boer, C. | Injection of nano-scale iron for the in-situ remediation of contaminated groundwater | 2009 | Environmental Effects of Nanoparticles and Nanomaterials | inproceedings | |
| Abstract: In order to remove contaminant plumes from the groundwater, permeable reactive barriers can be used. Instead of an excavated trench filled with granular zero-valent iron, a relatively new and promising method is the injection of nano-scale iron suspension in the subsurface using injection wells. The goal is to deposit the iron in the pores space and hence form an injected reactive barrier. However, little is known about the transport behavior of nano-scale iron during the injection. A better understanding of the transport behavior is necessary to design a field application such that the reactive barrier will be continuous in space and sufficiently wide. So far, there are no measuring techniques available to continuously and non-destructively determine the nano-scale iron concentration in the soil directly. Hence, the spreading and distribution of the nano-scale iron in the subsurface during injection could not be proven. In the presented work, measuring devices w ith a very high resolution based upon magnetic susceptibility have been developed to non-destructively determine the concentration of nano-scale iron during and after the injection in a column and in a large-scale container experiment. Several batch, horizontal column and container experiments were conducted to find the parameters controlling the reactivity, longevity and mobility of nano-scale iron in the subsurface. In a field application the injection in a well would result in a radial flow field around the well. An experiment was constructed to create such a 2-D radial flow field in a confined aquifer. The radius of the segment is 2 m and the height was 60 cm, which is a near-field scale setup. The experiment has the additional advantage that that measuring probes can be installed and after the injection the container can be excavated for a detailed investigation of the spreading of the nano-scale iron. In the ongoing research this measuring technique is further developed to make it suitable also for field applications. |
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BibTeX:
@inproceedings{deboer_2009b,
author = {de Boer, C.V.},
title = {Injection of nano-scale iron for the in-situ remediation of contaminated groundwater},
booktitle = {Environmental Effects of Nanoparticles and Nanomaterials},
year = {2009},
note = {Oral Presentation}
}
|
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| de Boer, C., Braun, J. & Klaas, N. | Transport of zero-valent iron colloids in aquifers | 2010 | 11th International UFZ- Deltares/TNO Conference on Management of Soil, Groundwater and Sediment (ConSoil 2010), pp. ThS A13 | inproceedings | |
| Abstract: Reactive zero-valent iron is currently being used for remediation of contaminated groundwater. Permeable reactive barriers are the current state-of-the-art method for using zero-valent iron. Instead of an excavated trench filled with granular zero-valent iron, a relatively new and promising method is the injection of a nano- to micro-scale zero-valent iron colloid suspension in the subsurface using injection wells. The goal is to deposit the iron in the aquifer and hence form a reactive permeable zone which is no longer bound to limited depths and plume treatment, but can also be used directly at the source. A good understanding of the transport behavior of zero-valent iron colloids is necessary to design a field application. So far, there are no measuring techniques available to continuously and non-destructively determine the iron colloid concentration in the soil directly. Hence, the spreading and distribution of the iron in the subsurface during injection could not be proven. In the presented work, column experiments were conducted to better understand transport phenomena of iron colloids in porous media and to find constitutive relations of the parameters controlling the transport in the subsurface. Based on the columns, large scale experiments with a radial flow field and, hence, a hyperbolically decreasing velocity profile, were conducted. Within these large container experiments a radial symmetrical spreading with a radius of close to two meters was possible. Parallel to the transport experiments measuring devices with a very high resolution based upon magnetic susceptibility have been developed to non-destructively determine the concentration of nano-scale iron during and after the injection in a column as well as the large (field-) scale container experiment. The new method was used to quantitatively monitor movement of iron colloids throughout the injection. To predict the results of the large scale experiment and later a field application, a method is being developed to upscale the results from column experiments. Additionally, within the ongoing EU research project AQUAREHAB the measuring technique is being further developed to make it suitable for field usage. |
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BibTeX:
@inproceedings{deboer++_2010c,
author = {de Boer, C.V. and Braun, J. and N. Klaas},
title = {Transport of zero-valent iron colloids in aquifers},
booktitle = {11th International UFZ- Deltares/TNO Conference on Management of Soil, Groundwater and Sediment (ConSoil 2010)},
year = {2010},
pages = {ThS A13},
note = {Oral Presentation}
}
|
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| de Boer, C., Braun, J. & Klaas, N. | Chemical Reduction of PCE by Zero Valent Iron Colloids - Comparison of Batch and Column Experiments | 2010 | 4th International Symposium on Permeable Reactive Barriers & Reactive Zones (PRB/RZ-2010) | inproceedings | |
| Abstract: In order to remove contaminants from the groundwater, a relatively new and promising method is the injection of an aqueous suspension of zero valent iron colloids into the subsurface using injection wells. The iron attaches to the sand grains and fills up favourite deposition sites in the porous medium to form a reactive zone. One of the advantages of this technology is the possibility to inject the reactants directly into the source zone. The reactant is then very close to the contaminant phase and chemically reduces the dissolved chlorinated solvent before the contaminants are being diluted, as it would be the case further downstream. The reaction close to the pure phase strongly reduces the contaminant concentration in water. This in turn increases the rate of dissolution and hence the remediation time. In order to determine degradation rates, and hence, longevity of the iron particles, batch experiments are conducted. However, the results are not directly transferable to the field scale since in batch experiments the contact between iron colloids and the chlorinated solvent is optimized by shaking or rotating the vial. In porous media flow, the distribution of the chlorinated solvent is diffusion controlled resulting in a decrease in the availability of contaminants for the chemical reduction. In addition, the corrosion is self inhibiting due to the rising pH which does not occur in the field, where the continuous flow of fresh ground water keeps the pH neutral. In the field the corrosion is thus much stronger, which shortens the longevity and, moreover, hydrogen as a by-product of the corrosion process will be produced. If this happens in larger amounts, the hydrogen becomes a separate gas phase and can clog the porous medium. The continuous delivery of fresh water thus is necessary to be able to transfer the lab results to the field situation. Preliminary column experiments have therefore been performed. These experiments showed that the production of hydrogen gas could be reduced by adding burned chalk (Ca(OH)2) in granular form to the suspension during injection. |
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BibTeX:
@inproceedings{deboer++_2010e,
author = {de Boer, C.V. and Braun, J. and N. Klaas},
title = {Chemical Reduction of PCE by Zero Valent Iron Colloids - Comparison of Batch and Column Experiments},
booktitle = {4th International Symposium on Permeable Reactive Barriers & Reactive Zones (PRB/RZ-2010)},
year = {2010},
note = {Oral Pressentation}
}
|
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| de Boer, C., Braun, J. & Klaas, N. | Injection of Nano-Scale Iron for the In-Situ Remediation of Contaminated Groundwater | 2009 | International Conference on Non-linearities and Upscaling in Porous Media | inproceedings | |
| Abstract: In order to remove contaminant plumes from the groundwater, permeable reactive barriers can be used. Instead of an excavated trench filled with granular zero-valent iron, a relatively new and promising method is the injection of nano-scale iron suspension in the subsurface using injection wells. The goal is to deposit the iron in the pores space and hence form an injected reactive barrier. However, little is known about the transport behavior of nano-scale iron during the injection. A better understanding of the transport behavior is necessary to design a field application such that the reactive barrier will be continuous in space and sufficiently wide. So far, there are no measuring techniques available to continuously and non-destructively determine the nano-scale iron concentration in the soil directly. Hence, the spreading and distribution of the nano-scale iron in the subsurface during injection could not be proven. In the presented work, measuring devices w ith a very high resolution based upon magnetic susceptibility have been developed to non-destructively determine the concentration of nano-scale iron during and after the injection in a column and in a large-scale container experiment. Several batch, horizontal column and container experiments were conducted to find the parameters controlling the reactivity, longevity and mobility of nano-scale iron in the subsurface. In a field application the injection in a well would result in a radial flow field around the well. A large scale experiment was constructed to create such a 2-D radial flow field in a confined aquifer, also the experiment was equipped with the newly developed measuring technique. To predict the results of the large scale experiment and later a field application, a method is being developed to combine and upscale the results from column experiments. |
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BibTeX:
@inproceedings{deboer++_2009b,
author = {de Boer, C.V. and Braun, J. and N. Klaas},
title = {Injection of Nano-Scale Iron for the In-Situ Remediation of Contaminated Groundwater},
booktitle = {International Conference on Non-linearities and Upscaling in Porous Media},
year = {2009},
note = {Poster Presentation}
}
|
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| de Boer, C., Braun, J., Klaas, N. & Steiert, S. | Injection of Nano-Scale Iron for the In-Situ Remediation of Chlorinated Hydrocarbons in Soil and Groundwater [BibTeX] |
2008 | Flow & Transport in Permeable Media, Gordon Research Conferences, 13 - 18 July, Magdalan College, Oxford, United Kingdom | conference | URL |
BibTeX:
@conference{deboer_gordon2008,
author = {de Boer, C. and Braun, J. and Klaas, N. and Steiert, S.},
title = {Injection of Nano-Scale Iron for the In-Situ Remediation of Chlorinated Hydrocarbons in Soil and Groundwater},
booktitle = {Flow & Transport in Permeable Media, Gordon Research Conferences, 13 - 18 July, Magdalan College, Oxford, United Kingdom},
year = {2008},
url = {http://www.cjestmir.com/science/bib/Gordon_2008_CVdeBoer_Poster.pdf}
}
|
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| de Boer, C. & Klaas, N. | Grundlagenuntersuchungen zum hydraulischen Verhalten von Nano-Eisen im Aquifer [BibTeX] |
2006 | VEGAS - Statuskolloquium 2006, pp. 88-94 | inproceedings | |
BibTeX:
@inproceedings{deboer+klaas_2006,
author = {de Boer, C.V. and N. Klaas},
title = {Grundlagenuntersuchungen zum hydraulischen Verhalten von Nano-Eisen im Aquifer},
booktitle = {VEGAS - Statuskolloquium 2006},
year = {2006},
pages = {88-94},
note = {Oral Presentation}
}
|
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| de Boer, C., Klaas, N. & Braun, J. | Injektion von Nano-Eisen zur LHKW-Sanierung - Ergebnisse aus VEGAS-Laboruntersuchungen. [BibTeX] |
2007 | VEGAS-Statuskolloquium 2007 | inproceedings | |
BibTeX:
@inproceedings{deboer++_2007a,
author = {de Boer, C.V. and Klaas, N. and J. Braun},
title = {Injektion von Nano-Eisen zur LHKW-Sanierung - Ergebnisse aus VEGAS-Laboruntersuchungen.},
booktitle = {VEGAS-Statuskolloquium 2007},
publisher = {Eigenverlag, Institut für Wasserbau, Universität Stuttgart},
year = {2007},
note = {Oral Presentation}
}
|
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| de Boer, C., Klaas, N. & Braun, J. | Measuring Techniques to Monitor the Application of Nano-Sized Zero-Valent Iron for Subsurface Remediation [BibTeX] |
2010 | VEGAS-Kolloquium 2010 In-Situ-Sanierung - Stand und Entwicklung Nano und ISCO, pp. 91-99 | inproceedings | |
BibTeX:
@inproceedings{deboer++_2010b,
author = {de Boer, C.V. and Klaas, N. and J. Braun},
title = {Measuring Techniques to Monitor the Application of Nano-Sized Zero-Valent Iron for Subsurface Remediation},
booktitle = {VEGAS-Kolloquium 2010 In-Situ-Sanierung - Stand und Entwicklung Nano und ISCO},
publisher = {Eigenverlag, Institut für Wasserbau, Universität Stuttgart},
year = {2010},
pages = {91-99},
note = {Oral Presentation}
}
|
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| de Boer, C., Klaas, N. & Braun, J. | Verification of Transport of Zero-Valent Iron Colloids in Porous Media [BibTeX] |
2010 | 4th International Symposium on Permeable Reactive Barriers & Reactive Zones (PRB/RZ-2010) | inproceedings | |
BibTeX:
@inproceedings{deboer++_2010d,
author = {de Boer, C.V. and Klaas, N. and J. Braun},
title = {Verification of Transport of Zero-Valent Iron Colloids in Porous Media},
booktitle = {4th International Symposium on Permeable Reactive Barriers & Reactive Zones (PRB/RZ-2010)},
year = {2010},
note = {Poster Presentation}
}
|
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| de Boer, C., Klaas, N., Braun, J. & Steiert, S. | Transport und Reaktivität von nullwertigen Eisenkolloiden im Untergrund | 2010 | Wasser 2010 - Jahrestagung der Wasserchemischen Gesellschaft | inproceedings | |
| Abstract: Der Einsatz von Eisensuspensionen zur Sanierung von Grundwasserschäden mit CKW stellt eine interessante Alternative zu reaktiven Wänden dar, in denen granulares Eisen mit Tiefbaumethoden in den Untergrund eingebaut wird. Während diese reaktiven Wände nur zur Sanierung von Schadstofffahnen im Abstrom geeignet sind, können Eisenkolloide auch direkt in den Schadensherd injiziert werden und so die Sanierungszeit effektiv herabsetzen. In den meisten Untersuchungen aus der Literatur wird die Reaktivität des Eisens anhand von Batch-Versuchen beschrieben. In der vorliegenden Arbeit konnte gezeigt werden, dass durch die Selbstinhibierung der Korrosion durch das Ansteigen des pH-Werts in Batch-Tests die Verhältnisse in durchströmten Systemen, wie sie auch im Feld vorliegen, nicht richtig erfasst werden. Ohne eine gezielte Anpassung des pH-Werts scheint nach den vorliegenden Ergebnissen ein Einsatz von Eisenkolloiden wegen der zu erwartenden Probleme mit Korrosion und damit die Bildung von Wasserstoff nicht erfolgversprechend. Dies könnte auch einen Grund für einen Teil der gescheiterten Feldanwendungen darstellen. Im Rahmen der vorliegenden Arbeit wurde eine Methodik entwickelt, mit der es möglich ist, das Ausbreitungsverhalten von Kolloidsuspensionen systematisch zu untersuchen. Dazu wurden die einzelnen Parameter, die einen möglichen Einfluss auf das Transportverhalten haben isoliert und in einer eindimensionalen Anordnung untersucht. Durch die Entwicklung einer Methode zur Eisenbestimmung mit einem modifizierten Metall-Suchgerät konnten die Grundlagen gelegt werden für eine quantitative Beschreibung der Einflussfaktoren. |
|||||
BibTeX:
@inproceedings{deboer++_2010a,
author = {de Boer, C.V. and Klaas, N. and Braun, J. and S. Steiert},
title = {Transport und Reaktivität von nullwertigen Eisenkolloiden im Untergrund},
booktitle = {Wasser 2010 - Jahrestagung der Wasserchemischen Gesellschaft},
year = {2010},
note = {Poster Presentation}
}
|
|||||
| de Boer, C., Steiert, S., Klaas, N. & Braun, J. | Reaktivität und Langzeitstabilität von nullwertigem Nano-Eisen bei der Sanierung von Grundwasserschadensfällen [BibTeX] |
2008 | VEGAS-Kolloquium 2008, Ressource Fläche III, pp. 113-122 | inproceedings | |
BibTeX:
@inproceedings{deboer++_2008,
author = {de Boer, C.V. and Steiert, S. and Klaas, N. and J. Braun},
title = {Reaktivität und Langzeitstabilität von nullwertigem Nano-Eisen bei der Sanierung von Grundwasserschadensfällen},
booktitle = {VEGAS-Kolloquium 2008, Ressource Fläche III},
year = {2008},
pages = {113-122},
note = {Oral Presentation}
}
|
|||||
| Braun, J., de Boer, C. & Klaas, N. | Nano-Partikel: Strömung und Transport im Untergrund [BibTeX] |
2010 | VEGAS-Kolloquium 2010 In-Situ-Sanierung - Stand und Entwicklung Nano und ISCO, pp. 51-60 | inproceedings | |
BibTeX:
@inproceedings{braun++_2010,
author = {Braun, J. and de Boer, C.V. and N. Klaas},
title = {Nano-Partikel: Strömung und Transport im Untergrund},
booktitle = {VEGAS-Kolloquium 2010 In-Situ-Sanierung - Stand und Entwicklung Nano und ISCO},
publisher = {Eigenverlag, Institut für Wasserbau, Universität Stuttgart},
year = {2010},
pages = {51-60},
note = {Oral Presentation}
}
|
|||||
| Steiert, S., de Boer, C., Klaas, N. & Braun, J. | Reactivity and longevity of zero-valent nano iron for the in-situ remediation of CHC-contaminated groundwater | 2009 | International Conference on Non-linearities and Upscaling in Porous Media | inproceedings | |
| Abstract: In recent years permeable reactive barriers (PRBs) have been used more and more to remediate groundwater polluted with chlorinated hydrocarbons (CHCs). Thereby the usage of zero-valent iron as a reductive component has proved its worth. A new alternative to build a PRB is the injection of zero-valent nano-sized iron particles suspended in water. The reactive iron is distributed in the pore space by injecting the suspension into a well to form a “reactive zone”. Contaminants in the groundwater that pass through this reactive zone are chemically reduced to environmental benign products. The goal of the presented work was to investigate the reactivity and longevity of zero valent nano iron with the model contaminant Perchloroethylene (PCE) at the laboratory and semi-field scale. In batch experiments under ideal conditions as well as in a simulation of a natural aquifer in column experiments it was shown that it is possible to degrade PCE with the used reactive nano iron particles (RNIP). Anaerobic corrosion reduces in time the amount of zero valent iron and releases hydrogen (H2) gas in a stored suspension. Therefore a simple construction was designed to determine the actual weight percentage of zero valent iron in the suspension. The results of the batch experiments showed that due to anaerobic corrosion a certain stoichiometrical excess of iron compared to the pollutant is needed for full degradation. Furthermore the batch experiments showed that it was possible to eliminate 60% of the model contaminant within 42 days. The hydrogen production caused clogging of the pore space in the column experiments. This proved that the particles are not stable in a pH-neutral environment. In following column experiments calcium hydroxide (slaked lime) was added to the nano iron suspension before the injection into the column. With this modification the hydrogen production was reduced severely and the long-term stability was increased considerably. This approach has been filed for patent in Germany by VEGAS. |
|||||
BibTeX:
@inproceedings{steiert++_2009,
author = {Steiert, S. and de Boer, C.V. and Klaas, N. and J. Braun},
title = {Reactivity and longevity of zero-valent nano iron for the in-situ remediation of CHC-contaminated groundwater},
booktitle = {International Conference on Non-linearities and Upscaling in Porous Media},
year = {2009},
note = {Poster Presentation}
}
|
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Created by JabRef on 01/08/2012.
Research projects I worked on (click on title for more info)
- Innovative Technologies for Groundwater Remediation (INTEGRATE) (08/2012 - Present)
- Development of rehabilitation technologies and approaches for multipressured degraded waters and the integration of their impact on river basin management (AQUAREHAB) (02/2009 - 03/2012)
- Injection of Nano-Scale Iron for the In-Situ Remediation of Chlorinated Hydrocarbons in Soil and Groundwater (Investigations on Transport in large-scale Experiments and in Field Applications) (06/2007 - 01/2009)
- Feasability Study on the In-Situ Application of Reactive Nano-Sized Iron Particles to Remediate CHC-Contaminations (10/2005 - 05/2007)
| Innovative Combined Treatment Technologies for Remediating Contaminated Groundwater |
| Finding solution to a legacy of contaminated soils and groundwater that exist throughout Canada in the form of brownfield sites is the target of our research group. We apply innovative combinations of treatment technologies that will lead to brownfield rehabilitation and allow for subsequent re-use of the land.
Contaminated industrial and commercial sites, also known as brownfield sites, here and abroad represent a significant economic opportunity. But redeveloping them is a challenge because current cleanup techniques are expensive and time consuming. At the University of Toronto, Prof. Brent Sleep is developing innovative water treatment technologies to restore these properties, research that will help to put Ontario companies at the leading edge of the fast growing site redevelopment market. This project is a collaboration of University of Toronto, Western University, and Queens University. It involves the private sector and this partnership will allow field trials involving a wide variety of contaminants, including chlorinated solvents and fuels. |
| Source: integrate.utoronto.ca |
| Project manager: | Juergen Braun, Ph.D. | |
| Deputy: | Dr.-Ing. Norbert Klaas, M.Sc. | |
| Research assistants: | Cjestmir de Boer, M.Sc. | |
| Duration: | 1.5.2009 - 31.1.2014 | |
| Funding: | The European Commission through the 7th Research Framework Programme | |
| Source: | Link | |
Abstract: Please click here for more information. | ||
| Project manager: | Juergen Braun, Ph.D. | |
| Deputy: | Dr.-Ing. Norbert Klaas, M.Sc. | |
| Research assistants: | Cjestmir de Boer, M.Sc. | |
| Duration: | 1.8.2007 - 31.12.2008 | |
| Funding: | Umweltministerium Baden-Wuerttemberg, Foerderprogramm: Betriebliche Umwelttechnik | |
| Project Partners: | Alenco Environmental Consult GmbH | |
| Source: | Link | |
Abstract: Permeable reactive barriers have been extensively used and investigated. Their disadvantages include the cost of implementation which increases with increasing depth, the requirement of open access to machinery and the restriction to the treatment of contaminant plumes. A relatively new and promising method to overcome these obstacles is the injection of nano-scale zero-valent iron suspended in water into the subsurface. The idea is that this iron will be transported with the injected water to form a reactive wall (plume treatment). Alternatively, the iron may be injected directly into the source (source treatment).The method has been applied at several locations around the world; however, to date not much is known about the transport distance of nano-iron and hence the effectiveness, of this technology. While reports on transport distance range from few centimetres to several meters (or even tens of meters), no direct measurement of the iron distribution has been made and reports about the distance are based on the measurement of secondary parameters. During previous experiments at VEGAS (Feasability Study on the In-Situ Application of Reactive Nano-Sized Iron Particles to Remediate CHC-Contaminations), horizontal column experiments were performed. Additionally, a measuring technique, based upon the magnetic susceptibility was developed to determine the transport distance of the nano-iron.. In these experiments, the qualitative and (semi-)quantitative influence of various parameters on the transport distance were investigated.
In the current project the column experiments will be continued in order to better quantify the parameters that influence the transport distance of nano-iron. | ||
| Project manager: | Juergen Braun, Ph.D. | |
| Deputy: | Dr.-Ing. Norbert Klaas, M.Sc. | |
| Research assistants: | Cjestmir de Boer, M.Sc. | |
| Duration: | 1.10.2005 - 1.5.2007 | |
| Funding: | Baden-Wuerttemberg Programm Lebensgrundlage Umwelt und ihre Sicherung (BWPLUS) | |
| Source: | Link | |
Abstract: Aquifers contaminated with chlorinated solvents promises to be very effectively remediated with reactive nano-iron. The large specific surface of nano-iron results in extremely fast reaction rates. Due to the small size, the particles are thought of to be able to be injected into the aquifer and reach the contaminants through simple injection wells. So far, very little is known about the exact transport capacity of nano-iron. In the literature the claims toward this differ greatly. In this research project, systematic experiments were conducted to get a better understanding of the mobility and characteristics of nano-iron. It was shown that the transport distance of nano-iron particles was affected by the age (and with that the aggregation stage) of the particles, by the discharge and the concentration of the suspension during injection, by the grain size distribution, as well as the permeability and heterogeneity of the porous media. There was no significant change in the retardation of nano-iron at different velocities. Apart from the experiments, a technology to accurately and non-destructively measure the concentration distribution of nano-iron in a column was developed. | ||
YoungNano
 |
At the University of Stuttgart I initiated a network to discuss ideas and problems regarding nano colloids in the subsurface. By using a very successful formula we were able to have very constructive and open discussions. The main differences with a general conference was that we didn't let supervisors be present and that each short presentation was followed by a much longer discussion round about the presented topic. I had set up a mailing list and also wrote a website for our YoungNano network which could be found at www.YoungNano.eu, currently only a snapshot of the site from just before closing the network down is shown on my own domain.
I collected a set of various links to nano related research and information websites, which can be found here: NanoLinks |