Niels Hartog

Niels Hartog
KWR Water Research Institute · Water Systems & Technology Research Group

32.16
 · 
PhD in Geochemistry, MSc in Contaminant Hydrogeology
About
96
Research items
12,685
Reads
654
Citations
Research Experience
Jan 2013
Utrecht University
Position
  • Guest Associate Professor in Environmental Hydrogeology
Nov 2012
KWR Water Research Institute
Position
  • Senior Researcher
Aug 2003 - Aug 2006
University of Waterloo
Position
  • Post-Doctoral Research Fellow
Network
Cited By
Followers
Following
Projects
Projects (6)
Project
Research focussing on the interdependencies between operational and environmental factors and risks, geothermal brine chemistries and operational conditions
Archived project
Research
Research items (96)
Article
Full-text available
Managed Aquifer Recharge (MAR) is a promising method of increasing water availability in water stressed areas by subsurface infiltration and storage, to overcome periods of drought, and to stabilize or even reverse salinization of coastal aquifers. Moreover, MAR could be a key technique in making alternative water resources available, such as reuse...
Article
Full-text available
Different types of managed aquifer recharge (MAR) schemes are widely distributed and applied on various scales and for various purposes in the European countries, but a systematic categorization and compilation of data has been missing up to now. The European MAR catalogue presented herein contains various key parameters collected from the availabl...
Article
Full-text available
The use of multiple partially penetrating wells (MPPW) during aquifer storage and recovery (ASR) in brackish aquifers can significantly improve the recovery efficiency (RE) of unmixed injected water. The water quality changes by reactive transport processes in a field MPPW-ASR system and their impact on RE were analyzed. The oxic freshwater injecte...
Article
Full-text available
Aquifer thermal energy storage (ATES) is a technology with worldwide potential to provide sustainable space heating and cooling using groundwater stored at different temperatures. The thermal recovery efficiency is one of the main parameters that determines the overall energy savings of ATES systems and is affected by storage specifics and site-spe...
Article
Full-text available
The efficiency of heat recovery in high-temperature (>60 °C) aquifer thermal energy storage (HT-ATES) systems is limited due to the buoyancy of the injected hot water. This study investigates the potential to improve the efficiency through compensation of the density difference by increased salinity of the injected hot water for a single injection-...
Conference Paper
Full-text available
Aquifer Thermal Energy Storage (ATES) systems combined with a heat pump save energy for space heating and cooling of buildings. In most countries the temperature of the stored heat is allowed up to 25-30°C. However, when heat is available at higher temperatures (e.g. waste heat, solar heat), it is more efficient to store higher temperatures because...
Conference Paper
Full-text available
Energy consumption for space heating and cooling of buildings can be decreased by 40-80% by use of Aquifer Thermal Energy Storage (ATES). ATES is a proven technique, however, it is not known how efficient currently operating systems are recovering stored energy from the subsurface and how this can be determined with available data. Recent research...
Conference Paper
Full-text available
To minimize fossil fuel combustion, geothermal heat production is increasingly applied in the horticultural sector and for domestic heating in The Netherlands. One of the major operational challenges for further development of geothermal energy in The Netherlands is dealing with the large volumes of geothermal brine that are produced during well de...
Article
Full-text available
Methane leakage caused by well integrity failure was assessed at 28 abandoned gas wells and 1 oil well in the Netherlands, which have been plugged, cut and buried to below the ground surface (≥3 mbgl). At each location, methane concentrations were thoroughly scanned at the surface. A static chamber setup was used to measure methane flow rates from...
Article
Aquifer thermal energy storage (ATES) is a technology with worldwide potential to provide sustainable space heating and cooling using groundwater stored at different temperatures. The thermal recovery efficiency is one of the main parameters that determines the overall energy savings of ATES systems and is affected by storage specifics and site-spe...
Article
Full-text available
Industrial use has led to the presence of liquid elemental mercury (Hg0) worldwide in the subsurface as Dense NonAqueous Phase Liquid (DNAPL), resulting in long lasting sources of contamination, which cause harmful effects on human health and detrimental consequences on ecosystems. However, to date, insight into the infiltration behaviour of elemen...
Answer
Thanks Julio for the update, very interesting! Good luck with your research,
Niels
Answer
You're welcome Julio, hope you're able to make some progress with your interesting quest. If you have further questions or need some help, let me know. Curious about the root of your quest... distinction of natural vs. contaminated for legal purposes?
In addition, one aspect on natural mercury that came up in a recent discussion on LinkedIn was also it's use in mineral prospecting (https://goo.gl/8xWpo9).
Answer
Hi Julio,
Yes, liquid natural elemental mercury does occur. A well known source is the production of elemental Hg with natural gas production which then condenses. A lesser known source is the production of elemental mercury during in (deeply) anoxic aquifers where Hg2+ (and Hg+ for that matter) can start to act as an electron acceptor. This process results in the production of liquid elemental mercury.
Hope this helps! If you're interested I have a few articles Hg contamination and treatment in my profile.
Best regards,
Niels
Article
Full-text available
Liquid elemental mercury occurrence in the subsurface as DNAPL is reported worldwide in proximity of several industrial facilities, such as chlor-alkali plants. Insight into Hg0 DNAPL infiltration behaviour is lacking and, to date, there are no experimental observations of its infiltration and distribution in water saturated porous media, except fo...
Answer
Dear Xiao,
Chlorinated solvents are only heavier than water when you consider them as a separate non-aqueous phase liquid (NAPL). Because of the low solubility you mention, the dissolution of chlorinated solvents in water does not increase the density of water significantly to drive downward transport.
However, for the conditions of a plume coming out of a landfill, the salinity of that plume can be high enough to facilitate density-driven downward flow of that plume with its constituents (e.g. dissolved chlorinated solvents). For such conditions of density dependent transport of water you can use groundwater codes such as MODFLOW coupled to SEAWAT to account for density-dependent groundwater flow. Just to emphasize, you cannot use these codes to model the transport of a separate chlorinated solvent phase heavier than water.
In my research I use MODFLOW-SEAWAT to simulate density effects for the storage of fresh (lighter) water (lighter) in brackish/saline (heavier) groundwater aquifers (aquifer storage and recovery, e.g.: goo.gl/c5i2Gp) or the storage of hot (lighter) water in cooler (heavier) groundwater aquifers (High Temperature Aquifer Thermal Energy Storage, HT-ATES).
Good luck, I hope this helps :)
Niels
Answer
Hi Xiao Zhang,
You'll need a model code that can describe multi-phase flow. Examples are UTHCHEM or STOMP. Typically flow is described in more than just the vertical direction to allow for some lateral spreading, but can 1-D can be considered too.
If you're interested in an example, this study includes the 1-D multi-phase simulation of liquid mercury (even higher density) with STOMP: goo.gl/GYz1HW
Best regards,
Niels
Article
Full-text available
Mercury is a contaminant of global concern due to its harmful effects on human health and for the detrimental consequences of its release in the environment. Sources of liquid elemental mercury are usually anthropogenic, such as chlor-alkali plants. To date insight into the infiltration behaviour of liquid elemental mercury in the subsurface is lac...
Article
Full-text available
Blowouts present a small but genuine risk when drilling into the deep subsurface and can have an immediate and significant impact on the surrounding environment. Nevertheless, studies that document their long-term impact are scarce. In 1965, a catastrophic underground blowout occurred during the drilling of a gas well in The Netherlands, which led...
Article
Full-text available
Bodemenergiesystemen worden veelvuldig toegepast om energie te besparen. De warmtepomp van zulke systemen gebruikt echter nog altijd veel elektriciteit, waardoor voor grootschalige toepassing ook grootschalige netverzwaring nodig is. Daarom is het voor de verduurzaming van de gebouwde omgeving belangrijk om alternatieve duurzame technieken voor ver...
Answer
Hi Jos, nice to see you're working on mercury also :) Partitioning of mercury is a challenging topic in my view, partly because of the potential for redox transformation of the mercury in addition to sorption processes. Though not in sediment/soil, I was involved with a study looking into partioining of ionic mercury on cork stoppers. Maybe you find it usefull:
CB Lopes, JR Oliveira, LS Rocha, DS Tavares, CM Silva, SP Silva, N Hartog, AC Duarte, and E Pereira, Cork stoppers as an effective sorbent for water treatment: the removal of mercury at environmentally relevant concentrations and conditions. Environmental Science and Pollution Research, 2014. 21 (3): p. 2108-2121
Most recently I supervised a PhD research on elemental mercury in soils by Andrea D'Aniello, if you're interested we can discuss that too.
Good luck with the research,
Niels
Article
Full-text available
In several places in The Netherlands, industrial areas are redeveloped into residential areas with sustainable heating systems based on aquifer thermal energy storages (ATES). At these sites, groundwater is contaminated with chlorinated ethenes. In this project various pilot set-ups were tested as a non-invasive technique to remove chlorinated ethe...
Article
Full-text available
To be able to overcome water shortages, Abu Dhabi Emirate started an Aquifer Storage and Recovery (ASR) project with desalinated seawater (DSW) as source water near Liwa. It is the largest DSW-ASR project in the world (stored volume ~10 Mm³/year), and should recover potable water for direct use. DSW is infiltrated into a desert dune sand aquifer us...
Article
Full-text available
In this work we introduce a 1-D analytical solution that can be used for the design of horizontal permeable reactive barriers (HPRBs) as a vapor mitigation system at sites contaminated by chlorinated solvents. The developed model incorporates a transient diffusion-dominated transport with a second-order reaction rate constant. Furthermore, the mode...
Conference Paper
Full-text available
Aquifer thermal energy storage (ATES) is a technology to sustainably provide space heating and cooling. Particularly in The Netherlands the number of ATES systems has grown rapidly in the past decade, often with the (re)development of urban areas. To meet objectives for greenhouse gas emission reduction the number of ATES systems is expected and re...
Answer
That's right Moonmoon, if both models fit equally well and linearly you can't use them to distinguish between different types and complexities of sorption. So you would default to the simplest: a linear Freundlich Isotherm (K.c). This doesn't mean there aren't complexities, just that within the experimental range simple linear sorption dominates. I hope this helps
Best regards,
Niels
Answer
So if the experimental data shows strongly a linear trend, then there is no need to be surprised that when using linear forms of Freundlich and Langmuir isotherms they BOTH fit the data with very high correlation coefficients.
Answer
Hi Moonmoon,
Since you're fitting the Langmuir isotherm very well, I assume you're looking at non-linear adsorption behaviour and you're fitting an n<1 (Q=K.cPOW(1/n))for the Freundlich isotherm? In that case you don't have to be surprised that both models fit when it becomes a fitting excersize for the (semi-) emprical models.
Besides, both correlation coefficients are exceptionally high, do you have only a few data points? In any case, just the correlation coefficients are not enough to judge. Perhaps you could share a figure of the sorption data you are trying to fit?
Best regards,
Niels
Answer
Dear Koubaa,
In the Netherlands the boom of aquifer thermal energy storage systems for seasonal buffering between summer and winter has exactly done that.
Best regards,
Niels
Answer
Dear Nezha,
Typically Fe and Mn are indeed (positively) correlated. However, when dissolved Fe(II) is introduced in a Mn-oxide containing zone, the reduction of these oxides by Fe(II) results in a depletion of Mn-oxides and enrichment in Fe-oxide in the sediment. If this process is significant it would distort the Mn-Fe correlation till the point where all Mn-oxides have depleted. I'm attaching a recent publication where we observed this process. Not knowing the conditions in your lagoon, this might or might not be a usefull explanation for your observation. Let me know what you think :)
Good luck with your research,
Niels
Chapter
Full-text available
http://www.iwapublishing.com/books/9781780406992/filtration-materials-groundwater-guide-good-practice
Answer
Dear Kouakou,
What is the chemistry of the rock that the groundwater interacts with? If the rock the groundwater interacts contains magnesite than you would expect Mg to correlate with bicarbonate according:
MgCO3 + H2O + CO2 --> Mg2+ +  2HCO3-
Magnesite can also form from the weathering step of serpentine.
2 Mg3Si2O5(OH)4 + 3 CO2 --> Mg3Si4O10(OH)2 + 3 MgCO3 + H2O
Best regards,
Niels
Answer
Hi Roberto,
It sounds like you're having an injectivity problem. What are the chemical, physical conditions of your system? Poor injectivity in such wells can be caused by various precipitation/scaling reactions, for example due to mixing of different water chemistries, or a large difference between extraction and injection temperature. If you're injecting into a different aquifer than where you are extracting from this could also be a cause.
Curious to hear more about your system. Feel free to send me a message.
Best regards,
Niels
Article
Full-text available
The temperature inside wells used for gas, oil and geothermal energy production, as well as steam injection, is in general significantly higher than the groundwater temperature at shallower depths. While heat loss from these hot wells is known to occur, the extent to which this heat loss may result in density-driven flow and in mixing of surroundin...
Article
Full-text available
Polycyclic aromatic hydrocarbon (PAH)-degrading bacteria capable of growing under electrokinetic conditions were isolated using an adjusted acclimation and enrichment procedure based on soil contaminated with heavy PAHs in the presence of an electric field. Their ability to degrade heavy PAHs under an electric field was individually investigated in...
Answer
Hi Saad,
Not sure whether I understand your question fully, or the particular conditions you describe. Maybe you can explain further. But under the conditions of no pumps and no pressure differences the Archimedes' screw (screwpump) comes to mind. Or the use of buckets of course ;)
Hope this helps.
Best regards,
Niels
Article
Full-text available
Highlights • Published rate constants for pH-independent TCE oxidation by MnO4- lack consistency • Inapt use of pseudo-1st-order approach yields bias in rate constant estimates • Negative bias in 2nd-order rate constant estimates is below 5% for P/N over 40 • Range in rate constant estimates for pH-dependent oxidation calls for further study
Article
Full-text available
Permeable reactive barriers are commonly used to treat contaminant plumes in the saturated zone. However, no known applications of horizontal permeable reactive barriers (HPRBs) exist for oxidizing volatile organic compounds (VOCs) in the unsaturated zone. In this study, laboratory column experiments were carried out to investigate the ability of a...
Technical Report
Full-text available
The horticultural sector is making increasing use of geothermal heat as a renewable substitute for the burning of natural gas. However, so far many of the completed geothermal systems in the Netherlands do not function as planned. After heat extraction, the water is reinjected into the reservoir. A frequent problem with this is the poor injectivity...
Article
Full-text available
Water quality deterioration is a common occurrence that may limit the recovery of injected water during aquifer storage and recovery (ASR) operations. This limitation is often induced by the oxidation of the reduced aquifer components by the oxygenated injection water. This study explores the potential of aquifer pre-oxidation using permanganate to...
Answer
Hello Kshitiz,
Bromide would typically be measured using an ion chromatograph (IC). It would work with a saturated or unsaturated packed soil, as long your able to collect water samples at the bottom of the column. Since the bromide is negatively charged it would normally not suffer from adsorption to sands and soils that are typically positively charged as long conditions are not acidic. Assuming you have homogeneous soil conditions, the size of the column would be expected to relate linearly to your measured residence time.
Good luck,
Niels
Answer
Dear Kshitiz,
The anion bromide is a relatively low cost tracer that is often used to determine conservative (no interaction) transport parameters in sand. Sodium bromide salt can be used to make the tracer solution. Alternatively, you might want determine breakthrough visually after infiltrating water with any type of colourant added. This would be even more cost-effective, but would prohibit determination of dispersion factors. Hope this helps.
Best regards,
Niels
Article
Full-text available
Bioremediation is a safe and cost-effective technology for the removal of polycyclic aromatic hydrocarbons (PAHs) contaminated soils, but its remediation rate is usually very slow at soils contaminated with heavy PAHs in high concentrations. This paper describes the feasibility of using electrokinetics to enhance the degradation of heavy PAHs in so...
Answer
If it's pure calcite rather than a dolomite/ankerite matrix...wouldn't dilute HCl (0.1M) work for your purpose? A milder alternative could be to flush the samples with CO2-saturated water.
disclaimer: no experience with fossil extraction
Answer
Assuming a bulk atomic composition of CH2O often works well for the organic matter in sediments I studied. So then for the conversion you can use the molar weight ratio CH2O/C=30/2=15. The C:H of 0.5 is quite a bit higher than your 0.15. So you could use that together with other measurements or expectations on your bulk atomic composition to calculate another ratio.
I hope this helps.
Book
Full-text available
NanoRem (Taking Nanotechnological Remediation Processes from Lab Scale to End User Applications for the Restoration of a Clean Environment) is a research project, funded through the European Commission’s Framework 7 research programme. NanoRem focuses on facilitating practical, safe, economic and exploitable nanotechnology for in situ remediation....
Article
Full-text available
Mercury is a contaminant of global concern. The use of elemental mercury in various (former) industrial processes, such as chlorine production at chlor-alkali plants, is known to have resulted in soil and groundwater contaminations worldwide. However, the subsurface transport behaviour of elemental mercury as an immiscible dense non-aqueous phase l...
Article
Full-text available
The present study evaluated the coupling interactions between bioremediation (BIO) and electrokinetics (EK) in the remediation of total petroleum hydrocarbons (TPH) by using bio-electrokinetics (BIO-EK) with a rotatory 2-D electric field. The results demonstrated an obvious positive correlation between the degradation extents of TPH and electric in...
Article
Full-text available
The main aim of this work was to assess the potential of in situ carbonation as a treatment to modify the properties of alkaline materials such as industrial soil in terms of leaching behaviour and mineralogy and to store the CO2 generated by specific treatments applied in the context of Brownfield regeneration. The process was investigated through...
Article
Full-text available
The use of permanganate solutions for in-situ chemical oxidation (ISCO) is a well-established groundwater remediation technology, particularly for targeting chlorinated ethenes. The kinetics of oxidation reactions is an important ISCO remediation design aspect that affects the efficiency and oxidant persistence. The overall rate of the ISCO reactio...
Article
Full-text available
The technical feasibility of using stopper-derived cork as an effective biosorbent towards bivalent mercury at environmentally relevant concentrations and conditions was evaluated in this study. Only 25 mg/L of cork powder was able to achieve 94 % of mercury removal for an initial mercury concentration of 500 μg/L. It was found that under the condi...
Technical Report
Full-text available
This document presents the opportunities that Aquifer storage and recovery (ASR) projects may provide in urban, agricultural and industrial areas and is intended to be used by urban water utilities (such as drinking water companies), horticulture, industries and municipalities. At an introductory level, this document summarizes the relevant informa...
Article
Full-text available
Groundwater systems are increasingly used for seasonal aquifer thermal energy storage (SATES) for periodic heating and cooling of buildings. Its use is hampered in contaminated aquifers because of the potential environmental risks associated with the spreading of contaminated groundwater, but positive side effects, such as enhanced contaminant reme...
Article
Full-text available
Volatile organic compounds (VOCs) may frequently contaminate groundwater and pose threat to human health when migrating into the unsaturated soil zone and upward to the indoor air. The kinetic of chemical oxidation has been investigated widely for dissolved VOCs in the saturated zone. But, so far there have been few studies on the use of in situ ch...
Conference Paper
Full-text available
This study illustrates that several processes contribute to groundwater quality effects of ATES systems, in which the effect of mixing is predominant for the lowtemperature ATES systems studied. Only for ATES systems in aquifers with relatively homogeneous groundwater quality, minor temperature effects could be observed. At higher temperatures (>30...
Book
Full-text available
In the context of this report, unless otherwise specified, the term iron nanoparticles (NPs) refer to zero-valent (e.g. Fe(0)) as opposed to any of the oxidized nanoparticles of iron (e.g. Fe(II) or Fe(III) present in one or more forms of oxohydroxides, carbonates, or other species). In 2004, in a joint report, the Royal Society and Royal Academy o...
Article
Full-text available
The deep (>10 km) Permian to present day Perth Basin in southwest Western Australia is composed of sedimentary successions of continental to shallow marine origin. This study examines the compositional variation, weathering and provenance of the early Cretaceous Leederville Formation within the Perth Basin. Over 200 sediment samples were retrieved...