References of "Orban, Philippe"
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See detailPotentiel de valorisation de sites miniers et carriers en step en France et en Belgique
Gombert, Philippe; Poulain, Angélique; Goderniaux, Pascal et al

in La Houille Blanche (2020), 4

Pumped Hydro-Energy Storage (PHES) account for more than 97% of the world's electrical energy storage and cumulate approximately 170 GW of installed capacity. France and Belgium currently have 9 PHES with ... [more ▼]

Pumped Hydro-Energy Storage (PHES) account for more than 97% of the world's electrical energy storage and cumulate approximately 170 GW of installed capacity. France and Belgium currently have 9 PHES with a total capacity of 6.3 GW, but there are no longer any new sites acceptable for conventional PHES as they require the excavation of two basins on the surface, and can only be installed in areas with a marked relief. Following the foreseeable demand for energy storage generated by the development of intermittent renewable energies, it is proposed to study the possibility of creating new non-conventional PHES using existing basins in abandoned mines or quarries. These may be surface or underground basins, the latter providing access to subterranean or semi-subterranean PHES technology (3S-PHES). This paper describes the potential of these new PHES technologies and the risks and impacts they are likely to generate. These risks concern first of all adjacent aquifers: hydromechanical disturbances (propagation of water level variations in the aquifer) and hydrochemical interactions (precipitation of carbonates and iron oxides). They also concern the ground surface with the possibility of ground movements or surface gas emissions. However, these are risks that have already been identified and controlled in the context of other underground activities. [less ▲]

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See detailHydrogeological characterization and hydrodynamic behaviour of the overexploited Diass aquifer system (Senegal) inferred from long term groundwater level monitoring
Madioune, Hélène Diakher; Diaw, Moctar; Mall, Ibrahima et al

in American Journal of Water Resources (2020), 8(3), 104-117

Dakar, the Capital city of Senegal concentrates about 23.2% (about 3 millions inhabitants) of the total population and a large proportion of the industrial activities. Water supply is ensured by surface ... [more ▼]

Dakar, the Capital city of Senegal concentrates about 23.2% (about 3 millions inhabitants) of the total population and a large proportion of the industrial activities. Water supply is ensured by surface water pumped and piped from the Guiers Lake (250 km distant from the capital) and from groundwater resources. Among these latter, the Diass aquifer system contributes to a substantial proportion (31% in 2019) of the total water supply distribution due to growing demand induced by the rapid demographic growth (about 2.5%). The Diass horst aquifer system located 50 km east of Dakar (Senegal) is exploited with two main aquifers covered by a sandy superficial aquifer: the confined/unconfined Palaeocene karstic limestone and the confined Maastrichtian sandstone aquifer underneath. This system has experienced intensive groundwater abstraction during the last 60 years to meet the increasing water demand. Abstraction for urban drinking water occurs in nine pumping fields with a rate reaching 174,000 m3/d in 2019. This high yield together with the drought conditions since the 1970s is likely to affect groundwater imbalance and change the flow regime. The objective of the study is to improve our understanding of the system dynamic with regards to the high pumping rate in order to build a conceptual scheme for further hydrogeological modeling of the system. In this study, we use monitored pumping rates, piezometric level from 1960s to 2019 and rainfall data from 1931 to December 2016 together with the hydrogeological configuration to infer the dynamics of the aquifer system. The high abstraction rate during the period 1958-2019 which vary from 16,000 to 174,000 m3/d has caused a continuous groundwater level decline (up to 30 m), a modification of the flow patterns and to some extent a quality deterioration through salinization processes as shown in a few boreholes in Sébikotane and Mbour. The piezometric levels which were above the sea level prior 1959 exhibit now negative values and can even reach -40 m in the vicinity of the pumping fields creating therefore piezometric depressions and convergent flow pattern. The hydrodynamic of the system derived from the results show that the reservoir acts as a multilayer aquifer system with interconnected compartments by faults that allow flux exchanges except the confining Ponty and Sébikotane faults. Overexploitation inducing important drawdown has induced an increase of the drainance fluxes between those different compartments. In order to foster more appropriate and sustainable groundwater abstraction in the complex hydrogeological system with regards to demand and water quality conservation, it is important to assess the main system behavior. [less ▲]

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See detailUnderground pumped-storage hydropower (UPSH) at the Martelange mine (Belgium): interactions with groundwater flow
Pujades, Estanislao; Orban, Philippe ULiege; Archambeau, Pierre ULiege et al

in Energies (2020), 13

Underground pumped-storage hydropower (UPSH) is a promising technology to manage the electricity production in flat regions. UPSH plants consist of an underground and surface reservoirs. The energy is ... [more ▼]

Underground pumped-storage hydropower (UPSH) is a promising technology to manage the electricity production in flat regions. UPSH plants consist of an underground and surface reservoirs. The energy is stored by pumping water from the underground to the surface reservoir and is produced by discharging water from the surface to the underground reservoir. The underground reservoir can be drilled, but a more efficient alternative, considered here, consists in using an abandoned mine. Given that mines are rarely waterproofed, there are concerns about the consequences (on the efficiency and the environment) of water exchanges between the underground reservoir and the surrounding medium. This work investigates numerically such water exchanges and their consequences. Numerical models are based on a real abandoned mine located in Belgium (Martelange slate mine) that is considered as a potential site to construct an UPSH plant. The model integrates the geometrical complexity of the mine, adopts an operation scenario based on actual electricity prices, simulates the behavior of the system during one year and considers two realistic scenarios of initial conditions with the underground reservoir being either completely full or totally drained. The results show that (1) water exchanges may have important consequences in terms of efficiency and environmental impacts, (2) the influence of the initial conditions is only relevant during early times, and (3), an important factor controlling the water exchanges and their consequences may be the relative location of the natural piezometric head with respect the underground reservoir. [less ▲]

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See detailInnovative contaminant mass flux monitoring in an aquifer subject to tidal effects.
Jamin, Pierre ULiege; Cosme, Frédéric; Briers, Pierre ULiege et al

in Groundwater Monitoring & Remediation (2020), (Winter),

Exposure from groundwater contamination to aquatic receptors residing in receiving surface water is dependent upon the rate of contaminated groundwater discharge. Characterization of groundwater fluxes is ... [more ▼]

Exposure from groundwater contamination to aquatic receptors residing in receiving surface water is dependent upon the rate of contaminated groundwater discharge. Characterization of groundwater fluxes is challenging, especially in coastal environments where tidal fluctuations result in transient groundwater flows towards these receptors. This can also be further complicated by the high spatial heterogeneity of subsurface deposits enhanced by anthropogenic influences such as the mixing of natural sediments and backfill materials, the presence of subsurface built structures such as sheet pile walls or even occurrence of other sources of contaminant discharge. In this study, the Finite Volume Point Dilution Method (FVPDM) was successfully used to characterize highly transient groundwater flows and contaminant mass fluxes within a coastal groundwater flow system influenced by marked tides. FVPDM tests were undertaken continuously for more than 48 hours at 6 groundwater monitoring wells, in order to evaluate groundwater flow dynamics during several tide cycles. Contaminant concentrations were measured simultaneously which allowed calculating contaminant mass fluxes. The study highlighted the importance of the aquifer heterogeneity, with groundwater fluxes ranging from 10-7 to 10-3 m s-1. Groundwater flux monitoring enabled a significant refinement of the conceptual site model, including the fact that inversion of groundwater fluxes was not observed at high tide. Results indicated that contaminant mass fluxes were particularly higher at a specific monitoring well, by more than 3 orders of magnitude, than at other wells of the investigated aquifer. This study provided crucial information for optimizing further field investigations and risk mitigation measures. [less ▲]

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See detailUnderground Pumped-Storage Hydropower (UPSH) at the Martelange Mine (Belgium): Underground Reservoir Hydraulics
Kitsikoudis, Vasileios ULiege; Archambeau, Pierre ULiege; Dewals, Benjamin ULiege et al

in Energies (2020), 13(14), 3512

The intermittent nature of most renewable energy sources requires their coupling with an energy storage system, with pumped storage hydropower (PSH) being one popular option. However, PSH cannot always be ... [more ▼]

The intermittent nature of most renewable energy sources requires their coupling with an energy storage system, with pumped storage hydropower (PSH) being one popular option. However, PSH cannot always be constructed due to topographic, environmental, and societal constraints, among others. Underground pumped storage hydropower (UPSH) has recently gained popularity as a viable alternative and may utilize abandoned mines for the construction of the lower reservoir in the underground. Such underground mines may have complex geometries and the injection/pumping of large volumes of water with high discharge could lead to uneven water level distribution over the underground reservoir subparts. This can temporarily influence the head difference between the upper and lower reservoirs of the UPSH, thus affecting the efficiency of the plant or inducing structural stability problems. The present study considers an abandoned slate mine in Martelange in Southeast Belgium as the lower, underground, reservoir of an UPSH plant and analyzes its hydraulic behavior. The abandoned slate mine consists of nine large chambers with a total volume of about 550,000 m3, whereas the maximum pumping and turbining discharges are 22.2 m3/s. The chambers have different size and they are interconnected with small galleries with limited discharge capacity that may hinder the flow exchange between adjacent chambers. The objective of this study is to quantify the effect of the connecting galleries cross-section and the chambers adequate aeration on the water level variations in the underground reservoir, considering a possible operation scenario build upon current electricity prices and using an original hydraulic modelling approach. The results highlight the importance of adequate ventilation of the chambers in order to reach the same equilibrium water level across all communicating chambers. For fully aerated chambers, the connecting galleries should have a total cross-sectional area of at least 15 m2 to allow water flow through them without significant restrictions and maintain similar water level at all times. Partially aerated chambers do not attain the same water level because of the entrapped air; however, the maximum water level differences between adjacent chambers remain relatively invariant when the total cross-sectional area of the connecting galleries is greater than 8 m2. The variation of hydraulic roughness of the connecting galleries affects the water exchange through small connecting galleries but is not very influential on water moving through galleries with large cross-sections. [less ▲]

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See detailUnderstanding Groundwater Mineralization Changes of a Belgian Chalky Aquifer in the Presence of 1,1,1-Trichloroethane Degradation Reactions
Boudjana, Youcef ULiege; Brouyère, Serge ULiege; Jamin, Pierre ULiege et al

in MDPI WATER (2019)

An abandoned industrial site in Belgium, located in the catchment of a chalk aquifer mainly used for drinking water, has been investigated for groundwater pollution due to a mixture of chlorinated ... [more ▼]

An abandoned industrial site in Belgium, located in the catchment of a chalk aquifer mainly used for drinking water, has been investigated for groundwater pollution due to a mixture of chlorinated solvents with mainly 1,1,1-trichloroethane (1,1,1-TCA) at high concentrations. The observed elevated groundwater mineralization was partly explained by chemical reactions associated with hydrolysis and dehydrohalogenation (HY/DH) of 1,1,1-TCA in the chalky aquifer. Leaching of soluble compounds from a backfilled layer located in the site could also have influenced the groundwater composition. In this context, the objective of this study was to investigate the hydrochemical processes controlling groundwater mineralization through a characterization of the backfill and groundwater chemical composition. This is essential in the context of required site remediation to define appropriate remediation measures to soil and groundwater. Groundwater samples were collected for chemical analyses of chlorinated aliphatic hydrocarbons, major ions, and several minor ones. X-Ray Diffraction Analysis (XRD), Scanning Electron Microscopy (SEM) and a leaching test according to CEN/TS 14405 norm were carried out on the backfill soil. δ34S and δ18O of sulphate in groundwater and in the backfill eluates were also compared. Both effects influencing the groundwater hydrochemistry around the site were clarified. First, calcite dissolution under the 1,1,1-TCA degradation reactions results in a water mineralization increase. It was assessed by geochemical batch simulations based on observed data. Second, sulphate and calcium released from the backfill have reached the groundwater. The leaching test provided an estimation of the minimal released quantities. [less ▲]

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See detailInnovative contaminant mass flux monitoring in an aquifer subject to tidal effects
Jamin, Pierre ULiege; Cosme, Frédéric; Orban, Philippe ULiege et al

Conference (2019, September 11)

Exposure from groundwater contamination to aquatic receptors residing in receiving surface water is dependent upon the rate of contaminated groundwater discharge. Characterization of groundwater fluxes is ... [more ▼]

Exposure from groundwater contamination to aquatic receptors residing in receiving surface water is dependent upon the rate of contaminated groundwater discharge. Characterization of groundwater fluxes is challenging, especially in coastal environment where tidal fluctuations result in transient groundwater flows towards these receptors. This can be further complicated by the high spatial heterogeneity of subsurface deposits enhanced by anthropogenic influence such as the mixing of natural sediments and backfill materials, presence of subsurface built structures or even occurrence of other sources of contaminant discharge. There is thus a need to address the risk posed by groundwater contaminations in coastal ecosystems using contaminant mass flux calculations based on direct continuous groundwater flux measurements able to capture the time variability of transient flows. In this study, the Finite Volume Point Dilution Method (FVPDM) was successfully used to characterize highly transient groundwater flows and contaminant mass fluxes within a coastal groundwater flow system influenced by marked tides. The investigated aquifer is separated from a river by a sheet pile wall whose hydraulic effect was not fully characterized. The aquifer is constituted by materials of both anthropogenic and natural origins used as backfills. FVPDM tests were undertaken continuously for more than 48 hours at 6 groundwater monitoring wells, in order to evaluate groundwater flow dynamics during several tide cycles. Contaminant concentrations were measured simultaneously and allowed to calculate contaminant mass fluxes. Groundwater and contaminant mass flux monitoring enabled a significant refinement of the conceptual site model. The study emphasized the high heterogeneity of the aquifer with groundwater fluxes ranging from 10-7 to 10-3 m/s. Groundwater fluxes monitoring showed no clear evidence of inversion of groundwater flow direction that would have resulted from river water infiltration in the aquifer. This is certainly due to combined effect of strong groundwater discharge from inland and of flaps present in the sheet pile wall preventing sea water intrusion in the aquifer when closed at high tide. Although contaminant concentrations varies by one order of magnitude between different monitoring wells, contaminant mass fluxes are 7 to 3500 times higher in one particular monitoring well compared to other wells due to a combination of significant contaminant concentrations and high groundwater fluxes. Spatial variability of calculated solute mass fluxes allows to suggest that contaminant transfer within the aquifer should be considered as localized channel flows. These results constitutes highly valuable information for optimization of further investigations and risk mitigation measures. [less ▲]

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