05-11-2009 |
Successful application of GCW technology requires that its zone of influence (ZOI) be known and predicted prior to installation. For each GCW System, a unique, site-specific hydraulic zone of influence will be established.
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Lire la suite... [Modeling GCW Efficiency]
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05-11-2009 |
Un lavage complet de la zone d’eaux souterraines contaminées, y compris de la frange capillaire et de la zone de fluctuation de la nappe phréatique, est décisive pour un assainissement effectif. Les eaux souterraines de la zone des pores doivent être échangées plusieurs fois en fonction de la concentration en substances toxiques et de la lithologie. Un lavage intensif permanent, en particulier des zones de l’aquifère faiblement perméables, est indispensable, afin d’éviter les « effets rebonds » et d’atteindre un assainissement durable. Si ce n’est pas le cas, les assainissements des eaux souterraines durent souvent des décennies et engendrent des coûts de longue durée élevés.
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Lire la suite... [Assainissement des nappes phréatiques in-situ]
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29-07-2008 |
With a GCW it is possible to remove non-miscible liquids of higher density than water (DNAPL) from an aquifer. In order to remove dense non aqueous phase liquids (DNAPL) that have accumulated on the bottom of the aquifer, the GCW is operated in standard mode. The DNAPL is removed by means of a sensor-controlled, pneumatically-driven submersible pump. Thus it is made sure that just pure phase and no groundwater is extracted.
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Lire la suite... [DNAPL-Recovery]
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29-07-2008 |
With a GCW it is possible to remove non-miscible liquids of lower density than water (LNAPL) from an aquifer. In order to remove light non aqueous liquids floating on the groundwater, the GCW is operated in a reverse mode. The LNAPL is removed by means of a sensor-controlled, pneumatically-driven submersible pump. Thus it is made sure that just pure phase and no groundwater is extracted.
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Lire la suite... [LNAPL-Recovery]
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02-04-2008 |
By means of different techniques oxygen, gas mixtures but also nutrient solutions can be added to the GCW circulation water. Thus, more oxygen-rich and contaminant-reduced groundwater circulates through the aquifer and stimulates microbiological degradation respectively creates better bio-availability. Metabolites impeding the growth of autochthonic microorganisms or the CO2 produced by the biological decomposition can be transported to the well with the groundwater and can be selectively removed there.
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Lire la suite... [Microbiologically enhanced GCW]
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02-04-2008 |
The achievable sphere of influence of a GCW-System depends on the distance of the two active screen sections, the anisotropy of the aquifer, the groundwater flow velocity and the selected pumping rate. The bigger the circulation cell is, the longer a water molecule needs to pass through the cell.
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Lire la suite... [Stacked GCW]
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02-04-2008 |
IEG uses an innovative type of Vacuum Vapor Extraction system using a specially engineered and patented Double-Cased Screen (DMF) in combination with a very low negative pressure blower. The double-cased screen consists of fine-grained filter granules sandwiched between two layers of metal sieve web with an open screened area of over 50%. The metal web is constructed such that an artificial well pack cannot significantly reduce the open screened area.
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Lire la suite... [Double cased screen]
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02-04-2008 |
Non-volatile contaminants in the unsaturated zone and in the groundwater fluctuation area can be removed by means of the soil flushing technique. Cleaned and possibly oxygen-enriched groundwater re-accesses the subsoil via drain pipes or vertical screen sections after passing a cleaning system (e.g. bio-reactor etc.).Â
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Lire la suite... [Soil flushing]
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02-04-2008 |
Soil air circular flow is employed to remediate soils polluted with volatile contaminants (e.g. CHC, BTEX, jet fuels), some semi-volatile contaminants and/or biodegradable substances. Due to the application of low negative pressure, TESAC systems can be implemented in soil, where the horizontally induced flow bypasses contaminants trapped in low-permeability layers.
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Lire la suite... [Thermally enhanced soil air circulation (TESAC)]
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19-03-2008 |
With a GCW it is possible to remove non-miscible liquids of lower or higher density than water (LNAPL and DNAPL) from an aquifer. In order to remove light non aqueous liquids floating on the groundwater, the GCW is operated in a reverse mode.
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Lire la suite... [Free product recovery]
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19-03-2008 |
IEG uses an innovative type of Vacuum Vapor Extraction system using a specially engineered and patented Double-Cased Screen (DMF) in combination with a very low negative pressure blower. The double-cased screen consists of fine-grained filter granules sandwiched between two layers of metal sieve web with an open screened area of over 50%. The metal web is constructed such that an artificial well pack cannot significantly reduce the open screened area.
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Lire la suite... [Double cased screen for soil air venting]
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18-03-2008 |
The scientific calculation methods for the hydraulic functioning of GCW-Systems with pump and packer are developed by the Institute for Hydromechanics, University of Karlsruhe, under a research program funded by IEG.
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Lire la suite... [VEGAS- large-scale Laboratory Investigation]
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19-02-2007 |
A GCW can also be operated in a way that a certain quantity of water passing through the well shaft is pumped-off or infiltrated into it. Extracting exactly the same amount of water as the upstream into the well, the groundwater downstream from the well is blocked.
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Lire la suite... [GCW - Partial Extraction Technology]
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