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05-11-2009 |
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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 |
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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 |
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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 |
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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 |
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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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19-02-2007 |
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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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Applications 
