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Friday, 12 March 2010 |
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Groundwater - Saturated Zone
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Thursday, 05 November 2009 |
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With the conventional "Pump & Treat" method, groundwater is normally extracted from one or several wells, cleaned above ground and disposed off to the either groundwater or surface water. Even when extraction and injection wells are combined, predominantly higher permeable areas are preferentially penetrated and more fine-grained structures are circumflowed. The bulk of contaminants are absorbed to the less permeable materials like fine-grained sands, silty or clayey layers. By diffusion, the contaminants are released out of these reservoirs very slowly. After a short period of time they effect a stagnation of the contamination discharge ("Tailing Effect").
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Read more... [Groundwater Circulation Well Technology]
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Tuesday, 29 July 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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Read more... [DNAPL-Recovery]
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Tuesday, 29 July 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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Read more... [LNAPL-Recovery]
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Wednesday, 02 April 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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Read more... [Microbiologically enhanced GCW]
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Wednesday, 02 April 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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Read more... [Stacked GCW]
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Monday, 19 February 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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Read more... [GCW - Partial Extraction Technology]
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Applications 
