Hydraulic and earth engineering – Soil remediation – In situ contaminant removal or stabilization
Patent
1990-11-21
1992-10-13
Taylor, Dennis L.
Hydraulic and earth engineering
Soil remediation
In situ contaminant removal or stabilization
210104, 405 52, 405 60, E02B 1508
Patent
active
051545381
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
My present invention relates to a method of and an apparatus for removing a liquid phase floating on a surface of groundwater.
BACKGROUND OF THE INVENTION
To limit or remedy environmental damage, a problem often recurring in practice is the removal of liquid pollutants such as hydrocarbons which have entered the ground, in order to decontaminate the groundwater. For this purpose, a variety of decontamination methods are known which, however, are all very complex and costly.
In a known method (German published patent application DE-OS 3,721,981), groundwater is drawn from the ground, treated biologically above ground and subsequently returned to the ground, with a flushing stream being produced in the ground causing pollutant discharge. This known method has the disadvantage that removal of the pollutants is effected only indirectly through the flushing stream in dissolved or suspended form, so that large amounts of groundwater have to be pumped up for pollutant removal. As a consequence, the method is time-consuming and costly. It is a further disadvantage of the known method that it necessitates a separation or treatment plant above ground in order to separate the pollutants pumped up together with the water.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide a method by means of which liquid phases floating on a surface of groundwater can be removed within a short period of time and with little effort.
It is a further object of the invention to provide a simple and reliable apparatus for implementing this method.
SUMMARY OF THE INVENTION
According to the present invention, this requirement is satisfied by a method comprising the lowering of the liquid level in a well by continually pumping out groundwater, and the separate withdrawal of the liquid phase floating on the groundwater surface by means of a pump, with a lifting device which is controlled by the liquid level operating to lower the inlet aperture of the pump to a level below the liquid level in the well such that it does not come to lie below the groundwater surface.
The method of the invention enables a liquid phase such as hydrocarbons floating on a groundwater surface to be pumped out separately, thereby utilizing the fact that separation of the liquid phase has already taken place in the region of the ground or in the well. Accordingly, the need to provide special facilities above ground for separating the liquid phase from water is obviated. It is a further advantage of the method of the invention that the delivery rate at which the liquid phase can be pumped out is independent of the replenishment rate of the groundwater and the amount of groundwater delivered, resulting in high delivery rates in the presence of favorable flow properties of the liquid phase.
In the method of the invention, further provisions may include a treatment of the groundwater delivered for lowering the liquid level in the well prior to returning it to the ground, in order to remove pollutants dissolved or suspended in the groundwater. In the method of the invention, this treatment operation can be performed with greater ease and effectiveness because the groundwater no longer contains the liquid phase pumped out separately.
To implement the method described, the invention provides an apparatus in which a bucket-shaped vessel having an inlet aperture arranged above the vessel bottom in the vessel wall is adapted to be lowered into the well by means of a lifting device, with the lifting device being controllable in dependence upon the liquid level in the well, such that the inlet aperture is below the liquid level by a predetermined amount, and in which a pump is provided to pump out the liquid flowing into the vessel. An apparatus of this type affords a simple means of removing the light phase floating on the groundwater, with the lifting device enabling the vessel to adapt its position to the changes in liquid level easily, in order to prevent the entry of groundwater in the vessel. The separation of water
REFERENCES:
patent: 3745115 (1923-07-01), Olsen
patent: 4088579 (1978-05-01), Yoshioka
patent: 4273650 (1981-06-01), Solomon
patent: 4945988 (1990-08-01), Payne et al.
patent: 4974674 (1990-12-01), Wells
patent: 4983282 (1991-01-01), Roy et al.
patent: 4998585 (1991-03-01), Newcomer et al.
Dubno Herbert
Preussag Aktiengesellschaft
Taylor Dennis L.
LandOfFree
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