Apparatus and method for treating groundwater

Abstract

The invention relates to a device and a method for treating groundwater with a pipe (5) arranged in a well which is drilled into the soil (2) and the upper side of which opens into the surface (2a) of the soil (2). The tube (5) has at least two water-permeable sections which are kept at a distance from each other at different height levels. The groundwater circuit is formed in such a way that a pump (9) for pumping water from the soil (2) is associated with the first water-permeable section. The sucked water is supplied through the first water permeable section to the first channel and is conveyed there in the direction of the earth surface (2a). The re-permeation of water is carried out through a second channel separate from the first channel, said water being discharged to the soil (2) through a second permeable section. A pulsation means is provided by means of which pulsation is applied to the water introduced from the soil (2) through the first permeable section.

Description

Technical Field

[0001] The invention relates to a device and a method for treating groundwater. Background Art

[0002] Such a device is designed in particular in the form of a filter assembly.

[0003] Such filter assemblies are generally used for treating and purifying groundwater. For this purpose, a plurality of filter units constituting the filter assembly are arranged in an underground well in a manner stacked one above the other and spaced apart from each other, wherein groundwater present in the soil can be purified by a single filter unit. At least one filter unit is provided with an assembly with a pump and a delivery pipe. With the aid of such an assembly, water is pumped out of the soil and supplied to a water treatment unit arranged above ground. The water discharged from the water treatment unit can be supplied to another filter unit via another delivery pipe, and the water is discharged into the soil via the filter unit. Thus, a groundwater circuit is formed in the soil.

[0004] The problem with such devices is that there are fine structures in the soil, in particular capillary structures and dead pores, in which pollutants can settle. When the groundwater comes into contact with these pollutants, it becomes contaminated accordingly. Although the groundwater can be purified with the aid of known filter assemblies, this is incomplete, since the pollutants trapped in the capillary structures and dead pores can only be released after a long time. Summary of the invention

[0005] The invention is based on the following object, which is to provide a device and a method which enable effective treatment of groundwater and aquifers.

[0006] The features of the independent claim are used to achieve this object. Advantageous embodiments and practical developments of the invention are described in the dependent claims.

[0007] The invention relates to a device for treating groundwater with a pipe, which is arranged in a well, which is drilled into the soil and whose upper part leads to the surface of the soil. The pipe has at least two permeable sections, which are arranged one above the other at different height levels with a spacing therebetween. A groundwater circuit is formed in the following way: a pump for extracting water from the soil is assigned to the first permeable section. The extracted water is supplied to a first channel through the first permeable section and is transported there in the direction of the surface. The water is re-permeated through a second channel separated from the first channel, and the water is discharged into the soil through the second permeable section. There is a pulsation device, by means of which pulsation is applied to the water introduced from the soil through the second permeable section.

[0008] The invention also relates to a corresponding method.

[0009] The device according to the invention has a pipe which is assigned to a well drilled into the soil. In order to treat groundwater, a groundwater circuit is created in the soil by means of the device.

[0010] For this purpose, the longitudinal axis of the pipe extends at least approximately in the vertical direction, and the pipe has at least two water-permeable sections, which are arranged one above the other at different height levels and spaced apart from each other. In addition to these water-permeable sections, the pipe also has a water-tight wall.

[0011] A pump is associated with the first permeable section, which draws water from the soil and supplies it via the permeable section to a first channel, in which the water is conveyed in the direction of the ground surface. In particular, the water is supplied to a water treatment unit. The water permeates again into the soil via a second channel leading to the second permeable section, wherein the water is advantageously guided into the soil at the outlet of the water treatment unit. The groundwater circuit is formed by the negative pressure of the first permeable section and the positive pressure of the second permeable section.

[0012] This device is especially configured as a filter assembly. In this case, the filter unit is integrated in the pipe, wherein the water-permeable section of the pipe is assigned a corresponding filter unit.

[0013] The basic idea of ​​the invention is to form a groundwater circuit which varies in time, in particular pulsates or oscillates.

[0014] The main advantage is that the temporally varying flow direction of the groundwater circulation can better remove pollutants present in the soil, thereby achieving a significantly improved purification of the groundwater or of the aquifer or soil.

[0015] In particular, it is possible to remove pollutants present in the capillaries or dead-end pores of the soil by the groundwater circuit that changes in time. In addition, pollutants in the adsorption water layer of the soil can also be removed by the groundwater circuit that changes in time.

[0016] The time cycle, in particular the frequency of change of the groundwater circuit, is adapted to the soil conditions, in particular to the capillary structure and dead pores in the soil in which the pollutants are present, so that the pollutants in the soil are optimally removed and thus the groundwater is optimally purified.

[0017] According to the invention, the formation of a temporally varying groundwater circuit is achieved by means of a pulsation device which imparts pulsations (ie generally temporal variations) to the water which is pumped from the soil via a first permeable section by means of a pump.

[0018] The pulsating means are advantageously controlled by a control unit.

[0019] The type of control of the pulsation element and thus the temporal behavior of the groundwater circuit can be predetermined by configuring the control unit or by an input by an operator.

[0020] According to a first variant, the pulsation means is designed in the form of a pressure generator, by means of which an overpressure or underpressure is selectively generated in the air column above the water level present in the first channel.

[0021] The water level in the first channel is increased by generating negative pressure. The water level is correspondingly lowered by generating overpressure. These pressure changes influence the water that is pumped from the soil by means of the pump and thus the groundwater circuit.

[0022] Particularly advantageously, the pulsation means generates an underpressure and an overpressure in the air column alternately within predetermined time intervals.

[0023] In particular, the pulsation device periodically generates underpressure and overpressure in the air column.

[0024] The pulsations generated in the water column react to the groundwater circuit in the soil, so that a pulsating groundwater circuit is correspondingly maintained, which improves the removal of pollutants from the soil.

[0025] This pulsation can be set and optimized via the control unit.

[0026] According to a first embodiment, the pressure generator has a blower unit which is controlled by a valve assembly.

[0027] By suitable actuation of the valve arrangement, in particular by means of a control unit, the blower unit generates an overpressure or underpressure.

[0028] According to a second embodiment, the pressure generator has a pneumatic piston pump.

[0029] The piston pump can also be controlled by the control unit and thus selectively generate an overpressure or a negative pressure.

[0030] According to a second variant, the pulsation means have switching means, by means of which the delivery flow generated by means of the pump is interrupted within predetermined time intervals.

[0031] In particular, the delivery flow of the pump is interrupted periodically by means of the switching means.

[0032] The switching device is advantageously controlled by a control unit, which generates a temporal, preferably pulsating, change in the delivery flow (i.e. the water delivered upward by the pump in the first channel), which reacts on the groundwater circuit, thereby obtaining a corresponding time dependency of the groundwater circuit.

[0033] Since the pump must be prevented from resisting resistance in the event of an interruption in the delivery system and thus being damaged, it is provided that the water delivered by the pump is fed back to the pump in the event of an interruption in the delivery flow.

[0034] This is advantageously achieved in that a return line branches off from the first channel, a valve being present in the branch.

[0035] The valve is controlled by a control unit.

[0036] According to an advantageous embodiment, the channel is configured in the form of a conveying tube.

[0037] This embodiment is particularly advantageous in devices in the form of filter arrangements in which a corresponding filter unit is associated with a water-permeable section of a pipe.

[0038] A pump is arranged in or on the first supply line in the region of the water-permeable section and the associated filter unit, which pump conducts the water through the first supply line in the direction of the ground surface, in particular to a water treatment unit.

[0039] The second supply pipe here forms a permeate pipe, through which water, in particular from a water treatment unit, is conducted back into the soil.

[0040] The structural configuration can be realized in this case in such a way that the supply tube runs inside the tube or in such a way that the supply tube is designed in the form of a surrounding tube running outside the tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The present invention is explained below with reference to the accompanying drawings. It shows:

[0042] Figure 1 : A first embodiment of the device according to the present invention.

[0043] Figure 2 :according to Figure 1 Detailed illustration of the delivery pipe of the device.

[0044] Figure 3 : A second embodiment of the device according to the present invention.

[0045] Figure 4 :according to Figure 3 Embodiment of the pressure generator of the device

[0046] a) When negative pressure is generated.

[0047] b) When overvoltage occurs. DETAILED DESCRIPTION

[0048] Figure 1 An embodiment of a device according to the invention in the form of a filter assembly 1 is schematically shown.

[0049] The filter assembly 1 is integrated in an underground well which is drilled into the soil 2 and opens at the surface 2a of the soil 2. The filter assembly 1 is assigned a water treatment unit 3 arranged above ground which usually has a plurality of treatment stations 4 for treating the groundwater present in the soil 2.

[0050] The filter assembly 1 installed in a well has a cylindrical tube 5, the longitudinal axis of which extends in the vertical direction. The tube 5 is advantageously made of stainless steel or plastic.

[0051] In this case, two filter units 6a and 6b are arranged one above the other in the pipe 5 at a distance. There is a sealing material (not shown) between the filter units 6a, 6b. The filter units 6a, 6b can be made of plastic, steel or other metal materials. In the present case, the filter units 6a, 6b are configured as wound filters. Physical treatments such as absorption processes or degradation processes, especially microbiological processes, are carried out in the filter units 6a, 6b to filter pollutants.

[0052] The tube 5 has water-tight walls. These walls have water-permeable sections in the region of the filter units 6a, 6b, which form openings 7. Water is exchanged between the surrounding soil 2 and the filter units 6a, 6b via the openings 7. The individual filter units 6a, 6b are arranged individually in chambers separated from one another in a water-tight manner.

[0053] The water-impermeable wall section of the tube 5 is surrounded by a water-impermeable material, in particular a swelling material such as bentonite.

[0054] In contrast, the openings 7 of the pipe 5 corresponding to the filter units 6a, 6b are surrounded by a water-permeable material (e.g. gravel). As a result, water exchange is achieved between the filter units 6a, 6b and the soil 2. In the present case, groundwater from the soil 2 is supplied to the lower filter unit 6a. In addition, treated water is introduced into the soil 2 from the upper filter unit 6b.

[0055] Therefore, negative pressure is generated in the area of ​​the lower filter unit 6a, and overpressure is generated in the area of ​​the upper filter unit 6b. As a result, a groundwater circuit ( ) is generated in the soil 2 from the upper filter unit 6b to the lower filter unit 6a. Figure 1 Marked with arrow I).

[0056] like Figure 1 As shown, the filter assembly 1 has a peripheral supply pipe 8a, 8b extending outside the pipe 5. The longitudinal axes of the supply pipes 8a, 8b extend parallel to each other and to the longitudinal axis of the pipe 5. The supply pipes 8a, 8b are arranged at a distance from each other and from the pipe 5.

[0057] The upper ends of the conveying pipes 8a, 8b are sealed and lead to the surface of the soil 2. The lower ends of the conveying pipes 8a, 8b lead to the pipe 5. Here, each conveying pipe 8a, 8b is respectively assigned to a filter unit 6a, 6b. Figure 1 As shown, each supply line 8 a , 8 b opens into the tube 5 in a sealed manner below the associated filter unit 6 a , 6 b .

[0058] The pump 9 is located in the lower delivery pipe 8a, which forms the first chamber of the device. The pump 9 is fixed in a nominal position in the lower region of the delivery pipe 8a. The pump 9 draws water from the soil 2 and guides it upwards in the delivery pipe 8a (arrow II) and advantageously supplies it to the water treatment unit. This generates a negative pressure in the region of the lower perforation 7, so that water is drawn from the soil 2.

[0059] The upper conveying pipe 8b forms a permeation pipe 11a as a second chamber of the device, through which water (preferably water from the water treatment device 3) is introduced into the soil 2 via the filter unit 6b and the opening 7 (arrow III). As a result, an overpressure is generated in the region of the opening 7, through which the water is discharged into the soil 2.

[0060] A control unit 10 is provided for controlling the components of the filter assembly 1, in particular for controlling the pump 9. The control unit 10 is usually formed by a computer unit, for example in the form of a microprocessor system. The control unit 10 is connected to the components to be controlled via lines not shown.

[0061] According to the invention, there is a pulsation device, by means of which a temporal change in the groundwater circuit is achieved. In general, the water flow extracted from the soil 2 is temporally changed by means of the pulsation device, so that a corresponding temporal change is imposed on the groundwater circuit.

[0062] The pulsation means are controlled by the control unit 10 , so that an advantageously pulsating, in particular oscillating, groundwater circuit can be obtained.

[0063] Figure 2 An embodiment of the pulsation means is shown. In the conveying pipe 8 a there is a riser 11 in which the water sucked from the soil 2 by means of the pump 9 via the aperture 7 is conveyed upwards in the conveying pipe 8 a , in particular to the water treatment unit 3 .

[0064] To generate a pulsating delivery system in the riser 11, the delivery of the pump 9 is interrupted at predetermined time intervals, in particular periodically, by a switching device (not shown) controlled by the control unit 10. A correspondingly pulsating groundwater circuit is obtained by the pulsating delivery flow in the delivery pipe 8a.

[0065] In order to prevent the pump 9 from running without resistance and being damaged when its delivery operation is interrupted, the pump 9 is supplied with a short-circuit water flow during the interruption time interval. For this purpose, a valve 12, in particular a three-way valve, is present in the standpipe 11, at which a return line 13 branches. When the delivery operation of the pump 9 is interrupted, the valve 12 is actuated by the control unit 10 so that the pump 9 is supplied with water via the return line 13.

[0066] Figure 3 Another embodiment of the filter assembly 1 according to the present invention is shown. Figure 1 In a similar manner to the embodiment of , two filter units 6a, 6b are arranged in the pipe 5 in the region of the opening 7. The filter units 6a, 6b are hydraulically separated by a parker 14. In addition, a control unit 10 and a water treatment unit 3 are present.

[0067] Corresponding to Figure 1 , which in turn creates a groundwater loop ( Figure 3 As shown in the arrow I in FIG. 1 , a time dependency, in particular a pulsation or oscillation, is imparted to the groundwater circuit by means of a pulsation device.

[0068] In accordance with Figure 3 In the embodiment of FIG. 1 , a riser 11 is shown, which is associated with the pump 9 and by means of which water is sucked from the soil 2 and supplied to the water treatment unit 3 ( Figure 3 There is also a permeation tube 11a, by means of which the water is re-permeated through the filter unit 6b ( Figure 3 Arrow III).

[0069] The longitudinal axis of the standpipe 11 coincides with the longitudinal axis of the tube 5 .

[0070] In the present case, the pulsation means for generating a pulsating, in particular oscillating, groundwater circuit is constituted by a pressure generator 15, which is controlled by a control unit 10. By means of said pressure generator 15, an underpressure or overpressure is selectively generated in the air column above the water level 16 in the pipe 5, thereby increasing or decreasing the water level 16 in the pipe 5. By periodically generating underpressure and overpressure by means of the pressure generator 15, the water level 16 in the pipe 5 periodically increases and decreases, which is transmitted to the groundwater circuit, so that a pulsating or oscillating groundwater circuit is obtained.

[0071] The pressure generator 15 may be constituted by a pneumatic piston pump or the like.

[0072] Figure 4 a and Figure 4b shows an embodiment of a pressure generator 15 with a blower unit 17 and a valve assembly consisting of valves 18a to 18c, in particular three-way valves. From the pressure generator 15 there is a connection of a line 19 to the upper side of the conveying pipes 8a, 8b.

[0073] In order to generate an overpressure, the valve assembly is connected in such a way that the blower unit 17 draws in fresh air ( Figure 4 a), and introduced into the delivery pipe 8a through the pipeline 19.

[0074] To generate negative pressure, the blower unit 17 draws air from the delivery pipe 8a and discharges it into the environment as exhaust air ( Figure 4 Arrow B in b).

[0075] Reference numerals list

[0076] (1) Filter assembly

[0077] (2) Soil

[0078] (2a) Surface

[0079] (3) Water treatment unit

[0080] (4) Processing station

[0081] (5) Tube

[0082] (6a,b) Filter unit

[0083] (7) Through opening

[0084] (8a,b) Delivery pipe

[0085] (9) Pump

[0086] (10) Control unit

[0087] (11) Riser

[0088] (11a) Permeation tube

[0089] (12) Valve

[0090] (13) Return tube

[0091] (14) Parker

[0092] (15) Pressure generator

[0093] (16) Water level

[0094] (17) Blower unit

[0095] (18a-c) Valve

[0096] (19) Pipeline

Claims

1. A device for treating groundwater, comprising a pipe (5), which is arranged in a well, which is drilled into the soil (2) and the upper side of which opens to the surface (2a) of the soil (2), wherein: The pipe (5) has at least two permeable sections, which are arranged one above the other at different height levels and at a distance from each other, wherein a groundwater circuit is formed in the following manner: a pump (9) for extracting water from the soil (2) is assigned to the first permeable section, wherein the extracted water is supplied to a first channel through the first permeable section and transported there in the direction of the ground surface (2a), the water re-permeates through a second channel separated from the first channel, and is discharged to the soil (2) through the second permeable section, characterized in that a pulsation device is present, by means of which pulsation is applied to the water introduced from the soil (2) through the first permeable section.

2. The device according to claim 1, characterized in that The pulsating device is controlled by a control unit (10).

3. The device according to any one of claims 1 or 2, characterized in that The pulsation means is designed in the form of a pressure generator (15), by means of which an overpressure or underpressure is selectively generated in the air column above the water level (16) present in the first channel.

4. The device according to claim 3, characterized in that The pressure generator (15) has a blower device (17) controlled by a valve assembly.

5. The device according to claim 3, characterized in that The pressure generator (15) has a pneumatic piston pump.

6. The device according to any one of claims 3 to 5, characterized in that The pulsation means generates an underpressure and an overpressure in the air column alternately within predetermined time intervals.

7. The device according to claim 6, characterized in that The pulsation device periodically generates underpressure and overpressure in the air column.

8. The device according to any one of claims 1 or 2, characterized in that The pulsation means have switching means, by means of which the delivery flow generated by means of the pump (9) is interrupted within predetermined time intervals.

9. The device according to claim 8, characterized in that The delivery flow of the pump (9) is interrupted periodically by means of the switching device.

10. The device according to any one of claims 8 or 9, characterized in that When the delivery flow is interrupted, the water delivered by the pump (9) is directed back to the pump.

11. The device according to claim 10, characterized in that The return is effected via a return line (13) which branches off at the first channel, wherein a valve (12) is located in the branch.

12. The device according to any one of claims 2 and 11, characterized in that The valve (12) is controlled by the control unit (10).

13. The device according to any one of claims 1 to 12, characterized in that In the region of each water-permeable section of the tube (5) there is a filter unit (6a, 6b).

14. The device according to any one of claims 1 to 13, characterized in that The channels are configured in the form of delivery tubes (8a, 8b).

15. The device according to claim 14, characterized in that The conveying tubes (8a, 8b) extend inside the tube (5), or the conveying tubes (8a, 8b) are designed in the form of a surrounding tube (5) extending outside the tube (5).

16. A method for treating groundwater by means of a device having a pipe (5), the pipe being arranged in a well, the well being bored into the soil (2) and the upper side of the pipe opening out at the surface (2a) of the soil (2), wherein: The pipe (5) has at least two water-permeable sections which are arranged one above the other at different height levels and at a distance from each other, wherein a groundwater circuit is formed in that a pump (9) for extracting water from the soil (2) is associated with the first water-permeable section, wherein: The pumped water is supplied into a first channel through the first permeable section and transported there in the direction of the ground surface (2a), the water re-permeates through a second channel separated from the first channel and is discharged to the soil (2) through a second permeable section, characterized in that a pulsation device is provided, by means of which pulsation is applied to the water introduced from the soil (2) through the first permeable section.

Images