JPH05323040A - Method and apparatus for monitoring flow rate and specified water quality of underground water and removing pollution thereof - Google Patents

Abstract

PURPOSE:To keep specified matters exceeding an allowable concentration from flowing down by monitoring the flow rate of underground water and specified matters to be monitored such as contaminants continuously to automatically remove the matters to be monitored. CONSTITUTION:A part of underground water to be pumped is sent to a recorder/specified matter detector 9 via a water supply pipe 10 to measure and record the concentration of individual matters. The remainder of the underground water pumped is sent to an aeration column 12 passing through a pumping pipe 11. At the column, a volatile gas is volatilized to pass through a corrector when it exceeds an allowable concentration and is discharged after it is confirmed to be below the allowable concentration. The water which passes through a filter tank 13 for filtering the specified matters via a connecting pipe 14 from the aeration column 12 is sent to the detector 9 again via a return pipe 19 from a delivery pipe 18. The concentration of each material is measured and recorded again and the water is sent to the deliver pipe 18 via a reverse return pipe 20 again. When the concentration obtained gives a value lower than all allowable concentration values of the materials, a valve 15 is changed to open and the water is sent for water injection 16 via the reverse return pipe 20 to be delivered to a location according to the purposes of application.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for monitoring and decontaminating groundwater flow rate and specific water quality.

[0002]

2. Description of the Related Art Conventionally, the method of measuring the flow rate of groundwater is based on Darcy's theory. An observation well in which a screen is attached to a part of a circular pipe with a diameter of 5 to 10 cm is assumed to be located upstream and downstream of the assumed groundwater flow. Located in the area, the hydraulic gradient obtained by dividing the difference in groundwater level between the two wells by the distance, the thickness of the aquifer obtained by electrical logging when installing the observation well, and the aquifer obtained by the pumping test at the observation well. The indirect flow rate is calculated as the product of the three factors called the hydraulic conductivity of.

However, since the groundwater flow generally consists of a pipe-shaped water flow scattered in the aquifer in a width of several meters, the groundwater level in the observation well and its level depend on the probability that the observation well encounters the water flow. There is a problem that fluctuations change drastically.

The conventional method of measuring groundwater quality is to measure the groundwater in the observation well described above, but the low probability of a narrow observation well encountering a water flow is due to the fact that the quality of the groundwater in the circulating water is the observation well. The probability of appearing in is greatly reduced.

As a conventional method for collecting specific water quality such as pollutants, the method of collecting specific water quality in pumping water by pumping from the observation well described above or a new well having the same structure and a large diameter is used. ..

[0006] However, even if the collection range is widened by lowering the water level in the well due to pumping, the effective collection width of the circulating water flow is only in the range of several meters, and during pumping, it stagnates in the natural aquifer. A large amount of water is drawn in, and groundwater is drawn in from a shallower layer that passes through the waterway that grows upward from the well area by pumping. These contaminants lower the concentration of specific substances in the pumped water, reduce the collection efficiency, generate a large amount of unnecessary pumped water, and cause ground subsidence around the well. In addition, there was a problem that it was not possible to collect the specific substance flowing except when pumping water.

[0007] In recent years, it has been recognized that there is a horizontal flow above the water channel in the unsaturated layer above the water table, which plays a major role in water recharge and water pollution. No method or device for accurate recovery has been developed.

[0008]

Therefore, the present invention aims to more reliably grasp the water flow in the aquifer and increase the collection efficiency of the specific substance by greatly widening the cross section of the water collection. To

Further, the groundwater flow rate is grasped more surely by pumping the pumped water so that the pumped water level is always kept constant and measuring and recording the change over time of the pumped water amount.

By setting the pumping water level to a value slightly lower than the minimum value of the natural water level, the intake of natural stagnant water accompanying the pumping and the development of water channels are greatly suppressed, and the ground subsidence is hardly caused.

The concentration of the specific substance in the pumped water is automatically measured and recorded, and the concentration is measured again after removing the specific substance by filtering or filtering the pumped water. Use or dispose of sewage accordingly, but when the concentration exceeds the allowable level, return it to the trench for re-decontamination.

It is an object of the present invention to provide a method and apparatus for preventing a specific substance having a concentration higher than an allowable concentration from flowing down to the downstream portion of the trench by the various facility functions by the trench construction method.

[0013]

The present invention is a method for continuously monitoring the flow rate of groundwater and the concentration of a specific substance to be monitored such as pollutants and automatically removing the substance to be monitored.

In order to realize this method, a substantially rectangular parallelepiped trench provided with a screen is installed upstream of the aquifer or the unsaturated layer, and water is collected at a part of the bottom of the trench. A recorder provided with a groove, the bottom surface of which is inclined in the direction of the water collecting groove and is inclined toward the downstream side, and the water collecting groove is provided with a suction port and is installed on the ground from a pump connected to the suction port. A water supply pipe is installed in the detector / specific substance detector and the water vapor tower, and a connecting pipe is arranged from this water vapor tower to the filter tank, and the delivery pipe under this filter tank is connected to the recorder / specific substance detector. In this device, a reciprocating pipe is installed, and a valve provided in the delivery pipe is connected to a water injection pipe that flows out to a proper place on the ground and a drain pipe that returns to the underground trench again.

[0015]

[Function] Part of the groundwater pumped from the suction port of the water collection groove at the bottom of the trench is sent to the recorder and the specified substance detector via the water supply pipe, and the concentration of each substance contained here is checked. The remaining part of groundwater is sent from the pumping pipe to the waterfall tower, where volatile gas is volatilized and released, and the water part is sent to the filtration tank through the connecting pipe, where specific substances are adsorbed. Filter.

A part of the water from this filtration tank is sent to the recorder / specified substance detector again, and the concentration of each substance is measured and recorded. When the concentration becomes lower than the expected value, the valve is opened. Water to the right place via the water pipe.

If the permissible concentration is still exceeded, the valve is switched to feed the drain pipe to the trench again.
Then, the above-mentioned action is circulated and performed.

[0018]

Example The structure of the trench 1 of the present invention is a substantially rectangular parallelepiped having a length l of several meters to several tens of meters and a width w of several tens of centimeters in the target aquifer or unsaturated layer. And a part thereof has a height h capable of opening the screen portion 2.

Surfaces other than one surface of the trench 1 forming the screen portion 2 are geological layer portions not targeted.

The trench 1 is provided with a water collecting groove 4 in a part of a bottom surface portion 3, and the bottom surface portion has a surface inclined toward the water collection groove 4 and a surface 5 inclined toward the downstream side of the groundwater flow. The sedimentation specific substance that has been configured and flowed into the trench is the water collection groove 4
Make it easier to get together. “A” indicates the upstream side and “b” indicates the downstream side.

Reference numeral 6 is a suction port for sucking up the sinking specific substance accumulated at the bottom of the water collecting groove 4.

Reference numeral 7 denotes a pump connected to the suction port 6, which pumps water so as to maintain a predetermined groundwater level. 8 is a sensor that controls to keep a predetermined groundwater level,
The recording of the groundwater level by the sensor over time is performed by the recorder / specified substance detector 9.

As a general rule, this groundwater level should be set to a value slightly lower than the minimum value of the surrounding natural water level, but when the secular change of the groundwater position is large, or when the inflow of a specific substance is abnormally large, etc. In addition, the sensor should have a function to reset the water level to an arbitrary level.

A portion of the pumped-up groundwater is sent to the recorder / specified substance detector 9 via the water supply pipe 10 to measure and record the concentration of each substance. The remaining part of the pumped groundwater is sent as it is to the waterfall tower 12 through the pumping pipe 11, where the volatile gas is volatilized in the waterfall tower, and when it exceeds the allowable concentration, it is passed through the repair device and allowed. Release after confirming that the concentration is below the concentration.

Reference numeral 13 is a filtration tank installed from the water vapor tower 12 through a connecting pipe 14 for adsorbing and filtering a specific substance. The water that has passed through this filtration tank is sent from the delivery pipe 18 through the return pipe 19 to the recorder / specified substance detector 9 again, and the concentration of each substance is measured again and recorded. It is then sent to the delivery pipe 18.

When the concentration becomes lower than all the allowed concentration values of each substance planned, the water passing through the return pipe 20 is sent to the water injection pipe 16 by switching the valve 15 and opening it. Deliver water to a place suitable for the purpose.

If one or more substances exceed the permissible concentration, the valve 15 is switched to return from the drain pipe 17 to the inside of the trench 1 and the above-described action is circulated.

[0028]

Since the present invention has the above-mentioned structure and operation, it exhibits the following effects as compared with the conventional method and apparatus.

First, the function of grasping the natural groundwater flow rate is improved. That is, in the conventional method, the groundwater flow rate is assumed from the Darcy theory using the value of the groundwater level or hydraulic gradient as an index, but the fluctuation rate of the groundwater level during the rising and falling periods of the groundwater level depends on the water content of the unsaturated layer. Since the method of the present invention can control the pumping amount so as to keep the pumping water level constant, the pumping amount is controlled by the groundwater flow rate. It will be proportional.

Secondly, the rate of grasping the specific substance contained in the groundwater amount is improved. That is, in the conventional method, the flow having a width of only several centimeters to ten and several centimeters is collected by the observation well, but the method of the present invention collects the entire cross section of the flow having a width of several meters to ten and several meters. Therefore, it is possible to completely collect the water flow that is partially scattered in the aquifer.

Since the other side surface portion and the downstream surface portion of the trench are made impermeable, a groove is provided at the bottom portion, and the groundwater level in the trench is set lower than the surrounding groundwater level, the specific substance flowing into the trench Does not flow to the downstream side at all.

Since the bottom of the trench is inclined, the water collecting groove is deepened and the water at the bottom of the water collecting groove is pumped up. Therefore, even a specific material having a specific gravity higher than that of water does not stagnate in the trench. Can be pumped.

Thirdly, the pumping efficiency is improved. That is, the conventional method of pumping water from a well draws in a large amount of stagnant water that does not flow under natural conditions that are not related to the removal of specific substances, and also develops upward water channels around the well to remove groundwater in the shallow layer. In contrast to the fact that a large amount of stagnant water will cause ground subsidence, the method of the present invention in which the pumping water level is slightly lower than the minimum natural water level causes The development of water paths in the direction becomes almost negligible, and the ground subsidence phenomenon does not occur at all.

Fourth, the function of monitoring the flow rate and the concentration of the specific substance is improved. That is, in the conventional method, water level measurement and sample water concentration analysis, which are generally performed intermittently, are limited, so that the state of the intermittent portion cannot be grasped, whereas in the method of the present invention, these can be known in almost continuous detail. Like

Fifth, the decontamination function for specific substances is continuously automated. That is, in the conventional method, decontamination was only performed at a specific time, and the remaining period was left alone, whereas in the method of the present invention, decontamination is continuously performed, and the decontamination effect is continuously measured. From the comparison between the result and the permissible concentration, it becomes possible to automatically determine the subsequent treatment of the treated water.

Therefore, not only the decontamination of the specific substance can be performed labor-savingly and continuously, but also the outflow of the specific substance to the downstream side of the trench can be completely blocked. Further, in the construction of the trench, it becomes possible to prevent the specific substance in the range where the flow does not occur on the downstream side from flowing to the downstream side.

[Brief description of drawings]

[Fig. 1] Front sectional view of the entire equipment

FIG. 2 is a side sectional view of the main part of FIG.

[Explanation of symbols]

 1 trench 2 screen part 3 bottom part of trench 4 water collection groove 5 inclined surface part 8 water level sensor 9 recorder and specific substance detector 12 waterfall tower 13 filter tank 15 valve 16 water injection pipe 17 drainage pipe 18 delivery pipe 19 return pipe 20 Return pipe

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[Procedure amendment]

[Submission date] June 25, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction content]

[0005] Methods of collecting capturing a certain quality, such as a conventional pollutants uses a method in which pumping from new wells of large diameter at observation wells or the same structure described above, the current capturing a certain quality in the pumping ..

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

[0006] However, even if spread the catching collection range in the decline of Iuchi water level by pumping, effective catching Atsumarihaba of circulating water flow will stop a few meters stand, also stagnation in the nature of the aquifer in during the pumping A large amount of water is drawn in, and groundwater is drawn in from a shallower layer that passes through the waterway that grows upward from the well area by pumping. These contaminants lower the concentration of specific substances in the pumped water, reduce the collection efficiency, generate a large amount of unnecessary pumped water, and cause ground subsidence around the well. Furthermore, there is a problem such that can not collecting capturing a specific substance flowing except during pumping.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

[0008]

Therefore [0007] The present invention provides water collecting section more surely grasp the water conducting flow aquifer in by significantly wider, and to enhance the collection efficiency of a specific substance To

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0023

[Correction method] Change

[Correction content]

[0023] The underground water level, but as a rule to be slightly lower value than the lowest value of the natural water level of the peripheral, underground water level
When there is a large change over time, or when the inflow of a specific substance is abnormally large, the sensor should have a function that allows it to be reset to an arbitrary water level.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0030

[Correction method] Change

[Correction content]

Secondly, the rate of grasping the specific substance contained in the groundwater amount is improved. That is, in the conventional method is merely capturing current flow width of 10 centimeters from only a few centimeters by the observation well, the method of the present invention to current capturing the entire cross-section of the flow of a width of several meters to 10 meters that since it is, the water conducting flow partially interspersed aquifer in completely capturing collection.

Claims (2)

[Claims] 1. A method comprising continuously monitoring the flow rate of groundwater and the concentration of a specific substance to be monitored such as pollutants and automatically removing the substance to be monitored. 2. A substantially rectangular parallelepiped trench provided with a screen is provided on the upstream side of the aquifer or the unsaturated layer, and a water collecting groove is provided in a part of the bottom of the trench, and the bottom is It is inclined toward the water collection groove and inclined toward the downstream side.The water collection groove is provided with a suction port and a pump connected to this suction port is connected to the recording machine and the specified substance detector and the waterfall installed on the ground. A water supply pipe is arranged in the tower, a connecting pipe is arranged in the filtration tank from the waterfall tower, and a reciprocating pipe connected to the recording machine and the specific substance detector is arranged in the delivery pipe under the filtration tank. A device in which a valve provided in the delivery pipe is connected to a water injection pipe that flows out to a proper place on the ground and a drain pipe that returns to the underground trench again.