JPH1048197A - Method and apparatus for monitoring water quality with use of fish - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly detect abnormality in water quality from an activity of fishes by arranging a sensor detecting the activity of fishes as a change of an air pressure in a water bath or pond to which a water to be tested is introduced. SOLUTION: The water quality-monitoring apparatus is constituted of a water bath 1, a feed pipe 2 for feeding a water to be tested and a minute pressure sensor 3. When minute vibrations are generated in the water by an activity of a fish 30, the vibration is transmitted through a tube 13 to vibrate the air in the tube 13. The vibration of the air acts as a pressing force to a piezoelectric element of the minute pressure sensor 3. The amount of a deformation of the piezoelectric element is turned to an electric output, amplified at an amplifier and output. In monitoring the fish 30 by the minute pressure sensor 3, if a mad desperate activity of the fish 30 is intended to be detected, a state when a pressure change value is larger than a set value is judged as abnormal. If a death or weakening of the fish 30 is to be detected, a state when the pressure change value becomes smaller than the set value is judged as abnormal. An alarm is generated on each occasion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water quality monitoring method for monitoring the influx of toxic substances into raw water and treated water in a water purification plant, treated and discharged water in a sewage treatment plant, and raw material intake in the food industry, based on the activity of fish. And devices.

[0002]

2. Description of the Related Art Generally, tap water sources and the like may be contaminated with toxic substances such as industrial wastewater and agricultural chemicals, and the quality of the water must be continuously monitored.

[0003] However, it is technically and economically difficult to continuously measure many types of poisons chemically.

In a water purification plant or the like, a part of the raw water is guided to a water tank or pond as a system for constantly monitoring for these toxic substances. They are bred and monitored.

That is, when poisons are mixed in raw water, the influx of poisons into raw water is monitored by utilizing the phenomenon that the fish frenzy, weaken, or die.

[0006] The inflow of toxic substances is monitored in the same manner for treated water and effluent from water purification plants and sewage treatment plants, and raw material intake in the food industry.

[0007] The above-mentioned monitoring has been performed visually by humans. However, with the unmanned facilities such as water purification plants, automatic measurement and remote measurement have been demanded.

Therefore, as a method of automatically monitoring, a method as described in Japanese Patent Publication No. 5-58504 has been proposed.

In this method, an aquatic animal is photographed and subjected to image processing to detect a crazy behavior at the time of poison inflow from a moving speed, acceleration and the like.

[0010]

In general, fish sometimes die without taking crazy action on the influx of toxic substances, and the above method has a problem that the presence or absence of toxic substances cannot be reliably detected. doing.

[0011] In addition, fish may be almost inactive at night or when the water temperature is low.
There is a problem that it is very difficult to determine whether the activity is normal but the activity has been moderated.

An object of the present invention is to provide a water quality monitoring method and apparatus which can accurately detect abnormalities in water quality from fish activities.

[0013]

According to a first aspect of the present invention, there is provided a water quality monitoring method using fishes, which detects vibrations of water caused by fish activities. The system is designed to detect water quality abnormalities.

Further, as described in claim 2, vibration of water due to the activity of fish is detected as air pressure fluctuation, and abnormality of water quality is detected based on the pressure fluctuation value.

According to a third aspect of the present invention, there is provided a water quality monitoring method using fish when a pressure fluctuation value becomes larger or smaller than a set value, or when a signal information is subjected to frequency analysis and its waveform pattern is formed. A warning is issued when there is a difference between the water levels, and the vibration of water caused by fish activities is detected in a state where the supply of the test water into the water tank or the pond is temporarily stopped as described in claim 4. In the case where the vibration of water due to the activity of fish cannot be detected as described in claim 5, the vibration of water due to the activity of fish is detected in a state where the fish is stimulated. An abnormality in water quality can be detected.

According to the water quality monitoring device using fish of the present invention, a sensor for detecting the activity of fish as a pressure fluctuation of air is disposed in a tank or a pond into which the test water is introduced. It has a configuration.

In the water quality monitoring device using fish of the present invention, a sensor for detecting vibration of water due to fish activity as a pressure fluctuation of air as described in claim 7; A configuration comprising a micromanometer for outputting a fluctuation signal value, a configuration in which a funnel-shaped vibration collecting means is attached to the end of the conduit as described in claim 8, and a stimulus to fish as described in claim 9 The means for providing the means in the water tank or the pond, and the means for stimulating the fish as described in claim 10 may be constituted by a flat movable wire net or a movable basket surrounding the fish.

[0018]

FIG. 1 is a schematic sectional view showing one embodiment of the configuration of a water quality monitoring apparatus according to the present invention. The water quality monitoring apparatus comprises a water tank 1, a supply pipe 2 for test water, and a water tank 1. And a low pressure sensor 3 installed on a wall portion near the center in the longitudinal direction of the water tank 1 so that the detection section is located in the water.

The above-mentioned water tank 1 is preferably made of a transparent material such as glass or transparent acrylic resin so that the state of the fish 30 can be observed by humans.

A pond or the like can be used in place of the water tank 1 described above.

A pump 4 is connected to the water supply pipe 2 so that a predetermined amount of test water is supplied into the water tank 1.

The distal end of the water supply pipe 2 is located underwater and covered with a fine wire mesh 5 or the like so that irregular and uneven flows are eliminated as much as possible and almost no undulation occurs.

The above-mentioned water tank 1 is provided with a drain pipe 6, and the water guided to the water tank 1 overflows from the drain pipe 6 and is discharged so that the water level is always maintained at a constant level.

The above-mentioned minute pressure sensor 3 is disclosed in, for example,
It is sufficient to use at least one pressure sensor as described in Japanese Patent No. 268230.

As shown in FIG. 2, the micro-pressure sensor 3 includes a pressure detector 8 having two piezoelectric elements 8a and 8b,
An amplifier 9 amplifies and outputs the difference between the outputs of the two piezoelectric elements 8a and 8b.

The micro pressure sensor 3 has two inlets 1
0 and 11 are formed, and communication holes 12 are formed crosswise so that pressure signals can be amplified and taken out from the respective holes.

A tube 13 whose tip is immersed in the water of the water tank 1 is connected to the above-described inlet 10, and a tube 14 whose tip is located in the atmosphere is connected to the inlet 11.

When a minute vibration occurs in the water,
This vibration causes the air existing in the tube to vibrate through the tube 13, and this air vibration acts on the lower surface of the piezoelectric element 8a and the upper surface of the piezoelectric element 8b as a pressing force. On the other hand, the lower surface of the piezoelectric element 8b and the upper surface of the piezoelectric element 8a are opened to the atmosphere above the water tank 1 by a tube 14, so that the differential pressure between the underwater pressure and the atmospheric pressure can be taken out.

The piezoelectric element 8 generated by the differential pressure at this time
The amounts of deformation a and 8b are electrically added and output, and the detected output is amplified by the amplifier 9 and output.

If a funnel-shaped collector 15 such as a sound collector is attached to the distal end of the above-mentioned tube 13, it is possible to detect an extremely minute vibration and improve the S / N ratio in some cases. .

The distal end of the tube 14 may be left open. However, if the external sound is loud, it may act as noise. Therefore, the tube 14 may be covered with a sponge or glass wool or the like having micro holes communicating therewith. Is preferred.

In the monitoring of fish by the above-described micro-pressure sensor 3, when the purpose of detecting a crazy activity is to detect a state in which the pressure fluctuation value is larger than a set value, the state is determined to be abnormal, and the purpose is to detect the death or weakness of the fish. In such a case, a state in which the pressure fluctuation value becomes smaller than the set value is determined to be abnormal, and an alarm is issued.

It goes without saying that a sensor configured to directly detect an extremely small fluctuation pressure of water can be used in place of the above-mentioned minute pressure sensor that converts the fluctuation pressure of water into the fluctuation pressure of air and detects it.

Using the above-mentioned water quality monitoring device, water from rivers and lakes and water in a water purification plant is used in a water purification plant, incoming sewage and treated water is used in a sewage treatment plant, and groundwater and the like are used in the food industry. Water is supplied from the water supply pipe 2 into the water tank 1 by the pump 4.

When a predetermined amount of test water enters the water tank 1, a plurality of goldfish, carp, crucian or fish normally inhabiting the test water are bred to start the test.

The above-mentioned fish 30 typically has a fish length of 5 to 30 cm per 5 to 10 liters of water, preferably 10 to 15 cm.
It is appropriate to breed several cm-sized fishes according to the size of the aquarium.

Then, water is supplied by operating the pump 4 so that the water in the water tank 1 is exchanged about 1 to 3 times per hour.

The normal swimming, gill movement of the fish 30 described above,
Alternatively, when a certain danger is detected and the water flow changes irregularly in the water or the water surface undulates due to crazy behavior or the like, the tube 1
3, the air existing in the tube is vibrated, and this air vibration is changed as air pressure, the sum of the outputs from the piezoelectric elements 8a and 8b is amplified and output from the amplifier 9, and the signal is frequency-converted. Taken out.

Here, the vertical dimension is 400 mm and the horizontal dimension is 60
10 goldfishes having a body length of 8 to 10 cm were placed in an aquarium 1 having a size of 0 mm and a width of 350 mm, and vibrations in the water were detected by a micro-pressure sensor 3 to make a diagram, as shown in FIG.

On the other hand, when the vibration in the water in a state where the fish 30 is not bred in the aquarium 1 is detected by the micro-pressure sensor 3 and is plotted, the state is as shown in FIG.

As is clear from FIGS. 3 and 4, when a fish is present, a voltage signal of -25 dV and a frequency between 1 and 3 Hz output a large number of frequency signals. -35d due to the signal generated by noise such as
V, the frequency is coarse between 1 and 3 Hz, and the difference between the presence and absence of fish is characteristically extracted.

In general, when a toxic substance is mixed in water, the goldfish, carp, crucian, etc. in the aquarium 1 are almost all divided into two cases, that is, the death or the living fish without significant influence. Yes, when Fig. 3 is normal,
FIG. 4 shows a dead state of a goldfish, a carp, a crucian or the like.

Therefore, the state of FIG. 4 is stored in memory, and the difference from the state of FIG. 3 is detected to determine whether the fish is normal or abnormal.

The above-mentioned micro-pressure sensor 3 moves the fish gill,
In addition, since the vibration of water caused by swimming of the fish is detected, it is impossible to distinguish the movement of the water caused by the inflow of the test water from the normal state of the fish.

Therefore, in order to accurately determine whether the sample is normal or abnormal, the inflow of the test water is temporarily stopped, and the output signal of the micro-pressure sensor 3 is output without disturbance to the water in the water tank. Although it depends on the size of the water tank and the inflow of the test water, it is possible to obtain reliable data as measured data after about 3 minutes after stopping the electromagnetic valve.

The above-mentioned water tank 1 is installed via a vibration isolator or the like,
It is also possible to reduce the influence of external vibration propagation.

When the detection signal from the above-mentioned micro-pressure sensor 3 is in the state of the diagram as shown in FIG. 4, this diagram is displayed on a CRT (not shown) to notify the monitoring operator of the water quality abnormality or to issue an alarm. A buzzer, which is a container (not shown), sounds and a lamp blinks to notify a monitoring worker of a water quality abnormality.

The output signal of the micro pressure sensor 3 can be transmitted to a remote place by a signal line, wireless, or the like for processing.

In the above-mentioned water quality monitoring, when the water temperature is low at night or in winter, fish may hardly be active.

In such a state, the diagram detected by the micro-pressure sensor 3 is the same as the state in which the goldfish, carp, crucian, etc. are dead as shown in FIG. 4, and a water quality abnormality alarm is issued. .

Therefore, in order to eliminate such a detection error, in the second embodiment, as shown in FIG. 5, a flat wire mesh 16 which is moved up and down in the water tank 1 by an elevating mechanism 17 as shown in FIG. At a preset time.
To stimulate the fish in the aquarium 1.

The above-described wire mesh 16 is a mesh having a roughness that does not allow fish to pass through, and is formed in substantially the same shape as the water tank 1 provided with holes or cutouts so that the supply pipe 2 and the drain pipe 6 are not caught. is there.

The wire mesh 16 is made of stainless steel or a plastic such as polyester synthetic resin or Teflon synthetic resin. In addition, in order to minimize the influence of the vertical movement of the wire mesh 16, a mesh having a maximum mesh through which fish cannot pass is used. It is preferred to use.

The elevating mechanism 17 is provided with a driving motor 18.
, A shaft pulley 19, which is rotatably supported by a support member 20, and guide pulleys 23, 24 which are mounted on the shafts 21, 22.
And ropes 25 and 26 having one end attached to the winding pull 19 and the other end attached to the wire mesh 16.

In place of the above-described wire net 16, a basket having a rectangular shape, a circular shape, an elliptical shape, or the like as viewed in plan can be used.

Further, in order to detect the movement of the fish more reliably, the bottom of the wire net 16 or the basket may be formed to have a deeper shape near the center.

It is preferable that the above-described wire mesh 16 is located at the bottom of the water tank 1 when it is suspended at the lowest position, and is located almost at the water surface when the wire mesh 16 is pulled up to the uppermost position. .

In the case of a basket, it is assumed that the upper edge is still slightly above the water surface in a state of being suspended at the bottom,
It is preferable that the bottom of the basket be located substantially near the surface of the water with the basket being raised to the top.

The signal level obtained by the micro-pressure sensor is significantly different between the state in which the fish is stimulated by the wire net 16 and the normal movement of the fish.

Therefore, it is necessary to provide a low pressure sensor 3 for detecting a normal fish movement and a low pressure sensor 3 'for detecting a state where the fish is stimulated by the wire net 16.

In the case of one micro pressure sensor, it is necessary to change the signal amplification factor.

The above-described wire net 16 is preferably operated at night or in winter when the activity of the fish is reduced. However, when it is operated during the day when the fish is active, the movement of the fish can be detected more reliably.

In the above embodiment, a method of mechanically stimulating fish has been presented, but a method of stimulating fish by light, sound waves, or electricity is also possible.

[0064]

According to the method for monitoring water quality using fish of the present invention, the vibration of water due to the activity of fish is detected as described in claim 1, and an abnormality in water quality is detected based on the detected value. It is possible to clearly determine whether a fish raised in an aquarium is normal, dead, or very weak by a simple and inexpensive method. By breeding and detecting whether it is normal, it is possible to discover and grasp an abnormal state such as the inflow of toxic substances into raw water at an early stage, and to ensure the safety of water quality.

According to the second aspect of the invention, the vibration of water caused by the activity of fish is detected as air pressure fluctuation, and the abnormality of water quality is detected based on the pressure fluctuation value, whereby the vibration generated by the activity of fish is reliably detected. can do.

As set forth in claim 3, an alarm is issued when the pressure fluctuation value becomes larger or smaller than the set value, or when a signal information is subjected to frequency analysis and a difference occurs in its waveform pattern. Thus, it is possible to reliably inform the operator of the abnormality.

As described in claim 4, when the supply of the test water into the water tank or the pond is temporarily stopped, and the vibration of the water due to the activity of the fish is detected, the flow of the test water may occur. Accurate data without noise and the like can be obtained.

In the case where the vibration of water due to the activity of fish cannot be detected, the vibration of water due to the activity of fish is detected in a state in which the fish is stimulated. If the fish is almost inactive at night, or if the water temperature is low and the fish are almost inactive during the night, it is possible to detect the abnormal condition despite the normal condition of the fish. It is possible to prevent fish from emitting an abnormal signal of water quality as dead.

The water quality monitoring device using fish of the present invention is provided with a sensor for detecting the activity of fish as pressure fluctuation of air in a tank or a pond into which the test water is introduced. With this configuration, the effect according to claim 1 can be reliably obtained.

According to a seventh aspect of the present invention, the sensor comprises a conduit for detecting the vibration of water due to the activity of fish as a pressure fluctuation of air, and a micromanometer for outputting the air pressure fluctuation as a pressure fluctuation signal value. Then, the vibration of the water due to the activity of the fish can be detected as the pressure fluctuation signal value.

If a funnel-shaped vibration collecting means is attached to the end of the conduit as described in claim 8, even a minute change can be reliably detected.

When the means for stimulating fish is provided in a water tank or a pond as described in claim 9, the effect according to claim 5 can be reliably obtained.

If the means for stimulating the fish as described in the tenth aspect is a flat wire mesh or a movable basket surrounding the fish, the stimulus can be reliably applied to the fish.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing one embodiment of a water quality monitoring device using fishes of the present invention.

FIG. 2 is a schematic view showing an embodiment of a configuration of a micro pressure sensor for detecting movement of water.

FIG. 3 is a chart showing the presence of fish detected by the micro-pressure sensor of FIG. 2;

FIG. 4 is a chart when no fish is detected by the micro-pressure sensor of FIG. 2;

[Explanation of symbols]

 Reference Signs List 1 water tank 2 water supply pipe 3, 3 'micro pressure sensor 4 pump 5 wire mesh 6 drain pipe 8 pressure detector 9 amplifier 10, 11 inlet 12 communication hole 13, 14 tube 15 collector 16 wire mesh 17 elevating mechanism 18 motor 19 winding Pulley 20 Support frame 21, 22 Shaft 23, 24 Pulley 25, 26 Rope 30 Fish 8a, 8b Piezoelectric element

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[Procedure amendment]

[Submission date] September 13, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing one embodiment of a water quality monitoring device using fishes of the present invention.

FIG. 2 is a schematic view showing an embodiment of a configuration of a micro pressure sensor for detecting movement of water.

FIG. 3 is a chart when fish are detected by the micro-pressure sensor of FIG. 2;

FIG. 4 is a chart when there is no fish detected by the micro-pressure sensor in FIG. 2;

FIG. 5 is a schematic perspective view showing a second embodiment of the water quality monitoring device using fishes of the present invention.

[Description of Signs] 1 Water tank 2 Water supply pipe 3, 3 ′ Low pressure sensor 4 Pump 5 Wire mesh 6 Drain pipe 8 Pressure detector 9 Amplifier 10, 11 Inlet 12 Communication hole 13, 14 Tube 15 Collector 15 Wire mesh 17 Elevating mechanism Reference Signs List 18 motor 19 winding pulley 20 support frame 21, 22 shaft 23, 24 pulley 25, 26 rope 30 fish 8a, 8b piezoelectric element

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kiyama Gen 1-1-45, Oe, Otsu, Shiga Prefecture Inside Toray Engineering Co., Ltd. (72) Inventor Tetsuhiko Endo 3-4-1, Nakanoshima, Kita-ku, Osaka-shi (Mitsui Building No.2) Toray Engineering Co., Ltd. (72) Inventor Mineo Sato 1-145 Oe, Otsu City, Shiga Prefecture Toray Engineering Co., Ltd. (72) Inventor Takuo Mano Oe, Oga City, Shiga Prefecture 1-45-1 Toray Engineering Co., Ltd. (72) Inventor Yasunori Aoyama 1-1-45 Oe, Otsu City, Shiga Prefecture Toray Engineering Co., Ltd.

Claims (10)

[Claims] 1. A method for detecting the presence or absence of toxic substances in water using fish in an aquarium or pond into which test water is introduced,
A water quality monitoring method using fish, wherein water vibration due to fish activity is detected, and an abnormality in water quality is detected based on the detected value. 2. The water quality monitoring using fish according to claim 1, wherein the vibration of water due to the activity of fish is detected as air pressure fluctuation, and the abnormality of water quality is detected based on the pressure fluctuation value. Method. 3. An alarm is issued when the pressure fluctuation value becomes larger or smaller than a set value, or when the signal information is subjected to frequency analysis to produce a difference in its waveform pattern. A method for monitoring water quality using fish according to claim 2. 4. The method according to claim 1, wherein the vibration of the water due to the activity of the fish is detected in a state where the supply of the test water into the water tank or the pond is temporarily stopped. A water quality monitoring method using the fish according to one of the claims. 5. When the vibration of water caused by the activity of fish cannot be detected, the vibration of water caused by the activity of fish is detected in a state where the fish is stimulated, and the abnormality of the water quality is detected based on the detected value. The method for monitoring water quality using fish according to claim 1, wherein: 6. A water quality monitoring device using fish, wherein a sensor for detecting the activity of fish as pressure fluctuation of air is disposed in a tank or a pond into which the test water is introduced. 7. A pressure sensor comprising two piezoelectric elements which are provided with electrode layers on both sides of a film-shaped piezoelectric body and are stretched in a plane, and an amplifier for amplifying the sum of outputs of both piezoelectric elements. And a conduit for detecting the vibration of water due to the activity of fish as a pressure fluctuation of air is connected to one of the two nozzles for introducing fluid pressure provided in the pressure detection unit, and the other is connected to the other nozzle. The water quality monitoring device using fish according to claim 6, wherein the nozzle is configured to communicate with the atmosphere. 8. The water quality monitoring device using fish according to claim 7, wherein a funnel-shaped vibration collecting means is attached to a tip of the conduit. 9. The water quality monitoring device using fish according to claim 6, wherein means for stimulating the fish is provided in a water tank or a pond. 10. The water quality monitoring device using fish according to claim 9, wherein the means for stimulating the fish is a flat movable wire net or a movable basket surrounding the fish.