JP2004279105A - Biosensor type abnormal water quality detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To continuously obtain a stable long-term operation by preventing bubbles generated by the temperature difference between water to be inspected and the inside of a measuring bath from adhering to the surface of a microbe film surface. <P>SOLUTION: A biosensor type abnormal water quality detector comprises a means 23 for heating water to be inspected to be preheated before supplying to the measuring bath 16; and a temperature control means 24 for controlling the means 23 for heating water to be inspected so that the temperature difference between the water to be inspected and the measuring bath 16 is reduced. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention introduces test water, which has been brought into a saturated dissolved oxygen state by a diffuser water tank, into a measurement tank holding a microbial membrane on an oxygen electrode, and removes harmful substances to the test water by the amount of oxygen passing through the microbial membrane. The present invention relates to a biosensor type abnormal water quality detection device that detects contamination.
[0002]
[Prior art]
Conventionally, a water purification plant takes in river water, and supplies the drinking water through a sedimentation filtration tank. When harmful substances that cannot be removed by such normal treatment, that is, substances such as various heavy metals, pesticides, and environmental hormones, are mixed into river water, an emergency situation occurs in which water intake is stopped.
[0003]
At the sewage treatment plant, on the other hand, various heavy metal ions and arsenic cyanide are mixed into the wastewater of factories or chemical plants due to sudden accidents or carelessness. As a result, the activity of the activated sludge is reduced, and a large amount of time is required until the treatment capacity is restored.
[0004]
Therefore, in a water purification plant and a sewage treatment plant, when the above-mentioned various harmful substances are mixed, a device which detects inflow water quickly and with high sensitivity has been desired.
[0005]
In response to this demand, water purification plants have installed fish behavior monitoring type toxic substance detection devices or devices that attach various microbial membranes to dissolved oxygen electrodes and detect toxic substances by measuring their respiratory activity. In, various sensors for detecting wastewater mixed with a specific chemical substance are installed at respective water intakes.
[0006]
Among them, the fish behavior monitoring type toxic substance detection device installed in the water purification plant takes a long time until the fishes react to the toxic substance, so that the detection takes a long time. In addition, the reaction sensitivity of fish varies considerably depending on the type and individual differences of the breed fish and the environmental conditions of breeding.Furthermore, the toxicological detection device of the fish behavior monitoring type is large-scale, and the breeding and management of fish is difficult. There is a problem that the required expenses are large.
[0007]
Therefore, a biosensor-type water quality monitoring device using, as a probe, an iron-oxidizing bacterium that can be operated at a relatively low pH value at which harmful substances and various germs are not easily propagated has been developed (for example, see Patent Document 1). . In the biosensor type water quality monitoring device, as shown in FIG. 4, the water source to be inspected, that is, the test water of the test water source (for example, flowing water of a river, inflow water to a water purification plant, inflow water to a sewage treatment plant, ) Is once stored in the test water tank 3 by the pump 1 via the test water introduction pipe 2, and the test water is supplied from the test water tank 3 to the aeration tank 5 by the pump 4. The test water sent to the water diffuser tank 5 is supplied with air or a gas whose oxygen concentration is adjusted to be constant from the gas supply unit 6 and the test water is introduced by the pump 7 in a state where the dissolved oxygen concentration is in a saturated state. It is delivered to tube 8. An acidic solution is supplied to the test water introduction pipe 8 from the acidic solution pack 9 via a pump 10 and an acidic solution pipe 11, and from the iron solution pack 12 via an iron solution supply pump 13 and an iron solution pipe 14. A ferrous-containing solution is provided, where it is mixed with the test water. This mixed liquid is introduced into the measuring tank 16 from the inlet 15 in a state where the dissolved oxygen concentration is saturated by the gas supplied from the gas supply device 6.
[0008]
The temperature of the measuring tank 16 is adjusted by a temperature adjuster 17. Before supplying the test water to the measuring tank 16, air or a gas whose oxygen concentration is adjusted to be constant is supplied from the gas supply device 6, and the test water is always set to the saturated dissolved oxygen concentration, and the output of the oxygen electrode 19 is output. It is necessary to stabilize the maximum value of. Here, since the saturated dissolved oxygen concentration changes depending on the liquid temperature, it is important at this point to maintain the measurement tank 16 at a constant temperature by the temperature controller 17. An oxygen electrode 19 provided with a microbial membrane 18 holding an iron bacterium capable of converting ferrous iron to ferric iron using oxygen is provided in the measuring tank 16. Further, the electrical output from the oxygen electrode 19 is taken out, the electrical output is amplified and converted by the conversion calculating means 20, and the calculation is performed to determine the abnormal water quality of the test water. The iron bacterium held on the microbial membrane 18 is, for example, Thiobacillus ferrooxidans. The test water passing through the measuring tank 16 is drained from the discharge tube pipe 21 via the discharge pipe 22.
[0009]
The chemical equation of this chemical behavior is
4FeSO ₄ + O ₂ + 2H ₂ SO ₄ → 2Fe ₂ (SO ₄ ) ₃ + 2H ₂ O
This produces Fe ³⁺ ions. The Fe ³⁺ ions further react with water (H ₂ O) to form iron hydroxide Fe (OH) ₃ , which precipitates. As the iron bacteria held on the microbial membrane 18, all microorganisms having the function of the above chemical reaction formula can be applied, in addition to Thiobacillus ferrooxidans. For example, it has been confirmed that Thiobacillus ferrooxidans, Gallionella ferruginea, Leptospirillum ferrooxidans, Leptothrix, Sphaerotilus, and the like are suitable.
[0010]
Since the activity of iron bacteria, that is, the amount of oxidized iron, may change due to the influence of temperature, the measuring tank 16 is maintained at a temperature at which the activity of iron bacteria is stabilized by the temperature controller 17. It is desirable. The temperature controller 17 is provided in that sense. In the water quality detection device shown in FIG. 4, a mixed solution of test water and iron solution is sent to the dissolved oxygen electrode 19 equipped with iron oxidizing bacteria as a probe by the pump 7, and the electric output from the oxygen electrode 19 at the time of sending the solution. Is to monitor. In this case, when a water-soluble harmful substance is mixed into the test water, the harmful substance permeates the diaphragm and reaches the oxygen electrode 19 due to a decrease in the respiratory activity of the iron-oxidizing bacteria, and the oxygen concentration increases. As a result, the current value for detecting this is increased, thereby detecting the contamination of harmful substances.
[0011]
When such a biosensor type water quality detection device is continuously operated, pollutants in the test water gradually adhere to and accumulate on the inner surface of the drainage pipe 22. In addition, part of ferrous iron in the iron liquid is oxidized to ferric iron, and this is gradually deposited. These may lead to blockage of the piping system and decrease in sensitivity of water quality detection measurement, which may cause a decrease in detection accuracy. Therefore, in the apparatus of FIG. 4, the acidic solution is supplied from the acidic solution pack 9 to the introduction pipe 8 through which the mixed solution of the test water and the ferrous solution is sent through the pump 10 and the acidic solution pipe 11. It is possible to perform "acid cleaning" in which contaminants and iron oxide which are supplied and adhered and deposited in the test water passage such as the introduction pipe 8 and the measuring tank 16 are removed and discharged.
[0012]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2000-32233 (FIGS. 1 and 2 and description thereof)
[0013]
[Problems to be solved by the invention]
In a biosensor type abnormal water quality detection device using microorganisms as a probe, it is necessary to stabilize the detection sensitivity of harmful substances by always keeping the activity of microorganisms constant. It is necessary to keep around 30 ° C. On the other hand, the temperature of river water in winter falls to 4 ° C or less. When the river water is used as the test water, the oxygen is sufficiently saturated in the aeration tank 5 and then introduced into the measurement tank 16, the test water undergoes a rapid temperature change in the measurement tank 16. Normally, the solubility of gas in water decreases as the temperature rises, so that the dissolved air vaporizes and becomes air bubbles and adheres to the electrode surface, obstructing the flow of the test water to the microbial membrane 18. As a result, the detection sensitivity for abnormal water quality is reduced. In addition, usually, in the biosensor type abnormal water quality detection device, it is necessary to maintain the activity of the microorganism for a long period of time. However, due to the above action, the amount of nutrient supply to the microorganism also decreases, and stable growth of the microorganism cannot be maintained.
[0014]
Therefore, an object of the present invention is to prevent a situation in which bubbles generated due to a temperature difference between the test water and the inside of the measurement tank adhere to the surface of the microbial membrane, thereby inhibiting the flow of the test water to the microbial membrane. It is an object of the present invention to provide a biosensor type abnormal water quality detection device capable of continuing stable long-term operation without any problem.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 introduces test water, which has been brought into a saturated dissolved oxygen state by a diffuser water tank, into a measurement tank holding a microbial membrane on an oxygen electrode and transmits the microbial membrane. In a biosensor type abnormal water quality detection device that detects contamination of test water with harmful substances based on the amount of oxygen to be measured, a test water heating means for preheating the test water before supplying it to the measurement tank, Temperature control means for controlling the test water heating means so as to reduce the temperature difference between the tank and the tank.
[0016]
The invention according to claim 2 is the biosensor-type abnormal water quality detection device according to claim 1, wherein a heating heater that heats the test water upstream of the diffused water tank is provided as the test water heating unit, A temperature controller for controlling the heating heater is provided as the temperature control means.
[0017]
According to a third aspect of the present invention, in the biosensor type abnormal water quality detection device according to the first aspect, a heating heater for heating the test water in the diffused water tank is provided as the test water heating means, and the temperature control is performed. As means, a temperature controller for controlling the heating heater is provided.
[0018]
According to a fourth aspect of the present invention, in the biosensor type abnormal water quality detecting device according to the first aspect, common hot water is circulated between the diffused water tank and the measurement tank while the test water is insulated. The heating water circulating system is configured as described above, and a heating heater for heating the hot water circulating in the hot water circulating system is provided as the heating means for the test water, and as the temperature control means, a heater for adjusting the temperature of the hot water is provided. A temperature controller for controlling the heater is provided.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0020]
<First embodiment>
FIG. 1 is a configuration diagram showing a biosensor type abnormal water quality detection device according to a first embodiment of the present invention.
[0021]
The illustrated abnormal water quality detection device is configured based on the abnormal water quality detection device illustrated in FIG. 4 as one embodiment. In this embodiment, a heating heater 23 is provided as heating means for heating the test water on the upstream side of the aeration water tank 5, and the temperature of the test water is controlled via the heating heater 23 as the temperature control means. A temperature controller 24 is provided. The heating controller 23 is controlled by the temperature controller 24 so that the temperature of the test water sent to the measuring tank 16 becomes equal to the temperature in the measuring tank 16.
[0022]
As described above, the test water introduced into the measurement tank 16 is heated in advance, and the temperature difference between the test water and the existing test water in the measurement tank 16 is eliminated or made small. The generation of air bubbles is prevented, and the adhesion of air bubbles to the surface of the microbial membrane 18 is prevented.
Therefore, according to the present embodiment, the stable long-term operation of the apparatus can be continued without obstructing the flow of the test water to the microorganism membrane 18.
[0023]
(Second embodiment)
FIG. 2 is a schematic configuration diagram showing a biosensor type abnormal water quality detection device according to a second embodiment of the present invention.
[0024]
In this embodiment, the heating means is provided not in the upstream of the diffused water tank 5 but in the diffused water tank 5 itself. That is, a heating heater 25 for heating the test water is provided in the diffuser water tank 5, and the heating heater 25 is provided with a temperature controller 26 for controlling the generated heat. The heating heater 25 heats the test water in the diffused water tank 5 to the same temperature as that in the measurement tank 16 under the control of the temperature controller 26.
[0025]
Thereby, the generation of bubbles due to the temperature difference between the test water and the inside of the measurement tank 16 can be suppressed, and the situation in which bubbles adhere to the surface of the microbial membrane 18 can be prevented. As a result, the flow of the test water to the microbial membrane 18 is not hindered by air bubbles, and the stable long-term operation of the apparatus can be continued.
[0026]
<Third embodiment>
FIG. 3 is a schematic configuration diagram showing a biosensor type abnormal water quality detection device according to a third embodiment of the present invention.
[0027]
In the present embodiment, the diffusing water tank 27 and the measuring tank 28 in place of the above-described diffusing water tank 5 and the measuring tank 16 are configured so that warm water whose temperature is controlled and insulated from the test water can be circulated. To form a hot water circulation system through which common hot water circulates via pipes 29 and 30. Further, a heating heater 31 for heating the circulating water and a pump 32 for circulating the warm water heated here in the hot water circulation system are arranged in the pipe 30. The heating heater 31 is provided with a temperature controller 33 that controls the temperature of the circulating water via the heating heater 31. The flow system of the test water is the same as that of FIGS. However, in this embodiment, the measuring tank 28 also serves as a temperature controller, and there is no need to provide a special temperature controller 17 (FIG. 1 and the like).
[0028]
In the present embodiment, a circulating temperature control system is configured to keep the measurement tank 28 and the diffused water tank 27 in common hot water, and the test water introduced into the measurement tank 28 and the existing test water therein are configured. Are controlled to the same temperature, so that no air bubbles are generated in the measuring tank 28, and the temperature difference between the test water in the measuring tank 28 and the test water introduced therein causes the microbial membrane 18 A situation in which air bubbles adhere to the surface of the substrate can be prevented. Thereby, stable long-term operation of the apparatus can be continued without obstructing the flow of the test water to the microorganism membrane 18.
[0029]
【The invention's effect】
As described above, according to the present invention, by reducing the temperature difference between the test water to be introduced and the inside of the measurement tank, the difference in solubility of air in water does not occur, and the oxygen of the biosensor type abnormal water quality detection device is reduced. It is possible to prevent air bubbles from adhering to the microbial membrane held at the tip of the electrode, thus preventing the flow of the test water to the microbial membrane from being hindered and preventing the detection sensitivity of abnormal water quality from lowering.
[0030]
Normally, in a biosensor type abnormal water quality detection device, nutrients for microorganisms are mixed with and supplied to the test water in order to maintain the activity of the microorganisms for a long period of time. Nutrient supply is also stable. As a result, stable growth of microorganisms can be maintained, and stable long-term operation of the device can be continued.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a first embodiment of a biosensor type abnormal water quality detection device according to the present invention.
FIG. 2 is a schematic configuration diagram showing a second embodiment of a biosensor type abnormal water quality detection device according to the present invention.
FIG. 3 is a schematic configuration diagram showing a third embodiment of a biosensor type abnormal water quality detection device according to the present invention.
FIG. 4 is a schematic configuration diagram showing a configuration example of a known biosensor type abnormal water quality detection device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Pump 2 Test water introduction pipe 3 Test water tank 4 Pump 5 Aeration tank 6 Gas supply device 7 Pump 8 Test water introduction pipe 9 Acid solution pack 10 Pump 11 Acid solution pipe 12 Iron solution pack 13 Iron solution supply pump 14 Iron Liquid Pipe 15 Inlet 16 Measurement Tank 17 Temperature Controller 18 Microbial Membrane 19 Oxygen Electrode 20 Conversion Calculation Means 21 Discharge Tube Pipe 22 Discharge Pipe 23 Heating Heater 24 Temperature Controller 25 Heating Heater 26 Temperature Controller 27 Spray Water tank 28 Measurement tank 29 Piping 30 Piping 31 Heating heater 32 Pump 33 Temperature controller

Claims (4)

The test water brought into the saturated dissolved oxygen state by the aeration water tank is introduced into a measurement tank holding a microbial membrane on an oxygen electrode, and contamination of the test water with harmful substances is determined by the amount of oxygen passing through the microbial membrane. In the biosensor type abnormal water quality detection device for detecting, a test water heating means for preheating the test water before supplying the test water to the measurement tank, and reducing a temperature difference between the test water and the measurement tank. And a temperature control means for controlling the test water heating means as described above. As the test water heating means, a heating heater for heating the test water upstream of the diffused water tank is provided, and as the temperature control means, a temperature controller for controlling the heating heater is provided. The biosensor type abnormal water quality detection device according to claim 1, wherein: A heating heater for heating the test water in the aeration tank is provided as the test water heating means, and a temperature controller for controlling the heating heater is provided as the temperature control means. The biosensor type abnormal water quality detection device according to claim 1, wherein: A hot water circulation system configured to circulate common hot water in a state where the test water is insulated between the aeration water tank and the measurement tank is configured, and the hot water circulating system is configured as the test water heating unit. A heating heater for heating hot water circulating in a circulation system is provided, and a temperature controller for controlling the heating heater for adjusting the temperature of the hot water is provided as the temperature control means. The biosensor type abnormal water quality detection device according to claim 1.

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