JPH06123705A - Toxic substance monitor - Google Patents

Abstract

PURPOSE:To simply and quickly detect underwater toxic substance with a microorganism by providing a flow cell having an immobilized microorganism film immobilizing nitrous acid production bacteria. CONSTITUTION:An immobilization microorganism film 1 immobilizing purely cultivated nitrous acid production bacteria is attached to a flow cell 3 set in a constant temperature bath 2, a pump 4 is driven, a valve 5 is opened, first buffer solution 6 containing no microorganism substrate on either surface of the microorganism film 1 is allowed to flow and carried to a detection part 10 having an optical system from the outlet of the flow cell 3. Next, after it is washed with pure water, second buffer solution containing ammonia nitrogen with specified concentration is allowed to flow from the flow cell 3 through the same route as the buffer solution 6 to the detection part 30. Ammoniacal nitrogen is converted into nitrous nitrogen in the flow cell 3 with nitrous acid production bacteria of the microorganism film 1, the concentration of nitrous nitrogen increases in the buffer solution 22, a degree of ultraviolet absorbance becomes high, and since it becomes constant concentration corresponding to the concentration of feed ammonia, the degree of the ultraviolet absorbance becomes constant in the detection part 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a harmful substance monitor for monitoring the quality of water sources such as dams and river water, the safety of water intake at water purification plants, or the inflow water at sewage treatment plants, using microorganisms.

[0002]

2. Description of the Related Art Up to now, in the field of clean water, many fish have been bred in an aquarium and the harmful substances have been monitored from the situation. Therefore, recently, 1) a device for monitoring the behavior of fish in more detail using AI (artificial intelligence) 2) a device for monitoring harmful substances by measuring the respiration rate of fish has been developed. None of these have been put to practical use yet.

On the other hand, in the field of sewerage, toxic substances, especially heavy metals, have been indirectly monitored by measuring pH and ORP (oxidation-reduction potential).

[0004]

[Problems to be Solved by the Invention] However, the above 1),
None of the devices of 2) have been put to practical use yet,
The main reason for this is that maintenance is required to keep a large number of fish in a healthy condition at all times. The device configuration is complicated and expensive.

It takes time to determine the concentration or toxicity level of harmful substances. Resistance to harmful substances increases as the fish grows. And so on. In the field of sewerage, the pH cannot be measured because the wastewater is neutralized before flowing.

ORP cannot detect various harmful substances. There are problems such as. The present invention has been made in view of the above points, and an object thereof is to provide a harmful substance monitor that can detect a harmful substance in water simply and quickly by using a microorganism.

[0007]

In order to solve the above-mentioned problems, the harmful substance monitor of the present invention has a first invention in which an immobilized microbial membrane on which nitrite-producing bacteria are immobilized is retained and A flow cell having a liquid flow path flowing on one surface of the microbial membrane, a liquid flow path discharged after flowing on the other surface of the immobilized microbial membrane, and a substrate-free buffer solution on one surface of the immobilized microbial membrane And a solution sending system that switches the solution to a buffer solution containing a predetermined concentration of ammonia nitrogen, and a solution sending system that switches pure water onto the other surface of the immobilized microbial membrane and then switches it to test water. A quartz flow cell into which the two types of buffer solutions of (1) and (2) respectively flow in and out after passing through the flow cell;
An interference filter and a detection unit of an optical system having a photodiode, and a measurement unit including a measurement calculation unit, a display unit, and a recording unit connected to the detection unit,
The invention holds a fixed microbial membrane on which nitric acid-producing bacteria are fixed, and a liquid flow path flowing on one surface of the fixed microbial membrane,
A flow cell having a liquid flow path that is discharged after flowing on the other surface of the immobilized microbial membrane, and after flowing a substrate-free buffer solution through the first quartz flow cell on one surface of the immobilized microbial membrane, A liquid supply system for switching to a buffer solution containing a predetermined concentration of nitrite nitrogen, and a liquid supply system for flowing pure water on the other surface of the immobilized microbial membrane and then switching it to water for detection, a first quartz flow cell, A second quartz flow cell into which the above-mentioned two kinds of buffer solutions respectively flow in and out after passing through the flow cell, a light source and a beam splitter for irradiating these two quartz flow cells with ultraviolet rays, a plurality of lenses, an interference filter, and a first A detection part of an optical system having a first photodiode that receives light from a quartz flow cell and a second photodiode that receives light from a second quartz flow cell, and a connection to this detection part Measurement computation unit that, the display unit, in which a measuring section composed of a recording unit.

[0008]

Since the harmful substance monitor of the present invention is constructed as described above, in the first invention, a nitrite-producing bacterium having high sensitivity to harmful substances is used as a microorganism. The function of converting nitrogen to nitrite nitrogen using dissolved oxygen is inhibited by harmful substances, the concentration of nitrite nitrogen in the buffer solution decreases, and the ultraviolet light around 350 nm caused by the concentration of nitrite nitrogen in the buffer solution is reduced. By optically measuring the decrease in absorbance (UV ₃₅₀ ), it is possible to detect harmful substances. In the second invention,
Nitrate-producing bacteria, which are highly sensitive to harmful substances, are used as microorganisms.This microorganism inhibits the function of converting nitrite nitrogen to nitrate nitrogen using dissolved oxygen, and the microorganisms in the buffer solution It is possible to detect harmful substances by optically measuring that the concentration of nitrate nitrogen increases, the above-mentioned ultraviolet absorbance increases, and the ultraviolet absorbance difference (ΔUV ₃₅₀ ) at the inlet and outlet of the flow cell decreases. it can.

[0009]

EXAMPLES The present invention will be described below based on examples.Example 1 First, change ammoniacal nitrogen to nitrite nitrogen
(NH_Four ⁺-N → NO₂ ^--N) When using microorganisms
State. Figure 1 shows nitrite-producing bacteria (Nitrosomonas)
Schematic showing the configuration of the hazardous substance monitor according to the present invention used
It is a figure, and an arrow represents with the flowing direction of a liquid. Figure 2
It is a diagram which shows the measurement result using this. Below in Figure 1
With reference to FIG.
explain about.

In FIG. 1, an immobilized microbial membrane 1 on which pure cultivated nitrite-producing bacteria have been immobilized is attached to a flow cell 3 (shaded area of dotted line) installed in a thermostatic layer 2 (shaded area), and a pump 4 is attached. The valve 5 is opened by driving, the buffer solution 6 containing no microbial substrate is caused to flow on one surface of the immobilized microbial membrane 1, and the buffer solution 6 is sent from the outlet of the flow cell 3 to the detection unit 10 having an optical system. At the same time, the pump 7 is driven, the valve 8 is opened, and the pure water 9 is made to flow to the other surface of the immobilized microbial membrane 1 to be washed and discharged to the outside.

In the detector 10 , ultraviolet rays having a wavelength of 350 nm emitted from the mercury lamp of the light source 11 are passed through the lenses 12a and 1a.
The buffer solution 6 flowing through the quartz flow cell 14 is irradiated through 2b and the interference filter 13 between them,
The light is received by the photodiode 16 through the lens 15, and the ultraviolet absorbance of the buffer solution 6 is optically measured by the measuring unit 17 connected to the photodiode 16. The measuring unit 17 includes a measurement / calculation unit 18, a display unit 19, and a recording unit 20, which are surrounded by a dashed line. Quartz flow cell 14
The buffer solution 6 that has flowed through is discarded as it is outside. This state is designated as A, and the elapsed time-ultraviolet absorbance (UV
₃₅₀ ) Also shown on the curve.

Next, the valve 5 is closed and the valve 21 is opened, and a buffer solution 22 containing ammonia nitrogen (NH ₄ ⁺ -N) at a predetermined concentration is passed from the flow cell 3 to the detecting section 10 along the same route as the buffer solution 6. Shed on. The ammonia nitrogen in the flow cell 3 is converted into nitrite nitrogen by the nitrite-producing bacteria of the immobilized microbial membrane 1, the concentration of nitrite nitrogen in the buffer solution 22 increases, and the ultraviolet absorbance increases, but it is supplied. Since the concentration becomes constant corresponding to the ammonia concentration, the detection unit 10
The UV absorbance at is constant. This state is B shown in the curve of FIG.

Next, the valve 8 is closed and the valve 23 is opened, and the sample water (sample water) 24 is introduced into the flow cell 3 through the same path as the pure water 9. That is, with respect to the immobilized microbial membrane 1, the surface on the back side of the surface where the buffer solution 6 is flowing is subjected to the test water 24.
Will flow. At this time, when the test water 24 does not contain any harmful substances, the absorbance is almost at a constant level, but when the test water 24 contains harmful substances, the activity of the microorganisms in the flow cell 3 decreases. However, since the amount of nitrite nitrogen produced decreases, the absorbance becomes low, and the contamination of harmful substances can be detected when the curve goes downward from the end point of B in FIG. After that, the absorbance becomes constant while the harmful substance is present. This state is C shown in the curve of FIG.

After the harmful substances have flowed away, the state of D shown in the curve of FIG. 2 is restored, and the original absorbance is restored. Thus, according to the harmful substance monitor of the present invention,
The presence or absence of harmful substances can be easily determined. The following Example 2 alters the nitrite nitrogen to nitrate nitrogen (NO ₂ ^- -N
→ NO ₃ ^- -N) is a case of using microorganisms. FIG. 3 is a schematic diagram showing the configuration of a harmful substance monitor according to the present invention using a nitric acid-producing bacterium (nitrobactor), in which the direction in which a liquid flows is indicated by an arrow. FIG. 4 is a diagram showing a measurement result using this apparatus. With reference to FIGS. 3 and 4 together, the configuration of the apparatus and the operating procedure will be described in the same manner as in Example 1.

In FIG. 3, a flow cell 3a having the same structure as in Example 1 in which an immobilized microbial membrane 1a (shaded area) on which purely cultured nitric acid-producing bacteria are immobilized is installed in a thermostatic layer (not shown). Attach it to the shaded area of the dotted line. The pump 4a is driven to open the valve 5a, and the buffer solution 6a containing no microbial substrate is added to the first quartz flow cell 14a.
Flow through one surface of the immobilized microbial membrane 1a, which is further passed through the second quartz flow cell 14b and then discharged. In this case, nitrite nitrogen is changed to nitrate nitrogen, and therefore, there is a difference in ultraviolet absorbance between the inlet and outlet of the flow cell 3a. Therefore, here, the ultraviolet absorbance should be measured before and after the buffer solution 6a flows through the flow cell 3a. The device is configured so that it can. At the same time as the buffer solution 6a is flown, the pump 7a is driven, the valve 8a is opened, and the pure water 9a is flown to the other surface of the immobilized microbial membrane 1a for cleaning, and then discharged as it is.

In this case, as described above, the flow cell 3a
Since the UV absorbance of the buffer solution 6a is measured near the inlet and outlet of the light source 1, the light source 1 is used in the detection unit 10a having an optical system.
The ultraviolet ray having a wavelength of 350 nm emitted from the mercury lamp 1a passes through the lenses 12c and 12d and the interference filter 13a, and then is split by the beam splitter 25.
One is the buffer solution 6 flowing through the first quartz flow cell 14a.
After irradiating a, it is received by the first photodiode 16a through the lens 15a, and the other is received by the second quartz flow cell 1.
After irradiating the buffer solution 6a flowing through 4b, the lens 15b
It is received by the second photodiode 16b. First
Photodiode 16a and second photodiode 1
The measurement unit 17a connected to the 6b includes a measurement calculation unit 18a,
It has a display unit 19a and a recording unit 20a, which are surrounded by a dashed line.

In this way, the ultraviolet absorbance on the buffer solution 6a side is measured in the vicinity of the inlet and outlet of the flow cell 3a. The absorbance at the inlet and the absorbance at the outlet are almost the same, and there is almost no difference between them. Absent. This state is designated as A, and the elapsed time-ultraviolet absorbance difference (ΔUV) shown in FIG.
₃₅₀ ) Also shown on the curve. Then, opening the valve 21a closes the valve 5a, nitrite nitrogen ^- flowing in the flow cell 3a to (NO ₂ -N) a predetermined concentration, including buffer solution 22a with a buffer solution 6a the same path. The nitrite nitrogen in the flow cell 3a is converted into nitrate nitrogen by the nitric acid-producing bacteria of the immobilized microbial membrane 1a, so that the ultraviolet absorbance on the outlet side of the flow cell 3a decreases and the buffer solution at the inlet and the outlet of the flow cell 3a. There is a certain difference in the UV absorbance of 6a, after which this ΔUV ₃₅₀ holds that value. This state is B shown along with the curve in FIG.

Next, the valve 8a is closed and the valve 23a is opened, and the sample water (sample water) 24a is added to the flow cell 3a with pure water 9a.
It is introduced by the same route as a. As in the case of Example 1, the sample water 24a flows on the surface on the back side of the surface of the immobilized microbial membrane 1a on which the buffer solution 22a is flowing. When harmful substances are mixed in the test water 24a, the nitrite-oxidizing activity of the nitric acid-producing bacteria in the flow cell 3a decreases, the nitrite nitrogen concentration at the outlet of the flow cell 3a increases, and the ultraviolet absorbance increases. Therefore, the difference in ultraviolet absorbance between the inlet and the outlet of the flow cell 3a becomes small, and it is possible to detect the mixture of harmful substances when the curve goes downward from the end point of B in FIG. After that, ΔUV ₃₅₀ becomes constant while the harmful substances are present. This state is C shown in the curve of FIG.

After the harmful substances have flowed away, the state of D shown in the curve of FIG. 4 is restored and the original difference in absorbance is restored, as in the case of FIG. As described above, in the harmful substance monitor of the present invention, the buffer solution 22 or 22a is constantly flown through the flow cell 3 or 3a.
Since 4a only flows on the surface opposite to the surface on which the buffer solution 22 or 22a flows, it is characterized in that the sample water 24 or 24a does not have to be contaminated. It has the advantage of being sensitive to the detection of agents.

[0020]

INDUSTRIAL APPLICABILITY The harmful substance monitor of the present invention is provided with an immobilized microbial membrane on which nitrite-producing bacteria or nitric acid-producing bacteria are immobilized in a flow cell. This flow cell has a buffer solution and a test water as described in the Examples. Since each of the flow paths is on the front and back sides of the immobilized microbial membrane, the measurement part (quartz flow cell) is not affected by dirt due to test water, and the optical absorbance is measured optically. By using a simple device, it is possible to efficiently monitor the intake of harmful substances in river water, water intake from water purification plants and inflow water from sewage treatment plants in a short time.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a device configuration of a harmful substance monitor of the present invention using a nitrite-producing bacterium as an immobilized microbial membrane.

FIG. 2 is a diagram showing the relationship between elapsed time measured by the device of FIG. 1 and ultraviolet absorbance (UV ₃₅₀ ).

FIG. 3 is a schematic diagram showing the constitution of a harmful substance monitor of the present invention in which nitrate-producing bacteria are used as an immobilized microbial membrane.

FIG. 4 is a diagram showing a relationship between elapsed time measured by the device of FIG. 3 and ultraviolet absorption difference (ΔUV ₃₅₀ ).

[Explanation of symbols]

1 immobilized microbial membrane 1a immobilized microbial membrane 2 thermostat 3 flow cell 3a flow cell 4 pump 4a pump 5 valve 5a valve 6 buffer solution 6a buffer solution 7 pump 7a pump 8 valve 8a valve 9 pure water 9a pure water 10 detection part 10a detection Part 11 Light source 11a Light source 12a Lens 12b Lens 12c Lens 12d Lens 13 Interference filter 13a Interference filter 14 Quartz flow cell 14a First quartz flow cell 14b Second quartz flow cell 15 Lens 15a Lens 15b Lens 16 Photodiode 16a First photodiode 16b the second photodiode 17 measuring portion 17a measuring section 18 measuring arithmetic unit 18a measures arithmetic unit 19 display unit 19a display unit 20 recording unit 20a records 21 valve 21a valve 22 NH ₄ ⁺ - Buffer containing -N solution 23 valve 23a valve 24 test water 24a test water 25 beam splitter ^- buffer 22a NO ₂ containing

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroshi Hoshikawa 1-1 Tanabe Nitta, Kawasaki-ku, Kawasaki-shi, Kanagawa Fuji Electric Co., Ltd.

Claims (2)

[Claims] 1. A. Holding an immobilized microbial membrane on which nitrite-producing bacteria are immobilized, a liquid flow channel flowing on one surface of the immobilized microbial membrane, and a liquid flow channel discharged after flowing on the other surface of the immobilized microbial membrane. A flow cell having b. After flowing a substrate-free buffer solution on one surface of the immobilized microbial membrane, a liquid delivery system that switches it to a buffer solution containing a predetermined concentration of ammonia nitrogen, and pure water on the other surface of the immobilized microbial membrane. A liquid-sending system in which the water is flown and then switched to a test water, c. A quartz flow cell into which the two types of buffer solutions respectively flow in and out after passing through the flow cell, a light source for irradiating the quartz flow cell with ultraviolet rays, a plurality of lenses, an interference filter, and a detection unit of an optical system having a photodiode. And d. A hazardous substance monitor characterized by comprising a measuring unit comprising a measuring / calculating unit, a display unit and a recording unit connected to the detecting unit. 2. A. The immobilized microbial membrane on which the nitrate-producing bacteria are immobilized is retained, and the liquid flow channel that flows on one surface of the immobilized microbial membrane and the liquid channel that is discharged after flowing on the other surface of the immobilized microbial membrane are provided. A flow cell having b. A solution sending system in which a substrate-free buffer solution is caused to flow through the first quartz flow cell on one surface of the immobilized microbial membrane, and then switched to a buffer solution containing a predetermined concentration of nitrite nitrogen,
And a liquid sending system in which pure water is caused to flow on the other surface of the immobilized microbial membrane and then switched to test water, and c. The first quartz flow cell, the second quartz flow cell into which the two kinds of buffer solutions respectively flow through the flow cell and then flow out, the light source and the beam splitter for irradiating the two quartz flow cells with ultraviolet rays, and a plurality of them. Lens, an interference filter, a first photodiode that receives light from the first quartz flow cell, and the second photodiode
A detection section of an optical system having a second photodiode for receiving light from the quartz flow cell of d. A toxic substance monitor, comprising: a measurement / calculation unit connected to the detection unit; a display unit; and a measurement unit including a recording unit.