JPS5875062A - Automatic measuring apparatus for bod - Google Patents

Abstract

PURPOSE:To shorten treating time of BOD measurement and to improve the reliability of measured value, by diluting water to be tested with as automatic dilution apparatus and measuring dissolved oxygen by an automatic DO measuring apparatus and processing the result by a data pocessing device. CONSTITUTION:Dilution water is charged into each culture bottle 10 by an automatic dilution device restricted by a microcomputer and three bottles of water to be tested are diluted in four stages. A culture bottle cassette 20 for dilution time measurement is set on an automatic DO measuring apparatus shown in the figure, and measurement of the quantity of dissolved oxygen of the water to be tested in the bottle 10 is performed successively. After cultivation, the cassette 20 is set after leaving it as it is for five days and the measurement is performed. Measured result is recorded on a recording medium by a recording device 92 and is set on a read out device of a data processing apparatus and BOD is found by a CPU.

Description

[Detailed description of the invention] The present invention relates to an automatic 110D@J determination device.

Biochemical oxygen demand (li・eb・1・alOxy-
If the sample water is left in an aerobic state under certain conditions, the growth of microorganisms or respiratory effects in the sample water may occur.
It is currently used as an international water pollution indicator, and in Japan, environmental standards have been set for each grade to protect the living environment of the people.

This IOD measurement is performed according to the following analysis procedure.

First, the sample water is set to -17, and pretreatment is performed to reduce residual chlorine and remove supersaturated oxygen. Then, the child side of the 10D value is determined using COD or the like, and the dilution ratio is determined. This dilution ratio is determined as follows.

Since water at 20°C can only contain dissolved oxygen at 8.84 ppmi, BODil determination of 8.84 ppm+ or higher cannot be performed as is. Oxygen consumption is 8
．． It can be reduced to 84 ppm or less.

A dilution factor at which the consumption amount of dissolved oxygen after culturing is thought to be spp- is determined using a tongue saw, and usually, four dilution factors of 5 to 10 inches are determined around this dilution factor.

Two samples of test water were prepared for each dilution stage using the nine dilution factors determined as described above, and the amount of dissolved acid I ice was immediately determined for each sample, and for each of the other samples. The cells were incubated at 20° C. for 5 days, and the amount of dissolved acid was measured after 5 days.

Next, BOD calculation is performed using the measurement results of the dissolved oxygen amount during the dilution and the measurement results of the dissolved oxygen amount after culturing. This calculation of 1100 is performed by the following formula.

110D == Pi (Do, -Do, ) -
...Formula (1), in the first equation above, DO8 is the measured value of dissolved oxygen amount at the time of dilution and DO, #i culture, D indicates the dilution ratio, and (Do, -Do, ) is The dilution level whose value is closest to the 5pp level is selected.
l0D is determined.

BOD measurement is carried out by the above procedure, but in the past, this IOD measurement was mainly carried out manually.

Therefore, conventionally, there have been disadvantages such as requiring a lot of manpower for lOD measurement, requiring a long time for the measurement, and further, that the measurement result lacks reliability.

The present invention has been made in view of the above-mentioned conventional problems,
The purpose is to dilute the sample water to 1ODillJ constant.
[By automating the process and saving labor,
An automatic IOD measurement device that can shorten the processing time required for the above-mentioned sample water dilution, dissolved oxygen amount measurement, and IOD calculation, and improve the reliability of IOD measurement values. Our goal is to provide the following.

In order to achieve the above object, the present invention provides culture in which a pre-treated sample water is injected for a certain period of time during dilution or for measurement after culture, and a culture bottle in which the number of bottles corresponding to the number of dilution stages is arranged and stored. cassette, an automatic diluter that dilutes the sample water of the culture bottle at the nasal dilution stage after the culture bottle cassette has been removed, at a predetermined dilution ratio for each dilution stage, and a test tube for each culture bottle for measurement at the time of dilution immediately after dilution. An automatic Do measuring device' that measures the amount of dissolved oxygen in the sample water of each culture bottle after the culture period has elapsed and the measurement period after nine incubations, and the biochemical oxygen concentration of the sample water based on the measurement result of the dissolved oxygen amount. and a data processing device that calculates a requested amount value.

Further, in the present invention, the automatic diluter has a control circuit to which a dilution ratio command value i for each dilution stage is given in advance, and a control signal from a scissors control circuit to set each dilution ratio to a pair of culture bottles at each dilution stage. The invention is characterized by comprising: a diluent injector for injecting a diluent according to the conditions; and an injection amount detector that detects the amount of diluent injected into each culture bottle and supplies the detection signal to a control circuit. .

In the present invention, the automatic DO measuring device has a nozzle that enters into the culture bottle, a solenoid valve that throws sand at the base of the nozzle, and sample water in each culture bottle that is supplied through the nozzle and the solenoid valve. A measuring cell, a diaphragm electrode type DO sensor that measures the amount of dissolved oxygen in sample water introduced into the measuring cell, and nine electromagnetic valves installed in the discharge pipe of the sample water discharged from the measuring cell. and a solenoid valve disposed in an inflow pipe for air to be fed into the discharge pipe, and a control circuit for controlling opening and closing of each of the solenoid valves, and a control circuit for controlling the opening and closing of each of the solenoid valves, and a control circuit for controlling the opening and closing of each of the solenoid valves. The method is characterized in that the operation of supplying water to the measuring cell to create a negative pressure inside the measuring cell is repeated, and the sample water is drawn into the measuring cell and discharged from the measuring cell in sequence for each culture bottle.

Furthermore, the present invention is characterized in that stirring means for stirring the test water introduced into the measurement cell is provided.

The present invention is characterized in that the upper inner wall surface of the measurement cell is formed in a substantially conical shape.

The present invention is characterized in that the automatic Do#14 determination device includes a printer for printing out the dissolved oxygen amount measurement results.・Furthermore, in the present invention, the automatic l0DIl station transfers the dissolved oxygen content measurement result to the digital processing device through %, and records it on the cassette card or disk in the processing device. At the same time, the data processing device is connected to the cassette. Or, it is characterized by a readout device for reading out the dissolved volume measurement results from the 7a disk.

Hereinafter, preferred embodiments of the present invention will be explained based on the drawings.

In the system of the present invention, culture bottles are stored in culture bottle cassettes, their sample water is diluted by an automatic diluter, dissolved oxygen is then measured for each sample water by an automatic Do measuring device, and the constant results are processed into data. Processed with equipment
Get OD.

Figure 1 shows nine culture bottle cassettes 2 in which culture bottles 10 are arranged and stored.
FIG. 2 is a side view of the culture bottle cassette 20.

In the figure, a frame 22F1 of a culture bottle cassette 20 is formed into a box shape, with grips 24 formed at both ends thereof, and the inside thereof is cut off by dividing plates 26, 28, and 30.

An engagement hole 32 is formed in one grip portion 24bK.

Two culture bottles (10 Tsuru, 10b, 10.
and 104. and 1Of, 10g and 10, 10 amount and lej, 1ak and 101) are stored in each culture bottle 10. A predetermined amount of pretreated nine test water is injected into each culture bottle 10, In this embodiment, the culture bottle 10a.

10, 1◎-110- and culture bottle 10., 10t.

Separate sample water was injected into 10 g and 10 culture bottles (ziOkslol and Ktj), and 10D measurements were performed on these 5 samples.

Two similar culture bottle cassettes 2 (l) are prepared, one of which is used for measurement during dilution, and the other is used at a certain period after culturing. Prize: only one culture bottle cassette 20. The culture bottles stored in this can also be used separately for measurement during dilution.

The culture bottle cassette 20 is an automatic type shown in FIG.

It is inserted into the measuring device.

In FIG. 5i, the culture bottle cassette 20 is placed on a moving table 36 that moves on a rail 34 provided at the lower part of the automatic diluter, and a latch member 38 latches the retaining hole 32. As a result, it is locked to the moving table 36. The movable table 36 on which the culture bottle cassette 20 is placed is introduced into the automatic diluter along the rail 34, and is positioned and held by a positioning latch 40 provided on its real part. In this way, the positioning of the automatic diluter for each culture bottle 10 is performed.

Inside the automatic diluter, above the positioned culture bottle 10 KFi, another moving table 42 that moves left and right and in the direction of the front firefly in the figure is suspended.
44. is placed on each of the diluent injection devices 441 and 44. These diluent injection devices 44a144b144・
The nozzle 46at46m+1 advances and retreats downward.
41! - The nozzle 4g is set up for each culture @
The diluted solution is injected into each culture bottle 1o,
The diluent is injected into each of the other culture bottles 10 by moving the moving stage 42&. Similarly, each diluent injection device 44 is supplied with diluent from a diluent reservoir 48.

Movement control of the moving table 42 and diluent injection device 44;
A control circuit 50 controls the amount of diluent injected into each culture bottle 10.
It is carried out by In controlling the injection amount of the diluent, an injection amount detector that detects the amount of diluent injected into each culture bottle 10 and supplies the detection signal to the control circuit 50' is connected to each diluent injection device 44. It is provided about. In this embodiment, a tank is provided in which the KFi diluent is stored in each diluent injection device, and when the tank is filled with a predetermined amount of diluent, the diluted solution is injected into each culture bottle 10. Therefore, each injection amount detector described above is an electronic level detector 5.
2-. 52b and S2.

As described above, the automatic diluter can inject a predetermined amount of diluent into each culture bottle 10 of the culture bottle cassettes 10 set therein. In this device, Totosa ratio, culture bottle 10at10@i01 and culture bottle 10 have 10f, 10
j and culture bottle 10-.

10 t e l Q k culture bottle 10dlOk, 1
The test water No. 01 is diluted at four dilution ratios centered around a preset dilution ratio.

Next, the automatic DO measuring device will be explained based on FIG.

In FIG. 4, the culture bottle cassette 20 is placed on a moving table 54 that is controlled to move vertically. Twelve nozzles 56 are arranged above each culture bottle 10 (only six nozzles 56 are water type because they are omitted in the figure), and electromagnetic valves 58 are respectively covered at their bases. ing. The sample water in each culture bottle 10 is sucked up by a nozzle 56, passes through a conduit 60 via each electromagnetic valve, and is passed through a measurement cell 62.
A stirrer 64 that is driven by a motor (not shown) is installed at the bottom of the measurement cell 62, and the 9-dilution sample water introduced into the measurement cell 62 is This allows for further stirring. The upper inner wall of the measurement cell is formed into a substantially conical shape, and a discharge port 66 is formed at the upper part.

The discharge pipe 68 is connected to the discharge port 55KFi, and a solenoid valve 70 is provided in the middle thereof.The discharge pipe 68 between the discharge port 66 and the solenoid valve 7'0 is An air inflow pipe 72 is connected to the air inflow pipe 72, and a solenoid valve 74 is provided in the conduit of this air inflow pipe 72. Therefore, electromagnetic 1I
When f70 is turned on and solenoid valve T4 is also turned on, air is fed from the air inflow pipe 72 to the discharge pipe 68, and the inside of the measurement cell 62 becomes negative pressure. At this time, when any of the solenoid valves 58 is turned on, that nozzle enters the culture bottle 1.
The water is diluted to within 0 and is sucked into the running test water Fim constant cell 62 or discharged from it. The test water for measurement which can be discharged to the discharge pipe is discharged to the storage tank T6.

The measurement cell 62 is opened and closed by the joint venture 5B and 70.74.
The diluted sample water sucked into the cell 62 is stirred by a stirrer 64 and brought to a predetermined temperature by constant temperature water fed from a constant temperature water tank 78 to a pipe 80 wound around inside the measurement cell 62. be done. In this embodiment, nine diaphragm electrode type D
The dissolved oxygen amount is measured by the o sensor 82. This Do- is supplied to the output I pressure tiDo of the inner cylinder 82, digitized, and supplied to the control circuit 86.

By controlling the opening and closing of the solenoid valves 58, 70, and 74 of the control circuit 86Fi, the diluted test water in each culture bottle 210 is sequentially introduced into the adjustment cell 62, and the amount of dissolved oxygen is measured. Control can be performed to sequentially perform operations such as discharging the sampled water from the measurement cell 62. Then, the control circuit 86 can display the measurement value given from the DO meter 84 on the panel meter 88 and print it out on the printer 90, and further send the measurement result to the recording device 92 of this processing device through /6. It can be transferred to a data processing device and recorded on a storage medium such as a cassette magnetic tape or floppy disk.

The automatic DOIII determination device described above can sequentially measure the amount of dissolved oxygen in the diluted sample water of each culture bottle 10 of the culture bottle cassette 20 set therein. Of course, the diluted sample water in the culture bottle 10 for measurement during dilution is diluted and the above-mentioned Ill determination is performed on nine straight bales, and then used for measurement after culture. Therefore, in this embodiment, when the dilution measurement is performed and the culture adjustment is performed, the dilution measurement cassette and the post-culture measurement cassette are respectively set in the apparatus shown in FIG. 4.

Next, the data processing apparatus used in this embodiment will be explained with reference to FIG.

In this embodiment, the automatic DO II determination device and the data processing device are offline, and the automatic DOII determination device and the data processing device are offline, and the
The recording medium on which the measurement results are recorded is read out by the reading device 9.
4, and the data is read out and sent to the CPU 96.
supplied to

The CPU 96 calculates the lOD for each of the five samples by calculating the equation (1) described above using the measurement results for each test water at the time of dilution and the measurement results for each test water after culturing supplied from the reading device 94. can.

Furthermore, in this embodiment, the CPU 96 receives each of the measurement results and M
The OD can be printed out on the printer 9B.

In addition, in the figure, the CP and U96Ktfca 100 are connected, and the various data mentioned above are transferred to the CPU96Fi from the CI?
It can be displayed on a 100-degree display screen.
Various data can be imported by operating the provided keyboard, and various processes can be performed using these data.

A preferred embodiment of the present invention has the above configuration, and its operation will be explained below with reference to FIG.

After pretreatment is performed on the sampled sample, BOD prediction is performed and the dilution factor is determined.

The culture bottle cassette 20 (for measurement during dilution or for culture measurement) shown in FIGS. 11 and 2 is set in the automatic diluter shown in FIG. Water is diluted in four stages. In this example, the time required for this dilution step is about 1 minute.

After the above dilution is performed, the culture bottle and cassette 20 are set in the automatic DO1iII determination apparatus shown in FIG. The culture bottle cassette 20 for measurement during dilution is set first, and each culture bottle 10
The amount of dissolved oxygen will be measured sequentially in the sample water.

On the other hand, culture bottle cassette 2 (1, for example 5
After 9 days, the culture bottles 10 are set and the water sample in each culture bottle 10 is sequentially measured. The automatic DO measuring device 1IIFi shown in FIG. 4 completes each of the above measurements in about 1 minute.

The measurement results of this automatic doll determination device are recorded on a recording medium by the recording device 92, and the recording medium is set in the reading device 94 of the data processing device shown in FIG. In this data processing device, the CPU! 16 calculates lOD. This data processing takes approximately 3 minutes.

As explained above, according to the present invention, l0D after dilution
Since the II constant value and * are automated, this procedure can be labor-saving, the processing time required for this process can be shortened, and the reliability of the 11ODllj constant value can be improved. Incidentally, in the case of the above example, the time Fi required for processing each sample is 21 minutes, which is 101 minutes compared to the conventional manual operation.
It is understood that the time has been significantly reduced.

The control circuit of the automatic diluter of the above-mentioned example can be controlled by the OK microcomputer.
It can be automated and reliability can be increased. Further, since electronic level detection 1) 52 is used here, dilution can be performed with high accuracy and reproducibility. Furthermore, this device can dilute five samples at the same time. The generation of air bubbles is suppressed when diluent is injected into the culture bottle 10, and no DO change occurs in the sample.

Further, in the automatic DO#l determination apparatus shown in FIG. 4, pre-measurement is performed using the diaphragm electrode method, so that measurement can be performed easily and quickly. Since it is not necessary to use a culture bottle 10 with a definite capacity, a constant error due to this capacity error does not occur, and the cost of the culture bottle 10 can be significantly reduced. First, this device does not require titration by the analyst, allowing accurate measurement without individual differences, and also eliminates the need for adjusting reagents for the Do-electrode layer and processing of analysis waste liquid.

Furthermore, by adopting the Fi70-cell method in this device, it is possible to continuously measure a large number of samples, and the stirring speed in the measurement cell 62 can be made the same for each measurement, making it extremely accurate. Stones that give accurate measurement results.

In addition, this device uses Sunsol's 70-[tifon system, so there is no need for liquid feeding, and it is suitable for cell 62, which is trouble-free and sensitive to pressure fluctuations, and prevents solenoid valve T4 from being damaged by sand. Since the upper inner wall of the cell 62 is formed into a conical shape, no air bubbles are generated in the sample water due to a pressure drop, and therefore no measurement error occurs.

By employing a personal computer in the data processing device, data processing does not require transcription or calculation, and processing can be performed quickly and accurately. In addition, it is possible to store the various data on a single medium such as a 7P disc, and it is also possible to systematically print out measured values, IOD, etc., making data storage and utilization easy. Become. Furthermore, it is possible to carry out the determination function within the program, select the optimum solution, and perform the IOD calculation, thereby eliminating the need for manual intervention.

Furthermore, it is preferable to connect the device online with the manual issuing system.

Furthermore, since the culture bottles are unitized into cassettes, they are easy to handle.

In addition, since the apparatus shown in FIG. 4 uses a siphon type, it is necessary to set the atmospheric drainage port of the pipe 68 at a position lower than the KFi culture bottle 10. The suction side portion and the discharge side portion of the pipe 68 beyond the electromagnetic valve TO need to have diameters that do not allow water droplets to fall inside them.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a culture bottle cassette according to the present invention, Fig. 2 is a plan view of a culture bottle cassette according to the present invention;
Figure 1 is a side view of the culture bottle cassette, Figure 6 is a configuration diagram of an automatic dilution device according to the present invention, Figure 4 is a configuration diagram of an automatic NO measurement device according to this invention, and Figure 5 is a configuration diagram of an automatic NO measurement device according to this invention. FIG. 6 is a block diagram of such a data processing device, and is a time chart diagram showing the processing procedure of the system according to the present invention in comparison with a conventional manual operation. 10... Culture bottle, 20... Culture bottle cassette, 44...
... Diluent injection device, 46... Nozzle, 48... Diluent, 50... Control circuit, 52... Electronic level detector, 56... Nozzle, 58... Solenoid valve, 60 ...
Tube, 62...Measurement cell, 64...Stirrer, 6B.
... Discharge pipe, 70 ... Solenoid valve, T2 ... Air inflow pipe, T4 ... Solenoid valve, 80 ... Pipe, 82 - Do sensor, 84 - DO meter, 86 - Control circuit , 90-・
- Printer, 92... 1 Threat device, 94... Reading device, 98-... Printer, 100... CRT. Patent applicant Hataji Ikeda

Claims (1)

[Scope of Claims] (1) A culture bottle cassette in which a predetermined amount of pretreated sample water for measurement during dilution or for measurement after culture is injected into the culture bottle is housed in an array according to the number of dilution stages; An automatic diluter in which a bottle cassette is set and dilutes the test water of each dilution stage culture bottle at a predetermined dilution rate for each dilution stage, and a test water of each culture bottle for measurement at the time of dilution immediately after dilution and the diluted culture bottle. An automatic Do measurement device that measures the amount of dissolved oxygen in the sample water of each culture bottle for measurement after culture after a period of time has passed, and a deheta processing device that calculates the biochemical oxygen demand value of the sample water based on the dissolved oxygen amount measurement result. An automatic BOD measurement device comprising: (2) The automatic diluter includes a control circuit to which a dilution ratio command value for each dilution stage is given in advance, and a control signal from the control circuit to apply a diluted liquid to each dilution stage culture bottle according to the dilution ratio. Claim (1) characterized in that it includes a diluent injection device for injecting, and an injection amount detector that detects the amount of diluted liquid injected into each culture bottle and supplies a scissor detection signal to a control circuit. Automatic 10D @ fixed device. (3) The automatic Dell determination device consists of a nozzle that enters the culture bottle, a solenoid valve provided at the base of the nozzle, and a measurement cell to which sample water in each culture bottle is supplied through the nozzle and the solenoid valve. When the sample water is guided into a certain cell and the diaphragm electrode type DO sensor is used to measure the amount of dissolved oxygen, nine solenoid valves are installed in the discharge pipe of the sample water discharged from the measurement cell. and a solenoid valve provided in the inflow pipe for air to be fed into the discharge pipe, and a control circuit for controlling opening/closing of each of the solenoid valve pipes, and a control circuit for controlling opening/closing of each of the solenoid valve pipes. Repeatedly perform the operation of feeding and creating a negative pressure inside the measurement cell, and the sample water is drawn into the measurement cell and discharged from the measurement cell (4). Automatic B according to claim (3), characterized in that a stirring means for stirring is provided.
OD measuring device. (5) The automatic 10D measuring device according to claim (3) or (4), wherein the upper inner wall surface of the measuring cell is formed in a substantially conical shape. 16) The automatic DO measuring device according to claim (1), (3), (4) or (5), characterized in that the automatic DO measuring device includes a printer that prints out the results of measuring the amount of oxygen present. BOD measuring device. (7) The data processing device is connected to a recording device that is transferred through the bow and records the dissolved oxygen content measurement results on a weight distribution medium such as a 70 disk or Madane Chicuteso, and a measurement device placed on the recording medium. Claims (1), (2),
(3), (4), (25) and Fi (automatic 10 described in 61)
D measuring device.