JP2595166Y2 - BOD measuring device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a BOD measuring device for measuring biochemical oxygen consumption using a microbial electrode.

[0002]

2. Description of the Related Art As is well known, in this type of measuring apparatus, a flow cell enclosing a microbial electrode is installed inside a thermostat, and a standard solution and washing water are flowed into the flow cell together with a buffer.
At the time of measurement, the required measurement is performed by flowing the sample to be measured through this flow cell.

[0003] Referring to Fig. 1, reference numeral 1 denotes a water sample switching unit, which is connected to pipes 2 to 4 for supplying a washing solution, a standard solution, and a sample, respectively. Reference numeral 5 denotes a feed pump which sends out each liquid sent from the water sample switching unit 1 and a buffer supplied from the pipe 6. 7 is an air pump, 8 is a flow cell,
It is installed inside a thermostat 9 maintained at about 30 to 35 degrees.

In the measurement, washing water is supplied from a pipe 2
Further, a standard solution is sequentially supplied from the pipe 3 through the water sampling switching unit 1 via the fido pump 5 to clean the pipe system and perform calibration for measurement. After that, water is supplied from the pipe 4. The buffer solution from the pipe line 6 is added to the wash water, the standard solution, and the test water that are sequentially switched and sent from the test water switching unit 1 and injected into the flow cell 8.
Each liquid flowing out of the flow cell 8 is discharged from a pipe 10. The output current of the flow cell 8 is
, Where it is appropriately processed and recorded.

[0005] In such a configuration, slime due to various bacteria is generated in a pipe through which the water sample passes, which may cause an error in measurement. In order to prevent the generation of the slime, conventionally, a method of cleaning a pipeline by ultrasonic waves, a method of adding an antibiotic or a chlorine compound to the cleaning water, a method of lowering the pH of the cleaning water, and the like have been proposed.

[0006] However, the method using ultrasonic waves has no effect on sterilization in a place not irradiated with ultrasonic waves, and the method using an antibiotic has no effect on bacteria resistant to antibiotics. The method of addition has drawbacks in that the chlorine concentration cannot be increased to a concentration that affects the microbial electrode used in the flow cell, and the method of lowering the pH cannot be expected for low pH-resistant bacteria. .

[0007]

DISCLOSURE OF THE INVENTION The object of the present invention is to easily and surely kill various bacteria causing slime in BOD measurement.

[0008]

Means for Solving the Problems The present invention is provided in a constant temperature bath.
Feed cell into the flow cell containing the placed microbial electrode.
Wash water, standard solution and measuring solution through the line connected to the pump.
A BOD measuring device that sequentially supplies the water samples to be measured
Further , a sterilization heater is provided in the conduit between the constant temperature bath and the feed pump .

[0009]

By installing a heater inside or outside the pipe through which the sample passes, various bacteria in the sample passing through the pipe are heat-sterilized. This makes it possible to prevent the generation of slime.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. In accordance with the present invention, a heater 13 is disposed on a pipe through which the water sample passes, specifically, on the outer circumference or inside of the pipe line 12 between the feed pump 5 and the flow cell 8 so as to heat the water sample passing through the pipe 13. To

[0011] In the above configuration, before passing the water sample,
The pipe line 12 is washed by adding a chlorine compound to the washing water. The added chlorine compound kills some germs.
The added chlorine compound is decomposed by the heat of the heater 13. Therefore, increasing the concentration of chlorine to be added does not affect microorganisms in the flow cell. Thereafter, the water sample passes through the pipe 12. At this time, the germs in the sample are sterilized by the heat of the heater 13 and drastically reduced.

According to the experiment of the present inventors, the free oxygen concentration of the chlorine compound added to the washing water was adjusted to 5 ppm,
When the water sample by the heater 13 was heat-sterilized at 80 ° C. for 1 minute, the continuous test using the standard solution was able to perform stable output for two months or more without maintenance. In the case of continuous measurement at a sewage treatment plant, the conventional method required replacement of the piping once every two weeks. However, when heat sterilization was carried out according to the present invention, it was possible to operate without maintenance for more than one month. did it.

[0013]

According to the present invention as it has been described above devised], constant
Sterilization line for water sample between hot water tank and feed pump
Since it is provided a heater, a flow Upon BOD measurement
Heats sample bacteria without affecting cell microbes
Can be sterilized by this sterilization.
Can prevent the occurrence of
The error can be reduced. Also, this heating
Cleans pipes before passing test water as it breaks down chlorine compounds
Concentration of chlorine compounds added to washing water when sterilizing various bacteria
The effect of preventing the occurrence of slime can be increased
It has the effect that it can be increased .

[Brief description of the drawings]

FIG. 1 is a layout view showing an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 water sampling switching unit 8 flow cell 12 pipeline through which water sampling passes 13 heater

Claims (1)

(57) [Scope of request for utility model registration] 1. A microbial electrode installed in a thermostat .
In that the flow cell, through a conduit connected to a feed pump
In the BOD measuring device which sequentially supplies the washing water, the standard solution and the test sample to be measured, the thermostat and the filter are provided.
A BOD measuring device comprising a sterilizing heater provided in the pipe line between the BOD measuring device and the pressure pump .