JPH01176936A - Instrument for measuring activity of microorganism sludge - Google Patents

Abstract

PURPOSE:To digitize the activity of microorganisms by measuring the quantity of dissolved oxygen prior to injection of a substrate and measuring the quantity of the dissolved oxygen after injection of said substrate, then calculating the quantity of the oxygen consumed by the microorganisms. CONSTITUTION:A buffer soln. is put into a liquid storage tank 2 while the existing state of the dissolved oxygen is maintained by feeding air thereto from an air pump 1, the liquid is fed into a pipe 7 for measuring the activity of the microorganisms by using a constant-feed pump 3. The liquid filled in the pipe 7 comes into contact with an enzyme electrode 8 through a pipe and is discharged through a drain 10 to the outside. After the buffer soln. is filled in the entire route until no more air bubbles exist, the specified amt. of the sample microorganisms are injected from an injection port 4 and are subjected to microorganism supporting 6 in the pipe 7 while the buffer soln. is kept run. On the other hand, the quantity of the dissolved oxygen in the buffer soln. is continuously measured by the electrode 8 and after the microorganisms are stuck to the support, the specified amt. of the substrate is injected from the injection port 4 into the pipe. The decrease in the quantity of the dissolved oxygen is measured to measure the capacity that the microorganisms adsorbed on the support 6 digests and decomposes the substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for accurately performing microbial treatment of organic wastewater such as domestic wastewater and industrial wastewater.

[Conventional technology]

The center of the purification effect in the activated sludge method (microbial treatment method) for organic wastewater is the biochemical action that occurs in the aeration tank, so the growth capacity and amount of microorganisms contained in the aeration tank mixture and the dissolution of oxygen are important. Amount is an important factor that affects processing efficiency. This will be used as an indicator in some way, and as long as the treatment conditions are good, an indicator is needed to understand how the indicator changes and use it when operating the aeration tank. It is being However, no method has been established to test the activity of microorganisms.

[Problem that the invention seeks to solve]

As mentioned above, in the activated sludge method, one of the requirements is to constantly check the growth status of microorganisms and to ensure smooth wastewater treatment.

[Means for solving problems]

In order to solve the above problems, the present invention proposes a simple microbial activity measuring device characterized by combining a microbial activity testing device and an oxygen electrode.

〔Example〕

Embodiments of the present invention will be described in more detail based on FIGS. 1, 2, and 3, but it goes without saying that the present invention is not limited to this description.

The principle of the device of the present invention is that aerobic microorganisms are
This method is based on the fact that dissolved oxygen in water is required to grow and multiply by digesting and absorbing substrates, and it is known that there is a proportional relationship between the amount of digested substrate and the consumption of dissolved oxygen. It is.

Utilizing this proportional relationship, the present inventors collected a small amount of microorganisms, washed them to make them completely free of substrate, and then placed them in a buffer solution containing sufficient dissolved oxygen. We have invented a method for measuring the activity of sample microorganisms by adding a substrate and measuring the amount of dissolved oxygen consumed at the same time as the amount of substrate digested and absorbed by microorganisms.

FIG. 1 shows an overall view of the microbial activity measuring device of the present invention. The microorganism activity reaction device ■ and the dissolved oxygen measuring device ■ are combined, and the microorganism growing part and the detection part using the oxygen electrode need to be kept at a constant temperature, so they are housed in a constant temperature bath 5.
The temperature was kept at around 7°C. The mechanism of action will be explained step by step below.

To measure the total microbial activity, first put all the buffer solution into the storage tank 2, and while keeping a sufficient amount of dissolved oxygen by constantly pumping air from the air pump 1, use the metering pump 3 to pump the inside of the microbial activity measuring tube 7. Send liquid to. The liquid filling the pipe 7 passes through the pipe and comes into contact with the oxygen electrode 8, and then drains into the drain 10Q.
is discharged to the outside through the At this time, it is preferable that the portion of the pipe 9 in contact with the oxygen electrode 8 be made thin in order to increase the flow rate of the liquid, and have a structure such that the liquid is jetted directly to the oxygen electrode 8 .

After the entire channel was filled with the buffer solution and there were no air bubbles, a fixed amount of the sample microorganism was injected through the injection port 4 backed with silicone rubber with a syringe needle, while the buffer solution was flowing. The microorganisms are attached and supported on the microorganism support 6 in the microorganism activity measuring tube 7.

On the other hand, at the oxygen electrode 8, the amount of dissolved oxygen in the buffer solution is continuously measured, and after attaching microorganisms, it is confirmed that the concentration has recovered to the level when only the buffer solution was passed, and then the substrate for activity measurement is inserted into the injection port. The ability of the microorganisms adsorbed on the microorganism support 6 to digest and decompose the substrate is measured by measuring the decrease in the amount of dissolved oxygen.

That is, regarding the amount of dissolved oxygen after injecting the substrate, the buffer solution that has passed through the microbial activity reaction tube is ejected to the oxygen electrode 8 through the pipe 9, but the amount of oxygen in the solution at this time is consumed by the microorganisms and is initially The oxygen concentration decreases]. Therefore, measure the amount of dissolved oxygen before injecting the substrate, then measure the amount of dissolved oxygen after injecting the substrate, calculate the amount of oxygen consumed by the microorganisms, and quantify the activity of the microorganisms. It was very successful.

FIG. 2 is an enlarged view of the contact area between the oxygen electrode and the liquid after the microbial reaction.

The oxygen electrode is a type of diaphragm electrode, and when this sensor is brought into contact with sample water, dissolved oxygen passes through the diaphragm and enters the interior, and a current proportional to the dissolved oxygen concentration flows between the positive and negative electrodes. Measure the dissolved oxygen concentration. However, considering that the electrode reaction takes about 30 to 90 seconds and that measurement cannot be performed when the aqueous solution is stationary, the oxygen electrode and the sample water are The tip of the pipe where it makes contact is made thinner to increase the flow velocity.

FIG. 3 shows the microbial activity measuring tube 7. Diameter 15W11
A sponge-like object is fixed to the front part of the tube as a microorganism support 6, and both ends of the tube are closed with silicone rubber plugs a and b, which are processed into a funnel shape and have holes, and connected to the front and rear parts with a pipe. I did it like that.

[Experiment example]

First, using the microbial activity measuring device according to the present invention, microbial sludge is cultured under the best conditions to digest and decompose organic matter with high efficiency, and microbial sludge that has passed the growth phase and is digested and decomposed only with low efficiency. FIG. 4 shows the results of measuring the activity of three intermediate species using the apparatus according to the present invention.

Curve A is microbial sludge when decomposing organic matter with high efficiency;
Curve B has medium ability to decompose organic matter, curve C
is a microbial sludge with low organic matter decomposition ability.

Next, to examine the practicality of this method, we conducted an experiment by pumping up activated sludge from a wastewater treatment facility at a fish processing factory.

Figure 5 shows the activity of microbial sludge when wastewater treatment is operating smoothly. Figure 6 shows the activity level of microbial sludge when wastewater treatment is malfunctioning.

The meaning of the diagram here is that dissolved oxygen, which was initially around 20 ppm, is consumed by microorganisms by injecting the substrate, decreases over time to around 5 ppm, and increases as soon as the absorption of the substrate by the microorganisms ends. This indicates that highly active microorganisms have deeper valleys. Therefore, by knowing the depth of this valley, it is possible to determine how active the microorganism in the sample is.

[Brief explanation of the drawing]

FIGS. 1, 2, and 3 are schematic diagrams showing the apparatus of the present invention, and FIGS. 4, 5, and 6 are graphs showing the activity of microbial sludge in each test. In the figure, ■, Microbial activity reaction device ■, Dissolved oxygen measuring device 1, Air pump 2, Buffer solution storage tank 5, Quantitative, Constant pressure pump 4, Sample microorganism and substrate injection port 5, Constant temperature tank 6, Microbial support 7, Microbial activity reaction tube 8, Oxygen electrode 9, Contact part between oxygen electrode and sample water 10, Drain 11, Dissolved oxygen meter 12, Data processing device

Claims (1)

[Claims] A microbial sludge activity measuring device characterized by combining a microbial activity reaction device in which microorganisms are attached to a support and an oxygen electrode.