JPH0634985B2 - Bioreactor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a bioreactor, and in particular, it uses a separation membrane such as an ultrafiltration membrane or a precision filtration membrane in which microorganisms are immobilized to form a living organism. The present invention relates to a bioreactor designed to carry out a reaction.

[Prior Art] A bioreactor in which a biotreatment device is combined with a membrane separator is known in the field of wastewater treatment devices and the like.
For example, Japanese Patent Laid-Open No. 57-7293 discloses a method in which a biological treatment liquid from a biological treatment device is subjected to membrane separation treatment and the concentrated liquid is returned to the biological treatment device.
584 discloses that the treated water after biological treatment is separated into membranes to improve the quality of the treated water.

Thus, the role of the membrane separation membrane in the bioreactor equipped with a conventional membrane separator, the sludge concentration in the biological treatment device is maintained at a predetermined value or more, SS removal of biological treatment water,
It removes residual components that are not decomposed by biological treatment, and plays a role in final precipitation, coagulation precipitation, and filtration.

Even in such a conventional bioreactor, for example, it is possible to increase the concentration of microorganisms (eg, sludge concentration) in the biotreatment device, and thus a treatment device with a high load can be provided.

[Problems to be Solved by the Invention] However, the above-mentioned conventional bioreactor is merely a combination of a biotreatment device and a membrane separation device, each of which has a different action, and there is a limit to increase the efficiency. In addition, membrane contaminants from biological treatment equipment (such as sludge, residual components, inorganic substances in undiluted solution, and metabolites of organisms) from biological treatment equipment adhere to the separation membrane in the conventional bioreactor, and the amount of permeated water through the separation membrane increases. It was necessary to remove the substances adhering to the film surface, such as chemical cleaning and ball cleaning. Therefore, in the above-mentioned biological reaction device, in addition to the biological treatment device (reaction tank) and the separation membrane, a membrane cleaning device is required, and a unit having three different functions is required.

[Means for Solving Problems] The present invention provides a separation membrane on a liquid-permeable support material, and allows the raw solution-side surface of the separation membrane to carry a microorganism for biological treatment.
This is installed in the reaction vessel. Then, the stock solution is introduced into the reaction vessel, subjected to biological treatment by the microorganism for biological treatment carried on the separation membrane, and then the separation membrane and the supporting material are permeated and taken out from the reaction vessel.

[Operation] In the present invention, since the microorganism for biological treatment is carried on the surface of the separation membrane, unlike the conventional bioreactor in which the biological treatment apparatus and the membrane separation apparatus are simply combined, a biological treatment means The membrane separation means and the membrane separation means can be incorporated into one unit, and a highly efficient and compact processing apparatus can be obtained. Further, since the substances adhering to the separation membrane are decomposed by the immobilized microorganisms, it is not necessary to wash the membrane or the frequency thereof is extremely low.

Embodiments Embodiments will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a bioreactor according to an embodiment of the present invention, and FIGS. 2 and 3 are FIG. 1 II-II line and III, respectively.
Fig. 4 is a sectional view taken along line -III, and Fig. 4 is a longitudinal sectional view of a bioreactor according to another embodiment.

Since FIG. 4 shows the most basic configuration of the present invention, the configuration of the present invention will be described first with reference to FIG.

In FIG. 4, reference numeral 1 denotes a container of the reactor, which is provided with an inlet port 2 for the undiluted solution in the upper part and an outlet port 3 for the product solution in the lower part. A support material 4 made of a liquid-permeable material is installed so as to traverse the container 1 in the horizontal direction, whereby the inside of the container 1 is divided into a stock solution chamber 1a and a production solution chamber 1b. A separation membrane 5 is provided on the liquid introduction side of the support material 4, and a layer (biological immobilization layer) 6 carrying a biological treatment microorganism is provided on the surface of the separation membrane 5.

In the bioreactor configured in this way, the inlet 2
The stock solution introduced into the reaction vessel 1 from the above is brought into contact with the biological immobilization layer 6 to undergo biological treatment and is biologically decomposed. Then, the decomposition products pass through the separation membrane 5, pass through the support material 4, enter the product liquid take-out chamber 1 b, and are taken out from the take-out port 3.

Thus, the substance decomposed or modified by the biological treatment microorganisms carried on the surface of the separation membrane 5 is immediately separated by the separation membrane. Further, the membrane surface blocking contaminants that adhere to the membrane surface and reduce the amount of permeated water are biologically decomposed by the immobilized microorganisms. Therefore, the treatment efficiency is high, the clogging of the membrane is suppressed, and the frequency of the membrane cleaning treatment is extremely reduced.

The members 11 to 13 will be described in the section of Experimental Example.

Next, a preferred embodiment of the present invention will be described with reference to FIG.

In FIG. 1, the reaction container 1 has a stock solution inlet 2 at the top,
Further, it has a production liquid outlet 3 at the bottom, and a partition plate 7 is provided inside the outlet. The partition plate 7 has a plurality of circular holes, and a cylindrical support member 4 is provided so as to rise from the holes toward the stock solution chamber 1a. Then, a separation membrane 5 is provided on the peripheral surface of the cylindrical support member 4, and the separation membrane 5 is provided.
The biological immobilization layer 6 is provided on the surface of the. The support member 4, the separation membrane 5, and the biological immobilization layer 6 have lid-shaped members 8 on their upper end surfaces.
Is sealed by.

Also in the embodiment shown in FIG.
The stock solution introduced into a is subjected to biological treatment (for example, decomposition, reforming reaction, etc.) by the biological treatment microorganisms immobilized on the biological immobilization layer 6. The produced substance permeates the separation membrane 5 and the support material 4, enters the production liquid chamber 1b, and is taken out from the take-out port 3. In the figure, 10 is a gas vent port.

In the embodiment shown in FIG. 1, the surface area of the support material 4 provided in the reaction vessel 1 is larger than that in the embodiment shown in FIG.
The area of the microorganism immobilization layer 6 is also large, and therefore the amount of stock solution that can be treated with the same volume is extremely large.

In the present invention, as shown in FIGS. 1 and 4, a pipe 1c is provided so as to return a part of the production liquid to the stock solution chamber 1a side.
May be provided. Of course, it may be allowed to flow down temporarily.

In the present invention, as the support material 4, a sintered alloy, porous ceramics, unglazed pottery, or the like can be used.

The separation membrane is not particularly limited and various kinds can be used, but it is preferable to select it according to the type of reaction. For example, a precision filtration membrane having a pore size of 1 to 0.1 μm can be used when performing ordinary wastewater treatment, and a cut-off molecular weight of 20,000 to 10 when performing advanced wastewater treatment.
An ultrafiltration membrane of 00 can be used.

The biological treatment microorganisms carried on the surface of the separation membrane are selected according to the intended reaction. For example, when anaerobic wastewater treatment is performed, acid-producing bacteria and methanogenic bacteria are used. When aerobic wastewater treatment is performed, zoo glare or the like is used.

In addition, anaerobic bacteria such as acid-producing bacteria and methanogenic bacteria were immobilized. When anaerobic organism treatment is performed, the stock solution chamber 1a is placed in an anaerobic state. When immobilizing aerobic microorganisms and performing aerobic biological treatment, an oxygen diffuser is provided in the stock solution chamber 1a, or oxygen is sufficiently dissolved in the stock solution in advance and introduced into the stock solution chamber 1a.

The following method can be used as a means for supporting the microorganism for biological treatment on the surface of the separation membrane.

Microorganisms are attached to the surface of the separation membrane by using a paste material having a water-permeable property such as acrylamide or carrageenan.

A porous filler such as activated carbon or sponge is attached to the surface of the separation membrane using the above-mentioned acrylamide or a carrageenan paste, and microorganisms are attached and proliferated on the surface or in the pores of the filler.

Therefore, in the present invention, the membrane surface clogging contaminant that adheres to the membrane surface and reduces the permeated water as described above is biologically decomposed by the biological treatment microorganisms carried on the separation membrane surface. Therefore, the separation membrane is hardly clogged.
However, if the operation of the apparatus is continued for a long period of time, inorganic substances, hardly decomposable substances, bio-metabolites, etc. in the stock solution may accumulate on the surface or voids of the separation membrane and cause blockage. In that case, a clean liquid or a production liquid is supplied from the production liquid chamber 1b side through the support material 4, and the separation membrane is backwashed to remove the blocking substances.

Next, a suitable experimental example will be described.

Experimental Example 1 (Example of the present invention) In the apparatus shown in FIG.
cm, using a column with a stirrer 11 of 20 cm in height,
As the support material 4, unglazed pottery was used. An ultrafiltration membrane 5 having a fractional separation amount of 8000 was provided thereon, and a sponge having a thickness of 10 mm as a biological immobilizing material was further adhered thereon using 1% agar solution.

Anaerobic bacteria were adhered to this sponge as follows. That is, 1 g of anaerobic bacterial cells, which had been grown using a synthetic substrate in which glucose and acetic acid were mixed, was concentrated into the reaction vessel 1 as a VSS amount, and the bacterial cells were attached to the sponge using agar.

This agar concentration was 0.1% or less.

As a substrate for the experiment, C mixed with glucose and acetic acid was used.
ODcr10000 mg / synthetic substrate was used.

This substrate is continuously pumped into the reaction vessel 1 by 10 times.
While injecting at 0 ml / day, a level meter is installed to keep the liquid level in the reaction container 1 constant, and the level is detected. When the liquid level falls, a part of the production liquid is placed in the stock solution chamber 1a. I sent it back. Further, a pipe 13 having a back pressure valve 12 was connected to the raw liquid quality 1a and the production liquid chamber 1b, and the operating pressure was adjusted to 2 kg / cm ² by adjusting the back pressure valve 12.
The amount of liquid in the reaction vessel 1 was 1, and the pH of the liquid in the stock solution chamber 1a was 6.8 to 7.2 using a phosphate buffer.

Table 1 shows the water quality of the produced liquid and the amount of liquid permeated through the ultrafiltration membrane 10 days, 20 days, and 30 days after the start of operation.

Experimental Example 2 (Comparative Example) Only the ultrafiltration membrane 5 having a molecular weight cut off of 8000 was provided on the support material 4, and the biological immobilization layer 6 thereon was not provided.
Then, instead of the organism-immobilized layer, the cells were suspended in the stock solution chamber 1 and the experiment was conducted in the same manner as in Experimental Example 1 above.
Table 1 shows the measurement results of the water quality of the produced liquid and the permeation amount of the ultrafiltration membrane after 10 days, 20 days, and 30 days of operation.

In Table 1, the water quality of the production liquid is shown as the removal rate of CODcr from the stock solution.

From Table 1, there is no difference in the water quality of the produced liquid in both Experimental Examples 1 and 2, but the liquid permeation amount in the case of the present invention example is more than twice that in the comparative example, and even if the operation period is extended, the liquid It is recognized that there is no reduction in the amount of permeation.

[Effect] As described in detail above, in the biological reaction device of the present invention,
Since the biological treatment microorganisms are carried on the separation membrane surface,
The configuration of the entire device becomes extremely compact. Furthermore, the action of the microorganism for biological treatment prevents clogging of the separation membrane, and the decrease in the amount of the membrane permeate is extremely small. Further, the cleaning of the separation membrane is unnecessary or extremely small. Furthermore, it is not necessary to perform chemical cleaning like the conventional separation membrane,
Even when cleaning, a simple backwash is sufficient.

Further, in the apparatus of the present invention, the production liquid is a liquid that has permeated the separation membrane, and therefore is a highly advanced purification liquid without SS components. Furthermore, power for separating membrane permeation may be unnecessary.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a bioreactor according to an embodiment of the present invention, FIGS. 2 and 3 are FIG. 1 line II-II, and FIG.
FIG. 4 is a sectional view taken along line III-III, and FIG. 4 is a sectional view of a bioreactor according to a different embodiment. 1 ... Reaction container, 2 ... Inlet port, 3 ... Outlet port, 4 ... Support material, 5 ... Separation membrane, 6 ... Bioimmobilization layer, 7 ... Partition plate.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-58-187190 (JP, A) Haruhiko Oya ed. “Reverse osmosis method, ultra ▲ ro ▼ past ▲ II ▼ application membrane application technology handbook” Koshobo first edition (Sho 53-6-30), P90-92, P233-236, and P363-364.

Claims (1)

[Claims] 1. A bioreactor for biologically treating an organic waste liquid by using a microorganism for biological treatment, comprising a reaction container having an inlet for a raw liquid and an outlet for a product liquid, and the inlet. A liquid-permeable support material disposed in the reaction vessel so as to separate the outlet, a separation membrane provided on the surface of the support material on the side of the undiluted solution, and a surface of the separation membrane on the side of the undiluted solution. A bioreactor comprising: a layer supporting a microorganism for biological treatment.