JPS62181772A - biological reactor - Google Patents

Abstract

PURPOSE:To enable membrane separation in high efficiency, by placing a vertically extending separation membrane in a tank in a manner to enable the discharge of liquid permeated through the separation membrane outside of the tank and placing a gas-blowing means under the separation membrane of the tank. CONSTITUTION:The objective bioreactor is composed of a tank 1 containing microorganisms to effect biological reaction. A vertically extended separation membrane 6 such as hollow fiber membrane is placed in the tank 1 in a manner to enable the discharge of permeated liquid of the separation membrane out of the tank and a gas blowing means 4 is placed under the separation membrane 6 in the tank. A gas generated in the tank is collected, recycled and used as the blowing gas. The flow rate of the liquid on the membrane surface is increased by the upward stream of the blown gas along the membrane surface to enable the maintenance of the rate of permeation at a high level. The concentration polarization on the membrane surface and the formation of gel layer can be suppressed to ensure high-efficiency membrane separation treatment.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a biological reaction device, and particularly to a method for increasing the flow rate of a stock solution along the membrane surface of a separation membrane installed in a tank body of a reaction device to reduce the amount of permeated liquid. The present invention relates to a biological reaction device designed to increase the number of biological reactors.

[Prior Art] A biological reaction device that combines a biological treatment device and a deassertion device is known in the field of wastewater treatment devices. There are systems in which the liquid is returned to the biological treatment equipment, and systems in which the treated liquid after biological treatment is separated by a membrane to improve the quality of the treated water.

An apparatus that combines such membrane separation means and biological reaction means allows advanced biological treatment such as wastewater treatment to be performed.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional reaction device that combines a biological reaction means and a membrane separation means, the biological reaction tank and the membrane separation device are provided separately. It is necessary to separately provide a means for feeding to the processing means and a power unit for membrane separation, which increases the power cost and increases the size of the entire apparatus, which limits the ability to make it compact.

[Means for Solving the Problems] In order to solve these problems, the unapplicant has charged and installed a separation membrane in a closed biological reaction tank, and transferred the permeate of this separation membrane to the tank. A biological reaction device configured to be able to be taken out of the body and to allow liquid to permeate through a membrane using the pressure inside the tank (Japanese Patent Application No. 60-92953. Hereinafter referred to as "Prior Application I
), and a separation membrane is installed below the fluidized bed formation part in the tank of the fluidized bed reactor, and the fluidized bed treated water is taken out from the top of the tank and circulated to the bottom of the tank to pass through the membrane. A biological reaction device in which the liquid is taken out of the tank as produced water (filed on January 9, 1985, hereinafter referred to as "Prior Application II J
) was proposed. According to the above prior applications I and II,
Since the separation membrane is installed inside the tank, there is no need to separately provide a power unit for 119 separation, and the entire device can be made more compact.

The present invention is based on the above-mentioned prior application I and prior application (2), and furthermore, -!
It was completed as a result of the results of the 11/1 test, and was designed to increase the total flow rate on the fI'2 surface by blowing gas into the biological reaction device, thereby maintaining a high permeate IJ-.

That is, 1 the present invention provides a separation membrane in the tank body of a biological reaction device, -
I:, ) 1'' direction so that the permeated liquid of this separation 1 pattern can be taken out of the tank body, and a gas blowing means is provided below the separation pattern 1 inside the tank body.

[Effect] Flow velocity of raw water (undiluted solution) flowing along the membrane surface (n-plane flow velocity)
As a result of various studies, it has been empirically found that the amount of permeated liquid can be maintained at a high level by increasing the
In the present invention, the blown gas rises along the membrane surface, thereby increasing the flow rate and maintaining a high permeate amount. In addition, since the separation membrane is charged and installed in the tank body, there is no need to separately provide a power unit for membrane separation, as in the above-mentioned prior application, and it is possible to make the entire apparatus more compact.

Moreover, the contact of gas bubbles and liquid flow with the separation membrane surface suppresses concentration polarization and gel layer formation on the membrane surface, making it possible to maintain a higher amount of permeated liquid.

[Example] Examples will be described below with reference to the drawings.

Fig. 1 is a longitudinal cross-sectional view of a biological reaction device according to an embodiment of the present invention, Fig. 2 is a cross-sectional view taken along line rr-n in Fig. 1, and Fig. 3 is an enlarged view of the part marked ■ in Fig. 1. It is.

1 is the tank body of the reaction apparatus, which is an airtight pressure vessel.

A stock solution introduction pipe 2 is connected to the bottom of the tank l. Further, a pipe 3 for gas circulation is connected to the upper part of the tank body 1, and the extracted gas is transferred to the tank body by a blower B.
The air is ejected from the air diffuser port 4 at the bottom of the air diffuser. Note that 5 is a gas vent pipe for regulating the pressure inside the tank body, and a pressure regulating valve 5a is inserted therein.

Inside the tank l, there are a large number of hollow fiber or tube-shaped parts 11.
1 model module 7 consisting of a collection of 11196 is arranged 6
1 has been done. This membrane module 7 has a cylindrical casing 8, a perforated support plate 9.10 provided in the shape of a mirror plate on both sides (5V40) under the hill of the cylindrical casing 8, and
The upper and lower ends of the Il film 6 are connected to the through holes 9a of the support plate 9°10.
, 10a and fixed. In this way, the minute KII! membranes 6 are each arranged in the vertical direction (almost vertically in this embodiment), and the minute KII! The inside of J6 is in direct communication with the inside of tank l.

On the other hand, the outer periphery of the 1/1/1I membrane 6 is surrounded by the cylindrical casing 8, and forms a permeate chamber 11.

As shown in FIG. 3, the lower side wall of the casing 8 and the lower side wall of the tank l are provided with transparent wood extraction ports 12.13 at approximately the same height, respectively. 1
3 are communicated with each other via a short pipe 14 protruding from the periphery of the outlet 13 of the tank l toward the center of the tank. Reference numeral 15 is a sealing member that seals the tip of the short tube 14 and the edge of the extraction port 12.

In the embodiment device configured as described above, the stock solution introduced into the tank l from the introduction pipe 2 by the liquid supply pump P is subjected to biological reactions (e.g. decomposition, Fermentation, etc.), the low-molecular products are followed by bubbles G blown out from the air diffuser 4 by the operation of the blower B, enter the interior 6a of the chamber membrane 6, and pass through the interior 6a. Minutes on the way, III! Permeated water chamber 11 through J6
to go into.

The permeated water is then taken out of the tank body l through the permeated water outlet 12.13 (arrow A).

In addition, among the polymer components contained in the introduced stock solution, those that have not undergone sufficient biological treatment are removed from the inside 6a of the separation membrane 6.
1, 41, and after exiting the upper end, it descends between the module 7 and the tank body 1, and is returned to the bottom of the 4PJ body 1.

During this process or during the subsequent circulation, the products that have been biologically treated and reduced in molecular weight pass through the membrane 6 from the inside 6a of the separation 11126 for several minutes, and pass through the permeated water outlet. It is taken out of the tank body 1 from 12.13.

Further, gas such as methane is generated as a result of this biological reaction, and the required amount of gas is circulated through the pipe 3, and the excess gas is discharged from the gas vent 115 to the outside of the tank body.

[As shown in -, in this embodiment, the separation membrane 6 is inserted into the tank 1, and the pump pressure is used to feed raw water into the tank 1. Since liquid separation and permeation can be achieved, there is no need to separately install a pressure supply mechanism (power unit) like in conventional membrane separation devices, and the device configuration can be simplified and made more compact.

In addition, in the device of the present invention, the air bubbles G ejected from the air diffuser port 4
passes through the inside of the separation membrane 6 and rises, and the raw water velocity (membrane surface flow velocity) along the membrane surface of the membrane 6 is increased by being followed by the -1: rise of this bubble G. This allows a high amount of permeated water to be maintained.

Also, minutes! The air bubbles blown out from below the separation pattern 6 rise together with the liquid inside the separation pattern 6, but at this time, the gel layer and cake layer adhering to the membrane surface are removed by the bubbles and liquid flow. Mechanically 2q6 removed. Furthermore, the J: 'i1 of the gas and the liquid flow prevent the liquid C degree polarization on the surface of the separation membrane and make it uniform. Therefore, in the device of the present invention, extremely high permeation efficiency and high amount of permeated water can be maintained for a long period of time.

In the two-legged embodiment, the pressure inside the tank body 1 is increased by the liquid supply pump P to obtain the membrane permeation pressure, but the permeation water pressure can also be obtained by deepening the water depth inside the tank body. Of course, both may be used together.

Further, the aeration port 4 is not limited to one location, but may be provided at multiple locations below the separation membrane.

Furthermore, a support plate 9 for the separation membrane 6 is used as a permeate extraction mechanism.
10 may be replaced by a support member 16 as shown in FIG. 4. In FIG. Himuro 2
1 is formed. A short cylindrical member 22 is arranged to pass 1'j through this permeable ice chamber 21, thereby communicating the 4: side 18 of the support member 16 with the chamber 23. Further, a large number of through holes 24 are bored in the lower plate 20 of the support member 16, and the upper end of the #L membrane 6 is connected to the through hole 4L.
24, and the liquid that has permeated into the separation membrane 6 is
It is configured so that the ice can flow into the permeable ice chamber 21 from the upper end of the ice cube 6.

A support member is also provided at the bottom in vertical symmetry with the support member 16, and has a permeable ice chamber and a cylindrical member (both not shown) similar to those shown at 21 and 22 in Fig. 4. ,
The lower end of the portion 1111196 is allowed to flow into the permeable ice chamber of the supporting member of the receding part, and a portion near the bottom of the tank body 1 and the inside of the chamber 23 are communicated with each other.

When such upper and lower support members are used, the first
The casing 8 shown in the figure is not installed, and instead, piping for extracting permeated water from the permeated water chamber 21 of the support member is connected to the side wall of the tank body 1, and the permeated water is extracted by this. Even in the case of this configuration, the same effects as in the above embodiment can be obtained.

In addition, in the present invention, Vl-71 shown in FIGS.
As shown in FIG. 6, which is a sectional view along the line, a plurality of membrane modules 7 may be arranged in the tank body 1. In this case, it is preferable to provide a plurality of air diffusers 4 for each module. With such a device, the separation efficiency per unit volume or installation space can be increased considerably. In the embodiment shown in Fig. 5.6, the permeated water may be extracted from each module, or a separate permeated water collection pipe may be installed to collect and extract the water (in addition, the permeated water may be extracted from the In Fig. 6 and Fig. 6, the first
Components that are the same as those in the figures and FIG. ) In the present invention, as the form of 1 separation 1 pattern 6, hollow fiber 1
1, capillary membranes, tubular membranes, etc. are suitable.

The type of separation membrane is not particularly limited, such as reverse osmosis membranes, ultrafiltration membranes, precision filtration membranes, etc., and can be selected depending on the type of reaction.
For example, when used for wastewater treatment, the pore size is 0.1-0.0.
A precision filtration membrane of about 11 Lm or an ultrafiltration membrane with a molecular weight cut-off of about 20,000 to 1,000 can be used when performing advanced wastewater treatment. In addition, when performing organic acid fermentation or alcohol fermentation, the organic acid produced.

Precision membrane that allows alcohol to pass through, ultrafiltration 11
can be used.

The apparatus of the present invention is suitable for performing aerobic treatment or fermentation treatment, but can also be applied to J111 aerobic treatment.

In the IJI of the present invention, the microorganisms can be charged and maintained in the tank by various methods, such as a fluidized bed method, a sludge blanket method, or a floating method.

[Effects of the Invention] As described above, in the biological reaction device of the present invention, a separation membrane is incorporated in the reaction tank body, and permeation through the separation membrane is achieved using the stock solution supply pressure in the 4PI body.
11 The surface flow velocity is increased and the amount of permeate is maintained at a high level. Furthermore, concentration polarization on the membrane surface and formation of a gel layer are suppressed, and membrane separation processing is performed with extremely high efficiency.

In addition, since the device of the present invention combines membrane separation and biological reaction, it is capable of performing advanced biological reactions, and the overall configuration of the device is extremely compact. There is no need to provide a separate one.

[Brief explanation of drawings]

7JS1 is a longitudinal cross-sectional view of the apparatus according to the embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line TI-II in FIG. 1, and FIG. 3 is an enlarged view of section m in FIG. 1. FIG. 4 is an enlarged cross-sectional view of a support member illustrating another embodiment of the present invention. FIG. 5 is a longitudinal cross-sectional view of another embodiment of the device of the present invention, and FIG. 6 is a cross-sectional view taken along the line Vl--Vl in FIG. ■... Tank body, 3... Gas vent pipe, 4...
・Vent, 6 minutes #1 model. 7...Membrane module. Agent Patent Attorney Tsuyoshi Shigeno Figure 4 Figure 6

Claims (3)

[Claims] (1) In a biological reaction device that performs a biological reaction using microorganisms in a tank body, a separation membrane is provided in the tank body in the vertical direction and the permeate of the separation membrane can be taken out from the tank body,
A biological reaction device characterized in that a gas blowing means is provided below the separation membrane in the tank body. (2) The biological reaction device according to claim 1, wherein the separation membrane is a hollow fiber membrane, a capillary membrane, or a tubular membrane. (3) The biological reaction device according to claim 1 or 2, wherein the gas is a gas generated in the tank body that is collected and recirculated.