JP2023149243A - Treatment system and treatment method - Google Patents

Abstract

To provide a treatment system and a treatment method that perform backwashing according to a blockage state of a membrane and reduce the number of times of backwashing in biological treatment and membrane separation of an object to be treated.SOLUTION: In order to solve the above problem, there are provided a treatment system and a treatment method, the treatment system including: a biological treatment tank; a membrane module that membrane-separates treated liquid generated in the biological treatment tank; a storage tank that stores permeated liquid; and flow rate adjustment means for adjusting a flow rate of the permeated liquid supplied from the membrane module to the storage tank, wherein the flow rate adjustment means also detects a blockage state of the membrane module based on an operation amount related to the flow rate adjustment of the permeated liquid, and backwashing of the membrane module is performed by using water in the storage tank as backwash water on the basis of the detection result. The present invention enables backwashing to be performed in accordance with the blockage state of the membrane module, making it possible to reduce the number of times of backwashing. Thereby, it is possible to suppress a decrease in a recovery rate of the treated water (permeated liquid) obtained as the treatment system.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a processing system and a processing method for processing objects to be processed containing organic substances. More specifically, the present invention relates to a treatment system and a treatment method related to membrane separation biological treatment that combines biological treatment and membrane separation treatment.

BACKGROUND ART Biological treatment using microorganisms such as aerobic microorganisms and anaerobic microorganisms is widely used as a technology for processing objects containing organic substances, such as organic liquid waste and organic waste. In particular, methane fermentation treatment is attracting attention as a highly useful technology because it reduces the amount of the target material and allows the generated methane to be used as energy.

In addition, solid-liquid separation is performed to separate and recover the microorganisms contained in the treated liquid after biological treatment (methane fermentation treatment), and the solid content (concentrated liquid) containing many microorganisms is subjected to biological treatment again. is also being carried out. Known solid-liquid separation treatments for the treated liquid after biological treatment include centrifugation using a centrifugal separator, sedimentation separation using a sedimentation tank, dehydration using a dehydrator, and membrane separation (membrane filtration) using a membrane. The combination of membrane separation and methane fermentation treatment (membrane separation methane fermentation treatment) is widely known.

Here, in the membrane separation methane fermentation treatment, the treated liquid after the methane fermentation treatment is subjected to membrane separation. As a result, solids from methane fermentation treatment (methane fermentation sludge) adhere to the membrane surface and inside the membrane, causing blockage in membrane separation (clogging of the filtration membrane), resulting in a reduction in treatment efficiency in membrane separation. .

For example, in Patent Document 1, in a process that combines a fermenter that anaerobically treats organic wastewater and an external membrane separation device installed outside the fermenter, the water inside the fermenter (processed liquid) is filtered through a membrane separation device. It is described that the permeate is supplied to a separation device and subjected to membrane separation treatment, and the obtained permeate is sent to a treated water tank, while the concentrated liquid is returned to the fermentation tank. Further, Patent Document 1 describes that treated water (permeate) in a treated water tank is periodically supplied to the permeate side of a membrane separation device to backwash the membrane separation device.

Japanese Patent Application Publication No. 2020-151681

Patent Document 1 discloses that in a treatment system that combines biological treatment and membrane separation, treated water (permeate) after membrane separation treatment is periodically used for backwashing of the membrane separation device, thereby reducing the blockage state of the membrane separation device. It is stated that the problem can be resolved. That is, in the treatment system described in Patent Document 1, even if the membrane separation device is not clogged, backwashing is forcibly performed at predetermined intervals.

On the other hand, in membrane separation treatment of a treatment liquid from a biological treatment tank, it is difficult to obtain a high permeation flux due to the properties and concentration of solids (SS) contained in the treatment liquid. In particular, in membrane separation treatment of treated liquid containing methane fermentation sludge obtained through anaerobic treatment (methane fermentation), the permeation flux is lower than in membrane separation treatment of treated liquid containing activated sludge obtained through aerobic treatment. It has been known. Therefore, increasing the number of times of backwashing in membrane separation treatment poses a problem in that the recovery rate of treated water (permeate) decreases.

Therefore, an object of the present invention is to perform backwashing in accordance with the clogging state of the membrane in biological treatment and membrane separation for processing objects containing organic substances, thereby making it possible to reduce the number of times of backwashing. An object of the present invention is to provide a processing system and a processing method using this processing system.

As a result of intensive studies on the above-mentioned issues, the present inventors have determined that in a process that performs biological treatment and membrane separation, the permeated liquid of the concentrated liquid and permeated liquid obtained in the membrane separation process using a membrane module is added to the treated liquid after biological treatment. When storing the liquid in the storage tank, in addition to adjusting the flow rate of the permeated liquid, the blockage state of the membrane module is detected from the operation amount related to the flow rate adjustment of the permeated liquid, and based on this detection result, the flow rate of the permeated liquid is adjusted. The present invention was completed by discovering that backwashing can be performed in accordance with the membrane's clogging state by performing a backwashing operation using water of 300 ml, thereby reducing the number of times of backwashing.
That is, the present invention provides the following processing system and processing method.

The treatment system of the present invention for solving the above problems includes a biological treatment tank for biologically treating the object to be treated, and a treatment liquid generated in the biological treatment tank, which is separated by a membrane outside the biological treatment tank to form a concentrated liquid and a permeated liquid. a storage tank for storing the permeate; and a flow rate adjustment means for adjusting the flow rate of the permeate supplied from the membrane module to the storage tank, and the flow rate adjustment means adjusts the flow rate of the permeate. Based on the amount of operation, the blockage state of the membrane module is also detected, and based on the detection result by the flow rate adjustment means, it is possible to backwash the membrane module by using the water in the storage tank as backwash water. Features.
According to this treatment system, in a treatment system that performs biological treatment and membrane separation on an object to be treated, a concentrated liquid and a permeated liquid obtained by subjecting the treated liquid generated in the biological treatment tank to membrane separation treatment using a membrane module. Among them, the permeated liquid is stored in a storage tank, and at this time, the flow rate of the permeated liquid is adjusted, and the clogging state of the membrane module is detected from the manipulated variable related to the flow rate adjustment of the permeated liquid, and based on this detection result, By performing a backwashing operation using water in the storage tank, backwashing can be performed in accordance with the clogged state of the membrane, and the number of times of backwashing can be reduced. This makes it possible to suppress a decrease in the recovery rate of treated water (permeate) obtained by this treatment system.

The treatment method of the present invention for solving the above problems includes a biological treatment process in which the object to be treated is biologically treated in a biological treatment tank, and a membrane module provided outside the biological treatment tank to receive the treatment liquid generated in the biological treatment process. A membrane separation process for obtaining a concentrated liquid and a permeated liquid through membrane separation, a storage process for storing the permeated liquid, and a flow rate adjustment process for adjusting the flow rate of the permeated liquid supplied from the membrane separation process to the storage process. In the flow rate adjustment step, the blockage state of the membrane module is also detected based on the manipulated variable for adjusting the flow rate of the permeate, and the water in the storage step is backwashed based on the detection results in the flow rate adjustment step. It is characterized by backwashing the membrane module with water.
According to this treatment method, in a treatment method that performs biological treatment and membrane separation on an object to be treated, concentration obtained by performing a membrane separation process in which a treatment liquid generated in the biological treatment process is membrane-separated using a membrane module. Among the liquid and permeate, the permeate is stored in a storage process, and the flow rate of the permeate at this time is adjusted, and the blockage state of the membrane module is detected from the operation amount related to the flow rate adjustment of the permeate. By performing a backwashing operation using water in the storage tank based on this detection result, backwashing can be performed in accordance with the blocked state of the membrane, and the number of times of backwashing can be reduced. This makes it possible to suppress a decrease in the recovery rate of treated water (permeate) obtained by this treatment method.

According to the present invention, a treatment system that performs backwashing in accordance with the clogging state of the membrane and reduces the number of backwashes in biological treatment and membrane separation of processing objects containing organic substances. , and a processing method using this processing system can be provided.

FIG. 1 is a schematic explanatory diagram showing the structure of a processing system in a first embodiment of the present invention. FIG. 2 is a schematic explanatory diagram showing the structure of a processing system in a second embodiment of the present invention.

A processing system and a processing method of the present invention are a processing system and a processing method for processing a processing object containing an organic substance. Moreover, the treatment system and treatment method of the present invention are a treatment system and treatment method that combine biological treatment and membrane separation treatment.
Biological treatment in the present invention may be either aerobic treatment or anaerobic treatment, but anaerobic treatment (methane fermentation) is preferable because biogas generated during the treatment process can be recovered and used as energy. preferable.

The objects to be treated in the present invention include, for example, organic wastewater containing solids such as kitchen garbage, food waste, vegetation, and sludge, as well as organic wastewater and organic waste such as livestock manure and surplus sludge. It will be done.
In particular, the object to be treated in the present invention is preferably organic wastewater or organic wastewater that has a low solid content and contains organic substances that are easily decomposed by biological treatment. This makes it easier to increase the concentration of microorganisms in biological treatment, and at the same time reduces the amount of solids contained in the treatment liquid, making it possible to prevent the membrane module from becoming blocked in membrane separation.
Among the objects to be treated in the present invention, examples of objects particularly suitable for anaerobic treatment (methane fermentation) include organic wastewater and highly concentrated waste liquid discharged from food factories, chemical factories, etc. . More specifically, examples include organic wastewater and highly concentrated wastewater containing alcohols such as methanol and ethanol, glucose, glycerin, organic acids such as acetic acid, higher fatty acids, surfactants, phenols, and the like.
Note that the object to be treated in the present invention is not limited to this, and as long as it contains an organic substance that can be biologically treated, it becomes the object to be treated in the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a processing system and a processing method according to the present invention will be described in detail with reference to the drawings. Furthermore, the description of the processing method according to the present invention will be replaced with the description of the configuration and operation of the processing system according to the present invention.
Note that the processing system described in the embodiments is merely an example for explaining the processing system according to the present invention, and is not limited thereto. Further, the processing method of this embodiment is merely exemplified to explain a processing method using the following processing system, and is not limited thereto.
Further, in the following embodiments, anaerobic treatment (methane fermentation) will be mainly explained as biological treatment, but the present invention is not limited to this.

[First embodiment]
[Processing system]
FIG. 1 is a schematic explanatory diagram showing the structure of a processing system according to a first embodiment of the present invention.
The processing system 100A according to the first embodiment of the present invention performs methane fermentation processing and membrane separation processing on the processing object S, and as shown in FIG. A biological treatment tank 1 that performs methane fermentation treatment on the object to be treated S, a membrane module 2 that separates the treated liquid W generated in the biological treatment tank 1 into a concentrated liquid F1 and a permeated liquid F2, and a membrane module that separates the treated liquid W into a membrane module. 2, a return path 4 that returns the concentrated liquid F1 to the biological treatment tank 1, a sludge extraction means 5 that extracts the sludge from the biological treatment tank 1, and a storage tank that stores the permeated liquid F2. 6, and a flow rate adjustment means 7A that adjusts the flow rate of the permeate F2 supplied to the storage tank 6.
Note that the arrow indicated by a dashed dotted line indicates that the connection is possible for control or input/output.

The processing system 100A according to this embodiment may be provided with equipment other than the configuration shown in FIG. 1. For example, in the previous stage of the biological treatment tank 1, there is a concentration tank that concentrates the target substance S, a solubilization tank that solubilizes the target substance S, and the amount of the target substance S supplied to the biological treatment tank 1 is adjusted. A regulating tank or the like may be provided for this purpose. Furthermore, a water treatment facility for treating the permeated liquid F2 may be provided downstream of the storage tank 6. Furthermore, biogas (methane gas) generated from the biological treatment tank 1 may be collected via the line L2, and biogas utilization equipment including a desulfurization device and a gas storage tank may be provided to utilize this biogas. .

Based on FIG. 1, an outline of the processing of the processing object by the processing system 100A in this embodiment will be explained.
First, the object to be treated S is supplied to the biological treatment tank 1 via the line L1. Then, methane fermentation treatment is performed on the treatment object S within the biological treatment tank 1. Then, the treatment target S treated in the biological treatment tank 1 becomes a treatment liquid W, which is sent to the membrane module 2 side via the liquid feeding path 3 and the circulation pump 31 provided on the liquid feeding path 3. . Then, the treatment liquid W is membrane-separated via a plurality of membrane modules 2 (membrane modules 2a to 2c) connected via pipes 32a and 32b to obtain a concentrated liquid F1 and a permeated liquid F2. The permeate F2 is collected via the pipes 32a to 32c, and further stored in the storage tank 6 via the pipe 61a. On the other hand, the concentrated liquid F1 is returned to the biological treatment tank 1 via the return path 4.
The above is the flow related to the processing on the processing object S in the processing system 100A of this embodiment.
Although not shown in FIG. 1, the treatment system 100A may include a line for returning the permeated liquid F2 to the biological treatment tank 1 so that the liquid level in the biological treatment tank 1 does not drop.

The processing system 100A in this embodiment is provided with means for detecting the blocked state of the membrane module 2 and performing a backwash operation based on the detection result.

While the processing by the processing system 100A continues, the solid content (SS) contained in the processing liquid W adheres to the surface and inside of the membrane module 2, clogging the membrane, resulting in a decrease in processing efficiency.
For this reason, in conventional treatment systems that combine biological treatment and membrane separation, backwashing water is periodically supplied to the membrane separation processing device (membrane module) to perform backwashing operations.
On the other hand, in a treatment system that combines biological treatment and membrane separation, when the treated liquid from the biological treatment tank is subjected to membrane separation treatment, a high permeation flux may occur due to the properties and concentration of solids (SS) contained in the treated liquid. In particular, in membrane separation treatment of treated liquid containing methane fermentation sludge obtained by anaerobic treatment (methane fermentation), the permeate flow is It is known that the bundle becomes low.
From this, unnecessarily increasing the number of times the membrane module 2 is backwashed in the treatment system 100A will lead to a decrease in the recovery rate of water (permeate F2) subjected to membrane separation by the membrane module 2.

Therefore, in the treatment system 100A in this embodiment, the membrane module 2 is equipped with a membrane as a means for enabling backwashing according to the blocked state of the membrane module 2, reducing the number of times of backwashing, and suppressing a decrease in the recovery rate of the permeated liquid F2. A flow rate adjustment means 7A is provided to adjust the flow rate of the permeate F2 supplied from the module 2 to the storage tank 6, and this flow rate adjustment means 7A also detects the blockage state of the membrane module 2, and based on the detection result, , it is possible to provide a device that performs a backwash operation using the water in the storage tank 6 as the backwash water W1.

Each configuration in the processing system 100A of this embodiment will be described below.

(biological treatment tank)
The biological treatment tank 1 in this embodiment is a treatment tank for carrying out a biological treatment process in which the object to be treated S is subjected to methane fermentation using anaerobic microorganisms (such as methane bacteria), and is a closed container to maintain anaerobic properties. It is desirable to do so, and other specific structures are not particularly limited.
The structure of the biological treatment tank 1 is preferably selected appropriately depending on the object S to be treated, for example. More specifically, we will discuss the structure of treatment tanks used for the anaerobic treatment of organic wastewater and organic waste liquids that contain a large amount of liquid components, and the treatment that is used for the anaerobic treatment of organic waste that contains a large amount of solid components. The structure of the tank can be appropriately selected and used.
Note that the biological treatment tank 1 in this embodiment may be a treatment tank that performs aerobic treatment using aerobic microorganisms. In this case, a structure known as an aerobic treatment tank (aerobic reaction tank) can be used in the biological treatment tank 1, such as providing incidental equipment such as an aeration device to maintain aerobic properties.

The treatment system 100A of this embodiment supplies the treatment liquid W generated in the biological treatment tank 1 to the membrane module 2 to perform membrane separation. Therefore, when methane fermentation treatment using granules is performed in the biological treatment tank 1, solids with large particle sizes such as granules are mixed into the treatment liquid W generated in the biological treatment tank 1, and the biological treatment tank 1 There is a possibility that the blockage of the membrane module 2 arranged in the latter stage will progress. Therefore, it is preferable that the biological treatment tank 1 in this embodiment has a structure known as a fully mixed methane fermentation tank to perform methane fermentation treatment.

The biological treatment tank 1 in this embodiment is preferably provided with stirring means 10 for stirring the inside.
As a specific configuration of the stirring means 10, for example, as shown in FIG. Examples include providing a stirring pump and circulation piping for circulating the processing liquid W in the processing tank 1.

As an example of a specific structure of the biological treatment tank 1, it is preferable that the bottom of the biological treatment tank 1 has a slope. This facilitates the collection of solid residues and improves the stirring efficiency at the bottom of the biological treatment tank 1.
Further, as an example of other structures related to the biological treatment tank 1, there may be mentioned, for example, a structure further including an internal structure for increasing the stirring efficiency by the stirring means 10.

The treatment object S treated in the biological treatment tank 1 in this embodiment is sent to the membrane module 2 as a treatment liquid W.

(membrane module)
The membrane module 2 is for performing solid-liquid separation (membrane separation) using a membrane on the treated liquid W generated in the biological treatment tank 1, and performing a membrane separation process to obtain a concentrated liquid F1 and a permeated liquid F2. .
Further, the number of membrane modules 2 and the arrangement (arrangement) of membrane modules 2 in this embodiment are not particularly limited. For example, as shown in FIG. 1, a plurality of membrane modules 2a, 2b, and 2c are arranged in series, and treated water W that has not passed through the membrane module 2a is supplied to the membrane module 2b via a pipe 32a. Furthermore, the arrangement is such that the treated water W that has not passed through the membrane module 2b can be supplied to the membrane module 2c via the piping 32b, and by sequentially supplying the treated water W to the membrane module 2, One example of this is to increase the concentration rate of the solid content (methane fermentation sludge).
Other examples of the arrangement (array) of the membrane modules 2 include, for example, forming an array in which a plurality of membrane modules 2 are connected in parallel, forming a unit in which a plurality of membrane modules 2 are connected in series, An example is one in which a plurality of these units are connected in parallel to form an array.

Further, as shown in FIG. 1, the treated liquid W that has undergone membrane separation processing by all the membrane modules 2 is returned to the biological treatment tank 1 via the return path 4 as a concentrated liquid F1.

Here, the treatment liquid W sent to the membrane module 2 contains anaerobic microorganisms (such as methane bacteria) in the biological treatment tank 1 . That is, when the treatment liquid W is discharged from the biological treatment tank 1 and sent to the membrane module 2, anaerobic microorganisms (such as methane bacteria) are also discharged from the biological treatment tank 1.
On the other hand, as shown in FIG. 1, a treatment system 100A in this embodiment includes a plurality of membrane modules 2a, 2b, 2c, and each membrane module 2 By sequentially supplying the treatment liquid W to the biological treatment tank 1 and returning it to the biological treatment tank 1 as the concentrated liquid F1 via the return path 4, the anaerobic microorganisms (such as methane bacteria) that have flowed out from the biological treatment tank 1 are removed from the concentrated liquid F1. It will be collected and returned to the biological treatment tank 1. Thereby, it is possible to prevent anaerobic microorganisms from flowing out of the biological treatment tank 1 and to maintain the concentration of microorganisms in the biological treatment tank 1.

On the other hand, the permeated liquid F2 is stored in the storage tank 6 via the pipes 33a to 33c provided in each membrane module 2 and the pipe 61a where the pipes 33a to 33c join together.

The membrane module 2 performs membrane separation of the treated liquid W, and separates a concentrated liquid F1 containing solids (methane fermentation sludge) containing many anaerobic microorganisms (methane bacteria, etc.) and a permeated liquid F2 from which the solids have been removed. It is fine as long as it can obtain the following.
Specific examples of the membrane module 2 include tubular type, hollow fiber type, and submerged flat membrane. As the membrane module 2 in this embodiment, as shown in FIG. 1, it is preferable to use what is called an outside-tank type provided outside the biological treatment tank 1. Moreover, it is particularly preferable to use a tubular type membrane module 2. The tubular type can perform membrane separation using the so-called cross-flow method, which increases the linear velocity of the membrane surface to create turbulent flow near the membrane surface to suppress reversible fouling. Therefore, even if the processing liquid W to be sent has high SS concentration or high viscosity, it has the advantage that the membrane module 2 is less likely to be clogged.

In the membrane module 2 of this embodiment, a pressure gauge is provided at the processing liquid inlet and/or concentrated liquid outlet of each membrane module 2 (membrane modules 2a to 2c) to monitor and manage the smooth operation of the processing system 100A. It may also be used for. For example, when a plurality of membrane modules 2 are arranged, pressure gauges should be arranged so that information regarding the pressure difference between the processing liquid inlet on the most upstream side and the concentrated liquid outlet on the most downstream side, where the membrane modules 2 are provided, can be obtained. can be mentioned. Specifically, as shown in FIG. 1, a pressure gauge PI1 is provided at the processing liquid inlet of the most upstream membrane module 2a, and a pressure gauge PI2 is provided at the concentrated liquid outlet of the most downstream membrane module 2c. can be mentioned.

(Liquid sending path and return path)
The liquid sending path 3 is made up of piping that performs a liquid sending process for sending the treated liquid W generated in the biological treatment tank 1 to the membrane module 2, and the return path 4 is for carrying the concentrated liquid F1 from the membrane module 2. It consists of piping that performs the return process of returning to the biological treatment tank 1. Further, the circulation pump 31 provided on the liquid sending path 3 passes the processing liquid W (concentrated liquid F1) into the circulation path formed by the liquid sending path 3, the pipes 32a and 32b, and the return path 4. It is for the purpose of As a result, the anaerobic microorganisms (such as methane bacteria) contained in the treatment liquid W discharged from the biological treatment tank 1 are returned to the biological treatment tank 1 as the concentrated liquid F1. It becomes possible to suppress the outflow of.

(Sludge removal means)
The sludge drawing means 5 is for carrying out a sludge drawing process of drawing out the sludge in the biological treatment tank 1.
In the treatment system 100A, the concentration of microorganisms (such as methane bacteria) is set to a high concentration in order to increase the biological treatment efficiency, and if the concentration of solids (SS) in the biological treatment tank 1 becomes excessive, the treatment liquid W Since the amount of solids contained increases, the membrane module 2 is likely to be clogged in the subsequent membrane separation process. For this reason, a sludge extraction means 5 is provided to draw out the sludge in the biological treatment tank 1, thereby maintaining the microorganism concentration (SS concentration) in the biological treatment tank 1.

As shown in FIG. 1, the sludge drawing means 5 includes a pipe 51 branched from the liquid feeding path 3 and a drawing part 52 provided on the pipe 51.
The drawing section 52 may be any member that can draw out sludge through the piping 51, and its specific structure is not particularly limited. For example, as shown in FIG. 1, a combination of a flow rate regulating valve provided on a pipe 51 and a liquid feeding pump may be used.
The sludge extraction means 5 may be operated periodically by manual operation by an operator or controlled by a timer, or may be operated based on control parameters related to maintaining the microorganism concentration in the biological treatment tank 1. good.

(Storage tank)
The storage tank 6 is a tank for performing a storage process in which the permeated liquid F2 from the membrane module 2 is stored via a pipe 61a.
The storage tank 6 may be any tank as long as it can store the permeated liquid F2, and the shape, material, and size of the tank are not particularly limited.

The storage tank 6 is connected to piping 61b and 61c in addition to the piping 61a through which the permeated liquid F2 is supplied.
The pipe 61b is for discharging the stored water out of the system, and the water discharged at this time may be further treated by other water treatment equipment.
The pipe 61c is for supplying a part of the water stored in the storage tank 6 to the permeation side of each membrane module 2 (membrane modules 2a to 2c) as backwash water W1. A backwash pump 62 is provided.

(Flow rate adjustment means)
The flow rate adjustment means 7A is for performing a flow rate adjustment step of adjusting the flow rate of the permeated liquid F2 supplied from the membrane module 2 to the storage tank 6, and at the same time, a detection step of detecting a blockage state of the membrane module 2. It is meant to be done.

In the treatment system 100A in this embodiment, in order to smoothly continue the treatment of the object S, it is necessary to discharge the amount introduced as the object S to be treated outside the system as treated water (permeate F2). Therefore, by providing the flow rate adjustment means 7A and quantitatively recovering (storing) the permeated liquid F2, clogging of the membrane module 2 is suppressed, and a decrease in the recovery rate of the treated water (permeated liquid F2) is suppressed. becomes possible.

Furthermore, the flow rate adjustment means 7A in this embodiment also has a function of detecting the blocked state of the membrane module 2 from information regarding the operation amount related to the flow rate adjustment of the permeated liquid F2 from the membrane module 2. This makes it possible to quickly and accurately grasp the timing at which backwashing of the membrane module 2 is required.

Further, based on the detection result by the flow rate adjustment means 7A in this embodiment, the backwash pump 62 on the pipe 61c is operated to supply the water in the storage tank 6 as backwash water W1 to the membrane module 2, and perform backwash operation. shall be carried out. This makes it possible to perform backwashing in accordance with the blocked state of the membrane module 2, and to reduce the number of times of backwashing.

As shown in FIG. 1, the flow rate adjustment means 7A in this embodiment includes one that includes a flow rate adjustment valve 71 and a flow meter 72 provided on the pipe 61a.
The flow rate adjustment valve 71 keeps the amount of permeated liquid F2 supplied to the storage tank 6 constant by adjusting its opening so that the value indicated by a flow meter 72 provided downstream of the flow rate adjustment valve 71 remains constant. It is something to do. That is, in this embodiment, the opening degree of the flow rate adjustment valve 71 corresponds to the manipulated variable related to flow rate adjustment. Although the opening degree adjustment of the flow rate regulating valve 71 may include manual operation by an operator, it is preferable that the opening degree of the flow rate regulating valve 71 is automatically controlled according to the measured value of the flow meter 72.
At this time, as the membrane module 2 becomes closed, the amount of permeated liquid F2 from the membrane module 2 decreases. will be made larger. In other words, when the opening degree of the flow rate adjustment valve 71, which is the manipulated variable related to flow rate adjustment in the flow rate adjustment means 7A of this embodiment, exceeds a certain value, it is possible that the membrane module 2 is in a closed state or has a tendency to close. Detected.
Then, based on the detection result regarding the blockage state of the membrane module 2, the backwash pump 62 on the pipe 61c is operated to supply the water in the storage tank 6 as backwash water W1 to the membrane module 2, and perform a backwash operation. shall be taken as a thing.

Here, the acquisition of information related to the opening degree of the flow rate adjustment valve 71, the judgment related to the detection of the blockage state of the membrane module 2, and the operation of the backwash pump 62 based on the detection result (judgment result) are manually performed by the operator. Although it may include operations, it has a data input/output function for acquiring information (measured values), and includes calculations related to detection (judgment) of the blockage state of the membrane module 2 and control for the backwash pump 62. It is preferable to enable automatic control using a computing device in which a processor such as a CPU executes a program for transmitting signals. Thereby, the backwashing operation in the processing system 100A can be automated, and stable operation of the processing system 100A can be facilitated.

As described above, according to the treatment system 100A and the treatment method of the present embodiment, in the process of performing biological treatment and membrane separation on an object to be treated, the treatment liquid generated in the biological treatment tank is subjected to membrane separation using the membrane module. Of the concentrated liquid and permeated liquid obtained by this, the permeated liquid is stored in a storage tank, and at this time, in addition to adjusting the flow rate of the permeated liquid, the clogging state of the membrane module is detected from the flow rate of the permeated liquid, By performing a backwashing operation using water in the storage tank based on this detection result, backwashing can be performed in accordance with the blocked state of the membrane, and the number of times of backwashing can be reduced. Thereby, it becomes possible to suppress a decrease in the recovery rate of treated water (permeate) obtained by this treatment, and it becomes easy to continue stable operation as a treatment system.

[Second embodiment]
FIG. 2 is a schematic explanatory diagram showing the structure of a processing system according to a second embodiment of the present invention.
A processing system 100B according to the second embodiment of the present invention includes a flow rate adjustment means 7B including a transfer pump 73 in place of the flow rate adjustment means 7A in the first embodiment. Note that, among the configurations of the processing system 100B in this embodiment, descriptions of the same components as the configuration of the processing system 100A in the first embodiment will be omitted.

As shown in FIG. 2, the flow rate adjusting means 7B in this embodiment includes one including a transfer pump 73 and a flow meter 72 provided on the piping 61a.
The transfer pump 73 has a drive mechanism (inverter) that drives the transfer pump 73 (not shown), and controls the transfer pump 73 so that the value indicated by the flow meter 72 provided downstream of the transfer pump 73 is constant. By adjusting the output of the drive mechanism, the amount of permeated liquid F2 supplied to the storage tank 6 is made constant. That is, in this embodiment, the output of the drive mechanism of the transfer pump 73 corresponds to the manipulated variable related to flow rate adjustment. More specifically, the operating frequency value and current value, which are parameters related to the output of the drive mechanism of the transfer pump 73, correspond to the manipulated variable related to flow rate adjustment. Note that the output adjustment of the drive mechanism of the transfer pump 73 may include manual operation by the operator, but the parameter value (operating frequency) related to the output of the drive mechanism of the transfer pump 73 may be value or current value) is preferably automatically controlled.
At this time, as the membrane module 2 becomes closed, the amount of permeate F2 from the membrane module 2 decreases, so in order to keep the value indicated by the flow meter 72 constant, it is necessary to This will increase output. In other words, if the parameter value related to the output of the drive mechanism of the transfer pump 73, which is the manipulated variable related to flow rate adjustment in the flow rate adjustment means 7B of this embodiment, exceeds a certain value, the membrane module 2 is in a blocked state or A trend is detected.
Then, based on the detection result regarding the blockage state of the membrane module 2, the backwash pump 62 on the pipe 61c is operated to supply the water in the storage tank 6 as backwash water W1 to the membrane module 2, and perform a backwash operation. shall be taken as a thing.

Here, in the flow rate adjusting means 7B of this embodiment, information acquisition regarding the output of the drive mechanism of the transfer pump 73, judgment regarding the detection regarding the blockage state of the membrane module 2, and a backwash pump based on the detection result (judgment result) The operation of 62 may include manual operation by the operator, similar to the above-mentioned flow rate adjustment means 7A, but it has a data input/output function for acquiring information (measured values), and the membrane It is preferable to enable automatic control using a calculation device that executes a program for detecting (judging) the blockage state of the module 2 and for issuing a control signal to the backwash pump 62 using a processor such as a CPU. Thereby, the backwash operation in the processing system 100B can be automated, and stable operation of the processing system 100B can be facilitated.

Note that the embodiment described above is an example of a processing system and a processing method. The processing system and processing method according to the present invention are not limited to the embodiments described above, and the processing system and processing method according to the embodiments described above may be modified without changing the gist of the claims. good.

The treatment system and treatment method of the present invention are used to treat objects to be treated that contain organic substances, such as organic waste liquid and organic waste. Moreover, the treatment system and treatment method of the present invention are particularly suitably used as a technology related to methane fermentation treatment and membrane separation methane fermentation treatment using membrane separation.

100A, 100B treatment system, 1 biological treatment tank, 10 stirring means, 11 stirrer, 11a stirring blade, 11b drive unit, 2, 2a, 2b, 2c membrane module, 3 liquid feeding path, 31 circulation pump, 32a, 32b piping , 33a to 33c piping, 4 return path, 5 sludge extraction means, 51 piping, 52 extraction part, 6 storage tank, 61a to 61c piping, 62 backwash pump, 7A, 7B flow rate adjustment means, 71 flow rate adjustment valve, 72 flow rate Total, 73 Transfer pump, F1 Concentrated liquid, F2 Permeated liquid, L1, L2 Line, PI1, PI2 Pressure gauge, S Processing object, W Processing liquid, W1 Backwash water

Claims (2)

A biological treatment tank that biologically treats the object to be treated;
A membrane module that separates the treated liquid generated in the biological treatment tank with a membrane outside the biological treatment tank to obtain a concentrated liquid and a permeated liquid;
a storage tank that stores the permeate;
a flow rate adjustment means for adjusting the flow rate of the permeate supplied from the membrane module to the storage tank;
The flow rate adjustment means also detects the blocked state of the membrane module based on the operation amount related to the flow rate adjustment of the permeated liquid,
A treatment system, wherein the membrane module is backwashed using water in the storage tank as backwash water based on a detection result by the flow rate adjustment means. A biological treatment process in which the object to be treated is biologically treated in a biological treatment tank;
A membrane separation step in which the treated liquid generated in the biological treatment step is subjected to membrane separation using a membrane module provided outside the biological treatment tank to obtain a concentrated liquid and a permeated liquid;
a storage step of storing the permeate;
a flow rate adjustment step of adjusting the flow rate of the permeate supplied from the membrane separation step to the storage step,
The flow rate adjustment step also includes detecting the blocked state of the membrane module based on the manipulated variable related to the flow rate adjustment of the permeate,
A treatment method, characterized in that the membrane module is backwashed using water from the storage step as backwash water based on the detection result in the flow rate adjustment step.