Processing system, monitoring cell, and method for monitoring a processing system

Abstract

To provide a processing system, a monitoring cell, and a monitoring method of a processing system in membrane separation methane fermentation processing assembled with a methane fermentation tank and a membrane module, capable of easily and properly grasping a state of a membrane module under a processing environment.SOLUTION: A processing system assembled with a methane fermentation tank and a membrane module is provided with a monitoring cell which is assembled with a membrane element having the similar characteristics as a membrane element forming a membrane module and monitors a state of the membrane element from a penetration liquid side. By this, the membrane module and a monitoring membrane are set under the same processing environment, monitoring of the membrane module under a processing environment can be replaced to a monitoring of the monitoring membrane. Moreover, by performing monitoring from a penetration liquid side of the monitoring membrane, influence of disturbance is reduced so as to easily and properly grasp a state of the membrane module.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a treatment system for a treatment object containing an organic substance, and a monitoring cell provided in this treatment system. More specifically, the present invention relates to a treatment system for a membrane separation methane fermentation treatment that combines a methane fermentation treatment and a membrane separation treatment, and a monitoring cell provided in this treatment system. Further, the present invention relates to a method for monitoring a treatment system for a treatment object containing an organic substance. More specifically, the present invention relates to a method for monitoring a treatment system for a membrane separation methane fermentation treatment that combines a methane fermentation treatment and a membrane separation treatment.

Background Art

[0002] As a technology for treating treatment objects containing organic substances such as organic waste liquids and organic waste, biological treatment using anaerobic microorganisms is widely performed. In particular, the methane fermentation treatment has attracted attention as a highly useful technology because it can reduce the amount of the treatment object and utilize the generated methane as energy.

[0003] In addition, solid-liquid separation is performed to separate and recover anaerobic microorganisms contained in the treatment liquid after biological treatment (methane fermentation treatment) from the treatment liquid, and the solid content (concentrate) containing a large amount of anaerobic microorganisms is again subjected to biological treatment. As solid-liquid separation treatment for the treatment liquid after biological treatment, in addition to centrifugation by a centrifugal separator, sedimentation separation by a sedimentation tank, dehydration by a dehydration device, membrane separation (membrane filtration) by a membrane is known. In particular, the combination of membrane separation and methane fermentation treatment (membrane separation methane fermentation treatment) is widely known.

[0004] For example, Patent Document 1 describes a membrane separation methane fermentation treatment apparatus including a methane fermentation tank and a membrane filtration tank for separating filtrate from the liquid to be treated in the methane fermentation tank. As means for suppressing clogging of the filtration membrane, it is described that it includes heating means for heating the liquid to be treated supplied to the membrane filtration tank to a temperature higher than the set temperature of the methane fermentation tank and cleaning means for the filtration membrane provided in the membrane filtration tank.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] As described in Patent Document 1, membrane separation methane fermentation treatment is to subject the treated liquid after methane fermentation treatment to membrane separation. Therefore, solid matter (methane fermentation sludge) based on the methane fermentation treatment adheres to the membrane surface and inside the membrane, resulting in clogging (clogging of the filtration membrane) in membrane separation, and a problem is a decrease in the treatment efficiency in membrane separation.

[0007] Patent Document 1 describes means for suppressing the occurrence of clogging in membrane separation. However, it is difficult to completely suppress the clogging of membrane separation itself in the continuous process of treatment. In addition, in membrane separation methane fermentation treatment, the treated liquid that has undergone methane fermentation treatment is the object of membrane separation. Therefore, the nature and amount of solid matter contained in the liquid to be treated, which is the object of membrane separation, are not always uniform.

[0008] From this, in the treatment system in membrane separation methane fermentation treatment, it is difficult to accurately judge the clogging state of the membrane module only based on the time of subjecting it to membrane separation treatment. For this reason, regularly cleaning or replacing the membrane module does not result in an operation that appropriately reflects the clogging state of the membrane module, and it leads to performing maintenance that was originally unnecessary. In addition, in the treatment system for membrane separation methane fermentation treatment, the properties of the solids adhering to the membrane module are not always uniform. Therefore, in the maintenance of the membrane module, it is difficult to determine which of membrane replacement or cleaning should be performed, and what the work content related to cleaning should be, that is, it is difficult to judge what kind of maintenance is appropriate.

[0009] Therefore, in the membrane separation methane fermentation treatment, in order to appropriately determine the frequency and content of the maintenance work for the membrane module used for membrane separation, it is required to accurately grasp the state (actual situation) of the membrane module in the treatment environment. At this time, it is desirable to grasp the state of the membrane module in a form that does not affect the membrane separation treatment by the membrane module.

[0010] An object of the present invention is to provide a treatment system, a monitoring cell provided in the treatment system, and a monitoring method of the treatment system, which can monitor the state of a membrane module in a treatment environment without affecting the membrane separation treatment, and can simply and accurately grasp the state of the membrane module, in a treatment system that performs methane fermentation treatment by a methane fermentation tank and membrane separation by a membrane module as a treatment of an object to be treated containing an organic substance.

Means for Solving the Problems

[0011] As a result of intensive studies on the above problems, the present inventor has found that by providing a treatment system that performs methane fermentation treatment and membrane separation with a membrane element having the same performance as the membrane element forming the membrane module, and providing a monitoring cell that monitors from the permeation side of the membrane element, it is possible to monitor the state of the membrane module in the treatment environment without affecting the membrane separation treatment, and it is possible to simply and accurately grasp the state of the membrane module, and thus the present invention has been completed. That is, the present invention is the following treatment system, a monitoring cell provided in this treatment system, and a monitoring method of the treatment system according to this treatment system.

[0012] The processing system of the present invention for solving the above problems is a processing system for processing an object to be processed containing an organic substance, comprising: a methane fermentation tank for subjecting the object to be processed to methane fermentation; a membrane module for membrane-separating the processing liquid generated in the methane fermentation tank to obtain a concentrated liquid and a permeate; a monitoring cell provided with a membrane element having the same performance as the membrane element forming the membrane module, and monitoring the state of the membrane element from the permeate side. According to this processing system, in a processing system that performs methane fermentation treatment and membrane separation, by providing a monitoring cell equipped with a monitoring membrane (a membrane element having the same performance as the membrane element forming the membrane module) separately from the membrane module to be subjected to the membrane separation treatment, the membrane module and the monitoring membrane can be placed in the same processing environment. As a result, monitoring the monitoring membrane is equivalent to monitoring the membrane module in the processing environment, eliminating the need to directly monitor the membrane module itself. Therefore, it becomes possible to perform monitoring in a form that does not affect the membrane separation treatment by the membrane module. In addition, by monitoring from the permeate side of the monitoring membrane, the membrane surface, which is originally in an environment not directly in contact with the solid content in the processing liquid, becomes the monitoring target. As a result, changes in the membrane surface due to membrane fouling or deterioration can be detected without being affected by the adhesion or deposition of solid content. Therefore, it becomes possible to simply and accurately grasp the state of the membrane module.

[0013] Moreover, as an embodiment of the processing system of the present invention, the monitoring cell is characterized by comprising monitoring means for monitoring a change in the color of the surface of the membrane element. In the membrane separation methane fermentation treatment, the processing liquid generated in the methane fermentation tank contains fine solid content (methane fermentation sludge), and this solid content is generally colored. Therefore, as the membrane becomes fouled or deteriorated, the colored solid content enters the membrane, causing a change in the color of the membrane surface on the permeate side. Therefore, by providing a monitoring means for monitoring the color change of the surface of the membrane element as the monitoring film, it becomes possible to easily and accurately grasp the state of the membrane element.

[0014] Further, as an embodiment of the processing system of the present invention, the monitoring cell is characterized in that it includes a permeate discharge section for discharging the permeate in the monitoring cell. According to this feature, when the permeate is colored or the like, in the case where the permeate itself becomes a disturbance in monitoring, the permeate in the monitoring cell is discharged, and the membrane element as the monitoring film is monitored in a state where the influence of the disturbance is suppressed. This makes it possible to easily and accurately grasp the state of the membrane element.

[0015] The monitoring cell of the present invention for solving the above problems is a monitoring cell provided for a processing system including a methane fermentation tank for methane-fermenting a treatment object containing an organic substance, and a membrane module for membrane-separating the treatment liquid generated in the methane fermentation tank to obtain a concentrated liquid and a permeate, the monitoring cell including a membrane element having the same performance as the membrane element forming the membrane module in the processing system, and monitoring the state of the membrane element from the permeate side. According to this monitoring cell, for a processing system that performs methane fermentation treatment and membrane separation, a monitoring film (a membrane element having the same performance as the membrane element forming the membrane module) placed in the same processing environment as the membrane module can be provided separately from the membrane module used for the membrane separation treatment. As a result, monitoring of the monitoring film is equivalent to monitoring of the membrane module in the processing environment, so there is no need to directly monitor the membrane module itself. Therefore, it becomes possible to perform monitoring without affecting the membrane separation treatment by the membrane module. In addition, by monitoring from the permeate side of the monitoring film, the membrane surface, which is originally in an environment not directly in contact with the solid content in the treatment liquid, becomes the monitoring target. As a result, it is possible to capture changes in the membrane surface due to membrane clogging or deterioration without being affected by the adhesion or deposition of solid content. Therefore, it becomes possible to easily and accurately grasp the state of the membrane module.

[0016] A monitoring method for a treatment system of the present invention for solving the above problems is a monitoring method for a treatment system including a methane fermentation tank that performs methane fermentation treatment on a treatment object containing an organic substance, and a membrane module that performs membrane separation on the treatment liquid generated in the methane fermentation tank to obtain a concentrated liquid and a permeate. The method is characterized by including a monitoring step of providing a monitoring cell equipped with a membrane element having the same performance as the membrane element forming the membrane module in the treatment system, and monitoring the state of the membrane element from the permeate side through the monitoring cell. According to this monitoring method for the treatment system, in a treatment system that performs methane fermentation treatment and membrane separation, by providing a monitoring cell equipped with a monitoring membrane (a membrane element having the same performance as the membrane element forming the membrane module) separately from the membrane module used for membrane separation treatment, the membrane module and the monitoring membrane can be placed in the same treatment environment. As a result, monitoring of the monitoring membrane corresponds to monitoring of the membrane module in the treatment environment, so there is no need to directly monitor the membrane module itself. Therefore, it is possible to perform monitoring in a form that does not affect the membrane separation treatment by the membrane module. In addition, by performing monitoring from the permeate side of the monitoring membrane, the membrane surface, which is originally in an environment not directly in contact with the solid content in the treatment liquid, becomes the monitoring target. As a result, changes in the membrane surface due to membrane clogging or deterioration can be captured without being affected by the adhesion or deposition of solid content. Therefore, it is possible to easily and accurately grasp the state of the membrane module.

Effects of the Invention

[0017] According to the present invention, in a treatment system that performs methane fermentation treatment by a methane fermentation tank and membrane separation by a membrane module as a treatment of a treatment object containing an organic substance, it is possible to monitor the state of the membrane module in the treatment environment in a form that does not affect the membrane separation treatment, and it is possible to easily and accurately grasp the state of the membrane module. A treatment system, a monitoring cell provided in the treatment system, and a monitoring method for the treatment system can be provided.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0019] The processing system of the present invention is a processing system for processing a processing target containing an organic substance, and particularly relates to a membrane separation methane fermentation process combining a methane fermentation process and a membrane separation process. And the processing system of the present invention monitors the state of the membrane module used for the membrane separation process in the processing environment and in a form that does not affect the membrane separation process, and can simply and accurately grasp the state of the membrane module.

[0020] Further, the monitoring cell and the monitoring method of the processing system of the present invention relate to the monitoring of the membrane module in the processing system of the present invention.

[0021] Examples of the processing target in the present invention include, for example, organic wastewater containing solids such as food waste, grass and trees, sludge, etc., as well as organic waste liquids and organic wastes such as livestock manure and excess sludge. In addition, the processing target in the present invention is not limited to this, and any substance containing an organic substance capable of undergoing methane fermentation treatment under anaerobic conditions can be the processing target of the present invention.

[0022] Hereinafter, embodiments of the processing system, monitoring cell, and monitoring method of the processing system according to the present invention will be described in detail with reference to the drawings. In addition, the description of the monitoring method of the processing system according to the present invention shall be replaced with the description of the configuration and operation of the processing system and monitoring cell according to the present invention. Note that the processing system and monitoring cell described in the embodiments are merely examples for explaining the processing system and monitoring cell according to the present invention, and are not limited thereto. In addition, the monitoring method of the processing system of the present embodiment is merely an example for explaining the following monitoring method related to the processing system, and is not limited thereto.

[0023] 〔First Embodiment〕 [Processing System] FIG. 1 is a schematic explanatory diagram showing the structure of the processing system in the first embodiment of the present invention. FIG. 2 is a schematic explanatory diagram related to the structure of the monitoring cell in the processing system of the present embodiment. Note that FIG. 2 is an enlarged view of the vicinity of the monitoring cell in FIG. 1, and the structures related to the methane fermentation tank 1, and the membrane modules 2a and 2b are not shown.

[0024] The processing system 100A according to the first embodiment of the present invention performs methane fermentation treatment and membrane separation treatment on the object to be processed S. As shown in FIG. 1, a methane fermentation tank 1 that performs methane fermentation treatment on the object to be processed S supplied through line L1, a membrane module 2 that performs membrane separation on the treatment liquid W generated in the methane fermentation tank 1 to obtain a concentrated liquid F1 and a permeate F2, and a circulation pump 3 that feeds the treatment liquid W to the membrane module 2 and returns the concentrated liquid F1 to the methane fermentation tank 1. In addition, as shown in FIGS. 1 and 2, the processing system 100A according to the present embodiment includes a monitoring cell 4A. As will be described later, the monitoring cell 4A includes a membrane element 40 having the same performance as the membrane element forming the membrane module 2.

[0025] Note that the processing system 100A according to this embodiment may be provided with facilities other than the configuration shown in FIG. 1. For example, a concentration tank for concentrating the object S to be processed, a solubilization tank for solubilizing the object S to be processed, an adjustment tank for adjusting the supply amount of the object S to be supplied to the methane fermentation tank 1, etc. may be provided in the stage before the methane fermentation tank 1. Further, a water treatment facility for treating the permeate F2 may be provided in the stage after the membrane module 2. Further, a biogas utilization facility including a desulfurization device and a gas storage tank for recovering the biogas (methane gas) generated from the methane fermentation tank 1 via the line L2 and using this biogas may be provided.

[0026] Based on FIG. 1, an overview of the treatment of the object to be treated by the treatment system 100A in this embodiment will be described. First, the object S to be treated is supplied to the methane fermentation tank 1 via the line L1. Then, a methane fermentation treatment is performed on the object S to be treated in the methane fermentation tank 1. Then, the object S treated in the methane fermentation tank 1 becomes the treatment liquid W and is sent to the membrane module 2 side. At this time, via the circulation pump 3 and the pipes 31a to 31d, 32a to 32c, the treatment liquid W is membrane-separated through a plurality of membrane modules 2 to obtain a concentrated liquid F1 and a permeate F2. The permeate F2 is discharged outside the system, while the concentrated liquid F1 is returned to the methane fermentation tank 1. The above is the flow related to the membrane separation methane fermentation treatment in the treatment system 100A in this embodiment.

[0027] And in the processing system 100A in this embodiment, a monitoring cell 4A is provided to grasp the state of the membrane module 2 used for membrane separation. As shown in FIG. 2, this monitoring cell 4A is equipped with a membrane element 40 having the same performance as the membrane element forming the membrane module 2 used for membrane separation processing. Further, as shown in FIG. 1, the monitoring cell 4A is provided in parallel with one of the membrane modules 2 (membrane module 2c in FIG. 1). As a result, the membrane element 40 in the monitoring cell 4A is placed in the same processing environment as the membrane module 2 (membrane module 2c). That is, since monitoring of the membrane element 40 in the monitoring cell 4A corresponds to monitoring of the membrane module 2 in the processing environment, it is not necessary to directly monitor the membrane module 2 itself. Therefore, it becomes possible to perform monitoring in a form that does not affect the membrane separation processing by the membrane module 2.

[0028] Hereinafter, each component in the processing system 100A of this embodiment will be described.

[0029] (Methane fermentation tank) The methane fermentation tank 1 is a processing tank for subjecting the object to be processed S to methane fermentation treatment by anaerobic microorganisms (methanogens). It is preferably a sealed container to maintain anaerobism, and other specific structures are not particularly limited. As the structure of the methane fermentation tank 1, for example, it is preferably selected as appropriate according to the object to be processed S. More specifically, the structure of a processing tank used for anaerobic treatment of organic wastewater or organic waste liquid containing a large amount of liquid components, the structure of a processing tank used for anaerobic treatment of organic waste containing a large amount of solid components, etc. can be appropriately selected and used. The treatment system 100A of this embodiment supplies the treatment liquid W generated in the methanogenic digester 1 to the membrane module 2 for membrane separation. Therefore, when methanogenic fermentation treatment using granules is performed in the methanogenic digester 1, solids with a large particle diameter such as granules are mixed into the treatment liquid W generated in the methanogenic digester 1, which may cause the blockage of the membrane module 2 arranged in the subsequent stage of the methanogenic digester 1 to progress. Therefore, it is preferable to use the methanogenic digester 1 in this embodiment having a structure known as a completely mixed methanogenic digester to perform methanogenic fermentation treatment.

[0030] In the methanogenic digester 1 of this embodiment, it is preferable to provide stirring means 10 for stirring the inside. As a specific configuration of the stirring means 10, for example, as shown in FIG. 1, in addition to the stirrer 11 including the stirring blades 11a and the drive unit 11b installed on the rotating shaft, those composed of a stirring pump for circulating the treatment liquid W in the methanogenic digester 1 and a circulation pipe can be mentioned.

[0031] The specific structure of the methanogenic digester 1 is not particularly limited, and examples include cylindrical, prismatic, tortoise shell-shaped, abacus ball-shaped, oval-shaped, etc. Note that as an example of the structure of the methanogenic digester 1, it is preferable to have an inclination at the bottom of the methanogenic digester 1. This facilitates the recovery of solid residue and also improves the stirring efficiency at the bottom of the methanogenic digester 1. In addition, as an example of other structures related to the methanogenic digester 1, for example, those further provided with an internal structure for increasing the stirring efficiency by the stirring means 10 can be mentioned.

[0032] The object S to be treated treated in the methanogenic digester 1 of this embodiment is sent as the treatment liquid W to the membrane module 2.

[0033] (Membrane module) The membrane module 2 performs solid-liquid separation (membrane separation) on the treatment liquid W generated in the methanogenic digester 1 to obtain a concentrated liquid F1 and a permeate F2. Also, the number of the membrane modules 2 in the present embodiment is not particularly limited. For example, as shown in FIG. 1, a plurality of membrane modules 2a, 2b, 2c may be arranged in series, and by sequentially supplying the concentrated liquid F1 to the membrane modules 2, the concentration rate of the solid content (methanogenic sludge) in the treatment liquid W can be increased. Note that the arrangement (array) of the membrane modules 2 is also not particularly limited. For example, an array may be formed by connecting a plurality of membrane modules 2 in parallel, or a unit may be formed by connecting a plurality of membrane modules 2 in series, and an array may be formed by connecting a plurality of these units in parallel.

[0034] Also, as shown in FIG. 1, the concentrated liquid F1 is returned to the methanogenic reactor 1 via the circulation pump 3 and the pipes 31a to 31d. On the other hand, the permeate F2 is discharged to the outside of the system via the pipes 32a to 32c. As described above, the permeate F2 discharged to the outside of the system may be further treated by other water treatment facilities.

[0035] Here, the treatment liquid W fed to the membrane module 2 contains anaerobic microorganisms (methanogens) in the methanogenic reactor 1. That is, when the treatment liquid W is discharged from the methanogenic reactor 1 and fed to the membrane module 2, the anaerobic microorganisms (methanogens) are also discharged from the methanogenic reactor 1. On the other hand, as shown in FIG. 1, in the treatment system 100A in the present embodiment, a plurality of membrane modules 2a, 2b, 2c are provided, and the treatment liquid W is circulated via the circulation pump 3 and the pipes 31a to 31d and returned to the methanogenic reactor 1 as the concentrated liquid F1, so that the anaerobic microorganisms (methanogens) flowing out of the methanogenic reactor 1 are recovered as the concentrated liquid F1 and returned to the methanogenic reactor 1. Thereby, it is possible to suppress the outflow of anaerobic microorganisms from the methanogenic reactor 1 and maintain the concentration of anaerobic microorganisms in the methanogenic reactor 1.

[0036] As the membrane module 2, any module can be used as long as it can perform membrane separation of the treatment liquid W to obtain a concentrated liquid F1 containing a large amount of solid matter (methanogenic sludge) containing anaerobic microorganisms (methanogens) and a permeate F2 from which the solid matter has been removed. Specific examples of the membrane module 2 include a tubular type, a hollow fiber type, a spiral type, an immersion flat membrane, and the like. As the membrane module 2 in the present embodiment, as shown in FIG. 1, it is preferable to use a so-called tank external type provided outside the methanogenic tank 1. Moreover, it is particularly preferable to use a tubular type as the membrane module 2. Membrane separation by a so-called cross-flow method can be performed, in which the linear velocity of the membrane surface is increased to cause turbulent flow near the membrane surface and reversible fouling is suppressed. In addition, in the tubular type, it is known that the flow path through which the treatment liquid W passes is larger than those of the hollow fiber type and the spiral type. Therefore, even if the physical properties of the treatment liquid W to be fed, such as the SS concentration and viscosity, are high, there is an advantage that the membrane module 2 is less likely to be blocked.

[0037] As the membrane module 2 in the present embodiment, as shown in FIG. 2, an example is one including a plurality of tubular membrane elements 20. Here, the membrane element 20 refers to an object in which a membrane such as a UF membrane is integrated with a support, and the membrane module 2 refers to an aggregate of the membrane elements 20. Moreover, the membrane element 20 in the present embodiment preferably includes a UF membrane and an MF membrane in view of the size of the solid matter (methanogenic sludge) in the treatment liquid W. This enables the membrane module 2 to be repeatedly used, and also facilitates maintenance work.

[0038] Note that a separate line for backwashing may be provided for the membrane module 2 (not shown). Also, the conditions (such as the chemicals used) for backwashing may be determined based on the monitoring results by the monitoring cell 4 described later.

[0039] (Circulation pump) The circulation pump 3 is for sending the treatment liquid W generated in the methane fermentation tank 1 to the membrane module 2 and returning the concentrated liquid F1 to the methane fermentation tank 1. As a result, the anaerobic microorganisms (methanogens) contained in the treatment liquid W discharged from the methane fermentation tank 1 are returned to the methane fermentation tank 1 as the concentrated liquid F1, so that the outflow of anaerobic microorganisms in the methane fermentation tank 1 can be suppressed. In addition, in FIG. 1, the circulation pump 3 sends the treatment liquid W generated in the methane fermentation tank 1 to the membrane module 2 (membrane module 2a) via the pipe 31a, and passes the concentrated liquid F1 through the membrane modules 2 (membrane modules 2b and 2c) sequentially via the pipes 31b to 31d and returns it to the methane fermentation tank 1.

[0040] (Monitoring cell) The monitoring cell 4A is for monitoring the state of the membrane module 2. As shown in FIGS. 1 and 2, the monitoring cell 4A in the present embodiment does not directly monitor the membrane module 2, but includes a membrane element 40 having the same performance as the membrane element 20 forming the membrane module 2 in the monitoring cell 4A, and monitors this membrane element 40. Also, as shown in FIG. 1, the monitoring cell 4A is provided in parallel with the membrane module 2 (membrane module 2c), and the same treatment liquid W (concentrated liquid F1 from the membrane module 2b) is supplied to the monitoring cell 4A and the membrane module 2c via the pipe 31c. As a result, monitoring of the membrane element 40 provided in the monitoring cell 4A corresponds to monitoring of the membrane module 2 in the treatment environment, so there is no need to directly monitor the membrane module 2 itself. Therefore, it is possible to perform monitoring in a form that does not affect the membrane separation treatment by the membrane module 2.

[0041] Further, as shown in FIG. 2, the monitoring cell 4A performs monitoring from the permeate side of the membrane element 40. Thereby, the membrane surface that is originally in an environment not directly in contact with the solid content in the treatment liquid W can be made the monitoring target. Therefore, it is possible to detect changes in the membrane surface due to blockage or deterioration of the membrane element 40 without being affected by adhesion or deposition of solid content, etc., and at the same time, it is possible to accurately grasp the tendency related to blockage or deterioration of the membrane module 2 etc.

[0042] The monitoring cell 4A may be arranged so as to be able to indirectly monitor the state of the membrane module 2, and the location where the monitoring cell 4A is arranged is not particularly limited. However, as shown in FIGS. 1 and 2, when the membrane module 2 arranges a plurality of membrane modules 2a, 2b, 2c in series, it is preferable to provide the monitoring cell 4A in parallel with respect to the membrane module 2c corresponding to the most downstream. Thereby, it is possible to monitor the membrane module 2c at the location where the solid content in the treatment liquid W is the largest and the load in the membrane module 2 is the largest, and it is possible to take appropriate measures before the entire membrane module 2 becomes blocked or deteriorated. Further, this makes it possible to reduce the influence on the treatment system 100A.

[0043] Based on FIG. 2, an example of the structure related to the monitoring cell 4A and its vicinity will be described in detail. As shown in FIG. 2, the monitoring cell 4A is provided with a membrane element 40 inside, and the treatment liquid W (the concentrated liquid F1 from the membrane module 2b) is supplied via a pipe 41a branched from the pipe 31c, and the concentrated liquid F1 and the permeate F2 are discharged outside the monitoring cell 4A via the pipes 41b and 41c. At this time, as shown in FIG. 2, the concentrated liquid F1 and the permeate F2 discharged from the monitoring cell 4A are connected to the pipes 41b and 41c so as to be introduced into the line (pipe 31d) of the concentrated liquid F1 and the line (pipe 32c) of the permeate F2 discharged by membrane separation by the membrane module 2c, respectively. However, it is not limited to this. For example, connecting the pipe 41b to the methane fermentation tank 1 or directly connecting the pipe 41c to other water treatment facilities etc. can be mentioned. Note that, as shown in FIG. 2, the pipes 41a to 41c may each be provided with on-off valves V1 to V3 so that the monitoring cell 4A can be disconnected from the processing flow of the processing system 100A.

[0044] In the monitoring cell 4A, the structure for performing monitoring from the permeate side of the membrane element 40 and the means related to monitoring are not particularly limited. For example, as the membrane element 40 provided in the monitoring cell 4A, in order to directly monitor the surface of the membrane element 40, the support (outer jacket tube) constituting the membrane element 40 may be made of a transparent member. At this time, similar to the membrane module 2, the membrane element 40 is of a tubular type. As shown in FIG. 2, the treatment liquid W is supplied to the inside of the tubular membrane element 40 through the pipe 41a for membrane separation. The concentrated liquid F1 is discharged from the inside of the membrane element 40, and the permeate F2 is discharged to the outside of the membrane element 40. Such a structure is preferable. Thereby, it becomes possible to easily perform monitoring from the permeate side of the membrane element 40. In addition, the monitoring cell 4A itself in which the membrane element 40 is disposed may also be made of a transparent member so as to enable monitoring from the outside of the monitoring cell 4A.

[0045] The means related to monitoring of the monitoring cell 4A may be any means that can monitor the surface state of the membrane element 40 and is not particularly limited. For example, as shown in FIG. 2, it is preferable to provide monitoring means 42 that can monitor the change in the color of the surface of the membrane element 40.

[0046] In the processing system 100A according to this embodiment, the processing liquid W generated in the methane fermentation tank 1 contains fine solids (methane fermentation sludge), and these solids are generally colored. Therefore, as the membrane element 40 becomes clogged or deteriorated, the colored solids enter the inside of the membrane, causing the color of the membrane surface on the permeate side to change. Therefore, by monitoring the change in the color of the surface of the membrane element 40 with the monitoring means 42, it becomes possible to easily and highly accurately grasp the state of the membrane element 40.

[0047] Examples of the monitoring means 42 include image acquisition devices such as cameras and videos, as well as sensors such as color discrimination sensors. As a result, it becomes possible to acquire and store information related to the surface state of the membrane element 40 as data, and by performing accumulation and comparison operations on this data, it becomes possible to further improve the accuracy of grasping and judging the state of the membrane element 40, that is, the state of the membrane module 2. Here, as an example of the comparison operation using the information related to the surface state of the membrane element 40 accumulated as data, it is possible to obtain the change in the surface color over time, the change compared to the color of the surface of a new membrane element 40, and the change compared to the color when it is determined that membrane separation is being performed normally based on the operating state of the processing system 100A.

[0048] Note that the configuration related to the monitoring cell 4A can be made independent as the monitoring cell according to the present invention. This monitoring cell can be applied to an existing processing system, particularly a processing system including a methane fermentation tank for methane fermentation treatment of a treatment object containing an organic substance, and a membrane module for membrane-separating the processing liquid generated in the methane fermentation tank to obtain a concentrated liquid and a permeate liquid. As a result, without updating the entire processing system, the processing system and the processing system monitoring method of the present invention can be provided by a simple attachment operation.

[0049] As described above, with the monitoring cell 4A and the monitoring means 42 in the present embodiment, the state of the membrane element 40 incorporated in the processing system 100A can be grasped simply and with high accuracy. That is, it becomes possible to simply and accurately grasp the state of the membrane module 2 in the processing environment. And based on the state of the membrane module 2 grasped by the monitoring cell 4A and the monitoring means 42, it becomes possible to appropriately determine and execute the content of the maintenance work (cleaning or membrane replacement), the frequency and timing of the maintenance.

[0050] When cleaning is performed as maintenance for the membrane module 2, it may be possible to obtain information about effective cleaning using the monitoring cell 4A. For example, in the processing system 100A shown in FIGS. 1 and 2, with all the on-off valves V1 to V3 closed and the monitoring cell 4A separated from the processing system 100A, a cleaning chemical solution is introduced into the monitoring cell 4A via the lines L3 and L4, immersed for a certain period of time, the cleaning chemical solution is discharged, and data related to the surface of the membrane element 40 is acquired by the monitoring means 42. Thereby, it becomes possible to obtain information about cleaning with the cleaning chemical solution and to evaluate the cleaning effect. Also, based on this evaluation, it becomes possible to obtain useful information regarding the determination of the cleaning chemical solution for effective cleaning of the membrane module 2 and other conditions related to effective cleaning of the membrane module 2.

[0051] 〔Second Embodiment〕 FIG. 3 is a schematic explanatory diagram showing the structure of a monitoring cell in a processing system according to a second embodiment of the present invention. The processing system 100B in the second embodiment of the present invention is a monitoring cell 4B having a permeate discharge section 43 for discharging the permeate, instead of the monitoring cell 4A in the first embodiment. Among the configurations of the processing system 100B in the present embodiment, for those that are the same as the configurations of the processing system 100A in the first embodiment, part of the description and illustration are omitted.

[0052] The monitoring cell 4B in this embodiment has a permeate discharge section 43 for discharging the permeate F2 discharged from the membrane element 40 from the monitoring cell 4B. Depending on the type of the treatment liquid W, the permeate F2 obtained by membrane separation may be colored. In this case, the permeate F2 itself becomes a disturbance in the monitoring, making it difficult to perform monitoring by the monitoring means 42 or the like from outside the monitoring cell 4B. Therefore, in the monitoring cell 4B of this embodiment, by discharging the permeate F2 through the permeate discharge section 43, it becomes possible to monitor the membrane element 40 in a state where the influence of the disturbance is suppressed. As a result, regardless of the properties of the permeate F2, it becomes possible to easily and highly accurately grasp the state of the membrane element 40.

[0053] As the permeate discharge section 43, as shown in FIG. 3, examples include connecting a pipe 43a provided with a drain valve V4 and a pipe 43b provided with an open valve V5 to the monitoring cell 4B. Thereby, by opening both the drain valve V4 and the open valve V5, the permeate F2 in the monitoring cell 4B can be quickly discharged. Note that the timing for operating the permeate discharge section 43 is not particularly limited. For example, the permeate discharge section 43 may be operated periodically for monitoring, or may be operated constantly for monitoring. Moreover, as the permeate discharge section 43, any means can be used as long as it can discharge the permeate F2 in the monitoring cell 4B. For example, the pipe 43b provided with the open valve V5 may be connected to the pipe 41c.

[0054] When discharging the permeate F2 in the monitoring cell 4B by the permeate discharge section 43, monitoring related to the surface of the membrane element 40 can be executed by a simple means. In this case, it is desirable to stop the supply of the treatment liquid W to the monitoring cell 4B.

[0055] On the other hand, as another aspect of the monitoring cell 4B in this embodiment, in addition to the permeate discharge section 43, a replacement water supply section 44 for replacing the permeate with water (pure water) may be provided. FIG. 4 is a schematic explanatory diagram showing another aspect of the monitoring cell 4B in the present embodiment. As shown in FIG. 4, examples of the replacement water supply unit 44 include those provided with a water storage tank 44a, a pipe 44b, and a water supply valve V6. Further, as shown in FIG. 4, at this time, as the permeate discharge unit 43, while connecting a pipe 43a provided with a drain valve V4 to the monitoring cell 4B, a pipe 43b provided with an open valve V5 is connected to the pipe 41c. By opening both the drain valve V4 and the open valve V5, the permeate F2 in the monitoring cell 4B can be quickly discharged, and the replacement water (pure water) in the water storage tank 44a can be supplied to the monitoring cell 4B through the water storage tank 44a, the pipe 44b, and the water supply valve V6. As a result, since the inside of the monitoring cell 4B is replaced with transparent water (pure water), continuous monitoring can be performed without being affected by the disturbance caused by the permeate F2 and without stopping the supply of the treatment liquid W to the monitoring cell 4B. Note that the replacement water supply unit 44 may be integrated with the configuration of the permeate discharge unit 43. For example, instead of providing the pipe 44b and the water supply valve V6, a water storage tank 44a may be provided for the pipe 43b provided with the open valve V5 connected to the monitoring cell 4B, and by opening the open valve V5 and the drain valve V4, the discharge of the permeate and the supply of the replacement water may be performed simultaneously.

[0056] 〔Third Embodiment〕 FIG. 5 is a schematic explanatory diagram showing the structure of a monitoring cell in a treatment system according to the third embodiment of the present invention. The treatment system 100C in the third embodiment of the present invention uses a monitoring cell 4C having a load applying means 45 for applying a treatment load to the membrane element 40 instead of the monitoring cell 4A in the first embodiment. Among the configurations of the treatment system 100C in the present embodiment, for those having the same configuration as the treatment system 100A in the first embodiment, some of the descriptions and illustrations are omitted.

[0057] The monitoring cell 4C in this embodiment is in a state where a processing load is applied thereto by the load applying means 45, which is greater than that on the membrane module 2 (membrane module 2c in FIG. 5). Thereby, the state change of the membrane in the membrane element 40 occurs earlier than in the membrane module 2, and the signs of blockage and deterioration in the membrane module 2 can be predicted at an early stage, enabling early countermeasures.

[0058] As the load applying means 45, as shown in FIG. 5, a flow rate adjusting mechanism 45a is provided on the pipe for supplying the processing liquid W to the monitoring cell 4C, and it is supplied at a flow rate smaller than the flow rate per one of the membrane elements 20. Also, the load applying means 45 is not limited to those that separately provide a mechanism for applying a load, such as the flow rate adjusting mechanism 45a. Another example of the load applying means 45 includes arranging the monitoring cell 4C with respect to the location where the solid content in the processing liquid W is the highest (the most downstream membrane module 2c in FIG. 5), or arranging the monitoring cell 4C with respect to the location where the pressure (water pressure) in the supply of the processing liquid W is the highest. Furthermore, as the load applying means 45, in addition to providing a mechanism for applying a load such as the flow rate adjusting mechanism 45a, the arrangement setting of the monitoring cell 4C may be performed.

[0059] Note that the above-described embodiment shows an example of a processing system, a monitoring cell, and a method for monitoring a processing system. The processing system, monitoring cell, and method for monitoring a processing system according to the present invention are not limited to the above-described embodiment, and the processing system, monitoring cell, and method for monitoring a processing system according to the above-described embodiment may be modified without changing the gist described in the claims.

Industrial Applicability

[0060] The processing system of the present invention is used for the treatment of objects to be treated containing organic substances, such as organic waste liquids and organic wastes. In particular, it is suitably used for the treatment related to methane fermentation treatment and membrane separation methane fermentation treatment by membrane separation. In addition, the monitoring method of the monitoring cell and the processing system of the present invention is preferably used in the monitoring of a processing system related to methane fermentation treatment and membrane separation methane fermentation treatment by membrane separation.

Explanation of Signs

[0061] 100A, 100B, 100C Processing systems, 1 Methane fermentation tank, 10 Stirring means, 11 Stirrer, 11a Stirring blades, 11b Driving part, 2, 2a, 2b, 2c Membrane modules, 20 Membrane elements, 3 Circulation pump, 31a to 31d Pipes, 32a to 32c Pipes, 4A, 4B, 4C Monitoring cells, 40 Membrane elements, 41a to 41c Pipes, 42 Monitoring means, 43 Permeate discharge part, 43a, 43b Pipes, 44 Replacement water supply part, 44a Water storage tank, 44b Pipe, 45 Loading means, 45a Flow rate adjustment mechanism, F1 Concentrate, F2 Permeate, L1 to L4 Lines, S Object to be processed, V1 to V6 Valves, W Processing liquid

Claims

1. A treatment system for treating a treatment object containing an organic substance, comprising: An anaerobic digester for subjecting the treatment object to anaerobic digestion; A membrane module for membrane-separating the treatment liquid generated in the anaerobic digester to obtain a concentrated liquid and a permeate; A monitoring cell having a membrane element with the same performance as the membrane element forming the membrane module, and monitoring the state of the membrane element from the permeate side; A treatment system, comprising a load applying means for applying a treatment load to the membrane element of the monitoring cell.

2. The treatment system according to claim 1, wherein the monitoring cell comprises monitoring means for monitoring a change in the color of the surface of the membrane element.

3. The treatment system according to claim 1 or 2, wherein the monitoring cell comprises a permeate discharge section for discharging the permeate in the monitoring cell.

4. An anaerobic digester for subjecting a treatment object containing an organic substance to anaerobic digestion; A monitoring cell provided for a treatment system comprising a membrane module for membrane-separating the treatment liquid generated in the anaerobic digester to obtain a concentrated liquid and a permeate, the monitoring cell comprising: A membrane element having the same performance as the membrane element forming the membrane module in the treatment system; A load applying means for applying a treatment load to the membrane element; A monitoring cell, characterized in that the state of the membrane element is monitored from the permeate side.

5. An anaerobic digester for subjecting a treatment object containing an organic substance to anaerobic digestion; A monitoring method for a treatment system comprising a membrane module for membrane-separating the treatment liquid generated in the anaerobic digester to obtain a concentrated liquid and a permeate, the method comprising: Providing a monitoring cell having a membrane element with the same performance as the membrane element forming the membrane module in the treatment system; A monitoring step of monitoring the state of the membrane element from the permeate side through the monitoring cell; A load applying step of applying a treatment load to the membrane element of the monitoring cell, the monitoring method for the treatment system being characterized by including the above steps.

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