KR101870598B1 - Biological treatment apparatus, biological treatment method, and program - Google Patents

Abstract

The present invention provides a biological treatment device capable of stably obtaining a flow rate of permeated water even when fouling proceeds in a tubular filter, a biological treatment method, and a program for the same. The biological treatment device (100) has: a biological treatment water tank (11); a filter separating device (1) having the tubular filter with a single-layered structure in which a hydrophilic monomer is copolymerized; a pressing pump (21) supplying supply water (W3) to the filter separating device (1); a suction pump (22) sucking the permeated water (PW) from the filter separating device (1); a back pressure adjusting device (23) adjusting the back pressure of a permeation side space; a transmembrane pressure measuring device (14) measuring the transmembrane pressure; and a control device (13) controlling the pressing pump (21), the suction pump (22), and the back pressure adjusting device (14) based on the transmembrane pressure. The control device (13) has: a back pressure adjusting unit (13a) reducing the back pressure when the transmembrane pressure is increased to a predetermined value or greater; and a setting change unit (13b) increasing the back pressure and increasing one side of a suction force of the suction pump and a pressing force of the pressing pump by controlling one side of the suction pump and the pressing pump in a case of reaching a limit of an adjusting range of the back pressure adjusting device.

Description

TECHNICAL FIELD [0001] The present invention relates to a biological treatment apparatus, a biological treatment method,

The present invention relates to a biological treatment apparatus, a biological treatment method, and a program.

In the case of treating organic wastewater such as manure, it is the mainstream to use membrane separation such as MF (microfiltration) and UF (ultrafiltration) for the liquid separation.

As a membrane separation device, there is known a device comprising a casing and a plurality of tubular filtration membranes (hollow fiber membranes) housed in a casing, and filtering the feed water while circulating the feed water to the inside of the tubular filtration membranes (see, for example, Patent Document 1 Reference). In a biological treatment apparatus provided with such a membrane separation device for biological treatment of organic wastewater, permeated water permeating the tubular filtration membrane is sucked by a suction pump and stored in, for example, a storage tank and suitably used.

Japanese Laid-Open Patent Publication No. 2013-052338

By the way, in the membrane separation apparatus using the tubular filtration membrane, the filtration is continued, and the fouling in which the fine particles adhere to the membrane surface proceeds. In the conventional biological treatment apparatus, since the flow rate of the permeated water decreases as the fouling proceeds, there is a problem that it is difficult to stably secure the flow rate of the permeated water.

It is an object of the present invention to provide a biological treatment apparatus, a biological treatment method, and a program that can stably ensure the flow rate of permeated water even when fouling proceeds on the tubular filtration membrane.

According to a first aspect of the present invention, there is provided a biological treatment apparatus comprising: a biological treatment water tank for treating an organic matter contained in water to be treated; a casing; a concentrated side space to which the supply water flowing out from the biological treatment water tank is supplied; A membrane separation device having a tubular filtration membrane having a single-layer structure in which hydrophilic monomers are copolymerized and partitioned into a permeation-side space in which permeate water separated from the feed water is contained; a pressurizing pump , A suction pump for sucking the permeated water from the permeable side space, a back pressure regulating device for regulating the back pressure of the permeable side space, and a return line for conveying the concentrated water discharged from the membrane separation device to the biological treatment water tank An inter-membrane pressure difference measuring device for measuring a pressure difference between the enriched space and the permeable space; Wherein the control device controls the back pressure regulator to decrease the back pressure when the inter-membrane pressure difference is increased to a predetermined value or more, And at least one of the pressurizing pump and the suction pump is controlled to increase at least one of a pressing force of the pressurizing pump and a suction force of the suction pump when reaching the limit of the adjustment range of the back pressure regulating device And a setting changing unit for controlling the back pressure adjusting device to increase the back pressure.

According to such a configuration, the flow rate of the permeated water can be adjusted by using the movable range of the back pressure regulating device even when the inter-membrane pressure difference is increased by fouling by reducing the back pressure of the tubular filtration membrane based on the inter-membrane pressure differential.

When the upper limit of the operating range of the back pressure regulating device is reached, at least one of the pressing force and the suction force is increased and the back pressure is increased, so that the flow rate of the permeated water can be adjusted again using the operating range of the back pressure regulating device.

In addition, since the tubular filtration membrane has hydrophilicity, the flow velocity of the feed water supplied to the concentrated side space is low, and even when the pressure of the feed water is low, permeated water can be taken.

In the biological treatment apparatus, the setting change unit may perform control to increase the suction force of the suction pump after increasing the pressing force of the pressure pump to the upper limit.

According to such a configuration, the pressing force of the pressurizing pump is increased to increase the flow velocity on the membrane surface, so that the cleaning effect of the tubular filtration membrane can be generated.

In the biological treatment apparatus, the control apparatus may have a cleaning control section for increasing the suction force of the suction pump to control the tubular filtration membrane to the upper limit, and then cleaning the tubular filtration membrane.

According to such a constitution, by performing the cleaning of the tubular filtration film, the pressing force and the suction force can be reduced again. In addition, by performing cleaning after controlling both the pressing force and the suction force to the upper limit, the number of times of cleaning can be reduced.

The biological treatment apparatus according to any one of the preceding claims, wherein the return line includes: a branch line for supplying the concentrated water between the biological treatment water tank and the membrane separation device; and a circulation line formed on the downstream side of the branch line, And a second flow rate adjusting valve for adjusting the flow rate of the fluid.

According to this configuration, the flow rate of the concentrated water to be introduced into the biological treatment water tank can be adjusted.

According to a second aspect of the present invention, there is provided a biological treatment method comprising: a pressurizing step of pressurizing and supplying supply water flowing out from a biological treatment water tank to a concentrated side space on one side of a tubular filtration membrane having a monolayer structure in which a hydrophilic monomer is copolymerized; A condensing water discharge port for discharging the concentrated water discharged from the concentrated-side space to the biological treatment water tank; a suction step of sucking the permeated water from the permeated side space on the other side of the tubular filtration membrane; A back pressure adjusting step of reducing a back pressure of the permeated space when the inter-membrane pressure difference of the permeated water increases to a predetermined value or more; And a setting changing step of increasing the back pressure.

According to a third aspect of the present invention, there is provided a biological treatment apparatus comprising: a biological treatment water tank for treating organic matters contained in water to be treated; a casing; a concentrated side space to which the supply water flowing out from the biological treatment water tank is supplied, A membrane separation device having a tubular filtration membrane having a single-layer structure in which hydrophilic monomers are copolymerized and partitioned into permeation-side spaces in which permeated water separated from water is received; a pressurizing pump for supplying the feed water to the enriched space; A return line for returning the concentrated water discharged from the membrane separation device to the biological treatment water tank; and a supply line for supplying the concentrated water discharged from the membrane separation device to the biological treatment water tank, And an inter-membrane pressure difference measuring device for measuring a pressure difference between the thickening-side space and the permeation-side space, When the inter-film pressure difference has increased to a predetermined value or more, the back pressure control device controls the back pressure adjusting device to reduce the back pressure, and when reaching the limit of the adjustment range of the back pressure adjusting device, And at least one of the pressure of the pressurizing pump and the suction force of the suction pump is increased and the back pressure is increased by controlling the back pressure regulating device.

According to the present invention, by reducing the back pressure of the tubular filtration membrane based on the inter-membrane pressure differential, the flow rate of the permeated water can be adjusted using the movable range of the back pressure regulator even when the inter-membrane pressure difference is increased by fouling.

When the upper limit of the operating range of the back pressure regulating device is reached, at least one of the pressing force and the suction force is increased and the back pressure is increased, so that the flow rate of the permeated water can be adjusted again using the operating range of the back pressure regulating device.

1 is a schematic configuration diagram of a biological treatment apparatus according to a first embodiment of the present invention.
2 is a schematic cross-sectional view of the membrane separation apparatus of the first embodiment of the present invention.
3 is a flowchart for explaining control I of the biological treatment method of the first embodiment of the present invention.
4 is a flowchart for explaining control II of the biological treatment method of the first embodiment of the present invention.
5 is a flowchart for explaining control III of the biological processing method according to the first embodiment of the present invention.
6 is a schematic cross-sectional view of a membrane separation apparatus according to a modification of the first embodiment of the present invention.
7 is a schematic perspective view of a membrane separation apparatus according to a second embodiment of the present invention.
8 is a schematic cross-sectional view of a membrane separation apparatus according to a second embodiment of the present invention.
9 is a perspective view of a reinforcing member according to a second embodiment of the present invention.
10 is a side view of the reinforcing member of the second embodiment of the present invention viewed from the axial direction of the reinforcing member.
11 is a perspective view of a reinforcing member according to a third embodiment of the present invention.

[First Embodiment]

Hereinafter, the biological treatment apparatus, biological treatment method, and program according to the first embodiment of the present invention will be described in detail with reference to the drawings.

1, the biological treatment apparatus 100 according to the present embodiment includes a biological treatment water tank 11 for treating organic matter contained in the for-treatment water W1 (organic wastewater containing manure and septic tank sludge) The raw water tank 12 in which the supply water W2 flowing out from the biological treatment water tank 11 is accommodated and the supply water W3 supplied from the raw water tank 12 are passed through the permeated water PW and the concentrated water W4, A first flow rate regulating valve 23 (back pressure regulating device) for regulating the flow rate (flow path resistance) of the permeated water PW and a storage tank for storing the permeated water PW 20, a conveyance line 19 for conveying the concentrated water W4 to the biological treatment water tank 11, and a control device 13.

The control device 13 controls various parts of the biological treatment apparatus 100 to execute various functions. The control device 13 is configured, for example, by a CPU (Central Processing Unit, central processing unit) provided in the biological processing apparatus 100, reading out a program from the storage unit and executing the program.

2, the membrane separation apparatus 1 includes a casing 2 and a casing 2 connected to the other side of the tubular filtration membrane 3 and the concentrated side space S which is one side of the tubular filtration membrane 3, And a tubular filtration membrane (3) partitioning the permeation space (P). Supply water W3 is supplied to the concentrated side space S and permeated water PW separated from the supply water W3 is accommodated in the permeation side space P. [

The membrane separation device 1 is an apparatus for extracting the permeated water PW from the feed water W3 by using a method of circulating the feed water W3 to the inside of a plurality of tubular filtration membranes 3 and filtering the same.

1, the biological treatment apparatus 100 pressurizes the supply water W3 (supply water W2 flowing out from the biological treatment water tank 11) supplied from the raw water tank 12, And a suction pump 22 for sucking the permeation-side space P of the membrane separation device 1. The suction pump 22 sucks the permeation space P of the membrane separation device 1,

The pressurizing pump 21 has a function of changing the pressing force by the rotation speed control to change the flow velocity on the film surface (the velocity at which the feed water W3 flows inside the tubular filtration film 3). The operating range of the pressurizing pump 21 of the present embodiment is 0.15 m / s to 0.60 m / s in terms of the membrane surface flow velocity. It is not preferable to operate the pressurizing pump 21 out of the movable range in relation to the specification of the tubular filtration film 3 of the present embodiment.

The suction pump 22 has a function of changing the suction force from the transmission-side space P by the rotation speed control. The lower limit frequency of the suction pump 22 of this embodiment is 6 Hz and the upper limit frequency thereof is 60 Hz. Thereby, the suction pump 22 can arbitrarily change the pressure in the permeation-side space P.

The biological treatment water tank 11 decomposes and removes BOD and nitrogen compounds in the liquid by the action of, for example, nitrifying bacteria and denitrifying bacteria. To-treat water (W1) is supplied to the biological treatment water tank (11) through the first line (15). The biological treatment water tank 11 and the raw water tank 12 are connected by a second line 16.

The raw water tank 12 and the membrane separation device 1 are connected via a supply line 17. The pressurizing pump 21 is formed in the supply line 17. The supply water W3 discharged from the raw water tank 12 is supplied to the concentration side space S of the membrane separation apparatus 1 while being pressurized by the pressurization pump 21. [

The supply line 17 is provided with a first flow meter 25 for measuring the flow rate of the supply water W3 flowing through the supply line 17 and a second flow meter 25 for measuring the pressure of the supply water W3 flowing through the supply line 17. [ 1 pressure gauge 26 is formed.

The permeated water PW separated from the membrane separator 1 is introduced into the permeated water line 18. The permeate water line 18 is connected to the storage tank 20. The first flow control valve 23 and the suction pump 22 are formed in the permeated water line 18. The first flow rate adjusting valve 23 of the present embodiment is formed on the downstream side of the suction pump 22, but the present invention is not limited to this. The first flow rate regulating valve 23 may be formed on the upstream side of the suction pump 22.

The first flow rate regulating valve 23 is a back pressure regulating device for regulating the flow path resistance of the permeated water PW flowing through the permeated water line 18 to adjust the back pressure of the permeation side space P of the tubular filtration film 3 Function. For example, by setting the opening degree of the first flow control valve 23 to 20%, the back pressure of the permeation side space P becomes large, and by setting the opening degree of the first flow control valve 23 to 100% The back pressure of the fuel P is reduced. The back pressure of the permeation-side space P can be increased by controlling the opening degree of the first flow regulating valve 23 in the direction to reduce the opening degree. The back pressure of the permeation-side space P can be reduced by controlling the opening degree of the first flow rate regulating valve 23 in the increasing direction.

The permeated water line 18 is provided with a second flow meter 27 for measuring the flow rate of the permeated water PW flowing through the permeated water line 18 and a second flow rate meter 26 for measuring the pressure of the permeated water PW flowing through the permeated water line 18 And a second pressure gauge 28 for measurement is formed.

The concentrated water W4 separated from the permeated water PW and discharged from the membrane separator 1 is introduced into the conveying line 19 except for the excess sludge so that at least a part of the concentrated water W4 is returned to the biological treatment water tank 11 do. The supply water W2 flowing out of the biological treatment water tank 11 is returned to the biological treatment water tank 11 through the raw water tank 12 and the membrane separation apparatus 1. That is, the supply water W2 discharged from the biological treatment water tank 11 circulates through the line constituting the biological treatment apparatus 100. [

A siphon breaker 40 is formed in the conveying line 19. The siphon breaker (40) has a branch pipe (41) and a valve (42).

A third pressure gauge 44 for measuring the pressure of the concentrated water W4 flowing through the transfer line 19 is formed between the membrane separation device 1 and the siphon breaker 40 on the transfer line 19 .

The transfer line 19 has a branch line 45 branched from the middle of the transfer line 19 and supplying the concentrated water W4 to the raw water tank 12. Further, the raw water tank 12 does not necessarily have to be formed. When the raw water tank 12 is not formed, the branch line 45 is connected to the line between the biological treatment water tank 11 and the pressurizing pump 21.

A second flow rate regulating valve 24 for regulating the flow rate of the concentrated water W4 supplied to the biological treatment water tank 11 on the downstream side of the branch point D of the branch line 45 on the return line 19, And a third flow meter 43 for measuring the flow rate of the concentrated water W4 supplied to the biological treatment water tank 11 are formed. The third flow meter 43 is formed on the downstream side of the second flow rate adjusting valve 24 (between the second flow rate adjusting valve 24 and the biological treatment water tank 11).

The pressure gauges 26, 28 and 44 and the flow meters 25, 27 and 43 are connected to the control device 13 via electric signal cables.

The first pressure gauge 26, the second pressure gauge 28 and the third pressure gauge 44 function as an inter-membrane pressure difference measuring device 14 for measuring the inter-membrane pressure difference of the membrane separator 1. The control device 13 compares the pressure of the supply water W3 measured by the first pressure gauge 26 with the pressure of the permeated water PW measured by the second pressure gauge 28 and the pressure of the third pressure gauge 44 ) Of the membrane separation apparatus 1 based on the pressure of the concentrated water W4 measured by the pressure sensor (not shown).

The biological treatment apparatus 100 has a cleaning device 29 that performs cleaning of the tubular filtration film 3 of the membrane separation device 1. The cleaning device 29 may be a device that performs cleaning by physical cleaning, a device that performs cleaning by chemical cleaning, or a device that performs cleaning by both of them.

The physical cleaning is a cleaning method in which cleaning is performed by a physical method such as back pressure cleaning, scrubbing, flushing, ball cleaning, or the like. The chemical cleaning is a cleaning method in which cleaning is performed using an acid, an alkali, an oxidizing agent, a detergent or the like.

The control device 13 controls the pressure pump 21, the suction pump 22, the first flow rate adjusting valve 23, and the second flow rate adjusting valve 23 based on the flow rate of the permeated water PW, the transmembrane pressure difference, The second flow rate adjusting valve 24, the cleaning device 29, and the like. The control device 13 includes a back pressure regulating section 13a for controlling the first flow rate regulating valve 23 (back pressure regulating device) based on the flow rate of the permeated water PW and the inter-membrane pressure difference, A setting change section 13b for changing the setting of the pressurizing pump 21 and the like and a cleaning control section 13c for controlling the cleaning device 29 when the movable range of the adjustment valve 23 reaches the limit have.

The control device 13 has a function of adjusting the flow rate of the concentrated water W4 introduced into the biological treatment water tank 11. [ The control device 13 determines whether the flow rate of the concentrated water W4 to be introduced into the biological treatment water tank 11 is equal to or greater than the flow rate of the concentrated water W4 measured by the third flow meter 43 And controls the second flow rate adjusting valve 24 so as to be equal to or smaller than a predetermined value. As a result, a part of the concentrated water W4 is introduced into the branch line 45.

Next, the details of the membrane separation device 1 will be described.

2, the casing 2 includes a casing main body 4, a supply water inlet port 7 formed below the casing main body 4, and a concentrated water discharge port (not shown) formed above the casing main body 4 8 and a permeated water outlet 9 formed in the casing main body 4.

The casing main body 4 has a cylindrical section 4a having a cylindrical shape and a first conical section 5 closing the upper end of the cylindrical section 4a and a second conical section 4b closing the lower end of the cylindrical section 4a 6). The first conical portion 5 has a gradually decreasing tapered shape as it goes upward. The second conical portion 6 has a tapered shape gradually decreasing in diameter as it goes downward.

The membrane separation apparatus 1 of the present embodiment is configured such that the feed water W3 introduced into the tubular filtration membrane 3 from below flows through the tubular filtration membrane 3 upward.

The membrane separation apparatus 1 has a first partition 30 and a second partition 31 dividing the interior of the casing 2 into three spaces. A plurality of insertion holes 32 are formed in the first partition 30 and the second partition 31. The insertion hole 32 is a hole penetrating in the thickness direction of the first partition 30 and the second partition 31. The inner diameter of the insertion hole 32 is slightly larger than the outer diameter of the tubular filtration film 3.

The plurality of tubular filtration membranes 3 extend in the axial direction A (in the vertical direction in this embodiment) in the casing 2, one end is connected to the first partition 30, And is connected to the partition 31.

The first partition 30 is a plate-shaped member and is fixed above the casing 2 in the extending direction (on the side of the first conical portion 5). The space enclosed by the casing main body 4, the first bank 30, and the first conical portion 5 is the first header space S1. The first header space S1 is a space above the first partition 30 in the internal space of the casing 2. [

The second partition 31 is a plate-shaped member and is fixed below the extending direction of the casing 2 (on the side of the second conical portion 6). The space enclosed by the casing main body 4, the second partition 31 and the second conical portion 6 is the second header space S2. The second header space S2 is a space below the second partition 31 in the internal space of the casing 2. [

The space on the outer peripheral side of the tubular filtration film 3 surrounded by the casing main body 4, the first bank 30 and the second bank 31 is the permeable side space P. The permeated water PW taken out from the plurality of tubular filtration membranes 3 is discharged into the permeated side space P and then introduced into the permeated water line 18 through the permeated water outlet 9.

The feed water inlet port 7 is an opening for communicating the outside of the casing 2 and the second header space S2. The supply water inlet 7 is formed in the second conical portion 6 of the casing main body 4.

The concentrated water outlet 8 is an opening for communicating the outside of the casing 2 and the first header space S1. The concentrated water outlet 8 is formed in the first conical portion 5 of the casing main body 4.

The permeated water outlet 9 is an opening which communicates the outside of the casing 2 and the permeated space P. [ The permeated water outlet 9 is formed in the upper portion of the cylindrical portion 4a of the casing main body 4. [

The concentrated side space S is a space into which the feed water W3 is introduced and has a first header space S1, a filtration membrane space S3 as a space on the inner circumferential side of the tubular filtration membrane 3, (S2).

The permeation-side space P is a space in which the permeated water PW separated from the supply water W3 is accommodated.

One end of each tubular filtration membrane 3 is inserted into the insertion hole 32 of the first partition wall 30 and then fixed to the inner peripheral surface of the insertion hole 32. The inner peripheral surface of the insertion hole 32 and the outer peripheral surface of the tubular filtration membrane 3 are sealed with a sealing material (not shown). As the sealing material, a material such as an epoxy resin or a urethane resin is preferably used which has an initial viscosity and hardens as time elapses.

The other end of each tubular filtration membrane 3 is fixed to the insertion hole 32 of the second partition 31 in the same manner as one end of the tubular filtration membrane 3.

The tubular filtration membrane (3) has a cylindrical filtration membrane having a single-layer structure in which a hydrophilic monomer is copolymerized with a single main constituent material.

That is, the polymeric filtration membrane is formed of one kind of material as the main material. The fact that the main material is formed of one kind of material means that a kind of resin occupies 50% by mass or more in the material (for example, resin) forming the polymeric filtration film.

The fact that the main material is formed of one kind of material means that the nature of the one type of material dominates the properties of the constituent material. Specifically, it means a material in which one type of resin has 50% by mass to 99% by mass. However, when there is a supporting body for supporting the membrane, the supporting body may be the same material as the polymer membrane or may be a different material.

Examples of the main material constituting the polymeric filtration membrane include a polyolefin such as a vinyl chloride resin, a polysulfone (PS), a polyvinylidene fluoride (PVDF), a polyethylene (PE), a polyacrylonitrile (PAN) Polyether sulfone type, polyvinyl alcohol (PVA) type, and polyimide (PI) type.

As the main material constituting the tubular filtration film 3, a vinyl chloride resin is particularly preferable. Examples of the vinyl chloride resin include a vinyl chloride homopolymer (a vinyl chloride homopolymer), a copolymer of a monomer having an unsaturated bond copolymerizable with a vinyl chloride monomer and a vinyl chloride monomer, a graft copolymer obtained by graft copolymerizing a vinyl chloride monomer with a polymer, And (co) polymers in which these vinyl chloride monomer units are chlorinated.

As the hydrophilic monomer, for example,

(1) vinyl monomer containing a cationic group such as an amino group, an ammonium group, a pyridyl group, an imino group and a betaine structure and /

(2) hydrophilic nonionic group-containing vinyl monomers such as hydroxyl group, amide group, ester structure and ether structure,

(3) vinyl monomer containing an anionic group such as a carboxyl group, a sulfonic acid group and a phosphoric acid group and /

(4) other monomers.

The diameter of the tubular filtration membrane 3 can be appropriately selected according to the property of the water supply W3. For example, when the crude fiber amount? Is not more than 200 mg / liter with respect to the water supply W3 , The inner diameter of the tubular filtration film 3 is 5 mm or less and the amount of crude fiber (?) Is larger than 200 mg / (?) is 500 mg / L or more, the tubular filtration membrane (3) can have an inner diameter of 10 mm or more. By selecting the diameter of the tubular filtration membrane 3, the blockage of the tubular filtration membrane 3 due to the crude fiber fractions can be suppressed.

Next, the operation of the biological treatment apparatus 100 of the present embodiment will be described.

The treated water W1 such as manure is sent to the biological treatment water tank 11 through the first line 15 after being pretreated in a pretreatment facility (not shown). The water W1 to be treated is treated in the biological treatment water tank 11. Specifically, the organic substance contained in the for-treatment water W1 is decomposed by microorganisms.

The supply water W2 discharged from the biological treatment water tank 11 is then stored in the raw water tank 12 and then supplied to the membrane separation apparatus 1 via the pressurizing pump 21. [ The feed water W3 supplied to the membrane separation device 1 is sent into the tubular filtration membrane 3 of the membrane separation device 1. [ The pressurizing pump 21 is controlled by the control device 13 as described later.

On the other hand, the permeation-side space P in the casing 2 of the membrane separation apparatus 1 becomes a negative pressure by the operation of the suction pump 22. The suction pump 22 sucks in the direction substantially orthogonal to the flow of the supply water W3 flowing through the tubular filtration membrane 3 through the permeated water outlet 9. The operation of the suction pump 22 is controlled by the control device 13 as described later. The permeated water PW permeated from the tubular filtration membrane 3 is stored in the storage tank 20 through the permeated water outlet 9 and the permeated water line 18.

The concentrated water W4 (returned sludge) discharged from the membrane separating apparatus 1 is introduced into the conveying line 19 in its entirety except the excess sludge. At least a part of the concentrated water W4 is transferred to the biological treatment water tank 11, and the treatment is carried out again.

Next, a control method (biological treatment method) of the biological treatment apparatus 100 according to the present embodiment, which is a detailed control method of the pressurization pump 21, the suction pump 22, and the first flow rate control valve 23 do. The control device 13 of the biological treatment apparatus 100 according to the present embodiment can control the biological treatment apparatus 100, particularly the permeated water PW, by executing the following control I, control II, The control of the flow rate of the fluid is performed.

The membrane separation apparatus 1 of the present embodiment has a tubular filtration membrane 3 having a single layer structure in which hydrophilic monomers are copolymerized and has a low flow rate (membrane surface velocity: 0.15 m / s to 0.60 m / s) and the low pressure (the pressure of the supplied water W3: 0.1 MPa or less). The control device 13 of the biological treatment apparatus 100 performs control taking into consideration the progress of fouling of the tubular filtration film 3 while taking advantage of these characteristics.

[Control I]

As shown in Fig. 3, the control I of the biological treatment method using the biological treatment apparatus 100 of the present embodiment includes an operation step S11, an inter-membrane pressure difference determination step (S12), a back pressure adjusting step (S13), and an adjustment range determining step (S14).

The operating step S11 is a step of setting the operating conditions and controlling the pressurizing pump 21, the suction pump 22, and the first flow rate adjusting valve 23. The operation step S11 includes a pressurizing step S11a for controlling the pressurizing pump 21 to pressurize and supply the feed water to the membrane separation apparatus 1 and a control step for controlling the suction pump 22 to control the operation of the membrane separation apparatus 1 A suction step S11b for sucking the permeated water PW from the permeable space P and an opening setting step S11c for setting the opening degree of the first flow rate adjusting valve 23 to 20% ) To the biological treatment water tank (11).

The operating conditions can be appropriately determined based on the specifications of the biological treatment apparatus 100 and the like. In the pressurizing step S11a, the control device 13 controls the pressure pump 21 so that the flow velocity on the membrane surface is 0.15 m / s, based on the value of the flow rate of the feed water W3 received from the first flow meter 25. [ . In the suction step S11b, the control device 13 controls the suction pump 22 so that the suction pump 22 operates at a low frequency of 6 Hz to 20 Hz. In the opening degree setting step S11c, the control device 13 controls the first flow rate adjusting valve 23 so that the opening degree becomes 20%. By these controls, the concentrated water W4 is conveyed to the biological treatment water tank 11 through the conveying line 19 (conveying step S11d).

With the above setting, the supplied water W3 becomes low and the permeated water PW is sucked at a low pressure. Further, by reducing the opening degree of the first flow control valve 23, FLUX (outflow amount of permeated water PW) is controlled to a range that satisfies the planned value.

The inter-membrane pressure difference judgment step (S12) is a step of judging whether or not the inter-membrane pressure difference of the membrane separation device 1 is equal to or larger than the first predetermined value. In the inter-membrane pressure difference judgment step (S12), the control device 13 compares the inter-membrane pressure difference measured by the inter-membrane pressure difference measuring device 14 (the first pressure gauge 26, the second pressure gauge 28 and the third pressure gauge 44) It is determined whether or not the differential pressure has reached the first predetermined value or more. That is, in order to satisfy the flow rate plan of the permeated water PW, the control device 13 determines whether or not the inter-membrane pressure difference rises as the fouling progresses in the tubular filtration film 3.

As a result of this determination, when it is determined that the inter-membrane pressure difference is smaller than the first predetermined value (NO in S12), the pressurization and suction are continued. That is, when the progress of the fouling is determined to be within the permissible range, the operation is continued without changing the operation condition.

If it is determined that the inter-membrane pressure difference is equal to or larger than the predetermined value (YES in S12), the back pressure adjusting process S13 is executed. In the back pressure adjusting step S13, the back pressure adjusting part 13a of the control device 13 gradually opens the first flow rate adjusting valve 23 to reduce the back pressure of the permeating side space P. In other words, the flow rate of the permeated water PW is ensured by increasing the opening degree of the first flow rate regulating valve 23.

The adjustment range determination step S14 determines whether or not the adjustment range of the first flow rate adjustment valve 23 (back pressure adjustment device) reaches the limit (100%) in order to satisfy the flow rate plan of the permeated water PW . In the adjustment range determination step S14, the control device 13 determines whether or not the adjustment range (operation range) of the first flow rate adjustment valve 23 functioning as the back pressure adjustment device reaches the upper limit (opening degree 100%) do. As a result of the determination, if it is determined that the adjustment range of the first flow adjustment valve 23 has not reached the limit (NO in S14), the first flow adjustment valve 23 is gradually opened.

On the other hand, when it is determined that the adjustment range of the first flow rate regulating valve 23 has reached the limit (YES in S14), the flow of control proceeds to control II since no further increase in the flow rate of the permeated water PW can be expected.

[Control II]

As shown in Fig. 4, the control II of the biological treatment method includes a first setting change step (S21), a first inter-membrane pressure difference judging step (S22), and a second inter- The first back pressure adjusting step S23, the first adjusting range judging step S24, the second setting changing step S25, the second inter-membrane pressure difference judging step S26, the second back pressure adjusting step S27, And a second adjustment range determination step (S28).

The first setting changing step S21 is a step of changing the setting of the operating condition when the adjusting range of the first flow adjusting valve 23 reaches the limit in the adjusting range judging step S14 of the control I . In the first setting changing step S21, the control device 13 changes the setting of the pressurizing pump 21 so that the flow velocity on the film surface is 0.30 m / s. That is, the pressing force of the pressurizing pump 21 is increased. The setting change of the suction pump 22 is not performed.

By increasing the pressing force of the pressurizing pump 21, the flow velocity on the film surface and the flow rate of the supply water W3 are increased, and the cleaning effect of the film surface is increased. Further, the flow rate of the permeated water PW increases due to the increase of the pressure of the feed water W3.

The control device 13 controls the first flow rate regulating valve 23 so that the opening degree is 20% which is the initial setting value. Thereby, the flow rate of the permeated water PW is controlled to a range that satisfies the planned value.

In the first inter-membrane pressure difference judging step (S22), the control device 13 judges whether or not the inter-membrane pressure difference measured by the inter-membrane pressure difference measuring device 14 reaches the second predetermined value (inter-membrane pressure difference higher than the first predetermined value) ≪ / RTI >

As a result of this determination, when it is determined that the inter-membrane pressure difference is smaller than the second predetermined value (NO in S22), the pressurization and suction are continued.

When it is determined that the inter-membrane pressure difference is equal to or greater than the second predetermined value (YES in S22), the first back pressure adjustment step (S23) is executed. The back pressure adjusting section 13a of the control device 13 gradually opens the first flow rate adjusting valve 23 to reduce the back pressure of the permeation side space P. [

In the first adjustment range determination step (S24), the control device 13 determines whether or not the adjustment range of the first flow adjustment valve 23 reaches the limit (100%). As a result of the determination, when it is determined that the adjustment range of the first flow adjustment valve 23 has not reached the limit, the first flow adjustment valve 23 is gradually and continuously opened.

On the other hand, when it is determined that the adjustment range of the first flow control valve 23 has reached the limit, the increase in the flow rate of the permeated water PW can not be expected any more, so the setting of the pressure pump 21 is changed .

The second setting changing step (S25) is a step of changing the setting of the operating condition again when the adjustment range of the first flow adjusting valve 23 reaches the limit. In the second setting change step (S25), the control device (13) changes the setting of the pressurizing pump (21) so that the flow velocity on the bare surface is 0.60 m / s. That is, the control device 13 changes the setting so that the supplied water W3 supplied by the pressurizing pump 21 becomes a large flow rate.

The control device 13 controls the first flow rate regulating valve 23 so that the opening degree is 20% which is an initial setting value. Thereby, the flow rate of the permeated water PW is controlled to a range that satisfies the planned value.

In the same manner as the first inter-membrane pressure difference judging step (S22), the first back pressure adjusting step (S23) and the first adjusting range judging step (S24), the second inter-membrane pressure difference judging step (S26), the second back pressure adjusting step S27), and a second adjustment range determination step (S28).

If it is determined in the second adjustment range determination step (S28) that the adjustment range of the first flow adjustment valve 23 has reached the limit, increase in the flow rate of the permeated water PW beyond that is not expected, Lt; / RTI >

Particularly, in the control II, since the concentrated water W4 increases with the increase of the supply water W3, the control device 13 controls the flow rate of the concentrated water W4 measured by the third flow meter 43 And controls the second flow rate adjusting valve 24 based on the flow rate of the second flow rate adjusting valve 24. Thereby, the flow rate of the concentrated water W4 introduced into the biological treatment water tank 11 is adjusted.

[Control III]

5, the control III of the biological treatment method includes a setting change step S31, an inter-membrane pressure difference judging step S32, and a back pressure adjusting step (step S31) to satisfy the flow rate plan value of the permeated water PW S33), an adjustment range determination step (S34), and a cleaning step (S35).

The setting changing step S31 is a step of changing the setting of the operating condition when the adjustment range of the first flow adjusting valve 23 reaches the limit in the second adjusting range determining step S28 of the control II .

In the setting changing step S31, the control device 13 changes the setting of the suction pump 22 so that the suction pump 22 is operated at 20 Hz to 40 Hz. The setting change of the pressurizing pump 21 is not performed. The flow rate of the permeated water PW increases due to the increase of the suction force by the suction pump 22.

The control device 13 controls the first flow rate regulating valve 23 so that the opening degree is 20% which is the initial setting value. Thereby, the flow rate of the permeated water PW is controlled to a range that satisfies the planned value.

In the inter-membrane pressure difference determination step S32, the control device 13 determines whether or not the inter-membrane pressure differential measured by the inter-membrane pressure differential measurement device 14 is equal to or higher than a third predetermined value (inter-membrane pressure difference higher than the second predetermined value) .

As a result of the determination, when it is determined that the inter-film pressure difference is smaller than the third predetermined value (NO in S32), the pressurization and suction are continued.

When it is determined that the inter-membrane pressure difference is equal to or greater than the third predetermined value (YES in S32), the controller 13 executes the back pressure adjusting process S33. The back pressure adjusting step S33 is a step of decreasing the back pressure of the permeation side space P and increasing the suction force of the suction pump 22 when the inter-membrane pressure difference is increased to the third predetermined value or more.

The back pressure adjusting step (S33) includes a step (S33a) of adjusting the first flow rate adjusting valve and a step (S33b) of adjusting the suction pump.

In the step S33a of adjusting the first flow rate adjusting valve, the back pressure adjusting unit 13a of the controller 13 gradually opens the first flow rate adjusting valve 23 to reduce the back pressure of the permeating side space P . In the step of adjusting the suction pump (S33b), the control device (13) gradually increases the suction force of the suction pump (22). That is, the control device 13 gradually increases the frequency of the suction pump 22 from 40 Hz.

The adjustment range determination step (S34) is a step of determining whether or not the adjustment range of the first flow rate adjustment valve (23) reaches the limit when the suction pump (22) reaches the maximum frequency.

In the adjustment range determination step (S34), the control device (13) determines whether or not the adjustment range of the first flow rate adjustment valve (23) and the adjustment range of the suction pump (22) have reached their limits. As a result of the determination, when it is determined that the adjustment range has not been reached, control is performed so as to gradually increase the suction force of the suction pump 22 and to gradually increase the first flow rate adjustment valve 23.

On the other hand, when it is determined that the adjustment range of the first flow regulating valve 23 and the suction pump 22 has reached the limit, the flow rate of the permeated water PW can not be expected to increase further, .

In the cleaning step S35, the cleaning control unit 13c of the control device 13 controls the cleaning device 29 to clean the tubular filtration film 3. [

After the cleaning step S35, if it is determined by the control device 13 that the inter-membrane pressure difference has been restored, the flow returns to the control I.

According to the above-described embodiment, the back pressure of the tubular filtration film 3 is reduced based on the inter-membrane pressure difference, so that even when the inter-membrane pressure difference is increased by fouling, the movable range of the first flow rate adjustment valve 23 The flow rate of the permeated water PW can be adjusted.

When the limit of the adjustment range of the first flow control valve 23 is reached, the pressure is increased and the back pressure is increased (the first flow control valve 23 is closed) The flow rate of the permeated water PW can be adjusted by using the movable range of the permeable membrane 23.

In addition, when the tubular filtration membrane 3 has hydrophilicity, the flow velocity of the feed water W3 supplied to the concentrated side space S is low and the permeated water PW is low even when the pressure of the feed water W3 is low. Can be withdrawn.

It is also possible to adjust the sludge concentration (concentration ratio) of the concentrated water W4 conveyed to the biological treatment water tank 11 by performing control by using the pressure pump 21 and the suction pump 22 in combination. When the sludge concentration is increased, the suction force is increased and the pressing force is decreased. When the sludge concentration is made small, the suction force is made small and the pressing force is made large.

In the control II, by increasing the pressing force of the pressurizing pump 21 and controlling the pressure to the upper limit, the pressing force of the pressurizing pump 21 is increased to increase the flow velocity on the curtain surface, which can cause the cleaning effect of the tubular filtration film 3 .

In the control III, the suction force of the suction pump 22 is increased to the upper limit, and then the tubular filtration membrane 3 is cleaned, so that the pressing force and suction force can be reduced again. In addition, by performing cleaning after controlling both the pressing force and the suction force to the upper limit, the number of times of cleaning can be reduced.

In addition, since the biological treatment apparatus 100 according to the present embodiment can lower the flow velocity on the membrane surface, the circulating flow rate can be reduced. Thereby, the power of the pressurizing pump 21 can be reduced. In addition, since the flow rate of the circulating water is reduced, the piping can be hardened.

In addition, by selecting the inner diameter of the tubular filtration film 3 in accordance with the amount of the crude fiber of the supply water W3, the tubular filtration film 3 can be prevented from being blocked by the crude fiber.

In addition, by forming the upper and lower portions of the casing 2 in a tapered shape, it is possible to prevent water or the like from being deposited on the header spaces S1 and S2, and the water or the like of the crude fibers to become granular. That is, when the casing 2 has a cylindrical shape, the edge portion of the end portion becomes a dead space. However, by making the upper and lower portions of the casing 2 into a tapered shape, the dead space is eliminated, .

When the biological treatment water tank 11 is located at a position lower than the membrane separation apparatus 1, the liquid inside the membrane separation apparatus 1 is permeated by the siphon effect at the time of stopping the pressurization pump 21 PW). When the permeated water PW is discharged, the suction pump 22 continues to operate unnecessarily until the permeated water PW is filled again, which is a factor of failure. The biological treatment apparatus 100 of the present embodiment can prevent the liquid from escaping due to the siphon effect at the time of stopping the apparatus by forming the siphon breaker 40 on the transfer line 19. [

In the above embodiment, the siphon breaker 40 is formed on the transfer line 19. However, the present invention is not limited to this. For example, the pressure release tank may be formed in the transfer line 19. [

In the above embodiment, control is performed so that the suction force of the suction pump 22 is increased in the control III after increasing the pressing force of the pressure pump 21 in the control II, but the order is not limited to this. For example, after the control I, control to increase the suction force of the suction pump 22 of the control III may be performed, and control II may be performed after the control III.

The control for increasing the pressing force of the pressurizing pump 21 and the control for increasing the suction force of the suction pump 22 may alternatively be carried out at the same time.

That is, in the control I, at least one of the pressure pump and the suction pump may be controlled after the adjustment device of the first flow control valve 23 reaches the limit.

Although the suction force of the suction pump 22 is increased to the upper limit of the adjustment range of the suction pump 22 in the back pressure adjustment step S33 of the control III in the above embodiment, the control of the pressure pump 21 of the control II The suction force may be increased in two steps.

In the above embodiment, the first flow rate regulating valve 23 is used as the back pressure regulating device for regulating the back pressure of the permeation-side space P, but the present invention is not limited thereto. For example, a line on the downstream side of the membrane separation device 1 may be extended upwardly and a plurality of open valves may be formed to change the back pressure of the permeation side space P by changing the water pressure of the permeated water PW .

In the above embodiment, the membrane separation device 1 in which the tubular filtration membranes 3 are arranged in parallel is employed as the membrane separation device 1, but the present invention is not limited thereto. For example, as shown in Fig. 6, a plurality of tubular filtration membranes 3 may be connected in series. That is, a plurality of U-shaped first connecting members (46) for connecting a plurality of tubular filtration membranes (3) at one ends and connecting the other ends of the tubular filtration membranes (3) ).

At this time, the plurality of tubular filtration membranes 3 connected in series and the effluent inlet are directly connected to the tubular second connecting member 59, and a plurality of tubular filtration membranes 3 connected in series and a concentrated water- And the outlet 8 may be directly connected to the tubular third connecting member 60. In this case, the first header space S1 and the second header space S2 may be omitted. The configuration of the casing 2 may be changed by eliminating the first conical portion 5 and the second conical portion 6, for example.

In the membrane separation apparatus 1 of the above embodiment, the supply water W3 introduced into the tubular filtration membrane 3 from below flows through the tubular filtration membrane 3 downward. However, the present invention is not limited thereto. The concentrated water outlet 8 may be formed in the lower part of the casing 2 so that the feed water W3 flows downward in the tubular filtration membrane 3. [

The program for realizing all or part of the functions of the control unit may be recorded on a computer-readable recording medium, and the programs recorded on the recording medium may be loaded into a computer system and executed to execute the processing of each unit. Here, the " computer system " includes hardware such as an OS and peripheral devices. The "computer system" also includes a homepage providing environment (or display environment) if the WWW system is used.

The "computer-readable recording medium" refers to a storage medium such as a flexible disk, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk built in a computer system. The program may be one for realizing a part of the functions described above, or may be realized by a combination with the program already recorded in the computer system.

[Second embodiment]

Hereinafter, a biological treatment apparatus according to a second embodiment of the present invention will be described with reference to the drawings. In addition, in the present embodiment, description will be made mainly on the differences from the above-described first embodiment, and description of the same portions will be omitted. The difference between the present embodiment and the first embodiment is that the membrane separation apparatus unit 50 shown in Fig. 7 is employed in the biological treatment apparatus 100 of the first embodiment.

7, in the membrane separation device unit 50 of the present embodiment, a plurality of membrane separation devices 1B are disposed laterally in the case 51 of the membrane separation device unit 50 have. That is, the axis A (see Fig. 8) of the cylindrical casing 2 of the membrane separation device 1 extends in the horizontal direction, unlike the first embodiment.

8, the membrane separation apparatus 1B includes a cylindrical casing 2, a plurality of tubular filtration membranes 3, and a reinforcing member 34 for reinforcing the tubular filtration membranes 3 .

The membrane separation apparatus 1B of the present embodiment includes a reinforcing member 34 for reinforcing each of the tubular filtration membranes 3. The reinforcing member 34 is a normal member covering each of the tubular filtration membranes 3 from the outer peripheral side. The tubular filtration membrane (3) is inserted into the inner peripheral side of the reinforcing member (34).

9, the reinforcing member 34 includes a normal body portion 35 disposed on the outer peripheral side of the tubular filtration film 3 and a plurality of support portions (not shown) formed on the inner peripheral surface 35a of the normal body portion 35 36 and a plurality of through holes 37 formed in the main body portion 35.

Normally, the main body portion 35 is cylindrical. 10, the inner diameter (the diameter of the inner peripheral surface 35a) of the main body portion 35 is generally larger than the outer diameter of the tubular filtration film 3. As shown in Fig. A gap G is usually formed between the inner peripheral surface 35a of the main body portion 35 and the outer peripheral surface of the tubular filtration film 3. [ When the outer diameter of the tubular filtration membrane 3 is, for example, 5 mm, the inner diameter of the main body portion 35 may be, for example, 7 mm. In this case, the gap G between the inner peripheral surface 35a of the main body portion 35 and the outer peripheral surface of the tubular filtration film 3 is 2 mm. Normally, the body portion 35 is formed such that the gap G between the body portion 35 and the tubular filtration film 3 becomes constant.

The length of the main body portion 35 is generally the same as the distance between the first bank 30 and the second bank 31. That is, the length of the main body portion 35 is the same as the length of the tubular filtration film 3 exposed in the permeation-side space P.

Usually, the main body portion 35 can be formed of, for example, lightweight metal such as titanium or aluminum, or plastic such as polyacetal resin. It is preferable that the thickness of the main body portion 35 is as thin as possible within a range that does not impair the strength of the reinforcing member 34. [

The support portion 36 is a protrusion that extends generally in the axial direction Da (extending direction) of the main body portion 35. A plurality of support portions 36 (eight in this embodiment) are formed at intervals in the circumferential direction of the main body portion 35 in general. The height of each support portion 36 is generally the same as the width of the gap G between the inner peripheral surface 35a of the main body portion 35 and the outer peripheral surface of the tubular filtration film 3.

The reinforcing member 34 of the present embodiment has eight supporting portions 36, but is not limited thereto as long as it can support the tubular filtration membrane 3. [ In order to secure a larger space between the main body portion 35 and the tubular filtration film 3, that is, the space through which the permeated water PW is discharged, the number of the support portions 36 is preferably three desirable.

In the above embodiment, the support portion 36 is formed continuously in the axial direction Da of the main body portion 35, but the present invention is not limited thereto. It is only necessary that the support portion 36 can support the tubular filtration membrane 3 while keeping the space between the main body portion 35 and the tubular filtration membrane 3 as clear as possible. For example, the support portion 36 may be intermittently formed in the axial direction Da. In addition, the tubular filtration membranes 3 may be point-supported by a plurality of support protrusions for separating the tubular filtration membranes 3 from each other.

The through hole 37 is an opening that communicates between the outer peripheral side of the main body portion 35 and the inner peripheral side of the normal main body portion 35. The plurality of through holes 37 are regularly (evenly) arranged on the entire surface of the outer surface of the main body portion 35. It is preferable that the through holes 37 are formed as much as possible within a range that does not hinder the strength of the reinforcing member 34. It is preferable that the position of the through hole 37 in the circumferential direction of the main body portion 35 is different from that of the support portion 36. [

According to the above embodiment, even when a plurality of membrane separation devices 1B are arranged by horizontally laying the membrane separation device 1B, that is, by arranging the casing 2 to extend in the horizontal direction, 1B can be easily exchanged. As a result, the maintenance of the membrane separation device unit 50 comprising a plurality of membrane separation devices 1B can be facilitated.

Since the plurality of tubular filtration membranes 3 are reinforced by the reinforcing members 34, even when the tubular filtration membranes 3 are arranged to extend in the horizontal direction, the tubular filtration membranes 3 can be prevented from being bent .

The gap G is formed between the inner peripheral surface 35a of the reinforcing member 34 and the outer peripheral surface of the tubular filtration film 3 by the support portion 36 of the reinforcing member 34, It is possible to support the tubular filtration membrane 3 without bending it without hindering the flow of the permeated water PW.

Further, when the membrane separator is placed vertically, the head difference (resistance) at one end and the other end of the tubular filtration membrane 3 becomes large. By placing the membrane separator 1B horizontally, the head difference becomes smaller as compared with the case where the membrane separator is placed vertically, and the FLUX (flow rate) distribution can be reduced.

Moreover, by placing the membrane separator 1B horizontally, it is easy to connect the plurality of membrane separators 1B in series. Even in the case of arranging the plurality of membrane separation devices 1B constituting the membrane separation device unit 50 in series, it is easy to deal with them.

Although the length of the reinforcing member 34 is the same as the distance between the first partition 30 and the second partition 31 in the above embodiment, the present invention is not limited thereto. For example, the length of the reinforcing member 34 may be longer than the distance between the first and second ribs 30 and 31 so that the reinforcing member 34 may be spaced apart from the first and second ribs 30 and 31 Through the insertion hole 32 of the main body 32. [ By adopting such a configuration, the burden imposed on the tubular filtration film 3 can be further reduced.

The reinforcing member 34 may be a mesh-like network structure which is normally formed and arranged so as to be in contact with the tubular filtration membrane 3 on the outer peripheral side of the tubular filtration membrane 3. [ The network structure can be, for example, a plastic tube formed by combining a plurality of linear plastics in a lattice pattern with each other.

For example, a wire formed of a metal such as stainless steel may be used as a substitute for the plastic on board the line. Alternatively, a wire coated with vinyl or the like may be employed.

The method of combining a plurality of line-shaped plastics is not limited to a lattice, and a plurality of line-shaped plastics may be formed into a hexagonal shape.

[Third embodiment]

Hereinafter, a reinforcing member used in the membrane separation device according to the third embodiment of the present invention will be described with reference to the drawings. In addition, in the present embodiment, differences from the above-described second embodiment will be mainly described, and description of the same portions will be omitted. The difference between the present embodiment and the second embodiment is that not only the membrane separator unit 50 shown in Fig. 7 is employed in the biological treatment apparatus 100 of the first embodiment but also the membrane separator unit 50, The reinforcing member 34C of Fig. 11 is employed instead of the reinforcing member 34 of Fig.

11, the reinforcing member 34C of the present embodiment has a plate-shaped main body portion 48 forming a circular plate and a plurality of film insertion holes 49 formed in the plate-shaped main body portion 48 . The tubular filtration membrane (3) is inserted into each of the plurality of membrane insertion holes (49). Three reinforcing members 34C are formed at intervals in the axial direction Da of the casing 2. [

The outer circumferential surface 48a of the plate-like main body portion 48 of the reinforcing member 34C abuts against the inner circumferential surface of the casing 2. The reinforcing member 34C is supported by abutting the lower portion of the reinforcing member 34C against the inner peripheral surface of the casing 2. [ The outer peripheral surface 48a of the lower portion of the reinforcing member 34C functions as a reinforcing member supporting portion for supporting the reinforcing member 34C. It is also preferable that the notch 55 exists in a part of the reinforcing member 34C, for example, so that the permeated water PW can flow in the permeation side space P.

According to the above embodiment, the plurality of tubular filtration membranes 3 are mechanically connected by the reinforcing member 34C. Thus, even when the tubular filtration film 3 is arranged to extend in the horizontal direction, it is possible to prevent the tubular filtration film 3 from bending.

Further, the reinforcing member 34C of the present embodiment supports the tubular filtration film 3 only at three points in the extending direction, so that the permeated water PW can be transmitted more.

The reinforcing member 34C of the above embodiment is not limited to this in that the outer peripheral surface 48a of the reinforcing member 34C is in contact with the inner peripheral surface of the casing 2. [ That is, if the reinforcing member 34C is supported by the inner circumferential surface of the casing 2, the upper portion of the reinforcing member 34C does not have to be in contact with the inner circumferential surface of the casing 2. [ In addition, for example, a part of the outer periphery such as a polygonal shape may be in contact with the casing 2. [

The number of the reinforcing members 34C is not limited to three but may be appropriately increased or decreased according to the strength of the tubular filtration film 3. [

Although the embodiments of the present invention have been described in detail above, various modifications can be made within the scope of the present invention.

For example, regarding the number of tubular filtration membranes 3, five tubular filtration membranes 3 are shown in Fig. 2 and the like, but the number of tubular filtration membranes 3 is not limited to this.

In the control II and the control III, the controller 13 resets the opening of the first flow regulating valve 23 to the initial value of 20%, but it is not limited to the initial value. For example, within the adjustment range of 30% Value may be reset to a changed value.

The configuration shown in the modified example of the first embodiment may be applied to the second embodiment and the third embodiment.

1: membrane separator
2: Casing
3: tubular filtration membrane
4: Casing body
5: First cone part
6: second conical part
7: Feed water inlet
8: Concentrated water outlet
9: Permeated water outlet
11: Biological treatment tank
12: Circulating water tank
13: Control device
13a:
13b: Setting change section
13c:
14: Inter-terminal differential pressure measuring device
15: First line
16: second line
17: Supply line
18: Permeable water line
19: return line
20: Storage tank
21: Pressure pump
22: suction pump
23: First flow regulating valve (back pressure regulating device)
24: second flow regulating valve
25: First flow meter
26: 1st pressure gauge
27: Second flow meter
28: Second manometer
29: Cleaning device
30: first partition
31: second partition
32: Insertion hole
34: reinforcing member
35: Normally,
36: Support
37: Through hole
40: Siphon breaker
43: Third flow meter
44: Third pressure gauge
45: Branch line
46: first connecting member
48: plate-
49: Insertion through hole
50: membrane separation unit
51: Case
55: The cut
59: second connecting member
60: third connecting member
100: biological treatment device
P: Permeation side space
PW: permeable water
S: Enriched space
S1: first header space
S2: second header space
S3: space in the filtration membrane
W1: treated water
W2, W3: Supplied water
W4: Concentrated water

Claims (6)

A biological treatment water tank for treating the organic matter contained in the water to be treated,
And the casing is divided into a concentrated side space to which the supply water flowing out from the biological treatment water tank is supplied and a permeable side space in which the permeated water separated from the supply water is contained and a tubular structure having a single layer structure in which a hydrophilic monomer is copolymerized A membrane separation device having a filtration membrane,
A pressurizing pump for supplying the supply water to the concentrated side space,
A suction pump for sucking the permeated water from the permeable space,
A back pressure regulating device for regulating the back pressure of the permeable space,
A conveyance line for conveying the concentrated water discharged from the membrane separation device to the biological treatment water tank, an inter-membrane pressure difference measuring device for measuring a pressure difference between the thickened space and the permeated space,
And a control device for controlling the pressurizing pump, the suction pump, and the back pressure regulating device based on the inter-membrane pressure difference,
The control device includes:
A back pressure regulator for controlling the back pressure regulator to reduce the back pressure when the inter-membrane pressure difference has increased to a predetermined value or more,
Wherein at least one of the pressurizing pump and the suction pump is controlled to increase at least one of a pressurizing force of the pressurizing pump and a suction force of the suction pump when the adjustment range of the back pressure regulating device reaches a limit, And a setting changing unit for controlling the apparatus to increase the back pressure. The method according to claim 1,
Wherein the setting changing unit performs control to increase the suction force of the suction pump after increasing the pressing force of the pressure pump to the upper limit. 3. The method of claim 2,
Wherein the control device has a cleaning control section for increasing the suction force of the suction pump to control the tubular filtration membrane to an upper limit and then cleaning the tubular filtration membrane. 4. The method according to any one of claims 1 to 3,
Wherein the return line includes a branch line for supplying the concentrated water between the biological treatment water tank and the membrane separation device and a second line formed on the downstream side of the branch line for adjusting the flow rate of the concentrated water flowing through the return line, A biological treatment device having a flow control valve. A pressurizing step of pressurizing and supplying supply water flowing out from the biological treatment water tank to a concentrated side space on one side of a tubular filtration membrane having a monolayer structure in which a hydrophilic monomer is copolymerized,
A suction step of sucking permeated water from the permeate side space on the other side of the tubular filtration membrane,
A conveying step of conveying the concentrated water discharged from the concentrated side space to the biological treatment water tank;
A back pressure adjusting step of reducing the back pressure of the permeating space when the pressure difference between the thickening space and the permeating space increases to a predetermined value or more,
And a setting changing step of increasing at least one of a pressing force of the supply water and a suction force of the permeated water when the adjustment range of the back pressure reaches a limit, and increasing the back pressure. A biological treatment water tank for treating the organic matter contained in the water to be treated,
And the casing is divided into a concentrated side space to which the supply water flowing out from the biological treatment water tank is supplied and a permeable side space in which the permeated water separated from the supply water is contained and a tubular structure having a single layer structure in which a hydrophilic monomer is copolymerized A membrane separation device having a filtration membrane,
A pressurizing pump for supplying the supply water to the concentrated side space,
A suction pump for sucking the permeated water from the permeable space,
A back pressure regulating device for regulating the back pressure of the permeable space,
A conveying line for conveying the concentrated water discharged from the membrane separation device to the biological treatment water tank and an inter-membrane pressure difference measuring device for measuring a pressure difference between the enriched side space and the permeation side space Stored on your computer,
Wherein when the inter-membrane pressure difference is increased to a predetermined value or more, the back pressure regulator is controlled to reduce the back pressure,
Wherein at least one of the pressurizing pump and the suction pump is controlled to increase at least one of a pressurizing force of the pressurizing pump and a suction force of the suction pump when the adjustment range of the back pressure regulating device reaches a limit, A program for controlling an apparatus to increase the back pressure.

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