Electron donor supply and recovery device, electron donor supply method, and electron donor recovery method

Abstract

This electron donor supply and recovery device is provided with: a plurality of sealed bag-shaped containers for accommodating a liquid containing an electron donor; a buffer tank assembly, which is disposed above the container, is formed by connecting a plurality of buffer tanks in series, the internal volumes of which do not vary with pressure, and has one side which is a liquid injection side and the other side which is a liquid discharge side; a pump mechanism including a plurality of valve devices respectively connected to the injection side and the discharge side of the liquid, and a pump device connected to the discharge side of the liquid; a control means for controlling the operation of the pump mechanism; a first tank for storing the supplied liquid; and a second tank for storing the recovered liquid or the used waste liquid. And the buffer tank is only connected with one corresponding container.

Description

Technical Field

[0001] This invention relates to an electron donor supply and recovery device, an electron donor supply method, and an electron donor recovery method for biological denitrification. Background Technology

[0002] Traditionally, for example, in aquaculture, water changes are typically performed by adding fresh aquatic water to remove nitrogen from the water, such as excrement and leftover feed. However, continuous water changes require large quantities of aquatic water, increasing operating costs for water supply and temperature maintenance. Furthermore, the energy consumption required to maintain temperature leads to increased carbon dioxide emissions.

[0003] Therefore, in recent years, it has been necessary to reduce the amount of aquaculture water replenished by recycling it without water exchange. However, reducing the amount of water exchanged leads to an increase in nitrate nitrogen in the aquaculture water, which has an adverse effect on aquatic organisms. Therefore, it is necessary to efficiently remove nitrate nitrogen from aquaculture water.

[0004] As a method for removing nitrate nitrogen from treated water such as aquaculture water, methods utilizing microorganisms such as denitrifying bacteria are known. For example, as a treatment technology for treated water such as sewage and domestic wastewater, there is a method that involves adding a certain amount of methanol (an electron donor) to the treated water using a pool-type intermittent aeration device (see Patent Document 1) to allow denitrifying bacteria to convert nitrate nitrogen into nitrogen. This conversion of nitrate nitrogen into nitrogen (denitrification) reduces the amount of nitrate nitrogen in the treated water.

[0005] On the other hand, in devices such as denitrification bioreactors (see Patent Document 2) and electron donor supply devices (see Patent Document 3), a sealed container with a bag-like structure formed by bonding a membrane containing alcohols such as methanol (electron donors) is placed into an aquaculture pond. This provides denitrifying bacteria attached to the outer surface of the bag-like container with electron donors that have penetrated the container membrane, thereby denitrifying the treated water.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent No. 3260554

[0009] Patent Document 2: Japanese Patent No. 3025964

[0010] Patent Document 3: Japanese Patent No. 5222234 Summary of the Invention

[0011] The technical problem that the invention aims to solve

[0012] However, in the prior art pool-type intermittent aeration device disclosed in Patent Document 1, the entire denitrification reaction tank needs to be kept in an anaerobic state. Therefore, when denitrifying water used for aquaculture, the denitrification reaction tank and the aquaculture tank need to be set up separately, resulting in a large equipment size. Furthermore, even when the reaction tank and the aquaculture tank are set up separately, the risk of aquatic organisms dying due to lack of oxygen cannot be denied when the denitrified water from the reaction tank mixes into the aquaculture tank due to accidents or other reasons.

[0013] In contrast, the prior art devices disclosed in Patent Documents 2 and 3 only require the outer surface of the container in contact with the water being treated to be kept in an anaerobic state, thus eliminating the need for the entire reaction tank to be anaerobic, allowing aquaculture ponds to be used as reaction tanks. Furthermore, since the risk of aquatic organism mortality due to anaerobic treated water can be reduced to a very low level, highly safe denitrification is also possible.

[0014] On the other hand, the liquid containing the electron donor, sealed in a bag-like container, needs to be periodically replenished. If the electron donor contains components that cannot permeate the container's membrane, the residual liquid inside the container also needs to be properly recycled, resulting in time-consuming and labor-intensive processes. Furthermore, if the supply of the electron donor-containing liquid through filling the container is inconsistent, or if the residual liquid inside the container cannot be fully recycled, stable denitrification performance cannot be achieved. Additionally, because the container has a bag-like structure with the membrane bonded together, it may rupture if pressurized from the inside during filling and liquid supply.

[0015] Furthermore, to accurately supply and recover liquid containing the electron donor, it is typically envisioned to connect the pump unit to the container using a switching valve. However, in the case of multiple containers, a separate switching valve must be installed for each container, increasing the number of components and complicating the equipment. Additionally, if the supply is based on directly measuring the volume of liquid containing the electron donor, a flow meter is required, potentially increasing equipment costs.

[0016] Furthermore, in order to fill and supply liquid containing the electron donor to multiple containers without using such a flow meter, there is also a method of connecting multiple containers to a tank containing liquid containing the electron donor through various pipes and supplying it by gravity. However, if the pipe conditions, such as pipe resistance, are inconsistent, there is a problem that the supply amount to each container will be different.

[0017] The present invention was made in view of the above-mentioned problems, and its object is to provide an electronic supply and recycling device, an electronic supply method, and an electronic supply recycling method that accurately and efficiently supply and recycle liquid containing an electronic supply to a container while reducing the number of parts, lowering equipment costs, and preventing container breakage, thereby achieving labor-saving electronic supply and recycling.

[0018] Methods for solving technical problems

[0019] The electron donor supply and recovery device of the present invention comprises: a plurality of sealed bag-shaped containers containing liquid containing electron donors supplied to microorganisms; a buffer tank assembly disposed above the containers, consisting of a plurality of buffer tanks connected in series with an internal volume that does not change with pressure, one side of the buffer tank assembly being a liquid injection side and the other side being a liquid discharge side; a pump mechanism including a plurality of valve devices respectively connected to the liquid injection side and the liquid discharge side of the buffer tank assembly, and a pump device connected to the liquid discharge side; a control unit controlling the operation of the pump mechanism; and a first tank, which is equipped with... A first tank is positioned on the liquid injection side of the buffer tank assembly and stores the liquid supplied to the container; and a second tank is positioned on the liquid discharge side of the buffer tank assembly and stores the liquid recovered from the container or used waste liquid; wherein each buffer tank is connected to only one corresponding container, and the control unit controls the pump mechanism to supply the liquid from the first tank to multiple buffer tanks of the buffer tank assembly, to supply the liquid contained in the buffer tank to the container, and to control the pump mechanism to recover the liquid or the waste liquid from the container to the second tank.

[0020] In one embodiment of the invention, the buffer tank is formed in a cylindrical shape and configured such that its central axis extends vertically. It has a first connection port and a second connection port arranged side by side at the upper end in a horizontal direction, and a third connection port arranged at the lower end, and is connected to the container through the third connection port. The buffer tank assembly has the plurality of buffer tanks arranged horizontally. The second connection port of the adjacent front buffer tank and the first connection port of the rear buffer tank are connected by pipes from the upstream buffer tank on the liquid injection side to the downstream buffer tank on the liquid discharge side. The first connection port of the upstream buffer tank and the second connection port of the downstream buffer tank are respectively connected to different valve devices among the plurality of valve devices.

[0021] In another embodiment of the invention, the pump mechanism includes: a first valve device disposed between the first connection port of the upstream buffer tank in the buffer tank assembly and the first tank; a second valve device for atmospheric opening connected to the first connection port of the upstream buffer tank; a third valve device disposed between the second connection port of the downstream buffer tank and the suction port of the pump device; a fourth valve device disposed between the third connection ports of the plurality of buffer tanks in the buffer tank assembly and the suction port of the pump device; a fifth valve device disposed between the discharge port of the pump device and the first tank; and a sixth valve device disposed between the discharge port of the pump device and the second tank.

[0022] In another embodiment of the invention, the buffer tank is formed in a cylindrical shape and configured such that its central axis extends horizontally. At one end of the central axis, it has a first connection port and a second connection port arranged side-by-side on the lower and upper sides in a vertical direction, respectively, and is connected to the container via the first connection port. The buffer tank assembly has the plurality of buffer tanks arranged horizontally. The second connection port of the adjacent front buffer tank and the first connection port of the adjacent rear buffer tank are connected via pipes, from the upstream buffer tank on the liquid injection side to the downstream buffer tank on the liquid discharge side. The first connection port of the upstream buffer tank and the second connection port of the downstream buffer tank are respectively connected to different valve devices among the plurality of valve devices.

[0023] In another embodiment of the invention, the pump mechanism includes: a first valve device disposed between the first connection port of the upstream buffer tank in the buffer tank assembly and the first tank; a second valve device for atmospheric opening connected to the first connection port of the upstream buffer tank; a third valve device disposed between the second connection port of the downstream buffer tank and the suction port of the pump device; a fourth valve device disposed between the first connection port of the upstream buffer tank and the suction port of the pump device; a fifth valve device disposed between the discharge port of the pump device and the first tank; a sixth valve device disposed between the discharge port of the pump device and the second tank; and a seventh valve device for atmospheric opening connected to the second connection port of the downstream buffer tank.

[0024] In another embodiment of the invention, a flow regulating mechanism is provided between the first valve device and the first tank.

[0025] In another embodiment of the invention, each buffer tank of the buffer tank assembly is provided with a pipe joint between the buffer tank and the container, which allows the container to be detachably connected to the buffer tank.

[0026] The method for supplying an electronic supply according to the present invention is a method for supplying an electronic supply through the aforementioned electronic supply and recycling device, comprising: the step of the control unit operating the pump mechanism to make the pressure in the plurality of buffer tanks of the buffer tank assembly negative, thereby supplying the liquid from the first tank to the plurality of buffer tanks; and the step of the control unit operating the pump mechanism to make the pressure in the plurality of buffer tanks close to atmospheric pressure, thereby supplying the liquid contained in the buffer tanks to the container.

[0027] In one embodiment of the present invention, the method for supplying an electronic supply through the aforementioned electronic supply and recovery device includes: when supplying the liquid into the container, by means of the control unit, opening the third valve device and the fifth valve device and starting the pump device, so that the pressure in each buffer tank of the buffer tank assembly becomes a negative pressure lower than the head between the buffer tank assembly and the container, and opening the first valve device to transport the liquid in the first tank to each buffer tank of the buffer tank assembly; and by means of the control unit, opening the second valve device to allow the pressure in each buffer tank of the buffer tank assembly to be released to the atmosphere, and supplying the liquid in each buffer tank to the container by gravity.

[0028] In another embodiment of the invention, the method includes: when the pressure in each of the buffer tanks is opened to the atmosphere, the control unit repeatedly opens and closes the second valve device so that the negative pressure in each of the buffer tanks of the buffer tank assembly is restored to atmospheric pressure after a predetermined period.

[0029] The method for recycling the electron supply involved in this invention is a method for recycling the electron supply through the above-mentioned electron supply recycling device, including: when recycling the liquid from the container, the control unit opens the fourth valve device and the sixth valve device and starts the pump device to recycle the liquid or waste liquid in the container into the second tank.

[0030] Another method for recycling an electron provider involved in this invention is a method for recycling an electron provider through the aforementioned electron provider supply and recycling device, comprising: when recycling the liquid from the container, by means of the control unit, opening the fourth valve device and the sixth valve device and starting the pump device, and recycling the liquid or the waste liquid in the container to the second tank through the first connection port of the buffer tank disposed upstream.

[0031] In one embodiment of the invention, the method includes: opening the third valve device via the control unit during the recycling step to make the negative pressure in each buffer tank of the buffer tank assembly lower than the negative pressure of the water head between the buffer tank assembly and the container, thereby drawing the liquid or the waste liquid from the container into each buffer tank and temporarily storing it.

[0032] In another embodiment of the invention, the method includes: repeatedly opening and closing the 7th valve device via the control unit during the storage step, maintaining the negative pressure in each buffer tank of the buffer tank assembly at a negative pressure less than a predetermined pressure, while supplementing air into each buffer tank of the buffer tank assembly through the 2nd connection port of the downstream buffer tank, and conveying the liquid or waste liquid temporarily stored in each buffer tank from the downstream buffer tank to the upstream buffer tank; and in the recovery step, recovering the liquid or waste liquid conveyed in the transportation step into the 2nd tank through the 1st connection port, the 4th valve device, the pump device, and the 6th valve device of the upstream buffer tank.

[0033] The effects of the invention

[0034] According to the present invention, it is possible to supply and recycle liquid containing an electron donor into a container, while reducing the number of parts and lowering equipment costs and preventing container breakage, and to operate accurately and efficiently, thereby achieving labor-saving. Attached Figure Description

[0035] Figure 1 This is a schematic diagram showing the basic structure of the electron supply and recycling device according to the first embodiment of the present invention.

[0036] Figure 2 This is a perspective view showing the structure of the buffer tank assembly and container of the electronic supply recycling device.

[0037] Figure 3 This is a timing diagram illustrating an example of the supply operation performed by the electronic supply recovery device.

[0038] Figure 4 This is a timing diagram illustrating an example of the recycling operation performed by the electronic supply recycling device.

[0039] Figure 5 This is a schematic diagram showing the structure of the buffer tank assembly and container of the electronic supply recycling device according to the second embodiment of the present invention.

[0040] Figure 6 This is a schematic diagram showing the basic structure of the electron supply and recycling device according to the third embodiment of the present invention.

[0041] Figure 7 This is a schematic diagram showing a modified example of the electron supply recycling device according to the first embodiment of the present invention.

[0042] Figure 8 This is a schematic diagram showing the basic structure of the electron supply and recycling device according to the fourth embodiment of the present invention.

[0043] Figure 9 This is a perspective view showing the structure of the buffer tank assembly and container of the electronic supply recycling device.

[0044] Figure 10 This is a diagram illustrating an example of pressure changes within the buffer tank assembly during the supply of the electronic supply and recovery device, as well as a timing diagram illustrating an example of the supply operation.

[0045] Figure 11 This is a graph illustrating an example of pressure changes within the buffer tank assembly during the recycling of the electronic supply by the electronic supply recycling device, and a timing diagram illustrating an example of the recycling operation.

[0046] Figure 12 This is a schematic diagram showing the structure of the buffer tank assembly and container of the electronic supply recycling device according to the fifth embodiment of the present invention.

[0047] Figure 13 This is a schematic diagram showing the basic structure of the electron supply and recycling device according to the sixth embodiment of the present invention.

[0048] Figure 14 This is a schematic diagram showing a modified example of the electron supply recycling device according to the fourth embodiment of the present invention. Detailed Implementation

[0049] Hereinafter, with reference to the accompanying drawings, a method for supplying and recycling an electron provider, and a method for recycling an electron provider according to embodiments of the present invention will be described in detail. However, the following embodiments are not intended to limit the invention to the extent claimed, and the combinations of features described in the embodiments are not all necessary for the solutions of the invention. Furthermore, in the following embodiments, the same or equivalent components are marked with the same symbols, and repeated descriptions are omitted. Additionally, in the embodiments, the arrangement, proportions, and dimensions of each component may be enlarged or reduced to show a state inconsistent with reality, and the description of some components may be omitted.

[0050] [First Implementation]

[0051] Figure 1 This is a schematic diagram showing the basic structure of the electron supply and recycling device according to the first embodiment of the present invention. Figure 2 This is a perspective view showing the structure of the buffer tank assembly and container of the electronic supply recycling device.

[0052] like Figure 1 As shown, the electron donor supply and recovery device 100 according to the first embodiment of the present invention includes: a plurality of containers C1, C2, C3, ..., Cn (n is a natural number of 2 or more, the same below), which are filled and sealed with liquid containing electron donors (hereinafter also referred to as "liquid") for microorganisms; and a buffer tank assembly 1, which includes a plurality of buffer tanks BT1, BT2, BT3, ..., BTn (n is a natural number of 2 or more, the same below) respectively connected to each of the containers C1 to Cn.

[0053] In addition, the electronic supply recovery device 100 includes: a pump mechanism 3, which includes automatic valves AV1, AV2, AV3, AV4, AV5, AV6 as a plurality of valve devices connected to the liquid injection side and the liquid discharge side of the buffer tank assembly 1, respectively, and a suction pump (pump device) P disposed on the liquid discharge side; and a control device (control unit) 2 for controlling the operation of the pump mechanism 3.

[0054] Furthermore, the electron feedstock supply and recovery device 100 includes: a supply tank (first tank) ST for storing liquid supplied to each container C1 to Cn; and a recovery tank (second tank) RT for storing liquid recovered from each container C1 to Cn or used waste liquid (hereinafter sometimes referred to as "waste liquid"). It should be noted that the buffer tank assembly 1, pump mechanism 3, and control device 2 of the electron feedstock supply and recovery device 100 are, for example, modularized into a portable device unit (not shown). Furthermore, each container C1 to Cn is immersed in the treated water W stored in a water tank WT containing nitrate nitrogen. Regarding the liquid supply performed by the electron feedstock supply and recovery device 100, this embodiment describes a filling supply as an example, but it is not limited to this.

[0055] Here, substances such as methanol, ethanol, propanol, toluene, benzene, and phenol can be used as electron donors for microorganisms, but are not limited to these; various known electron donor substances can be used. In this embodiment, alcohols such as methanol and ethanol are used as electron donors, and water containing about 60% of the electron donor is supplied and recovered as the liquid described above, but the ratio of electron donor to water is not limited to this.

[0056] Each container C1 to Cn may be formed, for example, into a sealed bag shape in which at least a portion is composed of a non-porous membrane, thus enabling it to seal the liquid. It should be noted that each container C1 to Cn is not limited thereto and may adopt various known shapes and structures. There are no particular limitations on each container C1 to Cn, as long as it allows the internal electron donor to penetrate through the non-porous membrane to supply the surrounding area.

[0057] It should be noted that in the electron supply and recycling device 100 according to this embodiment, the pipes connecting each container C1 to Cn, the buffer tank assembly 1, each buffer tank BT1 to BTn, the pump mechanism 3, the supply tank ST, and the recycling tank RT can be, for example, known pipes and flexible hoses or other tubular connecting components. Therefore, unless otherwise specified, the pipes of the electron supply and recycling device 100 are all composed of these tubular connecting components.

[0058] like Figure 1 and Figure 2As shown, the buffer tank assembly 1 is configured such that multiple buffer tanks BT1 to BTn are arranged side-by-side in the horizontal direction, i.e., the X direction (first direction), and adjacent buffer tanks BT1 to BTn are connected to each other via pipes 4. Each buffer tank BT1 to BTn in the buffer tank assembly 1 is made of a rigid resin or metal material with a structure whose internal volume does not change due to pressure variations, and is formed into a cylindrical shape whose central axis extends along a vertical direction (perpendicular direction), i.e., the Z direction (second direction), intersecting the X direction. It should be noted that the connection method between each buffer tank BT1 to BTn and each container C1 to Cn can be such that each buffer tank is connected to only one corresponding container C1 to Cn.

[0059] Buffer tank assembly 1 is positioned above each container C1 to Cn in the Z direction, at a height difference h between the lower ends of each container C1 to Cn and the lower ends of each buffer tank BT1 to BTn. Buffer tank BT1, located upstream of the liquid injection side of buffer tank assembly 1, is connected to supply tank ST via automatic valve (first valve device) AV1. Buffer tank BTn, located downstream of the liquid discharge side of buffer tank assembly 1, is connected to recovery tank RT via automatic valve (third valve device) AV3, suction pump P, and automatic valve (sixth valve device) AV6.

[0060] Each buffer tank BT1 to BTn in the buffer tank assembly 1 has: a first connection port 5 and a second connection port 6 arranged side by side in the X direction at the upper end (one side end) in the Z direction; and a third connection port 7 arranged at the center of the lower end (the other side end) in the Z direction. Each buffer tank BT1 to BTn is connected to each container C1 to Cn through the third connection port 7 and the pipe 4c.

[0061] The buffer tank assembly 1 specifically has the following structure: the second connection port 6 and the first connection port 5 of adjacent buffer tanks BT1 to BTn are connected in series through a pipe 4 arranged in a straight line along the X direction from the upstream buffer tank BT1 to the downstream buffer tank BTn.

[0062] Furthermore, the buffer tank assembly 1 is configured such that the first connection port 5 of the upstream buffer tank BT1 and the second connection port 6 of the downstream buffer tank BTn are connected to different automatic valves AV1 and AV3 respectively through pipes 4a and 4b.

[0063] On the other hand, the automatic valve AV1 of the pump mechanism 3 is configured to connect one side and the other side of the pipe 4a midway through the pipe. The pipe 4a is connected to the first connection port 5 of the buffer tank BT1 located upstream of the buffer tank assembly 1, and to the supply tank ST pipe connection port 8a. In addition, the automatic valve (second valve device) AV2 functions as an atmospheric open valve with one side open to the atmosphere. The other side of the valve is connected to the pipe 4a located between the first connection port 5 of the buffer tank BT1 located upstream of the buffer tank assembly 1 and the automatic valve AV1.

[0064] Automatic valve AV3 is configured to be connected midway through pipe 4b, which is connected to the second connection port 6 of the downstream buffer tank BTn of the buffer tank assembly 1, and to the pipe connection port 8c of the recovery tank RT. It should be noted that on pipe 4b, from the downstream buffer tank BTn to the recovery tank RT, automatic valve AV3, suction pump P, and automatic valve AV6 are sequentially connected. Therefore, specifically, automatic valve AV3 has one side connected via pipe 4b to the second connection port 6 of the downstream buffer tank BTn, and the other side connected via pipe 4b to the suction port (not shown, the same below) of suction pump P, positioned between the two.

[0065] Automatic valve (fourth valve device) AV4 is configured to be connected midway through pipe 4d, which branches off from pipe 4c between each buffer tank BT1-BTn and each container C1-Cn, and connects to pipe 4b on the suction port side of suction pump P. Therefore, specifically, automatic valve AV4 has one side connected in parallel to the third connection port 7 of each buffer tank BT1-BTn of buffer tank assembly 1 via pipe 4d branching off from pipe 4c, and the other side connected to the suction port of suction pump P via pipe 4b connected to pipe 4d, positioned between the two. It should be noted that, according to this connection method, the other side of automatic valves AV3 and AV4 will be connected in parallel to the suction port of suction pump P.

[0066] Automatic valve (fifth valve device) AV5 is configured to be connected midway through pipe 4e, which branches off from pipe 4b on the side of the discharge port (not shown, the same below) of suction pump P and connects to pipe connection port 8b of supply tank ST. In other words, automatic valve AV5 has one side connected to the discharge port side of suction pump P via pipes 4e and 4b, and the other side connected to pipe connection port 8b of supply tank ST via pipe 4e, positioned between the two.

[0067] Furthermore, automatic valve AV6 is configured to connect midway along pipe 4b between the outlet of suction pump P and recovery tank RT. That is, one side of automatic valve AV6 is connected to the outlet side of suction pump P via pipe 4b, and the other side is connected to the pipe connection port 8c of recovery tank RT via pipe 4b, positioned between the two. It should be noted that, according to this connection method, one side of automatic valves AV5 and AV6 is connected in parallel to the outlet of suction pump P via pipes 4e and 4b respectively, while the other side of automatic valves AV5 and AV6 is connected to the pipe connection port 8b of supply tank ST via pipe 4e and to the pipe connection port 8c of recovery tank RT via pipe 4b respectively.

[0068] The control device 2 can be composed of a dedicated system controller for controlling valves and pumps. The control device 2 operates the pump mechanism 3, which is connected and configured as described above, to bring the pressure in each buffer tank BT1-BTn and each container C1-Cn of the buffer tank assembly 1 to a negative pressure below a predetermined pressure (e.g., atmospheric pressure). Thus, when supplying liquid, the control device 2 operates the pump mechanism 3 to supply liquid from the supply tank ST to each container C1-Cn through negative pressure; simultaneously, when recovering liquid, the control device 2 operates the pump mechanism 3 to recover the liquid or used waste liquid from each container C1-Cn to the recovery tank RT through negative pressure.

[0069] It should be noted that, in the electron donor supply and recovery device 100, as described above, each buffer tank BT1 to BTn is provided as a buffer tank assembly 1 above each container C1 to Cn in the Z direction. Therefore, in order to uniformly fill and supply the liquid containing the electron donor to each container C1 to Cn, the internal pressure of the buffer tank assembly 1 (the pressure inside each buffer tank BT1 to BTn) needs to be lower than atmospheric pressure relative to the head h between each buffer tank BT1 to BTn and each container C1 to Cn during supply.

[0070] Therefore, in the electronic supply and recovery device 100 according to this embodiment, a flow regulating valve FCV, which serves as a flow regulating mechanism, is provided on the other side of the valve of the automatic valve AV1 on the pipeline 4a, between the pipeline connection port 8a and the supply tank ST. Through this flow regulating valve FCV, a sufficiently low pressure (negative pressure) lower than the head h can be obtained by utilizing the pressure loss relative to the head h.

[0071] It should be noted that, in addition to the aforementioned flow control valve (FCV), the flow regulation mechanism can also be composed of components such as an orifice and a thin tube. Furthermore, as... Figure 2As shown, each container C1 to Cn can also be configured such that the pipe 4ca connected to the pipe connection port 8d is detachably connected to the pipe 4c via the pipe coupler 9, thereby connecting to the third connection port 7 of each buffer tank BT1 to BTn respectively. In the following operation description, the case where each container C1 to Cn is directly connected to the third connection port 7 via the pipe 4c is described, but it is not limited to this.

[0072] [The supply operations of electronic providers]

[0073] Next, refer to Figure 3 This describes the supply operation of liquid containing an electron provider performed by the electron provider supply and recovery device 100. Figure 3 This is a timing diagram illustrating an example of the supply operation performed by the electronic supply recovery device 100. It should be noted that since the control device 2 is the main controller of the supply operation, a detailed description is omitted here.

[0074] First, open automatic valves AV3 and AV5, and simultaneously start the suction pump P(t1). Next, when the pressure in each buffer tank BT1-BTn of buffer tank assembly 1 becomes less than the negative pressure h between each buffer tank BT1-BTn and each container C1-Cn, open automatic valve AV1(t2). Thus, the liquid in supply tank ST is transported to each buffer tank BT1-BTn of buffer tank assembly 1 through pipes 4a and 4.

[0075] It should be noted that, for example, liquid delivery to the buffer tank assembly 1 is carried out until a preset time has elapsed in the control device 2. This liquid delivery can also be performed, for example, by installing a level sensor on the supply tank ST and, based on the information from the level sensor, delivering a preset volume of liquid to the buffer tank assembly 1.

[0076] Then, to ensure a uniform supply of liquid to each of the containers C1 to Cn, the automatic valve AV1(t3) is closed. As a result, the pressure in each of the buffer tanks BT1 to BTn of the buffer tank assembly 1 is lower than the negative pressure during liquid delivery, and the liquid that has been immersed in each of the containers C1 to Cn through the pipe 4c is temporarily returned to each of the buffer tanks BT1 to BTn.

[0077] Furthermore, to ensure a uniform supply of liquid to each of the containers C1 to Cn, the automatic valve AV2 is repeatedly opened and closed (t4-t5) for a predetermined period (until the predetermined period has elapsed) at a preset time and number of times. This causes the pressure (negative pressure) within each of the buffer tanks BT1 to BTn in the buffer tank assembly 1 to gradually return to atmospheric pressure over an appropriate period. Additionally, this reduces the movement of liquid between the buffer tanks BT1 to BTn caused by pressure differences, while simultaneously allowing the liquid to fall under its own weight, thus supplying the liquid from each of the buffer tanks BT1 to BTn to each of the containers C1 to Cn through filling.

[0078] It should be noted that during the process of restoring the pressure in each buffer tank BT1 to BTn of the buffer tank assembly 1 to atmospheric pressure over a specified period, the liquid moving in each buffer tank BT1 to BTn due to the pressure difference between them is recovered back to the supply tank ST through the action of the suction pump P via pipe 4b, automatic valve AV3, suction pump P, automatic valve AV5, and pipe 4e, thereby making the supply of liquid to each container C1 to Cn uniform.

[0079] Thus, after the liquid moving in each buffer tank BT1 to BTn has finished being recovered to the supply tank ST, automatic valves AV3 and AV5 are closed, and the suction pump P(t5) is stopped. Then, when the pressure in each buffer tank BT1 to BTn of the buffer tank assembly 1 approaches atmospheric pressure, automatic valve AV2 is opened to allow access to the atmosphere. After the liquid filling supply to each container C1 to Cn is completed, automatic valve AV2 is closed, ending the supply operation.

[0080] [Electron donor recycling process]

[0081] Next, refer to Figure 4 This describes the recovery operation of liquid containing the electron provider performed by the electron provider supply recovery device 100. Figure 4 This is a timing diagram illustrating an example of the recycling operation performed by the electron supply recycling device 100. It should be noted that since the control unit 2 is the main controller of the recycling operation, a detailed description is omitted here.

[0082] First, open automatic valves AV2, AV4, and AV6, and simultaneously start the suction pump P(t11). This allows the residual liquid (waste liquid) in each of the buffer tanks BT1 to BTn of the buffer tank assembly 1 to be recovered into the recovery tank RT within a preset time period via pipe 4d, automatic valve AV4, pipe 4b, suction pump P, and automatic valve AV6.

[0083] Next, the automatic valve AV2 is closed, and the residual waste liquid in each container C1 to Cn is recovered within a preset time (t12). After the waste liquid recovery from each container C1 to Cn is completed, the automatic valves AV4 and AV6 are closed, and the suction pump P is stopped (t13). Then, in order to make the amount of residual waste liquid (recovery amount) in each buffer tank BT1 to BTn and each container C1 to Cn of the buffer tank assembly 1 uniform, the automatic valve AV2 is repeatedly opened and closed for a preset time and number of times (t13-t14).

[0084] This allows the pressure (negative pressure) within each buffer tank BT1 to BTn of buffer tank assembly 1 to gradually return to atmospheric pressure over a specified period of time. Furthermore, this reduces the movement of residual liquid (including used waste liquid) between buffer tanks BT1 to BTn caused by pressure differences. After restoring the pressure within each buffer tank BT1 to BTn to atmospheric pressure, the automatic valve AV2 (t14) is closed. This concludes the process of recovering waste liquid from the recovery tank RT.

[0085] According to the aforementioned electronic supply and recovery device 100, liquid is temporarily filled into each of the buffer tanks BT1-BTn, which are connected one-to-one with each of the containers C1-Cn, and then the liquid in each of the buffer tanks BT1-BTn is supplied to each of the containers C1-Cn. Since the internal volume of each of the buffer tanks BT1-BTn remains unchanged, an accurate amount of liquid can be supplied to each of the containers C1-Cn. Moreover, the filling of liquid into each of the buffer tanks BT1-BTn is carried out by the negative pressure generated by the suction pump P, while the supply to each of the containers C1-Cn is carried out by natural descent, so no pressure load is applied to the containers C1-Cn.

[0086] Furthermore, when opening the buffer tanks BT1 to BTn to the atmosphere, the atmosphere is not opened completely at once. Instead, the pump mechanism 3 is precisely controlled by the control device 2 to gradually raise the pressure inside the buffer tanks BT1 to BTn from negative pressure to atmospheric pressure. Therefore, when opening the atmosphere, the movement of liquid containing the electron donor between the buffer tanks BT1 to BTn can be minimized, thereby enabling the liquid to be uniformly filled from the buffer tank assembly 1 and supplied to each container C1 to Cn. In addition, the used waste liquid remaining in each container C1 to Cn can be automatically recovered to the recovery tank RT as much as possible. Thus, the supply and recovery of the electron donor can be carried out efficiently.

[0087] Furthermore, according to the electron feed supply and recovery device 100, since the pump mechanism 3, which includes multiple automatic valves AV1 to AV6, is connected to the buffer tank assembly 1, there is no need to install separate valve devices for each container C1 to Cn, nor is a flow meter required, thereby reducing the number of components and suppressing equipment costs. In addition, because it has a structure that easily unifies the overall piping conditions, including the pipes 4c between the buffer tank assembly 1 and each container C1 to Cn, the supply and recovery of liquid containing the electron feed can be uniform and accurate. Thus, the electron feed supply and recovery device 100 according to this embodiment can supply and recover liquid containing the electron feed to each container C1 to Cn, while reducing the number of components to lower equipment costs, preventing container breakage, and operating accurately and efficiently, thereby achieving labor-saving operation.

[0088] [Second Implementation]

[0089] Figure 5 This is a schematic diagram illustrating the structure of the buffer tank assembly and container of the electron supply and recycling device according to the second embodiment of the present invention. It should be noted that, including... Figure 5 In subsequent explanations, where parts are repeated from those already explained, the same symbols are sometimes used and the explanation is omitted.

[0090] like Figure 5 As shown, the electron supply and recycling device 100A according to the second embodiment has the same basic structure as the electron supply and recycling device 100 of the first embodiment, but the connection method of each buffer tank BT1 to BTn and each container C1 to Cm (m is a natural number of 2 or more and less than n, the same below) of the buffer tank assembly 1 is different from that of the first embodiment.

[0091] In other words, in the electronic supply and recycling device 100A, one container is connected to multiple buffer tanks. Specifically, for example, container C1 is connected to buffer tanks BT1 and BT2, and container Cm is connected to buffer tanks BTn-2, BTn-1, and BTn. Figure 5 The containers C1 to Cm shown are configured to have a larger capacity than the containers C1 to Cn of the first embodiment.

[0092] It should be noted that in the example shown, buffer tanks BT1 and BT2 are connected to container C1 via a pipe 4c extending from the third connection port 7 and connecting midway, and buffer tanks BTn-2 to BTn are connected to container Cm via three pipes 4c extending from the third connection port 7, but this is not the only example. As long as a container connects multiple buffer tanks, various connection methods can be used.

[0093] According to the second embodiment of the electron supply and recovery device 100A, by utilizing containers C1 to Cm with larger volumes, the number of containers immersed in the treated water W in the water tank WT can be reduced. Furthermore, by designing the connection method of the pipe 4c, it can be used directly without changing the structure of the buffer tank assembly 1 of the first embodiment for supplying and recovering liquid containing the electron supply. Thus, the same effects as in the first embodiment can be achieved, and container maintenance time can be reduced.

[0094] [Third Implementation]

[0095] Figure 6 This is a schematic diagram showing the basic structure of the electron supply and recycling device according to the third embodiment of the present invention.

[0096] like Figure 6 As shown, the electron supply and recycling device 100B according to the third embodiment has the same basic structure as the electron supply and recycling device 100 according to the first embodiment, but the difference is that multiple buffer tank assemblies 1 and 1' are provided, which are respectively connected to containers C1 to Cn immersed in multiple water tanks WT and WT', and are connected in parallel with the pump mechanism 3.

[0097] In other words, in the electronic supply and recovery device 100B, the pipe 4a connected to the first connection port 5 of the buffer tank BT1 located upstream of the buffer tank assembly 1, and the pipe 4a' connected to the first connection port 5 of the buffer tank BT1 located upstream of the buffer tank assembly 1', are respectively connected to one side of the valve of the automatic valve AV1.

[0098] In addition, the pipe 4b connected to the second connection port 6 of the buffer tank BTn configured downstream of the buffer tank assembly 1, and the pipe 4b' connected to the second connection port of the buffer tank BTn configured downstream of the buffer tank assembly 1', are respectively connected to one side of the valve of the automatic valve AV3.

[0099] Furthermore, pipe 4d, branching from pipe 4c between buffer tank assembly 1 and each container C1 to Cn, and pipe 4d', branching from pipe 4c between buffer tank assembly 1' and each container C1 to Cn, are respectively connected to one side of the valve of automatic valve AV4. It should be noted that the example shown illustrates the parallel connection of two buffer tank assemblies 1 and 1', but it is not limited to this; three or more buffer tank assemblies can also be connected in parallel.

[0100] According to the electron donor supply and recovery device 100B of the third embodiment, the same effects as those of the first embodiment can be achieved. Furthermore, when denitrifying the treated water W stored in multiple water tanks WT and WT', the supply and recovery of liquid containing electron donors to each container C1 to Cn can be carried out simultaneously. Therefore, the denitrification capacity and efficiency of the electron donor supply and recovery device 100B can be further improved.

[0101] [Modifications of the first embodiment]

[0102] Figure 7 This is a schematic diagram showing a modified example of the electron supply recycling device according to the first embodiment of the present invention.

[0103] like Figure 7 As shown, the electron supply and recycling device 100 of the modified embodiment of the first embodiment has the following structure: each container C1 to Cn connected to each buffer tank BT1 to BTn of the buffer tank assembly 1, by... Figure 2 The pipe fittings 9 shown are connected by unitizing them according to their quantity to form pipe fitting units CU1~CUp (p is a positive integer, the same below).

[0104] In other words, for example, each container C1 to Cn in multiple water tanks WT1, WT2, ..., WTp (p is a positive integer, the same below) is pre-connected to the pipe fittings 9 of pipe fitting units CU1 to CUp via pipe 4ca. The connection between each container C1 to Cn in each water tank WT1 to WTp and each buffer tank BT1 to BTn in buffer tank assembly 1 is achieved by assembling and disassembling the pipe fittings 9 of pipe fitting units CU1 to CUp, thereby allowing for free assembly and disassembly.

[0105] According to this modified example of the electron donor supply and recovery device 100, for each water tank WT1 to WTp, the number of containers C1 to Cn is a multiple of the number of buffer tanks BT1 to BTn constituting the buffer tank assembly 1, and the supply and recovery of liquid containing the electron donor can be carried out using a single buffer tank assembly 1. Therefore, the denitrification processing capacity of the electron donor supply and recovery device 100 can be continuously maintained and the processing capacity increased without significantly expanding the device structure.

[0106] [Fourth Implementation]

[0107] Figure 8 This is a schematic diagram showing the basic structure of the electron supply and recycling device according to the fourth embodiment of the present invention. Figure 9 This is a perspective view showing the structure of the buffer tank assembly and container of the electronic supply recycling device.

[0108] like Figure 8 As shown, the electron supply and recycling device 100C according to the fourth embodiment has the same basic structure as the electron supply and recycling device 100 of the first embodiment, but the structure of the buffer tank assembly 1A and the contents of the pump mechanism 3 are different from those of the first embodiment.

[0109] In other words, the electronic supply and recovery device 100C includes: multiple containers C1 to Cn; a buffer tank assembly 1A comprising multiple buffer tanks BT1 to BTn respectively connected to each of the containers C1 to Cn; and a pump mechanism 3, which includes automatic valves AV7, AV8A, AV8B, AV9, AV10, AV11, AV12 and a suction pump P respectively connected to the liquid injection side and the discharge side of the buffer tank assembly 1A.

[0110] In addition, the electron supply and recycling device 100C includes a control device 2, a supply tank ST, and a recycling tank RT. The buffer tank assembly 1A, pump mechanism 3, and control device 2 of the electron supply and recycling device 100C can be modularized into a portable device unit (not shown).

[0111] like Figure 8 and Figure 9 As shown, the buffer tank assembly 1A is configured such that multiple buffer tanks BT1 to BTn are arranged side by side along the X direction, and adjacent buffer tanks BT1 to BTn are connected by pipes 4. The basic structure and shape of each buffer tank BT1 to BTn in the buffer tank assembly 1A are the same as those in the first embodiment, but in this embodiment, they are formed as cylinders whose central axis extends along the Y direction (third direction) that intersects the X direction (first direction) and the Z direction (second direction), respectively.

[0112] Buffer tank assembly 1A is positioned above each container C1 to Cn in the Z direction, at a height difference h between the lower end of each container C1 to Cn and the lower end of each buffer tank BT1 to BTn. Buffer tank BT1, located upstream of the liquid injection side of buffer tank assembly 1A, is connected to supply tank ST via automatic valve (first valve device) AV7. Buffer tank BTn, located downstream of the liquid discharge side of buffer tank assembly 1A, is connected to recovery tank RT via automatic valve (third valve device) AV9, suction pump P, and automatic valve (sixth valve device) AV12.

[0113] Each buffer tank BT1 to BTn of the buffer tank assembly 1A has a lower first connection port 5 and an upper second connection port 6 arranged side by side on the lower and upper sides along the vertical direction (Z direction) at its front end (one end) in the Y direction. Each buffer tank BT1 to BTn is connected to each container C1 to Cn through the first connection port 5 and the pipe 4c.

[0114] Specifically, the buffer tank assembly 1A includes the following: the second connection port 6 and the first connection port 5 of the adjacent buffer tanks BT1 to BTn are connected in series from the upstream buffer tank BT1 to the downstream buffer tank BTn through a pipe 4 arranged parallel to each other in a direction that is obliquely downward relative to the Z direction.

[0115] Furthermore, the buffer tank assembly 1A is configured such that the first connection port 5 of the upstream buffer tank BT1 and the second connection port 6 of the downstream buffer tank BTn are connected to different automatic valves AV7 and AV9 respectively via pipes 4a and 4b.

[0116] On the other hand, the automatic valve AV7 of the pump mechanism 3 is configured such that one side and the other side of the valve are respectively connected to the middle of the pipeline 4a, which is connected to the first connection port 5 of the buffer tank BT1 located upstream of the buffer tank assembly 1A, and to the pipeline connection port 8a of the supply tank ST. In addition, the automatic valve (second valve device) AV8A functions as an atmospheric opening valve with one side open to the atmosphere, and the other side of the valve is connected to the pipeline 4a located between the first connection port 5 of the buffer tank BT1 located upstream of the buffer tank assembly 1A and the automatic valve AV7.

[0117] Automatic valve AV9 is configured to be connected midway through pipe 4b, which is connected to the second connection port 6 of the downstream buffer tank BTn of buffer tank assembly 1A, and to the pipe connection port 8c of recovery tank RT. It should be noted that on pipe 4b, from the downstream buffer tank BTn to the recovery tank RT, automatic valve (seventh valve device) AV8B, automatic valve AV9, suction pump P, and automatic valve AV12 are sequentially connected. Therefore, automatic valve AV9, specifically, has one side connected via pipe 4b to the second connection port 6 of the downstream buffer tank BTn, and the other side connected via pipe 4b to the suction port (not shown, the same below) of suction pump P, positioned between the two.

[0118] Automatic valve (fourth valve device) AV10 is configured to be connected midway through pipe 4d, which is connected in parallel to one side of automatic valve AV7 (connected to pipe 4a) and the other side of automatic valve AV8A, as well as the other side of automatic valve AV9 (connected to pipe 4b) and the suction port of suction pump P. Therefore, specifically, automatic valve AV10 has one side connected via pipes 4d and 4a to the first connection port 5 of buffer tank BT1 located upstream, and the other side connected via pipes 4d and 4b to the suction port of suction pump P, positioned between the two. It should be noted that, according to this connection method, the other sides of automatic valves AV9 and AV10 will be connected in parallel to the suction port of suction pump P.

[0119] Automatic valve (fifth valve device) AV11 is configured to be connected midway through pipe 4e, which branches off from pipe 4b on the side of the discharge port (not shown, the same below) of suction pump P and connects to pipe connection port 8b of supply tank ST. In other words, automatic valve AV11 has one side connected to the discharge port side of suction pump P via pipes 4e and 4b, and the other side connected to pipe connection port 8b of supply tank ST via pipe 4e, positioned between the two.

[0120] Furthermore, automatic valve AV12 is configured to connect midway along pipe 4b between the outlet of suction pump P and recovery tank RT. Specifically, one side of automatic valve AV12 is connected to the outlet side of suction pump P via pipe 4b, and the other side is connected to the pipe connection port 8c of recovery tank RT via pipe 4b, positioned between the two. It should be noted that, according to this connection method, one side of automatic valves AV11 and AV12 is connected in parallel to the outlet of suction pump P via pipes 4e and 4b respectively, and the other side of automatic valves AV11 and AV12 is connected to the pipe connection port 8b of supply tank ST via pipe 4e and to the pipe connection port 8c of recovery tank RT via pipe 4b respectively.

[0121] It should be noted that the automatic valve (7th valve device) AV8B functions as an atmospheric open valve with one side open to the atmosphere, and the other side of the valve is connected to the pipe 4b located between the second connection port 6 of the buffer tank BTn downstream of the buffer tank assembly 1A and the automatic valve AV9.

[0122] The control device 2 can be configured the same as in the first embodiment. Furthermore, the flow regulating valve FCV, which serves as the flow regulating mechanism, can also be configured the same as in the first embodiment. Additionally, as... Figure 9As shown, each container C1 to Cn can also be configured such that the pipe 4ca connected to the pipe connection port 8d is detachably connected to the pipe 4c via the pipe fitting (joint) 9, thereby connecting to the first connection port 5 of each buffer tank BT1 to BTn respectively. In the following operation description, the case where each container C1 to Cn is directly connected to the first connection port 5 via the pipe 4c is described, but it is not limited to this.

[0123] [The supply operations of electronic providers]

[0124] Next, refer to Figure 10 This describes the supply operation of liquid containing the electron provider performed by the electron provider supply and recovery device 100C. It should be noted that since the control device 2 is the main controller of the supply operation, a detailed description is omitted here. Figure 10 This is a graph illustrating an example of pressure changes within the buffer tank assembly during the supply of electrons by the electron supply recovery device, and a timing diagram illustrating an example of the supply operation. Figure 10 The example described is based on the case where the buffer tank assembly 1A consists of 20 buffer tanks (BT1 to BT20), but the number of tanks is not limited to this.

[0125] First, open automatic valves AV9 and AV11, and simultaneously start the suction pump P(t21). Then, as shown in period tp1, when the pressure in each buffer tank BT1-BTn of buffer tank assembly 1A becomes less than the negative pressure h between each buffer tank BT1-BTn and each container C1-Cn, open automatic valve AV7(t22). Then, as shown in period tp2, the liquid in supply tank ST is transported to each buffer tank BT1-BTn of buffer tank assembly 1A through pipes 4a and 4.

[0126] It should be noted that, for example, liquid delivery to the buffer tank assembly 1A is carried out until a preset time (period tp2) has elapsed in the control device 2. This liquid delivery can also be carried out, for example, by installing a level sensor on the supply tank ST, and delivering a preset volume to the buffer tank assembly 1A based on the information from the level sensor.

[0127] Then, to ensure a uniform supply of liquid to each of the containers C1 to Cn, the automatic valve AV7 (t23) is closed. As a result, as shown in period tp3, the pressure in each of the buffer tanks BT1 to BTn of the buffer tank assembly 1A is further reduced, and the liquid that has been immersed in each of the containers C1 to Cn through the pipe 4c is temporarily returned to each of the buffer tanks BT1 to BTn.

[0128] Furthermore, to ensure a uniform supply of liquid to each of the containers C1 to Cn, the automatic valve AV8A is repeatedly opened and closed (t24-t26) for a predetermined time and number of times within a specified period (period tp4). This causes the pressure (negative pressure) within each of the buffer tanks BT1 to BTn of the buffer tank assembly 1A to gradually return to atmospheric pressure over the appropriate time specified (period tp4). Additionally, as shown in period tp4, this reduces the movement of liquid between the buffer tanks BT1 to BTn caused by pressure differences, while simultaneously allowing the liquid to fall under its own weight, thus supplying the liquid from each of the buffer tanks BT1 to BTn to each of the containers C1 to Cn through filling.

[0129] It should be noted that during the process of restoring the pressure in each buffer tank BT1 to BTn of the buffer tank assembly 1A to atmospheric pressure over a specified period (period tp4), as shown in the enlarged display area surrounded by the dotted line in the figure, the liquid moving in each buffer tank BT1 to BTn due to the pressure difference between each buffer tank is recovered to the supply tank ST within period tp5 through the action of the suction pump P, via pipe 4b, automatic valve AV9, suction pump P, automatic valve AV11, and pipe 4e, thereby uniformizing the supply of liquid to each container C1 to Cn.

[0130] After period tp5, automatic valves AV9 and AV11 are closed, and suction pump P(t25) is stopped. Then, after period tp4, when the pressure in each buffer tank BT1 to BTn of buffer tank assembly 1A is close to atmospheric pressure, automatic valve AV8A is opened to allow access to the atmosphere. After the liquid filling supply to each container C1 to Cn is completed, automatic valve AV8A is closed, ending the supply operation. It should be noted that this supply operation also applies to the supply operation in the first embodiment, and the pressure change will be similar to... Figure 10 The pressure changes follow the same trajectory.

[0131] [Electron donor recycling process]

[0132] Next, refer to Figure 11 This describes the recovery operation of the liquid containing the electron supply in the electron supply recovery device 100C. It should be noted that since the control device 2 is the main controller of the recovery operation, a detailed description is omitted here. Figure 11 This is a graph illustrating an example of pressure changes within the buffer tank assembly during the recovery of the electron supply by the electron supply recovery device, and a timing diagram illustrating an example of the recovery operation. Figure 11 The example described is based on the case where the buffer tank assembly 1A consists of 20 buffer tanks (BT1 to BT20), but the number of tanks is not limited to this.

[0133] First, open automatic valves AV10 and AV12, and simultaneously start the suction pump P (t31), which operates for a preset time (period tp6). Thus, as shown in period tp6, through the first connection port 5 of the upstream buffer tank BT1, pipes 4a and 4d, automatic valve AV10, suction pump P, and automatic valve AV12, the liquid (waste liquid) remaining in each container C1 to Cn is recovered to the recovery tank RT via the buffer tanks BT1 to BTn of the buffer tank assembly 1A within the time period shown in period tp6.

[0134] Next, the automatic valve AV10 is closed and the automatic valve AV9 is opened, and the suction pump P is used to siphon the contents of the buffer tank assembly 1A (t32). As shown in tp7, the pressure in each buffer tank BT1 to BTn is reduced to below the head h (becoming a negative pressure less than the head h), thereby drawing the residual waste liquid in each container C1 to Cn into each buffer tank BT1 to BTn for temporary storage.

[0135] Then, the automatic valve AV9 is closed, and the automatic valve AV10 is opened. The automatic valve AV8B is repeatedly opened and closed within a preset time and number of cycles for a specified period (period tp8) (t33-t34). This maintains a constant pressure (negative pressure) within each buffer tank BT1-BTn of the buffer tank assembly 1A for the specified period (period tp8). While ensuring that waste liquid does not flow back into each container C1-Cn, air is supplied to each buffer tank BT1-BTn of the buffer tank assembly 1A through the second connection port 6 of the downstream buffer tank BTn.

[0136] After air is replenished, the waste liquid temporarily stored in each buffer tank BT1 to BTn will be transported sequentially from the downstream buffer tank BTn to the upstream buffer tank BT through pipeline 4, with minimal residual amount. Then, the transported waste liquid is recovered to the recovery tank RT through the first connection port 5 of the upstream buffer tank BT1, pipeline 4a, pipeline 4d, automatic valve AV10, pipeline 4b, suction pump P, and automatic valve AV12.

[0137] Then, the actions (t32-t33 and t33-t34) during periods tp7 and tp8, as described above, are performed alternately a preset number of times (e.g., Figure 11After 7 times in each example, to ensure a uniform amount of residual waste liquid (recovery volume) in each buffer tank BT1-BTn and in pipes 4c and 4, the automatic valve AV8A is repeatedly opened and closed (t35) for a preset time and number of times. Thus, after an appropriate period of time, the pressure (negative pressure) in each buffer tank BT1-BTn of the buffer tank assembly 1A is gradually restored to atmospheric pressure, and then the automatic valve AV8A is closed. This concludes the process of recovering waste liquid to the recovery tank RT.

[0138] According to the above-described electronic supply and recycling device 100C, not only can the same effects as in the first embodiment be achieved, but the number of pipes and joints can also be reduced. Therefore, the number of components in the device structure can be reduced, resulting in lower costs.

[0139] [Fifth Implementation]

[0140] Figure 12 This is a schematic diagram showing the structure of the buffer tank assembly and container of the electronic supply recycling device according to the fifth embodiment of the present invention.

[0141] like Figure 12 As shown, the electron supply and recycling device 100D of the fifth embodiment has the same basic structure as the electron supply and recycling device 100C of the fourth embodiment, but the connection method of each buffer tank BT1 to BTn of the buffer tank assembly 1A and each container C1 to Cm (m is a natural number of 2 or more and less than n, the same below) is different from that of the fourth embodiment.

[0142] In other words, in the electronic supply and recycling device 100D, a container is connected to multiple buffer tanks. Specifically, for example, buffer tanks BT1 and BT2 are connected to container C1 via pipe 4c, and buffer tanks BTn-2, BTn-1, and BTn are connected to container Cm via pipe 4c. Figure 12 The containers C1 to Cm shown are configured to have a larger capacity than the containers C1 to Cn of the fourth embodiment.

[0143] According to the fifth embodiment of the electron supply and recovery device 100D, by utilizing larger capacity containers C1 to Cm, the number of containers immersed in the treated water W in the water tank WT can be reduced, and the structure of the buffer tank assembly 1A of the fourth embodiment can be used directly for the supply and recovery of liquid containing electron supplies without changing it. Thus, the same effects as in the fourth embodiment can be obtained, and container maintenance time can be reduced.

[0144] [Sixth Implementation]

[0145] Figure 13This is a schematic diagram showing the basic structure of the electron supply and recycling device according to the sixth embodiment of the present invention.

[0146] like Figure 13 As shown, the electron supply and recycling device 100E according to the sixth embodiment has the same basic structure as the electron supply and recycling device 100C of the fourth embodiment. However, the difference from the fourth embodiment is that multiple buffer tank assemblies 1A and 1A' are provided. They are respectively connected to containers C1 to Cn immersed in multiple water tanks WT and WT', and are connected in parallel with the pump mechanism 3.

[0147] In other words, in the electronic supply and recovery device 100B, the pipe 4a connected to the first connection port 5 of the buffer tank BT1 located upstream of the buffer tank assembly 1A, and the pipe 4a' connected to the first connection port 5 of the buffer tank BT1 located upstream of the buffer tank assembly 1A', are respectively connected to one side and the other side of the valve of the automatic valve AV7.

[0148] Furthermore, pipe 4b, which connects to the second connection port 6 of the downstream buffer tank BTn of buffer tank assembly 1A, and pipe 4b', which connects to the second connection port 6 of the downstream buffer tank BTn of buffer tank assembly 1A', are respectively connected to one side and the other side of the valve of automatic valve AV9. It should be noted that the illustrated example shows the case of two buffer tank assemblies 1A and 1A' connected in parallel, but it is not limited to this, and three or more buffer tank assemblies can also be connected in parallel.

[0149] According to the electron donor supply and recovery device 100E of the sixth embodiment, the same effects as those of the fourth embodiment can be achieved. Moreover, when denitrifying the treated water W stored in multiple water tanks WT and WT', the supply and recovery of liquid containing the electron donor can be carried out simultaneously in each container C1 to Cn. As a result, the denitrification capacity and processing efficiency of the electron donor supply and recovery device 100E can be further improved.

[0150] [Modifications of the fourth embodiment]

[0151] Figure 14 This is a schematic diagram showing a modified example of the electron supply recycling device according to the fourth embodiment of the present invention.

[0152] like Figure 14 As shown, the electron supply and recycling apparatus 100C of the modified embodiment of the fourth embodiment has the following structure: each container C1 to Cn of each buffer tank BT1 to BTn connected to the buffer tank assembly 1A, by... Figure 7The pipe fittings 9 shown are connected by unitizing them according to their quantity to form pipe fitting units CU1~CUp (p is a positive integer, the same below).

[0153] In other words, for example, each container C1 to Cn in multiple water tanks WT1, WT2, ..., WTp (p is a positive integer, the same below) is pre-connected to the pipe fittings 9 of pipe fitting units CU1 to CUp via pipe 4ca. The connection between each container C1 to Cn in each water tank WT1 to WTp and each buffer tank BT1 to BTn in the buffer tank assembly 1A is achieved by assembling and disassembling the pipe fittings 9 of pipe fitting units CU1 to CUp, thereby allowing for free assembly and disassembly.

[0154] According to this modified example of the electron donor supply and recovery device 100C, for each water tank WT1 to WTp, the number of containers C1 to Cn is a multiple of the number of buffer tanks BT1 to BTn constituting the buffer tank assembly 1A. Therefore, the denitrification processing capacity of the electron donor supply and recovery device 100C can be continuously maintained and the processing capacity increased without significantly expanding the device structure.

[0155] The foregoing has described several embodiments of the present invention, but these embodiments are provided as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included both within the scope and spirit of the invention and within the scope of the invention as described in the claims and its equivalents.

[0156] Explanation of reference numerals in the attached figures

[0157] 1,1A Buffer Tank Assembly

[0158] 2. Control device

[0159] Pipes 4,4a~4e

[0160] 5. First connection port

[0161] 6. Second connection port

[0162] 7. Third connection port

[0163] Pipe connection ports 8a~8c

[0164] 9 Pipe fittings

[0165] AV1~AV12 Automatic Valves

[0166] BT1 to BTn buffer tanks

[0167] C1~Cn containers

[0168] ST supply tank

[0169] RT recycling tank

[0170] W is the water being treated

[0171] WT water tank

[0172] 100 Electronic supply recycling device

Claims

1. An electronic supply and recycling device, comprising: Multiple sealed, bag-like containers containing liquids containing electron donors supplied to microorganisms; A buffer tank assembly, disposed above the container, is composed of multiple buffer tanks connected in series, the internal volume of which does not change with pressure. One side of the buffer tank assembly is the liquid injection side, and the other side is the liquid discharge side. The pump mechanism includes a plurality of valve devices connected to the liquid injection side and the liquid discharge side of the buffer tank assembly, respectively, and a pump device connected to the liquid discharge side. A control unit that controls the operation of the pump mechanism; A first tank, disposed on the liquid injection side of the buffer tank assembly, stores the liquid supplied to the container; and The second tank is disposed on the liquid discharge side of the buffer tank assembly and stores the liquid recovered from the container or the used waste liquid; The buffer tank is connected to only one corresponding container. The control unit controls the pump mechanism to supply the liquid from the first tank to multiple buffer tanks of the buffer tank assembly, to supply the liquid contained in the buffer tanks to the container, and controls the pump mechanism to recover the liquid or the waste liquid from the container to the second tank.

2. The electronic supply and recycling device as described in claim 1, wherein, The buffer tank is formed in a cylindrical shape and configured such that its central axis extends in a vertical direction. It has a first connection port and a second connection port arranged side by side at the upper end in a horizontal direction, and a third connection port arranged at the lower end, and is connected to the container through the third connection port. The buffer tank assembly has the plurality of buffer tanks arranged in a horizontal direction; The second connection port of the front buffer tank and the first connection port of the rear buffer tank, which are arranged adjacent to each other, are connected by pipes from the buffer tank located upstream of the liquid injection side to the buffer tank located downstream of the liquid discharge side. The first connection port of the buffer tank located upstream and the second connection port of the buffer tank located downstream are respectively connected to different valve devices among the plurality of valve devices.

3. The electronic supply and recycling device as described in claim 2, wherein, The pump mechanism includes: A first valve device is provided between the first connection port of the buffer tank arranged upstream of the buffer tank assembly and the first tank; A second valve device for atmospheric opening is connected to the first connection port of the buffer tank located upstream; A third valve device is provided between the second connection port of the buffer tank located downstream and the suction port of the pump device; A fourth valve device is disposed between the third connection port of the plurality of buffer tanks of the buffer tank assembly and the suction port of the pump device; A fifth valve device is located between the outlet of the pump device and the first tank; and The sixth valve device is located between the outlet of the pump device and the second tank.

4. The electronic supply and recycling device as described in claim 1, wherein, The buffer tank is formed in a cylindrical shape and is configured such that its central axis extends in a horizontal direction. At one end of the central axis, there are a first connection port and a second connection port arranged in parallel on the lower and upper sides in a vertical direction, respectively, and the buffer tank is connected to the container through the first connection port. The buffer tank assembly has the plurality of buffer tanks arranged in a horizontal direction; The second connection port of the adjacent front buffer tank and the first connection port of the rear buffer tank are connected by pipes from the upstream buffer tank on the liquid injection side to the downstream buffer tank on the liquid discharge side. The first connection port of the buffer tank located upstream and the second connection port of the buffer tank located downstream are respectively connected to different valve devices among the plurality of valve devices.

5. The electronic supply and recycling device as described in claim 4, wherein, The pump mechanism includes: A first valve device is provided between the first connection port of the upstream buffer tank in the buffer tank assembly and the first tank. A second valve device for atmospheric opening is connected to the first connection port of the buffer tank located upstream; A third valve device is provided between the second connection port of the buffer tank located downstream and the suction port of the pump device; A fourth valve device is disposed between the first connection port of the buffer tank located upstream and the suction port of the pump device; The fifth valve device is located between the outlet of the pump device and the first tank; A sixth valve device is disposed between the outlet of the pump device and the second tank; and The seventh valve device for atmospheric opening is connected to the second connection port of the buffer tank located downstream.

6. The electronic supply and recovery device as described in claim 3 or 5, wherein, A flow regulating mechanism is provided between the first valve device and the first tank.

7. The electronic supply and recovery device as described in claim 3 or 5, wherein, Each buffer tank in the buffer tank assembly is provided with a pipe fitting between the buffer tank and the container, which allows the container to be detachably connected to the buffer tank.

8. A method for supplying an electron donor, which is carried out by the electron donor supply and recycling device according to claim 1, comprising: The step of the control unit operating the pump mechanism to make the pressure in the plurality of buffer tanks of the buffer tank assembly negative, thereby supplying the liquid from the first tank to the plurality of buffer tanks; as well as The step of the control unit operating the pump mechanism to bring the pressure inside the plurality of buffer tanks close to atmospheric pressure, thereby supplying the liquid contained in the buffer tanks to the container.

9. A method for supplying an electron donor, which is carried out by the electron donor supply and recovery device according to claim 3 or 5, comprising: When supplying the liquid to the container, the control unit opens the third and fifth valve devices and starts the pump device to make the pressure in each buffer tank of the buffer tank assembly a negative pressure lower than the head between the buffer tank assembly and the container, and opens the first valve device to deliver the liquid in the first tank to each buffer tank of the buffer tank assembly; and The control unit opens the second valve device to release the pressure in each buffer tank of the buffer tank assembly to the atmosphere, and supplies the liquid in each buffer tank to the container by gravity.

10. The method for supplying an electronic provider as claimed in claim 9, wherein, include: The step of repeatedly opening and closing the second valve device through the control unit while opening the pressure in each of the buffer tanks to the atmosphere, so that the negative pressure in each of the buffer tanks of the buffer tank assembly is restored to atmospheric pressure after a specified period.

11. A method for recycling an electron donor, which is a method carried out by the electron donor supply recycling device according to claim 3, comprising: When recovering the liquid from the container, the control unit opens the fourth and sixth valve devices and starts the pump device to recover the liquid or waste liquid in the container into the second tank.

12. A method for recycling an electron donor, which is carried out through the electron donor supply recycling device as described in claim 5, comprising: When recovering the liquid from the container, the control unit opens the fourth and sixth valve devices and starts the pump device to recover the liquid or waste liquid in the container to the second tank through the first connection port of the buffer tank located upstream.

13. The method for recovering an electron donor as described in claim 12, wherein, include: The control unit opens the third valve device during the recycling step to make the negative pressure in each buffer tank of the buffer tank assembly lower than the negative pressure between the buffer tank assembly and the container, thereby drawing the liquid or waste liquid from the container into each buffer tank for temporary storage.

14. The method for recovering an electron donor as described in claim 13, wherein, include: Through the control unit, during the storage step, the seventh valve device is repeatedly opened and closed to maintain the negative pressure in each buffer tank of the buffer tank assembly at a negative pressure less than a specified pressure, while simultaneously replenishing air into each buffer tank of the buffer tank assembly through the second connection port of the downstream buffer tank, thereby transferring the liquid or waste liquid temporarily stored in each buffer tank from the downstream buffer tank to the upstream buffer tank; and In the recycling step, the liquid or waste liquid transported in the conveying step is recycled back to the second tank through the first connection port, the fourth valve device, the pump device and the sixth valve device of the buffer tank located upstream.

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