JP6887574B1 - Membrane cleaning equipment and membrane separation activated sludge system, and membrane cleaning method - Google Patents

Abstract

An object of the present invention is to obtain a membrane cleaning device, a membrane separation activated sludge system, and a membrane cleaning method capable of preventing a decrease in the dissolution efficiency of ozone gas. The membrane cleaning device (40) has an ozone gas supply unit (10) that supplies ozone gas to the ozone water generation unit (9) and a dissolved water supply unit (8) that supplies dissolved water to the ozone water generation unit (9). The ozone water supply unit (11) that sends the ozone water stored in the ozone water generation unit (9) to the separation membrane (2), and the ozone gas from the ozone gas supply unit (10) to the ozone water generation unit (9). In a state where the supply is supplied to the ozone gas supply unit (10), the solution water supply unit (8) is used to supply the dissolved water from the dissolved water supply unit (8) to the ozone water generation unit (9). A control unit (12) for controlling the water supply of ozone water from the ozone water generation unit (9) to the separation film (2) to the ozone water water supply unit (11) is provided.

Description

The present application relates to a membrane cleaning device, a membrane separation activated sludge system, and a membrane cleaning method.

In the membrane separation activated sludge method, which is a wastewater treatment method using MBR (Membrane BioReactor), the wastewater reacts with microorganisms to remove the generated pollutants as sludge. The generated pollutants are removed from the wastewater by solid-liquid separation using a separation membrane. This separation membrane filters and separates pollutants contained in wastewater, but continuous use may cause pollutants to adhere to the surface and pores, resulting in clogging. A clogged separation membrane deteriorates its filtration performance, that is, solid-liquid separation performance. Therefore, it has been conventionally proposed to wash the separation membrane by a washing method called "backwashing" in which washing water containing an oxidizing agent such as ozone is injected in the direction opposite to the filtration direction. In the conventional membrane cleaning device, ozone gas is dissolved in the water to be dissolved in a semi-batch method to generate ozone water. That is, the dissolved water is supplied to the ozone water generation unit that can store the dissolved water, the supply of the dissolved water is stopped when the predetermined amount is reached, and then the dissolved water is maintained at the predetermined amount. Ozone water is generated from the water to be dissolved by continuously supplying ozone gas. When the ozone water generated by the ozone water generation section is sent to clean the separation membrane, in order to maintain the dissolved ozone concentration of the ozone water, the supply of the dissolved water to the ozone water generation section is stopped and the ozone gas The supply will continue (see, for example, Patent Document 1).

Japanese Patent No. 6430091

However, in the membrane cleaning apparatus as described above, the amount of water in the ozone water generating section decreases during cleaning of the separation membrane, and the water level of ozone water in the ozone water generating section drops. Here, since the ozone gas supplied to the ozone water in the ozone water generation unit rises toward the water surface, if the ozone water level is low, the gas-liquid contact time will be shortened, and the ozone gas dissolution efficiency will decrease. There is a problem.

The present application discloses a technique for solving the above-mentioned problems, and obtains a membrane cleaning device, a membrane separation active sludge system, and a membrane cleaning method capable of preventing a decrease in the dissolution efficiency of ozone gas. The purpose.

The film cleaning device disclosed in the present application is a film cleaning device that cleans a separation film that separates pollutants contained in the water to be treated from the water to be treated with ozone water stored in an ozone water generation unit, and uses ozone water for ozone gas. An ozone gas supply unit that supplies the ozone gas supply unit to the generation unit, and a water-dissolved water supply unit that supplies the dissolved water to the ozone water generation unit by using water introduced from the outside or treated water treated with a separation membrane as the dissolved water. The dissolved water supply unit is in a state where the ozone water supply unit that sends the ozone water stored in the ozone water generation unit to the separation membrane and the ozone gas supply unit supplies ozone gas from the ozone gas supply unit to the ozone water generation unit. A control unit that controls the supply of dissolved water from the ozone water generation unit to the dissolved water supply unit and the supply of ozone water from the ozone water generation unit to the separation membrane to the ozone water supply unit. The control unit includes an ozone concentration acquisition unit that acquires the dissolved ozone concentration of ozone water, a storage unit that stores a predetermined first threshold value and a predetermined second threshold value, and water to be dissolved and ozone. It is equipped with a determination unit that determines whether or not water can be sent, and the determination unit supplies ozone gas from the ozone gas supply unit to the ozone water generation unit when the dissolved ozone concentration is equal to or higher than a predetermined first threshold value. In the state where the ozone gas supply unit is used, the dissolved water supply unit is made to supply the dissolved water from the dissolved water supply unit to the ozone water generation unit, and the ozone water is sent from the ozone water generation unit to the separation membrane. Is supplied to the ozone water supply unit, and the dissolved water is supplied from the dissolved water supply unit to the ozone water generation unit when the dissolved ozone concentration is less than a predetermined second threshold value. In addition to stopping the water supply unit, the ozone water supply unit stops the ozone water supply from the ozone water generation unit to the separation membrane, and the determination unit supplies the dissolved water from the dissolved water supply unit to the ozone water generation unit. In the process of supplying ozone gas from the ozone gas supply unit to the ozone water generation unit to generate ozone water while the supply of ozone water from the ozone water generation unit to the separation membrane is stopped, the dissolved ozone concentration is predetermined. In addition, it is determined whether or not it is equal to or higher than the first threshold value, and the determination unit determines whether or not the ozone gas is supplied from the ozone gas supply unit to the ozone water generation unit to the ozone gas supply unit. The dissolved ozone concentration is predetermined in the step of causing the dissolved water supply unit to supply the dissolved water to the water generation unit and the ozone water supply unit to supply the ozone water from the ozone water generation unit to the separation membrane. Whether it is less than the second threshold It is shall be determined whether.

Also, membrane cleaning method disclosed in the present application, the membrane cleaning method for cleaning with ozone water separation membrane, which is stored in the ozone water generating unit for separating the pollutants contained in the treated water from the treated water, ozone water The ozone gas supply process of supplying ozone gas to the ozone water generation unit with the supply of dissolved water to the generation unit and the supply of ozone water from the ozone water generation unit to the separation membrane stopped, and the introduction from the outside. Water or treated water treated with a separation membrane is used as dissolved water, and the dissolved water supply step of supplying the dissolved water to the ozone water generation unit and the ozone water stored by the ozone water generation unit are sent to the separation membrane. It is equipped with an ozone water supply process and a continuous operation process in which the dissolved water supply process and the ozone water supply process are performed while supplying ozone gas to the ozone water generation unit, and the ozone water is dissolved during the ozone gas supply process. If the ozone concentration reaches a first threshold value than the predetermined, the start of the ozone water supply step, switching the step of performing a continuous operation process, and the dissolved ozone water while carrying out the continuous operation process When the ozone concentration becomes less than a predetermined second threshold value, the ozone gas supply step is a step of stopping the supply of the dissolved water to the ozone water generation unit and the supply of the ozone water to the separation membrane. It switches to.

According to the membrane cleaning apparatus and the membrane cleaning method disclosed in the present application, it is possible to prevent a decrease in the dissolution efficiency of ozone gas.

It is a block diagram which shows the membrane separation activated sludge system and the membrane cleaning apparatus in Embodiment 1, and is the figure explaining the process of supplying water to be dissolved. It is a block diagram which shows the membrane separation activated sludge system and the membrane cleaning apparatus in Embodiment 1, and is the figure explaining the ozone gas supply process. It is a block diagram which shows the membrane separation activated sludge system and the membrane cleaning apparatus in Embodiment 1, and is the figure explaining the continuous operation process. It is a figure which shows the structural example of the control part which concerns on Embodiment 1. FIG. It is a flow figure which shows the operation of the membrane cleaning apparatus in Embodiment 1. FIG. It is a block diagram which shows the membrane separation activated sludge system and the membrane cleaning apparatus in Embodiment 2, and is the figure explaining the ozone gas supply process. It is a block diagram which shows the membrane separation activated sludge system and the membrane cleaning apparatus in Embodiment 2, and is the figure explaining the continuous operation process. It is a figure which shows the example of the hardware composition of the control part which concerns on Embodiment 1. FIG.

Hereinafter, embodiments of the membrane separation activated sludge system and the membrane cleaning device disclosed in the present application will be described in detail with reference to the accompanying drawings. The embodiment shown below is an example.

Embodiment 1.
The first embodiment will be described with reference to FIGS. 1A to 3. 1A to 1C are configuration diagrams showing the membrane separation activated sludge system and the membrane cleaning device according to the first embodiment, FIG. 1A is a water to be dissolved supply step, FIG. 1B is an ozone gas supply step, and FIG. 1C is continuous. It is a figure explaining each operation process. When an arrow is attached to each pipe, it indicates that the fluid flowing in the pipe is flowing in the direction of the arrow. If no arrow is attached, it indicates that there is no flow in the process. As shown in FIG. 1A, the membrane separation active sludge system 100 includes a membrane separation active sludge device 20 having a membrane separation tank 1 and a separation membrane 2, and a membrane cleaning device 40 for cleaning the separation membrane 2. An inflow pipe 5 which is a piping member through which drainage or the like flows is connected to the membrane separation tank 1, and drainage or the like flows into the membrane separation tank 1 through the inflow pipe 5. The wastewater that has flowed into the membrane separation tank 1 is stored in the membrane separation tank 1 as water to be treated 6.

The side surface and the bottom surface of the membrane separation tank 1 are made of concrete to prevent water leakage in the membrane separation tank 1. The water to be treated 6 stored in the membrane separation tank 1 contains not only pollutants but also microorganisms that catch pollutants (hereinafter referred to as activated sludge). Therefore, the pollutant substance in the water to be treated 6 is contained in the water to be treated 6 in a state of being caught in the activated sludge.

The separation membrane 2 is a rectangular parallelepiped membrane member whose surfaces are composed of a membrane such as a hollow fiber membrane, and the direction from the outside to the inside of the rectangular parallelepiped space partitioned by the respective surfaces is the direction of the separation membrane 2. It is the filtration direction. The separation membrane 2 is arranged in the membrane separation tank 1 and is immersed in the water to be treated 6. Further, one end of the filtered water pipe 3a is inserted inside the separation membrane 2. The filtered water pipe 3a is a piping member that discharges the treated water 6 filtered by the separation film 2 to the outside of the system as the treated water 7, and is provided with a filtration pump 4 that sucks the treated water 7 by using pressure. There is. When the filtration pump 4 operates, the treated water 7 inside the separation membrane 2 flows into the filtered water pipe 3a, and the water to be treated 6 outside the separation membrane 2 flows into the inside of the separation membrane 2. At this time, the water to be treated 6 flowing through the separation membrane 2 is filtered, and the activated sludge in the water to be treated 6 is separated by the separation membrane 2. As described above, since the activated sludge captures the pollutants in the water to be treated 6, the pollutants contained in the water to be treated 6 are also separated by separating the activated sludge in the water to be treated 6. .. The activated sludge and pollutants separated from the water to be treated 6 adhere to the separation membrane 2. The water to be treated 6 from which pollutants have been removed in this manner becomes treated water 7, is sucked into the filtration pump 4 as described above, flows through the filtered water pipe 3a, and is discharged from the other end of the filtered water pipe 3a to the outside of the system. Will be done. The membrane constituting the separation membrane 2 is not limited to the hollow fiber membrane described above, and a flat membrane or the like may be applied. Further, since the separation membrane 2 may be a membrane member capable of separating the solid and the liquid in the water to be treated 6 containing activated sludge, an ultrafiltration (UF) membrane, a microfiltration (MF) membrane and the like can be separated. It can also be used as 2.

When the separation of the solid and the liquid in the water to be treated 6 by the separation membrane 2 is continued, in other words, when the filtration treatment for filtering the water to be treated 6 outside the separation membrane 2 is continued, the surface of the separation membrane 2 is continued. Alternatively, the active sludge and pollutants in the water to be treated 6 may adhere to the pores of the separation membrane 2 to cause clogging. When clogging occurs, the filtration rate by the separation membrane 2 may decrease, and the treatment rate of the water to be treated 6 may decrease. As described above, continuous use of the separation membrane 2 may reduce the water treatment efficiency of the membrane separation activated sludge system 100. Therefore, it is necessary to appropriately wash the separation membrane 2 to prevent clogging and the like.

The membrane cleaning device 40 is a cleaning device that cleans the separation membrane 2. The membrane cleaning device 40 uses the dissolved water supply unit 8 that supplies the dissolved water to the ozone water generation unit 9, the ozone water generation unit 9 that dissolves ozone gas in the dissolved water to generate ozone water, and the ozone gas as ozone. The ozone gas supply unit 10 that supplies the water to the water generation unit 9, the ozone water supply unit 11 that injects the ozone water generated by the ozone water generation unit 9 into the inside of the separation film 2, the water to be dissolved unit 8, and the ozone gas supply unit. 10 and a control unit 12 that controls the operation of the ozone water supply unit 11 according to the process are provided. The water to be dissolved water supply unit 8, the ozone gas supply unit 10, the ozone water water supply unit 11, and the control unit 12 are connected to each other via signal lines 50a, 50b, and 50c, respectively. In FIGS. 1A to 1C, the arrows in the signal lines 50a to 50c indicate that the control unit 12 is operating the target functional unit in the process shown in each figure. For example, in the dissolved water supply step of FIG. 1A, the dissolved water supply unit 8 is operating, but the ozone gas supply unit 10 and the ozone water supply unit 11 are stopped. Further, the control unit 12 is connected to the dissolved ozone sensor 9b of the ozone water generation unit 9, that is, the concentration measurement unit via a signal line 51.

The water-dissolved water supply unit 8 is connected to the ozone water generation unit 9 via the water-dissolved water supply pipe 3c. The ozone water is dissolved in the ozone water generation unit 9 to become ozone water, and is supplied from the dissolved water supply unit 8 to the ozone water generation unit 9 through the dissolved water supply pipe 3c. The water-dissolved water supply unit 8 starts or stops the supply of the water to be dissolved to the ozone water generation unit 9 in response to a control signal from the control unit 12. The water to be dissolved is not particularly limited, and for example, tap water, industrial water, or treated water 7 filtered through the separation membrane 2 can be used. When the treated water 7 is used as the water to be dissolved, a pipe for sending the treated water 7 from the filtered water pipe 3a to the water to be dissolved supply 8 and a pump for sending the treated water 7 are required, but water is newly added from the outside. Since it is not necessary to introduce it into the water, the cost required for cleaning can be reduced.

The ozone water generation unit 9 is connected to the ozone water water supply unit 11 via the ozone water water supply pipe 3b1. The ozone water generation unit 9 is configured to be able to store a liquid inside, and can store the dissolved water supplied from the dissolved water supply unit 8 and the ozone water generated from the dissolved water. An air diffuser 9a connected to the ozone gas supply unit 10 via the ozone gas supply pipe 3d is provided at the bottom of the ozone water generation unit 9. The ozone gas supplied from the ozone gas supply unit 10 is discharged as bubbles from the air diffuser 9a and is injected into the dissolved water in the ozone water generation unit 9. The connection between the ozone water generation unit 9 and the dissolved water supply pipe 3c (not shown) is provided on one side wall of the ozone water generation unit 9, and the connection between the ozone water generation unit 9 and the ozone water supply pipe 3b1 (not shown). ) Is provided on the other side wall of the ozone water generation unit 9. Further, the connection portion between the ozone water generation unit 9 and the dissolved water supply pipe 3c is provided at a position higher than the connection portion between the ozone water generation unit 9 and the ozone water water supply pipe 3b1. Further, an exhaust ozone gas pipe 3e communicating with the outside of the ozone water generation unit 9 is provided above the ozone water generation unit 9. The exhaust ozone gas pipe 3e discharges the ozone gas that has not been dissolved in the ozone water generation unit 9 to the outside of the system as exhaust ozone gas.

The installation position of the air diffuser 9a is not limited to the bottom of the ozone water generation unit 9, but the bubbles of ozone gas released from the air diffuser 9a flow upward toward the surface of the dissolved water. It is preferable to provide the air diffuser 9a as downward as possible. By providing the air diffuser 9a below, the contact time between the water to be dissolved and the ozone gas can be extended and the dissolution efficiency can be improved. Further, the position of the connection portion between the ozone water generation unit 9 and the dissolved water supply pipe 3c and the position of the connection portion between the ozone water generation unit 9 and the ozone water water supply pipe 3b1 are not particularly limited, but between the two. It is preferable that the distance between the two is as large as possible. Further, as described above, the dissolution efficiency of ozone gas can be improved by providing the connection portion with the water to be dissolved supply pipe 3c at a position higher than the connection portion with the ozone water water supply pipe 3b1. This is because, in this case, since the water to be dissolved flows in from a high position, the flow of the water to be dissolved becomes a downward flow, and the flow of the water to be dissolved and the flow of ozone gas become a countercurrent. In this case, countercurrent contact occurs between the water to be dissolved and the ozone gas, and the dissolution efficiency is improved.

The ozone water generation unit 9 is provided with a dissolved ozone sensor 9b. The dissolved ozone sensor 9b continuously or intermittently measures the dissolved ozone concentration of the ozone water (including the case where the dissolved water is mixed; the same applies hereinafter) in the ozone water generation unit 9, and is a signal line. The measurement result is transmitted to the control unit 12 via 51.

The ozone water generating unit is not particularly limited as long as it has a structure capable of generating ozone water by dissolving ozone gas in dissolved water. The ozone water generation unit 9 of the first embodiment is an ozone water generation unit that can store the dissolved water and has a function of storing the dissolved water and a function of dissolving ozone gas in the dissolved water. A storage tank for storing the water and a dissolution mechanism for dissolving ozone gas in the dissolved water stored in the storage tank may be separated. As a method for dissolving ozone gas in the water to be dissolved, in addition to the method of providing the air diffuser 9a in the ozone water generation unit 9 (air diffuser type), an ozone gas dissolution method such as an ejector type or a dissolution film type can be used. it can.

The ozone gas supply unit 10 supplies ozone gas to the air diffuser 9a in the ozone water generation unit 9 via the ozone gas supply pipe 3d. The ozone gas supply unit 10 starts or stops the supply of ozone gas to the ozone water generation unit 9 in response to a control signal from the control unit 12. The ozone gas supply unit 10 is composed of a raw material gas supply unit (not shown) and an ozone gas generator (not shown) that generates oxygen gas from oxygen supplied from the raw material gas supply unit as a raw material. As the raw material gas generating unit, for example, an oxygen generator using a liquid oxygen cylinder or VPSA (Vacuum Pressure Swing Adsorption) is used, but the device is not particularly limited as long as it can supply oxygen. As the ozone gas generator, for example, a discharge type ozone gas generator can be used.

The pH adjusting means may be provided in the water to be dissolved supply unit 8 and the ozone water generation unit 9, and the pH of ozone water, water to be dissolved, or both may be adjusted from 2 to 6. Since the lower the pH, the more difficult the self-decomposition of ozone occurs, the self-decomposition of ozone can be suppressed by adjusting the pH of the dissolved water as described above, and ozone water can be efficiently generated. The same effect can be obtained when adjusting the pH of ozone water. In these cases, the amount of ozone gas required can be reduced, so that the cost required for cleaning can be reduced. Further, the temperature adjusting means may be provided in the dissolved water supply unit 8 and / or the ozone water generating unit 9 to adjust the temperature of the ozone water and the dissolved water to a certain level or less. Since the solubility of ozone increases as the water temperature decreases, adjusting the water temperature below a certain level produces higher-concentration ozone water and improves the cleaning effect of ozone water. In this case, the required amount of water to be dissolved can be reduced, so that the cost required for cleaning can be reduced.

The ozone water water supply unit 11 is connected to the ozone water generation unit 9 via the ozone water water supply pipe 3b1 and is connected to the filtered water pipe 3a via the ozone water water supply pipe 3b2. The ozone water water supply unit 11 sends the ozone water generated by the ozone water generation unit 9 from the ozone water generation unit 9 and injects it into the separation membrane 2 via the filtration pipe 3a. When ozone water is sent to the inside of the separation membrane 2 by the ozone water supply unit 11, ozone water flows from the inside to the outside of the separation membrane 2 (in the direction opposite to the filtration direction), and the separation membrane 2 is backwashed. It is said. As a result, the pollutants and sludge adhering to the separation membrane 2 are separated from the separation membrane 2, and the separation membrane 2 is washed. The ozone water supply unit 11 starts or stops the ozone water supply to the separation membrane 2 in response to the control signal from the control unit 12.

The control unit 12 transmits a control signal to the dissolved water supply unit 8, the ozone gas supply unit 10, and the ozone water water supply unit 11 to control switching between steps to be performed. That is, the control signal of the control unit 12 has a function as a switching signal for switching the steps to be performed. The steps implemented in the first embodiment include a "dissolved water supply step", an "ozone gas supply step", a "ozone water supply step", and a "continuous operation step". The "dissolved water supply step" is a step of supplying the dissolved water from the dissolved water supply unit 8 to the ozone water generation unit 9. As shown in FIG. 1A, in the dissolved water supply step, the dissolved water supply unit 8 operates according to the control signal from the control unit 12, and ozone water is generated from the dissolved water supply unit 8 in the dissolved water supply pipe 3c. Water to be dissolved flows in part 9. On the other hand, since the ozone gas supply unit 10 is stopped, there is no flow of ozone gas in the ozone gas supply pipe 3d, and there is no discharge of exhaust ozone gas from the exhaust ozone gas pipe 3e. Further, since the ozone water water supply unit 11 is also stopped, there is no flow of ozone water in the ozone water water supply pipes 3b1 and 3b1. In the water to be dissolved supply step, the treatment of the water to be treated 6 by the membrane separation activated sludge device 20 can also be carried out in parallel. In FIG. 1A, the treated water 6 flows through the inflow pipe 5 and flows into the membrane separation tank 1, and the treated water 7 sucked by the filtration pump 4 flows through the filtered water pipe 3a and is discharged to the outside of the system. It is shown.

The "ozone gas supply step" is a step of generating ozone water in a semi-batch system in which ozone gas is continuously supplied to the dissolved water stored in a predetermined amount. As shown in FIG. 1B, in the ozone gas supply process, the ozone gas supply unit 10 operates according to the control signal from the control unit 12, and ozone gas flows from the ozone gas supply unit 10 to the ozone water generation unit 9 in the ozone gas supply pipe 3d. Further, the exhausted ozone gas is discharged from the exhausted ozone gas pipe 3e. On the other hand, since the dissolved water supply unit 8 is stopped, there is no flow of the dissolved water in the dissolved water supply pipe 3a. Further, since the ozone water water supply unit 11 is also stopped, there is no flow of ozone water in the ozone water water supply pipes 3b1 and 3b1. In the ozone gas supply step as well, the treatment of the water to be treated 6 by the membrane separation activated sludge device 20 can be carried out in parallel as in the water supply step to be dissolved.

The "ozone water supply step" is a step of sending the ozone water stored in the ozone water generation unit 9 to the separation membrane 2 to clean the separation membrane 2. Further, in the "continuous operation process", the dissolved water is supplied from the dissolved water supply unit 8 to the ozone water generation unit 9 while the ozone gas supply unit 10 is supplying the ozone water to the ozone water generation unit 9. This is a step of continuously generating ozone water from the ozone water supply unit 11 to the separation membrane 2 and sending ozone water to the separation membrane 2 to clean the separation membrane 2. In other words, in the continuous operation process, ozone water is sent from the ozone water generation unit 9 to the separation membrane 2, and at the same time, new dissolved water is supplied to the ozone water generation unit 9, so that the separation membrane 2 is continuously washed with ozone water. Ozone water is generated by the formula in parallel. That is, the "continuous operation step" of the first embodiment is a step of carrying out the dissolved water supply step and the ozone water supply step while supplying ozone gas to the ozone water generation unit 9. As shown in FIG. 1C, in the continuous operation process, the dissolved water supply unit 8, the ozone gas supply unit 10, and the ozone water water supply unit 11 operate according to the control signal from the control unit 12. As a result, the dissolved water flows from the dissolved water supply unit 8 to the ozone water generation unit 9 in the dissolved water supply pipe 3c, and the ozone gas flows from the ozone gas supply unit 10 to the ozone water generation unit 9 in the ozone gas supply pipe 3d. .. Further, the exhausted ozone gas is discharged from the exhausted ozone gas pipe 3e. Further, ozone water flows from the ozone water generation unit 9 to the ozone water supply unit 11 in the ozone water supply pipe 3b1, and ozone water flows from the ozone water supply unit 11 to the filtered water pipe 3a in the ozone water supply pipe 3b2. The ozone water flowing through the filtered water pipe 3a flows into the separation membrane 2, and the separation membrane 2 is backwashed as described above. In the continuous operation step, ozone water needs to flow through the separation membrane 2 through the filtered water pipe 3a, so that the membrane separation activated sludge device 20 does not treat the water to be treated 6.

A specific configuration of the control unit 12 will be described. FIG. 2 is a diagram showing a configuration example of the control unit according to the first embodiment. The control unit 12 includes an ozone concentration receiving unit 13, a storage unit 14, a determination unit 15, and a control signal transmitting unit 16. The ozone concentration receiving unit 13 and the determining unit 15 are connected via a signal line 52a. The storage unit 14 and the determination unit 15 are connected to each other via a signal line 52b. Further, the determination unit 15 and the control signal transmission unit 16 are connected via a signal line 52c. The ozone concentration receiving unit 13 is connected to the dissolved ozone sensor 9b via the signal line 51, and receives the data of the dissolved ozone concentration which is the measurement result of the dissolved ozone sensor 9b via the signal line 51. The ozone concentration receiving unit 13 transmits the received dissolved ozone concentration data to the determining unit 15 via the signal line 52a. The storage unit 14 stores the dissolved ozone concentration, which is a predetermined threshold value. The threshold value stored in the storage unit 14 is a threshold value for determining whether or not the continuous operation process can be switched. The ozone concentration receiving unit 13 corresponds to an ozone concentration acquiring unit.

The determination unit 15 determines the steps to be performed by the membrane cleaning device 40. The determination unit 15 acquires the data of the measured value of the dissolved ozone concentration of the ozone water in the ozone water generation unit 9 from the ozone concentration receiving unit 13, and compares the measured value of the dissolved ozone concentration with the threshold value stored in the storage unit 14. To do. When the measured value of the dissolved ozone concentration is equal to or higher than the threshold value, the step to be carried out is determined to be a continuous operation step. If the measured value of the dissolved ozone concentration is less than the threshold value, the step to be carried out is determined to be the ozone gas supply step. In this way, the determination unit 15 determines whether or not the process to be performed between the ozone gas supply process and the continuous operation process can be switched based on the dissolved ozone concentration of the ozone water in the ozone water generation unit 9.

When the determined process and the currently executed process are different, the determination unit 15 generates a control signal for switching the process to be performed, and transmits the generated control signal to the control signal transmission unit via the signal line 52c. To do. The control signal transmission unit 16 transmits the control signal received from the determination unit 15 to the dissolved water supply unit 8, the ozone gas supply unit 10, and the ozone water water supply unit 11 via the signal lines 50a, 50b, and 50c, respectively. ..

For example, when switching from the ozone gas supply process to the continuous operation process, a water supply start control signal is generated as a control signal to the dissolved water supply unit 8, and a water supply start control signal is generated as a control signal to the ozone water supply unit 11. To do. Since the operation of the ozone gas supply unit 10 does not change before and after the process is switched (the supply of ozone gas is continued), the control signal to the ozone gas supply unit 10 is not generated in this case.

FIG. 5 is a diagram showing an example of a hardware configuration that realizes the control unit 12. Each functional unit of the control unit 12 described above is realized by the processor 71 executing a program stored in the memory 72 or the hard disk 73. Further, the plurality of processors 71 and the plurality of memories 72 or the hard disk 73 may cooperate to realize each function of the control unit 12. Further, the control unit 12 includes a receiving circuit 74, and receives data from the dissolved ozone sensor 9b via the receiving circuit 74. The dissolved ozone concentration data received from the dissolved ozone sensor 9b, the result of calculation by the processor 71, and the predetermined threshold value described above are stored in the memory 72 or the hard disk 73. Further, the control unit 12 includes a transmission circuit 75, and transmits a control signal to the dissolved water supply unit 8, the ozone gas supply unit 10, and the ozone water water supply unit 11 via the transmission circuit 75.

Next, the operation will be described. FIG. 3 is a flow chart showing the operation of the membrane cleaning device according to the first embodiment. First, it is checked whether a predetermined amount of water to be dissolved is stored in the ozone water generation unit 9 (step ST001). When a predetermined amount of water to be dissolved is stored in the ozone water generation unit 9, the process proceeds to step ST003.

When a predetermined amount of dissolved water is not stored in the ozone water generating unit 9, the dissolved water is supplied to the ozone water generating unit 9 (step ST002, dissolved water supply step). First, the control unit 12 switches the process to be performed to the process to be dissolved and supplied. Specifically, the control unit 12 transmits a control signal for starting water supply to the water to be dissolved supply unit 8 to start water supply to be dissolved. The dissolved water sent from the dissolved water supply unit 8 flows to the ozone water generation unit 9 via the dissolved water supply pipe 3c, and the dissolved water is supplied to the ozone water generation unit 9. After starting the supply of the water to be dissolved, step ST001 is periodically carried out to check the water to be dissolved stored in the ozone water generation unit 9. When a predetermined amount of water to be dissolved is stored in the ozone water generation unit 9, the process proceeds to step ST003.

When a predetermined amount of dissolved water is stored in the ozone water generation unit 9, the ozone gas supply unit 10 stops the supply of the dissolved water from the dissolved water supply unit 8 to the ozone water generation unit 9. The supply of ozone gas to the ozone water generation unit 9 is started (step ST003). Specifically, the control unit 12 transmits a control signal for stopping the water supply to the water to be dissolved supply unit 8 to stop the water supply to be dissolved. Further, the control unit 12 transmits a control signal for starting supply to the ozone gas supply unit 10 to start the supply of ozone gas. As a result, the process to be carried out is switched to the ozone gas supply process, and the generation of ozone water by the semi-batch method is started. When the water to be dissolved has not been supplied as in the case where the step ST002 has not been passed, the operation of stopping the water supply is unnecessary.

In the ozone gas supply step, ozone gas is dissolved in the dissolved water stored in the ozone water generation unit 9 to generate ozone water (step ST004). The ozone gas supplied from the ozone gas supply unit 10 flows to the air diffuser 9a in the ozone water generation unit 9 via the ozone gas supply pipe 3d, and bubbles of ozone gas are injected from the air diffuser 9a into the dissolved water. Bubbles of ozone gas flow from the diffuser portion 9a toward the surface of the water to be dissolved. The bubbles of ozone gas come into contact with the water to be dissolved while flowing upward in the water to be dissolved, and a part of them is dissolved in the water to be dissolved. The undissolved ozone gas is discharged to the outside of the system via the exhaust ozone gas pipe 3e. Ozone water is generated by dissolving ozone gas in the water to be dissolved as described above. During the ozone gas supply step, the dissolved ozone sensor 9b continuously or intermittently measures the dissolved ozone concentration of the ozone water in the ozone water generation unit 9, and transmits the measurement result to the control unit 12.

At a predetermined timing during the ozone gas supply process, it is determined whether the dissolved ozone concentration of the generated ozone water is equal to or higher than a predetermined threshold value, and whether or not the process to be performed is switched from the ozone gas supply process to the continuous operation process. Is determined (step ST005). The determination unit 15 of the control unit 12 compares the measured value of the dissolved ozone concentration of ozone water in the ozone water generation unit 9 with the threshold value stored in the storage unit 14, and the measured value of the dissolved ozone concentration is less than the threshold value. If so, the ozone gas supply process is continued (step ST006). After that, step ST005 is periodically performed, and it is determined whether or not to switch the step to be performed based on the comparison result between the measured value of the dissolved ozone concentration and the threshold value.

When the measured value of the dissolved ozone concentration is equal to or higher than the threshold value, the ozone water is supplied to the ozone water generation unit 9 and the ozone water is supplied to the separation membrane 2 while the ozone gas is continuously supplied to the ozone water generation unit 9. Is started (step ST007). Specifically, the control unit 12 transmits a control signal for starting water supply to the dissolved water supply unit 8 and the ozone water supply unit 11, respectively, and the dissolved water supply unit 8 sends the dissolved water to the ozone water generation unit 9. The supply and the supply of ozone water from the ozone water generation unit 9 to the separation membrane 2 are started. As a result, the step to be carried out is switched from the ozone gas supply step to the continuous operation step, the cleaning of the separation membrane 2 with ozone water is started, and the generation of ozone water is switched from the semi-batch type to the continuous type. The supply of ozone gas from the ozone gas supply unit 10 to the ozone water generation unit 9 is continued even after switching to the continuous operation process.

In the continuous operation step, the dissolved water is supplied from the dissolved water supply unit 8 to the ozone water generation unit 9 while the ozone gas is continuously supplied to the ozone water generation unit 9, and the separation membrane 2 is supplied from the ozone water generation unit 9. Ozone water is sent to the water, and the separation membrane 2 is washed with the ozone water (step ST008). The supply of the water to be dissolved is the same as in the case of the water supply step to be dissolved in step ST002. The ozone water is supplied by the ozone water supply unit 11. First, the ozone water in the ozone water generation unit 9 is supplied from the ozone water generation unit 9 to the ozone water supply unit 11 via the ozone water supply pipe 3b1. Next, the ozone water sent to the ozone water feeding unit 11 is sent to the filtered water pipe 3a via the ozone water feeding pipe 3b2, and the ozone water is injected from the filtered water pipe 3a into the inside of the separation membrane 2. As described above, when ozone water is sent to the inside of the separation membrane 2, ozone water flows from the inside to the outside of the separation membrane 2 (in the direction opposite to the filtration direction), and the separation membrane 2 is washed by backwashing. To. In this way, that is, the control unit 12 during the continuous operation process is in a state where the ozone gas supply unit 10 supplies the ozone gas from the ozone gas supply unit 10 to the ozone water generation unit 9, and the water to be dissolved unit 12 is supplied. The dissolved water supply step is carried out by causing the dissolved water supply unit 8 to supply the dissolved water from the 8 to the ozone water generation unit 9, and the ozone water is supplied from the ozone water generation unit 9 to the separation film 2. The ozone water feeding unit 11 is used to carry out the ozone water feeding step. The measurement of the dissolved ozone concentration by the dissolved ozone sensor 9b is continued even during the continuous operation step.

In the continuous operation step of the first embodiment, both the dissolved water is supplied to the ozone water generating unit 9 and the ozone water is sent from the ozone water generating unit 9, so that the supplied amount of the dissolved water and the ozone water are performed. The amount of water and the water level in the ozone water generation unit 9 are maintained by appropriately setting the amount of water to be sent. In addition, since ozone gas is also supplied, a decrease in the dissolved ozone concentration is suppressed.

At a predetermined timing during the continuous operation step, it is determined whether the dissolved ozone concentration of the ozone water in the ozone water generation unit 9 is less than a predetermined threshold, and the step to be carried out is from the continuous operation step to the ozone gas supply step. It is determined whether or not to switch to (step ST009). The determination unit 15 of the control unit 12 compares the measured value of the dissolved ozone concentration of ozone water in the ozone water generation unit 9 with the threshold value stored in the storage unit 14, and the measured value of the dissolved ozone concentration is equal to or higher than the threshold value. In this case, it is determined whether or not the cleaning of the separation membrane 2 is completed (step ST011). When the cleaning is completed, the supply of ozone gas to the ozone water generation unit 9, the supply of the dissolved water to the ozone water generation unit 9, and the supply of ozone water to the separation membrane 2 are stopped (step ST013). Specifically, the control unit 12 transmits a control signal for stopping water supply to the dissolved water supply unit 8 and the ozone water water supply unit 11, respectively, and the dissolved water supply unit 8 sends the dissolved water to the ozone water generation unit 9. The supply and the supply of ozone water from the ozone water generation unit 9 to the separation membrane 2 are stopped, the control unit 12 transmits a control signal for stopping the supply to the ozone gas supply unit 10, and the ozone gas supply unit 10 sends the ozone water generation unit 9 to the ozone water generation unit 9. Stop the supply of ozone gas to. If the cleaning of the separation membrane 2 is not completed, the continuous operation step is continued (step ST012). After that, step ST009 is periodically performed, and it is determined whether or not to switch the step to be performed based on the comparison result between the measured value of the dissolved ozone concentration and the threshold value.

When the measured value of the dissolved ozone concentration is less than the threshold value, the ozone water is supplied to the ozone water generation unit 9 and the ozone water is supplied to the separation membrane 2 while the ozone gas is continuously supplied to the ozone water generation unit 9. Is stopped (step ST010). Specifically, the control unit 12 transmits a control signal for stopping water supply to the dissolved water supply unit 8 and the ozone water water supply unit 11, respectively, and the dissolved water supply unit 8 sends the dissolved water to the ozone water generation unit 9. The supply and the supply of ozone water from the ozone water generation unit 9 to the separation membrane 2 are stopped. As a result, the step to be carried out is switched from the continuous operation step to the ozone gas supply step, the cleaning of the separation membrane 2 is stopped, and the generation of ozone water is switched from the continuous type to the half-time type. After that, the process returns to step ST004. As described above, the control unit 12 carries out a continuous operation step when the measured value of the dissolved ozone concentration of ozone water in the ozone water generation unit 9 is equal to or higher than the threshold value, and dissolves the ozone water in the ozone water generation unit 9. If the measured value of ozone concentration is less than the threshold value, the step to be carried out is controlled so that the ozone gas supply step is carried out.

The order of step ST009 and step ST011 may be exchanged, that is, the cleaning completion may be determined first in the continuous operation process, and if not completed, it may be determined whether or not the switching to the ozone gas supply process is possible.

Further, the threshold value used in step ST005, that is, the threshold value for determining whether or not to switch from the ozone gas supply process to the continuous operation process, and the threshold value used in step ST009, that is, the threshold value for determining whether or not to switch from the continuous operation process to the ozone gas supply process are , The same value or different values.

According to the first embodiment, it is possible to prevent a decrease in the dissolution efficiency of ozone gas. More specifically, the supply of dissolved water from the dissolved water supply unit to the ozone water generation unit is dissolved while the ozone gas supply unit supplies the ozone gas from the ozone gas supply unit to the ozone water generation unit. The separation membrane is cleaned by a continuous operation step in which the water supply unit is made to feed the ozone water from the ozone water generation unit to the separation membrane to the ozone water generation unit. During the continuous operation process, the dissolved water is supplied from the dissolved water supply unit to the ozone water generation unit, so that the amount of water in the ozone water generation unit is reduced and the water level is lowered by the ozone water supply, and these The shortening of the gas-liquid contact time due to the above is suppressed. Therefore, in the continuous ozone water generation in the continuous operation process, the decrease in the dissolution efficiency of ozone gas is prevented. In addition, since ozone gas is also supplied from the ozone gas supply unit to the ozone water generation unit, even if undissolved ozone gas is discharged to the outside of the system as exhaust ozone gas or ozone is autolyzed, the ozone water generation unit is inside. The amount of ozone gas in is maintained. Further, since the amount of water in the ozone water generation unit is maintained in the continuous operation process, it is not necessary to supply the dissolved water again when the ozone gas supply process is performed again. Therefore, the time required to generate a predetermined amount of ozone water can be shortened.

Further, since the continuous operation step is carried out when the dissolved ozone concentration of ozone water is equal to or higher than the threshold value and the ozone gas supply step is carried out when the dissolved ozone concentration of ozone water is less than the threshold value, the ozone water having an insufficient concentration is carried out. It is possible to suppress poor cleaning due to. This is especially true when there is a risk that the dissolved ozone concentration will decrease due to changes in the water quality when generating ozone water in a continuous manner, such as when treated water whose water quality is liable to fluctuate is used as the dissolved water. effective.

The control unit in the first embodiment switches between the ozone gas supply process and the continuous operation process based on the water quality of the ozone water, more specifically, the concentration of the dissolved ozone in the ozone water. As the water quality of ozone water as a criterion for switching, the water temperature, pH, and organic substance concentration of ozone water may be used. In these cases as well, the ozone water supply process and the continuous operation process are switched by measuring the water temperature, pH, or organic matter concentration of the ozone water in the ozone water generation unit and comparing the measured value with the threshold value. More specifically, if the measured value of water temperature, pH or organic matter concentration is less than the threshold value, the ozone gas supply process is switched to the continuous operation process, and if it is above the threshold value, the continuous operation process is switched to the ozone gas supply process. Configure to. As a result, the same effect as when the dissolved ozone concentration is used as in the first embodiment can be obtained.

Further, the ozone gas supply process may be switched to the continuous operation process based on the ozone gas supply time or the ozone gas supply amount. When the process is switched based on the ozone gas supply time, a timer is provided in the control unit, the elapsed time from the start of the ozone gas supply process is regarded as the ozone gas supply time, and whether or not the process can be switched is determined. When the process is switched based on the supply amount of ozone gas, a calculator for the supply amount of ozone gas is provided in the control unit, and whether or not the process can be switched is determined based on the calculation result. When the ozone gas supply amount is used, a configuration is also conceivable in which the ozone gas supply amount is measured in the ozone gas supply unit or the ozone gas supply pipe, and the measurement result is transmitted to the control unit.

The ozone water generation unit may be provided with a water quality adjustment unit that adjusts the water quality such as water temperature, pH and organic matter concentration. By positively adjusting the water quality by the water quality adjusting unit, it is possible to prevent a decrease in the dissolution efficiency of ozone gas and a poor cleaning of the separation membrane, and it is possible to further improve the cleaning effect.

Further, the start of the supply of the dissolved water and the start of the ozone water supply at the start of the continuous operation process may be configured at the same timing, or the ozone water supply is started first and the water level in the ozone water generation unit is below a certain level. The configuration may be such that the water to be dissolved is started to be sent when

Embodiment 2.
Next, the second embodiment will be described with reference to FIGS. 4A and 4B. The same or corresponding parts as those in FIGS. 1A to 3 are designated by the same reference numerals, and the description thereof will be omitted. The second embodiment is different from the first embodiment in that a plurality of ozone water generating units are provided. 4A and 4B are block diagrams showing the membrane separation activated sludge system and the membrane cleaning device according to the second embodiment, FIG. 4A is a diagram for explaining an ozone gas supply process, and FIG. 4B is a diagram for explaining a continuous operation process. There is. The water to be dissolved supply step is the same as that of the first embodiment except for the case described below, and is not shown. As shown in FIG. 4A, the membrane separation active sludge system 200 includes a membrane separation active sludge device 20 having a membrane separation tank 1 and a separation membrane 2, and a membrane cleaning device 401 for cleaning the separation membrane 2.

The membrane cleaning device 401 is a cleaning device that cleans the separation membrane 2. The membrane cleaning device 401 includes a water-dissolved water supply unit 8 that supplies the water to be dissolved to the first ozone water generation unit 91, and a first ozone water generation unit that generates ozone water by dissolving ozone gas in the water to be dissolved. 91, a second ozone water generation unit 92, an ozone gas supply unit 10 that supplies ozone gas to the second ozone water generation unit 92, and an ozone water generated by the second ozone water generation unit 92 are separated from each other. It includes an ozone water supply unit 11 for injecting into the inside, a water supply unit 8 to be dissolved, an ozone gas supply unit 10, and a control unit 12 for switching the operation of the ozone water supply unit 11 according to the process. The second ozone water generation unit 92 is provided with a dissolved ozone sensor 9b for measuring the dissolved ozone concentration of ozone water in the second ozone water generation unit 92, and the control unit 12 is provided with the dissolved ozone sensor 9b and a signal line. It is connected via 51.

The water-dissolved water supply unit 8 is connected to the first ozone water generation unit 91 via the water-dissolved water supply pipe 3c. The water to be dissolved is one in which ozone gas is dissolved in the first ozone water generation unit 91 and the second ozone water generation unit 92 to become ozone water, and the water to be dissolved passes through the water supply pipe 3c to be dissolved. It is supplied from the 8th to the 1st ozone water generation unit 91.

The first ozone water generation unit 91 is connected to the second ozone water generation unit 92 via the dissolved water water supply pipe 3f, and the second ozone water generation unit 92 is connected to the second ozone water generation unit 92 via the ozone water water supply pipe 3b1. It is connected to the ozone water supply unit 11. The first ozone water generation unit 91 and the second ozone water generation unit 92 are configured to be capable of storing liquids therein, and are composed of the dissolved water and the dissolved water supplied from the dissolved water supply unit 8. The generated ozone water can be stored. The dissolved water stored in the first ozone water generation unit 91 is supplied to the second ozone water generation unit 92 via the dissolved water water supply pipe 3f.

An air diffuser 91a and an air diffuser 92a are provided at the bottom of the first ozone water generation unit 91 and the bottom of the second ozone water generation unit 92, respectively. The air diffuser 92a is connected to the ozone gas supply unit 10 via the ozone gas supply pipe 3d, and the ozone gas supplied from the ozone gas supply unit 10 is released as bubbles from the air diffuser 92a to provide a second ozone. It is injected into the water to be dissolved in the water generating section 92. An ozone gas transfer pipe 3g connected to the air diffuser 91a of the first ozone water generation unit 91 is connected to the upper part of the second ozone water generation unit 92, and is dissolved in the second ozone water generation unit 92. The ozone gas that has not been used is supplied as dissolved ozone gas to the first ozone water generation unit 91 via the ozone gas transfer pipe 3 g. The undissolved ozone gas supplied through the ozone gas transfer pipe 3g is discharged as bubbles from the air diffuser 91a and injected into the dissolved water in the first ozone water generating unit 91. The ozone gas that has not been dissolved in the first ozone water generation unit 91 is discharged to the outside of the system via the exhaust ozone gas pipe 3e provided above the first ozone water generation unit 91.

A connection portion (not shown) between the first ozone water generation unit 91 and the water to be dissolved water supply pipe 3c is provided on one side wall of the first ozone water generation unit 91, and is dissolved with the first ozone water generation unit 91. A connection portion (not shown) of the water supply pipe 3f is provided on the other side wall of the first ozone water generation portion 91. Further, the connection portion between the first ozone water generation unit 91 and the dissolved water supply pipe 3c is provided at a position higher than the connection portion between the first ozone water generation unit 91 and the dissolved water water supply pipe 3f. As a result, the dissolved water flows in from a high position and the flow of the dissolved water becomes a downward flow, and the flow of ozone gas, which is an upward flow from the air diffuser 91a, and the flow of the dissolved water become countercurrents. In this case, countercurrent contact occurs between the water to be dissolved and the ozone gas, and the dissolution efficiency in the first ozone water generation unit 91 is improved.

A connection portion (not shown) between the second ozone water generation unit 92 and the water to be dissolved water supply pipe 3f is provided on one side wall of the second ozone water generation unit 92, and the second ozone water generation unit 92 and ozone water are provided. A connection portion (not shown) of the water supply pipe 3b1 is provided on the other side wall of the second ozone water generation portion 92. Further, the connection portion between the second ozone water generation unit 92 and the dissolved water water supply pipe 3f is provided at a position higher than the connection portion between the second ozone water generation unit 92 and the ozone water water supply pipe 3b1. As a result, the flow of the water to be dissolved and the flow of ozone gas also become countercurrents in the second ozone water generation unit 92, and the dissolution efficiency in the second ozone water generation unit 92 is improved by the countercurrent contact.

In the "dissolved water supply step" in the second embodiment, first, the dissolved water is supplied from the dissolved water supply unit 8 to the first ozone water generation unit 91, and then supplied to the first ozone water generation unit 91. The dissolved water is supplied to the second ozone water generation unit 92. At this time, a predetermined amount of water to be dissolved may be stored in the first ozone water generation unit 91, and then the supply of the water to be dissolved to the second ozone water generation unit 92 may be started. Others are the same as the “water to be dissolved supply step” in the first embodiment.

In the "ozone gas supply step" in the second embodiment, as shown in FIG. 4A, the supply of the dissolved water from the first ozone water generation unit 91 to the second ozone water generation unit 92 is stopped. Further, the ozone gas supplied from the ozone gas supply unit 10 is dissolved in the dissolved water in the second ozone water generation unit 92, and the ozone gas not dissolved in the second ozone water generation unit 92 is used as undissolved ozone gas. It is supplied to the ozone water generation unit 91 of No. 1, and the undissolved ozone gas is dissolved in the water to be dissolved in the first ozone water generation unit 91. As a result, both the first ozone water generation unit 91 and the second ozone water generation unit 92 generate ozone water by a semi-batch method. The dissolved water in which the undissolved ozone gas is dissolved in the first ozone water generation unit 91 is supplied to the second ozone water generation unit 92 via the dissolved water water supply pipe 3f, and is supplied to the second ozone water generation unit 92. Ozone gas is further dissolved in 92. Others are the same as the “ozone gas supply step” in the first embodiment.

The "ozone water water supply step" in the second embodiment is a step of sending the ozone water stored in the second ozone water generation unit 92 to the separation membrane 2 to clean the separation membrane 2. Further, in the "continuous operation step" in the second embodiment, as shown in FIG. 4B, the dissolved water supply unit 8 supplies the dissolved water to the first ozone water generation unit 91 and the second ozone water generation unit 91. In addition to the supply of ozone water from the unit 92, the water to be dissolved is also supplied from the first ozone water generation unit 91 to the second ozone water generation unit 92. Further, as in the case of the ozone gas supply step described above, both the first ozone water generation unit 91 and the second ozone water generation unit 92 dissolve ozone gas in the water to be dissolved. As a result, both the first ozone water generation unit 91 and the second ozone water generation unit 92 continuously generate ozone water. Others are the same as the “continuous operation step” in the first embodiment.

In the second embodiment, the number of ozone water generating units is two, but three or more ozone water generating units may be provided. The configuration is such that the ozone gas that has not been dissolved in one ozone water generation unit is supplied as undissolved ozone gas to another ozone water generation unit, and the undissolved ozone gas is injected into the dissolved water stored in the other ozone water generation unit. Just do it. Further, undissolved ozone gas that has not been dissolved even in the other ozone water generation unit may be supplied to the other ozone water generation unit.

According to the second embodiment, the same effect as that of the first embodiment can be obtained.
In addition, a plurality of ozone water generation units are provided, and an ozone gas transfer pipe for transferring ozone gas that has not been dissolved in one ozone water generation unit to the other ozone water generation unit as undissolved ozone gas is provided. As a result, the ozone gas that was not dissolved in one ozone water generation unit can be dissolved again in the other ozone water generation unit without being discharged as exhaust ozone gas, so that the dissolution efficiency of ozone gas can be further improved. it can.

Although the present application describes various exemplary embodiments and examples, the various features, embodiments, and functions described in one or more embodiments are applications of a particular embodiment. It is not limited to, but can be applied to embodiments alone or in various combinations.
Therefore, innumerable variations not illustrated are envisioned within the scope of the techniques disclosed in the present application. For example, it is assumed that at least one component is modified, added or omitted, and further, at least one component is extracted and combined with the components of other embodiments.

1 Membrane separation tank, 2 Separation membrane, 3b1, 3b2 Ozone water supply pipe, 3c Dissolved water supply pipe, 3d Ozone gas supply pipe, 3f Dissolved water water supply pipe, 3g Ozone gas transfer pipe, 8 Dissolved water supply part, 9 Ozone Water generation unit, 9b dissolved ozone sensor, 91 1st ozone water generation unit, 92 2nd ozone water generation unit, 10 ozone gas supply unit, 11 ozone water supply unit, 12 control unit, 13 ozone concentration receiver, 14 memory Part, 15 Determining part, 20 Membrane separation active sludge device, 40, 401 Membrane cleaning device, 100, 200 Membrane separation active sludge system

Claims (9)

In a membrane cleaning device that cleans a separation film that separates pollutants contained in water to be treated from the water to be treated with ozone water stored in an ozone water generation unit.
An ozone gas supply unit that supplies ozone gas to the ozone water generation unit, and
A water-dissolved water supply unit that supplies the dissolved water to the ozone water generation unit , using water introduced from the outside or treated water treated with the separation membrane as the dissolved water.
An ozone water supply unit that sends the ozone water stored in the ozone water generation unit to the separation membrane, and an ozone water supply unit.
In a state where the ozone gas supply unit supplies the ozone gas from the ozone gas supply unit to the ozone water generation unit.
The supply of the dissolved water from the dissolved water supply unit to the ozone water generation unit is made to the dissolved water supply unit, and the ozone water is sent from the ozone water generation unit to the separation membrane to the ozone. A control unit that controls the water supply unit and
With
The control unit includes an ozone concentration acquisition unit that acquires the dissolved ozone concentration of the ozone water, a storage unit that stores a predetermined first threshold value and a predetermined second threshold value, the dissolved water, and the solution unit. The determination unit includes a determination unit for determining whether or not the ozone water can be sent.
When the dissolved ozone concentration is equal to or higher than the predetermined first threshold value,
In a state where the ozone gas supply unit supplies the ozone gas from the ozone gas supply unit to the ozone water generation unit.
The supply of the dissolved water from the dissolved water supply unit to the ozone water generation unit is made to the dissolved water supply unit, and the ozone water is sent from the ozone water generation unit to the separation membrane to the ozone. Let the water supply section and
When the dissolved ozone concentration is less than the predetermined second threshold value,
The supply of the dissolved water from the dissolved water supply unit to the ozone water generation unit is stopped by the dissolved water supply unit, and the ozone water is supplied from the ozone water generation unit to the separation membrane. stops the ozone water supply unit,
The determination unit is in a state in which the supply of the dissolved water from the dissolved water supply unit to the ozone water generation unit and the supply of the ozone water from the ozone water generation unit to the separation membrane are stopped. In the step of supplying the ozone gas from the ozone gas supply unit to the ozone water generation unit to generate the ozone water, it is determined whether or not the dissolved ozone concentration is equal to or higher than the predetermined first threshold value.
The determination unit is in a state where the ozone gas supply unit supplies the ozone gas from the ozone gas supply unit to the ozone water generation unit.
The supply of the dissolved water from the dissolved water supply unit to the ozone water generation unit is made to the dissolved water supply unit, and the ozone water is sent from the ozone water generation unit to the separation membrane to the ozone. in the step of the water water unit, membrane cleaning apparatus in which the dissolved ozone concentration is characterized that you determine whether the is less than a second predetermined threshold value. The ozone water generation unit includes a first ozone water generation unit connected to the dissolved water supply unit, a second ozone water generation unit connected to the ozone gas supply unit and the ozone water supply unit, and the above. An ozone gas transfer pipe that transfers ozone gas that has not been dissolved in the second ozone water generation unit as undissolved ozone gas to the first ozone water generation unit, and the second ozone water generation from the first ozone water generation unit. Equipped with a water supply pipe for water to be dissolved, which feeds water to be dissolved.
The undissolved ozone gas is dissolved in the dissolved water in the first ozone water generation unit, and the dissolved water in which the undissolved ozone gas is dissolved is the second ozone water generation unit from the first ozone water generation unit. The film cleaning device according to claim 1, wherein water is sent to the ozone water generation unit. The membrane cleaning apparatus according to claim 1 or 2, wherein the predetermined first threshold value and the predetermined second threshold value are different values. In a membrane cleaning device that cleans a separation film that separates pollutants contained in water to be treated from the water to be treated with ozone water stored in an ozone water generation unit.
An ozone gas supply unit that supplies ozone gas to the ozone water generation unit, and
A water-dissolved water supply unit that supplies the dissolved water to the ozone water generation unit , using water introduced from the outside or treated water treated with the separation membrane as the dissolved water.
An ozone water supply unit that sends the ozone water stored in the ozone water generation unit to the separation membrane, and an ozone water supply unit.
A control unit that switches the process to be executed, and
With
The control unit
Ozone gas supply to supply ozone gas to the ozone water generation unit in a state where the supply of the dissolved water to the ozone water generation unit and the supply of the ozone water from the ozone water generation unit to the separation membrane are stopped. Process and
A control unit that switches between a continuous operation step of supplying ozone gas to the ozone water generation unit, supplying the dissolved water to the ozone water generation unit, and sending the ozone water to the separation membrane. hand,
The control unit has an ozone concentration acquisition unit that acquires the dissolved ozone concentration of the ozone water, and a storage unit that stores a predetermined first threshold value and a predetermined second threshold value.
When the dissolved ozone concentration of the ozone water becomes equal to or higher than the predetermined first threshold value during the ozone gas supply step, the ozone water supply to the separation membrane is started and carried out. Is switched to the continuous operation step, and when the dissolved ozone concentration of the ozone water becomes less than a predetermined second threshold value during the continuous operation step, the subject to the ozone water generation unit is covered. A membrane cleaning apparatus characterized in that the supply of dissolved water and the supply of the ozone water to the separation membrane are stopped, and the step to be carried out is switched to the ozone gas supply step. The membrane cleaning apparatus according to claim 4, wherein the predetermined first threshold value and the predetermined second threshold value are different values. It has a membrane separation tank and a separation membrane arranged inside the membrane separation tank, and water to be treated containing a pollutant is circulated through the separation membrane in the filtration direction, and the pollutant is removed from the water to be treated. A membrane separation active sludge system equipped with a membrane separation active sludge device for removing and acquiring treated water and a membrane cleaning device for cleaning the separation membrane with ozone water stored in an ozone water generation unit.
The membrane cleaning device is
An ozone gas supply unit that supplies ozone gas to the ozone water generation unit, and
A water-dissolved water supply unit that supplies the dissolved water to the ozone water generation unit , using water introduced from the outside or treated water treated with the separation membrane as the dissolved water.
An ozone water supply unit that sends the ozone water stored in the ozone water generation unit to the separation membrane, and an ozone water supply unit.
In a state where the ozone gas supply unit supplies the ozone gas from the ozone gas supply unit to the ozone water generation unit.
The supply of the dissolved water from the dissolved water supply unit to the ozone water generation unit is made to the dissolved water supply unit, and the ozone water is sent from the ozone water generation unit to the separation membrane to the ozone. A control unit that controls the water supply unit and
With
The control unit includes an ozone concentration acquisition unit that acquires the dissolved ozone concentration of the ozone water, a storage unit that stores a predetermined first threshold value and a predetermined second threshold value, the dissolved water, and the solution unit. The determination unit includes a determination unit for determining whether or not the ozone water can be sent.
When the dissolved ozone concentration is equal to or higher than the predetermined first threshold value,
In a state where the ozone gas supply unit supplies the ozone gas from the ozone gas supply unit to the ozone water generation unit.
The supply of the dissolved water from the dissolved water supply unit to the ozone water generation unit is made to the dissolved water supply unit, and the ozone water is sent from the ozone water generation unit to the separation membrane to the ozone. Let the water supply section and
When the dissolved ozone concentration is less than the predetermined second threshold value,
The supply of the dissolved water from the dissolved water supply unit to the ozone water generation unit is stopped by the dissolved water supply unit, and the ozone water is supplied from the ozone water generation unit to the separation membrane. stops the ozone water supply unit,
The determination unit is in a state in which the supply of the dissolved water from the dissolved water supply unit to the ozone water generation unit and the supply of the ozone water from the ozone water generation unit to the separation membrane are stopped. In the step of supplying the ozone gas from the ozone gas supply unit to the ozone water generation unit to generate the ozone water, it is determined whether or not the dissolved ozone concentration is equal to or higher than the predetermined first threshold value.
The determination unit is in a state where the ozone gas supply unit supplies the ozone gas from the ozone gas supply unit to the ozone water generation unit.
The solutionized water is supplied from the dissolved water supply unit to the ozone water generation unit to the dissolved water supply unit, and the ozone water is sent from the ozone water generation unit to the separation membrane to the ozone. in the step of the water water unit, membrane separation activated sludge system in which the dissolved ozone concentration is characterized that it determines whether the is less than a second predetermined threshold value. In a film cleaning method in which a separation film that separates pollutants contained in water to be treated from the water to be treated is washed with ozone water stored in an ozone water generation unit.
Ozone gas supply step of supplying ozone gas to the ozone water generation unit in a state where the supply of dissolved water to the ozone water generation unit and the supply of the ozone water from the ozone water generation unit to the separation membrane are stopped. When,
A water to be dissolved supply step of supplying the water to be dissolved to the ozone water generation unit , using water introduced from the outside or treated water treated with the separation membrane as the water to be dissolved.
An ozone water supply step of supplying the ozone water stored in the ozone water generation unit to the separation membrane, and
A continuous operation step of carrying out the dissolved water supply step and the ozone water supply step while supplying the ozone gas to the ozone water generation unit, and
When the dissolved ozone concentration of the ozone water becomes equal to or higher than a predetermined first threshold value during the execution of the ozone gas supply step , the ozone water supply step is started and the steps to be carried out are continuously performed. When the ozone water is switched to the operation process and the dissolved ozone concentration of the ozone water becomes less than a predetermined second threshold value during the continuous operation process, the dissolved water in the ozone water generation unit is subjected to the operation process. A film cleaning method characterized in that the supply and the supply of the ozone water to the separation film are stopped, and the step to be carried out is switched to the ozone gas supply step. The ozone water generation unit includes a first ozone water generation unit to which the dissolved water is supplied and a second ozone water generation unit to which the ozone gas is supplied.
The ozone gas that was not dissolved in the second ozone water generation unit is transferred to the first ozone water generation unit as undissolved ozone gas, and the undissolved ozone gas is transferred to the dissolved water in the first ozone water generation unit. The film cleaning method according to claim 7, wherein the dissolved water in which the undissolved ozone gas is dissolved is sent from the first ozone water generation unit to the second ozone water generation unit. The membrane cleaning method according to claim 7 or 8, wherein the predetermined first threshold value and the predetermined second threshold value are different values.

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