JP2014050810A - Water treatment apparatus and operation method of water treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water treatment apparatus and an operation method of the water treatment apparatus that when the water treatment apparatus with RO membrane is activated in emergency, time before providing treated water can be reduced, and degradation of the RO membrane in a stand-by state is prevented.SOLUTION: A water treatment apparatus 10 returns back both of treated water and concentrated water discharged from an RO membrane facility 16 to a raw water tank 11. The returned treated water and concentrated water are pooled in the raw water tank, the pooled water to be treated is pressurized by pressurize means, and the pressurized water to be treated is supplied to the RO membrane. The water treatment apparatus continues supplying the water to be treated to the RO membrane by circulate operation circulating the treated water and the concentrated water in a stand-by state where the treated water is not supplied to outside of the apparatus as drinking water.

Description

  The present invention relates to a water treatment apparatus that treats raw water using an RO membrane, and a method for operating the water treatment apparatus.

  For example, a water treatment apparatus for producing drinking water or miscellaneous water by treating groundwater (raw water) with an RO membrane (Reverse Osmosis, reverse osmosis membrane) is known (for example, Patent Document 1). Such a water treatment apparatus processes the raw | natural water taken using the RO membrane, and distributes the treated water which permeate | transmitted the RO membrane as drinking water. Further, the concentrated water that has not permeated the RO membrane is generally discarded.

JP 2011-177653 A

  For example, in an emergency in which a normal water supply cannot be used, it is required to take groundwater in an emergency to obtain drinking water. However, in the prior art, it takes time to start up the water treatment apparatus that is stopped urgently. In addition, the RO membrane is vulnerable to drying, microbial growth, and the like, and there is a concern about deterioration. Therefore, it is difficult to apply the RO membrane to a water treatment device that is used irregularly, and is not suitable for an emergency response device.

  Therefore, in a water treatment device equipped with an RO membrane, when the device is urgently started up, it is possible to shorten the time until the treated water is provided, and to suppress degradation of the RO membrane in a standby state. It is an object of the present invention to provide a possible water treatment device and a method for operating the water treatment device.

  The present invention relates to a raw water tank for storing raw water, a pressure increasing means for boosting the water to be treated stored in the raw water tank, an RO membrane for treating the water to be treated that has been pressurized by the pressure raising means, and the RO membrane. The treated water tank that stores the treated water, the water supply unit that supplies the treated water to the outside of the apparatus, the treated water return means that can return the treated water stored in the treated water tank to the raw water tank, and the RO membrane did not permeate There is provided a water treatment device comprising: concentrated water returning means capable of returning concentrated water (RO membrane concentrated water) to a raw water tank.

  For example, in the case of producing potable water, this water treatment apparatus receives raw water and stores it in a raw water tank, pressurizes the stored treated water by a boosting means, and treats the pressurized treated water with an RO membrane. can do. The water treatment apparatus can provide treated water that has passed through the RO membrane as drinking water. For example, the water treatment device may provide drinking water only in an emergency, and may be in a standby state in which drinking water is not provided during normal times.

  In this water treatment apparatus, treated water is stored in a treated water tank, and the stored treated water is returned to the raw water tank by the treated water returning means, and concentrated water that has not permeated the RO membrane is returned to the original by the concentrated water returning means. Can be returned to the aquarium. The water treatment apparatus can store the returned treated water and concentrated water in the raw water tank, pressurize the stored treated water by a pressure-increasing means, and supply the pressurized treated water to the RO membrane. The water treatment apparatus can return both the treated water that has passed through the RO membrane and the concentrated water that has not passed through the RO membrane to the raw water tank again. Thereby, the water treatment apparatus can continue supplying the water to be treated to the RO membrane by performing a circulation operation for circulating the treated water and the concentrated water. The water treatment device can keep the pipeline of the water treatment device clean and prevent deterioration of the RO membrane by performing a circulation operation in a standby state where the treated water is not supplied as drinking water to the outside of the device.

  The water treatment device is disposed upstream of the pressure increasing means, and a filter that separates impurities in the water to be treated supplied from the raw water tank, and a reverse water supply that supplies the treated water to the filter and backwashes the filter. And a washing means. Thereby, the function of a filter can be recovered | restored by carrying out backwashing of a filter using treated water.

  The water treatment apparatus may include a hypochlorous acid injecting means for injecting hypochlorous acid into the treated water tank, and a reducing agent injecting means for injecting a reducing agent into the water to be treated on the upstream side of the RO membrane. Good. Thereby, hypochlorous acid can be inject | poured into the treated water returned to a raw | natural water tank, and the inside of an apparatus can be sterilized. In addition, since the reducing agent can be injected upstream of the RO membrane, after the hypochlorous acid in the water to be treated is reduced by the reducing agent, the water to be treated can be supplied to the RO membrane. Therefore, the deterioration of the RO membrane due to hypochlorous acid can be suppressed.

  The water treatment apparatus may include a hypochlorous acid injection means for injecting hypochlorous acid into the treated water tank, and a reducing agent injection means for injecting a reducing agent into the water to be treated on the upstream side of the pressure raising means. Good. Thereby, hypochlorous acid can be inject | poured into the treated water returned to a raw | natural water tank, and the inside of an apparatus can be sterilized. In addition, since the reducing agent can be injected upstream of the pressurizing means, the injected reducing agent is diffused by the pressurizing means, and hypochlorous acid in the water to be treated can be uniformly reduced. Therefore, it is possible to more suitably suppress the deterioration of the RO membrane due to hypochlorous acid.

  The water treatment device further includes a water quality sensor for water to be inspected by distributing a part of the water to be treated and inspecting the water quality while circulating the water to be treated, and the water to be treated inspected by the water quality sensor. The structure which returns to a raw | natural water tank may be sufficient. Thereby, water quality can be managed without reducing the flow rate of circulating water. In addition, in the water treatment device, most of the area is filled with water, and the place where the water after inspection can be merged is limited, but by injecting the water into the raw water tank close to atmospheric pressure, Water can be circulated without being discarded.

  The water treatment apparatus further includes a treated water quality sensor that divides a part of the treated water and inspects the water quality while distributing the separated treated water, and treats the treated water inspected by the water quality sensor. The structure which returns to a water tank may be sufficient. Thereby, water quality can be managed without reducing the flow rate of circulating water. In addition, in the water treatment device, most of the area is filled with water, and the place where the water after inspection can be merged is limited. However, by injecting the water into the treatment water tank close to atmospheric pressure, Water can be circulated without being discarded.

  The water treatment device may be configured such that the filter disposed on the upstream side of the pressurizing unit and separating impurities in the for-treatment water supplied from the raw water tank is a sand filtration device and / or a membrane filtration device. Thereby, impurities can be suitably removed from the water to be treated supplied to the RO membrane.

The water treatment apparatus may include a second hypochlorous acid injection unit that injects hypochlorous acid into the raw water supplied to the raw water tank. Thereby, since it can supply to a raw | natural water tank after sterilizing raw | natural water, the pipe line of a water treatment apparatus can be kept cleaner.

  The present invention is a water treatment device that receives raw water in a raw water tank and stores it, treats water to be treated stored in the raw water tank using an RO membrane, and supplies the treated water that has passed through the RO membrane to the outside of the device. In the above operation method, the pressurizing step for boosting the water to be treated stored in the raw water tank, the reverse osmosis membrane treatment step for treating the water to be treated in the pressure boosting step using the RO membrane, and the permeation through the RO membrane A method of operating a water treatment apparatus comprising: a treated water returning step for returning the treated water to the raw water tank; and a concentrated water returning step for returning the RO membrane concentrated water to the raw water tank is provided.

  In the operation method of the water treatment apparatus of the present invention, the water to be treated stored in the raw water tank is pressurized, and the pressurized water to be treated is treated with the RO membrane. In this operation method, treated water that has passed through the RO membrane is returned to the raw water tank, and concentrated water that has not passed through the RO membrane is also returned to the raw water tank. The treated water and concentrated water that have been returned are stored in the raw water tank, pressurized again, and supplied to the RO membrane. In the operation method of the water treatment apparatus, both the treated water that has permeated the RO membrane and the concentrated water that has not permeated the RO membrane can be returned to the raw water tank. Thereby, the to-be-processed water can be continuously supplied to RO membrane by performing the circulating operation which circulates treated water and concentrated water. In the operation method of the water treatment apparatus, the RO membrane can be prevented from deteriorating by performing the circulation operation in a standby state where the treated water is not supplied as drinking water to the outside of the apparatus.

  In the treated water return process, hypochlorous acid is injected into the treated water, the treated water into which hypochlorous acid has been injected is returned, and a reducing agent is injected into the treated water before supplying the treated water to the RO membrane. May be. Thereby, hypochlorous acid can be inject | poured into the treated water returned to a raw | natural water tank, and the inside of an apparatus can be sterilized. In addition, since the water to be treated is supplied to the RO membrane after hypochlorous acid is reduced by the injected reducing agent, deterioration of the RO membrane due to hypochlorous acid is suitably suppressed.

  In the treated water return process, hypochlorous acid is injected into the treated water, the treated water into which hypochlorous acid has been injected is returned, and the treated water stored in the raw water tank is reduced to the treated water before being pressurized. An agent may be injected. Thereby, hypochlorous acid can be inject | poured into the treated water returned to a raw | natural water tank, and the inside of an apparatus can be sterilized. Further, since the injected reducing agent is diffused by the pressurizing step, hypochlorous acid in the for-treatment water is uniformly reduced by the reducing agent. Since the treated water in which hypochlorous acid is uniformly reduced by the reducing agent is supplied to the RO membrane, the deterioration of the RO membrane due to hypochlorous acid is further suitably suppressed.

  The operation method of the water treatment apparatus may further include a filtration step that is performed before the pressure increasing step and separates impurities in the water to be treated. Thereby, the impurities in to-be-processed water can be isolate | separated in the front | former stage of a pressure | voltage rise process and a reverse osmosis membrane process.

  The operation method of the water treatment device is to reverse the treated water returning process to the raw water tank, supply the treated water to the filter used in the filtration process, and perform reverse flow cleaning of the filter. You may further provide the washing process. Thereby, the function of a filter can be recovered | restored by carrying out backwashing of a filter using treated water.

  The operation method of the water treatment apparatus is to divide a part of the treated water, inspect the water quality while circulating the separated treated water, and return the treated water to the raw water tank. A water quality inspection process may be further provided. Thereby, water quality can be managed without reducing the flow rate of circulating water. In addition, in the water treatment device, most of the area is filled with water, and the place where the water after inspection can be merged is limited, but by injecting the water into the raw water tank close to atmospheric pressure, Water can be circulated without being discarded.

  The operation method of the water treatment apparatus is a process of water quality inspection for distributing a part of the treated water, inspecting the water quality while distributing the separated treated water, and returning the inspected treated water to the treated water tank. Furthermore, you may provide. Thereby, water quality can be managed without reducing the flow rate of circulating water. In addition, in the water treatment device, most of the area is filled with water, and the place where the water after inspection can be merged is limited. However, by injecting the water into the treatment water tank close to atmospheric pressure, Water can be circulated without being discarded.

  The operation method of the water treatment equipment is to stop the return of treated water in the treated water return process, stop the return of concentrated water in the concentrated water return process, and discharge raw water without discharging treated water and concentrated water outside the equipment. The raw water tank is started to be received, the pressure increasing step and the reverse osmosis membrane treatment step are executed, and the treated water treated in the reverse osmosis membrane treatment step can be supplied to the outside of the apparatus. Thereby, treated water can be immediately supplied as drinking water in an emergency.

  The operation method of the water treatment apparatus is to stop returning the treated water in the treated water returning process, stop returning the concentrated water in the concentrated water returning process, and discharge or discharge the treated water and the concentrated water to the outside of the apparatus. At the same time, it is possible to start receiving raw water into the raw water tank, execute the pressurization step and the reverse osmosis membrane treatment step, and supply the treated water treated in the reverse osmosis membrane treatment step to the outside of the apparatus. Before the treated water is supplied to the outside of the apparatus, after the treated water and concentrated water in the water treatment apparatus are drained or simultaneously with the drainage, new raw water can be received to produce potable water. Thereby, a sense of security can be given to the user of drinking water.

  According to the water treatment apparatus and the water treatment apparatus operating method of the present invention, it is possible to shorten the time until the treated water is provided when the apparatus is started up urgently while suppressing the deterioration of the RO membrane in the standby state. Can do.

It is a schematic block diagram which shows the water treatment apparatus which concerns on embodiment of this invention. It is a schematic block diagram which shows the connection of piping around a water quality sensor. It is process drawing which shows the procedure of the operating method of the water treatment apparatus which concerns on embodiment of this invention. It is process drawing which shows the procedure in a startup process. It is process drawing which shows the procedure in a circulating operation process.

  Hereinafter, preferred embodiments of a water treatment apparatus and a water treatment apparatus operating method according to the present invention will be described with reference to the drawings. In the description of the drawings, the same or corresponding elements are denoted by the same reference numerals, and redundant description is omitted.

  A water treatment device 10 shown in FIG. 1 is a device that can produce drinking water by applying a reverse osmosis membrane treatment to raw water in an emergency, for example. The water treatment apparatus 10 may be in a standby state during normal times and produce potable water only in an emergency. As raw water, for example, groundwater, water stored in a reservoir, or the like can be used.

  The water treatment apparatus 10 includes a raw water tank 11 that can store the acquired raw water. The raw water tank 11 is a container capable of storing water. For example, a vent pipe is connected to the raw water tank 11, and the inside is maintained at atmospheric pressure.

  The raw water tank 11 is connected to a water intake pipe 21 for receiving raw water. The raw water passes through the intake pipe 21 and is supplied into the raw water tank 11. The intake pipe 21 is provided with an on-off valve 41 that can stop receiving raw water. By closing the on-off valve 41 (flow rate adjusting unit), the acceptance of raw water is stopped.

  The water treatment apparatus 10 has an injection pipe 22 (second hypochlorous acid injection means) capable of injecting hypochlorous acid into the raw water tank 11. The hypochlorous acid injection pipe 22 may be connected to the intake pipe 21 or may be connected to the raw water tank 11.

  The raw water tank 11 is connected to a sand filter 12 (filter) via a pipe 23. A pump 13 for feeding the water to be treated supplied to the sand filter 12 is connected to the pipe 23. The treated water is water stored in the raw water tank 11. The treated water stored in the raw water tank 11 is fed by the pump 13 and supplied to the sand filter 12.

  The sand filter 12 removes solids (impurities) in the water to be treated. The sand filter 12 accommodates sand as a filter medium in a container. The water to be treated is supplied from the upper side of the sand filter 12, passes through the sand layer, solids of a predetermined size are removed, and the water is discharged from the lower side. The water treatment device 10 may be configured to include other filter (membrane filter device) instead of the sand filter 12. Examples of other filter include MF membrane (Microfiltration), UF membrane (Ultra filtration) and the like.

  A pipe 24 is connected to the lower side of the sand filter 12 to which the water to be treated from which the solid matter has been removed is sent. The sand filter 12 is connected to the prefilter 14 via a pipe 24. The water to be treated that has passed through the sand filter 12 circulates in the pipe 24 and is supplied to the prefilter 14. The prefilter 14 removes the sand contained in the water to be treated when the sand of the sand filter 12 flows out. The prefilter 14 has a filter medium capable of removing sand in the container.

  The pre-filter 14 is connected to a pipe 25 that feeds the water to be treated that has passed through the pre-filter 14. The prefilter 14 is connected to the mixer 15 via a pipe 25. The water to be treated that has passed through the prefilter 14 flows through the pipe 25 and is supplied to the mixer 15.

An injection pipe 26 (reducing agent injection means) that can inject a reducing agent is connected to the pipe 25. The reducing agent neutralizes hypochlorous acid contained in the water to be treated. As the reducing agent, SBS (NaHSO ₃ , sodium bisulfite) can be used.

  Further, an injection pipe 27 (dispersant injection means) capable of injecting a dispersant is connected to the pipe 25. The dispersant is injected in order to suppress calcium precipitation and silica precipitation on the RO membrane. The injection tube 27 is provided on the downstream side of the injection tube 26, for example.

  The mixer 15 mixes the water to be treated, and the reducing agent and the dispersant contained in the water to be treated are diffused to make the concentration uniform.

  A pipe 28 is connected to the mixer 15 for feeding the water to be treated that has passed through the mixer 15. The mixer 15 is connected to the RO membrane facility 16 via a pipe 28. The water to be treated discharged from the mixer 15 is pressurized by the high-pressure pump 17 (pressure increase means) connected to the pipe 28 and supplied to the RO membrane facility 16. The high pressure pump 17 raises the water to be treated to a pressure larger than the osmotic pressure.

  The RO membrane facility 16 performs reverse osmosis membrane treatment of water to be treated, and includes an RO membrane in the container. The RO membrane facility 16 is divided into treated water that has permeated through the RO membrane and concentrated water that has not permeated through the RO membrane (RO membrane concentrated water). The water treatment apparatus 10 may include a plurality of RO membrane facilities 16 and supply the concentrated water sent from the upstream RO membrane facility 16 to the downstream RO membrane facility 16.

  A piping 29 through which treated water is sent is connected to the RO membrane facility 16. The RO membrane facility 16 is connected to the treated water tank 18 via a pipe 29. The treated water sent from the RO membrane facility 16 circulates in the pipe 29 and is supplied to the treated water tank 18.

  A piping 30 through which concentrated water is fed is connected to the RO membrane facility 16. The pipe 30 is connected to the sewage pipe 31 of the water treatment apparatus 10. The sewage pipe 31 is a pipe that discharges water (unnecessary water) discharged from the water treatment apparatus 10 to the outside of the apparatus 10. An open / close valve 42 is provided between the pipe 30 and the sewage pipe 31. When the concentrated water is not drained out of the apparatus 10, the on-off valve 42 is closed.

  The treated water tank 18 is a container capable of storing treated water. For example, a vent pipe is connected to the treated water tank 18, and the inside is maintained at atmospheric pressure.

  A pipe 32 through which treated water stored in the treated water tank 18 is fed is connected to the treated water tank 18. The pipe 32 is connected to a water receiving tank outside the apparatus 10. For example, when providing treated water as drinking water, the treated water stored in the treated water tank 18 is supplied to a water receiving tank outside the apparatus 10. A water supply pump 19 for supplying treated water is connected to the pipe 32.

  In addition, the pipe 32 is provided with an on-off valve 43 (water supply amount adjusting unit). When the treated water is provided as drinking water, the on-off valve 43 is opened, and the treated water passes through the pipe 32 and is supplied to the water receiving tank outside the apparatus 10. By adjusting the opening of the on-off valve 43, the amount of drinking water supplied to the outside of the apparatus 10 can be adjusted.

  Here, the water treatment apparatus 10 of the present embodiment has a treated water returning means 50 that returns treated water stored in the treated water tank 18 to the raw water tank 11 and concentrated water discharged from the RO membrane facility 16. And a concentrated water returning means 60 for returning to the home. The water treatment apparatus 10 can return the treated water and the concentrated water to the raw water tank 11, and returns the raw water tank 11 to the RO membrane facility 16 again to circulate the treated water and the concentrated water. Can be executed. That is, the water treatment apparatus 10 can perform the circulating operation in a standby state where no potable water is produced.

  The treated water return means 50 has a treated water return pipe 51 branched from the pipe 32. The treated water tank 18 is connected to the raw water tank 11 via a pipe 32 and a treated water return pipe 51. An open / close valve 44 is provided between the pipe 32 and the treated water return pipe 51. In a state where the on-off valve 44 is opened and the on-off valve 43 is closed, the treated water is returned from the treated water tank 18 to the raw water tank 11. The treated water stored in the treated water tank 18 is fed by the water pump 19, passes through the pipe 32 and the treated water return pipe 51, and is supplied to the raw water tank 11.

  The concentrated water return means 60 has a concentrated water return pipe 61 branched from the pipe 30. The outlet of the concentrated water of the RO membrane facility 16 is connected to the raw water tank 11 through the pipe 30 and the concentrated water return pipe 61. An open / close valve 45 is provided between the pipe 30 and the concentrated water return pipe 61. In a state where the on-off valve 45 is opened and the on-off valve 42 is closed, the concentrated water is returned from the RO membrane facility 16 to the raw water tank 11. The concentrated water discharged from the RO membrane facility 16 is supplied to the raw water tank 11 through the pipe 30 and the concentrated water return pipe 61. The water treatment apparatus 10 may have a configuration including a storage tank capable of storing concentrated water, for example. After the concentrated water discharged from the RO membrane facility 16 is stored, the raw water tank 11 may be supplied with water.

  Further, the water treatment apparatus 10 has an injection pipe 33 (hypochlorous acid injection means) capable of injecting hypochlorous acid into the treated water tank 18. By supplying hypochlorous acid into the treated water tank 18, the treated water flowing in the treated water return pipe 51 can be disinfected. The quality of the treated water circulating through the water treatment apparatus 10 can be maintained.

  The water treatment apparatus 10 may include backflow cleaning means 70 that supplies treated water to the sand filter 12 and performs backflow cleaning of the sand filter 12. The backwashing means 70 has a backwash pipe 71 branched from the treated water return pipe 51. The treated water tank 18 is connected to the outlet side 12 b of the sand filter 12 through a pipe 32, a treated water return pipe and a backwash pipe 71. The backwash pipe 71 is connected to the pipe 24 connected to the outlet side 12 b of the sand filter 12.

  The pipe 24 is provided with an open / close valve 46. The backwash pipe 71 is connected to the sand filter 12 side from the on-off valve 46. The backwash pipe 71 is provided with an on-off valve 47. The treated water return pipe 51 is provided with an open / close valve 48 on the downstream side (raw water tank 11 side) from the branch point with the backwash pipe 71. In a state where the on-off valve 47 is opened and the on-off valves 46 and 48 are closed, treated water is supplied from the treated water return pipe 51 to the outlet side 12 b of the sand filter 12.

  The inlet side 12 a of the sand filter 12 is connected to a sewage pipe 31 branched from the pipe 23. An open / close valve 49 is provided in the sewage pipe 31. The pipe 23 is provided with a check valve upstream of the branch point with the sewage pipe 31 (between the water pump 13 and the sand filter 12). The check valve prevents inflow of water from the sand filter 12 side to the water pump 13 side. In the state where the on-off valve 49 is opened, the washed water drained from the inlet side 12 a of the sand filter 12 passes through the sewage pipe 31 and is discarded outside the apparatus 10.

  By supplying the treated water to the outlet side 12b of the sand filter 12 and performing back-flow cleaning, the sand of the sand filter 12 is rolled up, and solids deposited on the sand, solids attached to the sand, etc. Is removed by the water stream. Waste water containing solid matter is discharged from the inlet side 12 of the sand filter 12. Thereby, the function of the sand filter 12 can be recovered.

  Next, the water quality sensor of the water treatment apparatus 10 will be described with reference to FIG. The water treatment apparatus 10 includes a water quality sensor 81 that inspects the quality of the water to be treated and a water quality sensor 82 that inspects the quality of the treated water. FIG. 2 shows a case where the treated water stored in the treated water tank 18 is inspected. In addition, since it is the same structure also when inspecting the to-be-processed water stored in the raw | natural water tank 11, in FIG. 2, the code | symbol is attached | subjected about the structure in the case of inspecting to-be-processed water.

  The treated water supplied to the treated water quality sensor 82 passes through the pipe 83 branched from the pipe 32 and is supplied to the water quality sensor 82. A water supply pump 84 is connected to the pipe 83. The treated water stored in the treated water tank 18 passes through the pipe 32, and a part of the treated water is divided and flows into the pipe 83. The separated treated water is fed by the water feed pump 84 and supplied to the water quality sensor 82.

  The water quality sensor 82 is connected to a pipe 85 for supplying treated water after inspection. The water quality sensor 82 is connected to the treated water tank 18 through a pipe 85. The treated water after the inspection passes through the pipe 85 and is returned to the treated water tank 18. Thereby, the treated water after the inspection can be returned to the treated water tank 18 without being discarded. Therefore, the flow rate by the circulation operation can be maintained without receiving new raw water.

  The treated water supplied to the water quality sensor 81 to be treated passes through the pipe 83 branched from the pipe 23 and is supplied to the water quality sensor 81. A water supply pump 84 is connected to the pipe 83. The treated water stored in the raw water tank 11 passes through the pipe 23, a part of the treated water is diverted and flows into the pipe 83. The treated water that has been diverted is fed by the water feed pump 84 and supplied to the water quality sensor 81.

  The water quality sensor 81 is connected to a pipe 85 for supplying the treated water after the inspection. The water quality sensor 81 is connected to the raw water tank 11 through a pipe 85. The treated water after the inspection passes through the pipe 85 and is returned to the raw water tank 11. Thereby, the to-be-processed water after a test | inspection can be returned to the raw | natural water tank 11, without discarding. Therefore, the flow rate by the circulation operation can be maintained without receiving new raw water.

  The water quality sensors 81 and 82 include a pH meter that measures the pH value of water, a turbidity meter / colorimeter that measures the turbidity of water and the color of water, and residual salt that measures the salinity contained in water. Totals are listed.

  Next, the operation method of the water treatment apparatus 10 will be described. The water treatment apparatus 10 is in a standby state in which drinking water is not produced at normal times, and is in a water supply state in which drinking water is produced, for example, in an emergency when the water supply cannot be used.

  FIG. 3 is a process diagram showing the procedure of the operation method of the water treatment apparatus 10. In the operation method of the water treatment apparatus 10, the raw water receiving process (step S1), the start-up process (step S2), the circulation operation process (step S3), the concentrated water draining process (step S4), and the backwashing process (step S5). Then, a draining process of concentrated water and treated water (step S6) and a potable water manufacturing process (step S7) are executed.

  In the raw water receiving step S1, the water treatment device 10 receives the raw water. The water treatment device 10 pumps up groundwater as raw water, for example, and stores it in the raw water tank 11. At this time, raw water is received while injecting hypochlorous acid.

  In the start-up process S2, reverse osmosis membrane treatment is started on the treated water (raw water) stored in the raw water tank 11, and the treated water is stored. FIG. 4 is a process diagram showing a procedure in the startup process. Specifically, the startup process S2 includes a filtration process (step S11), a reducing agent injection process (step S12), a dispersant injection process (step S13), a mixing process (step S14), a pressure increasing process (step S15), and the reverse. An osmosis membrane treatment process (Step S16) and a treated water storage process (Step S17) are performed. In the start-up process S2, the raw water is continuously received until a certain amount of treated water is stored.

  In filtration process S11, the solid substance in to-be-processed water is removed using the sand filter 12. FIG. The treated water stored in the raw water tank 11 is supplied to the sand filter 12 through the pipe 23, and the solid matter is removed. The treated water sent from the sand filter 12 is supplied to the prefilter 14 through the pipe 24. When sand flows out from the sand filter 12, the pre-filter 14 removes sand in the water to be treated.

  In the reducing agent injection step S12, a reducing agent is injected into the water to be treated. The reducing agent is injected into the pipe 25 through the injection pipe 26. In the dispersant injection step S13, the dispersant is injected into the water to be treated. The dispersant is injected into the pipe 25 through the injection pipe 27.

  In the mixing step S14, the reducing agent and the dispersing agent in the for-treatment water are mixed to make the concentration of the reducing agent and the dispersing agent in the for-treatment water uniform. In the mixing step S14, the water to be treated is supplied to the mixer 15, and the reducing agent and the dispersant in the water to be treated are mixed.

  In the boosting step S15, the water to be treated is boosted using the high-pressure pump 17. In the pressure increasing step S15, the water to be treated discharged from the mixer 15 is supplied to the high pressure pump 17 to increase the pressure to a pressure required for the reverse osmosis membrane treatment.

  In the reverse osmosis membrane treatment step S <b> 16, the reverse osmosis membrane treatment is performed using the RO membrane equipment 16. In the reverse osmosis membrane treatment step S16, the treated water pressurized by the high-pressure pump 17 is supplied to the RO membrane facility 16, and the treated water is treated water that has permeated the RO membrane and concentrated water that has not permeated the RO membrane. And to separate.

  In the treated water storage step S <b> 17, treated water is stored in the treated water tank 18. In the treated water storage step S <b> 17, treated water discharged from the RO membrane facility 16 is supplied to the treated water tank 18. At this time, the concentrated water discharged from the RO membrane facility 16 is discharged outside the apparatus 10. In the treated water storage step S17, hypochlorous acid is injected into the treated water tank 18.

  The start-up process S2 is executed until a certain amount of treated water is stored in the treated water tank 18. After a certain amount of treated water is stored, the process proceeds to the circulation operation step S3.

  In the circulation operation step S3, the concentrated water and the treated water are returned to the raw water tank 11, and the circulation operation is executed. FIG. 5 is a process diagram showing a procedure in the circulation operation process. Specifically, the circulation operation step S3 includes a filtration step (step S11), a reducing agent injection step (step S12), a dispersant injection step (step S13), a mixing step (step S14), a pressure increase step (step S15), A reverse osmosis membrane treatment process (step S16), a treated water storage process (step S17), a treated water return process (step S21), and a concentrated water return process (step S22) are executed. Circulation operation process S3 is continued for a fixed period. When the circulation operation step S3 is executed, the raw water reception is stopped. Moreover, it is the state which has stopped the water supply outside the apparatus of a treated water.

  Filtration step (step S11), reducing agent injection step (step S12), dispersant injection step (step S13), mixing step (step S14), pressure increasing step (step S15), reverse osmosis membrane treatment step (step S16), processing Since the water storage process (step S17) is the same as the startup process S2, description thereof is omitted here.

  In the circulation operation step S3, the treated water return step S21 is executed after the treated water storage step S17. In the treated water returning step S <b> 21, the treated water stored in the treated water tank 18 is returned to the raw water tank 11. The treated water is fed by the water pump 19, passes through the treated water return pipe 51, and is supplied to the raw water tank 11.

  In the circulation operation step S3, a concentrated water returning step S22 for returning the concentrated water discharged from the RO membrane facility 16 to the raw water tank 11 is executed. The concentrated water passes through the concentrated water return pipe 61 and is supplied to the raw water tank 11.

  The treated water and concentrated water returned to the raw water tank 11 are again supplied to the sand filter 12, and the filtration step S11 is performed. Similarly, steps S12 to S17, S21, and S22 are repeatedly executed. Thereby, in the standby state of the water treatment apparatus 10, the circulation operation which circulates treated water and concentrated water can be performed. By this circulation operation, water can be continuously supplied to the RO membrane, so that deterioration of the RO membrane can be suppressed.

  In the concentrated water draining step S4, the circulating operation is stopped and the concentrated water is drained. For example, if the production of potable water is not executed after the circulation operation for one month is continued, the process proceeds to step S4.

  In the concentrated water draining step S <b> 4, the concentrated water is discarded until the treated water tank 18 stores an amount of water that can be backwashed in the sand filter 12. At this time, the return of the treated water to the raw water tank 11 and the return of the concentrated water to the raw water tank 11 are stopped. The concentrated water discharged from the RO membrane facility 16 is discarded outside the apparatus. The treated water discharged from the RO membrane facility 16 is stored in the treated water tank 18.

  In the backwashing step S <b> 5, treated water is supplied to the sand filter 12 to perform backwashing of the sand filter 12. The treated water is supplied to the outlet side 12b of the sand filter 12, and the waste water from the sand filter 12 is discharged from the inlet side 12a and discarded outside the apparatus. Thereby, the function of the sand filter 12 can be recovered.

  After the backwash process S5 is performed, the start-up process S2 is performed again. When potable water is not manufactured in the standby state of the water treatment apparatus 10, steps S2 to S5 are repeated.

  For example, when it becomes necessary to produce potable water in an emergency, steps S6 and S7 are executed. Here, a case will be described in which the process proceeds to steps 6 and S7 during the execution of the circulation operation step S3.

  When it is required to produce potable water during the circulation operation, the process proceeds to the drainage step S6 of concentrated water and treated water. In the drainage step S6 of the concentrated water and the treated water, the circulation operation is stopped and the concentrated water and the treated water are drained. The treated water stored in the treated water tank 18 passes through the sewage pipe 31 and is discharged outside the apparatus. The drainage step S6 is executed until the treated water tank 18 becomes empty.

  After the execution of the drainage step S6 of the concentrated water and the treated water, a potable water production step S7 is executed. In potable water manufacturing process S7, after storing raw | natural water in the raw | natural water tank 11, steps S11-S17 are performed. The treated water stored in the treated water tank 18 is supplied outside the apparatus as drinking water. The concentrated water discharged from the RO membrane facility 16 passes through the sewage pipe 31 and is discarded outside the apparatus 11.

  Moreover, when providing drinking water outside the apparatus, a neutralizing agent is supplied into the treated water, and after adjusting the pH, the water is supplied outside the apparatus.

  In addition, during the execution of the circulation operation step S3 and the potable water production step S7, a water quality test for treated water and a water quality test for treated water are performed. A portion of the treated water is diverted and supplied to the water quality sensor 82. The treated water after the inspection is returned to the treated water tank 18. A part of the water to be treated is diverted and supplied to the water quality sensor 81. The treated water after the inspection is returned to the raw water tank 11.

  According to such a water treatment device 10 and an operation method, the water to be treated can be continuously supplied to the RO membrane by performing a circulation operation for circulating the treated water and the concentrated water. The water treatment device 10 keeps the pipeline of the water treatment device 10 clean and prevents the RO membrane from being deteriorated by performing a circulation operation in a standby state where the treated water is not supplied as drinking water to the outside of the device. Can do. Moreover, when it transfers to the manufacturing process of drinking water in an emergency, manufacturing of drinking water can be performed rapidly.

  Further, the water treatment apparatus 10 injects a reducing agent into the water to be treated on the upstream side of the injection pipe 33 (hypochlorous acid injection means) for injecting hypochlorous acid into the treated water tank 18 and the RO membrane facility 16. And an injection pipe 26 (reducing agent injection means). Thereby, hypochlorous acid can be inject | poured into the treated water returned to the raw | natural water tank 11, and the sterilization in the apparatus 10 can be performed. Further, since the reducing agent can be injected upstream of the RO membrane facility 18, the treated water can be supplied to the RO membrane facility 16 after reducing hypochlorous acid in the treated water with the reducing agent. Therefore, the deterioration of the RO membrane due to hypochlorous acid can be suppressed.

  Further, the water treatment apparatus 10 includes an injection pipe 22 (second hypochlorous acid injection means) for injecting hypochlorous acid into the raw water supplied to the raw water tank 11. Thereby, after sterilizing raw | natural water, it can supply to the raw | natural water tank 11, Therefore The pipe line of the water treatment apparatus 10 can be kept more clean.

  Although the present invention has been specifically described above based on the embodiment, the present invention is not limited to the above embodiment. Although the said embodiment demonstrated the water treatment apparatus which manufactures drinking water at the time of emergency, you may apply this invention to the water treatment apparatus 10 which always manufactures drinking water. For example, in a device downstream of the water treatment device 10, when maintenance work is performed, the production of potable water may be stopped and the treated water and concentrated water may be circulated.

  Moreover, in the said embodiment, although treated water and concentrated water are separately returned to the raw | natural water tank 11, you may return to raw | natural water tank 11, after making treated water and concentrated water merge.

  Further, in the operation method of the above embodiment, the treated water is drained in step S6. However, the receiving of the raw water into the raw water tank 11 is started without discharging the treated water to the outside of the apparatus, and the boosting step S15 and The reverse osmosis membrane treatment step S16 may be executed, and the treated water treated in the reverse osmosis membrane treatment step S16 may be supplied to the outside of the apparatus 10.

  In the operation method of the above embodiment, after draining the treated water and the concentrated water to the outside of the apparatus in step S6, the acceptance of the raw water into the raw water tank 11 is started. At the same time as the drainage of the raw water, acceptance of the raw water into the raw water tank 11 is started, the pressurization step S15 and the reverse osmosis membrane treatment step S16 are executed, and the treated water treated in the reverse osmosis membrane treatment step S16 is supplied to the outside of the apparatus 10 May be.

  DESCRIPTION OF SYMBOLS 10 ... Water treatment apparatus, 11 ... Raw water tank, 12 ... Sand filter, 16 ... RO membrane equipment, 17 ... High pressure pump (pressure | voltage riser), 18 ... Treatment water tank, 22 ... Injection pipe | tube (2nd hypochlorous acid injection) Means), 26 ... injection pipe (reducing agent injection means), 33 ... injection pipe (hypochlorous acid injection means), 41 ... on-off valve (inflow adjustment part), 50 ... treated water return means, 51 ... treated water return Pipe: 60 ... Concentrated water return means, 61 ... Concentrated water return pipe, 70 ... Backwashing means, 71 ... Backwash pipe, 81 ... Water quality sensor for treated water, 82 ... Water quality sensor for treated water.

Claims (17)

A raw water tank for storing raw water,
Pressurizing means for boosting the water to be treated stored in the raw water tank;
An RO membrane for treating the water to be treated that has been pressurized by the boosting means;
A treated water tank for storing treated water that has passed through the RO membrane;
A water supply unit for supplying the treated water to the outside of the apparatus;
Treated water return means capable of returning the treated water stored in the treated water tank to the raw water tank;
Concentrated water returning means capable of returning the RO membrane concentrated water to the raw water tank;
A water treatment apparatus comprising: A filter that is disposed on the upstream side of the pressurizing means and separates impurities in the water to be treated supplied from the raw water tank;
The water treatment apparatus according to claim 1, further comprising backwashing means for supplying the treated water to the filter and backwashing the filter. Hypochlorous acid injection means for injecting hypochlorous acid into the treated water tank;
The water treatment apparatus according to claim 1, further comprising a reducing agent injection unit that injects a reducing agent into the water to be treated on an upstream side of the RO membrane. Hypochlorous acid injection means for injecting hypochlorous acid into the treated water tank;
The water treatment apparatus according to claim 1, further comprising a reducing agent injection unit that injects a reducing agent into the water to be treated on an upstream side of the pressure increasing unit. A water quality sensor is further provided for inspecting water quality while distributing a part of the treated water and distributing the separated treated water.
The water treatment apparatus as described in any one of Claims 1-4 which returns the said to-be-processed water test | inspected by the said water quality sensor to the said raw | natural water tank. A part of the treated water, and further comprising a treated water quality sensor for inspecting the water quality while circulating the separated treated water,
The water treatment apparatus according to any one of claims 1 to 4, wherein the treated water inspected by the water quality sensor is returned to the treated water tank.   The water treatment device according to any one of claims 2 to 6, wherein the filter is a sand filtration device and / or a membrane filtration device.   The water treatment apparatus according to any one of claims 2 to 7, further comprising second hypochlorous acid injection means for injecting hypochlorous acid into the raw water when supplying the raw water to the raw water tank. Operation of a water treatment apparatus that receives raw water in a raw water tank, stores the treated water stored in the raw water tank using an RO membrane, and supplies the treated water that has passed through the RO membrane to the outside of the apparatus In the method
A step of boosting the water to be treated stored in the raw water tank;
A reverse osmosis membrane treatment step of treating the water to be treated that has been pressurized in the pressure raising step with the RO membrane;
A treated water returning step of returning treated water that has passed through the RO membrane to the raw water tank;
A concentrated water returning step of returning the RO membrane concentrated water to the raw water tank;
A method for operating a water treatment apparatus comprising: In the treated water returning step, hypochlorous acid is injected into the treated water, and the treated water into which the hypochlorous acid has been injected is returned,
The method for operating a water treatment apparatus according to claim 9, further comprising a reducing agent injection step of injecting a reducing agent into the water to be treated before supplying the water to be treated to the RO membrane. In the treated water returning step, hypochlorous acid is injected into the treated water, and the treated water into which the hypochlorous acid has been injected is returned,
The operating method of the water treatment apparatus of Claim 9 further equipped with the reducing agent injection | pouring process which inject | pours a reducing agent into the said to-be-processed water before pressurizing the to-be-processed water stored in the said raw | natural water tank.   The operation method of the water treatment apparatus according to any one of claims 9 to 11, further comprising a filtration step that is performed before the pressurization step and separates impurities in the water to be treated.   Stopping the return of the treated water to the raw water tank by the treated water returning process, supplying the treated water to the filter used in the filtering process, and performing a backwashing process for backwashing the filter The operation method of the water treatment apparatus according to claim 12 further provided.   A water quality inspection step of diverting a part of the treated water, inspecting the water quality while distributing the separated treated water, and returning the inspected treated water to the raw water tank The operation method of the water treatment apparatus as described in any one of Claims 9-13 provided.   A part of the treated water is diverted, water quality is inspected while circulating the treated water that has been diverted, and a water quality inspection step for returning the inspected treated water to the treated water tank is further provided. The operation method of the water treatment apparatus as described in any one of 14. While stopping the return of the treated water by the treated water return step, stopping the return of the concentrated water by the concentrated water return step,
Start accepting the raw water into the raw water tank without discharging the treated water outside the apparatus,
Operation of the water treatment apparatus as described in any one of Claims 9-15 which performs the said pressure | voltage rise process and the said reverse osmosis membrane treatment process, and supplies the said treated water processed by the said reverse osmosis membrane treatment process out of an apparatus. Method. While stopping the return of the treated water by the treated water return step, stopping the return of the concentrated water by the concentrated water return step,
After discharging the treated water and the concentrated water to the outside of the apparatus or at the same time as discharging, start receiving the raw water into the raw water tank,
Operation of the water treatment apparatus as described in any one of Claims 9-15 which performs the said pressure | voltage rise process and the said reverse osmosis membrane treatment process, and supplies the said treated water processed by the said reverse osmosis membrane treatment process out of an apparatus. Method.

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