Water treatment system, water treatment method, and water treatment module

Abstract

To provide a water treatment system and a water treatment method in which clogging of a filtration membrane is suppressed.SOLUTION: A water treatment system comprising: a filtration section including a filtration membrane configured to separate water to be treated into permeate and concentrate; a confluence section at which the water to be treated supplied to the filtration section and the concentrate extracted from the filtration section join together; and a control section configured to control transfer of the concentrate to the confluence section based on an index X of the water to be treated.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a water treatment system, a water treatment method, and a water treatment module.

Background Art

[0002] A filtration device using a filtration membrane is used for producing industrial pure water and domestic water because of its extremely high performance in removing impurities in water. For example, Patent Document 1 describes a vending machine for drinking water equipped with a reverse osmosis membrane type filtration device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a filtration device using a filtration membrane, pressure is applied to the water (raw water to be treated) supplied to the filtration device to separate it into water that permeates through the filtration membrane (permeate water) and water that does not permeate through the filtration membrane (concentrated water). When the raw water to be treated in contact with the filtration membrane contains a large amount of bacteria and nutrients such as domestic wastewater, there is a risk of blockage on the membrane surface due to the propagation and decay of fungi caused by the bacteria and nutrients contained in the raw water to be treated. The blockage of the filtration membrane causes the filtration membrane to be replaced earlier. In view of the above circumstances, an object of the present disclosure is to provide a water treatment system, a water treatment method, and a water treatment module that can suppress the blockage of the filtration membrane and achieve a longer lifespan of the filtration membrane.

Means for Solving the Problems

[0005] The means for solving the above problems include the following embodiments. <1>A filtration unit including a filtration membrane that separates raw water to be treated into permeate water and concentrated water, A confluence section where the water to be treated supplied to the filtration section and the concentrated water removed from the filtration section merge, A water treatment system comprising: a control unit that controls the transfer of concentrated water to the confluence based on an index X of the water to be treated; and <2> Indicator X includes electrical conductivity. <1> The water treatment system described above. <3> The control unit controls the transfer of concentrated water to the confluence section so that the electrical conductivity of the water to be treated is 2000 μS / cm or less. <2> The water treatment system described above. <4> The system further includes a discharge unit for discharging the concentrated water extracted from the filtration unit as wastewater. <1> ~ <3> A water treatment system as described in any one of the items. <5> A filtration process in which the water to be treated is separated into permeate and concentrated water using a filtration membrane, A mixing step in which the water to be treated and the concentrated water obtained in the filtration step are mixed, A water treatment method comprising a control step that controls the mixing of water to be treated and concentrated water based on an index X of the water to be treated. <6> Indicator X includes electrical conductivity. <5> The water treatment method described above. <7> The control step controls the mixing of the water to be treated and the concentrated water so that the electrical conductivity of the water to be treated is 2000 μS / cm or less. <6> The water treatment method described above. <8> The system further includes a discharge step for discharging the concentrated water obtained in the filtration step as wastewater. <5> or <6> The water treatment method described above. <9> <1> ~ <4> A water treatment module comprising at least one selected from the group consisting of a filtration unit, a confluence unit, and a control unit, which are included in the water treatment system described in any one of the items. [Effects of the Invention]

[0006] According to this disclosure, a water treatment system, a water treatment method, and a water treatment module are provided that can suppress clogging of the filtration membrane and extend the lifespan of the filtration membrane. [Brief explanation of the drawing]

[0007] [Figure 1] This is a conceptual diagram showing an example of a water treatment system configuration. [Figure 2] This is a conceptual diagram showing an example of a water treatment system configuration. [Figure 3] This is a conceptual diagram showing an example of a water treatment system configuration. [Modes for carrying out the invention]

[0008] In this disclosure, a numerical range indicated using "~" represents a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this disclosure, the upper or lower limit stated in one numerical range may be replaced with the upper or lower limit of another numerical range described in stages, or with the values ​​shown in the examples.

[0009] <Water Treatment System> The water treatment system disclosed herein is A filtration unit including a filtration membrane that separates the water to be treated into permeate and concentrated water, A confluence section where the water to be treated supplied to the filtration section and the concentrated water removed from the filtration section merge, The water treatment system includes a control unit that controls the transfer of concentrated water to the confluence based on an index X of the water to be treated.

[0010] According to the water treatment system disclosed herein, clogging of the filtration membrane is effectively suppressed. Causes of filtration membrane clogging include blockage of pores in the filtration membrane by inorganic components such as calcium, and blockage of pores in the filtration membrane by biofilms derived from organic matter. In the water treatment system disclosed herein, the transfer of concentrated water to the confluence is controlled based on an index X of the water to be treated supplied to the filtration section. By controlling the transfer of concentrated water to the confluence based on the index X of the water to be treated, changes in the state of the water to be treated (such as an increase in microbial concentration) due to mixing with the concentrated water are less likely to occur. As a result, clogging of the pores of the filtration membrane by biofilms derived from microorganisms is less likely to occur, and the lifespan of the filtration membrane is extended. Furthermore, in the water treatment system of the present disclosure, not only does the filtration membrane have a longer lifespan, but also the decrease in the amount of permeated water and the increase in filtration pressure due to the reduction of the effective filtration area caused by the formation of biofilms are suppressed.

[0011] In the present disclosure, "raw water to be treated" means all objects to be filtered in the filtration section. "Raw water" means raw water to be treated that has not been mixed with the concentrated water taken out from the filtration section. That is, the concept of "raw water to be treated" in the present disclosure includes raw water in a state not mixed with concentrated water and mixed water of raw water and concentrated water.

[0012] In the water treatment system of the present disclosure, the type of raw water to be treated is not particularly limited. For example, the raw water to be treated may include tap water, surface water, well water, rainwater, stored water stored in a tank, etc., and water discharged from living facilities.

[0013] Specific examples of water discharged from living facilities include water discharged from living facilities such as bathrooms, shower rooms, washbasins, kitchens, toilets, etc. The water discharged from living facilities may be in a state where biological treatment using microorganisms has been performed.

[0014] (Filtration section) The water treatment system of the present disclosure includes a filtration section including a filtration membrane that separates raw water to be treated into permeated water and concentrated water. In the water treatment system of the present disclosure, the configuration of the filtration section is not particularly limited as long as it includes a filtration membrane. For example, the filtration section may be in a state where a roll or laminate of the filtration membrane is housed in a container. The filtration section may include a mechanism for applying pressure to the raw water supplied to the filtration section, and the mechanism may be connected to an external power source.

[0015] The type of filtration membrane included in the filtration section is not particularly limited, and it can be selected from reverse osmosis membranes (RO membranes), nanofiltration membranes (NF membranes), ultrafiltration membranes (UF membranes), microfiltration membranes (MF membranes), etc. of the type that filters by applying pressure. From the perspective of impurity removal performance, reverse osmosis membranes and nanofiltration membranes are preferred as the filtration membrane, and reverse osmosis membranes are more preferred.

[0016] (Confluence) The water treatment system disclosed herein includes a confluence section into which water to be treated supplied to a filtration section and concentrated water removed from the filtration section merge. In other words, the water treatment system disclosed herein includes a mechanism that filters the concentrated water taken out of the filtration section again as treated water, rather than simply discarding it. In this disclosure, a water treatment system that includes a mechanism for filtering concentrated water extracted from a filtration unit as treated water again is also referred to as a "recirculating water treatment system." In other words, the water treatment system in this disclosure is a recirculating water treatment system.

[0017] In the water treatment system disclosed herein, the configuration of the confluence section is not particularly limited as long as it can combine the water to be treated with concentrated water. For example, the confluence section may be a tank capable of storing the water to be treated inside, or piping through which the water to be treated can flow.

[0018] In the water treatment system disclosed herein, the configuration of the confluence section is not particularly limited as long as the water to be treated and the concentrated water can be combined. For example, the confluence section may be a tank, piping, etc., in which the water to be treated and the concentrated water can come into contact.

[0019] (Control Unit) The water treatment system disclosed herein includes a control unit that controls the supply of concentrated water to the confluence based on an index X of the water to be treated.

[0020] Recirculating water treatment systems have a high recovery rate of permeate obtained in the filtration section (the ratio of permeate to treated water) and are highly water-saving. On the other hand, in recirculating water treatment systems, organic matter derived from concentrated water tends to accumulate in the treated water. As a result, the filtration membrane is prone to clogging due to the formation of biofilms derived from microorganisms that use organic matter as a nutrient source. The water treatment system disclosed herein controls the supply of concentrated water to the confluence based on an index X of the water to be treated. In the water treatment system disclosed herein, the method for controlling the supply of concentrated water to the confluence by the control unit is not particularly limited. For example, the amount of concentrated water transferred to the confluence and the timing of the transfer of concentrated water to the confluence may be included in the scope of control. The means by which the control unit controls the supply of concentrated water to the confluence section are not particularly limited. For example, the control unit may control the supply of concentrated water by opening and closing a valve (such as a solenoid valve) provided in the piping that transports the concentrated water.

[0021] The indicator X of the water to be treated, which serves as the basis for control by the control unit, is not particularly limited. Suitable indicators X in the water treatment system of this disclosure include electrical conductivity, bacterial count, chromaticity, turbidity, odor, and viscosity, with electrical conductivity being preferred among these. The indicator X of the water to be treated, which serves as the basis for control by the control unit, may be one or a combination of two or more.

[0022] The control unit may include a function to monitor an indicator X of the water to be treated. The method for monitoring the indicator X of the water to be treated is not particularly limited and can be carried out by known methods. For example, an indicator X measuring instrument (e.g., an electrical conductivity measuring instrument) may be installed in the tank storing the water to be treated or in the piping through which the water to be treated flows to perform the monitoring.

[0023] The control unit may include a function to control the discharge of concentrated water as wastewater from the filtration unit. By controlling the discharge of concentrated water as wastewater, the amount of concentrated water supplied to the confluence unit can be indirectly controlled. For example, if the indicator X of the water to be treated is below (or above) the set standard, the amount of concentrated water supplied to the confluence may be increased without discharging the concentrated water, or if the indicator X of the water to be treated is above (or below) the set value, the amount of concentrated water supplied to the confluence may be decreased by discharging the concentrated water.

[0024] The control unit may control the supply of concentrated water to the confluence so that the electrical conductivity of the water to be treated is 2000 μS / cm or less. By controlling the supply of concentrated water to the confluence so that the electrical conductivity of the treated water is 2000 μS / cm or less, the condition of the treated water supplied to the filtration section (especially the concentration of microorganisms and organic matter) is maintained in good condition, and clogging of the filtration membrane is effectively suppressed. From the viewpoint of maintaining a good condition of the water to be treated supplied to the filtration section, the control unit may control the supply of concentrated water to the confluence section so that the electrical conductivity of the water to be treated is 1500 μS / cm or less, or so that it is 1200 μS / cm or less, or so that it is 1000 μS / cm or less.

[0025] In the water treatment system disclosed herein, the control of the supply of concentrated water to the confluence may be performed for each water treatment module described later, for each water treatment system equipped with the water treatment module, or for multiple water treatment systems combined. In the water treatment system disclosed herein, the steps of extracting concentrated water from the filtration section, supplying concentrated water to the confluence section, and discharging concentrated water as wastewater may be performed manually or automatically.

[0026] (Discharge section) The water treatment system disclosed herein may include a discharge unit that discharges concentrated water taken from the filtration unit as wastewater. In the water treatment system disclosed herein, the configuration of the discharge section is not particularly limited as long as it is possible to discharge concentrated water as wastewater. For example, the discharge section may be a tank, piping, etc., equipped with a concentrated water outlet.

[0027] The confluence point where the concentrated water merges with the water to be treated and the discharge point where the concentrated water is discharged as wastewater may be connected or they may be independent of each other. For example, the water treatment system of the present disclosure may have a transfer line that has a structure branched into a transfer line A that transfers concentrated water taken out from the filtration section to a confluence section and a transfer line B that discharges the concentrated water as wastewater, or it may have transfer line A and transfer line B independently. If the confluence and discharge sections are connected, a switching valve for switching the destination of the concentrated water (confluence or discharge section) may be placed between the confluence and discharge sections.

[0028] (Preliminary filtration section) The water treatment system disclosed herein may further include a pre-filtration unit for filtering the water to be treated. By providing a pre-filtration section in the water treatment system to filter the water to be treated, impurities contained in the water supplied to the filtration section can be removed more effectively, and clogging of the filtration membrane can be more effectively suppressed. The configuration of the pre-filtration section is not particularly limited and can be selected according to the condition of the water to be treated and the state of foreign matter and impurities contained in the water. For example, one or more combinations of known materials such as sand, cellulose, porous synthetic resin, polymer fibers such as nonwoven fabric, activated carbon, zeolite, ceramic, and filter membrane can be used as materials for the pre-filtration section.

[0029] In a water treatment system, the location of the pre-filtration section is not particularly limited, as long as it is in a position where the water to be treated can be filtered (i.e., upstream of the main filtration section). When a water treatment system includes a confluence between the contact section and the filtration section, the pre-filtration section may be located either upstream or downstream of the confluence section. It is preferable that the pre-filtration section be located upstream of the confluence section. Examples of cases where the pre-filtration section is located upstream of the confluence include cases where the pre-filtration section is located between the contact section and the confluence section, and cases where the pre-filtration section is located upstream of the contact section (for example, between the raw water tank that stores the raw water supplied to the contact section and the contact section). One example of a case where the pre-filtration section is located downstream of the confluence is when the pre-filtration section is located between the confluence and the main filtration section. The number of pre-filtration units in the water treatment system may be one or two or more. The pre-filtration units in the water treatment system may consist of one or more types.

[0030] (Finishing filtration section) The water treatment system disclosed herein may further include a finishing filtration unit for filtering the permeate obtained in the filtration unit. By providing the permeate obtained from the filtration section, impurities contained in the permeate can be removed more reliably. The configuration of the final filtration section is not particularly limited and can be selected according to the state of the permeate and the state of foreign matter and impurities contained in the permeate. For example, one or more combinations of known materials such as sand, cellulose, porous synthetic resin, polymer fibers such as nonwoven fabric, activated carbon, zeolite, ceramic, and filter membrane can be used as materials for the final filtration section.

[0031] In a water treatment system, the location of the final filtration section is not particularly limited, as long as it is a location where the permeate can be filtered (i.e., a location downstream of the filtration section). The number of finishing filtration units in the water treatment system may be one or two or more. The number of finishing filtration units in the water treatment system may be one or more.

[0032] (Sterilization treatment) The water treatment system disclosed herein may include a sterilization unit for performing sterilization of the water to be treated. In this disclosure, the process of sterilizing the water to be treated is also referred to as "sterilization treatment." By sterilizing the water to be treated, microorganisms contained in the water can be killed or their concentration can be controlled to a predetermined level. As a result, clogging of the filter membrane due to the formation of biofilms derived from microorganisms is effectively suppressed. Sterilization treatments performed by a sterilization unit include, for example, contacting the water to be treated with ultraviolet (UV) light or ozone. When sterilization is performed using ozone, a decolorizing effect on the water to be treated can also be expected.

[0033] In the water treatment system disclosed herein, the configuration of the sterilization section is not particularly limited as long as it can perform sterilization of the water to be treated. For example, the sterilization processing unit may be a tank, piping, etc., connected to a UV generator or an ozone generator. In the sterilization section, the water to be treated may be either unmixed with the concentrated water extracted from the filtration section (i.e., raw water) or mixed with the concentrated water extracted from the filtration section. The sterilization treatment unit may perform sterilization of the water to be treated continuously or intermittently. Methods for the sterilization unit to intermittently perform sterilization of the water to be treated include, for example, setting a time for operating the sterilization unit and activating it when the set time arrives, or activating the sterilization unit when sterilization is required in response to fluctuations in the impurity concentration of the water to be treated.

[0034] (Other configurations) If necessary, the water treatment system of this disclosure may further include other configurations in addition to those described above. Other components that a water treatment system may include include a raw water tank for storing raw water, instruments for water quality management, a computer system for controlling the operation of the water treatment system, piping for transporting the water to be treated, concentrated water, and permeate, and valves (such as solenoid valves) for controlling the transport of the water to be treated, concentrated water, and permeate. If the water treatment system includes a raw water tank (including cases where the raw water tank includes a water treatment module), the raw water tank may be directly connected to the contact area or connected to the contact area via piping. If the raw water tank is connected to the contact area via piping, a filter may be placed in the piping. If a water treatment system includes a computer system for controlling the operation of the water treatment system, the computer system may either independently control the operation of one water treatment system or collectively control the operation of multiple water treatment systems.

[0035] As one embodiment of the water treatment system disclosed herein, an example of the configuration of a circulating water treatment system will be described with reference to the drawings. In the following figures, arrows indicate the direction of water flow before or after treatment. The configurations shown in the figures are illustrative, and the configuration of the water treatment system disclosed herein is not limited to these.

[0036] A preferred embodiment of the water treatment system disclosed herein is shown in Figure 1. The water treatment system 10 shown in Figure 1 is A filtration unit 11 including a filtration membrane that separates the water to be treated into permeate and concentrated water, A tank 12 for storing the water to be treated supplied to the filtration unit 11, A measuring instrument 13 for measuring the indicator X of the water to be treated, The system includes a transfer line 14 for transferring the concentrated water extracted from the filtration unit 11.

[0037] In the water treatment system 10, the tank 12 that stores the water to be treated supplied to the filtration unit 11 corresponds to the confluence section where the water to be treated and the concentrated water merge. Although not shown in the diagram, the water treatment system 10 includes a control unit that controls the supply of concentrated water to the tank 12 based on the measured value of index X of the water to be treated, which is measured by the measuring instrument 13.

[0038] In the water treatment system 10, the transfer line 14 has a structure that branches into a transfer line 14A that transfers concentrated water to the tank 12 and a transfer line 14B that discharges concentrated water as wastewater. The transfer line 14 shown in Figure 1 has a structure that branches into transfer line 14A and transfer line 14B, but the configuration of the water treatment system in this disclosure is not limited thereto. For example, the water treatment system 10 may have a transfer line for transferring concentrated water to a tank and a transfer line for discharging concentrated wastewater independently of each other.

[0039] In the water treatment system 10, the operation of discharging the concentrated water taken from the filtration unit 11 as wastewater may include the following operations 1 and 2. When performing operations 1 and 2, you may also perform operation 3 below. Performing operation 3 can facilitate the discharge of concentrated water as wastewater. However, operation 3 is not required.

[0040] Operation 1: Stop the inflow of raw water into tank 12. For example, close the valve located at the raw water inlet of tank 12. Operation 2: Discharge the concentrated water extracted from the filtration unit 11 as wastewater. For example, open the valve provided at the outlet of the transfer line 14B. Operation 3: Stop the transfer of concentrated water from the filtration unit 11 to the tank 12. For example, close the valve provided on the transfer line 14A.

[0041] A preferred embodiment of the water treatment system of the present disclosure is shown in Figure 2. The water treatment system 20 shown in Figure 2 is A filtration unit 21 including a filtration membrane that separates the water to be treated into permeate and concentrated water, A tank 22 for storing the water to be treated supplied to the filtration unit 21, A measuring instrument 23 for measuring the indicator X of the treated water, The system includes a transfer line 24 for transferring the concentrated water extracted from the filtration unit 21.

[0042] In the water treatment system 20, the transfer line 24 has a structure in which it is branched into a transfer line 24A that transfers concentrated water to branch 25 and a transfer line 24B that discharges concentrated water as wastewater.

[0043] The water treatment system 20 differs from the water treatment system 10 shown in Figure 1 in that the confluence point where the water to be treated and the concentrated water merge is not in the tank 22, but in a branch 25 provided in the piping connecting the filtration unit 21 and the tank 22.

[0044] A preferred embodiment of the water treatment system of the present disclosure is shown in Figure 3. The water treatment system 30 shown in Figure 3 is A filtration unit 31 including a filtration membrane that separates the water to be treated into permeate and concentrated water, A tank 32 for storing the water to be treated supplied to the filtration unit 31, A measuring instrument 33 for measuring the indicator X of the treated water, A transfer line 34 for transferring the concentrated water extracted from the filtration section 31, It includes a pre-filtration section 36 for filtering the water to be treated. It is equipped with a finishing filtration section 37 for filtering the permeate water.

[0045] The water treatment system 30 differs from the water treatment system 20 shown in Figure 2 in that it includes a preliminary filtration unit 36 ​​for filtering the water to be treated and a final filtration unit 37 for filtering the permeate. The water treatment system 30 has pre-filtration sections 36 between the tank 32 and the branch 35, and upstream of the tank 32, but the configuration of the water treatment system of this disclosure is not limited thereto. For example, the pre-filtration section 36 may be provided between the branch 35 and the filtration section 31. The water treatment system 30 is provided with two pre-filtration units 36, but the pre-filtration units 36 provided in the water treatment system may be one or three or more.

[0046] The operation of each component of the water treatment system disclosed herein may be performed manually, automatically, or in combination with manual operation. From the perspective of the operating costs of a water treatment system, it is preferable to automate at least part of the operation of each component of the water treatment system.

[0047] The uses of the permeate extracted from the water treatment system disclosed herein are not particularly limited. Specific uses for the permeate include use in living facilities such as bathrooms, showers, washbasins, kitchens, and toilets; use in industrial facilities such as factories and farms; use as tap water; and release into the natural environment. In one embodiment of the water treatment system disclosed herein, the permeate extracted from the water treatment system may be used, and the used permeate may then be supplied to the water treatment system as raw water. From the perspective of cost-effectiveness regarding the use of the water treatment system, it is preferable that the permeate extracted from the water treatment system disclosed herein be used in living facilities.

[0048] The water treatment system disclosed herein can reduce operating costs because clogging of the filtration membrane is suppressed, even in the case of a circulating water treatment system or water treatment module. For this reason, the water treatment system disclosed herein is excellent for effectively obtaining purified water under limited conditions where the available water quality is poor, such as in water-scarce areas or disaster-stricken areas, and can be suitably used.

[0049] The scale of water treatment performed by the water treatment system disclosed herein is not particularly limited. For example, the daily treatment volume of the water treatment system disclosed herein may be selected from the range of 100 mL to 50,000 L. When a water treatment system is used as a household water purifier, the scale of water treatment can be selected from, for example, a range of 100 mL to 50 L. When a water treatment system is used as a wastewater treatment device for household use, the scale of water treatment can be selected from, for example, a range of 1L to 1,000L. When a water treatment system is used as a relatively large-scale water treatment device, such as a rainwater purification system for rainwater stored in a rooftop tank, the scale of water treatment can be selected from, for example, a range of 100L to 50,000L. The water treatment system disclosed herein can also be suitably used for applications that produce permeate under conditions where the scale of water treatment is small and the supply of water to be treated is limited.

[0050] <Water Treatment Methods> The water treatment method disclosed herein is: A filtration process in which the water to be treated is separated into permeate and concentrated water using a filtration membrane, A mixing step in which the water to be treated and the concentrated water obtained in the filtration step are mixed, A water treatment method comprising a control step that controls the mixing of water to be treated and concentrated water based on an index X of the water to be treated.

[0051] According to the water treatment method disclosed herein, clogging of the filtration membrane is effectively suppressed. In the water treatment method of this disclosure, the filtration membrane used in the filtration step may be the filtration membrane used in the water treatment system of this disclosure described above.

[0052] The water treatment method disclosed herein comprises a mixing step in which concentrated water obtained in a filtration step is mixed with the water to be treated. In other words, the water treatment method disclosed herein is a circulating water treatment method. In recirculating water treatment methods, organic matter derived from concentrated water can accumulate in the treated water, increasing the microbial concentration in the treated water and potentially leading to clogging of the filtration membrane. The water treatment method disclosed herein includes a control step that controls the mixing of the water to be treated and concentrated water based on an index X of the water to be treated. Therefore, even if the water to be filtered contains concentrated water, the condition of the water to be treated is maintained in good condition, and clogging of the filtration membrane is effectively suppressed.

[0053] In the control process, there are no particular limitations on the method of controlling the mixing of the water to be treated and the concentrated water. For example, the amount of concentrated water mixed with the water to be treated and the timing of mixing the concentrated water with the water to be treated may be included in the control.

[0054] The indicator X of the water to be treated, which serves as the control standard in the control process, is not particularly limited. Suitable indicator X in the water treatment method of this disclosure include electrical conductivity, bacterial count, chromaticity, turbidity, odor, and viscosity, with electrical conductivity being preferred among these. The indicator X of the treated water, which serves as the control standard in the control process, may be one or a combination of two or more. That's fine.

[0055] The control process may include monitoring an indicator X of the water to be treated. The method for monitoring the indicator X of the water to be treated is not particularly limited and can be carried out by known methods. For example, an indicator X measuring instrument (e.g., an electrical conductivity measuring instrument) may be installed in the tank storing the water to be treated or in the piping through which the water to be treated flows to perform the monitoring.

[0056] The control process may include controlling the discharge of concentrated water as wastewater from the filtration section. By controlling the discharge of concentrated water as wastewater, the amount of concentrated water mixed with the water to be treated can be indirectly controlled. For example, if the indicator X of the water to be treated is below (or above) the set standard, the amount of concentrated water mixed with the water to be treated may be increased without discharging concentrated water. If the indicator X of the water to be treated is above (or below) the set value, concentrated water may be discharged and the amount of concentrated water mixed with the water to be treated may be decreased.

[0057] In the control process, the mixing of the water to be treated and the concentrated water may be controlled so that the electrical conductivity of the water to be treated is 2000 μS / cm or less. By controlling the mixing of the treated water and concentrated water so that the electrical conductivity of the treated water is 2000 μS / cm or less, the condition of the treated water supplied to the filtration section (especially the concentration of microorganisms and organic matter) is maintained in good condition, and clogging of the filtration membrane is effectively suppressed. From the viewpoint of maintaining a good condition of the water to be treated supplied to the filtration unit, the control unit may control the mixing of the water to be treated and the concentrated water so that the electrical conductivity of the water to be treated is 1500 μS / cm or less, or so that it is 1200 μS / cm or less, or so that it is 1000 μS / cm or less.

[0058] In the water treatment method of the present disclosure, the control of mixing the water to be treated and the concentrated water may be performed for each water treatment system of the present disclosure as described above or for each water treatment module of the present disclosure described later, for each water treatment system equipped with a water treatment module, or for multiple water treatment systems together. In the water treatment method disclosed herein, the steps of extracting concentrated water from the filtration section, mixing the concentrated water with the water to be treated, and discharging the concentrated water as wastewater may be performed manually or automatically.

[0059] The water treatment method disclosed herein may further include a discharge step of discharging concentrated water obtained in a filtration step as wastewater. The discharge process may involve discharging all of the concentrated water obtained in the filtration process as wastewater, or it may involve discharging only a portion of the concentrated water as wastewater. One example of discharging only a portion of the concentrated water as wastewater is when the concentrated water is combined with the water to be treated.

[0060] The timing of wastewater discharge in the discharge process may be determined based on the monitoring results of the indicator X of the treated water. For example, if the electrical conductivity of the water to be treated is below the set standard, wastewater discharge may be omitted, but if the electrical conductivity of the water to be treated exceeds the set value, wastewater discharge may be carried out.

[0061] The water treatment method disclosed herein may further include a pre-filtration step for filtering the water to be treated. The method for carrying out the pre-filtration step is not particularly limited and can be selected according to the condition of the water to be treated, the state of foreign matter and impurities contained in the water to be treated, etc. The preliminary filtration process can be carried out, for example, by a preliminary filtration unit that may be included in the water treatment system described above.

[0062] The method for carrying out the water treatment method disclosed herein is not particularly limited. For example, it may be carried out using the water treatment system described above.

[0063] <Water Treatment Module> The water treatment module disclosed herein is The system includes at least one selected from the group consisting of a filtration unit, a confluence unit, and a control unit, as described above. In this disclosure, "water treatment module" means a component or combination of components for use in a water treatment system. The water treatment modules of the present disclosure are not particularly limited as long as they are used in the water treatment systems of the present disclosure, and may be independent components used in connection with existing filtration systems, water treatment devices, or water distribution pipes. [Explanation of Symbols]

[0064] 10, 20, 30: Water treatment systems 11, 21, 31: Filtration section 12, 22, 32: Tank 13, 23, 33: Measuring instrument 14, 24, 34: Transfer lines 25, 35: Branch 36: Preliminary filtration section 37: Finishing filtration section

Claims

1. A filtration unit including a filtration membrane that separates the water to be treated into permeate and concentrated water, A confluence section where the water to be treated supplied to the filtration section and the concentrated water removed from the filtration section merge, A control unit that controls the transfer of concentrated water to the confluence based on an index X of the water to be treated, The system comprises a sterilization treatment unit for sterilizing the water to be treated, wherein the water to be treated includes water discharged from living facilities. In the aforementioned water treatment system, the indicator X of the water to be treated includes electrical conductivity.

2. The water treatment system according to claim 1, wherein the control unit controls the transfer of concentrated water to the confluence so that the electrical conductivity of the water to be treated is 2000 μS / cm or less.

3. The water treatment system according to claim 1, further comprising a discharge unit for discharging concentrated water extracted from the filtration unit as wastewater.

4. A water treatment method for treating water to be treated, including water discharged from living facilities, using the water treatment system described in any one of Claims 1 to 3, A filtration process in which the water to be treated is separated into permeate and concentrated water using a filtration membrane, A mixing step in which the water to be treated and the concentrated water obtained in the filtration step are mixed, A control process that controls the mixing of the treated water and concentrated water based on an index X of the treated water, The system includes a sterilization process for performing sterilization of the water to be treated. A water treatment method in which the indicator X of the water to be treated includes electrical conductivity.

5. The water treatment method according to claim 4, wherein the control step controls the mixing of the water to be treated and the concentrated water so that the electrical conductivity of the water to be treated is 2000 μS / cm or less.

6. The water treatment method according to claim 4, further comprising a discharge step of discharging the concentrated water obtained in the filtration step as wastewater.

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