Technical field
[0001]
The present disclosure, using a reverse osmosis membrane, to reverse osmosis membrane treatment method and reverse osmosis membrane treatment facility for separating the impurities containing salts from the raw water such as seawater.
BACKGROUND
[0002]
　Generally, reverse osmosis membrane, excellent have separating performance has been and since energy efficiency is relatively high, for example, widely used in sea water with the water treatment and various industrial started desalination.
[0003]
　One of the challenges in the reverse osmosis membrane treatment, microorganisms adhered to the film surface, biofouling clog a reverse osmosis membrane is known by the microorganism to grow.
　Conventionally, when biofouling has occurred, for example, chemical cleaning by removing the reverse osmosis membrane, and removal of microorganisms grown on the membrane surface. Patent Document 1 supplies a chlorine disinfectant upstream from the reverse osmosis unit, it is described that inhibit the growth of microorganisms.
　Further, although not to the reverse osmosis membrane and sterilized, Patent Document 2, downstream of the primary pure water producing device including a reverse osmosis membrane, secondary pure water producing device including a non-regenerative ion exchange cartridge in ultrapure water production system is provided, the inorganic salts were supplied to the ultrapure water circulation line including a secondary pure water producing device, a method of inhibiting the growth of microorganisms in ultrapure water circulation line is described.
CITATION
Patent Document
[0004]
Patent Document 1: JP KOKOKU No. 6-38953
Patent Document 2: JP KOKOKU No. 6-38955
Summary of the Invention
Problems that the Invention is to Solve
[0005]
　Incidentally, in the reverse osmosis membrane treatment as described above, while the working inhibiting biofouling is needed, these cleaning, avoiding the significantly reduced capacity utilization due to sterilization work has been required.
　For example, in the case of chemical cleaning by removing the reverse osmosis membrane, it is easy to remove the microorganisms attached to the reverse osmosis membrane, but operating rate because it takes time and effort to attachment and detachment of the reverse osmosis membrane is greatly reduced.
　In the case of chemical cleaning when it is installed a reverse osmosis membrane as in Patent Document 1, in order to sufficiently suppress biofouling becomes high concentration of disinfectant is required.
　Furthermore, the method of Patent Document 2, after circulating ultrapure water circulation line to supply inorganic salts 1-3 hours, is necessary step to wash over 3-5 hours inorganic salts remaining, these it takes a long time to process, lowering the operating rate can not be avoided.
[0006]
　Object of at least some embodiments of the present invention is to provide a reverse osmosis membrane treatment method and reverse osmosis membrane treatment facility which can suppress biofouling in the reverse osmosis membrane while avoiding a significant deterioration in the working rate .
Means for Solving the Problems
[0007]
(1) reverse osmosis membrane treatment method according to at least some embodiments of the invention,
　and separating the raw water to the permeate and the concentrated water by reverse osmosis,
　is adjusted to a different salt concentration and the raw water supplying the salt concentration adjusted water to the reverse osmosis membrane, a step of deactivating the accumulated microorganisms in the inlet side of the reverse osmosis membrane, comprising a,
　it repeats the step of deactivating said microorganisms intermittently .
[0008]
　In the method (1), by supplying the salt concentration adjusted water adjusted to different salt concentrations in the reverse osmosis membrane and raw water, the surrounding salt concentration environments of microbes accumulated on the inlet side of the reverse osmosis membrane so that to change. When the salt concentration environment around the microorganisms is changed, occurs movement of the liquid in the cell and out of the microorganisms by osmotic pressure difference, it is possible to reduce the activity of microorganisms. Accordingly, the eyes of the membrane clogging caused by growth of accumulated microorganisms on the inlet side of the reverse osmosis membrane, i.e. it is possible to suppress biofouling biofilm is formed by microorganisms and organic matter.
　Further, even if short supply time of the reverse osmosis membrane of the salt concentration adjusted water (e.g. 5 to 30 minutes) for the growth inhibitory effect of microorganisms can be obtained, significant reduction in operating rate due to the implementation of biofouling control measures the can be avoided.
　Further, by repeating the step of deactivating microorganisms intermittently, it is possible during the operation of the reverse osmosis membrane, the activity of the microorganisms to remain lowered. Usually, the growth rate of the microorganisms under proper environment for very large, by maintaining the state that prevent the growth of microorganisms (non-activated state), can be suppressed effectively biofouling.
[0009]
In (2) some embodiments, in the method of the above (1),
　the salt concentration adjusted water has a 0.8 or less and 1.25 or more salts concentration ratio with respect to the raw water.
[0010]
　The present inventors have intensively studied and, as a result, have found a correlation between the activity and salt concentration of microorganisms in the raw water. That is, the salt concentration ratio relative to the raw water under 0.8 or 1.25 or higher environment, it was found that the activity of microorganisms is significantly reduced. Therefore, by the salt concentration ratio of the raw water salt concentration adjusting water of 0.8 or less or 1.25 or more, it is possible to deactivate most of the microorganisms attached to the reverse osmosis membrane, thereby effectively It can inhibit biofouling in.
[0011]
(3) In some embodiments, in the method of the above (1) or (2),
　in the step of deactivating said microorganisms, without stopping the pump for supplying the raw water to said reverse osmosis membrane, supplying the salt concentration adjusted water to the reverse osmosis membrane by the pump.
[0012]
　Because water supplied to the inlet side of the reverse osmosis membrane is extremely high, a pump for supplying raw water to the reverse osmosis membrane, it takes time to start.
　In this respect, according to the method of the above (3), without stopping the pump, by supplying the salt concentration adjusted water reverse osmosis membrane, the plant after the deactivation of the microorganism with a salt concentration adjusting water again it is possible to perform the operation in a short period of time. Therefore, it is possible to improve the rate of operation of the plant.
[0013]
(4) In some embodiments, in any of the above methods (1) to (3),
　in the step of deactivating said microorganisms, said salt concentration adjusting water containing the concentrated water or the permeate supplied to the reverse osmosis membrane.
[0014]
　According to the method of the above (4), as the salt concentration adjusting water, the use of the concentrate or permeate separated by reverse osmosis membrane, it is possible to effectively utilize the water in the system. In particular, since the concentrated water is often discarded, by using the concentrated water as a salt concentration adjusting water, the greater the effect of reducing cost.
[0015]
(5) In some embodiments, in the method of the above (4),
　in the step of deactivating said microorganisms, without stopping the pump for supplying the raw water to said reverse osmosis membrane, the concentrated water or supplied to the reverse osmosis membrane a mixed water obtained by mixing the permeate in the raw water as the salt concentration adjusted water.
[0016]
　According to the method of the above (5), without stopping the pump, by supplying the mixed water obtained by mixing concentrate or permeate to the raw water to the reverse osmosis membrane, subjected to deactivation of the microorganism with a salt concentration adjusting water the re-activated plant with a reverse osmosis membrane after may be performed in a short time. Also, while deactivating microorganisms, so to continue the supply of the raw water as a raw material for mixed water (salt concentration adjusting water), upon re-operation of the plant, switching or the like becomes unnecessary for the valve on the upstream side of the pump, the plant it is possible to smoothly shift to the normal operation.
[0017]
(6) In some embodiments, in the method of the above (4),
　in the step of deactivating said microorganisms, a pump for supplying the raw water to said reverse osmosis membrane is stopped, the concentrated water or the supplied to the reverse osmosis membrane permeated water itself as the salt concentration adjusted water.
[0018]
　According to the method of the above (6), the pump stops and salt to the raw water in comparison with the case of using the concentrate or permeate itself by supplying to the reverse osmosis membrane as the salt concentration adjusting water, for example by mixing with raw water it is possible to increase the density difference. This can provide greater osmotic changes against microorganisms, it is possible to further enhance the inhibitory effect of biofouling.
[0019]
(7) In some embodiments, in any of the above methods (1) to (6),
　in the step of deactivating said microorganisms, first salt concentration salt concentration ratio relative to the raw water is less than 1 and adjusting water, salt concentration ratio relative to the raw water supplied to the reverse osmosis membrane and the second salt concentration adjusting water greater than 1, the alternating.
[0020]
　According to the method of the above (7), by changing the salt concentration of the salt concentration adjusting water supplied to the reverse osmosis membrane large, it is possible to provide greater osmotic changes to microorganisms, biofouling it is possible to enhance the suppressing effect more.
　Resistant Further, the inlet side of the reverse osmosis membrane, a microbial resistance is lower than the have resistance to low salt environments high salt environment, relative but low salt environments has resistance to high salt environments sometimes coexist low and microorganisms. Even in this case, according to the method of the above (7), by combined first and salt concentration adjusting water and a second salt concentration adjusting water, effectively deactivating different microorganisms properties be able to.
[0021]
(8) In some embodiments, in the method of the above (7),
　wherein the first salt concentration adjusting water comprises the permeate,
　the second salt concentration adjusting water comprises the concentrated water.
[0022]
　According to the method of the above (8), by effectively utilizing the permeate and concentrated water which has been separated by reverse osmosis membrane, two salts density adjustment with a salt concentration difference for effectively suppressing biofouling thereby obtaining a water (first salt concentration adjusting water and the second salt concentration adjusting water).
[0023]
(9) In some embodiments, in any of the above methods (1) to (8),
　based on an index indicating the raw water properties associated with biofilm formation rate, supplied to the reverse osmosis membrane salt concentration of the salt concentration adjusting water, frequency of performing deactivation treatment of the microorganism with the salt concentration adjusted water or, further comprising the step of adjusting at least one of the processing time of the deactivation process.
[0024]
　Usually, depending on the nature of the raw water, the type and amount of microorganisms are different. Therefore, as the method of (9), based on the indicator of the properties of the raw water associated with biofilm formation rate, the salt concentration of the salt concentration adjusting water deactivation treatment execution frequency or deactivation process by adjusting at least one of the processing times, be different properties of the raw water can be reliably prevented biofouling.
[0025]
(10) In some embodiments, in any of the above methods (1) to (9),
　the raw water supply line for supplying the raw water to said reverse osmosis membrane, a first valve, the supply water tank and which pump is provided in order from the upstream side,
　the supply water tank, the are adjusted water supply line the salt concentration adjusting water flows are connected,
　wherein the adjustment water supply line is provided with a second valve cage,
　in the step of separating the raw water, opening the first valve is closed said second valve to supply the raw water stored in the feed water tank by said pump to said reverse osmosis membrane,
　the in the step of deactivating microorganisms, by opening the second valve is closed said first valve to supply the salt concentration adjusted water to the reverse osmosis membrane via the feed water tank by said pump
[0026]
　According to the method of the above (10), the feed water tank is provided between the first valve and second valve and the pump can be adjusted to suction pressure of the pump by opening and closing of the first valve or the second valve . Thus, stable operation of the pump can be realized, it is possible to adequate supply of salt concentration adjusting water to the reverse osmosis membrane.
[0027]
(11) at least a reverse osmosis membrane treatment equipment according to some embodiments, the present invention
　includes a reverse osmosis membrane apparatus for separating raw water by reverse osmosis membrane to the permeate and the concentrated water,
　different salts and raw water the salt concentration adjusting water that has been adjusted to a concentration supplied to the reverse osmosis membrane of the reverse osmosis membrane apparatus, intermittently repeated microbial deactivation process of the inlet side deactivated accumulated in the reverse osmosis membrane configured.
[0028]
　According to the above configuration (11), by supplying the reverse osmosis membrane salt concentration adjusting water adjusted to a different salt concentration and raw water of the reverse osmosis membrane inlet side has been grown by the membrane of the microorganisms accumulate in the clogging, i.e. it is possible to suppress biofouling.
　Further, even if short supply time of the reverse osmosis membrane of the salt concentration adjusted water (e.g. 5 to 30 minutes) for the growth inhibitory effect of microorganisms can be obtained, significant reduction in operating rate due to the implementation of biofouling control measures the can be avoided.
　Further, by repeating the step of deactivating microorganisms intermittently, it can be maintained during the operation of the reverse osmosis membrane, a state in which the microorganism is inactivated. Usually, the growth rate of the microorganisms under proper environment for very large, by maintaining the state that prevent the growth of microorganisms (non-activated state), can be suppressed effectively biofouling.
Effect of the invention
[0029]
　According to at least some embodiments of the present invention, by supplying to the reverse osmosis membrane salt concentration adjusting water adjusted to a different salt concentration and raw, microorganisms accumulated on the inlet side of the reverse osmosis membrane proliferation eye membrane clogging by, that it is possible to suppress biofouling.
　Further, even if short supply time of the reverse osmosis membrane of the salt concentration adjusted water (e.g. 5 to 30 minutes) for the growth inhibitory effect of microorganisms can be obtained, significant reduction in operating rate due to the implementation of biofouling control measures the can be avoided.
　Further, by repeating the step of deactivating microorganisms intermittently, it can be maintained during the operation of the reverse osmosis membrane, a state in which the microorganism is inactivated. Usually, the growth rate of the microorganisms under proper environment for very large, by maintaining the state that prevent the growth of microorganisms (non-activated state), can be suppressed effectively biofouling.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030]
FIG. 1 is a block diagram illustrating a reverse osmosis membrane treatment method according to the first embodiment.
FIG. 2 is a block diagram illustrating a reverse osmosis membrane treatment method according to the second embodiment.
3 is a block diagram illustrating a reverse osmosis membrane treatment method according to the third embodiment.
4 is a block diagram illustrating a reverse osmosis membrane treatment method according to the fourth embodiment.
5 is a block diagram illustrating a reverse osmosis membrane treatment method according to the fifth embodiment.
6 is a block diagram illustrating a reverse osmosis membrane treatment method according to the sixth embodiment.
7 is a graph showing the correlation between survival and salt concentration ratio of microorganisms.
8 is a diagram showing the supply timings of the salt concentration adjusted water.
9 is a flowchart illustrating a reverse osmosis membrane treatment method according to a modification of the present embodiment.
[FIG. 10A] is a graph showing the frequency of performing optimal deactivation process for biofilm formation rate.
Is a graph showing the FIG. 10B] processing time optimal deactivation process for biofilm formation rate.
11 is a diagram showing the overall flow of the desalination process including a reverse osmosis membrane treatment according to one embodiment.
DESCRIPTION OF THE INVENTION
[0031]
　Hereinafter, with reference to the accompanying drawings Some embodiments of the present invention will be described. However, the dimensions of the components shown or drawings are described as an embodiment, the material, shape, its relative positions and the like, not intended to limit the scope of the invention thereto, merely illustrative examples Absent.
[0032]
　1 to 6 is a block diagram illustrating a reverse osmosis membrane treatment method according to the first to sixth embodiments.
　Referring to these figures, the reverse osmosis membrane treatment method according to some embodiments, the step of separating the raw water to the permeate and the concentrated water by reverse osmosis membrane device 10 having a reverse osmosis membrane, the raw water Prefecture deactivates the microorganisms accumulated on the inlet side of the different salt concentration adjusting water that has been adjusted to a salt concentration is supplied to the reverse osmosis unit (reverse osmosis membrane) 10, reverse osmosis unit (reverse osmosis membrane) 10 includes a step, a. Note that the microorganisms accumulated on the inlet side of the reverse osmosis unit 10 (supply side), a microorganism which remains in the retentate side without passing through the reverse osmosis membrane, for example, the supply-side membrane of the reverse osmosis membrane forming a biofilm on a surface.
[0033]
　Here, the raw water and is a water containing salt (e.g. salt), for example, sea water, underground water, river, lake water, or may be a wastewater treatment water, or industrial wastewater or the like. According to the above method, seawater or desalination, or to obtain a recycled water to purification of sewage treated water and industrial waste water, or can generate clean water from rivers and lakes water. Incidentally, the raw water, a filtration device may be water which has been subjected to pretreatment (see FIG. 11) or the like.
[0034]
　In the above method, the step of deactivating microorganisms is carried out intermittently and repeatedly.
　Figure 7 is a graph showing the correlation between the survival of microorganisms (activated) with the salt concentration ratio.
　For example, as shown in FIG. 7, in the above method, during the separation step to obtain a reverse osmosis unit to supply raw water permeate 10 and retentate, implement deactivation supplying a salt concentration adjustment Water to. In the illustrated example, the deactivation step, shows the case where the salt concentration using two different salt concentration adjusting water. Deactivation step is short as compared to the separation step. The non-activation step is carried out at a frequency capable of suppressing biofouling to the extent that may continue separation step.
[0035]
　According to the above method, the salt concentration surrounding the microorganism accumulated salt concentration adjusting water adjusted to different salt concentrations by supplying the reverse osmosis unit 10, to the inlet side of the reverse osmosis unit 10 to the raw water so that changing the environment. When the salt concentration environment around the microorganisms is changed, occurs movement of the liquid in the cell and out of the microorganisms by osmotic pressure difference, it is possible to reduce the activity of microorganisms. Thus, it is possible to suppress the biofilm biofouling biofilm is formed by a reverse osmosis membrane device 10 eye film clogging by growth of accumulated microorganisms on the inlet side of, i.e., microorganisms and organic matter.
　Further, because even short supply time to the reverse osmosis unit 10 of the salt concentration adjusted water (e.g. 5 to 30 minutes) effect of inhibiting proliferation of microorganisms obtained, the plant operating rate according to the practice of biofouling control measures You can avoid a significant decline.
　Further, by repeating the step of deactivating microorganisms intermittently, it is possible during the operation of the reverse osmosis unit 10, the activity of the microorganisms to remain lowered. Usually, the growth rate of the microorganisms under proper environment for very large, by maintaining the state that prevent the growth of microorganisms (non-activated state), can be suppressed effectively biofouling.
[0036]
　In one embodiment, the salt concentration adjusting water has a 0.8 or 1.25 or higher salt concentration ratio relative to the raw water.
　The present inventors have conducted extensive examination results, as shown in FIG. 7, it was found a correlation between survival (active) and the salt concentration of the microorganisms in the raw water. That is, the salt concentration ratio relative to the raw water under 0.8 or 1.25 or higher environment, it was found that the viability of the microorganism (active) is greatly reduced. Therefore, by the salt concentration ratio of the raw water salt concentration adjusting water of 0.8 or less or 1.25 or more, it is possible to deactivate most of the microorganisms attached to the reverse osmosis membrane, thereby effectively It can inhibit biofouling in.
[0037]
　Furthermore, the salt concentration adjusting water may have a 0.6 or 1.5 or higher salt concentration ratio relative to the raw water.
　As shown in FIG. 7, in the salt concentration ratio is 0.6 or less or 1.5 or more environment for raw water, it is possible to reduce the viability of the microorganisms to approximately 50%. Therefore, it is possible more effectively suppress biofouling.
[0038]
　As shown in FIGS. 1-6, in one embodiment, in step to deactivate the microorganisms, without stopping the pump 14 to be supplied to the reverse osmosis unit (reverse osmosis membrane) 10 raw water, the pump 14 supplying the salt concentration adjusted water reverse osmosis unit (reverse osmosis membrane) 10 by.
[0039]
　Usually, the raw water supplied to the inlet side of the reverse osmosis unit 10 is very high, the pump 14 for supplying raw water to the reverse osmosis unit 10, it takes time to start.
　In this respect, according to the above method, the pump 14 does not stop, by supplying the salt concentration adjusted water reverse osmosis unit 10, the plant re-activated for after the deactivation of the microorganism with a salt concentration adjusting water it can be carried out in a short period of time. Therefore, it is possible to improve the rate of operation of the plant.
[0040]
　In the step of deactivating said microorganisms, so as to supply to the reverse osmosis unit (reverse osmosis membrane) reverse osmosis unit the salt concentration adjusted water containing concentrate or permeate obtained in 10 (reverse osmosis membrane) 10 it may be.
　Thus, it is possible to effectively use the water in the system. In particular, since the concentrated water is often discarded, by using the concentrated water as a salt concentration adjusting water, the greater the effect of reducing cost.
[0041]
　Next, a specific method according to each embodiment.
[0042]
　Figure 1 is a block diagram illustrating a reverse osmosis membrane treatment method according to the first embodiment.
　In the first embodiment as shown in the figure, the reverse osmosis membrane treatment facility 1 includes a reverse osmosis membrane device 10, a raw water supply line 30 for supplying raw water to the reverse osmosis unit 10, a raw water supply line 30 a first valve 12 and a pump 14 provided, the permeate line 32 which leads to a permeate obtained by reverse osmosis membrane device 10, the concentrated water line 34 for guiding concentrated water separated in the reverse osmosis unit 10, concentrated comprising an energy recovery device 15 and the concentrated water valve 16 provided in the water line 34.
[0043]
　Here, the pump 14, via the raw water supply line 30, configured to supply raw water to the reverse osmosis unit 10. Normally, the pump 14, in both the step of deactivating step and microorganisms separating raw water, so as to continuously drive.
　The first valve 12 is configured to adjust the supply amount of the raw water.
　Energy recovery device 15 is a device for converting pressure energy of concentrated water to the power energy of the pump 14. The energy recovery apparatus 15 is, for example, to a pressure energy may be configured to directly convert the power energy, after converting the pressure energy into electrical energy, it may be configured to convert the power energy.
　Concentrated water valve 16 is configured to adjust the discharge amount of concentrated water. For example, concentrated water valve 16 is constant flow rate control.
[0044]
　Further, the reverse osmosis membrane treatment facility 1 is provided with adjusting water supply line (permeate return line) 36 for returning at least a portion of the permeate from the permeate line 32 to the raw water supply line 30 as a salt concentration adjusting water further comprising a second valve 19 and return pump 18 provided on the adjustment water supply line 36.
[0045]
　In the above reverse osmosis membrane treatment facility 1, the raw water supply line 30 for supplying a reverse osmosis unit (reverse osmosis membrane) 10 to the raw water, raw water or raw water and the salt concentration adjusted water is supplied supplied water tank 13 may be provided. That is, the raw water supply line 30 includes, in order from the upstream side, a first valve 12, the supply water tank 13 and a pump 14 is provided.
　The feed water tank 13, adjusting water supply line 36 is connected.
[0046]
　In the reverse osmosis membrane treatment method according to the first embodiment, in step to deactivate the microorganisms, without stopping the pump 14 to be supplied to the reverse osmosis unit (reverse osmosis membrane) 10 raw water, permeated water raw water supplied to the reverse osmosis unit (reverse osmosis membrane) 10 was mixed water mixture as the salt concentration adjusting water.
　That is, in the step of deactivating microorganisms, in a state where the first valve 12 is opened, the return pump 18 is driven with opening the second valve 19, via an adjusting water supply line 36, at least a portion of the permeate the return to the raw water supply line 30 as a salt concentration adjusting water. Salt concentration adjusting water introduced into the raw water supply line 30 is supplied to the reverse osmosis membrane apparatus 10 by the pump 14 is mixed with the raw water.
　Incidentally, the reverse osmosis membrane treatment installation 1, as intermittently repeats steps deactivating microorganisms, first valve 12, second valve 19 is controlled so as to operate the return pump 18 and the pump 14 as described above controller may have.
[0047]
　In the case where the supply water tank 13 is provided as in the example shown, the concentrated water is returned via the adjusting water supply line 38 is once raw water is introduced into the feed water tank 13 and the mixing after being supplied to the reverse osmosis unit 10 by the pump 14. Thus, if the feed water tank 13 is provided between the first valve 12 and second valve 21 and the pump 14, it can be adjusted suction pressure of the pump 14 by opening and closing of the first valve 12 or second valve 21. Thus, stable operation of the pump 14 can be realized, an adequate supply of salt concentration adjusting water to the reverse osmosis unit 10 is possible.
[0048]
　According to the above method, the pump 14 does not stop, by supplying the mixed water obtained by mixing concentrated water to the raw water to the reverse osmosis unit 10, reverse osmosis after the deactivation of the microorganism with a salt concentration adjusting water it can be performed in a short time re-operation of the plant with a membrane device 10. Also, while deactivating microorganisms, so to continue the supply of the raw water as a raw material for mixed water (salt concentration adjusting water), upon re-operation of the plant, switching or the like becomes unnecessary for the valve on the upstream side of the pump 14, the plant can be usually proceeds smoothly in operation.
[0049]
　Incidentally, in the step of separating the raw water, with the first valve 12 is opened, the return pump 20 together with the second valve 21 is closed is stopped, only the raw water is supplied to the reverse osmosis unit 10 by the pump 14.
[0050]
　Figure 2 is a block diagram illustrating a reverse osmosis membrane treatment method according to the second embodiment.
　In the second embodiment, as shown in the figure, the reverse osmosis membrane treatment facility 1 includes a reverse osmosis membrane device 10, a raw water supply line 30 for supplying raw water to the reverse osmosis unit 10, a raw water supply line 30 a first valve 12 and a pump 14 provided, the permeate line 32 which leads to a permeate obtained by reverse osmosis membrane device 10, the concentrated water line 34 for guiding concentrated water separated in the reverse osmosis unit 10, concentrated comprising an energy recovery device 15 and the concentrated water valve 16 provided in the water line 34.
　Note that the specific configuration of each device is substantially the same as the first embodiment described above, a detailed description thereof will be omitted.
[0051]
　Further, the reverse osmosis membrane treatment facility 1 is provided with adjusting water supply line (retentate return line) 38 for returning at least a portion of the concentrated water from the concentrated water line 34 to the raw water supply line 30 as a salt concentration adjusting water further comprising a second valve 21 and return pump 20 provided in the adjusting water supply line 38.
[0052]
　In the above reverse osmosis membrane treatment facility 1, the raw water supply line 30 for supplying a reverse osmosis unit (reverse osmosis membrane) 10 to the raw water, raw water or raw water and the salt concentration adjusted water is supplied supplied water tank 13 may be provided. That is, the raw water supply line 30 includes, in order from the upstream side, a first valve 12, the supply water tank 13 and a pump 14 is provided.
　The feed water tank 13, adjusting water supply line 38 is connected.
[0053]
　In the reverse osmosis membrane treatment method according to the second embodiment, in step to deactivate the microorganisms, without stopping the pump 14 to be supplied to the reverse osmosis unit (reverse osmosis membrane) 10 raw water, concentrated water raw water supplied to the reverse osmosis unit (reverse osmosis membrane) 10 was mixed water mixture as the salt concentration adjusting water.
　That is, in the step of deactivating microorganisms, in a state where the first valve 12 is opened, the return pump 20 is driven with opening the second valve 21, via an adjusting water supply line 38, at least part of the concentrated water the return to the raw water supply line 30 as a salt concentration adjusting water. Salt concentration adjusting water introduced into the raw water supply line 30 is supplied to the reverse osmosis membrane apparatus 10 by the pump 14 is mixed with the raw water.
　Incidentally, the reverse osmosis membrane treatment installation 1, to repeat the step of deactivating microorganisms intermittently, first valve 12, second valve 21 is controlled so as to operate the return pump 20 and the pump 14 as described above controller may have.
[0054]
　In the case where the supply water tank 13 is provided as in the example shown, the concentrated water is returned via the adjusting water supply line 38 is once raw water is introduced into the feed water tank 13 and the mixing after being supplied to the reverse osmosis unit 10 by the pump 14. Thus, if the feed water tank 13 is provided between the first valve 12 and second valve 19 and the pump 14, it can be adjusted suction pressure of the pump 14 by opening and closing of the first valve 12 or second valve 19. Thus, stable operation of the pump 14 can be realized, an adequate supply of salt concentration adjusting water to the reverse osmosis unit 10 is possible.
[0055]
　Further, in the above method, as the salt concentration adjusting water, salt (in the case of desalination, for example seawater NaCl) may be used concentrated water was added.
[0056]
　According to the above method, the pump 14 does not stop, by supplying the mixed water obtained by mixing permeate into the raw water to the reverse osmosis unit 10, reverse osmosis after the deactivation of the microorganism with a salt concentration adjusting water it can be performed in a short time re-operation of the plant with a membrane device 10. Also, while deactivating microorganisms, so to continue the supply of the raw water as a raw material for mixed water (salt concentration adjusting water), upon re-operation of the plant, switching or the like becomes unnecessary for the valve on the upstream side of the pump 14, the plant can be usually proceeds smoothly in operation.
[0057]
　Incidentally, in the step of separating the raw water, with the first valve 12 is opened, return pump 18 with the valve 19 is closed is stopped, only the raw water is supplied to the reverse osmosis unit 10 by the pump 14.
[0058]
　Figure 3 is a block diagram illustrating a reverse osmosis membrane treatment method according to the third embodiment.
　In the third embodiment as shown in the figure, the reverse osmosis membrane treatment facility 1 includes a reverse osmosis membrane device 10, a raw water supply line 30 for supplying raw water to the reverse osmosis unit 10, a raw water supply line 30 a first valve 12 and a pump 14 provided, the permeate line 32 which leads to a permeate obtained by reverse osmosis membrane device 10, the concentrated water line 34 for guiding concentrated water separated in the reverse osmosis unit 10, concentrated comprising an energy recovery device 15 and the concentrated water valve 16 provided in the water line 34.
　Note that the specific configuration of each device is substantially the same as the first embodiment described above, a detailed description thereof will be omitted.
[0059]
　In addition, the reverse osmosis membrane treatment facility 1, the adjustment water supply line for returning at least a portion of the permeate from the permeate line 32 to the raw water supply line 30 as a salt concentration adjusting water (permeate return line ) further comprises a 36, ​​a second valve 19 and return pump 18 provided on the adjustment water supply line 36. Moreover, the adjustment water supply line (retentate return line) 38 for returning to the raw water supply line 30 at least part of the concentrated water from the concentrated water line 34 as the salt concentration adjusting water is provided in the adjustment water supply line 38 further comprising a second valve 21 and the return pump 20, the.
[0060]
　In the above reverse osmosis membrane treatment facility 1, the raw water supply line 30 for supplying a reverse osmosis unit (reverse osmosis membrane) 10 to the raw water, raw water or raw water and the salt concentration adjusted water is supplied supplied water tank 13 may be provided. That is, the raw water supply line 30 includes, in order from the upstream side, a first valve 12, the supply water tank 13 and a pump 14 is provided.
　The feed water tank 13, adjusting water supply line 36 is connected.
[0061]
　In the reverse osmosis membrane treatment method according to the third embodiment, in step deactivating microorganisms, a first salt concentration adjusting water salt concentration ratio is less than 1 for raw water salt concentration ratio raw water greater than 1 reverse osmosis unit and a second salt concentration adjusting water are alternately supplied to the (reverse osmosis membrane) 10. In the illustrated example, a first salt concentration adjusting water comprises permeate, a second salt concentration adjusting water containing concentrated water.
[0062]
　That is, in the step of deactivating microorganisms, first, with open first valve 12, to drive the return pump 18 with opening the second valve 19 of the permeate side, via the adjusting water supply line 36 , returning at least a portion of the permeated water to the raw water supply line 30 as a salt concentration adjusting water. At this time, the second valve 21 of the concentrate water side is closed, return pump 20 is stopped. Therefore, the concentrate is not returned to the raw water supply line 30, and is discharged from the concentrated water line 34. Raw salt concentration adjusting water introduced into the supply line 30 (the permeate) is fed to the reverse osmosis membrane apparatus 10 by the pump 14 is mixed with the raw water.
　Incidentally, the reverse osmosis membrane treatment installation 1, to repeat the step of deactivating microorganisms intermittently, first valve 12, second valve (19, 21), a return pump (18, 20) and a pump 14 it may have a control unit for controlling so as to operate as described above.
[0063]
　Thereafter, the permeate side of the return pump 18 closes the second valve 19 is stopped, drives the return pump 20 by opening the second valve 21 of the concentrate water side. Thus, in place of the permeate, at least part of the concentrated water is returned to the raw water supply line 30 via the adjusting water supply line 38. Raw salt concentration adjusting water introduced into the supply line 30 (concentrated water) is supplied to the reverse osmosis membrane apparatus 10 by the pump 14 is mixed with the raw water.
　Incidentally, the description has been given of the case where the sending back only concentrated water after returning only permeate, on the contrary, the permeate only may return after return only concentrated water.
[0064]
　Figure 8 is a diagram showing the supply timings of the salt concentration adjusted water.
　For example, as shown in FIG. 8, in step of deactivating microorganisms, after returning the permeate, one cycle to return the concentrated water may be conducted during the step of separating the raw water. Alternatively, during the step of separating the raw water, after returning the permeate may be performed more than once a cycle to return the concentrated water.
[0065]
　Incidentally, in the step of separating the raw water, with the first valve 12 is opened, return pump 18, 20 with a second valve 19, 21 is closed is stopped, only raw water to the reverse osmosis unit 10 by the pump 14 It is supplied.
[0066]
　Further, in the above method, when using a concentrated water as a salt concentration adjusting water, salt (in the case of desalination, for example seawater NaCl) may be used concentrated water was added.
[0067]
　According to the above method, by changing the salt concentration of the salt concentration adjusting water supplied to the reverse osmosis unit 10 increases, it is possible to provide greater osmotic changes to microorganisms, the effect of suppressing biofouling it is possible to increase even more.
　Also, the inlet side of the reverse osmosis membrane device 10, and microbial resistance is lower than the have resistance to low salt environments high salt environment, resistant to high salt environments to low salt environments resistant Te is low and the microorganisms may coexist. Even in this case, according to the above method, by a combination first and salt concentration adjusting water and a second salt concentration adjusting water, it is possible to effectively deactivate the different microorganisms in nature.
[0068]
　Figure 4 is a block diagram illustrating a reverse osmosis membrane treatment method according to the fourth embodiment.
　In the fourth embodiment, as shown in the figure, the reverse osmosis membrane treatment facility 1 includes a reverse osmosis membrane device 10, a raw water supply line 30 for supplying raw water to the reverse osmosis unit 10, a raw water supply line 30 a first valve 12 and a pump 14 provided (and the supply water tank 13), the permeate line 32 which leads to a permeate obtained by reverse osmosis membrane device 10, the permeate valve 26 provided in the permeate line 32 , the permeate tank 37 for storing the permeate, a concentrate line 34 for guiding concentrated water separated in the reverse osmosis unit 10, an energy recovery device 15 and the concentrated water valve 16 provided on the concentrated water line 34, equipped with a.
　Note that the specific configuration of each device is substantially the same as the first embodiment described above, a detailed description thereof will be omitted.
[0069]
　Further, the reverse osmosis membrane treatment facility 1 is provided with adjusting water supply line (permeate return line) 36 for returning at least a portion of the permeate from the permeate line 32 to the raw water supply line 30 as a salt concentration adjusting water further comprising a second valve 19 and return pump 18 provided on the adjustment water supply line 36.
[0070]
　In the reverse osmosis membrane treatment method according to the fourth embodiment, the salt in step of deactivating microorganisms, a pump 14 to be supplied to the reverse osmosis unit (reverse osmosis membrane) 10 raw water was stopped, the permeate itself supplied to the reverse osmosis unit (reverse osmosis membrane) 10 as a concentration adjusting water.
[0071]
　Specifically, in the step of separating the raw water, as shown in FIG. 4 (a), an open state of the first valve 12, and the return pump 18 is stopped by closing the second valve 19, the pump 14 to drive. Thus, only the raw water is supplied to the reverse osmosis unit 10 by the pump 14. Permeate separated by reverse osmosis membrane device 10 is recovered, whereas the concentrated water is discharged from the concentrated water line 34. Incidentally, permeate valve 26 of the permeated water line 32 is in a state of open. Furthermore, concentrated water valve 16 of the concentrate line 34 is generally constant flow rate control.
　Figure 4 (b), the time of switching between the step of deactivating step and microorganisms separating the raw water, the first valve 12 will remain open, return pump 18 by opening the second valve 19 to drive. Thus, as at least part salt concentration adjusting water permeate separated by reverse osmosis membrane device 10, is returned via the adjusting water supply line 36 from the permeate tank 37 to the raw water supply line 30, temporarily raw water mixed water with a salt concentration adjusting water (permeate) is supplied to the reverse osmosis unit 10 and. In this case, permeate valve 26 is closed, like concentrated water valve 16 is maintained in an opened state.
　As shown in FIG. 4 (c), the step of deactivating microorganisms, closing the first valve 12, and the return pump 18 is driven to open the second valve 19, separated by the reverse osmosis membrane device 10 supplied to the reverse osmosis unit 10 to permeate only by the pump 14. In this case, the permeate valve 26 maintains the closed state, like concentrated water valve 16 is maintained in an opened state.
　Incidentally, when switching to the step of separating raw water from step of deactivating microorganisms, it may be switched by the operation shown in Figure 4 (b).
　Also, the reverse osmosis membrane treatment installation 1, as intermittently repeating the step of deactivating microorganisms, first valve 12, second valve 19, return pump 18, the pump 14, the permeate valve 26 and concentrated water valve 16 may have a control unit for controlling so as to operate as described above.
[0072]
　According to the above method, the pump 14 is stopped by supplying the reverse osmosis unit 10 to permeate itself as salt concentration adjusting water, increasing the salt concentration difference with respect to the raw water in comparison with the case of using by mixing for example raw water with can do. This can provide greater osmotic changes against microorganisms, it is possible to further enhance the inhibitory effect of biofouling.
[0073]
　Figure 5 is a block diagram illustrating a reverse osmosis membrane treatment method according to the fifth embodiment.
　In the fifth embodiment, as shown in the figure, the reverse osmosis membrane treatment facility 1 includes a reverse osmosis membrane device 10, a raw water supply line 30 for supplying raw water to the reverse osmosis unit 10, a raw water supply line 30 directing a first valve 12 and a pump 14 provided (and the supply water tank 13), the permeate line 32 which leads to a permeate obtained by reverse osmosis membrane device 10, the concentrated water that has been separated by reverse osmosis membrane device 10 It includes a concentrated water line 34, the energy recovery device 15 and the concentrated water valve 16 provided on the concentrated water line 34, a concentrated water tank 39 for storing the concentrated water, the.
　Note that the specific configuration of each device is substantially the same as the first embodiment described above, a detailed description thereof will be omitted.
[0074]
　Further, the reverse osmosis membrane treatment installation 1, as the salt concentration adjusted water at least part of the concentrated water from the concentrated water line 34, adjusting water supply line (enrichment for returning the concentrated water tank 39 to the raw water supply line 30 further comprising a water return line) 38, a second valve 21 and return pump 20 provided in the adjusting water supply line 38.
[0075]
　In the reverse osmosis membrane treatment method according to the fifth embodiment, in step deactivating microorganisms, the pump is stopped 14 to be supplied to the reverse osmosis unit (reverse osmosis membrane) 10 raw water, salt concentrate itself supplied to the reverse osmosis unit (reverse osmosis membrane) 10 as a concentration adjusting water.
[0076]
　Specifically, in the step of separating the raw water, as shown in FIG. 5 (a), an open state of the first valve 12, and the return pump 20 is stopped by closing the second valve 21, the pump 14 to drive. Thus, only the raw water is supplied to the reverse osmosis unit 10 by the pump 14. Permeate separated by reverse osmosis membrane device 10 is recovered, whereas the concentrated water is discharged from the concentrated water line 34. Incidentally, permeate valve 26 of the permeated water line 32 is in a state of open. Furthermore, concentrated water valve 16 of the concentrate line 34 is generally constant flow rate control.
　Figure 5 (b), the time of switching between the step of deactivating step and microorganisms separating the raw water, the first valve 12 will remain open, return pump 20 by opening the second valve 21 to drive. Thus, as at least part salt concentration adjusting water concentrated water separated in the reverse osmosis unit 10, is returned via the adjusting water supply line 38 from the concentrated water tank 39 to the raw water supply line 30, temporarily raw water mixed water with a salt concentration adjusting water (concentrated water) is supplied to the reverse osmosis unit 10 and. In this case, permeate valve 26 is closed, like concentrated water valve 16 is maintained in an opened state.
　As shown in FIG. 5 (c), the step of deactivating microorganisms, closing the first valve 12, and the return pump 20 is driven to open the second valve 21, separated by the reverse osmosis membrane device 10 supplied to the reverse osmosis unit 10 only concentrated water by the pump 14. In this case, the permeate valve 26 maintains the closed state, like concentrated water valve 16 is maintained in an opened state.
　Incidentally, when switching to the step of separating raw water from step of deactivating microorganisms, it may be switched by the operation shown in Figure 5 (b).
　Also, the reverse osmosis membrane treatment installation 1, to repeat the step of deactivating microorganisms intermittently, first valve 12, second valve 21, return pump 20, the pump 14, the permeate valve 26 and concentrated water valve 16 may have a control unit for controlling so as to operate as described above.
[0077]
　Further, in the above method, as the salt concentration adjusting water, salt (in the case of desalination, for example seawater NaCl) may be used concentrated water was added.
[0078]
　According to the above method, the pump 14 is stopped by supplying the reverse osmosis unit 10 a concentrated water itself as the salt concentration adjusting water, increasing the salt concentration difference with respect to the raw water in comparison with the case of using by mixing for example raw water with can do. This can provide greater osmotic changes against microorganisms, it is possible to further enhance the inhibitory effect of biofouling.
[0079]
　Figure 6 is a block diagram illustrating a reverse osmosis membrane treatment method according to the sixth embodiment.
　In the sixth embodiment, as shown in the figure, the reverse osmosis membrane treatment facility 1 includes a reverse osmosis membrane device 10, a raw water supply line 30 for supplying raw water to the reverse osmosis unit 10, a raw water supply line 30 a first valve 12 and a pump 14 provided (and the supply water tank 13), the permeate line 32 which leads to a permeate obtained by reverse osmosis membrane device 10, the permeate valve 26 provided in the permeate line 32 , the permeate tank 37 for storing the permeate, a concentrate line 34 for guiding concentrated water separated in the reverse osmosis unit 10, an energy recovery device 15 and the concentrated water valve 16 provided on the concentrated water line 34, It includes a concentrated water tank 39 for storing the concentrated water, the.
　Note that the specific configuration of each device is substantially the same as the first embodiment described above, a detailed description thereof will be omitted.
[0080]
　In addition, the reverse osmosis membrane treatment installation 1, as one salt concentration adjusting water of concentrated water from the permeate or retentate tank 39 from the permeate tank 37, adjustment for returning the raw water supply line 30 further comprising a water supply line 36, a second valve 19 and return pump 18 provided on the adjustment water supply line 36. Moreover, the adjustment water supply line 36 includes a permeate tank 37 permeated water separated by the reverse osmosis membrane apparatus (reverse osmosis membrane) 10 is stored, which is separated by a reverse osmosis membrane device (reverse osmosis membrane) 10 a concentrated water tank 39 which concentrated water is stored, is connected. Moreover, between the adjusting water supply line 36 with the permeate tank 37, the valve 27 for switching the communication state between the adjustment water supply line 36 with the permeate tank 37 is provided. Similarly, between the adjusting water supply line 36 and concentrated water tank 39, the valve 28 for switching the communication state between the adjustment water supply line 36 and concentrated water tank 39 is provided.
[0081]
　In the reverse osmosis membrane treatment method according to the sixth embodiment, in step deactivating microorganisms, the pump is stopped 14 to be supplied to the reverse osmosis unit (reverse osmosis membrane) 10 raw water, permeated water itself or concentrated reverse osmosis unit the water itself as the salt concentration adjusted water supplied to the (reverse osmosis membrane) 10.
[0082]
　Specifically, in the step of separating the raw water, as shown in FIG. 6 (a), an open state of the first valve 12, and the return pump 18 is stopped by closing the second valve 19, the pump 14 to drive. Thus, only the raw water is supplied to the reverse osmosis unit 10 by the pump 14. Permeate separated by reverse osmosis membrane device 10 is recovered, whereas the concentrated water is discharged from the concentrated water line 34. Incidentally, permeate valve 26 of the permeated water line 32 is in a state of open. Furthermore, concentrated water valve 16 of the concentrate line 34 is generally constant flow rate control.
　Figure 6 (b), the time of switching between the step of deactivating step and microorganisms separating the raw water, the first valve 12 will remain open, return pump 18 by opening the second valve 19 to drive. Also, by opening one of the valves 27 or valve 28, communicates one of the permeate tank 37 or concentrated water tank 39 to the adjustment water supply line 36. Accordingly, it sent back to the reverse osmosis unit adjusting water supply line 36 the raw water supply line 30 via one of the separated permeate or concentrate as the salt concentration adjusted water at 10 temporarily raw salt concentration adjusting water mixed water is supplied to the reverse osmosis unit 10 with. In FIG. 6 (b), the as an example, the case of returning the permeate as a salt concentration adjusting water. In this case, permeate valve 26 is closed, like concentrated water valve 16 is maintained in an opened state. Permeate and the concentrated water switching is performed by opening and closing control of the valve 27.
　As shown in FIG. 6 (c), the step of deactivating microorganisms, closing the first valve 12, and the return pump 18 is driven to open the second valve 19, the permeate from the permeate tank 37 or supplying concentrated water from the concentrated water tank 39 to the reverse osmosis unit 10 by the pump 14. In this case, the permeate valve 26 maintains the closed state, like concentrated water valve 16 is maintained in an opened state.
　Subsequently, in the closed state of the first valve 12, by opening the valve 28 by closing the valve 27 is switched to the concentrated water tank 39 a tank which is connected to conditioning water supply line 36 from the permeate tank 37. Thus, the salt concentration adjusting water to be returned to the raw water supply line 30 is switched between the permeate and the concentrated water.
　Incidentally, when switching to the step of separating raw water from step of deactivating microorganisms, it may be switched by the operation shown in Figure 6 (b).
　Also, the reverse osmosis membrane treatment installation 1, as intermittently repeating the step of deactivating microorganisms, first valve 12, second valve 19, return pump 18, the pump 14, the permeate valve 26, the concentrated water valve 16 may have a control unit for controlling so as to operate the valve 27 and valve 28 as described above.
[0083]
　In the above method, when using a concentrated water as a salt concentration adjusting water, salt (in the case of desalination, for example seawater NaCl) may be used concentrated water was added.
[0084]
　According to the above method, the pump 14 is stopped by supplying the reverse osmosis unit 10 a concentrated water itself as the salt concentration adjusting water, increasing the salt concentration difference with respect to the raw water in comparison with the case of using by mixing for example raw water with can do. This can provide greater osmotic changes against microorganisms, it is possible to further enhance the inhibitory effect of biofouling.
　Further, by changing the salt concentration of the salt concentration adjusting water supplied to the reverse osmosis unit 10 increases, it is possible to provide greater osmotic changes to microorganisms, further enhanced effect of inhibiting biofouling be able to.
　Furthermore, the inlet side of the reverse osmosis membrane device 10, and microbial resistance is lower than the have resistance to low salt environments high salt environment, resistant to high salt environments to low salt environments resistant Te is low and the microorganisms may coexist. Even in this case, according to the above method, by a combination first and salt concentration adjusting water and a second salt concentration adjusting water, it is possible to effectively deactivate the different microorganisms in nature.
[0085]
　Here, with reference to FIGS. 9, 10A and 10B, it will be described reverse osmosis membrane treatment method according to a modification of the present embodiment. This modification can be applied to any of the first to sixth embodiments described above.
　Figure 9 is a flowchart illustrating a reverse osmosis membrane treatment method according to a modification of the present embodiment. Figure 10A is a graph showing the frequency of performing optimal deactivation process for biofilm formation rate. Figure 10B is a graph showing the processing time for optimal deactivation process for biofilm formation rate.
[0086]
　Reverse osmosis membrane treatment method according to the modification of the present embodiment, based on the indicator of the properties of the raw water associated with biofilm formation rate, salt concentration adjusting water of the salt concentration is supplied to the reverse osmosis membrane, the salt concentration adjusted water execution frequency of deactivation treatment of the microorganism with, or further comprising the step of adjusting at least one of the processing time of the deactivation process.
[0087]
　Specifically, as shown in FIG. 9, the raw water by the reverse osmosis unit 10 it is first separated into a permeate and a retentate (S1). Next, the reverse osmosis unit 10 by supplying a salt concentration adjustment water deactivates microorganisms (S2). In the step of deactivating the microorganism, measuring an indicator of the properties of raw water associated with biofilm formation rate every predetermined time (S3). As the index, for example, biofilm formation rate (BFR: Biofilm Formation Rate) can be used. Based on this indicator, the salt concentration of the salt concentration adjusted water supplied to the reverse osmosis membrane, execution frequency of the deactivation process of the microorganisms using a salt concentration adjustment water, or the processing time of the deactivation process, at least It determines whether it is necessary to change one (S4). If there is no need to change continues the step of deactivating microorganisms. On the other hand, if there is a need to change, based on the index, the salt concentration of the salt concentration adjusted water supplied to the osmotic membranes, execution frequency of the deactivation process of the microorganisms using a salt concentration adjustment water or a non adjusting at least one of the processing time of the activation process (S5). After adjustment, perform deactivation treatment of microbial again (S2). Incidentally, the step of deactivating microorganisms terminated after a predetermined time has elapsed, the flow returns to step (S1) for separating the raw water.
[0088]
　As shown in FIG. 10A, the larger the biofilm formation speed, increasing the frequency of performing deactivation treatment of the microorganism with a salt concentration adjustment water. Note that the execution frequency, a number of times of execution of the deactivation process in a predetermined time period, i.e. when carrying out the step of deactivating the microbial step of separating raw water alternately, the step of separating the raw water treatment It is adjusted by the length of time.
　Similarly, as shown in FIG. 10B, the larger the biofilm formation speed, deactivation processing of the processing time of the microorganisms (duration) longer with salt concentration adjusting water.
　Further, as shown in FIG. 8, since there is a correlation between the survival of the microorganism and (active) and salt concentration, the larger the biofilm formation speed may be increased salt concentration ratio raw. For example, when using the permeate as a salt concentration adjusting water, it may be adjusted permeate ratio supplied to the reverse osmosis membrane. When using a concentrated water as a salt concentration adjusting water, may be adjusted to concentrate ratio supplied to the reverse osmosis membrane, the salt from the outside to the concentrated water may be added. Alternatively, as shown in FIG. 11 to be described later, reverse osmosis if the membrane is provided in two stages in series, the permeate or the retentate were mixed in the proper proportions salt concentration adjusting water are separated in the reverse osmosis membrane it may be used as.
[0089]
　Usually, depending on the nature of the raw water, the type and amount of microorganisms are different. Therefore, as described above methods, based on the indicator of the properties of the raw water associated with biofilm formation rate, the salt concentration of the salt concentration adjusting water, at least in the processing time of the execution frequency or deactivation process of deactivation process by adjusting the one, or different properties of the raw water can be reliably prevented biofouling.
[0090]
　Referring now to FIG. 11, as an application example of the reverse osmosis membrane treatment method according to the embodiments described above, it will be described desalination treatment method seawater. Figure 11 is a diagram showing the overall flow of the desalination process including a reverse osmosis membrane treatment according to one embodiment. In the same figure shows a case with a reverse osmosis membrane treatment facility 1 according to the first embodiment as an example.
[0091]
　As shown in the figure, desalination plant 100, a pre-treatment facility 50, and a reverse osmosis membrane treatment facility 1 described above, the post-processing equipment 60.
　Before treatment facility 50 includes a sea water tank 51, a pump 52, a filtration device 53, the filtered water tank 54, a pump 55, a cartridge filter 56. For example the filtration device 53 may be a sand filtration apparatus of the two-layer by anthracite and sand, it may also be a filtration device using a ultrafiltration membrane or microfiltration membrane.
　Reverse osmosis membrane processing equipment 1 includes a first reverse osmosis unit 10a and the second reverse osmosis unit 10b arranged in series. Pump 17 is provided between the first reverse osmosis unit 10a and the second reverse osmosis unit 10b.
　Post-processing equipment 60 includes a permeate tank 61, a pump 62, a.
　In each treatment facility, as appropriate, chemical injection equipment is installed.
[0092]
　In the desalination treatment method of seawater in accordance with one embodiment, first sea water is taken in storing seawater tank 51. Seawater in the seawater tank 51 is fed to the filtration device 53 by the pump 52. Seawater quality content turbidity filtration device 53 is removed, after being stored in the filtered water tank 54, it is sent by the pump 55 to the cartridge filter 56. Seawater smaller cloudy quality content particle diameter cartridge filter 56 is removed is sent to the first reverse osmosis unit 10 by the pump 14. Permeate obtained in the first reverse osmosis unit 10a is sent by the pump 17 to the second reverse osmosis unit 10b. These reverse osmosis unit 10a, by 10b, salts in seawater, ion, particles, permeate organic matter and microorganisms have been removed is stored in the permeate tank 61 is fed to the usage destination by a pump 62 as product water .
[0093]
　In the desalination plant, the salt concentration adjusting water used in the step of deactivating microorganisms described above, the permeate obtained in at least one of the first reverse osmosis unit 10a or the second reverse osmosis unit 10b or it can be used concentrated water. Further, from the viewpoint of a biofilm is easily formed, the step of deactivating microorganisms may be conducted in at least a first reverse osmosis unit 10a.
[0094]
　As described above, according to at least some embodiments of the present invention, by supplying to the reverse osmosis membrane salt concentration adjusting water adjusted to a different salt concentration raw water, accumulate on the inlet side of the reverse osmosis membrane have been eye membrane clogging by growth of microorganisms, i.e. it is possible to suppress biofouling.
　Further, even if short supply time of the reverse osmosis membrane of the salt concentration adjusted water (e.g. 5 to 30 minutes) for the growth inhibitory effect of microorganisms can be obtained, significant reduction in operating rate due to the implementation of biofouling control measures the can be avoided.
　Further, by repeating the step of deactivating microorganisms intermittently, it can be maintained during the operation of the reverse osmosis membrane, a state in which the microorganism is inactivated. Usually, the growth rate of the microorganisms under proper environment for very large, by maintaining the state that prevent the growth of microorganisms (non-activated state), can be suppressed effectively biofouling.
[0095]
　The present invention is not limited to the embodiments described above, the form and adding a modification to the embodiments described above, also includes appropriate combination form these forms.
[0096]
　For example, representation of the things such as "the same", "equal to" and "homogeneous" is equal condition, not only represents a strictly equal conditions, tolerance, or varying degrees of the same functions can be obtained It is intended to refer also existing set of conditions.
　Further, "comprising", "including" one component, or, the expression "comprising" does not exclusive representation exclude the presence of other elements.
DESCRIPTION OF SYMBOLS
[0097]
1 reverse osmosis membrane treatment facility
10, 10a, 10b reverse osmosis unit
12 first valve
13 supplies water tank
14,17 pump
15 energy recovery apparatus
16 concentrated water valve
18 return pump
19 second valve
20 return pump
21 second valve
30 the raw water supply line
32 permeate line
34 concentrated water line
36 and 38 adjust water supply line
37 the permeate tank
39 concentrated water tank
50 pretreatment facilities
51 seawater tank
53 filtration device
54 the filtered water tank
56 cartridge filter
60 post-treatment facility
61 permeate tank
100 seawater desalination plant

The scope of the claims
[Requested item 1]
　And separating the raw water by reverse osmosis membrane to the permeate and the concentrated water,
　the raw water supplied to the salt concentration adjusted water adjusted to different salt concentrations in the reverse osmosis membrane and, on the inlet side of the reverse osmosis membrane accumulated and step of deactivating microorganisms, including a
　reverse osmosis membrane treatment wherein the intermittently and repeatedly performing the step of deactivating said microorganisms.
[Requested item 2]
　The salt concentration adjusting water, reverse osmosis membrane treatment method according to claim 1, characterized in that it has a 0.8 or 1.25 or higher salt concentration ratios with respect to the raw water.
[Requested item 3]
　Wherein said microorganism in the step of deactivating, the without stopping the pump for supplying the raw water to said reverse osmosis membrane, and supplying the salt concentration adjusted water by the pump to the reverse osmosis membrane reverse osmosis membrane treatment method according to claim 1 or 2.
[Requested item 4]
　In the step of deactivating said microorganisms, according to the salt concentration adjusting water containing the concentrated water or the permeate in any one of claims 1 to 3, wherein the feeding to the reverse osmosis membrane reverse osmosis membrane treatment method.
[Requested item 5]
　The microorganism in step deactivating, without stopping the pump for supplying the raw water to said reverse osmosis membrane, a mixed water obtained by mixing the concentrate or the permeate water to the raw water as the salt concentration adjusted water reverse osmosis membrane treatment method according to claim 4, characterized by supplying to the reverse osmosis membrane.
[Requested item 6]
　In the step of deactivating said microorganisms, said pump to be supplied to the reverse osmosis membrane raw water is stopped to supply the concentrated water or the permeate itself to the reverse osmosis membrane as the salt concentration adjusted water reverse osmosis membrane treatment method according to claim 4, characterized in.
[Requested item 7]
　In the step of deactivating said microorganisms, a first salt concentration adjusting water salt concentration ratio relative to the raw water is less than 1, the second salt concentration adjusting water greater than the salt concentration ratio of 1 for raw water, an alternating reverse osmosis membrane treatment method according to any one of claims 1 to 6, characterized in that supplied to the reverse osmosis membrane.
[Requested item 8]
　Wherein the first salt concentration adjusting water comprises the permeate,
　the second salt concentration adjusting water reverse osmosis membrane treatment method according to claim 7, characterized in that it comprises the concentrated water.
[Requested item 9]
　Based on the indicator of the raw water properties associated with biofilm formation rate, the salt concentration of the salt concentration adjusted water supplied to the reverse osmosis membrane, the deactivation process of the microorganism using said salt concentration adjusting water execution frequency, or reverse osmosis membrane treatment method according to any one of claims 1 to 8, further comprising the step of adjusting at least one of the processing time of the deactivation process.
[Requested item 10]
　The raw water supply line for supplying the raw water to said reverse osmosis membrane, a first valve, the feed water tank and the pump are provided in this order from the upstream side,
　the supply water tank, the salt concentration adjusted water adjust water supply line to flow is connected,
　the adjustment water supply line is provided with a second valve,
　in the step of separating the raw water, the first valve open is closed the second valve Te, the raw water stored in the feed water tank is supplied to the reverse osmosis membrane by said pump,
　in the step of deactivating said microorganisms by opening the second valve is closed said first valve , supplies the salt concentration adjusted water through the feed water tank to the reverse osmosis membrane by the pump
reverse osmosis membrane treatment method according to any one of claims 1 to 9, characterized in that.
[Requested item 11]
　Includes a reverse osmosis membrane apparatus for separating raw water by reverse osmosis membrane to the permeate and the concentrated water,
　the reverse osmosis membrane of the reverse osmosis membrane apparatus salt concentration adjusting water adjusted to a different salt concentration and raw water supplied, reverse osmosis membrane treatment facility that is configured to perform intermittently repeated microbial deactivation process for deactivating accumulated on the inlet side of the reverse osmosis membrane.