[0001]The present disclosure relates to a method for cleaning a filtration apparatus for removing attached material fixed to the filtration layer, and to a filtration treatment facilities and desalination plant with a configuration for implementing the washing method.
BACKGROUND
[0002]Generally, the filtration layer filter medium, such as anthracite and quartz sand is filled by flowing the raw water, a filtration apparatus is known for filtering suspended solid content of the raw water (the suspended particulates). Filtration apparatus, for example, as a pre-treatment facility of the reverse osmosis membrane apparatus, is often used in various water treatment plant desalination plant or the like.
[0003]
　In such a filtration apparatus, with the operation, the clogging is generated by accumulation of turbid matter in a filtration layer, because pressure loss is increased, it is necessary to appropriately remove turbid matter adhering to the filtration layer.
　In a typical filtration device, typically by introducing the backwash water filtration layer, the backwashing to discharge from the filtration device turbid matter or the like from the. For example, Patent Document 1 discloses that to perform backwashing using a filtration treated filtrate in the filtration step as backwash water. Further, Patent Document 2, before performing backwash, air is blown into the filtration layer in a state of discharging the raw water from the filter device, it is described that for peeling the deposits adhered to the filtration layer.
CITATION
Patent Document
[0004]
Patent Document 1: JP-B 54-18780 Patent Publication
Patent Document 2: JP 2014-151278 JP
Summary of the Invention
Problems that the Invention is to Solve
[0005]
　Incidentally, the raw water is introduced into the filtration device, sometimes polymer flocculant is added. For example, if the filtering device is used as a pretreatment of the reverse osmosis membrane apparatus, in order to suppress quality deterioration of filtered water at the high load of the reverse osmosis membrane device, the polymer flocculant is added.
　In this case, a polymer flocculant will be fixed at the inlet side of the filtration layer, it is difficult alone backwashing of peeling the sticking material. As described in Patent Document 2, when blowing air to the filtration layer, it is necessary to provide an air cleaning equipment blower and pipes for supplying air, cost and installation space increases. Further, it is necessary to drain water from the filtration system before blow air, there is a problem that the washing time becomes longer.
[0006]
　Object of at least some embodiments of the present invention, a method of cleaning a filtration device capable of easily removing the adhered material of the filtration layer by adding polymeric flocculant to the raw water, as well as, the filtration equipment and desalination plant it is to provide.
Means for Solving the Problems
[0007]
(1) cleaning method of the filtering device according to at least some embodiments of the present invention,
　there is provided a method for cleaning a filtration apparatus fixation of polymer flocculant is stuck to the inlet of the filtration layer,
　at least the filtration layer wherein such inlet is immersed in the cleaning liquid containing alkali solution, and supplying the cleaning liquid to the filtration apparatus,
　and removing the attached material immersed in the cleaning solution from the filtration layer,
comprising a .
[0008]
　According to the method (1), as the inlet section of at least the filtration layer is immersed in the cleaning solution containing an alkaline solution, by supplying a cleaning liquid to the filtration device, fixation composed mainly of polymer swelling and, it is possible to reduce the fixing force of the fixing thereof relative to the filtration layer. Thus, by peeling off the adhering matter from the filtration layer and it can be easily removed. Further, since the equipment additional air cleaning equipment and the like for separating the fixation thereof by blowing air into the filtration layer becomes unnecessary, which is advantageous in terms of cost or installation space.
　In the step of removing attached material from the filtration layer, in addition to physically external force as such backwashing is peeled fixation thereof, may be removed from the filtration layer, a physical force to it may be removed themselves detached adhering matter from the filtration layer without.
[0009]
In (2) some embodiments, in the method of the above (1),
　wherein the filtration device is a first biological membrane filtration apparatus biofilm is supported on the filtration layer,
　in supplying the cleaning liquid, immersed in selectively the cleaning solution to said inlet portion of said filtration layer of said first biofilm filtration device.
[0010]
　Typical biological membrane filtration apparatus, in order to maintain the activity of microorganisms, it is required to hold the filter layer surrounding environment which the microorganisms are supported.
　In this respect, according to the method of the above (2). Thus fixation of the polymeric flocculant of the filtration layer of the first biological membrane filtration device immersed in selectively washes easily inlet attachment, microorganisms sites not immersed in the cleaning liquid without killing can maintain its activity. Thus, without significantly reducing the biological treatment function in the first biological membrane filtration apparatus, it is possible to improve the releasability of the fixing of the polymeric flocculant. Further, the cleaning liquid since it in an amount that selectively immersed inlet of the filtration layer, can be reduced in the supply amount and the cleaning time of the cleaning liquid.
[0011]
(3) In some embodiments, in the method (2),
　wherein the first biological membrane filtration device is configured raw water that flows upward to filter by the filtration layer,
　in supplying the cleaning liquid , inside such that the cleaning liquid accumulated in the filtering layer of the inlet portion of the first biological membrane filtration units to a height of, for supplying the cleaning liquid from the lower portion of the first biological membrane filtration device.
[0012]
　In the method (3), the first biological membrane filtration device is configured to filter by filtration layer raw water flows upward. Therefore, easy sticking of polymer flocculant below one of the first biological membrane filtration device is formed. Therefore, inside the first biofilm filtration device to the height of the inlet portion of the filtration layer as the cleaning liquid accumulates, by supplying the cleaning liquid from the lower portion of the first biological membrane filtration units, adhering matter is likely to be formed inlet part only it can be easily contacted with the washing liquid.
[0013]
(4) In some embodiments, in any of the above methods (1) to (3),
　on the upstream side of the filtration device, the second biofilm filtration device provided biofilm is supported on the filtration layer is and,
　said fixing substance attached to the inlet portion of the filtration layer of the filtration device, during the operation of the second biofilm filtration apparatus and the filtration device, the second biofilm filtration apparatus and the filtration device a fixing of the polymeric flocculant which is added between.
[0014]
　According to the method of the above (4), since adapted to supply cleaning liquid to the filtration device provided downstream of the second biofilm filtration device, it does not flow the cleaning liquid in the second biological membrane filtration units, a second it is possible to reduce the influence of the cleaning agent to the supported microorganisms filtration layer of the biological membrane filtration device. Therefore, it can be maintained high biological processing function by microorganisms in the second biological membrane filtration device. On the other hand, a filtration device to be cleaned provided downstream of the second biofilm filtration apparatus, to bear mainly aggregation processing function, although fixation of the filtration layer by polymer flocculant occurs, the (1) to ( 3) by supplying the cleaning liquid as a readily removable fixation thereof.
　Note that the second biofilm filtration device because the polymeric coagulant is not supplied, attached material is less likely to occur, the supply of the cleaning liquid is not required.
[0015]
In (5) some embodiments, in any of the above methods (1) to (4),
　in the step of removing the attached material, and supplies the backwash water to the filtering device, the backwash water by backwashing using to separate the solid deposits from the filter layer.
[0016]
　According to the method of the above (5), for example, even the filtration device no air cleaning equipment, In conjunction with the immersion by the cleaning solution containing an alkaline solution, and a backwash with the backwash water, the filtration layer the attached material which is fixed can be reliably removed. Thus, the possible reduction deployment costs of the air cleaning equipment, by not performing the air cleaning operation is necessary drainage process, it is possible to shorten the cleaning operation time to improve the operation rate of the filtration device .
[0017]
(6) In some embodiments, in any of the above methods (1) to (5),
　pH of the cleaning solution is 10 or more and 13 or less.
[0018]
　According to the method of the above (6), by the pH of the cleaning solution containing an alkali solution and 10 to 13, it can be properly removed sticking material formed by a polymeric flocculant.
[0019]
(7) In some embodiments, in any of the above methods (1) to (6),
　wherein the cleaning solution further comprises a dispersing agent.
[0020]
　According to the method of the above (7), since the cleaning liquid contains a dispersing agent, it is possible to suppress the attached material was peeled off from the filtration layer is re-attached to the filtration layer. Thus, it is possible to improve the removal rate of the adhering matter from the filtration layer.
[0021]
(8) filtration treatment facility according to at least some embodiments of the present invention,
　a filtration apparatus having a filtration layer for filtering the raw water,
　injected at the upstream side of the filtering device, a polymeric flocculant to the raw water a polymeric coagulant injection unit for,
　as an inlet portion of at least the filtration layer is immersed in the cleaning liquid containing an alkali solution, and a washing liquid supply portion for supplying the cleaning liquid to the filter device
comprising a.
[0022]
　According to the above configuration (8), as solid deposits derived from the polymer flocculant even occurred inlet of the filtration layer of the filtration device, the inlet of at least the filtration layer is immersed in the cleaning solution containing an alkaline solution to, by supplying a cleaning liquid to the filtration device, it can be fixed material swells mainly composed of a polymer, reduce the adhesive force of the sticking material for filtration layer. Thus, by peeling off the adhering matter from the filtration layer and it can be easily removed. Further, since the equipment additional air cleaning equipment and the like for separating the fixation thereof by blowing air into the filtration layer becomes unnecessary, which is advantageous in terms of cost or installation space.
　Incidentally, when the removal of attached material from the filtration layer, from the outside as such backwashing physically peeling the sticking material by applying a force, may be removed from the filtration layer, without applying a physical force it may be removed themselves detached adhering matter from the filtration layer.
[0023]
(9) In some embodiments, in the above configuration (8),
　the filtering device, while being constituted the raw water that flows upward to filter by the filtration layer, biofilm supported on the filtration layer a first biological membrane filtration apparatus that is,
　the cleaning liquid supply unit is composed of a lower portion of the first biological membrane filtration units so as to supply the cleaning liquid.
[0024]
　Typical biological membrane filtration apparatus, in order to maintain the activity of microorganisms, it is required to hold the filter layer surrounding environment which the microorganisms are supported.
　In this regard, according to the above configuration (9), it is first biofilm filtration device configured to filter the raw water flowing upwardly, and the cleaning liquid supply section, from the lower portion of the first biological membrane filtering device because and supplies the cleaning liquid, by appropriately adjusting the supply amount of the cleaning liquid, an inlet portion attached material easily adheres the polymeric flocculant of the filtration layer of the first biological membrane filtration device (filtration layer it can be immersed in selectively cleaning liquid bottom). In this case, microorganisms portion not immersed in the cleaning liquid without killing its activity is maintained. Thus, without largely decreasing the biological treatment function in the first biological membrane filtration apparatus, it is possible to improve the releasability of the fixing of the polymeric flocculant.
[0025]
(10) In some embodiments, in the above configuration (9),
　the cleaning liquid supply unit, so that the cleaning liquid inside the filtration layer of the inlet portion of the first biological membrane filtration units to a height of accumulation, configured to set the supply amount of the cleaning solution.
[0026]
　According to the above configuration (10), inside as washing liquid is accumulated in the first biological membrane filtering device to the height of the inlet portion of the filter layer, by supplying the cleaning liquid from the lower portion of the first biological membrane filtration units, solid kimono only easily formed inlet part can be selectively brought into contact with the washing liquid. Without significantly lowering the biological treatment function in the first biological membrane filtration apparatus, it is possible to improve the releasability of the fixing of the polymeric flocculant.
[0027]
(11) In some embodiments, in any of the above Paragraph (9) or (10),
　the filtration treatment facility,
　located on the upstream side of the filtration device, biofilm is supported on the filtration layer a second biological membrane filtration device,
　and an intermediate line for leading to the filtration device filtered water from the second biofilm filtration apparatus, further comprising a
　said polymeric coagulant injection unit, the high to the intermediate line configured to inject molecular coagulant.
[0028]
　In the configuration of the above (11), is provided with the second biofilm filtration device upstream of the filter, it is possible to efficiently remove the suspended solids containing organic matter. The downstream side of the polymeric flocculant second biofilm filtration device (i.e., intermediate line) to be injected into, never aggregate derived from the polymer flocculant is deposited on the second biofilm filtration device. Therefore, it is possible to suppress the increase of the differential pressure in the second biological membrane filtration units is maintained over the filtration efficiency of the second biofilm filtration device long-term.
[0029]
(12) In some embodiments, in the above configuration (11),
　the cleaning liquid supply section is configured to the cleaning solution via the intermediate line so as to supply to the filtration system.
[0030]
　According to the above configuration (12). Thus to inject a cleaning liquid to the intermediate line on the upstream side of the downstream side and the cleaned filtration device of the second biofilm filtration device, the second biofilm filtration apparatus the cleaning liquid does not flow, it is possible to avoid the influence of the cleaning agent to the supported microorganisms filtration layer of the second biofilm filtration device. Therefore, it can be maintained high biological processing function by microorganisms in the second biological membrane filtration device. On the other hand, the second biofilm filtration filtration device to be cleaned provided downstream of the device, to bear mainly aggregation processing function, although fixation of the filtration layer by polymer flocculant occurs via the intermediate line filtration the supply of cleaning liquid to the inlet portion of the layer, which is easily removable fixation thereof.
[0031]
(13) In some embodiments, in any of the above Paragraph (8) ~ (12),
　pH of the cleaning solution is 10 or more and 13 or less.
[0032]
　According to the above configuration (13), by the pH of the cleaning solution containing an alkali solution and 10 to 13, can be properly removed sticking material formed by a polymeric flocculant.
[0033]
(14) In some embodiments, in any of the above Paragraph (8) to (13),
　wherein the cleaning solution further comprises a dispersing agent.
[0034]
　According to the above configuration (14), the cleaning liquid contains a dispersing agent, it is possible to suppress the attached material was peeled off from the filtration layer is re-attached to the filtration layer. Thus, it is possible to improve the removal rate of the adhering matter from the filtration layer.
[0035]
(15) desalination plant according to at least some embodiments of the present invention,
　the (8) to a filtration treatment equipment of any one of the configurations (14),
　located downstream of the filtration treatment facility, the , a reverse osmosis membrane equipment comprising at least one reverse osmosis unit for separating the filtered water from the filtration equipment to the concentrated water and permeated water
comprising a.
[0036]
　According to the above (15), is provided with the filtration treatment equipment of any construction of the above (8) to (14), secured to the inlet of the filtration layer of the adhering matter from the polymer flocculant filtration device even the, as the inlet section of at least the filtration layer is immersed in the cleaning solution containing an alkaline solution, by supplying the filtration device a cleaning liquid by the cleaning liquid supply section, to swell the fixed composed mainly of polymer, the sticking force of the sticking material for filtration layer can be reduced. Thus, by peeling off the adhering matter from the filtration layer and it can be easily removed. Further, since the equipment additional air cleaning equipment and the like for separating the fixation thereof by blowing air into the filtration layer becomes unnecessary, which is advantageous in terms of cost or installation space.
Effect of the invention
[0037]
　According to at least some embodiments of the present invention, during cleaning of the filter by supplying the filtration device a cleaning liquid containing an alkali solution, fixed product swells mainly composed of polymer solid with respect to the filtration layer it is possible to reduce the adhesive force of the kimono. Thus, by peeling off the adhering matter from the filtration layer and it can be easily removed. Further, since the equipment additional air cleaning equipment and the like for separating the fixation thereof by blowing air into the filtration layer becomes unnecessary, which is advantageous in terms of cost or installation space.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038]
FIG. 1 is a block diagram showing the overall structure of a desalination plant in accordance with one embodiment.
[2] Configuration of the filtration equipment according to the first embodiment, and is a diagram for explaining a method of cleaning a filtration device.
[3] Configuration of the filtration equipment according to the second embodiment, and is a diagram for explaining a method of cleaning a filtration device.
[4] Configuration of the filtration equipment according to a modification of the second embodiment, and is a diagram for explaining a method of cleaning a filtration device.
[5] A third filtration treatment equipment according to the embodiment structure, and is a diagram for explaining a method of cleaning a filtration device.
DESCRIPTION OF THE INVENTION
[0039]
　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.
[0040]
　First, referring to FIG. 1, a description will be given of the overall configuration of a desalination plant 1 which is an example of the Apply method for cleaning a filtration apparatus according to the present embodiment.
[0041]
　Desalination plant 1 in accordance with some embodiments, a filtration treatment facility 100 including a filtering device 10 for filtering the raw water (seawater) by filtration layer 12 which biofilm is carried, situated downstream of the filter 10 comprising at least one of the reverse osmosis unit 16.
[0042]
　Filtration apparatus 10 of the filtration equipment 100 includes a filter material container 11, and provided in the filtration vessel 11 one or more layers of filtration layer 12 (12a, 12b), the.
　In the exemplary embodiment shown in FIG. 1, has a configuration plurality of filtration layers 12 (12a, 12b) are stacked vertically. For example, the upper filtering layer 12a slag material, carbon material such as anthracite is used as the filter layer 12b on the lower layer side, granular filtering material such as silica sand is used.
　At least one filtration layer 12 (12a, 12b) of the filtration device 10, the biofilm may be carried. In other words, microorganisms utilizing organic nutrients in the raw water to the filter material surface may form a biofilm. However, the filtration device 10 which cleaning method according to the present embodiment is applied is not limited to the biological membrane filtration device.
[0043]
　The filtration device 10, raw water (seawater) is supplied by a pump 13. Raw water introduced into the filtration apparatus 10, from the inlet portion 12c of the filtration layer 12 toward the outlet portion 12d passes through the filtration layer 12, and is discharged from the filtration device 10. At that time, the membrane filtration apparatus 10, turbid matter in the raw water (suspended particulates) is removed by filtration layer 12. Also, if the filtration device 10 is a biofilm filtration device, the dissolved organic matter in the raw water are decomposed and removed by biofilm.
　Filtered water discharged from the filtration apparatus 10, after being stored in the filtered water tank 14 is supplied to the reverse osmosis unit 16 by the pump 15.
　Incidentally, during the filtration treatment facility 100 (filtration device 10) and the reverse osmosis unit 16, for example may be another filtration device is provided, such as ultrafiltration membrane or microfiltration membrane.
[0044]
　Reverse osmosis unit 16 is configured to separate into a permeate and concentrate filtration layer 12a, the filtered water from 12b by the reverse osmosis membrane. In the illustrated example, although the reverse osmosis unit 16 1 group indicates a configuration provided with a plurality of reverse osmosis membrane apparatus 16 may be a connected to each other in series or in parallel.
　Permeate thus produced is subjected to a post-treatment, it is fed to the usage destination as product water.
[0045]
　Incidentally, in the above embodiment, as an example, the case has been described where the filtration treatment facility 100 (filtration device 10) is applied to the desalination plant 1, the Apply filtration treatment facility 100 according to this embodiment desalination It is not limited to plant 1. In other words, filtration treatment facility 100 according to this embodiment, if a configuration for filtering raw water by filtration layer, the Apply is not particularly limited.
　In this case, the raw water, 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.
[0046]
　Here, with reference to FIGS. 2 to 5, it will be described in detail specific configuration of the filtration equipment 100 described above and its cleaning method. Note that FIG. 2 to 5 are views for explaining a cleaning method of a specific configuration and filtering device 10 of the filtration treatment facility 100 according to each embodiment.
[0047]
　In some embodiments, as shown in FIGS. 2-5, filtration equipment 100 (100A-100D), the polymeric coagulant injection for adding polymeric flocculant to the raw water flowing into the filtration apparatus 10 includes a section 200, as the inlet portion 12c of the filtration layer 12 of at least the filtration device 10 is immersed in the cleaning liquid, a cleaning liquid supply unit 300 for supplying a cleaning liquid to the filtration device 10, the.
[0048]
　Polymeric coagulant injection unit 200 is configured with respect to the raw water flowing into the filter device 10 (including the permeate from the second organism membrane filtration units 17 on the upstream side), to inject polymer coagulant . Wherein the polymeric flocculant, for example, cationic polymer flocculants, anionic polymer flocculants may be an organic polymer flocculant, such as a nonionic polymer flocculant.
　In the exemplary embodiment shown in FIGS. 2-5, coagulant injection unit 200 includes a coagulant tank 210 flocculant stored, pressurized injection of coagulant from flocculant tank 210 to the raw water supply line 20 comprising a coagulant pump 220 for the.
[0049]
　Cleaning liquid supply unit 300 at the time of cleaning of the filtration unit 10, configured to supply a cleaning liquid against the filtration device 10. Wherein the cleaning liquid has the effect contains an alkaline solution, the adhering matter from aggregating agent which is fixed to the inlet portion 12c of the filtration layer 12 swell, promote the release of the fixation of the inlet portion 12c.
　In the exemplary embodiment shown in FIGS. 2-5, the cleaning liquid supply section 300 via the cleaning liquid tank 310 the cleaning liquid is stored, a cleaning liquid supply line 22 communicating with the cleaning fluid tank 310, a cleaning liquid supply line 22 the cleaning liquid including a washing liquid pump 320 for pumping the cleaning fluid from the tank 310 to the filtration device 10, the.
[0050]
　Method for cleaning a filtration device 10 in the above configuration of the filtration equipment 100 (100A ~ 100D), as the inlet portion 12c of the at least the filtration layer 12 is immersed in the cleaning liquid containing alkali solution, supplying a cleaning liquid to the filtration device 10 comprising the steps, removing the attached material 19 immersed in the cleaning solution from the filtration layer 12.
　The alkali solution contained in the washing solution, for example, may be used an aqueous solution of sodium or potassium hydroxide solution hydroxide.
[0051]
　According to the above method, as the inlet portion 12c of the at least the filtration layer 12 is immersed in the cleaning liquid containing an alkaline solution, by supplying a cleaning liquid to the filtration device 10, attached material 19 composed mainly of polymer swelling and, it is possible to reduce the fixing force of the fixing object 19 with respect to the filtration layer 12. This makes it possible to peel off the adhering matter 19 from the filtration layer 12, it can be easily removed. Further, since the equipment added such as air cleaning equipment for peeling the sticking material 19 by blowing air into the filtration layer 12 is unnecessary, which is advantageous in terms of cost or installation space.
　In the step of removing attached material 19 from the filtration layer 12, is peeled off the sticking material 19 physically by applying a force from the outside as such backwashing may be removed from the filtration layer 12, the physical may be removed attached material 19 which is itself peeled from the filtration layer 12 without applying a force.
[0052]
　Here, pH of the cleaning solution supplied to the filtration device 10 may be 10 to 13.
　Thus, by the pH of the cleaning solution containing an alkali solution and 10 to 13, it can be properly removed sticking material formed by a polymeric flocculant.
[0053]
　Further, the cleaning liquid is supplied to the filtration device 10, in addition to the alkaline solution may further contain a dispersant. As dispersing agents, it may be used a surfactant.
　For example, as dispersants, can be used phosphonate dispersant or a sulfonic acid salt-based dispersing agents, and the like.
　In this manner, the cleaning liquid contains a dispersing agent, it is possible to suppress the attached material was peeled off from the filtration layer 12 is re-attached to the filtration layer 12. Thus, it is possible to improve the removal rate of the adhering matter 19 from the filtration layer 12.
[0054]
　In one embodiment, the filtration device 10, when the filtration layer 12 is first biofilm filtration device 10 which biofilm is supported, in the step of supplying the above-described washing solution, the filtration layer of the first biological membrane filtering device 10 12 of the inlet portion 12c selectively may be immersed in the cleaning liquid.
[0055]
　Typical biological membrane filtration apparatus, in order to maintain the activity of microorganisms, it is required to hold the filter layer surrounding environment which the microorganisms are supported. In this respect, according to the above method. Thus immersed in selectively washes easily adheres adhering matter 19 of polymeric flocculant of the filtration layer 12 of the first biological membrane filtering device 10 inlet portion 12c, without microorganisms sites not immersed in the cleaning liquid are killed, it is possible to maintain its activity. Thus, without significantly reducing the biological treatment function in the first biological membrane filtration apparatus 10, it is possible to improve the releasability of the fixing material 19 of the polymeric flocculant. Further, the cleaning liquid since it in an amount that selectively immersed inlet portion 12c of the filtration layer 12, can be reduced in the supply amount and the cleaning time of the cleaning liquid.
[0056]
　Further, in the step of removing the attached material, and supplies the backwash water to the filtering device 10, the backwash water may be caused to peel the attached material from the filtration layer by backwashing using.
　Thus, for example, be a filtration device having no air cleaning equipment, In conjunction with the immersion by the cleaning solution containing an alkaline solution, and a backwash with the backwash water, ensuring attached material fixed to the filtration layer it can be removed. Thus, as well as a possible reducing installation costs of the air cleaning equipment, by not performing the air cleaning operation is necessary drainage process, it is possible to shorten the cleaning operation time to improve the operation rate of the filtration device.
[0057]
　Incidentally, biofilm process according to the present embodiment, in order to reduce the environmental impact of the addition of chemicals iron-based flocculants or the like to the raw water, biological membrane filtration process to perform the Mukusurichu pretreatment in is suitable when supplying polymer flocculant as required.
[0058]
　Next, the cleaning method of the filtering apparatus 10 according to the embodiments shown in FIGS. 2 to 5, will be described in detail. Note that, in FIGS. 2-5, lines indicated by a solid line, normally subject fluid during the operation of the filtering device 10 (the raw water, washing liquid, backwash water, etc.) indicates that the flow line indicated by a broken line, the filtering device 10 indicating that the flow is subject fluid during cleaning.
[0059]
　Figure 2 is a diagram showing the cleaning method of construction and the filtration device 10 of the filtration equipment 100A according to the first embodiment.
　As shown in the figure, the filtration treatment facility 100A, the top of the filtration apparatus 10 is connected to the raw water supply line 20, the bottom is connected to a filtrate discharge line 21. Further, the filtration treatment facility 100, the cleaning liquid supply unit 300, the cleaning liquid supply line 22 for supplying is provided a cleaning liquid containing alkaline solution as described above from the top of the filtration device 10. Cleaning liquid supply line 22 may be configured to supply a cleaning liquid to the raw water, it may be configured to directly supply the cleaning liquid to the top of the filtration device 10. Moreover, the filtration device 10, the backwash water supply line 23 for supplying the backwash water upward are provided from the bottom of the filtration device 10. Incidentally, the filtration device 10 may be a biological membrane filtration device.
[0060]
　Usually during operation of the filtration apparatus 10, the raw water is fed to the top of the filtration device 10 through the raw water supply line 20. In the filtration device 10, from the inlet portion 12c positioned above the filtration layer 12 toward the outlet portion 12d located below through the raw water, the filtered water through the filtered water discharge line 21 from the bottom of the filtration device 10 discharge It is.
　Also, during normal operation of the filtration device 10, for example in order to suppress quality deterioration of filtered water at high load in the subsequent stage of the reverse osmosis membrane device 16 (see FIG. 1), as appropriate, the raw water by a polymeric flocculating agent injection part 200 polymer flocculant is added to. Therefore, above the inlet portion 12c of the filtration layer 12 is attached material 19 which polymeric coagulant is stuck is formed on filtration layer 12.
[0061]
　On the other hand, at the time of cleaning of the filter 10, the cleaning liquid supply section 300, cleaning liquid is supplied from the top of the filtration apparatus 10 via the cleaning liquid supply line 22. Supplied to the filtration device 10 the cleaning liquid from the inlet portion 12c of the filtration layer 12 flows toward the outlet portion 12d, and is discharged from the bottom of the filtration device 10. The supply of cleaning fluid, typically may be carried out in backwash immediately before the operation, in this case, may be supplied to the filtering apparatus 10 by mixing the cleaning liquid to the raw water.
　Thus, attached material 19 composed mainly of a polymer adhered to the filtration layer 12 to swell, fixing force of fixing material 19 is reduced with respect to the filtration layer 12.
[0062]
　When cleaning liquid is discharged, supplying backwash water from the backwash water supply line 23, by passing the backwash water toward the inlet portion 12c from the outlet portion 12d of the filtration layer 12, sticking matter sticking fell 19 detached from the filtration layer 12, is discharged from the filtration device 10.
[0063]
　According to this method, during the cleaning of the filter 10, by supplying a cleaning liquid containing an alkaline solution to the filtration device 10, it is possible to reduce the fixing force of the fixing object 19 with respect to the filtration layer 12, filtration attached material 19 is peeled from the layer 12, it can be easily removed. Also it has the advantage that it is possible to use existing equipment.
[0064]
　Figure 3 is a diagram showing the cleaning method of construction and the filtration device 10 of the filtration equipment 100B according to the second embodiment.
　As shown in the figure, the filtration device 10 is configured to filter by filtration layer 12 raw water flowing upwardly. That is, the bottom of the filtration apparatus 10 is connected to the raw water supply line 20, the filtered water discharge line 21 is connected to the top. Further, the filtration device 10, cleaning liquid supply line 22 for supplying is provided a cleaning liquid containing alkaline solution as described above from the bottom of the filtration device 10. Cleaning liquid supply line 22 may be configured to supply a cleaning liquid to the raw water, it may be configured to directly supply the cleaning liquid to the bottom of the filtration device 10. Moreover, the filtration device 10, the backwash water supply line 23 for supplying the backwash water upward are provided from the bottom of the filtration device 10. Incidentally, the filtration device 10 may be a biological membrane filtration device.
[0065]
　Usually during operation of the filtration apparatus 10, the raw water is fed into the bottom of the filtration apparatus 10 via a raw water supply line 20. In the filtration device 10, passes through the raw water towards the outlet portion 12d is located from the inlet portion 12c located below the filtration layer 12 upwards, the filtrate through the filtered water discharge line 21 from the top of the filtration device 10 discharge It is.
　Also, during normal operation of the filtration device 10, for example in order to suppress quality deterioration of filtered water at high load in the subsequent stage of the reverse osmosis membrane device 16 (see FIG. 1), as appropriate, the raw water by a polymeric flocculating agent injection part 200 polymer flocculant is added to. Therefore, the inlet portion 12c of the lower filtration layer 12 is attached material 19 which polymeric coagulant is stuck is formed on filtration layer 12.
[0066]
　On the other hand, at the time of cleaning of the filter 10 is inside so the washing liquid is accumulated in the filtering device 10 to the height of the inlet portion 12c of the filtration layer 12, the cleaning liquid dispenser 300, from the bottom of the filtration apparatus 10 via the cleaning liquid supply line 22 supplying a cleaning liquid. Thus, attached material 19 composed mainly of a polymer adhered to the filtration layer 12 to swell, fixing force of fixing material 19 is reduced with respect to the filtration layer 12. Then, after a predetermined time has elapsed, to discharge the cleaning liquid from the bottom of the filtration device 10.
　Incidentally, the cleaning liquid supply unit 300, so that the cleaning liquid accumulated in the filter material container 11 to the height of the inlet portion 12c of the filtration layer 12 of the filter 10, the supply amount of the cleaning liquid may be set. For example, the cleaning liquid supply section 300, the cumulative supply quantity setting the supply amount of the cleaning liquid obtained from the detection value of the flow meter provided in the cleaning liquid supply line 22 (= for the cleaning liquid reaches the height of the inlet portion 12c of the filtration layer 12 it may be configured to operate the washing liquid pump 320 until a cleaning liquid supply amount) required. Alternatively, necessary in order to, based on the displacement volume of the cleaning liquid pump 320, it supplies the cleaning liquid of setting the supply amount (= cleaning solution supply amount required for the washing liquid reaches the height of the inlet portion 12c of the filtration layer 12) in the filtration device 10 leave determine the operating time of the cleaning liquid pump 320, by operating only the washing liquid pump 320 the operating time, it may be supplied to the cleaning liquid of setting the supply amount to the filtration device 10.
[0067]
　In the present embodiment, by appropriately setting the supply amount of the cleaning liquid by the cleaning liquid supply section 300, an inlet portion 12c of the filtration layer 12 of the filter 10 selectively immersed in the cleaning liquid, the cleaning liquid a large part of the filtration layer 12 it can be prevented by contacting the. Therefore, the filtration device 10 suppresses the decrease in activity due to contact with the cleaning liquid of microorganisms that inhabit the filtration layer 12 of the biofilm even if a filtration device, the filtration device (first biofilm filtration apparatus) 10 be able to.
[0068]
　When cleaning liquid is discharged, supplying backwash water from the backwash water supply line 23, by passing the backwash water toward the outlet portion 12d from the inlet portion 12c of the filtration layer 12, sticking matter sticking fell 19 detached from the filtration layer 12, is discharged from the filtration device 10.
[0069]
　According to this method, during the cleaning of the filter 10, by supplying a cleaning liquid containing an alkaline solution to the filtration device 10, it is possible to reduce the fixing force of the fixing object 19 with respect to the filtration layer 12, filtration attached material 19 is peeled from the layer 12, it can be easily removed. Also, inside such cleaning liquid accumulated in the filtration apparatus 10 to the height of the inlet portion 12c of the filtration layer 12, by supplying the cleaning liquid from the lower portion of the first biological membrane filtration apparatus 10, easily adhering matter 19 is formed an inlet portion 12c alone can easily be contacted with the cleaning solution.
[0070]
　Figure 4 is a diagram showing the cleaning method of construction and the filtration device 10 of the filtration equipment 100C according to a modification of the second embodiment.
　Modification of the second embodiment is different from configuration of the backwash water supply line 23 and the second embodiment shown in FIG.
　That is, as shown in FIG. 4, the backwash water supply line 23 is configured to supply the backwash water from the upper part of the filtration device 10. Therefore, it is possible to easily discharge the attached material 19 from the filtration device 10 by the backwash.
　Note that the other configurations are similar to the second embodiment described above, and detailed description thereof will be omitted.
[0071]
　Figure 5 is a diagram showing the cleaning method of construction and the filtration device 10 of the filtration equipment 100D according to the third embodiment.
　As shown in the figure, filtration equipment 100D is upstream of the filter 10, the second biofilm filtration device 17 is provided. The second biofilm filtration device 17 has a structure provided in the filtration layer 18 Garozai container 11 biofilm is supported.
　In the illustrated example, the filtration device 10 has the same structure as the first embodiment. However, the filtration device 10 may comprise the same configuration as the second embodiment or its modification. Filtration device 10 may be a biological membrane filtration device.
[0072]
　In the embodiment shown in FIG. 5, the polymeric coagulant injection unit 200 is configured to add the polymeric flocculant to an intermediate line 25, located between the filtering device 10 and the second biofilm filtration device 17 . Further, the cleaning liquid supply unit 300, when cleaning the filtration unit 10, and supplies the cleaning liquid to the filter device 10 via the cleaning liquid supply line 22 and the intermediate line 25.
[0073]
　As shown in FIG. 5, the intermediate line 25, it may be buffer tank 50 and the pump 60 is provided.
　Polymeric coagulant injection unit 200, the downstream side of the buffer tank 50, and, at the upstream side of the filtration device 10, the intermediate line 25 may be adapted to inject polymer flocculant. In this case, directly it becomes possible to add polymeric flocculating agent to the filtered water supplied to the filtering apparatus 10, the polymeric flocculant between the second biofilm filtration device 17 and the buffer tank 50 as compared with the case of adding, easily manage the amount of aggregating agent required to properly perform the aggregation filtration in the filtration device 10.
　In order to easily carry out the injection of polymer flocculant from the polymeric coagulant injection unit 200, the suction side of the pump 60 (i.e., between the buffer tank 50 and the pump 60) is added polymer flocculant it may be so.
　Further, the cleaning liquid supply line 22 of the cleaning liquid supply section 300, the downstream side of the buffer tank 50, and, at the upstream side of the filter 10, may be connected to the intermediate line 25.
[0074]
　During normal operation of the filtration apparatus 10 and the second biofilm filtration device 17, the raw water at the top of the second biofilm filtration device 17 is supplied through a raw water supply line 20. In the second biological membrane filtration device 17, a filtration layer 18 is the raw water passes, filtered water is discharged from the bottom of the second biofilm filtration device 17. Filtered water from the second biofilm filtration device 17 is fed to the filtration device 10 via an intermediate line 25. In the filtration device 10, a filtration layer 12 passes through the raw water, filtered water is discharged from the bottom of the filtration device 10 through the filtered water discharge line 21.
　Also, during normal operation of the filtration apparatus 10 and the second biofilm filtering device 17, for example in order to suppress quality deterioration of filtered water at high load in the subsequent stage of the reverse osmosis membrane device 16 (see FIG. 1), as appropriate, the polymer flocculant is added to the filtered water 2 biofilm filtration device 17 (the filtered water flowing in the intermediate line 25). Therefore, the inlet portion 12c of the filtration layer 12 of the filter device 10 located downstream of the intermediate line 25, adhering matter 19 which polymeric coagulant is stuck is formed on filtration layer 12. That is, adhering matter 19 that adheres to the inlet portion 12c of the filtration layer 12 of the filter 10, during the operation of the second biofilm filtration device 17 and the filtering device 10, the filtering device 10 and the second biofilm filtration device 17 a solid deposits 19 of polymeric flocculant which is added during.
[0075]
　On the other hand, during the cleaning of the first biological membrane filtration device 10, cleaning liquid is supplied to the filtration apparatus 10 via the cleaning liquid supply line 22. Supplied to the filtration device 10 the cleaning liquid from the inlet portion 12c of the filtration layer 12 flows toward the outlet portion 12d, and is discharged from the bottom of the filtration device 10.
　Thus, attached material 19 composed mainly of a polymer adhered to the filtration layer 12 to swell, fixing force of fixing material 19 is reduced with respect to the filtration layer 12.
[0076]
　When cleaning liquid is discharged, supplying backwash water to the filtration device 10 from the backwash water supply line 23, separating the adhering matter 19 that fixing strength is lowered from the filtration layer 12, is discharged from the filtration device 10. Further, in the second biological membrane filtration apparatus 17, the backwash water supply line 26 to the second biofilm filtration device 17 supplies the backwash water discharging turbid component deposited on the filtration layer 18.
[0077]
　According to this method, during the cleaning of the filter 10, by supplying a cleaning liquid containing an alkaline solution to the filtration device 10, it is possible to reduce the fixing force of the fixing object 19 with respect to the filtration layer 12, filtration attached material 19 is peeled from the layer 12, it can be easily removed.
　Moreover, since so as to supply cleaning liquid to the filter device 10 provided downstream of the second biofilm filtration device 17, does not flow the cleaning liquid in the second biological membrane filtration apparatus 17, the second biological membrane filtration units 17 it is possible to avoid the influence of the detergent to the supported microorganisms filtration layer 18. Therefore, it is possible to maintain high biological treatment function by microorganisms in the second biological membrane filtration device 17. On the other hand, a filtration device 10 provided downstream of the second biofilm filtration device 17, to bear mainly aggregation processing function, but sticking of the filtration layer 12 by polymeric flocculant occurs, the cleaning liquid as described above by supplying a readily removable anchoring material 19.
　Since the second biological membrane filtration units 17 is not supplied polymer coagulant, attached material 19 hardly occurs, supply of the cleaning liquid may be required.
[0078]
　As described above, according to at least some embodiments of the present invention, during cleaning of the filter 10, by supplying a cleaning liquid containing an alkaline solution to the filtration device 10, attached material as a main component a polymer 19 There swell, it is possible to reduce the fixing force of the fixing object 19 with respect to the filtration layer 12. Thus, by peeling off the adhering matter 19 from the filtration layer 12, it can be easily removed. Further, since the equipment added such as air cleaning equipment for peeling the sticking material 19 by blowing air into the filtration layer 12 is unnecessary, which is advantageous in terms of cost or installation space.
[0079]
　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.
[0080]
　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
[0081]
1 desalination plants
10 filtration device (first biofilm filtration
device) 11 material container
12, 12a, 12b, 18 filtration layer
12c inlet
12d outlet
14 filtrate tank
16 the reverse osmosis unit
17 second biological membrane filtration units
19 adhering matter
20 raw water supply line
21 filtered water discharge line
22 the cleaning liquid supply line
23 backwash water supply line
25 intermediate line
26 backwash water supply line
50 the buffer tank
60 pump
100 filtration equipment
200 coagulant injection unit
210 flocculant tank
220 agglomeration agent pump
300 cleaning liquid supply section
310 solution tank
320 cleaning fluid pump

WE CLAIM

A method for cleaning a filtration apparatus fixation of polymer flocculant is stuck to the inlet of the filtration layer,
　so that the inlet portion of at least the filtration layer is immersed in the cleaning solution containing an alkaline solution, the said washing liquid and supplying the filtration device,
　and removing the attached material immersed in the cleaning solution from the filtration layer
cleaning method of the filtering device, characterized in that it comprises a.
[Requested item 2]
　The filtration device is a first biological membrane filtration apparatus biofilm is supported on the filtration layer,
　the step of supplying the cleaning liquid, selectively said inlet portion of said filtration layer of said first biofilm filtration device method for cleaning a filtration apparatus according to claim 1, characterized in that immersion in the cleaning solution.
[Requested item 3]
　Wherein the first biological membrane filtration device is configured raw water that flows upward to filter by the filtration layer,
　the step of supplying the cleaning liquid, the first biological membrane filtration units to a height of the inlet portion of said filtration layer inside such that the cleaning liquid accumulated in the cleaning method of the filtering device according to claim 2, characterized by supplying the cleaning liquid from the lower portion of the first biological membrane filtration device.
[Requested item 4]
　Upstream of the filtering device, a second biological membrane filtration device is provided biofilm is supported on the filtration layer,
　the sticking material adhered to said inlet portion of said filtration layer of the filtration device, the first in 2 during operation of the biological membrane filtration apparatus and the filtration device, according to claim 1, characterized in that the fixing of the polymeric flocculant which is added between the second biofilm filtration apparatus and the filtration device method for cleaning a filtration device according to to any one of 3.
[Requested item 5]
　In the step of removing the attached material, and supplies the backwash water to the filtering device, according to claim 1 to 4, characterized in that to separate the solid deposits by backwashing with the backwash water from the filtration layer method for cleaning a filtration device according to any one of.
[Requested item 6]
　Method for cleaning a filtration apparatus according to any one of claims 1 to 5, wherein the pH of the cleaning solution is 10 or more and 13 or less.
[Requested item 7]
　The cleaning solution, the cleaning method of the filtering device according to any one of claims 1 to 6, further comprising a dispersing agent.
[Requested item 8]
　A filtration apparatus having a filtration layer for filtering the raw water,
　the upstream side of the filtration device, and a polymeric coagulant injection unit for injecting a polymeric flocculant to the raw water,
　an inlet portion of at least the filtration layer as it is immersed in the cleaning liquid containing an alkali solution, and a washing liquid supply portion for supplying the cleaning liquid to the filter device
filtering processing equipment, characterized in that it comprises a.
[Requested item 9]
　The filtration device, while being constituted the raw water that flows upward to filter by the filtration layer, a first biological membrane filtration apparatus biofilm is supported on the filtration layer,
　the cleaning liquid supply section, wherein filtration treatment facility according the lower part of the first biological membrane filtration apparatus in claim 8, characterized in that it is configured to supply the cleaning liquid.
[Requested item 10]
　The cleaning liquid supply unit, so that the cleaning liquid inside the inlet portion of the first biological membrane filtration units to a height of the filtering layer is accumulated, characterized in that it is configured to set the supply amount of the cleaning solution filtration treatment installation according to claim 9.
[Requested item 11]
　Positioned upstream of the filtering device, a second biofilm filtration apparatus biofilm is supported on the filtration layer,
　and the intermediate line for introducing the filtered water from the second biofilm filtration device the filtration device, further comprising a
　said polymeric coagulant injection unit, filtration treatment according to any one of claims 8 to 10, wherein said configured to inject the polymer flocculant to the intermediate line Facility.
[Requested item 12]
　The cleaning liquid supply unit, a filtration treatment equipment according to claim 11, characterized in that the cleaning liquid through the intermediate line is configured to supply to the filtration system.
[Requested item 13]
　Filtration treatment installation according to any one of claims 8 to 12, wherein the pH of the cleaning solution is 10 or more and 13 or less.
[Requested item 14]
　The cleaning liquid, filtration equipment according to any one of claims 8 to 13, further comprising a dispersing agent.
[Requested item 15]
　And filtration equipment according to any one of claims 8 to 14,
　wherein the located downstream of the filtration equipment, at least for separating the concentrated water and permeated water filtered water from the filtration treatment facilities a reverse osmosis membrane equipment comprising a reverse osmosis unit,
desalination plants, characterized in that it comprises a.