JP2006051503A - Dynamic filter module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dynamic filter module which can inhibit deterioration of the filtration flux due to deposition of sludge inside a filter to stably give good treated water. <P>SOLUTION: This dynamic filter module for the separation of activated sludge has a water permeable filtration layer support material for forming a dynamic filtration layer as at least a part of the surrounding wall of a support 21 whose inside is hollow. The module has a filtration section with the water permeable filtration layer support material arranged for forming the dynamic filtration layer, a filtrate water outlet 27 arranged above and/or below the filtration section, and further a sludge collection section 30 having a sludge discharge outlet 29 arranged below the filtration section. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a filter module used for solid-liquid separation of an activated sludge mixed liquid produced by a biological treatment process of wastewater, concentration of excess sludge, etc., and particularly for treatment of organic industrial wastewater and domestic wastewater. The present invention relates to a filter module that can be used.

  Conventionally, in water treatment with activated sludge, solid sludge separation of activated sludge has to be performed in order to obtain treated water. Usually, for this purpose, a method has been used in which activated sludge is introduced into a sedimentation basin, the sludge is sedimented by gravity sedimentation, and the supernatant is discharged from the sedimentation basin as treated water. However, in this method, a sedimentation basin having a sufficient sedimentation area and residence time is required to settle activated sludge, which has been a factor in increasing the size of the processing apparatus and increasing the installation volume. Moreover, when activated sludge deteriorated sedimentation property by bulking etc., the sludge flowed out from the sedimentation basin and caused deterioration of treated water.

  In recent years, a method of performing solid-liquid separation of activated sludge by membrane separation instead of a sedimentation basin has been used. In this case, a microfiltration membrane or an ultrafiltration membrane is generally used as the solid-liquid separation membrane. However, in this method, suction or pressurization by a pump is necessary as a filtration separation means, and filtration is usually performed at a pressure of several tens kPa to several hundred kPa. Therefore, power consumption by the pump is large, which increases running costs. It was. In addition, clear treated water without any SS was obtained by membrane separation, but the permeation flux was low, and it was necessary to wash the medicine regularly in order to prevent membrane contamination.

  More recently, as a solid-liquid separation method for activated sludge as an alternative to a sedimentation basin, a filter body made of a water-permeable sheet such as non-woven fabric is immersed in an aeration tank, and an adhering layer of sludge particles itself is secondarily formed on the surface of the filter body. And a method of obtaining clear filtered water at a low water head pressure using this sludge layer as a filtration layer has been proposed. This method is called dynamic filtration, and the filter body itself made of a water-permeable sheet allows sludge particles to pass through. However, the sludge flocs are attached by generating a cross-flow flow of the activated sludge mixed liquid on the surface of the filter body. A kimono layer is secondarily formed on the water-permeable sheet, and this sludge layer functions as a filtration layer (dynamic filtration layer), so that sludge and SS in the liquid to be treated are solid-liquid separated. The thickness of the dynamic filtration layer increases as the filtration time elapses, and as a result, the filtration resistance increases and the filtration flux decreases, but in that case, the dynamic filtration layer is aerated from the air diffuser installed at the bottom of the filter body. After removing the sludge dynamic filtration layer formed on the filter body surface, a stable filtration flux is obtained by forming the dynamic filtration layer again.

  However, in such solid-liquid separation of activated sludge by dynamic filtration, sludge particles pass through the filter body until a dynamic filtration layer, that is, a deposit layer of activated sludge is formed on the surface of the filter body. Therefore, sludge accumulates inside the filter body and the filtration resistance increases, thereby reducing the filtration flux. In this case, external air washing by aeration from the air diffuser placed at the bottom of the filter body only removes the sludge layer on the surface of the filter body and has no effect on discharging the sludge accumulated inside the filter body. In addition, sludge infiltrate from the surface of the filter body to the inside immediately after washing, so the sludge inside the filter body accumulates without being discharged, and the sludge inside the filter body is concentrated with the passage of processing time, and the filtration resistance The filtration flux gradually decreases.

  In dynamic filtration, an internal water cleaning method for introducing treated water into a filter body is known as a method for discharging sludge that has entered the filter body. In this case, treated water is introduced into the filter body module, the sludge is passed through the filter layer to the outside of the filter body, and a part of the infiltrated sludge is discharged. Discharge from water discharge pipe). That is, during a predetermined time after the start of filtration, the filtered water is not collected and the mud inside the filter body is discharged. However, in such water washing inside the filter body, generally, only one or two wash water inlets into the filter body module are formed. It is not possible to evenly discharge adhered / deposited sludge inside the body. Also, when discharging the washed sludge from the filtered water discharge pipe, only the sludge located at the top of the filtered water discharge pipe is discharged, and the sludge is not discharged at a position not adjacent to the filtered water discharge pipe. The sludge gradually accumulates at that position and concentrates and solidifies. Once the sludge has been concentrated and solidified inside the filter body, it is extremely difficult to remove it.

  Moreover, in dynamic filtration, as another method for discharging sludge entering the filter body, a method of supplying air (bubbles) to the filter body and washing it with air is known. Also in this case, since the cleaning air is generally introduced from the filtered water discharge pipe, the inflow of gas into the filter body becomes uneven, and a portion where no gas is introduced, particularly the filtrate water discharge pipe at the bottom of the filter body is arranged. In places that are not, sludge tends to accumulate, which causes a reduction in filtration flux.

  Furthermore, in conventional filter bodies for dynamic filtration, sludge accumulates inside the filter body, and the surface of the filter layer is blocked by accumulated sludge, particularly at the bottom of the filter body, reducing the effective filtration area. Therefore, there is a problem that the filtration flux decreases. Further, when the sludge accumulates in the upper part of the filtered water discharge pipe, there is a problem that the accumulated sludge blocks the inlet of the discharge pipe and the filtered water cannot be obtained at all.

  Moreover, in the conventional dynamic filter body module, since the filtrate water outlet is usually about one place or two places, the flow rate of filtrate water at a location close to the filtrate water outlet is larger than other locations. . For this reason, the accumulation of sludge particles on the dynamic filtration layer becomes larger at the portion where the flow rate of the filtrate water is large, and there is a problem that the cycle of separation / reformation of the dynamic filtration layer is shortened.

  The present invention has been made in view of such conventional problems, and in dynamic filtration, it is possible to suppress a decrease in filtration flux due to sludge accumulation inside the filter body, and to obtain stable treated water. It is an object to provide a filter module.

  As a result of intensive studies to solve the above problems, the inventors of the present invention have provided a sludge accumulation part below the filtration layer in the dynamic filter module, and accumulated infiltrated sludge inside the filter body here. As a result, it was found that a stable filtration operation can be performed, and the present invention has been completed.

  In addition, the present inventors further have a flow of filtered water in the dynamic filter module by discharging the filtered water through a rectifying member that uniformly flows over the cross-sectional area of the module. It has also been found that a stable filtration operation can be performed by making it possible to uniformly use the entire filtration surface.

Various aspects of the present invention that solve the above-described problems are as follows.
1. A dynamic filter body module for separating activated sludge in which a water-permeable filter layer support for forming a dynamic filter layer is disposed as at least a part of a peripheral wall of a hollow support body. A filtration section in which a water-permeable filtration layer support material is disposed; a filtered water outlet disposed above and / or below the filtration section; and a sludge outlet disposed below the filtration section. A dynamic filter body module, wherein a sludge accumulation part is provided.

  2. A filtered water collection unit is disposed above and / or below the filtration unit, and a filtered water outlet is connected to the filtered water collection unit. Further, filtration is performed between the filtered water collection unit and the filtration unit. The dynamic filter module according to the above item 1, wherein a water rectifying member is disposed.

  3. A dynamic filter body module for separating activated sludge in which a water-permeable filter layer support for forming a dynamic filter layer is disposed as at least a part of a peripheral wall of a hollow support body. It has a filtration part in which a water-permeable filtration layer support material is disposed, and a filtrate collection part disposed above and / or below the filtration part, and a filtrate outlet is provided in the filtration water collection part. Is connected, and a filtered water rectifying member is further disposed between the filtered water collecting part and the filtering part.

4). The dynamic filter body module according to any one of the first to third aspects, wherein the filtered water outlet is disposed above the filtration unit.
5. The dynamic filter body module according to any one of Items 1 to 4, wherein a sludge agitation unit is disposed in the sludge accumulation section.

6). 6. The dynamic filter module according to item 5, wherein the sludge agitating means is an air diffuser.
7). The dynamic filter module according to any one of the first to sixth aspects, wherein a filter body internal cleaning water inlet is further disposed above and / or below the filter unit.

8). The dynamic filter module according to claim 7, wherein the filter body internal cleaning water inlet is connected to the filtered water collecting section.
9. The dynamic filter module according to claim 7, wherein the filter inner cleaning water inlet is connected to the sludge accumulation section.

10. The dynamic filter module according to any one of Items 1 to 9, wherein the filter layer support material is a woven fabric, a nonwoven fabric, or a metal net material.
11. Item 11. The dynamic filter module according to Item 10, wherein the filter layer support material is a woven fabric, a nonwoven fabric, or a metal net material reinforced by a reinforcing material.

  12 12. A method for cleaning / removing sludge that has entered the inside of the module of the dynamic filter module according to any one of the above items 1 to 11, wherein the sludge is aerated by aeration of the outer surface of the filter body and the interior of the filter body. The filter body is washed with air and then the filter body internal cleaning water is introduced into the filter body from the filtered water outlet or the filter body inner cleaning water inlet, and the sludge is discharged from the sludge outlet. Method.

13. 13. The method according to item 12 above, wherein the filter body washing water is filtered water obtained by a dynamic filter module.
14 13. The method according to item 12 above, wherein the filter body internal cleaning water is an aqueous oxidizing agent solution.

  15. 14. The method according to item 13, further comprising a step of cleaning the inside of the filter body by introducing a cleaning solution of an aqueous oxidant solution into the inside of the filter body after the water cleaning inside the filter body and the discharge of sludge are completed.

  In the dynamic filter module according to one aspect of the present invention, the sludge accumulation part is provided below the filter part, so that the inside of the filter body is formed until the dynamic filter layer is formed on the surface of the filter layer support material. The sludge that has entered the area gathers in the sludge accumulation section by gravity settling and is discharged to the outside from the sludge outlet of the sludge accumulation section. For this reason, it is possible to prevent sludge that has entered the inside of the filter body from adhering or accumulating inside the filter body, and the filtration area as the infiltrated sludge accumulates, concentrates and solidifies on the effective filtration surface. This reduces the problem that the filtration flux decreases, and a stable amount of filtered water can be obtained.

  Further, according to a more preferable aspect of the present invention, by arranging the sludge agitation means in the sludge accumulation part, the sludge is regularly stirred and dispersed in the sludge accumulation part and in the filter body, so that the sludge is inside the filter body. It can be discharged at a stable flow rate without resistance from the sludge outlet without adhering or accumulating in the sludge accumulation part, or concentrating / solidifying. The sludge agitation means is preferably disposed at a location in the sludge accumulation portion where sludge is likely to accumulate, and this can be determined by a person skilled in the art empirically or by preliminary experiments.

  As the sludge agitation means, various mechanical agitation means known in the art can be used, but an air diffuser is preferably used. In this case, the sludge in the sludge accumulation part is agitated by aeration from the air diffuser. Furthermore, when an aeration tube is used, air bubbles rise from the sludge accumulation portion into the filter body during aeration, and the inside of the filter body is stirred by the gas-liquid mixture, so that the attached sludge inside the filter body may also be peeled off. it can. Therefore, it is preferable to arrange the air diffusing tube so that the air uniformly rises inside the filter body during aeration. As far as the present inventors know, there is no example in which a diffuser tube is arranged inside the filter body in the conventional dynamic filter body module.

  Moreover, the dynamic filter body module which concerns on the other aspect of this invention arrange | positions the filtered water collection part connected with the filtered water outflow port above and / or below the filtration part, A filtered water collection part and a filtration part A filtered water straightening member is disposed between the two. Here, the filtered water rectifying member is one that allows the filtered water flowing from the filtration part to circulate uniformly over the entire cross-sectional area of the water collecting part.For example, a large number of communication holes are provided over the entire cross-sectional area. A filtered water rectification member can be comprised by arrange | positioning. In the conventional dynamic filter body module in which such a filtrate rectifying member is not disposed, the filtrate flows faster in a location close to the filtrate outlet, and thus the flow of filtrate within the filter body is uneven. As a result, the entire filtration surface could not be filtered uniformly, and the accumulation of sludge in the portion where the flow of filtered water was fast was accelerated. According to this aspect of the present invention, by providing the filtered water rectifying member, such a problem is solved, the flow of filtered water inside the filter body is made uniform, and the filtration is advanced evenly over the entire filtration surface. As a result, the frequency of peeling and reforming of the dynamic filtration layer can be reduced. In addition, when such a flow regulating member is similarly provided in the introduction portion of the washing water inside the filter body, the washing water is uniformly introduced into the inside of the filtration body when washing the water inside the filtration body. The sludge can be washed.

In addition, it is more preferable that the two constituent elements described above are provided at the same time because a dynamic filter module capable of performing a more stable filtration operation can be obtained.
In the dynamic filter module according to the present invention, the filtered water outlet and the filtered water collecting part can be arranged above and / or below the filtering part where the filtering layer is arranged. More preferably, it is arranged above. By placing the filtered water outlet and the filtered water collection part above the filtration part and the sludge accumulation part below the filtration part, the infiltrated sludge entering the filter body is gravity settled downward even during filtration operation. Since the filtered water can be taken out from above, it is possible to obtain a filtered water of higher quality with less sludge mixing.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. However, the following description will explain one specific example that embodies the technical idea of the present invention, and the present invention is not limited to this description.

  FIG. 1 is a flow sheet of a system for biological treatment of wastewater using the dynamic filter module of the present invention. Inflow raw water (treated wastewater) 1 flows into the biological treatment tank 2, and the activated sludge is subjected to aerobic treatment in the biological treatment tank 2. The activated sludge mixed liquid is discharged from the biological treatment tank 2 and supplied to the filtration separation tank 4 from the sludge mixed liquid supply pump 3. The activated sludge mixed liquid that has flowed into the filtration separation tank 4 is filtered by the dynamic filter module 6 at a water head pressure ΔH, and filtered water is obtained from the filtered water line 15 and flows into the treated water tank 13 through the filtered water valve 7. Treated water 19 is obtained from the treated water tank 13. The sludge mixed liquid after the filtration treatment is returned to the biological treatment tank 2 as a circulating sludge mixed liquid 18.

  Next, a specific configuration example of the dynamic filter module according to the present invention is shown in FIG. Fig.2 (a) is a front view of a filter body module structure, (b) shows a side sectional view. The dynamic filter body module according to one embodiment of the present invention shown in FIG. 2 includes a support body 21 having a hollow inside and a filter layer support material constituting at least a part of a peripheral wall of the support body. Specifically, a part of the peripheral wall of the support 21 is an opening, and the opening is configured to cover the opening with the filter layer support material.

  As the filter layer support material, any of known nonwoven fabrics, woven fabrics, metal net materials and the like as a support material for forming a dynamic filter layer in the art may be used. Further, as shown in FIG. 2, for example, a woven fabric 23 is pasted on the support spacer 25, and a support net 26 is further stacked on the support spacer 25, and fixed by the presser plate 22. preferable. By reinforcing the woven fabric with a reinforcing material such as a support spacer and a support net, the filter layer support material such as the woven fabric is bent inward during filtration, or the surface of the filter layer is washed and filtered. It is possible to suppress the phenomenon that the filter layer support material bends outward during washing with water inside the body, preventing the filter layer support material from being deformed, and being able to withstand long-term use. Furthermore, since the surface of the filtration layer support material is no longer stretched and the surface of the filtration layer support material is always flat compared to the case where a woven fabric or nonwoven fabric is used alone, a uniform sludge is formed on the entire surface of the filtration layer support material. A dynamic filtration layer is formed, and a stable filtration flux is obtained. The support spacer 26 arranged inside the woven fabric or the like is 5 to 50 mm, more preferably, from the function of preventing the bending of the woven fabric / nonwoven fabric etc. that can sufficiently pass through the sludge particles and the sludge floc, It is preferable to use a net-like member having an opening of 5 to 25 mm. In addition, the support net 26 arranged on the outside of the woven fabric or the like should have an opening of 10 mm or more so as to prevent expansion of the woven fabric and prevent sludge accumulation with the woven fabric or the like. Is preferred. Further, the reinforcing member 26 outside the woven fabric may be constituted by a support member in which rod-like members are combined in a lattice shape, for example, instead of the net-like member.

Furthermore, it is more preferable to arrange the internal support pillar 24 for the purpose of reinforcing the inside of the support.
In the dynamic filter module shown in FIG. 2, a filtered water collecting unit 35 is disposed above the filtering unit formed by the filter layer support material, and a filtration is performed between the collecting unit 35 and the filtering unit. A filtered water rectifying member formed by the water communication hole 31 is disposed. In addition, a filtered water outlet 27 and a filter body internal cleaning water inlet 28 are connected to the filtered water collecting unit 35. With such a configuration, the filtrate water filtered from the dynamic filtration layer is rectified through the communication hole 31, flows into the filtrate collection part 35, and is discharged from the filtrate outlet 27. Accordingly, the flow of filtered water inside the filter body becomes uniform, and the filtration layer can be used uniformly over the entire surface.

  In addition, a sludge accumulation unit 30 to which a sludge discharge port 29 is connected is disposed below the filtration unit, and a filter body internal air diffusion pipe 33 to which an air supply pipe 34 is connected is disposed in the sludge accumulation unit 30. ing.

Next, the operation method of the dynamic filter module of the present invention described above will be described with reference to FIGS.
A dynamic filter body module according to the present invention as shown in FIG. 2 is arranged in the filtration / separation tank 4 of FIG. 1, and a cross-flow flow of the sludge mixed liquid is formed in the filtration / separation tank 4. Thereby, the dynamic filtration layer of sludge floc particles is formed on the filtration layer support material. Until the dynamic filtration layer is formed, the filtrate outlet 27 and the filter interior washing water inlet 28 of the filter module are closed and the sludge discharge port 29 is opened, and the sludge entering the filter body is removed. It discharges from the sludge discharge port 29. The sludge discharge port 29 is connected to the sludge discharge line 17 in FIG. 1, and the discharged sludge is returned to the biological treatment tank 2.

  When the dynamic filtration layer is formed on the filtration layer support material, the sludge discharge port 29 is closed, the filtered water outlet 27 is opened, and the filtered water filtered by the dynamic filtration layer is subjected to water head pressure (ΔH in FIG. 1). ) Is discharged from the filtered water outlet 27. The filtered water outlet 27 is connected to the filtered water line 15 in FIG. 1, and the filtered water is introduced into the treated water tank 13. At this time, in the dynamic filter module according to the preferred embodiment of the present invention shown in FIG. 2, the filtered water collecting part is arranged on the upper part of the filtering part via the filtered water rectifying member 31, so that the dynamic filtering layer is provided. The filtered water that has passed flows uniformly into the water collection section over the entire cross section by the rectifying member 31. For this reason, the flow of filtered water inside the filter body is uniform, and the cycle of peeling and reforming of the dynamic filtration layer can be made longer.

  When the filtration operation is continued for a certain time, the infiltration sludge inside the filter body is removed together with the separation and re-formation of the dynamic filtration layer. In the dynamic filter module according to the present invention, the surface of the dynamic filter layer is washed with air and the filter body is washed with air, and then the filter is washed with water and sludge is discharged more efficiently. Intrusion sludge can be washed and removed.

  First, air washing of the dynamic filtration layer surface (filter body external air washing) can be performed by aeration from an air washing air diffuser 5 disposed in the filtration separation tank. Further, with respect to the air washing inside the filter body, the air washing valve 9 is closed, the internal air washing valve 10 is opened and air is supplied from the air washing blower 12, and the filter body is passed through the air supply pipe 34 shown in FIG. By aeration from the internal air diffusion pipe 33, the sludge existing in the sludge accumulation part 30 is stirred and the inside of the filter body is washed with air. The introduced air is discharged from the filtered water outlet and released into the atmosphere by opening the air vent valve 8. Either the washing of the surface of the filtration layer (rinsing outside the filter body) and the washing inside the filter body may be performed first or simultaneously.

  When the external air washing and the internal air washing of the filter body module are finished, aeration from the air diffusion pipe 33 is stopped, the filtrate outlet 27 is closed, the filter interior washing water inlet 28 is opened, and the filter interior washing water is opened. Is introduced into the filter body. It is preferable to perform the water washing inside the filter body immediately after the above washing or 0.5 to 5 minutes after the washing. By this water washing inside the filter body, a part of the infiltrated sludge inside the filter body is discharged to the outside of the filter body through the filter layer, and the remaining sludge is discharged from the sludge discharge port 29. The sludge discharged from the sludge discharge port 29 is returned to the biological reaction tank 2 from the sludge discharge line 17 through the sludge discharge valve 11 shown in FIG. It is preferable to discharge the sludge at the same time as cleaning the filter internal water, since the internal infiltrated sludge can be discharged together with the filter internal cleaning water, and the accumulation of the infiltrated sludge is reduced. You can also. The timing of sludge discharge can be determined by opening the sludge discharge port 29. The sludge discharge is preferably continued for about several minutes even after the filter body water cleaning is stopped. That is, even after the above washing operation is finished and the filtration operation is started, it is preferable that the filtered water is not collected for about several minutes and discharged as a sludge mixed liquid from the sludge discharge port. In the dynamic filter module of the form shown in FIG. 2, the filter body internal cleaning water inlet is connected to the outside of the filtered water rectifying member in the same manner as the filtrate water outlet, and the filter body internal cleaning water is filtered. It is introduced into the filter body through the water rectifying member. With such a configuration, the inflow amount of the filter body internal cleaning water in the horizontal direction inside the filter body becomes uniform, and the sludge adhering to the inner surface of the filter body can be completely washed away. Further, in the dynamic filter module of the form shown in FIG. 2, the filter body internal washing water inlet 28 is provided separately from the filtrate water outlet 27, but the filtrate water outlet 27 is also used as the filter body internal wash water inlet. You can also. Furthermore, the filter body cleaning water can be supplied into the filter body from the sludge accumulation section below the filter section.

  If SS and clear water with low turbidity are used as cleaning water inside the filter body, sludge inside the filter body is diluted and discharged to the outside easily. The filtered water of the dynamic filter module usually has a turbidity of 10 degrees or less and an SS of 10 mg / liter or less, and can be used as washing water inside the filter body. Therefore, as shown in FIG. 1, filtered water obtained from the filter module is stored in the treated water tank 13, and a part of the filtered water is washed inside the filter body through the filter body washing water line 16 by the filter body washing water pump 14. It is preferable to supply the water inlet (28 in FIG. 2). Further, treated water obtained by further filtering the filtered water of the dynamic filter module by sand filtration or MF membrane filtration is more preferable as washing water inside the filter module because there is almost no SS. Furthermore, an aqueous solution of an oxidizing agent such as sodium hypochlorite is preferable because it can remove biological slime, and can be expected to be more effective as washing water inside the filter module. When an aqueous solution of an oxidizing agent such as sodium hypochlorite is used as the washing water inside the filter body, the filter body is subjected to a series of processes of the above-described air washing, water washing inside the filter body, and waste mud. It is preferable to clean the inside of the filter body by introducing an oxidizing agent aqueous solution inside.

  When these series of cleaning / drainage processes are completed, the formation of the dynamic filtration layer and the filtration operation described above are performed again. The frequency of performing these series of cleaning operations varies greatly depending on the properties of the sludge mixed liquid to be treated, but it is generally preferable to perform the cleaning operations at a frequency of about once every 2 to 4 hours.

  In addition, in FIG. 2, although the form which has arrange | positioned the filtered water outlet 27 above the filtration part was shown, filtered water can also be taken out from the bottom part of a filter body module. In this case, by providing the piping and the switching valve, the sludge discharge port 29 can be used also as the filtrate water outlet, and the filtrate water can be taken out from this during the filtration operation. In addition to the sludge discharge port 29, a filtrate water outlet can be disposed below the filtration unit.

  As the sludge mixed liquid that can be filtered and separated by the dynamic filter module according to the present invention, any of an activated sludge mixed liquid, an agglomerated sludge mixed liquid, an initial sedimentation sludge mixed liquid, and the like can be used. In addition, the dynamic filter module of the present invention can be used as a solid-liquid separator for drainage with high SS, river water, and the like.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited only to the following examples.
Example 1
Using the dynamic filter module shown in FIG. 2, the solid-liquid separation treatment of the activated sludge mixed liquid obtained from the activated sludge treatment system for the aggregate groundwater shown in FIG. 1 was performed.

As a support material for forming the dynamic filtration layer, a material in which a polyester woven fabric having a thickness of about 0.1 mm and a pore diameter of 114 μm was sandwiched between two polyethylene nets having an opening of 10 mm and a thickness of 2.0 mm was used. Five flat filter modules having an effective area of 1 m ² / sheet were immersed in the filtration separation tank. The water head pressure at the time of filtration was about 10 cm, and the cross flow velocity of the sludge mixed liquid on the surface of the filter body was 0.025 m / s on average.

  Every 2 hours of filtration operation, the filter body was subjected to air washing, the inside of the filter body, the inside of the filter body, and the waste water. Table 1 shows conditions for the washing operation.

FIG. 3 shows the course of the filtration flux in this example.
In operation for about 3 months from the start of the treatment, the filtration flux was almost 4 m / d or more, and a stable treatment was obtained.

Industrial applicability

  According to the present invention, by providing the sludge accumulation part below the filtration part of the dynamic filter module, the sludge that has entered the filter body until the dynamic filtration layer is formed is caused by gravity settling. And discharged outside from the sludge outlet of the sludge accumulation section. For this reason, sludge that has entered the filter body can be prevented from adhering to or accumulating inside the filter body, and sludge that has entered the filter body can be accumulated, concentrated, and solidified in the filtration unit. Accordingly, the problem that the effective filtration area accompanying the reduction and the filtration flux decreases is solved, and a stable amount of filtered water can be obtained.

  Further, in a more preferred aspect of the present invention, by providing the sludge agitation means in the sludge accumulation part, the sludge is periodically agitated and dispersed in the sludge accumulation part and the filter body by this sludge agitation means. The sludge in the accumulating section and the filter body can be discharged at a stable flow rate without resistance from the sludge outlet without condensing, solidifying, adhering or accumulating. Furthermore, when using aeration with an air diffuser as the sludge agitation means, bubbles are raised from the sludge accumulation part to the inside of the filter body during aeration, and the internal agitation with the gas-liquid mixture is performed inside the filter body. Adhering sludge inside the body can be more efficiently removed.

As a result, a decrease in filtration flux due to sludge accumulation inside the filter body can be suppressed, and stable treated water can be obtained.
Furthermore, in another aspect of the present invention, by providing a filtrate collection part above and / or below the filtration part, and arranging a filtrate rectification member between the filtration water collection part and the filtration part, The flow of filtered water inside the filter body becomes uniform, and it becomes possible to perform filtration evenly over the entire filtration area. In addition, when washing the filter body with water, if the filter body wash water is supplied to the inside of the filter body through the rectifying member, the inflow amount of the filter body washing water in the horizontal direction inside the filter body becomes uniform, and the filter body It becomes possible to completely wash off the sludge adhering to the inner surface.

It is a flow sheet of one specific example of the system which performs biological treatment of sewage using the dynamic filter module of the present invention. It is a figure which shows the structure of one specific example of the dynamic filter body module which concerns on this invention, (a) is a front view, (b) is a sectional side view. It is a graph which shows the relationship between the filtration operation progress days and the average filtration Flux in the Example of this invention.

Explanation of symbols

1 Inflow raw water;
2 biological treatment tanks;
3 Sludge mixture supply pump;
4 filtration separation tank;
5 Air diffuser for washing the outer surface of the filter body;
6 Dynamic filter module;
7 Filtration water valve;
8 Air vent valve;
9 Air washing valve;
10 Filter body internal flush valve;
11 Sludge discharge valve;
12 Air-washing blower;
13 treated water tank;
14 Filter body internal wash water pump;
15 filtered water line;
16 Filter body internal washing water line;
17 sludge discharge line;
18 Circulating sludge mixed liquid;
19 treated water;
21 filter body support part;
22 holding plate;
23 Woven fabric;
24 internal support pillars;
25 support spacers;
26 support net;
27 filtered water outlet;
28 Filter body internal wash water inlet;
29 Sludge outlet;
30 Sludge accumulation part;
31 Straightening member for filtered water;
33 Filter body internal diffuser;
34 air supply pipe;
35 filtered water collection section;

Claims (15)

A dynamic filter body module for separating activated sludge in which a water-permeable filter layer support for forming a dynamic filter layer is disposed as at least a part of a peripheral wall of a hollow support body. A filtration section in which a water-permeable filtration layer support material is disposed; a filtered water outlet disposed above and / or below the filtration section; and a sludge outlet disposed below the filtration section. A dynamic filter body module, wherein a sludge accumulation part is provided. A filtered water collection unit is disposed above and / or below the filtration unit, and a filtered water outlet is connected to the filtered water collection unit. Further, filtration is performed between the filtered water collection unit and the filtration unit. The dynamic filter module according to claim 1, wherein a water rectifying member is arranged. A dynamic filter body module for separating activated sludge in which a water-permeable filter layer support for forming a dynamic filter layer is disposed as at least a part of a peripheral wall of a hollow support body. It has a filtration part in which a water-permeable filtration layer support material is disposed, and a filtrate collection part disposed above and / or below the filtration part, and a filtrate outlet is provided in the filtration water collection part. Is connected, and a filtered water rectifying member is further disposed between the filtered water collecting part and the filtering part. The dynamic filter module according to any one of claims 1 to 3, wherein the filtered water outlet is disposed above the filtration unit. The dynamic filter body module according to any one of claims 1 to 4, wherein sludge agitation means is disposed in the sludge accumulation section. 6. The dynamic filter module according to claim 5, wherein the sludge stirring means is an air diffuser. The dynamic filter body module according to any one of claims 1 to 6, wherein a filter body internal cleaning water inlet is further disposed above and / or below the filter section. The dynamic filter body module according to claim 7, wherein the filter body internal cleaning water inlet is connected to the filtrate water collecting section. The dynamic filter module according to claim 7, wherein the filter inner cleaning water inlet is connected to the sludge accumulation part. The dynamic filter module according to any one of claims 1 to 9, wherein the filter layer support material is a woven fabric, a nonwoven fabric, or a metal net material. The dynamic filter module according to claim 10, wherein the filter layer support material is a woven fabric, a nonwoven fabric, or a metal net material reinforced by a reinforcing material. A method for cleaning / removing sludge that has entered the inside of the module of the dynamic filter body module according to any one of claims 1 to 11, wherein the sludge is aerated by aeration of the outer surface of the filter body and aeration inside the filter body. A method characterized by carrying out air washing, and then introducing the filter body internal cleaning water into the filter body from the filtered water outlet or the filter body internal cleaning water inlet and discharging the sludge from the sludge outlet. The method according to claim 12, wherein the filter body washing water is filtered water obtained by a dynamic filter module. The method according to claim 12, wherein the filter body internal cleaning water is an aqueous oxidizer solution. The method according to claim 12 or 13, further comprising a step of cleaning the inside of the filter body by introducing a cleaning solution of an aqueous oxidant solution into the inside of the filter body after completion of water cleaning and sludge discharge inside the filter body.

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