JPH10263324A - Solid-liquid separation in sewerage disposal system, filter cloth rotation type solid-liquid separator and sewerage disposal system using the separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid-liquid separation method for a sewerage disposal system by which solid/liquid separation of sewerage can be effectively performed without needing large site area and to provide a filter cloth rotation type solid-liquid separator and a sewerage disposal system using the solid-liquid separator. SOLUTION: An inner vessel 102 is installed within an outer vessel 101, a sewerage inflow pipe 103 and a sludge discharge pipe 104 are connected to the outer vessel 101, and a belt-shaped filter cloth 111 subjected to rotary driving by a motor 119 is installed on the inner vessel 102 in that it travels round. In the wall surface of the inner vessel 102 in contact with the filter cloth 111, a filtering window part 108 for introducing water filtrate into the vessel is provided. A water filtrate discharge pipe 107 for discharging the water filtrate to the outside is connected to the inner vessel 102, and on the upstream side of the filter cloth 111, a filter cloth washer 120 for washing off sludge or stains stuck on the surface of the filter cloth is installed. Instead of a gravity sedimentation type initial sedimentation basin and a sludge concentration tank in a conventional sewerage treating system, a filter cloth rotation type solid-liquid separator is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-liquid separation method using a filter cloth for separating sewage into treated water and sludge, a filter cloth rotary solid-liquid separation apparatus used in the solid-liquid separation method, and this solid-liquid separation apparatus. The present invention relates to a sewage treatment system configured using a separation device.

[0002]

2. Description of the Related Art The configuration of a conventional sewage treatment system is shown in FIG. In the figure, 1 is a sewage pump, 2 is the first sedimentation tank, 3 is the aeration tank, 4 is the final sedimentation tank, 5 is the disinfection device, 6 is the sludge thickening tank, 7 is the dehydrator, and 8 is the incinerator.
The first sediment 2, the aeration tank 3, the final sediment 4, and the disinfection device 5 constitute a so-called water treatment system, and the sludge concentration tank 6, the dehydrator 7, and the incinerator 8 constitute a so-called sludge treatment system. . In addition, a large-scale sewage treatment plant is provided with both the water treatment system and the sludge treatment system, but a small-scale sewage treatment plant includes only a water treatment system. In the treatment plant, the generated sludge is pumped by a pump or the like to a sewage treatment plant equipped with a sludge treatment system, and is subjected to centralized treatment.

In FIG. 8, sewage sent from a sand basin or the like is firstly pumped to a sedimentation place 2 by a pump 1, and after solid matter contained in the sewage is removed by gravity sedimentation in the sedimentation place 2, It is sent to the aeration tank 3. In the aeration tank 3, the sewage containing the sent sludge is stirred while blowing air (oxygen) into the activated sewage to oxidize organic pollutants. The oxidized sewage and sludge are sent to the final sedimentation site 4, where they are separated into solids and liquids by gravity sedimentation, and then the supernatant is chlorinated by the disinfection device 5 and discharged as treated water. Also, a part of the activated sludge accumulated at the bottom of the pond in the final sedimentation area 4 is returned sludge (seed sludge) to the aeration tank 3.
And the remaining excess sludge is first returned to the sedimentation basin 1 and the filtration process is repeated.

On the other hand, the sludge initially collected at the bottom of the sedimentation basin 1 is drawn out by a pump or the like and sent to a sludge concentration tank 6.
The supernatant and the concentrated sludge are separated by gravity sedimentation in the sludge concentration tank 6, and the concentrated sludge is sent to a dehydrator 7 and dewatered, then incinerated in an incinerator and discharged as ash. The filtered water discharged from the sludge thickening tank 6 and the dehydrator 7
The separated water dehydrated in the step is returned to the upstream side of the pump 1 to repeat the filtration process.

[0005]

As described above, in the conventional sewage treatment system, sludge and water contained in sewage are separated by using a gravity sedimentation type initial sedimentation place or a sludge concentration tank. For this reason, a large site area was required according to the amount of sewage flowing in.

[0006] However, recently, in urban areas, houses and factories are becoming overcrowded, and it is becoming difficult to secure a large site for sewage treatment. On the other hand, the amount of sewage from households and factories is increasing due to the overcrowding, and some urgent solution is needed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and purifies sewage without requiring a large site area as in a conventional gravity sedimentation type sedimentation or sludge thickening tank. A solid-liquid separation method in a sewage treatment system capable of performing treatment efficiently, a filter cloth rotating solid-liquid separation device used for the solid-liquid separation method, and a sewage treatment system configured using the solid-liquid separation device The purpose is to provide.

[0008]

According to a first aspect of the present invention, there is provided a solid-liquid separation method according to the first aspect, wherein the sewage flowing into the sewage treatment system is filtered by using a filter cloth. It is characterized in that it is separated into

A second aspect of the present invention is a filter cloth rotating type solid-liquid separation device having an outer container and an inner container, and a space for inflow of sewage having a desired volume is formed between the outer container and the inner container. The inner container is disposed in the outer container so that the outer container is connected to a sewage inflow pipe and a sludge discharge pipe, and the inner container is provided with a belt-shaped filter cloth that is rotationally driven by driving means. Provided so as to be in contact with the outer peripheral surface of the container so as to extend around the outer periphery of the container, and guide the filtered water filtered by the filter cloth into the inner container at an appropriate position on the outer wall surface of the inner container in contact with the belt-shaped filter cloth. A filtration window for discharging filtered water collected inside is connected to the inner container, and the upper part of the belt-shaped filter cloth driven by rotation is connected to the inner container. Wash sludge and dirt adhering to the filter cloth surface In which it is disposed a filter cloth cleaning device for dropping.

In a third aspect of the present invention, there is provided a solid-liquid separation device for rotating a filter cloth, wherein the plurality of the inner containers are disposed at predetermined intervals in the outer container. The belt-shaped filter cloths are provided so as to be in contact with the outer peripheral surfaces of the plurality of inner containers so as to be wound in a zigzag manner.

In the sewage treatment system according to the present invention, the incoming sewage is separated by gravity sedimentation in the sediment first, and the sludge and the sewage separated in the first sediment are aerated in an aeration tank. Thereafter, in a sewage treatment system in which solid-liquid separation is performed at the final sediment, the separated treated water is disinfected and discharged, and the sludge separated at the final sediment is returned to the first sediment and the aeration tank. A rotary cloth solid-liquid separation device according to claim 2 or 3 is used in place of the first sedimentation place.

In the sewage separation system according to a fifth aspect of the present invention, the incoming sewage is first separated by gravity settling in the sediment, and the sludge and the sewage separated in the first sediment are aerated in an aeration tank. Thereafter, solid-liquid separation is performed at the final sedimentation site, the separated treated water is disinfected and discharged, and the sludge separated at the final sedimentation site is returned to the first sedimentation site and the aeration tank, and is obtained at the first sedimentation basin. The sludge is sent to a sludge thickening tank and concentrated by gravity sedimentation, then dewatered by a dehydrator, and incinerated in a sewage treatment system in an incinerator. 4. A filter cloth rotary solid-liquid separation device according to claim 2 or 3, wherein the gravity sedimentation type sludge thickening tank is replaced with the filter cloth rotary solid-liquid separation device according to claim 2 or 3. It is assumed that.

[0013]

In the solid-liquid separation method according to the first aspect, since the sewage flowing in is filtered using a filter cloth and separated into treated water and sludge, the sewage is large as in a gravity sedimentation type sewage treatment system. The site area is not required.

According to a second aspect of the present invention, in the filter cloth rotating type solid-liquid separation device, the sewage flowing into the outer container through the sewage inflow pipe is driven by a belt-shaped filter that is rotationally driven along the outer periphery of the inner container. It is strained off with a cloth, flows into the inside of the inner container through the filtering window of the inner container, and is discharged outside through the filtered water discharge pipe. On the other hand, the concentrated sludge after filtration collected in the lower bottom of the outer container is pulled out through the sludge discharge pipe and discharged to the outside. Each time the belt-shaped filter cloth that is driven to rotate is rotated once, it is washed by a filter cloth cleaning device provided on an upper side, and sludge and dirt adhering to the surface thereof are washed away and purified. Accordingly, the filtration efficiency is extremely high, and a filtration process that is as small as a conventional gravity sedimentation type sedimentation site or a sludge thickening tank can be realized even though the device has a small volume.

According to a third aspect of the present invention, there is provided a filter cloth rotating type solid-liquid separation apparatus, wherein a plurality of the inner containers are arranged at predetermined intervals in the outer container, and the belt-shaped filter is provided. Since the cloth is provided so as to be wound around the outer peripheral surfaces of the plurality of inner containers so as to make a round circuit, the area of the filter cloth becomes extremely large, and the throughput of sewage can be further increased.

Further, in the sewage treatment system according to the fourth aspect, since the filter cloth rotating type solid-liquid separation device is used instead of the gravity sedimentation type first sedimentation site, the water treatment system can be installed in a small site area. Can be realized.

Further, in the sewage treatment system according to claim 5, the filter cloth rotating type solid-liquid separation device is used in place of the gravity sedimentation type initial sediment and the sludge thickening tank. A sewage treatment plant equipped with both facilities of a sludge treatment system can be realized with a smaller site area.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 5 shows an embodiment of a sewage treatment system according to the present invention. The sewage treatment system according to this embodiment has basically the same block configuration as the above-described conventional sewage treatment system (FIG. 8), but differs in that the conventional gravity sedimentation type first sedimentation area 2 and The point is that instead of the sludge thickening tank 6, a filter cloth rotating type solid-liquid separator 10A, 10B of the present invention having a structure described later is used. In FIG. 5, the same parts as those of the conventional sewage treatment system are denoted by the same reference numerals. In addition, since both of the filter cloth rotary solid-liquid separation devices 10A and 10B are structurally identical, in the following description, the suffixes A and B will be used only when it is necessary to distinguish them. The suffixes A and B are omitted for the description part common to both.

The filter cloth rotary solid-liquid separator 10 of the present invention, which is used in place of the conventional first settling tank 2 and sludge thickening tank 6, comprises:
The structure is as shown in FIGS. FIG. 1 is a perspective view in which a part of a filter cloth rotating solid-liquid separator is shown by a virtual line.
FIG. 2 is a longitudinal sectional view of the filter cloth rotating solid-liquid separator of FIG. 1, and FIG.
FIG. 4 is a cross-sectional plan view of the filter cloth rotating solid-liquid separator of FIG. 1, and FIG. 4 is a schematic cross-sectional view taken along the line IV-IV in FIG.

The filter cloth rotating solid-liquid separator 10 is shown in FIG.
As shown in FIG. 4, the outer container 101 and the inner container 102 each having a volume corresponding to the sewage treatment amount are provided.
An inner container 102 is fixedly located inside the outer container 101. The outer container 101 forms a storage tank for sewage, and the inner container 102 forms a storage tank for filtered water. A sewage inflow pipe 103 for introducing sewage to be filtered into the outer container 101 is provided on one side wall of the outer container 101, and the concentrated sludge separated by the filtering process is externally provided at a lower bottom thereof. A sludge discharge pipe 104 for discharging the sludge is provided.

On the outer wall surface of the inner container 102, a strained plate portion 105 cut into a concave shape is formed, and the strained plate portion 105 is located outside the strained plate portion 105.
A water collecting tank 106 is provided for temporarily storing filtered water flowing to the outside beyond the area 05.
, A filtered water discharge pipe 107 is provided. The water collecting tank 106 is not always necessary, and the filtered water discharge pipe 107 may be directly connected to the upper side of the inner container 102.

On the other hand, filtering windows 108 having a desired size are formed on both outer peripheral surfaces of the inner container 102. A belt-type filter cloth 111 is provided so as to cover the filtering windows 108. It is wrapped around the outer peripheral surface of the inner container 102. This belt type filter cloth 111 is
As shown in FIG. 4, the driving roller 112, the filter cloth meandering correction roller 113, the upper driven roller 114, the lower driven rollers 115 and 116, the auxiliary roller 117, and the filter cloth tensioning roller 118 are rotatably rotated. And motor 11
The driving roller 112 is driven to rotate by a driving means such as 9 so as to always rotate in a constant direction at a constant speed. The filtering windows 108, 1
In 08, a rough wire mesh 109 or the like is provided in order to prevent the rotating filter cloth 111 from being pushed by water pressure and pushed into the inner container 102.

The belt-type filter cloth 111 is pressed inward by a filter cloth tensioning roller 118 to be tensioned, and the filtration windows 108 and 10 of the inner container 102 are filtered.
8 as close as possible. Thereby, when the filter cloth 111 is pressed against the filtering windows 108, 108 due to the difference in water pressure between the inside and the outside during the filtration, the filter cloth 111 is made as close as possible to the watertight, and is filtered through the upper, lower, left and right gaps of the filtering windows 108, 108. It is designed so that untreated sewage does not flow into the inner container 102.

Further, at an appropriate position on the upper side of the belt-type filter cloth 111, a filter cloth cleaning device 120 for cleaning the surface of the filter cloth is provided. As the filter cloth cleaning device 120, for example, a high-pressure water sprinkler or the like is used.
The washing water is constantly or intermittently sprayed toward the surface of the filter to wash off the attached solid substances and dust, and keep the filter cloth 111 clean at all times. In addition, as a material of the filter cloth 111, a filter cloth made of felt or a woven cloth used as a filter cloth for dehydration such as a belt press dehydrator can be used.

The sewage treatment system shown in FIG. 5 employs a filter cloth rotary solid-liquid separator 10 having the above-mentioned structure in place of the conventional first settling tank 2 and sludge settling tank 6 (see FIG. 8). By using the solid-liquid separation device 10, water treatment and sludge treatment can be performed efficiently while eliminating the need for a large site area such as the conventional first sedimentation site 2 and the sludge concentration tank 6. It was made.

Next, the filtration principle of the filter cloth rotating solid-liquid separator 10 will be described with reference to FIG. As described above, the belt-type filter cloth 111 is rotationally driven by a motor or the like, and is rotated at a constant speed in a constant direction. In addition, the washing water is constantly or intermittently sprayed from the filter cloth cleaning device 120 toward the filter cloth surface, so that solid matter and dirt attached to the filter cloth surface by the filtration treatment are washed off, and clogging does not occur. Has been washed.

In such a state, the sewage inflow pipe 10
When sewage containing sludge flows in from 3, the sewage accumulates in the outer container 101. And this outer container 10
The sewage accumulated in 1 flows into the inner container 102 through the filter cloth 111 due to the pressure difference between the inside of the inner container 102 and the solid matter contained in the sewage is filtered out when passing through the filter cloth. Only the filtered water flows into the inner container 102.

The filtered water that has flowed into the inner container 102 passes through the strainer 105 (see FIGS. 1 and 2), and is collected in a water collecting tank 106.
It is sent to the outside through. On the other hand, the concentrated sludge accumulated at the lower bottom of the outer container 101 is drawn by a pump or the like through a sludge discharge pipe 104 and discharged to the outside.

Generally, the average particle size of the solid matter contained in the sewage or sludge is about 20 to 30 μm, but the fibrous coarse suspended matter contained in the sewage or sludge adheres to the filter cloth 111 during filtration. Since the surface is covered, for example, even when using a filter cloth 111 having a mesh diameter of about 20 to 30 μm, which is approximately the same as the average particle diameter of the solid matter, the solid matter having a small particle diameter of about ten and several μm is surely captured. Can be filtered. By the way, when using the filter cloth rotating solid-liquid separator 10 of the present invention, the filter cloth width is about 3 m, the filter cloth belt height is about 2 m, and the inner container thickness is about 1 m.
With such a device, a sewage treatment capacity of about 200 m ³ / hour can be realized.

For reference, Table 1 shows the experimental results of the filtration treatment using the filter cloth rotating solid-liquid separator having the above structure.

[0031]

[Table 1]

Comparing the properties of the raw water and raw mud No. 0 in Table 1 with the treatment results of the filter cloths Nos. 1 to 5, especially the filter cloths Nos. 2 to 5, a sufficient filtration effect can be obtained. You can see that it is done.

Next, the processing operation of the sewage treatment system of FIG. 5 constituted by using the filter cloth rotating solid-liquid separator 10 having the above structure will be described. The sewage sent from a sand basin or the like is pumped by a pump 1 and sent to a sewage inflow pipe 103 of a first filter cloth rotary solid-liquid separator 10A arranged in place of a conventional first settling place. The sewage flowing into the sewage inflow pipe 103 accumulates in the outer container 101 and is filtered by the belt-type filter cloth 111 rotating at a constant speed, while being filtered through the filter windows 108 and 10 of the inner container 102.
8 into the inner container 102. At this time, as described above, the fibrous coarse suspended matter contained in the sewage or sludge adheres to the cloth of the filter cloth 111 and becomes entangled with the cloth, so that solid matter having a particle size smaller than the actual cloth is surely obtained. Can be captured and filtered.

In the filtered water collected in the inner container 102, only the supernatant liquid overflows from the strainer 105, and the collected water 106
The water is collected. This collected filtered water is filtered water drain pipe 1
07 and sent to the aeration tank 3, and thereafter, as in the conventional sewage treatment system, oxidize organic pollutants in water by mixing with activated sludge while supplying air in the aeration tank 3, After the oxidized sewage and activated sludge are separated into solid and liquid by gravity sedimentation in the final sedimentation site 4, they are disinfected with chlorine in a disinfecting apparatus 5 and discharged as treated water.

On the other hand, the concentrated sludge that has been filtered by the filter cloth 111 and accumulated at the lower bottom of the outer container 101 is supplied to the sludge discharge pipe 10.
4, a second filter cloth rotary solid-liquid separation device 10B which is pulled out by a pump or the like and is arranged in place of a conventional sludge concentration tank
Into the sewage inflow pipe 103. The sludge sent to the second filter cloth rotary solid-liquid separator 10B is filtered in the same manner as the first filter cloth rotary solid-liquid separator 10A, and the sludge contained in the sewage is further reduced. It is concentrated.

The concentrated sludge collected at the lower bottom of the outer container 102 is drawn out by a pump or the like through a sludge drain pipe 104, sent to the dehydrator 7, dehydrated to a predetermined moisture content, and then incinerated in an incinerator. Processed and discharged as ash as before. In addition, the second filter cloth rotary solid-liquid separation device 1
The filtered water accumulated in the inner container 102 in OB is returned to the front side of the pump 1 and the filtration process is repeated.

The second filter cloth rotating type solid-liquid separation device 10
The solid matter concentration of the concentrated sludge sent from B to the dehydrator 7 is generally concentrated to about 3 to 4% TS, which is easy to handle such as sludge feeding. Therefore, if only one of the second filter cloth rotating solid-liquid separators 10B is used, sludge can be reduced to T
If the concentration cannot be increased to S3 to 4%, a plurality of filter cloth rotating solid-liquid separators 10B may be installed in tandem.

The amount of sewage pumped by the pump 1 is large, and one filter cloth rotating solid-liquid separator 1 is used.
If the processing capacity is insufficient at 0A and 10B,
A plurality of devices may be arranged in parallel and operated in parallel.

FIG. 7 shows a second embodiment of a filter cloth rotating solid-liquid separator according to the present invention. FIG. 7 schematically shows the second embodiment by a schematic vertical sectional view. Four inner containers 102 _{1 to} 102 ₄ are arranged in an outer container 101 at a predetermined interval, and Inner containers 102 _1-
102 is ₄ which belt-like filter cloth 111 looped over and round the zigzag shape. Thus, the inner container is 4
If it is configured as a continuous system, the filtration capacity can be dramatically increased. In addition, since the filtration principle itself as the device is exactly the same as that of the first embodiment, the same or corresponding parts are denoted by the same reference characters, and detailed description thereof will be omitted. In addition, in the case of the example of FIG. 7, the case where the inner container is formed in a quadruple type is shown, but it is needless to say that any number of inner containers of two or more can be used.

[0040]

As described above, according to the solid-liquid separation method of the first aspect, the flowing sewage is separated into treated water and sludge by filtering using a filter cloth. A large site area such as a gravity sedimentation type sewage treatment system is not required. For this reason, the installation area for sewage treatment can be reduced.

According to the second aspect of the present invention, there is provided a filter cloth rotating type solid-liquid separator, comprising an outer container and an inner container, wherein a space for inflow of sewage having a desired volume is formed between the outer container and the inner container. Position the inner container inside the outer container so that
A sewage inflow pipe and a sludge discharge pipe are connected to the outer container, and a belt-shaped filter cloth that is rotationally driven by a driving unit is wound around the inner periphery of the container so as to make a round around the outer periphery of the container. A filter window for guiding filtered water filtered by the filter cloth into the inner container at an appropriate position on the outer wall surface of the inner container in contact with the belt-shaped filter cloth. Is connected to a filtered water discharge pipe for discharging the collected filtered water to the outside, and at an appropriate position on the upper side of the rotatably driven belt-shaped filter cloth, the sludge and dirt attached to the filter cloth surface are washed off. Is provided with a filter cloth cleaning device for the purpose, it is possible to provide a device having a very small filtration capacity and an extremely high filtration capacity. For this reason, it is possible to realize a filtering treatment equivalent to that of a conventional gravity sedimentation type primary sedimentation site or sludge thickening tank using a separation device having a small volume.

In the solid-liquid separation device according to the second aspect of the present invention, the filter cloth rotating type solid-liquid separation device according to the third aspect is arranged such that the inner container is positioned inside the outer container at a predetermined interval. The belt-shaped filter cloth is provided in such a manner that the belt-shaped filter cloth is in contact with the outer peripheral surfaces of the plurality of inner containers so as to wrap around in a zigzag manner. Can be increased. For this reason, the processing capacity can be further increased with a device having a small volume.

In the case of the sewage treatment system according to the fourth aspect, since the solid-liquid separation apparatus of the second or third aspect of the present invention is used instead of the gravity sedimentation type first sedimentation ground, The processing system can be realized with a small site area. For this reason, it is possible to construct a sewage treatment plant with a small site area and excellent treatment capacity even in an urban area where there is no room for the site.

Further, in the case of the sewage treatment system according to the fifth aspect, instead of the gravity sedimentation type initial sediment and the sludge thickening tank, the filter cloth rotary solid-liquid separation device according to the second or third aspect is used, respectively. Since it was used, both a water treatment system and a sludge treatment system can be realized with a small site area. For this reason, it is possible to construct a sewage treatment plant having an excellent treatment capacity with a small treatment area even in an urban area where there is not enough room on the site.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of a filter cloth rotating type solid-liquid separation device of the present invention, a part of which is shown by phantom lines in order to make the structure easily understandable.

FIG. 2 is a longitudinal sectional view of the filter cloth rotating type solid-liquid separator of FIG. 1;

FIG. 3 is a cross-sectional plan view of the filter cloth rotating solid-liquid separator of FIG. 1;

FIG. 4 is a schematic sectional view taken along line IV-IV in FIG. 3;

FIG. 5 is a system block diagram showing a configuration of a sewage treatment system of the present invention.

FIG. 6 is an explanatory view of a filtration principle of a filter cloth rotating solid-liquid separator of the present invention.

FIG. 7 is a schematic vertical sectional view showing a second embodiment of the filter cloth rotating type solid-liquid separation device of the present invention.

FIG. 8 is a system block diagram showing a configuration of a conventional sewage treatment system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Pump-up pump 2 Initial sedimentation site 3 Aeration tank 4 Final sedimentation site 5 Disinfection device 6 Sludge concentration tank 7 Dehydrator 8 Incinerator 10A Filter cloth rotary solid-liquid separator 10B Filter cloth rotary solid-liquid separator 101 Outer container 102 Inside Vessel 103 Sewage inflow pipe 104 Sludge discharge pipe 105 Strain plate 106 Water collecting tank 107 Filtration water discharge pipe 108 Filtration window 109 Wire mesh 111 Filter cloth 112 Drive roller 119 Motor 120 Filter cloth cleaning device 102 _{1 to} 102 ₄ 4-type Inside container

Claims (5)

[Claims] 1. A solid-liquid separation method in a sewage treatment system, comprising separating treated water and sludge by filtering incoming sewage using a filter cloth. 2. An outer container and an inner container, wherein the inner container is located in the outer container such that a space for sewage inflow of a desired volume is formed between the outer container and the inner container. A sewage inflow pipe and a sludge discharge pipe are connected to the outer container, and a belt-shaped filter cloth that is rotationally driven by a driving unit is wound around the inner periphery of the container so as to make a round around the outer periphery of the container. At an appropriate position on the outer wall surface of the inner container in contact with the belt-shaped filter cloth, a filtration window portion for guiding filtered water filtered by the filter cloth into the inner container is perforated. Is connected to a filtered water discharge pipe for discharging the collected filtered water to the outside, and at an appropriate position on the upper side of the rotatably driven belt-shaped filter cloth, the sludge and dirt attached to the filter cloth surface are washed off. That a filter cloth cleaning device for Filter cloth rotating solid-liquid separation device according to symptoms. 3. A plurality of said inner containers are arranged in said outer container at predetermined intervals, and said belt-shaped filter cloth is wound around said inner container in a zigzag manner in contact with outer peripheral surfaces of said plurality of inner containers. 3. The solid-liquid separation device for rotating a filter cloth according to claim 2, wherein the separation device is provided so as to extend over the filter cloth. 4. The inflowing sewage is first separated by gravity sedimentation in a sedimentation place, and the sludge and sewage separated in the first sedimentation place are aerated in an aeration tank, and then solid-liquid separated in a final sedimentation place. ,
In a sewage treatment system wherein the separated treated water is disinfected and discharged, and the sludge separated in the final sediment is returned to the first sediment and the aeration tank. A sewage treatment system using the filter cloth rotating solid-liquid separator according to 2 or 3. 5. The inflowing sewage is first separated by gravity settling in a sedimentation place, and the sludge and sewage separated in the first sedimentation place are aerated in an aeration tank, and then solid-liquid separated in a final sedimentation place. ,
The separated treated water is disinfected and discharged, and the sludge separated in the final sedimentation place is returned to the first sedimentation place and the aeration tank, and the sludge obtained in the first sedimentation tank is sent to a sludge concentration tank to be gravity sedimented. The sewage treatment system according to claim 2 or 3, wherein the gravitational sedimentation first sedimentation site is used instead of the gravity sedimentation first sedimentation site. Using a separation device,
A sewage treatment system using the filter cloth rotating type solid-liquid separation device according to claim 2 or 3 in place of the gravity sedimentation type sludge thickening tank.