JPH0634794U - Solid-liquid separation device in wastewater recycling device using hollow fiber membrane module - Google Patents

Abstract

(57) [Summary] [Purpose] Separation of the solid-phase sludge in a consolidated state that is extruded to the return side pipe of the circulation flow path by switching the direction of the hollow fiber membrane module flowing through the circulation flow path. In order to remove the sludge, a solid-liquid separator installed in the middle of the return side pipe can efficiently separate and remove the solid-phase sludge. [Structure] A circulation flow path for circulating sewage in a module of hollow fiber membranes is configured so that the flow direction of sewage flowing in the module is alternately switched between a forward direction and a reverse direction, and a return side of the circulation flow path. A solid-phase chamber w having a box-shaped solid-liquid separation tank 80 connected in the middle of the pipeline, and a discharge port 81 for discharging solid-phase sludge at the bottom is provided in the solid-liquid separation tank 80; Liquid phase chamber y provided with an outlet 82 at the bottom for discharging sewage to the circulation flow path 5
And a screen inclined downward toward the bottom of the solid phase chamber w at a boundary position between the solid phase chamber w and the liquid phase chamber y at a position below the inflow port 83 of the waste water from the circulation flow path 5, or An inclined filter body 84 made of a mesh is installed so as to cover the upper surface of the liquid phase chamber y.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention performs a membrane permeation treatment of sewage containing organic substances such as building wastewater and domestic wastewater using a cross-flow internal pressure type hollow fiber membrane module consisting of an ultrafiltration membrane, Separation of solid-phase sludge in sewage into a pipe on the return side of a circulation channel that circulates sewage in a sewage tank through a hollow fiber membrane module Regarding the improvement of the solid-liquid separator installed so as to be eliminated.

[0002]

[Prior art]

 As shown in FIG. 1, a wastewater recycling device A that uses a cross-flow internal pressure type hollow fiber membrane module usually has several hundred thin pipe-shaped hollow fiber membranes a ... Wastewater discharged from a building or the like and led to a wastewater tank d by an inflow pipe c is bundled into a module b, and the hollow fiber membrane a is provided with a circulation passage e equipped with a pump device P. ... is passed from one end side of the module b to the other end side and pumped so as to return to the sewage tank d and circulated, and during this circulation, a part of the sewage flowing down in each hollow fiber membrane a ... The permeation through the membrane wall of the hollow fiber membrane a, the permeated filtrate is collected in the outer cylinder f surrounding the module b, taken out through the pipe g, and used for water such as water supply through a disinfection device. Is configured.

[0003]

[Problems to be solved by the device]

 In the wastewater reuse device A using the hollow fiber membrane module configured as described above, the concentration of the wastewater in the wastewater tank permeates through the membrane wall of the hollow fiber membranes a ... The amount of the filtrate taken out in this way is concentrated and the liquid concentration increases. Therefore, when the sewage in the sewage tank is concentrated to a certain liquid concentration, the sludge liquid in the sewage tank is extracted and carried out to the outside of the circulation system, or a separate dehydrator or concentrator is installed. It is necessary to adjust the concentration of wastewater in the wastewater tank by performing dehydration or concentration treatment.

In the case where the liquid concentration is adjusted by extracting the liquid, if the liquid is to be carried out and disposed of by a vacuum vehicle, the liquid content of about MLSS 6000 to 10,000 ppm is discarded, and the water content is 99.4 to 99. However, there is a problem that the cost increases due to the disposal in a state of high water content.

When the wastewater in the wastewater tank is treated by using a dehydrator or a concentrator and sludge in the wastewater is disposed of as having a low water content, the dehydrator / concentrator is naturally used. Machines and facilities such as pipes and pumps for supplying sewage liquid to these and returning the discharged liquid to the sewage tank are required, which causes a problem of increased facility cost.

By the way, the above-mentioned problem is that when circulating the sewage in the module b of the hollow fiber membranes a by the circulation channel e, the direction in which the sewage flows through the hollow fiber membranes a ... When the hollow fiber membranes a ... are alternately switched between the forward direction from one end side to the other end side and the opposite direction from the other end side to the one end side, the operation up to that time is performed when the switching is performed. The solid-phase sludge accumulated in the state of compacted sludge inside each hollow fiber membrane a by the operation is connected to a thin thread or string by the flow of the switched sewage, and returns to the circulation channel e. Therefore, a solid-liquid separator is installed in the middle of the return-side pipeline of the circulation channel e, and the solid-phase separator in the state of the compressed sludge is pushed out. If sludge is collected and removed outside the circulation system, this It has become clear that the concentration of sewage can be reduced and an effective solution to this problem can be achieved.

From this, whether the efficiency of separating and removing solid-phase sludge by the solid-liquid separator provided in the return-side pipe of the circulation channel e is effective in increasing the above-mentioned liquid concentration of wastewater. Whether it can be suppressed or not depends on how to improve the performance of this solid-liquid separator.

Therefore, in the present invention, by separating the hollow fiber membrane module in the circulation flow passage, the solid-phase sludge in a consolidated state that is pushed out to the return-side pipe of the circulation flow passage is separated. -To provide a new means to configure a solid-liquid separator that is installed in the middle of the return side pipeline to remove sludge so that solid-phase sludge can be efficiently separated and eliminated. And

[0009]

[Means for Solving the Problems]

 In the present invention, as a means for achieving this purpose, a module of a cross-flow internal pressure type hollow fiber membrane composed of an ultrafiltration membrane is used to circulate sewage from a sewage tank to return to the sewage tank through the module. In the wastewater reuse device that connects the circulation flow paths, the flow direction of the wastewater flowing through the inside of the hollow fiber membrane of the module is from the one end side to the other end side of the hollow fiber membrane in the circulation flow path. It is configured such that it is alternately switched between the forward direction and the reverse direction from the other end side of the hollow fiber membrane to the one end side, and a box-shaped box is provided in the middle of the return-side pipeline passing through the module of the circulation flow channel. A solid-liquid separation tank is connected to the solid-liquid separation tank, and in the solid-liquid separation tank, there is a solid-phase chamber with a discharge port for discharging solid-phase sludge at the bottom and an outlet for discharging the wastewater into the circulation channel at the bottom. At the boundary position between the solid phase chamber and the liquid phase chamber. A slant filter made of a screen or a net slanting downward toward the bottom of the solid phase chamber is installed below the inlet of the waste water from the circulation channel so as to cover the upper surface of the liquid phase chamber. It proposes a solid-liquid separation device in a wastewater reuse device that uses a module of hollow fiber membranes.

[0010]

【Example】

 Next, embodiments will be described in detail with reference to the drawings. FIG. 2 is a flow sheet of a wastewater reuse device A using a hollow fiber membrane module according to the present invention. In the figure, 1 is an inflow pipe for guiding wastewater from a building or the like, and 2 is this inflow pipe 1. A waste water tank for collecting waste water, 3 is waste water in the waste water tank 1, 4 is a module in which the hollow fiber membranes 40 are bundled, 5 is a circulation channel for circulating the waste water in the waste water tank 2 to the module 4, and 6 is The bypass flow paths V1, V2, V3, V4 provided by connecting to the circulation flow path 5 so that the direction in which the dirty water flows through the hollow fiber membranes 40 of the module 4 is the reverse direction is the circulation flow. The flow of sewage circulating in the path 5 is divided into a positive direction from one end side of the module 4 to the other end side and a reverse direction flow from the other end side of the module 4 to the one end side through the bypass flow path 6. A switching valve provided so as to be connected to the circulation flow path 5 so as to switch to the hollow fiber membrane 40. Pipe deriving the transmitted filtrate membrane wall 8 shows a solid-liquid separator which is provided in the middle of the return side of the pipe 5b in the circulation flow path 5.

The inflow pipe 1 is a normal pipe whose downstream side is connected to a sand settling tank for pretreating wastewater discharged from a building or the like, an adjusting tank and a screen.

The sewage tank 2 for storing sewage guided by the inflow pipe 1 is configured as an aeration tank, and the sewage 3 is stored as activated sludge.

The module 4 is an ordinary one formed by bundling hundreds of hollow fiber membranes 40 ... Formed in a pipe having a diameter of about 2 mm by using an ultrafiltration membrane. , Connection ports 41 and 42 for connecting the hollow fiber membranes 40 ... Further, the outer peripheral side of the bundled hollow fiber membranes 40 is surrounded by an outer cylinder 43 for collecting the filtrate permeated through the membrane wall of each hollow fiber membrane 40, and the outer cylinder 43 is provided with an outlet 44 for taking out the permeated filtrate. A pipe 7 for guiding the filtrate to a desired place is connected to the outlet 44.

The circulation flow path 5 for circulating the sewage in the module 4 of the hollow fiber membranes 40 ... Supplies the sewage in the sewage tank 2 by pumping it to the connection port 41 on one end side of the module 4 by the pump device P. Side pipe line 5a and return line pipe line 5b for returning sewage flowing through the hollow fiber membrane 40 of the module 4 to the connection port 42 on the other end side to the sewage tank 2. The pipes 5a and 5b are respectively provided with connecting pipes 50 and 51 for connecting the pipes of the bypass flow path 6.

The bypass passage 6 has one end connected to the middle of the supply-side pipe 5 a of the circulation passage 5 and the other end connected to the connection pipe 51 provided in the return-side pipe 5 b of the circulation passage 5. One end is connected to the supply-side pipeline 6a to be connected and the return-side pipeline 5b of the circulation channel 5, and the other end is connected to the supply-side pipeline 5a of the circulation channel 5. It is composed of a pipe line 6b connected to.

The switching valves V1, V2, V3, and V4 are located upstream of the connection position of the bypass passage 6 with the supply-side pipeline 6a in the supply-side pipeline 5a of the circulation flow passage 5. The first switching valve V1 is provided at the portion where the second switching valve V1 is provided, and the second switching valve V1 is provided at the portion downstream of the connection position of the return passage 6b of the bypass passage 6 with the return passage 6b of the circulation passage 5. The connection pipes 50 and 51 provided on the supply-side and return-side pipes 5a and 5b of the circulation passage 5 and the supply-side and return-side pipes 6a of the bypass passage 6 are provided with the switching valve V2. The third switching valve V3 and the fourth switching valve V4 are provided so as to be connected to the respective connection portions with 6b.

As a result, as shown in FIG. 3, in a state where the first and second switching valves V1 and V2 are opened and the third and fourth switching valves V3 and V4 are closed, By operating the pump device P provided in the supply-side pipe line 5a of the circulation flow path 5, the waste water in the waste water tank 2 is supplied to the module 4 from one end side of the connection port 41 side. As a result, the hollow fiber membranes 40 of the module 4 are made to flow so as to flow toward the connection port 42 on the other end side, and the first and second switching valves V1 and V2 are turned on. By closing the valves and opening the third and fourth switching valves V3 and V4 in advance, as shown in FIG. 4, the waste water pumped by the pump device P is transferred to the module 4 by the bypass passage 6. On the other hand, the hollow fiber membrane 40 is supplied from the side of the connection port 42 on the other end side thereof. The inside of ... is made to flow toward the connection port 41 on the one end side.

The switching valves V1, V2, V3, and V4 are of a type in which the switching operation of the switching valves V1, V2, V3, and V4 is performed manually, and the opening / closing operation is controlled by energization. It is configured as a valve, and this is automatically controlled by a timer installed in the control panel, and the switching valves V1, V2, V3, and V4 automatically perform the switching operation at fixed time intervals. When the state of FIG. 4 and the state of FIG. 5 are switched, or the flow rate or pressure of waste water flowing in the circulation channel 5 or the flow rate of the filtrate taken out to the pipe 7 is detected by a sensor. Then, it may be automatically controlled.

The pipe 7 permeates the membrane wall of the hollow fiber membranes 40 ... While the sewage is pressurized and flows through the inner cavity of the hollow fiber membranes 40. It is a pipe for guiding the filtrate accumulated in the surrounding outer cylinder 43 to a desired place and for using it for water such as the water supply through the disinfection device.

The solid-liquid separator 8 connected and provided in the middle of the return-side pipe line 5 b of the circulation flow passage 5 performs the switching operation of the changeover valves V 1 to V 4 provided in the circulation flow passage 5, and the hollow fiber When the flow direction of the sewage with respect to the module 4 of the membrane 40 ... Is reversed, the solid-phase sludge clogged in the inner cavity of the hollow fiber membrane 40 ... Before being returned to the waste water tank 2, the pipe on the return side of the circulation flow path 5 is pushed out because it is pushed out from the thread film 40 and flows into the return side pipe path 5b of the circulation flow path 5. It is a separator provided in the middle of the pipe line 5b on the return side so as to be separated and eliminated in the middle of the line 5b, and as shown in FIG. 5, inside the solid-liquid separation tank 80 formed in a box shape. , A solid-phase chamber w provided with a discharge port 81 for discharging solid-phase sludge at the bottom, and returning sewage to the circulation channel 5 at the bottom A liquid phase chamber y provided with an outflow port 82 for flowing out is provided in the middle of the pipe line 5b on the upstream side, and the return of the circulation flow path 5 is made at the boundary position between the solid phase chamber w and the liquid phase chamber y. A slanted filter body 84 made of barsculin or a wire mesh, which is slanted downward toward the bottom of the solid phase chamber w, is provided at a position below the inflow port 83 of the sewage which is a connection port with the side pipe 5b. It is formed by forming a mesh capable of separating solid-phase sludge of about a millimeter and installing it so as to cover the upper surface of the liquid phase chamber y.

As a result, by switching operation of the switching valves V1 to V4 provided in the circulation flow path 5, the flow directions of the sewage to the modules 4 of the hollow fiber membranes 40 ... The solid-phase sludge, which is pushed out of the hollow fiber membranes 40 by the reverse flow of sewage every time it is switched and flows out to the return-side pipe 5b of the circulation channel 5, from the inflow port 83 together with the sewage. When it flows into the solid-liquid separation tank 80, it is guided down the discharge port 81 at the bottom of the solid phase chamber along the upper surface of the inclined filter body 84, and is discharged from the discharge port 81 to the outside of the circulation system. is there.

Next, FIG. 6 shows another embodiment of the solid-liquid separator 8 provided in the middle of the conduit 5 b on the return side of the circulation channel 5.

The solid-liquid separator 8 of this embodiment has a solid-phase separation chamber 80 formed in a box shape, a solid-phase chamber w having a discharge port 81 for discharging solid-phase sludge at the bottom, and a bottom part. Is equipped with a liquid phase chamber y provided with an outflow port 82 for flowing out the waste water in the middle of the return-side conduit 5b of the circulation flow channel 5, and at the boundary position between the solid phase chamber w and the liquid phase chamber y, The provision of a filter body made of barscoulin or a wire mesh below the wastewater inflow port 83, which is a connection port with the middle of the return line 5b of the circulation channel 5, is shown in FIG. It is no different from that of the embodiment.

However, the filter body is formed into a cylindrical rotary filter body 85 which is formed by forming a barscoulin or a wire mesh into a cylindrical shape, and is freely rotated by a rotary shaft 85a in a state where the axial direction is horizontal. I am doing it. Then, as shown by the arrow in FIG. 6, the upper peripheral surface side of the rotary filter body 85 is driven so as to rotate toward above the discharge port 81 at the bottom of the solid phase chamber w. Further, the partition walls 86a and 86b that partition the solid phase chamber w and the liquid phase chamber y in cooperation with the rotary filter body 85 are the partition walls 86b on the side adjacent to the bottom of the solid phase chamber w. The filter 85 is configured so as to also function as a scraper that is in sliding contact with the outer peripheral surface of the filter 85.

In this embodiment, sewage flows from the inflow port 83 into the solid-liquid separation tank 80, passes through the rotary filter 85, and flows out from the outflow port 82 to the return-side pipe line 5 b of the circulation flow path 5. In the meantime, the solid phase sludge (consolidated sludge) separated and collected by the peripheral surface of the rotary filter body 85 is gradually rotated by the gentle rotation of the rotary filter body 85, and the sludge discharge port 81 at the bottom of the solid phase chamber w is sequentially. Will be forcibly transferred to and will be separated and removed efficiently.

Next, FIG. 7 shows still another embodiment of the solid-liquid separator 8 described above. In this embodiment, a box-shaped solid-liquid separation tank 80 is arranged and connected in the middle of the return-side pipe line 5b of the circulation channel 5. At the time of connection, the box-shaped solid-liquid separation is performed. A sewage inlet 87 is provided on one of the left and right sides of the upper end of the tank 80, and the sewage inlet 87 is provided on the upstream side of a pair of connection ports formed by cutting off the middle of the return passage 5b of the circulation passage 5. Connect to the connection port. Then, the solid-liquid separation tank 80 located on the opposite side of the inflow port 87 is provided with an outflow port 88 formed on the upper left and right sides of the other side so as to face the inflow port 87. The outlet 88 is connected to the downstream side connection port of the pair of connection ports formed by cutting off the return side conduit 5b in the middle thereof. Also, in the solid-liquid separation tank 80, the liquid of the flow of wastewater flowing through the tank 80 such that it flows into the tank 80 from the above-mentioned inlet 87 and flows out from the outlet 88. A pair of inclined plates 89, 89 facing each other in an inverted V shape are arranged at a position slightly lower than the surface so that the facing interval is gradually narrowed downward as viewed from the flow direction of the wastewater. At the bottom of the tank 80 below the facing space of the inclined plates 89, 89, a discharge pipe 90 for extracting the solid-phase sludge to the outside and sending it to a separately installed sludge storage tank (not shown) is provided. It is composed of.

In this embodiment, each time the flow direction of the sewage flowing through the lumen of the hollow fiber membranes 40 is switched, the compressed state in which the sewage is extruded into the return-side conduit 5 b of the circulation channel 5 is maintained. When the sludge flows into the solid-liquid separation tank 80 together with the wastewater, the solid-liquid separation tank 80 is used as a sedimentation tank to separate and settle from the wastewater, and a discharge pipe 90 connected to the bottom of the tank 80 can be used to remove the sludge. It will be discharged to the place.

[0028]

[Effect of device]

 As described above, the solid-liquid separation device in the wastewater reuse device using the module of the hollow fiber membrane according to the present invention, the solid-phase sludge that is accumulated in the inner cavity of the hollow fiber membrane 40 ... By alternately switching the flow directions of the wastewater flowing through the hollow fiber membranes 40 in a reverse order, the wastewater is pushed out to the return-side conduit 5b of the circulation flow channel 5 at each time of switching, and this is returned to the return side. Of the solid-liquid separator 8 connected and provided in the middle of the pipe line 5b of the rotary filter body 85 by falling down by the slanted filter body 84 composed of a screen or a net and sorted and transferred to the discharge port 81, or by the peripheral surface of the rotary filter body 85. Since the solid phase sludge is separated and transferred to the discharge port 81 or settled and separated by the solid-liquid separation tank 80 serving as a settling tank and discharged, the solid-phase sludge can be efficiently separated and removed.

[Brief description of drawings]

FIG. 1 is a development view of a conventional wastewater reuse device using a hollow fiber membrane module.

FIG. 2 is a development view of a wastewater reuse device using a hollow fiber membrane module according to the present invention.

FIG. 3 is an explanatory diagram showing a state in which a flow direction of sewage with respect to a module of the same apparatus is a forward direction.

FIG. 4 is an explanatory diagram showing a state in which the flow direction of sewage with respect to the module of the same apparatus is reversed.

FIG. 5 is a vertical sectional side view of the solid-liquid separator of the same apparatus.

FIG. 6 is a vertical cross-sectional side view of another embodiment of the solid-liquid separator of the same apparatus.

FIG. 7 is a vertical sectional side view of still another embodiment of the solid-liquid separator of the same apparatus.

FIG. 8 is a vertical sectional front view of the embodiment.

FIG. 9 is a chart showing a change with time of the amount of permeated water in the wastewater recycling apparatus according to the present invention.

[Explanation of symbols]

A ... Reuse device of sewage, a ... Hollow fiber membrane, b ... Module, c ... Inflow pipe, d ... Sewage tank, e ... Circulation flow path, f ... Outer cylinder, g ... Piping, w ... Solid phase chamber, y ... Liquid tank chamber, P ... Pump device, V1, V2, V3, V4 ... Switching valve, 1 ... Inflow pipe, 2
... sewage tank, 3 ... sewage, 4 ... module, 40 ... hollow fiber membrane, 41/42 ... connection port, 43 ... outer cylinder, 44 ... outlet,
5 ... Circulation flow path, 5a / 5b ... Pipe line, 50/51 ... Connection pipe, 6 ... Detour flow path, 6a / 6b ... Pipe line, 7 ... Piping, 8 ...
Solid-liquid separator, 80 ... Solid-liquid separation tank, 81 ... Discharge port, 82 ...
Outflow port, 83 ... Inflow port, 84 ... Inclined filter body, 85 ... Rotating filter body, 85a ... Rotating shaft, 86a / 86b ... Partition wall, 87 ... Inflow port, 88 ... Outflow port, 89 ... Inclined plate, 90 ... Discharge pipe .

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location B01D 65/02 8014-4D

Claims (3)

[Scope of utility model registration request] 1. A module 4 of a cross-flow internal pressure type hollow fiber membrane 40 ... composed of an ultrafiltration membrane is provided with a circulation channel 5 for circulating sewage from the sewage tank 2 through the module 4 and back to the sewage tank 2. In the sewage water reuse device that is connected, the flow direction of sewage flowing through the circulation channel 5 inside the hollow fiber membranes 40 of the module 4 is from one end side to the other end side of the hollow fiber membranes 40. It is configured to alternately switch between the forward direction and the opposite direction from the other end side of the hollow fiber membranes 40 ...
In the middle of b, a box-shaped solid-liquid separation tank 80 is connected and provided, and in the solid-liquid separation tank 80, a solid-phase chamber w having a discharge port 81 for discharging solid-phase sludge at the bottom, and a bottom part Circulation channel 5 for sewage
And a liquid phase chamber y provided with an outflow port 82 for allowing the liquid to flow out into the liquid phase chamber y at the boundary position between the solid phase chamber w and the liquid phase chamber y.
A slanted filter body 84 made of a screen or a net slanting down toward the bottom of the solid phase chamber w is installed below the inflow port 83 of the dirty water chamber so as to cover the upper surface of the liquid phase chamber y. A solid-liquid separation device in a wastewater reuse device using a hollow fiber membrane module. 2. A module 4 of a cross-flow internal pressure type hollow fiber membrane 40, which comprises an ultrafiltration membrane, is provided with a circulation channel 5 for circulating sewage from the sewage tank 2 to the module 4 and back to the sewage tank 2. In the sewage water reuse device that is connected, the flow direction of sewage flowing through the circulation channel 5 inside the hollow fiber membranes 40 of the module 4 is from one end side to the other end side of the hollow fiber membranes 40. It is configured to alternately switch between the forward direction and the opposite direction from the other end side of the hollow fiber membranes 40 ...
In the middle of b, a box-shaped solid-liquid separation tank 80 is connected and provided, and in the solid-liquid separation tank 80, a solid-phase chamber w having a discharge port 81 for discharging solid-phase sludge at the bottom, and a bottom part Circulation channel 5 for sewage
And a liquid phase chamber y provided with an outflow port 82 for allowing the liquid to flow out into the liquid phase chamber y at the boundary position between the solid phase chamber w and the liquid phase chamber y.
A cylindrical rotary filter body 85 composed of a screen or a mesh body and having an axial direction in the lateral direction is provided below the inflow port 83 of the sewage from the discharge port 8 at the bottom of the solid phase chamber w with its upper peripheral surface side.
A solid-liquid separation device in a wastewater reuse device that uses a hollow fiber membrane module that is mounted so as to rotate toward 1. 3. A cross-flow passage 5 for circulating the sewage from the sewage tank 2 through the module 4 and back to the sewage tank 2 in the module 4 of the cross-flow internal pressure type hollow fiber membrane 40 ... In the sewage water reuse device that is connected, the flow direction of sewage flowing through the circulation channel 5 inside the hollow fiber membranes 40 of the module 4 is from one end side to the other end side of the hollow fiber membranes 40. It is configured to alternately switch between the forward direction and the opposite direction from the other end side of the hollow fiber membranes 40 ...
A box-shaped solid-liquid separation tank 80 is connected and provided in the middle of b, and a wastewater inlet 87 provided on one side of the upper end side of the solid-liquid separation tank 80 is provided in the middle of the pipeline 5b on the return side of the circulation channel 5. Is connected to the upstream side connection port of the pair of connection ports formed separately, and the wastewater outlet 88 provided on the other side is connected to the downstream side connection port of the pair of connection ports. In the solid-liquid separation tank 80, at a portion located below the liquid surface of the wastewater flowing from the inflow port 87 to the outflow port 88, the facing interval becomes gradually narrower downward as viewed in the flow direction of the wastewater. A pair of inclined plates 89, 89 facing each other in an inverted c-shape are provided, and a discharge pipe 90 for taking out solid-phase sludge to the outside is connected to the bottom of the solid-liquid separation tank 80 below them. Solid-liquid separation device in a wastewater reuse device using a hollow fiber membrane module.