KR20160139596A

KR20160139596A - Apparatus for reducing excess sludge

Info

Publication number: KR20160139596A
Application number: KR1020150074775A
Authority: KR
Inventors: 쇼이치 다케다; 게이스케 요시즈미
Original assignee: 가부시키가이샤 야스카와덴키
Priority date: 2015-05-28
Filing date: 2015-05-28
Publication date: 2016-12-07

Abstract

A surplus sludge reducing apparatus capable of sufficiently efficiently treating bubbles generated by mixing of water to be treated and ozone gas, thereby sufficiently suppressing the inconvenience caused by bubbles containing ozone gas. The surplus sludge reducing apparatus according to the present invention includes a flow path for transferring the water to be treated including biological sludge in contact with ozone gas, an expansion section having a flow path cross-sectional area expanded as a part of the flow path, and a defoaming device provided in the expansion section .

Description

[0001] APPARATUS FOR REDUCING EXCESS SLUDGE [0002]

The present invention relates to an apparatus for reducing excess sludge.

Conventionally, an activated sludge process is known as one of water purification processes. The purification principle is that microorganisms metabolize (metabolize) the organic substances contained in the water to be treated, whereby the organic substances are decomposed or removed. The water treatment apparatus used in the activated sludge process comprises a biological reaction tank for containing activated sludge and a sedimentation tank for solid-liquid separation. Since the apparatus has high processing performance, it is widely used in various fields such as public sewage treatment and factory drainage treatment.

In the activated sludge process, microorganisms proliferate with the water treatment. Microorganisms that have grown beyond the amount required for water treatment are called surplus sludge and are disposed of as industrial waste. In order to dispose of a large amount of surplus sludge, it is necessary to secure a final repository having a sufficient processing capacity, and at the same time, there is a cost burden depending on the disposal amount. Therefore, it is preferable to reduce the amount of excess sludge generated as much as possible. Patent Documents 1 to 3 disclose techniques for reducing sludge using ozone.

Japanese Patent Laid-Open No. 6-206088 Japanese Patent Laid-Open No. 2001-191097 Japanese Patent Application Laid-Open No. 2008-221114

A conventional apparatus for reducing excess sludge comprises a mechanism for injecting ozone into a pipe for transferring sludge from a biological reaction tank or a pipe for transferring sludge. When the sludge and the ozone gas come into contact with each other, the cell walls of the microorganisms constituting the sludge are destroyed, whereby the sludge is solubilized. Further, by the solubilization of the sludge, the components (soluble organic substances) accumulated in the body of the microorganism are released to the outside by destruction of the cell wall. By supplying this component to the bioreactor, excess sludge can be reduced.

Bubbles are generated with mixing of the water to be treated including the sludge and ozone gas. This bubble contains ozone gas used for solubilization of sludge. Since ozone has a strong oxidizing power, parts of the apparatus may be corroded if bubbles containing ozone gas reach the apparatus such as a pump.

An object of the present invention is to provide a surplus sludge reducing apparatus capable of sufficiently efficiently treating bubbles generated by mixing of water to be treated and ozone gas and thereby sufficiently suppressing problems caused by bubbles containing ozone gas The purpose is to provide.

The surplus sludge reducing apparatus according to one aspect of the present invention includes a flow path for transferring treated water containing biological sludge and ozone gas in contact with each other, an expansion section having a flow path cross-sectional area expanded as a part of the flow path, (Defoaming) device.

According to the present invention, it is possible to sufficiently efficiently treat the bubbles generated by mixing the for-treatment water and the ozone gas, and to solve the problems caused by the bubbles containing ozone gas (for example, Corrosion of equipment and deterioration of function) can be sufficiently suppressed.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a configuration diagram schematically showing a wastewater treatment system provided with an excess sludge reducing apparatus according to an aspect of the present invention. FIG.
Fig. 2 is a configuration diagram schematically showing an excess sludge reducing apparatus shown in Fig. 1. Fig.
3 is a cross-sectional view schematically showing an example of a defoaming device installed in the vicinity of the outlet of the flow path.
4 is a cross-sectional view schematically showing a position where a defoaming device in a flow path is installed.
5 is a perspective view schematically showing a decomposition state of the defoaming device.
6 is a cross-sectional view schematically showing the lower surface of the defoaming device.
7 is a perspective view schematically showing another example of the flow path of the surplus sludge weight reducing apparatus.
8 is a perspective view schematically showing another example of the flow path of the surplus sludge weight reducing apparatus.
Fig. 9 is a perspective view schematically showing another example of the flow path of the surplus sludge weight reducing apparatus. Fig.
10 is a longitudinal sectional view schematically showing another example of the flow path of the surplus sludge reducing apparatus.
Fig. 11 is a diagram schematically showing the construction when an excess sludge reducing apparatus is provided in a sludge return line.

BEST MODE FOR CARRYING OUT THE INVENTION A plurality of embodiments of the present invention will be described below with reference to the drawings. The same reference numerals are assigned to the same elements in the description of the drawings, and redundant explanations are omitted. The drawings and related art are provided to illustrate embodiments of the present invention and do not limit the scope of the present invention.

1 is a schematic diagram showing a wastewater treatment system 100 provided with an excess sludge reducing apparatus 10 for bringing sludge into contact with ozone gas. The wastewater treatment system 100 includes a first settling basin 1 installed as required, a bioreactor 2 disposed on the downstream side thereof, a final settling basin 3 provided on the downstream side thereof, A sludge transfer line L5a for transferring at least a part of the sludge discharged from the bioreactor 2 to the bioreactor 2 and an excess sludge reduction device 10 provided at the sludge transfer line L5a. Hereinafter, each configuration will be described. Here, the term " line " means a pipe for transporting a fluid. A pump, a valve, a pressure gauge, a thermometer, a flow meter, and a water gauge, which are not shown, are appropriately installed in the middle of the line.

The first settling basin 1 is for removing the dust from the drainage by submerging small particles contained in the drainage supplied through the line L1. In the case where the waste water to be treated contains large amounts of dust, sand or the like, a judgment sheet (not shown) may be provided on the upstream side of the first settling sheet 1, and these sheets may be removed from the examination sheet.

The biological reaction tank 2 is provided with a bath main body 2a for retaining activated sludge (biological sludge) for a predetermined time, a diffuser 2b for aeration of air in the bath main body 2a, And a blower 2c. The bioreactor 2 is supplied with a large amount of water from the first settler 1 through the line L2. The BOD (Biochemical oxygen demand) of this scale should be about 100 mg / L to 1000 mg / L, and may be about 100 mg / L to 3000 mg / L. Organics and nitrogen compounds (for example, ammonia) contained in the liquid crystals are decomposed into carbon dioxide, water, nitrogen gas and the like by metabolism of the activated sludge contained in the bath main body 2a.

In the final settling basin 3, a mixed liquid of the treated water and the activated sludge is supplied from the bioreactor 2 through the line L3. The final settling basin 3 is for separating the treated water from the activated sludge. The overflow of the final settling basin 3 is discharged through the line L4 and discharged to a river or sea. The BOD (Biochemical oxygen demand) of this scale should be about 1 mg / L to 160 mg / L, and may be about 1 mg / L to 2000 mg / L. In addition, treatment with chlorine may be carried out, if necessary, prior to discharge, for example.

A line L5 is connected to the bottom of the final settling basin 3. [ The activated sludge precipitated in the final sedimentation bed 3 is discharged through the line L5. The line L5 is branched in the middle, and one branched line is the above-mentioned sludge return line L5a. At least a part of the activated sludge discharged from the final sedimentation tank 3 through the sludge return line L5a is returned to the bioreactor 2. On the other hand, one branched line is the excess sludge discharge line L5b. The excess sludge is conveyed to, for example, a disposal site after dehydration treatment is performed.

The excess sludge weight reducing apparatus 10 (hereinafter simply referred to as " apparatus 10 " in brief) advances the solubilization of activated sludge by bringing the activated sludge conveyed in the sludge return line L5a into contact with ozone , And supplying it to the bioreactor 2 to reduce the amount of excess sludge (reduce the amount of excess sludge generated). When the amount of excess sludge generated when the waste water treatment system 100 is operated without operating the apparatus 10 is set to 100 parts by mass, by operating the apparatus 10, preferably 100 parts by mass or more, More preferably, at least 300 parts by mass of the activated sludge can be introduced into the apparatus 10. As a result, the amount of excess sludge (activated sludge fed from the line L5b) can be sufficiently reduced.

As shown in Fig. 2, the apparatus 10 is installed in the middle of the branch line L6 branched from the sludge return line L5a. The apparatus 10 includes a treatment section 12 for bringing the activated sludge and ozone gas into contact with each other, a circulation line (circulation path) L7, and a defoaming device 20). The circulation line L7 branches from the vicinity of the upstream side of the outlet 15 of the processing section 12 and is connected to a position on the upstream side of the processing section 12 of the branch line L6. The apparatus 10 also includes a cavitation generator 16 and an ejector (gas injector) 18 for injecting ozone gas in order from the upstream side in the middle of the circulation line L7. The circulation line L7 may be branched from the branch line L6 on the downstream side of the outlet 15 of the treatment section 12 or may be connected to the vicinity of the downstream side of the inlet 14 of the treatment section 12 .

The apparatus 10 includes at least a processing section 12 including a flow path 13 and a defoaming device 20 and a circulation line L7 including an ejector (gas injector) 18 as a common base (not shown) As shown in Fig. This makes it possible to further contribute to downsizing of the apparatus. The squares of the broken lines in Fig. 2 surround the configuration to be arranged on the common base. The ozone gas (ozone-containing gas) is generated by, for example, supplying air or oxygen gas to a discharge type ozone generator (not shown).

The treatment section 12 ozone-processes the suspended water (untreated water) including the activated sludge supplied through the branch line L6. As shown in Fig. 2, the processing unit 12 has a meandering flow path 13, and may further include a water level gauge, a pressure gauge, and the like (not shown). As the mixed fluid of the activated sludge and the ozone gas flows in the flow path 13, the cell walls of the microorganisms constituting the activated sludge are destroyed by the oxidizing power of the ozone. As a result, the solubilization of the activated sludge proceeds. The flow path 13 has an inlet 14 and an outlet 15 at a position higher than the inlet 14. The flow path 13 also has paths 13a and 13b extending in the lateral direction (preferably substantially in the horizontal direction) and also reaches the outlet 15 through the winding path from the inlet 14. Since the flow path 13 has the paths 13a and 13b extending in the substantially horizontal direction, an extrusion flow can be generated in the mixed fluid of the activated sludge and the ozone gas in this path. In addition, since the retention of gas and bubbles in the flow path 13 can be sufficiently suppressed, the contact efficiency between the activated sludge and the ozone gas can be sufficiently increased. The term " substantially horizontal direction " in the present invention means that the angle formed with the horizontal direction is 10 DEG or less, and the flow path 13 may be inclined upward or downward within this range. The flow path 13 can be constituted by a tubular pipe (for example, a circular pipe). As the tubular pipe, a commercially available pipe may be used. The piping may be a metallic or resin piping.

The flow path 13 includes a first path (first portion) 13a extending in a substantially horizontal direction, a second path (second portion) 13b extending in a direction different from the first path 13a, And a folded portion (bent portion) 13c connecting the first path 13a and the second path 13b. In one combination, the second path 13b is provided at a position higher than the first path 13a and extends substantially parallel to the first path 13a. The mixed fluid flows in the direction of the left arrow shown in Fig. 2, and the direction of the mixed fluid is reversed in the folded portion 13c, and the second path 13b is moved in the direction of the rightward arrow Lt; / RTI > The mixed fluid passes through the inside of the flow path 13 and is then transferred from the inlet 14 located at the bottom to the outlet 15 positioned above. By reversing the direction of the flow in the folding section 13c, the active sludge and ozone can be sufficiently mixed. According to the present embodiment, since ozone can be sufficiently dissolved in the for-treatment water including the activated sludge, there is an advantage that an excessive amount of ozone gas need not be introduced into the flow path 13. In the present invention, the upper side means the upper side in the vertical direction, and the lower side means the lower side in the vertical direction.

In the conventional sludge reduction technique using ozone gas, since a large amount of foam is generated when the ozone gas is injected into the activated sludge, it is necessary to take measures enough to treat the foam. On the other hand, in the present embodiment, the extruding flow of the mixed fluid can be formed in the flow path 13. Therefore, even if the bubbles once formed in the flow path 13, the bubbles and the activated sludge (suspension including microorganisms) flow together in the meandering flow path 13 for a certain period of time, The amount of bubbles is sufficiently reduced at this point. This is confirmed by visual inspection in a test plant manufactured by the present inventors. According to the present embodiment, it is possible to sufficiently suppress the amount of foam generation accompanying the ozone treatment, and to make the mechanism (defoaming device 20) for bubble treatment simple and easy (see Fig. 3). In addition, the amount of the atmospheric release of the discharged ozone gas produced by the treatment of the bubbles can be sufficiently reduced, so that the mechanism for detoxifying the ozone gas can be made simple and easy.

The distance in the vertical direction from the inlet 14 to the outlet 15 (the difference in height between the inlet 14 and the outlet 15) in the flow path 13 may be about 1.0 m to 1.5 m, It is also good. The flow path cross-sectional area of the flow path 13 may be about 6.0 占^10-4 m2 to 7.3 占^10-2 m2, and may be about 3.8 占^10-4 m2 to 2.0 占^10-1 m2. The lengths of the first path 13a and the second path 13b may both be about 1.5 m to 3.0 m, or about 1.0 m to 4.0 m. The flow passage section of the flow passage 13 constituting the processing section 12 is preferably larger than the flow passage sectional area of the circulation line L7 described later and the flow passage 13 is longer than the circulation line L7. The linear velocity of the mixed fluid in the flow path 13 is preferably 0.05 m / sec to 0.2 m / sec, more preferably 0.07 m / sec, from the viewpoint of sufficiently advancing the contact and reaction between the activated sludge and the ozone gas. m / sec to 0.15 m / sec. The pH of the mixed fluid in the flow path 13 is preferably 3 to 8, more preferably 3 to 6 from the viewpoint of suppressing the autolysis of ozone.

2, the circulation line L7 is branched from the vicinity of the upstream side of the outlet 15 of the processing section 12 and is connected to a position on the upstream side of the processing section 12 of the branch line L6 have. By repeatedly passing the mixed fluid through the circulation line L7, the cavitation generator 16 and the ejector 18 can repeatedly apply the impact force to the activated sludge. In addition, even when there is a limitation in the ozone concentration of the ozone-containing gas that can be produced by an ozone generator (not shown), the ozone injection amount for the mixed fluid can be sufficiently increased by employing the circulation line L7 have. The linear velocity of the mixed fluid in the circulation line L7 is preferably 0.5 m / sec to 2.0 m / sec, more preferably 0.8 m / sec, from the viewpoint of applying an impact force of sufficient strength to the activated sludge. Sec to 1.8 m / sec.

The cavitation generator 16 is for applying an impact force to the activated sludge. By depressurizing the flow path section of the circulation line L7 locally, a depressurized portion is formed by the Venturi effect. Thereby, cavitation can be generated in the circulating line L7. One example of the cavitation generator 16 is a hole. The cavitation generator 16 may not be employed if the ejector 18 described later can sufficiently apply an impact force to the activated sludge.

The ejector 18 utilizes the flow of the fluid in the circulation line L7 and makes a reduced pressure state by the Venturi effect, thereby injecting ozone gas into the circulation line L7. In order to make the reduced pressure state, for example, a hole may be used to locally narrow the flow path section of the circulation line L7. The mechanism for supplying ozone gas into the circulation line L7 is not limited to the ejector 18. For example, ozone gas may be supplied into the circulation line L7 by using a normal pipe and a gas flow rate controller installed in the middle of the pipe, It may be injected.

The most downstream side of the discharge pipe L6a is connected to the sludge return line L5a (Figs. 1 and 2). The treatment liquid in the discharge pipe L6a abundantly contains components (soluble organic substances) accumulated in the body of the microorganism. This treatment liquid is supplied to the bioreactor 2 through the sludge return line L5a. The soluble organic matter contained in the treatment liquid is decomposed by the activated sludge in the bioreactor 2, whereby the excess sludge is reduced. The distal end side of the discharge pipe L6a may be connected to the bioreactor 2 instead of being connected to the sludge return line L5a.

The defoaming device (20) is for defoaming the fluid flowing in the flow path (13). The defoaming device (20) is provided in the path at the uppermost end of the flow path (13). That is, the defoaming device 20 is disposed at the same position as the connection portion of the circulation line L7 or at the upstream side of the connection portion as the vicinity of the outlet 15. The term " near " here means a position within 2 m from the exit 15. By providing the defoaming device 20 at such a position in the flow path 13, the foam F containing ozone gas can be sufficiently reduced at the position. As a result, it is possible to more reliably suppress the mixing of the foam F into the circulation line L7. In addition, it is possible to sufficiently prevent the occlusion by the foam F or the corrosion by the ozone gas in the flow path (for example, the discharge pipe L6a) on the downstream side of the flow path 13. Hereinafter, the defoaming device 20 will be described with reference to Figs. 3 to 6. Fig.

As shown in FIG. 3, the defoaming device 20 is provided above the flow path 13. On the other hand, the circulation line L7 branches off from the lower side of the flow path 13 on the downstream side of the defoaming device 20. Further, the circulation line L7 may be branched from the lower side of the discharge pipe L6a. As shown in Fig. 3, the base end side of the circulation line L7 is located downstream of the defoaming device 20. The base end side of the circulation line L7 is connected to a discharge port 19 provided so as to penetrate from the inner surface of the lower side of the flow path 13 to the outer surface. That is, the base end side of the circulation line L7 is connected to the flow path 13 so as to branch off from the lower side of the flow path 13. It is possible to more reliably suppress the mixing of the foam F into the circulation line L7 by introducing the mixed fluid into the circulation line L7 through the discharge port 19 provided on the lower side of the flow path 13. [ This is confirmed by visual inspection of the test plant manufactured by the present inventors.

The defoaming device 20 includes a main body portion (extension portion) 21 connected to the upper side of the flow path 13, an impeller 25 disposed in the main body portion 21, an electric motor 28 for rotating the impeller 25 . In the present embodiment, the impeller 25 and the electric motor 28 constitute a defoaming device. A space 21s having a circular sectional shape in the horizontal direction is formed in the main body portion 21. [ The upper end side of the main body portion 21 is closed by the plate 22 and the lower end side of the main body portion 21 is in communication with the flow path 13 as shown in Fig. The plate 22 is attached to and detached from the flange 21a provided on the upper end side of the main body portion 21 and is mounted on the flange 21a by the bolts 23. [ The plate 22 has an opening 22a for passing the shaft 25a of the impeller 25 and an opening 22b for discharging the ozone containing gas separated from the liquid by the fouling treatment (see Figs. 3 and 5) Respectively. Further, the opening 22a is sealed so that the ozone-containing gas does not leak from the space between the inner surface of the opening 22a and the outer surface of the shaft 25a.

By connecting the body portion 21 to the flow path 13, the space through which the fluid flows is partially expanded. Therefore, the flow rate of the mixed fluid in the portion where the main body portion 21 is provided can be lowered, and the foam F can be inserted into the main body portion 21 more reliably. The impeller 25 can be poured by rotating in the main body 21. The total volume of the volume V1 of the defoaming device 20 and the volume V2 of the passage 13 where the defoaming device 20 is installed and the volume V2 of the passage 13 (V1 + V2) / V2 may be about 1.1 to 2.0, and may be about 1.2 to 1.8. If the ratio is 1.1 or more, the foam F can be surely inserted into the defoaming device 20, while if it is 2.0 or less, the defoaming device 20 can be prevented from becoming excessively large in size.

The impeller 25 has a blade and is configured to rotate the blade. More specifically, the impeller 25 includes a shaft 25a, a disk 25b extending in a direction orthogonal to the shaft 25a, and six blades 25c provided on the lower surface of the disk 25b do. The shaft 25a is rotated by the power of the electric motor 28. [ The disk 25b rotates with the rotation of the shaft 25a. The number of revolutions of the impeller 25 may be about 2,000 revolutions / minute to about 5,000 revolutions / minute.

The gap (the width Wb in Fig. 6) between the periphery of the disk 25b and the inner wall of the main body 21 may be about 1 mm to 5 mm, or about 1 mm to about 3 mm. When the gap (width Wb) is 1 mm or more, it is possible to sufficiently prevent the periphery of the disk 25b from contacting the inner wall of the main body portion 21. On the other hand, if the gap is 5 mm or less, It is possible to sufficiently suppress reaching the opening 22b.

The six blades 25c extend radially outward from the center side of the disk 25b. The gap (width Wc in Fig. 6) between the tip of the blade 25c and the inner wall of the main body 21 may be about 2 mm to 5 mm, or about 2 mm to 4 mm. If the gap (width Wc) is 2 mm or more, it is possible to sufficiently prevent the tip of the blade 25c from contacting the inner wall of the main body portion 21. If the gap is 5 mm or less, It is possible to sufficiently reliably deliver it. The height of the blade 25c may be about 10 mm to 50 mm, or about 15 mm to 35 mm. The number of the blades 25c is not limited to six.

In the present embodiment, the defoaming device provided with the impeller 25 is exemplified, but a defoaming device having a chemical means may be employed instead. For example, an apparatus having a mechanism for adding a defoaming agent to the expanded portion may be employed as the defoaming apparatus. The ozone gas separated from the fluid in the flow path 13 by the defoaming treatment may be transferred to a facility for detoxifying the ozone gas or may be reused for treatment of the sludge.

According to the surplus sludge weight reducing apparatus 10, the defoaming device 20 installed in the flow path 13 can perform defoaming treatment on the fluid flowing through the flow path 13. Particularly, the space of the flow path 13 is expanded by the main body portion 21 of the defoaming device 20 in a direction orthogonal to the flow direction of the fluid (the flow path cross-section is partially expanded). With this configuration, the flow rate of the fluid passing in the vicinity of the expanded portion (the main body portion 21) is delayed and the separation of the bubbles containing ozone gas and the for-treatment water (gas-liquid separation) The bubble treatment can be more reliably performed. For example, when a liquid containing a large amount of bubbles including ozone gas is transferred to the pump, idling of the pump may occur, or the pump may be corroded by ozone gas. On the other hand, this problem can be sufficiently suppressed by applying a defoaming treatment to the fluid in the flow path 13 before the liquid is transferred to the pump.

Although the embodiments of the present invention have been described in detail, the present invention is not necessarily limited to the above-described embodiments, and various modifications are possible without departing from the gist of the invention. For example, in the above embodiment, the apparatus 10 having the flow path 13 of the configuration shown in Fig. 2 is exemplified. However, the mode of the flow path 13 is a path extending in the direction crossing the vertical direction But it is not limited to this as long as it has the inlet 15 and the inlet 14 and the outlet 15. For example, the flow path 13 may be the one shown in Figs. 7 to 10. In such a case, sufficient compactness of the entire device can be achieved.

In the embodiment shown in Fig. 7, a substantially rectangular channel 13A is provided in a multi-stage shape in the vertical direction. That is, the flow path 13 shown in Fig. 7 has a first path 13d extending substantially in the horizontal direction and a second path 13d provided substantially at the same height as the first path 13d, A second path 13e extending in a direction orthogonal to the first path 13e and a third path 13f extending substantially in the same direction as the second path 13e, And a fourth path 13g which is provided at substantially the same height as the third path 13f and which extends in a direction substantially orthogonal to the third path 13f, and by connecting them in series And the first to fourth paths 13d to 13g are arranged to be substantially rectangular in plan view. The flow path 13 shown in Fig. 7 has a substantially rectangular flow path, such as the flow path 13A, in a vertically multi-step shape. The embodiment shown in Fig. 7 has a four-stage flow path 13A. Arrows in Fig. 7 indicate the direction in which the mixed fluid flows. As indicated by these arrows, the flow direction of the mixed fluid in the flow path 13A adjacent to each other in the up-and-down direction is configured to be opposite. By adopting such a configuration, there is an advantage that the whole device can be made compact. The flow path 13A is not limited to a substantially rectangular shape. For example, the flow path 13A may have a substantially triangular shape, a substantially triangular shape, (For example, a parallelogram (including a rhombus) and a trapezoid) or a polygon having a pentagon or more may be used.

In the embodiment shown in Fig. 8, the U-shaped path is provided in a multi-stage shape (three-tiered) in the vertical direction. That is, the flow path 13 shown in Fig. 8 includes a first-stage U-shaped path 13h arranged substantially in the horizontal direction and a second U-shaped path Shaped path 13j and a third-stage U-shaped path 13j disposed above and in a substantially horizontal direction, and these are connected in series by the upward tubes 13k and 13l. The arrows in Fig. 8 indicate the direction in which the mixed fluid flows. As indicated by these arrows, the direction in which the mixed fluid flows in the U-shaped paths adjacent to each other in the up-and-down direction is configured to be the reverse direction. By adopting such a configuration, there is an advantage that the whole device can be made compact.

In the embodiment shown in Fig. 9, the spiral-shaped flow path 13 extends upward from below. The angle (? In Fig. 9) between the tangential direction of the helical channel 13 and the horizontal direction is preferably 10 degrees or less, and more preferably 0 to 3 degrees. If the angle alpha is less than 10 degrees, it is possible to sufficiently generate the extruding flow of the mixed fluid in the flow path 13, and to prevent the gas or foam contained in the mixed fluid from reaching the outlet 15 remarkably faster than the liquid phase . The arrows in Fig. 9 indicate the direction in which the mixed fluid flows.

The embodiment shown in Fig. 10 has a substantially rectangular parallelepiped container 12a and a plurality of partition plates 12d and 12e which respectively base inner side surfaces 12b and 12c facing each other of the container 12a, 13). The partition plates 12d and 12e are alternately arranged from the lower side toward the upper side. In this case, the shape of the flow path cross-section of the flow path 13 is typically rectangular. The arrows in Fig. 10 indicate the direction in which the mixed fluid flows. As shown in Fig. 10, the flow path 13 includes a first path 13a, a second path 13b, and a folding portion 13c.

In the above embodiment, the case where the processing unit 12 is installed in the middle of the branch line L6 branched from the sludge transfer line L5a is exemplified. However, instead of using the branch line L6, Likewise, the treatment section 12 may be provided on the sludge return line L5a. Alternatively, the water in the bioreactor 2 may be directly introduced into the apparatus 10. Conditions such as the supply amount may be appropriately set according to the property of the water to be treated (for example, BOD, activated sludge concentration, etc.) supplied to the apparatus 10. [

In the above embodiment, the water treatment apparatus (apparatus 10) for treating the public sewage or the factory drainage and for reducing the amount of the excess sludge is exemplified. However, the treatment object and purpose of the water treatment apparatus according to the present invention are It is not limited thereto. The object to be treated may be water containing organic matter to be decomposed, and specific examples thereof include sewage-treated water (so-called heavy water), treated water of factory drainage, tap water and the like. The water treatment apparatus according to the present invention may be for the purpose of decolorizing, deodorizing, disinfecting, etc. the treated water of sewage treatment water or factory drainage, and may be for the purpose of eliminating mold odor of tap water.

According to the present invention, it is possible to sufficiently efficiently treat bubbles generated by mixing the for-treatment water and the ozone gas, thereby sufficiently suppressing the inconvenience caused by bubbles containing ozone gas, Is provided.

L7: circulation line (circulation path) 10: surplus sludge weight reduction device
13: flow path 13a: first path (first part)
13b: second path (second part) 13c: folded portion (bent portion)
13d: first path 13e: second path
13f: third path 13g: fourth path
19: outlet 20: defoaming device
21: main body (extension) 25: impeller
28: Electric motor

Claims

A flow path for transferring the water to be treated including the biological sludge in contact with the ozone gas,
An expansion portion having a flow path cross-sectional area expanded as a part of the flow path,
And a defoaming device installed in the expansion part
Reduced sludge weight reduction device.

The method according to claim 1,
The flow path includes:
A first portion extending in the transverse direction,
A second portion extending in a transverse direction and extending in a direction different from the first portion,
And a bending portion connecting the first portion and the second portion
Reduced sludge weight reduction device.

3. The method of claim 2,
The first portion, the bent portion and the second portion are arranged in this order from the upstream side to the downstream side of the flow path,
Wherein the second portion is located higher than the first portion
Reduced sludge weight reduction device.

4. The method according to any one of claims 1 to 3,
An outlet for extracting at least a part of the treated water treated by the ozone gas from the flow path,
And a circulation path for returning the treated water from the discharge port to the upstream side of the flow path,
Wherein the outlet is formed at a position where the expanding portion is formed in the flow path or at a position downstream of the position
Reduced sludge weight reduction device.

5. The method of claim 4,
And the discharge port is formed on the lower side of the flow path
Reduced sludge weight reduction device.

4. The method according to any one of claims 1 to 3,
The defoaming device comprises an impeller
Reduced sludge weight reduction device.