JP2015039671A - Wastewater treatment equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide wastewater treatment equipment capable of achieving stable operation, with suppressed abrasion of apparatus in sludge volume reduction equipment.SOLUTION: Wastewater treatment equipment 1 has biological treatment equipment 4 for biological treatment of a treatment liquid W, sludge separation equipment 3 and 5 for separating sludge of the treatment liquid W at at least one of upstream and downstream of the biological treatment equipment 4, a sludge storage tank 11 for storing sludge separated in the sludge separation equipment 3 and 5, and sludge volume reduction equipment 13 disposed downstream of the sludge storage tank 11 for reducing the volume of sludge. A sand removal device 16 is provided at least between the sludge separation equipment 3 and 5 and the sludge storage tank 11, and between the sludge storage tank 11 and the sludge volume reduction equipment 13.

Description

  The present invention relates to a wastewater treatment facility provided with a sludge separation facility for separating sludge from a treatment liquid such as sewage sewage.

In a wastewater treatment facility (sewage treatment plant) that purifies sewage wastewater, in the first sedimentation pond provided in the first stage of biological treatment, which is the main process of purification, and in the final sedimentation basin provided in the subsequent stage of biological treatment, The sludge separation process by separation is performed (for example, refer patent document 1).
The sludge separated in the sedimentation basin has a solid concentration of about 2% to 5%, but is dewatered by a sludge dehydrator to a solid concentration of about 15% to 30%, and further solidified by a sludge dryer. In general, the volume is reduced so that the product concentration is about 60% to 80%. The dried sludge having an increased solid concentration is carried out of the system or incinerated.

JP 2002-361300 A

  In the sludge dewatering machine and the sludge drying machine for reducing the volume by dehydrating and drying the sludge, the part in contact with the sludge may be worn by inorganic substances such as sand contained in the sludge. For example, when a centrifuge is employed as the sludge dewatering machine, parts that come into contact with sludge such as screws and balls constituting the centrifuge are worn out. Further, when a paddle type dryer is adopted as the sludge dryer, parts such as the paddle and the shaft are worn. This may hinder stable processing and increase maintenance costs.

  In addition, in order to remove these inorganic substances, a method of removing sand from wastewater introduced into a wastewater treatment facility is also known. However, when a large amount of wastewater is treated like sewage treatment, May not catch up and sand removal may be insufficient.

  The present invention has been made in consideration of such circumstances, and an object thereof is to provide a wastewater treatment facility capable of realizing stable operation by suppressing the wear of sludge volume reduction equipment. It is in.

In order to achieve the above object, the present invention provides the following means.
The wastewater treatment facility of the present invention includes a biological treatment facility that biologically treats a treatment liquid, a sludge separation facility that separates sludge of the treatment liquid at least one of upstream and downstream of the biological treatment facility, and the sludge separation facility. In a wastewater treatment facility having a sludge storage tank for storing separated sludge, and a sludge volume reduction facility disposed downstream of the sludge storage tank to reduce the sludge, the sludge separation facility and the sludge storage tank A sand removing device is provided in at least one of the sludge storage tank and the sludge volume reducing equipment.

According to the said structure, by providing the sand removal apparatus, the abrasion of the apparatus of the sludge volume reduction equipment which arises with sand can be suppressed. Thereby, the waste water treatment facility can be stably operated, and the maintenance cost can be reduced.
Moreover, compared with the structure which provides the means which removes sand with respect to the process liquid introduce | transduced into a biological treatment facility, the liquid quantity made into object can be reduced. That is, the sand contained in the treatment liquid can be removed more efficiently.

  In the wastewater treatment facility, the sand removal device is provided on a first sludge line into which the first sludge separated by the first sludge separation facility provided upstream of the biological treatment facility is introduced. Is preferred.

  According to the above configuration, sand removal by the sand removal device is performed on the first sludge separated from the first sludge separation device that is located upstream of the biological treatment facility and collects the most sludge. Sand can be removed efficiently.

In the wastewater treatment facility, a first sludge line into which sludge separated from a first sludge separation facility provided upstream of the biological treatment facility is introduced, and a second sludge separation provided downstream of the biological treatment facility. A second sludge line into which sludge separated from the facility is introduced, and a mixed sludge line in which the first sludge line and the second sludge line are joined and connected to the sludge storage tank, and The sand removing device may be configured to be provided on the mixed sludge line.
According to the said structure, the sand which flowed downstream from the 1st sludge separation equipment can be removed.

  In the wastewater treatment facility, the sludge storage tank may have a circulation line for circulating the sludge in the sludge storage tank, and the sand removing device may be provided on the circulation line.

  According to the above configuration, since sand is removed from the sludge stored in the sludge storage tank, sand can be removed without being affected by the amount of sludge separated by the sludge separation facility.

In the wastewater treatment facility, the sand removing device is preferably a hydrocyclone.
According to the said structure, the sand contained in sludge can be isolate | separated stably using the liquid cyclone which is easy to handle.

  It is preferable to have a concentrating tube connected to the lower part of the hydrocyclone, and the concentrating tube has a cylindrical shape extending with the same diameter in the vertical direction.

  According to the above configuration, since the concentrated processing liquid discharged from the liquid cyclone is once accumulated in the concentration tube, it is possible to prevent the solid matter contained in the concentrated processing liquid from affecting the operation of the liquid cyclone. Further, by replacing the concentrating tube, maintenance can be easily performed, and blockage in the liquid cyclone due to the scale component can be prevented.

  In the wastewater treatment facility, it is preferable to provide a hydrogen ion improving device for improving the hydrogen ion index of the sludge introduced into the sand removing device before the sand removing device.

  According to the said structure, the heavy metal and scale component which are contained in sludge can be deposited, and the deposited heavy metal and scale component can be removed with sand.

  In the wastewater treatment facility, it is preferable to provide a carbon dioxide supply device for blowing carbon dioxide into the sludge introduced into the sand removal device before the sand removal device.

  According to the said structure, even when hardness components, such as calcium and magnesium, are contained in waste_water | drain, the carbonate of calcium and magnesium can be made to deposit and can be removed with sand.

ADVANTAGE OF THE INVENTION According to this invention, by providing a sand removal apparatus, abrasion of the apparatus of sludge volume reduction equipment can be suppressed with sand. Thereby, the waste water treatment facility can be stably operated, and the maintenance cost can be reduced.
Moreover, compared with the structure which provides the means which removes sand with respect to the process liquid introduce | transduced into a biological treatment facility, the liquid quantity made into object can be reduced. That is, the sand contained in the treatment liquid can be removed more efficiently.

It is a schematic block diagram of the waste water treatment facility of 1st embodiment of this invention. It is a schematic block diagram of the sand removal apparatus of the waste water treatment facility of 1st embodiment of this invention. It is a schematic block diagram of the waste water treatment facility of 2nd embodiment of this invention. It is a schematic block diagram of the waste water treatment facility of 3rd embodiment of this invention. It is a schematic block diagram of the waste water treatment facility of 4th embodiment of this invention.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic configuration diagram illustrating the configuration of the wastewater treatment facility 1 of the present embodiment. The wastewater treatment facility 1 of this embodiment is a treatment facility for organic wastewater W containing nitrogen, phosphorus, or organic substances such as sewage sludge and factory wastewater.

First, the water treatment system of the wastewater treatment facility 1 will be described.
The water treatment system of the wastewater treatment facility 1 includes a pretreatment facility 2 into which the organic wastewater W is introduced, and a first sedimentation basin 3 (first sludge separation facility) that separates sludge from the wastewater treated in the pretreatment facility 2. And a biological treatment facility 4 that performs biological treatment on the wastewater from which sludge has been separated in the first sedimentation basin 3, and a final sedimentation basin 5 (second sludge separation facility that further separates the sludge from the biologically treated wastewater. ) And advanced treatment equipment 6 for treating wastewater from which sludge has been separated in the final sedimentation basin 5.
That is, in the water treatment system, sludge is generated by solid separation in the first sedimentation basin 3 at the preceding stage of the biological treatment facility 4 and the final sedimentation basin 5 at the subsequent stage of the biological treatment facility 4. The organic waste water W is discharged into the river through the above facilities.

  The pretreatment facility 2 is a facility for removing impurities contained in the introduced organic waste water W. Examples of the pretreatment facility 2 include crushing means for crushing large-diameter sludge and separation means such as a screen capable of removing impurities.

  The first sedimentation basin 3 is a sludge separation facility that separates fine sludge contained in the organic waste water W by sinking it to the bottom. A first sludge line 8 is connected to the bottom of the first sedimentation basin 3. That is, the sludge separated in the first sedimentation basin 3 (hereinafter referred to as the first sludge P1) is introduced into the first sludge line 8. In the first sedimentation basin 3, the organic waste water W is slowly flowed. During this time, the first sludge P 1 is accumulated at the bottom of the first sedimentation basin 3 and introduced into the first sludge line 8.

  The biological treatment facility 4 has a structure in which a plurality of anaerobic tanks that perform anaerobic treatment such as methane fermentation, aerobic tanks that perform aeration, and precipitation tanks, and mainly the action of nitrifying bacteria and denitrifying bacteria. Is a facility that decomposes and removes BOD, nitrogen compounds, etc. in the liquid.

  In the final sedimentation basin 5, sludge including the organisms used for treatment in the biological treatment facility 4 accumulates at the bottom. A second sludge line 9 is connected to the bottom of the final sedimentation basin 5. The sludge separated in the final sedimentation basin 5 (hereinafter referred to as the second sludge P2) is introduced into the second sludge line 9. The solid concentration of the first sludge P1 and the second sludge P2 is 2% to 5%.

In addition, although the sludge separation equipment comprised from the first sedimentation basin 3 and the final sedimentation basin 5 isolate | separated sludge by gravity sedimentation, it is not restricted to this. For example, as means for separating sludge, separation means such as dynamic filtration, flocculation separation, membrane separation, sand filtration, or the like having a dehydrating function such as a belt press or a screw press can be employed.
Examples of the advanced treatment facility 6 include a coagulation separation device, an ozone oxidation device, and an activated carbon adsorption tower.

Next, the sludge treatment system of the wastewater treatment facility 1 will be described.
The sludge treatment system includes a first sludge line 8 that collects sludge from the first sedimentation basin 3, a second sludge line 9 that collects sludge from the final sedimentation basin 5, and a first sludge line 8 and a second sludge line 9. A mixed sludge line 10 that is a line to join, a sludge storage tank 11 provided on the downstream side of the mixed sludge line 10, a concentrated sludge line 12 into which sludge from the sludge storage tank 11 is introduced, and a sludge storage tank 11 And a sludge volume reduction facility 13 provided on the downstream side.

The sludge volume reducing facility 13 is a facility for reducing the volume of sludge, and includes a sludge dehydrator 14 and a sludge dryer 15 provided on the downstream side of the sludge dewaterer 14.
Further, on the first sludge line 8, a sand removing device 16 for removing sand contained in the first sludge P1 is provided.

  Further, on the first sludge line 8, on the upstream side of the sand removing device 16, a hydrogen ion improving device 19 that improves the hydrogen ion index (pH) of the first sludge P 1 introduced into the sand removing device 16. Is provided. The hydrogen ion improving device 19 is a device that injects an alkaline agent such as sodium hydroxide into the first sludge P1 in the first sludge line 8. It is also possible to employ a chelating agent as an alternative to sodium hydroxide.

Further, on the downstream side of the hydrogen ion improving device 19 and on the upstream side of the sand removing device 16, a carbon dioxide supply device 20 for blowing carbon dioxide (CO ₂ ) into the first sludge P 1 introduced into the sand removing device 16. Is provided.

The sludge dehydrator 14 is a device that dehydrates the sludge sent from the sludge storage tank 11 by the pressure feed pump 17. As the sludge dewatering machine 14, a centrifugal separator or a screw press type sludge dewatering machine can be adopted. The separated liquid separated by the sludge dehydrator 14 is sent to the biological treatment facility 4 for biological treatment.
For example, a centrifuge separates a separation liquid and sludge with a screw that rotates at a high speed, and further sends out sludge by a relative motion difference between balls that rotate slightly slowly. In addition, the screw press type sludge dewatering machine is configured to dehydrate the sludge while applying shear force to the sludge by arranging two screws in an overlapping manner and screw blades meshing with each other.

  The sludge dryer 15 is a device that dries the dewatered sludge that has been dehydrated by the sludge dehydrator 14. As the sludge dryer 15, a paddle dryer can be employed. A paddle type dryer dries dehydrated sludge by arranging two shafts having huddle blades in an overlapping manner and engaging the paddle blades with each other.

Next, the sand removal device 16 provided in the first sludge line 8 will be described.
The sand removal device 16 is a classification device that employs the mechanism of the hydrocyclone 22, and performs centrifugal classification on the first sludge P1 introduced through the first sludge line 8, and is included in the first sludge P1. It is a device that removes sand.
As shown in FIG. 2, the sand removing device 16 includes a liquid cyclone 22, a concentration pipe 23 connected to the lower part of the liquid cyclone 22, a rotary valve 24 connected to the lower part of the concentration pipe 23, and a rotary valve A draining tank 25 that receives the sand S containing moisture discharged from 24 and a pipe conveyor 26 that lifts the sand S that has settled in the lower part of the draining tank 25 are provided.

  The hydrocyclone 22 has a cylindrical casing 27 that gradually decreases in diameter as it goes downward, and an introduction duct 28 that is provided in the vicinity of the upper end of the casing 27 and introduces the first sludge P1 so as to swirl within the casing 27. The upper outlet 29 is provided on the upper surface of the casing 27 so as to protrude upward, and the lower outlet 30 is provided on the lower end of the casing 27. The introduction duct 28 is connected to the upstream side of the first sludge line 8, and a pump that generates a high-speed swirling flow inside the cyclone body at the connection portion between the introduction duct 28 and the first sludge line 8. (Not shown) is provided.

An upper outlet 29 of the sand removing device 16 is connected to the downstream side of the first sludge line 8. That is, the first sludge P 1 from which the sand S has been removed is introduced into the mixed sludge line 10 via the first sludge line 8.
The concentrating tube 23 has a cylindrical shape extending with the same diameter in the vertical direction. Specifically, the diameter of the concentration tube 23 is 45 mm or more and 55 mm or less.

  The rotary valve 24 is a mechanism for quantitatively discharging the sand S containing moisture discharged from the lower part of the cyclone. The rotary valve 24 includes a housing 31 and a rotor 32 that is rotated in the housing 31 by a drive source (not shown). The rotor 32 divides the inside of the casing 27 into a plurality of transfer chambers 33. The rotary valve 24 of the present embodiment includes six transfer chambers 33. That is, six blades are provided in the rotor 32 of the rotary valve 24, and a transfer chamber 33 is formed between the blades.

The draining tank 25 is a sedimentation tank that accumulates sand S containing water sent from the rotary valve 24, and is a sediment classification mechanism that performs sediment classification. An overflow liquid receiver 35 is provided in the draining tank 25, and an opening 36 is provided in the lower part of the draining tank 25.
An overflow line 37 for sending the liquid in the overflow liquid receiver 35 to the pretreatment facility 2 is connected to the discharge part of the overflow liquid receiver 35.

The pipe conveyor 26 includes a cylindrical pipe 38 connected to the opening 36 of the draining tank 25, a plurality of blades 39 that can move in the pipe 38, and a discharge port 40 formed in the pipe 38. Yes.
The pipe 38 is arranged with a height difference, and the discharge port 40 is arranged at a position higher than at least the liquid level 41 of the draining tank 25. Since the draining tank 25 and the pipe 38 of the pipe conveyor 26 are connected, the liquid level 41 of the liquid exists in the draining tank and also in the pipe 38 of the pipe conveyor 26.

  The pipe conveyor 26 further includes a tow rope 42 that connects the plurality of blades 39 in a ring shape, and a drive device 43 that drives the tow rope 42. The tow rope 42 is driven so that the blade 39 moves in an annular shape inside the pipe 38. Specifically, the towing rope 42 is driven so that the blade 39 rises in the ascending portion of the pipe 38 and the blade 39 descends in the descending portion.

Next, the effect | action of the waste water treatment facility 1 of this embodiment is demonstrated.
First, the operation in the water treatment system will be described.
The organic waste water W is introduced into the pretreatment facility 2 to remove impurities. Next, the organic waste water W is first introduced into the biological treatment facility 4 after sludge is separated in the sedimentation basin 3. Next, the organic waste water W is subjected to biological treatment in the biological treatment facility 4, and then the sludge including living organisms is separated in the final sedimentation basin 5. And the organic waste water W is discharged after an advanced process is performed.

In the sludge treatment system, an alkaline agent such as sodium hydroxide is injected into the first sludge P1 separated in the first sedimentation basin 3 by the hydrogen ion improving device 19.
Next, carbon dioxide is blown into the first sludge P1 by the carbon dioxide supply device 20.

Next, the first sludge P1 is introduced into the sand removing device 16.
The hydrocyclone 22 causes the centrifugal force to act on the first sludge P1 by the swirling flow and separates the sand S from the first sludge P1. The first sludge P1 from which the sand S has been removed overflows and is discharged from the upper outlet 29 of the liquid cyclone 22, and the concentrated treatment liquid containing the sand S moves under the casing 27 of the liquid cyclone 22 while turning. It is discharged from the lower outlet 30.

  The concentrated treatment liquid containing the sand S separated by the hydrocyclone 22 is temporarily accumulated in the concentration tube 23. The concentration tube 23 has a role of preventing the solid matter contained in the concentrated treatment liquid from affecting the operation of the liquid cyclone 22. In the lower part of the concentration tube 23, a solid substance contained in the concentrated treatment liquid is precipitated. The concentrating tube 23 has such a length that the sediment precipitated in the lower part thereof is not caught in the swirling flow generated in the liquid cyclone 22.

  The rotary valve 24 sequentially sends the concentrated processing liquid accumulated in the concentration tube 23 to the settling tank of the draining tank 25. Specifically, the concentrated processing liquid is filled into the transfer chamber 33 at the upper inlet of the rotary valve 24. When the rotor 32 of the rotary valve 24 rotates and the transfer chamber 33 filled with the concentrated processing liquid reaches the position of the lower outlet, the concentrated processing liquid flows out from the transfer chamber 33 and is sent to the settling tank of the draining tank 25. According to such an operation, the concentrated processing liquid is intermittently sent to the draining tank 25.

The draining tank 25 accumulates the concentrated processing liquid sent from the rotary valve 24 and performs precipitation classification. Sand S which precipitates by sedimentation classification is introduced into the pipe conveyor 26 through the opening 36 of the draining tank 25.
On the other hand, when the liquid level 41 of the concentrated processing liquid exceeds the upper end of the overflow liquid receiver 35, the liquid component flows into the overflow liquid receiver 35 and is sent to the pretreatment facility 2 via the overflow line 37. The liquid component flowing into the overflow liquid receiver 35 does not include the sand S that is a precipitate.

  The sand S introduced into the pipe conveyor 26 through the opening 36 is captured by the blade 39 and moves up the rising portion of the pipe 38. The sand S is introduced into the discharge port 40 and discharged from the discharge port 40 when it reaches the rising portion. Since the sand S is transported beyond the liquid level 41 existing inside the pipe 38 of the pipe conveyor 26, the liquid component is removed from the sand S.

  The first sludge P1 from which the sand S has been removed by the sand removing device 16 is stored in the sludge storage tank 11, and then dehydrated by the sludge dehydrator 14. Further, the separation liquid generated by the sludge dehydrator 14 is sent to the biological treatment facility 4. The dehydrated sludge that has been dehydrated is sent to the sludge dryer 15 to be dried sludge.

  According to the said embodiment, by providing the sand removal apparatus 16, abrasion of apparatuses, such as the sludge dehydrator 14 and the sludge dryer 15 which occur with the sand S, can be suppressed. Thereby, the waste water treatment facility 1 can be stably operated, and the maintenance cost can be reduced.

  Moreover, compared with the structure which provides the means which removes the sand S with respect to the process liquid introduce | transduced into the biological treatment equipment 4, the liquid quantity made into object can be reduced. That is, the sand contained in the treatment liquid can be removed more efficiently.

  Moreover, since the sand removal by the sand removal apparatus 16 is performed with respect to the 1st sludge P1 isolate | separated from the first sedimentation basin 3 which is located in the upstream of the biological treatment equipment 4 and collects most sludge, it is efficiently. Sand can be removed.

  Further, by employing the hydrocyclone 22 as the sand removing device 16, the sand S contained in the sludge can be stably separated using the hydrocyclone 22 that is easy to handle.

  Moreover, since the concentrated processing liquid discharged from the liquid cyclone 22 is temporarily accumulated in the concentration pipe 23 by providing the concentrating tube 23 at the lower part of the liquid cyclone 22, the solid matter contained in the concentrated processing liquid is liquid cyclone 22. Can be prevented from affecting the operation. Moreover, by exchanging the concentration tube 23, maintenance can be easily performed, and blockage in the liquid cyclone 22 due to scale components can be prevented.

In addition, the volume of the draining tank 25 can be reduced by quantitatively discharging the concentrated processing liquid separated by the liquid cyclone 22 by the rotary valve 24.
Further, when the sand S is transferred in the pipe 38 of the pipe conveyor 26, the liquid component accompanying the sand S is separated when the sand S is lifted up from the liquid surface 41 of the draining tank 25. Thereby, even when the liquid component remains in the sand S discharged from the draining tank 25, the liquid component can be removed.

  In addition, sodium hydroxide is injected into the first sludge P1 in the front stage of the sand removing device 16 to improve the pH of the first sludge P1, so that lead (Pb) and cadmium ( Heavy metals such as Cd) and scale components can be deposited. Then, the precipitated heavy metal and scale components can be removed together with the sand S. Thereby, the safety | security at the time of sludge landfill and reuse after dehydration or drying can be improved.

  Further, by blowing carbon dioxide into the first sludge P1, even when the organic waste water W contains hardness components such as calcium (Ca) and magnesium (Mg), carbonates of calcium and magnesium are produced. It can be deposited and removed together with the sand S. Thereby, since at least a part of scale components such as calcium and magnesium is removed, troubles caused by the scale around the sludge volume reducing equipment 13 can be prevented.

(Second embodiment)
Hereinafter, the waste water treatment facility 1B according to the second embodiment of the present invention will be described with reference to the drawings. In the present embodiment, differences from the first embodiment described above will be mainly described, and description of similar parts will be omitted.
As shown in FIG. 3, the wastewater treatment facility 1 </ b> B of the present embodiment is characterized in that the sand removing device 16 is provided in the mixed sludge line 10. That is, the first sludge P1 and the second sludge P2 are introduced into the sand removing device 16. The sand removing device 16 removes sand contained in the first sludge P1 and the second sludge P2.

  According to the above embodiment, the sand that has flowed to the downstream side of the first sedimentation basin 3 can be removed. That is, the sand contained in the sludge that has flowed into the biological treatment facility 4 can be removed without first being settled in the settling tank 3.

(Third embodiment)
Hereinafter, a wastewater treatment facility 1C according to a third embodiment of the present invention will be described with reference to the drawings. In the present embodiment, differences from the first embodiment described above will be mainly described, and description of similar parts will be omitted.
As shown in FIG. 4, the wastewater treatment facility 1 </ b> C of this embodiment is characterized in that a sand removal device 16 is provided in the concentrated sludge line 12. That is, the sludge discharged from the sludge storage tank 11 is introduced into the sand removing device 16.

  According to the said embodiment, the load of the sand removal apparatus 16 can be adjusted by adjusting the storage time etc. in the sludge storage tank 11. FIG.

(Fourth embodiment)
Hereinafter, waste water treatment equipment 1D of a 4th embodiment is explained to the present invention based on a drawing. In the present embodiment, differences from the first embodiment described above will be mainly described, and description of similar parts will be omitted.
As shown in FIG. 5, the sludge storage tank 11 of the wastewater treatment facility 1 </ b> D of the present embodiment has a circulation line 44 for circulating the sludge in the sludge storage tank 11. The sand removing device 16 is provided on the circulation line 44. The circulation line 44 is provided with a circulation pump 45 for circulating the sludge. The capacity of the circulation pump 45 is sufficient to circulate sludge on the circulation line 44, and can be, for example, smaller than the pressure feed pump 17 on the concentrated sludge line 12.

  According to the above embodiment, since the sand is removed from the sludge stored in the sludge storage tank 11, the sand is not affected by the amount of sludge separated in the first sedimentation basin 3 and the final sedimentation basin 5. Can be removed.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. Moreover, the structure which combined the characteristic demonstrated by said several embodiment arbitrarily may be sufficient.
For example, in each of the above embodiments, the sludge in the water treatment system is configured to separate in the first sedimentation basin 3 and the final sedimentation basin 5, but the sludge settled on the bottom of the biological treatment facility 4 is separated to obtain the sludge treatment system. It is good also as a structure introduced in.

1,1B, 1C, 1D Wastewater treatment facility 2 Pretreatment facility 3 First sedimentation basin (first sludge separation facility)
4 Biological treatment facility 5 Final sedimentation basin (second sludge separation facility)
6 Advanced treatment equipment 8 First sludge line 9 Second sludge line 10 Mixed sludge line 11 Sludge storage tank 12 Concentrated sludge line 13 Sludge volume reduction equipment 14 Sludge dewatering machine 15 Sludge dryer 16 Sand removal device 17 Pressure feed pump 19 Hydrogen ion improvement Device 20 Carbon dioxide supply device 22 Hydrocyclone 23 Concentrating tube 24 Rotary valve 25 Drain tank 26 Pipe conveyor 27 Casing 28 Introduction duct 29 Upper outlet 30 Lower outlet 31 Housing 32 Rotor 33 Transport chamber 35 Overflow liquid receiver 36 Opening 37 Overflow line 38 Pipe 39 Blade 40 Discharge port 41 Liquid level 42 Towing line 43 Drive unit 44 Circulation line 45 Circulation pump P1 First sludge P2 Second sludge S Sand W Organic wastewater (treatment liquid)

Claims (8)

A biological treatment facility for biologically treating the treatment liquid;
Sludge separation equipment for separating the sludge of the treatment liquid at at least one of upstream and downstream of the biological treatment equipment;
A sludge storage tank for storing sludge separated by the sludge separation facility;
In a wastewater treatment facility that is disposed downstream of a sludge storage tank and has a sludge volume reduction facility that reduces the volume of sludge,
A wastewater treatment facility characterized in that a sand removal device is provided between at least one of the sludge separation facility and the sludge storage tank and between the sludge storage tank and the sludge volume reduction facility.   The sand removal device is provided on a first sludge line into which a first sludge separated by a first sludge separation facility provided upstream of the biological treatment facility is introduced. The waste water treatment facility according to 1. A first sludge line into which sludge separated from a first sludge separation facility provided upstream of the biological treatment facility is introduced;
A second sludge line into which sludge separated from a second sludge separation facility provided downstream of the biological treatment facility is introduced;
The first sludge line and the second sludge line are joined and connected to the sludge storage tank; and
The waste water treatment facility according to claim 1, wherein the sand removing device is provided on the mixed sludge line. The sludge storage tank has a circulation line for circulating the sludge in the sludge storage tank,
The waste water treatment facility according to claim 1, wherein the sand removing device is provided on the circulation line.   The wastewater treatment facility according to any one of claims 1 to 4, wherein the sand removing device is a hydrocyclone. Having a concentrating tube connected to the bottom of the hydrocyclone;
6. The waste water treatment facility according to claim 5, wherein the concentrating pipe has a cylindrical shape extending with a diameter equal to a vertical direction.   The hydrogen ion improvement apparatus which improves the hydrogen ion index | exponent of the sludge introduce | transduced into this sand removal apparatus was provided in the front | former stage of the said sand removal apparatus, It is any one of Claims 1-6 characterized by the above-mentioned. Wastewater treatment equipment.   The waste water according to any one of claims 1 to 7, wherein a carbon dioxide supply device for blowing carbon dioxide into sludge introduced into the sand removal device is provided in a front stage of the sand removal device. Processing equipment.

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