KR101842807B1 - Waste water treatment facility - Google Patents

Abstract

A wastewater treatment facility (1) of the present invention comprises a biological treatment facility (4) for biological treatment of a treatment liquid (W), and a sludge treatment unit for separating sludge of the treatment liquid (W) from at least one of upstream and downstream of the biological treatment facility And a sludge storage tank (11) for storing sludge separated from the sludge separation facilities (3, 5), a sludge storage tank disposed downstream of the sludge storage tank (11) A sand removal device 16 (16) is provided on at least one side between a sludge separation facility (3, 5) and a sludge storage tank (11), a sludge storage tank (11) ).

Description

{WASTE WATER TREATMENT FACILITY}

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

This application claims priority to Japanese Patent Application No. 2013-172338 filed on August 22, 2013, and the contents of the application are hereby incorporated herein by reference.

In the wastewater treatment facility (sewage treatment plant) that purifies the sewage sludge, the sludge separation process is performed by solid-liquid separation in the initial settling basin installed at the biological treatment front end and at the final settling basin installed at the rear end of the biological treatment , See Patent Document 1).

The sludge separated from the sedimentation basin is dehydrated so that the concentration of solids is about 2% ~ 5% by the sludge dehydrator, and the concentration of solids is 60% ~ 80% by the sludge dryer And the like. For dry sludge with a high solid concentration, out-of-system removal or incineration is performed.

Patent Document 1: JP-A-2002-361300

In the sludge dewatering machine and the sludge dryer that performs dewatering by sludge and drying by dewatering, portions of the sludge which are in contact with sludge due to minerals such as sand may be worn. For example, when a centrifugal separator is employed as the sludge dehydrator, the portion of the centrifugal separator which contacts the sludge, such as a screw or a ball, is worn. Also, when a paddle type drier is used as a sludge drier, parts such as paddles and shafts are worn. As a result, there is a possibility that the stabilization process may be hindered or the maintenance cost may increase.

There is also known a method of performing sand removal treatment on wastewater introduced into a wastewater treatment facility to remove these minerals. However, when a large amount of wastewater is treated as in wastewater treatment, the treatment can not be followed and the removal of sand may become insufficient .

An object of the present invention is to provide a waste water treatment facility capable of realizing stable operation by suppressing abrasion of sludge reducing facility equipment.

According to a first aspect of the present invention, a wastewater treatment facility includes a biological treatment facility for biological treatment of a treatment liquid, a sludge separation facility for separating sludge of the treatment liquid from at least one of upstream and downstream of the biological treatment facility, A sludge storage tank for storing the sludge separated from the facility; and a sludge storage facility having a sludge storage facility disposed downstream of the sludge storage tank for sludge draining treatment, the sludge storage tank and the sludge storage tank, A sand removing device is provided on at least one side between the facilities.

According to the above arrangement, it is possible to suppress abrasion of sludge reducing equipment caused by sand by providing a sand removing device. This makes it possible to stably operate the wastewater treatment facility and reduce the maintenance cost.

In addition, as compared with a configuration in which means for removing sand is provided for a treatment liquid introduced into a biological treatment facility, the amount of liquid to be treated can be reduced. That is, the sand contained in the treatment liquid can be removed more efficiently.

The sand removal device may be installed on the first sludge line into which the first sludge separated from the first sludge separation facility installed upstream of the biological treatment facility is introduced.

According to the above construction, since the sand removal by the sand removal device is performed on the first sludge separated from the first sludge separation device located on the upstream side of the biological treatment facility and the sludge is collected the most, the sand can be efficiently removed .

A first sludge line for introducing sludge separated from a first sludge separation facility installed upstream of the biological treatment facility in the wastewater treatment facility; and a sludge separation unit for introducing sludge separated from a second sludge separation facility installed downstream of the biological treatment facility A second sludge line connected to the first sludge line and the second sludge line, and a mixed sludge line connected to the sludge storage tank by joining the first sludge line and the second sludge line, wherein the sand removal device is provided on the mixed sludge line do.

According to the above construction, sand flowing downstream of the first sludge separation facility can be removed.

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

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

In the wastewater treatment facility, the sand removing device may be a liquid cyclone.

According to the above configuration, sand contained in the sludge can be stably separated using a liquid cyclone that is easy to handle.

And a condensing tube connected to a lower portion of the liquid cyclone, and the condensing tube may have a cylindrical shape extending to a diameter equal to the vertical direction.

According to the above configuration, since the rich treatment liquid discharged from the liquid cyclone is temporarily accumulated in the concentration pipe, it is possible to prevent the solid matter contained in the rich treatment liquid from affecting the operation of the liquid cyclone. Also, by exchanging the concentrating tube, the retention can be easily performed, and clogging in the liquid cyclone due to the scale component can be prevented.

A hydrogen ion-increasing device for improving the hydrogen ion index of the sludge introduced into the sand removing device may be provided at the front end of the sand removing device in the drainage treatment facility.

According to the above arrangement, heavy metals and scale components contained in the sludge can be precipitated, and the precipitated heavy metals and scale components can be removed together with the sand.

A carbon dioxide supplying device for injecting carbon dioxide into the sludge introduced into the sand removing device may be provided at a front end of the sand removing device in the wastewater treatment facility.

According to the above constitution, even when the hardness component such as calcium or magnesium is contained in the wastewater, the carbonate of calcium and magnesium can be produced and precipitated and removed together with the sand.

According to the above arrangement, it is possible to suppress abrasion of sludge reducing facility equipment by sand by providing a sand removing device. This makes it possible to stably operate the wastewater treatment facility and reduce the maintenance cost.

In addition, as compared with a configuration in which means for removing sand is provided for a treatment liquid introduced into a biological treatment facility, the amount of liquid to be treated can be reduced. That is, the sand contained in the treatment liquid can be removed more efficiently.

1 is a schematic configuration diagram of a wastewater treatment facility according to a first embodiment of the present invention.
Fig. 2 is a schematic configuration diagram of a sand removal device of a wastewater treatment facility according to the first embodiment of the present invention.
3 is a schematic configuration diagram of a wastewater treatment facility according to a second embodiment of the present invention.
4 is a schematic configuration diagram of a wastewater treatment facility according to a third embodiment of the present invention.
5 is a schematic configuration diagram of a wastewater treatment facility according to a fourth embodiment of the present invention.

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 for explaining the configuration of the wastewater treatment facility 1 of the present embodiment. The wastewater treatment facility 1 of the present 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 organic wastewater W is introduced and a first settler 3 separating the sludge from wastewater treated in the pretreatment facility 2 A biological treatment facility 4 for biological treatment of wastewater from which the sludge is separated from the first settling basin 3 and a final settling basin 5 for separating the sludge again from the biologically treated sludge A second sludge separation process), and an advanced treatment facility 6 for advanced treatment of wastewater from which the sludge has been separated in the final settling basin 5.

That is, in the water treatment system, sludge is generated by solid separation in the first settling basin 3 at the front end of the biological treatment facility 4 and at the final settler 5 at the rear end of the biological treatment facility 4. The organic wastewater W is discharged to the river via each of the above facilities.

The pretreatment facility 2 is a facility for removing impurities contained in the organic wastewater W to be introduced. As the pretreatment facility 2, crushing means for crushing large-diameter sludge and separating means such as a screw capable of removing impurities can be mentioned.

The initial settling basin 3 is a sludge separation facility for separating fine sludge contained in organic wastewater W by depositing on the bottom. A first sludge line (8) is connected to the bottom of the first settling tank (3). That is, the sludge separated from the first sedimentation bed 3 (hereinafter referred to as the first sludge P1) is introduced into the first sludge line 8. The organic wastewater W flows slowly in the first settling basin 3 and the first sludge P1 is introduced into the first sludge line 8 while being solid at the bottom of the initial settling basin 3. [

The biological treatment facility 4 has an anaerobic tank for performing anaerobic treatment such as methane fermentation, an aerobic tank for aerating and a plurality of sedimentation tanks, and is mainly composed of nitrifying bacteria and denitrification bacteria to remove BOD, nitrogen compounds Is a facility to disassemble and remove.

In the final settling basin (5), the sludge, including the organisms used for treatment in the biological treatment facility (4), sinks to the bottom. A second sludge line (9) is connected to the bottom of the final settler (5). The sludge separated from the final sedimentation bed 5 (hereinafter referred to as a 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, the sludge separation equipment composed of the initial settling basin 3 and the final settling basin 5 separated the sludge by gravity sedimentation, but the present invention is not limited thereto. For example, separation means such as dynamic filtration, coagulation separation, membrane separation, and sand filtration, or a dehydrating function such as a belt press or a screw press may be employed as the means for separating the sludge.

Examples of the advanced treatment facility 6 include an agglomerate 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 comprises a first sludge line 8 for recovering the sludge of the first settling basin 3, a second sludge line 9 for recovering the sludge of the final settling basin 5, a first sludge line 8, A mixed sludge line 10 which is a line in which the second sludge line 9 joins the sludge storage tank 11 installed on the downstream side of the mixed sludge line 10 and sludge from the sludge storage tank 11 are introduced And a sludge reducing facility 13 provided on the downstream side of the sludge storage tank 11. The sludge storage facility 12 is connected to the sludge storage facility 11 through the sludge storage facility 12,

The sludge reducing facility 13 is a facility for depressurizing the sludge and has a sludge dewatering device 14 and a sludge dryer 15 installed downstream of the sludge dewatering device 14.

A sand removing device 16 for removing sand contained in the first sludge (P1) is provided on the first sludge line (8).

A hydrogen ion enhancing device 19 for improving the pH of the first sludge P1 introduced into the sand removing device 16 is provided at the upstream side of the sand removing device 16 as the first sludge line 8, Respectively. The hydrogen ion enhancer 19 is a device for injecting an alkali 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 a substitute for sodium hydroxide.

A carbon dioxide supplying device 20 for injecting carbon dioxide (CO ₂ ) into the first sludge P1 introduced into the sand removing device 16 is provided at the upstream side of the sand removing device 16, ).

The sludge dewatering device 14 is a device for dewatering the sludge sent from the sludge storage tank 11 by the feed pump 17. As the sludge dehydrator 14, a centrifugal separator or a screw press type sludge dehydrator may be employed. The separated liquid separated from the sludge dehydrator 14 is sent to the biological treatment facility 4 for biological treatment.

For example, a centrifuge separates the sludge from the separation liquid with a high-speed rotating screw, and discharges the sludge by the relative motion difference between the balls, which is slightly slower rotation. In addition, the screw press type sludge dewatering machine arranges two screws in a superposed state, and the screw wing is engaged with each other to dehydrate the screw while giving a shear force thereto.

The sludge dryer (15) is a device for drying the dehydrated sludge subjected to dehydration in the sludge dehydrator (14). As the sludge dryer 15, a paddle type dryer may be employed. The paddle-type dryer dries the dehydrated sludge by arranging two shafts having paddle wings in a superimposed manner, and arranging the paddle wings to mesh with each other.

Next, the sand removing device 16 installed in the first sludge line 8 will be described.

The sand removing device 16 is a classifying device employing the mechanism of the liquid cyclone 22. The sand removing device 16 performs centrifugal classification on the first sludge P1 introduced through the first sludge line 8 to classify the first sludge P1 ) Of the sand.

2, the sand removing device 16 includes a liquid cyclone 22, a concentration pipe 23 connected to the lower portion of the liquid cyclone 22, a rotary valve 23 connected to a lower portion of the concentration pipe 23, A dewatering tank 25 for receiving the sand S containing moisture discharged from the rotary valve 24 and a pipe conveyor for pumping sand S precipitated in the lower portion of the dewatering tank 25 26).

The liquid cyclone 22 is provided with a cylindrical casing 27 whose diameter is gradually reduced as it goes downward and a cylindrical casing 27 which is provided in the vicinity of the upper end of the casing 27 and in which the first sludge P1 is swung in the casing 27 An upper outlet 29 provided so as to protrude upward on the upper surface of the casing 27 and a lower outlet 30 provided at the lower end of the casing 27. [ The induction duct 28 is connected to the upstream side of the first sludge line 8 and is provided at the connection portion between the induction duct 28 and the first sludge line 8 so as to generate a high- A pump (not shown) is provided.

The 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 P1 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 in a diameter equal to the vertical direction. Specifically, the diameter of the concentrating pipe 23 is set to 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 portion of the cyclone. The rotary valve 24 has a housing 31 and a rotor 32 rotated by a driving source (not shown) in the housing 31. The rotor 32 divides the inside of the casing 27 into a plurality of transport chambers 33. The rotary valve 24 of the present embodiment is provided with six transport chambers 33. That is, the rotor 32 of the rotary valve 24 is provided with six blades, and a transfer chamber 33 is formed between the blades.

The dewatering tank 25 is a sedimentation tank for accumulating the sand S containing water sent from the rotary valve 24, and is a sedimentation classifying mechanism for performing sediment classification. An overflow receiver 35 is provided in the dewatering tank 25 and an opening 36 is provided in the lower portion of the dewatering tank 25.

An overflow line 37 is connected to the discharge portion of the overflow receiver 35 to send the liquid in the overflow receiver 35 to the pretreatment facility 2. [

The pipe conveyor 26 includes a cylindrical pipe 38 connected to the opening 36 of the dewatering tank 25, a plurality of blades 39 movable in the pipe 38, (40).

The pipe 38 is disposed with a gap at the bottom and the outlet 40 is disposed at a position higher than at least the liquid level 41 of the dewatering tank 25. Since the dehydration tank 25 and the pipe 38 of the pipe conveyor 26 are connected to each other, the liquid level 41 of the liquid is present inside the dehydration tank and also inside the pipe 38 of the pipe conveyor 26 .

The pipe conveyor 26 also has a cable 42 that is an example of connecting the plurality of blades 39 in an annular shape and a drive device 43 that drives the towing cable 42. The towing cable 42 is driven such that the blades 39 are annularly moved in the interior of the pipe 38. Specifically, the towing cable 42 is driven such that the blade 39 rises in the ascending portion of the pipe 38, and the blade 39 descends in the descending portion thereof.

Next, the operation of the wastewater treatment facility 1 of the present embodiment will be described.

First, the operation of the water treatment system will be described.

The organic wastewater W is introduced into the pretreatment facility 2 to remove impurities and the like. Subsequently, the organic wastewater (W) is separated from the sludge in the first sedimentation tank (3) and introduced into the biological treatment facility (4). Subsequently, the biological wastewater (W) is subjected to biological treatment in the biological treatment facility (4), and the sludge containing organisms is separated from the final sedimentation tank (5). The organic wastewater (W) is discharged after the advanced treatment.

In the sludge treatment system, an alkali agent such as sodium hydroxide is injected into the first sludge (P1) separated from the first settler (3) through the hydrogen ion enhancer (19).

Carbon dioxide is then injected into the first sludge (P1) through the carbon dioxide supply device (20).

Subsequently, the first sludge (P1) is introduced into the sand removing device (16).

The liquid cyclone 22 separates the sand S from the first sludge P1 by applying a centrifugal force to the first sludge P1 by the swirling flow. The first sludge P1 from which the sand S has been removed is overflowed from the upper outlet 29 of the liquid cyclone 22 and the rich treatment liquid containing the sand S is circulated while passing through the liquid cyclone 22 Moves downward of the casing (27) and is discharged to the lower outlet (30).

The rich treatment liquid containing the sand S separated from the liquid cyclone 22 is once accumulated in the concentration pipe 23. The concentrating pipe 23 has a role of preventing the solid matter contained in the rich treatment liquid from affecting the operation of the liquid cyclone 22. In the lower part of the concentrating pipe (23), a solid body liquid contained in the rich treatment liquid is precipitated. The concentrating pipe 23 has a length such that the precipitate settled in the lower part is not caught in the swirling flow generated in the liquid cyclone 22.

The rotary valve 24 sends out the rich treatment liquid accumulated in the concentrating pipe 23 to the settling tank of the dewatering tank 25 in order. Specifically, the rich processing liquid is filled in the transfer chamber 33 at the upper inlet of the rotary valve 24. [ When the transfer chamber 33 in which the rotor 32 of the rotary valve 24 rotates and the rich liquid is filled reaches the lower outlet position, the rich liquid flows out of the transfer chamber 33, Lt; / RTI > According to this operation, the rich treatment liquid is sent to the dehydration tank 25 intermittently.

The dewatering tank (25) accumulates rich treatment liquid sent out by the rotary valve (24) and performs sediment classification. The sand S precipitated by the sediment classification is introduced into the pipe conveyor 26 from the opening 36 of the dewatering tank 25.

On the other hand, when the liquid surface 41 of the rich liquid treatment solution exceeds the upper end of the overflow receiver 35, the liquid component flows into the overflow receiver 35, (2). The liquid component flowing into the overflow receiver (35) does not include the sand (S) which is a precipitate.

The sand S introduced into the pipe conveyor 26 via the opening 36 is caught by the blade 39 and ascends on 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 the rising part is climbed to the end. The sand S is transported past the liquid level 41 present inside the pipe 38 of the pipe conveyor 26 and therefore the liquid component is removed from the sand S.

The first sludge P1 from which the sand S has been removed in the sand removing device 16 is stored in the sludge storage tank 11 and then dehydrated in the sludge dehydrator 14. [ Further, the separated liquid produced in the sludge dehydrator 14 is sent to the biological treatment facility 4. The dehydrated dehydrated sludge is sent to the sludge dryer 15 to become a dried sludge.

According to the above embodiment, it is possible to suppress the wear of the sludge dryer 14, the sludge dryer 15, and the like caused by the sand S by providing the sand removing device 16. This makes it possible to stably operate the wastewater treatment facility 1 and reduce the maintenance cost.

In addition, as compared with the configuration in which the means for removing the sand S is provided for the treatment liquid introduced into the biological treatment facility 4, the amount of liquid to be treated can be reduced. That is, the sand contained in the treatment liquid can be removed more efficiently.

Since the sand removal by the sand removing device 16 is performed on the first sludge P1 which is located on the upstream side of the biological treatment facility 4 and separated from the first settling basin 3 where the sludge is collected the most, Sand can be removed.

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

Since the thickening pipe 23 is provided below the liquid cyclone 22, the thickened liquid discharged from the liquid cyclone 22 is temporarily accumulated in the thickening pipe 23, It is possible to prevent influences on the operation of the switch 22. Also, by exchanging the concentrating pipe 23, it is possible to easily carry out maintenance and to prevent the clogging in the liquid cyclone 22 due to the scale component.

In addition, the volume of the dewatering tank 25 can be reduced by discharging the rich treatment liquid separated from the liquid cyclone 22 by the rotary valve 24 in a fixed amount.

In addition, at the time of transferring the sand S along the pipe 38 of the pipe conveyor 26, when the sand S is pushed up from the liquid level 41 of the dewatering tank 25, The liquid component is separated. Thus, even when the liquid component remains in the sand S discharged from the dewatering tank 25, the liquid component can be removed.

Sodium hydroxide is injected into the first sludge P1 at the front end of the sand removing device 16 to improve the pH of the first sludge P1 so that the amount of lead Pb, (Cd) or the like can be precipitated. The precipitated heavy metal or scale component can be removed together with the sand (S). This makes it possible to enhance the safety at the time of sludge embedding or reuse after dehydration or drying.

Also, when carbon dioxide is injected into the first sludge (P1), even if the organic waste water (W) contains hardness components such as calcium (Ca) and magnesium (Mg), calcium carbonate and magnesium carbonate are precipitated and precipitated S). As a result, at least a part of scale components such as calcium and magnesium are removed, thereby preventing troubles due to the scale around the sludge reducing facility 13. [

(Second Embodiment)

Hereinafter, a wastewater treatment facility 1B according to a second embodiment of the present invention will be described with reference to the drawings. In addition, in the present embodiment, differences from the first embodiment will be mainly described, and description of the same portions will be omitted.

As shown in Fig. 3, the wastewater treatment facility 1B of the present embodiment is characterized in that the sand removal device 16 is installed in the mixed sludge line 10. Fig. 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-described embodiment, it is possible to remove the sand that has flowed to the downstream side of the initial sedimentation paper 3. That is, the sand contained in the sludge flowing into the biological treatment facility 4 can be removed without sedimentation in the initial sedimentation bed 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 addition, in the present embodiment, differences from the first embodiment will be mainly described, and description of the same portions will be omitted.

As shown in Fig. 4, the wastewater treatment facility 1C of the present embodiment is characterized in that the sand removing device 16 is installed in the concentrated sludge line 12. Fig. That is, the sludge discharged from the sludge storage tank 11 is introduced into the sand removing device 16.

According to the above embodiment, the load of the sand removing device 16 can be adjusted by adjusting the retention time or the like in accordance with the sludge storage tank 11.

(Fourth Embodiment)

Hereinafter, a wastewater treatment facility 1D according to a fourth embodiment of the present invention will be described with reference to the drawings. In addition, in the present embodiment, differences from the first embodiment will be mainly described, and description of the same portions will be omitted.

As shown in Fig. 5, the sludge storage tank 11 of the wastewater treatment facility 1D of the present embodiment has a circulation line 44 for circulating sludge in the sludge storage tank 11. The sand removing device 16 is installed 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 set at a capacity sufficient to circulate the sludge on the circulation line 44 and can be set to a smaller capacity than the pressure feeding pump 17 on the concentrated sludge line 12, for example.

According to the above embodiment, since the sand is removed from the sludge stored in the sludge storage tank 11, the sand is removed without being influenced by the amount of the sludge separated in the first settler 3 and the final settler 5 .

The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention. It is also possible to adopt a configuration in which the features described in the above-mentioned several embodiments are arbitrarily combined.

For example, in each of the above embodiments, the sludge according to the water treatment system is separated from the initial sedimentation bed 3 and the final sedimentation bed 5, but the sludge settling at the bottom of the biological treatment facility 4 is separated, Or may be introduced into the system.

Industrial availability

According to the drainage treatment facility, it is possible to suppress abrasion of sludge reducing equipment caused by sand by providing a sand removal device. This makes it possible to stably operate the wastewater treatment facility and reduce the maintenance cost.

In addition, as compared with a configuration in which means for removing sand is provided for a treatment liquid introduced into a biological treatment facility, the amount of liquid to be treated can be reduced. That is, the sand contained in the treatment liquid can be removed more efficiently.

1, 1B, 1C, 1D Wastewater Treatment Plant
2 Pre-treatment equipment
3 First settling basin (first sludge separation facility)
4 Biological treatment facilities
5 Final settling basin (2nd sludge separation facility)
6 Advanced Treatment Facilities
8 First sludge line
9 Second sludge line
10 Mixed sludge line
11 Sludge reservoir
12 Concentrated sludge line
13 Sludge digging facility
14 Sludge Dehydrator
15 Sludge dryer
16 Sand removal unit
17 pressure pump
19 Hydrogen ion enhancer
20 Carbon dioxide supply
22 liquid cyclone
23 concentrator
24 rotary valve
25 Dewatering tank
26 Pipe Conveyor
27 Casing
28 Introduction duct
29 Upper exit
30 Lower exit
31 Housing
32 rotor
33 Carrier
35 overflow receiver
36 aperture
37 Overflow line
38 pipe
39 blades
40 outlet
41 denominations
42 Tow Cable
43 drive
44 circulation line
45 circulation pump
P1 first sludge
P2 second sludge
S Sand
W organic wastewater (treatment liquid)

Claims (12)

A biological treatment facility for biological treatment of the treatment liquid,
A sludge separation facility for separating sludge of the treatment liquid from at least one of upstream and downstream of the biological treatment facility;
A sludge storage tank for storing sludge separated from the sludge separation facility,
In a waste water treatment plant having a sludge reducing facility disposed downstream of the sludge storage tank and depressurizing the sludge,
A sand removal device is provided at least between the sludge separation facility and the sludge storage tank, between the sludge storage tank and the sludge storage facility,
Wherein the sludge storage tank has a circulation line for circulating sludge in the sludge storage tank,
Wherein the sand removing device is installed on the circulation line,
A carbon dioxide supplying device for injecting carbon dioxide into the sludge introduced into the sand removing device is installed at a front end of the sand removing device,
A hydrogen ion enhancing device for improving the hydrogen ion index of the sludge introduced into the sand removing device is provided on the upstream side of the carbon dioxide supplying device as the front end of the sand removing device,
Wherein the carbon dioxide supplying device and the hydrogen ion enhancing device are installed on a first sludge line into which a first sludge separated from a first sludge separation facility formed upstream of the biological treatment facility is introduced,
The sand removing device comprises:
A liquid cyclone into which the first sludge treated in the carbon dioxide supplying device is introduced,
A cylindrical condensing tube connected to a lower portion of the liquid cyclone and extending in a diameter equal to the vertical direction,
A rotary valve connected to a lower portion of the concentrating tube,
A dehydration tank disposed below the rotary valve for separating the rich treatment liquid containing the sand discharged from the rotary valve into a liquid component and sand;
An overflow line for sending the liquid component that overflows from the dehydration tank to the upstream side of the biological treatment facility and the sludge separation facility,
At least a part of which is disposed at a position higher than the liquid level of the settling tank of the dewatering tank and at least a part of which is extended toward the vertical direction and which is connected to the bottom of the dewatering tank, And a pipe,
And a pipe which is disposed in the pipe and in which a gap is formed between the pipe and the pipe so as to extend from below the liquid level formed at a portion extending toward the vertical direction of the pipe to above the liquid level, A plurality of blades which are held on a surface and are lifted up,
A cable that connects each of the plurality of blades so that each of the plurality of blades is disposed perpendicular to the extending direction of the pipe;
A drive unit for driving the towed cable,
And a discharge port installed in the pipe and discharging the sand pumped up by the blade. The method according to claim 1,
Wherein the sand removal device is installed on the first sludge line. The method according to claim 1,
The first sludge line,
A second sludge line into which sludge separated from a second sludge separation facility installed downstream of the biological treatment facility is introduced,
And a mixed sludge line in which the first sludge line and the second sludge line join together and are connected to the sludge storage tank,
Wherein the sand removal device is installed on the mixed sludge line. delete delete delete delete delete delete delete delete delete

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