JPH0919700A - Sewage treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sewage treating device with which the removal of unnecessary phosphorus components is possible and there is no need for charging the waste liquid of scum removal, methanol, etc., into a biological treating vessel. SOLUTION: This sewage treating device has a screen 11, a sludge storage tank 32 which mixes scum and excess sludge, a flocculating vessel 34 which flocculates the liquid mixed with the sludge from this sludge storage tank 31, a dehydrating machine 35 which dehydrates the liquid mixed with flocs, a storage tank 12 for the waste liquid of scum removal which mixes the waste water after filtration and the dehydrated filtrate and forms the mixed and adjusted night soil, the biological treating vessel 37 which subjects the mixed and adjusted night soil to a biological nitrifying and denitrifying treatment, a flocculating, concentrating and separating vessel 38 which flocculates the biologically treated and mixed liquid from the biological treating vessel 37 and a membrane separating vessel 38 which subjects the separated liquid from the flocculating, concentrating and separating vessel 38 to sepn. of solid from the liquid. The activated sludge separated in the flocculating, concentrating and separating vessel 38 is sent to a sludge storage tank 32. The amt. of the phosphorus component in the waste water after the filtration is adjusted in correspondence to the amt. of the phosphorus component necessary for the biological nitrifying and denitrifying treatment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewage treatment apparatus.

[0002]

2. Description of the Related Art Conventionally, there has been provided a sewage treatment apparatus having two stages of membrane separators for treating wastewater such as human waste and septic tank sludge. FIG. 2 is a block diagram of a conventional sewage treatment apparatus that performs a two-stage membrane treatment. In the figure, 11 is a screen for filtering wastewater such as human waste and septic tank sludge, and the wastewater after being filtered by the screen 11 (hereinafter referred to as “removal waste liquid”) is sent to a residual waste liquid storage tank 12. The residue that has been stored and stored and separated by filtration is sent to a dehydrator 13, where it is dehydrated into a dehydrated filtrate, and the dehydrated filtrate is sent to the waste residue storage tank 12.

Next, the waste sludge waste liquid sent to the waste sludge waste liquid storage tank 12 is mixed with the dehydrated filtrate to be mixed and adjusted into urine, and the mixed and adjusted urine is sent to the biological treatment tank 15. In the biological treatment tank 15, the urine is subjected to biological nitrification and denitrification treatment (hereinafter referred to as “biological denitrification treatment”) after being mixed and adjusted, and BOD component, COD component and nitrogen (TN) in the urine are adjusted and mixed. ) The components and the like are removed, and a biological treatment mixture of biological sludge and biological treatment water is formed. The biological treatment mixture is
Further, it is sent to the membrane separation device 16 and separated by the membrane separation device 16 into biological sludge and biological treated water. And
The biological sludge separated by the membrane separator 16 is returned to the biological treatment tank 15 as return sludge, while the biological treated water is sent to the coagulation treatment tank 17.

In the coagulation treatment tank 17, by adding a coagulant, the biologically treated water is coagulated to produce coagulated sludge. At this time, phosphorus (TP) components, COD components, chromaticity components, etc. remaining in the biologically treated water are fixed and removed in the coagulated sludge. Then, the coagulated sludge is sent to the membrane separation device 19 and is solid-liquid separated in the membrane separation device 19.

Further, the permeated liquid of the membrane separation device 19 is sent to an activated carbon treatment device 20, treated with activated carbon to remove COD components, chromaticity components and the like, and discharged as treated water. Thus, since the two-stage membrane treatment is performed, the quality of treated water can be improved. However, since it is necessary to dispose two membrane separation devices 16 and 19, the cost becomes high.

Therefore, the urine is mixed and adjusted before being sent to the biological treatment tank 15, and the urine is subjected to coagulation / dehydration treatment.
There is provided a sewage treatment apparatus that does not require the 7 and the membrane separation apparatus 19. FIG. 3 is a block diagram of a conventional sewage treatment apparatus that performs one-stage membrane treatment. In the figure, 11 is a screen for filtering waste water such as human waste and septic tank sludge, and the residual waste liquid is sent to a residual waste liquid storage tank 12.

Next, the waste sludge waste liquid sent to the waste sludge waste liquid storage tank 12 is sent to the flocculation tank 21, and in the flocculation tank 21, the inorganic flocculant and the polymer are added to the waste sludge waste liquid to obtain the waste sludge waste liquid. The floc mixture liquid is formed by flocculation to form flocs. Then, the floc mixed solution is sent to the dehydrator 22 and dehydrated by the dehydrator 22 to become a dehydrated filtrate,
The dehydrated filtrate is sent to the biological treatment tank 24 via the storage tank 23.

In the biological treatment tank 24, the dehydrated filtrate is subjected to biological denitrification treatment so that the BOD component and CO in the dehydrated filtrate are reduced.
The D component, the nitrogen component, etc. are removed, and a biological treatment mixed liquid of biological sludge and biological treated water is formed. The biological treatment mixed liquid is further sent to the membrane separation device 25, and is separated into biological sludge and biological treatment water by the membrane separation device 25. Then, the biological sludge separated by the membrane separation device 25 is returned to the biological treatment tank 24 as return sludge,
On the other hand, the biologically treated water is sent to the activated carbon treatment device 26. Then, the biologically treated water is treated with activated carbon to obtain C
OD components, chromaticity components, etc. are removed and discharged as treated water.

[0009]

However, in the above-mentioned conventional sewage treatment apparatus, as a result of introducing chemicals such as an inorganic coagulant and a polymer for the coagulation treatment by the coagulation tank 21 and dehydrating it, the biological treatment tank 24 The balance (about 2.86: 1: 0.1) of BOD components, nitrogen components, and phosphorus components necessary for the biological denitrification process due to the above is destroyed.

That is, BOD component, C
Various components such as OD component, SS component, nitrogen component, and phosphorus component are contained.
Each component is removed at different removal rates. In particular, since the removal rates of BOD components, SS components, and phosphorus components are high, the load of the BOD components of the biological denitrification treatment is small, but the waste waste liquid before and after the coagulation treatment by the coagulation tank 21 is performed. B, which has a different water quality component ratio and is required for biological denitrification
The OD component and the phosphorus component are insufficient, and the activity of the activated sludge becomes insufficient.

Therefore, in order to replenish these components,
In some cases, it may be necessary to add the residual waste liquid, methanol, etc. to the biological treatment tank 24. However, the biological treatment tank 24
When the waste sludge waste liquid is added to, the phosphorus component in the waste sludge waste liquid is added. In this case, it is difficult to completely remove the phosphorus component because there is no coagulation treatment after biological treatment. Therefore, it is necessary to dispose an anaerobic tank upstream of the biological treatment tank 24 to perform biological dephosphorization treatment, or to add a coagulant downstream of the biological treatment tank 24 to remove residual phosphorus. is there.

If methanol is added to the biological treatment tank 24, the cost will increase accordingly. The present invention
An object of the present invention is to solve the problems of the conventional sewage treatment apparatus, to remove unnecessary phosphorus components, and to provide a sewage treatment apparatus that does not need to add residual waste liquid, methanol, etc. to a biological treatment tank. And

[0013]

Therefore, in the sewage treatment apparatus of the present invention, a screen for filtering wastewater and removing residue, and a mixture of the residue and excess sludge to form a sludge mixed solution, A sludge storage tank for storing the sludge mixed liquid, a flocculation tank for aggregating the sludge mixed liquid from the sludge storage tank to form a floc mixed liquid in which flocs are formed, and a floc mixed liquid from the flocculation tank are dehydrated. A dehydrator for separating the dehydrated cake and the dehydrated filtrate, the waste water after being filtered in the screen, and the dehydrated filtrate from the dehydrator are mixed and adjusted into urine, and the mixed and adjusted urine is stored. A waste sludge waste liquid storage tank, a biological treatment tank that performs biological nitrification denitrification treatment on the mixed conditioned urine to form a biological treatment mixture of biological sludge and biological treated water, and biological treatment from the biological treatment tank Aggregate the mixed solution to activate A and the coagulation concentration and separation tank that is separated into a separated liquid, and a membrane separation device for solid-liquid separating liquid separated from aggregated concentration and separation tank.

The activated sludge separated in the coagulation / concentration separation tank is sent to the sludge storage tank as an excess sludge, and the amount of phosphorus component in the waste water after being filtered in the screen is determined by the biological treatment. It is adjusted according to the amount of phosphorus component required for the biological nitrification and denitrification treatment in the tank. In another sewage treatment apparatus of the present invention, a sludge storage tank for filtering a wastewater and removing a sludge and a sludge mixed solution by mixing the sludge with an excess sludge to store the sludge mixed solution And a flocculating tank that flocculates the sludge mixed solution from the sludge storage tank to form a floc mixed solution, and dehydrates the floc mixed solution from the flocculating tank to form a dehydrated cake and a dehydrated filtrate. A dehydrator to be separated, waste water after being filtered in a screen, and dehydrated filtrate from the dehydrator are mixed and adjusted into urine, and a desalted waste liquid storage tank that stores the adjusted urine by mixing and mixing, and the mixing adjustment A biological treatment tank that performs biological nitrification and denitrification treatment on human waste to form a biological treatment mixture of biological sludge and biologically treated water, a biological treatment mixture from the biological treatment tank, and activated sludge and separated liquid. Equipped with a membrane separation device for solid-liquid separation That.

The activated sludge separated in the membrane separation device is sent to the sludge storage tank as excess sludge, and the amount of phosphorus component in the wastewater after being filtered in the screen is the biological treatment tank. Is adjusted in accordance with the amount of phosphorus component required for the biological nitrification and denitrification treatment in.

[0016]

According to the present invention, as described above, in the sewage treatment apparatus, a screen for filtering wastewater to remove sludge, and the sludge and excess sludge are mixed to form a sludge mixed solution,
A sludge storage tank for storing the sludge mixed liquid, a flocculation tank for aggregating the sludge mixed liquid from the sludge storage tank to form a floc mixed liquid in which flocs are formed, and a floc mixed liquid from the flocculation tank are dehydrated. A dehydrator for separating the dehydrated cake and the dehydrated filtrate, the waste water after being filtered in the screen, and the dehydrated filtrate from the dehydrator are mixed and adjusted into urine, and the mixed and adjusted urine is stored. A waste sludge waste liquid storage tank, a biological treatment tank that performs biological nitrification denitrification treatment on the mixed conditioned urine to form a biological treatment mixture of biological sludge and biological treated water, and biological treatment from the biological treatment tank Aggregate the mixture,
It has a coagulation-concentration separation tank for separating activated sludge and a separation liquid, and a membrane separation device for performing solid-liquid separation of the separation liquid from the coagulation concentration separation tank.

In this case, the wastewater sent to the screen is
The waste water after being filtered by the screen is sent to the sludge waste liquid storage tank, and the sludge removed by the filtration is sent to the sludge storage tank. Then, in the sludge storage tank, the sludge and the excess sludge are mixed to form a sludge mixed liquid. The sludge mixed solution is sent to a flocculation tank and is flocculated in the flocculation tank to form a floc mixed solution in which flocs are formed. The floc mixed solution is sent to a dehydrator, dehydrated by the dehydrator, and separated into a dehydrated cake and a dehydrated filtrate. Then, the dehydrated filtrate is sent to the decontamination waste liquid storage tank.

Further, in the waste sludge waste liquid storage tank, the waste liquid after the filtration and the dehydrated filtrate are mixed and mixed to form urine, and the mixed and adjusted urine is sent to the biological treatment tank. Then, in the biological treatment tank, the mixed conditioned urine is subjected to biological nitrification and denitrification treatment to form a biological treatment mixed liquid of biological sludge and biological treated water. Further, the biological treatment mixed liquid is sent to a flocculation / concentration separation tank, and is agglomerated by the flocculation / concentration separation tank to be separated into activated sludge and a separation liquid. The separated liquid is sent to a membrane separation device and is subjected to solid-liquid separation.

The activated sludge separated in the coagulation / concentration separation tank is sent to the sludge storage tank as excess sludge, and the amount of phosphorus component in the waste water after being filtered in the screen is the biological treatment. It is adjusted according to the amount of phosphorus component required for the biological nitrification and denitrification treatment in the tank. In another sewage treatment apparatus of the present invention, a sludge storage tank for filtering a wastewater and removing a sludge and a sludge mixed solution by mixing the sludge with an excess sludge to store the sludge mixed solution And a flocculating tank that flocculates the sludge mixed solution from the sludge storage tank to form a floc mixed solution, and dehydrates the floc mixed solution from the flocculating tank to form a dehydrated cake and a dehydrated filtrate. A dehydrator to be separated, waste water after being filtered in a screen, and dehydrated filtrate from the dehydrator are mixed and adjusted into urine, and a desalted waste liquid storage tank that stores the adjusted urine by mixing and mixing, and the mixing adjustment A biological treatment tank that performs biological nitrification and denitrification treatment on human waste to form a biological treatment mixture of biological sludge and biologically treated water, a biological treatment mixture from the biological treatment tank, and activated sludge and separated liquid. Equipped with a membrane separation device for solid-liquid separation That.

In this case, the wastewater sent to the screen is
The waste water after being filtered by the screen is sent to the sludge waste liquid storage tank, and the sludge removed by the filtration is sent to the sludge storage tank. Then, in the sludge storage tank, the sludge and the excess sludge are mixed to form a sludge mixed liquid. The sludge mixed solution is sent to a flocculation tank and is flocculated in the flocculation tank to form a floc mixed solution in which flocs are formed. The floc mixed solution is sent to a dehydrator, dehydrated by the dehydrator, and separated into a dehydrated cake and a dehydrated filtrate. Then, the dehydrated filtrate is sent to the decontamination waste liquid storage tank.

Further, in the waste sludge waste liquid storage tank, the waste liquid after the filtration and the dehydrated filtrate are mixed and mixed to form urine, and the mixed and adjusted urine is sent to the biological treatment tank. Then, in the biological treatment tank, the mixed conditioned urine is subjected to biological nitrification and denitrification treatment to form a biological treatment mixed liquid of biological sludge and biological treated water. Then, the activated sludge separated in the membrane separator is sent to the sludge storage tank as excess sludge, and the amount of phosphorus component in the wastewater after being filtered in the screen is the biological amount in the biological treatment tank. It is adjusted according to the amount of phosphorus component required for the selective nitrification and denitrification treatment.

[0022]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram of a sewage treatment apparatus according to the first embodiment of the present invention. In the figure,
11 is a screen for filtering wastewater such as human waste and septic tank sludge, and the residual waste liquid after being filtered by the screen 11 is sent to and stored in the residual waste liquid storage tank 12,
The screen residue separated by filtration is sent to a screen residue crusher 31, is crushed by the screen residue crusher 31, and then sent to a sludge storage tank 32.

Here, the distribution ratio between the waste residue waste liquid sent to the waste residue waste liquid storage tank 12 and the residue sent to the residue crusher 31 is set in advance by analyzing the components of the waste water. It In addition, in this example, 7
The residue was set to 0 [%] and the residue was set to 30 [%]. Therefore, a control valve (not shown) is provided between the screen 11 and the residual waste liquid storage tank 12 and between the screen 11 and the residual crusher 31.

To the sludge storage tank 32, in addition to the screen residue sent from the screen residue crusher 31, excess sludge extracted from the coagulation / concentration separation tank described later is sent to the sludge storage tank 32. The residue and the excess sludge are mixed to form a sludge mixed liquid, which is stored. Next, the sludge mixed solution is sent to the coagulation tank 34, and the inorganic coagulant and the polymer are added in the coagulation tank 34. In addition, since the agglomerated PH region is usually neutral or less, if necessary, for example, in the case of using an iron salt, by adding a PH adjusting agent, PH4.5 to
It is desirable to adjust the value to about 6.0. As a result, the fibers in the residue serve as a dehydration aid, and the sludge mixed solution forms strong flocs and becomes a floc mixed solution. At this time, the phosphorus component is almost completely removed.

Thereafter, the floc mixed solution is sent to the dehydrator 35, dehydrated in the dehydrator 35 and separated into a dehydrated cake and a dehydrated filtrate. Then, the dehydrated cake is sent to a dryer (not shown), dried, and then incinerated in an incinerator. On the other hand, the dehydrated filtrate is sent to the waste residue waste liquid storage tank 12, and in the waste residue liquid storage tank 12, the waste residue liquid and the dehydrated filtrate are mixed and adjusted to be urine. Therefore, when the amounts of human waste, septic tank sludge, etc. supplied to the screen 11 change, the influence of the change can be eliminated by adjusting the distribution rate.

Next, the mixed and adjusted urine is sent to the biological treatment tank 37, where the mixed and adjusted urine is subjected to biological denitrification treatment, and the mixed and adjusted urine BOD component, CO
The D component, the nitrogen component, etc. are removed, and a biological treatment mixed liquid of biological sludge and biological treated water is formed. By the way, the mixed and adjusted urine is sent to the biological treatment tank 37, and the waste sludge and the dehydrated filtrate are mixed so as to contain a slightly larger amount of phosphorus component than the amount necessary for the biological denitrification treatment in the biological treatment tank 37. The amount is set. For example, B in the residual waste liquid at the actual facility
The ratio of the phosphorus component used to the OD component is set to about 2 to 4% with a margin.

In this case, it is possible to secure an amount of phosphorus component necessary for the biological denitrification treatment in the biological treatment tank 37, and the components other than the phosphorus component are the balance of the water quality components originally required for the biological denitrification treatment. Therefore, the biological denitrification treatment in the biological treatment tank 37 can be stably performed. Further, a flocculation / concentration separation tank 38 is disposed adjacent to the biological treatment tank 37, and a flocculant is added to the biological treatment mixed liquid in the flocculation / concentration separation tank 38, and the biological treatment mixed liquid is activated sludge and a separation liquid. And can be separated. At this time,
The phosphorus component slightly remaining in the biological treatment mixture becomes a phosphorus compound and is suspended together with the activated sludge. Therefore,
Since the amount of the flocculant product remaining in the biological treatment tank 37 can be reduced, the influence of the flocculant product on the biological denitrification treatment can be reduced.

A part of the separated activated sludge is returned to the inlet side of the biological treatment tank 37 as return sludge, and the rest is sent to the sludge storage tank 32 as excess sludge. Therefore, the residue and the excess sludge can be managed in a unified manner. Further, since the excess sludge is dehydrated together with the screen residue by the dehydrator 35, dehydration in the dehydrator 35 is facilitated and the water content of the dehydrated cake can be lowered.

On the other hand, the separated liquid separated in the coagulation / concentration separation tank 38 is used as secondary treated water in the membrane separation device 4
Sent to 1. Then, in the membrane separation device 41, the separated liquid is solid-liquid separated. In this case, the flocculation / concentration separation tank 38
As a result, the concentration of the SS component becomes low, and the flocculation tank 34
Since the concentrations of the COD component and the chromaticity component are low, the removal rate of the COD component, the SS component, the chromaticity component, etc. in the separation liquid is high, and the permeation rate of the membrane separation device 41 can be increased. it can. Moreover, since the membrane of the membrane separation device 41 is less likely to be contaminated, the membrane cleaning frequency can be reduced.

Further, the permeated liquid of the membrane separation device 41 is sent to the activated carbon treatment device 42 as secondary treated water, treated with activated carbon to remove COD components, chromaticity components and the like, and discharged as treated water. Thus, the screen 11
In the above, unnecessary phosphorus components other than the phosphorus components required for the biological denitrification treatment of the waste sludge waste liquid are combined with the residual sludge, and the residual sludge crusher 3
1 and is completely removed by the coagulation treatment by the coagulation tank 34.

Therefore, it is possible to maintain the balance of the water quality components necessary for performing the biological denitrification treatment in the biological treatment tank 37, so that the stable biological denitrification treatment can be performed. FIG. 4 is a first diagram showing a component table for each step in the first embodiment of the present invention, and FIG. 5 is a second diagram showing a component table for each step in the first embodiment of the present invention.

In this case, the components of human waste and septic tank sludge sent to the screen 11 (FIG. 1), the components of waste sludge waste liquid sent from the screen 11 to the waste sludge waste liquid storage tank 12, and the screen sludge crusher 31 are sent. The components of the residual sludge, the components of the excess sludge sent from the coagulation / concentration separation tank 38 to the sludge storage tank 32, the components of the dehydrated filtrate sent from the dehydrator 35 to the waste residue waste liquid storage tank 12, and the dehydrator 35 Dehydrated cake components, process water components added to the decontamination waste liquid storage tank 12, the decontamination waste liquid storage tank 12 to the biological treatment tank 37
The components of the mixed conditioned urine sent to, the components of the secondary treated water sent from the coagulation / concentration separation tank 38 to the membrane separation device 41, and the components of the treated water discharged from the activated carbon treatment device 42 are shown.

In FIG. 4, the flow rate of human waste is set to 0.
The flow rate of the septic tank sludge was set to 0.6 [Q]. In addition, in FIG. 5, the flow rate of human waste is set to 0.1 [Q].
And the flow rate of the septic tank sludge was set to 0.9 [Q]. next,
A second embodiment of the present invention will be described. FIG. 6 is a block diagram of a sewage treatment apparatus according to the second embodiment of the present invention. It should be noted that the same reference numerals are given to those having the same structure as the first embodiment, and the description thereof will be omitted.

In this case, the membrane separation device 41 is directly connected to the biological treatment tank 37, and the biological treatment mixture is fed to the membrane separation device 4.
1, and the membrane separation device 41 performs solid-liquid separation into activated sludge and separated liquid. The permeate of the membrane separation device 41 is sent to the activated carbon treatment device 42 as secondary treated water,
It is treated with activated carbon to remove COD components, chromaticity components, etc., and is discharged as treated water. On the other hand, the membrane separation device 4
A part of the activated sludge that has been solid-liquid separated by 1 is returned to the inlet side of the biological treatment tank 37 as return sludge, and the rest is sent to the sludge storage tank 32 as excess sludge.

The present invention is not limited to the above-mentioned embodiments, but can be variously modified within the scope of the present invention, and they are not excluded from the scope of the present invention.

[0036]

As described in detail above, according to the present invention, in the sewage treatment apparatus, the screen for filtering the wastewater to remove the residue and the sludge prepared by mixing the residue with the excess sludge A sludge storage tank that stores the sludge mixed solution as a mixed solution, a flocculation tank that flocculates the sludge mixed solution from the sludge storage tank to form a floc mixed solution in which flocs are formed, and a floc mixture from the flocculation tank A dehydrator that dehydrates the liquid and separates it into a dehydrated cake and a dehydrated filtrate, waste water that has been filtered in a screen, and dehydrated filtrate from the dehydrator are mixed and adjusted into urine, and the mixing adjustment is performed. A waste sludge waste liquid storage tank for storing human waste, a biological treatment tank for forming a biological treatment liquid mixture of biological sludge and biological treated water by subjecting the mixed and adjusted urine to biological nitrification denitrification treatment, and the biological treatment tank The biological treatment mixture from With the activated sludge and flocculation concentration and separation tank that is separated into a separated liquid, and a membrane separation device for solid-liquid separating liquid separated from aggregated concentration and separation tank.

In this case, in the sludge storage tank, the sludge and the excess sludge are mixed to form a sludge mixed liquid. Therefore, not only can the residue and the excess sludge be managed in an integrated manner, but since the excess sludge is dehydrated together with the residue, the dehydration in the dehydrator is facilitated and the moisture content of the dehydrated cake is lowered. You can Then, the sludge mixed liquid is sent to the coagulation tank and is coagulated by the coagulation tank. At this time, since the fibers in the residue serve as a dehydration aid, the sludge mixed solution can form strong flocs. As a result, the phosphorus component can be almost completely removed by the aggregating treatment in the aggregating tank.

The activated sludge separated in the coagulation / concentration separation tank is sent to the sludge storage tank as excess sludge, and the amount of phosphorus component in the wastewater after being filtered in the screen is the biological treatment. It is adjusted according to the amount of phosphorus component required for biological denitrification treatment in the tank. In this case, it is possible to secure an amount of phosphorus component necessary for the biological denitrification treatment in the biological treatment tank, and the components other than the phosphorus component are
Since the original balance of water components of the waste sludge waste liquid is maintained as it is, the biological nitrification denitrification treatment in the biological treatment tank can be stably performed.

In another sewage treatment apparatus of the present invention, a screen for filtering waste water to remove residue and a mixture of the residue and excess sludge to form a sludge mixed solution, and the sludge mixed solution is stored. A sludge storage tank, a flocculation tank that flocculates the sludge mixed solution from the sludge storage tank to form a floc mixed solution in which flocs are formed, and a floc mixed solution from the flocculation tank is dehydrated to form a dehydrated cake and a dehydration filter. A dehydrator for separating into a liquid, a waste water after being filtered in a screen, and a dehydrated filtrate from the dehydrator are mixed and adjusted into urine, and a residual waste liquid storage tank that stores the mixed and adjusted urine, A biological treatment tank for forming a biological treatment mixture of biological sludge and biologically treated water by subjecting the mixed urine to biological nitrification and denitrification treatment, a biological treatment mixture from the biological treatment tank, and activated sludge. Membrane component for solid-liquid separation into separated liquid And a device.

In this case, the sludge and the excess sludge are mixed in the sludge storage tank to form a sludge mixed liquid. Therefore, not only can the residue and the excess sludge be managed in an integrated manner, but since the excess sludge is dehydrated together with the residue, the dehydration in the dehydrator is facilitated and the moisture content of the dehydrated cake is lowered. You can Then, the sludge mixed liquid is sent to the coagulation tank and is coagulated by the coagulation tank. At this time, since the fibers in the residue serve as a dehydration aid, the sludge mixed solution can form strong flocs. As a result, the phosphorus component can be almost completely removed by the aggregating treatment in the aggregating tank.

The activated sludge separated in the membrane separator is sent to the sludge storage tank as excess sludge, and the amount of phosphorus component in the waste water after being filtered in the screen is the biological treatment tank. Is adjusted in accordance with the amount of phosphorus component required for the biological nitrification and denitrification treatment in. In this case, it is possible to secure the required amount of phosphorus components for the biological denitrification treatment in the biological treatment tank, and the components other than the phosphorus components maintain the original balance of the water quality components of the residual waste liquid. Therefore, the biological nitrification denitrification treatment in the biological treatment tank can be stably performed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a sewage treatment apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a conventional sewage treatment apparatus that performs a two-stage membrane treatment.

FIG. 3 is a block diagram of a conventional sewage treatment apparatus that performs one-stage membrane treatment.

FIG. 4 is a first diagram showing a component table for each step in the first embodiment of the present invention.

FIG. 5 is a second diagram showing a component table classified by process in the first embodiment of the present invention.

FIG. 6 is a block diagram of a sewage treatment apparatus according to a second embodiment of the present invention.

[Explanation of symbols]

 11 Screen 12 Waste sludge waste liquid storage tank 32 Sludge storage tank 34 Coagulation tank 35 Dehydrator 37 Biological treatment tank 38 Coagulation concentration separation tank 41 Membrane separation device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C02F 9/00 503 C02F 9/00 503C 504 504A 3/34 101 3/34 101C 11/14 ZAB 11 / 14 ZABA

Claims (2)

[Claims] 1. A sludge storage tank for storing (a) a screen for filtering wastewater and removing residue, (b) mixing the residue and excess sludge to form a sludge mixed solution, and storing the sludge mixed solution. When,
(C) an aggregating tank for aggregating the sludge mixed solution from the sludge storage tank into a floc mixed solution having flocs formed,
(D) A dehydrator for dehydrating the floc mixed solution from the flocculation tank to separate it into a dehydrated cake and a dehydrated filtrate, (e) waste water after being filtered through a screen, and a dehydrated filter from the dehydrator. The liquid is mixed and mixed to prepare urine, and the mixed waste is stored in the residual sludge waste liquid storage tank, and (f) the mixed and adjusted urine is subjected to biological nitrification and denitrification, and biological sludge and biologically treated water A biological treatment tank for forming a biological treatment mixture,
(G) aggregating the biological treatment mixture from the biological treatment tank,
A coagulation / concentration separation tank for separating activated sludge and a separation liquid,
(H) having a membrane separation device for solid-liquid separating the separated liquid from the coagulation-concentration separation tank, and (i) the activated sludge separated in the coagulation-concentration separation tank is stored in the sludge storage tank as excess sludge. The amount of the phosphorus component in the waste water after being sent (j) after being filtered by the screen is adjusted according to the amount of the phosphorus component required for the biological nitrification and denitrification treatment in the biological treatment tank. Sewage treatment equipment characterized by. 2. A sludge storage tank for storing (a) a screen for filtering wastewater and removing residue, and (b) a mixture of the residue and excess sludge to form a sludge mixed solution and storing the sludge mixed solution. When,
(C) an aggregating tank for aggregating the sludge mixed solution from the sludge storage tank into a floc mixed solution having flocs formed,
(D) A dehydrator for dehydrating the floc mixture from the flocculation tank to separate it into a dehydrated cake and a dehydrated filtrate, (e) waste water after being filtered through a screen, and a dehydrated filter from the dehydrator. The liquid is mixed and mixed to prepare urine, and the mixed waste is stored in the residual sludge waste liquid storage tank, and (f) the mixed and adjusted urine is subjected to biological nitrification and denitrification treatment to obtain biological sludge and biologically treated water. A biological treatment tank for forming a biological treatment mixture,
(G) The biological treatment mixed solution from the biological treatment tank has a membrane separation device for performing solid-liquid separation into activated sludge and a separation liquid, and (h) the activated sludge separated in the membrane separation device is Sent to the sludge storage tank as excess sludge,
(I) The amount of the phosphorus component in the wastewater after being filtered by the screen is adjusted according to the amount of the phosphorus component required for the biological nitrification / denitrification treatment in the biological treatment tank. Sewage treatment equipment.