JP2006116463A - Operation method for sewage treatment device, and sewage treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable drawing sludge from a filter tank without deterioration of reversal washability. <P>SOLUTION: When operating a sewage treatment device 1 equipped with an upstream side tank F, the filter tank E2, a first transfer mechanism H1 for transferring water to be treated to the filter tank E2, a reversal washdevice G for peeling off the sludge adhering to a filter carrier C2, and a second transfer mechanism H2 for transferring the sludge in the filter tank E2, operation of the reversal wash device G and operation of the second transfer mechanism H2 are started in a state of stopping the first transfer mechanism H1. When the water level of the filter tank E2 is lowered to a prescribed lower limit position WL, the water to be treated is supplied to the filter tank E2 so as to restore the water level to a prescribed upper limit position WH. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is a filtration tank in which an upstream tank for storing water to be treated is provided, and a deposition filtration layer is formed in a state where a plurality of filtration carriers are settled and deposited inside the downstream tank. A first washing mechanism that is provided in a state in which the water to be treated is received from the upstream side tank, is provided with a backwashing device that peels sludge adhering to the filtration carrier, and transfers the water to be treated to the filtration tank; The present invention relates to a method for operating a sewage treatment apparatus that operates a sewage treatment apparatus provided with a second transfer mechanism for transferring sludge in a filtration tank, and a sewage treatment apparatus.

Conventionally, as this kind of sewage treatment technology, it has been implemented using the apparatus shown in FIG. 5, and the treatment process will be briefly described below.
The treated water that has flowed into the sewage treatment apparatus 30 enters the flow rate adjustment tank (an example of the upstream tank) N2 through the screen 10 and is temporarily stored. And according to the state of sewage treatment on the downstream side, it is transferred to the carrier flow tank (an example of the upstream tank) E1 by the first transfer mechanism (for example, submersible pump) H1, and is efficiently transferred to the carrier C1 by bubbling from the air diffuser D1. The aerobic treatment with the treating microorganism is performed with good contact. Then, the treated water overflows and flows into the filtration tank E2, is filtered by the deposited filtration layer R, is sterilized and discharged. On the other hand, the sludge accumulated in the filtration layer R by filtration of the water to be treated in the filtration tank E2 is stirred together with the water to be treated and the filter carrier C2 by bubbling of the backwashing apparatus G and peeled off from the filter carrier C2, thereby being transferred to the second transfer mechanism. It is transferred to the sludge concentration storage tank Y by H2 (see, for example, Patent Document 1).
Thus, according to the operation of the conventional sewage treatment apparatus, in the backwashing process in the filtration tank E2, the operation of the backwashing apparatus G and the second transfer are performed with the first transfer mechanism H1 stopped. The operation of the mechanism H2 was started, and the treated water mixed with sludge was sent from the filtration tank E2 to the sludge concentration storage tank Y.

Japanese Patent Laying-Open No. 2003-010871 (FIG. 1)

According to the conventional sewage treatment technology described above, the water to be treated mixed with sludge is transferred to the sludge concentration storage tank together with the backwash process, resulting in a decrease in the water level in the filtration tank. However, as described above, since the backwash process can be separated from the filter carrier by stirring the sludge together with the water to be treated and the filter carrier by bubbling, the lower the water level, the harder it is to stir. , Sludge stripping ability decreases.
That is, there is a problem that the backwashing capacity is likely to be lowered with the transfer of the sludge.

  Accordingly, an object of the present invention is to provide a sewage treatment technique capable of eliminating the above-mentioned problems and extracting sludge from a filtration tank without reducing the backwashing ability.

  The first characteristic means of the present invention is that an upstream tank for containing the water to be treated is provided, and a deposition filtration layer is formed in a state where a plurality of filtration carriers are sedimented and deposited inside the upstream tank. A filtration tank is provided in a state in which treated water can be received from the upstream tank, a backwashing device for removing sludge adhering to the filtration carrier is provided, and the treated water is transferred to the filtration tank. In the operation method of the sewage treatment apparatus for operating the sewage treatment apparatus provided with one transfer mechanism and the second transfer mechanism for transferring the sludge in the filtration tank, the first transfer mechanism is stopped, The operation of the backwashing device and the operation of the second transfer mechanism are started, and when the water level of the filtration tank is lowered to a predetermined lower limit position, the water to be treated is supplied to the filtration tank.

According to the first characteristic means of the present invention, in the state where the first transfer mechanism is stopped, the operation of the backwashing device and the operation of the second transfer mechanism are started, and the water level of the filtration tank is Since the water to be treated is supplied to the filtration tank when it falls to a predetermined lower limit position, even if the sludge is transferred together with the backwash operation in the filtration tank, the water level of the filtration tank is predetermined by replenishment of the water to be treated. It can prevent falling from a lower limit position. Therefore, by setting the predetermined lower limit water level so as not to adversely affect the backwash capacity, it is possible to extract sludge from the filtration tank without reducing the backwash capacity.
And, for example, if the water level in the filtration tank is too low in the conventional sewage treatment technology and the filter carrier is exposed on the water surface, the processing microorganisms attached to the filter carrier will be killed, and thereafter However, according to the characteristic means, this problem can be solved and the growth environment of the treatment microorganism can be maintained.

  According to a second feature of the present invention, an upstream tank for containing the water to be treated is provided, and a deposited filtration layer is formed in a state where a plurality of filtration carriers are sedimented and deposited inside the upstream tank. A filtration tank is provided in a state in which treated water can be received from the upstream tank, a backwashing device for removing sludge adhering to the filtration carrier is provided, and the treated water is transferred to the filtration tank. In the operation method of the sewage treatment apparatus for operating the sewage treatment apparatus provided with one transfer mechanism and the second transfer mechanism for transferring the sludge in the filtration tank, the first transfer mechanism is stopped, If the water level of the filtration tank is lowered to a predetermined lower limit position before the operation of the backwashing apparatus and the second transfer mechanism, the water to be treated is supplied to the filtration tank.

  According to the second characteristic means of the present invention, the water level of the filtration tank is predetermined before the operation of the backwashing device and the operation of the second transfer mechanism with the first transfer mechanism stopped. Since the water to be treated is supplied to the filtration tank when it is lowered to the lower limit position, it is possible to prevent the water level of the filtration tank from being lowered from a predetermined lower limit position during the backwash operation. Therefore, by setting the predetermined lower limit water level so as not to adversely affect the backwash capacity, it is possible to extract sludge from the filtration tank without reducing the backwash capacity.

  The 3rd characteristic means of this invention exists in the place which supplies the said to-be-processed water to the said filtration tank until the water level of the said filtration tank restore | restores to a predetermined | prescribed upper limit position.

  According to the third characteristic means of the present invention, in addition to being able to achieve the above-described operation and effect by the first or second characteristic means of the present invention, the water to be treated is supplied to the filtration tank. Until the water level is restored to the predetermined upper limit position, it is possible to prevent the treated water from being unnecessarily supplied to the filtration tank, and the treated water overflows from the filtration tank inadvertently. It is possible to prevent it from being discharged while containing it.

  According to a fourth feature of the present invention, the sewage treatment apparatus includes a flow rate adjustment tank for adjusting the flow rate of the water to be treated and a carrier carrying the treatment microorganisms as the upstream side tank. A carrier flow tank for supplying air bubbles to the carrier and having a carrier flow tank for aerobic treatment is provided, and as the first transfer mechanism, water to be treated in the flow rate adjustment tank is transferred to the carrier flow tank. The water to be treated is supplied to the filtration tank by transferring the water to be treated to the carrier flow tank by the first transfer mechanism.

According to the fourth characteristic means of the present invention, in addition to being able to achieve the above-described operational effect by any one of the first to third characteristic means of the present invention, the first transfer mechanism supports the water to be treated. By being transferred to the fluid tank, the water to be treated can be supplied to the filtration tank while overflowing the carrier fluid tank. Therefore, in addition to the supply of water to be treated to the filtration tank, the carrier fluidized tank is replenished with water to be treated mixed with organic matter preferable for the growth of the microorganisms for treatment, which is preferable for the microorganisms for treatment carried on the carrier. It is possible to maintain the growth environment.
Moreover, since a dedicated device for supplying the water to be treated to the filtration tank is not required, it is possible to prevent an increase in cost.

  According to a fifth characteristic configuration of the present invention, in the sewage treatment apparatus used in the method for operating the sewage treatment apparatus according to claims 1 to 4, an upstream tank for storing the water to be treated is provided, and the downstream side of the upstream tank. A filtration tank in which a deposition filtration layer is formed in a state where a plurality of filtration carriers are settled and deposited therein is provided in a state in which water to be treated can be received from the upstream tank, and sludge adhering to the filtration carrier is removed. A backwashing device for peeling is provided, a first transfer mechanism for transferring the water to be treated to the filtration tank, and a second transfer mechanism for transferring the sludge of the filtration tank are provided, and the water level of the filtration tank is predetermined. A water level detection means capable of detecting whether the upper limit position is a predetermined lower limit position, and according to the detection result of the water level by the water level detection means, the backwash device, the second transfer mechanism, and the first transfer mechanism, An operation control mechanism is provided for switching the operation of It is in place.

According to the 5th characteristic structure of this invention, it becomes possible to implement the operating method of the sewage treatment apparatus of Claims 1-4 in a more preferable state.
That is, in addition to being able to carry out normal sewage treatment operation, during the backwash operation of the filtration tank, the operation of the backwash device and the operation of the second transfer mechanism are performed with the first transfer mechanism stopped. When the operation control mechanism obtains a result that the water level of the filtration tank has dropped to a predetermined lower limit position as a detection result of the water level detection means, the first transfer mechanism is operated, and the predetermined upper limit position is In the state where the `` sewage treatment device operation '' for switching control to restore to, or the first transfer mechanism stopped, before the operation of the backwash device and the operation of the second transfer mechanism, When the water level of the filtration tank has dropped to a predetermined lower limit position, it becomes possible to carry out “operation of the sewage treatment apparatus” for supplying the treated water to the filtration tank so as to restore the predetermined upper limit position. As a result, in the filtration tank Maintaining the water level in the appropriate range, it is possible to extract the sludge from the filtration tank without reducing the backwash capability.
Further, since the operation of the first transfer mechanism switched by the operation control mechanism is performed only until the water level of the filtration tank is restored to the predetermined upper limit water level, the water to be treated is unnecessarily supplied to the filtration tank. Furthermore, it is possible to prevent the water to be treated from overflowing from the filtration tank inadvertently and being discharged while containing sludge.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the parts indicated by the same reference numerals as those in the conventional example indicate the same or corresponding parts.

As shown in FIG. 1, the septic tank 1 constituting the sewage treatment apparatus of the present invention includes an aeration type screen tank N1, a flow rate adjustment tank N2, an aerobic treatment tank E, a treated water tank T1, and a disinfection tank Q from the upstream side. The discharge pump tank S is provided, and the aerobic treatment tank E is provided with a carrier flow tank E1 and a filtration tank E2.
The aerated screen tank N1, the flow rate adjusting tank N2, and the carrier flow tank E1 are referred to as an upstream tank F.

  The raw water to be treated flows into the aeration type screen tank N1 from the raw water inflow portion In, and is decomposed while being transferred downstream in the order of the flow rate adjusting tank N2, the carrier flow tank E1, the filtration tank E2, and the treated water tank T1. Then, after passing through the disinfection tank Q and the discharge pump tank S, it is discharged from the discharge port Z to the outside of the tank.

The aeration type screen tank N1 is configured to be able to store the raw water to be treated to flow in, and captures contaminants such as paper mixed in the raw water inside the aeration type screen tank N1. A pneumatic screen 10 is provided. A diffuser pipe D4 for discharging air is provided below the aeration type screen 10, and the air is discharged toward the aeration type screen 10 to divide the foreign matters locked to the comb-shaped portion.
Solid content such as sludge that is not easily decomposed in the raw water to be treated flowing into the aerated screen tank N1 is precipitated and separated in the lower part of the aerated screen tank N1. Moreover, it is transferred to the flow rate adjusting tank N2 in a state where coarse organic matter is subdivided by stirring.

The flow rate adjusting tank N2 has a relatively large storage capacity, and is configured to be able to adjust the flow rate in the range of LWL to HWL. Thereby, since it has composition which absorbs the peak amount of the amount of inflow processing water which concentrates on morning and evening specific time etc., it contributes to stabilization of the processing performance of downstream said carrier fluidized tank E1 and said filtration tank E2.
The flow rate adjusting tank N2 is provided with an air diffusion pipe D3 for blowing air from the blower device into the tank, and agitating action is given to the stored water by air in a range in which no solid matter stays. Aeration from the air diffusing tube D3 can be performed by repeatedly performing, for example, aeration for 2 minutes and aeration stop for 15 minutes. Thereby, extreme solid-liquid separation can be suppressed by the stirring action by the air gently discharged from the air diffusion pipe D3, and the water to be treated can be made uniform.
The treated water that has flowed into the flow rate adjusting tank N2 is sent to the carrier flow tank E1. As the first transfer mechanism H1 for transferring the water to be treated from the flow rate adjusting tank N2 to the carrier flow tank E1, the submersible pump P3 for pumping the water to be treated from the flow rate adjusting tank N2 and the target to be pumped by the submersible pump P3. A fine screen device 11 that exhibits a filter function for water and a metering / adjusting / transferring device 12 are provided, and the metering / adjusting / transferring device 12 transports the flow from the flow rate adjusting tank N2 to the carrier flow tank E1. While detecting the transferred amount of treated water, the transferred amount is adjusted so that the treated amount in the carrier fluidized tank E1 does not become excessive.

The carrier fluid tank E1 accommodates and holds the carrier C1 formed to be flowable together with the water to be treated in a state where microorganisms are supported, and is connected to an air supply pipe to cause the carrier C1 to flow by supplying bubbles. The air diffuser pipe (corresponding to the air diffuser) D1 is built in, and the carrier C1 is caused to flow in the carrier fluid tank E1 by supplying bubbles from the air diffuser pipe D1. With such a configuration, the water to be treated that flows into the carrier fluid tank E1 is purified by aerobic decomposition by the aerobic microorganisms carried on the carrier C1.
If the carrier C1 has an uneven surface, the carrier C1 has a preferable shape for supporting a biofilm on the surface of the carrier C1.

The filtration tank E2 has a specific gravity greater than that of water and a specific gravity close to 1 and is filled with a carrier C2 at a high density up to a predetermined height to form a deposited filtration layer R. Thereby, the to-be-processed water containing the sludge transferred to the filtration tank E2 passes through the sedimentation filtration layer R, becomes almost free of solids, and is transferred to the adjacent treated water tank T1. The
In the lower part of the filtration tank E2, a backwashing tube D2 is provided as a backwashing device G for the carrier C2, which diffuses air to separate sludge that causes clogging attached to the carrier C2.

  About the said air diffusion pipes D1, D3, D4 and the said backwash pipe D2, it is preferable that a bubble supply amount can be adjusted.

  The backwashing of the carrier C2 by the backwashing pipe D2 is performed by, for example, connecting an air supply pipe to the backwashing pipe D2 via a timer-controlled solenoid valve and periodically operating the backwashing pipe D2. The carrier C2 may be backwashed. Further, the frequency of backwashing can be appropriately determined depending on the season or inflow load.

  Further, when the carrier C2 has a smooth surface, the sludge that causes clogging during backwashing can be easily peeled off, and the filtration area can be designed freely.

Furthermore, in the filtration tank E2, the air lift pump A2 as the second transfer mechanism H2 for transferring the water to be treated and sludge to the sludge concentration storage tank Y described later, or the water level of the filtration tank E2 is a predetermined upper limit position, A water level detection means K is provided which can detect whether the position is a predetermined lower limit position.
The air lift pump A2 is configured to be able to transfer the water to be treated and sludge in the filtration tank E2 to the sludge concentration storage tank Y. Thereby, the back including the sludge settled on the bottom of the filtration tank E2 at the time of back washing for separating the sludge adhering to the carrier C2 on which the deposited filtration layer R is formed and causing clogging or after back washing. The washing waste water can be transferred to the sludge concentration storage tank Y to store sludge.
The said water level detection means K can feed back the detection result to control of each apparatus by the operation control mechanism 20 mentioned later by detecting the water level of the filtration tank E2.

  The sludge concentration storage tank Y is provided with an air lift pump A1 for returning the intermediate water in which the solids are precipitated to the flow rate adjustment tank N2, so that the sludge concentration storage tank Y can be efficiently stored and extracted. Adopted.

  The treated water tank T1 is configured to be able to separate and prevent the separated sludge, and only clean treated water that has passed through the filtration tank E2 can be transferred to the disinfection tank Q. The treated water that has flowed into the sterilization tank Q is sterilized in contact with the solid disinfectant, and then flows into the discharge pump tank S in which the discharge pump P2 is provided. In the discharge pump tank S, sterilized water to be treated is temporarily stored, and then discharged from the discharge port Z to the outside of the tank.

The air lift pump A3 is configured to be able to transfer the water to be treated and sludge flowing out from the carrier flow tank E1 and flowing into the filtration tank E2 into the flow rate adjusting tank N2.
As a result, the sludge transferred to the flow rate adjusting tank N2 by the air lift pump A3 is transferred to the downstream carrier fluid tank E1, and is subjected to an aerobic treatment in the carrier fluid tank E1. That is, since the sludge flowing out from the carrier fluid tank E1 is transferred again to the carrier fluid tank E1 via the flow rate adjusting tank N2, the sludge can be circulated efficiently, so that the inside of the carrier fluid tank E1 can be circulated. The total amount of organisms in the carrier fluidized tank E1, which has been reduced by the flowing sludge flowing easily to the filtration tank E2, can be recovered early. Since the total amount of organisms in the carrier fluidized tank E1 is recovered, the opportunity for contact between microorganisms and the water to be treated is increased, and the decomposition efficiency of BOD and SS in the water to be treated is improved. It can be decomposed, and even high-load treated water can be efficiently decomposed. Furthermore, since the nitrification reaction of the ammonia component in the water to be treated can be promoted, the ability to decompose the water to be treated can be improved.

  Part of the sludge grows in the carrier fluid tank E1 and is transferred to the filtration tank E2. Therefore, the total amount of organisms reduced after back washing of the carrier C2 in the filtration tank E1 can be recovered early. The recovery of the total amount of organisms thus reduced improves the efficiency of decomposing BOD and decomposing and removing SS, so that filtration can be performed under favorable conditions.

Next, the backwashing operation by the backwashing device G will be described. By stirring the carrier C2 while floating in the water to be treated by bubbling by aeration from the backwashing tube D2, the attached sludge is removed. It is to be peeled off. And with this backwash operation, backwash drainage is carried out from the filtration tank E2 to the sludge concentration storage tank Y by the air lift pump A2.
Therefore, in order to exhibit an appropriate backwashing capability, it is preferable to ensure that the water level of the water to be treated in the filtration tank E2 is at a predetermined level or higher and to be sufficiently stirred. In this sense, a detection water level on the lower limit side by the water level detection means K is set.
Further, at the time of backwashing, the sludge peeled off in the water to be treated in the filtration tank E2 is floating. Therefore, it is not preferable that the sludge is discharged and discharged to the downstream side in this state. In this sense, the water level detection means The detected water level on the upper limit side by K is set.
That is, the predetermined lower limit position WL set in the water level detection means K means the water level lower limit value in a range in which the backwashing ability can be maintained, and the predetermined upper limit position WH set from the filtration tank E2 to the water to be treated. Means the upper limit of the water level in the range that does not overflow to the downstream side.
The flowchart of the backwash operation is as shown in FIG. 2, and the operation control mechanism 20 is configured to control each device during the backwash operation based on the detection result of the water level detection means K. In the state where the first transfer mechanism H1 is stopped, the operation of the backwashing device G and the operation of the second transfer mechanism H2 are started, and the detection result of the water level detection means K is the predetermined lower limit position. When lowered to WL, the submersible pump P3 of the flow rate adjusting tank N2 is driven to restore the predetermined upper limit position WH, and the water to be treated is supplied to the filtration tank E2 via the carrier flow tank E1. is there.

  According to the sewage treatment operation using the septic tank 1 of the present embodiment, the sludge separated from the carrier C2 is transferred to the sludge concentration storage tank Y and concentrated efficiently without reducing the backwashing capacity of the filtration tank E2. It can be stored.

[Another embodiment]
Other embodiments will be described below.

<1> The sewage treatment apparatus is not limited to the configuration described in the previous embodiment. For example, the sludge concentration storage tank Y accepts backwash wastewater instead of one storage tank, and the sludge content is reduced. It may be configured to include a sludge concentration tank for sedimentation, a storage tank for receiving sludge settled in the settling tank, and a transfer mechanism for transferring the sludge from the sludge concentration tank to the storage tank. It becomes possible to store the sludge in a more concentrated state. Moreover, the said sludge concentration tank and the storage tank may be comprised by isolate | separating the inside of one tank other than comprising as a separate container. In addition, the second transfer mechanism H2 transfers to the upstream tank F (preferably, the aerated screen tank N1 or the flow rate adjusting tank N2) instead of the configuration for transferring the sludge in the filtration tank E2 to the sludge concentration storage tank Y. It may be configured to do so.
<2> The water level detection unit may employ various known configurations, and various types such as a float switch, a level switch, and a proximity sensor can be used. However, in the operation method of the sewage treatment apparatus according to the present invention, it is not always necessary to provide the water level detection means, and visual confirmation of the water level and manual operation control of the first transfer mechanism H2 may be performed.
Further, the water level detection means in the sewage treatment apparatus of the present invention may detect only the predetermined lower limit position instead of detecting both the predetermined upper limit position and the predetermined lower limit position (claim). 1). In that case, when the water level in the filtration tank E2 falls to the predetermined lower limit position, the control operation is performed so that the water level rises to the vicinity of the predetermined upper limit position, for example, by operating the first transfer mechanism H2 for a predetermined time by a timer or the like. It is also possible. In this case, the process (7) in the flowchart of FIG. 2 is an operation time detection instead of the water level detection.
<3> The operation method of the sewage treatment apparatus is not limited to that described in the previous embodiment. For example, as shown in the flowchart of FIG. Is stopped after the operation of the backwashing device G and the operation of the second transfer mechanism H2 are stopped, and the next operation of the backwashing device G and the operation of the second transfer mechanism H2 are stopped. If the water level of the filtration tank E2 has been lowered to a predetermined lower limit position WL before, a method of supplying the treated water to the filtration tank E2 so as to restore the predetermined upper limit position WH may be performed. .
In addition, regarding the timing of detecting the predetermined lower limit position of the water level of the filtration tank E2, it is not limited to performing before the second and subsequent backwash operations, for example, before each backwash operation, Or after that, or before and after, you may implement in the interval of a predetermined number of cycles of backwash operation. An example of detecting the water level before the backwash operation is as shown in the flowchart of FIG.
In any of these cases, detection of the predetermined upper limit position WH can be omitted, and the control can be replaced with timer control.
<4> The water to be replenished to the filtration tank E2 at the time of backwashing drives the submersible pump P3 of the flow rate adjustment tank N2 described in the previous embodiment to the filtration tank E2 via the carrier flow tank E1. For example, a configuration in which a first transfer mechanism is provided in the carrier fluid tank E1 and the water to be treated in the carrier fluid tank E1 is directly fed to the filtration tank E2 by the first transport mechanism, The discharge pump tank S may be provided with a first transfer mechanism, and the treated water in the discharge pump tank S may be directly sent to the filtration tank E2 by the first transfer mechanism.
<5> Further, the first transfer mechanism and the second transfer mechanism are not limited to the submersible pump and the air lift pump described in the previous embodiment, and in addition to using any of them, Other types of pumps may be used.

  In addition, as mentioned above, although the code | symbol was written in order to make contrast with drawing convenient, this invention is not limited to the structure of an accompanying drawing by this entry. In addition, it goes without saying that the present invention can be carried out in various modes without departing from the gist of the present invention.

Schematic diagram showing sewage treatment equipment Flow chart showing operation method of sewage treatment equipment Flow chart showing another operation method of sewage treatment equipment Flow chart showing another operation method of sewage treatment equipment Schematic diagram showing a conventional sewage treatment device

Explanation of symbols

1 Septic tank (sewage treatment equipment)
20 Operation control mechanism C1 carrier C2 carrier D1 Air diffuser (corresponding to air diffuser)
E1 carrier flow tank E2 filtration tank F upstream tank G backwash device H1 first transfer mechanism H2 second transfer mechanism K water level detection means WH predetermined upper limit position WL predetermined lower limit position N2 flow rate adjustment tank R sediment filtration layer Y sludge concentration Storage tank

Claims (5)

An upstream tank for storing water to be treated is provided, and a filtration tank in which a deposition filtration layer is formed in a state where a plurality of filtration carriers are settled and deposited in the downstream of the upstream tank is the upstream tank. A first washing mechanism for removing the sludge adhering to the filtration carrier, a first washing mechanism for transferring the treated water to the filtration tank, and a sludge for the filtration tank. A sewage treatment apparatus for operating a sewage treatment apparatus provided with a second transfer mechanism for transferring
With the first transfer mechanism stopped, the operation of the backwashing device and the second transfer mechanism are started, and when the water level of the filtration tank is lowered to a predetermined lower limit position, the water to be treated A method for operating a sewage treatment apparatus for supplying a filtration tank to the filtration tank. An upstream tank for storing water to be treated is provided, and a filtration tank in which a deposition filtration layer is formed in a state where a plurality of filtration carriers are settled and deposited in the downstream of the upstream tank is the upstream tank. A first washing mechanism for removing the sludge adhering to the filtration carrier, a first washing mechanism for transferring the treated water to the filtration tank, and a sludge for the filtration tank. A sewage treatment apparatus for operating a sewage treatment apparatus provided with a second transfer mechanism for transferring
If the water level of the filtration tank is lowered to a predetermined lower limit position before the operation of the backwashing device and the operation of the second transfer mechanism with the first transfer mechanism stopped, the treated water A method for operating a sewage treatment apparatus for supplying a filtration tank to the filtration tank.   The operation method of the sewage treatment apparatus according to claim 1 or 2, wherein the water to be treated is supplied to the filtration tank until the water level of the filtration tank is restored to a predetermined upper limit position.   The sewage treatment apparatus includes, as the upstream tank, a flow rate adjusting tank that adjusts the flow rate of water to be treated, and an air diffuser that accommodates a carrier carrying processing microorganisms in a flowable manner and supplies bubbles to the carrier. And a carrier flow tank for aerobic treatment, and the first transfer mechanism is configured to transfer the water to be treated in the flow rate adjustment tank to the carrier flow tank. The operation of the sewage treatment apparatus according to any one of claims 1 to 3, wherein the water to be treated is supplied to the tank by transferring the water to be treated to the carrier flow tank by the first transfer mechanism. Method. It is a sewage treatment apparatus used for the operating method of the sewage treatment apparatus of Claims 1-4,
An upstream tank for storing water to be treated is provided, and a filtration tank in which a deposition filtration layer is formed in a state where a plurality of filtration carriers are settled and deposited in the downstream of the upstream tank is the upstream tank. A first washing mechanism for removing the sludge adhering to the filtration carrier, a first washing mechanism for transferring the treated water to the filtration tank, and a sludge for the filtration tank. And a second transfer mechanism for transferring water, and a water level detection means capable of detecting whether the water level of the filtration tank is a predetermined upper limit position or a predetermined lower limit position is provided, and the water level detection result by the water level detection means Accordingly, a sewage treatment apparatus provided with an operation control mechanism for switching and controlling the operations of the backwashing device, the second transfer mechanism, and the first transfer mechanism.

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