JP3901441B2 - Septic tank operation - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides an anaerobic treatment tank for anaerobically treating raw water to be treated, accommodates and holds a carrier that is formed to be flowable with the treated water in a state where microorganisms are supported, and supplies bubbles. A carrier flow tank provided with an air diffuser for flowing the carrier together with the water to be treated, and a filtration tank for filtering the water to be treated in the carrier fluid tank on the downstream side of the carrier fluid tank, the method of operation of the purification tank is provided with an air lift pump the sludge and treated water from the filtration tank to allow transfer to the anaerobic treatment tank.
[0002]
[Prior art]
In a conventional septic tank equipped with an air lift pump, the air lift pump is erected so as to be able to suck up water to be treated that is transferred from the carrier flow tank to the downstream side via the bottom of the septic tank, and the anaerobic treatment A horizontal pipe that is held in a horizontal posture from the upper side of the tank to the upper side of the carrier flow tank and connected to the upper part of the vertical pipe, and an air supply pipe that supplies the lower part of the vertical pipe to allow the water to be treated to be transferred And was configured. And this air supply pipe adopts a configuration that allows air to be constantly supplied by supplying air from a blower or the like, pumps the water to be treated in the vertical pipe, and allows the water to be treated and sludge to be steadily transferred. Is known.
And, with such a configuration, the water to be treated is highly aerobically treated by the carrier fluidized tank, and the acidity tends to increase, but it is difficult to increase the acidity by denitrifying by anaerobic treatment again. The septic tank can be operated in a controllable manner.
[0003]
[Problems to be solved by the invention]
However, in the septic tank having the above-described configuration, a filtration tank is provided so that the treated water in a state in which sludge is filtered can be transferred to the anaerobic treatment tank. It is expected that the function of advancing the denitrification of the water to be treated will be exhibited by the transfer of. On the other hand, if the filtration tank starts to be clogged, the filtration tank may not function normally. Therefore, the filtration tank may be regenerated for the purpose of preventing this. During such a regeneration process, a large amount of sludge is generated, which may adversely affect the quality of the treated water discharged from the septic tank.
[0004]
In such a case, if an attempt is made to operate such that the above-described conventional air diffuser can always transport such sludge, a relatively large amount of water to be treated is always transported to the anaerobic treatment tank. Because it is necessary, it is necessary to always supply air with a large capacity, which increases the operating cost or forms an environment in which treated water after being always aerobically treated flows into the anaerobic filter bed tank Therefore, the anaerobic treatment tank on the upstream side is steadily biased to aerobic condition, and there is a possibility that the growth environment of microorganisms may change.
[0005]
Then, the objective of this invention is providing the operating method of the septic tank which is easy to maintain the circulation of to-be-processed water in the state which maintained the environment in a septic tank on the suitable conditions.
[0006]
[Means for Solving the Problems]
The characteristic configuration of the operation method of the septic tank of the present invention for achieving the above object is to provide an anaerobic treatment tank for anaerobically treating the raw water to be treated, and to flow with the treated water in a state where microorganisms are supported. The carrier fluidized tank that contains and holds the formed carrier and is provided with an air diffuser for supplying bubbles to flow the carrier together with the water to be treated, and in the carrier fluidized tank on the downstream side of the carrier fluidized tank A filtration tank for filtering the water to be treated, and a method of operating a septic tank provided with an air lift pump that enables transfer of sludge and water to be treated from the filtration tank to the anaerobic treatment tank,
The filtration tank is provided with a deposition filtration layer filled with a carrier up to a predetermined height, and an air diffusion tube is provided below the deposition filtration layer to diffuse the carrier and allow the inside of the filtration tank to be stirred. In addition, a vertical pipe installed to be able to suck water to be treated from the carrier flow tank to the downstream side through the bottom of the purification tank to the air lift pump , and the carrier flow tank from the upper side of the anaerobic treatment tank A horizontal pipe that is held in a horizontal position over the upper side and connected to the upper part of the vertical pipe, a first air supply pipe that supplies air to the lower part of the vertical pipe to allow the water to be treated to flow, and the vertical pipe A second air supply pipe for supplying sludge to the lower part of the air supply , the first air supply pipe being always in an operating state, and supplying air from the second air supply pipe when the air diffuser pipe of the filtration tank is in operation It is in the point which is constituted so that .
[0009]
[Function and effect]
That is, the air lift pump has a vertical pipe installed so as to be able to suck water to be treated from the carrier flow tank to the downstream side through the bottom of the purification tank, and the carrier flow tank from above the anaerobic treatment tank. A horizontal pipe that is held in a horizontal position over the upper side and connected to the upper part of the vertical pipe, a first air supply pipe that supplies air to the lower part of the vertical pipe to allow the water to be treated to flow, and the vertical pipe A second air supply pipe for supplying sludge to the lower part of the air supply, and when the water to be treated is mainly circulated by the air lift pump, the first air supply pipe In the operation state, the sludge is mainly transferred, and the function of the air lift pump can be switched by setting the second air supply pipe to the operation state. Therefore, an appropriate water treatment can be selected according to the operation status of the septic tank, and the water treatment performance can be maintained high.
In addition, when both supply pipes are in an operating state, in general, when sludge is transferred, sludge is transferred because a large amount of air is supplied compared to the case of transferring the water to be treated. The objective is mainly achieved. Therefore, in particular, the first air supply pipe is always in an operating state, when the operation that allows the sludge transfer function to be performed with a low frequency is not expected, and the first air supply pipe is always in an operating state. The same effect can be expected by controlling the second air supply pipe to the operating state only.
[0010]
In addition, when sludge transfer with a large amount of air supply is made to function, even if sludge adheres to the inside of the vertical pipe, the sludge is removed and the effect of cleaning is exhibited. Always keep it clean to stabilize the amount of circulating water to be treated and contribute to maintaining it in a state of maintaining suitable conditions.
[0011]
In the configuration described above, the filtration tank the carrier fluidizing tank water treatment tank provided adjacent to, Ru Thea configured to form a deposited filtration layer are filled with a charge of material to a predetermined height.
[0012]
When a diffusion tube is provided below the deposition filtration layer to diffuse the carrier and allow the inside of the filtration tank to be stirred, the deposition filtration layer formed in the filtration tank by the diffusion of the diffusion tube The solid component adhering to the carrier can be peeled off as sludge.
[0013]
At this time, the sludge will be transferred to the treated water tank, downstream of the filtration tank, together with the water to be treated, and in the state where the air lift pump is easily arranged to transfer the sludge transferred from the filtration tank to the treated water tank. Then, sludge is transferred from the treated water tank to the anaerobic treatment tank on the upstream side by the air lift pump. Here, assuming that the raw water to be treated does not flow into the septic tank, the flow of the treated water in the septic tank reaches from the anaerobic treatment tank to the carrier flow tank, the filtration tank, and the treated water tank. Since the circulation of returning to the treatment tank is repeated, the sludge generated in the filtration tank is precipitated and separated when passing through the anaerobic treatment tank while circulating to the filtration tank again, and the air lift While the sludge is transferred by the pump, the water to be treated filtered in the filtration tank is clean. Further, even if raw water flows into the septic tank in such a situation, the amount of treated water transferred for the sludge transfer can be set to be much larger than the normal raw water inflow, It is sufficiently mixed with the water to be treated, and it is easy to be biologically treated, and the carrier can be sufficiently regenerated. In view of these, it is understood that the sludge transfer is preferably performed in a time zone in which the raw water to be treated is little inflow.
Furthermore, when the carrier having undergone the regeneration treatment has a specific gravity greater than that of water, for example, it quickly accumulates in the filtration tank to form a deposited filtration layer, so that the filtration function is restored. There is little possibility that the water to be treated that is insufficiently treated will be discharged. If the density of the carrier is too large, it is difficult to stir even by aeration during regeneration, and if it is too small, it takes time to form the deposited filtration layer. Therefore, a specific gravity of about 1.08 to 1.2 is preferable. For example, in the case of a specific gravity of 1.2, it is stirred and loosened with an air diffuse of about 80 liters / minute, and the deposited filtration layer is restored about 25 minutes after the end of the air diffuse.
Further, when the carrier regeneration process is performed in this way, the process can be performed collectively in a relatively short time, so that the amount of water to be treated that is simultaneously transferred to the anaerobic treatment tank can be suppressed, so that the upstream side This is also preferable in that the possibility of adversely affecting the environment of the anaerobic treatment tank is minimized.
[0014]
Further, by supplying air through the second air supply pipe of the air lift pump based on the air diffusion state of the filter tank, sludge can be suspended and transferred at the same time, so that the carrier regeneration process can be performed efficiently. For example, the switching device that switches between the supply of air to the first supply pipe and the supply of air to the second supply pipe, and the diffusion of the diffusion pipe and the supply of air to the second supply pipe are synchronized. It is preferable to achieve these cooperations by providing a control device.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIGS. 1 and 2, the septic tank of the present invention comprises an anaerobic treatment tank N, an aerobic treatment tank E, treated water tanks T1, T2, and the like from the upstream side. It consists of one chamber N1 and an anaerobic filter bed tank second chamber N2, and the aerobic treatment tank E consists of a carrier flow tank E1 and a filtration tank E2. The raw water to be treated flows into the first anaerobic filter bed tank N1 from the raw water inflow section I, and downstream in the order of the anaerobic filter bed tank second chamber N2, the carrier flow tank E1, the filter tank E2, and the treated water tank T1. It is decomposed while being transferred to the tank, and after passing through the disinfection tank Q provided above the treated water tank T2, it is discharged from the outlet Z to the outside of the tank.
[0016]
The anaerobic filter bed first chamber N1 is configured to be capable of storing raw water to be treated, and is capable of growing anaerobic microorganisms therein. The raw water to be treated flowing into the first anaerobic filter bed first chamber N1 is stored in the first anaerobic filter bed first chamber N1 and is anaerobically decomposed, mainly to divide coarse organic matter. And transferred from the lower part of the first anaerobic filter bed tank N1 to the lower part of the second chamber N2 of the anaerobic filter bed tank. Solids such as sludge that are not easily decomposed are stored as precipitates in the lower part of the anaerobic filter bed first chamber N1 or as scum in the upper part of the anaerobic filter bed first chamber N1.
The anaerobic filter bed second chamber N2 is provided with an anaerobic filter bed F, and anaerobic microorganisms are fixed and grown on the anaerobic filter bed F. The water to be treated which has flowed into the second chamber N2 of the anaerobic filter bed is further subjected to anaerobic treatment, decomposed to a state having almost no solid matter, and then sent to the carrier flow tank E1 by overflow. Between the anaerobic filter bed tank N and the carrier fluidized tank E1, the overflow portion 1 is configured to allow free movement of the treated water, and the overflow portion 1 is provided with a slit-like portion 2 to provide the treated water. The carrier and sludge in the carrier fluid tank E1 can be prevented from flowing back.
[0017]
The carrier fluid tank E1 accommodates and holds a carrier C1 that is formed so as to be able to flow together with the water to be treated in a state where microorganisms are supported, and is provided with an air diffuser D1 that allows the carrier to flow by supplying bubbles. An air diffuser is provided to allow the carrier C1 to flow in the carrier flow tank E1 by supplying bubbles from the air diffuser D1. With such a configuration, the water to be treated flowing into the carrier fluid tank E1 is purified by aerobic decomposition by aerobic microorganisms. The treated water that has undergone such treatment is transferred to the filtration tank E2 through the transfer wall portion 3 provided in the first partition wall W1 that partitions the carrier flow tank E1 and the adjacent filtration tank E2.
The advection wall portion 3 is formed in a lattice shape or a slit shape, and is configured to prevent the advection of the carrier C1, but to permit the advection of sludge and water to be treated.
[0018]
The filtration tank E2 is configured by filling a carrier C2 having a specific gravity greater than that of water up to a predetermined height. Moreover, the filtration wall part which distribute | circulates to-be-processed water freely in the position lower than the said predetermined height of the 2nd partition W2 which separates the said filtration tank E2 and the said treated water tank T1 provided adjacent to the said filtration tank E2. 4 is formed. As a result, the water to be treated containing sludge that is transferred to the filtration tank E2 is filtered through the deposited filtration layer B on which the carrier C2 is deposited, so that the solid water is hardly contained, and the adjacent treatment is performed. It is transferred to the water tank T1. The second partition wall W2 is connected to the septic tank side wall at the upper end, and the treated water tank T1 is arranged to be hidden under the filtration tank E2 in a plan view.
The filtration wall portion 4 is formed in a lattice shape or a slit shape, and prevents the advancing of the carrier C2, but allows the advancing of sludge and water to be treated.
Furthermore, an aeration pipe D2 as a stirring device for agitating the inside of the filtration tank E2 by agitating the carrier C2 is provided below the constructed filtration layer B, and the load on the septic tank such as at night is reduced. In the time zone when there is little inflow, the carrier is regenerated by performing aeration from the diffusion tube D2.
In addition, air diffuses toward the advection wall portion 3 in the aeration tube D2, and bubbles due to the aeration pass through the advection wall portion 3, and along the advection wall portion 3 on the carrier flow tank E1 side. The advection wall diffuser Da configured to be raised, and similarly diffused toward the filtration wall, and air bubbles due to the aeration pass through the filtration wall 4 and the treatment water tank T1 side As the structure which provides the filtration wall part aeration part Db comprised so that it can be raised along the filtration wall part 4, and wash | cleans the advection wall part 3 and the filtration wall part 4, respectively, and prevents clogging etc. is there.
[0019]
Here, the advection wall part 3 and the filtration wall part 4 have a predetermined upper end height of the deposition filtration layer B so that the water to be treated must be allowed to flow after passing a predetermined distance of the deposition filtration layer B. What is necessary is just the structure which is provided in the position lower than height, accept | permits the advection of to-be-processed water, and enables filtration of the to-be-processed water in the said deposition filtration layer B. FIG.
Each of the carriers C1 and C2 is formed to have a specific gravity of 1 or more and 1.2 or less that can flow together with the water to be treated.
Thereby, even when it is necessary to take the diffuser tube out of the septic tank, for example, when the diffuser tube D1 is maintained, the diffuser tube can be easily inserted and removed through the diffuser tube insertion hole 14, and the outflow The work can be performed with almost no disassembly of the prevention member.
[0020]
Further, the treated water tank T1 is provided with an air lift pump A for transferring the treated water to the anaerobic filter bed first chamber N1, and the sludge generated by the regeneration of the carrier C2 is collected from the filtration tank E2 into the treated water tank T1. It can be transferred to the first chamber N1 of the anaerobic filter bed tank together with the water to be treated.
The air lift pump A has a lower end opening at the bottom of the treated water tank T1 and a vertical pipe A1 extended to the upper part on the carrier flow tank side, and a connection part of the upper part of the vertical pipe A1 to the anaerobic filter bed tank first. A first air supply pipe that is provided with a horizontal pipe A2 that extends horizontally over the upper part of the chamber N1 and that supplies water to the lower part of the vertical pipe A1 to the lower part of the vertical pipe A1 so that the water to be treated can be transferred A3 and a second air supply pipe A4 that supplies air to the lower part of the vertical pipe A1 and allows sludge to be transferred are connected in series, and each air supply pipe A3, A4 can supply air into the vertical pipe A1. It is. The connection portion of the first air supply pipe A3 is provided at a deeper position than the connection portion of the second air supply pipe A4, and the cover is approximately 2 liters / minute by supplying air of 10 liters / minute almost always. The second supply pipe A4 is connected to a slightly upper part of the connection part of the first supply pipe A3, and is once a day only when the diffuser pipe D2 is operated. About 10 minutes, 80 liters / minute of air is supplied, and about 60 liters / minute of treated water is transferred, and almost all of the treated water and sludge from the filtration tank T1 is transferred to the anaerobic filter bed tank 1 It is configured to be transferred to the chamber N1.
[0021]
Thus, specifically, in a normal operation state, the water to be treated that has flowed into the septic tank is transferred to the anaerobic filter bed tank first and second chambers N1 and N2 while being subjected to anaerobic treatment in this order. Reach tank E1. And soluble BOD etc. are aerobically processed and the component used as a BOD source is oxidatively decomposed | disassembled by a biofilm. Further, the clean water to be treated which is filtered by the carrier C constituting the sedimentation filtration layer B in the filtration tank E2 and does not contain suspended matters is transferred to the treatment water tank T1, passes through the vicinity of the bottom of the purification tank, and the treatment water tank T2. And finally, treated water containing almost no suspended components and BOD of 20 mg / liter or less is obtained. This treated water flows into the disinfecting tank Q provided in the upper part of the treated water tank 2, and after being disinfected in contact with the solid disinfectant Q1, it is discharged outside the tank.
At the same time, according to the biofilm treatment, it is expected that the purification of the water to be treated is likely to be biased toward acidity. Therefore, the water to be treated that is being biased toward acidity by the air lift pump A is removed from the first anaerobic filter bed tank 1. By recirculating from the chamber N1, it is expected that the nitrate nitrogen component is denitrified and the acidity of the treated water is lowered. Therefore, in the treated water tank, it is possible to maintain a state in which solid components, particularly scum, are hardly generated, and it is possible to realize advanced water treatment.
[0022]
Further, when the air diffuser D2 is operated, the filtration tank E2 hardly functions, and solid components generated in the carrier flow tank E1 and captured in the filtration tank E2 are contained in the filtration tank E2. It peels from the carrier and circulates in the filtration tank E2. This solid component gradually flows into the treated water tanks T1 and T2. When a large amount of treated water is transferred to the first anaerobic filter bed tank N1 by the air lift pump A, the treated water While the transfer is being performed, the treatment water treatment proceeds so that almost all of the treatment water continues to circulate from the first chamber of the anaerobic filter bed tank to the filtration tank B.
Then, the solid component that has flowed into the treated water tank T1 does not enter the treated water tank T2 side, but is transferred to the anaerobic filter bed tank first chamber N1, and is precipitated and stored as it is sequentially transferred to the downstream side. As a result, the filtration tank E2 is regenerated, and sludge reprocessing and sediment storage by the anaerobic filter bed tank N are effectively achieved.
In addition, when a large amount of air is supplied into the vertical pipe A1 in order to transfer a large amount of water to be treated in this way, it is possible to peel off and remove deposits and the like adhering to the vertical pipe A1. Therefore, this contributes to prevention of clogging of the air lift pump A.
[0023]
Further, even if a large amount of water to be treated flows into the septic tank above the steady water level of the carrier flow tank E1 and the filtration tank E2, the carriers C1 and C2 in the tank flow out so as not to flow into other tanks. The outflow prevention member 10 to be prevented is composed of mesh members 11 and 11 having finer meshes than the carriers C1 and C2, and is divided into a plurality of parts and can be taken out from the manhole H. The outflow prevention member 10 is provided with an opening 12 in a part thereof, and a duct-shaped carrier charging portion 13 is extended.
Thereby, even if it diffuses in the said carrier flow tank E1 and the filtration tank E2 and forms the convection of to-be-processed water, the flow is formed so that it may flow smoothly, without being inhibited by the said outflow prevention member 10. The In addition, when the carriers C1 and C2 are filled in the carrier flow tank E1 and the filtration tank E2 or when the carriers C1 and C2 are exchanged, they can be easily charged and sucked through the carrier loading part 13. It becomes.
[0024]
Further, the outflow prevention member 10 is provided with a diffuser tube insertion hole 14 that allows the diffuser tube D1 to be inserted and removed, and the air supply tube D1a connected to the diffuser tube D1 includes the diffuser tube D1. With a position fixed in the carrier flow tank E1, a dam mechanism is configured to block the carrier outflow by integrally connecting a lid member 15 that covers the diffuser tube insertion hole. The air diffusion pipe D1 and the air supply pipe for the air lift pump A are gathered in the upper space of the filtration tank, and the upper pipe of the carrier flow tank E1 is arranged to a minimum.
[0025]
As a result, the carrier fluid tank E1 and the filtration tank E2 are arranged in a state in which the upper side is provided in an open state and the carrier can be easily replaced and the water quality can be confirmed from the upper space. By simply removing the lid member from the air supply pipe without disassembling the inside of the septic tank, the insertion hole can be opened and can be easily performed from above via the manhole H provided in the septic tank. At this time, even when various measuring devices (pH meter, BOD meter, etc.) are brought into the tank for water quality inspection and the like, it is difficult to pay attention to handling and workability is improved.
[0026]
Air supply to the air lift pump and the diffuser pipe is performed from the blower, and air supply switching to each pipe line is synchronized using various known switching control devices.
[0027]
[Another embodiment]
In the previous embodiment, the structure in which the advection wall portion 3 and the filtration wall portion 4 are integrally formed with the first and second partition walls W1 and W2 is shown. The first and second partition walls W1 and W2 provided with the advection wall portion 3 or the filtration wall portion 4 may be detachably provided with respect to the septic tank. good. Moreover, although each aerobic processing tank E1, E2 was provided in parallel in the width direction in FIG. 1, the arrangement | sequence in planar view, such as providing in series in a longitudinal direction, is not restricted to the above-mentioned thing.
[0028]
Moreover, although the said carrier injection | throwing-in part 13 is not essential, it is desirable to form in the duct shape to the vicinity of the said manhole H according to the embedding condition of the said septic tank.
Further, the connecting portion of the first and second air supply pipes to the vertical pipe is not necessarily provided in two upper and lower stages, and may be joined at the connecting section, or the vertical position may be reversed. Good.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view of a septic tank according to the present invention. FIG. 2 is a perspective view of essential parts of the septic tank of the present invention. FIG. 3 is a perspective view of essential parts of a conventional septic tank.
C1 Carrier D1 Air diffuser E1 Carrier fluid tank 10 Outflow prevention member

Claims (1)

An anaerobic treatment tank for anaerobically treating the raw water to be treated is provided, and a carrier that is formed so as to be able to flow with the treated water is accommodated in a state where microorganisms are supported, and bubbles are supplied to cover the carrier. Sludge from the filtration tank is provided with the carrier flow tank provided with a diffuser for flowing together with the treated water, and a filtration tank for filtering the treated water in the carrier flow tank on the downstream side of the carrier flow tank. And an operation method of a septic tank provided with an air lift pump that enables transfer of water to be treated to the anaerobic treatment tank,
The filtration tank is provided with a deposition filtration layer filled with a carrier up to a predetermined height, and an air diffusion tube is provided below the deposition filtration layer to diffuse the carrier and allow the inside of the filtration tank to be stirred. In addition, a vertical pipe installed to be able to suck water to be treated from the carrier flow tank to the downstream side through the bottom of the purification tank to the air lift pump , and the carrier flow tank from the upper side of the anaerobic treatment tank A horizontal pipe that is held in a horizontal position over the upper side and connected to the upper part of the vertical pipe, a first air supply pipe that supplies air to the lower part of the vertical pipe to allow the water to be treated to flow, and the vertical pipe A second air supply pipe for supplying sludge to the lower part of the air supply , the first air supply pipe being always in an operating state, and supplying air from the second air supply pipe when the air diffuser pipe of the filtration tank is in operation To operate the septic tank .

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