JP5814583B2 - Septic tank - Google Patents

Description

The present invention filters an anaerobic treatment tank for anaerobically treating treated water and a biological treatment unit including an aerobic treatment tank for treating treated water aerobically, and the treated water treated in the aerobic treatment tank. The present invention relates to a septic tank provided with a carrier filtration tank.

In the septic tank , in order to wash the carrier filled in the carrier filtration tank, conventionally, a diffusion pipe for washing the carrier is provided in the carrier filtration tank, and the water to be treated is stirred with the air blown from the diffusion pipe. Thus, the carrier can be washed (see, for example, Patent Document 1).
This cleaning of the carrier is performed in a specific time zone where there is little possibility of adversely affecting the filtration of the water to be treated in the carrier filtration tank, for example, at a time zone where the possibility of the water to be treated is low.

JP 2007-61705 A

For this reason, it is necessary to provide a control device for controlling the carrier cleaning operation to be performed in a specific time zone, which may increase the production cost of the septic tank .
In addition, when inflow of water to be treated occurs during a time period for washing the carrier, the water to be treated may flow into the carrier filtration tank during the washing operation and cannot be appropriately filtered.

This invention is made | formed in view of the said situation, Comprising: It aims at providing the septic tank which can aim at reduction of manufacturing cost, without requiring the control apparatus which controls washing | cleaning driving | operation.

The first characteristic configuration of the septic tank according to the present invention is processed in the anaerobic treatment tank including an anaerobic treatment tank for anaerobically treating the treated water and an aerobic treatment tank for treating the treated water aerobically. A carrier filtration tank for filtering the treated water, and a carrier filled in the carrier filtration tank with a specific gravity greater than that of water is sucked into the pumping channel from the bottom of the tank together with the treated water and returned to the upper part of the carrier filtration tank. An air lift pump, a transfer unit that transfers a part of the water to be treated discharged from the pumping path to the anaerobic treatment tank disposed in the biological treatment unit, and the transfer unit that can transfer the treatment water to the treatment tank and a transfer amount limit section which limits the transfer of such water to be treated, the transfer amount limit section, Ri Thea disposed on the discharge opening neighborhood provided at the upper end of the pumping path, said discharge port, Provided at a position higher than the level of the water to be treated in the carrier filtration tank. Cage is that a carrier is drawn into the pumping channel is configured to drop the liquid surface of the water to be treated without staying from said discharge port together with the water to be treated.

The septic tank of this configuration has an air lift pump that sucks a carrier having a higher specific gravity than water filled into the carrier filtration tank from the bottom of the tank together with the water to be treated into the pumping channel and returns it to the upper part of the carrier filtration tank. ing.
Therefore, the carrier filled in the carrier filtration tank is filtered by the rising flow of the treated water in the pumping channel while filtering the treated water without adversely affecting the filtration of the treated water in the carrier filtration tank. By sucking into the pumping channel from the bottom and returning to the top of the tank, the carrier filtration tank can be circulated and moved across the tank bottom and the tank top.

The carrier sucked into the pumping path from the tank bottom along with the circulation movement between the tank bottom and the tank top of the carrier filtering tank is washed by collision with the air supplied to the pumping path, and the tank upper part of the carrier filtering tank. To reflux.
The air in the pumping path is refined by collision with the carrier and dispersed in the water to be treated, and the inside of the carrier filtration tank is maintained in an aerobic atmosphere to promote aerobic decomposition of the water to be treated.

Therefore, in the septic tank of this configuration, the carrier is circulated and moved between the tank bottom and the tank top while filtering the water to be treated without adversely affecting the filtration of the water to be treated in the carrier filtration tank. Therefore, a control device for controlling the cleaning operation is not required, and the manufacturing cost can be reduced.
In addition, aerobic decomposition of water to be treated in the carrier filtration tank can be promoted.

Further, the septic tank of this configuration has a transfer unit that transfers a part of the water to be treated discharged from the pumping channel to a treatment tank upstream of the aerobic treatment tank disposed in the biological treatment unit. doing.
For this reason, while being able to ensure the circulation amount of the to-be-processed water required for nitrification denitrification reaction, the floating substance in the to-be-processed water in the carrier filtration tank which increases with the washing | cleaning of a support | carrier or aerobic decomposition of to-be-processed water (SS) can be reduced to increase filtration efficiency.
Moreover, even if the suspended matter and sludge staying in the treated water in the carrier filtration tank is reduced and the inflow load of the treated water is increased, the suspended matter and sludge may be discharged together with the treated water to the outside of the septic tank. Few.

Furthermore, the septic tank of this structure has the transfer amount restriction | limiting part which restrict | limits the transfer amount of the to-be-processed water which can be transferred to a processing tank by a transfer part.
For this reason, the transfer amount of the to-be-processed water with much dissolved oxygen amount to the treatment tank upstream from the aerobic treatment tank can be limited to prevent a decrease in anaerobic treatment efficiency in the anaerobic treatment tank.

  The second characteristic configuration of the present invention is that the transfer amount limiting unit is provided so that the transfer amount can be adjusted.

  If it is this structure, the circulation amount of to-be-processed water can be adjusted according to the processing capacity of nitrification denitrification processing.

  The third characteristic configuration of the present invention is that the transfer amount limiting portion is provided so as to be able to prevent the carrier from passing through the transfer portion.

  With this configuration, it is not necessary to provide another means for preventing the carrier from passing through the transfer section.

It is a top view which shows the inside of a septic tank. It is a side view which shows the inside of a septic tank. It is the III-III arrow directional view of FIG. It is the IV-IV arrow directional view of FIG. It is the VV arrow directional view of FIG. It is a perspective view which shows the inside of a support | carrier flow tank and a support | carrier filtration tank, (a) shows the state in which the support | carrier is accommodated in the support | carrier filtration tank, (b) makes it easy to understand the inside of a support | carrier filtration tank. The state where the carrier is omitted is shown. It is a side view which shows the inside of a carrier filtration tank. It is a perspective view which shows a transfer amount restriction | limiting part. It is a perspective view which shows the transfer amount restriction | limiting part of 2nd Embodiment. It is a perspective view which shows the transfer amount restriction | limiting part of 3rd Embodiment.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
1 to 5 show a septic tank that purifies domestic wastewater (sewage) as treated water as an example of the sewage purification facility according to the present invention.

  As shown in FIGS. 1 and 2, the septic tank has a biological treatment tank (biological treatment unit) A for biologically treating the treated water, and a moving bed for filtering the treated water treated in the biological treatment tank A. Is divided into a carrier filtration tank B, a treated water tank C that temporarily stores the treated water filtered in the carrier filtration tank B, and a disinfection tank D that disinfects the treated water stored in the treated water tank C. .

The biological treatment tank A has a primary treatment tank (anaerobic treatment tank) A1 for receiving an anaerobic treatment water (raw water) flowing from the outside and an anaerobic treatment tank A2 for anaerobically treating the treatment water. It is divided into tanks.
The anaerobic treatment tank A1 is divided into a precipitation separation tank E1 and an anaerobic filter bed tank E2.

  The treated water (raw water) from the outside flows into the sedimentation separation tank E1 from the inflow part 1, and the treated water sterilized in the disinfection tank D is discharged from the discharge part 2 to the outside.

  The sedimentation separation tank E1 and the anaerobic filter bed tank E2 are divided forward and backward by the first horizontal partition wall 4, and the anaerobic filter bed tank E2, the carrier flow tank A2 and the carrier filtration tank B are partitioned forward and backward by the second horizontal partition wall 5. Has been.

  The carrier flow tank A2, the carrier filtration tank B, and the treated water tank C are divided into left and right by the vertical partition wall 7, the carrier filtration tank B and the treated water tank C are divided forward and backward by the partition wall 8, and the disinfection tank D is flowed through the carrier. It is divided in the inner upper part of tank A2.

  As shown in FIGS. 3 and 4, the first horizontal partition 4 is provided with a first advection port 11 for advancing water to be treated from the precipitation separation tank E1 to the anaerobic filter bed tank E2. The first baffle plate 17 and the second baffle plate 19 are attached.

As shown in FIG. 5, the second horizontal partition wall 5 is provided with a second advection port 12 for advancing water to be treated from the anaerobic filter bed tank E2 to the carrier flow tank A2.
As shown in FIG. 6, in the partition wall portion of the vertical partition wall 7 near the surface of the water to be treated, a third advection port 13 for flowing the water to be treated from the carrier flow tank A2 to the carrier filtration tank B has a water surface WL. It is provided over a higher position and a lower position.

At the lower end portion of the partition wall 8 between the carrier filtration tank B and the treated water tank C, a fourth advection port 14 through which the water to be treated is transferred from the carrier filtration tank B to the treated water tank C is provided.
The third advection port 13 and the fourth advection port 14 are formed with a large number of slit holes so that the carriers 21 and 23 accommodated in the carrier flow tank A2 and the carrier filtration tank B do not flow out.
The precipitation separation tank E1 and the anaerobic filter bed tank E2 may have a function as a flow rate adjusting unit that temporarily stores water to be treated at the peak inflow in a time zone such as morning and evening.

  Therefore, the water to be treated which has flowed in from the inflow portion 1 is transferred in the order of the precipitation separation tank E1, the anaerobic filter bed tank E2, the carrier fluidized tank A2, the carrier filtration tank B, the treated water tank C, and the disinfection tank D in order. Is released to the outside.

The water to be treated which has flowed in from the inflow portion 1 is precipitated and separated in the precipitation separation tank E1, guided along the first baffle plate 17 and rises along the first horizontal partition 4 and is provided in the first horizontal partition 4. It flows into the anaerobic filter bed tank E2 from the first advection port 11.
The anaerobic filter bed tank E2 includes an anaerobic filter bed 18 that holds anaerobic microorganisms.

  The water to be treated which has flowed into the anaerobic filter bed tank E2 from the first advection port 11 is guided by the second baffle plate 19 and descends along the first horizontal partition 4 and passes upward through the anaerobic filter bed 18 to anaerobically. Water to be treated in which suspended solids are captured and solid matter is almost decomposed is guided to the third baffle plate 20 from the second advection port 12 provided in the second horizontal partition wall 5, and then the carrier fluid tank A 2. It flows into the upper part of the tank.

  As shown in FIG. 6, a large number of fluid carriers 21 carrying aerobic microorganisms are accommodated in the carrier fluid tank A2 so that they can flow together with the water to be treated, and an aeration diffuser 22 is provided at the bottom of the tank. Is provided.

  The water to be treated that has flowed into the carrier fluid tank A2 is aerobically treated with the fluid carrier 21 while being supplied with oxygen by supplying air bubbles from the air diffuser 22, and then, along with the suspended solids (sludge), the vertical partition walls. 7 constantly flows into the carrier filtration tank B from the third advection port 13 provided in the carrier 7, and the suspended matter (sludge) in the carrier flow tank A2 decreases.

As shown in FIGS. 6 and 7, the lower part of the carrier filtration tank B is filled with a large number of substantially spherical filtration carriers 23 having a specific gravity larger than that of water so as to sink and accumulate in their own weight. .
The carrier filtration tank B includes an air lift pump P that constantly cleans the filter carrier 23 by sucking the filter carrier 23 together with the water to be treated from the bottom of the tank into the pumping path 25 and returning it to the upper part of the carrier filtration tank B. Yes.

The pumping channel 25 is formed inside a cylindrical channel wall 26 fixed along the vertical direction at the corner where the second horizontal partition wall 5 and the vertical partition wall 7 intersect.
An air supply pipe 27 that constantly supplies air lift air to the pumping path 25 is attached to the carrier flow tank A2 side of the vertical partition wall 7, and an air blowing part 27a is opened inside the water channel wall 26.

The water channel wall 26 is provided such that the discharge port 28 (the upper end portion of the pumping channel 25) is higher than the level of the water to be treated in the carrier filtration tank B.
At the lower end on the outer peripheral side of the water channel wall 26, two flat water channel side inclined surfaces 29 are formed that are separated from the pumping channel 25 side toward the lower end side.
The water channel side inclined surface 29 is formed by an upward surface of the inclined plates 30 provided with two flat inclined plates 30 surrounding the water channel wall 26 in a skirt shape (pyramidal shape).

At the tank bottom of the carrier filtration tank B, two flat tank-side inclined surfaces 31 that are closer to the lower side of the suction port of the pumping channel 25 are formed at the lower end side, and the lower ends of these tank-side inclined surfaces 31 are connected to the pumping channel 25. It is inserted under the suction port 32.
The tank side inclined surface 31 is formed by an upward surface of the bottom wall 33 of the carrier filtration tank B formed in a downward truncated pyramid shape.

As shown in FIG. 7, the water channel side inclined surface 29 has a lower end 34 disposed at the same height as the lower end of the water channel wall 26 and at a position higher than the upper end 35 of the tank side inclined surface 31. Since the horizontal cross-sectional area of the inner wall of the carrier filtration tank B becomes narrower toward the lower end 34 of the water channel side inclined surface 29, the filter carrier 23 sinking in the tank stays in the upper part of the water channel side inclined surface 29. A staying portion is formed, and gradually moves toward the tank inner surface 36 along the water channel side inclined surface 29. A staying portion of the filter carrier 23 on the upper side of the water channel side inclined surface 29 forms a filtration layer for filtering the water to be treated.
The minimum interval H1 between the lower end 34 of the water channel side inclined surface 29 and the tank side inclined surface 31 is set to be larger than the interval H2 along the horizontal direction between the lower end 34 of the water channel side inclined surface 29 and the inner surface 36 of the tank. is there.

  The filter carrier 23 settled between the lower end 34 of the water channel side inclined surface 29 and the tank inner surface 36 at a position higher than the upper end 35 of the tank side inclined surface 31 is formed along the tank side inclined surface 31 of the suction port 32. It moves downward and is sucked into the pumping path 25 together with the water to be treated from the suction port 32.

On the discharge port side of the pumping channel 25, a part of the water to be treated discharged from the discharge port 28 is a tank other than the carrier flow tank A2 and a tank other than the carrier filtration tank B, together with suspended solids (sludge). Is provided with a transfer part 37 for constant transfer.

The air lift pump P and the transfer unit 37 constitute the water to be treated circulating means F, and the water to be treated that has passed through the carrier filtration tank B after being treated in the carrier flow tank (aerobic treatment tank) A2 is disposed in the carrier filtration tank B. The air is transferred to the precipitation separation tank E1 through the air lift pump P and the transfer unit 37.
By transferring and circulating the water to be treated from the carrier fluid tank A2 to the anaerobic treatment tank (primary treatment tank) A1, the nitrification and denitrification treatment of the water to be treated is promoted.

  As shown in FIG. 8, the transfer unit 37 has a sediment separation tank E1 disposed on the upstream side of the carrier fluidized tank A2 in the treatment tank disposed in the biological treatment tank A for a part of the water to be treated. Is provided with a transfer rod for transfer (return).

  A transfer rod (transfer unit) 37 is arranged so that the transfer start end portion faces the vicinity of the discharge port 28 of the pumping channel 25, is supported by the second horizontal partition wall 5, and is one of the treated water discharged from the discharge port 28. The portion is introduced and transferred to the precipitation separation tank E1.

The transfer start part of the transfer tank 37 is provided with a transfer amount limiting unit 38 that limits the transfer amount of the water to be treated that can be transferred to the precipitation separation tank E1.
The transfer amount limiting unit 38 is configured by providing a weir plate that allows the water to be treated to pass along with the sludge and that is formed with a large number of slit holes 38a arranged in the slit width direction to prevent the filtration carrier 23 from passing therethrough. is there.

  The weir plate (transfer amount limiting portion) 38 is supported at the transfer start side end of the transfer rod 37 by the guide frame 39 provided on the second horizontal partition wall 5 so as to be slidable in the vertical direction. Thus, the transfer amount of the water to be treated to the precipitation separation tank E1 can be adjusted.

As shown in FIG. 6, in the vertical partition wall 7 that divides the carrier fluid tank A2 and the carrier filter tank B, there is a circulation path 40 through which the water to be treated can circulate between the carrier fluid tank A2 and the carrier filter tank B. It is provided.
The circulation path 40 has a third advection port 13 as an upper advection port formed in the vertical partition wall 7 and a lower advection port formed in a partition wall portion at a position lower than the third advection port 13 in the vertical partition wall 7. 5 advection ports 41 are provided.
The fifth advection port 41 is provided with a large number of slit holes that prevent the filtration carrier 23 from passing therethrough.

  In the circulation path 40, the water to be treated in the carrier filtration tank B flows from the fifth advection port (lower advection port) 41 into the carrier flow tank A2, and the water to be treated in the carrier flow tank A2 flows into the third advection port (upper advection port). ) The water to be treated is circulated while flowing into the carrier filtration tank B from 13.

  The fifth advection port 41 is formed so as to face the staying portion of the filtration carrier 23 in the carrier filtration tank B, and the third advection port 13 and the fifth advection port 41 are the aeration diffuser in the carrier flow tank A2. The partition wall part facing the air part 22 is formed by shifting the position in the vertical direction.

  The treated water filtered in the carrier filtration tank B is transferred to the treated water tank C through the fourth transfer port 14 formed in the partition wall 8 and temporarily stored, and then transferred to the disinfection tank D, disinfected, and externally. To be released.

[Second Embodiment]
FIG. 9 shows another embodiment of the present invention.
In the present embodiment, the barrier plate (transfer amount limiting portion) 38 is supported by a guide frame 39 fixed to the transfer start side end of the transfer rod 37 so as to be slidable in the vertical direction.

In addition, a large number of slit holes 38a formed in the weir plate 38 are located on the center side in the plate width direction so that the change amount of the transfer amount with respect to the unit slide movement amount of the weir plate 38 constituting the transfer amount limiting unit is small. The slit holes 38a are formed side by side in a V-shape that is at a lower position.
According to the present embodiment, it is easy to finely adjust the transfer amount by sliding the weir plate 38.
Other configurations are the same as those of the first embodiment.

[Third Embodiment]
FIG. 10 shows another embodiment of the present invention.
In the present embodiment, the transfer rod 37 is divided into a transfer end portion 37a and a main body portion 37b so as to be connectable, and the transfer end portion 37a is configured to be connectable to the upper part of the water channel wall 26 of the air lift pump P. Is provided with a weir plate (transfer amount limiting portion) 38.
The transfer end portion 37 a is integrally provided with a guide frame 39 that supports the dam plate 38 so as to be slidable, and a cylindrical connection portion 42 that is fitted onto the upper portion of the water channel wall 26.

  Then, the main body portion 37b is placed on the outer peripheral side of the transfer end portion 37a so that the upper edge portion 43 of the transfer end portion 37a connected to the water channel wall 26 enters the downward groove portion 37c formed in the upper edge portion of the main body portion 37b. By being inserted, the main body portion 37b and the transfer end portion 37a are configured to be connectable.

According to the present embodiment, the relative position between the air lift pump P and the transfer rod 37 can be easily positioned, and even if vibration occurs in the water channel wall 26 of the air lift pump P, the water to be treated is transferred. 37 can be stably transferred.
Other configurations are the same as those of the first embodiment.

[Other Embodiments]
In the above-described embodiment, the anaerobic treatment tank (primary treatment tank) is composed of a precipitation separation tank and an anaerobic filter bed tank, but is not limited to this structure, and is a tank that performs solid-liquid separation and anaerobic treatment. What is necessary is just to be comprised, for example, the thing provided with the aeration tank in the combination of several anaerobic filter bed tanks, or an inflow part.
The aerobic treatment tank may be a contact aeration tank equipped with a fixed filter medium or an aeration tank not equipped with a filter medium.

23 carrier 25 pumping path 37 transfer part 38 transfer amount restriction part A biological treatment part A1 anaerobic treatment tank B carrier filtration tank E1 treatment tank A2 aerobic treatment tank P air lift pump

Claims (3)

A biological treatment section comprising an anaerobic treatment tank for anaerobically treating the treated water and an aerobic treatment tank for aerobically treating the treated water;
A carrier filtration tank for filtering the treated water treated in the aerobic treatment tank;
An air lift pump that sucks a carrier having a specific gravity greater than water filled in the carrier filtration tank into the pumping path from the bottom of the tank together with the water to be treated and returns to the upper part of the carrier filtration tank;
A transfer unit that transfers a portion of the water to be treated discharged from the pumping path to the anaerobic treatment tank disposed in the biological treatment unit;
A transfer amount limiting unit that limits a transfer amount of water to be treated that can be transferred to the treatment tank by the transfer unit;
The transfer amount limit section, Ri Thea disposed on the discharge opening neighborhood provided at the upper end of the pumping path,
The discharge port is provided at a position higher than the liquid level of the water to be treated in the carrier filtration tank, and the carrier sucked into the pumping path does not stay with the water to be treated from the discharge port. A septic tank that is configured to drop onto the surface of water . The septic tank according to claim 1, wherein the transfer amount limiting unit is provided so that the transfer amount can be adjusted. The septic tank according to claim 1 or 2, wherein the transfer amount limiting unit is provided so as to prevent passage of the carrier to the transfer unit.

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