JP2007117908A - Septic tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a septic tank in which scum in an anaerobic tank is hardly transferred to an aerobic tank and consequently even water to be treated such as water flowing in from a disposer and having high treatment load is easily and properly purified. <P>SOLUTION: The septic tank is provided with: the anaerobic tank A into which the water to be treated flows; the aerobic tank B for treating the water to be treated after treated in the anaerobic tank; and a settling tank C for settling solid matter in the water to be treated after treated in the aerobic tank, wherein the water to be treated in the settling tank is discharged to the outside, and wherein the anaerobic tank comprises a solid liquid separation tank A1 into which the water to be treated flows from the outside and a flow rate adjusting tank A2 to which the water-to-be-treated separated in the solid liquid separation tank is transferred by overflow. The septic tank is further provided with: a pump 13 for transferring the water to be treated in the flow rate control tank to the aerobic tank; a transferring port 22 for transferring the water to be treated in the aerobic tank to the settling tank by overflow; and a returning means 25 for returning the solid matter settled in the settling tank to the anaerobic tank, wherein the bottom of the settling tank is given a downwardly tapered shape so that the cross-sectional area of the inside of the settling tank along the horizontal direction is decreased toward below. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention includes an anaerobic tank into which treated water flows from the outside, an aerobic tank for aerobically treating the treated water that has been anaerobically treated in the anaerobic tank, and the treated water that has been aerobically treated in the aerobic tank. The present invention relates to a septic tank comprising a settling tank for precipitating the solid content of the settling tank and configured to discharge water to be treated in the settling tank to the outside.

In the septic tank, conventionally, an anaerobic tank is divided into a contaminant removal tank into which treated water flows from the outside and an anaerobic filter bed tank with a partition wall, and the inlet for communicating the contaminant removal tank and the anaerobic filter bed tank Is provided on the partition wall in a vertical width that matches the elevation level position of the liquid level in the normal operation state, and in the normal operation state, depending on the inflow amount of the treated water into the contaminant removal tank, The liquid level in the removal tank and the liquid level in the anaerobic filter bed tank are configured to rise and fall at the same level while being continuous through the inlet, and the water to be treated in the anaerobic filter bed tank is pumped to the aerobic tank. It is comprised so that it may be transferred to.
In addition, the water to be treated aerobically treated in the aerobic tank is allowed to flow into the lower part of the settling tank from the inlet between the lower end of the suspension wall and the bottom of the tank that separates the aerobic tank and the settling tank. The water to be treated in the settling tank is configured to be discharged to the outside (see, for example, Patent Document 1).

JP-A-8-24880

In the conventional septic tank, as described above, in the normal operation state, the liquid level of the contaminant removal tank and the liquid level of the anaerobic filter bed tank flow according to the inflow amount of the treated water into the contaminant removal tank. It is configured to move up and down at the same level in a continuous state through the inlet, and it is configured to transfer the water to be treated in the anaerobic filter bed tank to the aerobic tank with a pump. The entire filter bed tank functions substantially as a flow rate adjustment tank, and the scum floating in the treated water in the contaminant removal tank flows into the anaerobic filter bed tank through the inlet, In addition, there is a drawback that it is easily transferred to the aerobic tank.
In addition, when a large amount of treated water having a relatively high solid content and a high processing load flows into the contaminant removal tank, such as treated water flowing from the disposer, the treated water having a large solid content passes through the inlet. It flows into the anaerobic filter bed tank and is transferred to the aerobic tank by a pump. From the aerobic tank, it flows into the sedimentation tank from the bottom of the tank, and the solids flow from the bottom of the treated water in the sedimentation tank to the top. There is a drawback that it is easy to be discharged to the outside together with the water to be treated without being sufficiently settled on the rising flow.
The present invention has been made in view of the above circumstances, and is a septic tank in which the scum of an anaerobic tank is difficult to be transferred to an aerobic tank, and it is easy to appropriately purify even water to be treated having a high processing load flowing from a disposer The purpose is to provide.

  The first characteristic configuration of the present invention includes an anaerobic tank into which treated water flows from the outside, an aerobic tank for aerobically treating the treated water that has been anaerobically treated in the anaerobic tank, and an aerobic treatment in the aerobic tank. And a sedimentation tank for precipitating solids in the treated water, wherein the treated water in the settling tank is configured to be discharged to the outside, wherein the anaerobic tank is treated from outside. An inflow solid-liquid separation tank, and a flow rate adjustment tank in which the water to be treated solid-liquid separated in the solid-liquid separation tank is transferred in an overflow state in a normal operation state, and the water to be treated in the flow rate adjustment tank is A pump for transferring to the aerobic tank; a transfer port for transferring the water to be treated in the aerobic tank to the settling tank by overflow; and a return means for returning the solid content precipitated in the settling tank to the anaerobic tank. Set the bottom shape of the settling tank along the horizontal direction inside the settling tank Lies in the product is is formed on the lower Subomari shape becomes smaller as the bottom.

[Action and effect]
The anaerobic tank is composed of a solid-liquid separation tank into which treated water flows from the outside, and a flow rate adjusting tank in which the treated water separated in the solid-liquid separation tank in an ordinary operation state is transferred by overflow. Therefore, the water to be treated in the solid / liquid separation tank gently flows into the flow adjustment tank by overflow, and the scum floating in the water to be treated in the solid / liquid separation tank is difficult to flow into the flow adjustment tank and flows from the disposer. Even if water to be treated, such as water to be treated, having a relatively high solid content and a high processing load flows into the solid-liquid separation tank, it is easy to separate the solid and liquid over a sufficient amount of time. Difficult to flow in.
In addition, since a pump for transferring the water to be treated in the flow rate adjustment tank to the aerobic tank is provided, the water to be treated with little inflow of scum and solids can be transferred to the aerobic tank for aerobic treatment. Since the advection port for advancing the treated water in the tank to the settling tank by overflow is provided, the solid content in the treated water that has been aerobically treated in the aerobic tank is transferred from the treated water transfer port in the settling tank to the bottom of the tank. It is easy to precipitate efficiently by putting it on the downward flow, and since there is a return means for returning the solid content precipitated in the settling tank to the anaerobic tank, the solid content can be anaerobically treated again in the anaerobic tank. .
In addition, since the bottom shape of the precipitation tank is formed in a constricted shape in which the cross-sectional area along the horizontal direction inside the precipitation tank becomes smaller in the lower part, it is easy to deposit the precipitated solid content at the bottom of the precipitation tank, It can be returned efficiently to the anaerobic tank by the return means.
Therefore, the scum of the anaerobic tank is difficult to be transferred to the aerobic tank, and the treated water with a relatively high solid content and a high processing load flows into the solid-liquid separation tank in a short time. Even if the water flows into the sedimentation tank via the flow rate adjustment tank and the aerobic tank, it is easy to efficiently deposit these solids on the bottom of the precipitation tank and return them to the anaerobic tank. Even with high water to be treated, it is easy to purify appropriately so that the solid content is not discharged to the outside.

  The second characteristic configuration of the present invention includes a downward regulating channel for regulating the flow direction of the water to be treated in the solid-liquid separation tank downward, and the flow direction of the water to be treated in the solid-liquid separation tank regulated upward. And an upward restriction flow path separately provided along the tank wall portions facing each other in the radial direction of the solid-liquid separation tank, so that water to be treated from the outside passes through the downward restriction flow path and the solid-liquid separation tank The solid-liquid separation tank is configured so that the water to be treated in the solid-liquid separation tank can be transferred to the flow rate adjustment tank by overflow through the upward restriction flow path, and the solid content is transferred from the downward restriction flow path to the solid-liquid separation tank. It is in a point that it can be returned to.

[Action and effect]
Solid-liquid separation of a downward regulating channel that regulates the flow direction of the water to be treated in the solid-liquid separation tank and an upward regulating channel that regulates the flow direction of the water to be treated in the solid-liquid separation tank upward Provided separately along the tank walls facing each other in the radial direction of the tank, the water to be treated from the outside can flow into the solid-liquid separation tank through the downward regulating channel, and the water to be treated of the solid-liquid separation tank Is configured to be able to be transferred to the flow rate adjustment tank by overflow through the upward restriction flow path, so that the treated water from the outside flows in from the outlet of the downward restriction flow path to the entrance of the upward restriction flow path. The water to be treated which has been sufficiently solid-liquid separated by being retained in the solid-liquid separation tank for a long time in a state where it is forcibly mixed with the water to be treated is easily transferred to the flow rate adjusting tank.
In addition, since the solid content precipitated in the sedimentation tank can be returned from the downward regulating channel to the solid-liquid separation tank, the solid content is retained in the solid-liquid separation tank for a long time. Thus, solid-liquid separation can be performed efficiently.

Embodiments of the present invention will be described below with reference to the drawings.
1 to 4 show a septic tank according to the present invention for purifying domestic wastewater (sewage) as water to be treated, and as shown in FIGS. 1 and 2, a tank body 2 having a manhole 1 and the like, Anaerobic in the anaerobic tank A into which the water to be treated flows in from the outside through the inflow pipe 3 as the inflow port, the aerobic tank B in which the treated water that has been anaerobically treated in the anaerobic tank A, and the aerobic tank B A settling tank C for precipitating the solid content in the treated water and a disinfecting tank D for disinfecting the treated water that has passed through the settling tank C are partitioned, and the solid content is precipitated in the settling tank C. The treated water can be discharged to the outside through the sterilization tank D from the outflow pipe 4 serving as a discharge outlet.

  The anaerobic tank A is partitioned by the first partition wall 5 and the solid-liquid separation tank A1 into which the water to be treated flows from the outside through the inflow pipe 3, and the solid-liquid separation tank A1 in the normal operation state. The separated water to be treated is constituted by a flow rate adjusting tank A2 that flows from the first advection port 6 formed in the upper part of the first partition wall 5 by overflow.

  The solid-liquid separation tank A1 has a downward regulating channel 7 for regulating the flow direction of the water to be treated flowing into the solid-liquid separation tank downward, and the flow direction of the water to be treated flowing out of the solid-liquid separation tank upward. And an upward restriction flow path 8 that is separately provided along the tank wall portions 2a and 5a facing each other in the radial direction of the solid-liquid separation tank A1, so that water to be treated from the outside faces downward from the inflow pipe 3. The solid-liquid separation tank A1 can flow into the solid-liquid separation tank A1 through the restriction channel 7, and the water to be treated in the solid-liquid separation tank A1 can be transferred from the first advection port 6 to the flow rate adjustment tank A2 through the upward restriction channel 8 by overflow. It is.

  The downward regulating flow path 7 has the highest liquid in the flow rate adjustment tank A2 in the normal operation state with the first baffle 9 having a substantially U-shaped horizontal cross section surrounding the outlet side of the inflow pipe 3 at the upper end portion thereof. It is provided inside the tank wall portion 2a of the tank body 2 over the position higher than the surface height HWL and the height position substantially the same as the minimum liquid level height LWL.

  The upward restricting flow path 8 includes a second baffle 10 having a substantially U-shaped horizontal cross section and surrounds the first advection port 6 at the upper end portion of the second baffle 10, and the highest liquid level of the flow rate adjusting tank A2 in the normal operation state. It is provided on the solid-liquid separation tank side of the tank wall portion 5a of the first partition wall 5 over a position higher than the height HWL and a position lower than the minimum liquid level height LWL. is there.

  As shown in FIG. 3, the flow rate adjusting tank A <b> 2 is an anaerobic filter bed that decomposes soluble organic substances contained in the water to be treated by anaerobic microorganisms attached to the filter medium of the anaerobic filter bed 11. A constant-capacity type first air lift pump 13 that transfers the water to be treated in the flow rate adjusting tank A2 to the aerobic tank B through the pipe 12 at a substantially constant flow rate, and backwashing the anaerobic filter bed 11 A tube 14 is provided.

  The first air lift pump 13 has a third baffle 16 having a substantially U-shaped horizontal cross section on the side of the second partition wall 15 that partitions the anaerobic tank A and the aerobic tank B in a normal operation state. It is provided over a position higher than the maximum liquid level height HWL of the flow rate adjusting tank A2 and a height position substantially the same as the lower surface of the anaerobic filter bed 11, and is installed inside thereof.

  The aerobic tank B is obtained by aeration and stirring of a carrier made of resin such as polyethylene resin, polypropylene resin, and polyurethane resin filled in a fluidized state in the tank with air blown from the aeration tube 17 for aeration. It consists of a carrier reaction tank that repeatedly contacts the biofilm deposited and formed on the surface of the carrier with the water to be treated, and decomposes and removes organic substances in the water to be treated and oxidizes nitrogen compounds. A sludge drawer pipe 20 is provided that can draw the sludge out of the tank.

  As shown in FIG. 4, the settling tank C has a second advection port 22 provided with a porous plate 21 for preventing carrier outflow, and a third partition wall 23 that partitions the aerobic tank B and the settling tank C. It is formed in the upper part so that the water to be treated in the aerobic tank B is transferred from the second transfer port 22 by overflow, and the shape of the bottom surface 24 is lower in the transverse area along the horizontal direction inside the settling tank. Returning means 25 is provided for returning the solid content formed in the constricted shape that becomes smaller and precipitated in the settling tank C to the anaerobic tank A.

  Then, the fourth baffle 26 having a substantially U-shaped horizontal cross section surrounds the second advection port 22 and has a position higher than the maximum liquid level height HWL of the flow rate adjustment tank A2 in the normal operation state, The water to be treated, which is provided on the sedimentation tank side of the third partition wall 23 over the position lower than the liquid level height LWL, is formed inside the downward flow path 27, and is transferred from the second transfer port 22. It is configured to flow downward through the downward flow path 27 toward the tank bottom.

  The return means 25 is connected to a return pipe 19 forming a return path 18 by inserting a suction pipe 29 having a second air lift pump 28 at an intermediate position in the vertical direction through a downward flow path 27, and The inlet 30 is opened near the bottom of the tank, and the solid content precipitated on the bottom of the bottom-shaped tank passes through the return path 18 by the operation of the second air lift pump 28 and flows downward in the solid-liquid separation tank A1. It is comprised so that it can return to the anaerobic tank A from the path 7.

  The said disinfection tank D forms the 3rd transfer port 32 in the 4th partition wall 31 which partitions the precipitation tank C and the disinfection tank D, and the to-be-processed water of the settling tank C is transferred from the 3rd transfer port 32 by overflow. In this way, after the water to be treated is sterilized with the chlorine-based disinfectant in the drug tube 33, it can be discharged to the outside through the outflow pipe 4.

[Other Embodiments]
1. The septic tank according to the present invention may be provided so that the water to be treated in the aerobic tank is transferred to the sedimentation tank by overflow through a treatment tank for performing an appropriate treatment as necessary.
2. The septic tank according to the present invention may be configured such that the water to be treated in the settling tank can be discharged from the disinfection tank to the outside via a treatment tank for performing an appropriate treatment as necessary.

Vertical section of septic tank Plan view showing the inside of the septic tank Cross-sectional view taken along line III-III in FIG. IV-IV cross-sectional view in FIG.

Explanation of symbols

2a Tank wall part 5a Tank wall part 7 Downward regulation channel 8 Upward regulation channel 13 Pump 22 Transfer port 25 Return means A Anaerobic tank A1 Solid-liquid separation tank A2 Flow rate adjustment tank B Aerobic tank C Precipitation tank

Claims (2)

An anaerobic tank into which treated water flows from the outside, an aerobic tank for aerobically treating the treated water that has been anaerobically treated in the anaerobic tank, and a solid content in the treated water that has been aerobically treated in the aerobic tank A precipitation tank for precipitation,
A septic tank configured to discharge the treated water of the settling tank to the outside,
The anaerobic tank is composed of a solid-liquid separation tank into which treated water flows from the outside, and a flow rate adjusting tank in which the treated water separated in the solid-liquid separation tank in an ordinary operation state is transferred by overflow. ,
A pump for transferring the water to be treated in the flow rate adjusting tank to the aerobic tank, a transfer port for transferring the water to be treated in the aerobic tank to the settling tank by overflow, and a solid content precipitated in the settling tank. A return means for returning to the anaerobic tank;
The septic tank which formed the bottom face shape of the said sedimentation tank in the constriction shape where the cross-sectional area along the horizontal direction inside a sedimentation tank becomes small as the lower part. A downward regulating channel for regulating the flow direction of the water to be treated in the solid-liquid separation tank downward, and an upward regulating channel for regulating the flow direction of the water to be treated in the solid-liquid separation tank upward, Provided separately along the tank wall portions facing each other in the radial direction of the solid-liquid separation tank, water to be treated from the outside can flow into the solid-liquid separation tank through the downward regulating channel, and the solid-liquid separation The water to be treated in the separation tank is configured to be able to be transferred to the flow rate adjusting tank by overflow through the upward regulating channel,
The septic tank of Claim 1 comprised so that the said solid content can be returned to the said solid-liquid separation tank from the said downward control flow path.

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