JP4848435B2 - Return sludge activation enhancement equipment - Google Patents

Description

  This invention becomes a part of the return line of the return sludge in the sewage treatment line, and while giving air to the return sludge that passes, the return that can effectively enhance the activity of microorganisms in the return sludge by the applied air The present invention relates to an apparatus for enhancing sludge activation.

  In sewage treatment plants, human waste treatment plants, septic tanks, etc., sewage treatment using activated sludge is performed. In the sewage treatment line in these facilities, a sedimentation tank is typically arranged following the aeration tank. The sewage flows into the aeration tank containing the activated sludge, and the pollutant in the sewage becomes the bait of microorganisms in the activated sludge to purify the sewage. Water containing activated sludge overflowing from the aeration tank is sent to the settling tank. In this sedimentation tank, the activated sludge settles and the activated sludge settled is returned to the aeration tank as return sludge. Therefore, in such a sewage treatment line, it is important to maintain the activity of the returned sludge above a certain level.

  The main problem to be solved by the present invention is that the activity of the return sludge returned in the sewage treatment line can be effectively enhanced with a simple structure in the return process.

In order to achieve the above object, in the present invention, the activated sludge activation strengthening device is a device that becomes a part of the return sludge return line in the sewage treatment line,
Means for supplying air to the return sludge;
Downstream of the supply means, tubular mixing means for mixing the return sludge and air that are passed by the alternately enlarged diameter portions and reduced diameter portions, and
A tank-like mixing means that is downstream of the tubular mixing means and receives return sludge,
This tank-like mixing means is located in front of the inflow part of the return sludge provided on the upper side of the tank and divides the inside of the tank into a primary side space on the inflow part side and a secondary side space on the outflow part side, and the lower end of the plate And having a partition plate as a discharge part to the secondary side space of the return sludge between the tank bottom and
The secondary side space is made wider as it goes upward.

  The return sludge mixed with air in the air supply means can be finely mixed with the energy of the cavitation phenomenon in the tubular mixing means. The return sludge that has passed through the tubular mixing means is pumped into the primary space of the tank-like mixing means and sent into the secondary side space from the discharge section, but the flow of return sludge becomes faster at this discharge section and above the secondary space. In this tank-like mixing means, in addition to the same effect as the tubular mixing means, an appropriate reaction time is provided to further mix the air taken in the air supply means into the returned sludge. Can do. In addition, the excess air mixed with the return sludge in the air supply means generates an air pool in the upper part of the primary space, and the return sludge pumped from the inflow portion is pushed and spread on the plate surface of the partition plate. It is exposed to the air in the lever reservoir and flows down. Thereby, the air can be mixed with the returned sludge even in the primary side space. In the secondary space, finely mixed air can be adapted to the return sludge while decreasing the flow rate of the return sludge as it goes upward, and the activity of microorganisms in the return sludge can be increased.

  A plurality of the tank-like mixing means may be connected so that the outflow part of the preceding tank-like mixing means becomes the inflow part of the subsequent tank-like mixing means. In this case, the action of the tank-like mixing means is repeated a plurality of times in the process of returning the returned sludge, and the activity of microorganisms in the returned sludge can be further enhanced.

  According to this invention, the activity of the return sludge returned in the sewage treatment line can be effectively enhanced with a simple structure in the return process.

FIG. 1 is a plan view showing an example of the activation processing apparatus B. FIG. 2 is a longitudinal sectional view showing an example of the activation processing apparatus B. FIG. 3 is a cross-sectional configuration diagram of an ejector 2a as the air supply means 2 constituting the activation processing apparatus B. FIG. 4 is a cross-sectional configuration diagram of the tubular mixing means 3 constituting the activation processing apparatus B.

  Hereinafter, based on FIGS. 1-4, an example of the activation reinforcement apparatus B of the return sludge M comprised by applying this invention is demonstrated.

  The activation strengthening device B becomes a part of the return line 1 of the return sludge M in the sewage treatment line, and applies air to the return sludge M in the process of passing through the device B and returns by the supplied air. The activity of microorganisms in the sludge M can be effectively increased.

  Such an apparatus B is typically provided and used in a return line 1 of turbid water-like activated sludge that is returned from a sedimentation tank (not shown) in a wastewater treatment line to an aeration tank (not shown), that is, return sludge M. Alternatively, it is used in the return line 1 from the sludge tank or the sludge concentration tank to the aeration tank following the settling tank.

Such a device B is
(1) Air supply means 2 to the return sludge M;
(2) Downstream of the supply means 2, the tubular mixing means 3 for mixing the return sludge M and the air that are passed by the alternately enlarged diameter portions 3 a and reduced diameter portions 3 b,
(3) A tank-like mixing means 4 that is downstream of the tubular mixing means 3 and receives the return sludge M is provided.

  The return sludge M is pumped from the settling tank to the aeration tank, for example, via the return line 1 by a pump. An air supply means 2 is arranged on the primary side 1a (return sludge M inflow side) of the return line 1 and a tank-like mixing means 4 is arranged on the secondary side 1b (outflow side of the return sludge M). A tubular mixing means 3 is arranged between them.

  In the illustrated example, an ejector 2 a is used as the air supply means 2. In the illustrated example, the ejector 2a is formed by combining a main pipe portion 2b and a branch pipe portion 2f. The main pipe portion 2b includes a narrowed portion 2e between the primary side end 2c and the secondary side end 2d. The branch pipe part 2f allows the pipe one end 2g to communicate with the main pipe part 2b in the narrowed part 2e and receives air from the other pipe end 2h. Since the flow rate of the return sludge M passing through the main pipe portion 2b of the ejector 2a is increased by the stenosis portion 2e and the pressure of the stenosis portion 2e is reduced by the pressure feeding, air is drawn into the main pipe portion 2b through the branch pipe portion 2f and returned. Supplyed and mixed with sludge M. Typically, air is fed into the branch pipe portion 2f by a compressor. It is also possible to provide a plurality of such branch pipe portions 2f, and in such an ejector 2a, activated sludge adjusting agents (nutrients, bulking inhibitors, etc.) can be fed into the return sludge M in addition to air.

  Further, in the illustrated example, the tubular mixing means 3 has a plurality of reduced diameter portions 3b with an interval in the length direction between the primary side end 3c and the secondary side end 3d. In the example shown in the figure, the reduced diameter portion 3b is provided at three locations. A portion between the primary side end 3c of the tubular mixing means 3 and the first reduced diameter portion 3b is formed in a funnel shape in which the inner diameter gradually decreases toward the reduced diameter portion 3b. The space between the next end 3d and the last reduced diameter portion 3b is also formed in a funnel shape in which the inner diameter gradually decreases toward the reduced diameter portion 3b. In addition, the first reduced diameter portion 3b and the intermediate reduced diameter portion 3b are configured to have a spindle-shaped contour that gradually increases the inner diameter as they move between them, and the final reduced diameter portion 3b. And the intermediate reduced diameter portion 3b are configured to have a spindle shape with an inner diameter gradually increasing toward the gap between the two and the intermediate reduced diameter portion 3b. Thereby, in the illustrated example, the air taken in the air supply means 2 is finely mixed with the return sludge M passing through the tubular mixing means 3 by the energy due to the cavitation phenomenon in the reduced diameter portion 3b of the tubular mixing means 3. It is like that.

  Next, the tank-like mixing means 4 is located in front of the inflow portion 4a of the return sludge M provided on the upper side of the tank, and the inside of the tank is the primary side space 4e on the inflow portion 4a side and the secondary side on the outflow portion 4o side. A partition plate 4b is provided which is divided into a space 4f and serves as a discharge portion 4h for the return sludge M to the secondary side space 4f between the plate lower end 4c and the tank bottom 4g. At the same time, the tank-like mixing means 4 is configured to make the secondary space 4f wider as it goes upward.

  In the illustrated example, three such tank-like mixing means 4 are connected in series, and the air supply means 2, the tubular mixing means 3, and the like are connected to the upper part of the tank-like mixing means 4 connected in series in this way. The activation strengthening device B is configured by arranging. In the illustrated example, a pipe 1c of the return line 1 is arranged on a top plate 4i that closes the upper surface of the connected tank-shaped mixing means 4 so as to form a U shape in a plan view, and a part of this pipe 1c is The air supply means 2 and the tubular mixing means 3 are provided. A pipe 1c that hangs down and communicates with the secondary side end 3d of the tubular mixing means 3 in the pipe 1c is connected to the tank upper side of the first tank-like mixing means 4 connected as described above, and this connection point is This is the inflow portion 4 a of the first tank-like mixing means 4.

  Each tank-like mixing unit 4 has a narrow primary side space 4e in the continuous direction of the return line 1 and a secondary side space 4f wider than this. The partition plate 4b has a plate surface arranged vertically, and the tank outer structure 4j on the upper side 4d and the left and right sides so that the primary side space 4e communicates with the secondary side space 4f only at the discharge part 4h. Are connected in a watertight manner. In addition, each tank-like mixing means 4 includes an inclined plate 4k that is connected to the tank bottom 4g in a water-tight manner in the vicinity of the discharge portion 4h and obliquely rises toward the plate upper end 4m. The secondary space 4f is made wider as it goes upward by the inclined plate 4k. The left and right sides of the inclined plate 4k are connected to the tank outer structure 4j in a watertight manner. An interval is formed between the upper end 4m of the inclined plate 4k and the top plate 4i. Further, on the secondary side of the inclined plate 4k, there is provided a vertical plate 4n in which the upper side is connected to the upper end 4m of the inclined plate 4k, and both the left and right sides and the lower side are connected in a watertight manner to the tank outer structure 4j. It has been. Thereby, each tank-shaped mixing means 4 makes the outflow part 4o of the return sludge M on the plate upper end 4m of the inclined plate 4k, respectively. And in the example of illustration, three tank-shaped mixing means 4 are connected in series so that the outflow part 4o of the preceding tank-shaped mixing means 4 becomes the inflow part 4a of the subsequent tank-shaped mixing means 4. The activation enhancing apparatus B is configured. The returned sludge M sent to the tank-like mixing means 4 is finally sent to the space between the vertical plate 4n of the tank-like mixing means 4 and the tank outer structure 4j located at the end, and the lower part of this space. It is sent to the aeration tank from the final outflow part 4p communicated with.

  The return sludge M, which is mixed with air in the air supply means 2 and then finely mixed with the air in the tubular mixing means 3, is pumped to the primary side space 4e of the tank-like mixing means 4 and is discharged from the discharge part 4h to the secondary side space. Although it is sent to 4f, the flow of the return sludge M becomes faster at the discharge part 4h and becomes slower toward the upper side of the secondary space 4f. Therefore, the tank-like mixing means 4 has the same effect as the tubular mixing means 3. By giving an appropriate reaction time in addition to (effect by cavitation phenomenon), the air taken in the air supply means 2 can be further finely mixed with the returned sludge M. Further, excess air mixed with the return sludge M in the air supply means 2 generates an air reservoir S in the upper part of the primary space 4e, and the return sludge M pumped from the inflow portion is placed on the plate surface of the partition plate 4b. The air is spread and exposed to the air in the air reservoir S. Thereby, the air can be mixed into the return sludge M also in the primary side space 4e. In the secondary space 4f, the air finely mixed with the return sludge M can be adjusted to increase the activity of microorganisms in the return sludge M while decreasing the flow rate of the return sludge M as it goes upward.

  In the illustrated example, by connecting a plurality of tank-like mixing means 4 as described above, the action of the tank-like mixing means 4 is repeated a plurality of times in the process of returning the returned sludge M, and the microorganisms in the returned sludge M are removed. The activity can be further enhanced.

M return sludge 1 return line 2 supply means 3 tubular mixing means 3a expanded diameter part 3b reduced diameter part 4 tank-shaped mixing means 4a inflow part 4b partition plate 4c plate lower end 4e primary side space 4f secondary side space 4g tank bottom part 4h discharge part

Claims (2)

A device that is part of the return sludge return line in the sewage treatment line,
Means for supplying air to the return sludge;
Downstream of the supply means, tubular mixing means for mixing the return sludge and air that are passed by the alternately enlarged diameter portions and reduced diameter portions, and
A tank-like mixing means that is downstream of the tubular mixing means and receives return sludge,
This tank-like mixing means is located in front of the inflow part of the return sludge provided on the upper side of the tank and divides the inside of the tank into a primary side space on the inflow part side and a secondary side space on the outflow part side, and the lower end of the plate And having a partition plate as a discharge part to the secondary side space of the return sludge between the tank bottom and
An apparatus for enhancing the activation of return sludge, characterized in that the secondary space is made wider as it goes upward.   2. The return sludge activity according to claim 1, wherein a plurality of tank-shaped mixing means are connected such that the outflow part of the preceding tank-shaped mixing means becomes the inflow part of the subsequent tank-shaped mixing means. Strengthening equipment.

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