JP4062585B2 - Membrane separation wastewater treatment equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a membrane separation wastewater treatment apparatus.
[0002]
[Prior art]
In the conventional membrane separation wastewater treatment apparatus, when biological treatment is involved, the treatment liquid contains a large amount of impurities. In particular, this tendency is strong when a membrane separation wastewater treatment device is applied to sewage treatment. Even when screens (about 1 mm in mesh width) are installed in all stages and raw water is used as post-screen water, fibrous substances (hair Etc.) will pass through the screen, and will be mixed into the liquid to be treated (containing activated sludge). In the conventional apparatus, no countermeasures against foreign matters have been taken except for the fine screens at all stages.
[0003]
[Problems to be solved by the invention]
However, in the case of a membrane separation wastewater treatment apparatus, since solid-liquid separation is performed with a membrane, once the contaminants enter the reaction tank, they are not discharged out of the system except during sludge extraction. In most cases, fibrous impurities are entangled with the devices in the reaction tank, which may hinder the stable operation of the devices. When entangled with the membrane element, the solid-liquid separation function is often greatly damaged, and particularly in the membrane element using the hollow fiber membrane, when entangled with the yarn, normal scrubbing cleaning cannot be performed at all. May cause increased transmembrane pressure difference. Furthermore, fibrous contaminants entangled with the membrane element cannot be removed by ordinary chemical cleaning, and in the worst case, the membrane element must be taken out and manually removed.
[0004]
Therefore, it has been desired to provide some trapping means for the foreign matters that have passed through the narrow screens of all stages (about 1 mm mesh width).
[0005]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a membrane separation wastewater treatment apparatus that can perform stable wastewater treatment over a long period of time, reduces the need for maintenance, and facilitates maintenance work. Yes.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, in the membrane separation wastewater treatment apparatus according to claim 1 according to the present invention, in the membrane separation wastewater treatment apparatus for performing solid-liquid separation by immersing the membrane element in a water tank filled with a liquid to be treated, In the circulation pipe for circulating the liquid to be treated in the water tank, a contaminant trapping part is provided , and the contaminant trapping part arranges a plurality of traps in parallel to the pipe by branch pipes, and these branch pipes It is characterized by interposing a shut-off valve .
[0007]
According to the present invention, in particular, since the fibrous contaminants are captured by the contaminant capturing unit, it is reduced that the fibrous contaminants are entangled with the devices in the reaction tank or the membrane element. The number of washings can be reduced, and the work efficiency can be increased accordingly.
[0008]
When the contaminant capture unit is installed in the circulation pipe, it will pass through the contaminant capture unit multiple times until the liquid to be treated is discharged out of the system, so high capture is possible regardless of the contaminant capture unit structure. The effect can be expected. Furthermore, it is preferable to install a contaminant trapping part in both the raw water inflow pipe and the circulation pipe for supplying the liquid to be treated , depending on the properties of the raw water and the liquid to be treated .
[0009]
Moreover, in the membrane separation wastewater treatment apparatus according to claim 1 of the present invention, the contaminant trapping unit includes a plurality of traps arranged in parallel to the pipe by branch pipes, and a shutoff valve is provided to the branch pipes. It is characterized by being interposed.
[0010]
According to this invention, since some traps can be used and cleaning and maintenance of other traps can be performed, continuous operation is possible.
[0011]
Further, in the membrane separation wastewater treatment apparatus according to claim 2 of the present invention, each branch pipe is provided with a pressure gauge, and when the pressure exceeds a predetermined value, the shut-off valve of the branch pipe is closed. It is said.
[0012]
According to the present invention, when the efficiency of some of the foreign matter traps is lowered, it is automatically switched to the other foreign matter traps, so that more stable performance can be continuously maintained.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a membrane separation wastewater treatment apparatus according to the present invention will be described with reference to the accompanying drawings.
[0014]
FIG. 1 is a schematic diagram showing an overall configuration when configured as a nitrification / denitrification apparatus incorporating a membrane separation wastewater treatment apparatus according to the present invention.
[0015]
As shown in the figure, the reaction tank 10 of the nitrification / denitrification apparatus is partitioned into a denitrification tank 12 and a nitrification tank 13 by a partition wall 11, and raw water is fed from a raw water storage tank 14 through a raw water supply line 15. It flows into the denitrification tank 12. The raw water supply line 15 is provided with a contaminant catching unit 30 described later, and the contaminant catching unit 30 captures the contaminant of the raw water flowing through the raw water supply line 15. Further, the nitrification tank 13 is connected to the denitrification tank 12 through a circulation line 16. In the circulation line 16, a pump 17 and a contaminant capturing unit 30 described later are interposed. By driving the pump 17, a part of the liquid 18 to be treated in the nitrification tank 13 is removed through the contaminant capturing unit 30. It is returned to the nitrogen tank 12. Thereby, the liquid 18 to be treated circulates between the nitrification tank 13 and the denitrification tank 12.
[0016]
A membrane element 19 is provided inside the nitrification tank 13, and an air diffuser 20 is disposed below the membrane element 19. The air diffuser 20 is connected to a blower 22 via an air supply line 21. When air is supplied from the blower 22, this air is diffused as fine bubbles in the liquid 18 to be treated in the nitrification tank 13. To do. As a result, the liquid to be treated 18 is agitated, and deposits adhering to the filtration membrane (not shown) of the membrane element 19 can be peeled off. Further, oxygen is supplied to the activated sludge in the liquid 18 to be treated. be able to.
[0017]
A discharge line 23 is connected to the membrane element 19, and a pump 24 is interposed in the discharge line 23. Then, by driving the pump 24, the liquid to be processed 18 processed by the membrane element 19 is discharged to the outside through the discharge line 23.
[0018]
The above-described contaminant capturing unit 30 disposed in the raw water supply line 15 and the circulation line 16 has branch lines 31a and 31b branched from the lines 15 and 16, and is captured by the branch lines 31a and 31b. Containers 32a and 32b are interposed. Further, in each branch line 31a, 31b, shutoff valves 33a, 33b, 34a, 34b are respectively interposed on the upstream side and the downstream side of the traps 32a, 32b. In addition, pressure gauges 35a and 35b are interposed in the branch lines 31a and 31b, and the pressures of the pressure gauges 35a and 35b are measured by the controller 36. The controller 36 then closes the stop valves 33a, 33b, 34a, and 34b. Is controlled.
[0019]
As shown in FIG. 2 (a), the catchers 32a and 32b are configured such that the wire 37 is stretched in a net shape in the cylindrical container, or in the cylindrical container as shown in FIG. 2 (b). A wire 38 having a bulging portion 38a at the tip is implanted. These wires 37 and 38 are installed over several stages in the axial direction of the cylindrical container.
[0020]
Next, the operation of the membrane separation wastewater treatment apparatus configured as described above will be described.
[0021]
While the raw water in the raw water storage tank 14 is being supplied to the denitrification tank 12 via the raw water supply line 15, the raw water is sent to the contaminant capturing unit 30. In the contaminant capturing unit 30, the closing valves 33a and 34a corresponding to one capturing device, for example, the capturing device 32a are opened, and the closing valves 33b and 34b corresponding to the other capturing device 32b are closed. Therefore, the raw water is supplied to the denitrification tank 12 through the closing valve 33a, the trap 32a, and the closing valve 34a, and impurities are trapped by the trap 32a.
[0022]
On the other hand, a part of the liquid 18 to be treated in the nitrification tank 13 is returned to the denitrification tank 12 through the circulation line 16 by driving the pump 17. At this time, the liquid 18 to be processed is sent to the contaminant capturing unit 30. In the contaminant capturing unit 30, the closing valves 33a and 34a corresponding to one capturing device, for example, the capturing device 32a are opened, and the closing valves 33b and 34b corresponding to the other capturing device 32b are closed. Therefore, the liquid 18 to be treated is circulated through the closing valve 33a, the trap 32a, and the closing valve 34a, and the trap 32a traps impurities.
[0023]
In any foreign matter capturing unit 30, when the pressure gauge 35a reaches a predetermined pressure, the value is detected by the controller 36, and the controller 36 closes the shut-off valves 33a and 34a, and the other trap 32b. The closing valves 33b and 34b corresponding to are opened. Therefore, in the raw water supply line 15, the raw water is supplied to the denitrification tank 12 through the closing valve 33b, the trap 32b, and the closing valve 34b. In the circulation line 16, the liquid 18 to be treated is closed in the closing valve 33b and the trap 32b. , It is circulated to the denitrification tank 12 through the closing valve 34b.
[0024]
Then, the closed trap 32a is removed from the branch line 31a in the meantime, cleaned, and attached to the branch line 31a again.
[0025]
In the above embodiment, the contaminant capturing unit 30 is installed in both the raw water supply line 15 and the circulation line 16, but the contaminant capturing unit 30 is installed in either the raw water supply line 15 or the circulation line 16. You may just install.
[0026]
Moreover, in the said embodiment, although the two traps 35a and 35b are used for the contaminant capture | acquisition part 30, the number of traps may be one or three or more.
[0027]
Moreover, in the said embodiment, although the pressure gauges 35a and 35b are installed in the branch lines 31a and 31b, this pressure gauge shall also contain a pressure sensor.
[0028]
Furthermore, in the above embodiment, the case of a nitrification / denitrification apparatus incorporating a membrane separation wastewater treatment apparatus has been described, but a nitrification apparatus incorporating a membrane separation wastewater treatment apparatus may be used.
[0029]
【The invention's effect】
As described above, according to the membrane separation wastewater treatment apparatus of the first aspect of the present invention, it is effective to remove contaminants (particularly, fiber contaminants) derived from raw water that are entangled with membrane elements and greatly reduce membrane separation. Can be removed.
[0030]
Therefore, the membrane separation wastewater treatment apparatus of the present invention can prevent accidental blockage of the membrane surface and can maintain stable performance for both membrane separation and biological treatment.
[0031]
Moreover, according to the membrane separation wastewater treatment apparatus of claim 2 according to the present invention, a part of the traps can be used, and cleaning and maintenance of the other traps can be performed, so that continuous operation is possible. .
[0032]
Further, according to the membrane separation wastewater treatment apparatus of claim 3 according to the present invention, when the efficiency of some traps is reduced, the traps are automatically switched to other traps, so that more stable performance is continued. Can be maintained.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing the overall configuration of a nitrification / denitrification apparatus incorporating a membrane separation wastewater treatment apparatus according to the present invention.
FIG. 2 is a partially enlarged view showing a fibrous contaminant capturing structure of a trap in a contaminant capturing section of a membrane separation wastewater treatment apparatus according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Reaction tank, 11 ... Partition wall, 12 ... Denitrification tank, 13 ... Nitrification tank, 14 ... Raw water storage tank, 15 ... Raw water supply line, 16 ... Circulation line, 17 ... Pump, 18 ... Liquid to be processed, 19 ... Membrane Element, 20 ... Air diffuser, 21 ... Air supply line, 22 ... Blower, 23 ... Discharge line, 24 ... Pump, 30 ... Contaminant trapping part, 31a, 31b ... Branch line, 32a, 32b ... Trap, 33a, 33b , 34a, 34b ... shut-off valve, 35a, 35b ... pressure gauge, 36 ... controller, 37, 38 ... wire, 38a ... bulge part

Claims (2)

In a membrane separation wastewater treatment apparatus that performs solid-liquid separation by immersing the membrane element in a water tank filled with the liquid to be treated,
In the circulation pipe that circulates the liquid to be treated in the water tank, a contaminant capturing unit is provided,
The membrane separation wastewater treatment apparatus is characterized in that the contaminant trapping part is configured by arranging a plurality of traps in parallel with the pipe by branch pipes and interposing a stop valve in the branch pipes . The membrane separation wastewater treatment apparatus according to claim 1 , wherein a pressure gauge is provided in each of the branch pipes, and the shutoff valve of the branch pipe is closed when the pressure exceeds a predetermined level.

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