JPH02237693A - Sewage treating device - Google Patents

Abstract

PURPOSE:To improve working efficiency and to use the device in large-sized equipment by providing an activated sludge treating tank and a tank filter separately from each other, separating the inside of the tank filter into plural arrays of filtration chambers by a partition wall and vertically arranging the membrane modules in plural stages. CONSTITUTION:The inside of the tank filter 12 is separated into plural arrays of filtration chambers 14 by the partition walls 13. The upper and lower parts of each chamber 14 are connected to the upper and lower parts of the activated sludge treating tank 11 through a communicating pipe 16 provided with a gate valve 15 as a partition device. The cylindrical membrane modules 17 provided with a filter membrane are vertically arranged in plural stages in each filtration chamber 14. When separation by filtration is carried out, a part of the scale depositing on the surface of the module 17 is removed by the upward current of a mixed soln. 21, and the remaining scale is periodically cleaned off by chemicals in each filtration chamber 14. Consequently, the modules are chemically cleaned without stopping the operation, and the device can be used in large-sized equipment.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a sewage treatment device equipped with an ultrafiltration membrane.

BACKGROUND OF THE INVENTION In conventional sewage treatment equipment of this type, for example, the eighth
As shown in the figure and FIG. 9, cylindrical membrane modules 3 equipped with ultrafiltration membranes are installed in multiple rows in the horizontal direction on a mounting plate 2 provided in an activated sludge treatment tank 1. 4 rows》
, and are arranged in a plurality of stages (three stages in the figure) in the vertical direction, and an aeration pipe 4 is provided for each row of membrane modules 3 at the bottom of the processing tank 1. In addition, for each row of the membrane module 3, a bomb 5 and an air blower l! The pump 5 is connected to the discharge port side of the membrane module 3 in each row, and the blower 6 is connected to each diffuser pipe 4.

Then, the sewage is supplied into the activated sludge treatment 11, mixed with the activated sludge in the tank to form a mixed solution 7, and is oxidized and decomposed by microorganisms contained in the activated sludge. On the other hand, the dead trachea 4 is supplied with aeration air from the blower 6, and by blowing it out as bubbles into the mixed solution 7, it supplies oxygen for growth to the microorganisms in the mixed solution 7, and also directs the air upward into the mixed solution 7. A water stream is generated to circulate the mixed solution 7 in the direction of the arrow in FIG. This mixed solution 7 is sucked by the pump 5 through the membrane module 3, and filtered and separated by the membrane module 3 into a concentrated liquid and clean treated water.

The concentrated liquid remains in the tank and circulates upward, and the treated water is discharged outside the tank. At that time, the solid content (so-called S.S.
) is placed on the surface of the water module 3 as a scale. A portion of this scale is removed by the upward water flow of the mixed solution 7, but the remaining part gradually grows and clogs the ultrafiltration membrane of the membrane module 3, so the membrane module 3 is regularly cleaned with chemicals. This removes the remaining scale.

Problems to be Solved by the Invention However, in the conventional sewage treatment apparatus described above, when chemicals are directly introduced into the activated sludge treatment tank 1 during chemical cleaning, activated sludge microorganisms are killed. Furthermore, it is not permissible to completely suspend operation of equipment for cleaning purposes. Therefore, for chemical cleaning, it is necessary to take out the membrane modules 3 one row at a time out of the tank.
There were problems in that the work efficiency was poor and it was not suitable for large-scale equipment.

The present invention aims to solve these problems by improving the conventional sewage treatment VCFF.

Means for Solving the Problems In order to achieve the above object, the sewage treatment device of the present invention has the following features:
The activated sludge treatment tank and the filtration treatment tank are provided separately from each other, and each filtration treatment tank is divided into multiple rows of filtration chambers by a partition wall, and within the filtration chamber, membrane modules are stacked vertically in multiple stages. , an aeration pipe is provided at the bottom, and both the upper and lower parts of each filtration chamber are connected to the upper and lower parts of the activated sludge treatment tank through communication passages equipped with partition devices.

Function In the configuration of the present invention described above, sewage is supplied to the activated sludge treatment facility, mixed with the activated sludge in the tank to form a mixed solution, and is oxidized and decomposed by microorganisms contained in the activated sludge. On the other hand, the air diffuser pipe is supplied with air from a blower and blows it out as bubbles into the mixed solution in each filtration chamber, thereby supplying oxygen for growth to the microorganisms in the mixed solution, and also directing upward water flow into the mixed solution. occurs. This mixed solution rises in the filtration chamber, flows into the activated sludge treatment tank via the upper communication pipe or communication path such as a weir, mixes with the mixed solution in the activated sludge treatment tank, and descends. By flowing into each filtration chamber via the lower communication passage, it circulates between the activated sludge treatment tank and the filtration treatment tank. When this mixed solution rises in each filtration chamber, it is sucked by the pump through the membrane module, and the membrane module
It is filtered and separated into I condensate and clean treated water. The concentrated liquid remains in the filtration chamber and circulates upward together with the mixed solution, and the treated water is taken out of the filtration chamber through the membrane module. During the above-mentioned filtration and separation, part of the scale attached to the surface of the membrane module is removed by the upward water flow of the mixed solution, but the remaining part is removed by periodic chemical cleaning for each filtration chamber as described below. removed.

That is, first, close the partition 8rx such as a valve in the upper and lower communication passage between the filtration chamber to be cleaned and the activated sludge treatment tank, disconnect the filtration chamber from the activated sludge treatment tank, and then Leave the filtration chamber as it is and continue operation. Next, fill the filtration chamber, etc. to be cleaned, draw out the mixed solution after washing, and if necessary, connect it to a tap water chemical tank and add cleaning liquid, and use a cleaning pump to filter the cleaning liquid and connect it to the chemical tank. The membrane module is cleaned by circulating the membrane module between the membranes, and then the membrane module is washed with water in the same manner as above. When the cleaning is finished, all the partitions such as the upper and lower valves are opened and the normal operating state is restored. The membrane modules in other filtration chambers are also cleaned in the same manner as above.

As described above, according to the configuration of the present invention, it is possible to chemically clean the membrane module without completely stopping the operation of the equipment and without removing the membrane module.

Embodiments Hereinafter, embodiments of the present invention will be explained based on FIGS. 1 to 7.

The sewage treatment apparatus of this embodiment comprises an activated sludge treatment@11 and a filtration treatment tank 12, as shown in FIGS. 1 and 2. The inside of the filtration treatment tank 12 is divided into a plurality of rows (four rows in the figure) of filtration chambers 14 by a partition wall 13, and both the upper and lower parts of each filtration chamber 14 have valves 15 as a partition device. A communication pipe 16 as a communication path provided
They are connected to both the upper and lower parts of the activated sludge treatment tank 11 via the above. Inside each filtration chamber 14, cylindrical membrane modules 17 equipped with filtration membranes are stacked vertically in multiple stages (three stages in the figure), and an air diffuser v118 is provided at the bottom. Furthermore, a bomb 19 and a blower 20 are provided for each filtration chamber 14, and the bomb 19 is connected to the outlet side of the membrane module 17 in each filtration chamber 14,
The feeding Mel 20 is connected to each diffuser pipe 18 .

Next, the operation of the above configuration will be explained.

The sewage is supplied into the activated sludge treatment tank 11, mixed with the activated sludge in the tank to form a mixed solution 21, and is oxidized and decomposed by microorganisms contained in the activated sludge. On the other hand, the trachea 18 is supplied with atomizing air from the blower 20 and blows it out as bubbles into the mixed solution 21 in each filtration chamber 14, thereby supplying the microorganisms in the mixed solution 21 with oxygen for growth. An upward water flow is generated in the mixed solution 21. This mixed solution 21 fills the inside of the filtration chamber 14, flows into the activated sludge treatment tank 11 via the upper delivery pipe 16, mixes with the mixed solution 21 in the activated sludge treatment tank 11, and descends. By flowing into each filtration chamber 14 via the lower communication pipe 16, it circulates in the direction of the arrow in FIG. 1 between the activated sludge treatment tank 11 and the filtration treatment tank 12.

When this mixed solution 21 rises in each filtration chamber 14, it is sucked by the pump 19 through the membrane module 17, and is filtered and separated by the membrane module 17 into a concentrated liquid and clean treated water. The concentrated liquid remains in the filtration chamber 14 and circulates upward together with the mixed solution 21, and the treated water is taken out of the filtration chamber 14 through the membrane module 17. During the above-mentioned filtration and separation, part of the scale attached to the surface of the membrane module 17 is removed by the upward water flow of the mixed solution 21, but the remaining part is removed by regular chemical cleaning for each filtration chamber 14.

There are two methods for this chemical cleaning as described below.

In the first cleaning method, first, the filtration chamber 1 to be cleaned is
4 and the activated sludge treatment tank 11 are closed, and the filtration chamber 14 is connected to the activated sludge treatment tank 1.
In order to remove the liquid in the filtration chamber 14 and empty it, the valve 28 of the pipe 31 provided at the bottom of the filtration chamber 14 is opened. After draining all the liquid, close it again. Furthermore, before cleaning the membrane module 17 with chemicals, the valve 29 of the tap water supply pipe 30 is opened to send air from the air blower 20, which has filled the filtration chamber 14 with tap water, to wash the module. Thereafter, the blower 20 is stopped, and the other filtration chambers 14 from which the wash water is drawn out in the same manner as before, continue to operate. Next, as shown in FIG. 3, the bottoms of the filtration chamber 14 to be cleaned and the chemical tank 22 are connected to each other by a chemical delivery pipe 23, and the membrane module 17 in the filtration chamber 14 is taken out. A cleaning pump 24 is connected to the side, and the discharge pipe 25 of the cleaning pump 24 is returned to the chemical tank 22.

After doing this, the cleaning liquid from the chemical tank 22 is transferred to the filtration chamber 1.
4 and operates the cleaning bomb 24, the cleaning liquid 26 in the filtration chamber 14 is sucked into the membrane module 17 by the cleaning bomb 24 in the eight directions of arrows in FIG. Return to The cleaning liquid 26 in the chemical tank 22 flows into the filtration chamber 14 via the transport pipe 23.

In this way, the cleaning liquid 26 is transferred to the filtration chamber 14 and the chemical tank 2.
Both the inside and outside of the membrane module 17 are cleaned while circulating between the membrane module 17 and the membrane module 17. Note that it is also possible to circulate the cleaning liquid 26 in the opposite direction to that described above and to perform so-called backwashing of the membrane module 17 in the direction of arrow B in FIG. 4. After cleaning, the filtration chamber 14
is returned to its original operating state, and the membrane modules 17 in other filtration chambers 14 are cleaned in the same manner as above.

In addition, in the second cleaning method, first, in the same way as the first method, the filtration chamber 14 to be cleaned is removed from the activated sludge treatment tank 1.
1, and the other filtration chambers 14 are left as they are to continue operation. Next, as shown in FIG. 5, the bottoms of the filtration chamber 14 to be cleaned and the chemical tank 22 are connected to each other by a chemical delivery pipe 23 equipped with a cleaning pump 24, and the inside of the filtration chamber 14 is Top membrane module 17
One end of the overflow pipe 27 is connected to a slightly upper part of the tank, and the other end is returned to the chemical tank 22. Next, the cleaning liquid 26 is poured into the filtration chamber 14 to be cleaned from the chemical tank 22, and the cleaning pump 24 is operated.

Then, the cleaning liquid 26 in the chemical tank 22 flows into the filtration chamber 14 via the communication pipe 23. Therefore, the level of the cleaning liquid 26 in the filtration chamber 14 rises, flows out from the overflow pipe 27, and returns into the chemical tank 22. In this way, the cleaning liquid 26 cleans the surface of the membrane module 17 while circulating between the filtration chamber 14 and the chemical tank 22. At this time, a part of the cleaning liquid 26 also acts to clean the membrane module 17 by penetrating into the inside from the surface of the membrane module 17, as shown in FIG. When the cleaning is completed, the filtration chamber 14 is returned to its original operating state, and the membrane modules in the other filtration chambers 14 are cleaned in the same manner as described above. In addition,
This cleaning method and the first cleaning method may be used together.

As described above, according to the configuration of this embodiment, regardless of the cleaning method, the membrane module 17 can be cleaned without completely stopping the operation of the wastewater treatment equipment and without removing the membrane module 17. The module 17 can be cleaned with chemicals.

FIG. 7 shows an upper communication path and partition device using a communication channel 33 and a weir 32 provided in this channel instead of the communication pipe 16 and valve 15 shown in FIG. show.

Although the above description deals with the case of activated sludge method, the apparatus of the present invention can also be applied to other microbial reaction methods and separation of suspended solids.

Effects of the Invention As explained above, the present invention provides an activated sludge treatment tank and a filtration treatment tank separately from each other, divides the interior of the filtration treatment tank into a plurality of rows of filtration chambers, and separates each filtration chamber from the activated sludge treatment tank. The structure allows communication and isolation between the tank and the membrane module in each filtration chamber, so chemicals in the membrane module can be removed without completely stopping equipment operation and without removing the membrane module. Can be washed. Therefore, it can be suitably used even in large-scale equipment.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a sewage treatment equipment showing an embodiment of the present invention, Fig. 2 is a plan view of the equipment shown in Fig. 1, and Fig. 3 is an embodiment of the chemical cleaning method for a membrane module according to the invention. FIG. 4 is an explanatory diagram showing the cleaning state of the membrane module in FIG. 3, FIG. The figure is an explanatory view showing the cleaning state of the membrane module in Fig. 5, Fig. 7 is a sectional view illustrating the case where the upper partition equipment is a weir, and Fig. 8 is a sectional view showing an example of a conventional sewage treatment facility. figure,
FIG. 9 is a plan view of the apparatus of FIG. 8. 11... activated sludge treatment tank, 12... filtration treatment tank, 1
3... Partition wall, 14... Filtration chamber, 15... Valp (partition device), 16... Transportation pipe (communication path), 17...
- Membrane module, 18... Diffuser pipe, 32... Weir (partition device), 33... Transportation channel (communication path). Agent Yoshihiro Morimoto Figure 1 13 Figure 3 Figure ψ @ Figure 5

Claims (1)

[Claims] 1. The activated sludge treatment tank and the filtration treatment tank are separated from each other, and the inside of the filtration treatment tank is divided into multiple rows of filtration chambers by a partition wall, and within each filtration chamber, membrane modules are stacked in multiple stages vertically. At the same time, a diffuser pipe is installed at the bottom.
A sewage treatment device characterized in that both upper and lower parts of each filtration chamber are respectively connected to both upper and lower parts of an activated sludge treatment tank via a communication path provided with a partition device.