JPH0584495A - Device for waste water treatment and cleaning method thereof - Google Patents

Abstract

PURPOSE:To provide a device for waste water treatment possible to effectively and simply execute cleaning work. CONSTITUTION:The treating vessel 10, the upper supporting member 21 and lower supporting member 22 provided in the treating vessel 10 and the filtration medium 23 held between the upper supporting member 21 and the lower supporting member 23 are provided. The air jetting nozzle 40 having the air opening and closing valve 41 is provided downward of the lower supporting member 22. The 1st discharge pipe 31 having the 1st opening and closing valve 31a is connected to right above the upper supporting member 21 and the 2nd discharge pipe 34 having the 2nd opening and closing valve 34a is connected to the bottom of the treating vessel 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wastewater treatment apparatus using a biofilm and a cleaning method therefor.

[0002]

2. Description of the Related Art A conventional wastewater treatment apparatus will be described with reference to FIG. The wastewater flowing into the treatment tank 2 through the wastewater pipe 1 is purified by the biofilm formed on the surface of the filter material 3 provided in the treatment tank 2. Subsequently, the purified treated water is stored in the storage tank 4 and then discharged.

When the processing in the processing tank 2 is performed for a predetermined time, the inside of the processing tank 2 is cleaned. That is, the on-off valve 7 between the processing tank 2 and the storage tank 4 is closed, and the drain valve 6 is opened. Subsequently, the backwash pump 5 is driven to backwash the inside of the treatment tank 2, and the biofilm excessively grown in the wastewater treatment is discharged from the drain valve 6 to the drain tank 8.

[0004]

However, in the conventional wastewater treatment apparatus, since the amount of cleaning wastewater discharged from the processing tank 2 at the time of cleaning increases, there is a problem that a large drain tank 8 must be provided. is there. Further, since the amount of cleaning water sent from the storage tank 4 into the processing tank 2 during cleaning increases, it is necessary to increase the power of the backwash pump 5.

The present invention has been made in view of the above points, and an object of the present invention is to provide a wastewater treatment apparatus and a method for washing the same, which can be washed efficiently and easily.

[0006]

According to the present invention, there is provided a treatment tank for treating wastewater, an upper support member and a lower support member provided in the treatment tank, and a space between the upper support member and the lower support member. With a filter material that is retained and has a biofilm formed on its surface,
An air blowing nozzle having an air opening / closing valve is provided below the lower support member in the treatment tank, a first drain pipe having a first opening / closing valve is connected directly above the upper support material of the treatment tank, and the bottom portion of the treatment tank is connected. A second drain pipe having a second on-off valve is connected to the waste water treatment apparatus and the inflow of waste water to the treatment tank is stopped, and the air on-off valve is opened to supply air from the air blowing nozzle. Open the on-off valve and open from above the filter
The water is drained through a drain pipe, the air on-off valve is subsequently closed, and then the second on-off valve is opened to drain the water from below the filter through the second drain pipe. It is a method of cleaning a wastewater treatment device.

[0007]

According to the present embodiment, the air opening / closing valve is opened during backwashing, and the first opening / closing valve is opened while air is being supplied from the air blowing nozzle. The membrane is discharged from the first drainage pipe, then the air opening / closing valve is closed, and then the second opening / closing valve is opened to discharge the finely separated biofilm from the bottom of the filter material from the second drainage pipe. can do.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are views showing an embodiment of the present invention. In FIG. 1, the wastewater treatment apparatus includes a treatment tank 10 for treating wastewater, and a wastewater pipe 36 having a wastewater valve 37 is connected to the treatment tank 10. Further, in the processing tank 10, partition walls 1 that form liquid junctions 12 and 13 above and below are formed.
4 are provided, and the oxygen dissolving portion 15 is formed on one side of the partition wall 14, and the reaction portion 16 is formed on the other side. Also, the oxygen dissolution part 1
An air diffuser 17 is arranged slightly above the lower end of the partition wall 14 in the container 5, and the air diffuser 17 is connected to a pressurized air pipe 19 via a regulating valve 18.

On the other hand, a large number of openings 21 are formed in the reaction section 16.
The upper support member 21 having a and the lower support member 22 having a large number of openings 22a are arranged.
A filter material 23 is filled between the lower support member 22 and the lower support member 22.
A plastic molding material having a specific gravity of more than 1 is used as the filter 23, and the filling volume of the filter 23 is 50 to 80% of the space volume between the upper support 21 and the lower support 22. ..

A first drainage port 30 is provided on the wall of the treatment bath 10 directly above the upper supporting member 21, and the first drainage port 30 is provided.
Is connected to a first drain pipe 31 having a first opening / closing valve 31 a, and the first drain pipe 31 is connected to a drain pipe 32. A second drainage port 33 is provided at the bottom of the processing tank 10, and a second drainage pipe 34 having a second opening / closing valve 34a is connected to the second drainage port 33, and the second drainage pipe 34 is the drainage pipe 32. It is connected to the.

An air blowing nozzle 40 is provided in the processing tank 10 and below the lower support member 22, and the air blowing nozzle 40 is connected to the pressurized air pipe 19 via an air opening / closing valve 41 and a regulating valve 42. Has been done. Also, the lower support member 22
The one end 44 of the treated water pipe 43 is opened between the and the air blowing nozzle 40, and the other end of the treated water pipe 43 is connected to a discharge pipe 47 via a liquid level adjusting pipe 46.

[0012] In this example, the inflow of waste water flowing from the waste water pipe 38 to the treatment tank ^{_{10 Q L (m 3 / h}} ), the ventilation amount of diffusion pipe ^{_{17 Q G1 (N-m 3}} / h), If the aeration amount of air discharge nozzles ^{_{40 Q G2 (N-m 3}} / h), the effective volume of the processing tank 10 was set to _{V (m 3 / h),} V / Q L i.e. hydraulics wastewater in the treatment tank 10 retention time HRT is 0.5 to 10 (h), the volume ratio of Q _G1 i.e. Q _G1 / V
The 0.01~1 (h ^-1), Q volume ratio i.e. Q of _{G2 G2}
/ V is set to about 0.1 to 10 (h ^-1 ).

Next, the operation of this embodiment having such a configuration will be described.

First, during normal operation, the waste water valve 37 is opened,
Waste water flows into the treatment tank 10 from the waste water pipe 36. At the same time, the adjusting valve 18 is opened to supply air from the air diffuser 17.
In this case, the wastewater is circulated by the air lift of bubbles generated by the air from the air diffuser 17, and the wastewater descends in the filter 23. A biofilm is formed on the surface of the filter material 23, and the wastewater is purified by this biofilm and becomes treated water, which is discharged from the treated water pipe 43 to the outside through the discharge pipe 47.

Next, when the wastewater treatment in the treatment tank 10 progresses, the inside of the treatment tank 10 is cleaned as follows (FIG. 2).
reference). First, the waste water valve 37 is closed to stop the inflow of waste water into the processing tank 10. Then, the air valve 41 is opened to eject the bubbles from the air ejection nozzle 40. In this case, the volume of the filter 23 in the processing tank 10 increases. Then, the filter material 23 reaches the upper support material 21 and is subjected to the shearing action of the bubbles. By the shearing action of such bubbles,
Excessive biofilm attached to the surface of the filter material 23 is peeled off, and a relatively large peeled biofilm gathers near the liquid surface 35. On the other hand, the micronized separated biofilm uniformly flows in the processing tank 10.

After the time t ₁ (about 5 to 10 minutes) has elapsed, the first on-off valve 31a is opened for the time t ₂ (about 5 to 10 minutes). Then, the relatively large detached biofilm existing above the upper support member 21 is replaced with the first drain pipe 31 and the drain pipe 3.
Discharge to the outside via 2. The cleaning work up to here is the first
Called the process of.

Next, the second step of the cleaning work is performed. That is, the first opening / closing valve 31a is closed, and at the same time, the air opening / closing valve 4a is closed.
1 is closed to stop the ejection of bubbles from the air blowing nozzle 40, and the finely separated biofilm is settled. Time t
_{After 3} (about 10 to 30 minutes), the second on-off valve 34a
Is opened for a time t ₄ (about 1 to 10 minutes), and the treatment tank 1
The finely separated biofilm deposited in the vicinity of the bottom of 0 is discharged to the outside through the second drain pipe 34 and the drain pipe 32. In this way, the second step of cleaning is completed.

During this time, the adjusting valve 18 may be left open. When the adjustment valve 18 is opened, the liquid surface 35 is lower than the upper end of the partition wall 14, so that no circulating flow occurs in the processing tank 10. Therefore, it does not hinder the sedimentation of the finely divided biofilm.

After such cleaning work is completed, the first opening / closing valve 31a, the second opening / closing valve 34a and the air opening / closing valve 41 are closed, and the waste water valve 37 is opened to resume the normal operation.

As described above, according to this embodiment,
Since the processing tank 10 is partitioned by the partition wall 14 which forms the liquid junctions 12 and 13 on the upper and lower sides and the oxygen dissolving section 15 and the reaction section 16 are provided, it is possible to generate an appropriate circulating flow in the processing tank 10 to perform stirring. it can. Therefore, the biological film attached to the filter material 23 can be made uniform and the treatment efficiency of wastewater can be improved. Moreover, since the filling amount of the filter material 23 is set to 50 to 80% of the space volume between the upper and lower support members 21 and 22, it is possible to increase the occupied volume of the filter material 23 at the time of cleaning and perform uniform cleaning work. You can Further, by constantly ventilating from the air diffuser 17, it is possible to appropriately supply dissolved oxygen even during cleaning.

In the above embodiment, an example in which a plastic having a specific gravity of more than 1 is used as the filter material 23 is not limited to this, but a plastic having a specific gravity of less than 1 or a fired product having closed cells inside, etc. It is also possible to use a floatable material. At this time, by setting the specific gravity or bulk specific gravity to, for example, 0.95 to 0.99, the volume occupied by the filter material 23 can be easily increased during cleaning, and the fluidity of the filter material 23 can be enhanced.

[0022]

As described above, according to the present invention,
When cleaning, first remove a relatively large biofilm from above the filter material.
By discharging from the drainage pipe and discharging the finely separated biofilm from below the filter material from the second drainage pipe, the biofilm attached to the filter material can be effectively removed and discharged. Moreover, since a large amount of washing water is not used unlike the conventional case, it is not necessary to provide a large drain tank or a large backwash pump. Therefore, the cleaning operation can be performed easily and at low cost.

[Brief description of drawings]

FIG. 1 is a schematic system diagram showing an embodiment of a wastewater treatment apparatus according to the present invention.

FIG. 2 is a diagram showing a cleaning action of a wastewater treatment device.

FIG. 3 is a schematic system diagram showing a conventional wastewater treatment device.

[Explanation of symbols]

 10 Treated Water Tank 21 Upper Support Material 22 Lower Support Material 23 Filter Material 31 First Drain Pipe 31a First Open / Close Valve 34 Second Drain Pipe 34a Second Open / Close Valve 40 Air Blowing Nozzle 41 Air Open / Close Valve

Claims (2)

[Claims] 1. A treatment tank for treating wastewater, an upper support member and a lower support member provided in the treatment tank, and a biofilm formed on the surface of the upper support member and the lower support member which are held between the upper support member and the lower support member. And a first drain pipe having a first on-off valve directly above the upper support member of the processing tank is connected to the upper support member of the processing tank. And a second opening / closing valve at the bottom of the processing tank
A wastewater treatment measure characterized by connecting a drainage pipe. 2. The inflow of waste water to the treatment tank is stopped, the air on-off valve is opened and air is supplied from an air-blowing nozzle while the first on-off valve is opened to open the filter from above the filter through the first drain pipe. 2. The cleaning of a wastewater treatment device according to claim 1, wherein the wastewater treatment device is drained, and subsequently the air on-off valve is closed, and then the second on-off valve is opened to drain the water from below the filter through the second drainage pipe. Method.