JPS6224159B2 - - Google Patents

Description

Detailed Description of the Invention This invention relates to a device for treating water using a filtration device, specifically a filtration device that also has a biological treatment function (hereinafter referred to as a biological filtration device), and a filtration device that mainly processes suspended solids. The present invention relates to a water treatment device consisting of a combination of filter devices having the function of removing SS. In recent years, with the deterioration of water source quality in water supplies, there are cases where it is necessary to remove BOD components.
Furthermore, due to the lack of water resources, there is a tendency to treat gray water or to perform advanced treatment on sewage to obtain higher quality treated water, which is then used for industrial purposes.

The present invention is a water treatment device that can meet such demands, and in particular combines an upward flow type biological filtration device and a downward flow type gravity filtration device to perform water treatment in an energy-saving manner. The present invention will be described below with reference to one embodiment shown in the drawings.

1 is a pressure regulating tower, 2 is an upward flow type biological filtration device, 3
indicates a downward flow gravity flow device. The pressure regulating tower 1 is used to adjust the supply pressure of raw water supplied to the biological filtration device to a nearly constant level, and also to supply the raw water to the biological filtration device at a predetermined pressure without using a pump. A level switch 5 is installed inside the top of the tower to detect the upper and lower limits of the liquid level. The raw water supply pipe 6 into the tower is provided with an automatic opening/closing valve _V1 .

In addition, in order to prevent the layer 7 in the biological filtration device from becoming anaerobic and rotting, an aeration pipe 8 is installed inside the tower, and air is blown into the tower using a blower or the like, or pure oxygen gas or high concentration The raw water is aerated in the tower by blowing in oxygen gas to provide sufficient dissolved oxygen to the raw water. In this case, if air bubbles are mixed into the raw water supplied from the pressure regulating tower to the biological filtration device, the layer 7 of the biological filtration device will be agitated and the captured SS will leak.
Raw water transfer pipe 9 to the biological filtration device at the bottom of the pressure regulating tower
The aeration pipe 8 is placed above the transfer pipe 9 to prevent air bubbles from going to the biological filtration device, and the raw water supply pipe 6 to the pressure regulating tower is placed above the aeration pipe 8 to prevent air bubbles from going to the biological filtration device. The exposed raw water is supplied to the biological filtration device.

The upflow type biological filtration device 2 has the same basic configuration as the known upflow type filtration device for removing SS, but the type and particle size of the material constituting the layer 7 are different, and the treatment A drainage trough 10 for washing water is provided at a predetermined distance below the water sampling trough 4.

Layer 7 is constructed by laminating silica stone or artificial material with a particle size of 0.5 to 5 mm on top of a support layer made of gravel or the like in order to attach a biofilm to the surface. The particle size is that of raw water.
If the BOD is 10ppm or more, make it as large as possible to prevent clogging, and conversely, if the BOD of the raw water is
If it is 5ppm or less, you can reduce it.

Therefore, the BOD of treated water depends on the BOD of raw water.
The upward flow rate may be selected so that the particle size is 1 ppm or less.

Therefore, when the raw water containing dissolved oxygen supplied to the bottom of the biological filtration device flows upward in layer 7, BOD components are removed by the biofilm formed on the surface of the material, and the On the other hand, dissolved oxygen maintains aerobic conditions, activates the biofilm function, and improves the removal efficiency of BOD components. Then, the obtained treated water is transferred by gravity from the water sampling trough 4 to the liquid supply trough 11 of the subsequent gravity filtration device 3.

This downward flow gravity passing device 3 can be the same as a known gravity passing device, for example, the layer 12
may be one in which sand is layered on a support layer made of gravel or the like, and the treated water in the biological filtration device becomes clear as SS is removed as it flows downward through the layer 12.
It is taken out from the take-out pipe 13 and stored in a storage tank, for example.

Since the head of the water sampling trough 4 of the biological filtration device is used to transfer water from the biological filtration device 2 to the water supply trough 11 of this gravity filtration device, a pump is not required here either, and the operation can be performed in an energy-saving manner. I can do it.

When the biological filtration device is operated for a long time and the layer 7 becomes clogged and the head loss exceeds a certain level, the liquid level in the pressure regulating tower 1 reaches the upper limit detection part of the level switch. In this case, in addition to closing the valve V ₁ , the air supply pipe 14 that supplies air from the blower to the aeration pipe 8 or the valve V ₃ provided in the air supply pipe that supplies oxygen to the aeration pipe are also closed to stop aeration and The drain trough 10 is opened by opening the valve V ₃ in the drain pipe 10' leading to the drain trough 10 of the treatment equipment.
The water from the upper part of the biological filtration device is drained from the drain pipe 10'.
and lower the water level above layer 7.

Next, the valve V ₄ in the air supply pipe 14' from the blower was opened, and air was introduced into the bottom of the biological filtration device 2 to float air bubbles, which disturbed the layer 7 and formed adhesion on the surface of the material. After removing the turbidity and excessively grown biofilm, the air supply is stopped, and washing water is supplied from below and drained from the drainage trough 10 and drain pipe 10', and the removed turbidity is entrained in the washing water. Eject outside the device. This cleaning operation is repeated several times if the layer is heavily contaminated.

Note that raw water in the pressure regulating tower can be used as the washing water. Of course, piping may be connected to the bottom of the biological filtration device 2 from a storage tank for raw water or a storage tank for treated water passed through the filtration device 3, and raw water or treated water may be supplied by a pump to be used as washing water. And the drain pipe 10'
Although not shown, the washing water discharged from the washing water treatment device is sent to a washing water treatment device such as a sedimentation separation device for treatment.

Gravity overflow equipment should also be operated for long periods of time, and should be cleaned when the head loss rises above a certain level. The rise in head loss can be detected by installing a level switch (not shown) at the top of the device and detecting the rise in the liquid level in the device, or by installing pressure gauges at the top and bottom of the bed and detecting the clogging condition of the bed based on the differential pressure. Detect. When a certain level of clogging is detected, the water sampling trough 4 of the biological filtration device is
The biological filtration device is put into a rest state by closing the valve _V1 , thereby stopping the water supply of the second transfer pipe 15 for gravity-transferring water to the feed trough 11 of the gravity filtration device.

Washing water is then injected from the washing pipe 16, which injects washing water toward the top of the layer, and the upper layer of the heavily contaminated layer is stirred to remove suspended matter from the material.Then, the washing water is poured into the device from the bottom. to backwash the layer. By this backwashing, the material expands to a certain height below the liquid supply trough 11, and the turbidity, which is overwhelmingly lighter than the material, overflows into the liquid supply trough 11 along with the washing water, and from there the drain pipe 11 ' is discharged from the device. Of course, a valve _V8 is also provided on the drain pipe 11'.
Opens only during backwashing. Further, the pipe 17 for supplying wash water for backwashing may be connected to the extraction pipe 13.

As for the cleaning water injected from the cleaning pipe 16 and the cleaning water for backwashing, in addition to raw water and treated water from the take-out pipe as in the case of biological filtration equipment, filtration water passed through the biological filtration equipment can be used. Wastewater is treated in the same way as for biological filtration equipment.

Furthermore, when the layer is heavily contaminated, air backwashing may be performed by connecting an air pipe that blows air into the device from below, as in the case of a biological filtration device. In the case of a gravity filtration device, even if cleaning is completed and operation is restarted, the water is discarded and returned to the raw water storage tank until treated water of the specified water quality is discharged from the take-out pipe, and no SS or other contaminants are observed. When it gets old, put the treated water into the storage tank.

If a biological filtration device and a gravity filtration device are used as described above, operation must be interrupted while one or both are being cleaned, but if multiple units of each device are installed, cleaning can be performed alternately. Therefore, there is no need to interrupt driving. In this case, the transfer pipe 9 and the second transfer pipe 15 are used to stop the water supply to the equipment to be cleaned.
The valves V ₅ and V ₆ are provided respectively.

The water collection trough 4 of the biological filtration device is preferably located above the wash water drainage trough 10, within a range of about 500 to 1500 mm.

In this way, according to the present invention, raw water is supplied to a biological filtration device that causes raw water to flow upward at the head of the pressure regulating tower, and superhydric water is supplied to a gravity filtration device at the head of the biological filtration device. ,plankton,
Raw water containing a wide range of SS such as BOD and ammonia nitrogen can be treated in an energy-saving manner using both biological filtration equipment and gravity filtration equipment. And SS
By appropriately selecting the particle size of the biofilter material according to the concentration of BOD, complete treatment with a BOD of 1 ppm or less can be achieved.

When attempting to perform complete treatment using only an upflow type biological filtration device, there is a problem of leakage of SS into the treated water, and there is a drawback that it cannot be used as is for various water uses, but the present invention The following gravity filtration device plays a finishing role, making it suitable for treating various types of water.

In addition, since the water sampling trough is placed apart above the drainage trough, the head for supplying water to the gravity filtration device can be set high as mentioned above, and backwashing is also performed using air etc. to strongly disturb the layer 7. Can be completely washed.

[Brief explanation of the drawing]

The drawing is a flow sheet showing an embodiment of the present invention, and in the drawing, 1 is a pressure regulating tower, 2 is a biological filtration device exemplified as an upward flow filtration device, and 3 is a downward flow (gravity).
4 is a water sampling trough, 5 is a level switch,
7 is the layer of the upward flow device, 8 is the aeration pipe, 10 is the drainage trough, and 12 is the layer of the gravity filtration device.

Claims (1)

[Scope of Claims] 1. A pressure regulating tower that receives raw water and has an aeration means for adding dissolved oxygen; and means that has an overlayer and receives the raw water from the pressure regulating tower below the overlayer; an upward flow filtration device comprising a drainage trough for washing water provided above the superlayer and a water sampling trough provided further above the drainage trough; It consists of a downward flow filtration device equipped with a water supply trough that receives excess water from the water sampling trough of the upflow filtration device, and the height of the pressure regulating tower is set higher than the water sampling trough of the upward flow filtration device. At the same time, raw water is supplied from the pressure regulating tower to the upstream filtration device at the head, and the water sampling trough of the upstream filtration device is placed above the water supply trough of the downstream filtration device, and the head of the upstream filtration device is A water treatment device characterized by supplying excess water to a downward flow filtration device. 2. The water treatment device according to claim 1, wherein the material forming the layer of the upward flow device includes particles with biofilm attached thereto. 3. The water treatment device according to claim 1, wherein the water sampling trough of the upward flow device is provided 500 to 1500 mm above the drainage trough.