JP2023113302A - Sewage water treatment method - Google Patents

Abstract

To provide a sewage water treatment method for removing scum in a method for treatment of sewage water that generates scum.SOLUTION: A sewage water treatment method treats sewage water by a water stream gradient membrane row, which is configured in such a manner that water stream gradient membranes in which upper interval parts therebetween are blocked with a shielding member are continuously provided in a secondary sedimentation tank, is provided in the secondary sedimentation tank.SELECTED DRAWING: Figure 5

Description

The present invention relates to a sewage treatment method.

Conventionally, at a sewage treatment plant, large garbage, stones, sand, etc. are first removed in a settling basin, and then fine dirt that cannot be removed in the settling basin is slowly drained and settled in a primary sedimentation basin. Next, activated sludge and air are sent into the treated wastewater in the reaction tank and agitated, and then the treated water is slowly poured in the secondary sedimentation tank to settle the activated sludge. They were released into rivers and the sea.

Furthermore, in recent years, when treating the sewage, a sedimentation tank with an inclined plate and / or an inclined pipe is used as a secondary sedimentation tank. It is known to perform in a sedimentation tank in which a sheet membrane provided with is installed (Patent Document 1).

JP 2013-132621

However, even if the sedimentation tank using continuous sheet membranes described in Patent Document 1 treats sewage, a peculiar scum is generated, and the scum flows out from the interval between the sheet membranes. , there was a drawback that the desired processing could not be performed.
Accordingly, the present inventors have conducted extensive research on methods for simultaneously removing scum without impairing the sedimentation efficiency of contaminant particles, and as a result, have completed the present invention.

That is, in the present invention, in sequentially treating sewage in a settling tank, a primary sedimentation tank, a reaction tank, and a secondary sedimentation tank, a water flow gradient membrane having a hanging film suspended from the bottom of a float is installed in the secondary sedimentation tank. , the adjacent floats are closely connected and connected, and are provided so as to leave a gap between the adjacent hanging films, and further, the gap provided in the upper part between the continuous water flow hanging films is a shielding material. This is a sewage treatment method in which at least one line of water flow gradient membrane rows formed by sealing is spread out so as to face the water flow.

According to the method of the present invention, the scum generated during treatment is prevented from flowing out by means of the stream gradient membrane array, and the scum is aggregated and sedimented without lowering the sedimentation separation function of the polluted particles in the sewage. Therefore, the clarification efficiency of the treated water can be dramatically improved.

Front view of a series of water flow gradient membrane arrays Side view of water flow gradient membrane Front view of a row of water flow gradient membranes showing another embodiment of the present invention Side view of the water flow gradient membrane of FIG. Schematic plan view of the secondary sedimentation tank of the present invention

Description will be given of a series of water flow gradient membrane arrays used in the method of the present invention.
FIG. 1 is a front view of a series of water flow gradient membrane arrays of the present invention. A drooping film 2 is hung from the lower part of the float 1 to constitute a water flow gradient film. The drooping films 2 are provided so that a gap is provided between the adjacent drooping films 2 when the water flow gradient films are arranged in a row. A weight 3 is preferably provided at the lower edge of the drooping film 2 . The water-flow gradient film row thus constructed is connected between adjacent floats 1 in close contact with each other via, for example, a cushioning material 4 to form a water-flow gradient film row.
A shielding material 5 is provided so as to seal the upper part of the gap provided between the hanging films 2 of the series of water flow gradient film rows.
As shown in FIG. 1, the shielding material 5 is a horizontally long rectangular sheet-like shielding material that is provided so as to seal the upper space between the water flow drooping membranes, and is sewn on both edges of the drooping membranes 2. can be fixed by As another method, the drooping film 2 and the shielding material 5 can be heat-sealed or sealed with metal fittings (for example, bolts and nuts).
As shown in FIG. 3, the floats 1 are wrapped around the ends of the continuous floats 1 so as to be covered with the shielding material 5 and sealed, and fixed so as to seal the upper space.
The length of the shielding material 5 in the vertical direction is sufficient if it has a length that covers the thickness of the layer when the scum stays. Generally, a length of about 10 to 50 cm is sufficient.
As the shielding material 5 to be used, a film-like body, a plate-like body, or a net body made of natural fiber, synthetic fiber, metal, or rubber is used. When using a net body, the mesh size is preferably 10 mm or less, preferably 5 mm or less.

As a method of constructing a row of water flow gradient films by connecting water flow gradient films, for example, a rope insertion port 6 is provided in the float 1, and a rope 7 is passed through the insertion port 6 of the float 1 to connect a desired number of water flow gradient films. It can be manufactured by setting
FIG. 2 is a side view of a water flow gradient membrane. FIG. 3 is a front view showing another configuration of the water flow gradient membrane row. FIG. 4 is a side view of FIG. 3; FIG. 5 is a schematic plan view of the secondary sedimentation tank of the present invention.
As shown in FIG. 5, the treated water introduced from the treated water inlet 8 into the secondary sedimentation tank slowly flows through the rectifying wall 9, and sedimentation and separation of polluted particles is performed. In addition, the scum 10 generated during the treatment is dammed by a water-flow inclined membrane array provided in the vicinity of the outlet 11 of the secondary sedimentation tank so as to face the water flow, and The scum grows, aggregates, and sinks to the bottom of the pond.
The treated water from which the scum has been removed passes through the overflow wall 12 and the outflow port 11, is sent to the disinfection facility, is disinfected, and is then discharged into a river or the sea.
As the material for the hanging film 2 and the shielding material 5 used in the method of the present invention, polyester resin is particularly preferable as the raw material because of good releasability of aggregated scum. By using this raw material, even if the scum aggregated on the surface adheres to the surface, when it grows to a certain weight, it will separate from the surface and sink to the bottom of the pond, so that the buoyancy of the float 1 of the water flow gradient membrane can also be reduced. (The float can be made smaller).

1 float 2 drooping film 5 shielding material

Claims (1)

When sewage is sequentially treated in a settling tank, a primary sedimentation tank, a reaction tank, and a secondary sedimentation tank, a water-flow inclined membrane with a hanging film suspended at the bottom of the float is placed in the secondary sedimentation tank between adjacent floats. The water flow is formed by closely connecting and continuing, providing a gap between the adjacent hanging films, and further sealing the gap provided in the upper part between the continuous water flow gradient films with a shielding material. A method of treating sewage, characterized in that at least one row of inclined membrane rows is extended so as to face a water flow.

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