JP7437006B2 - Improved cross-flow sedimentation basin - Google Patents

Description

The present invention relates to an improved cross-flow settling basin for treating polluted water containing pollutants.

Conventionally, as devices for clarifying polluted water containing pollutants, a lateral flow normal sedimentation tank, a lateral flow chemical sedimentation tank, a radial flow normal sedimentation tank, and a radial flow chemical sedimentation tank have been used. These sedimentation basins generally have an inclined plate or inclined pipe (hereinafter referred to as an inclined plate, etc.) installed in the settling basin in order to remove pollutants from polluted water.
However, when using inclined plates, etc., the concentration of pollutants in the polluted water is high, or when the treatment flow rate is increased, pollutants adhere to the gaps of the inclined plates, etc., or the flow becomes uneven and does not flow down the inclined plates. In particular, when contaminated water was flowed at a flow rate higher than the original design value, a phenomenon was observed in which inclined plates etc. were blocked.
As a method to solve these problems, for example, in a cross-flow sedimentation basin equipped with inclined plates or inclined pipes, sheet membranes are installed on the upper side of the inclined plates or inclined pipes, with a space provided between adjacent sheet membranes. A cross-flow sedimentation tank is known that is characterized by the following (Patent Document 1).

JP2013-132621A

However, although the cross-flow sedimentation tank of Patent Document 1 has a certain effect, the present invention was completed as a result of various studies on the cross-flow sedimentation tank that can perform processing suitably even when the flow rate is further increased. Ta.

That is, the present invention provides, in a cross-flow sedimentation tank, a partition wall with an open lower end between a sedimentation tank provided with an inclined plate and/or a sloped pipe and a rectification sedimentation tank, and an overflow to the rectification sedimentation tank side of the partition wall. The present invention relates to an improved cross-flow sedimentation basin characterized in that a gutter is provided or a plurality of water flow passage openings are provided so as to be located near the water surface of the partition wall and below the water surface.

According to the cross-flow sedimentation tank of the present invention, by providing an overflow gutter or providing a water flow passage port in the partition wall, it is possible to treat a larger amount of polluted water than a conventional cross-flow sedimentation tank of the same size.
Moreover, since the present invention can be applied to an existing cross-flow sedimentation tank, a large amount of polluted water can be treated by the conventional cross-flow sedimentation tank.

Side sectional view of a conventional cross-flow sedimentation tank. FIG. 2 is a side sectional view of the cross-flow sedimentation tank of the present invention. FIG. 3 is a plan view of the cross-flow sedimentation basin in FIG. 2. FIG. 3 is a plan view of a cross-flow sedimentation basin showing another embodiment of the present invention. The state diagram when the partition wall which has a water flow passage opening is installed. A state diagram when a partition wall with multiple water flow passage ports is installed.

Next, the cross-flow sedimentation tank of the present invention will be explained, but the present invention is not limited to the following explanation.
FIG. 1 is a schematic diagram showing a side cross-sectional view of a conventional cross-flow sedimentation tank, FIG. 2 is a schematic diagram showing a side cross-section of a cross-flow sedimentation tank of the present invention, and FIG. FIG. 4 is a schematic plan view of a cross-flow sedimentation tank showing another embodiment of the present invention.
1 is a polluted water inlet, 2 is a rapid stirring tank, 3 is a slow stirring tank, 4 is a rectifying sedimentation tank, 5 is a sedimentation tank equipped with an inclined plate and/or an inclined pipe, 6 is a water collection trough, and 15 is a storage tank, 7 is a coagulant supply pipe, 8 is a polluted water supply pipe containing pollutants, 9 is sludge deposited at the bottom of the cross-flow sedimentation tank, 10 is a sludge collection pipe, 11 is a rectification sedimentation tank 4 and an inclined plate and/or Alternatively, a partition wall is provided between the sedimentation tanks 5 provided with inclined pipes, 12 is an overflow gutter, and 13 is a water flow passage port provided in the partition wall 11.
Reference numeral 17 denotes a water flow passage hole provided in the side wall 16, and reference numeral 18 denotes a water pipe for passing water from the overflow gutter 12 into the storage tank 15.

Polluted water taken from a river or the like is introduced into the polluted water inflow section 1 of the cross-flow sedimentation tank, and at the same time, a flocculant solution is introduced from the flocculant supply pipe 7. In addition to the flocculating solution, this flocculant solution can also be a solution prepared with a flocculant and sludge water collected from the sludge collection pipe 10 of the settling tank of the present invention.

The polluted water and the supplied flocculant solution are mixed in the polluted water introduction section 1 and introduced into the rapid stirring tank 2, where they are rapidly stirred and further uniformly mixed. The polluted water mixed in the rapid stirring tank 2 is then introduced into the slow stirring tank 3, where slow stirring is performed, and the pollutants in the polluted water are turned into flocs. The polluted water treated in the slow stirring tank 3 is introduced into the next rectifying sedimentation tank 4.

The polluted water introduced into the rectifying sedimentation tank 4 is either introduced into the next sedimentation tank 5 in the case of a conventional cross-flow sedimentation tank, or is introduced into the rectification tank in which a sheet membrane is spread as described in Patent Document 1. It is introduced from the settling tank 4 into the settling tank 5.
On the other hand, in the present invention, as shown in FIG. 2, there is a partition wall 11 with an open lower end between the rectification sedimentation tank 4 and the sedimentation tank 5, and the partition wall 11 is spaced apart from the bottom of the cross-flow sedimentation tank. will be established. The partition wall 11 is provided with an L-shaped overflow gutter 12 on the side of the rectifying sedimentation tank 4 at a position where polluted water overflows (a position below the water surface). The upper edge portion 14 of the standing wall of the L-shaped overflow gutter 12 is provided so as to be located below the water surface. This L-shaped overflow gutter 12 is preferably movable by appropriate means so that its position can be changed up and down, so that suitable treatment can be performed according to the amount of water to be treated.

Furthermore, instead of the L-shaped overflow gutter 12, the water flow passage ports 13 may be provided in parallel in the vicinity of the water surface of the partition wall 11 as shown in FIG. 5, or the water flow passage ports 13 may be provided in multiple stages as shown in FIG. This makes it possible to suitably respond to changes in water volume.

The present invention provides clarification on the rectification sedimentation tank 4 side of the partition wall 11 by providing a partition wall 11 with an open lower end between the sedimentation tank 5 and the rectification sedimentation tank 4 in which an inclined plate and/or an inclined pipe are installed. By providing an overflow gutter 12 on the rectifying sedimentation tank 4 side of the partition wall 11, the clarified treated water can be discharged to the outside of the system, thereby reducing the amount of polluted water to be treated. can be increased.
Furthermore, the treated water that has passed through the water flow passage port 13 is sent to the storage tank 15 via a water collection trough 6 provided in the sedimentation tank 5 equipped with an inclined plate and/or an inclined pipe, and is discharged to the outside of the system.
Furthermore, in the sedimentation tank 5 and rectification sedimentation tank 4 equipped with inclined plates and/or inclined pipes shown in FIG. It is sent to tank 15 and discharged outside the system.
Further, by providing an opening/closing valve (not shown) in the water flow passage port 13 provided in the partition wall 11 or the water flow passage port 17 provided in the side wall 16, it is possible to suitably respond to changes in the amount of water.

The present invention can treat not only polluted water with a flow rate greater than the design value, but also polluted water with turbidity greater than the design value.

Next, an example will be explained.
In a cross-flow sedimentation case of 38 m long and 15 m wide, the cross-flow sedimentation tank shown in Figure 1 and the cross-flow sedimentation tank of the present invention shown in Figure 2 were used, and both were treated by supplying 1440 m ³ /Hr of polluted water. In the cross-flow sedimentation tank, the inclined plate was blocked after 120 hours and operation was impossible, but when treated with the cross-flow sedimentation tank of the present invention shown in Figure 2, the treatment was not as good as when properly treated using a conventional cross-flow sedimentation tank. Similar clarified treated water could be obtained, and inclined plates etc. would not be clogged.

11...Partition wall 13...Water flow passage port

Claims (1)

A lateral flow sedimentation tank equipped with a polluted water inlet for mixing polluted water and a flocculant solution, a rapid stirring tank, a slow stirring tank, a rectifying sedimentation tank, a settling tank equipped with an inclined plate and/or an inclined pipe, and a storage tank. A partition with an open lower end is provided between the rectifying sedimentation tank and the sedimentation tank provided with an inclined plate and/or inclined pipe, and an overflow gutter is provided on the rectifying sedimentation tank side of the partition, or the water surface of the partition wall is A plurality of water flow passage ports are provided so as to be located below the water surface in the vicinity, a water flow pipe is provided in the overflow gutter to flow the treated water to the storage tank, and water flow is provided to the settling tank in which the tilted plate and/or the tilted pipe are installed. An improved cross-flow sedimentation tank characterized by being provided with a water collection trough that sends treated water that has passed through a passage port to a storage tank.

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