JP3285466B2 - River purification facility - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a river purification facility, and more particularly to a river purification facility installed on a riverbed to directly purify a high-concentration (more than 20 mg / l BOD) polluted river.

[0002]

2. Description of the Related Art At present, the only contact-oxidation method between gravel with aeration, which has been put into practical use as a high-concentration river purification facility on a trial basis, involves passing river water through a gravel tank buried in a high-water bed to form solid pollution in water. The material is deposited by the filtering action between gravel, and the soluble pollutants are purified by bio-oxidation of microorganisms naturally occurring on the surface of the gravel, and then discharged to rivers again.

In addition, a sludge reservoir is provided at the rear of the gravel tank, and the system is configured to aerate and discharge sludge when sludge is deposited.

[0004]

However, in the case of the intergranular contact oxidation method, the contact area between the river water and the microbial membrane on the surface of the gravel is increased by increasing the capacity of the gravel tank. It is difficult to install the system on urban rivers where application is expected most.

Further, since the purification time is short, purification is insufficient, and particularly, the removal rate of ammonia nitrogen is low.

Further, there is a problem that it is difficult to remove sludge inside the gravel tank, especially at the inflow portion.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to reduce the area of a site, improve the quality of treated water, easily discharge sludge, and reduce the time and effort required for cleaning a river. Is to provide.

[0008]

According to the present invention, there is provided a river purification facility for purifying and introducing river water and discharging the river water into a river. A contact sedimentation tank for slowly passing the river water in the horizontal direction, a first contact oxidation tank filled with a first contact material having a large specific surface area, and a second contact surface having a larger specific surface area than the first contact material. And a contact oxidizing second tank filled with the contact material are provided in order of passing the river water, and aeration means and a sludge reservoir are provided in the contact sedimentation tank, the contact oxidizing first and second tanks, respectively. And

[0009] The pollutants in the river can be mainly classified into solid pollutants, soluble pollutants and ammoniacal nitrogen, and these are compared with the contact settling tank, the first contact oxidation tank and the second contact oxidation tank in the present invention. Cope as follows.

A) Contact sedimentation tank; removal of coarse solid pollutants Coarse solid pollutants can be effectively precipitated by passing river water slowly and gently while rectifying. The rectifying action on river water is achieved by stacking corrugated contact materials in a honeycomb shape (see FIG. 2 in the embodiment).
However, it is most effective to pass the river water between the contact materials facing each surface. In addition, it is necessary to adjust the amount of water to be introduced in order to make the river water flow slowly.

The phrase "horizontal section in the horizontal section" means that each contact material is erected so that the laminated state as viewed from above the corrugated contact material becomes a honeycomb shape. There is an advantage that sludge removal is facilitated by standing.

B) Contact oxidation first tank; removal of fine solid contaminants and most of soluble contaminants Since coarse solid contaminants are removed by the contact sedimentation tank, the specific surface area is large and microorganisms adhere. Even if a large number of contact materials (first contact materials) capable of increasing the amount are filled, there is no fear of clogging due to sludge. Such a contact material does not increase the flow velocity of the river water in the tank (does not generate a swirling flow) while being aerated by the aeration means, so that fine solid contaminants can be well settled and removed.

In the first contact material, a large specific surface area means that the specific surface area is in the range of 50 to 150 m ² / m ^{3. If} the specific surface area is larger than the specific surface area, clogging occurs due to fine solid contaminants. If it is less than this, an effective amount of microorganisms cannot be secured.

(C) Contact oxidation second tank; removal of remaining soluble pollutants and ammonia nitrogen Nitrogen is almost completely removed by the previous two tanks, and there is no fear of clogging. Material can be used. Further, since the oxygen generated by the aeration in the first contact oxidation tank is exclusively used for the biological oxidation of the soluble pollutants, the ammonia nitrogen is left as it is. This ammonia nitrogen is removed together with the remaining soluble pollutants in the second catalytic oxidation tank.

The specific surface area of the second contact material is not particularly limited as long as it is larger than that of the first contact material.

The aeration means is an air diffuser or a diffuser for supplying oxygen to the microorganisms and removing sludge from the contact material, and the sludge reservoir is installed at a lower part of each tank.

[0017]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an explanatory view schematically showing a main part of a river purification facility I according to the present invention. The river purification facility I is provided with a contact sedimentation tank 10, a plastic contact oxidation first tank 20, and a plastic contact oxidation second tank 30 in the order in which the river water is passed, and the tank 10 and the tank 20 are integrally continuous. , Tank 30 is slightly separated from tank 20. Each tank 10, 2
A diffuser pipe 2 is provided below 0 and 30 as aeration means, and a sludge reservoir 3 to which a sludge extraction pipe 4 is connected is further provided below.

The properties of the contact materials 11, 21, 31 filled in the tanks 10, 20, 30 are shown in the following table.

[0020]

[Table 1]

The contact settling tank 10 has a corrugated contact material 11
(Refer to FIG. 2 and FIG. 3)
F-56 "(a contact material for a septic tank manufactured by Daiho Chemical Co., Ltd.).

As shown in FIG. 2, the contact member 11 has a corrugated top 11 'on one surface provided with projections 12 at predetermined intervals and a corrugated top 1' on the other surface.
A convex concave portion 13 is arranged at 1 "in the same manner as the convex portion 12. As shown in the plan view of FIG. 3, such a contact material 11 faces the convex portion 12 of one contact material 11 face to face. The contacting sedimentation tank 10 is stacked so as to receive and engage with the convex concave portions 13 of the other adjacent contact members 11 and fill the contact sedimentation tank 10 with a honeycomb shape when viewed from above. The contact material 11 is erected so that the wave grooves extend in the vertical direction, so that the contact material 1 is aerated by the air diffuser 2.
1 facilitates the separation of the sludge deposited.

A first contact material 21 having a large specific surface area (see FIG. 4 and FIG. 5) is used as a first contact material 21 (see FIGS. 4 and 5) in a plastic contact oxidation first tank 20 (trade name: Violet 75) Is filled. The number of contact materials 21 to be charged is 215 / m ³ .

The second tank 30 for plastic contact oxidation is
As the contact material 31 (see FIG. 6)
II-Spirax "(contact material, manufactured by NCE Nippon Steel Chemical Co., Ltd.). The number of contact materials 31 to be filled is 17,5.
00 pieces / m ³ .

The purification flow of the above river purification facility I is shown in the following table.

[0026]

[Table 2]

Inflow water from the river is introduced into the contact sedimentation tank 10 from above through a pipe 1a, and the river water is gently passed horizontally through the tank 10 so that the flow velocity is about 10 cm / min. Water is allowed to flow (see the arrow in FIG. 3) to promote precipitation of mainly coarse solid pollutants floating in the water.
At this time, the contact materials 11 stacked in a honeycomb shape contribute to rectification of river water.

Next, the river water overflows from the tank 10 and enters the plastic contact oxidation first tank 20. In the tank 20, the tank 10 is used to deal with a high concentration of soluble pollutants.
The amount of aeration and the residence time are set to be longer than those of the above, and most of the soluble pollutants are decomposed by microorganisms adhering to the surface of the contact material 21. Fine solid pollutants are also settled out here. The aeration of the rear part of the tank 20 is stopped in order to settle the sludge. Therefore, the river water entering the plastic contact oxidation second tank 30 via the pipe 1b has a further reduced pollutant concentration.

In the tank 30, oxygen is used exclusively for decomposing the soluble pollutants in the tank 20, and the ammonia nitrogen remaining as it is and the remaining soluble pollutants can be efficiently biodegraded by supplying oxygen through the air diffuser 2. At this time, since the consumption of dissolved oxygen is small, the dissolved oxygen concentration of the water discharged from the pipe 1c is high. In addition, sufficient oxygen can be supplied even in winter, so that biological activity does not decrease and ammonia nitrogen can be effectively removed.

At the time of sludge discharge in the river purification facility I, the introduction of the river water is stopped, the sludge on the surface of the contact material is suspended in the water by aeration from the air diffuser 2, the water is collected in the sludge reservoir 3, and the supernatant is drained. The sludge to be discharged and settled and concentrated through the pipe 6 is discharged to a sludge receiving tank (not shown) through the sludge extraction pipe 4 and the sludge extraction pipe 5.

The following table shows a comparison between the conventional method of contact oxidation between gravel and the present invention under the condition of a purified water amount of 90 m ² / day.

[0032]

[Table 3]

[0033]

As described above, in the river purification facility according to the present invention, the contact area between the river water and the microorganisms per unit volume is significantly improved mainly by the first and second contact materials having a large specific surface area. Since it can be enlarged, the site area can be reduced to about 1/2 compared with the conventional gravel tank of the inter-gravel contact oxidation method, and it can be applied to an urban river which is expected to be most applied.

In addition, an oxidative sedimentation tank provided with respective functions of solid pollutants, soluble pollutants, and ammonia nitrogen, which are main pollutants in river water, and a first and second contact oxidation tanks are more efficiently dealt with. Therefore, the purification capacity can be improved, and in particular, the ammoniacal nitrogen, which could hardly be removed conventionally by the second catalytic oxidation tank, can be effectively removed.

Furthermore, the amount of aeration can be reduced as the volume of each tank is reduced, which is economical.

Further, by providing the aeration means and the sludge reservoir in each tank, various effects such as a great reduction in labor for drainage and cleaning can be achieved.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing a main part of a river purification facility according to the present invention.

FIG. 2 is a cutaway perspective view showing a corrugated contact member.

FIG. 3 is a plan view showing a laminated state of a corrugated contact material.

FIG. 4 is a perspective view showing a first plastic contact material having a large specific surface area.

FIG. 5 is a plan view of a first plastic contact member.

FIG. 6 is a perspective view showing a second plastic contact member having a large specific surface area.

[Explanation of symbols]

 I River Purification Facility 2 Aeration Tube 3 Sludge Reservoir 10 Contact Sedimentation Tank 11 Corrugated Contact Material 20 Plastic Contact Oxidation First Tank 21 First Plastic Contact Material 30 Plastic Contact Oxidation First Tank 31 Second Plastic Contact Material

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Katsuaki Nohara 2-5-8 Kitaaoyama, Minato-ku, Tokyo Hazumanai Co., Ltd. (56) References JP-A-7-265611 (JP, A) JP-A-7-251188 (JP, A) JP-A-7-108291 (JP, A) JP-A-5-337483 (JP, A) JP-A-5-253583 (JP, A) JP-A-4-215898 (JP, A) 2-218498 (JP, A) 6-52999 (JP, U) 4-78999 (JP, U) 4-70200 (JP, U) (58) Fields surveyed ( Int.Cl. ⁷ , DB name) B01D 21/02 C02F 3/06 C02F 3/10 E03B 3/32

Claims (1)

(57) [Claims] 1. A river purification facility for introducing and purifying river water and discharging the river water into a river, wherein the river water slowly passes horizontally between each of the corrugated plate-like contact members laminated in a horizontal cross-section honeycomb shape. A contact sedimentation tank, a first contact oxidation tank filled with a first contact material having a large specific surface area, and a second contact oxidation tank filled with a second contact material having a larger specific surface area than the first contact material Are provided in the order of passage of the river water, and an aeration means and a sludge reservoir are provided in the contact settling tank and the first and second contact oxidation tanks, respectively.