JPH10244281A - Device for cleaning contaminated water of low concentration - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable cleaning while taking in oxygen contained in air and also to narrow installation area by only introducing contaminated water of low concentration of a river into a water tank provided in a flood plain without using an aeration pipe during operation in a device for cleaning contaminated water of low concentration such as river water. SOLUTION: A plurality of pieces of cleaning tanks 16, 17, 18 different in water level are arranged so that water overflows in order from the cleaning tank 16 of high water level to the cleaning tanks 17, 18 of low water level and flows into the cleaning tanks while incorporating oxygen contained in air. Contact filter medium tanks 23-26 filled with many pieces of contact filter media are provided in the cleaning tanks 16-18. Contaminated water of low concentration of a river, lakes and marshes is allowed to flow into the cleaning tank 16 of the highest water level by an overflow through an introduction gutter 19 and upward passed through the contact filter media tanks 23, 25, 26 and discharged to the river, the lakes and marshes or the like through a leading-out gutter 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a purifying apparatus suitable for purifying low-concentration contaminated water containing organic pollutants such as water from rivers and lakes.

[0002]

2. Description of the Related Art As a purification device for purifying river water, river water is introduced into a gravel layer provided on a riverbed, and solid suspended solids in the water are filtered and precipitated by the gravel layer, and organic pollution in the river water is reduced. It is known that the substance is oxidatively decomposed by a microbial membrane naturally occurring on the surface of gravel, and the purified water is discharged to the original river. However, in the case of using the above-mentioned gravel layer, in order to remove the sludge deposited on the gravel layer and to prevent clogging, an air pipe is arranged inside the gravel layer and aeration is performed as needed.
It was necessary to suspend the sludge and collect it with a pump.
Moreover, about 40% smaller in volume 1 m ³ per space ratio of the gravel layer
Therefore, in order to increase the pollutant removal efficiency, it was necessary to increase the volume of the gravel layer and increase the installation area. In addition, since the gravel is irregular in shape, the size of the space where the sludge accumulates becomes non-uniform, making it difficult to uniformly aerate the gravel during washing. Further, since there is no replenishment of dissolved oxygen, the purification efficiency is reduced and an odor may be generated.

[0003] In order to solve this problem, a water tank is installed in the flow path of a river along the flow direction, and a large number of sheet-like contact materials (woven fabrics) are juxtaposed along the flow in the water tank. A diffuser pipe and a sludge withdrawal pipe are provided at the bottom of the tank (see JP-A-8-1180), and a filter medium tank filled with a substantially spherical filter medium (cement ball) is provided with a contact material having a large surface area per 1 m ^3. And a contact material tank filled with water are arranged in the flow direction, and a sludge removing means having an aeration function is provided in the filter material tank, and an air supply pipe is provided in the contact material tank (see JP-A-7-265611). Etc. are proposed,
Are known. However, these purifying devices require frequent driving of air supply pipes such as a diffuser pipe and an aeration pipe during operation, and thus have a problem that equipment costs and operation and maintenance costs increase.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a method for introducing low-concentration water from rivers and lakes, filtering and precipitating solid suspended solids from the contaminated water, and oxidizing and decomposing organic pollutants with a microbial membrane. In a purification device for discharging to the original rivers and lakes, BOD 20 ppm or less while taking in oxygen in the air by introducing low concentration polluted water such as rivers at the head without requiring aeration during operation, It can purify contaminated water of SS 30 ppm or less to BOD 5 ppm or less and SS 5 ppm or less, and can reduce the installation area.

[0005]

According to the present invention, there is provided an apparatus for purifying low-concentration contaminated water, in which a plurality of septic tanks having different water levels are provided so that water overflows from a high-purified septic tank into a low-purified septic tank. Arranged in the order of water level, the above-mentioned septic tank, the contact filter medium tank filled with a large number of contact filter media, so as to be in contact with the adjacent low water-level septic tank, and the lower surface of the contact filter medium tank is separated from the bottom of the septic tank, Water flowing into the septic tank is provided so as to flow upward from the bottom of the contact filter tank and overflow from the top of the contact filter tank to the adjacent low-water-side septic tank, and introduce low-concentration contaminated water, such as rivers and lakes, through the introduction gutter. The water flowing through the contact filter media tank in the septic tank at the lowest level overflows into the outlet trough, and is discharged to rivers, lakes, etc. through this outlet trough. Features.

As the contact filter medium, fillers such as Raschig rings, sash rings, Berl saddles, interlock saddles, terralette packings, and pole rings used for contacting gas and liquid of the absorber can be used. It is composed of the described contact filter medium, that is, a saddle-shaped flap, and a plurality of hollow cylinders and blades protruding from both sides of the saddle-shaped flap (Japanese Patent Publication Nos. 47-41225 and 63-21317). And JP-A-8-1
The surface area per 1 m ³ is 5
0 m ² / m ³ or more, in particular, 52 m ² / m ³ or more, and a space ratio per m ³ of 80% or more, particularly 95% or more. Toyo Hi-Rex ”and“ Toyo Bio Hi-Rex ”are particularly preferred because they are less clogged by filtration, have a large contact area with water, are light and easy to handle.

The above-mentioned contact filter medium is filled with a large number of box-shaped containers each having a grid or saw-like grid at the bottom, and a grid-like container is formed on the top layer to prevent the contact filter medium from floating. Are formed in the contact filter medium tank by stacking the holding plates. The above-mentioned holding plate is used when the contact filter medium is made of plastic having a small specific gravity.

When the apparatus for purifying low-concentration contaminated water according to the present invention is buried in a riverbed or the like, and contaminated water is pumped up from an upstream side of the river through an appropriate channel or by a pump, the contaminated water is guided to the above-mentioned introduction gutter. Due to the rise in the water level, the contaminated water flows into the upstream septic tank by overflow, and at that time, the oxygen in the air is taken in and the dissolved oxygen in the water is increased. Then, as the water level in the septic tank rises, part of the SS precipitates and accumulates at the bottom,
The contaminated water that has reached the lower surface of the contact filter medium tank flows upward through the contact filter medium tank, at which time filtration is performed, and a portion of the SS further precipitates and deposits, and the contaminated water contacts the surface of the contact filter medium. It is oxidized and decomposed by the action of a microbial membrane naturally adhering to the surface. Then, after passing through the above-mentioned contact filter medium tank, it flows into an adjacent low water level side purification tank by overflow.
Hereinafter, by repeating this, the above-mentioned contaminated water sequentially flows into the septic tank on the low water level side, is purified during that time, is discharged from the septic tank at the lowest water level to the discharge gutter by overflow, and the oxygen in the air at the time of the overflow. The oxygen is replenished by taking in the water, and is discharged to the original river or the like through an arbitrary water channel connected to the outlet gutter.

According to the present invention, contaminated water such as river water flows by overflow between the inlet gutter and the highest-level septic tank, between adjacent septic tanks, and between the lowest-level septic tank and the outlet gutter. Since dissolved oxygen is supplied at this time, aeration during operation becomes unnecessary. In addition, since the contaminated water flows upward from below in the contact filter medium tank of each of the purification tanks, the contaminated water uniformly disperses and flows in the contact filter medium tank, and the contact efficiency of the contaminated water with the microbial membrane on the surface of the contact filter medium is improved. In addition, by providing a plurality of V-grooves in the overflow portion and overflowing through the V-grooves,
The bias of the overflow is eliminated, and the water flow through the contact filter medium tank becomes more uniform. In addition, the overflow is performed not only on one of the adjacent low-water-level septic tanks, but also on three sides including the left and right sides, and is received by a gutter. The water flow in the contact filter medium tank becomes more uniform, and the contact efficiency with the microorganism membrane is further improved.

[0010] Since the contact filter medium tank is provided above the bottom of the septic tank, SS in the contaminated water easily precipitates and deposits on this bottom, and the organic components in the sediment layer are easily self-digested. Since the amount of SS accumulated by digestion is reduced, oxygen supplementation is performed at the time of overflow, so that aeration by air blowing using an air pipe etc. is almost unnecessary, and the accumulated SS is submerged slurry pump. Etc., and the number of removal operations is also reduced.

It is not necessary that all of the above-mentioned septic tanks have the same capacity. And a plurality of septic tanks can be made in an independent form, respectively, and as described in claim 3, by dividing one large water tank by a plurality of partition walls integrally formed with the large water tank, A plurality of septic tanks can also be made. In this case, the water level of each septic tank can be easily set and the installation area can be reduced as compared with a case where a plurality of septic tanks are installed independently. Further, the number of contact filter medium tanks installed in the septic tank is not limited to one, and two of them may be arranged in series in some of the septic tanks. However, in this case, only the lower side is communicated by interposing a weir plate separating the upper part between the two contact filter media tanks on the upstream side and the downstream side,
Overflowing the contaminated water from the purification tank adjacent to the upstream contact filter medium tank on the upstream side to cause the upstream contact filter medium tank to flow down,
Next, it is preferable to raise the downstream contact filter medium tank in the two.

According to a fourth aspect of the present invention, a plurality of purification tanks are provided in a large water tank having a length substantially equal to the arrangement length of the plurality of purification tanks. A partition plate for partitioning a large water tank to form a septic tank, a contact filter medium tank fixed to an upper portion on one side of the partition plate, and a sludge receiver fixed to a lower end on one side of the partition plate are detachably attached. In this case, while the shape and structure of the large water tank are simplified, the purification unit can be made of steel or FRP, and the production becomes easy and the production cost is reduced. When the water level decreases and the sludge receiver and contact filter media become dirty, the purification unit can be removed from the large water tank to remove accumulated sludge from the sludge receiver, and the contact filter media can be removed from the contact filter media tank and washed. Pull-out for the pipes and pump of the mud is not required.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 In FIG. 1, reference numeral 10 denotes a large concrete water tank, which is formed by a front wall 11, a rear wall 12, and a side wall 13 into a rectangular parallelepiped box shape which is long in the front-rear direction (the left-right direction in FIG. 1). The inside of the water tank 10 is partitioned into three tanks arranged in front and rear by a first partition 14 and a second partition 15 in the width direction, and a first purification tank 16 is provided between the front wall 11 and the first partition 14.
A second purification tank 17 is formed between the partition wall 14 and the second partition wall 15, and a third purification tank 18 is formed between the second partition wall 15 and the rear wall 12, respectively. However, the first septic tank 16 and the third
The septic tank 18 is formed to have substantially the same length, the second septic tank 17 is formed to have a length almost twice as long as the first septic tank 16, and the bottom of each tank is lower on the upstream side (left side in FIG. 1). Inclined so that sludge accumulates upstream.
An introduction gutter 19 and an extraction gutter 20 are provided in the width direction along the upper outer surfaces of the front wall 11 and the rear wall 12, respectively.

The front wall 11, the first partition 14, the second partition 15, and the rear wall 12 are formed such that the height of the front wall 11 is the highest, the height of the front wall 11 is reduced in order, and the height of the rear wall 12 is the lowest. You. And, between the above-mentioned introduction gutter 19 and the first septic tank 16,
The water level difference (head) between the first septic tank 16 and the second septic tank 17, between the second septic tank 17 and the third septic tank 18, and between the third septic tank 18 and the discharge gutter 20 is set to 5 cm to 20 cm. The upper edge of the wall 11 is provided with a plurality of V-grooves 11 a for communicating the introduction gutter 19 and the first septic tank 16, and the upper edge of the first partition 14 is connected to the first and second septic tanks 16 and 17. A plurality of V-grooves 14a, a plurality of V-grooves 15a at the upper edge of the second partition wall 15 for communicating the second septic tank 17 and the third septic tank 18 and a third V-groove at the upper edge of the rear wall 12 are provided. Septic tank 18
A plurality of V-grooves 12a are provided in parallel with each other and communicate with the outlet gutter 20.

Near the front of the first septic tank 16, there is provided a first weir plate 21 a for partitioning the upper half of the first septic tank 16 back and forth, between the lower end of the weir plate 21 a and the first partition 14. 1
The grid 22a is fixed horizontally, and the first grid 2a
A first contact filter medium tank 23 is formed by filling a contact filter medium 30 described later above the upper part 2a. A second dam plate 21b is provided at the center of the second septic tank 17 to partition the upper half of the second septic tank 17 back and forth, and the second dam plate 21b is provided in front of the lower end of the dam plate 21b.
The grid 22b and the third grid 22c on the rear side are fixed horizontally, respectively. The contact filter medium 30 is filled above each of the second grid 22b and the third grid 22c, and the third grid 22c is positioned above the second grid 22b. A two-contact filter medium tank 24 is formed, and a third contact filter medium tank 25 is formed above the third grid 22c. Further, a third partitioning the upper half of the third septic tank 18 forward and backward near the front of the third septic tank 18.
A dam 21c is provided, and the lower end of the dam 21c and the rear wall 1 are provided.
The fourth grid 22d is fixed horizontally between the second grid 2 and the contact filter medium 30 is filled above the fourth grid 22d to form a fourth contact filter medium tank 26. Note that a lattice-shaped pressing plate (not shown) for preventing the contact filter medium 30 from floating is superimposed on the upper surface of the layer of the filled contact filter medium 30.

FIG. 2 shows an example of the contact filter medium 30. The contact filter medium 30 is a molded product made of a synthetic resin such as polypropylene. The saddle-shaped flap 31 has a circular shape when viewed from directly above and directly below, and the front part 31a and the rear part 31b are higher than the center C thereof. The left and right sides 31
It is formed in a saddle shape in which c and 31d are lowered. Large circular holes 32a, 32b, 32c, and 32d are provided at 90-degree intervals when viewed from above at a total of four places on the front left and right sides and the rear right and left sides of the saddle flap 31, and the front left large circular hole 32a and the rear right side are provided. Frustoconical cylindrical bodies 33 and 36 project upward from the edges of the large circular hole 32d, respectively, and downwardly frustoconical cylindrical bodies 34 from the edges of the front right large circular hole 32b and the rear left large circular hole 32c, respectively. And 35 protrude, and a plurality of vertical holes 33a, 34a, 35a, 36a are provided in these cylindrical bodies 33, 34, 35, 36, respectively.

The upper two cylinders 33, 36 are connected by a plate-like central wing 37 passing through the center C of the saddle-shaped flap 31, and the left rear surface of the front left cylinder 33 and the rear right cylinder are formed. 36
Each of the supporting wings 37a is provided on the right front surface thereof, and a vertical hole 37b is provided in the supporting wing 37a. Further, the lower two cylinders 34, 35 are connected in the same manner by the center wing 38 (not shown), and are connected to the left front surface of the front right cylinder 34 and the right rear surface of the rear left cylinder 35. Each of the support wings 38a protrudes, and a vertical hole 38b is provided in the support wing 38a. In addition, the support wings 37 on the front, rear, left and right of the saddle flap 31
a, a small hole 32e is provided in a portion where 38a contacts,
The large holes 32a to 32d and the vertical holes 33a to 36
Together with a, 37b, and 38b, the contaminated water can flow smoothly without being stuck in one place.

The contact filter medium 30 shown in FIG. 2 is used as a packing material for a packed tower of a gas-liquid contact type absorption device.
As disclosed in Japanese Utility Model Publication No. 63-21317, a cylinder having a smaller diameter than the cylinders 33 to 36 is provided at the tip of the support wings 37a and 38a. And Japanese Patent Application Laid-Open No. 8-155478.
As described in Japanese Patent Application Laid-Open Publication No. H10-260, auxiliary wings are protrudingly provided on both surfaces of the center wing 37, and support wings 3 around the large-diameter cylindrical bodies 33 to 36 are provided.
The surface area and the porosity of the contact filter medium 30 can be increased by increasing the number of 7a and 38a.

The large water tank 10 shown in FIG. 1 is buried in the riverbed, and the upstream side of the river is connected to the above-mentioned introduction gutter 19 by an appropriate channel, and the downstream side of the above-mentioned river is connected to the outlet gutter 20 by an appropriate channel. . When the contaminated water W of the river is introduced into the introduction gutter 19 and the water level of the introduction gutter 19 rises, the contaminated water W of the introduction gutter 19 overflows from the V-groove 11a of the front wall 11, and the oxygen in the air And flows into the first septic tank 16 through between the front wall 11 of the large water tank 10 and the first dam plate 21a,
As a result, when the water level of the first septic tank 16 rises, the contaminated water W flows upward from below in the first contact filter medium tank 23,
At this time, the contaminated water W is filtered, and a part of the suspension precipitates on the bottom of the first septic tank 16 to form a first sedimentation layer Da. Filter media tank 23
It is decomposed in contact with the microbial membrane formed on the surface of the contact filter medium 30 inside. When the water level of the first septic tank 16 rises and reaches the V groove 14a of the first partition 14, the first septic tank 1
6 contaminated water W overflows the first partition 14 and the second septic tank 17
At that time, the oxygen in the air is taken in, and the air flows through the V-groove 14a.

The contaminated water W that has flowed into the second purification tank 17 passes through the second contact filter medium tank 24 downward and reaches the bottom of the second purification tank 17, and moves upward through the third contact filter medium tank 25 as the water level rises. Part of the suspended matter precipitates at the bottom of the second septic tank 17 to form a second sedimentation layer Db, and the organic pollutants in the contaminated water W are removed by the second contact filter medium tank 24 and the third contact layer. It is decomposed in contact with the microbial membrane formed on the surface of the contact filter medium 30 in the filter medium tank 25. When the water level in the second septic tank 17 rises and reaches the V groove 15a of the second partition 15, the second
The contaminated water W in the septic tank 17 overflows the second partition 15 and flows into the third septic tank 18. At this time, the overflowing contaminated water W takes in oxygen in the air and passes through the V-groove 15a, so that the flow is made uniform without being partially biased.

The contaminated water W flowing into the third septic tank 18 passes between the second partition wall 15 and the third weir plate 21c and reaches the bottom of the third septic tank 18, where the fourth contact filter medium is added as the water level rises. Passing upward through the tank 26, a part of the suspended matter is
To form a third sedimentation layer Dc, and the organic pollutants in the contaminated water W are decomposed in contact with the microbial membrane formed on the surface of the contact filter medium 30 of the fourth contact filter tank 26. Then, the water level of the third septic tank 18 rises and the rear wall 12
, The contaminated water W in the third septic tank 18 overflows the rear wall 12 and flows into the outlet gutter 20. At this time,
The overflowing contaminated water W takes in oxygen in the air and passes through the V-groove 12a, so that the flow is made uniform without being partially biased. Then, the contaminated water W flowing into the outlet gutter 20
Is returned to the river via a suitable channel.

In the first embodiment, the contaminated water W is
When flowing into the first septic tank 16 from 9, when flowing from the first septic tank 16 to the second septic tank 17, when flowing from the second septic tank 17 to the third septic tank 18, and from the third septic tank 18 to the outlet gutter 20. At this time, overflow is performed based on the heads between the tanks, and oxygen is supplied at that time, so that aeration during operation becomes unnecessary, and the flow of the contaminated water W in the contact filter medium tanks 23 to 26 is reduced. Become uniform. Further, since the overflow is performed via the V-grooves 14a, 15a, and 16a, the bias of the overflow is eliminated, and the flow of the contaminated water W in the contact filter media tanks 23 to 26 becomes more uniform.

The above-mentioned V-grooves 14a, 15a, 16a
Are provided on the left and right sides and the rear side of the first contact filter medium tank 23, the third contact filter medium tank 25, and the fourth contact filter medium tank 26 in total, and are allowed to overflow in three directions. To "Ko"
Can be collected in a gutter provided around the shape of a circle and flowed into the low water level septic tank or the outlet gutter 20. In this case, the overflow is performed more uniformly, the uptake of oxygen in the air is increased, and the contact is improved. The flow in the filter medium tanks 23 to 26 becomes more uniform.

In the first contact filter tank 23, the third contact filter tank 25, and the fourth contact filter tank 26, the contaminated water W flows upward through these contact filter tanks. The contact efficiency of the contaminated water with respect to the microorganisms flowing and adhering to the surface of the contact filter medium 30 is improved. Also,
In the contact filter medium tanks 23 to 26, the contact filter medium 30 of FIG. 2, that is, the saddle flap 31, the cylindrical bodies 33 to 36, the large number of blades 37, 3
Since the contact filter medium 30 composed of 8, 37a, 38a or the like and having a large surface area and a large opening ratio is filled, the above-described contact efficiency is further increased, and clogging hardly occurs. Since the contact filter media tanks 23 to 26 are provided so as to float from the bottom of the large water tank 10, the sedimentation layer D is provided below the contact filter media tanks 23 to 26.
a to Dc are easily formed, and these precipitation layers Da to Dc
In this case, the organic components are self-digested, and the amount of the accumulated components is reduced, so that aeration is almost unnecessary, even if it is performed, it may be very intermittent, and it can be easily removed by a submersible slurry pump or the like, and the number of times is reduced. .

The purifying apparatus of the first embodiment is manufactured according to the specifications shown in Table 1 below, and low-concentration contaminated water W (average temperature 16 ° C.)
86.4 m ³ per day processing speed and 36 without aeration
After continuous treatment for 0 days, BOD and SS before and after the treatment were compared, and the results are shown in Table 2 as average values. However, the overflow V groove 14a of the first septic tank 16 and the overflow V groove of the second septic tank 17
The groove 15a and the overflow V groove 12a of the third septic tank 18 are:
The first contact filter medium tank 23, the third contact filter medium tank 25, and the fourth contact filter medium tank 26 are provided on the left and right sides and on the rear side, respectively, to allow overflow in three directions. I sent it. As the contact filter medium, "Toyo Bio Hilex BH-100" and "Toyo Bio Hirex BH-150" manufactured by Toyo Tire & Rubber Co., Ltd., each having a blade added to the contact filter medium 30 in FIG. 2, were used. The contact filter medium tank volume shown in the column of the second purification tank in Table 1 is the capacity of the second contact filter medium tank and the third contact filter medium tank. The diameter of the contact filter medium is the diameter when the saddle flap 31 is projected in a circular shape, and the height is the distance between the ends of the center wings 37 and 38 projected perpendicularly to the above-mentioned projection direction.

Table 1 First septic tank Second septic tank Third septic tank Inner length (m) 1.7 2.4 1.4 Inner width (m) 1.0 1.0 1.0 Depth (m) 1.7 1.6 1.3 Volume (m ³ ) 2.9 3.8 1.8 Contact Filter media tank volume (m ³ ) 1.33 1.33 / 1.33 1.02 Types of contact media BH-150 BH-100 BH-100 直径 Diameter (mm) 156 95 95 〃 Height (mm) 128.5 78 78 表面積 Surface area (m ² / m ³ ) 52 75 75 〃 Space ratio (%) 95 95 95 Residence time (h) 0.35 0.7 0.27

Table 2 Before treatment After treatment BOD (ppm) 8.3 4.6 SS (ppm) 11.2 4.0

Embodiment 2 As shown in FIG. 3, four purification units 50A, 50B,
50C and 50D are arranged in series to make a low-concentration contaminated water purification device. Front wall 41 and rear wall 42 of large water tank 40
In the same manner as in the first embodiment, overflow V-grooves 41a and 42a are formed.
And an outlet gutter 46 are provided. However, large water tank 40
The inner surface of both the side wall 43 and the bottom plate 44 is formed flat.

The above purification units 50A, 50B, 50
C and 50D are partition plates 51A, 51B, and 51C that can partition the large water tank 40 back and forth, respectively.
And 51D, a partition plate 51A of the first purification unit 50A located at the front end, and a second plate located at the second position.
The first purification tank 47A, the second purification tank 47B, and the third purification tank 4 are separated by the partition plate 51B of the purification unit 50B and the partition plate 51C of the third purification unit 50C located third.
7C and the fourth purification tank 47D are formed, and the partition plate 51D of the fourth purification unit 50D located at the rear end contacts the rear wall 42 of the large water tank 40.

The first purification unit 50A is formed in the shape of a J-shaped box as shown in FIG. That is, the above-mentioned partition plate 51A, a pair of J-shaped side plates 52A fixed to the front left and right sides of the partition plate 51A, an upper front plate 53A connecting the vertical front ends of the J-shaped side plates 52A, and the pair of J A lower front plate 54A that connects the horizontal portion tip of the V-shaped side plate 52A, the partition plate 51A, the J-shaped side plate 52A,
A bottom plate 55A connecting the lower end of the lower front plate 54A, and a grid 56A fitted to the lower part of the rectangular tube portion formed by the partition plate 51A, the vertical portion of the J-shaped side plate 52A and the upper front plate 53A. It is formed by filling the contact filter medium 30 (not shown) on the grid 56A of the character box. The filling portion of the contact filter medium 30 constitutes the contact filter medium tank 57A, and the dish-shaped portion including the bottom plate 55A constitutes the sludge receiver 58A. In addition, the partition plate 51A
A plurality of overflow V-grooves are provided side by side at the upper edge.

The contact filter media tanks 57B, 57C, 57D of the second purification unit 50B, the third purification unit 50C, and the fourth purification unit 50D shown in FIG.
B, 58C, and 58D are formed substantially in the same manner as the contact filter medium tank 57A and the sludge receiver 58A of the first purification unit 50A, respectively. However, the first septic tank 47A, the second septic tank 47B, the third septic tank 47C, and the fourth septic tank 47D.
The height of the V-grooves on the partition plates 51B, 51C, and 51D and the contact filter media tanks 57B, 57C, and 57D are set to be lower than that of the first purification unit 50A so that the water level of each of the partition plates 51B, 51C, and 51D decreases stepwise. You.

The first to fourth purifying units 50A to 50A
OD are arranged in the large water tank 40 at predetermined intervals, and the contact filter medium tanks 57A to 57D are directed to the upstream with respect to the partition plates 51A to 51D. First and second purification tanks 47A and 47B adjacent to each other by packing rubber or other packing between third purification units 50A to 50C (excluding fourth purification unit 50D).
Between the second and third septic tanks 47B and 47C and between the third and fourth septic tanks 47C and 47D. Accordingly, the contaminated water W introduced into the introduction gutter 45 is purified in order through the first to fourth purification tanks 47A to 47D, and then discharged to a river or the like via the discharge gutter 46. , Contact filter media tanks 57A, 57B,
Contaminated water W flows upward in all of 57C and 57D.

[0033]

According to the invention described in claims 1 to 4, low-concentration contaminated water such as river water or the like having a BOD of 20 ppm or less and SS of 30 ppm or less can be purified to a BOD of 5 ppm or less and an SS of 5 ppm or less, and oxygen supply to the water can be achieved. Since it is performed by overflowing between the washing tanks, aeration by air blowing during operation is not required, and clogging of the contact filter medium hardly occurs.
Further, the amount of sludge accumulated is easily reduced by self-digestion, so that aeration of the accumulated sludge is not required, the sludge is easily removed, the running cost is greatly reduced, and the installation area is further reduced.

In particular, according to the second aspect of the present invention, clogging of the contact filter medium is further reduced, and the contact efficiency of the contaminated water with the microbial membrane on the surface of the contact filter medium is further improved. Also,
According to the third aspect of the invention, the water level can be easily set and the installation area can be reduced. According to the invention described in claim 4, while the shape and structure of the large water tank are simplified,
Purification unit can be made of steel or FRP,
Therefore, the entire purification device can be easily manufactured, the production cost can be reduced, and when the sludge receiver or the contact filter medium becomes dirty, the purification unit can be removed from the large water tank and washed.
There is no need for a sludge extraction pipe or pump.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a first embodiment.

FIG. 2 is a perspective view showing an example of a contact filter medium.

FIG. 3 is a longitudinal sectional view of the second embodiment.

FIG. 4 is a perspective view of a purification unit.

[Explanation of symbols]

 10, 40: large water tank 11, 41: front wall 12, 42: rear wall 13, 43: side wall 14, 15: partition wall 11a, 12a, 14a, 15a: overflow V-groove 16-18, 47A-47D: septic tank 19 , 45: Introductory gutter 20, 46: Outlet gutter 21a, 21b, 21c: Weir plate 22a, 22b, 22c, 22d: Grid 23-26, 57A-57D: Contact filter medium tank 30: Contact filter medium 31: Saddle flap 33- 36: hollow cylindrical body 37, 38, 37a, 38a: blade 50A to 50D: purification unit 51A to 51D: partition plate 58A to 58D: sludge receiver W: contaminated water Da to Dc: sedimentation layer

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Tetsuji Sato 2--17-18 Edobori, Nishi-ku, Osaka-shi, Osaka Inside Toyo Tire & Rubber Co., Ltd.

Claims (4)

[Claims] A plurality of septic tanks having different water levels are arranged in the order of water level such that water overflows from a high water septic tank to a low water septic tank, and a plurality of contact filter media are provided in the septic tank. The contact filter medium tank filled with is contacted with the adjacent low-water-side septic tank, and the lower surface of the contact filter medium tank is separated from the bottom of the septic tank, and the water flowing into the septic tank flows upward from the bottom of the contact filter tank and comes into contact therewith. It is installed so that it overflows from the top of the filter media tank to the adjacent low-water-level septic tank, and allows low-concentration contaminated water, such as rivers and lakes, to flow into the highest-water-level septic tank through the introduction gutter by overflowing. An apparatus for purifying low-concentration contaminated water, wherein water that has passed through a contact filter medium tank overflows into an outlet gutter, and is discharged to rivers, lakes and marshes through this outlet gutter. 2. A contact filter medium comprising a saddle-shaped flap, a plurality of hollow cylinders and blades protruding from both sides of the saddle-shaped flap, and a surface area per m ³ of 50 m ² / m ³ or more.
m ³ lower concentration contaminated water purification apparatus of claim 1 wherein per space ratio is a synthetic resin integrally molded product of 80% or more. 3. The low-pressure tank according to claim 1, wherein the plurality of septic tanks are formed by integrally providing a plurality of partition walls in a large water tank having a length corresponding to the arrangement length of the plurality of septic tanks. Concentration water purification equipment. 4. A plurality of septic tanks are arranged in a large water tank having a length corresponding to the arrangement length of the plurality of septic tanks, and a plurality of purification units (however, the purifying unit partitions the large water tank to form a septic tank. A partition plate, a contact filter medium tank fixed to an upper portion on one side of the partition plate, and a sludge receiver fixed to a lower end on one side of the partition plate). 3. The apparatus for purifying low-concentration contaminated water according to 1 or 2.