JP2564131B2 - Surface aeration immersion filter bed water treatment device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a surface aeration immersion filter bed water treatment device used for a catalytic oxidation method in a fixed contact method, which is a type of biological treatment method. Here, the catalytic oxidation method is to arrange a plurality of immersion filter beds for implanting biota (microbial membrane) in the treatment tank,
This is a kind of biological treatment method for wastewater in which water is circulated through the gap of the submerged filter bed by surface aeration.

<Prior Art> Conventionally, as a water treatment apparatus of the above-mentioned type, for example, there is one described in Japanese Patent Publication No. 58-54638.

A water turbine is rotatably fixed to the upper part of the treatment tank, and a circulation partition plate with an open lower part is provided from just below the water scraping member of the water turbine to the entire width of the treatment tank, just below the water scraping member of the water turbine. By providing a circulating partition plate whose lower part is opened over the entire width of the treatment tank, the water level is adjusted to a position where a part of the water scraping member of the water turbine is submerged, and at least one of the circulation partition plates is rotated by the rotation of the water turbine. It has a configuration in which a submerged filter bed is arranged on the side.

Then, the immersion filter bed was filled or formed with a contact material such as Raschig rings, net-like synthetic resin short tubes, and pebbles (crushed stones).

<Problems to be Solved by the Invention> However, as a result of examination by the present inventors, it has been found that the water treatment device is likely to cause the following problems.

The microbial membrane grows and expands so as to cover the small particles in the contact bed, the water channel is narrowed due to the expansion, and floating substances and peeled sludge are accumulated in the gaps between the small particles. However, the entire filter bed is integrated into a large lump, and the filter bed is easily clogged. For this reason, the raw water does not pass through the immersion filter bed as it is, but flows out through a short path, and corrosion may occur at a place where the water flow does not occur, which may worsen the water quality.

Therefore, it is necessary to wash the filter bed from time to time because sufficient treatment cannot be performed unless the blockage of the immersion filter bed is eliminated. This cleaning operation is more difficult the thicker the bed of the filter bed. Further, when washing is performed, there is a risk that the microbial membrane that has been implanted on the corner may be peeled off. Then, when the microorganisms have been peeled off, it takes a while until a new microorganism adheres, and during that time, the biological treatment effect decreases.
When it improves, the filter bed becomes blocked again.

Thus, the filter bed is repeatedly clogged and the microbial film is peeled off, which is stable in quality and quantity, making it difficult to obtain treated water.

There is a filter bed having a honeycomb structure. However, when trying to increase the contact area per volume and using a honeycomb having a small diameter, the flow is likely to be laminar, and it is difficult for the microorganisms to land only near the inlet and outlet of the upper and lower portions of the honeycomb. Further, the contact efficiency is good, and if it is too small, it tends to be blocked. When a honeycomb having a large diameter is used in order to improve the landing on the contact bed to generate turbulent flow, the larger the diameter, the smaller the contact area per volume. Therefore, it is difficult to obtain a filter bed having a honeycomb structure with a large processing capacity per volume.

In view of the above, an object of the present invention is to provide a surface aeration immersion filter bed water treatment apparatus in which clogging of the filter bed is unlikely to occur and the contact area per volume can be increased.

<Means for Solving the Problems> The present invention solves the above problems by the following configurations.

In the surface aeration immersion filter bed water treatment device used in the catalytic oxidation method in the fixed contact method, which is a type of biological treatment method, a water wheel is fixed rotatably horizontally to the upper part of the treatment tank, and From the lower part toward the lower part of the processing tank, a circulation partition plate whose lower part is opened over the entire width of the processing tank is provided, and the water level is adjusted so that a part of the water scraping member of the water wheel is submerged. The rotating partition is configured to generate a circulating flow at the boundary, and a plurality of immersion filter beds are arranged on at least one side of the circulating partition plate, and the immersion filter bed has a flat mesh tube as a main element. It is characterized in that a plurality of floor elements are formed upright.

<Examples> A. Examples of the present invention will be described below with reference to the drawings.

(1) FIGS. 1 to 3 show an embodiment of the present invention.

A water turbine 3 is fixed to the upper part of the treatment tank 1, and a circulation partition plate 2 whose lower portion is opened over substantially the entire width of the treatment tank 1 from just below the water scraping member 6 of the water turbine 3 toward the bottom of the treatment tank 1. Is provided. Here, the lower part of the circulation partition plate 2 is usually opened from the bottom of the processing tank by 1 of the vertical length of the circulation partition plate.
It is formed with a gap of about 30%.

Then, the water level is adjusted to a position where a part of the water scraping member 6 of the water wheel 3 is submerged, and the rotation of the water wheel 3 causes a circulation to be generated with the circulation partition plate 2 as a boundary.

A backflow prevention plate 8 is installed in the gap between the water wheel 3 and the side wall of the water tank 1. The water scraped out by the water scraping member 6 by the rotation of the water wheel 3 in the direction shown by the arrow 19 is prevented from flowing back from the gap between the water wheel 3 and the side wall of the water tank 1 due to the presence of the backflow blocking plate 8. . In the slight gap between the lower part of the water wheel 3 and the upper end of the circulation partition plate 2, the water is pushed out sequentially by the scraping member 6 due to the rotation of the water wheel 3, so that the water does not flow backward.

Therefore, the water level on the scraped side of the water wheel 3 rises, the water level on the scraped side falls, and the scraped water returns through the bottom opening of the diversion partition plate 2 and the inside of the treatment tank 1 Circulation 7 is generated.

In the figure example (especially Fig. 1), 9 is a water level adjustment overflow pipe,
10 is a treated water outlet pipe, 11 is a raw water inlet pipe, 12 is a sludge sedimentation part,
13 is a sludge pipe, 14 is a turbine rotation shaft, and 15 is a motor.

(2) The immersion filter bed 4 is arranged on one side of the circulation partition plate 2. The immersion filter bed 4 comprises a plurality of contact floor plates (plate-shaped filter bed elements) 4a having flat net tubes (see FIG. 7) as main elements, arranged in parallel with the circulation partition plate 2 (aligned vertically). )It is configured. As shown in FIG. 4, the circulating partition plate 2 may be orthogonal to each other so as to stand side by side.

(3) Further, the position where the submerged filter bed 4 is installed in the treatment tank 1 is
It is not limited to the above embodiment.

In FIG. 5, both sides of the circulation partition plate 2 are used as the impregnated filter bed 4. This device is suitable for treating relatively low concentration wastewater.

In FIG. 6, two sets of the water turbine 3 and the circulation partition plate 2 are installed on both sides of the treatment tank 1, and the immersion filter bed 4 is provided between the pair of circulation partition plates 2. This device is suitable for high-concentration wastewater treatment requiring a large amount of aerated circulation 7.

(4) The flat mesh tube 5 is a mesh wire depending on the sewage load.
You can freely choose from 16 thin to thick ones, small stitches to coarse stitches. Especially if the resin net is 1
Even if it breaks in several places, it will not conduct electricity, and it is also very strong, and is used as a net for retaining sand. Further, in the flat mesh tube 5, the water flow can pass through the mesh in any direction in all directions, which contributes to an increase in contact efficiency.

The flat mesh tube 5 is usually extruded from an olefin resin such as polyethylene or polypropylene. The flat net tube 5 is superior to other net-like objects (cylindrical net tube, fishing net, net sheet, etc.) in manufacturing, strength, material usage amount, cost,
It has excellent overall balance in terms of the surface to be processed into the contact floor plate 4a (or 4b), the contact area during use, the adhesion of microorganisms, and the like.

That is, since the flat mesh tube 5 can be mass-produced by extrusion molding and the mesh is doubled, even if the wire 16 is thin, it has strength, good contact efficiency and adhesion of microorganisms, and high concentration treatment from low concentration wastewater. Can be widely used up to. In addition, since the contact floor plates 4a (or 4b) are formed by a plurality of flat mesh tubes (contact floor elements) 5 that are separate from each other, they move flutteringly due to the water flow and water pressure. Then, even a slight movement thereof is expected to increase the contact efficiency against microorganisms.

As the flat mesh tube 5, the specification is a mesh tube width of 5 to 20 cm,
The net wire 16 has a thickness of 0.5 to 2 mm, a net tube thickness of 5 to 15 mm, and a stitch size of 3 to 15 mm.

(5) Next, various aspects of the contact floor plate 4a (or 4b) will be described.

As shown in FIG. 8, a flat mesh tube 5 is attached to the contact floor support frame 17.
Is a contact floor plate 4a which is attached at regular intervals.

As shown in FIG. 9, the flat bed tube 5 is provided on the contact floor support 7.
Is a contact floor plate 4a attached to vertical and horizontal plovers.

What is shown in FIG. 10 is a suspended contact floor plate 4b in which flat mesh tubes 5 are attached to the contact floor bars 18a and 18b at regular intervals.

What is shown in FIG. 11 is a suspended contact floor plate 4b in which flat mesh tubes 5 are attached to vertical and horizontal plovers on the contact floor rods 18a and 18b.

The contact floor plate 4a is formed by fixing the four ends of the flat mesh tube 5 to the support frame 17 with a holding plate and screws, winding the support frame 17 and adhering it, or using a string-like object such as a wire on the support frame 17. It can be fixed by knitting.

The suspended contact floor plate 4b is formed by folding back the upper and lower ends of the flat mesh tube 5 so as to wind around the upper contact floor bar 18a and the lower contact floor bar 18b and bonding the contact portions or knitting with a wire-like string. They may be tied together or fixed with a holding plate and screws. The lower contact floor bar 18b also serves as a weight.

And, this suspended contact floor plate 4b, as shown in FIG.
The notch portions 27 formed at both ends of the upper contact floor bar 18a of the suspension contact floor plate 4b are engaged with the slits 21 formed in the suspension frame 20 so as to be suspended from the suspension frame 20 for use.

In addition, the contact floor support frame 17, the suspension frame 20, the contact floor bars 18a, 18b
The material made of iron or stainless steel is easy to process, has strength, and is inexpensive.

(6) Next, a method for forming a submerged filter bed using the contact floor plates 4a and 4b will be described.

When forming the immersion filter bed 4 with the contact floor plate 4a, the contact floor plate
Although it may be fixed to the processing tank with screws or the like on 4a,
Attach the slide frame 22 to the processing tank 1 as shown in FIG.
The method of dropping and fitting the contact floor plate 4a is simple.

Further, when forming a submerged filter bed with the suspended contact floor plate 4b,
As described above, a number of hanging contact floor boards 4b are hung.
The suspension frame 20 shown in FIG. 12 may be supported by a receiving support 24 attached to the processing tank 1 as shown in FIG.

Then, the interval between the contact floor plate 4a or the suspended contact floor plate 4b is selected to be 30 to 100 mm according to the load of the water to be treated, that is, the contact area load. That is, in the case of low-concentration wastewater treatment, the contact area load is small and a large contact area is required. Therefore, a flat mesh tube 5 with a fine mesh is used and the contact floor plate 4 is used.
Install with the space between a and 4b narrowed. In addition, since the contact area load can be increased if the treatment is performed at a high concentration, the mesh may be rough or the distance between the contact floor plates 4a and 4b may be wide.

(7) Furthermore, the fourteenth aspects of the water turbine that can be used in the present invention are described.
~ Figure 16 shows.

FIG. 14 shows that the water scraping member 6 has a plate shape,
FIG. 15 shows that the water scraping member 6 has a tubular shape.
FIG. 16 shows a comb-shaped member 6 in which the water scraping member 6 is radially projected.

B. Next, the mode of use of the above embodiment will be described.

The present invention is a low-speed rotation (peripheral speed 30 ~ 60m / min) energy-saving water turbine 3
As a result, a large amount of water is scraped out over the entire length of the scraping member 6 of the water wheel 3, and a large amount of aerated swirl 7 is generated at the boundary of the swirling partition plate 2 to cause catalytic oxidation.

Since it does not have a circular arc partition plate as in Japanese Patent Publication No. 58-54638, the large circulation flow can be obtained with a small power as compared with the circulation according to the publication. Therefore, the amount of circulating water is large, and the dead space of the submerged filter bed 4 is relatively small, and the contact efficiency with respect to the microorganisms is improved accordingly.

Further, if a perforated plate or a perforated pipe having a large surface area is used for the scraping member 6 of the water wheel 3, a thin water film may drip on the surface of the scraping member 6 or may be exposed to air due to the rotation. Oxygen dissolves in water. Conversely, when exposed to volatile organic substances in water, the action of displacement is emitted into the air. Thus, it becomes possible that aeration with a water turbine cannot occur with aeration with a blower or compressor.

In the case of the existing treatment tank 1, after dropping and fixing the circulation partition plate 2 that matches the tank, install the water turbine 3 on the upper part and drop the contact floor plate 4a, or drop the suspended contact floor plate 4b through the suspension frame 20. By hanging it up, the existing treatment tank 1 can be easily modified. In particular, the modification of the standard activated sludge method can remarkably save energy compared to blower aeration. Since it is catalytic oxidation by the flat mesh tube 5, the aerated stream 7 promotes both aerobic digestion and anaerobic autolysis, and excess sludge is greatly reduced inside the implanted microbial (aerobic) membrane. Therefore, the amount of treated water can be greatly increased.

In the flat mesh tube 5 of the contact floor plates 4a (4b) in the very large number of the immersion filter beds 4, the film thickness of the microbial membrane increases, oxygen is not supplied to the inside, and it is inactivated to cause spontaneous peeling over time. Oxygen is supplied to the areas separated by the circulation 7 in a good aeration state over the entire area, and new microorganisms are immediately implanted. Therefore, there is almost no change in water quality due to natural exfoliation of the microbial membrane, and the immersion filter bed 4 of the treatment tank 1 is always qualitatively and quantitatively stable because the microbial environment is always kept in a natural condition under constant conditions. Water treatment is possible, and there is no need for artificial washing or the like.

As shown in FIG. 17, by deepening the processing tank 1 and lengthening the circulating partition plate 2, a large-capacity deep shaft type processing tank with a small installation area can be manufactured. This is very useful where there is no space. In this water treatment device, when trying to treat high-concentration sewage, when the number of water turbines installed is limited due to the installation space and the aerated circulation amount 7 seems to be insufficient even if the rotation speed of the water turbine 3 is increased. Does the auxiliary aeration with the air diffuser 25 on the side where the submerged filter bed 4 is not installed as shown in the figure, and /
Alternatively, the circulation circulation pump 26 may be installed, and the side where the water is being scraped by the water turbine 3 may be sprinkled and aerated. As the circulation pump 26, a large water pump with a low head such as a submersible propeller pump or a vertical pump is desirable because it is an energy-saving type and has a large discharge amount.

<Operation and Effect of the Invention> The surface aeration-immersed filter bed water treatment apparatus of the present invention has the above-described configuration, so that clogging of the filter bed is unlikely to occur and the contact area per volume can be increased.

That is, since the contact floor plate (filter bed element) has a flat mesh tube as a main element, the contact area per volume is very large, and even if the immersion filter bed is installed in a small treatment tank, the contact area is large, Since the circulation by the water turbine has a good aeration state, it can be designed much more compact than other treatment tanks.

Further, since the filter bed element (contact floor plate or suspended contact floor plate) is installed in the circulating water channel of the treatment tank at regular intervals, no obstruction obstacle can occur in the entire immersed filter bed. Furthermore, the water extruded by the scraping member of the water wheel will always have a pulsating flow,
The filter bed element is shaken by the pulsating flow to enhance the contact efficiency between microorganisms and wastewater.

Further, when the microbial membrane increases, almost no oxygen is supplied to the inside and the microorganisms (aerobic) are not activated and weakened, but the activation of facultative anaerobic bacteria is increased and the digestion of sludge is promoted. As a result, the lumps become larger than the mesh of the flat mesh tube, spontaneous peeling occurs, settles between the filter bed elements, and settles in the sludge settling section. Therefore, it is not necessary to wash the submerged filter bed, and the excess sludge in the settling section may be periodically discharged through the sludge pipe. Then, due to the good circulation of the aerated state over the entire area, oxygen is satisfactorily supplied, and new microorganisms are immediately implanted where the microbial membrane is peeled off.

There is almost no change in water quality due to natural exfoliation of the microbial membrane, and the immersive filter bed in the treatment tank always maintains the microbial environment in a natural condition under constant conditions, so qualitatively and quantitatively stable water treatment is always possible. Moreover, there is no need to add artificial washing or the like. In particular, the aeration effect is enhanced by saving energy, and the contact efficiency with microorganisms by the circulation of a large amount of water is also enhanced.
Since it can be used for tall and deep processing tanks that do not occupy an installation area, it is more effective in Japan where there is little land.

[Brief description of drawings]

1 is a sectional view taken along the line BB of FIG. 2 showing an embodiment of the device of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a plan view of FIG. FIG. 4 is a plan view of a modification of the embodiment of FIG. 1, a sectional view showing another example of the device of the present invention shown in FIG. 5, and FIG. 6 is a sectional view showing a further example of the device of the present invention. FIG. 8 is a perspective view of a flat mesh tube used for the contact floor plate of the present invention, FIG. 8 is a front view showing an example of the contact floor plate of the present invention, FIG. 9 is a front view showing another example thereof, and FIG. A front view showing an example of the vertical contact floorboard of the invention, FIG. 11 is a front view showing another example of the same, FIG. 12 is a perspective view of a submerged filter bed in which a suspension contact floorboard is hung on a contact floor suspension frame, The figure is a cross-sectional view showing an example of the device of the present invention using a suspended contact floor plate, FIG. 14 is a perspective view showing an example of a water turbine used in the present invention, and FIG. 15 is a perspective view showing another example of the same. Figure 16 is a perspective view showing still another example also, FIG. 17 is a cross-sectional view showing an example in which a longer circumfluence partition plate in the apparatus of the present invention. 1 ... Treatment tank 2 ... Circulating partition plate 3 ... Water turbine 4 ... Immersion filter bed 4a ... Contact floor plate (plate filter bed element) 4b ... Suspended contact floor plate (plate filter bed element) 5 ... Flat Net tube 6 …… Scraping member 7 …… Circulation

Claims (1)

(57) [Claims] 1. In a surface aeration submerged filter bed water treatment device used in a catalytic oxidation method in a fixed contact method, which is a kind of biological treatment method, a water turbine (3) can be horizontally rotated above a treatment tank (1). Fixed to the water tank (3), and the lower part of the water scraping member (6) of the water turbine (3) is directed toward the lower part of the processing tank (1), and the lower part is opened over the entire width of the processing tank (1). A plate (2) is provided, the water level is adjusted to a position where a part of the water scraping member (6) of the water turbine (3) is submerged, and the circulation partition plate (2) is rotated by the rotation of the water wheel (3). The dipping filter bed (4) is arranged on at least one side of the diversion partition plate (2), and the dipping filter bed (4) mainly comprises the flat mesh tube (5). A plurality of plate-shaped filter bed elements (4a), which are the base, are formed by arranging them in parallel. Surface aeration submerged biofilter water treatment device according to symptoms.