JPS63141698A - Biological reaction vessel for fixed bed type waste water treatment device - Google Patents

Abstract

PURPOSE:To prevent generation of clogging in a fixed bed by floating of deposited sludge by juxtaposing plural pieces of inverted V-shaped baffle plates at suitable spaced intervals in the transverse direction to the lower part of a biological reaction vessel thereby segmenting the fixed bed to a settling region and a concentrating region. CONSTITUTION:Plural pieces of the equilateral or scalene baffle plates 10 having the inverted V-shaped section and having discharge holes at the vertex or near the same are provided in the biological reaction vessel 1a in such a manner that the respective baffle plates 100 are paralleled in the transverse direction thereof, are partly overlapped via the spacings in the vertical direction and are fixed at both ends in the longitudinal direction to the inside wall in the lower part of the fixed bed 4 in the vessel 1a. The lower part of the fixed bed 4 is classified to the settling region 11 and the concentrating region 12 by such baffle plates 10. The sludge settling from the waste water admitted into the settling region passes the spacings between the baffle plates or the spacings between the baffle plates 10 and the inside surface of the vessel 1a. The respective baffle plates are so disposed that these spacings do not act as the passage for the sludge which deposits in the concentrating region then floats. As a result, the generation of the clogging in the fixed bed by floating of the deposited sludge is obviated.

Description

[Detailed description of the invention] [Technical field to which the invention pertains]

The present invention relates to the structure of a biological reaction tank used in a fixed bed treatment method for wastewater.

[Prior art and its problems]

There are two well-known methods for fixed bed wastewater treatment, one of which is the catalytic oxidation method in which wastewater is treated with a biofilm consisting of aerobic microorganisms grown on a carrier while supplying oxygen. The other method is the anaerobic fixed bed method, which uses a biofilm made of anaerobic bacteria to treat wastewater without supplying oxygen. For example, FIG. 2 shows a cross-sectional view of a main part of a conventional biological reaction tank using an anaerobic fixed bed method. In Figure 2, the inflow and direction of water flow are shown by solid arrows,
The direction of flow of generated gas is indicated by dotted arrows. To explain its function with reference to FIG. 2, first, wastewater flows into the biological reaction tank 1 through the central inflow pipe 2, reaches the sedimentation area 3 at the bottom of the biological reaction tank 1, which has a hopper shape, and is deposited here. A part of the suspended solids (hereinafter abbreviated as SS) are removed, and then, after passing through a fixed bed 4 (not shown in detail), it flows out from a waste water pipe 5 as treated water. The fixed bed 4 is made of plastic plates, crushed stones, etc. (not shown), and the wastewater is purified by the membrane of anaerobic microorganisms attached to the surface of these, but at that time, digestion gas is generated. The gas is exhausted from the exhaust pipe 6. The opening of the biological reaction tank 1 used for such wastewater treatment should be covered with M7 to prevent oxygen from the air from entering and dissolving. I am a connoisseur. At the bottom of the biological reaction tank 1 below the unilateral # area 3, SS in the wastewater and microorganisms detached from the fixed bed 4 accumulate as accumulated sludge 8. It is taken out as appropriate. Wastewater treatment using the conventional anaerobic fixed bed as described above is
There are major problems described below. One of them is that the accumulated sludge 8 floats to the surface, causing clogging of the fixed bed 4, which significantly reduces treatment efficiency. That is,
The microorganisms that are peeled off from the fixed bed 4 are anaerobic microorganisms that perform methane fermentation and generate digestive gas in the accumulated sludge 8, so that a part of the accumulated sludge 8 floats due to the buoyancy of the digestive gas bubbles. This causes clogging of the fixed bed 4 due to phenomena such as adhesion to the lower surface of the fixed bed 4 or penetration into the interior of the fixed bed 4 along with the flow of water. In order to prevent this phenomenon, the accumulated sludge 8 is frequently pulled out from the drawing pipe 9, but as the frequency of sludge drawing increases, the sludge drawn out becomes thinner, and the sludge that is removed in the subsequent process becomes thinner. It becomes difficult to process. The second problem is that when the flow rate of wastewater increases rapidly due to, for example, rainfall, the water flow in the settling area 3 is disturbed and stirs up the accumulated sludge 8, and some of the sludge that is rolled up can enter the inside of the fixed bed 4. This causes the fixed bed 4 to become clogged, leading to a decrease in processing efficiency. On the other hand, regarding the catalytic oxidation method, which is an aerobic treatment, a method of dividing the sedimentation RSS area into two by providing a perforated plate was developed in the Japanese Patent Publication Publication No. 57-42.
This method is described in Japanese Patent No. 551, and attempts to separate sludge from recycled water by dividing the lower part of the biological reaction tank into a sludge separation chamber and a settling chamber using a perforated plate. It is conceivable to apply this method to solve the above-mentioned problems in anaerobic fixed beds, but even though it is effective in aerobic fixed beds where sludge floats less,
For anaerobic fixed beds, it is highly likely that the floating sludge will reach the fixed bed through the holes in the perforated plate, or the perforated plate will become clogged, resulting in loss of its function. It cannot be adopted. Therefore, in fixed bed wastewater treatment, aerobic fixed bed,! ! In all cases of fixed-temperature beds, measures are desired to solve the above problems.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned points, and its purpose is to have the function of effectively separating SS in wastewater and microorganisms detached from a fixed bed from water, and to prevent the fixed bed from floating by floating the accumulated sludge. An object of the present invention is to provide a biological reaction tank for a wastewater treatment device that does not cause clogging.

[Key points of the invention]

The biological reaction tank of the fixed bed wastewater treatment equipment of the present invention has a plurality of baffles with an inverted V-shaped cross section arranged in parallel laterally below the fixed bed to separate the sludge into a settling slope and a concentration area. In the biological reaction tank, SS and exfoliated sludge easily progress from the settling area to the 1-contraction area along the walls of the baffle plates and through the gaps between the baffle plates, but the accumulated sludge does not move straight. By determining the mutual positional relationship of the baffles so that the baffles prevent the sludge from floating to the sedimentation area from the concentration area, it can simultaneously fulfill the role of solid-liquid separation ability and prevention of sludge floating. This made it possible.

[Embodiments of the invention]

The present invention will be explained below based on examples. FIG. 1 shows a sectional view of a main part of a biological reaction tank of a wastewater treatment apparatus according to the present invention, and is compared with FIG. 2, in which parts common to those in FIG. 2 are denoted by the same reference numerals. Similarly to FIG. 2, FIG. 1 also shows the flow of water with solid arrows and the flow of gas with dotted arrows. The biggest difference between FIG. 1 and FIG. 2 is that a plurality of funnel-shaped baffles 10 (inverted V-shaped baffles 10 are arranged in a narrow direction on the sloped part) in the biological reaction tank 1a, and the sedimentation slope 11 and γN
l'I? t@M region 12. The longitudinal directions of the plurality of boardworks 0 are parallel to each other, and both ends of each of the boardworks 0 are fixed to the inner wall surface of the biological reaction tank 1a. Next, the wastewater treatment process in the biological reaction tank 1a shown in FIG. 1 will be described. Wastewater is supplied from the outside to the biological reaction tank 1a through an inlet pipe 2a that passes through a part of the side wall of the biological reaction tank 1a and reaches the settling area 11 inside. The inflow pipe 2a is provided with a plurality of branched outflow ports 13 in the settling region 11, and the wastewater is gently settled from these outflow ports 13.
It flows into eJ area 11. Next, the wastewater slowly rises through the sedimentation area 11, but by setting the rising speed to about 10 to 20 m/day based on the ratio of the wastewater flow rate and the area of the sedimentation area 110, the SS settles in the sedimentation IQ IN area 11. ,
Furthermore, the microorganisms separated from the fixed bed 4 also settle. In this way, good solid-liquid separation is performed in the sedimentation region 11, and treated water with a low SS concentration is obtained, and after being subjected to biological treatment in the fixed bed 4, the treated water is discharged from the waste water pipe 5. The settled solids first reach the inner surface of the inclined part of the biological reaction tank 1a and the outer peripheral surface of the inverted V-shaped baffle plate 10, and then slide down along these surfaces, causing interference between the baffle plate 10 and the baffle plate 10 and the living organisms. It passes through the gap formed with the reaction tank 1a and enters the concentration region 12. Here, the apex angle α of the inverted V-shaped baffle plate 10 and the inclination angle β of the funnel-shaped inclined part of the biological reaction tank 1a are both approximately 60'' with respect to the floor surface, so that the baffle plate 10 Also, between the baffle plates 10, the sludge is prevented from accumulating on the slope of the biological reaction tank 1a.
Each baffle plate 10 is arranged so that the gap between the baffle plate 10 and the inclined part of the biological reaction tank 1a is approximately 100 fi at the narrowest point.
to prevent settling sludge from clogging the gaps. On the other hand, the solid content that settles into the concentration area 12 is transferred to the biological reaction tank 1a.
The accumulated sludge 8 that collects at the bottom of the pipe is pulled out from the drawing pipe 9, but as mentioned above, the accumulated sludge 8 is removed by the generation of digestion gas.
Some of them may surface. At this time, the inverted V-shaped baffle plates 10 are made of equilateral ones and unequal sided ones, and by arranging them in combination, the sludge that floats straight up will definitely collide with the inner surface of the baffle plate 10 and be captured, and no more Each baffle plate 1 so that it does not rise
It is necessary to determine the positional relationship of 0. That is, the gap between the baffle plates 10 described above is formed with an overlapping margin of about 150 fl in some parts. The sludge thus captured by the baffle plate 10 will eventually settle. In this process, air bubbles in the floating sludge grow and become larger over time, and due to the deaeration effect in which the grown air bubbles are pulled out of the sludge due to buoyancy, the sludge captured by the baffle plate 10 is reused. It settles. Moreover, since not much sludge floats up from the accumulated sludge 8, a large amount of sludge does not accumulate inside each baffle plate 10. Digestion gas bubbles extracted from the floating sludge need to be removed outside the equipment system, so holes (not shown) with a diameter of about 100mm are inserted near the apex of each inverted V-shaped baffle plate 10. It is effective to open one or two of them every day. Although there is a possibility that some of the accumulated sludge 8 may rise from this hole, since the diameter of the holes is small and there are few, there is almost no negative effect on wastewater treatment. However, when the flow of wastewater increases rapidly due to rainwater, for example, the water flow in the sink area 11 becomes turbulent, and the solid-liquid separation characteristics become slightly worse than normal. This disturbance of the water flow is blocked by the baffle plate 10, so that it does not reach the 1-contraction region 12. Therefore, the accumulated sludge 8 is not rolled up due to turbulence of water flow. As the material for the baffle plate 10 that plays this role, it is suitable to use, for example, a processed material such as plastic or iron plate coated with FRP, and the size and quantity will depend on the strength of the material and the volume of the biological reaction tank 1a. It is better to decide by filling in such things. In this embodiment, the inflow pipe 2a is connected to the external biological reaction tank 1.
Although it has been described as having a structure that penetrates the side wall of the sediment B S1 area 11 in a, the biological reaction tank 1 is
It is also possible to provide the baffle plate 10 for a structure in which the pipes are piped from the upper part of the pipe through the fixed bed 4, and the same effect can be obtained. The number of branches at the outlet 13 on the 2nd day of the inflow pipe is:
It may be determined as appropriate in relation to the size of the biological reaction tank 1a and the baffle plate 10. As mentioned above, the workability of the present invention has been described with reference to drawings regarding a biological reaction tank using an anaerobic fixed bed for convenience in theory UA (7). The same effect can be obtained even if the method is applied to a biological reaction tank using a bed.

【Effect of the invention】

In the biological reaction tank of a fixed-bed wastewater treatment device, the fixed bed is clogged due to the resurfacing of the sludge that has accumulated at the bottom or the lifting up of accumulated sludge due to an increase in the flow rate of wastewater, which reduces wastewater purification efficiency. While there was a problem of letting
As explained in the embodiment, in the present invention, a plurality of inverted V-shaped baffles are installed in parallel in the lower part of the biological reaction tank with appropriate gaps in the width direction to divide it into a sedimentation area and an illumination area. Therefore, the wastewater flowing into the biological reaction tank undergoes solid-liquid separation in the sedimentation area, and the sludge settles in the concentration area. It is less likely to reach the fixed bed because it is obstructed by the plate, and the fixed bed will not be clogged. In addition, even when the amount of wastewater increases rapidly due to rain, etc. and turbulence occurs in the water flow in the biological reaction tank, the turbulence in the water flow is blocked by the biological reaction tank and occurs only in the settling area, so that the accumulated sludge is There is no possibility that it will be rolled up and reach the fixed bed, thereby clogging the fixed bed. That is, by using the septic tank of the present invention, even if the accumulated sludge floats up, the fixed bed will not be clogged, thereby increasing treatment efficiency and making it possible to obtain high-quality treated water.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a biological reaction tank according to the present invention, and FIG. 2 is a sectional view of a main part of a conventional biological reaction tank. 1, la: biological reaction tank, 2.2a: inflow pipe, 3, 11:
Sedimentation area, 4: Fixed bed, 5: Waste water pipe, 6: Exhaust pipe, 7:
Lid, 8; Accumulated sludge, 9; Drawing pipe, 10; Baffle plate, 12:
Concentration area, 13: Outlet. /, □″− ↓ Figure 1 (.

Claims (1)

[Claims] 1) A funnel-shaped biological reaction tank for wastewater treatment equipment equipped with a fixed bed, in which the biological reaction tank has an inverted V-shaped cross section and an equilateral and scalene shaped biological reaction tank having an exhaust hole at or near the apex angle. A plurality of baffle plates are arranged in parallel in the width direction of the baffle plates, and in the vertical direction, they partially overlap with gaps in between, and in the longitudinal direction, both ends are fixed to the inner wall below the fixed bed in the biological reaction tank. The area below the fixed bed is divided by plates into a settling area and a concentration area, and the sludge that settles from wastewater flowing into the settling area passes through the gaps between the baffles or the gap between the baffles and the inner surface of the biological reaction tank. A biological reaction tank for a fixed-bed wastewater treatment device, characterized in that each baffle plate is arranged so as not to serve as a passage for sludge that floats up after being deposited in a concentration area.