JPH04349903A - Method and apparatus for treating waste water - Google Patents

Abstract

PURPOSE:To treat waste water within a short time without using a chemical agent by introducing foamable waste water into a pipeline provided with a mechanical defoaming means and controlling the flow velocity of the waste water in the pipeline to the diameter of the pipeline. CONSTITUTION:The raw water pumped up by a pump 21 is sent in a rotary contact mechanism tank 1 through a weighing tank 8. The excessive water from the weighing tank 8 and a part of the treated water from the rotary contact mechanism tank 1 are returned to the reflux pipe 22 provided on one side of a flow control tank 2. The raw water being waste water is introduced into a raw water tank 3 from a pipeline 30 but a partition wall 31 is arranged to the intermediate part of the raw tank 3 and a connect ion port 32 is provided to the bottom part of said wall 31 to sucessively transfer the raw water to the downstream demarcated chamber 33 of the raw water tank 3. The pumped-up raw water is sent to a screen 9 and a separated solid is received in a receiver 91 but water is supplied to one side of the flow control tank 2 and the raw water adjusted in its flow rate in the weighing tank 8 is led out in a constant water level to be sent to the rotary contact mechanism tank 1 by a connection pipe 81.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a wastewater treatment method and apparatus, and aims to provide a method and apparatus capable of efficiently treating various types of industrial or domestic wastewater with foaming properties using relatively compact equipment. It is something.

0002

[Prior art] Wastewater generated from food processing, dairy industry, cosmetics manufacturing, broilers and livestock farming, meat processing or hydrochloric acid processing, pickle manufacturing, school lunch centers, hotels, hospitals, restaurants, drive-ins, etc., photographic development, scouring dyeing, etc. Regarding various types of wastewater generated from garbage treatment and leaching processes, it is essential to treat the wastewater to remove organic components and other substances in order to prevent environmental pollution.

[0003] In other words, such wastewater is the main cause of water pollution in rivers, lakes, and sea areas, and since such wastewater is generated by the above-mentioned companies, the companies themselves are considered to be a social sin. Various equipment and methods have been developed and proposed for the purpose of treatment, but treatment methods using microorganisms are preferred in terms of cost, size of equipment, and post-treatment treatment. be. In other words, purification is carried out using aerobic fungi, which is the most natural method and does not require any special treatment agents.Therefore, after treatment, it can be simply separated by sedimentation and released.

The above-mentioned treatment methods include activated sludge method, aeration lagoon method, contact aeration method, etc., but all of them generally require at least several hundred m2 of equipment, so it is more efficient to use relatively compact equipment. As a method for purification in a targeted and efficient manner, it is recommended to
9) and Jitsukai Sho 61-33696 (Jitsuhei 1-23594
) have been announced.

[0005]

[Problems to be Solved by the Invention] It is clear that each of the conventional wastewater treatment techniques described above has its own merits, especially the above-mentioned Utility Model Publication No. 1-16559 and Utility Model Publication No. 1-235.
94 allows for vigorous growth of microorganisms and achieves efficient purification despite low operating costs; however, in recent years, the concentration of BOD and other components in the wastewater has gradually increased. As a result, it has been observed that it is difficult to necessarily obtain the desired treatment results, and this is the same in wastewater treatment by other methods.

In other words, food-related wastewater is likely to be contaminated with viscous organic components such as water-soluble proteins or starch, and other wastewaters are also contaminated with viscous components, and these viscous components Foaming tends to occur, especially when water-soluble proteins are organically decomposed, resulting in extreme foaming development. This bubbling phenomenon blocks the contact between the still water surface of the wastewater and the atmosphere, which reduces the amount of dissolved oxygen in the water that is replenished via the still water surface, and reduces the amount of microorganisms in the wastewater that take in the dissolved oxygen and proliferate. Growth is inhibited.

[0007] As the amount of dissolved oxygen decreases as described above, even the growth of anaerobic fungi is eventually observed, and the growth and proliferation of aerobic fungi is severely inhibited, and it is not easy to improve such a situation. Therefore, antifoaming agents and the like must be added to deal with the problem, but such agents need to be added continuously, and using such agents requires low-cost treatment using microorganisms. The intended technical purpose of water discharge is greatly hindered, and treatment for discharge is also required.

[0008] The conventional general methods as described above do not have sufficient processing efficiency. In other words, the BOD volumetric load is an index for determining the capacity of such wastewater treatment equipment, and it is the BOD load amount (kg-BOD/day) expressed as a unit of volume (kg-BOD/m3・day). However, in the conventional standard activated sludge method and catalytic oxidation method, this BO
The D loading amount is about 0.35 to 0.8 kg-BOD/m3・day, and even in the rotating disk method and biofilter method, which are considered relatively high, the maximum D load is 3 kg-BOD/m
3 days, and the processing efficiency is low.

[0009] Furthermore, this general method is expensive in processing cost. In other words, it is essential to supply oxygen and utilize the action of aerobic microorganisms in this type of wastewater treatment equipment, and the cost for this oxygen supply is determined by the amount of oxygen transferred per unit of electricity (KWH) (kgO2/KWH). However, except for the ultra-deep aeration method and surface aeration method, it is 0.5 to 1.8 kgO2/KW.
Moreover, since the ultra-deep aeration method involves constructing an aeration tank with a water depth of 80 m or more, it requires an earthquake-resistant structure and is extremely expensive, while the surface aeration method is extremely expensive due to noise, droplets, and bubbles. There are disadvantages such as secondary pollution caused by scattering, and in the end, a method with a low oxygen transfer rate has to be used, which inevitably results in a huge processing cost.

[0010] In contrast to such conventional methods, the above-mentioned Jikkō 1-16559 and Jikkō 1-235 by the present inventors
Since the method according to No. 94 can achieve highly efficient treatment in stages and can be operated at low cost with extremely compact equipment, its performance is at its limit. Moreover, in actual operation, there are great demands for higher efficiency and lower costs, and for wastewater treatment, it is important to promptly meet these demands in order to prevent environmental pollution.

[0011]Furthermore, in such wastewater treatment, it is unavoidable that the odor peculiar to each type of wastewater is generated, and as a result, the installation location of wastewater treatment equipment must be restricted, and as the treatment progresses, bubbles are generated. This cannot be avoided, and the generation and release of foul odors along with the generation of foam cannot be avoided in this type of treatment.

0012

[Means for Solving the Problems] The present invention has been devised after repeated studies in view of the above-mentioned actual circumstances, and includes a simple structure in the pipe line for introducing the wastewater into the treatment tank. By setting up a mechanism, we were able to appropriately suppress encapsulation and defoaming in the passing wastewater, and by improving the rotating contact mechanism and other parts that are the main body of the purification process, we succeeded in effectively and accurately performing the wastewater treatment. The details are as follows.

(1) Foaming wastewater is introduced into a conduit provided with a mechanical defoaming means, and the flow rate of the wastewater in the conduit is controlled in accordance with the pipe diameter. Wastewater treatment methods.

(2) Foamy wastewater to be treated is introduced into a rotary contact mechanism tank to bring about gas-liquid contact through the rotation of a rotating body, and then introduced into an aeration tank for aeration treatment, and this rotary contact treatment is also carried out. A part of the liquid is circulated and supplied to the rotary contact mechanism tank, the aerated liquid from the aeration tank is subjected to sedimentation treatment, separated into sludge and treated water, and defoamed in the foaming wastewater introduction system to the rotary contact mechanism tank. The above-mentioned (
The wastewater treatment method described in section 1).

(3) A plurality of rotating bodies made of synthetic fibers fastened together in an irregular loose shape and formed into plate shapes are arranged in a row,
These rotating bodies are partially immersed in the wastewater stored in the rotary contact mechanism tank and rotated, and the wastewater in the rotary contact mechanism tank is aerated by blowing air or other oxygen-containing gas, and the wastewater is removed from the rotary contact mechanism tank. The waste liquid is received in an aeration tank and subjected to aeration treatment again by blowing oxygen-containing gas, the intermediate liquid in the aeration tank is led to a sedimentation tank and separated by sedimentation, and the precipitated solid content is pumped out to a sludge tank. A wastewater treatment method characterized by discharging supernatant liquid as treated water.

(4) A rotary contact mechanism tank having a rotary contact mechanism in which multi-stage rotating plates are arranged has a pipe system for introducing the waste liquid to be treated from the raw water tank, and a mesh material is provided in the pipe system. 1. A wastewater treatment apparatus, characterized in that defoaming means arranged in multiple stages are provided, and a pressure pump is provided in a raw water tank or a regulating tank provided between the raw water tank and a rotating contact mechanism tank.

(5) A liquid volume adjustment tank and a measuring tank are provided between the raw water tank and the rotating contact mechanism tank, and the liquid volume adjustment tank is provided with a mechanism for blowing oxygen-containing gas such as air, and at the bottom of the flow rate adjustment tank. A lifting mechanism is provided to transfer the liquid in the adjustment tank to the measuring tank,
A wastewater treatment device characterized in that a pipe line is provided to constantly supply wastewater from the measuring tank to the rotating contact mechanism and return excess water to the liquid volume adjustment tank.

(6) An aeration tank and a settling tank are arranged in the rotary contact mechanism tank, and a lead-out pipe opened at the middle part of the aeration tank is opened into a compartment provided in the settling tank, and the outlet pipe is opened at the bottom of the aeration tank. A wastewater treatment device characterized in that a branch blowing pipe for blowing the gas into a slurry lifting pipe opened at the bottom of the sedimentation tank is connected to a gas supply pipe for the provided oxygen-containing gas blowing mechanism.

(7) Items (4) to (6) above, characterized in that a wastewater storage area is formed at the bottom of the rotary contact mechanism tank, and an aeration mechanism connected to a blower is provided in the wastewater storage area. The wastewater treatment device according to any one of the above.

(8) Any of the items (4) to (7) above, characterized in that the rotating contact mechanism tank is divided into multiple stages by providing a partitioning member, and the wastewater is sequentially passed through the divided regions. The wastewater treatment device described in the above.

(9) The above-mentioned method, characterized in that two or more sets of defoaming means each consisting of mesh material arranged in multiple stages at intervals of 2 to 5 mm are provided in the conduit at intervals of 0.5 to 3 m. (4
) to (8) The wastewater treatment device according to any one of the items.

[0022]

[Operation] By introducing foaming wastewater into a pipe line provided with a mechanical defoaming means, and controlling the flow rate of the wastewater in the pipe line according to the pipe diameter, a special antifoaming agent can be created. To eliminate foam under conditions that require almost no cost by utilizing the process of introducing wastewater into a wastewater treatment system or transferring wastewater within the wastewater treatment system, without employing complicated means for defoaming.

The foaming wastewater to be treated is introduced into a rotary contact mechanism tank to bring about gas-liquid contact through the rotation of a rotating body, and then introduced into an aeration tank for aeration treatment, and one of the liquids subjected to the rotary contact treatment is The aerated liquid from the aeration tank is subjected to sedimentation treatment to be separated into sludge and treated water, and the defoaming treatment is carried out in a foaming wastewater introduction system to the rotary contact mechanism tank. This allows for appropriate defoaming mainly in the rotating contact mechanism tank.

[0024] A plurality of rotating bodies made of synthetic fibers fastened in an irregularly loosened shape and formed into plate shapes are arranged in a row, and these rotating bodies are partially immersed in wastewater stored in a rotating contact mechanism tank and rotated. At the same time, the wastewater in the rotating contact mechanism tank is aerated by blowing air or other oxygen-containing gas to achieve gas-liquid contact using the irregular loose fastening structure made of synthetic fibers and the accompanying oxygen supply to the wastewater. Moreover, by blowing air or other oxygen-containing gas into the wastewater in the rotary contact mechanism tank, oxygen is supplied to the wastewater, and aerobic microorganisms are actively grown and propagated.

[0025] By receiving the waste liquid from the rotary contact mechanism tank as described above into the aeration tank, performing aeration treatment by blowing oxygen-containing gas again, and returning a part of the waste liquid to the rotary contact mechanism tank, The microorganisms in the returned wastewater act as seed crystals for wastewater treatment in the rotary contact mechanism tank, thereby promoting their growth and propagation.

[0026] The intermediate liquid in the aeration tank is led to a settling tank and separated by sedimentation, the precipitated solid content is pumped out to a sludge tank, and the supernatant liquid is discharged as treated water, and the above-mentioned rotary contact mechanism tank and aeration tank are discharged. By performing defoaming treatment in the foaming wastewater introduction system, foaming can be suppressed in the aeration tank, resulting in effective wastewater treatment, and in principle, the treated water can be discharged as is.

[0027] A rotary contact mechanism tank having a rotary contact mechanism in which multi-stage rotating plates are arranged has a pipe system for introducing the waste liquid to be treated from the raw water tank, and mesh materials are arranged in multi-stages in the pipe system. In addition to providing a foam defoaming means, a pressure pump is provided in the raw water tank or in the adjustment tank provided between the raw water tank and the rotating contact mechanism tank to ensure effective gas-liquid contact on the rotary plate surface, and to prevent wastewater. By supplying sufficient oxygen inside the tank, aerobic microorganisms can thrive, and the equipment can therefore be made more compact.
Furthermore, effective wastewater treatment will be carried out. In addition, the equipment is compact, and simply rotating the rotary plate requires less operating energy, resulting in low-cost processing.

A liquid volume adjustment tank and a measuring tank are provided between the raw water tank and the rotary contact mechanism tank, and the liquid volume adjustment tank is provided with a mechanism for blowing oxygen-containing gas such as air, and this adjustment tank is provided at the bottom of the flow rate adjustment tank. A lifting mechanism is provided to transfer the internal liquid to the measuring tank, and a pipe line is provided to constantly supply waste water from the measuring tank to the rotating contact mechanism and return excess water to the liquid volume adjustment tank. The wastewater treatment in the contact mechanism tank is carried out under appropriate and rational conditions to achieve the highest efficiency, and
Equalize the quality of wastewater during the treatment process and after treatment.

[0029] An aeration tank and a settling tank are arranged in the rotating contact mechanism tank, and a lead-out pipe opened at the middle part of the aeration tank is opened into a compartment provided in the settling tank, and an oxygen tank provided at the bottom of the aeration tank is opened. By connecting a branch blowing pipe for blowing the gas into the sludge pumping pipe opened at the bottom of the sedimentation tank to the gas supply pipe for the containing gas blowing mechanism, the aeration process in the aeration tank and the lifting of the sludge settled in the settling tank are performed. To smoothly and easily carry out extraction without using a special pump or the like.

By forming a wastewater storage area at the bottom of the rotary contact mechanism tank as described above and providing an aeration mechanism connected to a blower in the wastewater storage area, the amount of wastewater stored in the rotary contact mechanism tank can be increased. Increasing the throughput and achieving an aeration effect through contact with the air blown in from the blower.
In addition, air is supplied to the rotating plate part located in the wastewater in the tank, and microorganisms grow actively from both of them.
It also reduces the generation of bad odors in the wastewater, improves the efficiency of decomposing organic matter in the wastewater, reduces foaming, and furthermore avoids the expansion of the rotating contact mechanism.

[0031] By providing a partition material in the rotary contact mechanism tank described above and dividing it into multiple stages, and allowing wastewater to pass sequentially through the divided areas, the type of microorganisms can be changed or adjusted in each compartment, and a single Compared to the case of compartments, it generates a variety of microorganisms, activates chain reactions, and increases processing efficiency.
The sludge digestion rate is considerably increased and the amount of surplus sludge generated is reduced.

That is, by the multi-stage process as described above, the first stage consists of flagellates and flagellates as protozoa.
While the growth and reproduction is mainly carried out by fleshy insects and ciliates, in the later stage, metazoa (Metazoa)
As a result, the growth and reproduction of mainly rotifers, nematodes, oligochaetes, etc. takes place actively, which can improve treatment efficiency.

[0033] Experimentally, a high defoaming effect was obtained by providing two or more sets of defoaming means, each consisting of mesh material arranged in multiple stages at intervals of 2 to 5 mm, in the conduit at intervals of 0.5 to 3 m. Therefore, it is possible to obtain favorable defoaming results with a simple mechanism and to achieve effective wastewater treatment.

[0034]

[Embodiment] To explain a specific embodiment of the present invention as described above, an example of equipment for implementing wastewater treatment according to the present invention is as shown in FIGS. 1 and 2. 1 shows the general relationship as a block diagram, and FIG. 2 shows the state of the specific equipment as a block diagram.

That is, a flow rate adjustment tank 2 and a raw water tank 3 are provided in front of the rotary contact mechanism tank 1 which constitutes the main body of wastewater treatment according to the present invention, and an aeration tank 4 is provided in series with the rotary contact mechanism tank 1. , a settling tank 5 and a sludge storage tank 6 are provided, and a pipe 70 from the aeration blower 7 is led to the rotary contact mechanism tank 1, aeration tank 4 and sludge storage tank 6, and these tanks 1, 4, At the bottom of 6 the blowing nozzles 71, 7
2 and 73 are provided, and the settling tank 5 is further provided with a bubble pump 74.
and scum schema 75 are provided, and these mechanisms 7
4 and 75 are also connected to piping from the aeration blower 7.

The above-mentioned flow rate regulating tank 2 includes a regulating tank pump 2.
1 is provided, and the raw water pumped out by the pump 21 is sent to the rotary contact mechanism tank 1 via the measuring tank 8, and a return pipe 22 is provided on one side of the flow rate adjustment tank 2. The reflux pipe 22 is configured to return the excess from the metering tank 8 and a portion of the treated water from the rotary contact mechanism tank 1 to the flow rate adjustment tank 2, and is further equipped with another aeration blower 76. The blowing nozzle 77 is provided at the bottom of the tank 2 so that the raw water in the tank 2 is also aerated.

Raw water, which is waste water from the waste water generation source as described above, is introduced into the raw water tank 3 described above through a pipe 30, and a partition wall 31 is provided in the middle of this raw water tank 3. A connecting port 32 is provided at the bottom of the partition wall 31 to connect the raw water tank 3.
A raw water pump 34 is provided at the lower part of the downstream compartment 33, and the pumped raw water is sent to the screen 9.

The solid content separated in the screen 9 is received in a receiver 91, while the liquid content is supplied to one side of the flow rate adjustment tank 2, and the raw water whose flow rate is adjusted in the measuring tank 8 is led out at a constant water level. Raw water is sent to the rotating contact mechanism tank 1 through a connecting pipe 81.

The measuring tank 8 has an intermediate partition 82 opened at the bottom.
An intermediate partition 83 overflowing from the top is provided, and the intermediate partition 82 separates suspended matter, and raw water is quantitatively supplied to the tank 1 under controlled conditions by the intermediate partition 83.

In the sedimentation tank 5, the sludge pumped out by the bubble pump 74 and the suspended matter pumped out by the schemer 75 are both sent to the sludge tank 6, and the liquid separated over time in the sludge tank 6 is The liquid is returned to the aeration tank 4 by a drain line 62 opened at the top side. A gutter section 52 is provided around the upper circumference of the sedimentation tank 5, and the treated water obtained as a supernatant liquid in the tank 5 is, in principle, discharged as is.

FIG. 2 shows the planar arrangement of each of the mechanisms shown in FIG. 1 as described above. That is, a flow rate adjustment tank 2 is provided on one side of the rotary contact mechanism tank 1, a raw water tank 3 is located at one end of the flow rate adjustment tank 2, and a measuring tank 8 and a metering tank 8 are located at one end of the rotary contact mechanism tank 1. The aeration tank 4 is provided in a superposed manner, and a sedimentation tank 5 and a sludge storage tank 6 are provided in parallel on one end side of the aeration tank 4.

The air supply pipe 70 from the aeration blower 7 is guided to each tank 1, 4, 5, and 6 as shown in the figure, but in some cases, it may be branched to the flow rate adjustment tank 2 to supply air to the above-mentioned aeration blower. 76 can be omitted.

An example of a specific planar configuration of the equipment according to the present invention is as shown in FIG. 2, in which an aeration tank 4, a settling tank 5, and a sludge storage tank 6 are arranged in series with a rotating contact mechanism tank 1. A flow rate adjustment tank 2 and a raw water tank 3 are provided in parallel to these tank rows, making it a relatively low-profile facility. The site required for the entire facility is approximately 5 m x 7.3 m, and it is clear that it can be appropriately set within 50 m2.

Moreover, in the case of FIG. 2, it is clear that the raw water tank 3 and the flow rate adjustment tank 2 can be set up with the rotating contact mechanism tank 1, the aeration tank 4, etc. It is possible to reduce the amount by half, and it is sufficient to reduce the amount to at least one-tenth of the size of conventional waste water treatment equipment using microorganisms of this type.

[0045] In the general equipment configuration as described above,
Rotating contact mechanism tank 1 which is an important component in the present invention
An example of a specific configuration is shown in FIGS. 3 and 4,
A rotary plate group 11 includes a plurality of rotary plates 11 (generally 10 or more, but may be less than 10 in particularly small-scale cases) on a rotary shaft 10 that is continuously rotated by an appropriate driving means.
A pipe line 81 for introducing raw water and a pipe line for discharging treated water on the other side are appropriately provided on one side of the tank 1.

In the case shown in FIGS. 3 and 4, a blow pipe 71 is provided at the bottom of the tank 1, and by turning on and off the high pressure air supply to the blowing air pipe, air can be blown into the tank or stopped. Furthermore, a drain 12 is provided at the bottom of the tank so that the drain can be removed as needed, and a cover 13 is removably provided on the tank 1. , a see-through section 14 and a vent 14a are provided so that the operating status can be monitored.

The diameter of the rotating plate 11 adopted as a design condition suitable for storing and treating 8 m3 of waste water is about 2 m, and the rotating plate 11 is made of a loosely fastened structure made of synthetic fiber material as described later. When used, its thickness is 5
cm, and the width of tank 1 as shown in Figure 4 is 230 cm.
It will be about m. Further, under such design conditions, about 20 to 28 rotary plates 11 are employed, and therefore the length of the tank 1 is 3 m or less.

Furthermore, the rotational speed of the rotating plate 11 adopted under the above design conditions is 3 to 15 rpm, particularly 5 to 15 rpm.
7 rpm, which is a slow rotation of about 1 rotation per 10 seconds; if the speed is less than 4 rpm, there is a tendency that the attached supply of oxygen (air) and waste water to the decomposing structure of the fibrous material as described above cannot be obtained appropriately. Experimentally confirmed, while 1
Even when rotating at high speeds exceeding 5 rpm, the energy required to drive the rotation is large, and microorganisms can be obtained vigorously on the entire surface of the fibers due to slight processing, so the torque for rotation starts with a new rotating plate. 10 of time
Since the rotation speed increases more than twice as much, rotating at high speed under such conditions requires a significant increase in energy and wear and tear on the mechanism.

Specifically, it is preferable that each rotating plate 11 as described above is prepared as a fan-shaped divided unit body 15 as shown in FIG. 5 and combining about 3 to 10 pieces. . That is, the above-mentioned slowly decomposing structure fastened body of synthetic fiber material is made by irregularly dispersing curled synthetic fibers with a diameter of about 0.3 to 1.5 mm to form a slow decomposing layer with a predetermined thickness. It is obtained by spraying a binder, binding the joints of each fiber with a binder (the spread binder collects and binds at the joints by surface tension), and molding. Even if the rotary plate having a diameter of more than 1 m is integrally molded, under conditions where microbial adhesion and growth have progressed, the bonds between each fiber will be severed, and preferred durability will not be obtained.

As shown in FIG. 5, it is prepared as a divided unit 15, with a compressed molded part 15b surrounding it, and end plates 17 or 15 at both ends of the group of rotary plates 11 as shown in FIG. Insertion hole 1 of connecting rod 16 inserted into intermediate plate 18
By forming the pressed molded part 15a on the 9th circumference side, the synthetic fiber material in the pressed molded parts 15a and 15b strengthens the close bonding (particularly by heat welding), forming a reinforced part similar to a simple synthetic resin plate. This prevents the separation of each fiber material even due to the high resistance during rotation in water.

Note that the insertion hole 1 of the connecting rod 16 as described above
Each rotary plate 1 is assembled by inserting a spacer 28, which is a spacing cylinder 27 having flanges 26 at both ends as shown in FIG.
1 at a predetermined interval to allow good ingress of waste water and air into the tissue during rotation.

Mechanical defoaming means 4 employed in the present invention
An example of No. 0 is shown in FIG. 7 as a general installation state in a conduit, and FIG. 8 is a plan view of the mesh material. That is, a plurality of mesh materials 101 are provided in the conduit 100, and in a preferred embodiment, three or more mesh materials 101 made of synthetic resin wires knitted at intervals of 1 to 8 mm are set at intervals of 2 to 5 mm. Set as .

[0053] As mentioned above, a plurality of mesh materials 10
The defoaming means formed by combining 1.
, more preferably a distance of about 120 to 170 cm, and arranging them in multiple stages can enhance the defoaming effect.

In the case of the equipment shown in FIGS. 1 and 2 described above, the mechanical defoaming means 40 shown in FIGS. 7 and 8 described above is installed in the pipes as shown in FIG. Setting sections 40a, 40b, 40c and 40d are arranged. That is, before and after the rotating contact mechanism tank 1 described above, the raw water introduction pipe to the raw water tank, and the raw water supply pipe to the screen 9.

It is essential to provide this mechanical defoaming means 40 at least in the inlet pipe of the rotary contact mechanism tank 1, and also in the outlet pipe of the rotary contact mechanism tank 1. It is preferable to adopt For the other parts, the defoaming means 40 is disposed at an appropriate position selected according to each design condition.

Furthermore, as mentioned above, the passage speed of wastewater in a pipe provided with an antifoaming means is controlled by taking into account the inner diameter of the pipe. Table 1 below shows the results of a study on preferred flow rates for the pipes.

[0057]

[Table 1]

In other words, if the flow rate does not reach the above-mentioned preferred flow rate relative to the inner diameter of the pipe through which it flows, the defoaming effect will be insufficient; on the other hand, if the flow rate exceeds this preferred flow rate, foaming will occur again during passage. However, an appropriate defoaming effect cannot be obtained. That is, it is important to control the flow rate in consideration of the diameter of the pipe line to which it is applied in order to obtain effective defoaming results.

[0059] The amount of wastewater to be treated is therefore
In particular, the inner diameter of the pipe is appropriately determined from the relationships shown in Table 1, taking into consideration the capacity or processing level of the rotary contact mechanism tank.

[0060] To explain wastewater treatment in the above-mentioned equipment, the amount of treated wastewater is standardly 8 m3,
As shown in FIG. 6, in the rotary contact mechanism tank 1 without internal partitions, various kinds of wastewater are supplied with an internal capacity of 5 m3/hr, and synthetic fibers are fastened in an irregularly loosened shape. Twenty-four rotating plates with a diameter of 50 mm and a diameter of 2 m were submerged to about 45% in water and simply rotated at a speed of 5.6 times/min (that is, the residence time in the tank was 1 on average in this rotating contact mechanism tank). The treatment results are as shown in Table 2 below, in the case where no defoaming means (as described later) is provided for the wastewater that is supplied with the aim of time, and no air is blown into the rotating contact mechanism tank. It is.

[0061]

[Table 2]

In other words, the removal rate of BOD, which is the most important part of wastewater treatment, will vary depending on the properties, composition, amount of N-hexane, etc. of the wastewater to be treated, but the Under these operating conditions, where the wastewater residence time was less than 1 hour, a BOD removal rate of 55 to 80% was achieved simply by passing the wastewater through the rotary contact mechanism tank, which indicates that the treatment efficiency in the rotary contact mechanism tank is high. thing,
In other words, it is understood that aerobic bacteria are actively growing in the rotating contact mechanism tissue or in the tank.

That is, in the case of the conventional activated sludge method or aeration method, the time is at least 10 hours, and generally 24 hours.
It is well known that processing requires a long time, lasting more than 1 hour, and the equipment must inevitably become huge. It is something that you can get.

Under the above treatment conditions, according to the present invention as described above, the defoaming means 40a and 40b shown in FIG. carried out. The antifoaming means used was 4 to 6 pores made of vinylidene chloride fibers.
Two sets of four sheets of mesh material each having a diameter of 1.5 mm were used, and the flow rate was maintained within the preferred flow rate range using the pipe line A in Table 1. The results are shown in Table 3 below. .

[0065]

[Table 3]

[0066] In other words, in almost the same wastewater as in Table 2, the BOD removal rate was improved to 87 to 89% in all cases, and the antifoaming treatment significantly increased this removal rate and produced an orderly treatment result. It was confirmed that the results were obtained.

Further, as in the case of Table 2, after the treatment in the rotary contact mechanism tank, the liquid is introduced into the aeration tank for aeration treatment, and a part of the liquid contact-treated in the rotary contact mechanism tank is transferred to the rotary contact mechanism tank. The treatment results for another wastewater that was circulated and treated in a mechanical tank are as shown in Table 4 below.

[0068]

[Table 4]

That is, since the aeration treatment in the aeration tank was also used, the BOD removal rate of the treated water at the outlet of the aeration tank was higher than in the case shown in Table 2, reaching 80 to 85%. The cost increase for such aeration treatment after treatment of the rotary contact mechanism tank is simply due to the operation of the air pump, and in any case, it is known that an effective removal rate can be achieved in a short time and with compact equipment. Ta.

Further, regarding the rotary contact mechanism tank as described above, the bottom of the tank 1 was divided into three parts by a partition plate 25 as shown in FIG. 1, and a diffuser blower 7 was provided in each of the divided regions. That is, in this case, the capacity of the rotary contact mechanism tank 1 was increased by 8 m3 due to the expansion of the bottom part where the aeration blower 7 was set as described above, and the processing speed was 8 m3/hr. It is.

Rotating contact mechanism tank 1 as shown in FIG.
As in the case of Table 3, an anti-foaming mechanism was adopted and the air was diffused by a diffuser blower at 0.6 Nm3/mi.
The processing results when executed as n are shown in Table 5 below.
As shown.

[0072]

[Table 5]

In other words, although it is not possible to make an accurate comparison because the wastewater to be treated varies in various ways, the BOD removal rate in all cases exceeds 90%, which is more sufficient than in either Table 3 or Table 4. It is elevated. Using the same rotating contact mechanism,
The capacity is increased to 8 m3/hr, and the significance of achieving such a high BOD removal rate is obvious.

Specifically, it is clear from the illustration of the apparatus configuration according to the present invention that the treatment shown in Table 5 above is also carried out in combination with aeration treatment, and therefore, in this case, It is clear from the results in Tables 2 and 4 that the BOD removal rate is even higher than the results in Table 5. That is, by further subjecting the materials in Table 5 to aeration treatment, a BOD removal rate of 95% or more can be achieved easily and in a short time.

[0075]

Effects of the Invention: According to the present invention as explained above, chemical treatment, including defoaming treatment, can be used to treat this type of wastewater, which requires special chemicals or large-scale and long-time treatment in the prior art. It can be smoothly carried out in a short period of about 1 to 2 hours using relatively compact equipment without using chemicals, and moreover, the drive operation is approximately half of the rotating plate part. This invention has great industrial effects because it rotates slowly under the buoyant action of submerging an area of less than 1 in wastewater, so it has advantages such as energy efficiency and low cost. It is.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the general configuration of an example of a wastewater treatment facility according to the present invention.

FIG. 2 is a plan view of one example of a specific structural relationship shown in FIG. 1;

FIG. 3 is a partially cutaway side view of an example of a rotating contact mechanism tank according to the present invention.

FIG. 4 is an end view of the one shown in FIG. 3;

FIG. 5 is a perspective view of a unit body forming a rotary plate, also showing a spacing cylinder.

FIG. 6 is a perspective view of another example of a rotating contact mechanism tank.

FIG. 7 is a sectional view of an example of a mechanical defoaming means installed in a tube.

FIG. 8 is a plan view of the mesh material.

[Explanation of sign]

1 Rotating contact mechanism tank 2 Flow rate adjustment tank 3 Raw water tank 4 Aeration tank 5 Sedimentation tank 6 Sludge storage tank 7 Aeration blower 8 Measuring tank 9 Screen 10 Rotation axis 11 Rotating plate 12 Drain removal 13 Cover 14 Transparent part 15 Split unit body (insertion hole part) 15a Pressed molded part (periphery part) 15b Pressing forming part 16 Connecting rod 17 End plate 18 Intermediate plate 19 Insertion hole 21 Adjustment tank pump 22 Reflux tube 25 Partition plate 26 Tsuba 27 Spacing cylinder 30 Pipeline 31 Partition wall 32 Connection port 33 Downstream section 34 Raw water pump 40 Mechanical defoaming means 40a Installation position of defoaming means 40 40b Installation position of defoaming means 40 40c Installation position of defoaming means 40 40d Installation position of defoaming means 40 52 Gutter section 62 Drainage line 70 Air supply pipe 71 Blow nozzle 72 Blow nozzle 73 Blow nozzle 74 Bubble pump 75 Scum Schema 76 Aeration blower 77 Blow nozzle 81 Pipeline 82 Middle partition 83 Intermediate partition 91 Receiver 100 Pipeline 101 Mesh material

Claims (9)

[Claims] 1. A wastewater wastewater system characterized by introducing foaming wastewater into a pipe provided with a mechanical defoaming means, and controlling the flow rate of the wastewater in the pipe according to the diameter of the pipe. Processing method. 2. Foaming wastewater to be treated is introduced into a rotary contact mechanism tank to achieve gas-liquid contact by the rotation of a rotating body, and then introduced into an aeration tank for aeration treatment, and the liquid subjected to the rotary contact treatment is Circulatingly supplying a part of the liquid to the rotating contact mechanism tank,
The wastewater treatment according to claim 1, characterized in that the aerated liquid from the aeration tank is subjected to sedimentation treatment to be separated into sludge and treated water, and then subjected to defoaming treatment in a foaming wastewater introduction system to the rotary contact mechanism tank. Method. [Claim 3] A plurality of rotating bodies made of synthetic fibers fastened in an irregularly loose shape and formed into plate shapes are arranged in a row, and these rotating bodies are partially immersed in wastewater stored in a rotating contact mechanism tank. While rotating, the wastewater in the rotary contact mechanism tank is aerated by blowing air or other oxygen-containing gas,
The waste liquid from the rotary contact mechanism tank is received in an aeration tank, where it is again subjected to aeration treatment by blowing in oxygen-containing gas, and the intermediate liquid in the aeration tank is led to a settling tank for sedimentation and separation.
A wastewater treatment method characterized by pumping out precipitated solids into a sludge tank and discharging supernatant liquid as treated water. 4. A pipe system for introducing the waste liquid to be treated from the raw water tank into a rotary contact mechanism tank having a rotary contact mechanism in which multi-stage rotating plates are arranged, and a mesh material is installed in the pipe system in multiple stages. What is claimed is: 1. A wastewater treatment device, comprising: defoaming means arranged in series; and a pressure pump provided within a raw water tank or a regulating tank provided between the raw water tank and a rotary contact mechanism tank. 5. A liquid volume adjustment tank and a measuring tank are provided between the raw water tank and the rotary contact mechanism tank, and the liquid volume adjustment tank is provided with a mechanism for blowing oxygen-containing gas such as air, and at the bottom of the flow rate adjustment tank. A lifting mechanism is provided to transfer the liquid in the adjustment tank to the measuring tank, and a pipe line is provided to constantly supply waste water from the measuring tank to the rotating contact mechanism and return excess water to the liquid volume adjustment tank. A wastewater treatment device featuring: 6. A rotary contact mechanism tank is provided with an aeration tank and a settling tank, and a lead-out pipe opened in the middle part of the aeration tank is opened in a compartment provided in the settling tank, and the lead-out pipe is provided at the bottom of the aeration tank. A wastewater treatment device characterized in that a branch blowing pipe for blowing the gas into a slurry pumping pipe opened at the bottom of the sedimentation tank is connected to a gas supply pipe for the oxygen-containing gas blowing mechanism. 7. A wastewater storage area is formed at the bottom of the rotary contact mechanism tank, and an aeration mechanism connected to a blower is provided in the wastewater storage area. wastewater treatment equipment. 8. The wastewater according to any one of claims 4 to 7, characterized in that a partition material is provided in the rotary contact mechanism tank to divide the tank into multiple stages, and the wastewater is sequentially passed through the divided regions. Processing equipment. 9. A claim characterized in that two or more sets of defoaming means each consisting of mesh material arranged in multiple stages at intervals of 2 to 5 mm are provided in the conduit at intervals of 0.5 to 3 m. 4-8
The wastewater treatment equipment described in .