JP2008136912A - Sewage treatment apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sewage treatment apparatus which can reduce the amount of sludge generated when treating sewage. <P>SOLUTION: The sewage treatment apparatus comprises a water tank and a partition plate that divides the water tank into a microbial reaction tank and a water passage by partitioning the water tank so as to completely separate a liquid level part in the water tank and to allow passage of water at the bottom of the water tank. The microbial reaction tank has a charging port through which the sewage is charged, an air supply pipe for supplying air, an air lifter installed above the air supply pipe, an inner cylinder installed above the air lifter to prevent air bubbles blown from the air supply pipe and air lifter from directly hitting a fixed bed, and the fixed bed installed around the inner cylinder in the microbial reaction tank and having a microorganism fixing and contacting material onto which microorganism groups are fixed to form their colonies. The water passage has a sewage discharge port through which the sewage treated in the microbial reaction tank is discharged. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an apparatus and a method for treating sewage, and particularly in purifying sewage using a metabolic action, which is a biochemical reaction of a microbial group, in an aerobic environment, The present invention relates to a sewage treatment method and a treatment apparatus for making residue (sludge) as close to zero as possible.

  In recent years, many sewage treatment techniques using biochemical techniques have been established in order to treat organic sewage generated in kitchen wastewater such as hotels and food processing factories. However, the generation of sludge has become an extremely important issue since the idea that the generation of sludge from the microorganisms to be used is inevitable and the question that the disposal costs of sludge cause economic disadvantages is raised. In the treatment of organic wastewater, attempts have been made to utilize the biochemical functions of microbial groups. For example, organic sewage is allowed to act on the metabolic functions of microbial groups. Methods such as activated sludge method and catalytic oxidation method to purify are known.

  The activated sludge method is a treatment method based on the idea that a predetermined amount of sewage is taken into a microbial reaction tank, and the sewage is purified by utilizing the metabolic action between the soluble organic substances contained in the sewage and the microbial group (growth of microbial group). It is. The utilization form of the microorganism group at this time is a mixed floating method, and the ecology of the microorganism is shown as a lag phase, a logarithmic growth phase, a stable phase, and a death phase. Then, except for the residual microorganism group, it flows out of the water tank together with the treated water (for example, see Non-Patent Document 1).

  An example of sewage treatment using this activated sludge method will be described with reference to FIG.

The processing apparatus shown in FIG. 12 includes a water tank 81, a sewage inlet 88 and outlet 89 provided in the water tank 81, an air supply pipe 86 and an air diffusion pipe 84 for supplying air into the water tank 81. ing. The inside of the water tank 81 is divided into two stages by a partition wall 87, and the liquid phase can be moved by a water inlet 89 a provided in the partition wall 87. A precipitation tank 200 is provided outside the processing apparatus.
Moreover, the microorganism group in the water tank 81 is represented by a point, and the behavior of the water flow in the water tank 81 is represented by an arrow. The group of microorganisms in the water tank 81 becomes a semi-solid having viscosity due to a high-molecular substance that exhales itself, and exists as a small group (lumb) called floc.

  Next, a method for treating sewage using the treatment apparatus of FIG. 12 will be described.

  First, sewage is introduced from the inlet 88, and the sewage is purified by utilizing the metabolic action of the microbial group by bringing the sewage into contact with the microbial group in the water tank 81. Then, the water (purified water) purified by the microorganism group in the water tank 81 is discharged from the outlet 89 to the precipitation tank 200.

  The inside of the water tank 81 is in an aerobic condition because air is supplied to the water tank 81 as fine bubbles from the air supply pipe 86 through the air diffusion pipe 84. Further, the liquid phase in the water tank 81 is agitated so as to circulate in the water tank 81 by the fine bubbles from the diffuser tube 84 as indicated by arrows.

In addition, flocs due to microorganisms in the water tank 81 are very weak against external force. For this reason, it must be avoided that the floc is disassembled by the external force of the air from the air diffuser 84. Accordingly, the supply of air from the air diffuser 84 is performed by fine bubbles in order to reduce the external force to the floc.
Since the circulating flow generated by the fine bubbles supplied from the air diffuser 84 has a gentle speed, the relative speed between the sewage and the floc is very low and the contact degree is also small.

In the sewage treatment method using the above-described treatment apparatus, the purified water discharged from the outlet 89 includes flocs of microbial groups in the water tank 81. For this reason, a mixture of purified water and flocs of microorganism groups is discharged from the treatment apparatus.
For this reason, it is necessary for the discharged purified water to precipitate the microorganism group in the sedimentation tank 200 and to separate the precipitated microorganism group and the supernatant liquid 89. And the supernatant liquid 89 is extract | collected and discharged | emitted as treated water, and the used microorganism group which settled needs to be disposed of again as sludge.

Further, the air supplied from the air diffuser 84 is miniaturized in order to avoid disassembling the floc. The micronized bubbles are weak at the force of circulating the liquid phase in the water tank 81, and accumulate on the bottom of the water tank 81 when microorganisms that cannot circulate in the liquid phase settle.
For this reason, a microorganism group settles in the bottom part of the water tank 81, and when the deposit accumulates, the bottom mud 85 is generated.
This bottom mud 85 also needs to be disposed of in the same manner as the sludge in the sedimentation tank 200.

  Next, the catalytic oxidation method purifies sewage by providing a carrier to a microorganism group in an aerobic environment and forming a biofilm on the carrier, thereby bringing sewage into contact with the biofilm attached to the carrier. It is a processing method of the idea of doing.

As the above-mentioned carrier, there are a carrier having a specific gravity heavier than water and having a sedimentation property in a water tank, and a carrier having a lighter specific gravity than water and a property of floating in the water tank.
Examples of the carrier having a higher specific gravity than water include natural stone blocks, ore, charcoal, ceramic balls, and the like, and the carrier having a specific gravity lighter than water is processed into, for example, a ball shape, a thread shape, a honeycomb shape, or the like. There are resin molded products.

  As an example of sewage treatment using the contact oxidation method, a sewage treatment method using a treatment apparatus using a carrier having a specific gravity heavier than water will be described with reference to FIG.

The processing apparatus shown in FIG. 13 includes a water tank 91, a sewage inlet 98 and outlet 99 provided in the water tank 91, an air supply pipe 96 and a diffuser pipe 94 for supplying air into the water tank 91, and a contact material. The fixed floor 92 thrown in in the metal cage | basket 93 is provided. The water tank 91 is divided into three stages by a partition wall 97, and the liquid phase can be moved by a water passage port 99 a provided in the partition wall 97. A precipitation tank 200 is provided outside the processing apparatus.
In addition, the point in the water tank 91 represents a microorganism group, and the arrow in the water tank 91 represents the behavior of a water flow.

  The fixed floor 92 is formed of a natural stone block, magnetic ore, charcoal, ceramic balls, a resin molded product, and the like. Then, microorganisms form a biofilm on the surface of the fixed bed 92, so that attachment of microorganisms begins to occur.

  Next, a method for treating sewage using the treatment apparatus of FIG. 13 will be described.

  First, sewage is introduced from the inflow port 98 and the sewage is purified by utilizing the metabolic action of the microbial group by bringing the sewage into contact with the microbial group in the water tank 91. Then, the water (purified water) purified by the microorganism group in the water tank 91 is discharged from the outflow port 99 to the sedimentation tank 200.

  Since air is supplied as fine bubbles from the air supply pipe 96 through the air diffusion pipe 94 into the water tank 91, the inside of the water tank 91 is in an aerobic condition. Further, the fine bubbles from the air diffuser 94 agitate the liquid phase in the water tank 91 so as to circulate in the water tank 91 as indicated by arrows.

By the way, since the fixed floor 92 is arrange | positioned so that it may mutually contact within the eaves 93, the porosity of a contact material is comprised low. Furthermore, since a biofilm grows on the surface of the fixed bed 92, the void is gradually reduced by the grown biofilm.
As a result, a clogging phenomenon occurs in the gap between the contact materials, the circulation of the liquid phase in the water tank 91 and the supply of air are hindered, the supply of sewage gradually decreases, and finally the supply becomes impossible.

  In order to eliminate such clogging, there are a method of washing the contact material with water to remove excess biofilm, and a method of injecting a large amount of air toward the fixed bed 92 in the water tank to destroy the biofilm. It was broken.

However, in the method of destroying the biofilm attached to the fixed bed 92, the destroyed biofilm is released, and many of the microbial groups forming the biofilm are ejected to the upper surface area of the fixed bed in the water tank 91. Problem arises.
For this reason, in the sewage treatment method using the treatment apparatus of FIG. 13, the purified water discharged from the outflow port 99 includes a group of microorganisms floating in the water tank 91, so that the mixture of the purified water and the microorganism group is discharged. Will be. In addition, since natural repair of a destroyed biofilm takes about one to two weeks, it leads to instability of the biofilm.

  Therefore, it is necessary for the discharged purified water to precipitate the microorganism group in the sedimentation tank 200 and to separate the precipitated microorganism group and the supernatant liquid. Then, the supernatant is collected and discharged as treated water, and the settled used microorganism group needs to be disposed of again as sludge.

Moreover, when the microorganism group which floats in the water tank 91 settles, a deposit accumulates in the bottom part of the water tank 91, and the bottom mud 95 generate | occur | produces.
For this reason, a microorganism group settles in the bottom part of the water tank 91, and the bottom mud 95 generate | occur | produces when a deposit accumulates. This bottom mud 95 also needs to be disposed of again like the sludge in the sedimentation tank 200.

  Moreover, although it is a method which belongs to the contact oxidation method mentioned above, the treatment of the sewage using the microorganisms fixed contact material which consists of a ceramic material which has a continuous pore as a fixed bed is known (for example, refer patent document 1).

  This sewage treatment apparatus forms a fixed bed by placing a microorganism-adhering contact material in a water tank as a contact material used in the above-described contact oxidation method, and supplies air therein to maintain an aerobic environment. It is a sewage treatment apparatus which purifies sewage by a typical technique.

  FIG. 14 shows a microorganism-adhering contact material used for the microorganism-fixed bed disclosed in Patent Document 1.

The microorganism fixing contact material 100 forming the microorganism fixed bed is composed of a plurality of porous ceramic materials 101 and a gap support 102 for supporting the ceramic materials 101 at predetermined intervals.
This ceramic material 101 is a fired product of clay containing silicic acid (SiO ₂ ) as a main component. By baking the clay containing silicic acid as a main component at 1260 ° C. before and after vitrification, the ceramic material 101 has a size of about 1 μm. It has continuous pores of about 2 to 30 μm that are easy for microorganisms to enter.

  For this reason, the progeny of minute bacteria and microorganisms can be caught in the pores of the ceramics, and can be stably propagated. Large protozoa and metazoans (several tens of μm to several hundred μm) also have irregularities on the surface of the porous ceramic material, so that they can stably grow and form a biofilm called a fixed colony.

  The ceramic material 101 and the gap support body 102 thus configured are fixed to the frame body 103 and submerged in water. And the sewage is treated by the biochemical metabolic function brought about by the microorganisms fixed inside and outside the pores of the ceramic material.

  If the ceramic material 101 shown in FIG. 14 is used as the fixed bed for the microorganism group using the microorganism-adhering contact material 100, the microorganism group forms a strong colony biofilm. it can. In particular, the gap support 102 maintains the mutual gap between the ceramic materials 101 at about 32 mm, and the clogging phenomenon occurs without contact between the formed biofilms as long as an appropriate dissolved oxygen environment is maintained. Therefore, it has been proved to be effective when applied to an apparatus for treating organic sewage.

That is, the invention described in Patent Document 1 improves the oxidative degradation ability even for high-concentration sewage by realizing mass culture of microorganisms using a porous ceramic material, and treats sewage in a short time. Can do.
Therefore, industrial wastewater such as wastewater containing fats and oils of food processing factories, hotel kitchen wastewater with high concentration pollution load, which was difficult to cope with the above-mentioned activated sludge method and the conventional catalytic oxidation method, or This is extremely effective in that it can efficiently purify low-concentration regional sewage treatment (for example, rural village drainage treatment).

JP-A 64-30697 Edited by Ikuo Muto “Practical Manual for Wastewater Treatment” (October 30, 1955) "Soil" written by Toshinao Yokoi (published May 15, 1982, Tokyo University of Agriculture Correspondence Department), page 127

  However, even the processing apparatus described in Patent Document 1 described above is in the range of common sense that the generation of sludge is inevitable even though it is small, and has a sedimentation tank. In other words, the problem remains that the sludge is disposed of again and the economic burden of the sludge disposal cost.

Therefore, also in the processing apparatus described in Patent Document 1, a group of microorganisms floating in the water tank is discharged together with the purified water, as in the case of the activated sludge method and the fixed bed type contact oxidation method described above.
Moreover, when the microbial group which floats in the water tank settles, a deposit accumulates in the bottom part of a water tank, and bottom mud generate | occur | produces.

  For this reason, it is necessary to provide a sedimentation tank in addition to the processing apparatus. In this sedimentation tank, the microorganism group is precipitated, and the precipitated microorganism group and the supernatant liquid are separated. The supernatant of this sedimentation tank can be collected and discharged as treated water, but the settled microorganisms must be disposed of again as sludge.

  In order to solve the above-described problem, in the present invention, the sludge generated when processing sewage is a mechanism in which the residual residue (sludge) of the used microorganism group is brought to 0 as much as possible and the sludge is hardly present. The processing apparatus and the processing method are provided.

  The sewage treatment apparatus of the present invention includes a water tank and a partition plate that divides the water tank into a microbial reaction tank and a water channel by completely blocking the liquid surface portion in the water tank and partitioning the water tank at the bottom of the water tank. , An inlet for introducing sewage into the microbial reaction tank, an air supply pipe for supplying air to the microbial reaction tank, an air lifter provided above the air supply pipe, and an ejection from the air supply pipe and the air lifter In order to prevent direct air bubbles from hitting the fixed floor, an inner cylinder located above the air lifter and around the inner cylinder in the microbial reaction tank, the microbial group adheres to form a colony of the microbial group And a fixed bed having a microorganism-adhering contact material, and a wastewater outlet provided in a water channel and through which wastewater treated in a microorganism reaction tank is discharged.

  Further, the sewage treatment method of the present invention divides a water tank into a microorganism reaction tank and a water channel by a partition plate, and a microorganism group that is utilized by providing a fixed bed composed of a microorganism-adhering contact material around the inner cylinder of the microorganism reaction tank. Are used in two ways: fixed colonies and planktonic microorganisms. Then, a predetermined amount of sewage per hour is continuously taken into the water tank, and air is continuously supplied into the microbial reaction tank, so that the sewage in the microbial reaction tank is brought into an aerobic environment with a high concentration of dissolved oxygen. By placing it, the organic matter contained in the sewage in the microbial reaction tank is decomposed by a degrading enzyme secreted by the microorganism group. Furthermore, the floating microorganism group in the microbial reaction tank is kept inside the microbial reaction tank by the partition plate provided in the water tank, and the sewage treated by the decomposition is discharged from the microbial reaction tank through the lower part of the partition plate through the water channel. It is characterized by discharging from the outlet to the outside of the water tank.

What is most effective in the above-described means is that sludge is not generated.
For example, in the term “physiology” of the book “Soil” (see Non-Patent Document 2), these events are described as follows: Microorganisms continue to work for a while after their death, and their cell solids are also autolyzed. is described. The present invention utilizes the function of self-degradation of this microorganism group.

Since the soil is solid, the microorganisms in it hardly move. However, microbial groups in the gas phase and liquid phase move easily.
That is, it means that the microorganism group in the soil exists in and on the soil (solid phase) and is not free, so it remains in the soil. For this reason, it is important to be able to induce the phenomenon of self-decomposition, which is one of the factors that remain in the solid phase.
And the condition that the environment necessary for self-decomposition of high concentration dissolved oxygen is prepared is another important factor.

Conventionally, a water tank in which a microbial group of equipment using biological wastewater purification technology (activated sludge method or catalytic oxidation method) exists is divided not only by one tank but by a partition wall having a water passage, and is formed in multiple stages. .
Here, in a continuous system in which sewage is continuously charged and purified, the microorganism group is also moving simultaneously with the flow of the sewage flow path. For this reason, the outflow of the microorganism group was received in the settling tank. That is, both the treated water and the microorganisms flowed out in the conventional continuous reaction tank.

  A method for keeping the above-described microorganism group in a solid phase and a liquid phase was sought. The resulting solution led to the idea of a partition plate and came up with a method of dividing the water flow.

  For example, by dividing a bioreaction tank of one section with a partition plate, two other spaces are generated before and after the partition plate. This partition plate completely cuts off the water flow at the liquid surface portion, and has a gap that allows appropriate water flow at the bottom of the water tank.

  In the space located at the front of these two other spaces, a fixed bed composed of a microorganism-adhering contact material, an air supply pipe for supplying air, an air lifter for changing the supplied air to a rotating flow, and air This is a microbial reaction tank having an inner cylinder provided to prevent the rotating flow from directly hitting the fixed colonies on the fixed bed.

  In addition, a space that is formed behind a partition wall having a water passage opening in a space behind another partition plate is called a water channel, and air is not supplied.

  Therefore, the microorganism group to be used lost the colony colonization that settles on the fixed bed in the microorganism reaction tank located in front of the partition plate and the ability of the microorganism group to adhere beyond the logarithmic growth phase in the ecology of the microorganism group. It comes in two forms: planktonic microorganisms consisting of aging microorganisms (stable and dead).

  The microbial group in the form of a fixed colony must remain in the microbial reaction tank, and the presence of the partition plate prevents the floating microbial group from moving to the water channel.

  By using the above-mentioned means as a prototype of a mechanism that does not generate sludge, it is possible to simultaneously purify sewage without generating sludge.

  The sewage treatment apparatus and treatment method of the present invention can treat sewage by placing sewage in an environment of high-concentration dissolved oxygen, inducing the metabolic function of the microbial group, and further, self-degradation of the microbial group This function can be induced to finally self-decompose the microorganism group in an aerobic environment.

According to the wastewater treatment apparatus and treatment method of the present invention, the microorganisms used for the treatment of wastewater are self-decomposed in the treatment apparatus, thereby reducing the discharge amount of the microorganisms to the outside of the apparatus to zero and treating the wastewater. can do.
In addition, by making the generation of sludge as close to zero as possible, it is possible to improve the uneconomical cost of disposal of sludge that has been disposed of as industrial waste.

  Prior to the description of specific embodiments of the present invention, an outline of the present invention will be described.

The basis of conventional sewage treatment by biochemical reaction has been limited to inducing a phenomenon of biochemical decomposition of organic substances contained in sewage by metabolism of microorganisms.
In contrast, in the sewage treatment of the present invention, the ecology of microorganisms is further as described above. However, the phenomenon of self-decomposition of the microorganism group is the treatment of the microorganism group until the stable period and the death period in the organism. The issue of how to do this is taken up, and the function of self-degradation of the microbial community is utilized.

First, an outline of a method for treating sewage using a microorganism group will be described.
Sewage containing organic matter is derived from animal and plant bodies and is susceptible to biochemical degradation. And decomposition | disassembly of the organic substance by an animal and plant body is performed by consuming dissolved oxygen in a water area, and finally changes to a simple inorganic substance.
By the way, the reaction that consumes oxygen in the water area can be classified into a pure chemical reaction and a biochemical reaction due to the intervention of a living organism.
And most of decomposition | disassembly reaction of organic substance is performed by biochemical reaction.
In this biochemical reaction, organic substances are oxidatively decomposed by a series of reactions accompanying metabolism of the microorganism group. The amount of dissolved oxygen consumed at this time is BOD (Biological Oxygen Demand).

Oxidative decomposition of organic substances by metabolism of microorganisms under aerobic conditions where oxygen is sufficiently supplied is performed under aerobic conditions where oxygen is sufficiently supplied, and complex organic substances are also oxidized and decomposed. By this, it changes to an inorganic substance saturated with oxygen, such as carbon dioxide (CO ₂ ), water (H ₂ O), sulfate radical (—SO ₄ ), and nitrate radical (—NO ₃ ).
As described above, sewage containing organic matter can be purified by metabolism of the microorganism group.

  Next, self-decomposition of the microorganism group unique to the present invention will be described. The outline of this self-decomposition is described in the book “Soil” (see Non-Patent Document 2). This book contains a liquid phase (water), a gas phase (air), a solid phase (soil), and a microbial group (aerobic) based on the natural composition of rivers, rainfall, air, soil, and microbial groups on Earth. The concept of realizing this relationship in water is depicted.

  The biochemical action of each microbial group in and outside the microbial group is performed by the action of enzymes. And since an enzyme is secreted not only inside the microbial group but also outside the body, the microbial group that uses organic matter as a nutrient can decompose and ingest complex organic matter. That is, the decomposition of the organic matter due to the metabolism of the microorganism group described above is also due to the action of the enzyme secreted from the microorganism group.

  However, this enzyme continues its action to some extent even after the death of the microbial community. For this reason, the microorganism group itself will be decomposed | disassembled by the effect | action of an enzyme by hold | maintaining a microorganism group and an enzyme in the same water area. Such an action of being decomposed by an enzyme secreted by the microorganism group itself is an idea of self-degradation of the microorganism group.

In addition, it is known that if a lot of air is continuously sent to microorganisms, it is decomposed by autooxidation.
The following reaction equation is an equation representing the autooxidation of a microbial group in an aerobic environment.

[Chemical 1]
_{(C 5 H 7 NO 2)} n + 5nO 2 → 5nCO 2 + 2nH 2 O + nNH 3 -ΔH

This reaction formula shows a biochemical reaction in which the group of microorganisms (C ₅ H ₇ NO ₂ ) n responsible for the purification action in the aerobic environment reacts with air (oxygen · 5nO ₂ ) by the action of the enzyme shown on the left side. And carbon dioxide (CO ₂ ) and water (H ₂ O) are generated as shown on the right side. ΔH is the thermal energy released during the chemical reaction.

In this way, by supplying air (oxygen) to the microorganism group, the microorganism group is decomposed by oxygen, and changes to carbon dioxide, water, and inorganic substances finally saturated with oxygen, such as nitrogen compounds. To do.
For this reason, by continuing to supply oxygen to the microorganism group, the microorganism group can be decomposed by autooxidation of the microorganism group.
In the present invention, the autooxidation of the microorganism group is also included in the above-described autolysis of the microorganism group.

  The principle of biological sewage treatment technology is that it depends on the action of organic substance degrading enzymes and the metabolism of microorganisms. Therefore, the concept of sewage purification is established. However, since the time period for the microorganism group to be used to stay in the reaction tank is limited, there is a fact that the microorganism group is forced to flow out with the passage of this time.

  Next, the behavior of the above-described microorganism group in the processing apparatus will be described.

First, the microbial group that biologically decomposes organic matter contained in sewage has a fixed bed composed of microorganism-adhering contact materials, and has a variety of abundant biota (bacteria, protozoa, metazoans, microanimals). ).
According to the predatory action by the food chain reaction, the various biota manifests a phenomenon such as bacteria preying on the flocs of the floating microorganism group.
And, in the environment of high concentration dissolved oxygen value, when the sewage is purified by the decomposition of organic matter, the organic matter that becomes the nutrient source in turn decreases, the microbial group becomes a kind of starvation state, by the contraction action of the cells, Cell solids decay.
Then, when the predatory action and the contraction action occur in the processing apparatus, the number of cells of the microorganism group in the processing apparatus decreases.

  Furthermore, as described above, the microorganism group is decomposed by the enzyme secreted in the processing apparatus, and the microorganism is oxidized and decomposed by continuing to send air to the microorganism group, thereby causing the self-decomposition.

In order to induce the above-mentioned action in the processing apparatus, the above-mentioned action occurs in the liquid phase inside the microbial reaction tank where the water tank is formed with a partition plate to form a microbial reaction tank and a water channel. , Leading to the self-degradation of the life of microorganisms.
In other words, the microorganism group to be used is made into two forms (fixed colony and floating microorganism group) and stays on the fixed bed material as well as strong fixed colony, but the floating microorganism group also stays inside the microorganism reaction tank. is important.
And the microorganisms after metabolism which were discharged | emitted conventionally are decomposed | disassembled within a processing apparatus, The discharge | emission of the sludge from the processing apparatus by the process of sewage can be made into zero infinitely.
Therefore, it is possible to treat sewage from the treatment apparatus with almost no sludge.

Further, if a large amount of oxygen is continuously fed as in the above-described reaction formula, the microorganism group is self-decomposed, but means for continuously feeding a large amount of oxygen is extremely uneconomical. For that purpose, means for increasing the value of dissolved oxygen with a small amount of oxygen supply is necessary and important.
In this invention, it utilizes in the form of the colony which adheres to a fixed bed, and the form of the aging microorganisms which seceded from the colony. In order to form this fixed colony, a large amount of high-molecular substance discharged by the microorganism group is consumed. Therefore, it leads to the phenomenon that the viscosity of a liquid phase falls remarkably. This decrease in viscosity can easily increase the value of dissolved oxygen with a small supply of air.

  Next, specific embodiments of the present invention will be described with reference to the drawings.

  As a first embodiment of the present invention, a schematic configuration diagram of a sewage treatment apparatus is shown in FIGS. 1A and 1B. FIG. 1A is a perspective view, and FIG. 1B is a cross-sectional view taken along the line AA of FIG. 1A and shows a state of circulation inside the processing apparatus.

1A and 1B is provided with a partition plate 5, a sewage inlet 8 for introducing sewage, and a discharge port 9 for discharging water treated by the processor to the outside of the apparatus. It consists of a water tank 1.
Further, the water tank 1 includes a microorganism reaction tank 10 for treating sewage with a group of microorganisms fixed to the microorganism fixing contact material, and a water channel 11 for allowing water treated in the microorganism reaction tank 10 to communicate with the discharge port 9. It is configured separately. A partition plate 5 is provided as means for separating the microbial reaction tank 10 and the water channel 11.

  Below the partition plate 5, there is a predetermined interval between the water tank 1 and the liquid phase is configured to be able to move between the microorganism reaction tank 10 and the water channel 11.

  The sewage (liquid phase) introduced into the water tank 1 from the sewage introduction port 8 is filled up to the liquid level 12, which is substantially the same height as the discharge port 9.

In the microbial reaction tank 10, the fixed bed 3 made of a microorganism-adhering contact material is disposed below the liquid surface 12 so as not to be shaken in the liquid phase.
The fixed bed 3 has the same configuration as that of the microorganism-adhering contact material 100 shown in FIG. 14, and a plurality of porous ceramic materials are supported by a spacing support member with a predetermined spacing of, for example, 3 cm or more. And it is comprised so that the filling rate (volume ratio) of the porous ceramic raw material with respect to the volume of microorganisms fixed contact material may be 15% or less.
This porous ceramic material is mainly composed of silica oxide (SiO), and has continuous pores of about 2 μm to 30 μm so that microbes having a size of about 1 μm can easily enter.

For this reason, the progeny of minute bacteria and microorganisms can crawl into the pores of the porous ceramic and can be stably propagated. In addition, irregularities are formed on the surface of the porous ceramic material, and a large protozoan or metazoan microorganism group can adhere to form a stable biofilm. As described above, the porous ceramic material constituting the fixed bed 3 is compatible with the microbial group in the processing apparatus to be stably fixed. Therefore, by using the fixed bed shown in FIG. The microorganism group can be present in the form of a fixed colony by fixing a biofilm to a fixed bed.
The remaining about 10% or less of the microbial group is peeled off from the fixed colony and exists in the form of a floating microbial group floating in the microbial reaction tank 10.

In addition, since about 90% of microbial groups can be made to exist in the form of a fixed colony by attaching a biofilm to the fixed bed, most of the high-molecular substances discharged from the microbial group are in the fixed bed. Is consumed to form a colony of colonies.
Therefore, since the polymer substance that the microorganism group exhales hardly remains in the liquid phase, the increase in the viscosity of the liquid phase due to the polymer substance does not occur.
Thus, by using the above-mentioned fixed bed 3 in the first embodiment, since the high-molecular substance discharged from the microorganism does not remain in the liquid phase, the viscosity of the liquid phase can be lowered, The dissolved oxygen concentration in the liquid phase can be increased even with a small supply amount of air.

  The microbial reaction tank 10 is provided with an air supply pipe 6 and an air lifter 4 that generates an air lift effect for circulating the liquid phase in the microbial reaction tank 10 at the bottom. Air is supplied into the microorganism reaction tank 10 by the air supply pipe 6 and the air lifter 4, and the liquid phase is circulated in the microorganism reaction tank 10 by the air lift effect generated by the air lifter 4. ing.

  In the microbial reaction tank 10 of the first embodiment, the fixed bed 3 is formed of 12 (three-stage, four-row) microorganism-adhering contact materials, and the fixed bed 3 is not placed at the center thereof, and the air lifter The inner cylinder 2 is provided so that the air supplied from 4 passes to the liquid level 12.

In addition, as a means for dividing into the water tank 1, the microorganism reaction tank 10, and the water channel 11, it is not restricted to the partition plate 5, and what kind of structure may be sufficient.
If the discharge port 9 is provided in the microbial reaction tank 10, the floating microorganism group in the liquid phase is discharged from the discharge port 9 to the outside of the processing apparatus. For this reason, the discharge port 9 cannot be provided in the microbial reaction tank 10, and it is necessary to provide the discharge port 9 at a position separated from the microbial reaction tank 10. And the water channel 11 for letting this microbial reaction tank 10 and the discharge port 9 pass is needed.
Further, the water channel 11 is a passage until the liquid phase moving from below the microbial reaction tank 10 reaches the discharge port 9, and any configuration as long as the liquid phase from the microbial reaction tank 10 is guided to the discharge port 9. It doesn't matter.

  In 1st Embodiment, by dividing the water tank 1 with the partition plate 5, the microorganisms reaction tank 10 and the water channel 11 can be formed simultaneously in one water tank, and the structure other than the water tank 1 and the partition plate 5 is unnecessary. Is advantageous.

  The air lifter 4 will be described in detail later, but in the first embodiment of the present invention, an air supply facility (aerator: trade name) manufactured by OA Corporation is used.

  Next, the processing method of the sewage using the above-mentioned processing apparatus is demonstrated using FIG. 1B.

  First, sewage is introduced into the water tank 1 from the sewage introduction port 8 of the treatment apparatus having the above-described configuration. At this time, the introduced sewage (liquid phase) passes below the partition plate 5 from the microbial reaction tank 10, rises in the water channel 11, and reaches the liquid level 12, and the discharge port 9 provided in the water tank 1. Through the water tank 1. For this reason, while the sewage is supplied from the sewage input port 8, the liquid level 12 always maintains a constant height.

Next, the air mass 20 is discharged into the microorganism reaction tank 10 from the air supply pipe 6 through the air lifter 4. At this time, the released air mass 20 exists only in the microorganism reaction tank 10, and no air is supplied into the water channel 11 partitioned by the partition plate 5.
The supply amount of air is measured by measuring the dissolved oxygen value in the microbial reaction tank 10, and becomes a high concentration required for the treatment of sewage and the self-decomposition of the microorganism group, for example, a dissolved oxygen value of 4 to 6 ppm. Thus, the supply amount of air from the air supply pipe 6 is adjusted.

  The air mass 20 released into the microbial reaction tank 10 expands in the air lifter 4 and grows like an air mass 20a. And if it discharge | releases from the air lifter 4, it will raise the inside of the inner cylinder 2, expanding further like the air masses 20b and 20c. At this time, the air masses 20, 20 a, 20 b, and 20 c rise in the inner cylinder 2 by their buoyancy, and thereby induce an upward flow 21 indicated by an arrow in FIG. 1B with respect to the liquid phase 10. .

  At this time, when the upward flow 21 rises inside the inner cylinder 2, it is possible to prevent the air masses 20, 20 a, 20 b, 20 c and the upward flow 21 from colliding directly with the fixed bed 3. For this reason, it can prevent that the biofilm of the microbial group currently formed in the fixed bed 3 is destroyed by these collisions.

When the upward flow 21 reaches the liquid level 12, the upward flow 21 diffuses in all directions of the liquid level 20 and becomes a horizontal flow 21a. And the horizontal flow 21a becomes the downward flow 21b which descend | falls between the outer side of the inner cylinder 2, and an inner wall by colliding with the inner wall of the microorganisms reaction tank 10. FIG.
The downward flow 21b passes through the fixed bed 3 and reaches the bottom surface of the microorganism reaction tank 10, and is attracted by the suction force generated when the air lump 20 is continuously generated from the air lifter 4, and the suction flow 21c, It becomes 21d, becomes the upward flow 21 again, and rises in the inner cylinder 2.

  Thus, due to the air lift effect generated by the air lifter 4, the liquid phase in the microbial reaction tank 10 becomes an upward flow 21, a horizontal flow 21 a, and a downward flow generated by the buoyancy of the air masses 20, 20 a, 20 b, and 20 c. It circulates by 21b and suction flow 21c, 21d.

  At this time, most of the air mass 20c in the upward flow 21 is scattered in the atmosphere when it reaches the liquid level 12. However, the minute bubbles 20d generated below the liquid level 12 at this time move in the microorganism reaction tank 10 together with the horizontal flow 21a and the downward flow 21b. The bubbles 20d are dissolved in the liquid phase while moving in the microorganism reaction tank 10, and become dissolved oxygen in the liquid phase.

The downflow 21b mixed with the dissolved oxygen passes through the fixed bed 3 provided around the inner cylinder 2, and is a colony of microorganisms grown on the ceramic material constituting the microorganism-adhering contact material of the fixed bed 3. To touch.
In this way, the circulated flow containing dissolved oxygen generated in the microbial reaction tank 10 can bring sewage into contact with the microbial groups that are fixed colonies in the fixed bed 3, and the microbial groups on the ceramics The wastewater can be decomposed by reacting with organic substances contained in the wastewater under aerobic conditions.

  In the microbial reaction tank 10, about 90% of the above-mentioned microbial group is fixed to the fixed bed 3 as a fixed colony, and the remaining about 10% is floated in the liquid phase in the microbial reaction tank 10 as a floating microbial group. ing. In addition, a part of the planktonic microorganism group has a sedimentation property and tends to settle toward the bottom of the microorganism reaction tank 10.

At this time, the floating microorganism group circulates in the microbial reaction tank 10 by riding on a water stream circulating in the microbial reaction tank 10 by the air lift effect. That is, the floating microorganism group rises in the inner cylinder 2 as the upward flow 21 due to the air lift effect of the air lifter 4, reaches the bottom of the tank as the horizontal flow 21a and the downward flow 21b, and the suction flows 21c and 21d. Then, the air is lifted by the air lifter 4 again to become the upward flow 21.
For this reason, even when a suspended microbe group having sedimentation properties is present, since it is moved again from the air lifter 4 to the upward flow 21 by the suction flows 21c and 21d from the bottom of the microorganism reaction tank 10, the water tank 1 No microbial community accumulates on the bottom of the soil, and no bottom mud is generated.

  Further, since the sewage is continuously fed into the water tank 1 from the sewage inlet 8, the amount of liquid phase exceeding the liquid level 12 is discharged out of the water tank 1 through the outlet 9. Since the partition plate 5 is provided in the water tank 1, the introduced sewage passes through the lower part of the partition plate 5 from the microorganism reaction tank 10 and is discharged from the discharge port 9 through the water channel 11.

At this time, the planktonic microorganism group reaches the bottom of the microorganism reaction tank 10 by the downward flow 21b, and is then drawn toward the center of the microorganism reaction tank 10 by the suction flows 21c and 21d by the air lifter 4. 5 passes through the water channel 11 from below, and is difficult to be discharged from the discharge port 9.
That is, in the processing apparatus of the first embodiment, the floating microorganism group stays in the microorganism reaction tank 10 by the circulation flow in the microorganism reaction tank 10 and is hardly discharged from the microorganism reaction tank 10. .

As described above, in the processing apparatus according to the first embodiment, the floating microorganism group does not accumulate on the bottom of the water tank 1. Further, since the floating microorganism group is hardly discharged from the discharge port 9 to the outside of the processing apparatus, the microorganism group can remain in the microorganism reaction tank 10.
Then, as the microorganism group stays in the microorganism reaction tank 10, the metabolized microorganism group is decomposed in the treatment apparatus as described above for the self-decomposition of the microorganism group under the aerobic condition, and the sewage The discharge of sludge from the processing equipment due to the processing can be reduced to zero.

  Therefore, in the treatment apparatus of the first embodiment, the microbial group self-decomposes, so that the sewage can be treated with almost no sludge from the treatment apparatus.

  Next, based on FIG. 2, the air supply pipe 6 and the air lifter 4 used in the first embodiment and the air lift effect generated by the air lifter 4 will be described.

  As described above, the air lifter 4 used in the first embodiment is disposed in the liquid phase slightly apart from the bottom of the water tank 1, and the tip of the opening of the air supply pipe 6 is disposed upward below the air lifter 4. Has been.

  Two semicircular guide vanes 26a and 26b are arranged in the lower part inside the air lifter 4 so as to be orthogonal to each other. And the triangular partition plate 25 is provided along the edge part of the guide vanes 26a and 26b from the intersection of the two guide vanes 26a and 26b orthogonal to a lower direction.

  The air discharged from the air supply pipe 6 is divided into two by the triangular partition plate 25 in the directions of the two guide vanes 26a and 26b. The bisected liquid phase and air collide with the two guide vanes 26a and 26b, rise along the inclination angle of 45 degrees of the guide vanes, and rise as a swirl flow in the right direction as viewed from below.

As a result, when the swirl flow generated by the guide vanes 26 a and 26 b rises, the centrifugal force due to the rotation acts, so that the liquid in the air lifter 4 rises while being pressed toward the inner wall of the air lifter 4.
Moreover, since the center part inside the air lifter 4 becomes a low pressure part with a small pressure gradient, most of the compressed air mass rises while expanding, and a large buoyancy is generated in the air lifter 4. For this reason, a large pressure difference is generated inside and outside the air lifter 4, and this pressure difference generates an extremely strong suction force on the lower side of the air lifter 4, so that liquid is sucked into the air lifter 4 from the bottom of the water tank 1. It is possible to discharge air and liquid from the air lifter 4 continuously.

Thus, the liquid phase in the microorganism reaction tank 10 can be circulated by the air lift effect generated by the air lifter 4.
Moreover, since a strong suction force is generated on the lower side of the air lifter 4 due to the air lift effect, it is possible to circulate the floating microorganism group having sedimentation properties to be settled in the bottom of the water tank 1 in the microorganism reaction tank 10. . For this reason, it is possible to prevent the accumulation of sludge generated at the bottom of the processing apparatus due to the precipitation of the microorganism group.

In addition, on the inner wall of the air lifter 4, a large number of protrusions (currant cutters) 27 shaped like abacus balls are formed above the guide vanes 26 a and 26 b.
Six projections 27 are provided on the inner wall of the air lifter 4 per stage, and further, four projections 27 are provided by providing four projections 27 on the inner wall.

The liquid that rises while being pressed against the inner wall of the air lifter 4 mentioned above collides with the projection 27, generates turbulent flow and vortex flow, and rises while entraining air. And a part of the entrained air dissolves in the liquid, so that a liquid with a high dissolved oxygen is obtained.
For this reason, the aerobic conditions of the microbial reaction tank can be maintained under the high concentration required for the treatment of sewage and the self-decomposition of the microorganism group, for example, 4 to 6 ppm of oxygen.

  Next, a processing apparatus according to a second embodiment of the present invention is shown in FIGS. 3A, 3B, and 3C.

  As shown in FIG. 3A, FIG. 3B, and FIG. 3C, the processing apparatus of the second embodiment is configured by connecting three water tanks in series using the same configuration as the processing apparatus of the first embodiment described above. It is configured by 3A is a perspective view, FIG. 3B is a plan view, and FIG. 3C is a cross-sectional view taken along the line BB in FIGS. 3A and 3B, showing a state of circulation inside the processing apparatus.

In the processing apparatus of the second embodiment, the water tank 1 is divided into three parts of a water tank 1a, a water tank 1b, and a water tank 1c by partition walls 7a and 7b.
The water tanks 1a, 1b, and 1c have the same configuration as that of the processing apparatus according to the first embodiment.
The first tank 1a is provided with a sewage inlet 8 for introducing sewage, and the third tank 1c is provided with an outlet 9 for transferring the water treated by the treatment apparatus to the outside of the treatment apparatus. ing. In addition, water inlets 9a and 9b are provided in the water tank 1a and the water tank 1b and the partition walls 7a and 7b between the water tank 1b and the water tank 1c. The water outlets 9a and 9b are configured to connect the outlet of the water tank 1a and the inlet of the sewage of the water tank 1b, and the outlet of the water tank 1b and the inlet of the sewage of the water tank 1c so that the water tanks communicate with each other. It is configured.

Moreover, each water tank 1a, 1b, 1c was processed by the microorganism reaction tank 10a, 10b, 10c for treating wastewater by the microorganism group adhering to the microorganisms fixed contact material, and the microorganism reaction tank 10a, 10b, 10c. A partition plate 5 is provided as a means for separating water from the water passages 9a, 9b and the water channels 11a, 11b, 11c through which the water leads to the discharge port 9.
The lower part of the partition plate 5 has a predetermined interval between the bottom of the water tank and the microorganism reaction tanks 10a, 10b, 10c and the water channels 11a, 11b, 11c are configured to be able to move the liquid phase. .

  The sewage (liquid phase) introduced into the water tank 1 a from the sewage introduction port 8 is filled up to the liquid level 12. The liquid phase moved from the water tank 1a through the water passage 9a to the water tank 1b and the liquid phase moved from the water tank 1b through the water passage 9b to the water tank 1c are similarly filled up to the liquid level 12. The height of the liquid surface 12 is substantially the same as the height of the water inlets 9a, 9b and the outlet 9. The liquid phase exceeding this height moves to the adjacent water tank through the water inlets 9a, 9b. Then, it is discharged out of the apparatus through the discharge port 9 of the water tank 1c.

  In the microbial reaction tanks 10a, 10b, and 10c, the fixed bed 3 made of a microorganism-adhering contact material is disposed below the liquid surface 12 so as not to be shaken in the liquid phase. This fixed bed 3 is the same as that described in the first embodiment, and has the same configuration as the microorganism-adhering contact material 100 shown in FIG.

  For this reason, the progeny of minute bacteria and microorganisms can crawl into the pores of the porous ceramic and can be stably propagated. In addition, irregularities are formed on the surface of the porous ceramic material, and a large protozoan or metazoan microorganism group can adhere to form a stable biofilm. As described above, the porous ceramic material constituting the fixed bed 3 is compatible with the microbial group in the processing apparatus to be stably fixed. Therefore, by using the fixed bed shown in FIG. The microorganism group can be present in the form of a fixed colony by fixing a biofilm to a fixed bed. Then, the remaining about 10% or less of the microorganism group is peeled off from the colony and is present in the form of a floating microorganism group floating in the microorganism reaction tanks 10a, 10b, and 10c.

In addition, since about 90% of microbial groups can exist in the form of fixed colonies by attaching a biofilm to the fixed bed, most of the high-molecular substances spouted by the microbial group are in the above fixed bed. Consumed to form a colony of colonies.
Accordingly, since the polymer substance discharged by the microorganism group is hardly discharged in the liquid phase, the liquid phase does not increase in viscosity due to the polymer substance.
As described above, by using the fixed bed 3 in the second embodiment, the polymer substance discharged from the microorganisms does not remain in the liquid phase, so that the viscosity of the liquid phase can be lowered, and the amount of air Even in the supply amount, the dissolved oxygen concentration in the liquid phase can be easily increased.

  The microbial reaction tanks 10a, 10b, and 10c are provided with an air supply pipe 6 at the bottom and an air lifter 4 that generates an air lift effect for circulating the liquid phase in the microbial reaction tank 10. Air is supplied into the microorganism reaction tanks 10 a, 10 b, and 10 c by the air supply pipe 6 and the air lifter 4, and a liquid phase is generated in the microorganism reaction tanks 10 a, 10 b, and 10 c due to the air lift effect of the air lifter 4. It is configured to circulate.

  In the microbial reaction tank 10 of the second embodiment, the fixed bed 3 is formed of eight (two-stage, four-row) microorganism-adhering contact materials, and the fixed bed 3 is not placed at the center thereof, and the air lifter The inner cylinder 2 is provided so that the air supplied from 4 passes to the liquid level 12.

The means for dividing the water tanks 1a, 1b, and 1c into the microorganism reaction tanks 10a, 10b, and 10c and the water channels 11a, 11b, and 11c is not limited to the partition plate 5, and any configuration may be used.
When the water flow ports 9a, 9b or the discharge port 9 are provided in the microbial reaction tanks 10a, 10b, 10c, the floating microorganism group in the liquid phase is moved from the water flow ports 9a, 9b and the discharge port 9 to the adjacent water tank. And discharged outside the processing apparatus. For this reason, the discharge port 9 cannot be provided in the microbial reaction tank 10, and it is necessary to provide the water flow ports 9a, 9b or the drain port 9 at a position separated from the microbial reaction tanks 10a, 10b, 10c. And in order to pass through this microorganism reaction tank 10 and the discharge port 9, the water channels 11a, 11b, and 11c are needed.
The water channels 11a, 11b, and 11c are paths through which the liquid phase moving from below the microorganism reaction tanks 10a, 10b, and 10c reaches the water inlets 9a and 9b and the discharge port 9, and the microorganism reaction tank Any configuration may be used as long as the liquid phase from 10 is guided to the discharge port 9.

  In the second embodiment, by dividing the water tanks 1a, 1b, 1c with the partition plate 5, the microorganism reaction tanks 10a, 10b, 10c and the water channels 11a, 11b, 11c can be simultaneously formed in one water tank. This is advantageous in that no configuration other than 1a, 1b, 1c and the partition plate 5 is required.

  For the air lifter 4, as described above, air supply equipment (aerator: trade name) manufactured by OEI Corporation is used as in the first embodiment.

  Next, the wastewater treatment method using the treatment apparatus of the second embodiment will be described with reference to FIG. 3C.

First, sewage is introduced into the water tank 1a from the sewage introduction port 8 of the treatment apparatus having the above-described configuration. At this time, the charged sewage (liquid phase) passes from the microorganism reaction tank 10a under the partition plate 5 and rises in the water channel 11a and reaches the liquid level 12, and then the water inlet 9a provided in the water tank 1a. Through the water tank 1b. Similarly, the liquid phase that has flowed into the water tank 1b passes through the lower part of the partition plate 5 from the microbial reaction tank 10b, rises in the water channel 11b, and reaches the liquid surface 12 to be provided in the water tank 1b. It flows into the water tank 1c through the water inlet 9b.
And the liquid phase which flowed into the water tank 1c passes the lower part of the partition plate 5 from the microorganism reaction tank 10c, goes up the water channel 11c, and reaches the liquid level 12, through the discharge port 9 provided in the water tank 1c, It is discharged out of the device.
For this reason, while the sewage is supplied from the sewage input port 8, the liquid level 12 always maintains a constant height.

Next, air (not shown) is discharged from the air supply pipe 6 through the air lifter 4 into the microorganism reaction tanks 10a, 10b, and 10c. At this time, the released air is supplied only into the microorganism reaction tanks 10a, 10b, and 10c, and no air is supplied into the water channels 11a, 11b, and 11c partitioned by the partition plate 5.
The supply amount of air is determined by measuring dissolved oxygen levels in the microbial reaction tanks 10a, 10b, and 10c, and is dissolved at a high concentration, for example, 4 to 6 ppm required for the treatment of sewage and the self-decomposition of microbial groups. The supply amount of air from the air supply pipe 6 is adjusted so that the oxygen value is obtained.

  The air released into the microbial reaction tank 10 expands in the air lifter 4. And if it discharge | releases from the air lifter 4, it will raise the inside of the inner cylinder 2, expanding further. At this time, the expanded air rises in the inner cylinder 2 by its buoyancy, and thereby induces an upward flow 21 indicated by an arrow in FIG. 3C with respect to the liquid phase.

  At this time, it is possible to prevent the upward flow 21 from directly colliding with the fixed bed 3 by the upward flow 21 moving up the inner cylinder 2. For this reason, it is possible to prevent the biofilm of the microbial group formed on the fixed bed 3 from being destroyed by the collision of the upward flow 21.

When the upward flow 21 reaches the liquid level 12, the upward flow 21 diffuses in all directions of the liquid level 20 and becomes a horizontal flow 21a. And the horizontal flow 21a becomes the downward flow 21b descend | falling between the outer side of the inner cylinder 2, and an inner wall by colliding with each inner wall of microorganism reaction tank 10a, 10b, 10c.
The downward flow 21b passes through the fixed bed 3 and reaches the bottom surface of the microorganism reaction tank 10, and is attracted by the suction force generated when the air lump 20 is continuously generated from the air lifter 4, and the suction flow 21c, It becomes 21d, becomes the upward flow 21 again, and rises in the inner cylinder 2.

  Thus, due to the air lift effect generated by the air lifter 4, the liquid phase in the microorganism reaction tanks 10 a, 10 b, and 10 c causes the upward flow 21 generated by the buoyancy of the air released from the air lifter 4, the horizontal flow 21 a, It circulates by the downward flow 21b and the suction flows 21c and 21d.

  At this time, most of the air mass 20c in the upward flow 21 is scattered in the atmosphere when it reaches the liquid level 12. However, minute bubbles generated below the liquid surface 12 at this time move in the microorganism reaction tanks 10a, 10b, and 10c together with the horizontal flow 21a and the downward flow 21b. The minute bubbles dissolve in the liquid phase while moving in the microorganism reaction tanks 10a, 10b, and 10c, and become dissolved oxygen in the liquid phase.

The downflow 21b mixed with the dissolved oxygen passes through the fixed bed 3 provided around the inner cylinder 2, and is a colony of microorganisms grown on the ceramic material constituting the microorganism-adhering contact material of the fixed bed 3. To touch.
In this way, the sewage is brought into contact with a group of microorganisms that are fixed colonies in the fixed bed 3 by a circulating flow containing dissolved oxygen generated in the microorganism reaction tanks 10a, 10b, and 10c. Thereby, the microorganisms on ceramics are made to react with the organic substance etc. which are contained in sewage under aerobic conditions, and a sewage can be decomposed | disassembled.

  In the microbial reaction tanks 10a, 10b, and 10c, about 90% of the microbial groups described above are fixed to the fixed bed 3 as fixed colonies, and the remaining about 10% are buoyant microbial groups as microbial reaction tanks 10a, 10b, It floats in the liquid phase in 10c. In addition, a part of the planktonic microorganism group has a sedimentation property and tends to settle toward the bottom of the microorganism reaction tank 10.

At this time, the floating microorganism group is circulated by the water flow circulating in the microbial reaction tanks 10a, 10b, and 10c by the air lift effect. That is, the floating microorganism group rises in the inner cylinder 2 as the upward flow 21 due to the air lift effect of the air lifter 4, reaches the bottom of the tank as the horizontal flow 21a and the downward flow 21b, and the suction flows 21c and 21d. Then, the air is lifted by the air lifter 4 again to become the upward flow 21.
For this reason, even when a suspended microbe group having sedimentation properties is present, it is moved again from the air lifter 4 to the upward flow 21 by the suction flow 21c, 21d from the bottom of the microorganism reaction tanks 10a, 10b, 10c. Therefore, microbial groups do not accumulate at the bottom of the water tank 1 and no bottom mud is generated.

  Further, since sewage is continuously fed into the water tank 1a from the sewage inlet 8, the liquid phase in an amount exceeding the liquid level 12 flows into the water tank 1b through the water inlet 9a and further flows into the water tank 9b. Through the water tank 1c. And it is discharged | emitted out of a processing apparatus through the discharge port 9 from the water tank 1c.

  At this time, since the introduced sewage is provided with the partition plate 5 in the water tanks 1a, 1b, 1c, it passes from the microorganism reaction tanks 10a, 10b, 10c below the partition plate 5 and passes through the water channels 11a, 11b, The water is discharged from the discharge port 9 through the water flow ports 9a and 9b through 11c.

  At this time, the floating microorganism group reaches the bottom of the microorganism reaction tanks 10a, 10b, and 10c by the downward flow 21b, and is then drawn toward the center of the microorganism reaction tank 10 by the suction flows 21c and 21d by the air lifter 4. . For this reason, the floating microorganism group circulating in the microorganism reaction tanks 10a, 10b, and 10c passes through the water channels 11a, 11b, and 11c from the lower side of the partition plate 5, and is discharged from the water flow ports 9a and 9b and the discharge port 9. It has a difficult structure.

  That is, the floating microorganism group stays in the microorganism reaction tanks 10a, 10b, and 10c by the circulating flow in the microorganism reaction tanks 10a, 10b, and 10c, and is hardly discharged from the microorganism reaction tanks 10a, 10b, and 10c. Yes.

That is, in the processing apparatus of the second embodiment, the floating microorganism group is not deposited on the bottom of the water tank 1, and the floating microorganism group is hardly discharged from the outlet 9 to the outside of the processing apparatus. The group remains in the circulation flow within the microbial reactor 10.
And since this planktonic microorganism group remains in the circulating flow in the microorganism reaction tank 10, as described above for the self-decomposition of the microorganism group under the aerobic condition, the microorganism group after metabolism is contained in the processing apparatus. By being decomposed, the discharge of sludge from the treatment device by the treatment of sewage can be reduced to zero.

  Therefore, in the treatment apparatus of the second embodiment, the microorganisms are self-degraded, so that the sewage can be treated with almost no sludge generated from the treatment apparatus.

Thus, the wastewater with a high BOD density | concentration can be processed efficiently by connecting a processing apparatus in multiple steps and connecting in series. Such treatment of sewage with a high BOD concentration is inefficient because only one microorganism reaction tank takes time for the treatment. That is, in order to treat sewage with a high BOD concentration in one microbial reaction tank, it is necessary to lengthen the time for circulating the sewage in the microbial reaction tank. The amount is reduced. However, by using a multi-stage microbial reaction tank, high-concentration sewage can be reduced to a constant BOD concentration in the first stage and moved to the next stage. Furthermore, by configuring so as to decrease the BOD concentration every time the process passes, the burden of processing performed in one process is reduced. For this reason, the time which keeps sewage in one processing apparatus becomes short, and the quantity of the sewage which can be thrown into a processing apparatus per time increases.
Therefore, wastewater with a high BOD concentration load can be efficiently treated by using a multi-stage treatment apparatus.

Next, with reference to FIGS. 4A and 4B, a description will be given of the state of the microorganism group when sewage is treated by the treatment apparatus of the second embodiment.
FIG. 4A is a cross-sectional view of porous ceramic materials 30a, 30b, and 30c constituting the fixed floor 3 in the water tanks 1a, 1b, and 1c. And the microorganism group adheres to the surface of this ceramic raw material 30a, 30b, 30c, and the adhering colony 31a, 31b, 31c is formed. Further, around the ceramic materials 30a, 30b, 30c and the fixed colonies 31a, 31b, 31c, there are floating microorganism groups 32a, 32b, 32c floating in the liquid phase. At this time, about 90% of the microbial groups in the treatment tank are present as microbial groups forming a fixed colony, and the remaining about 10% are present as floating microbial groups.

FIG. 4B shows the above-mentioned planktonic microorganism groups 32a, 32b, and 32c with dots in the cross-sectional view of the processing apparatus of the second embodiment shown in FIG. 3C. Further, the density of the floating microorganism group in the liquid phase is changed by changing the density of the dots indicating the floating microorganism group 32a, 32b, 32c in the microorganism reaction tanks 10a, 10b, 10c and the water channels 11a, 11b, 11c. This is schematically shown.
As shown in FIG. 4A, fixed colonies 31a, 31b, and 31c are formed on the ceramic material of the fixed floor 3, but the description is omitted in FIG. 4B for simplification. Moreover, since it is the same as that of the structure shown to FIG. 3C except the mode of microorganisms group, the same code | symbol is attached | subjected and description is abbreviate | omitted.

As shown in FIGS. 4A and 4B, the microorganism group in the treatment apparatus exists in the liquid phase as two forms of the colony colonies 31a, 31b, and 31c and the floating microorganism group 32a, 32b, and 32c.
The fixed colonies 31a, 31b, and 31c are a group of microorganisms that are firmly adhered to the surfaces of the ceramic materials 30a, 30b, and 30c by a high-molecular substance spouted by the microorganisms themselves to form strong colonies. The floating microorganism groups 32a, 32b, and 32c are microorganism groups that are no longer able to evacuate the high-molecular substance to become a colony, and are floating on the circulating flow in the liquid phase.

As shown in FIG. 4A, the film thickness of the fixed colonies 31a, 31b, and 31c on the surfaces of the ceramic materials 30a, 30b, and 30c decreases as the water tank 1a progresses to the water tank 1c.
At this time, when the dissolved oxygen value is 4 to 6 ppm suitable for the activity of the microorganism group, the film thickness of each of the fixed colonies 31a, 31b, and 31c is, for example, 3 to 4 mm. Yes, the film thickness of the fixed colony 31b in the water tank 1b is 1 to 2 mm, and the film thickness of the fixed colony 31c in the water tank 1c is less than 1 mm.
This is because organic matter in the sewage is decomposed by microorganisms every time the sewage introduced into the treatment apparatus passes from the water tank 1a through the water tank 1b and the water tank 1c. For this reason, the quantity of the organic matter in the sewage which becomes a nutrient of a microorganism group reduces, and the amount of microorganisms reduces. That is, it is considered that the contraction effect described above occurs in the processing apparatus, thereby reducing the number of cells of the microbial group in the processing apparatus.

Moreover, as shown to FIG. 4A, B, the density of the floating microorganism group 32a, 32b, 32c is falling as it progresses from the water tank 1a to the water tank 1c.
Furthermore, when the density of the floating microorganism group in the microorganism reaction tanks 10a, 10b, and 10c of the water tanks 1a, 1b, and 1c is compared with the density of the floating microorganism group in the water channels 11a, 11b, and 11c, the water channels 11a and 11b are compared. , 11c has a low density of planktonic microorganisms.
This is presumably because the number of cells of the microorganism group in the treatment apparatus decreases for the same reason as the above-mentioned decrease in the thickness of the fixed colony.

Further, in the case of the floating microorganism group, in addition to the decrease in the number of individuals, the existence of the partition plate 5 is considered to prevent the movement of the microorganism group from the inside of the microorganism reaction tank 10a of the water tank 1a to the water channel 11a. It is done. Similarly, in the water tanks 1b and 1c, the presence of the partition plate 5 is considered to prevent the movement of the microorganism group from the microorganism reaction tanks 10b and 10c to the water channels 11b and 11c.
Therefore, it is considered that the density of the floating microorganism group 32a, 32b, 32c decreases as the water tank 1a progresses to the water tank 1c.

  Note that the processing apparatus according to the second embodiment includes three stages, but the number of stages, the size of the processing apparatus, and the like are not particularly limited and are arbitrary. That is, it may be designed according to the amount of sewage that needs to be treated per hour, the BOD concentration of sewage, the place where the treatment device is installed, and the like. For example, since the treatment capacity is improved by increasing the number of stages of the treatment apparatus, it is effective to increase the number of stages in order to treat a large amount of highly concentrated sewage.

(Experimental example 1)
Next, a sewage treatment apparatus was actually produced and sewage was treated.
In addition, since the produced processing apparatus is the same structure as the processing apparatus demonstrated using FIG. 3A-C as 2nd Embodiment, it uses the same code | symbol as FIG. 3A-C also in the following description. explain. Moreover, the processing apparatus was produced with the transparent acrylic resin board so that the behavior of the water flow inside a water tank and microorganisms group could be observed.

First, each dimension of the processing apparatus produced in Experimental Example 1 is as follows.
In addition, since the water tanks 1a, 1b, and 1c of the processing apparatus are both configured in the same size, the dimensions of the apparatus will be described only for the water tank 1a, and the water tanks 1b and 1c are omitted.

The plane dimensions of the water tank 1a were configured such that the microorganism reaction tank 10a was 750 mm in length and width, the water channel 11a was 750 mm in length and 100 mm in width, and the effective water depth was 1500 mm. Therefore, the effective volume of the microbial reactor 10a is about 0.84 m ^3, the effective volume of the water channel 11a is about 0.11 m ^3, total effective volume of the tank 1a is about 0.96 m ^3.
The total length of the processing apparatus in which the water tanks 1b and 1c are added to the water tank 1a is 2550 mm, and the volume is about 2.87 m ³ .

  The air lifter 4 has a total length of 300 mm and an inner diameter of 50 mm, and the lower end of the air lifter 4 is installed at a position 150 mm away from the bottom surface of the water tank 1a. And the diameter of the front-end | tip of the air supply pipe 6 installed in the lower part of the air lifter 4 is 15 mm.

The dimension of the microorganism-adhering contact material constituting the fixed bed 3 is 200 × 200 × 500 mm, and 16 microorganism-adhering contact materials (four stages, four rows) are arranged around the inner cylinder 2. The total surface area of the porous ceramic material of the microorganism-adhering contact material is about 8.0 m ² .
The inner cylinder 2 is about 300 × 300 mm.

  The interval between the partition plate 5 and the water tank 1a for the liquid phase to move from the microorganism reaction tank 10a to the water channel 11a is 100 mm.

The sewage was treated by introducing the sewage into the treatment apparatus having the above-described configuration.
The sewage to be input has a BOD concentration of 740 ppm, and the input amount is ^{3 to} 5 m ³ (2 to 4 L / min) per day of sewage treatment.

  First, using FIG. 5 and FIG. 6, the supply amount of air for making the inside of the treatment apparatus of Experimental Example 1 aerobic conditions of 4 to 6 ppm suitable for the treatment of sewage and the self-degradation of microorganisms, and The dissolved oxygen concentration in the liquid phase in the apparatus by supplying air will be described.

FIG. 5 shows measured values of the amount of air supplied to the processing apparatus. In FIG. 5, the horizontal axis represents the time axis until the input sewage moves through the treatment apparatus and is discharged, and the microbial reaction tanks 10 a, 10 b, 10 c of the water tanks 1 a, 1 b, 1 c and the water channels 11 a, 11 b, 11 c. The vertical axis indicates the amount of air (NL / min) supplied to each microbial reaction tank 10a, 10b, 10c.
The air supply amount was measured by attaching a flow meter to each of the air supply pipes 6.

  From FIG. 5, the supply amount of air to the microbial reaction tank 10a of the water tank 1a is about 380 NL / min, the supply amount of air to the microbial reaction tank 10b of the water tank 1b is about 280 NL / min, and the microorganisms in the water tank 1c. The amount of air supplied to the reaction vessel 10c was about 250 NL / min.

As the water tank 1a goes to the water tank 1c, the supply amount of air is reduced. This is because, in a multi-stage treatment apparatus, the BOD concentration decreases each time the number of stages is lowered, so that the required amount of oxygen of the microorganism group is reduced. And in order to maintain each dissolved oxygen value of microbial reaction tank 10a, 10b, 10c with 4-6 ppm suitable for the treatment of sewage, the supply amount of air was reduced as shown in FIG.
Since air was not supplied to the water channels 11a, 11b, and 11c, the amount of air supplied to the water channels 11a, 11b, and 11c was shown as 0 in FIG.

Next, FIG. 6 shows measured values of dissolved oxygen values in the liquid phase in the microbial reaction tanks 10a, 10b, and 10c and the water channels 11a, 11b, and 11c. In FIG. 6, the horizontal axis represents the time axis until the input sewage moves through the treatment apparatus and is discharged, the microbial reaction tanks 10 a, 10 b, 10 c of the water tanks 1 a, 1 b, 1 c and the water channels 11 a, 11 b, 11 c. The vertical axis indicates the amount of dissolved oxygen (ppm) in the microbial reaction tanks 10a, 10b, 10c and the water channels 11a, 11b, 11c.
The dissolved oxygen value was measured by collecting the liquid phases in the microorganism reaction tanks 10a, 10b, and 10c and the water channels 11a, 11b, and 11c and measuring them with a dissolved oxygen meter.

As shown in FIG. 6, in the microbial reaction tank 10a of the water tank 1a, the amount of dissolved oxygen was 3.8 to 4.2 ppm, and the average was 4.0 ppm. And in the water channel 11a, the amount of dissolved oxygen showed 3.6-4.0 ppm, and it was a grade slightly less than the average of the amount of dissolved oxygen in the microorganisms reaction tank 10a.
In the microbial reaction tank 10b of the water tank 1b, the dissolved oxygen content was 4.0 to 4.5 ppm, and the average was 4.25 ppm. In the water channel 11b, the amount of dissolved oxygen was about 4 ppm, and was slightly below the average amount of dissolved oxygen in the microorganism reaction tank 10b.
In the microbial reaction tank 10c of the water tank 1c, the amount of dissolved oxygen was 4.0 to 5.0 ppm, showing an average of 4.5 ppm. In the water channel 11c, the dissolved oxygen amount was about 4.5 ppm, and was slightly below the average of the dissolved oxygen amount in the microorganism reaction tank 10c.

  As shown in FIG. 6, by providing the air supply amount shown in FIG. 5 in the microbial reactor, the induction of the function of self-decomposition of the microbial group is maintained at 4 to 6 ppm, which is the most effective environment. be able to. Conventionally, in the environment where the dissolved oxygen value is mainly set to 1.8 to 2.2 ppm, the action of self-decomposition of the microorganism group does not occur, so the dissolved oxygen having a high concentration of 4 to 6 ppm compared to the conventional one. Is required. Further, it has been rarely performed to operate a microbial reaction tank of a sewage treatment apparatus with such a high concentration of dissolved oxygen.

  The reason why the dissolved oxygen value in the water channel is lower than the dissolved oxygen value in the microbial reaction tank is that oxygen is consumed by the oxidative decomposition reaction in the microbial reaction tank, and air is not supplied into the water channel. This is because the dissolved oxygen value of the liquid phase moving from the microbial reaction tank to the water channel is relatively lower than the dissolved oxygen value of the microbial reaction tank.

  As described above, as shown in FIGS. 5 and 6, air is supplied into the processing apparatus of Experimental Example 1, and oxygen contained in the air is dissolved in the liquid phase, thereby making the liquid phase an aerobic condition. This aerobic condition can lead to biochemical reactions of the microbial community.

  Next, how the sewage thrown into the apparatus is treated will be described using the BOD attenuation curve shown in FIG.

  FIG. 7 shows a BOD attenuation curve representing the degree of attenuation of the BOD concentration in the liquid phase in the microorganism reaction tanks 10a, 10b, and 10c and the water channels 11a, 11b, and 11c.

The BOD attenuation curve shown in FIG. 7 indicates the degree of attenuation of the BOD concentration based on a measurement certificate obtained by analysis by an authorized analysis organization (private company).
In FIG. 7, the horizontal axis represents the time axis until the input sewage moves through the treatment apparatus and is discharged. The microbial reaction tanks 10 a, 10 b, 10 c of the water tanks 1 a, 1 b, 1 c and the water channels 11 a, 11 b, 11 c. The vertical axis indicates the BOD concentration (ppm) of the liquid phase in the water tanks 1a, 1b, 1c.

In FIG. 7, first, sewage having a BOD concentration of 740 ppm is introduced into the microbial reaction tank 10a of the water tank 1a. In the microbial reaction tank 10a, there are two types of microbial groups (fixed colonies and free-floating microbial groups). Due to the metabolic action of these microbial groups, the residence time in the water tank 1a (about 3 to 4 hours) , The BOD concentration is attenuated from 740 ppm to about 50 ppm.
Next, the liquid phase in the processing apparatus moves from the water tank 1a to the water tank 1b, and the BOD concentration attenuates from about 50 ppm to about 5 ppm in the residence time (3 to 4 hours) in the water tank 1b. Furthermore, it moves from the water tank 1b to the water tank 1c, and the BOD concentration is attenuated from about 5 ppm to about 2 ppm.

  That is, the organic matter contained in the sewage was decomposed by the metabolic action of the microorganism group, and the sewage having a BOD concentration of 740 ppm was purified to about 2 ppm. Further, this numerical value of BOD concentration of 2 ppm indicates that almost colorless and transparent treated water was obtained.

Therefore, it can be seen from the BOD attenuation curve shown in FIG. 7 that the treatment apparatus of Experimental Example 1 was able to treat sewage.
In Experimental Example 1, sewage with a BOD concentration of 740 ppm was used. However, sewage with a higher concentration than this, for example, sewage with about 1200 ppm can be treated. In that case, the BOD concentration can be lowered by making the residence time in the microorganism reaction tank longer than in this experiment. Moreover, it can respond to the sewage whose BOD density | concentration discharged | emitted from a food processing factory etc. exceeds 3000 ppm by increasing the number of the water tanks which consist of a microbial reaction tank and a water channel rather than the processing apparatus of Experimental example 1. FIG. . For example, one water tank is further added to the three water tanks of Experimental Example 1, and high concentration wastewater can be treated by reducing the BOD concentration of wastewater from 3000 ppm to 1200 ppm in the added water tank.

Moreover, in Experimental example 1, the sewage treatment daily amount put into the treatment apparatus was 3 to 5 m ³ (2 to 4 L per minute), but when it is necessary to treat more sewage, By increasing the bottom area of the processing apparatus, the volume of the processing apparatus can be increased.
In particular, in a scene where the daily processing amount exceeds 500 m ³ , it is effective to arrange the processing devices configured in a multistage manner in parallel. For example, when the daily processing amount is 500 m ³ , the processing amount of one row of processing devices is 100 m ³ / day, and five rows of processing devices are arranged in parallel to treat this sewage.
In such a case, it is also important to satisfy the structural standard (strength etc.) of the building in order to configure the processing apparatus.

  Next, it demonstrates that a planktonic microorganism group is not discharged | emitted from the processing apparatus of Experimental example 1 when processing sewage using FIGS. 8-10.

  FIG. 8 shows the amount of microorganisms floating in the liquid phase in the microorganism reaction tanks 10a, 10b, and 10c and the water channels 11a, 11b, and 11c.

The amount of microorganisms shown in FIG. 8 is obtained by collecting the liquid phase in the microorganism reaction tanks 10a, 10b, and 10c and the water channels 11a, 11b, and 11c in a 500 cc beaker, and then allowing the beaker to stand for 30 minutes. Precipitating floating microorganisms. And the scale of 500 cc in a beaker was made into 100%, and the amount of microbial precipitation was represented by the ratio for which the microorganism group which settled occupied in the 500 cc beaker.
In FIG. 8, the horizontal axis represents the time axis until the input sewage moves through the treatment apparatus and is discharged. The microbial reaction tanks 10 a, 10 b, 10 c of the water tanks 1 a, 1 b, 1 c and the water channels 11 a, 11 b, 11 c The vertical axis indicates the amount of precipitation (%) of the microorganism group in the microorganism reaction tanks 10a, 10b, 10c and the water channels 11a, 11b, 11c.

From FIG. 8, the amount of microbial precipitation in the microbial reaction tank 10a of the water tank 1a was about 35%, and the amount of microbial precipitation in the water channel 11a was about 15%. Further, it was about 12% in the microbial reaction tank 10b of the water tank 1b, about 5% in the water channel 11b, about 3% in the microbial reaction tank 10c in the water tank 1c, and less than 1% in the water channel 11c.
In other words, the amount of precipitates decreases as the time elapsed since the sewage was introduced, and the amount of microorganisms in the water channel is reduced in the water channel than in the microbial reaction tank even in the same water tank.

Thus, in the same water tank, the amount of sediment differs greatly between the microorganism reaction tank and the water channel, and the amount of sediment in the water channel is larger and lower than that in the microorganism reaction tank. This indicates that the amount of microorganisms floating in the liquid phase in the water channel is very small compared to that in the microorganism reaction tank.
Since there are no microorganisms in the liquid phase in the water channel, the microorganisms in this liquid phase are thought to have moved into the water channel as the liquid phase moved. It is done.
In other words, the amount of microorganisms in the channel is significantly lower than the amount of microorganisms in the microorganism reaction tank. When the liquid phase moves from the microorganism reaction tank to the channel, the partition plate separating the microorganism reaction tank from the channel. This means that the movement of the microbial group is hindered.
Therefore, by separating the microbial reaction tank and the water channel by the partition plate, the floating microorganism group in the liquid phase can be circulated in the microbial reaction tank, and the sewage can be treated without discharging the microbial group from the treatment apparatus. It can be carried out.

  Next, FIG. 9 shows the transparency of the liquid phase in the microorganism reaction tanks 10a, 10b, and 10c and the water channels 11a, 11b, and 11c.

  The transparency shown in FIG. 9 is obtained by measuring the liquid phase in the microorganism reaction tanks 10a, 10b, and 10c and the water channels 11a, 11b, and 11c using a “permeability meter” defined by JIS. The fluorometer is a glass container having a diameter of 50 mm and a length of 500 mm, and a plate (JIS designation) with a cross mark is provided on the bottom of the container. The liquid phase in the microbial reaction tanks 10a, 10b, and 10c and the water channels 11a, 11b, and 11c was collected on this fluorometer, and the water depth at which the cross mark on the bottom of the container was visible was measured.

  In FIG. 9, the horizontal axis represents the time axis until the input sewage moves through the treatment apparatus and is discharged. The microbial reaction tanks 10 a, 10 b, 10 c of the water tanks 1 a, 1 b, 1 c and the water channels 11 a, 11 b, 11 c The vertical axis indicates the transparency (cm) of the liquid phase in the microorganism reaction vessels 10a, 10b, 10c and the water channels 11a, 11b, 11c.

  As shown in FIG. 9, in the sample collected from the microbial reaction tank 10a of the water tank 1a, the transparency was approximately 0 cm. However, in the sample of the water channel 11a, it is 5 cm, and it can be seen that the transparency is increased. And the transparency of the microbial reaction tank 10b of the water tank 1b was 10-15 cm, and the transparency of the water channel 11b was 20 cm. The transparency of the microbial reaction tank 10c of the water tank 1c was 25 to 30 cm, and the transparency of the water channel 11c was 50 cm or more.

Thus, the transparency of the liquid phase increases as time passes after the sewage is introduced. This indicates that the amount of visible impurities such as organic matter and microorganisms in the sewage contained in the liquid phase decreased while the liquid phase moved from the water tank 1a to the water tank 1c.
In particular, the transparency of the liquid phase in the water channel 11c being 50 cm or more indicates that there are almost no impurities such as microorganisms. It can be seen that the transparency of 50 cm or more is very excellent, for example, compared to the transparency of BOD of 20 ppm or less by the water pollution prevention method being 30 cm or more.

  Next, FIG. 10 shows the density of the floating microorganism group in the liquid phase in the microorganism reaction tanks 10a, 10b, and 10c and the water channels 11a, 11b, and 11c.

The density of the floating microorganism group shown in FIG. 10 was measured by converting the microorganism group in the microorganism reaction tanks 10a, 10b, and 10c and the water channels 11a, 11b, and 11c into the weight of SS (Suspended Solid). The SS weight is measured in accordance with JIS with a diameter of 2 mm or less and the filter paper (6 types) remaining in the eye. After weighing with the dry weight (g) of SS, The density when it was assumed that it was dissolved was expressed in units of ppm (g / m ³ ).

  In FIG. 10, the horizontal axis represents the time axis until the input sewage moves through the treatment apparatus and is discharged, and the microbial reaction tanks 10 a, 10 b, 10 c of the water tanks 1 a, 1 b, 1 c and the water channels 11 a, 11 b, 11 c. The vertical axis indicates the density (ppm) of the floating microorganism group in the microorganism reaction tanks 10a, 10b, 10c and the water channels 11a, 11b, 11c.

  From FIG. 10, the density of the floating microorganism group in the microorganism reaction tank 10a of the water tank 1a is 400 ppm, and 22 ppm in the water channel 11a. Moreover, it was 42 ppm in the microbial reaction tank 10b of the water tank 1b, 2 ppm in the water channel 11b, 18 ppm in the microbial reaction tank 10c of the water tank 1c, and 1 ppm or less in the water channel 11c.

In the microbial reaction tank 10a of the water tank 1a, the density of the floating microorganism group of 400 ppm means that 336 g (dry weight) of SS is mixed in the volume of 0.84 m ³ of the microbial reaction tank 10a. And in the water channel 11a of the water tank 1a, the density of the floating microorganism group of 22 ppm represents that about 2.5 g of SS is mixed in the volume of the water channel 11a of 0.11 m ³ .
That is, only about 0.75% of the floating microorganism group moved from the microorganism reaction tank 10a to the water channel 11a, and about 99.25% of the floating microorganism group remained in the microorganism reaction tank 10a. Yes.

In the microbial reaction tank 10b of the water tank 1b, the density of the floating microorganism group of 42 ppm means that about 35 g of SS is mixed. And in the water channel 11b of the aquarium 1b, the density of the floating microorganism group of 2 ppm represents that about 0.2 g of SS is mixed.
That is, only about 0.57% of the floating microorganism group moved from the microorganism reaction tank 10b to the water channel 11b, and about 99.43% of the floating microorganism group remained in the microorganism reaction tank 10b. Yes.
Further, when the SS content weight of about 35 g in the microbial reaction tank 10b is compared with the SS content weight of 336 g in the microbial reaction tank 1a, the SS content weight is reduced by about 89.6% in the microbial reaction tank 10b.

Furthermore, the density of the floating microorganism group in the microbial reaction tank 10c of the water tank 1c is 4 ppm, which means that about 3.4 g of SS is mixed. And in the water channel 11c of the water tank 1c, the density of the floating microorganism group is 1 ppm or less indicates that the weight of the mixed SS component is 0.1 g or less.
In other words, only about 2.9% of the floating microorganisms moved from the microorganism reaction tank 10c to the water channel 11c, and about 97.1% of the floating microorganisms remained in the microorganism reaction tank 10c. .
Furthermore, when the SS content weight of about 3.4 g in the microbial reaction tank 10c is compared with the SS content weight of about 35 g in the microbial reaction tank 10b, the SS content weight is reduced by about 90.3% in the microbial reaction tank 10c. Become. When the SS content weight of about 3.4 g in the microbial reaction tank 10c is compared with the SS content weight of 336g of the microbial reaction tank 10a, the SS content in the microbial reaction tank 10c is reduced by about 99%.
Moreover, when the SS content weight of 0.1 g or less in the water channel 11c of the water tank 1c is compared with the SS content weight of 336g in the microorganism reaction tank 10a of the water tank 1a, the SS content in the water channel 11c is reduced by 99.9% or more. Become.

Thus, it can be seen that the amount of floating microorganisms in the liquid phase decreases as the water tank 1a progresses to the water tank 1c.
This shows that the movement of the floating microorganism group from the microorganism reaction tank to the water channel is prevented by providing the partition plate in the water tank.
Accordingly, by providing a water channel separated from the microbial reaction tank, and providing the water flow ports 9a, 9b and the discharge port 9 there, the floating microorganism group in the liquid phase can be circulated in the microbial reaction tank. The sewage can be treated with almost no microorganisms discharged from the apparatus.

(Experimental example 2)
Next, the number of stages is reduced by one from the three-stage processing apparatus using the water tanks 1a, 1b, and 1c used in Experimental Example 1, and the processing apparatus of Experimental Example 2 is configured as a two-stage processing apparatus using the water tanks 1a and 1b. The wastewater containing oil and fat was treated. Since the processing apparatus used in Experimental Example 2 has the same configuration as the processing apparatus described as the second embodiment except that the water tank has two stages of water tanks 1a and 1b, FIG. 3A is also used in the following description. It demonstrates using the same code | symbol as -C.

Each dimension of the processing apparatus produced in this experimental example 2 is as follows.
In addition, since the water tanks 1a and 1b of the processing apparatus are both configured to have the same size, the dimensions of the apparatus will be described only for the water tank 1a and omitted for the water tank 1b.

As for the plane dimensions of the water tank 1a, the microorganism reaction tank 10a is 750 mm in length and width, the water channel 11a is 750 mm in length and 100 mm in width, and the effective water depth is both 1,500 mm. Therefore, the effective volume of the microbial reactor 10a is about 0.84 m ^3, the effective volume of the water channel 11a is about 0.11 m ^3, total effective volume of the tank 1a is about 0.96 m ^3.
The length of the whole processing apparatus which added the water tank 1b to the water tank 1a is 1700 mm, and a volume is about 1.91 m < ³ >.

  The air lifter 4 has a total length of 300 mm and an inner diameter of 50 mm, and the lower end of the air lifter 4 is installed at a position 150 mm away from the bottom surface of the water tank 1a. And the diameter of the front-end | tip of the air supply pipe 6 installed in the lower part of the air lifter 4 is 15 mm.

The dimension of the microorganism-adhering contact material constituting the fixed bed 3 is 200 × 200 × 500 mm, and 16 microorganism-adhering contact materials are arranged around the inner cylinder 2 (four stages, four rows). The total surface area of the material is about 8.0 m ² .
The inner cylinder 2 is about 300 × 300 mm.

  The interval between the partition plate 5 and the water tank 1a for the liquid phase to move from the microorganism reaction tank 10a to the water channel 11a is 100 mm.

The sewage was treated by introducing the sewage into the treatment apparatus having the above-described configuration.
The sewage to be input has a BOD concentration of 850 ppm and an oil and fat concentration of 150 ppm, and the input amount is ^{3 to} 5 m ³ (2 to 4 L / min) per day of sewage treatment.

  Next, a state in which sewage containing oil and fat charged in the apparatus is treated using the BOD attenuation curve and the oil and fat attenuation curve shown in FIG. 10 will be described.

  FIG. 10 shows a BOD attenuation curve that represents the degree of attenuation of the BOD concentration in the liquid phase in the microorganism reaction tanks 10a and 10b and the water channels 11a and 11b, and an oil and fat attenuation curve that represents the degree of attenuation of the oil and fat.

The BOD attenuation curve and the fat / oil attenuation curve shown in FIG. 10 indicate the degree of attenuation of the BOD concentration and the oil / fat concentration based on a measurement certificate obtained by analysis by an authorized analysis organization (private company).
In FIG. 10, the horizontal axis indicates the time axis until the input sewage moves through the treatment apparatus and is discharged, as the microorganism reaction tanks 10 a and 10 b and the water channels 11 a and 11 b of the water tanks 1 a and 1 b, and the vertical axis indicates The BOD concentration (ppm) and the fat and oil content concentration (ppm) of the liquid phase in the water tanks 1a and 1b are shown.

In FIG. 10, first, sewage having a BOD concentration of 850 ppm and an oil and fat content of 150 ppm is charged into the microorganism reaction tank 10a of the water tank 1a. In the microbial reaction tank 10a, there are two types of microbial groups (fixed colonies and free-floating microbial groups). Due to the metabolic action of these microbial groups, the residence time in the water tank 1a (about 3 to 4 hours) The BOD concentration is attenuated from 850 ppm to about 80 ppm, and the fat and oil concentration is attenuated from 150 ppm to about 60 ppm.
Next, the liquid phase in the processing apparatus moves from the water tank 1a to the water tank 1b, and in the residence time (3 to 4 hours) in the water tank 1b, the BOD concentration is attenuated from about 80 ppm to about 40 ppm, and the fat and oil concentration is about Attenuation from 60 ppm to 10 ppm.

  That is, the organic matter and fats and oils contained in the sewage were decomposed by the metabolic action of the microorganism group, and the sewage having a BOD concentration of 850 ppm and a fats and oils concentration of 150 ppm was purified to a BOD concentration of about 40 ppm and a fats and oils concentration of about 10 ppm. It shows that.

  As described above, the fixed colonies of the fixed bed 3 provided in the treatment apparatus exhibit various biota, so that the microorganism group includes a group of microorganisms that secrete enzymes that degrade fats and oils. The function enables hydrolysis of fats and oils. Oils and fats are decomposed into water-soluble fatty acids (carboxylic acids) and glycerin by hydrolysis, but if they are short-chain carboxylic acids, they are oxidized by the metabolism of microorganisms as well as organic substances contained in wastewater. Can be disassembled.

Therefore, from the BOD attenuation curve and the fat / oil attenuation curve shown in FIG. 10, it is possible to treat both the organic matter and the oil / fat contained in the sewage by using the treatment apparatus of Experimental Example 2.
In Experimental Example 2, sewage having a BOD concentration of 850 ppm and an oil / fat concentration of 150 ppm was used, but sewage having a higher concentration than this, for example, a sewage having a BOD concentration of 4000 ppm or more and an oil / fat concentration of about 200 ppm is treated. Is also possible. In that case, the BOD concentration and the fat and oil content concentration can be lowered by making the residence time in the microorganism reaction tank longer than in this experiment. Furthermore, it is possible to cope with high-concentration sewage by increasing the number of water tanks including microbial reaction tanks and water channels as compared with the treatment apparatus of Experimental Example 2. For example, it is possible to treat high-concentration sewage by adding one more aquarium to the two aquariums in Experimental Example 2 and treating sewage.

  The present invention is not limited to the above-described configuration, and various other configurations can be employed without departing from the gist of the present invention.

It is the perspective view (A) of the processing apparatus of the 1st Embodiment of this invention, and sectional drawing (B) of the processing apparatus of the 1st Embodiment. It is a block diagram of the air lifter used in embodiment. It is the perspective view (A) of the processing apparatus of the 2nd Embodiment of this invention, a top view (B), and sectional drawing (C). It is the figure (A) which shows the mode of the microorganisms in the processing apparatus of the 2nd Embodiment of this invention, and sectional drawing (B) of the processing apparatus of 2nd Embodiment. It is a figure which shows the air supply amount to the processing apparatus of Experimental example 1. FIG. It is a figure which shows the dissolved oxygen value in the processing apparatus of Experimental example 1. FIG. It is a figure which shows the BOD attenuation | damping curve of Experimental example 1. FIG. It is a figure which shows the amount of deposits in the liquid phase in the processing apparatus of Experimental example 1. FIG. It is a figure which shows the transparency of the liquid phase in the processing apparatus of Experimental example 1. FIG. 6 is a diagram showing the density of a liquid phase microorganism group in the treatment apparatus of Experimental Example 1. FIG. It is a figure which shows the BOD attenuation | damping curve and fat-and-oils attenuation curve of Experimental example 2. FIG. It is sectional drawing of the conventional processing apparatus. It is sectional drawing of the conventional processing apparatus. It is a figure which shows the structure of the microorganisms adhesion contact material used for the processing apparatus of the former and this Embodiment.

Explanation of symbols

  1, 1a, 1b, 1c Water tank, 2 Inner cylinder, 3 Fixed floor, 4 Air lifter, 5 Partition plate, 6 Air supply pipe, 7a, 7b Bulkhead, 8 Sewage inlet, 9 Outlet, 9a, 9b Water inlet, 10, 10a, 10b, 10c Microbial reactor, 11, 11a, 11b, 11c water channel, 12 liquid surface, 20, 20a, 20b, 20c, 20d air mass, 21 upward flow, 21a horizontal flow, 21b downward flow, 21c, 21d suction flow, 25 guide vanes, 26a, 26b triangular partition plate, 27 protrusions, 30a, 30b, 30c ceramic material, 31a, 31b, 31c colony, 32a, 32b, 32c planktonic microorganisms

Claims (5)

A tank,
A partition plate that divides the water tank into a microbial reaction tank and a water channel by completely blocking the liquid surface portion in the water tank and partitioning into a configuration that allows water to flow at the bottom of the water tank,
An inlet for introducing sewage into the microorganism reaction tank;
An air supply pipe for supplying air to the microorganism reaction tank;
An air lifter provided above the air supply pipe;
An inner cylinder provided above the air lifter so as not to directly blow the air bubbles from the air supply pipe and the air lifter to the fixed floor;
A fixed bed having a microorganism-adhering contact material provided around the inner cylinder in the microorganism reaction tank, in which the microorganism group adheres to form a colony of the microorganism group;
A sewage treatment apparatus comprising: a sewage discharge port provided in the water channel and through which sewage treated in the microorganism reaction tank is discharged.   In the wastewater treatment apparatus, air bubbles supplied from the air supply pipe into the water tank rise through the air lifter, and the upward flow generated by the air bubbles is generated in the water tank. The liquid in the water tank moves from the liquid surface to a downward flow through the fixed bed, and the liquid in the water tank moves from the lower part of the water tank to the discharge port through the water channel. The sewage treatment apparatus as described in 1.   3. The sewage according to claim 1, wherein a plurality of the water tanks are provided in a multi-stage manner, and a sewage discharge port of the preceding water tank and a sewage input port of the subsequent water tank are connected to each other. Processing equipment.   The sewage treatment apparatus according to any one of claims 1 to 3, wherein the inner cylinder is provided near the liquid level of the microorganism reaction tank and with a gap at the bottom of the water tank. Dividing the water tank into a microbial reaction tank and a water channel by a partition plate,
As two utilization forms of a colony group and a floating microorganism group, a microorganism group to be used by providing a fixed bed composed of a microorganism adhesion contact material around the inner cylinder of the microorganism reaction tank,
Taking a predetermined amount of sewage per hour continuously into the aquarium,
By continuously supplying air into the microbial reactor, and placing the sewage of the microbial reactor in an aerobic environment with a high concentration of dissolved oxygen,
The organic matter contained in the sewage in the microorganism reaction tank is decomposed by a degrading enzyme secreted by the microorganism group,
The floating microorganism group in the microorganism reaction tank is kept inside the microorganism reaction tank by the partition plate provided in the water tank,
The wastewater treated by the decomposition is discharged from the microorganism reaction tank through the lower part of the partition plate and discharged from the discharge port to the outside of the water tank through the water channel.

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