JPH0985294A - Waste water treatment equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste water treatment equipment efficiently and inexpensively removing an oils and fats component and org. matter in waste water to obtain reclaimed water and stably performing removal treatment. SOLUTION: This waste water treatment equipment is equipped with an oils and fats decomposition tank 2 decomposing oils and fats in waste water, an org. matter decomposition tank 3 decomposing org. matter in waste water flowing in from the oils and fats decomposition tank 2 and a filter device 4a filtering waste water flowing out of the org. matter decomposition tank 3. Air diffusing pipes 15, 16 aerating waste water are respectively provided to the oils and fats decomposition tank 2 and the org. matter decomposition tank 3. An aerobic bacteria preparation capable of decomposing oils and fats is charged in the oils and fats decomposition tank from a chemical agent supply pipe 11 and activated sludge capable of decomposing org. matter is charged in the org. matter decomposition tank 3 from a sludge supply pipe 11a. Further, carriers 23, 24 supporting bacteria in waste water are provided to the oils and fats decomposition tank 2 and the org. matter decomposition tank 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste water treatment facility for treating waste water, for example, waste water containing a large amount of fats and oils such as kitchen waste water to obtain intermediate water.

[0002]

2. Description of the Related Art As a conventional wastewater treatment facility of this type,
Aeration treatment is performed on the wastewater that has flowed from the raw water tank to the oil decomposition tank to activate the decomposition of oil and fat contained in the wastewater, and then the wastewater that has flowed into the pressurized flotation separation tank from the oil decomposition tank is subjected to aeration processing. While adding oil and fat separation and floating agent, pressurize and depressurize in this state to float the oil and fat on the surface of the water, and remove the floating oil and fat by a fat and oil removing device such as a scraper, then pressurize. It is known that the wastewater flowing out of the flotation tank is filtered with a membrane treatment device having an ultrafiltration membrane or the like to remove organic substances, suspended matters and the like in the wastewater to obtain middle water.

[0003]

However, in such a conventional wastewater treatment facility, it is difficult to completely separate the oil and fat component of the wastewater in the pressure flotation separation tank, and the oil flows out of the pressure flotation separation tank. Since a high proportion of oil and fat remains in the wastewater, the load on the membrane treatment equipment becomes large and it becomes necessary to replace and clean the membrane frequently.As a result, the maintenance work of the equipment becomes very troublesome. If the water quality of the wastewater flowing out from the pressure flotation separation tank deteriorates and fluctuates, the membrane treatment equipment cannot cope with the load fluctuation and the performance can be fully demonstrated. However, there is a problem that it becomes difficult to use it as tap water.

In addition, not only a bad odor is generated during the treatment to deteriorate the treatment environment, but also a large amount of oil and fat is floated on the water surface in the pressure flotation separation tank, which makes the extraction work very troublesome. There is a problem in that the processing cost is further increased due to the complicated operation and maintenance work of the device. Furthermore, when the wastewater flowing out of the pressure flotation separation tank is replaced with a membrane treatment device, for example, when treated with an activated sludge method, it is difficult to deal with the load fluctuation due to the deterioration of water quality, and the pressure flotation is also performed. When the amount of organic matter remaining in the wastewater from the separation tank is extremely small, there is a problem that the concentration of activated sludge in the wastewater is lowered and the treatment becomes difficult.

The present invention has been made in order to eliminate such inconvenience, and it is possible to decompose and remove oil and fat components and organic substances in wastewater efficiently and at low cost to obtain intermediate water, and to perform the removal treatment. An object is to provide a wastewater treatment facility that can be stably performed.

[0006]

In order to achieve such an object, the wastewater treatment facility according to claim 1 is a wastewater treatment facility that treats wastewater to obtain intermediate water, and oil and fat in the wastewater. An oil and fat decomposing tank for decomposing oil, an organic matter decomposing tank for decomposing organic matter in the wastewater flowing from the oil and fat decomposing tank, a first aeration means for aerating the wastewater in the oil and fat decomposing tank, and the organic matter decomposing tank Aerobic microbial preparation capable of decomposing oil and fat in the oil and fat decomposing tank, comprising a second aerating means for aerating the effluent of the same and a filtering means for filtering the effluent of which the organic matter has been decomposed in the organic matter decomposing tank. In addition to the addition of activated sludge capable of decomposing organic matter into the organic matter decomposing tank, a carrier for supporting microorganisms in wastewater is further provided in the oil and fat decomposing tank and the organic material decomposing tank, respectively. .

The wastewater treatment facility according to claim 2 is characterized in that an aerobic microbial preparation capable of decomposing organic matter is added to the organic matter decomposing tank in place of the activated sludge. In the wastewater treatment facility according to claim 3, the filtering means is
It is characterized by having a filtration layer of sand or activated carbon.

[0008]

According to the first aspect of the present invention, while the wastewater is subjected to aeration treatment in the oil and fat decomposition tank, the oil and fat content in the wastewater is decomposed and removed by the aerobic microorganisms, and the oil and fat content is decomposed and removed in the organic matter decomposition tank and remains in the wastewater. The organic matter is decomposed and removed by activated sludge while subjecting the wastewater to aeration treatment. In addition, by installing a carrier that supports microorganisms in wastewater in the oil and fat decomposition tank and organic matter decomposition tank, respectively, it is possible to maintain a certain level of microorganisms in each tank at all times, thereby stabilizing the oil and fat and organic substances contained in the wastewater. It enables the decomposition process. Then, by filtering the wastewater in which the organic matter is decomposed in the organic matter decomposing tank by the filtering means, the fats and oils contained in the wastewater, organic substances, suspended substances, pigments, etc. are removed, and the concentration of the fats and oils, etc. It makes it possible to obtain very low treated water, for example tap water that can be reused as toilet wash water other than drinking water.

According to the second aspect of the present invention, while the wastewater is subjected to aeration treatment in the oil and fat decomposition tank, the oil and fat content in the wastewater is decomposed and removed by aerobic microorganisms, and the oil and fat content is decomposed and removed in the organic matter decomposition tank and remains in the wastewater. The organic substances are decomposed and removed by aerobic microbial preparation while subjecting the wastewater to aeration treatment. In addition, by installing a carrier that supports microorganisms in wastewater in the oil and fat decomposition tank and organic matter decomposition tank, respectively, it is possible to maintain a certain level of microorganisms in each tank at all times, thereby stabilizing the oil and fat and organic substances contained in the wastewater. It enables the decomposition process. Then, by filtering the wastewater in which the organic matter is decomposed in the organic matter decomposing tank by the filtering means, the fats and oils contained in the wastewater, organic substances, suspended substances, pigments, etc. are removed, and the concentration of the fats and oils, etc. It makes it possible to obtain very low treated water, for example tap water that can be reused as toilet wash water other than drinking water.

According to the invention of claim 3, in addition to the invention of claim 1 or 2, by using, as the filtering means, one having a filter layer of sand or activated carbon, as compared with the case of using a membrane treatment device or the like. It is possible to simplify the equipment cost and structure of wastewater treatment equipment.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An example of an embodiment of the present invention will be described below with reference to FIG. FIG. 1 is an explanatory schematic diagram for explaining wastewater treatment equipment which is an example of an embodiment of the present invention. Explaining the configuration with reference to FIG. 1, the wastewater treatment facility includes a raw water tank 1, a fat and oil decomposing tank 2, an organic matter decomposing tank 3, and a sedimentation tank 4, which are arranged in order from the left side to the right side. The wastewater that has flowed into the raw water tank 1 is circulated in the order of the oil / fat decomposition tank 2, the organic matter decomposition tank 3 and the precipitation tank 4 to purify the wastewater, and the treated water that has flowed out of the precipitation tank 4 is subjected to a sand or activated carbon filter layer. By passing through the filtering device 4a (filtering means) that it has, it is possible to obtain the inside water that can be reused as toilet wash water.

Waste water flows into the raw water tank 1 through a raw water introducing pipe 5, and a screen 6 for removing dust and the like in the waste water is interposed in the raw water introducing pipe 5. Raw water tank 1
A pump 7 is arranged inside. One end of an introduction pipe 8 is connected to the pump 7, and the other end of the introduction pipe 8 is introduced into the fat and oil decomposition tank 2. By driving the pump 7, the waste water in the raw water tank 1 is transferred into the fat and oil decomposition tank 2. Further, the sidewalls of the fat and oil decomposing tank 2 and the organic substance decomposing tank 3 facing each other and the sidewalls of the organic material decomposing tank 3 and the precipitating tank 4 facing each other are connected under the water surface by communication pipes 17 and 18, respectively. There is. As a result, the wastewater in the oil / fat decomposition tank 2 is sequentially transferred to the organic matter decomposition tank 3 and the precipitation tank 4 via the communication pipes 17 and 18.

Air diffusers 14, 15 (first aeration means) and 16 (second aeration means) are arranged at the bottoms of the raw water tank 1, the oil / fat decomposition tank 2 and the organic matter decomposition tank 3, respectively. Each air diffuser pipe 14, 15, 16 is connected to the air supply device 12 via an air supply pipe 13. By driving the air supply device 12, air is diffused from the diffuser pipes 14, 15 and 16 so that the wastewater in the raw water tank 1, the oil / fat decomposition tank 2 and the organic matter decomposition tank 3 is subjected to aeration treatment. .

One end of a chemical supply pipe 11 is introduced into the raw water tank 1 and the oil / fat decomposition tank 2, respectively. Drug supply pipe 1
The other ends of 1 merge with each other on the way and are then connected to a drug tank 9 via a pump 10. The drug tank 9 contains an aerobic microbial preparation. By driving the pump 10, the aerobic microbial preparation is added to the raw water tank 1 and the fat and oil decomposing tank 2 from the chemical supply pipe 11, respectively. Here, examples of the aerobic microbial preparation include Hypolka O (trade name; Shikoku Chemicals Co., Ltd.) or F.
There are K Eight Super H bacteria (trade name; Kondo FRP Industry Co., Ltd.) and the like, but they are not particularly limited as long as they are excellent in oil and fat degradability. In aerobic microbial preparations, enzymes and bacteria in the preparation start decomposition and digestion activities of oil and fat components in wastewater, and mutual activity of both decomposes polymer oils and fats at the molecular structure level. It reduces the oil and fat content. It should be noted that by appropriately adding nutrients such as nitrogen and phosphorus to the raw water tank 1 and the oil / fat decomposition tank 2 into which the aerobic microbial preparation is charged, the bacteria in the aerobic microbial preparation are activated, and thereby the decomposition of the oil / fat content is performed. The digestive activity can be made more active.

One end of a sludge supply pipe 11a is introduced into the organic substance decomposition tank 3. The other end of the sludge supply pipe 11a is connected to the sludge tank 9a via a pump 10a. The sludge tank 9a contains activated sludge capable of decomposing organic substances. By driving the pump 10a, the sludge supply pipe 11
Activated sludge is added to the organic substance decomposing tank 3 from a. Here, as the activated sludge, for example, what has been cultivated by a fill and draw system for 3 months in synthetic sewage mainly composed of meat extract / peptone can be used, but the one excellent in degradability of organic matter can be used. It is not particularly limited as long as it is. In addition, in this embodiment, the activated sludge is charged into the organic substance decomposition tank 3 only when the operation of the apparatus is started.

In the oil and fat decomposing tank 2 and the organic matter decomposing tank 3, carriers 23 and 24 for supporting microorganisms in the waste water are arranged, respectively. The carriers 23 and 24 support microorganisms so that the microorganisms always have a certain concentration or more in the waste water, and thereby stable decomposition treatment of oils and fats and organic matter contained in the waste water is possible. Here carriers 23, 24
For example, DB Race (trade name: Davies Inc.) or the like can be used, but is not particularly limited as long as it can favorably carry the microorganisms in the wastewater.

The bottom of the settling tank 4 has an inverted triangular shape in cross section and is formed so as to project downward, and the activated sludge is settled on the projecting bottom. A suction port 19 for sucking the activated sludge is arranged at a position facing the protruding bottom portion of the substantially central portion of the settling tank 4. One end of a sludge return pipe 21 is connected to the suction port 19. The other end of the sludge return pipe 21 is 2
One is introduced into the oil / fat separation tank 2 and the other is introduced into the sludge storage tank 25. Also, sludge return pipe 2
1, an air supply pipe 13 is connected to the position 1 near the suction port 19. By supplying air from the air supply pipe 13 to the sludge return pipe 21, the activated sludge is sucked from the suction port 19 by its air pressure and transferred to the fat decomposition tank 2 as return sludge through the sludge return pipe 21. The part is pulled out as excess sludge and stored in the sludge storage tank 25.

A drainage pipe 22 is provided on the wall of the settling tank 4 which is separated from the wall on the side of the connecting pipe 18 at substantially the same level as the water surface. Further, a partition wall 20 is provided between the sludge return pipe 21 and the drain pipe 22 in the settling tank 4, so that the drainage flowing from the communication pipe 18 into the settling tank 4 does not directly flow into the drain pipe 22. It has become.
The treated water flowing out from the drain pipe 22 is filtered by the filtering device 4a having a filter layer of sand or activated carbon.

Next, the operation of the waste water treatment facility will be described. For the wastewater flowing from the raw water introduction pipe 5 into the raw water tank 1,
An aerobic microbial preparation is introduced from the drug supply pipe 11, and aeration treatment is performed by the air emitted from the air diffusion pipe 14. As a result, the oil and fat content in the waste water is decomposed to some extent, and the decomposed waste water is driven by the pump 7 to introduce the introduction pipe 8
Through the oil and fat decomposition tank 2.

In the oil and fat decomposing tank 2, similarly, an aerobic microbial preparation is introduced from the chemical supply pipe 11, and air is supplied from the diffuser pipe 15 to perform aeration treatment, thereby decomposing the oil and fat in the waste water. Is done. At this time, since the carrier 23 for supporting the microorganisms in the wastewater is arranged in the oil and fat decomposing tank 2, microorganisms having a certain concentration or more are always fixed in the wastewater, whereby the fats and oils contained in the wastewater are removed. Stable decomposition processing is performed. The aerobic microbial preparation fed from the medicine feeding pipe 11 and the air fed from the diffuser pipe 15 are fed in a larger amount than in the raw water tank 1 and the treatment time is long. Then, when the oil and fat is decomposed to a predetermined degree, the wastewater is transferred to the organic substance decomposition tank 3 through the communication pipe 17.

In the organic substance decomposing tank 3, the activated sludge is introduced from the sludge supply pipe 11a into the wastewater from which the oil and fat components in the wastewater which reduce the treatment efficiency of the activated sludge in the raw water tank 1 and the oil and fat decomposing tank 2 are removed. At the same time, air is supplied from the air diffusing pipe 16 to perform aeration treatment, whereby the organic substances in the wastewater are decomposed. At this time, in the organic substance decomposing tank 3, as in the fat and oil decomposing tank 2, the carrier 2 that carries the microorganisms in the wastewater
Since No. 4 is arranged, microorganisms having a certain concentration or more are always immobilized in the wastewater, and thereby stable decomposition treatment of organic matter contained in the wastewater is performed. The amount of air supplied from the air diffuser 16 is approximately the same as in the case of the oil / fat decomposition tank 2, but the processing time is shorter than that of the oil / fat decomposition tank 2. When the organic substances are decomposed to a predetermined extent, the waste water is transferred to the settling tank 4 through the communication pipe 18.

In the settling tank 4, the waste water flowing in from the communication pipe 18 is temporarily stored in front of the partition wall 20 and is solid-liquid separated into a supernatant and an activated sludge settled at the bottom. The supernatant liquid flows out from the drainage pipe 22 as the treated water under the partition wall 20, the activated sludge is sucked from the suction port 19 by the air pressure from the air supply pipe 13, and then the sludge return pipe 21 returns the oil and fat as the returned sludge. While being returned to the decomposition tank 2, a part is withdrawn as excess sludge and stored in the sludge storage tank 25. The activated sludge returned to the oil / fat decomposition tank 2 takes in the oil / fat component in the waste water and decomposes it.

The treated water flowing out from the drainage pipe 22 is filtered through the filtration device 4a to remove oils and fats, organic matters, suspended substances, pigments and the like contained in the treated water to remove the oils and fats. The concentration is made extremely low so that the treated water can be reused as raw water for drinking water for purposes other than drinking water, for example, toilet wash water. As described above, in this embodiment, after the oil and fat content in the wastewater that reduces the organic matter decomposition treatment efficiency of the activated sludge is removed in the raw water tank 1 and the oil and fat decomposition tank 2, the organic matter decomposition tank 3 The organic matter is decomposed to satisfactorily remove oils and fats and organic matter in the wastewater, thereby reducing the proportion of oils and fats and the like remaining in the wastewater flowing out from the organic matter decomposition tank 3 as compared with the conventional one. By treating the wastewater flowing out from the decomposition tank 3 with the filtration device 4a having the filtration layer of sand or activated carbon, the treated water can be reused as raw water of the intermediate water, so that the conventional membrane treatment device is used. It is not necessary to frequently replace or clean the membrane, and the maintenance work of the wastewater treatment facility is greatly reduced, and the treatment cost can be reduced.

Further, by installing the carriers 23 and 24 in the oil and fat decomposing tank 2 and the organic matter decomposing tank 3, the oil and fat contained in the waste water is always kept in the tanks 2 and 3 so that the microorganisms having a certain concentration or more are kept in each tank. Since stable decomposition treatment of organic matter and organic matter is carried out, load fluctuation of wastewater is remarkably reduced, and reuse of treated water as middle water can be ensured.

Further, unlike the conventional pressure levitation method, it is not a type that floats a large amount of oil and fat on the surface of the water, so that it is possible to almost eliminate the generation of a bad odor, and also to eliminate the work of withdrawing a large amount of oil and fat. Therefore, it is possible to further reduce the processing cost together with the reduction of the maintenance work of the apparatus described above. Furthermore, much of the oil and fat and SS in the wastewater are CO ₂ and H ₂ due to the action of microorganisms.
Since it is converted into O, the amount of excess sludge generated can be reduced as compared with the pressure flotation method, and the treatment cost can be further reduced.

In the above embodiment, the organic substance decomposing tank 3 is used.
An example was given in which activated sludge was added to decompose organic matter in wastewater, but instead of activated sludge, an aerobic microbial preparation excellent in degradability of organic matter, for example, Hypolka O (trade name;
Shikoku Kasei Kogyo Co., Ltd.) can be used to obtain substantially the same effects. In the above embodiment, the first
Although an air diffuser is adopted as the second aeration means, the present invention is not limited to this, and for example, an air diffuser (not shown) may be provided in the oil and fat decomposing tank 2 and the organic matter decomposing tank 3 to perform the aeration process. May be.

In the above embodiment, the case where the treated water flowing out of the drain pipe 22 is treated with a filter having a filter layer of sand or activated carbon in order to simplify the filtering means is taken as an example. There is no need to limit it, and in some cases, the treated water flowing out of the drain pipe 22 may be treated by the membrane treatment device. Even in this case, as described above, the proportion of oil and fat remaining in the drainage flowing out from the drainage pipe 22a is small, so that the load on the membrane treatment device is reduced as compared with the conventional case, and membrane replacement and cleaning are frequently performed. Therefore, the maintenance work of the wastewater treatment facility can be greatly reduced and the treatment cost can be reduced as in the above.

[0028]

[Example] Kitchen drainage (raw water) from an actual hotel building
Was subjected to aerobic continuous wastewater treatment according to the flow shown in FIG. In FIG. 2, reference numeral 31 is an oil and fat decomposing tank in which real kitchen waste water is continuously fed from a raw water tank 38 by a roller pump 39, 32 is an organic matter decomposing tank into which waste water in which an oil and fat content is decomposed in the oil and fat decomposing tank 31 flows, and 33 is an organic matter. Decomposition tank 32
The sedimentation tank in which the wastewater in which the organic matter has been decomposed is solid-liquid separated into a supernatant and activated sludge, and 40 is a treated water tank in which the supernatant (treated water) naturally flows down. The oil and fat decomposing tank 31 and the organic matter decomposing tank 32 are provided with diffusing balls 34 and 35, respectively, for maintaining an aerobic state and stirring in the tank, and aeration of waste water is performed. Air is supplied to the air diffusers 34 and 35 by driving the air compressor 42. Incidentally, reference numeral 41 is an air diffuser 3
It is a flow meter interposed in the air supply pipe between 4, 35 and the air compressor 42.

Hypolka O (trade name; Shikoku Kasei Co., Ltd.) is used in the oil and fat decomposing tank 31, and organic matter decomposing tank 32 is filled with sewage containing meat extract and peptone for 3 months. ) Add the activated sludge cultivated by the method. Further, in the oil and fat decomposing tank 31 and the organic matter decomposing tank 32, carriers 36 and 37 for supporting microorganisms in the waste water are arranged respectively, and microorganisms having a certain concentration or more are always fixed in the waste water so that the oil and fat components contained in the waste water are fixed. In addition, stable decomposition treatment of organic substances can be performed.

Here, sampling is performed on the oil / fat decomposition tank outflow water and the treated water, and the respective hydrogen ion concentration (pH), biochemical oxygen demand (BOD), suspended matter amount (SS), and n-hexane extraction. (N-HEX) and chromaticity values were measured. Table 1 shows the actual kitchen drainage and 2 from the start of operation.
Shows the water quality of the effluent and treated water after a week.
The experiments were performed from Run 1 to Run 4 and the hydraulic retention time of the oil and fat decomposition tank 31 (hereinafter, abbreviated as HRT).
Was unified in 20 hours, but the HR of the organic matter decomposition tank 32
T is 4, 6, for Run 1, 2, 3, 4 respectively
It was set to 8 to 12 hours.

[0031]

[Table 1]

As is clear from Table 1, the oil / fat decomposition tank 31 has an excellent ability to remove BOD and SS.
It can be seen that the removal capacity of HEX is high. In the organic substance decomposition tank 32, BOD, SS, and
It can be seen that all of the n-HEX can be made quite low.
Almost no offensive odor was generated during the treatment, and when the treated water was filtered with activated carbon, the chromaticity dropped to 1 or less.

[0033]

As is apparent from the above description, in the invention of claim 1, the oil and fat decomposing tank is used to remove the oil and fat components in the waste water which reduce the organic substance decomposing efficiency of the activated sludge. The organic matter in the wastewater is decomposed by the sludge to remove the oil and fat and the organic matter in the wastewater well, thereby reducing the ratio of the oil and fat remaining in the wastewater discharged from the organic matter decomposition tank. Since the treated water can be reused as raw water for raw water by filtering the wastewater flowing out from the decomposition tank with a filtering means, the membrane of the membrane treatment device is frequently replaced or cleaned as in the conventional case. There is no need, and the maintenance work of the wastewater treatment facility is greatly reduced, and the treatment cost can be reduced.

By installing a carrier in the oil and fat decomposing tank and the organic matter decomposing tank, a stable decomposition treatment of the oil and fat components and organic matter contained in the wastewater can be carried out so that microorganisms having a certain concentration or more are always kept in each tank. Therefore, it is possible to obtain an effect that the load fluctuation of the waste water is remarkably reduced and the reuse of the treated water as the middle water can be ensured.

Further, unlike the conventional pressure levitation method, it is not a type that floats a large amount of oil and fat on the surface of the water, so that it is possible to almost eliminate the generation of a bad odor and to eliminate the work of withdrawing a large amount of oil and fat. Therefore, it is possible to obtain an effect that the processing cost can be further reduced in combination with the reduction of the maintenance work of the apparatus described above. Furthermore, the amount of surplus sludge generated can be reduced as compared with the conventional pressurized flotation method, so that it is possible to further reduce the treatment cost.

According to the second aspect of the invention, after the oil and fat in the wastewater is removed by the aerobic microbial preparation in the oil and fat decomposing tank, the organic matter in the wastewater is decomposed by the aerobic microbial preparation in the organic matter decomposing tank and the Satisfactorily removes oil and fat and organic matter of the product, thereby reducing the proportion of oil and fat remaining in the wastewater flowing out of the organic matter decomposition tank, and further filtering the wastewater flowing out of the organic matter decomposition tank with a filtering means. As a result, the treated water can be reused as raw water for raw water, which eliminates the need for frequent replacement and cleaning of the membrane of the membrane treatment device as in the conventional case, and the maintenance work of the wastewater treatment facility can be drastically reduced. The effect is obtained that the processing cost is reduced and the processing cost can be reduced.

Further, by installing a carrier in the oil and fat decomposing tank and the organic matter decomposing tank, a stable decomposition treatment of oil and fat components and organic substances contained in the wastewater is carried out so that microorganisms having a certain concentration or more are always kept in each tank. Therefore, it is possible to obtain an effect that the load fluctuation of the waste water is remarkably reduced and the reuse of the treated water as the middle water can be ensured.

Further, unlike the conventional pressure levitation method, it is not a type that floats a large amount of oil and fat on the surface of the water, so that it is possible to almost eliminate the generation of a bad odor, and also to eliminate the work of extracting a large amount of oil and fat. Therefore, it is possible to obtain an effect that the processing cost can be further reduced in combination with the reduction of the maintenance work of the apparatus described above. Furthermore, the amount of surplus sludge generated can be reduced as compared with the conventional pressurized flotation method, so that it is possible to further reduce the treatment cost.

According to the invention of claim 3, in addition to the invention of claim 1 or 2, compared to the case of using a membrane treatment device or the like, by using sand or activated carbon having a filtration layer as the filtration means. The effect that the facility cost and structure of the wastewater treatment facility can be simplified can be obtained.

[Brief description of drawings]

FIG. 1 is an explanatory schematic diagram for explaining wastewater treatment equipment which is an example of an embodiment of the present invention.

FIG. 2 is an explanatory schematic diagram for explaining an example of the present invention.

[Explanation of symbols]

 2 ... Oil and fat decomposing tank 3 ... Organic matter decomposing tank 4a ... Filtration device (filtration means) 15 ... Air diffuser (first aeration means) 16 ... Air diffuser (second aeration means) 23, 24 ... Carrier

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication C02F 3/06 ZAB C02F 3/06 ZAB 3/12 3/12 M (72) Inventor Hisashi Yoshioka Tokyo 1-25-1 Nishi-Shinjuku, Shinjuku-ku, Tokyo Inside Taisei Corporation

Claims (3)

[Claims] 1. A wastewater treatment facility for treating wastewater to obtain intermediate water, which decomposes fats and oils in wastewater, and decomposes organic substances in wastewater flowing from the fats and oils decomposition tank. An organic matter decomposing tank, a first aeration means for aerating the wastewater in the oil and fat decomposing tank, a second aerating means for aerating the wastewater in the organic matter decomposing tank, and an organic matter decomposing treatment in the organic matter decomposing tank Equipped with a filtering means for filtering the discharged wastewater, adding an aerobic microbial preparation capable of decomposing oil and fat to the oil and fat decomposing tank, and introducing activated sludge capable of decomposing organic matter into the organic matter decomposing tank, and A wastewater treatment facility, wherein a carrier for supporting microorganisms in wastewater is provided in each of the oil and fat decomposing tank and the organic matter decomposing tank. 2. The wastewater treatment facility according to claim 1, wherein an aerobic microbial preparation capable of decomposing organic matter is added to the organic matter decomposing tank in place of the activated sludge. 3. The wastewater treatment facility according to claim 1, wherein the filtering means has a filter layer of sand or activated carbon.