JP2003062425A - Malodorous gas treatment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a malodorous gas treatment method constituted so as to deodorize and detoxify a malodorous component generated by the decomposition of organic sewage or the like containing solids such as dust, excretions or the like by effectively putting microorganisms present in water innumerably to practical use without using new heat energy or chemicals such as a deodorant or the like. SOLUTION: Organic sewage is charged in a hermetically closed first treatment tank 1 to be treated and the malodorous gas generated in the first treatment tank is guided into a hermetically closed second treatment tank 6 so as to be discharged as fine gas bubbles through a gas mixing nozzle 3 and subjected to decomposition treatment by the action of microorganisms in the second treatment tank 6 before discharged to the atmosphere.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to organic sewage, for example, human excrement sewage, wastewater discharged from general households, dust such as dust or crushed dust, and other organic sewage.
When sludge and filth (hereinafter referred to as "organic filth water, etc.") is treated by the action of microorganisms, odorous gases such as ammonia gas generated in the biological treatment process can be decomposed more reliably by an inexpensive method. However, the present invention relates to a method for treating malodorous gas that is made odorless.

[0002]

2. Description of the Related Art Conventionally, organic wastewater such as domestic wastewater discharged from each household is led to a sewage treatment plant through a culvert, where it is biologically treated and then the treated water is discharged to a river or the like. The sludge and other precipitates are fried, incinerated, or discarded, but odorous gas including ammonia may be generated in the treatment tank during the treatment process of the sewage. When treating sewage in a lidless treatment tank, the entire gas including the generated malodorous gas is directly discharged into the atmosphere. Also, in the case of a so-called closed type using a lidded treatment tank, the gas body generated in this treatment tank is guided to an incinerator and thermally decomposed or passed through a deodorant layer using activated carbon or the like. After the malodorous gas is adsorbed and deodorized, the treated gas is released into the atmosphere and exhausted. In addition, garbage such as vegetable waste and leftovers generated at homes and businesses is collected by a garbage truck and incinerated at a garbage incinerator.

[0003]

However, in the conventional wastewater treatment of organic wastewater and the like, when an open-type treatment facility using a lidless treatment tank is used, a malodorous gas is released into the atmosphere. However, since it causes a great deal of foul odor pollution to the residents near the treatment plant, as in recent years, a closed treatment facility is often used in an area where the treatment plant and the residential area are in close contact with each other.

However, in order to deodorize and detoxify a gas body containing a malodorous gas generated by this closed type processing facility, thermal decomposition by incineration or adsorption deodorization by a deodorant is carried out. In any of the adsorption deodorizing methods, there is a problem that the treatment is expensive and the deodorizing treatment is expensive. Furthermore, when the malodorous gas is thermally decomposed, carbon dioxide gas is started again, and other gases and There was a problem that a large amount of heat was generated and secondary pollution such as global warming was newly generated. Further, in the method using a deodorant such as activated carbon, there is a problem that the deodorant after the adsorption and deodorization must be disposed of, such as discarding, and this treatment is expensive. In addition, when incinerating garbage such as vegetable waste and leftover food, it is costly and troublesome to dispose of the ash after incineration, and harmful substances such as dioxins are easily generated. It was

Therefore, in view of the problems of the conventional methods for treating wastewater, the present invention aims to activate the innumerable microorganisms existing in water and effectively utilize the microorganisms in water or treated wastewater. , Decontamination of organic filth water containing solids such as dust and human waste, and decomposition of malodorous components, without using new heat energy or chemicals such as deodorizers An object is to provide a method for treating malodorous gas.

[0006]

The method for treating malodorous gas according to the first aspect of the present invention is generated when an aerobic and / or anaerobic treatment is carried out on an organic filth water charged in a closed first treatment tank. The malodorous gas that is discharged into the sealed second treatment tank filled with the treatment water containing the treatment bacteria through the air-mixing nozzle that is formed into fine bubbles in the treatment water, and the second treatment tank It is characterized in that the malodorous components are decomposed by the action of the microorganisms inside and then released into the atmosphere. The term "organic wastewater" used here means domestic wastewater discharged from ordinary households, dust such as dust, crushed dust, sewage flowing into sewage treatment plants, sludge, and livestock produced at livestock farms. It includes human waste.

In the method for treating malodorous gas according to the present invention, biological treatment is carried out by aeration and stirring the organic filth water by flowing all kinds of organic filth water into the first treatment tank. After that, the odorous gas generated in the first treatment tank is discharged into the second treatment tank water filled with the treatment water containing the treatment bacteria (microorganisms) in a state of being mixed with water so as to form fine bubbles. Therefore, part of the malodorous gas dissolves in the water in the second treatment tank, and part of the gas also serves as a nutrient for the microorganisms in the water, and the microorganisms are activated by the action of the microorganisms. Since no other chemicals or heat energy is used, the malodorous component can be continuously decomposed at a lower cost and easier than the conventional method. Further, since no chemicals such as deodorant and thermal energy are used for decomposing the malodorous components, the processing cost is low and the problem of secondary pollution does not occur.

Further, the method for treating malodorous gas according to the second aspect of the present invention is to decompose malodorous components by microorganisms in the second treatment tank according to the concentration of malodorous gas generated in the first treatment tank. It can be diluted with air so that the above can be properly performed.

As described above, when the processing such as fermentation in the first treatment tank is accelerated, the concentration of the malodorous gas discharged from the first treatment tank may increase. By supplying atmospheric air into the second treatment tank, the malodorous gas concentration can be diluted.
Since the concentration of the gas supplied to the processing tank can be adjusted, the decomposition processing of the malodorous gas component in the second processing tank can be performed continuously and efficiently.

Further, in the method for treating malodorous gas according to the third aspect of the present invention, the organic waste water to be charged into the first treatment tank is introduced into the waste water filled in the first treatment tank by an air-mixing nozzle. By crushing the supply air finely by the supplied high-speed water stream and injecting it as fine bubbles, the microorganisms in the wastewater can be activated and aerobic and / or anaerobic treatment can be efficiently performed.

As described above, since the air finely bubbled by the air-mixing nozzle is blown into the wastewater in the first treatment tank, microorganisms in the wastewater, for example, aerobic bacteria,
Alternatively, by activating anaerobic bacteria, the biological treatment of the organic waste water in the first treatment tank is promoted by the microorganism, the treatment can be performed within a relatively short time, and the tank bottom is in an unfermented state. It is possible to promote volume reduction of the amount of settled sludge, reduce the amount of discharged sludge, and reduce the treatment cost including the treatment of residual sludge as a whole.

Further, in the method for treating a malodorous gas according to the fourth aspect of the present invention, fine air bubbles jetted into the first or second treatment tank are formed by using an air-mixing nozzle, and the air-mixing nozzle is Gas is sucked from the nozzle hole by the action of high-speed running water that flows at high speed in the flow path of the nozzle member connected in multiple stages, and it is finely crushed by the high-speed running water and mixed with the high-speed running water and ejected from the nozzle tip into the water. You can

As described above, due to the water flow flowing down the flow passage of the nozzle member connected in a plurality of stages, air or gas is sucked from the nozzle hole by the negative pressure generated in the flow passage and finely crushed by the high-speed running water. Therefore, the solubility of oxygen in water is improved, the residence time in water is lengthened, and the treatment of malodorous gas is promoted. Further, when the air-mixing nozzle is arranged in the waste water, the fragile organic waste in the waste water can be destroyed by the high-speed water flow, and the aerobic fermentation is promoted.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a method for treating malodorous gas in sewage treatment according to the present invention will be described with reference to the drawings. 1 to 3 show an embodiment of the present invention.

The method for treating malodorous gas according to the present invention is described below.
Domestic wastewater and dust discharged from general households, so-called household waste will be explained.This method is used for municipal wastewater treatment facilities by municipalities and human waste treatment facilities at livestock farms where a large amount of human excrement occurs, and other buildings. It can also be used as a wastewater treatment facility for buildings that are more drained, and as a waste treatment facility in food processing plants and business establishments.

[0016] Organic waste water containing domestic refuse (dust) discharged from a home or the like is put into the first treatment tank 1. The first treatment tank 1 is a closed treatment tank having a lid, and a dry compost or sewage treatment tank is adopted.
The sewage treatment tank is filled with a certain amount of sewage and organic sewage water, and the organic sewage water to be introduced into the first treatment tank 1 is sequentially supplied by aerobic or anaerobic microorganisms (bacteria). The biological treatment is performed by a single treatment of aerobic fermentation or anaerobic fermentation, or by alternate treatment of aerobic treatment and anaerobic treatment. At this time, household waste can be charged in a solid state, but it can also be crushed to a predetermined size in advance, and this can be fed from the organic waste water charging pipe 2 to the first treatment tank 1
So that it is supplied from above or from the side.
The organic filth water is added continuously or periodically, which is appropriately selected depending on the treatment method.

Further, in order to accelerate the biological treatment of the organic waste water in the first treatment tank 1, aeration is performed regularly, periodically, or continuously. For this aeration, air can be supplied into the first treatment tank 1 by a diffusing pipe or the like, or sewage can be agitated in the air to be supplied as fine air bubbles. However, in the present invention, air is turned into fine air bubbles. For this purpose, the air-fuel mixture nozzle 3 as shown in FIG. 2 is adopted. This mixture nozzle 3
Is a position where the aeration can be efficiently performed while stirring the waste water in the first treatment tank 1, for example, as shown in the drawing, on the side surface of the inner bottom portion of the first treatment tank 1 from the air-mixing nozzle 3. Arranged so that the mixed water is sprayed into the tank. The water that is supplied to the air-fuel mixture nozzle 3 and flows down at high speed is, as shown in FIG. 1, a pump P that collects the dirty water in the first treatment tank 1 filtered by the strainer S.
To supply water. Thereby, the sewage in the first treatment tank 1 can be circulated and used.

The air-fuel mixture nozzle 3 sucks air or gas at a negative pressure by a high-speed water flow to finely pulverize the air, and ultrasonic waves generated when the gas is miniaturized and when fine bubbles are destroyed. One example is the one that is capable of decomposing odorous components along with the aeration of sewage, and further decomposing and detoxifying harmful substances such as dioxins and PCBs dissolved in water by using a. Other than those shown in the figure can also be adopted.

Further, by injecting fine bubbles into the wastewater in the first treatment tank 1, the activity of the microorganisms contained in the wastewater is activated in the organic wastewater, and the decomposition treatment is promoted. To be done. At this time, the organic substance is decomposed into water and carbon dioxide gas. This treated water is
The drain pipe 5 is arranged so that when the water level in the first treatment tank 1 reaches or exceeds the set position, the water is naturally drained by overflow. This drain pipe is usually connected to the overflow water level, but it can also be drained forcibly by a pump. Most of the solid matter to be added is decomposed in the first treatment tank 1 and reduced in volume, but a small amount of untreated matter may precipitate as sludge on the bottom of the vessel. A sludge discharge pipe 8 for discharging the settled sludge periodically or when it reaches a certain amount is connected to the tank bottom. The mud discharge pipe 8 is provided with a mud discharge valve 9, and the mud discharge valve 9 is opened and closed to enable simple mud discharge.

On the other hand, the decomposed gas body comes to be stored in the sealed upper part of the first processing tank 1, and the pressure rises to some extent. Furthermore, this gas also contains odorous components such as ammonia. Therefore, the gas body generated in the first processing tank 1 is discharged through the exhaust gas pipe 4, which connects the upper part of the first processing tank 1 and the second processing tank 6. 1st treatment tank 1
The gas generated therein is supplied into the second processing tank 6. In addition, the air valve 7 is branched off in the middle of the exhaust gas pipe 4.
1 is connected to an air suction pipe 7 and air is sucked from the atmosphere by opening and closing the air valve 71, and is supplied into the exhaust gas pipe 4 through the air suction pipe 7 to generate in the first treatment tank 1. The gas concentration to be introduced is diluted so that it is introduced into the second treatment tank 6. Thereby, when the malodorous gas is decomposed by using the microorganisms in the water in the second treatment tank 6, the malodorous gas is supplied into the second treatment tank 6 according to the concentration of the gas sucked from the first treatment tank 1. Air is appropriately sucked and adjusted from the atmosphere so that the gas concentration and the supply oxygen amount are appropriate, so that the treatment can be performed efficiently.

The second treatment tank 6 is filled with clean water or intermediate water up to the set water level and is hermetically sealed. More preferably, it is disposed in the first treatment tank at or near the inner bottom. With the same configuration as that described above, a small air-fuel mixture nozzle 3 is provided, and the malodorous gas from the first treatment tank 1 is atomized into the second treatment tank 6 through the air-mixing nozzle 3. To release. In this case, by releasing a gas body containing a malodorous component and residual oxygen into the water in the second treatment tank 6, as in the first treatment tank 1, due to the action of microorganisms such as aerobic bacteria contained in the water, the malodorous The components are decomposed and the deodorized gas is released into the atmosphere through the exhaust port.

The second processing tank 6 and the air-fuel mixture nozzle 3 arranged in the first processing tank 1 will be described based on the embodiment shown in FIG. Pressurized water supply pipe P1 at the end and air supply pipe P2 at the outer peripheral surface
The suction nozzle member 31 having a tubular shape and the intermediate nozzle having one or more stages (two stages in the embodiment shown in the drawings, but may be three stages or more) in the outer casing 30 in which The members 32 and 33 and the injection nozzle member 34 are fitted so as to be sequentially arranged so that their respective axial centers are arranged on the same straight line, and are integrally connected. The pressurized water supply pipe P1 is connected to the suction nozzle member 31 arranged at the leading edge. At the tip of the suction nozzle member 31, high pressure water, preferably tap water or clean water from which dust or the like has been previously removed, is used to prevent clogging of the nozzle at high pressure.
A pump or a submersible pump (not shown) is connected so as to supply into the suction nozzle member 31.

Further, an air supply pipe P2 connected to the outer casing 30.
The tip of the device is released to the air introduction chamber 30h in the outer casing 30 so that air can be sucked from the atmosphere by itself, or a pressure tank or blower (both are not shown in the drawing) so that pressurized air or a gas such as oxygen can be taken in. No)). In addition, the suction nozzle member 31, the intermediate nozzle member 32, and the cylindrical nozzle member 3, 3,
Air introduction nozzles 3a, 3b, and 3c are formed at the connection positions of 3 and the injection nozzle member 34. The air introduction nozzles 3a in the front row (first stage) are small holes, and a plurality of air introduction nozzles 3a and 3c are formed in the circumferential direction at substantially equal intervals. Ring slit shape.
The ring slit-shaped air introduction nozzles 3b, 3
When the intermediate nozzle members 32, 33 and the injection nozzle member 34 are fitted and connected to each other, c is formed with a predetermined small gap, and the air introduction nozzle 3b formed by the gap between the nozzle members, 3c is set to be most suitable depending on the conditions such as the amount of water, the flow velocity, the dissolved oxygen ratio. This may be determined in advance at the time of design, or the connection between the members may be appropriately adjusted by using an adjustable structure such as screw fitting.

As a result, the pressurized water introduced through the pressurized water supply pipe P1 has the flow passages 31a of the nozzle members 31, 32, 33, 34 arranged and connected so as to have the same axis.
Negative pressure is generated on the inner peripheral surface of the flow passage when flowing as a high-speed flow through the insides of 32a, 33a, and 34a. Due to this negative pressure, directly through the small-hole-shaped air introduction nozzle 3a formed between the suction nozzle member 31 and the intermediate nozzle member 32, and between the intermediate nozzle members 32 and 33, the intermediate nozzle member 33 and the injection nozzle member. 34 through the ring-slit-shaped air introduction nozzles 3b and 3c, respectively,
Air is sucked into the flow passage through the air introduction chamber 30h in the outer casing 30 and the air introduction hole formed in the tangential direction. When the sucked air flows through the flow passages on the inner peripheral surfaces of the intermediate nozzle members 32 and 33, the air is sheared so as to be beaten by a high-speed water stream, and is shattered into fine particles. It will be mixed with the stream of water.

In this case, as shown in FIG.
A plurality of grooves 3 for finely crushing air bubbles along the inner peripheral surface thereof along a.
6 is formed so as to disappear in the middle thereof, and at the starting end position in each groove 36 for finely crushing bubbles, the air introduction nozzle 3a in the front row having a small hole shape is bored and opened. . As a result, the small-hole-shaped air introduction nozzle 3
The air introduced from the a into the fine bubble crushing groove 36 is crushed by the flowing water pressure flowing at a high speed in the flow passage 32a, and all the bubbles flowing down in the fine bubble crushing groove are eventually bubbled. When escaping from the inside of the fine crushing groove, the corners of the fine bubble crushing groove become like a cutting edge and are further sheared and crushed, and the bubbles are further miniaturized.

The grooves 36 are arranged on the inner peripheral surface of the flow passage 32a at substantially regular intervals in the inner peripheral direction, and the depth thereof is such that the water flow flowing down in the flow passage is efficiently sheared and crushed. In this way, the bubbles are finely sheared and broken by the turbulent flow generated by the breaking of the water flow.
It can be arranged parallel to the axis or can be formed so as to be gently twisted, and this can be appropriately set according to the miniaturization of bubbles. Thus, the flow passage 32 in the intermediate nozzle member
The high-speed water flow, in which the bubbles are well mixed through a and 33a, passes through the trumpet-shaped injection nozzle member 34 disposed on the downstream side of the second intermediate nozzle member 32, becomes stable rectification, and is operated at high speed. It is sprayed into sewage or human waste, and further into chemical substance water dissolved in water. In this case, the amount of air sucked from the air introduction nozzle 3c formed between the second intermediate nozzle member 33 and the injection nozzle member 34 is smaller than the amount of suction of the front air introduction nozzles 3a and 3b, and is introduced. A part of the air is crushed to form fine bubbles, and a part of the air exists along the inner peripheral surface of the injection nozzle member 34 between the inner peripheral surface of the injection nozzle member 34 and the high-speed fluid to act as a lubricant. Then
The flow resistance of the high-speed fluid is reduced, and the fluid is discharged and discharged at a high speed without reducing the speed.

[0027]

According to the malodorous gas treatment method of the present invention, all kinds of organic waste water are allowed to flow into the first treatment tank so that the organic waste water is biologically treated by aeration and stirring. Then, the odorous gas generated in the first treatment tank was mixed with water in the second treatment tank water filled with the treatment water containing the treatment bacteria (microorganisms) so as to form fine bubbles. Since the malodorous gas is released, a part of the malodorous gas is dissolved in the water in the second treatment tank, and a part of the gas also serves as a nutrient for the microorganisms in the water. By the action, since no other chemicals or heat energy is used, the malodorous component can be continuously decomposed at a lower cost and easier than the conventional method. Further, since no chemicals such as deodorant and thermal energy are used for decomposing the malodorous components, the processing cost is low and the problem of secondary pollution does not occur.

According to the invention of claim 2, the first
Depending on the concentration of malodorous gas generated in the processing tank, the second
Since it is diluted with air in order to properly decompose the malodorous component by the microorganisms in the treatment tank, when the treatment such as fermentation in the first treatment tank is promoted, 1) The concentration of malodorous gas discharged from the inside of the treatment tank may become high.
By supplying the malodorous gas while it is being supplied to the treatment tank, the concentration of the malodorous gas can be diluted and the concentration of the gas supplied to the second treatment tank can be adjusted. However, it can be performed continuously and efficiently.

According to the invention described in claim 3, the first
The organic waste water to be charged into the treatment tank is blown into the wastewater filled in the first treatment tank by blowing fine air bubbles from the air-mixing nozzle into the wastewater in the first treatment tank. Therefore, the microorganisms in the wastewater, for example, aerobic bacteria or anaerobic bacteria, are activated, and the microorganisms promote biological treatment of the organic wastewater in the first treatment tank. It is possible to reduce the amount of settled sludge in the unfermented state at the tank bottom, reduce the amount of discharged sludge, and reduce the treatment cost including the treatment of residual sludge as a whole. You can

Further, according to the invention of claim 4, fine air bubbles ejected into the processing tank are formed by using the air-mixing nozzle, and the air-mixing nozzle is connected in a plurality of stages. Gas is sucked from the nozzle hole by the action of high-speed flowing water that flows at high speed in the flow passage, finely crushed by high-speed flowing water, and mixed with high-speed flowing water and ejected from the nozzle tip into the water. Due to the water flow flowing down the flow passage of the nozzle member connected to the stage, air or gas can be sucked from the nozzle hole by the negative pressure generated in the flow passage, and can be finely crushed by the high-speed running water, and oxygen in the water The solubility of water is improved, the residence time in water is prolonged, the processing of malodorous gas is promoted, and when this air-mixing nozzle is installed in wastewater, fragile organic waste in the wastewater The fast water Can also be destroyed by, aerobic fermentation is promoted.

[Brief description of drawings]

FIG. 1 is a flowchart showing an embodiment of a method for treating malodorous gas according to the present invention.

FIG. 2 is a vertical sectional front view of an air-mixing nozzle.

FIG. 3 is a sectional view taken along the arrow of FIG.

[Explanation of symbols] 1 First treatment tank 2 Organic wastewater input pipe 3 Air-mixing nozzle 4 exhaust gas pipe 5 drainage pipe 6 Second treatment tank 7 Air suction tube 71 Air valve 8 mud pipe 9 Sluice valve S strainer P pump

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B01F 5/02 C02F 3/28 Z 4F033 B05B 1/02 101 3/30 Z 4G035 C02F 3/12 11/00 F 3/28 11/02 3/30 11/04 11/00 B01D 53/34 116C 11/02 ZAB 11/04 F term (reference) 4D002 AA13 AB02 BA17 CA06 CA20 DA59 4D020 AA09 BA23 CB02 CC05 4D028 AA03 BC26 4D040 AA26 AA53 BB51 4D059 AA01 AA03 AA07 BA03 BA11 BA48 BJ08 CA17 4F033 AA13 BA02 DA01 EA01 JA07 LA06 NA01 4G035 AB07

Claims (4)

[Claims] 1. An odorous gas generated when aerobically and / or anaerobically treating organic filth water to be charged into a closed first treatment tank is filled with treated water containing treated bacteria. Into the second treatment tank, discharged into treated water through a mixture nozzle that is made into fine bubbles, and decomposes malodorous components by the action of microorganisms in the second treatment tank, and then to the atmosphere. A method for treating a malodorous gas, which is characterized in that the gas is released. 2. Diluting with air according to the concentration of the malodorous gas generated in the first treatment tank so that the malodorous components can be decomposed by the microorganisms in the second treatment tank properly. The method for treating malodorous gas according to claim 1, wherein 3. The organic filth water charged into the first treatment tank is finely crushed by the high-speed water flow supplied from the air-mixing nozzle into the sewage water filled in the first treatment tank. The treatment of malodorous gas according to claim 1 or 2, characterized in that the microorganisms in the wastewater are activated by injecting them as fine bubbles to efficiently perform aerobic and / or anaerobic treatment. Method. 4. A fine air bubble ejected into the first or second processing tank is formed by using an air-mixing nozzle, and the air-mixing nozzle is connected in a plurality of stages in a flow passage of a nozzle member, The gas is sucked from the nozzle hole by the action of the high-speed running water flowing at a high speed, finely crushed by the high-speed running water, mixed with the high-speed running water, and jetted into the water from the tip of the nozzle. 2. The method for treating malodorous gas according to 2 or 3.