JP5079116B2 - Biological deodorization method and biological deodorization apparatus - Google Patents

Description

  The present invention relates to a biological deodorization method and a biological deodorization apparatus that biologically removes odorous components in a gas to be treated, and more specifically, in addition to odorous components soluble in water in the gas to be treated. The present invention relates to a biological deodorization method and a biological deodorization apparatus that can effectively deodorize even when an insoluble or hardly soluble odor component is contained.

  Utilizes the oxidative decomposition action of odor components by microorganisms as a device to deodorize and remove gases containing odor components from sewage, sludge, industrial wastewater, etc., or sulfur compounds in digestion gas produced by methane fermentation Biological deodorization devices are known. For example, Patent Literature 1 discloses a biological deodorization apparatus that deodorizes a sulfur compound in a gas generated when an organic substance is fermented by desulfurization.

  The biological deodorization apparatus is provided with a packing part having a packing material supporting microorganisms inside the gas-liquid contact tower, and allows the gas to be treated introduced into the tower to pass through the packing part so as to contact the packing material. Deodorized and removed by the oxidative degradation action of microorganisms supported on the surface.

  A liquid is supplied to the filler for the purpose of maintaining the activity of the supported microorganisms and washing away the oxide adhering to the surface, and is kept in a wet state by forming a water film on the surface. For this reason, the odor component soluble in water in the gas to be treated dissolves in the water film, and comes into contact with the surface of the filler to be oxidatively decomposed and removed by microorganisms.

JP 2005-58841 A

  In the conventional biological deodorization apparatus, since the filler is always kept wet by supplying the liquid, if the gas to be treated contains an odor component that is insoluble or hardly soluble in water, Contact with the surface of the filler is blocked by the water film (boundary film) formed on the surface. For this reason, odor components that are insoluble or hardly soluble in water cannot be deodorized because they are disturbed by the water film and are not adsorbed on the surface of the filler and cannot come into contact with the microorganisms supported on the filler. there were.

  Therefore, the present invention effectively deodorizes while maintaining the activity of microorganisms even when the gas to be treated contains an odor component insoluble or hardly soluble in water in addition to an odor component soluble in water. It is an object of the present invention to provide a biological deodorization method and a biological deodorization apparatus.

  The other subject of this invention becomes clear by the following description.

  The above problems are solved by the following inventions.

(Claim 1)
A filling port having an inlet for introducing a gas to be treated in the lower part and a discharge port for a processing gas in the upper part, and having a specific surface area of 100 m ² / g or more and a filler carrying microorganisms. The liquid is provided in a multistage of three or more stages, and supplies a liquid made of water, activated sludge-treated water, or digestive juice generated by methane fermentation treatment to the filling section above the filling section of each stage. Using a gas-liquid contact tower in which a supply port is arranged, a gas to be treated containing an odor component insoluble or hardly soluble in water in addition to an odor component soluble in water is introduced from the introduction port, and filling in each stage Control is performed so that the operation of supplying and stopping the liquid alternately is performed, and the supply of the liquid is stopped in any one of the filling sections, and the liquid is supplied to the filling sections of the other stages. Biological deodorization method characterized by controlling as follows.

(Claim 2)
2. The biological deodorization method according to claim 1, wherein the liquid supply is stopped for 5 to 60 minutes.

(Claim 3)
In addition to an odor component soluble in water at the bottom, an inlet for introducing a gas to be treated containing an odor component that is insoluble or hardly soluble in water, and a discharge port for the treatment gas at the top, a specific surface area inside There are three or more multi-stage filling parts filled with a microorganism-supporting filler at 100 m ² / g or more, and water and activity are provided above the filling parts in each stage. A gas-liquid contact tower in which a liquid supply port for supplying a liquid consisting of digested liquid produced by sludge treated water or methane fermentation treatment is disposed;
Control means for controlling each of the supply and stop of the liquid to the filling section of each stage alternately,
The biological deodorizing apparatus is characterized in that the control means controls the supply of liquid to any one of the filling sections to be stopped and the liquid is supplied to the filling sections of the other stages.

(Claim 4)
The biological deodorization apparatus according to claim 3, wherein the liquid supply stop time is 5 to 60 minutes.

  According to the present invention, even when the gas to be treated contains an odor component insoluble or hardly soluble in water in addition to an odor component soluble in water, it effectively deodorizes while maintaining the activity of microorganisms. It is possible to provide a biological deodorization method and a biological deodorization apparatus that can perform such a process.

Schematic configuration diagram showing a biological deodorization apparatus according to the present invention Timing chart showing control of valve control unit Schematic configuration diagram showing another form of gas-liquid contact tower Plan view of the bottom Sectional drawing which follows the (a)-(a) line of FIG.

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

  FIG. 1 is a schematic configuration diagram showing a biological deodorization apparatus according to the present invention.

  The biological deodorization apparatus includes an airtight gas-liquid contact tower 1 and introduces a gas to be treated into the tower from an inlet 11 provided at the lower part thereof, and has been treated from an outlet 12 provided at the upper part. The process gas is discharged outside the tower.

  In the present invention, the gas to be treated introduced into the gas-liquid contact tower 1 is a gas containing an odor component insoluble or hardly soluble in water in addition to an odor component soluble in water.

  Examples of odor components that are insoluble or hardly soluble in water include esters and many aromatic hydrocarbon fragrance components.

  On the other hand, examples of odor components soluble in water include lower fatty acids, hydrogen sulfide, and ammonia. In the case of a sulfur compound, carbonyl sulfide, which is difficult to remove by chemical treatment, can be treated.

  In addition to various exhaust gases, process gases, biogas, pyrolysis gas, and the like can be used as the gas that includes these odor components and is an object of the present invention.

  Inside the gas-liquid contact tower 1, there is provided a gas-liquid contact portion 2 for deodorizing and removing odor components by contacting with the gas to be treated introduced into the tower from the inlet 11.

  The gas-liquid contact part 2 is provided with a plurality of shelf-shaped filling parts filled with a filler. Here, the three stages of the first filling part 21, the second filling part 22, and the third filling part 23 are arranged vertically from each other at a predetermined interval. The number of stages is not limited to three as long as it is a plurality of stages of two or more, and is appropriately determined depending on the permeation flow rate of the gas to be treated, the concentration of the odor component, the gas-circulating fluid amount ratio, and the like.

Fillers A1, A2, and A3 are placed on the filling portions 21, 22, and 23, respectively. Here, as the fillers A1, A2, and A3, those having a specific surface area of 100 m ² / g or more, or 100 m ² / m ³ (apparent volume) or more, and carrying microorganisms are used.

  Examples of the fillers A1, A2, and A3 as the carrier include, in addition to normal magnetic or resin fillers for gas-liquid contact, porous soft resins; porous particles such as activated carbon, charcoal, zeolite, and ceramics; Etc. can be used. For example, in order to carry sulfur-oxidizing bacteria mainly for the purpose of desulfurization, carbon-based materials such as activated carbon and charcoal are preferable, but in the case of gas-liquid contact in countercurrent, a normal resin filler for gas-liquid contact is also preferable. Can be used.

  The microorganisms to be supported on the fillers A1, A2, and A3 are determined in relation to the odor component in the gas to be treated. In many cases, these microorganisms spontaneously dominate depending on the gas component (substrate) to be treated, but it is important to take sufficient acclimatization time. For example, sulfur-oxidizing bacteria predominate mainly by acclimatization to gases containing sulfur compounds. Bacillus bacteria and the like dominate hydrocarbons.

  Each of the filling portions 21, 22, and 23 has at least bottom surface portions 21a, 22a, and 23a formed by using a perforated plate, a net-like body, and the like, and has air permeability and water permeability. In FIG. 1, the example using the perforated plate in which many through-holes were formed is shown.

  Liquid supply ports 31, 32, 33 are arranged above the filling parts 21, 22, 23 of the gas-liquid contact part 2. The circulating fluid stored in the storage tank 4 is supplied to the liquid supply ports 31, 32, 33 through the supply pipe 6 (61, 62, 63) by driving the circulation pump 5. Thereby, the circulating fluid is sprayed on the fillers A1, A2, A3 of the respective filling parts 21, 22, 23, and the surface of each of the fillers A1, A2, A3 is wetted and is carried. The activity of can be kept high.

  In the illustrated example, one liquid supply port 31, 32, 33 is disposed at each stage, but the present invention is not limited to this, and a plurality of liquid supply ports 31, 32, 33 may be disposed. The storage tank 4 is supplied with circulating fluid from the outside.

  As the liquid used for the circulating liquid, in addition to water, activated sludge treated water and digestive juice produced by methane fermentation treatment can be used. Since the digestive fluid can give the appropriate nutrients necessary for the microorganisms together with moisture on the surfaces of the fillers A1, A2, and A3, it also has an effect of promoting the growth of the microorganisms, which is preferable in the present invention.

  The supply pipes 61, 62, 63 for supplying the circulating fluid in the storage tank 4 to the liquid supply ports 31, 32, 33 are respectively provided with on-off valves 71, 72, 73, which are control means. Open / close control is individually performed by a control signal sent from the valve control unit 8, so that the gas-liquid contact ratio in each of the filling units 21, 22, and 23 can be adjusted.

  The circulating liquid flowing down to the lower part of the gas-liquid contact tower 1 is returned to the storage tank 4 from a discharge pipe 9 provided at the lower part of the gas-liquid contact tower 1.

  In the present invention, the valve control unit 8 opens and closes the valve opening operation for supplying the circulating fluid to the on-off valves 71, 72, 73 from the liquid supply ports 31, 32, 33 and the supply of the circulating fluid. It controls to perform each operation of operation alternately.

  The deodorizing method using such a biological deodorizing apparatus will be further described with reference to the timing chart shown in FIG.

  As shown in FIG. 2, in the present invention, the valve control unit 8 supplies the circulating fluid to any one of the filling units 21, 22 or 23, and the circulating fluid is supplied to the filling unit of the other stage. It is characterized in that it is controlled to stop while it is running. For example, the supply of the circulating fluid to the third filling unit 23 is stopped while the circulating fluid is supplied to the first filling unit 21 and the second filling unit 22, and the on-off valves 71 corresponding to the respective stages, It operates so that the timing of the opening / closing operation of 72 and 73 may be shifted. Accordingly, at any timing, the circulating fluid is always supplied to any two of the three stages of the filling sections 21, 22, 23, but the supply of the circulating fluid is always stopped in one stage. Will be.

  Thus, when a gas to be treated containing an odor component insoluble or hardly soluble in water in addition to an odor component soluble in water is introduced from the inlet 11 of the gas-liquid contact tower 1, the gas to be treated is The gas-liquid contact tower 1 is raised and discharged from the outlet 12 to the outside while contacting the fillers A1, A2, A3 of the filling parts 21, 22, 23 of each stage in the gas-liquid contact part 2.

  From the liquid supply ports 31, 32, 33 corresponding to the filling parts 21, 22, 23, the on / off valves 71, 72, 73 are controlled to be opened / closed by the valve control unit 8, thereby supplying and stopping the circulating fluid. Although it is controlled, if only the on-off valve 72 corresponding to the second filling unit 22 is closed and the supply of the circulating liquid from the liquid supply port 32 is stopped, the gas is mainly in the gas to be processed. The odor component soluble in water is formed on the surface of the first and third filling portions 21 and 23 to which the circulating fluid is supplied from the liquid supply ports 31 and 33, respectively, in contact with the fillers A1 and A3. It dissolves in the formed water film and comes into contact with the microorganisms supported on the fillers A1 and A3. Thereby, the odor component soluble in water is deodorized and removed by the oxidative decomposition action of the microorganism.

  At this time, since the supply of the circulating fluid from the liquid supply port 32 is stopped to the second filling portion 22, the supply of the circulating fluid to the filler A2 is cut off. A part of the circulating fluid supplied to the third filler 23 in the upper stage of the filler A2 is dripped through the through hole of the bottom surface 23a of the filler 23, but the position where the circulating fluid is dripped is limited. In addition, since the amount of water is very small compared to the amount of water directly sprayed from the liquid supply port 32, most of the filler A2 of the second filling portion 22 is in a dry state.

  Accordingly, a water film is not formed by the circulating liquid on the surface of most of the filler A2 of the second filling portion 22, and an odor that is insoluble or hardly soluble in water in the gas to be treated that has passed through the first filling portion 21. The component comes into direct contact with and adsorbs on the surface of the filler A2 in the dry state. As a result, even odor components that are insoluble or hardly soluble in water can be brought into contact with the microorganisms supported on the filler A2 without being disturbed by the water film, and are deodorized and removed by the oxidative decomposition action of the microorganisms. .

  This operation is the same even when the on-off valve 71 is controlled to be closed by the valve control unit 8 and the liquid supply to the first filling unit 21 is stopped, and most of the filler A1 is in a dry state, Odor components that are insoluble or hardly soluble in water in the processing gas can be deodorized and removed. Further, when the on-off valve 73 is controlled to be closed and the liquid supply to the third filling unit 23 is stopped, the entire filling material A3 is in a dry state. Odor components that are insoluble or hardly soluble in water can be deodorized and removed.

  As shown in FIG. 2, the supply of the circulating fluid is resumed to the filling sections 21, 22, and 23 in the stage where the supply of the circulating fluid is stopped after a predetermined time, and the filling materials A1, A2, and A3 in the dry state are It is again wet. For this reason, the activity of microorganisms is maintained. In order to keep the activity of the microorganisms supported on the fillers A1, A2 and A3 at a high level, the circulating fluid is preferably stopped for 5 to 60 minutes. When the time is less than 5 minutes, the surface of the filler is continuously liquid-flow coated, and particularly adsorption of hardly soluble and insoluble components to the microorganism carrier is suppressed. On the other hand, when it exceeds 60 minutes, it becomes difficult to maintain the activity of microorganisms. More preferably, it is 10 to 30 minutes.

  In addition, the supply time of the circulating fluid is set to be the stop time × (the number of stages of the filling unit−1).

  FIG. 3 is a schematic configuration diagram showing another aspect of the gas-liquid contact tower 1. Since the same reference numerals as those in FIG. 1 have the same configuration, detailed description thereof is omitted.

  In the gas-liquid contact tower 1, the second filling section 22 and the third filling section 23 have bottom surfaces 22 b and 23 b disposed in an inclined manner in the same direction in the gas-liquid contact tower 1. These bottom surface parts 22b and 23b are formed in the shape which crosses the gas-liquid contact tower 1 diagonally.

  Since the bottom portions 22b and 23b have the same shape, the details of the bottom portion 22b are shown in FIGS. 4 is a plan view of the bottom surface portion 22b, and FIG. 5 is a cross-sectional view taken along line (a)-(a) in FIG.

  The bottom surface portion 22b is formed in a shape that obliquely crosses the gas-liquid contact tower 1 by a bottom surface body 201 made of a perforated plate, a net-like body, and the like. A plurality of substantially V-shaped valley portions 201a are formed along the inclination direction.

  In addition, water troughs 202 are respectively provided at the bottom of the valley 201a. Fillers A2 and A3 are placed on the bottom surface main body 201.

  The circulating fluid supplied from the liquid supply ports 32 and 33 to the second filling unit 22 and the third filling unit 23 makes the surface of each of the fillers A2 and A3 wet, and then the surplus is supplied to the bottom surface main body 201. To reach. The circulating fluid that has reached the bottom surface main body 201 flows along the surface of the bottom surface main body 201. The bottom surface main body 201 has not only air permeability but also water permeability by a perforated plate or a net-like body. However, since the bottom surface main body 201 is formed with a plurality of valleys 201a, a through hole or a mesh is formed. Most of the water flows down into the valley 201a before passing through and forming dripping, and is collected in the trough 202 provided in the valley 201a.

  For this reason, most of the excess circulating liquid flows down in the inclined direction along the bowl 202, reaches the inner wall surface of the gas-liquid contact tower 1, and flows down through the inner wall surface. It does not drip on the fillers A1 and A2 in the lower filling portions 21 and 22.

  Thereby, in the filling part 21 or 22 where the liquid supply is stopped, the amount of circulating liquid dripped from the filling part 22 or 23 in the upper stage can be remarkably reduced, and the filler A1 or A2 can be efficiently used. Since it can be made into a dry state, the odor component which is insoluble or hardly soluble in water can be more effectively adsorbed to the filler A1 or A2, and the deodorization and removal effect can be further enhanced.

  The bottom portion 21b of the first filling portion 21 also has a bottom portion main body 201 similar to the second filling portion 22 and the third filling portion 23, and is disposed in an inclined manner in the gas-liquid contact tower 1. It may be.

  Hereinafter, although an Example demonstrates further in detail, this invention is not limited by this Example.

  The exhaust gas containing fatty acid was deodorized using three stages (the height of 750 mm that can be filled with a diameter of 150 mm) using a carbon fiber felt having the structure shown in FIG. 1 as a microorganism carrier.

  After sprinkling a small amount of water on the 1300 ° C. calcined polyacrylonitrile-based carbon fiber, it was heated to about 800 ° C. in a nitrogen stream containing 1 to 10% oxygen to perform surface treatment.

Carbon fiber felts with specific surface areas of about 70 m ² / g, about 150 m ² / g and about 300 m ² / g were made by varying the oxygen concentration content.

  Odor components mainly composed of fatty acids contained in the exhaust gas were analyzed by a capillary column gas chromatograph using a heat transfer cell as a detector.

As a result, it was about C4 to C18 and contained about 80 mg / Nm ³ of fatty acid mainly on the lower side.

  Circulating water has pH 7.8, BOD 25 mg / L, alkalinity 15 meq. / L biologically treated water was used. Circulation when the liquid supply shown in FIG. 2 is performed with the gas-liquid contact ratio in the deaeration tower during the treatment water circulation being 10 (10 L-gas / min vs. 100 mL-liquid / min: the gas-liquid temperature in the deodorization tower is about 35 ° C.). The relationship between the liquid stop time and the fatty acid content is shown in the following table.

From the above results, it was found that the fatty acid concentration that can be confirmed that the exhaust gas was sufficiently deodorized in terms of sensation (olfaction) is 20 to ³⁰ mg / Nm ³ or less.

1: Gas-liquid contact tower 11: Inlet port 12: Discharge port 2: Gas-liquid contact portion 21: First filling portion 21a, 21b: Bottom portion 22: Second filling portion 22a, 22b: Bottom portion 23: Third filling portion 23a, 23b: Bottom portion 31, 32, 33: Liquid supply port 4: Storage tank 5: Circulation pump 6, 61, 62, 63: Supply pipe 71, 72, 73: Open / close valve 8: Valve control section 9: Return pipe 201: bottom body 201a: valley 202: water ridge

Claims (4)

A filling port having an inlet for introducing a gas to be treated in the lower part and a discharge port for a processing gas in the upper part, and having a specific surface area of 100 m ² / g or more and a filler carrying microorganisms. The liquid is provided in a multistage of three or more stages, and supplies a liquid made of water, activated sludge-treated water, or digestive juice generated by methane fermentation treatment to the filling section above the filling section of each stage. Using a gas-liquid contact tower in which a supply port is arranged, a gas to be treated containing an odor component insoluble or hardly soluble in water in addition to an odor component soluble in water is introduced from the introduction port, and filling in each stage Control is performed so that the operation of supplying and stopping the liquid alternately is performed, and the supply of the liquid is stopped in any one of the filling sections, and the liquid is supplied to the filling sections of the other stages. Biological deodorization method characterized by controlling as follows.   2. The biological deodorization method according to claim 1, wherein the liquid supply is stopped for 5 to 60 minutes. In addition to an odor component soluble in water at the bottom, an inlet for introducing a gas to be treated containing an odor component that is insoluble or hardly soluble in water, and a discharge port for the treatment gas at the top, a specific surface area inside There are three or more multi-stage filling parts filled with a microorganism-supporting filler at 100 m ² / g or more, and water and activity are provided above the filling parts in each stage. A gas-liquid contact tower in which a liquid supply port for supplying a liquid consisting of digested liquid produced by sludge treated water or methane fermentation treatment is disposed;
Control means for controlling each of the supply and stop of the liquid to the filling section of each stage alternately,
The biological deodorizing apparatus is characterized in that the control means controls the supply of liquid to any one of the filling sections to be stopped and the liquid is supplied to the filling sections of the other stages. The biological deodorization apparatus according to claim 3, wherein the liquid supply stop time is 5 to 60 minutes.

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