JPH03161019A - Biological deodorizing apparatus - Google Patents

Abstract

PURPOSE:To stably and efficiently treat malodorous gas in a low cost by arranging a hydrogen sulfide decomposing tower, a methyl mercaptan decomposing tower and a methyl sulfide decomposing tower preliminarily decomposing respective malodorous components in succession corresponding to the easy decomposition of the components in series. CONSTITUTION:A hydrogen sulfide decomposing tower 5A mainly decomposing hydrogen sulfide is equipped with a packed bed 3A supporting hydrogen sulfide decomposing bacteria and gas to be treated is introduced into the tower 5A. A methyl mercaptan decomposing tower 5B mainly decomposing methyl mercaptan is equipped with a packed bed 38 supporting methyl mercaptan decomposing bacteria and the exhaust gas of the decomposing tower 5A is introduced into the tower 5B. Further, methyl sulfide decomposing towers 5C, 5D mainly decomposing methyl sulfide are equipped with packed beds 3C, 3D supporting methyl sulfide decomposing bacteria and the exhaust gas of the decomposing tower 5B is introduced into the towers 5C, 5D. As a result, malodorous gas containing sulfureous malodorous matters can be stably and efficiently treated in low cost.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a biological deodorizing device, and particularly to a deodorizing device that biologically deodorizes bad odors generated from human waste treatment plants, sewage treatment plants, and various other factories. In particular, biological deodorization equipment that targets sulfur-based malodorous substances can perform stable and efficient deodorization by treating each sulfur-based malodorous substance in stages based on the properties of the deodorizing microorganisms. Regarding possible biological deodorization equipment.

[Prior Art and Prior Art] There are sulfur-based odorous substances as odorous components of odorous gases such as human waste and sewage. Sulfur-based odorous substances in the odorous gas include hydrogen sulfide (hereinafter referred to as "H2S"), methyl mercaptan (hereinafter referred to as rMMJ), and methyl sulfide (hereinafter referred to as rDM).
It is written as SJ. ), and attempts have been made to remove these sulfur-based odorous substances by biological deodorization. Conventionally, biological deodorizing devices for deodorizing odorous gases from human waste, sewage, and other wastewater use activated sludge as a source of microorganisms for deodorizing.

For this reason, its microbial composition is not always optimal for biological deodorization, and it is difficult to achieve stable deodorization.
1111 for a long period of time (40 days or more) until it becomes a reformed composition.
It had the disadvantage of requiring i.

The present inventors have developed a technique for solving the above conventional problems, efficiently decomposing and removing sulfur-based odorous substances in odorous gas, and deodorizing with a short contact time using dimethyl sulfoxide (rDMsOJ A patent application was filed for the use of sulfur-based odor-degrading bacteria cultured in
538. Hereinafter, this will be referred to as "first application ■." ).

Based on the technology of the previous application (2), it is a biological deodorizing device that removes bad odors by ventilating a packed bed of deodorizing material, and the packed bed of deodorizing material is made of sulfur-based odor-degrading bacteria cultured in DMSO. A patent application has been filed for a biological deodorizing device in which two or more stages of deodorizing material filled layers supporting the
2. (hereinafter referred to as "Prior Application II J"). According to the above-mentioned No. 11I and Prior Application 1■, the amount of deodorizing microorganisms in the device is increased by adding sulfur-based malodorous substance degrading bacteria and its growth substrate, that is, DMSO. This makes it possible to shorten the acclimatization period and stabilize deodorization.

[Problems to be Solved by the Invention] However, since the deodorizing bacteria and growth substrate used in Prior Applications I and II are expensive, it is possible to improve their use by further improving deodorizing efficiency and deodorizing stability. It is desirable to keep the amount to a minimum.

An object of the present invention is to provide a biological deodorizing device that can stably and efficiently treat malodorous gas containing sulfur-based odorous substances at low cost.

[Means for Solving the Problems] The biological deodorizing device of the present invention has a packed bed supporting H2S decomposing microorganisms, a hydrogen sulfide decomposition tower mainly for decomposing hydrogen sulfide into which a gas to be treated is introduced, and a methyl A methyl mercaptan decomposition tower that mainly decomposes methyl mercaptan, into which exhaust gas from the hydrogen sulfide decomposition tower is introduced, a packed bed that supports mercaptan-degrading microorganisms, and a packed bed that supports DMS-degrading microorganisms; It is equipped with a methyl sulfide decomposition tower that mainly decomposes methyl sulfide into which the exhaust gas from the methyl mercaptan decomposition tower is introduced.

In the present invention, among the H2S decomposition tower, MM decomposition tower, and DMS decomposition tower, it is preferable to use a bed that supports activated sludge in the packed bed of the H2S decomposition tower. The packed bed of the MM column is filled with activated sludge and/or DMS depending on the load amount.
It is preferable to use one that supports O culture bacteria. Also,
The packed bed of the DMS decomposition tower may support activated slurry, but preferably supports DMSO cultured bacteria. For the packed bed that supports activated sludge, it is sufficient to occasionally wash it with water, and there is no need to particularly adjust the pH.
The packed bed supporting the MSO culture preferably maintains its pH at neutrality.

As a method for supporting activated sludge or DMSO cultured bacteria in the packed bed in the treatment tower, it is preferable to fix the activated sludge or DMSO cultured bacteria in advance to a carrier such as beet and fill it into the tower. May be sprayed.

It goes without saying that the biological deodorizing apparatus of the present invention can be applied not only to a fixed bed type using a carrier such as beet, but also to a fluidized bed type.

C action] When H2S, MM, and DMS are mixed in the malodorous gas,
H2S and MM%DMS are easily decomposed in this order, and the presence of easily decomposable gases such as H2S inhibits the decomposition of other odorous substances.

Therefore, in order to stably treat such malodorous gases using biological deodorization equipment, it is necessary to form a system that decomposes each malodorous substance in stages, but with conventional methods, this system cannot be formed. This is why it takes a long time! This resulted in prolonged Il+ feeding. In contrast, in the biological deodorizing apparatus of the present invention, three or more treatment towers each equipped with a packed bed carrying microorganisms that decompose each malodorous component are installed in series, and the treatment towers are arranged in series on the upstream side of the malodorous gas to be supplied. Since the H2S decomposition tower, the MM decomposition tower, and the DMS decomposition tower are set independently from each other in this order, stable treatment can be performed in each tower from the initial stage of operation.

In addition, in each treatment tower, each malodorous component can be decomposed individually, and optimal operational management can be performed for adjusting the load, increasing the amount of bacteria, etc., so it is possible to handle sudden load changes. Appropriate measures can also be taken against such cases. Note that the H2S decomposition tower, MM decomposition tower, and DMS decomposition tower only need to mainly decompose their respective sulfur-based odorous substances. For example, residual H2S may be decomposed at the bottom of the MM decomposition tower, or residual MM may be decomposed at the bottom of the DMS decomposition tower. or disassemble H
Some MM may be decomposed in the upper part of the 2S decomposition tower, and some DMS may be decomposed in the upper part of the MM decomposition tower.

Furthermore, depending on the malodorous components to be treated in each treatment tower, activated sludge or D
By selecting MSO-cultured bacteria, it is possible to suppress the amount of DMSO-cultured bacteria used and reduce processing costs.

Additionally, cleaning water, chemicals for pH adjustment, etc. can be kept to the minimum necessary level.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic vertical sectional view showing an embodiment of the biological deodorizing device of the present invention.

The biological deodorization apparatus of this embodiment includes four gas treatment towers 5A, 5B, 5C, and 5D connected in series. Each of the treatment towers 5A to 5D has an air supply pipe I for the gas to be treated at the bottom.
A, IB, IC, and ID, and processing gas discharge pipes 2A, 2B, 2C, and 2D are provided at the upper part. In addition, packed layers 3A, 3B, 3C, and 3D carrying microorganisms that decompose malodorous components in the gas to be treated to be vented are provided inside each, and each packed layer 3A, 3B, 3C, and 3D is provided with Water drain pipes 4A, 4B, 4C, and 4D for spraying washing water are provided above each of the packed beds 3A to 3D. 11, 12, 13
is a connecting pipe that communicates each exhaust pipe with the air supply pipe. 14
, 15, 16, and 17 are water supply pipes that supply water to the water sprinkler pipes 4A to 4D.

Each of the treatment towers 5A to 5D is provided with humidity sensors 6A, 6B, 6C, and 6D in the packed beds 3A to 3D, and pH sensors 7A and 7 are provided below the packed beds 3A to 3D.
B, 7C, and 7D are provided. The detected values of these humidity sensors 6A to 6D and pH sensors 7A to 7D are input to a control circuit (not shown) of the water supply control device 8.
Based on this detected value, the wastewater pipes 4A to 5D of each treatment tower 5A to 5D are
The structure is such that water, alkali, buffer solution, etc. are supplied to 4D.

In this embodiment, the treatment towers 5A to 5D are, from the upstream side, an H2S decomposition tower, a MM decomposition tower, a DMDS (methyl disulfide) decomposition tower, and a DMS decomposition tower, respectively.

That is, the packed beds 3A to 3D of each treatment tower 5A to 5D are filled with beets, the packed bed 113A of the treatment tower 5A is loaded with activated sludge, and the packed bed 3B of the treatment tower 5B is loaded with beets. Activated sludge or DMSO culture bacteria are supported. Furthermore, activated sludge or DMSO cultured bacteria is supported on the packed bed 3C of the treatment tower 5C depending on the load amount, and DMSO cultured bacteria is supported on the packed Fl3D of the treatment tower 5D.

Although not shown, in the upper part of each packed bed 3A to 3D of each treatment tower 5A to 5D, in addition to the water spray pipes 14 to 17, there is a supply pipe for adding DMSO cultured bacteria or activated sludge. is provided, and is configured such that DMSO cultured bacteria or activated sludge can be added in accordance with a decrease or fluctuation in the processing efficiency of each of the processing towers 5A to 5D.

In order to deodorize malodorous gas using such a biological deodorizing device, first, the malodorous gas is converted into H2S+ from the air supply pipe IA.
Introduce it to the awakening tower 5A. The foul-smelling gas and gas are processed by the activated sludge C in the process of passing through the packed bed 3A of the H2S decomposition tower 5A, and the H2S contained therein is oxidized and decomposed. H2S decomposition tower 5
Processing gas A is discharged from the exhaust pipe 2A, and connected to the connecting pipe 11.
, introduced into the MM decomposition tower 5B from the air supply pipe IB and packed into the packed bed 3.
In the step A where it passes through B, it is treated with activated sludge or DMSO cultured bacteria, and the contained MM is oxidized and decomposed. The treated gas from the MM decomposition tower 5B is discharged from the discharge pipe 2B, introduced into the DMDS decomposition tower 5C through the connection pipe 12 and the air supply pipe 1c, and is converted into activated sludge or DMS in the process of passing through the packed bed 3C.
The DMDS contained therein is oxidized and decomposed by the O-cultured bacteria. The processed gas from the DMDS decomposition tower 5C is discharged from the discharge pipe 2C, and is then discharged from the DMDS decomposition column 5C through the connection pipe 13 and the air supply pipe ID.
D is introduced into the S decomposition tower 5D and treated with DMSO cultured bacteria in the process of passing through the packed bed 3D.
MS is oxidized and decomposed.

In this way, the deodorized gas is discharged to the outside of the system through the discharge pipe 2D.

Note that sulfur-based malodorous substances such as H2S, MM, and DMDS%DMS are oxidized and decomposed into sulfate ions by activated sludge or DMSO culture bacteria.

Therefore, in each of the packed beds 3A to 3D, sulfuric acid ions are present in an amount approximately equal to the sulfur-based substances removed by oxidative decomposition of malodorous components, and gradually accumulate when left undisturbed. Since this sulfate ion inhibits the biological reaction of microorganisms, it is necessary to spray washing water onto each packed bed from the water sprinkler pipes 4A to 4D to wash the sulfate ion out of the tower.

It is also necessary to replenish water to maintain the activity of microorganisms.

That is, when forming the filled layers 3A to 3D by depositing long-fiber beets, the long-fiber beets are beets collected from peatland, left outdoors in the winter, and freeze-dried, with a mesh size of about 8 mm, for example. It can be used after sifting through a sieve to remove short pieces. The packing density of the packed bed is 100 to 150 in terms of dry beets per 1 m' of the packed bed.
kg is preferred. The filling height of the packed bed is preferably about 1 to 1.5 m, and the water content of the packed bed (the percentage of water weight in the total of beet weight and water weight) is preferably 50 to 80% in order to maintain the activity of microorganisms. is preferably 60 to 70%. Therefore, in order to obtain such a moisture content, water, water-containing sludge, DMSO aqueous solution,
It is desirable to pour out a culture solution containing DMSO as a substrate through a water sprinkler pipe.

Further, in order to maintain a pH suitable for microorganisms in each packed bed, it is desirable to dispose of water, alkaline solution, buffer solution, etc.

In the apparatus of this embodiment, in each treatment tower 5A to 5D, humidity sensors 6A to 6D and pH sensors 7A to 7D are provided.
When the beet moisture content of the packed beds 3A to 3D falls below the preferred range or is outside the predetermined pH range, the humidity and pH are detected by the water sprinkler pipes 4A to 4D according to a command from the sequencer 8. Spray water for adjustment, or water, alkaline solution, or 11 (E solution) for pH adjustment.

In addition, the suitable pH in each treatment tower 5A-5D is as follows.

The water etc. sprinkled on the packed beds 3A to 3D are sent to the respective treatment towers 5A to 3D.
It is discharged from a drain pipe (not shown) provided in 5D.

The biological deodorizing device shown in FIG. 1 is an embodiment of the present invention, and the present invention is not limited to the illustrated example unless it exceeds the gist thereof. For example, DMDS can be decomposed in the downstream part of the MM decomposition tower or in the upstream part of the DMS decomposition tower, so there is no need to provide a separate DMDS decomposition tower, and therefore the treatment tower is a H2S decomposition tower, a MM decomposition tower, There may be only three DMS decomposition towers. Alternatively, five or more towers may be provided, and a plurality of processing towers may be set for each gas.

[Effects of the Invention] As detailed above, in the biological deodorizing apparatus of the present invention, the H2S decomposition tower, the MM decomposition tower, and the DMS decomposition tower are sequentially connected in series. Since the decomposition towers are arranged in series to decompose each component in the appropriate order, there is almost no acclimatization period, and stable deodorization can be performed from an early stage, greatly shortening the time required to start up the equipment. can do.

- Since the operation of each treatment tower can be managed according to the malodorous gas to be decomposed, it is possible to take appropriate treatment and respond well to sudden load fluctuations.

- Since microorganisms can be selected for each treatment tower, it is possible to minimize the amount of DMSO cultured bacteria used, and the processing cost can be reduced.

■ The amount of cleaning water and chemicals used for pH adjustment can be kept to the minimum necessary.

Effects such as these are produced.

Therefore, according to the biological deodorizing device of the present invention, even malodorous gases containing many kinds of sulfur-based malodorous substances can be almost completely deodorized extremely stably, efficiently, and at low cost.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical sectional view showing an embodiment of the biological deodorizing device of the present invention. IA, IB, IC, ID...Air supply pipe, 2A, 2B, 2
C, 2D...Discharge pipe, 3A, 3B, 3C, 3D...
Filled bed, 4A, 4B, 4C, 4D... Water pipe, 5A.
... treatment tower (H2S decomposition tower), 5B ... treatment tower (MM decomposition tower), 5C ... treatment tower (DMDS decomposition tower), 5D ... treatment tower (DMS decomposition tower).

Claims (1)

[Claims] (1) A hydrogen sulfide decomposition tower having a packed bed supporting hydrogen sulfide-degrading microorganisms and mainly decomposing hydrogen sulfide into which the gas to be treated is introduced, and a packed bed supporting methyl mercaptan-degrading microorganisms; It has a methyl mercaptan decomposition tower that mainly decomposes methyl mercaptan, into which the exhaust gas from the hydrogen sulfide decomposition tower is introduced, and a packed bed supporting methyl sulfide decomposing microorganisms, and a methyl mercaptan decomposition tower into which the exhaust gas from the methyl mercaptan decomposition tower is introduced. A biological deodorizing device comprising: a methyl sulfide decomposition tower that decomposes methyl sulfide; and a methyl sulfide decomposition tower.