JPH07284629A - Biological deodorizing carrier - Google Patents

Abstract

PURPOSE:To obtain a biological deodorizing carrier with the treating activity of a decomposing microorganism never lowered while keeping the entire device compact by providing a reaction zone carrying a malodorous material decomposing microorganism and a malodorous material adsorbing and desorbing zone to the carrier. CONSTITUTION:A polymer is dissolved in water to form a gel material soln., and the soln. is subjected to a chemical method with a cross-linking agent, etc., and a physical method of repeated freezing and melting and cross-linked to obtain a gel bead. The gelled bead is then introduced into a soln. of a gel material of the same or different kind to coat the surface with the gel soln. A specified malodorous material decomposing microorganism is mixed into the outer soln. before being gelled to form a gel entrapping the microorganism. Consequently, the biological deodorizing carrier 3 is provided with a reaction zone 2 carrying a malodorous material decomposing microorganism and a malodorous material adsorbing and desorbing zone 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biological deodorizing carrier for decomposing malodorous substances using a malodorous substance-degrading microorganism, which carrier is, for example, a sewage treatment plant, a human waste treatment plant, a waste treatment plant, It can be used for deodorizing offensive odor gas or liquid (hereinafter sometimes collectively referred to as gas to be treated) generated from livestock industry facilities. In particular, the biological deodorizing carrier of the present invention can effectively perform deodorizing treatment in response to load fluctuations such as concentration fluctuations (including presence / absence) of malodorous substances to be treated.

[0002]

2. Description of the Related Art Activated carbon adsorption method, chemical cleaning method and biological deodorization method have been conventionally known as a method for treating odorous gas discharged from sewage treatment plants, human waste treatment plants, etc. The biological deodorization method utilizing the ability is becoming widespread in recent years because it is economically advantageous.

A packed tower system is mainly adopted as the biological deodorization method, and this system uses peat, ceramic porous body, plastic molded body, synthetic fiber, charcoal, polymer gel body, activated carbon as a support. The microorganism is fixed to the packed tower, and the packed tower is filled with the gas to be treated and decomposed by the microorganism to deodorize.

Among the substances that cause the malodor of the gas to be treated, methyl sulfide (hereinafter sometimes referred to as MS) and methyl disulfide (hereinafter sometimes referred to as DMS) are particularly problematic in decomposition and deodorization. A) and methyl mercaptan (hereinafter sometimes referred to as MMP).

The concentration of these malodorous substances in the gas to be treated is not so high, and moreover, the concentration changes with the generation time, and in some cases, it may not be contained at all. Due to such low concentration and load fluctuation, the malodorous substance as a substrate is not stably supplied to the microorganism that decomposes and proliferates the malodorous substance. It was inevitable that the production of odorous substances was reduced and the activity of decomposing malodorous substances was reduced, resulting in a reduction in the efficiency of the deodorizing device. For example, when the operation of the sewage treatment plant is suspended due to a holiday, a new malodorous substance is not supplied to the treatment tank containing the decomposing microorganisms, but in such a case, the deodorizing ability is lowered.

[0006] Substances accompanied by load fluctuations are often difficult to decompose by microorganisms as described above, and thus, in the past, they have often relied on physical adsorption treatment by activated carbon. Therefore, as an apparatus for solving the above-mentioned problem, Japanese Patent Laid-Open No. 3-181313
The biological deodorizing device described in Japanese Patent Publication (hereinafter referred to as prior invention) is disclosed.

This biological deodorizing apparatus has a plurality of packing layers carrying microorganisms for decomposing malodorous substances such as hydrogen sulfide decomposing layer, MMP decomposing layer and MS decomposing layer for each malodorous component. A layer is provided so as to be individually and specifically decomposed by each component in the malodorous gas to be supplied, and an adsorbent layer that has adsorbed MS through is adsorbed on the gas distribution upstream side of the MS decomposition layer. It is provided.

Among the degrading microorganisms, MS degrading microorganisms are
When MS that is a substrate disappears, the ability to decompose and decompose MS decreases. Therefore, when MS is not present in the malodorous gas to be supplied, MS is desorbed from the adsorbent layer to remove MS from the downstream side.
By supplying MS to the decomposition layer, MS is always supplied to MS-degrading microorganisms, and MS degrading ability is maintained to maintain high throughput.

[0009]

However, in the conventional biological deodorizing apparatus disclosed in the above publication, it is necessary to install a separate adsorbent layer, so the apparatus becomes large and the equipment cost becomes excessive. There was a problem. The present invention has been made in order to solve the above problems, in which the degrading microorganisms lack a substrate and the processing activity is reduced, while making the entire apparatus compact without providing a separate layer. It is an object to provide a biological deodorizing carrier that does not exist.

[0010]

A biological deodorizing carrier according to the present invention comprises a reaction zone carrying a malodorous substance-degrading microorganism (hereinafter referred to as a reaction zone) and an adsorption / desorption zone for malodorous substances (hereinafter referred to as an adsorption / desorption zone). Is called).
The arrangement of each of these zones should be such that the adsorption / desorption zone is in the center and the reaction zone is arranged so as to surround it, and conversely, the reaction zone is in the center and the adsorption / desorption zone is surrounded so as to surround it. May be placed. Alternatively, the reaction zone and the adsorption / desorption zone may face each other and be connected and arranged. Further, the adsorption / desorption zones may be arranged in a patch form inside the reaction zone, and various arrangements may be mentioned. It is preferable to use a gel-like one for the reaction zone.

Further, in the biological deodorant carrier according to the present invention, it is preferable that the reaction zone and the adsorption / desorption zone are integrated via a gas permeable partition wall. The partition wall has a skeleton function, and examples of the structure having this skeleton function include a cylindrical one having pores on the surface, and a spiral one.

[0012]

The reaction zone of the biological deodorizing carrier according to the present invention is
This is a zone in which microorganisms decomposing malodorous substances are carried by being attached to or contained in a carrier, and the malodorous substances are decomposed and deodorized in this reaction zone. Since the reaction zone immobilizes microorganisms entrapped therein, a gel-like material is recommended.

The adsorption / desorption zone of the biological deodorant carrier is a zone for temporarily absorbing and storing the above-mentioned malodorous substance, and the malodorous substance does not exist in the gas to be supplied or is very high. When the concentration becomes low, the malodorous substance is desorbed and diffused from the adsorption / desorption zone. The malodorous substance decomposing microorganisms in the reaction zone utilize this diffused malodorous substance as a substrate.

As described above, since the decomposing microorganisms are constantly supplied with a malodorous substance of a certain concentration, the microorganisms can always maintain a certain level of treatment activity without being killed or having a decrease in activity. That is, even if the concentration of the malodorous substance in the gas to be treated fluctuates (including the case where it is not contained), the microorganisms in the reaction zone can maintain a stable activity.

Examples of the gel used as the biological deodorant carrier include polyvinyl alcohol (hereinafter referred to as PVA), polyethylene glycol, polyacrylamide, gelatin, sodium alginate and the like. Although a gel is used in the reaction zone, a material other than gel is used in the adsorption / desorption zone,
For example, zeolite or the like may be used.

In the above-mentioned prior application published invention, microorganisms penetrate into the carrier of the adsorbent layer so that the entire layer becomes a growth layer for the microorganisms. I am concerned that microorganisms may adhere to the surface and reduce the adsorption and desorption ability of MS. From the viewpoint of avoiding this, a separate adsorbent layer is provided and the adsorbent layer is kept in a dry state to prevent the microorganisms from advancing. I tried not to attach it. However, the above-mentioned problems do not occur in the biological deodorizing carrier in which the microorganisms are entrapped and immobilized in the reaction zone and the microorganisms are not entrapped and immobilized in the adsorption / desorption zone as in the present invention. That is, since the microorganisms in the reaction zone are confined in the gel, they do not move to other layers, and even if the microorganisms crack due to the growth of microorganisms and the microorganisms go out of the gel, Since the desorption zone can be composed of a carrier into which microorganisms cannot invade, the adsorption / desorption zone does not become a reaction zone and retains the adsorption / desorption ability. Further, in the prior application published invention, since the microorganisms are gradually falling into the lower adsorbent layer, it was necessary to suppress the growth of the microorganisms by drying.
In the present invention, since the packing treatment tower of the biological deodorizing carrier is always sprinkled with water, the microorganisms that have come out from the cracks of the gel are washed away, and a large amount of microorganisms do not exist outside the gel in the reaction zone.

The biological deodorizing carrier of the present invention has a structure having both a reaction zone and an adsorption / desorption zone, unlike the invention disclosed in the prior application, and since it is not necessary to provide a separate adsorbent layer, the biological deodorizing device is compact. You can

Next, of the biological deodorant carrier of the present invention, a biological deodorant carrier in which a reaction zone and an adsorption / desorption zone are integrated via a gas permeable partition wall (hereinafter sometimes referred to as partition wall) will be described. In the case of using a carrier such as a gel carrier which has a low strength against a load, by providing a gas permeable partition wall as a skeleton inside the carrier, the strength against a load can be increased.

An adsorption / desorption zone for adsorbing and desorbing malodorous substances is provided on one side of the gas-permeable partition wall, and a reaction zone carrying malodorous substance-decomposing microorganisms is arranged on the other side.
Then, as described above, when the malodorous substance in the gas to be treated is absent or has an extremely low concentration, the malodorous substance is desorbed and diffused from the adsorption / desorption zone on the one side, and the malodorous substance on the other side is passed through the partition wall. It is supplied to the microorganisms carried in the reaction zone. Therefore, similarly to the above, even when the load of the malodorous substance changes, the required amount of malodorous substance is always supplied to the microorganisms, so that the activity of the deodorizing treatment is not lowered and is kept stable.

[0020]

1 and 2 are cross-sectional views showing a biological deodorizing carrier according to Examples 1 and 2 of the present invention. In the figure, 3 is a biological deodorizing carrier, which has a length of about 1 to 5 cm and a width of about 0.5 to
It is about 2.5 cm. An adsorption / desorption zone 1 is a zone in which a malodorous substance is temporarily absorbed and stored, and the malodorous substance is appropriately desorbed and diffused. Reference numeral 2 is a reaction zone, in which malodorous substance-degrading microorganisms are attached or supported by entrapment, and the microorganisms decompose the malodorous substance. Next, in the biological deodorizing carrier (Example 1) shown in FIG. 1, a production method in which the reaction zone and the adsorption / desorption zone are both gels will be described.

First, a gel polymer is dissolved in water to form a gel material solution, and a chemical or physicochemical method, for example, a crosslinking agent (boric acid in the case of PVA) is added to the gel material solution. Or, by repeating freeze-thawing, the molecules are cross-linked to partially block the chains of the polymer to form a gel (step 1). For example, in the case of PVA gel, PV
Solution A is mixed with a small amount of sodium alginate (when the inner zone is used as the reaction zone, the malodorous substance-degrading microorganism is mixed at this time), which is added dropwise to the calcium chloride solution to temporarily solidify it, and then frozen- Repeat melting to PVA
Cross-link to make gel beads.

Next, the gelled product is put into a solution containing a gel material of the same kind or different kinds, and the surface is coated with the gel solution. At this time, by changing the temperature of the gel solution to adjust the viscosity, the amount of coating can be increased,
Or it can be reduced. This is crosslinked by the chemical or physicochemical method in the same manner as described above and gelled (second step) to prepare a gel carrier having a double structure as shown in FIG.
By mixing a specific malodorous substance-decomposing microorganism into the solution on the outside before gelling, a gel (reaction zone 2) in which the microorganism is entrapped and immobilized can be obtained. In order to increase the strength of the carrier, the adsorption / desorption zone may be made of a material having high strength such as zeolite and used as a core material, and the gel in the reaction zone may be arranged so as to wrap the core material.

Next, the biological deodorizing carrier shown in FIG. 2 (Example 2)
In the above, a production method in which both the reaction zone and the adsorption / desorption zone are made of gel will be described. Similarly to the above, the gel formed in the first step was not completely immersed in the solution containing the gel material as in Example 1, but was partially contacted and adhered, and gelated in the same manner as described above. The reaction zone 2 and the adsorption / desorption zone 1 as shown in 2 form a gel carrier in which they are adjacent to each other.

<Experiment> Next, an experimental model for examining the ability of the biological deodorant carrier to adsorb and desorb malodorous substances will be described. FIG. 3 is a diagram for explaining this experimental model. In the figure,
Reference numeral 4 is a PVA gel block for absorbing and desorbing malodorous substances. Reference numeral 5 is a desiccator, and 6 is the MS gas filled in the desiccator 5. A glass container 11 is filled with an inorganic medium 7 in which the malodorous substance-degrading microorganisms are suspended. Initially, MS does not exist in the medium 7. A dissolved oxygen electrode 8 measures the amount of dissolved oxygen in the medium 7. Reference numeral 10 is a magnetic stirrer, and 9 is a rotor thereof, which is used to make the contact between the electrode 8 and the solution constant during measurement by the dissolved oxygen electrode 8. Reference numeral 12 is a constant temperature bath for keeping the environment of microorganisms at an appropriate temperature. In this experiment, the PVA gel block 4 corresponds to the adsorption / desorption zone, and the medium 7 corresponds to the reaction zone.

Next, the experimental method will be described. First, Fig. 3
As shown in (a), the desiccator 5 filled with 100 ppm of MS gas 6 (MS was used as a representative of malodorous substances).
The PVA gel block 4 was put therein and left for 12 hours.
After that, as shown in FIG. 3 (b), the PVA gel block 4 was immersed in the microorganism-suspended inorganic medium 7, and the change in the dissolved oxygen concentration of the medium 7 with time was examined. When MS is present in the medium 7, the microorganisms oxidize and decompose the MS, and the oxygen concentration in the container 11 is reduced. Therefore, by examining the decrease in dissolved oxygen in medium 7, the PVA gel block
S is absorbed (step in FIG. 3A) and released (FIG. 3)
Whether or not it is the step in (b). The measurement result of the dissolved oxygen concentration of the medium 7 is shown in FIG.

As shown in FIG. 4, the oxygen concentration is decreased, and as a result, the PVA gel has the ability to absorb and store malodorous substances (MS) and can be released to the outside by diffusion. I understand that.

<Embodiment 1> Next, the case where a malodorous gas is treated using the biological deodorizing carrier (Embodiment 1) shown in FIG. 1 will be described. A malodorous substance is adsorbed in advance in the adsorption / desorption zone 1 of the biological deodorizing carrier 3, and is filled in the treatment tower of the biological deodorizing device. When a malodorous substance is present in the gas to be treated during the treatment of the gas to be treated, the microorganisms carried in the reaction zone 2 decompose the malodorous substance in the gas to be treated and treat it as a deodorized gas in the treatment tower. Discharge to the outside. At this time, the malodorous substance in the adsorption / desorption zone 1 is kept stored in the adsorption / desorption zone 1.

Next, when the concentration of the malodorous substance in the gas to be treated is extremely low or absent, the malodorous substance in the adsorption / desorption zone 1 desorbs and diffuses, and the microorganisms in the reaction zone 2 remove the malodorous substance. Capture and disassemble. Thus, the above-mentioned microorganisms are constantly supplied with the malodorous substance as a substrate, and the microorganisms can keep their activity high. In addition, it is also possible to store excess malodor that has not been completely decomposed in the adsorption / desorption zone.

As the structure of the biological deodorizing carrier, as shown in FIG. 1 (Example 1), if the structure is such that the adsorption / desorption zone 1 is at the center and the reaction zone 2 is arranged so as to surround it. Since the microorganisms in the reaction zone 2 come into direct contact with the gas to be treated, the contact efficiency between the malodorous substance and the microorganisms is increased and the deodorization efficiency is increased.

On the contrary, if the adsorption / desorption zone is arranged so as to surround the reaction zone in the center, the physical and chemical environmental changes from the outside transmitted to the reaction zone are alleviated.
It is easy to stably maintain the physiological environment of microorganisms.

<Embodiment 2> FIG. 2 is a view showing a biological deodorizing carrier according to Embodiment 2 of the present invention. As shown in FIG. 2, the structure of the biological deodorizing carrier of Example 2 is such that the reaction zone 2 and the adsorption / desorption zone 1 are arranged adjacent to each other, but in this case, the reaction efficiency is high for the reaction zone. Has an advantage that the adsorption and desorption efficiency is improved for the adsorption and desorption zone.

As in Examples 1 and 2, as a carrier having both a reaction zone and an adsorption / desorption zone, both zones may be made of the same material or different materials. Although a gel is used in the reaction zone, a material other than gel may be used in the adsorption / desorption zone. For example, zeolite may be used in the adsorption / desorption zone, and the gel may be wrapped in the reaction zone as a core material. . When a PVA gel carrier is used as the carrier, it has the advantages of high durability and relatively low cost.

Example 3 Next, a biological deodorizing carrier having a partition will be described. FIG. 5 is a perspective view showing a third embodiment of the biological deodorant carrier according to the present invention. In the figure, 17 is a biological deodorant carrier, 13 is a partition wall, and a large number of pores 16 are provided on the surface thereof. 14 is a gel of the adsorption / desorption zone, which exists in the partition wall 13. 15 is a gel of the reaction zone, which exists so as to wrap the partition wall 13. FIG. 6 shows the treatment tower 18 in the biological deodorizer.
In the schematic cross-sectional view showing the above, the treatment tower 18 is filled with the biological deodorizing carrier 17. In the figure, 19 is an inlet pipe for the gas to be treated, and 20 is an exhaust pipe for the treated gas.

In the deodorization operation, the gas to be treated is introduced into the treatment tower 18 through the introduction pipe 19 as shown in FIG.
It is discharged to the outside of the tower through the biological deodorizing carrier 17. Similarly to the above, when the odorous substance is contained in the gas to be treated introduced from the introduction pipe 19 (concentration that does not reduce the activity of the microorganism), the odorous substance is removed by the microorganism of the reaction zone gel 15 (see FIG. 5). The decomposed gas becomes a deodorized gas and is discharged from the discharge pipe 20. If the malodorous substance in the introduced gas to be introduced is extremely low in concentration or does not exist, the malodorous substance stored in the adsorption / desorption zone gel 14 is desorbed and diffused, and passes through the pores 16 to the microorganisms of the reaction zone gel 15. Supplied. In this way, the malodorous substance is constantly supplied to the microorganisms, and thus the microorganisms continue to maintain a high decomposition treatment activity without being killed or reduced in activity due to lack of substrate.

Adsorption / desorption zone gel 14 deodorizing malodorous substances
When a gas to be treated containing a malodorous substance flows in, it absorbs a part of the malodorous substance (the other part is treated by microorganisms), and then the malodorous substance in the gas to be treated has a low concentration or Is prepared when it is not contained.

In the third embodiment, since the biological deodorizing carrier 17 has the partition wall 13, the strength of the carrier is improved and the gel is not crushed by the pressure. In particular, when the gel carrier is a low-concentration gel having a high water content ratio, the strength against load is weak, but the strength is increased by using the partition wall as in the third embodiment. The materials for the reaction zone gel 15 and the adsorption / desorption zone gel 14 may be the same as or different from each other, as in Examples 1 and 2, and the adsorption / desorption zone may be a non-gel material.

The biological deodorizing carrier 17 having the cylindrical partition wall 13 as in the third embodiment, for example, does not adhere to each other and forms an appropriate gap as compared with, for example, a spherical carrier. The loss can be kept low, and the cost of electricity for the blower fan can be reduced. Further, since the specific surface area with respect to the volume per carrier is large, the contact efficiency with the malodorous substance is improved. It should be noted that the adsorption / desorption zone gel 14 may be sufficiently adsorbed and stored with a malodorous substance in advance, or may be adsorbed and stored by using the malodorous substance contained in the gas to be treated after filling the treatment tower. Is also good.

The structure of the partition wall is not limited to the cylindrical skeleton structure having pores on the surface as shown in FIG. 5, and the shape, length, partition wall thickness, etc. may be variously changed. good. By using partition walls having such various shapes, the carrier can also have various shapes, for example, a spherical shape, a donut shape, a rod shape, a spiral shape, or the like. Further, the pores provided on the partition wall surface are not limited to the elliptical shape shown in FIG. 5 and may have any shape such as a rectangular shape or a slit shape as long as the malodorous substance can diffuse in and out. .

In the third embodiment, the reaction zone is on the outside and the adsorption / desorption zone is on the inside. However, not limited to this, the reaction zone may be on the inside and the adsorption / desorption zone may be on the outside. In this case, the external physical and chemical environment changes are mitigated before they reach the microorganisms in the reaction zone, which makes it easier to stably maintain the physiological environment of the microorganisms.

[0040]

As described above, since the biological deodorant carrier according to the present invention has both the reaction zone and the adsorption / desorption zone, even if there is a load fluctuation of the malodorous substance, the malodorous substance is absorbed. It is possible to keep the activity of the malodorous microorganisms high while keeping the biological deodorizing device compact without providing another layer for desorption. Therefore, there is an effect that the treatment efficiency of the biological deodorizing device is increased. Further, when the biological deodorizing carrier according to the present invention is adopted in the biological deodorizing device, since the device itself does not need to be modified, it can be easily applied to an existing device. Further, since the reaction zone and the adsorption / desorption zone are integrated through the gas permeable partition wall, the strength of the carrier is improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing a biological deodorizing carrier according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a biological deodorizing carrier according to Example 2 of the present invention.

FIG. 3 is an explanatory diagram of an experimental model for investigating the malodorous substance adsorption / desorption ability of the carrier.

FIG. 4 is a graph showing changes in dissolved oxygen concentration with time.

FIG. 5 is a perspective view showing a biological deodorizing carrier according to Example 3 of the present invention.

FIG. 6 is a schematic sectional view showing a treatment tower having a biological deodorizing carrier according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Adsorption / desorption zone 2 Reaction zone 3,17 Biodeodorant carrier 4 PVA gel block 13 Partition wall 14 Adsorption / desorption zone gel 15 Reaction zone gel 16 Pore 18 Treatment tower

Claims (2)

[Claims] 1. A biological deodorant carrier having both a reaction zone for supporting a malodorous substance-degrading microorganism and an adsorption / desorption zone for a malodorous substance. 2. A biological deodorizing carrier, characterized in that a reaction zone carrying a malodorous substance-degrading microorganism and an adsorption / desorption zone for a malodorous substance are integrated through a gas-permeable partition wall.