JP3291739B2 - Filter material for fixing microorganisms for deodorization - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a filter for fixing microorganisms for deodorization.
More particularly, the present invention relates to a filter material for fixing microorganisms for deodorization, comprising a surface layer neutralized lime-based porous hardened material useful as a deodorization filter material to be filled in a deodorization apparatus employing a microorganism deodorization method.

[0002]

2. Description of the Related Art A deodorizing apparatus based on a microorganism deodorizing method utilizing microorganisms and the like in soil has already been put into practical use as a deodorizing apparatus for odors generated from livestock raising facilities such as windowless poultry houses. In a general microorganism deodorizer, while spraying circulating water into a packed tower filled with a filter for fixing deodorized microorganisms,
Deodorization is performed by aerating an odorous air flow. Conventionally, a filter made of resin has been used as a filter for immobilizing deodorizing microorganisms used in such a deodorizing apparatus. However, the specific surface area is small, the apparatus is large, and the surface is smooth and the microorganisms are immobilized. And it takes time. Therefore, in recent years, ceramic fibers formed into paper and then formed into a honeycomb-shaped honeycomb structure have been used.

[0003]

However, in the filter made of the above-mentioned ceramic fiber, since the cost of the ceramic fiber is high, the processing cost rises, the handling property is difficult, and the used filter is difficult to replace. Has the drawback that processing is difficult.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a filter material for fixing microorganisms for deodorization which is suitable as a filter material for fixing microorganisms used in a deodorizing apparatus of a microorganism deodorizing method.

[0005]

The microorganisms for deodorization according to the present invention are provided.
The filter material for use is a porous hardened material containing CaO, and the surface layer of CaO on the outer surface and the inner surface of the pores is made of a surface-neutralized lime-based porous hardened material neutralized with phosphoric acid.
Characterized in that that.

Hereinafter, the present invention will be described in detail. Of the present invention
The surface neutralized lime-based porous hardened material constituting the filter material for fixing microorganisms for deodorization is a foamed lightweight concrete, and a surface hardened surface of the porous hardened material containing CaO such as calcium silicate and the surface layer of CaO are phosphorylated. It is obtained by neutralizing with an acid. As the lime-based porous hardened material, natural minerals and waste materials of foamed lightweight concrete can be used.
The content is preferably from 10 to 100% by weight. Further, the lime-based porous cured body may contain silica and other substances.

In particular, natural minerals generally contain compounds such as potassium, boron, manganese, and iron as trace components, and these components are effective as fertilizers. Therefore, after the surface neutralized lime-based porous hardened body of the present invention is used as a filter, it can be effectively used as a fertilizer, which is extremely advantageous. In addition, waste materials containing silica can be effectively used as silicate fertilizers.

In the present invention, the particle size of the surface layer neutralized lime-based cured porous material is preferably about 1 to 100 mm. However, when the particle size is 10 mm or less, the apparent size is set to 10 mm or more by placing the particles in a net-like bag. When the particle size is smaller than 10 mm, when the cured product is used in a packed tower as a filter material for a deodorizer, the pressure loss in the tower becomes large. In addition, the pores are destroyed, making it difficult for microorganisms to inhabit.

Conversely, if the particle size of the cured product is larger than 100 mm, the amount of the malodorous component dissolved in the circulating water decreases,
Deodorizing effect decreases. In addition, handling becomes difficult, and processing of used products becomes difficult.

The porosity of the surface-neutralized lime-based porous cured product is as follows:
It is preferred to be about 10 to 60%. This porosity is 1
If it is less than 0%, it becomes difficult for microorganisms to inhabit, and the amount of malodor components dissolved into the circulating water decreases, and the deodorizing effect decreases. On the other hand, if it is larger than 60%, the strength of the cured product is reduced, and the cured product may be broken during refilling work or the like.

In the present invention, the degree of neutralization with phosphoric acid depends on the total amount of CaO contained in the porous cured body before neutralization.
It is preferable that 5 to 50% of CaO is neutralized to form calcium phosphate.

[0012] To manufacture such table layer neutralizing lime porous cured material, for example, firstly, silica, lime (CaO)
And / or slaked lime (Ca (OH) ₂ ) and cement are mixed in an appropriate amount, and the resulting mixture is added to water containing a foaming agent, and the mixture is poured into a mold and cured to obtain a lime-based porous material. A cured product is manufactured. In this curing, it is desirable to perform high-temperature and high-pressure curing after primary curing. After taking out the obtained porous hardened body from the mold and pulverizing it to a predetermined particle size, the temperature is 20 to 50 ° C. and the concentration is 20 to 50% by weight.
It is immersed in a phosphoric acid aqueous solution for about 1 to 10 minutes. Of course, it is possible to use 20% by weight or less or 50% by weight or more. However, at a low concentration, it is necessary to lengthen the immersion time, and at a high concentration, a stirring operation or the like is required because the viscosity of the solution is high. As a result, CaO in the surface layer of the outer surface and the inner surface of the pores of the porous cured body becomes phosphate and is neutralized. After the neutralization treatment, if phosphoric acid remains in the porous cured product, 1
Dry at 00 ° C. or higher and remove the microorganism for fixing deodorant of the present invention.
A surface-neutralized lime-based porous hardened material constituting the ruther material is obtained.

In this neutralization treatment, the degree of neutralization can be easily adjusted by appropriately setting the concentration, temperature, immersion time and the like of the phosphoric acid aqueous solution to be used. In this case, the concentration and temperature of the phosphoric acid aqueous solution, the immersion time,
The surface layer of the surface layer neutralized lime-based porous hardened material obtained according to the drying temperature, etc. is neutralized with CaO to form one of calcium phosphate, calcium monohydrogen phosphate, calcium dihydrogen phosphate, and hydroxyapatite. The above is formed in various ratios.

[0014]

The filter material of the present invention for fixing microorganisms for deodorization is constituted.
The surface layer neutralized lime-based porous hardened body can be manufactured using waste material of lightweight foamed concrete, and is very inexpensive. In addition, since they are supplied as lumps or granules, they are excellent in handleability. Moreover, since it is a porous material, the pressure loss is small when used in a packed tower.

By the way, the main component of the offensive odor component generated from livestock raising facilities is ammonia. Among the microorganisms involved in this ammonia deodorization, there are aerobic nitrites and nitrates that convert ammonia to nitrite and further to nitrate, and anaerobic denitrifiers that convert nitrite and nitrate to nitrogen. In the case of general ammonia deodorization, a part of ammonia is changed to nitric acid (including nitrous acid) and deodorized by a neutralization reaction. However, in this method, the nitrogen concentration in the circulating water increases, and it is necessary to periodically change the circulating water. On the other hand, in the surface neutralized lime-based porous hardened material constituting the filter material for fixing microorganisms for deodorization of the present invention, aerobic nitrites and nitrates are circulated in the surface layer where circulating water is constantly replaced. Anaerobic denitrifying bacteria inhabit where water is not replaced. For this reason, ammonia can be finally decomposed to nitrogen, and the deodorizing treatment can be performed efficiently without increasing the nitrogen concentration in the circulating water.

Further, nitrogen and phosphorus are necessary as nutrient sources for microorganisms. In the case of ammonia deodorization, nitrogen is supplied as ammonia, but phosphorus is not supplied. Therefore, it is necessary to supply nitrogen from other sources.
In the surface-layer neutralized lime-based porous hardened material constituting the object-fixing filter material , the surface layer portion contains phosphorus, so that it is not necessary to separately supply it.

Further, the microorganism-fixing film for deodorization of the present invention.
In the surface-neutralized lime-based porous hardened material constituting the raw material, since CaO in the surface layer is insoluble phosphate, CaO is hardly eluted and p of the circulating water of the deodorizer is reduced.
H is a neutral pH suitable for the growth of microorganisms, that is, about pH7. Therefore, the microorganisms are maintained in a favorable growth environment. By the way, in the lime-based porous hardened body in which CaO in the surface layer is not converted to phosphate, the CaO contained is slightly eluted, so that the circulating water becomes alkaline with a pH of about 9 to 10, and the growth of microorganisms is reduced. Not preferred.

One of the problems of the microorganism deodorizing method is that it takes time to start the apparatus at the start of operation, but the filter material for fixing microorganisms for deodorizing of the present invention is not suitable.
In the surface layer neutralized lime-based porous hardened material constituting the surface layer portion, the following chemical reaction occurs due to the phosphate in the surface layer portion, and immediate start-up is possible. That is, the phosphate Ca contained in the surface layer portion
HPO ₄ uses Ca ₁₀ as a catalyst with ammonia as a malodorous component as a catalyst.
It changes to (PO ₄ ) ₆ (OH) ₂ , which releases excess phosphoric acid. The released phosphoric acid and ammonia precipitate as ammonium phosphate by a neutralization reaction. Thereby, ammonia can be removed.

Further, the present invention provides a deodorizing microorganism-fixing film according to the present invention.
Since the surface layer neutralized lime-based porous hardened material constituting the tar material is lime-based, it can be effectively used as a soil improving material after being used as a filter material. Furthermore, for the deodorization of the present invention
Since the surface layer neutralized lime-based porous hardened material constituting the filter material for fixing microorganisms contains a phosphate indispensable for the growth of plants, it can be effectively used as a fertilizer after use. Furthermore, when a large amount of silica is contained, it can be used very effectively as a silicate fertilizer as a fertilizer even when it contains a small amount of additives required for plants such as boron, manganese, and iron. In particular, when used for ammonia deodorization, it contains ammonia nitrogen and nitrate nitrogen formed by the action of microorganisms in addition to potassium and phosphoric acid, and all three major elements necessary for plants are included. It will be a good quality fertilizer including. Therefore , the filter material for fixing microorganisms for deodorization of the present invention is constituted.
The resulting surface neutralized lime-based porous hardened body has the advantage that after use, it can be sprayed on soil or agricultural land, and waste can be used effectively.

[0020]

The present invention will be described more specifically below with reference to examples and comparative examples.

Example 1, Comparative Examples 1 to 3 The filter materials shown in Table 1 were packed in a packed tower of an ammonia deodorizing apparatus of a microbial deodorizing system, and the exhaust air from the windowless poultry house was deodorized. The results are shown in Table 1. Was.

The lime-based porous hardened material used in Comparative Example 3 and the surface layer neutralized lime-based porous hardened material used in Example 1 were produced as follows.

The powdered silica, CaO, and cement were mixed at a weight ratio of 3: 1: 1, and added to and mixed with an aqueous solution containing 0.1% by weight of a foaming agent. Pour this into the formwork, 25
After primary curing at 2 ℃ for 2 hours, 10atm, 1 at 180 ℃
The foam was cured by heating at a high temperature and a high pressure (autoclave) for 6 hours. The obtained cured product was taken out of the mold and pulverized to obtain a lime-based porous cured product. The particle size of this is 50-80m
m and porosity was 42%.

The cured lime-based porous material was immersed in a 20% by weight aqueous solution of phosphoric acid at 25 ° C. for 2 minutes for neutralization, and then dried at 100 ° C. for 20 hours. The obtained surface layer neutralized lime-based porous hardened product was examined by X-ray fluorescence analysis. As a result, 22% of the total CaO of the lime-based porous hardened product before the neutralization treatment was obtained.
Weight% of CaO is neutralized to phosphate, and the surface calcium is mostly calcium monohydrogen phosphate,
Some were in the form of calcium phosphate and hydroxyapatite.

[0025]

[Table 1]

The following is clear from Table 1. That is,
When a conventional resin filter material (Comparative Example 1) or a ceramic honeycomb structure (Comparative Example 2) is used, the efficiency of removing ammonia is poor, and total nitrogen tends to accumulate in circulating water.

When the lime-based porous hardened material (Comparative Example 3) was used, the nitrogen concentration in the circulating water was relatively low, but the ammonia removal efficiency was slightly inferior, and the pH of the circulating water changed over time to an alkaline range. Show a tendency to.

[0028] On the contrary, in the case of using Table layer neutralized lime porous deodorizing microorganism fixing the filter material of the cured body from the consisting invention (Example 1) is significantly higher ammonia removal efficiency. In addition, the total nitrogen concentration in the circulating water is low, and the pH value of the circulating water is good.

[0029]

As described in detail above, the deodorizing microorganism of the present invention is used.
According to the filter material for fixing objects, the material exhibits neutrality suitable for the inhabitation of microorganisms. It can be made into a lump or a granule, and is excellent in handleability. Since it is a porous body, it has a small pressure loss when used in a packed tower. Provided at low cost. After use, it can be effectively used as fertilizer, soil modifying material, etc. Both aerobic and anaerobic microorganisms can be inhabited, whereby ammonia can be decomposed to nitrogen and good treatment can be performed. Excellent effects such as
Its industrial utility is extremely large.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C04B 41/00-41/72

Claims (1)

(57) [Claims] 1. A porous cured material containing CaO, that CaO of the surface layer portion of the outer surface and pore inner surfaces are made of Table layer neutralized lime porous cured material that has been neutralized with phosphoric acid
A filter material for fixing microorganisms for deodorization, comprising: