JPH0515732A - Deodorizing method and deodorant - Google Patents

Abstract

PURPOSE:To remove the malodor generated in livestock excretion treatment facilities in low cost by a method easy in maintenance and control. CONSTITUTION:The malodorous gas generated at the time of livestock excretion treatment is brought into contact with an acidic aqueous solution to remove basic malodorous components such as ammonia, trimethylamine or the like and subsequently brought into contact with a deodorant containing at least one kind of a compound selected from a group consisting of phosphoric acid, phosphorous acid, hypophosphorous acid, salts thereof and peroxide to be deodorized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deodorizing method and a deodorant for deodorizing or reducing the bad odor generated when treating the excrement of livestock in a livestock-related industry including pig farming and poultry farming. Is.

[0002]

2. Description of the Related Art In recent years, the number of complaints concerning offensive odors related to the livestock industry up to 1988 shows that the survey by the Livestock Bureau of the Ministry of International Trade and Industry shows a slight decrease as a whole. However, the number of complaints per farmer is increasing, as the number of complaints is more than the number of complaints, and it can be said that the number of complaints per farmer is relatively increasing.

As described above, the bad smell pollution related to livestock production has been annoying to the local residents, and as a result, it has been repelled as an economic burden for livestock farmers by taking measures against bad smell. Sources of offensive odors can be broadly divided into livestock odors from livestock sheds (including manure and feed odors in livestock sheds) and offensive odors from livestock manure processing facilities. The odor generated from livestock sheds is mainly the odor of livestock excrement, and is considerably mitigated by the rapid discharge of excrement from the livestock shed, but in manure processing facilities, gas containing a considerably high concentration of odor may be emitted. Many. For this reason, the latter case is usually taken as a countermeasure against the bad smell.

Examples of the method for treating livestock manure include composting, heat drying, sun drying, and methane fermentation. All of these methods generate a considerable amount of bad odor and require deodorization, but the following four methods are listed as the main deodorization methods as measures against bad odor. 1) Method using deodorant (deodorant) 2) Microbial treatment (use of aerobic and anaerobic fermentation) 3) Combustion method 4) Chemical liquid deodorization method (deodorization by acid and / or alkali treatment) These deodorization methods are Both of them have advantages and disadvantages, and they are currently used separately depending on the situation or used together.

For example, as a method of using the deodorizing agent of 1), there are physical adsorption by activated carbon, chemical decomposition by an oxidizing agent, and aroma imparting by a masking agent. These have problems such as a short life, a certain effective gas type, and a fundamental deodorizing method. The microbial treatment of 2) requires a long contact time because it takes a long time to treat the microorganisms. Therefore, the treated air volume must be reduced or a large-scale facility is required. In addition, it also requires maintenance work.
Regarding 3), there are a direct combustion method and a catalytic combustion method, but both have high running costs. Regarding 4), the running cost is not as high as in the combustion method of 3), but in alkaline cleaning carbon dioxide in the air causes a neutralization reaction with an alkaline chemical solution, forming carbonates and depositing solids inside the cleaning tower. . Therefore, the chemical solution must be used more than necessary, and maintenance is difficult.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a deodorizing method and a deodorizing agent used for this method, which removes the malodorous components generated during the processing of livestock excrement relating to the above-mentioned livestock industry at a low cost and by an easy maintenance method. In order to overcome the drawbacks of the above conventional methods.

[0007]

Means for Solving the Problems The present inventors have studied what kind of chemical component an offensive odor component generated during the treatment of livestock excrement related to such livestock industry, and as a result, mainly ammonia, lower fatty acid and It was clarified that it is composed of an extremely large number of components, such as sulfur compounds such as hydrogen sulfide and methyl mercaptan. The present inventors have completed the present invention as a result of studying a deodorant and a deodorizing method effective for these malodorous components.

That is, according to the present invention, (1) a malodorous gas generated during the treatment of livestock excrement is brought into contact with an acidic aqueous solution, and then phosphoric acid, phosphorous acid, hypophosphorous acid, salts thereof and peroxide A deodorizing method characterized by contacting with a deodorizing agent containing at least one selected from the group consisting of: (2) Phosphoric acid, phosphorous acid, hypochlorous acid for malodorous gas generated when treating livestock excrement The present invention relates to a deodorant containing at least one selected from the group consisting of phosphoric acid, salts thereof, and peroxides.

According to the deodorizing method of the present invention, ammonia,
Basic malodorous components such as trimethylamine can be easily maintained and maintained at low cost by washing with an acidic aqueous solution.
Other malodorous components can be effectively removed by a deodorizing device filled with a deodorant containing at least one selected from the group consisting of phosphoric acid, phosphorous acid, hypophosphorous acid, salts thereof and peracids.

The present invention will be described in detail below. Examples of livestock include pigs, chickens and cows. The treatment of manure includes various treatments that have been conventionally performed and is not particularly limited, and examples thereof include composting, heat drying, sun drying, methane fermentation, and the like. It is preferred to operate in a closed facility so that almost all of the gas can be sent to the process of the present invention.

The malodorous gas generated during the treatment of livestock manure is first contacted with an acidic aqueous solution. The method of this contact is not particularly limited, and a known method can be used. For example, using a generally used washing tower, an acidic aqueous solution is sprayed or flowed down from the upper part of the washing tower, and a malodorous gas is brought into countercurrent contact therewith. The temperature at the time of contact is usually 0 to 40 ° C. In addition, the contact time (the residence time of the malodorous gas in the cleaning tower) is
It usually takes 0.05 to 10 seconds.

As the acidic aqueous solution, various kinds can be used, and examples thereof include an aqueous solution of sulfuric acid and an aqueous solution of hydrochloric acid. However, the acidic aqueous solution is not particularly limited thereto, and any acidic aqueous solution may be used. PH of acidic aqueous solution
Is preferably in the range of 2 to 5, but is not limited thereto.

The malodorous gas is contacted with an acidic aqueous solution and then with the deodorant of the present invention. In the deodorant of the present invention,
Examples of salts of phosphoric acid, phosphorous acid and hypophosphorous acid include alkali metal salts such as sodium salt and potassium salt, alkaline earth metal salts such as magnesium salt, calcium salt, barium salt and strontium salt, iron salt and cobalt. There are various salts and the like, and there is no particular limitation.

The peroxide can be widely selected from inorganic peroxides and organic peroxides, but preferred ones are sodium peroxide, potassium peroxide, calcium peroxide, barium peroxide, sodium percarbonate, and peroxide. Examples thereof include sodium borate, perchloric acid and salts thereof.

The deodorant of the present invention further comprises iron, cobalt, nickel, chromium, titanium, zirconium, vanadium, molybdenum, tungsten, manganese, copper, silver, zinc, germanium, tin, lead, platinum, palladium, magnesium, calcium. The deodorizing ability is increased by adding one or more metals or compounds such as strontium and barium. Examples of the compound include oxides, carbonates, sulfates, chlorides and the like. When these metals or their compounds are used, their proportion in the deodorant is arbitrary, but is preferably 0.05 to 90% by weight, more preferably
0.1 to 60 weight percent.

The deodorant of the present invention can be supported or mixed in a commonly used porous carrier. Preferred carriers include silica, alumina, silica-alumina, natural zeolite, synthetic zeolite, diatomaceous earth, activated carbon,
Kanuma soil, clay minerals and the like can be mentioned, but the carrier is not particularly limited thereto, and any commonly used carrier can be used. When a carrier is used, the ratio of the carrier in the deodorant is arbitrary, but preferably 10
˜90 weight percent, more preferably 30 to 70 weight percent.

When the deodorant of the present invention contains two or more components, the deodorant of the present invention can be obtained by mixing these components. The deodorant of the present invention can be used as a deodorant in any of liquid and solid forms, but in the case of a liquid deodorant such as phosphoric acid, phosphorous acid and hypophosphorous acid, it is supported on a porous carrier, It can be used as a solid deodorant. Rather, it is often used as a solid deodorant by being supported on a porous carrier due to restrictions in use, but the form is not limited to these,
There is no restriction in either liquid or solid form.

When used as a solid deodorant, it can take a wide variety of forms depending on the size of the solid particles, from powder to granules having a particle size of about 1 mm and pellet granules having a particle size of about 2 mm to 20 mm. When molding into pellets, a binder is often used to facilitate molding. The deodorizing agent of the present invention is no exception, and it is possible to mold using a commonly used binder. Preferred binders are bentonite, colloidal silica, white clay, kaolin, inorganic substances such as water glass or sodium alginate, glue, glucose,
Dextrin, hydroxypropyl cellulose (HP
C), carboxymethyl cellulose sodium salt (CM
Examples of the binder include C), polyvinyl alcohol (PVA), polyvinylpyrrolidinone (PVP) and other organic polymer-based binders, but the binders are not limited to these and any commonly used binder can be used. is there.

The raw material used for the deodorant of the present invention is not particularly limited. What is usually available can be used, and any raw material can be used as long as it is a product which finally becomes the above compound by the preparation and molding method.

When the gas after being brought into contact with the acidic aqueous solution is brought into contact with the deodorant of the present invention, the temperature thereof is not particularly limited, but it is usually -10 to 50 ° C, and the contact time is not particularly limited, but it is usually It is 0.1 to 10 seconds.

[0021]

EXAMPLES Next, the present invention will be described more specifically with reference to examples.

Example 1 10 parts of 85% phosphoric acid, 50 parts of activated carbon, and 5 parts of sodium salt of carboxymethyl cellulose (hereinafter abbreviated as CMC) as a binder were sufficiently kneaded with a small amount of water, and then the mixture was extruded by an extruder. It was extruded from a die with a hole diameter of 4 mm. The udon-like deodorant that was extruded was immediately cut by a cutter for 3 to 10
It was cut into mm length and dried at 110 ° C. to obtain a deodorant.

1000 g of the obtained deodorizing agent was filled in a cylinder having a diameter of 70 mm to form a deodorizing tower. Ammonia 100ppm, hydrogen sulfide 5pp
m, a gas containing 5 ppm of methyl mercaptan is introduced into an acid washing tower (sulfuric acid aqueous solution is flown at room temperature at a flow rate of 1 liter / sec.) with a flow rate of 100 liters per minute to control the pH to 3 to 5, and a basic gas is introduced. After almost removing, it was led to a deodorizing tower filled with the above deodorant.

At the outlet of the deodorizing tower, the concentration of each malodorous substance was measured, but no malodorous substance was detected,
It was also sensually odorless.

Example 2 97% phosphorous acid 10 parts, activated carbon 50 parts and CMC as binder
Granulation and molding were carried out in the same manner as in Example 1 except that 5 parts were used to obtain a deodorant, which was used and tested in the same manner as in Example 1. The results were the same as in Example 1.

Example 3 Granulation was carried out in the same manner as in Example 1 except that 5 parts of 50% hypophosphorous acid, 50 parts of synthetic zeolite and 5 parts of CMC were used as a binder,
Molded to obtain a deodorant, which was tested in the same manner as in Example 1. The results were the same as in Example 1.

Examples 4 to 5 10 parts of magnesium phosphate or 10 parts of sodium hypophosphite were used in place of 10 parts of 85% phosphoric acid, and otherwise the same as in Example 1 except that the deodorant was granulated and molded. The obtained product was used and tested in the same manner as in Example 1. The results were almost the same as in Example 1 in all cases.

Example 6 Granulation and molding were carried out in the same manner as in Example 1 except that 10 parts of 50% calcium peroxide, 50 parts of activated carbon and 5 parts of sodium alginate as a binder were used to obtain a deodorant, which was used. Then, the same test as in Example 1 was performed. The results were the same as in Example 1.

Example 7 A deodorant was obtained by granulating and molding in the same manner as in Example 6 except that 10 parts of sodium percarbonate was used in place of 10 parts of 50% calcium peroxide. Tested as well. The results were the same as in Example 1.

Example 8 50 parts hypophosphorous acid 10 parts, 50% calcium peroxide 10 parts, titanium dioxide 10 parts, activated carbon 50 parts and acrylic acid methyl ester polymer emulsion (solid content 50%) 10 as a binder 10
Granulation and molding were carried out in the same manner as in Example 1 except that parts were used to obtain a deodorant, and this was used and tested in the same manner as in Example 1.
The results were the same as in Example 1.

Example 9 Granulation was carried out in the same manner as in Example 1 except that 10 parts of 97% phosphorous acid, 10 parts of 50% calcium peroxide, 10 parts of titanium dioxide, 50 parts of activated carbon and 5 parts of CMC were used as a binder. Then, it was molded to obtain a deodorant, which was tested in the same manner as in Example 1. The results were the same as in Example 1.

Example 10 Granulation and molding were carried out in the same manner as in Example 1 except that 6 parts of 50% calcium peroxide, 10 parts of zinc oxide, 10 parts of natural zeolite, 30 parts of activated carbon and 5 parts of CMC were used as a binder. Then, a deodorant was obtained, and the same deodorant was tested as in Example 1. The results were the same as in Example 1.

Comparative Example 1 A test was conducted in the same manner as in Example 1 except that commercially available granular activated carbon (the size of the particles was the same as in Example 1) was used as the deodorant. At the outlet of the deodorizing tower, ammonia gas that could not be neutralized by the acid washing tower was detected at 8 ppm from the outlet of the activated carbon tower (deodorizing tower), and odor was felt in the sensory test.

Example 11 85% phosphoric acid 10 parts, activated carbon 50 parts, 50% calcium peroxide 10 parts
Parts, titanium dioxide 10 parts and CMC 5 parts as a binder were used in the same manner as in Example 1, except that the same degreasing agent was obtained. Using this, the same test as in Example 1 was performed. The results were the same as in Example 1.

Examples 12 to 22 1000 kg of the deodorant obtained in Examples 1 to 11 was packed in a deodorizing tower having a cross section of 2 m in length and 2 m in width. The malodorous gas for the test was the malodorous gas from the processing facility for excrement discharged from the pig farm. The type of manure treatment facility is a plant for composting, and has a mechanical part for cutting back compost in the building and has a closed structure. The scale of the treatment facility is 6 m wide and 60 m long, and 100 m ³ of air (a foul-smelling gas) was extracted from the inside of the treatment facility by an exhaust fan.

Acid washing tower (pH of sulfuric acid aqueous solution is 5 liters /
Flow down at a flow rate of 2 seconds) to remove the basic gas,
It was led to a deodorizing tower filled with the above deodorant.

As a result, in each case, 100 ppm of ammonia and 2 ppm of methyl mercaptan were introduced at the inlet of the acid washing tower.
The hydrogen sulfide content was 2 ppm, but none was detected at the deodorization tower outlet, and it was almost sensory odorless.

Furthermore, when the same measurement was carried out after one day of operation, no malodorous component was detected at the outlet of the deodorizing tower in any case, and it was almost odorless in the sensory test.

Comparative Example 2 Ammonia and methyl mercaptan at the inlet of the washing tower and the outlet of the deodorizing tower were used in exactly the same manner except that the same manure treatment facility as in Examples 2 to 22 was used and the acid washing tower was changed to a water washing tower. The concentration of hydrogen sulfide was measured. At the inlet of the washing tower, the same as in Examples 2 to 22, but 2 ppm of ammonia was detected at the outlet of the deodorizing tower. No other components were detected. Further, the concentration of the malodorous component at the outlet of the deodorizing tower after one-day operation was measured as in the example.
It increased to around 10ppm.

[0040]

EFFECTS OF THE INVENTION Of malodorous components, basic gas, particularly ammonia gas, is generated in large quantities from a livestock manure treatment facility, and if it is attempted to be removed using a solid deodorant (for example, acid-impregnated activated carbon), it will be solid. The ammonia treatment amount of the deodorant does not exceed 10 g-ammonia / 100 g-deodorant (so-called treatment amount 10%) even with the commercially available ammonia-dedicated treatment agent, so the cost of the agent is compared with sulfuric acid (for acidic aqueous solution). Then, it can be seen that the treatment of the same amount of ammonia costs about 100 times. Thus, according to the present invention, the basic gas can be easily removed at low cost. Further, neutral and acidic gases can be easily removed by using the deodorant of the present invention.

Claims (2)

[Claims] 1. A malodorous gas generated during the treatment of livestock manure is contacted with an acidic aqueous solution, and then phosphoric acid, phosphorous acid,
A deodorizing method comprising contacting with a deodorizing agent containing at least one selected from the group consisting of hypophosphorous acid, salts thereof and peroxides. 2. Deodorizing for malodorous gas generated during the treatment of livestock excrement, containing at least one selected from the group consisting of phosphoric acid, phosphorous acid, hypophosphorous acid, salts thereof and peroxides. Agent.