JP2002291857A - Deodorization method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deodorization method by which malodor generated from an activated sludge in waste water and generated when treating waste water, excess sludge, digested sludge, cohered sludge, or the like, or wash water from a cleaning device or a mixture of them is rapidly removed with small chemical liquid quantity in an exhaust duct and the effect may be maintained with a solidified deodorant. SOLUTION: Exhaust which contains malodor containing at least one of hydrogen sulfide and mercaptans is treated in a liquid deodorization process by using a cationic compound represented by a quaternary ammonium salt compound and a guanidine compound and with a metal oxide and/or metal carbonate (the metal oxide and/or metal carbonate are oxides of iron, cobalt, nickel, zinc, lead, chromium, manganese, and copper and/or carbonates of nickel, zinc, lead, potassium, calcium, copper, barium, magnesium, and manganese). A porous natural adsorbent such as activated clay, natural yellow soil and natural zeolite, and an excipient such as silica oxide and dextran are incorporated as appropriate in these metal oxides and/or metal carbonates as occasion demands.

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 more particularly to a method for deodorizing exhaust gas containing an odor containing at least one of hydrogen sulfide and mercaptans.

[0002]

2. Description of the Related Art The amount of general wastewater from households has been rapidly increasing with the recent increase in population in cities and suburbs. Therefore, the maintenance of sewerage is urgently required, and the amount of wastewater is increasing year by year. These wastewaters contain large amounts of organic and inorganic substances and are treated at sewage treatment plants. In these wastewater treatment facilities, for example, sewage treatment facilities, an initial settling tank for sedimenting solids in sewage flowing into the sewage treatment facility (hereinafter referred to as inflow sewage), and aeration for aerobically treating an organic substrate in the sewage with microorganisms. It has a tank (aeration step) and a final sedimentation tank for separating sludge generated in the aeration step, and treats inflow sewage. A part of the sludge separated from the final sedimentation basin is returned to the aeration tank as returned sludge, and the rest is sent to the first settling tank as surplus sludge and treated as the first settling tank drawn sludge. In these processes, a unique odor is generated and activated sludge, surplus sludge, digested sludge and the like are produced.

[0003] In addition, in the case of factories and other business establishments, due to severe environmental pollution of rivers and oceans, wastewater regulations have been strengthened and it is obligatory to treat water to a predetermined quality. Activated sludge treatment also produces odor and produces a large amount of sludge.

[0004] As described above, odor is generated in the process of treating general household wastewater, wastewater from business establishments and wastewater, and the produced sludge contains various organic and inorganic substances.
Further, various organic and inorganic substances are also contained in the cleaning water of the cleaning device and the like. Also, in such a sewage treatment facility, even in the process of treating sludge, microorganisms in the sludge generate sulfur-based odorous substances such as hydrogen sulfide and mercaptan, thereby causing odor problems and facility corrosion problems. are doing.

[0005] Among these various organic and inorganic substances,
Contains sulfur compounds. Sulfate is generated in the process of these putrefactions. Sulfate-reducing bacteria are usually present in sludge, and sulfate is reduced to hydrogen sulfide in sludge for production activities. By generating hydrogen sulfide, the sludge is further anaerobic, the sulfate-reducing bacteria proliferate, and the amount of generated hydrogen sulfide further increases. The generated hydrogen sulfide is released to the gas phase. Hydrogen sulfide is a toxic and unpleasant odor substance, which is not only dangerous for workers, but also causes odor problems to the local residents. In addition, hydrogen sulfide is oxidized by sulfur oxidizing bacteria and air adhering in the concrete facility, and dissolves in the mist to generate sulfuric acid. The sulfuric acid produced in this way corrodes concrete and metal, causing fatal defects in the structure of buildings.

On the other hand, in recent years, when excavating soil covered with concrete or asphalt for a long time in a suburb of a city, a similar odor has become a problem, and deodorization and deodorization are performed simultaneously during excavation.

As a means for preventing the generation of these odors and the corrosion of structures, there is an activated carbon treatment for adsorbing hydrogen sulfide on activated carbon. However, when the amount of adsorption reaches saturation, it is necessary to replace the activated carbon with new activated carbon or regenerate it. However, there is also a problem in economics such as complicated replacement work and high regeneration cost.

[0008] As another method, there is a method of deodorizing by passing through a packed phase of organisms held on a carrier. However, this method has problems that the size of the apparatus is large and that it is difficult to maintain and manage living things.

[0009] As a method using a chemical, there is a method in which hydrogen peroxide is spray-mixed singly. Although hydrogen sulfide and mercaptans can be removed in a short time and effective, continuous removal is required to maintain the removal effect. If the amount of the spray mixture is small, the sulfuric acid-reducing bacteria cannot be disinfected sufficiently, and if the sludge is left for a long time, oxidized sulfur Alternatively, there is a problem that sulfate ions generate hydrogen sulfide again by the sulfate-reducing bacteria.

As a method of fixing hydrogen sulfide as a metal salt, there is a method of spray-mixing a salt (powder) containing an alkali metal. In this method, hydrogen sulfide reacts with metal ions, and a large amount of sludge is formed as metal sulfide. However, there is a drawback that it is generated.

[0011]

In the prior art, the removal of hydrogen sulfide and mercaptans is inadequate, the maintenance is complicated, and there is a problem in terms of economy. The present invention
It is an object of the present invention to provide a method for efficiently removing and removing hydrogen sulfide and mercaptans contained in exhaust gas containing odor under mild conditions to prevent the spread of bad odor and the corrosion of facilities.

[0012]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the method for removing odors from exhaust gas containing odors. As a result, quaternary ammonium salts were added to exhaust gas containing odors containing hydrogen sulfide and mercaptans. And a cationic compound such as a guanidine compound are mixed by a gas-liquid mixing method, and thereafter, water in the gas phase is removed by an eliminator or the like,
By passing hydrogen sulfide and mercaptans in exhaust gas containing odor by passing through a layer of powder deodorant made of metal oxide, it has been found that hydrogen sulfide and mercaptans can be efficiently removed, and that the removal can be given sustainability, and the present invention has been completed. .

That is, in the deodorizing method of the present invention, exhaust gas containing an odor containing at least one of hydrogen sulfide and mercaptans is treated with a guanidine or quaternary ammonium compound and a metal oxide and / or metal carbonate. It is characterized by doing. In the deodorizing method of the present invention,
It is preferable to include a step of neutralizing exhaust gas containing an odor containing at least one of hydrogen sulfide and mercaptans with a neutralizing agent before or simultaneously with treatment with a guanidine-based or quaternary ammonium compound. Further, in the deodorizing method of the present invention, the metal oxide is zinc oxide, silicon oxide, copper oxide, aluminum oxide, manganese oxide, iron oxide, titanium oxide, nickel oxide, calcium oxide. It is preferable to use one or more metal oxides selected from silver oxide, palladium oxide, platinum oxide, vanadium oxide and magnesium oxide. In the deodorizing method of the present invention, the metal carbonate is composed of one or more metal carbonates selected from zinc, lead, potassium, sodium, calcium, copper, barium, magnesium, and manganese carbonates. Is preferred. In the deodorizing method of the present invention,
The treated exhaust gas is further treated with one or more substances selected from dextrin, cyclodextrin, silica gel, calcium silicate, ceramic, cellulose, activated clay, natural loess, hydrous magnesium silicate clay mineral, zeolite and EVA resin. It is preferable that the method comprises performing an inclusion or adsorption treatment. Further, in the deodorizing method of the present invention, the exhaust containing the odor to be treated is wastewater,
It is preferable that the exhaust gas is generated from sludge, washing equipment, or discharged soil during soil excavation. In the deodorizing method of the present invention, the guanidine-based compound is represented by the following general formula (I)
Alternatively, the compound represented by the general formula (II) and a salt thereof with an acid are preferable.

Embedded image (Wherein, X is HN =, represents the following general formula (1) or general formula (2), Y is _{H-, NC-, H 2 N-,} HO-,
The following general formula (3) or general formula (4) is represented)

Embedded image

Embedded image

Embedded image (Wherein, R is an alkylene group having 20 or less carbon atoms;
Means a positive number of 20 or less. In the deodorizing method of the present invention, the quaternary ammonium compound is preferably any one of the compounds represented by the following general formulas (III) to (V). It is.

Embedded image (R ¹ , R ² , R ³ and R ⁴ represent a straight-chain or branched alkyl group having 20 or less carbon atoms, and may be the same or different)

Embedded image (R ¹ and R ² represent a linear or branched alkyl group having 20 or less carbon atoms and may be the same or different)

Embedded image (R ¹ and R ² represent a linear or branched alkyl group having 20 or less carbon atoms and may be the same or different)

[0014]

Next, the method of the present invention will be described specifically. The exhaust gas containing an odor according to the present invention includes general wastewater from homes, wastewater from factories and the like, and wastewater generated from washing water and the like contained in a washing device and the like. In addition, sludge generating odor includes raw sludge, excess sludge, digested sludge, coagulated sludge, etc. generated when treating sewage, human waste or industrial wastewater, and mixtures thereof, and odor generated from discharged soil during soil excavation. . The present invention provides (1) a step of treating exhaust containing these odors with a cationic compound represented by a quaternary ammonium salt compound or a guanidine compound by gas-liquid mixing, and (2) a step of removing metal oxides after removing water. This is a deodorant / deodorant method that uses a powder deodorant. Also,
Prior to or simultaneously with the step (1), a step of neutralization may be included. Further, in any of the steps (1) and (2), treatment with dextrin, cyclodextrin, silica gel, calcium silicate, ceramic, cellulose, activated clay, natural loess, zeolite, and an EVA resin to further reduce malodor. May be applied.

[0015]Neutralizer  In the method according to the present invention, the odor in the exhaust gas is neutralized with a neutralizing agent.
The neutralizing agent used in the method according to the present invention may be
If the target odor is acidic, use ammonia,
Tanolamine, caustic potassium solution, caustic soda solution
Treat with any alkaline substance. On the other hand,
In the case of luka, hydrogen peroxide, peracetic acid, persulfate, peroxide
Carbonates, perborates, and other inorganic and organic peroxides
It is preferred to treat with an organic acid. The amount of neutralizer used
The pH of the odor after treatment is 4.5 to 9.5, more preferably
Adjust to 5.5 to 8.5 before use.

[0016]Quaternary ammonium salt compound or guani
Gin compounds  In the method according to the present invention, the odor component in the exhaust gas is quaternary ammonium.
Cation such as ium salt compound or guanidine compound
Treat with a reactive compound. Used in the method according to the invention
For cationic deodorants, examples of guanidine compounds are
A salt represented by the general formula (I) or an acid thereof,
Ammonium salt compounds are represented by the general formulas (III) to (V).
And its salts.

[0017]

Embedded image (Wherein, X is HN =, represents the following general formula (1) or general formula (2), Y is _{H-, NC-, H 2 N-,} HO-,
The following general formula (3) or general formula (4) is represented)

Embedded image

Embedded image

For example, the abovementioned salts may be salts of carbonic acid, nitric acid, sulfuric acid, hydrochloric acid, silicic acid, phosphoric acid, formic acid and / or acetic acid. Further, it may be a biguanidine polymer represented by the following general formula (II).

Embedded image (Wherein, R is an alkylene group having 20 or less carbon atoms;
Means a positive number less than or equal to 20)

In the deodorizing method of the present invention, the quaternary ammonium compound is preferably any one of the following general formulas (III) to (V).

Embedded image (R ¹ , R ² , R ³ and R ⁴ represent a straight-chain or branched alkyl group having 20 or less carbon atoms, and may be the same or different)

[0020]

Embedded image (R ¹ and R ² represent a linear or branched alkyl group having 20 or less carbon atoms and may be the same or different)

Embedded image (R ¹ and R ² represent a linear or branched alkyl group having 20 or less carbon atoms and may be the same or different)

[0021]Metal oxide  The use of powdered deodorant with metal oxide is quaternary ammonium
Of the deodorizing effect of the salt and guanidine compounds
Higher degree due to deodorizing effect of powder deodorant by metal oxide
The realization of a deodorizing effect. The present inventors have proposed powder deodorants.
And deodorization of metal oxide powder
It is found that the deodorant effect lasts as well as the effect
Was.

[0022]Neutralization process  When using a neutralization step, treat with a neutralizing agent and cationic
The odorants may be mixed separately in gas-liquid or simultaneously.
I do not care. Gas-liquid mixing of pre-mixed materials is also acceptable.
No. If pre-mixed, use ethylenediamine as a stabilizer
Spray mixing of chelating agents such as organic and organic carboxylic acids
Can be. Alternatively, the mixture may be spray-mixed sequentially.
There is no particular restriction on the mixing order, but the neutralizer is mixed first.
Preferably.

[0023]Mixing method of neutralizer and liquid deodorant and exhaust  In order to carry out the process according to the invention efficiently, cationic
When mixing odorant and neutralizer with gas-liquid,
Deodorant is efficiently mixed into the whole odor when mixing
It is preferable, but as a mixing method used at that time
Uses a nozzle or tip to generate mist and exhaust
Whirlpool, turbulent flow and hit with mist,
Set up a bar room etc. to reduce the flow rate and increase the deodorizing efficiency,
There are methods such as increasing the supply points of the deodorant such as nozzles. Ma
The liquid phase is continuously contacted with the gas phase like an eliminator
There is also a way to make it happen. Odorous exhaust and neutralizer, Katio
Any method can be used as long as the deodorant can be mixed
good.

As a method of mixing the chemicals by a spraying method, any method such as a diaphragm type or a plunger type metering pump may be used as long as it can supply the chemicals accurately.

In order to carry out the method according to the invention efficiently,
As for the place where the gas-liquid mixing of the drug is performed, immediately after the exhaust is preferable in view of the reaction time until the release into the atmosphere, but if the effect is recognized, the gas-liquid mixing may be performed in any step.

[0026]Metal oxide powder deodorant  The powdered deodorant made of the metal oxide of the present invention may be used as needed.
Then, it is molded and used as a molded article. Means for molding and
Extrusion molding, tablet molding, rolling granulation, compression molding, etc.
Is preferred. The shape of the molded article depends on the purpose and method of use
Decide. The shape of the molded body is cylindrical, crushed, spherical
Shape, honeycomb shape, uneven shape, corrugated shape and the like. Special
The odorous gas to the deodorizing composition
When touching and removing by adsorption, mesh-like, corrugated
Filter or honeycomb-shaped filter
Filter to a certain degree of pressure.
A shape that can obtain a sufficient deodorizing effect by loss of force is preferable.

[0027]Substance for inclusion or adsorption treatment  The deodorizing method of the present invention is used for the purpose of further reducing odor.
Various material layers with the aim of expanding the contact area (expanding the contact area)
It is desirable to let the odor pass through and include or absorb the odor.
New This step is preferably at the end of the deodorization step
But it can be inserted into other parts of the process.
Wear. The clathrate used in the clathration process of the present invention is dex
Trin, cyclodextrin, silica gel, calcium silicate
Available with calcium, ceramic, cellulose and EVA resin
Described above in one or more of these substances
It is also possible to react with bad odor by including a deodorant cationic deodorant
is there.

Cyclodextrins are those in which d-glucose is cyclically linked by α-1,4 bonds, six of which are α-cyclodextrins, and seven of which are β-cyclodextrins.
Cyclodextrins, eight of which are γ-cyclodextrins. In the present invention, any of α-type, β-type and γ-cyclodextrin can be used. However, β-cyclodextrin is preferable in consideration of economy, but β-cyclodextrin derivatives may be used. As derivatives of cyclodextrin, for example,
Hydroxymethylcyclodextrin, hydroxyethylcyclodextrin, hydroxypropylcyclodextrin, hydroxybutylcyclodextrin, dimethylcyclodextrin, trimethylcyclodextrin, diethylcyclodextrin, triethylcyclodextrin, carboxymethylcyclodextrin, glucosylcyclodextrin, maltosylcyclodextrin, Examples thereof include dimaltosyl cyclodextrin and cyclodextrin epichlorohydrin polymer, and among them, those belonging to hydroxyalkylcyclodextrin are preferable.

For the same purpose, a hydrous magnesium silicate clay mineral (hereinafter referred to as a clay mineral) can be used in the exhaust gas adsorption treatment of the present invention. Clay minerals are mainly composed of hydrous magnesium silicate and have highly reactive hydroxyl groups on the surface. The clay mineral has a diameter of 0.005 to 0.005.
Consisting of about 0.6 μm fiber, about 6 to 1 in the fiber direction
There are pores (channels) having a rectangular cross section of about 0 Å. In the above clay mineral, magnesium or silicon is partially aluminum, iron, nickel,
It may be replaced by sodium or the like. For example, palygorskite, a type of clay mineral, contains some aluminum.

Specifically, as the clay mineral, synthetic clay is used.
Aluminum magnesium silicate and ideal composition formula, Al
_0.66Si₈O₂₀(OH)₄ Na_0.66Indicated by
Colloidal hydrous aluminum silicate, ideal composition formula, M
g_3.54Si₈O₂₀(OH)₄ Li _0.66Na
_0.66Hectorite, ideal composition formula, Mg₈
Si₁₂O_{3 0}(OH)₄ (OH₂)₄ (H₂O)₈ Indicated by
Sepiolite, Mg₅Si₈O
₂₀(OH)₂ (OH₂)₄ (H₂O)₄ Paris shown by
Palygorskite, Mg₃Si₂O₅(OH)
₄There is a chrysotile indicated by
Uses a mixture of two or more. Also these mixtures
Is calcined in a temperature range of 150 to 750 ° C.
You may.

[0031] Also known as Mountain Cork
cork), Mountain wood, Mountain leather, Meerschau
m), minerals called Attapulgite and the like correspond to the above clay minerals. The clay mineral may be in the form of a powder, or a dispersion or paste dispersed in water or an organic solvent.

Further, silica gel, calcium silicate, ceramic, cellulose, zeolite and EVA resin can be used as the porous substance used in the adsorption treatment of the present invention. One or a mixture of two or more of these substances may be used. Further, each of them may be shaped.

[0033]

Next, the method of the present invention will be described more specifically with reference to examples. However, the present invention is not limited by these examples. The percentages in the examples are mass% unless otherwise specified.

Prior to the examples, the apparatus used for the deodorizing test will be described. A schematic diagram is shown in FIG. Exhaust gas containing the odor of sludge is generated from the aeration tank 10,
The neutralizer 12 is sprayed into the eliminator 20 through the nozzle 30 by 6 and circulated while being mixed with the exhaust gas containing odor, thereby adjusting the gas phase pH. Next, the liquid deodorant 14 is sprayed by the pressurizing pump 18 through the nozzle 32, and is mixed with the exhaust gas containing the odor in a gas-liquid manner. Then, the exhaust gas sent from the exhaust duct 22 to the eliminator 24 is exhausted by an exhaust fan after excess water is removed. Next, the exhaust gas is sent to the metal oxide cartridge 28 by the vacuum pump 26 and discharged as deodorized exhaust gas. For Test Examples 2 to 10 to be described later,
Furthermore, it passed through the inclusion or adsorption treatment layer. Before passing the blank sample through the metal oxide cartridge 28, the blank sample is discharged from the blank exhaust outlet 34.
In the present invention, the deodorizing effect was evaluated using such a schematic device.

Prior to the examples, the sensory evaluation criteria of the deodorization evaluation test are shown below. <Deodorization evaluation test: sensory evaluation> Sensory evaluation specialized panel (n = 8) for deodorized exhaust gas obtained in each deodorization effect test
Was used to perform a sensory evaluation. 5L for sensory evaluation
The exhaust was guided from the duct to the odorless bag of No. and the judgment was made. The judgment was made according to the judgment table in Table 1 below. Sensors were also measured from this bag.

[0036]

[Table 1]Odor intensity evaluation criteria  5 Strong smell 4 Strong smell 3 Easily detectable and recognizable 2 Feel clearly (understand what smell) 1 Feel slightly (understand smell; threshold density)0 Do not feel (odorless)

The present inventors have studied a method for deodorizing odors with hydrogen sulfide using a metal oxide which has been conventionally recognized as having a deodorizing effect. Hereinafter, the test results obtained in the process are shown. (Example 1) An exhaust duct (600 mm x 600 mm, wind speed 5 m / s, gas phase pH 1.
In 7), a liquid deodorant previously mixed with 15 ml of a 20% by mass aqueous solution of biguanidine and 5 ml of didecyldimethylammonium chloride was spray-mixed with a nozzle in an amount of 100 ml per minute with respect to 100 liters of exhaust gas. . Excess water was distilled off from the exhaust gas by an eliminator. After passing through the eliminator, it was treated with zinc oxide, and the sensory value and the time-dependent change of the odor sensor manufactured by Futaba Electronics Co., Ltd. were measured. Example 1 used zinc oxide formed into a honeycomb shape as a metal oxide, and Example 2 used zinc oxide formed into a corrugated plate shape. Otherwise, as metal oxide,
A 24-mesh pass, 35 mesh-on granular zinc oxide was used. In the case of the blank, untreated exhaust gas was similarly measured. Table 2 shows the amount of drug and the type of metal oxide,
Table 3 shows the results obtained by examining changes in sensory values and sensor indicated values.

[0038]

[Table 2]

[0039]

[Table 3] Blank Sensor reading:> 4000 Sensory value: 5.9

As is evident from the results in Table 3, the deodorizing effect was observed in each case when compared with the blank. The deodorizing methods of Examples 1 to 5 which were treated with a guanidine-based compound or a quaternary ammonium compound all showed a deodorizing effect as compared with Comparative Example 1 in which treatment was performed with only zinc oxide. Further, from the results of Examples 3 to 5, it can be seen that the deodorizing effect is synergistically improved by combining the guanidine compound and the quaternary ammonium compound. It can also be seen that the deodorizing effect is considerably improved by forming zinc oxide into a honeycomb shape (Example 1) or corrugated plate (Example 2).

Next, the present inventors studied the introduction of a neutralization treatment step to further improve the deodorizing effect. Hereinafter, the test results obtained in the process are shown. (Example 6) A triethanolamine aqueous solution as a neutralizing agent was circulated from an aeration tank containing 200 ppm of hydrogen sulfide to an exhaust duct (600 mm x 600 mm, air velocity 5 m / s) by an eliminator treatment to adjust the gas phase pH to 5.5. After that, the displacement 100
A liquid deodorant prepared by previously mixing 5 ml of distearyldimethylammonium chloride (quaternary ammonium salt compound) and 15 ml of a 20% by mass aqueous solution of biguanidine was spray-mixed with the exhaust gas by a nozzle in an amount of 100 ml per minute. Excess water was distilled off from the exhaust gas by an eliminator. Sensory values after passing through the eliminator and changes over time of the odor sensor manufactured by Futaba Electronics Co., Ltd. were measured. The amount of drug added is shown in Table 4, and the results of pH, sensor indicated value, and sensory value are shown in Table 5.

[0042]

[Table 4]

[0043]

[Table 5] Blank Sensor reading:> 4000 Sensory value: 5.9

From the results shown in Table 5, the guanidine compounds and 4
It can be seen that the deodorizing methods of Examples 6 to 12 which were treated with a quaternary ammonium compound and various metal oxides were excellent in the deodorizing effect. In contrast, the deodorizing method of Comparative Example 2 in which the metal oxide treatment was not performed had a deodorizing effect as compared with the blank, but had a poor sensory evaluation as compared with the present invention. Further, when the cationic liquid deodorant was reacted with the metal oxide without gas-liquid mixing as in Comparative Example 4, the effect of the sensor indication value and the sensory judgment was also improved in comparison with Example. There was a tendency not to go up slightly,
It was considered that the amount that could be treated by reacting with the malodor of the metal oxide was limited in a unit time, so that the amount of malodor present in the exhaust gas from the activated sludge used in the experiment was too large. In Comparative Example 4, the deodorizing effect after one hour was lower than that immediately after. From this, it is considered that when the liquid deodorant is not used, there is a problem in persistence of the deodorizing effect.

Further, as can be seen by comparing the results in Tables 3 and 5, when used without using a neutralizing agent,
It can be seen that the deodorizing effect is not as high as that of the system using the neutralizing agent. This may be because the reactivity of each deodorant tended to be better in the neutral region than in the acidic region.

Next, the present inventors studied a deodorizing method using a premixed neutralizing agent and liquid deodorant. (Example 13) An exhaust duct (600 mm x 600 mm, wind speed 5 m / s, gas phase pH) was supplied from an aeration tank containing 200 ppm of hydrogen sulfide.
In 1.7), a neutralizing agent-containing liquid deodorant was previously mixed in an amount of 100 ml of an aqueous solution of biguanidine containing 20% by mass of a guanidine compound per 100 liters of exhaust gas.
The mixture was spray-mixed with a nozzle in an amount of 0 ml. Excess water was distilled off from the exhaust gas by an eliminator. After passing through the eliminator, it was treated with a metal oxide, and the sensory value and the time-dependent change of an odor sensor manufactured by Futaba Electronics Co., Ltd. were measured. The amount of drug added is shown in Table 6, and the results of pH, sensor indicated value, and sensory value are shown in Table 7.

[0047]

[Table 6]

[0048]

[Table 7]

From the results in Table 7, it can be seen that an excellent deodorizing effect can be obtained even when the neutralizing agent and the guanidine compound are formulated in advance and sprayed simultaneously.

Next, the present inventors used Example 7 to spray the liquid deodorant and the neutralizing agent separately, and to formulate and spray simultaneously without separately spraying, It was examined whether there was any difference in the deodorizing effect. Table 8 shows the results. Example 7 is a deodorizing method by separate spraying, and Example 14 is a deodorizing method by formulation spraying. Table 8 shows the results of pH, sensor indicated value, and sensory value.

[0051]

[Table 8]

From the results shown in Table 8, it can be seen that both in the case of formulation and in the case of spraying each drug separately, the bad odor is removed immediately after the addition, and the effect can be maintained thereafter.

Next, the change in the deodorizing effect over time was examined. Table 9 shows the results.

[0054]

[Table 9]

From the results shown in Table 9, it can be seen that Examples 13 and 3 of the present invention maintain the deodorizing effect even after one month. Further, comparing the data after one month, it was found that the deodorizing effect of the metal oxide alone in Comparative Example 1 decreased over time. This seems to be due to the problem of the amount of the powder deodorant used in the experiment. However, since the effect was maintained in Example 3, the system using only the powder deodorant had a cationic deodorant effect for a long time. It appears to be shorter compared to the present invention in combination with the agent.

Next, the present inventors tried to improve the deodorizing effect by performing post-treatment of exhaust air with various substances conventionally used for inclusion and adsorption treatments. Table 9 shows the processing method
Table 10 shows the results. In addition, as a post-treatment, 5 liter / min of exhaust gas was treated with a target substance of 500 g or less.
For comparison, a sample which was not subjected to post-treatment was designated as Test Example 1. Table 10 shows chemicals, metal oxides, and substances used for post-treatment, and Table 11 shows pH, sensory values, and sensor readings.
Shown in

[0057]

[Table 10]

[0058]

[Table 11]

From the results shown in Table 11, after the exhaust treatment, H
In Test Examples 2 to 10 in which inclusion or adsorption treatment was performed with P-β-cyclodextrin, aluminum magnesium silicate, colloidal hydrous aluminum silicate, hectorite, sepiolite, silica gel, calcium silicate, zeolite, or cellulose, It is clear that the deodorant effect is superior to that of Test Example 1 in which no test was performed.

When the post-treatment is not performed after the treatment with the cationic liquid deodorant and the metal oxide as in Test Example 1, the effect of the sensor reading and the sensory judgment tend not to be slightly improved in comparison with the examples. was there. This was thought to be due to the fact that the amount that could be treated by reacting with the odor increased by performing post-treatment.

Next, the change in the deodorizing effect over time was examined. Table 12 shows the results of pH, sensory values, and sensor readings.
Shown in

[0062]

[Table 12]

From the results shown in Table 12, it can be seen that according to the deodorizing method in which the post-treatment is further performed, this excellent deodorizing effect can be maintained even after one month. This is presumably because the post-treatment increased the deodorizing effect and compensated for the effect of the metal oxide, which is expected to decrease over time, and improved the deodorizing effect.

[0064]

According to the deodorizing method of the present invention, the exhaust gas containing an odor containing at least one of hydrogen sulfide and mercaptans is subjected to gas-liquid mixing with a guanidine or quaternary ammonium compound and then treated with powder of metal oxide. By treating with a deodorant, it is possible to remove hydrogen sulfide, which is a malodorous component in exhaust gas, and to further maintain a deodorizing effect on hydrogen sulfide. Further, the deodorizing effect can be improved by neutralizing the exhaust gas with a neutralizing agent or by simultaneously performing a liquid deodorizing treatment. Further, as a post-treatment, one or more selected from dextrin, cyclodextrin, silica gel, calcium silicate, ceramic, cellulose, activated clay, natural loess, zeolite and EVA resin for the purpose of inclusion and adsorption of malodorous components By passing through the layer of the substance, it is possible to exhibit a higher deodorizing effect. According to the deodorizing method of the present invention, hydrogen sulfide in exhaust gas can be quickly deodorized and continuously deodorized.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a test apparatus according to the deodorizing method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Aeration tank 12 Neutralizer 14 Liquid deodorant 16, 18 Pressure pump 20, 24 Eliminator 22 Exhaust duct 26 Vacuum pump 28 Metal oxide cartridge 30, 32 Nozzle 34 Exhaust outlet for blank

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B01D 53/52 B01J 20/04 B01J 20/02 A B 20/04 20/06 A B C 20/06 20 / 10 D 20/16 20/18 B 20/10 20/24 A 20/16 20/26 A 20/18 B01D 53/34 ZAB 20/24 121C 20/26 121D 126 (72) Inventor Kenzo Ito Kanagawa 2-2-1 Hayabuchi, Tsuzuki-ku, Yokohama-shi, F-term in Shiseido Research Center (Shin-Yokohama) 4C080 AA05 AA06 AA07 BB02 CC04 CC05 CC12 KK08 MM01 MM02 MM04 MM06 MM23 MM24 MM29 MM40 4D002 AA03 AB02 BA02 BA04 CA01 DA05 DA08 DA11 DA16 DA22 DA23 DA24 DA45 DA46 EA01 4G066 AA02B AA13B AA15B AA18B AA20B AA26B AA27B AA43B AA61B AA63B AA70B AA72B AC01B AC12B CA24 CA25 DA02

Claims (8)

[Claims] 1. A deodorizing method characterized by treating exhaust gas containing an odor containing at least one of hydrogen sulfide and mercaptans with a guanidine or quaternary ammonium compound and a metal oxide and / or metal carbonate. Method. 2. The method according to claim 1, wherein the exhaust gas containing an odor containing at least one of hydrogen sulfide and mercaptans is neutralized with a neutralizing agent before or simultaneously with the treatment with a guanidine or quaternary ammonium compound. A deodorizing method comprising the step of performing. 3. The method of claim 1, wherein the metal oxide is zinc oxide, silicon oxide, copper oxide, aluminum oxide, manganese oxide, iron oxide, titanium oxide,
A deodorizing method comprising one or more metal oxides selected from nickel oxide, calcium oxide, silver oxide, palladium oxide, platinum oxide, vanadium oxide and magnesium oxide. . 4. The method of claim 1, wherein the metal carbonate is zinc, lead, sodium, potassium, calcium,
A deodorizing method comprising one or more metal carbonates selected from copper, barium, magnesium and manganese carbonates. 5. The method according to claim 1, wherein the treated exhaust gas is further treated with dextrin, cyclodextrin, silica gel, calcium silicate, ceramic, cellulose, activated clay, natural loess, hydrous magnesium silicate clay. A deodorizing method comprising subjecting one or more substances selected from minerals, zeolites and EVA resins to inclusion or adsorption treatment. 6. The method according to claim 1, wherein the exhaust gas containing odor to be treated is exhaust gas generated from wastewater, sludge, a washing device, or discharged soil during soil excavation. Deodorizing method. 7. The method according to claim 1, wherein the guanidine compound is a compound represented by the following formula (I) or (II) and a salt thereof with an acid. And deodorant method. Embedded image (Wherein, X is HN =, represents the following general formula (1) or general formula (2), Y is _{H-, NC-, H 2 N-,} HO-,
Represents the following general formula (3) or (4): Embedded image Embedded image (Wherein, R is an alkylene group having 20 or less carbon atoms;
Means a positive number less than or equal to 20) 8. The method according to claim 1, wherein the quaternary ammonium compound is represented by the following general formula (III):
A deodorizing method characterized by being any one of the compounds shown in (V) to (V). Embedded image (R ¹ , R ² , R ³ and R ⁴ represent a linear or branched alkyl group having 20 or less carbon atoms and may be the same or different.) (R ¹ and R ² represent a linear or branched alkyl group having 20 or less carbon atoms, and may be the same or different.) (R ¹ and R ² represent a linear or branched alkyl group having 20 or less carbon atoms and may be the same or different)