JPH10216697A - Deodorant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently decompose and remove hydrogen sulfide and mercaptans under mild conditions and to prevent diffusion of malodor and corrosion of facilities by preparing a deodorant from a peroxide, zinc salt and chelating agent. SOLUTION: As for the peroxide used for the deodorant, peracetate, persulfate, percarbonate, perforate and other inorg. or org. peroxides can be used, and preferably hydrogen peroxide and sodium percarbonate are used. As for the zinc salt, an inorg. salt such as sulfate, nitrate, halide, perchloride, hydroxide or an org. salt such as oxalate and formate, or oxide is used. As for the chelating agent, an acid having two or more carboxyl groups or its salt, or an acid having two or more sulfonate groups or its salt is used. These peroxide, zinc salt and chelating agent are mixed to prepare the deodorant which is effective even in a small amt. to deodorize a waste water or sludge containing odor of one or more kinds of hydrogen sulfide and mercaptans.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a deodorant. More specifically, it is a deodorant composition that effectively deodorizes wastewater and sludge containing hydrogen sulfide and at least one odor of mercaptans in a small amount.

[0002]

2. Description of the Related Art In recent years, population density in cities and suburbs has been increasing.
This has led to massive consumption of water resources. The water resources used there are discharged as wastewater containing various organic and inorganic substances into public sewers and residence tanks in buildings. In addition, they produce large amounts of raw sludge, excess sludge, and digested sludge in the process of being treated in a sewage treatment plant.

[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. A large amount of sludge is produced even in the process of activated sludge treatment.

[0004] Sulfate-reducing bacteria are present in wastewater and sludge as described above, and production activities are carried out by reducing sulfate in sludge to hydrogen sulfide. By generating hydrogen sulfide, wastewater and sludge are further anaerobic, 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 that leaks from manholes and underground buildings, causing odor problems to nearby residents, and the danger to workers when treating sludge. Also,
Hydrogen sulfide is oxidized by sulfur oxidizing bacteria and air adhering in concrete facilities, 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.

Further, as in the case of hydrogen sulfide, mercaptans such as methyl mercaptan and ethyl mercaptan are produced in the process of spoilage of waste water and sludge, causing a problem of odor. As a means for preventing the generation of these odors and the corrosion of structures, there is also a method of making the pH alkaline by using caustic soda or the like to suppress the emission of hydrogen sulfide, but this does not decompose or remove hydrogen sulfide itself. Therefore, when neutralized, hydrogen sulfide is regenerated and alkali scale is generated.

As a method of oxidizing the malodorous component, there is a method of adding hydrogen peroxide, which can remove hydrogen sulfide and mercaptans. However, if the added amount is small, the sulphate-reducing bacteria cannot be sufficiently sterilized.If the sludge is left for a long time, oxidized sulfur or sulphate ions will be removed again by the sulphate-reducing bacterium. And a large amount of hydrogen peroxide must be added.

As a method for immobilizing hydrogen sulfide as a metal salt, there is a method in which zinc chloride is added as shown in the following reaction formula. In this method, hydrogen sulfide and zinc ions are mixed as shown in formula (1). There is a disadvantage that a large amount of zinc must be added because the reaction is performed in a molar manner. Furthermore, there was a problem that mercaptans could not be removed with zinc compounds.

[0008]

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[0009]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the prior art, to efficiently decompose and remove hydrogen sulfide and mercaptans under mild conditions, to diffuse malodor and corrode facilities. The purpose of the present invention is to provide a deodorant for preventing odor.

[0010]

Means for Solving the Problems The present inventors have conducted intensive studies on a deodorant composition for removing odors composed of hydrogen sulfide or mercaptans and the like. As a result, the present inventors have found that a composition composed of a peroxide, a zinc salt and a chelating agent is deodorized. The present inventors have found that the agent is stable, can rapidly and efficiently remove hydrogen sulfide and mercaptans in wastewater and sludge, and can impart sustainability to the removal, thereby completing the present invention. That is, the present invention is a deodorant comprising a peroxide, a zinc salt and a chelating agent.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION As the peroxide in the deodorizer according to the present invention, hydrogen peroxide, peracetic acid, persulfate, percarbonate, perborate and other inorganic and organic peroxides are used. Preferably, hydrogen peroxide, sodium percarbonate is used. Hydrogen peroxide having a concentration of 35% by weight or 60% by weight is commercially available, but it may be used as it is or may be used after being diluted.

Examples of the zinc salt include inorganic salts such as sulfates, nitrates, halides, perchlorates and hydroxides, and organic salts and oxides such as oxalates and formates. Any of salt and hydrated salt may be used.

As the chelating agent, an acid having two or more carboxylic acid groups and / or a salt thereof, or an acid having two or more phosphonic acid groups and / or a salt thereof is used. Here, an acid having two or more carboxylic acid groups and / or
Or chelating agents thereof, ethylenediaminetetraacetic acid, nitrilotriacetic acid, diethylenetriaminepentaacetic acid,
Examples of the chelating agent for an acid having two or more phosphonic acid groups and / or a salt thereof include 1-hydroxyethylidene-1,1-diphosphonic acid and aminotri (methylene phosphonic acid). Acid), ethylenediaminetetra (methylenephosphonic acid), 1,2-propylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid), hexamethylenediaminetetra (methylenephosphonic acid), triethylenetetraminehexa (methylenephosphonic acid) Acid), triaminotriethylaminehexa (methylenephosphonic acid), trans-1,2
-Cyclohexanediaminetetra (methylenephosphonic acid), glycoletherdiaminetetra (methylenephosphonic acid), tetraethylenehepta (methylenephosphonic acid) and the like, and one or more of these are used. They may be free acids or salts. When used in the form of a salt, alkali metal salts, alkaline earth metal salts,
Ammonium salts and organic amine salts can be used,
Sodium salts and ammonium salts are preferably used.

The amount of the zinc salt with respect to the peroxide is not particularly limited, but usually about 0.1 to 50% by weight as zinc metal with respect to 100% of the peroxide. The use amount of the chelating agent depends on the zinc salt, but is preferably about 10 to 50,000 ppm based on the mixture of the peroxide and the zinc salt. The amount of chelating agent used is independent of the peroxide concentration. Furthermore, it does not prevent the use of other stabilizers if necessary. The deodorant of the present invention, hydrogen peroxide,
Although the zinc salt and the chelating agent can be used as mixed, it is preferable to further lower the pH for stabilization. As the acid used at this time, inorganic acids such as sulfuric acid, nitric acid, hydrochloric acid, and phosphoric acid, and organic acids such as formic acid, acetic acid, and oxalic acid can be used. Preferably, the inorganic acids can be used alone or in combination.

[0015]

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.

Example 1 35 wt% hydrogen peroxide in 1000 ml of sewage sludge
2 g, zinc nitrate hexahydrate 36.4 g, 1,2-propylenediaminetetra (methylenephosphonic acid) 0.114 g
0.38 g of a deodorant having a composition of
mg / L, zinc 20 mg / L), stirred and mixed, left for 5 minutes and 12 hours after the treatment, and measured the hydrogen sulfide and methyl mercaptan by the head space method using a gas detector tube. 1 is shown. The heating stability after dipping hydrogen peroxide of this deodorant in a hot bath at 100 ° C. for 5 hours was 98.3%.

[0017]

(Equation 1)

Comparative Example 1 0.57 g of 35% by weight of hydrogen peroxide (200% of hydrogen peroxide)
(equivalent to mg / L), and the same treatment as in Example 1 was performed. The results are shown in Table 1.

Comparative Example 2 The same treatment as in Example 1 was performed except that 0.27 g of zinc nitrate (corresponding to 60 mg / L of zinc) was added. The results are shown in Table 1.

[0020]

[Table 1]

The removal of hydrogen sulfide using only hydrogen peroxide has a quick effect, but hydrogen sulfide has been restored. Also, the removal of methyl mercaptan was not sufficient with only zinc nitrate. The product of the present invention can remove hydrogen sulfide and methyl mercaptan with a small amount of use, and can maintain the deodorizing ability.

Example 2 Zinc sulfate heptahydrate in 100 g of 35% by weight hydrogen peroxide.
After immersing a deodorant having a composition of 7 g and 0.01 g of a 25% by weight aqueous solution of diethylenetriaminepenta (methylenephosphonic acid) in a warm bath at 100 ° C. for 5 hours, the concentration of hydrogen peroxide was measured to determine the heating stability. The results are shown in Table 2.

[0023]

(Equation 2)

Example 3 Diethylenetriaminepenta (methylenephosphonic acid) 2
Example 2 except that the addition amount of the 5% aqueous solution was 0.05 g.
A deodorant having the same composition as in Example 2 was treated in the same manner as in Example 2.
The results are shown in Table 2.

Comparative Example 3 A deodorant having the same composition as in Example 2 was treated in the same manner as in Example 2 except that no chelating agent was used. Table 2 shows the results
It was shown to.

[0026] By adding a chelating agent, the stability of hydrogen peroxide is significantly improved.

Example 4 Zinc nitrate hexahydrate in 100 g of 35% by weight hydrogen peroxide
A deodorant having a composition of 5.8 g and 0.01 g of a 1% by weight aqueous solution of 1-hydroxyethylidene-1,1-diphosphonic acid was immersed in a hot bath at 100 ° C. for 5 hours, and the concentration of hydrogen peroxide was measured to stabilize the heat. Seeking sex. The results are shown in Table 3.

Example 5 A heating test was carried out with the same composition as in Example 4 except that the pH was adjusted to 1.0 by adding sulfuric acid. The results are shown in Table 3.

Example 6 A heating test was conducted using the same composition as in Example 4 except that the pH was adjusted to 0.5 by adding sulfuric acid. The results are shown in Table 3.

[0030] The lower the pH, the higher the stability of hydrogen peroxide, the main component of the present deodorant.

Example 7 Zinc nitrate hexahydrate 1 in 100 g of 35% by weight hydrogen peroxide
5.8 g, ethylenediaminetetraacetic acid as a chelating agent /
A deodorant having a composition of 0.01 g of tetrasodium salt / tetrahydrate was allowed to stand at room temperature for one month, and the concentration of hydrogen peroxide was measured to determine the stability at room temperature. The results are shown in Table 4.

[0032]

(Equation 3)

Example 8 The same composition as in Example 7 was used except that diethylenetriaminepentaacetic acid was used as a chelating agent, and the stability at room temperature was determined. The results are shown in Table 4.

Comparative Example 5 The same composition as in Example 7 was used except that the chelating agent was not used, and the stability at room temperature was determined. The results are shown in Table 4.

[0035]

[0036]

The deodorant of the present invention can remove hydrogen sulfide and mercaptans quickly and continuously with a small amount of addition.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C09K 3/00 108 C09K 3/00 108B 108E (72) Inventor Tadashi Shimomura 6-1-1 Shinjuku, Katsushika-ku, Tokyo Mitsubishi Gas Tokyo Research Laboratory, Chemical Co., Ltd.

Claims (5)

[Claims] 1. A deodorant comprising a peroxide, a zinc salt and a chelating agent. 2. The deodorant according to claim 1, wherein the peroxide is hydrogen peroxide or sodium percarbonate. 3. The deodorant according to claim 1, wherein the chelating agent is an acid having two or more carboxylic acid groups and / or a salt thereof. 4. The deodorant according to claim 1, wherein the chelating agent is an acid having two or more phosphonic acid groups and / or a salt thereof. 5. A method for adding the deodorant according to claim 1 to wastewater or sludge containing hydrogen sulfide or mercaptans.