Deodorizing method for dehydrated cake and deodorizing device for dehydrated cake

Abstract

To provide a method and an apparatus for deodorizing a dehydrated cake capable of reusing the dehydrated cake as a compost raw material or the like and capable of efficiently deodorizing the dehydrated cake using a deodorant easy to handle.SOLUTION: The method for deodorizing the dehydrated cake is characterized in that the dehydrated cake obtained by dehydrating the organic sludges is sprayed with the tea leaves dry distillation liquid containing the tea leaves dry distillation product 1 to 1000g / m2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method and apparatus for deodorizing dehydrated cake, and more particularly to a method and apparatus for deodorizing dehydrated cake produced from organic sludge generated by treating organic wastewater such as sewage, human waste, and wastewater. [Background technology]

[0002] Organic sludge produced by treating organic wastewater such as sewage, human waste, and drainage water emits odors due to hydrogen sulfide, methyl mercaptan, ammonia, and other substances. The odors can worsen the working environment near the wastewater and sludge treatment processes, and in severe cases can even lead to poisoning. Not only does the odor quickly disperse when the dehydrated cake is dropped from the cake hopper onto the loading platform of a transport vehicle, but the odor also becomes a problem on public roads when the dehydrated cake is transported, causing inconvenience to the general public.

[0003] Various deodorizers and odor removal methods have been devised to prevent odors from these dehydrated cakes. For example, Japanese Patent Laid-Open No. 10-80677 (Patent Document 1) describes a method of adding a solution of an iron compound or zinc compound to wastewater or sludge to remove odors generated from waste liquids or waste gases such as wastewater, sludge, or human waste. Japanese Patent Laid-Open No. 63-205197 (Patent Document 2) describes a method of adding a solution of a zinc compound to liquids, sludge, or gases containing malodorous substances. Japanese Patent Laid-Open No. 2002-186995 (Patent Document 3) describes a method of adding nitrite to dehydrated sludge cake.

[0004] Japanese Patent Publication No. 61-8694 (Patent Document 4) proposes a deodorizer containing dry distillate of tea as an active ingredient. Japanese Patent Application Laid-Open No. 2005-143770 (Patent Document 5) proposes an industrial deodorizer containing matcha powder and at least one selected from sodium bicarbonate, sodium carbonate, sodium percarbonate, and magnesium oxide as active ingredients. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 10-80677 [Patent Document 2] Japanese Patent Application Publication No. 63-205197 [Patent Document 3] Japanese Patent Application Laid-Open No. 2002-186995 [Patent Document 4] Special Publication No. 61-8694 [Patent Document 5] Japanese Patent Application Laid-Open No. 2005-143770 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the inventions described in Patent Documents 1 and 2, metals such as iron and zinc contained in the components used to deodorize the dehydrated cake obtained from sludge remain in the dehydrated cake. Therefore, the dehydrated cake is not suitable for reuse as compost raw material, etc. The invention described in Patent Document 3 requires several hours for the deodorizing effect to appear after the addition of nitrite, so the dehydrated cake must be impregnated with the nitrite in advance, which requires a lot of effort and requires a large amount of use. Furthermore, sodium nitrite, a typical nitrite, is known to be toxic, so extreme caution is required when using it.

[0007] The invention described in Patent Document 4 states that by using naturally occurring ingredients such as dry distillation components of tea as a deodorizer, it is possible to remove malodors such as ammonia, hydrogen sulfide, and methyl mercaptan. However, the invention described in Patent Document 4 only shows that the removal rate of relatively high concentrations of malodorous gases is measured in a sealed container, and the deodorizing effect on actual objects is not measured, so it is unclear whether it will effectively deodorize malodors emitted from actual objects.

[0008] The invention described in Patent Document 5, like Patent Document 4, also uses naturally derived components as deodorizers, making it possible to reuse them as compost raw materials. However, Patent Document 5 proposes the use of a powdered deodorizer. A powdered deodorizer needs to be applied to the entire surface of the target object, necessitating the use of a large amount of the deodorizer. In addition, it is difficult to efficiently and uniformly apply a powdered deodorizer, making it difficult to handle when used to deodorize dehydrated cake.

[0009] In view of the above problems, the present invention provides a method and an apparatus for deodorizing dehydrated cake, which enable the dehydrated cake to be reused as a compost raw material or the like and which can efficiently deodorize the dehydrated cake using an easy-to-handle deodorizer. [Means for solving the problem]

[0010] The present inventors have conducted extensive research to solve the above problems and have discovered that spraying a predetermined amount of tea leaf dry distillation solution onto a dehydrated cake obtained by dehydrating organic sludge is effective.

[0011] In order to solve the above problems, in one aspect, the present invention provides a method for producing a dehydrated cake obtained by dehydrating organic sludge, the method comprising: adding 1 to 1,000 g / m of a dry distillation solution containing dry distilled tea leaves to the dehydrated cake; 2 This is a method for deodorizing dehydrated cake by spraying.

[0012] In one embodiment of the method for deodorizing a dehydrated cake according to the present invention, the dry distillation solution of tea leaves contains 0.1 to 20.0% by weight of dry distillation product of tea leaves.

[0013] In another embodiment of the method for deodorizing dehydrated cake according to the present invention, the dry distillation solution of tea leaves contains polyphenols.

[0014] In yet another embodiment of the method for deodorizing dehydrated cake according to the present invention, the tea leaf dry distillation solution is an aqueous solution.

[0015] In still another embodiment of the method for deodorizing a dehydrated cake according to the present invention, the pH of the dry distillation solution of tea leaves is 4.5 to 7.0.

[0016] In yet another embodiment of the method for deodorizing a dehydrated cake according to the present invention, a tea leaf dry distillation solution is sprayed onto a dehydrated cake having a moisture content of 65 to 85%.

[0017] In still another embodiment of the method for deodorizing a dehydrated cake according to the present invention, the dry distillation solution of tea leaves contains 0.01 to 0.50% by weight of a cationic surfactant having a bactericidal action.

[0018] In another aspect, the present invention provides a method for producing a dehydrated cake by dehydrating organic sludge, and a method for producing a dehydrated cake by adding a tea leaf dry distillation solution containing a tea leaf dry distillate to the dehydrated cake at a concentration of 1 to 1000 g / m 2 and a spraying means for spraying. [Effects of the Invention]

[0019] According to the present invention, a method and an apparatus for deodorizing dehydrated cake are provided, which enable the dehydrated cake to be reused as a compost raw material, etc., and which can efficiently deodorize the dehydrated cake using an easy-to-handle deodorizer. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a schematic diagram showing a deodorizing device for dewatered cake according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, an embodiment of the present invention will be described. A method for deodorizing dehydrated cake according to an embodiment of the present invention is a method for deodorizing dehydrated cake obtained by dehydrating organic sludge by adding 1 to 1000 g / m of a dry distillation solution containing dry distilled tea leaves. 2 This includes spraying.

[0022] (Tea leaf dry distillation solution) The tea leaf dry distillation solution according to an embodiment of the present invention is used as a deodorizer for deodorizing dehydrated cake and includes a tea leaf dry distillate (tea leaf dry distillation extract) obtained by dry distilling tea leaves. Methods for extracting tea leaf dry distillate from tea leaves by dry distillation include thermal extraction of fresh or dried tea leaves with an alcoholic solvent, a ketone solvent, water, or a mixture thereof, or extraction of tea leaves with a solvent followed by steaming under reduced pressure. In this embodiment, the dry distillate obtained by the latter method is preferred. The method for dry distilling tea leaves is not particularly limited, and methods well known to those skilled in the art can be used.

[0023] The deodorizing effect of dry-distilled tea leaf extract is believed to be due to polyphenols and flavonoids such as catechins and tannins. Green tea, in particular, contains epicatechin, epilocatechin, epicatechin gallade, epilocatechin gallade, and the like. These substances with phenolic groups easily form complex compounds with ammonia, hydrogen sulfide, and the like. Regardless of the type of tea, Japanese teas such as green tea, roasted green tea, and sweet tea, Chinese teas such as oolong tea and pu-erh tea, and black teas such as Assam and Darjeeling can be used as raw materials. In this embodiment, it is preferable to contain a green tea dry-distilled extract extracted by dry-distilling green tea.

[0024] The tea leaf dry distillation solution preferably contains 0.1 to 20.0 wt% of tea leaf dry distillate. If the concentration is less than 0.1 wt%, a large amount of solution must be sprayed to achieve the deodorizing effect, resulting in an increase in the moisture content of the dehydrated cake. On the other hand, the higher the concentration of the tea leaf dry distillate, the greater the deodorizing effect. However, if the concentration exceeds 20 wt%, the pharmaceutical price as a deodorizer becomes too high compared to the deodorizing effect of the dehydrated cake, making it difficult to say that it is desirable from the viewpoint of efficient treatment. In this embodiment, the concentration of the tea leaf dry distillate is preferably 0.2 to 15.0 wt%, more preferably 0.5 to 10.0 wt%, even more preferably 0.7 to 5.0 wt%, and even more preferably 1.0 to 2.0 wt%.

[0025] The tea leaf dry distillation solution preferably contains polyphenols. Polyphenols have reducing power due to the large number of hydroxyl groups in their molecules, and when they come into contact with dehydrated cake, they have the effect of eliminating odors emitted from the dehydrated cake. Therefore, by using a tea leaf dry distillation solution containing polyphenols as a deodorizer, it is possible to efficiently deodorize the dehydrated cake. Furthermore, because the tea leaf dry distillation solution is an aqueous solution, it can provide a more environmentally friendly raw material when producing compost raw material compared to tea leaf dry distillation solutions diluted with organic solvents, etc. Furthermore, because the tea leaf dry distillation solution is an aqueous solution containing approximately 98% water by weight, it is compatible with the dehydrated cake, allowing the deodorizing components to be distributed more uniformly and efficiently throughout the dehydrated cake.

[0026] The pH of the dry distillation solution of tea leaves is preferably 4.5 to 7.0, more preferably 4.8 to 6.9, and even more preferably about 5.0 to 6.0.

[0027] The tea leaf dry distillation solution may contain a cationic surfactant with bactericidal activity. The cationic surfactant with bactericidal activity facilitates penetration of the tea leaf dry distillation solution sprayed onto the surface of the dehydrated cake from the surface into the interior of the dehydrated cake and sterilizes the sludge, thereby suppressing the generation of malodorous components resulting from sludge fermentation for a long period of time. The cationic surfactant with bactericidal activity is not particularly limited, but examples of suitable surfactants include benzalkonium chloride, benzethonium chloride, cetylpyridinium chloride, and hexadecyltrimethylammonium bromide. Typically, alkyldimethylammonium chloride is preferred. From the viewpoints of composting and suppressing malodors from the dehydrated cake, the content of the cationic surfactant in the tea leaf dry distillation solution is preferably 0.01 to 0.50 wt %, more preferably 0.05 to 0.30 wt %, and even more preferably 0.10 to 0.20 wt %.

[0028] Although not limited to the following, in one embodiment, the tea leaf dry distillation solution according to the embodiment of the present invention may be composed of (a) 1.0 to 2.0 wt% tea leaf dry distillate, (b) 0.08 to 0.20 wt% cationic surfactant, and (c) water. Such a tea leaf dry distillation solution is a colorless to pale yellow, transparent liquid, and has a specific gravity of 1.005 at room temperature (20°C). The refractive index of the tea leaf dry distillation solution can be measured in accordance with JIS K0062 (1992).

[0029] The amount of tea leaf dry distillation solution sprayed onto the dehydrated cake is 1 to 1000 g / m 2 By doing so, it is possible to remove malodors such as ammonia odor and hydrogen sulfide odor generated from the dehydrated cake without increasing the moisture content of the dehydrated cake. The amount of the tea leaf dry distillation solution to be sprayed is 10 to 500 g / m 2 It is preferable to set the thickness to 20 to 350 g / m 2 It is more preferable to set the following.

[0030] The amount of tea leaf dry distillation solution sprayed onto the dehydrated cake is not limited to the above example, and may be adjusted as appropriate depending on the amount of odor emitted from the dehydrated cake, the shape of the dehydrated cake, its moisture content, etc. Note that the shape of the dehydrated cake when discharged varies greatly depending on the type of dehydration device and the type of conveyor that transports the dehydrated cake. In this case, since it is difficult to measure the surface area of ​​the dehydrated cake, the spray amount can be considered to be equivalent to the area of ​​the target area to be sprayed. Although the spraying method is not particularly limited, it is typically preferable to spray the tea leaf dry distillation solution onto the surface of the dehydrated cake using a spraying means equipped with a nozzle for spraying the tea leaf dry distillation solution.

[0031] (Dehydrated cake) The dehydrated cake is preferably obtained by mechanically dewatering the sludge obtained by supplying organic sludge generated from a biological treatment process or a biological treatment device to a sludge concentration tank or a sludge storage tank and concentrating or storing the sludge in the tank. Here, examples of organic sludge include primary sewage sludge, excess sewage sludge, mixed raw sludge obtained by mixing these, sewage digested sludge, excess sludge from human waste treatment, coagulation-sedimentation sludge, sewage septic tank sludge, raw human waste, or a mixture thereof, and sludge generated by treating industrial wastewater.

[0032] The dehydrated cake produced by mechanical dehydration is transported by conveyor and stored in a dehydrated cake storage tank. Storage methods are broadly divided into yard and hopper methods. The yard method requires a certain amount of space for the dehydrated cake removal work. Dehydrated cake has a strong odor, so odor control measures are necessary to consider the impact on work and the surrounding environment. The hopper method requires a small installation area, but because it has an enclosed structure, the odor generated from the dehydrated cake can fill the air at a high concentration. This can worsen the working environment when loading it onto the removal vehicle.

[0033] In the deodorizing method according to this embodiment, a spraying means for spraying the tea leaf dry distillation solution is connected to at least one of a dehydrator for mechanical dehydration, a transfer device such as a conveyor for transferring dehydrated cake produced by mechanical dehydration, or a storage device for storing the dehydrated cake, and the tea leaf dry distillation solution is sprayed onto the dehydrated cake via the spraying means. This allows for deodorizing treatment. In this specification, "spraying" includes not only spraying the tea leaf dry distillation solution in a mist form onto the surface of the dehydrated cake using a spray nozzle or the like, but also dripping the tea leaf dry distillation solution from above the dehydrated cake.

[0034] In this way, in the present deodorizing method, the above-mentioned dry distillation solution of tea leaves is sprayed at a concentration of 1 to 1000 g / m through a spraying means installed in at least one of a dehydrator, a transfer device, and a storage device. 2 Spraying the agent can suppress the odor of the dehydrated cake for a long period of time. There are no particular restrictions on the method of mechanical dehydration, and mechanical dehydration can be performed using a centrifugal dehydrator, belt press dehydrator, screw press dehydrator, filter press dehydrator, vacuum dehydrator, etc.

[0035] During mechanical dewatering, it is preferable to add a polymer flocculant to the organic sludge. This reduces the moisture content of the dewatered cake and its weight and volume. Examples of polymer flocculants include known polymer flocculants. Generally, cationic polymer flocculants or amphoteric polymer flocculants are preferred. Cationic polymer flocculants contain a cationic monomer as an essential component and are copolymers of cationic monomers or copolymers of cationic monomers and the above-mentioned nonionic monomers. Examples of cationic monomers include dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, or their neutralized salts or quaternary salts. Cationic polymer flocculants containing amidine units in the molecule can also be used. Cationic starch, cationic cellulose, and cationic guar gum can also be used.

[0036] Examples of cationic polymer flocculants include so-called amphoteric polymer flocculants obtained by copolymerizing cationic monomer units, anionic monomer units, and nonionic monomer units. Both powder and emulsion forms can be used. A two-component method can also be used, in which the cationic polymer flocculant is added to the sludge, followed by the anionic polymer flocculant described below. Examples of anionic polymer flocculants include partial hydrolyzates of polyacrylamide, copolymers of anionic monomers, and copolymers of anionic monomers and nonionic monomers such as acrylamide. Examples of anionic monomers include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, vinyl sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, styrene sulfonic acid, 2-allylamidoethanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, 2-methallylamidoethanesulfonic acid, 2-methacrylamido-2-methylpropanesulfonic acid, 2-acryloyloxyethanesulfonic acid, 3-acryloyloxypropanesulfonic acid, 4-acryloyloxybutanesulfonic acid, 2-methacryloyloxyethanesulfonic acid, 3-methacryloyloxypropanesulfonic acid, 4-methacryloyloxybutanesulfonic acid, and metal salts or ammonium salts thereof, such as alkali metals and alkaline earth metals. These anionic monomers may be used alone or in combination of two or more. Examples of nonionic monomers include acrylamide, methacrylamide, methacrylonitrile, vinyl acetate, etc. These nonionic monomers may be used alone or in combination of two or more. Preferred copolymers are acrylamide-acrylate copolymers and acrylamide-2-acrylamido-2-methylpropanesulfonic acid copolymers. Carboxymethyl cellulose and sodium alginate can also be used. Nonionic polymer flocculants are polymers or copolymers of the above nonionic monomers, with polyacrylamide being preferred.

[0037] Before mechanical dewatering, inorganic flocculants or organic polymer coagulants may be added to the dewatered cake, followed by the polymer flocculants described above. Examples of inorganic flocculants that can be used include aluminum sulfate, polyaluminum chloride (PAC), polyferric sulfate (polyiron), ferric chloride, or mixtures thereof. Examples of organic polymer coagulants include condensation polyamines, dicyandiamide-formaldehyde condensates, polyethyleneimine, polyvinylimidaline, polyvinylpyridine, diallylamine salt-sulfur dioxide copolymers, polydimethyldiallylammonium salts, polydimethyldiallylammonium salt-sulfur dioxide copolymers, polydimethyldiallylammonium salt-acrylamide copolymers, polydimethyldiallylammonium salt-diallylamine hydrochloride derivative copolymers, and allylamine salt polymers. Specific examples of condensation polyamines include condensates of alkylene dichloride and alkylene polyamines, condensates of aniline and formalin, condensates of alkylene diamine and epichlorohydrin, and condensates of ammonia and epichlorohydrin. Examples of alkylenediamines that condense with epichlorohydrin include dimethylamine, diethylamine, methylpropylamine, methylbutylamine, and dibutylamine. This deodorization method is also applicable to cases where, in order to use the dehydrated cake as a compost raw material, the above-mentioned inorganic flocculant or organic polymer coagulant is added to the organic sludge before mechanical dewatering without adding a polymer flocculant.

[0038] The moisture content of the dehydrated cake according to this embodiment is preferably adjusted by mechanical dehydration to about 65 to 85%, more preferably about 70 to 83%, and even more preferably about 75 to 82%. The dry distillation solution of the tea leaves according to this embodiment is added to such a dehydrated cake at a rate of 1 to 1000 g / m 2 By spraying, the dehydrated cake can be reused as a compost material, etc., and the dehydrated cake can be efficiently deodorized.

[0039] According to the method for deodorizing dehydrated cake of the embodiment of the present invention, by spraying a tea leaf dry distillation solution onto dehydrated cake obtained by dehydrating organic sludge, it is possible to add a deodorizing component to the dehydrated cake more efficiently and uniformly than by adding a powdered deodorizer to the dehydrated cake. Furthermore, because the tea leaf dry distillation solution is added to the dehydrated cake by spraying, the moisture content of the dehydrated cake does not increase significantly due to the addition of the tea leaf dry distillation solution, and therefore the dehydrated cake can be appropriately deodorized without deteriorating its handleability.

[0040] (Deodorizing device) As shown in FIG. 1, the deodorizing apparatus for dehydrated cake according to the embodiment of the present invention includes a dehydration means 2 for dehydrating organic sludge to obtain a dehydrated cake, and a tea leaf dry distillation solution containing the tea leaf dry distillate in an amount of 1 to 1000 g / m 3 for the dehydrated cake. 2 and a spraying means 6 for spraying.

[0041] Organic sludge is added to inorganic flocculants, organic polymer coagulants, etc. in a coagulation tank 1, and then mechanically dehydrated in a dehydration means 2 such as a dehydrator using a polymer flocculant to produce a dehydrated cake. The dehydrated cake is then stored in a storage device 4 such as a cake hopper by a transfer device 3 such as a conveyor. The dehydrated cake stored in the storage device 4 is transported by a transport device 5 such as a truck.

[0042] The spraying means 6 is preferably a sprayer equipped with a nozzle 61 for spraying the tea leaf dry distillation solution onto the dehydrated cake. The sprayer is not particularly limited. In the example shown in FIG. 1, the tea leaf dry distillation solution is sprayed onto the dehydrated cake in the transfer device 3, storage device 4, and conveying device 5, respectively. However, this is not a limitation. When manually spraying the tea leaf dry distillation solution onto the dehydrated cake, a sprayer that dispenses the tea leaf dry distillation solution in a mist, such as a trigger sprayer that sprays by operating a lever, is preferred. When spraying automatically, it is also preferable to use an electric horticultural sprayer or the like. The specific configuration of the sprayer is not particularly limited, but it is preferable to use a sprayer that can spray the tea leaf dry distillation solution at as wide an angle as possible toward the dehydrated cake, which is the target of spraying.

[0043] According to the deodorizing device for dehydrated cake according to the embodiment of the present invention, the dehydrated cake is treated with a dry distillation solution containing dry distilled tea leaves at a concentration of 1 to 1000 g / m 2 By providing the spraying means 6 for spraying, it becomes possible to efficiently deodorize the dehydrated cake. [Example]

[0044] Examples of the present invention will be described below together with comparative examples. These examples are provided for a better understanding of the present invention and its advantages, and are not intended to limit the invention.

[0045] (Examples 1 and 2) The dehydrated cake (moisture content 71.1%, TS: 14.3 g / L) obtained by mechanically dewatering mixed raw sludge generated from a sewage treatment plant was placed in a polystyrene foam container with an area of ​​0.068 m 2 The contents were evenly distributed to a temperature of 1.5 wt %, and the container was sealed with a lid. A tea leaf dry distillation solution (Fresh Shiraimatsu (registered trademark) FS-93M) with a tea leaf dry distillation concentration of 1.5 wt % was poured into the container at 81 g / m 2 ~324g / m 2 The hydrogen sulfide concentration was measured at regular intervals using a Kitagawa detector tube inserted through a hole in the center of the lid. The results are shown in Table 1.

[0046] [Table 1]

[0047] Example 3 The dehydrated cake (moisture content 71.1%, TS: 14.3 g / L) obtained by mechanically dewatering mixed raw sludge generated from a sewage treatment plant was placed in a polystyrene foam container with an area of ​​0.068 m 2 The mixture was leveled to a concentration of 162 g / m 2 and then sealed with a lid. 2 After spraying, a Kitagawa detector tube was inserted through a hole drilled in the side of the polystyrene foam container, and the hydrogen sulfide concentration was measured at regular intervals. The results are shown in Table 2.

[0048] (Comparative Example 1) The dehydrated cake (moisture content 71.1%, TS: 14.3 g / L) obtained by mechanically dewatering mixed raw sludge generated from a sewage treatment plant was placed in a polystyrene foam container with an area of ​​0.068 m 2 The container was then leveled to a level of 0.01g, and the lid was placed on the container to seal it. A Kitagawa detector tube was inserted through a hole drilled in the side of the polystyrene foam container, and the hydrogen sulfide concentration was measured at regular intervals. The results are shown in Table 2.

[0049] [Table 2]

[0050] (Examples 4 and 5) Dehydrated cake (moisture content 81.7%, pH 7.89, SS: 9.04 g / L, VSS 71.5%) obtained by mechanically dehydrating digested sludge generated from a sewage treatment plant was carried to an outdoor cake yard and left in the open (temperature 31.6°C). The same tea leaf dry distillation solution as in Examples 1 and 2 was added thereto at 29.0 to 38.7 g / m 2 The ammonia concentration was measured at regular intervals using a Kitagawa detector tube. The outdoor cake yard was sprayed using an electric garden sprayer (Koshinsha GT-5V, nozzle length 2 m). The results are shown in Table 3.

[0051] [Table 3]

[0052] (Reference Examples 1 and 2, Example 6) A comparison test of the deodorizing effect of natural deodorizers on dehydrated cake obtained by mechanically dehydrating sludge from a sewage treatment plant was conducted using sugarcane extract solution (Reference Example 1), wood vinegar (Reference Example 2), and a tea leaf dry distillation solution with a concentration of 12% by weight (Example 6) as deodorizers derived from natural ingredients. Each deodorizer was diluted 10 times with pure water, and equal amounts were sprayed onto the dehydrated cake. The results are shown in Table 4.

[0053] [Table 4]

[0054] As shown in Tables 1 to 4, it can be seen that in all of Examples 1 to 6, the hydrogen sulfide concentration or ammonia concentration can be reduced by using the tea leaf dry distillation solution according to this embodiment. Furthermore, as shown in Examples 4 and 5, it can be seen that the ammonia odor can be quickly deodorized even in an open system such as an outdoor cake yard by using the deodorizing method according to this embodiment. As can be seen from the comparison results in Table 4, it can be seen that, among natural ingredients, the use of the tea leaf dry distillation solution is most effective in deodorizing the malodor emanating from the dehydrated cake.

[0055] That is, according to the embodiment of the present invention, a tea leaf dry distillation solution derived from natural ingredients is used to deodorize the dehydrated cake, so even if the dehydrated cake is reused as compost material, an environmentally friendly compost material free of harmful substances can be produced. Furthermore, according to the embodiment of the present invention, a method of spraying a liquid tea leaf dry distillation solution onto the dehydrated cake is used, which makes the deodorizer easier to handle and more uniformly mixed into the dehydrated cake than when tablet or powdered deodorizers are used. Therefore, the deodorizing method and deodorizing device for dehydrated cake according to the embodiment of the present invention enable efficient deodorization of the dehydrated cake.

[0056] In the above-described embodiments and examples, an example has been shown in which the tea leaf dry distillation solution is used as a deodorizing agent for dehydrated cake. However, it goes without saying that the tea leaf dry distillation solution may also be used for various sludges produced in the treatment process of organic wastewater in sewage treatment plants, sewage treatment plants, food factories, paper and pulp factories, etc., in addition to dehydrated cake. [Explanation of symbols]

[0057] 1: Agglomeration tank 2: Dehydration means 3: Transfer device 4: Storage device 5:Transportation device 6: Spraying means 61: Nozzle

Claims

1. A dehydrated cake obtained by dehydrating organic sludge is added with 1 to 1000 g / m of a dry distillation solution containing dry distilled tea leaves. 2 A method for deodorizing dehydrated cake, comprising spraying.

2. 2. The method for deodorizing dehydrated cake according to claim 1, wherein the tea leaf dry distillation solution contains 0.1 to 20.0% by weight of the tea leaf dry distillate.

3. 2. The method for deodorizing dehydrated cake according to claim 1, wherein the tea leaf dry distillation solution contains polyphenols.

4. 2. The method for deodorizing dehydrated cake according to claim 1, wherein the tea leaf dry distillation solution is an aqueous solution.

5. 2. The method for deodorizing dehydrated cake according to claim 1, wherein the pH of the dry distillation solution of tea leaves is 4.5 to 7.

0.

6. 2. The method for deodorizing a dehydrated cake according to claim 1, wherein the tea leaf dry distillation solution is sprayed onto the dehydrated cake having a moisture content of 65 to 85%.

7. 2. The method for deodorizing dehydrated cake according to claim 1, wherein the tea leaf dry distillation solution contains 0.01 to 0.50% by weight of a cationic surfactant having a bactericidal effect.

8. a dehydration means for dehydrating the organic sludge to obtain a dehydrated cake; The dehydrated cake is added with a tea leaf dry distillation solution containing the tea leaf dry distillate in an amount of 1 to 1,000 g / m 2 A spraying means for spraying; A deodorizing device for dehydrated cake, comprising:

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