JP2004168614A - Method for manufacturing organic manure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an organic manure including humified matter of good quality by heating and drying organic wastes, such as organic sludge, garbage, and livestock feces, then heat treating the organic wastes, thereby rapidly and effective progressing humification. <P>SOLUTION: The humification of the treated objects is sufficiently progressed by holding the objects for 2 to 40 hours at 150 to 250°C in a heat treatment process after heating and drying. The heat treatment temperature and time for the humification can be lowered and shortened by adding inorganic catalysts, such as volcanic ash, pumice powder, aluminum oxide, iron oxide, kaolinite, and acidic clay to the organic wastes. <P>COPYRIGHT: (C)2004,JPO

Description

【００３９】
図１より、加熱乾燥後目標処理温度に到達した後直ちに加熱を停止した比較例１，２で得られた処理物では、未熟腐植酸しか含まれていないが、本発明によればより腐植化が進行した有機質肥料を得ることができる。特に、無機触媒を用いた場合には腐植化のための熱処理温度及び熱処理時間の低減を図ることができ、工業的に有利である。
【００４０】
【発明の効果】
以上詳述した通り、本発明の有機質肥料の製造方法によれば、有機汚泥や生ごみ、畜糞等の有機性廃棄物を加熱乾燥した後熱処理することにより有機質肥料を製造する方法において、腐植化を十分に進行させて、良質な腐植化物を含む腐植を短時間で効率的に製造することができる。
【図面の簡単な説明】
【図１】実施例及び比較例の結果を示す腐植酸分布図である。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing an organic fertilizer by heating and drying an organic waste such as organic sludge, garbage, and livestock dung as a raw material, and then continuing the heat treatment. To produce an organic fertilizer containing high-quality humic substances.
[0002]
[Prior art]
BACKGROUND ART Conventionally, as a method of recycling organic waste such as organic sludge, garbage, and livestock dung, a method has been proposed in which organic waste is dried and then heat-treated to produce an organic fertilizer. According to this method, by continuing the heat treatment even after heating and drying, in a short time treatment of about 10 to 20 hours, there is no bad smell, and the organic fertilizer component still remains sufficiently, and the salt content is also reduced. An organic fertilizer which is not so expensive and is effective as an organic fertilizer can be obtained.
[0003]
Japanese Patent Application Laid-Open No. 2002-028608 discloses that the end timing of the heat treatment after the heating and drying is properly determined, and the treatment is performed without excess or shortage of the heat treatment time. In order to efficiently produce an organic fertilizer, in the heat treatment step after heating and drying the organic waste, the heating is stopped when the temperature of the object to be treated reaches 110 to 200 ° C, preferably 150 to 200 ° C. In addition, a method of removing a product from a heat treatment apparatus has been proposed.
[0004]
In the embodiment described in JP-A-2002-028608, the heating of the heat treatment apparatus is stopped when the temperature of the object reaches 150 ° C., and the product is taken out in less than two hours.
[0005]
By the way, the process in which organic waste such as organic sludge and animal dung is decomposed by microorganisms in the soil and turned into humus is roughly as follows. That is, first, carbohydrates and proteins in organic waste are decomposed or resynthesized by microorganisms to produce quinoid substances, amino acids, and proteins. These are condensed to form primary humic substances. On the other hand, lignin-like substances and lignin that are hardly decomposable are also decomposed by microorganisms into low-molecular-weight quinone-based substances and polyphenols at a later stage of decomposition, and these are also condensed to produce primary humic substances. These generated primary humic substances undergo oxidative polymerization under the catalytic action of inorganic components in the soil, and change to true humic substances having a higher degree of polymerization.
[0006]
As described above, humus progresses to a high degree, and the true humic substance is present in a large amount (that is, there are few easily decomposable organic substances and many genuine humic substances, which are hardly decomposable organic substances). Effective and preferred for use as organic fertilizer. That is, the following effects can be obtained if the organic fertilizer has undergone humification.
[0007]
{Circle around (1)} The buffering action of the soil is large, and the soil is stably maintained at a pH suitable for plant roots against external influences.
{Circle around (2)} Since the adsorption and holding power of ions is large, by adsorbing and holding the base component of the fertilizer, the fertilization is improved, and obstacles when the amount of fertilizer applied is too large are prevented.
{Circle around (3)} By combining with clay minerals and the like in the soil, the soil can be formed into an aggregated structure, thereby forming a soil excellent in water retention, water permeability and air permeability.
{Circle around (4)} Active aluminum in the soil and a chelate compound are made to inactivate aluminum and prevent acidification of the soil and immobilization of phosphoric acid by active aluminum.
{Circle around (5)} It has a bioactive effect and enhances cell division, thereby promoting root hair development in plants.
[0008]
[Patent Document 1]
JP-A-2002-028608
[Problems to be solved by the invention]
After heating and drying the organic waste, when producing an organic fertilizer by heat treatment, conventionally, heat treatment after heat drying is performed mainly for the purpose of removing the bad smell of the organic waste as a raw material, Producing good quality humus was not considered.
[0010]
For this reason, the organic fertilizer produced by the conventional method has no odor and is excellent in handleability, but is inferior in effectiveness as an organic fertilizer.
[0011]
The present invention solves the above-described conventional problems, and heat-drys organic waste such as organic sludge, garbage, and livestock dung, and then heat-treats the humus to effectively promote humification in a short period of time. An object of the present invention is to provide a method for producing an organic fertilizer containing humic substances.
[0012]
[Means for Solving the Problems]
The method for producing an organic fertilizer according to claim 1 is a method for producing an organic fertilizer by heat-treating an organic waste after heat-drying the organic waste. It is characterized by holding for 8 to 40 hours.
[0013]
The method for producing an organic fertilizer according to claim 2, wherein the organic waste is a group comprising volcanic ash, pumice powder, aluminum oxide, iron oxide, kaolinite, and acid clay. After adding one or more kinds of inorganic catalysts selected from the group consisting of: (a) and (b), the mixture is heated and dried, and the object to be treated is kept at 150 to 200 ° C. for 2 to 40 hours in a heat treatment step after the heating and drying.
[0014]
Conventionally, when producing organic fertilizers by heating and drying organic waste such as organic sludge, garbage, and livestock dung, heat-denaturation of organic substances has not been sufficiently studied. Was not taken into account.
[0015]
The present inventors performed heat treatment after heating and drying at 150 to 200 ° C. for 2 to 40 hours, whereby humification sufficiently proceeded, and an organic fertilizer having a high content of highly humic substances effective as an organic fertilizer was obtained. I found that I can get it.
[0016]
According to the method of claim 2, after adding an inorganic catalyst such as volcanic ash, pumice powder, aluminum oxide, iron oxide, kaolinite, and acid clay, heat and dry, and then heat-treat to reduce the temperature and time required for humification. be able to.
[0017]
In the present invention, it is preferable to produce an organic fertilizer in which the relative chromaticity RF and the color tone coefficient ΔlogK satisfy the following formulas (1) and (2) by performing heat treatment after heating and drying under such conditions.
[0018]
RF> 20… ▲ 1 ▼
ΔlogK <1.0… ▲ 2 ▼
Here, the relative chromaticity RF and the color tone coefficient ΔlogK are defined as follows.
RF = {K ₆₀₀ / M (ml)} × 1000
_{ΔlogK =} logK 400 -logK ₆₀₀
logK ₄₀₀ : extinction coefficient at 400 nm wavelength of sample solution logK ₆₀₀ : extinction coefficient at ₆₀₀ nm wavelength of sample solution M: consumption of 0.02 M KMnO ₄ aqueous solution per 30 ml of sample solution used for measurement of absorbance (ml)
Sample solution: an aqueous solution obtained by dissolving about 70 mg of organic fertilizer in terms of organic carbon in 100 ml of water.
That is, as described in "Chemistry of soil organic matter, Kyouichi KUMADA, Japan Scientific Society Press and Elsevier" (Kumada (1987)), the relative color chromaticity [gamma] is lower as the coloration coefficient [gamma] is lower. It is an effective organic fertilizer with a high ratio of organic substances that are high and hardly decomposable and a small percentage of organic substances that are easily decomposable. According to the above-mentioned literature, the progress degree of humus can be determined by the humic acid distribution map of RF-ΔlogK (FIG. 1) shown in Examples described later, Rp type is immature humic acid, B type is moderate humic acid, and A type is Classified as highly humic. In this order, the proportion of the easily decomposable organic matter decreases, and the humic substance has a larger proportion of the more hardly decomposable organic matter.
[0020]
In the present invention, the combination of the heating time and the quality and quantity of the inorganic catalyst makes it possible to obtain the most stable and hardly decomposable type A in such a humic acid distribution map, the medium stability and the moderate degradability in such a humic acid distribution map. B-type and Rp-type humic acids that are much more stable than source sludge and organic matter, and that change to more gradual decomposition characteristics, but are more unstable and more readily decomposable than B-type. For example, it is possible to produce an organic fertilizer having a different humic acid composition depending on the purpose of use. The higher the activity of the inorganic catalyst with a longer heating and acidic surface and higher catalytic activity, the higher the proportion of type A humic acid. To improve the basic soil fertility, improve the basic physicochemical and biological properties, and stably retain organic carbon in the soil to contribute to measures such as global warming prevention, the proportion of A-type humic acid must be adjusted. Increased organic fertilizer is desirable. On the other hand, when an immediate fertilizer effect is more desirable, an organic fertilizer having a high ratio of Rp-type humic acid is desirable.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the method for producing an organic fertilizer of the present invention will be described in detail.
[0022]
In the present invention, examples of the organic waste as a raw material include sewage sludge, surplus sludge, digested sludge, and the like, biologically treated sludge generated in a biological treatment step of wastewater and waste, garbage, livestock dung, and the like.
[0023]
In the present invention, such organic waste is dried by heating, and after the drying treatment, water in the organic waste gradually evaporates to a moisture content of less than 1% and drying is completed. Heating is continued at 150 to 200 ° C. (hereinafter, this temperature may be referred to as “target processing temperature”) to perform heat treatment.
[0024]
The raw material organic waste, if necessary, may be mixed with an inorganic catalyst and subjected to heat drying and heat treatment. By using the inorganic catalyst, the heat treatment temperature and time for humification are reduced. be able to. As the inorganic catalyst, for example, one or two or more selected from the group consisting of volcanic ash, pumice powder, aluminum oxide, iron oxide, kaolinite, and acid clay can be used. The amount is preferably about 1 to 50% by weight based on the dry reference amount of the organic waste. If the addition amount is less than 1% by weight, a sufficient catalytic effect due to the addition of the inorganic catalyst cannot be obtained. If the addition amount exceeds 50% by weight, the production cost is increased, the weight is increased, and the transportation cost is too high.
[0025]
In the process of evaporating water in the heating and drying process of organic waste, while water remains, the temperature of the organic waste to be treated is lower than 100 ° C, but the water is completely evaporated and removed. If the heating is continued after the heating, the temperature of the object to be processed rises to 100 ° C. or more. In the present invention, the temperature of the object to be processed is increased to 100 ° C. or more by heating and drying, and even after reaching the target processing temperature, when the inorganic catalyst is used at the target processing temperature, the inorganic catalyst is used for 2 to 40 hours. If not used, hold for 8 to 40 hours.
[0026]
If the target treatment temperature is lower than 150 ° C., humification cannot proceed sufficiently. If the target processing temperature exceeds 250 ° C., there is a risk of ignition, which is not preferable. The preferred target treatment temperature varies depending on whether or not an inorganic catalyst is used, but is 170 to 190 ° C. when no inorganic catalyst is used, and 160 to 180 ° C. when an inorganic catalyst is used.
[0027]
The time for maintaining the target processing temperature is appropriately set in the range of 2 to 40 hours depending on the target processing temperature, whether or not the inorganic catalyst is used, and the like. If the heat treatment time is shorter than the above range, humification cannot be sufficiently promoted. If the heat treatment time is excessively long, humification reaches a peak and production efficiency is impaired, which is not preferable.
[0028]
As described above, in the present invention, in the heat treatment step after the heating and drying, the color tone coefficient ΔlogK is maintained at a predetermined target processing temperature for a predetermined time so that the relative chromaticity RF exceeds 20, especially 40 or more. It is preferable to produce an organic fertilizer having a value of less than 1.0, particularly 0.9 or less.
[0029]
In order to obtain such an organic fertilizer, the target treatment temperature T (° C.) and the holding time H (hr) are T (° C.) × H (hr) = 170 × 8 when an inorganic catalyst is not used. 190 × 40 (° C. · hr), when an inorganic catalyst is used, heat treatment after heating and drying can be performed at T (° C.) × H (hr) = 160 × 8 to 180 × 40 (° C. · hr). preferable.
[0030]
Note that, in the present invention, heating of the organic waste is liable to be ignited when performed by the direct heating method. Therefore, it is preferable to perform heating using an indirect heating device, preferably while stirring the object to be treated. .
[0031]
Thus, the heat treatment after the heating and drying may be performed by continuing the heating for compensating for the temperature drop as necessary while holding the object to be processed in such an indirect heating device. The processing may be performed by taking out the object to be processed which has reached the target processing temperature from the inside of the apparatus, transferring it to a container having excellent heat retention, and continuing the heating in this container as needed to compensate for the temperature drop. The former method is suitable when the batch processing type apparatus has a sufficient margin for the processing time, and the latter method is suitable for a continuous processing type apparatus or a batch processing type apparatus. This is effective when there is not enough time to increase the production volume.
[0032]
【Example】
Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.
[0033]
Examples 1 to 6, Comparative Examples 1 and 2
Excess sludge dewatered cake (water content: 83%) generated from the night soil treatment facility was used as a raw material, and was heated and dried by an indirect heating device equipped with a stirrer so that the temperature of the treatment target reached the target treatment temperature shown in Table 1. After reaching the target processing temperature shown in Table 1 by heating and drying, the temperature was further maintained at the same processing temperature shown in Table 1, and then the processed product was taken out.
[0034]
However, in Comparative Example 1, heating was stopped when the target processing temperature was reached, and the processed product was taken out. In Comparative Example 1, the time required for the temperature of the object to rise from 150 ° C. to 160 ° C. was one hour, and the object taken out of the apparatus was immediately cooled to a temperature of less than 150 ° C. by natural cooling. It was cooled down.
[0035]
In Examples 3 to 6, the inorganic catalysts shown in Table 1 were added to the raw materials at the ratios shown in Table 1.
[0036]
The relative chromaticity RF and the color tone coefficient Δlog K of the obtained processed product were measured, and the results are shown in FIG. The sample solution was prepared so that about 70 mg of the treated product in terms of organic carbon was dissolved in 100 ml of water. The absorption coefficients K ₄₀₀ and K ₆₀₀ were measured by “V-530DS” manufactured by JASCO Corporation.
[0037]
Table 1 also shows the form of humic acid.
[0038]
[Table 1]

[0039]
From FIG. 1, the processed products obtained in Comparative Examples 1 and 2 in which heating was stopped immediately after reaching the target processing temperature after heating and drying contained only immature humic acid. The advanced organic fertilizer can be obtained. In particular, when an inorganic catalyst is used, the heat treatment temperature and heat treatment time for humification can be reduced, which is industrially advantageous.
[0040]
【The invention's effect】
As described in detail above, according to the method for producing an organic fertilizer of the present invention, in a method for producing an organic fertilizer by heating and drying an organic waste such as organic sludge, garbage, and livestock dung, followed by heat treatment, Is sufficiently advanced to produce humus containing good humic substances in a short time and efficiently.
[Brief description of the drawings]
FIG. 1 is a humic acid distribution chart showing the results of Examples and Comparative Examples.

Claims (3)

After heating and drying the organic waste, in a method of producing an organic fertilizer by heat treatment,
A method for producing an organic fertilizer, wherein an object to be treated is kept at 150 to 200 ° C. for 8 to 40 hours in a heat treatment step after heating and drying. After heating and drying the organic waste, in a method of producing an organic fertilizer by heat treatment,
After adding one or more inorganic catalysts selected from the group consisting of volcanic ash, pumice powder, aluminum oxide, iron oxide, kaolinite, and acid clay to the organic waste, heat drying and heating drying A method for producing an organic fertilizer, wherein an object to be treated is kept at 150 to 200 ° C. for 2 to 40 hours in a subsequent heat treatment step. 3. The method for producing an organic fertilizer according to claim 1, wherein the relative chromaticity RF and the color tone coefficient .DELTA.logK satisfy the following formulas (1) and (2), respectively.
RF> 20… ▲ 1 ▼
ΔlogK <1.0… ▲ 2 ▼
Here, the relative chromaticity RF and the color tone coefficient ΔlogK are defined as follows.
RF = {K ₆₀₀ / M (ml)} × 1000
_{ΔlogK =} logK 400 -logK ₆₀₀
logK ₄₀₀ : extinction coefficient at 400 nm wavelength of sample solution logK ₆₀₀ : extinction coefficient at ₆₀₀ nm wavelength of sample solution M: consumption of 0.02 M KMnO ₄ aqueous solution per 30 ml of sample solution used for measurement of absorbance (ml)
Sample solution: An aqueous solution obtained by dissolving about 70 mg of organic fertilizer in terms of organic carbon in 100 ml of water

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