JPH06279158A - Fermentation composting method for organic matter - Google Patents

Abstract

PURPOSE:To enable fermentation composting in a period shorter than heretofore by adding the intermediate products of primary fermentation in a specific temp. range as seed bacteria to the raw material of org. matter and subjecting the raw material to primary fermentation, then to secondary fermentation. CONSTITUTION:The intermediate products of the primary fermentation held at 50 to 70 deg.C by adjusting a supply air quantity with, for example, the temp. of the raw material of the org. matter as an index are added as the seed bacteria to the org. matter in the process for production of a soil improving agent and/or fertilizer by subjecting the raw material to the primary fermentation with mainly thermophiles under aerobic condition, then to the secondary fermentation with mainly bacteria which like middle temp. to ordinary temp. The org. matter is fermented in the period shorter than heretofore according to the method for fermentation composting of the above org. matter Then, the capacity of a fermentation tank is reduced and an initial cost is reduced and, therefore, the production cost of the fertilizer, etc., is reduced.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a soil conditioner and / or fertilizer (hereinafter referred to as fertilizer) by aerobically fermenting an organic substance.
The present invention relates to a method for producing an organic substance by fermenting and fertilizing.

[0002]

2. Description of the Related Art Conventionally, fertilizer and the like are produced by primary and secondary fermentation of organic substances such as sludges, fresh food processing residues, and agricultural product residues generated from sewage treatment plants and wastewater treatment plants of various factories. In the method, a part of the fermented product after the primary and secondary fermentation is added to the raw material as an inoculum, and the primary and secondary fermentation is performed using this raw material.

[0003]

However, in the above-mentioned conventional method, it took a long time for the primary and secondary fermentations. Therefore, since the fermenter has a large capacity, the equipment cost increases and the manufacturing cost of fertilizer and the like also increases. Then, the subject of this invention is providing the method of fermenting and fertilizing an organic substance which can shorten a fermentation period than before. Another object of the present invention is to provide a method for fermenting and fertilizing an organic substance capable of reducing the capacity of a fermenter, reducing the equipment cost, and reducing the manufacturing cost of fertilizer and the like.

[0004]

Means for Solving the Problems In order to solve the above-mentioned problems, in claim 1, the organic substance raw material is aerobically conditioned under the aerobic condition, and the primary fermentation is mainly thermophilic bacteria and the bacteria preferring medium to normal temperature are mainly used. In the method for producing a soil improver and / or fertilizer by secondary fermentation, the fermentation intermediate product of primary fermentation having a temperature of 50 ° C. or higher and 70 ° C. or lower is added to the organic material raw material as an inoculum. The method for fermenting and fertilizing an organic substance according to claim 2, wherein the temperature condition in the primary fermentation is maintained at 50 ° C or higher and 70 ° C or lower. In the third aspect, the means for maintaining the temperature condition in the primary fermentation at 50 ° C. or higher and 70 ° C. or lower is performed by adjusting the supply air amount using the raw material temperature as an index, and the fermented fertilizer for organic substances according to claim 2. Create each conversion method It was.

The above-mentioned raw material of organic substances means substances containing organic substances which can be decomposed by microorganisms, such as sludge and urine sludge of wastewater treatment plants of various factories, livestock excrement, residues of agricultural products or processing residues of fresh foods.

In particular, the present invention is suitable for fertilizing a plant-based organic material raw material which has been difficult to ferment as a fertilizer in a short period of time. Examples of plant-based raw materials include okara, pruning waste of plant trees, and the like.

The above-mentioned primary fermentation and secondary fermentation refer to each of the early and late fermentation stages in which microbial flora involved in the reaction are different when fermenting an organic material raw material to produce a fertilizer and the like. The primary and secondary fermentations may be performed in different fermentation tanks or the same fermentation tank in some cases, but the fermentation conditions such as the supply air amount and the temperature are different between the primary fermentation and the secondary fermentation. In the primary fermentation, which is the first fermentation stage, the supply of air is higher and the temperature is higher than in the secondary fermentation.

[0008] The fermentation intermediate product having a temperature of 50 ° C or higher and 70 ° C or lower means that the number of thermophilic bacteria is increased by fermenting a raw material of an organic substance, and the temperature rise is 50 ° C or higher and 70 ° C due to the increase in activity. A raw material whose temperature is below ℃.
As the temperature rises, the use of the raw material of the microflora with an increased number of thermophilic bacteria as the inoculum produces the effect of promoting fermentation. The number of days required for the raw material to reach the above temperature depends on the type of raw material and fermentation conditions. More preferably 5
A fermentation intermediate product having a temperature of 5 ° C or higher and 65 ° C or lower is used as an inoculum.

The temperature of the intermediate fermentation product refers to the temperature of the intermediate fermentation product in the fermentation tank or the temperature of the intermediate fermentation product just cut out from the fermentation tank. When the temperature in the fermenter or at the time of cutting is 50 ° C. or higher and 70 ° C. or lower, the temperature of the fermentation intermediate product cut out from the fermenter after a lapse of time is lowered, but this may be used as an inoculum.

The amount of the intermediate fermentation product added to the raw material is preferably 5% by weight or more, more preferably 10% by weight or more of the raw material.

In the second aspect, the temperature condition in the primary fermentation is set to 50 ° C. or higher and 70 ° C. or lower because the activity of the thermophilic bacterium important in the primary fermentation increases in the above temperature range.
This is because the primary fermentation can be promoted, and a more preferable temperature condition is 55 ° C or higher and 65 ° C or lower.

As the method for maintaining the temperature condition in the primary fermentation at 50 ° C. or higher and 70 ° C. or lower in claim 2, various methods such as a method of heating from the outside of the fermentation tank and a method of heating supply air can be adopted. However, in the former method, it is difficult to uniformly heat the whole when the fermenter has a large volume. Further, it is known that the latter method results in a decrease in the water content of the raw material, resulting in a decrease in microbial activity. Therefore, like the method for fermenting and fertilizing an organic substance according to claim 3, a method of maintaining the temperature at 50 ° C. or higher and 70 ° C. or lower by adjusting the amount of supplied air using the temperature in the primary fermentation tank as an index is more preferable. In this method, the temperature in the primary fermenter can be maintained at 50 ° C or higher and 70 ° C or lower by suppressing the removal of heat by the supply air and maintaining the thermophilic microbial activity having an exotherm of about 50 ° C or higher. it can.

[0013]

In the method for fermenting an organic substance as a fertilizer according to claim 1, the microflora of the fermentation intermediate added as a seed bacterium accelerates the fermentation of the raw material. In the method for fermenting and fertilizing an organic substance according to claim 2, by setting the temperature condition of the primary fermentation to 50 ° C. or higher and 70 ° C. or lower, the activity of the thermophilic microorganism is maintained high and the fermentation of the raw material is further promoted. In the method for fermenting and fertilizing an organic substance according to claim 3, the temperature condition of the primary fermentation is 5
Since the method of maintaining the temperature at 0 ° C. or higher and 70 ° C. or lower depends on the adjustment of the amount of supply air, the raw material can be kept uniform in temperature and the decrease in water content can be suppressed.

[0014]

【Example】

Example 1 60 kg of sludge obtained by treating wastewater from a food factory that processes plant-based raw materials with activated sludge was mixed with sawdust to give a water content of 60%. The average air volume of the sludge after adjusting the water content in the primary fermentation tank which is a rigid continuous fermentation tank having a capacity of 80 liters is 9.
Fermentation was performed by passing 7 liters / minute of air. No temperature control was performed, so the temperature in the bath fluctuated between 68 ° C and 45 ° C. The primary fermentation was completed after 8 days of the primary fermentation, the obtained intermediate fermentation product in the primary fermentation tank was transferred to a secondary fermentation tank (80 liter capacity), and the secondary fermentation was further performed at an air flow rate of 0 to 5 liters / minute. Fertilizer consisting of fermented product was obtained after the day. Table 1 shows the microflora of the fermentation intermediate product at the end of the primary fermentation and the fermentation end product at the end of the secondary fermentation.

[0015]

[Table 1] In Table 1, each numerical value represents the number of microorganisms, and the numerical unit is c. f. u / g-ds. As shown in Table 1, the microbiota of the fermentation intermediate product at the end of the primary fermentation and the fermentation end product at the end of the secondary fermentation were significantly different. Next, 60 kg of fermentation intermediate product at a temperature of 60 ° C at the end of primary fermentation as raw material
To produce a fertilizer under the same conditions as above. For comparison, a fertilizer was produced under the same conditions as above by the conventional method of adding 6 kg of the fermented product as an inoculum to the primary fermentation tank. Table 2 shows the results of the number of fermentation days and the decomposition rate of organic substances in the above two production methods.

[0016]

[Table 2] In Table 2, the numerical unit of the organic matter decomposition rate is% -ds. As shown in Table 2, in the method of this example, the decomposition rate of organic matter was obtained in 20 days of fermentation, which was almost the same as that of 34 days of fermentation in the conventional method. Therefore, according to the method of this example, the period required for fermentation was shortened by 14 days as compared with the conventional method.

Fermentation 8 in the method of the present example and the conventional method
Table 3 shows the results of the number of fermentation days until the end of the day and the CO ₂ concentration in the exhaust gas.

[0018]

[Table 3] The numerical unit of CO ₂ in Table 3 is%. As shown in Table 3, in the method of this example, the decomposition of organic matter was greater in the number of fermentation days of 1 to 6 days than in the conventional method, and therefore, the decomposition of organic matter at the initial stage of fermentation was particularly promoted.

Example 2 In the method of this example in Example 1, the temperature in the primary fermentation tank was further maintained at 55 ° C. or higher by the method described below. That is, a temperature measuring sensor is provided in the primary fermentation tank (80 liters), and the temperature of the primary fermentation tank is maintained at 55 ° C or higher by controlling the amount of air supplied to the fermentation tank using the temperature measured by this sensor as an index. did.

The same experiment as in Example 1 was conducted except for the above conditions. As a result, the organic decomposition rate after 8 days of primary fermentation was
Fermentation was further promoted, which was 26.2% -ds, which was larger than the numerical value of 23.1% -ds in the case of the method of this example in which temperature control was not performed. Table 4 shows the results of counting the number of microorganisms after 8 days of primary fermentation in the case where the temperature was adjusted by controlling the amount of supplied air and the case where the temperature was not adjusted in the method of this example using the fermentation intermediate product as the inoculum.

[0021]

[Table 4] The numerical units in Table 4 are c. f. u / g. ds. Table 4
As shown in (1), the number of thermophilic bacteria and thermophilic actinomycetes is higher when the temperature is adjusted than when it is not adjusted. That is, it is understood that by keeping the temperature in the primary fermenter at 55 ° C. or higher, the thermophilic microorganisms in the primary fermenter increase and thus the fermentation is promoted.

Example 3 The method of this example when the temperature was adjusted in Example 2 was carried out using a large capacity (1.2 m ³ ) primary fermenter. That is, as the primary fermentation tank, a rigid continuous fermentation tank having an internal volume of 1.2 m ³ was used. In this primary fermentation tank, air supply holes are installed at predetermined height positions in five steps on the side wall of the tank, and air supply holes are also installed at the bottom of the air supply holes. The structure of the fermenter equipped with the air supply hole is the utility model registration Sho 57-150577.
No. 0 (Jitsuko 54-057255).
The device according to the registered utility model is suitable as a device for carrying out the method of this example because it can uniformly and multi-wisely supply air to a large-capacity sediment inside a fermenter.
Further, temperature sensors are installed at eight appropriate places inside the tank, and the temperature in the primary fermentation tank is maintained at 55 ° C or more by controlling the amount of air supplied from each air hole using the temperature measured by this sensor as an index. did.

The experiments described below were conducted using the primary fermenter whose temperature was adjusted by the above method. That is, sawdust was mixed with 110 kg of the same sludge as in the example, and the water content was adjusted to 60%. A raw material mixture (total volume of about 200 liters) obtained by adding 11 kg of inoculum to the sludge after the water content adjustment was continuously introduced from the upper part of the primary fermentation tank for 7 days every day. As the inoculum, the fermentation intermediate product after 8 days of primary fermentation obtained by the method of this example when the temperature was adjusted in Example 2 was used. The temperature at the end of primary fermentation of this intermediate fermentation product was 60 ° C.

On the 8th day, 120 liters are cut out from the bottom of the tank. The same raw material mixture (20 days) as in the first day, except that 11 kg of this cutout was used as the inoculum.
0 liter) was charged from the top of the tank. After that, 120 liters were cut out from the bottom of the tank every day, and a part of the cutout (11 kg) was used as a seed mixture (20
Continuous fermentation was carried out by adding 0 liter) from the upper part of the tank.

In the above continuous fermentation, the organic decomposition rate of the cutout after 8 days of the primary fermentation was 27.0% -ds, and the result of counting the microorganisms showed the same tendency as the method of this example when the temperature was adjusted in Example 2. there were. Therefore, it was understood that the cut-out product can be used as an inoculum, and the effect of the present invention was confirmed even when continuous fermentation was performed using a large capacity primary fermenter.

[0026]

According to the method for fermenting an organic substance as a fertilizer according to the first, second or third aspect, the organic substance can be fermented in a shorter period of time than the conventional method. Therefore, according to each of the methods of the present invention, the capacity of the fermenter can be reduced and the equipment cost can be kept low, so that the manufacturing cost of fertilizer and the like can be reduced.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mari Takemura 6-1, Nanyo Dori, Minami-ku, Nagoya-shi, Aichi Tokai Plant Engineering Co., Ltd.

Claims (3)

[Claims] 1. A soil improver and / or a fertilizer is produced by subjecting an organic material raw material to aerobic conditions for primary fermentation mainly of thermophilic bacteria and secondary fermentation mainly of bacteria preferring normal temperature. A method for fermenting an organic substance as a fertilizer, comprising adding a fermentation intermediate product of a primary fermentation having a temperature of 50 ° C. or more and 70 ° C. or less to the organic substance raw material as an inoculum. 2. The method for fermenting an organic substance as a fertilizer according to claim 1, wherein the temperature condition in the primary fermentation is maintained at 50 ° C. or higher and 70 ° C. or lower. 3. The fermentation of an organic substance according to claim 2, wherein the means for maintaining the temperature condition in the primary fermentation at 50 ° C. or higher and 70 ° C. or lower is performed by adjusting the amount of supply air using temperature as an index. Fertilization method.