JPH11157973A - Compost fermentative treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for the subject treatment of organic objects such as livestock droppings, intended for complete killing Escherichia coil and the like in a short time after beginning the treatment operation, preventing the above bacteria from proliferation again until ending the treatment and ensuring fermentation temperature to be controlled by a simple means. SOLUTION: This method for compost fermentation treatment has such a scheme that, when a compost fermentation is to be conducted by charging organic objects holding Escherichia coil into an open-type formentation tank equipped with a blower for feeding air into the tank, the air feed time and air feed that halting time for the blower are controlled and such operations are repeated so that the fermentatin temperature of the objects is kept at >=60 deg.C until the completion date of the treatment after the temperature rises rapidly to >=70 deg.C on the first day; alternatively, the fermentation tank is divided into a plurality of compartments, each of them is equipped with a blower, and both the air feed time and air feed halting time for each of the blowers may be controlled so as to satisfy the above-mentioned temperature conditions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for compost fermentation of an organic material to be treated, such as livestock dung, having Escherichia coli. More specifically, the present invention relates to a method for killing O157 and other Escherichia coli in a short time to prevent regrowth. The present invention relates to a compost fermentation method which is excellent in safety.

[0002]

BACKGROUND OF THE INVENTION As is well known, enterohemorrhagic Escherichia coli O15
No. 7 causes severe symptoms such as severe diarrhea accompanied by bleeding and hemolytic uremic disease when infected to humans. It is presumed that the main source of infection is caused by feces of livestock carrying O157. Therefore, in a compost center for fermenting a large amount of livestock manure, there is a concern about the safety of workers when livestock manure carrying O157 is carried in and the safety of the produced compost.

[0003] However, in a conventional compost center,
Simply fermenting livestock manure in a fermenter in a fermenter will slow the rise in fermentation temperature immediately after the livestock manure is brought into the fermenter,
Escherichia coli and the like in livestock dung are hardly completely killed because the fermentation temperature does not easily exceed 70 ° C, and it is difficult to maintain the fermentation temperature at 60 ° C or higher until the fermentation treatment is completed. Was difficult.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and when fermenting an organic material to be treated such as livestock dung, the fermentation temperature of the organic material to be treated is first raised rapidly. To completely kill Escherichia coli, etc. in a short period of time, and to maintain the fermentation temperature high until the fermentation process is completed to prevent regrowth of Escherichia coli, etc. To be implemented by such a simple means.

[0005]

According to a first aspect of the present invention, there is provided a fermentation method for compost fermentation, wherein E. coli is stored in an open fermentation tank provided with a blower for sending air into the tank. When the fermentation temperature of the organic material to be treated is rapidly increased to 70 ° C. or more on the first day and the fermentation temperature of the organic material to be maintained at 60 ° C. or more until the end date of the fermentation treatment, the fermentation of the compost fermentation is performed. The invention is characterized in that the air time and the stop time are controlled, and the air supply to the fermenter and the stop are repeated.

Further, according to the method for compost fermentation according to the second aspect of the present invention, Escherichia coli is stored in the first compartment of an open fermenter having a plurality of compartments and a blower for sending air to each compartment. When the compost fermentation is carried out while putting the organic material to be treated and moving it little by little to the last compartment, the blower of the first compartment is used so that the fermentation temperature of the organic material increases rapidly to 70 ° C. or more on the first day. The air supply time and the stop time are controlled to repeat the air supply and stop to the first section, and further, from the next section to the last section, so that the fermentation temperature is maintained at 60 ° C. or higher until the end date of the fermentation treatment. The invention is characterized in that the air supply time and the stop time of the blower of the section are controlled, and the air supply and stop to each section are repeated.

[0007] The compost fermentation method according to claim 3 is characterized in that, in the compost fermentation method according to claim 1 or 2, the organic material to be treated having Escherichia coli is livestock dung. is there.

[0008] In the compost fermentation treatment method of the first aspect, the fermentation temperature of the organic material to be treated rapidly rises to 70 ° C or more on the first day by controlling the air supply time and the stop time of the blower. When the temperature rapidly rises to a high temperature of 70 ° C. or more, E. coli and the like retained in the organic material to be treated are completely killed in about several seconds to several tens of seconds. In particular, O157 is weak to heat and is said to die in about 8 seconds even at 68.3 ° C. The fermentation temperature of the organic material to be treated is maintained at 60 ° C. or higher until the end date of the fermentation treatment by controlling the air supply time and the stop time of the blower thereafter. Proliferation is also prevented.

Thus, the compost fermentation treatment method of claim 1
Since the fermentation temperature is controlled by controlling the air supply time and the stop time of the blower, the control itself is extremely simple and requires complicated and expensive equipment such as an inverter and an air flow control valve. Therefore, it can be implemented at low cost.

[0010] In the compost fermentation treatment method according to the second aspect of the present invention, the air supply time and the stop time of the blower attached to the first section of the fermenter are controlled to ferment the organic material to be treated on the first day in the first section. Since the temperature rapidly rises to 70 ° C. or higher, Escherichia coli and the like retained in the organic material to be treated die in about several seconds to several tens of seconds, as in the case of the processing method of claim 1. And, while the organic material to be moved gradually moves from the next section to the last section to perform compost fermentation, the fermentation temperature of the organic material to be processed is controlled by controlling the air supply time and the stop time of the blower attached to each section. Since the temperature is maintained at 60 ° C. or higher until the end date of the fermentation treatment, the regrowth of Escherichia coli and coliforms is prevented as in the case of the treatment method of claim 1.

[0011] In the compost fermentation treatment method of the second aspect, the fermentation temperature is adjusted only by controlling the air supply time and the stop time of the blower attached to each section of the fermentation tank. In addition, since complicated and expensive equipment is not required, it can be implemented at low cost.

In the case where the organic material to be treated is livestock dung as in claim 3, the amount of organic matter contained in the livestock dung is large. The speed is raised rapidly as above until the process is completed.
It is easy to keep the temperature above ℃.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic explanatory view of one embodiment of the compost fermentation treatment method according to the present invention, and FIG. 2 is an enlarged cross-sectional view of a fermenter.

In the compost fermentation treatment method shown in FIG. 1, a long open fermenter 1 is divided into four sections A, B, C, and D, and blowers 2a, 2b, 2c, and 2b for sending air to each section. 2d
, And the compost fermentation is performed while the organic treatment object 3 carried into the first section A is gradually moved by the movable scoop 4 to the last section D.

Specifically, a concrete fermenter 1 having a length of 68 m, a width of 4 m, and a pile height of 1.8 m was installed, and the length of the fermenter was 17 m.
Is divided into four sections A, B, C, and D, and the ventilation capacity of each section is 9.3 m ³ /
Minute, blower 2a, 2b, 2c, 2d with output 0.6 kw
Is attached. The mobile scoop 4 is a mobile scoop having a scraping capacity of 4 m in width × 1.8 m in depth and a feed width of compost of 2 m per day (operated for 6 hours), and is an organic material to be treated. The livestock dung 3 is scraped up and the livestock dung 3 is moved from the section A to the section D over 30 days.

This livestock dung 3 is a cow dung of a fattening beef cattle, and is mixed with a fully-ripened compost (which is further accumulated for 40 days after fermentation and then matured) as a pretreatment to reduce the water content to about 65%.
Adjusted to the extent. The daily input amount of the livestock dung 3 whose water content has been adjusted is 12.7 m ³ (5.3 t).
It is.

As shown in FIG. 2, four diffusers 5 each having a diameter of 100 mm are provided per section at the bottom of the fermenter 1, and air is supplied from each blower 2a (2b, 2c, 2d) to 1 m ³ of compost.
Air can be supplied at a rate of 80 liters / minute. Then, crushed stones 6 are spread on the bottom of the fermenter 1, and rice hulls 7 are further spread thereon to a thickness of 10 cm, thereby facilitating the movement of the livestock dung 3 by the movable scoop 4.

In each of the blowers 2a, 2b, 2c, 2d, the air supply time and the stop time are controlled by the computer CP. That is, blower 2a of section A
The air supply time is 50 minutes and the stop time is 50 minutes so that the fermentation temperature of the introduced livestock dung 3 rapidly rises to 70 ° C. or more on the first day.
The air supply and stop are repeated in a cycle of minute, and each of the blowers 2b, 2c, 2d of the section B, the section C, and the section D,
In order to keep the fermentation temperature at 60 ° C. or higher until the final day, the air supply and the stop are controlled in a cycle of a gas supply time of 20 minutes and a stop time of 50 minutes.

FIG. 3 shows the cycle of the air supply time-stop time of the blower 2a in the section A, and the air supply time 50 minutes-the stop time 50 minutes (total air supply time per day is 12 hours), and the air supply time. 30 minutes-stop time 50 minutes (total air supply time per day is 9 hours), air supply time 20 minutes-stop time 50 minutes (total air supply time per day is 6.9 hours), air supply time 10 minutes A graph comparing four types of cycles with a stop time of 50 minutes (total air supply time of four hours per day) and the rate of increase in fermentation temperature (the relationship between fermentation temperature and fermentation days) in each cycle. It is. The fermentation temperature is obtained by measuring the temperature at a depth of 30 cm from the surface of the livestock dung 3 using a mercury thermometer.

As shown in this graph, when the air supply and the stop were repeated in a cycle of the air supply time of 50 minutes and the stop time of 50 minutes, the fermentation temperature rapidly rose to 76.4 ° C. on the first day, Maintain high temperature after the second day, and keep 7
Maintain 7.4 ° C. On the other hand, when repeating air supply and stop in a cycle of air supply time 30 minutes-stop time 50 minutes,
Although the fermentation temperature rises rapidly, the temperature on the first day is 66.5 ° C., and the temperature rise is slightly slower compared to the cycle of 50 minutes of air supply time and 50 minutes of stop time. Moreover, in the cycle of the air supply time of 20 minutes and the stop time of 50 minutes, or the cycle of the air supply time of 10 minutes and the stop time of 50 minutes, no rapid increase in the fermentation temperature was observed. It takes six days. From these results, in order to rapidly increase the fermentation temperature to 70 ° C. or higher at which the E. coli is killed on the first day, the blower 2a in the A compartment as in the above-described embodiment was used.
By controlling the air supply time to 50 minutes and the stop time to 50 minutes,
It turns out that it is necessary to repeat the air supply to the compartment and the stop.

FIG. 4 shows that the blower 2a in the section A has a cycle of air supply time 50 minutes and stop time 50 minutes,
Air supply time of 20 minutes-
As a cycle of the stop time of 50 minutes, the compost fermentation is performed for 30 days while moving the livestock dung, and the blowers 2a, 2b, 2c, and 2d in each section from A to D are all supplied with the air supply time of 20 minutes-the stop time of 50 minutes. 12 is a graph showing a change in fermentation temperature (a relationship between fermentation temperature and fermentation days) when compost fermentation is performed for 30 days while moving livestock dung as a cycle.

As shown in this graph, the former case (A
The fermentation temperature rapidly rises to 76.8 ° C on the first day, and the condition of 75 ° C or higher is maintained until the 20th day. Thereafter, the fermentation temperature gradually decreased, but was maintained at 60.1 ° C. even on the 30th day. On the other hand, in the latter case (the air supply time of the blower in section A is 20 minutes), it takes 6 days for the fermentation temperature to reach 75 ° C. or higher, and the change in the fermentation temperature thereafter is almost the same as in the former case. Similar, but the final fermentation temperature is below 60 ° C. From this result, in order to rapidly increase the fermentation temperature to 70 ° C. or higher on the first day and maintain the fermentation temperature at 60 ° C. or higher until the end date of the fermentation treatment, the air supply time of the blower 2a in the A section as in the above-described embodiment is required. 50 minutes, stop time is controlled to 50 minutes,
In addition, it can be seen that the air supply time of the blowers 2b, 2c and 2d in each of the sections B to D should be controlled to 20 minutes, and the stop time should be controlled to 50 minutes.

Next, the blower 2a in the section A is set to the air supply time 5
A cycle of 0 minutes-stop time of 50 minutes, and the blowers 2b, 2c, and 2d of the sections B to D were cycles of air supply time of 20 minutes-stop time of 50 minutes, and 30 minutes while moving livestock dung.
When the compost fermentation is performed for a day, and the blowers 2a, 2b, 2c, and 2d in each section from A to D all have an air supply time of 20 minutes.
Table 1 below shows the change in the number of E. coli and Table 2 below shows the change in the number of E. coli in the case of performing compost fermentation for 30 days while moving livestock dung as a cycle of a stop time of 50 minutes.

The examination of Escherichia coli and coliforms was carried out in the following manner. That is, at each measurement point, livestock dung is about 1k.
g was collected in a sterilized vinyl bag and left at room temperature for 30 minutes.
Broth (manufactured by Elmex Co., Ltd.) is placed in a culture flask containing 27 ml, and shaken well for 10 minutes.
This was a 0-fold diluted sample solution. Next, 1 ml of the 10-fold diluted sample solution was taken with a sterile pipette, and 9 ml of sterilized 0.8
Well stirred in 5% sodium chloride solution, which was used as a 10 ^2-fold diluted sample solution. From the prepared diluted sample, a 10 ³ to 10 ⁹ -fold diluted sample solution was sequentially produced by the same operation. A 10-fold diluted sample solution is plugged with a cotton plug in the culture flask,
The cells were cultured as they were. With respect to the 10 ² to 10 ⁹ -fold diluted sample solution, 1 ml of each sample solution was inoculated into three test tubes containing 9 ml of Promedia XM broth and cultured. The culture was performed at 37 ° C. for 24 hours. Twenty-four hours later, those in which bacterial growth was observed and the culture solution turned blue (positive for β-galactosidase) were positive for coliform bacteria, and further, ultraviolet rays (366)
nm), and those that emit fluorescence (β-glucuronidase positive) were regarded as E. coli positive. If no bacterial growth was observed after culturing for 24 hours, the cells were further cultured for 24 hours, and similarly evaluated. The number of bacteria was represented by the most probable number (method 3-3-3) determined from the number of positive test tubes in three-step dilution. This test was repeated three times, and the average and standard deviation were determined.

[0026]

[Table 1]

[Table 2]

As shown in Tables 1 and 2, in the former case, in which the air supply time of the blower in section A was 50 minutes and the stop time was 50 minutes, on the first day when the fermentation temperature rapidly rose to 70 ° C. or more. In addition, the number of E. coli and the number of E. coli fell below the detection limit and were not detected thereafter. In contrast, in the latter case where the air supply time of the blower in section A was 20 minutes and the stop time was 50 minutes, Escherichia coli and coliforms were detected even on the fourth day when the fermentation temperature increased to 62 ° C. Thereafter, neither Escherichia coli nor the Escherichia coli group was detected, but from the compost on the 30th day, the Escherichia coli group was detected again. The coliform group was detected from the compost on day 30 in one of three tests.
Only once. The fermentation temperature of the compost at this time was 56.6.
° C, which was slightly lower than the temperatures in the other two tests at 57.6 ° C and 57.7 ° C. From this, it is considered that around 57 ° C. is probably the growth limit temperature of the coliform bacteria. In addition, the air supply time of section A is 5
In the former case where the stop time was controlled to 0 minutes and the stop time was controlled to 50 minutes, the regrowth of the coliform bacteria could be prevented because the fermentation temperature on day 30 was 6%.
It is considered that the temperature exceeded 0 ° C. (60.1 ° C.) and completely exceeded the growth limit temperature of the coliform bacteria.

From the above results, it was found that the fermentation temperature was 70
When the air supply time and the stop time of the blower are controlled so as to rapidly raise the temperature to at least 60 ° C. until the end date of the fermentation treatment, E. coli and coliform bacteria can be completely killed on the first day, It can be seen that, at the end of the fermentation treatment, regrowth of not only Escherichia coli but also Escherichia coli group can be prevented.

In the compost fermentation treatment method of this embodiment, livestock dung is used as an organic processed material containing Escherichia coli. However, various organic processed materials other than livestock dung, such as kitchen waste and household waste, are used. Of course, garbage can also be processed.

In the compost fermentation treatment method of this embodiment, the fermenter 1 is divided into four sections, and the air supply time and the stop time of the blower in each section are controlled as described above. The number of sections may be any number. In short, the fermentation temperature of the organic material to be treated is 70% on the first day, taking into account the amount of the organic material to be treated, the number of treatment days, the amount of air blown by the blower, and the output.
Control the air supply time and stop time of the blower in the first section so that it rapidly rises above ℃, and further, from the next section to the last section so that the fermentation temperature stays above 60 ℃ until the end date of the fermentation process. The air supply time and the stop time of the blower in each section up to may be controlled.

Next, when compost fermentation treatment is performed inside an open fermenter without moving the organic object to be treated by a movable scoop or the like, the fermentation temperature of the organic object to be treated is 70 ° C. or more on the first day. If the air supply time and the stop time of the blower attached to the fermenter are controlled over time so as to keep the temperature higher than 60 ° C. until the end date of the fermentation treatment, the air supply and stop to the fermenter are repeated. Good.

For example, when livestock manure is subjected to compost fermentation for 30 days, the air supply time of the blower is controlled to 50 minutes and the stop time is controlled to 50 minutes for the first 7 days, and the fermentation temperature is increased to 70% on the first day. ° C or more, and after the 8th day, the air supply time is controlled to 20 minutes and the stop time is controlled to 50 minutes.
The fermentation temperature may be maintained at 60 ° C. or more even on the 30th day.

Such a compost fermentation treatment method is suitably employed when a relatively small amount of an organic substance to be treated is subjected to a compost fermentation treatment in a batch system.

[0034]

As is clear from the above description, in the compost fermentation treatment method of the present invention, the fermentation temperature of the organic material to be treated is rapidly increased to 70 ° C. or more on the first day to completely kill E. coli and the like. Further, since the fermentation temperature can be maintained at 60 ° C. or higher until the fermentation process is completed, re-growth of E. coli and the like can be prevented, even when the organic substance to be treated has terrible E. coli such as O157. In addition to protecting the safety of workers, it is possible to improve the safety of the compost produced, and to adjust the fermentation temperature by extremely simple means of controlling the air supply time and stop time of the blower. It has a remarkable effect that it is extremely easy to manage, does not require complicated and expensive equipment such as an inverter and an air flow control valve, and can be implemented at low cost.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of one embodiment of a compost fermentation treatment method according to the present invention.

FIG. 2 is an enlarged cross-sectional view of a fermenter.

FIG. 3 is a graph showing the rate of increase in fermentation temperature (relationship between fermentation temperature and fermentation days).

FIG. 4 Changes in fermentation temperature (relationship between fermentation temperature and fermentation days)
FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fermenter 2a, 2b, 2c, 2d Blower 3 Livestock dung (organic material to be processed) 4 Mobile scoop 5 Air diffuser CP Computer

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tadaaki Mori 2-3-3, Showa-cho, Abeno-ku, Osaka-shi Mori Plant Co., Ltd.

Claims (3)

[Claims] When fermenting compost by putting an organic substance to be treated containing Escherichia coli into an open fermenter equipped with a blower for sending air into the tank, the fermentation temperature of the organic substance to be treated is increased on the first day. The temperature rises rapidly to 70 ° C or higher until the end of the fermentation treatment.
A compost fermentation treatment method characterized in that the air supply time and the stop time of the blower are controlled so as to maintain 0 ° C. or more, and the air supply to the fermenter and the stop are repeated. 2. The first compartment of an open fermenter having a plurality of compartments and a blower for sending air to each compartment,
When the fermentation temperature of the organic material to be processed rapidly rises to 70 ° C. or more on the first day when the compost fermentation is performed while the organic material to be treated having E. coli is put and gradually moved to the last compartment, the first compartment is used. The air supply time and the stop time of the blower are controlled to repeat the air supply and stop to the first section, and further, from the next section to the last section so that the fermentation temperature is maintained at 60 ° C. or higher until the end date of the fermentation treatment. A compost fermentation treatment method characterized in that the air supply time and the stop time of the blower of each section are controlled until the air supply and stop of each section are repeated. 3. The compost fermentation treatment method according to claim 1, wherein the organic substance to be treated having Escherichia coli is livestock dung.