JP7011811B2 - Fermented pellet manufacturing method - Google Patents

Description

The present invention relates to a method for producing fermented pellets using sewage sludge residue pellets. In particular, the present invention relates to a method for producing fermented pellets (functional compost) from a low molecular weight treated sewage sludge residue produced in a factory or facility having a process for reducing the molecular weight of the sewage sludge residue.

The amount of sewage sludge generated in Japan is gradually increasing with the spread of sewage, and according to the data of the Ministry of the Environment in 2008, the amount is 2.21 million tons / year on a dry weight basis. It is said that the amount of sewage sludge generated accounts for about 20% of the total industrial waste, and most of it is disposed of in landfills after burning. There is a need to reduce running costs. However, since the amount of sewage sludge generated is increasing year by year, it is difficult to secure landfills and waste treatment plants.

In recent years, recycling of sewage sludge residue has been promoted, and the dehydrated sewage sludge residue is used as a biomass resource such as fertilizer and fuel.
As an example, the Ministry of Land, Infrastructure, Transport and Tourism is also implementing the B-DASH project (sewerage innovative technology demonstration project), and is focusing on solving these problems.

The characteristics of biomass resources of sewage sludge residue are (1) that a certain amount is always generated according to the living environment of human beings, (2) that the components and conditions are constant, and (3) fuel, fertilizer, and cement raw materials. It is known that it can be used for such purposes. Taking advantage of this feature, the practical research for practical use of the sewage sludge treatment system developed by Mitsubishi Nagasaki Kiko Co., Ltd., which is one of the B-DASH projects of the Ministry of Land, Infrastructure, Transport and Tourism in 2012, is the eastern Nagasaki sewage treatment plant. It was carried out in. This system is a new sludge weight reduction technology that combines hydrothermal reaction technology and high-speed methane fermentation technology, and this system is called Metasaurus (see Patent Documents 1 and 2). With this system, the amount of sludge discharged has been reduced to one-fifth of that of the existing system, and it has become possible to significantly reduce the disposal cost when disposing of it. However, although the amount of dehydrated sludge generated has been significantly reduced, it is mainly disposed of.

Therefore, from the viewpoint of zero emissions in the area including the sewage treatment plant, an effective utilization method of the sewage sludge residue treated with low molecular weight was examined. Since the low molecular weight treated sewage sludge residue generated in this system contains nitrogen, phosphorus, and potassium components as elements necessary for plant growth, this sewage sludge residue is used as a fertilizer or a soil conditioner. Attempts have been made, and this sewage sludge residue is currently registered as "Higashi Nagasaki Demonstration No. 1" in the fertilizer registered by the Minister of Agriculture, Forestry and Fisheries.

However, this fertilizer has a problem that the water content is high, various germs are present, and the odor of ammonia is strong. In addition, since it is not a completely ripe compost, there is concern that if it is used as it is in the soil, it may cause problems such as growth disorders in the crops.

Japanese Unexamined Patent Publication No. 2012-200691 Japanese Unexamined Patent Publication No. 2012-0200692

An object of the present invention is to produce fermented pellets that can be used as compost without the above-mentioned problems in a short period of time.

In order to solve these various problems, the present inventors have been studying the improvement of the fertilizer, and have added two types of cells having different temperature active regions, such as Bacillus bacterium and lactic acid bacterium, to the inside and the surface layer of the sewage sludge residue pellet. It was found that useful fermented pellets without the above-mentioned problems can be produced by carrying each of them and fermenting the sewage sludge residue pellets carrying the bacteria. (PCT / JP2017 / 27662).

Following this, as a result of further research by the present inventors, the sewage sludge residue pellets were treated with ozone before being carried with Bacillus and lactic acid bacteria, as compared with the case where the sewage sludge residue pellets were not treated with ozone. It has been found that fermented pellets that are equally or more useful can be produced in a short period of time. That is, they have found that the fermentation period of the sewage sludge residue pellets carrying bacteria can be shortened by carrying Bacillus bacteria and lactic acid bacteria on the ozone-treated sewage sludge residue pellets, and have completed the present invention.

That is, the present invention is as follows.
[1] A method for producing fermented pellets in which Bacillus bacteria are carried inside the sewage sludge residue pellets and the sewage sludge residue pellets carrying the bacteria are fermented by carrying lactic acid bacteria on the surface layer. , A method for producing fermented pellets, which comprises carrying bacteria on sewage sludge residue pellets treated with ozone by a liquid or gas containing ozone.
[2] Bacterial-supported sewage sludge residue pellets are prepared by adding Bacillus bacteria to ozone-treated sewage sludge residue pellets, drying the surface layer of the pellets, and then adding lactic acid bacteria [1]. The method for producing fermented pellets according to the above.
[3] The method for producing a fermented pellet according to [1] or [2], wherein the sewage sludge residue pellets carrying bacteria are piled up and fermented.

[4] Bacillus bacteria against sewage sludge residue pellets that have undergone an ozone treatment step in which a liquid or gas containing ozone is brought into contact with the sewage sludge residue pellets, a flattening step in which the sewage sludge residue pellets are spread flat, and a flattening step. Addition of lactic acid bacteria to the sewage sludge residue pellets that have undergone the Bacillus addition step, the pellet surface layer drying step for drying the surface layer of the sewage sludge residue pellets that have undergone the Bacillus addition step, and the sewage sludge residue pellets that have undergone the pellet surface layer drying step. It is characterized by having a lactic acid bacterium addition step, a heaping step of stacking bacterium-supported sewage sludge residue pellets that have undergone the lactic acid bacterium addition step, and a fermentation step of fermenting the bacterium-supported sewage sludge residue pellets that have undergone the heaping step [1]. ] To [3] according to any one of the methods for producing fermented pellets.
[5] The method according to [4], wherein the fermentation step includes a turning step for turning back the bacterially-supported sewage sludge residue pellets and a water-adjusting step for adjusting the water content of the bacterial-supported sewage sludge residue pellets. Method for producing fermented pellets.
[6] The method for producing a fermented pellet according to any one of [1] to [5], which comprises fermenting for 7 to 14 days.
[7] The method for producing a fermented pellet according to any one of [1] to [6], wherein the sewage sludge residue pellet is a pellet-processed sewage sludge residue that has been subjected to a low molecular weight treatment.
[8] The method for producing a fermented pellet according to any one of [3] to [7], wherein the central portion excluding the top and bottom of the piled up bacteria-supported sewage sludge residue pellets is covered with a covering material and fermented. ..

[9] The method for producing a fermented pellet according to any one of [1] to [8], wherein the fermented pellet to be produced is compost.
[10] The method for producing a fermentation pellet according to any one of [1] to [9], wherein the ozone treatment is performed using a liquid containing ozone.
[11] The method for producing a fermentation pellet according to [10], wherein the ozone concentration of the ozone-containing liquid used in the ozone treatment is 0.5 to 5.0 ppm.
[12] The method for producing a fermented pellet according to [10] or [11], wherein the amount of the liquid containing ozone with respect to the sewage sludge residue pellet used in the ozone treatment is 0.005 to 0.5 L / kg. ..
[13] A method for fermenting pellets, characterized in that Bacillus bacteria are carried inside pellets treated with ozone by a liquid containing ozone, and bacteria-supported pellets carrying lactic acid bacteria on the surface layer are piled up and fermented.

According to the method for producing fermented pellets of the present invention, fermented pellets that can be used as compost can be produced in a short period of time.

It is a flow chart of one Embodiment of the manufacturing method of the fermented pellet of this invention. It is a schematic diagram explaining the state which ferments by covering the central part of the piled-up sewage sludge residue pellets with a coating material. It is a photograph showing a state in which a small animal was attracted to a fermented pellet (functional compost) produced by the production method of the present invention. It is a graph which shows the ozone concentration and pH with respect to the processing time at the time of preparing a liquid (ozone water) containing ozone using a commercially available ozone generator. It is a figure which shows the electric conductivity of the fermentation pellet produced in Example 1. FIG. It is a figure which shows the nitrate nitrogen concentration of the fermentation pellet produced in Example 1. FIG.

The method for producing the fermented pellet of the present invention is a method of fermenting a sewage sludge residue pellet carrying a bacterium, in which bacillus is carried inside the sewage sludge residue pellet and a lactic acid bacterium is carried on the surface layer, and the sewage sludge is carried by the sewage. The residual pellet is not particularly limited as long as it carries bacteria on the sewage sludge residual pellet treated with ozone by a liquid or gas containing ozone, and the fermented pellet produced by the production method of the present invention is not particularly limited. It can be used as compost. This compost is a ripe compost containing a large amount of fulvic acid and humic acid, and can be used in solid, semi-solid or liquid form, and can also be used as a soil conditioner.

The sewage sludge residue pellet (before carrying Bacillus and lactic acid bacteria) used for producing the fermented pellet of the present invention may be a pellet-shaped sewage sludge residue, for example, one side or a diameter of 5. A rectangular parallelepiped or columnar pellet having a length of about 15 mm and a length of about 20 to 40 mm can be mentioned, and one having a water content of 20% or less is preferable in consideration of transportation to a fermentation site and storage until fermentation treatment. Such pellets may be pelletized from sewage sludge residue that has been subjected to general sewage treatment, but have been subjected to a low molecular weight treatment for reducing the molecular weight of persistent polymers such as lignin and cellulose. It is preferable that the sewage sludge residue is pelletized. In the low molecular weight treatment, various organic resources such as food residues may be added. Examples of such low molecular weight treatment include hydrothermal treatment, ozone treatment, biological activated carbon treatment, ultrasonic treatment (for example, Japanese Patent Application Laid-Open No. 2003-144097), and various treatments may be combined. As a specific method for reducing the molecular weight by hydrothermal treatment, for example, a method using a hydrothermal reaction described in Japanese Patent Application Laid-Open No. 2012-0200691 and Japanese Patent Application Laid-Open No. 2012-0200692 can be mentioned.

The ozone treatment of the sewage sludge residue pellet in the production of the fermented pellet of the present invention is not particularly limited as long as it is a treatment in which a liquid or gas containing ozone is brought into contact with the sewage sludge residue pellet, and the liquid containing ozone in the sewage sludge residue pellet is not particularly limited. A method of immersing the sewage sludge residue pellet in a liquid containing ozone, a method of introducing a gas containing ozone into a container containing the sewage sludge residue pellet, and the like can be exemplified. In such ozone treatment, various bacteria such as Escherichia coli and Salmonella can be sterilized while utilizing the bacteria useful for fermentation contained in the sewage sludge residue pellets, whereby the subsequent fermentation treatment using Bacillus and lactic acid bacteria can be performed. Can be done in a short period of time.

The ozone concentration of the ozone-containing liquid used for ozone treatment is preferably 0.5 to 5.0 ppm, more preferably 0.8 to 4.0 ppm, and more preferably 1.0 to 3.0 ppm. Is even more preferable. When the concentration of the liquid containing ozone is in this range, it is possible to strongly suppress only various bacteria such as Escherichia coli and Salmonella while maintaining the activity of the bacteria useful for fermentation contained in the sewage sludge residue pellets. Further, since the liquid containing ozone having such a low concentration may be used, the production cost of the liquid containing ozone is low, and the total cost of producing fermentation pellets can be reduced.

The amount of the liquid containing ozone with respect to the sewage sludge residue pellet used in the ozone treatment is preferably 0.005 to 0.5 L / kg, more preferably 0.007 to 0.3 L / kg. , 0.008 to 0.1 L / kg, more preferably 0.01 to 0.05 L / kg.

The liquid containing ozone can be obtained by a known method such as a method of bubbling ozone gas into a liquid such as water to dissolve it or an electrolysis method of water, and can be prepared by using a commercially available ozone generator.

The method for preparing the sewage sludge residue pellets carrying bacteria is not particularly limited as long as the Bacillus bacteria can be carried inside the ozone-treated sewage sludge residue pellets and the lactic acid bacteria can be carried on the surface layer. It is preferable to add Bacillus bacteria to the sewage sludge residue pellets, dry the surface layer of the pellets, and then add lactic acid bacteria to prepare the pellets. (S2), a bacillus bacterium addition step (S3), a pellet surface layer portion drying step (S4), and a lactic acid bacterium addition step (S5) can be exemplified.

Further, the method for fermenting the bacteria-supported sewage sludge residue pellets of the present invention is not particularly limited as long as it can ferment the bacteria-supported sewage sludge residue pellets, and is not particularly limited as long as it can ferment the bacteria-supported sewage sludge residue pellets. A method in which sewage sludge residue pellets are piled up and fermented is preferable. The method of stacking and fermenting the sewage sludge residue pellets may be a method of stacking and fermenting fungus-bearing sewage sludge residues, and the stacking form is conical, pyramidal, headed conical, or headed pyramid. Or, a mountain range in which these shapes are extended in a predetermined direction can be mentioned. Specifically, the methods in the pile-up step (S6) and the fermentation step (S7), which will be described later, can be exemplified.

As shown in FIG. 1, the method for producing fermented pellets of the present invention is, for example, a flattening step (S1) of spreading the sewage sludge residue pellets in a plane and an ozone treatment in which a liquid containing ozone is brought into contact with the sewage sludge residue pellets. A sewage sludge addition step (S3) in which Bacillus bacteria are added to a sewage sludge residue pellet that has undergone a step (S2), a flattening step (S1), and an ozone treatment step (S2), and a sewage sludge addition step. A pellet surface layer drying step (S4) for drying the surface layer portion of the residual pellet, a sewage sludge residual pellet drying step (S4), and a lactic acid bacterium addition step (S5) for adding lactic acid bacteria to the sewage sludge residual pellet, and a lactic acid bacterium addition step. It has a pile step (S6) for stacking sewage sludge residue pellets that have passed through (S5) and a fermentation step (S7) for fermenting the sewage sludge residue pellets that have passed through the pile step (S6), and other steps. May have. Further, the fermentation step (S7) preferably includes a turning step (S71) and a water content adjusting step during fermentation (S72). The order of the flattening step (S1) and the ozone treatment step (S2) does not matter.

The flattening step (S1) is a step of spreading the sewage sludge residue pellets in a plane, as long as the pellets are uniformly spread, and the pellets may be partially overlapped. By this flattening step, it becomes possible to attach the added Bacillus bacterium to the whole, and it is possible to suppress a rapid temperature rise due to the metabolism of the Bacillus bacterium. Further, when ozone treatment is performed after the flattening step, a liquid containing ozone can be brought into contact with the entire sewage sludge residue pellet.

The ozone treatment step (S2) is, for example, a step of bringing a liquid containing ozone into contact with the sewage sludge residue pellets, and spraying the liquid containing ozone on the sewage sludge residue pellets spread out in a plane. Before spraying the liquid containing ozone, it is preferable to add water to the sewage sludge residue pellets spread flat in advance to adjust the water content. As a result, the liquid containing ozone can be permeated into the pellet. For example, the water content of the sewage sludge residue pellet is adjusted to be preferably about 20 to 60% by mass, more preferably 25 to 50% by mass, and further preferably about 30 to 50% by mass. By this ozone treatment, it is possible to sterilize various germs such as Escherichia coli and Salmonella in a state where the germs useful for fermentation existing in the sewage sludge residue pellets are kept alive, and the fermentation step (S7) can be shortened. ..

In this ozone treatment step, a part or all of the treatment may be performed before the flattening step. That is, the sewage sludge residue pellets may be ozone-treated before being spread flat, and the ozone-treated pellets may be spread flat.

The Bacillus bacterium addition step (S3) is a step of adding the Bacillus bacterium to the sewage sludge residue pellet that has undergone the flattening step and the ozone treatment step, and the bacillus bacterium is dissolved in a predetermined amount of water in the entire pellet. It is preferable to add them uniformly. As described above, when the sewage sludge residue pellets are spread in a plane, it becomes easy to attach Bacillus bacteria to the whole.

It is preferable to adjust the water content of the sewage sludge residue pellets before the step of adding Bacillus bacteria. Specifically, the water content of the sewage sludge residue pellet after the addition of Bacillus bacteria is adjusted to be preferably 25 to 70% by mass, more preferably 30 to 60% by mass, and further preferably 40 to 60% by mass. It is preferable to keep it. By this step, the pellet can be swollen, the cells can be infiltrated into the pellets, and the activity of the cells can be enhanced.

Examples of the Bacillus bacterium added in the method of the present invention include Bacillus subtilis, Bacillus tequilensis, Bacillus vallismortis, Bacillus mojavensis, Bacillus amyloliquefaciens, Bacillus subtilis subsp. Subtilis, Bacillus subtilis subsp. . Natto can be mentioned, and among these, Bacillus subtilis var. Natto (natto fungus) is preferable. These Bacillus bacteria can be used alone or in combination of two or more. The method for obtaining Bacillus is not particularly limited, and a commercially available product can be used. Further, for example, the food itself containing Bacillus such as natto, or the Bacillus isolated from the food itself may be used.

The subsequent step of drying the surface layer portion of the pellet (S4) is a step of drying the surface layer portion of the sewage sludge residue pellet, and is a step of supporting the Bacillus bacteria inside the pellet by drying the surface layer portion of the pellet. In this pellet surface layer drying step, for example, natural drying is performed for 12 to 48 hours after the addition of Bacillus bacteria, but if necessary, the pellet group may be dried while stirring. In addition, when it is dried as it is on a flat surface, the upper layer part and the lower layer part of the pellet group do not become a uniform dry state, but at least a part of the surface layer part of the pellet group becomes dry at least in the upper layer part of the pellet group. To dry.

The lactic acid bacterium addition step (S5) is a step of adding lactic acid bacteria to the sewage sludge residue pellets whose surface layer is dried, and lactic acid bacteria are added to the pellets spread flat from above, and lactic acid bacteria are added to the pellet surface layer. It is a step of carrying. Examples of the lactic acid bacteria to be added include Lactobacillus, Bifidobacterium, Lactococcus, Enterococcus, Streptococcus, and Pediococcus. Lactococci of the genus Leuconostoc can be mentioned. These lactic acid bacteria can be used alone or in combination of two or more. The method for obtaining lactic acid bacteria is not particularly limited, and a commercially available product can be used. Further, for example, the food itself containing lactic acid bacteria such as yogurt or the lactic acid bacteria isolated from the food itself may be used.

The addition of lactic acid bacteria is performed on at least the sewage sludge residue pellets in a flatly spread state, but by performing the addition again on the sewage sludge residue pellets in a piled state in the next step, the whole pellets can be added. It is possible to add lactic acid bacteria to the sewage.

Bacillus bacteria are added to the sewage sludge residue pellet as a raw material, the surface layer of the pellet is dried, and then lactic acid bacteria are added to support the Bacillus bacteria inside the pellet and to support the lactic acid bacteria on the surface layer. It is possible to form a two-layer structure of two types of bacteria on the pellet. By using two types of cells with different temperature active regions, each cell is mutually activated, so no physical heating device is required, and the fermentation temperature of 60 ° C to 70 ° C can be achieved only by natural fermentation. Can be sustained.

The piling step (S6) is a step of piling up sewage sludge residue pellets, for example, it is preferably performed within 1 hour, more preferably within 30 minutes after the addition of lactic acid bacteria is completed. In this step, for example, it is preferable to form a mountain so as to wrap the planar pellet group from the outside, it is desirable to form a mountain as high as possible, and it is particularly preferable to pile the pellets at a rest angle. In addition, it is preferable to stack pellets in a mountain range (extended in a predetermined direction) for fermentation because a large amount of fungus-supported sewage sludge residue pellets can be efficiently fermented.

The fermentation step (S7) is a step of fermenting a pile of sewage sludge residue pellets, and if necessary, turning back (cutting back step: S71) and adjusting the water content (water content adjusting step during fermentation: S72) are performed. That is, when the fermentation temperature of the pellet group drops, it is cut back and the water content is adjusted to supply oxygen and average the bacterial cell distribution, and to maintain uniform fermentation and growth of useful microorganisms. Make it possible. Further, by this cutting back, the surface layer portion of the pellet becomes powdery and separated from the pellet main body, and becomes a mixture of the pellet and powder in the form of a mass. In the method for producing the fermentation pellet of the present invention, since the ozone-treated sewage sludge residue pellet is used, various germs contained in the sewage sludge residue pellet are sterilized and bacteria useful for fermentation are kept alive. Therefore, the fermentation process proceeds in a short period of time. In addition, the required turning back can be reduced, and for example, the fermented pellet of the present invention can be produced by turning back once or twice and adjusting the water content.

In the present invention, since fermentation proceeds in a piled state, a high temperature region is formed for a long time by microorganisms from the center to the apex of the piled pellet group, so that useful microorganisms including Bacillus and lactic acid bacteria inside are used. Increases activity. In addition, regions having different temperature differences are formed in the outer surface layer portion and the deep layer portion, and active regions of bacterial cells having different temperature regions can be formed. For example, filamentous fungi grow in a layer 5 to 10 cm deep from the surface, lactic acid bacteria and oxidizing bacteria grow inside, and Bacillus fungi grow in the deep layer. The temperature near the surface layer is maintained in the temperature range of about 30 to 45 ° C., and the temperature of the deep layer portion is maintained in the temperature range of about 60 to 70 ° C.

In the fermentation process, it is considered that the following actions occur in the piled pellet group, which enables the production of useful fermentation pellets (functional compost) at high speed only by natural fermentation. Will be.
First, when looking at the activity of Bacillus and lactic acid bacteria carried on the sewage sludge residue pellets, since the active temperature range of lactic acid bacteria is lower than that of Bacillus, it becomes an accelerator for pellet fermentation and reaches the activity temperature range of Bacillus. Raise the temperature. That is, first, lactic acid bacteria in the active temperature range of 15 to 42 ° C. decompose monosaccharides, which are water-soluble components, on the surface layer of the pellet unit, and raise the temperature of the pellet unit by the heat of metabolism generated in the decomposition process. Furthermore, since lactic acid bacteria produce a large amount of lactic acid and antibiotics by metabolism, they acidify the environment around the surface of the pellet alone, keep other microorganisms that are not resistant to acid away, and eliminate microorganisms such as germs with antibiotics. .. The activation of lactic acid bacteria on the surface layer of the pellet unit gradually raises the temperature of the pellet unit, and the Bacillus bacteria (active temperature range 20 to 65 ° C) that are active in the high temperature range existing inside the pellet unit gradually become active. start.

Bacillus decomposes organic matter inside the pellet itself and converts it into monosaccharides, and the monosaccharides are used again by the metabolism of lactic acid bacteria in the surface layer. The heat of metabolism generated by the simultaneous decomposition of the organic matter of the pellets by a large number of these microorganisms raises the temperature of the deep layer of the piled pellet group to 60 to 70 ° C. in a narrow range. By raising the temperature of the deep layer of the piled pellet group to 60 to 70 ° C., it becomes possible to kill pathogens and germs having poor heat resistance. Furthermore, when the temperature of the deep part of the pile of pellets reaches the lactic acid bacterium killing temperature, the lactic acid bacterium is killed, but the killed lactic acid bacterium is used for the metabolism of the bacillus bacterium, so that the lactic acid bacterium can be stably grown. Furthermore, it becomes possible to add metabolic by-products such as lactic acid of lactic acid bacteria to a single pellet. However, since the temperature at which lactic acid bacteria are killed is not reached in the outer surface layer of the pile-shaped pellet group, a large number of microorganisms including lactic acid bacteria and oxidizing bacteria are present as compared with the deep layer. As described above, by using lactic acid bacteria and Bacillus bacteria in the fermentation process of the present invention, it is possible to efficiently perform natural fermentation without the need for a heating device.

On the other hand, when looking at the entire pile of pellets, in the initial stage of piles, a large amount of filamentous fungi propagate, and a high-density layer of filamentous fungi with a thickness of 5 to 10 cm is formed on the outer surface layer of the pile of pellets. After being produced, filamentous fungi begin to propagate throughout, and at the same time, the growth of Bacillus fungi and the metabolic activity of other oxidizing bacteria increase as the internal temperature rises. In the side surface layer of the pile-shaped pellet group, a temperature difference in a low temperature range of 30 to 45 ° C. is generated. Due to this difference in temperature, the activity of filamentous fungi that are active in the low temperature region becomes active in the surface layer of the pile of pellets, and inside it, it becomes the active region of the mixture of lactic acid bacteria, oxidizing bacteria and Bacillus, and the deep part. In, Bacillus bacteria, which are active in the high temperature range, are actively active.

In the deep part of the pile of pellets, aerobic fermentation is performed by useful microorganisms, and sugars, proteins, hemicellulose and cellulose are decomposed and mineralized into water, carbon dioxide and ammonia, but some of them are microorganisms. Remains as a metabolite of. Some of the generated water vapor is released from the top, but part of it is not released from the side surface due to the high-density layer of filamentous fungi on the surface of the pile of pellets, but from the top. Water vapor containing metabolites that have not been produced naturally convect inside the piled pellets. In the process of natural convection, the metabolite is polymerized to produce a persistent compound, and the persistent residue such as lignin and tannin contained in the pellet reacts with the polymer of the metabolite to produce humic acid (fulvic acid or fulvic acid). Fulvic acid) is produced. In addition, a part of the water vapor of the complexed metabolite is released from the top of the pile-shaped pellet group, so that the inside of the pile is depressurized, and the decompression causes air to be taken in from the gaps in the side surface layer. , Promotes aerobic fermentation of useful microorganisms inside the pile of pellets, and further causes a polymerization reaction.

In the method for producing fermented pellets of the present invention, it is preferable to cover the central portion excluding the top and bottom of the piled pellets with a covering material for fermentation (see FIG. 2). Examples of the covering material include a sheet, a head-mounted conical formwork, and the like, and it is preferable that the covering material is made of a material that blocks ultraviolet rays.

By covering with a covering material and fermenting, the pile-shaped pellet group is kept warm, the internal temperature rises and fermentation is promoted, and the fermentation of the pile-shaped pellet group proceeds more uniformly. That is, due to the heat retaining effect of this covering material, the temperature of the central lower part (deep layer part) of the pile-shaped pellet group where fermentation is difficult to proceed rises and fermentation is promoted, whereby water vapor containing ammonia generated by fermentation and the like are released. As it is released from the top of the mountain, outside air is introduced from the side surface of the bottom of the mountain. Furthermore, the introduction of outside air creates a virtuous cycle in which the activities of oxidizing bacteria and the like become active and the fermentation inside is further promoted. In addition, the coating material prevents the diffusion of water vapor containing ammonia generated by fermentation to the outside, increases the content of water vapor containing ammonia contained in the produced fermentation pellets, and causes ammonia by the activated bacteria. Can be efficiently digested to increase the content of nitrate nitrogen inside the fermented pellets, so that the fermenting effect of the fermented pellets (functional compost) can be enhanced. In addition, the covering material can prevent ultraviolet rays and prevent the death of useful bacteria (filamentous bacteria and the like inhabiting the surface) during fermentation.

Further, in the method for producing fermented pellets of the present invention, air may be introduced from the lower center to the upper side of the pile-shaped pellet group. This makes it possible to promote fermentation in the lower center (deep layer) of the pile-shaped pellet group in which fermentation is difficult to proceed. The amount of air introduced from the lower center of the pile-shaped pellet group may be increased, and the amount of air introduced around the pile-shaped pellet group may be reduced to introduce air from the entire lower part of the pile-shaped pellet group.

In the method for producing fermented pellets of the present invention, it can be used as compost equivalent to ripe compost within 7 to 14 days from the start of fermentation. Compared with the fact that the fermentation period in the conventional production of compost and bokeh fertilizer requires 1 to 2 months in a temperature range of 60 to 65 ° C., it can be seen that the fermentation by the method of the present invention proceeds at a high speed. In addition, it can be seen that the conventional fermentation period using sewage sludge residue pellets not subjected to ozone treatment requires 14 to 20 days from the start of fermentation, which is even faster than this.

The fermented pellet (functional compost) produced by the production method of the present invention contains 2 to 3 times or more of fulvic acid and humic acid as compared with the raw material sewage sludge residue pellet. Fulvic acid and humic acid are valuable resources that are produced only in trace amounts in nature, and are substances that are said to take about 100 years to form 1 cm deposits in nature. The production method of the present invention is characterized in that fulvic acid and humic acid, which require a long time to be produced, can be produced in an extremely short period of time.

In addition, the fermented pellets produced by the production method of the present invention have the effect of attracting small animals such as effective nematodes and white mites that are effective for soil improvement (see FIG. 3), and further propagate actinomycetes in the soil. effective. Further, when a plant is grown using the fermented pellet produced by the production method of the present invention, a phenomenon that the root of the plant has invaded into the fermented pellet can be seen. The attraction of nematodes and the introduction of roots are recognized by animals and plants as high-quality natural soil, and are proof that they are close to extremely high-quality natural soil. be.

Such improvement of biota by the fermented pellets produced by the production method of the present invention greatly improves the physicochemical properties in soil. Improving the soil environment also affects the promotion of plant growth, quality improvement, disease resistance, etc. Therefore, by effectively utilizing the fertilizer pellets produced by the production method of the present invention, the quality and yield of crops can be improved. It is possible to improve stability by unifying fertilizers, improve convenience by unifying fertilizers, and stabilize management by establishing a low-cost production system. Furthermore, it will lead to the establishment of sound-cycle agriculture and enable sustainable agriculture.

In addition, the produced fermented pellets (functional compost) are composed of two types: powdered compost decomposed by metabolism of useful microorganisms and pellet-shaped compost containing a large amount of undecomposed parts, and these are used for various purposes. Depending on the situation, they may be mixed and used, or they may be separated and used separately.

The functional compost, which is a mixture of powder and pellets produced by the production method of the present invention, is easily decomposed by soil microorganisms when used as a fertilizer for cultivated plants in agriculture and forestry, and expresses available nitrogen. The fast powdery substance exerts a great effect on the initial growth of plants, and then the pellet-like substance containing a large amount of unsupplied nitrogen is decomposed by soil microorganisms and the available nitrogen is expressed for a long period of time, so that it is stable. It is effective for plant growth.

Another invention of the present invention is a fermentation method in which Bacillus bacteria are carried inside the ozone-treated pellets and the bacteria-supported pellets carrying lactic acid bacteria on the surface layer are piled up and fermented. The details of the fermentation method are as described above. Examples of the pellets used in the present invention include the above-mentioned sewage sludge residue pellets and other organic material pellets (livestock manure pellets, wood pellets). According to the fermentation method of the present invention, fermentation can be performed in a shorter period than natural fermentation.

Hereinafter, the present invention will be specifically described with reference to Examples, but the scope of the present invention is not limited thereto.

[Preparation of ozone water]
5 liters of purified water was put into an 8 liter bottle, and ozone water was prepared using an ozone generator (ozone buster (underwater type): manufactured by Earthwalker Trading Co., Ltd.). The ozone concentration was measured every 5 minutes from the start to the end of the ozone treatment for 30 minutes. In addition, the pH of the treated water was measured together with the ozone concentration. The results are shown in FIG.

As shown in FIG. 4, it was confirmed that the ozone concentration in the liquid increased with the treatment time in the ozone treatment by the ozone generator. It was confirmed that the relationship between the ozone concentration and time has a positive relationship and can be approximated by "y = 0.099x + 1.0444".

As a result of confirming the decrease in ozone concentration of the generated ozone water having an ozone concentration of 3.5 ppm under the condition of opening to the atmosphere, the ozone concentration decreased by 1 ppm after 5 minutes to 2.5 ppm. Further, it decreased to 2.0 ppm after 10 minutes of standing, and decreased to 1.5 ppm after 20 minutes. Then, as a result of leaving it for 210 minutes, the ozone concentration decreased to 0.5 ppm.

As described above, the ozone water used in the method for producing fermented pellets of the present invention can be produced by using a commercially available small ozone generator. Therefore, since the fermentation period of the fermented pellets can be shortened by ozone treatment, the total cost of producing the fermented pellets can be reduced.

[Example 1]
[Manufacturing of fermented pellets]
As the raw material sewage sludge residue pellets, "Higashi Nagasaki Demonstration No. 1" (fertilizer registered by the Minister of Agriculture, Forestry and Fisheries) consisting of sewage sludge residue treated with low molecular weight was pelletized into a shape with a diameter of about 10 mm and a length of about 25 mm. I used the one.

First, about 2000 kg of sewage sludge residue pellets as a raw material was taken out from the flexible container, spread flat, and left for one week.

After being left for 1 week, 100 L of water was poured into the whole from above the sewage sludge residue pellets spread out in a plane, and water was added. After adding water, 20 L of ozone water having an ozone concentration of 2 ppm to 2.5 ppm was further added from above.

Then, the Bacillus bacterium isolated from commercially available natto was dissolved in water, adjusted to 12 L, and charged into the entire sewage sludge residue pellet. Initially, only the upper part was moist, but after about 3 hours, it was moist to the lower part.

After drying the sewage sludge residue pellets to which Bacillus was added for 12 hours, 10 L of water in which 200 mL of lactic acid bacteria (lactic acid bacteria cultured from rice bran) was dissolved was added from above the sewage sludge residue pellets, piled up, and then again. 10 L of water in which 200 mL of lactic acid bacteria was dissolved was sprayed over the whole, and 10 L of water was further sprayed.
At this time, the height and width of the pile were about 65 cm in height and about 100 cm in width.

After fermenting for 3 days, the first rounding was performed, and after stacking, 100 L of water was added.

After further fermenting for 7 days, the pellets were spread flat to complete the fermented pellets (functional compost).

The number of fermentation days is 10 days, and the fermentation treatment can be performed in a shorter period of time as compared with the case where the ozone treatment is not performed (Reference Example 1 described later). In addition, the produced fermented pellets contained a large amount of fulvic acid and humic acid, as in Reference Example 1. In addition, when the maturity was judged based on the putrefaction evaluation criteria, the water content was 40% or less, the hue was whitened by actinomycetes, the shape was disintegrated by microbial decomposition, there was almost no ammonia odor, and EC. Since the value of was also 4 mS / cm or less (see FIG. 5), it was also confirmed that the product was fully matured. Furthermore, it was also confirmed that the concentration of nitrate nitrogen was higher than that of the previous one because the emission of excess nitrogen was suppressed by shortening the fermentation process (see FIG. 6). That is, according to the method of the present invention, it is possible to produce a compost having a high fertilizing effect containing a large amount of nitrate nitrogen.

[Reference Example 1]

Fermentation pellets were produced in the same manner as in Example 1 except that ozone treatment was not performed. Specifically, fermented pellets were produced by the method shown below.

As the raw material sewage sludge residue pellets, "Higashi Nagasaki Demonstration No. 1" (fertilizer registered by the Minister of Agriculture, Forestry and Fisheries) consisting of sewage sludge residue treated with low molecular weight was pelletized into a shape with a diameter of about 10 mm and a length of about 25 mm. I used the one.

First, about 1000 kg of sewage sludge residue pellets as a raw material was taken out from the flexible container, spread flat, and left for one week.

170 L of water was poured into the whole from above the sewage sludge residue pellets spread flat after being left for 1 week, and water was added. Then, the Bacillus bacterium isolated from commercially available natto was dissolved in water, adjusted to 30 L, and charged into the entire sewage sludge residue pellet.

After drying the sewage sludge residue pellets to which Bacillus was added for 12 hours, 10 L of water in which 200 mL of lactic acid bacteria (lactic acid bacteria cultured from rice bran) was dissolved was added from above the sewage sludge residue pellets, piled up, and then again. 10 L of water in which 200 mL of lactic acid bacteria was dissolved was sprayed over the whole, and 10 L of water was further sprayed.
At this time, the height and width of the pile were about 65 cm in height and about 100 cm in width.

After fermenting for 1 week, the first rounding was performed, and after stacking, 100 L of water was added.

After further fermenting for 5 days, the second rounding was performed, and after stacking, 100 L of water was added and further fermented for 8 days to produce fermented pellets (functional compost).

[Evaluation of functional compost manufactured in Reference Example 1]
The functional compost produced in Reference Example 1 and the sewage sludge residue pellets used as raw materials (Reference Comparative Example 1) were subjected to component analysis at a third-party organization. For the analysis of fulvic acid and humic acid, the method of the International Humus Society was used. For the analysis of the cation exchange capacity, the fertilizer analysis method 5.31.2 was used. For the analysis of nitrate nitrogen and nitrite nitrogen, fertilizer analysis method 7.6 was used. For the analysis of carbon-nitrogen ratio, the fertilizer analysis method was used.
The results are shown in Table 1 below.

As shown in Table 1, in the functional compost of Reference Example 1, fulvic acid was about 3 times and humic acid was about 2 times that of Reference Comparative Example 1. That is, it was clarified that by using the treatment method of Reference Example 1, the sewage sludge residue pellet, which is a raw material, is humified in a very short period of time.

Since the present invention can produce a very useful functional compost, it has high industrial usefulness.

Claims (13)

It is a method for producing a fermentation pellet by fermenting a sewage sludge residue pellet carrying a bacterium-supported sewage sludge residue pellet having bacillus-supported bacteria on the inside of the sewage sludge residue pellet and a lactic acid bacterium on the surface layer.
A method for producing a fermentation pellet, wherein the sewage sludge residue pellet carrying bacteria is a sewage sludge residue pellet treated with ozone by a liquid or gas containing ozone and carrying bacteria. The fermentation according to claim 1, wherein the sewage sludge residue pellets carrying bacteria are prepared by adding Bacillus bacteria to the ozone-treated sewage sludge residue pellets, drying the surface layer of the pellets, and then adding lactic acid bacteria. How to make pellets. The method for producing a fermented pellet according to claim 1 or 2, wherein the sewage sludge residue pellets carrying bacteria are piled up and fermented. An ozone treatment process in which a liquid or gas containing ozone is brought into contact with the sewage sludge residue pellets.
Flattening process to spread sewage sludge residue pellets in a plane,
A process of adding Bacillus bacteria to the pellets of sewage sludge residue that has undergone a flattening process, and a process of adding Bacillus bacteria.
A pellet surface layer drying step for drying the surface layer of sewage sludge residue pellets that have undergone the Bacillus bacterium addition step, and a pellet surface drying step.
A lactic acid bacterium addition step of adding lactic acid bacteria to the sewage sludge residue pellets that have undergone the pellet surface layer drying step,
A pile-up process for stacking bacterial-supported sewage sludge residue pellets that have undergone the lactic acid bacteria addition process,
Fermentation process to ferment the fungus-supported sewage sludge residue pellets that have undergone a pile process,
The method for producing a fermented pellet according to any one of claims 1 to 3, wherein the fermented pellet is produced. The fermentation process is
A turning process for turning back the sewage sludge residue pellets carrying bacteria, and
Moisture adjustment step to adjust the moisture content of fungus-supported sewage sludge residue pellets,
4. The method for producing a fermented pellet according to claim 4. The method for producing a fermented pellet according to any one of claims 1 to 5, which comprises fermenting for 7 to 14 days. The method for producing a fermented pellet according to any one of claims 1 to 6, wherein the sewage sludge residue pellet is a pellet-processed sewage sludge residue that has been subjected to a low molecular weight treatment. The method for producing a fermented pellet according to any one of claims 3 to 7, wherein the central portion excluding the top and bottom of the piled up fungus-supported sewage sludge residue pellets is covered with a covering material and fermented. The method for producing a fermented pellet according to any one of claims 1 to 8, wherein the fermented pellet to be produced is compost. The method for producing a fermented pellet according to any one of claims 1 to 9, wherein the ozone treatment is performed using a liquid containing ozone. The method for producing a fermentation pellet according to claim 10, wherein the ozone concentration of the liquid containing ozone used in the ozone treatment is 0.5 to 5.0 ppm. The method for producing a fermented pellet according to claim 10 or 11, wherein the amount of the liquid containing ozone with respect to the sewage sludge residue pellet used in the ozone treatment is 0.005 to 0.5 L / kg. Fermentation of organic material pellets characterized in that bacillus-supported organic material pellets carrying Bacillus bacteria on the inside of organic material pellets treated with ozone by a liquid containing ozone and lactic acid bacteria on the surface layer are piled up and fermented. Method.

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