JP2023067396A - Compost production method, production method of spray liquid, and spray liquid - Google Patents

Abstract

To provide a compost production method capable of producing, from a raw material containing an organic substance, a compost low in an ammonia nitrogen content and high in fertilization value.SOLUTION: A compost production method for producing a compost from a raw material containing an organic substance comprises the steps of: immersing an iron source and a carbon material into an aqueous solution containing sodium chloride and water, standing the mixture still, and obtaining a liquid part to be made a spray liquid; spraying the spray liquid to the raw material containing an organic substance while stirring the raw material; piling the sprayed raw material and standing the same still; and spraying the spray liquid while stirring the raw material after standing still, piling the same again, and standing the same still to obtain the compost. The content of ammonium nitrogen in the compost is less than 100 mg/kg.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a compost manufacturing method, a spray liquid manufacturing method, and a spray liquid.

BACKGROUND ART A compost manufacturing method is known in which raw materials containing organic matter such as livestock manure, garbage, and sewage sludge are fermented to manufacture compost. Conventionally, in such a compost production method, malodor generated during fermentation sometimes poses a problem, and various measures have been taken to prevent malodor.

As such a odor prevention technology, Patent Document 1 discloses that ``Ferrous sulfate and quicklime are mixed at 10 to 50% by weight with respect to the water content in manure of pigs, cows, chickens, or the like, which contains a large amount of water. A method for producing a fertilizer characterized by

JP-A-55-100289

In general, when compost is produced using raw materials containing raw organic matter, ammonium nitrogen often remains in the resulting compost. According to the technique described in Patent Document 1, ammonia is supposed to be fixed as ammonium sulfate, but after all, it exists in the form of ammonia.

Ammonia nitrogen is sometimes used as a fast-acting fertilizer, but it is known to cause disease, growth failure, etc. to plants when present in the soil more than necessary. Therefore, it is preferable that the compost does not contain ammonium nitrogen.
On the other hand, when ammonium nitrogen is removed to produce compost, the nitrogen content in the compost is insufficient, and the compost tends to be of low fertilizer value.

Therefore, an object of the present invention is to provide a method for producing compost that can produce compost having a low ammonia nitrogen content and high fertilizer value from raw materials containing organic matter. Another object of the present invention is to provide a method for producing a spray liquid and a spray liquid.

As a result of intensive studies aimed at achieving the above object, the inventors of the present invention have found that the above object can be achieved with the following configuration.

[1] A compost production method for producing compost from a raw material containing organic matter, comprising immersing an iron source and a carbon material in an aqueous solution containing sodium chloride and water and leaving the liquid part a step of obtaining and making a spray liquid; a step of spraying the spray liquid onto the raw material while stirring the raw material containing an organic matter; a step of depositing the sprayed raw material and allowing it to stand still; and a step of spraying the spray liquid while stirring the raw material of, depositing again, and allowing to stand to obtain compost, wherein the content of ammonium nitrogen in the compost is less than 100 mg/kg. Method.
[2] The method for producing compost according to [1], wherein the carbon material is at least one selected from the group consisting of coal, charcoal, coke, graphite, dust, carbon black, peat, and peat.
[3] The method for producing compost according to [1] or [2], further comprising a step of diluting the spray solution.
[4] The method for producing compost according to any one of [1] to [3], further comprising adding a chelating agent to the spray solution.
[5] The method for producing compost according to [4], wherein the chelating agent is at least one selected from the group consisting of pyroligneous acid, bamboo vinegar, and unrefined sake.
[6] The compost manufacturing method according to any one of [1] to [5], wherein the spray solution is prepared in a closed container.
[7] The method for producing compost according to any one of [1] to [6], wherein the organic matter includes manure of livestock.
[8] The method for producing compost according to any one of [1] to [7], wherein the content of nitrate nitrogen in the compost is 1000 mg/kg or more.
[9] A method for producing a spray solution used for producing compost by spraying raw materials containing organic matter, wherein an iron source and a carbon material are immersed in an aqueous solution containing sodium chloride and water to stand still. A method for producing a spray liquid, comprising the steps of: placing a liquid portion on the surface of the liquid and obtaining a liquid portion; and adding a chelating agent to the obtained liquid to obtain a spray liquid.
[10] A spray liquid containing iron (II) ions, sodium ions, and a chelating agent, which is used for producing compost by spraying raw materials containing organic matter.

ADVANTAGE OF THE INVENTION According to this invention, the content of ammonium nitrogen is low, and the manufacturing method of the compost which can manufacture the compost with high fertilizer value from the raw material containing organic matter can be provided. Further, according to the present invention, a method for producing a spray liquid and a spray liquid can also be provided.

1 is a flow diagram of an embodiment of a method for producing compost of the present invention; FIG.

The present invention will be described in detail below.
Although the description of the constituent elements described below may be made based on representative embodiments of the present invention, the present invention is not limited to such embodiments.
In this specification, a numerical range represented by "-" means a range including the numerical values before and after "-" as lower and upper limits.

[Method for producing compost]
An embodiment of the compost manufacturing method of the present invention will be described with reference to the drawings. FIG. 1 is a flow diagram of an embodiment of the compost manufacturing method of the present invention.

First, in step S10, the iron source and the carbon material are immersed in an aqueous solution containing sodium chloride (NaCl) and water and allowed to stand, and the liquid portion is obtained as a spray liquid.

Although the mechanism by which the effect of the present invention is obtained by spraying the above spray liquid onto the raw material and depositing it is not necessarily clear, the present inventors presume as follows. In addition, since the following mechanisms are speculations, the present invention is not limited to those in which effects can be obtained by the following mechanisms.

First, when the iron source and the carbon material are immersed in an aqueous solution containing sodium chloride (hereinafter simply referred to as "aqueous solution") and allowed to stand, the liquid portion gradually turns pale green. From this, it is presumed that iron (II) ions are eluted in the liquid portion.
In the natural world, iron (II) ions are considered to exist by forming a chelate compound "iron fulvic acid" with "fulvic acid" which is an organic acid component in soil and water. Iron fulvic acid is easily taken up by plants and has been considered to be one of the components necessary for plant growth.

On the other hand, regarding the use of iron (II) ions in the process of producing compost, iron (II) sulfate and the like have been conventionally used to prevent offensive odors, which is a problem in the production of compost, as in the technique described in Patent Document 1. It was sometimes used as
However, the present inventors have found that when iron (II) sulfate is used as a deodorizing agent to produce compost, the content of sulfur atom (S)-containing compounds in the resulting compost may increase more than necessary. are doing. When such compost is applied, it often causes root growth failure called "root scorch" in plants.

Therefore, in view of the usefulness of iron (II) ions, the present inventors have earnestly studied methods of using iron (II) ions without using iron (II) sulfate. As a result, the inventors conceived that the above-mentioned spray liquid can utilize iron (II) ions without increasing the content of sulfur atom (S)-containing compounds in the resulting compost, and conducted a demonstration experiment.

As a result, it was surprisingly found that the content of ammonium nitrogen in the compost obtained was remarkably reduced by using the spray solution. Initially, it was believed that the decrease in the ammonia nitrogen content was due to the effusion of ammonia by the spray solution. However, as described in Examples described later, when the components of the obtained compost were analyzed, it was found that the compost contained a sufficient amount of nitrate nitrogen instead of ammonium nitrogen. It was.

When ammonium nitrogen is present in the soil in an amount that does not match the fertilizer-retaining capacity, absorption of other cations (mineral components) into the plant is hindered, which may cause disease and physiological disorders. On the other hand, nitrate nitrogen is one of the components necessary for plant growth. It becomes compost.

As described above, the content of ammonium nitrogen in the compost was reduced, while the content of nitrate nitrogen was increased, and in addition, the period required for producing compost was shortened. By using the spray liquid, the microorganisms (nitrifying bacteria, filamentous fungi, yeasts, lactic acid bacteria, actinomycetes, etc.) that contribute to the production of compost are activated, fermentation proceeds rapidly, and the ammonia state is improved. It was assumed that the nitrogen was converted to nitrate nitrogen.
The above-mentioned effects have not been obtained with iron compounds known simply as deodorants, and have been clarified for the first time through long-term studies by the present inventors.

Next, each component for producing the spray liquid is described in detail.

The iron (Fe) source preferably contains at least one selected from the group consisting of metallic iron and iron oxides. Although the shape of the iron source is not particularly limited, it may be in the shape of a block (plate-like, rod-like, etc.), granular, or powdery.

It is presumed that pale green iron (II) ions are eluted from the iron source when the iron source and the carbon material, which will be described later, come into contact with each other in the aqueous solution.
From this point of view, the iron source and the carbon material are preferably kept in contact with each other in the aqueous solution, and the shape of the iron source is preferably selected according to the shape of the carbon material. For example, if the carbon material is in the form of a block, it is preferable to form the iron source into a block as well, and fix the two in contact with each other (for example, by bundling them with a string).

If the carbon material is powdery or granular, the iron source may be powdery or granular, and both of them may be solidified with a water-soluble binder (for example, starch paste, etc.) and granulated for use.

The content of the iron source in the aqueous solution is not particularly limited, but is preferably 1 to 50 kg, more preferably 10 to 15 kg with respect to 1000 L of water, in that more excellent effects of the present invention can be easily obtained.

A carbon material is a material containing carbon (C) that has a function of eluting iron (II) ions due to a difference in ionization tendency. Examples of such carbon materials include, but are not limited to, coal, charcoal, coke, graphite, dust, carbon black, peat, peat, and the like.

Although the shape of the carbon material is not particularly limited, it may be lumpy, granular, or powdery. As already explained, it may be appropriately selected according to the shape of the iron source.

Although the content of the carbon material in the aqueous solution is not particularly limited, it is preferably 1 to 100 kg, more preferably 15 to 30 kg with respect to 1000 L of water, in that the more excellent effects of the present invention can be easily obtained.

The aqueous solution contains sodium chloride (NaCl), but may contain electrolyte components other than sodium chloride. Examples of such components include magnesium chloride and calcium chloride.

The method for preparing the aqueous solution is not particularly limited, but sodium chloride may be added to a predetermined amount of water. For example, sodium chloride and the like can be included by adding sea salt to the water.

The content of sodium chloride in the aqueous solution is not particularly limited, but is preferably 1 to 30 kg, more preferably 10 to 20 kg, for 1000 L of water. Note that sodium chloride may exist as sodium ions (Na ⁺ ) in the spray solution.

The method for immersing the iron source and the carbon material in the aqueous solution is not particularly limited, but as a specific form, a container contains an aqueous solution containing sodium chloride, and the iron source and the carbon material are placed therein. should be immersed.

When the iron source and the carbon material are immersed in the aqueous solution, it is presumed that the iron (II) ions can be eluted more efficiently by keeping the iron source and the carbon material in contact. From this point of view, a plate-like iron source and a plate-like carbon material are bundled together, or a powdery iron source and a powdery carbon material are collectively solidified and granulated with a water-soluble binder, and then immersed. A method is preferred.

The shape and material of the container used for preparing the spray liquid are not particularly limited, but from the viewpoint of further suppressing oxidation of the generated iron (II) ions, a closed container is preferable. A specific example of the sealed container includes a main body having an opening and a lid for sealing the opening. In this case, the main body and the lid may be made of different materials. For example, the container may have a main body made of FRP (Fiber Reinforced Plastics) and a cover made of a plastic sheet that closes the opening of the main body.

When the sealed container has a container having an opening and a lid made of a flexible sheet for sealing the opening, contact between the aqueous solution and oxygen is achieved by bringing the sheet into contact with the liquid surface of the aqueous solution. is preferable in that it is possible to further suppress the

A predetermined amount of the above materials are mixed and allowed to stand at 10 to 50° C. for 10 days to 3 months, and this liquid portion can be used as a spray liquid.
Oxidation proceeds immediately after the prepared spray solution is taken out of the sealed container. As mentioned above, the iron(II) ions are presumed to promote rapid composting, so it is preferable to use the spray solution immediately after preparation so that the iron(II) ions are less susceptible to oxidation.

The spray liquid may contain other components as long as the effects of the present invention are achieved. Other ingredients include, for example, chelating agents. The chelating agent is not particularly limited, and known chelating agents can be used.

Among them, the chelating agent is preferably a compound having an amino group and a carboxyl group. Iron (II) ions can be chelated and stabilized, just as iron (II) ions are stabilized as iron fulvic acid in the natural world.
When the spray liquid contains a chelating agent, it becomes more difficult to oxidize, and the spray liquid becomes easier to manage.

Although the chelating agent is not particularly limited, at least one selected from the group consisting of pyroligneous acid, bamboo vinegar, and moromi is preferable from the viewpoint of less adverse effects on plants when used as compost.

Although the content of the chelating agent in the spray solution is not particularly limited, it is preferably 0.1 to 10 kg of the chelating agent per 1000 L of water.

Returning to FIG. 1, next, in step S11, the spray liquid is sprayed onto the raw material containing the organic matter while stirring the raw material.

The organic matter is not particularly limited, but specifically, it preferably includes organic waste such as food residue, agricultural processing residue, livestock manure, and sewage sludge. In particular, when the organic matter includes manure of livestock, the value of the obtained compost as a fertilizer tends to be high, and resource-recycling agriculture can easily be realized.

The method of spraying the spray liquid onto the raw material is not particularly limited, but it is preferable to spray the spray liquid onto the raw material while stirring and injecting the spray liquid using an apparatus having a mania spreader with a spray device.

Although the spray liquid may be used as it is, it is preferable to dilute it before use. The dilution ratio is not particularly limited, but when the concentration of sodium chloride in the spray solution is 1 to 30 kg per 1000 L of water, it is preferable to dilute the solution 50 to 100 times.

In the production of the spray solution, if the sodium chloride content in the water is 1 kg/1000 L or more, the time required to produce the spray solution can be shortened. If the concentration becomes high, salt damage may occur.
From such a point of view, by making a 50 to 100-fold difference in concentration between the production of the spray liquid and the use (spraying) of the spray liquid, the production efficiency can be further increased, and The quality of the obtained compost is more likely to improve.

Next, in step S12, the material that has been sprayed with the spray liquid is deposited and allowed to stand still. Although the deposition method is not particularly limited, it is preferable to deposit in the form of ridges with a width of 1 to 3 m and a height of 1 to 2 m.

The period of standing is not particularly limited, but as one form, it is preferably about 20 to 40 days. Also, the temperature at which it is left to stand is not particularly limited, and in one form, 5 to 35°C is preferable.

Next, in step S12, the spray liquid is sprayed while stirring the raw material after standing, and this is deposited again and left standing.
The process of stirring the raw material after standing and depositing it again is generally called "cutting". The kirikaeshi is expected to have the effect of agitating the raw material to contain oxygen and promoting the activity of microorganisms.
Furthermore, in this production method, it is presumed that the composition of the microflora is likely to be more suitable for compost production by spraying the spray liquid even at the time of turning.

The timing of carrying out this step is not particularly limited, and it may be carried out after 20 to 40 days have passed since the start of deposition. Alternatively, it may be performed after confirming that the deposited raw material is in a predetermined state.

The predetermined state is not particularly limited, but includes, for example, a state in which a cross section of the deposited raw material is observed, and substantially concentric striped patterns are observed from the surface toward the center.

The mechanism by which this striped pattern appears is not necessarily clear, but the present inventors speculate that it is due to the contribution of filamentous fungi, yeasts, lactic acid bacteria, actinomycetes, etc. that contribute to the fermentation of compost. That is, since the oxygen concentration differs along the direction from the surface to the center of the deposited raw material, different layers of the microbiota are formed in circles to form a striped pattern. I'm guessing.

In such a state, it is preferable to re-deposit by stirring the surface and the central portion to make the whole uniform. By doing so, the microflora is homogenized and the fermentation proceeds more easily. Furthermore, in this production method, it is expected that the fermentation is further promoted by spraying the spray liquid again at this time.

In the flow of FIG. 1, the compost is completed by turning over only once in step S13, but the turning over is preferably repeated three to four times. That is, it is preferable to repeat the process of spraying the spray liquid while stirring the raw material containing the organic matter and depositing it again 3 to 4 times to finally obtain compost.

According to this production method, even if a raw material containing livestock manure as an organic matter contains a large amount of ammonium nitrogen, it is possible to produce a compost with an incomparably low ammonium nitrogen content compared to conventional compost.
The content of ammonium nitrogen in the resulting compost is less than 100 mg/kg, more preferably less than 50 mg/kg, even more preferably less than 20 mg/kg, and less than 5 mg/kg as measured by ion chromatography. It is particularly preferred to have

Moreover, the compost produced by this production method preferably contains nitrate nitrogen. The content of nitrate nitrogen in the compost is not particularly limited, but is preferably 1000 mg/kg or more, more preferably 2000 mg/kg or more, still more preferably 5000 mg/kg or more, and particularly preferably 10000 mg/kg or more.

EXAMPLES The present invention will be described below with reference to Examples, but the present invention is not limited to these Examples.

First, 15 kg of sea salt was added to 1000 L of water in an FRP container having an opening and stirred to prepare an electrolyte aqueous solution. Next, 15 kg of iron and 20 kg of charcoal were added here. The opening was sealed with a poly sheet and allowed to stand at room temperature for one month to prepare a spray solution.

Next, the prepared spray solution was diluted 100-fold and sprayed while stirring chicken manure. Atomization was performed by a mania spreader equipped with a nebulization device. The sprayed raw material was piled up in a ridge shape of 3 m in width and 1 to 2 m in height, covered with a poly sheet and allowed to stand at room temperature for 1 month.

After standing for one month, confirm that the cross section is layered (3 to 4 layers), spray the spray liquid while stirring with the mania spreader again, stack up in the same manner as above, and leave for one month. bottom. This was repeated three times and finally compost was obtained.

The obtained compost was extracted with pure water, and the composition of ions contained in the extracted water was measured by ion chromatography.
For comparison, a commercially available compost (Reference Example 1) and bark compost (two types) made from garbage were also measured in the same manner. Table 1 is the result.

From the results in Table 1, the poultry manure compost of the example has ammonium nitrogen (NH ₄ ⁺ ) content of less than 5 mg/kg, which is the lower limit of quantification, while nitrate nitrogen (NO ₃ ⁻ ) is 14000 mg. /kg, it was found to be highly valuable as a fertilizer.
On the other hand, the kitchen waste compost of Reference Example 1 had a high ammonium nitrogen content of 3500 mg/kg and a low nitrate nitrogen content of 240 mg/kg.
In addition, in the bark compost of Reference Examples 2 and 3, although the content of ammonium nitrogen is both low (28 mg / kg, less than the lower limit of determination), the content of nitrate nitrogen is also low, and it is not valuable as a fertilizer. was low.

From the above results, it was found that, according to the compost production method of the present invention, compost having a high fertilizer value and a reduced ammonia nitrogen content can be produced in a short period of time.

Claims (10)

A compost production method for producing compost from raw materials containing organic matter, comprising:
A step of immersing an iron source and a carbon material in an aqueous solution containing sodium chloride and water and allowing the carbon material to stand, obtaining a liquid portion to obtain a spray liquid;
A step of spraying the spray liquid onto the raw material containing an organic substance while stirring the raw material;
A step of depositing the sprayed raw material and allowing it to stand;
A step of spraying the spray liquid while stirring the raw material after standing, depositing it again, and leaving it to stand to obtain compost,
A method for producing compost, wherein the content of ammonia nitrogen in the compost is less than 100 mg/kg. The compost manufacturing method according to claim 1, wherein the carbon material is at least one selected from the group consisting of coal, charcoal, coke, graphite, dust, carbon black, peat, and peat. The compost manufacturing method according to claim 1 or 2, further comprising a step of diluting the spray liquid. The compost manufacturing method according to any one of claims 1 to 3, further comprising adding a chelating agent to the spray liquid. The compost manufacturing method according to claim 4, wherein the chelating agent is at least one selected from the group consisting of pyroligneous acid, bamboo vinegar, and unrefined sake. The compost manufacturing method according to any one of claims 1 to 5, wherein the spray liquid is prepared in a closed container. The compost manufacturing method according to any one of claims 1 to 6, wherein the organic matter includes livestock manure. The compost production method according to any one of claims 1 to 7, wherein the content of nitrate nitrogen in the compost is 1000 mg/kg or more. A method for producing a spray liquid used for producing compost by spraying it on raw materials containing organic matter,
a step of immersing the iron source and the carbon material in an aqueous solution containing sodium chloride and water and allowing them to stand to obtain a liquid portion;
A method for producing a spray liquid, comprising adding a chelating agent to the obtained liquid to obtain a spray liquid. A spray liquid containing iron (II) ions, sodium ions and a chelating agent, and used for producing compost by spraying raw materials containing organic matter.

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