JP2015129065A - Method for producing bark compost - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing bark compost where firstly bark is decontaminated and composted certainly and efficiently, and further secondly this is achieved readily and highly safely.SOLUTION: A method for producing bark compost comprises: washing, with wash water, bark to which a radioactive substance is adhered and peeling the radioactive substance off into the wash water in a first step (washing step); adding an organic polymer coagulant to the polluted water and separating into chemical precipitate and supernatant water in a second step (coagulation precipitation step); adding compost material and microbial bacteria to the bark from which radioactive cesium is peeled off and fermenting to obtain a raw material of bark compost in a third step (primary fermentation process); adding the coagulation precipitate to the raw material of bark compost and agitating it in a fourth step (dispersion homogenizing step); and further fermenting the raw material of bark compost to which the coagulation precipitate is added to obtain bark compost in a fifth step (secondary fermentation step).

Description

  The present invention relates to a method for producing bark compost. That is, the present invention relates to a method for producing bark compost, in which bark, that is, bark is decontaminated and composted.

《Technical background》
The impact of the nuclear accident at the Fukushima Daiichi Nuclear Power Station following the Great East Japan Earthquake in March 2011 is significant, leaving serious damage to various industrial fields.
Due to radioactive leakage, a large amount of radioactive material is released and diffused in the environment, and there are still many problems that must be solved for recovery. For example, decontamination of various contaminants to which diffused radioactive cesium is attached is a big problem.

<Conventional technology>
In the field of forestry, processing of bark, which is a by-product, that is, bark, is a problem at the lumbering industry in Tohoku prefectures, mainly in Fukushima Prefecture. The bark obtained as a by-product when peeling the tree skin during lumbering is contaminated with radioactive cesium that continues to emit strong radiation, and its peeling, separation, and decontamination are necessary.
Bark produced as a by-product of the lumbering industry has been reused as compost, etc., but it has been suspended due to the next radioactive cesium contamination and is still piled up (Fig. 5 described later). (See also photos).
On the other hand, there is no effective processing technology at present. No treatment technology has been developed so far to decontaminate the contaminated bark and make it reusable as compost. Generally, adsorption and ion exchange techniques using zeolite are known, but zeolite may be used, and efficient application to bark as a composting material has been considered difficult.

"problem"
With respect to such a conventional example, the following problems have been pointed out. The technology for decontaminating contaminated bark and reusing it as compost has not been developed as described above.
In the sawmill industry in Tohoku prefectures, mainly in Fukushima Prefecture, barks are left untreated. For example, tens of thousands of tons are piled up in a situation where neither reuse nor disposal is possible.
Therefore, the development expectation of the manufacturing method of the bark compost which decontaminates bark efficiently and composts is increasing.

<< About the present invention >>
In view of such circumstances, the method for producing bark compost of the present invention has been made in order to solve the above-described problems of the prior art.
And, the present invention provides, firstly, a method for producing bark compost, in which bark is reliably and efficiently decontaminated and composted, and secondly, this is realized easily and easily in terms of safety. The purpose is to propose.

<About each claim>
The technical means of the present invention for solving such a problem is as follows, as described in the claims.
About Claim 1, it is as follows.
The manufacturing method of the bark compost of Claim 1 decontaminates the bark to which the radioactive substance adhered, and composts it. And it has the following 1st process-5th process, It is characterized by the above-mentioned.
That is, a first step (cleaning step) in which the bark to which the radioactive substance is attached is washed with washing water, and the radioactive substance is peeled and separated from the bark into the washing water.
The washed water containing the separated and separated radioactive substance is grasped as contaminated water, and an organic polymer flocculant is added to the contaminated water, so that the contaminated water is separated from the radioactive substance and the organic polymer. A second step (flocculation precipitation step) in which the flocculant is mainly separated from the flocculent precipitate and the supernatant water.
A third step (primary fermentation step) in which the compost material and microbial bacteria are added to the bark from which the radioactive material has been separated and separated, and fermented to obtain a bark compost raw material.
A fourth step (dispersion homogenization step) in which the aggregated precipitate is added to the bark compost raw material and stirred. A fifth step (secondary fermentation step) in which the bark compost material to which the aggregated precipitate has been added is further fermented to obtain bark compost.
The manufacturing method of the bark compost of Claim 1 has such each process.

About Claim 2, it is as follows.
The manufacturing method of the bark compost of Claim 2 is as follows regarding this 1st process (cleaning process) in Claim 1.
That is, the bark consists of bark obtained as a by-product when the tree skin is peeled off during lumbering. The radioactive substance is composed of oxidized radioactive cesium 134,137. The washing water is made of activated hydrogen water in which hydrogen is pressurized at high pressure as a reducing agent and is in a high solubility and high saturation state.
Accordingly, in the first step (washing step), the radioactive cesium is reduced with the washing water, and is peeled and separated from the bark side to the washing water side by stirring to decontaminate the bark. It is characterized by this.
About Claim 3, it is as follows.
The manufacturing method of the bark compost of Claim 3 is as follows regarding this 2nd process (coagulation sedimentation process) in Claim 2.
That is, the organic polymer flocculant is mainly composed of Bacillus natto. Therefore, in the second step (aggregation precipitation step), the contaminated water in the first step (washing step) is the aggregation precipitate containing the radioactive cesium and the natto bacteria as main components by promoting the fermentation of the Bacillus natto. And the supernatant water.
About Claim 4, it is as follows.
The manufacturing method of the bark compost of Claim 4 is as follows regarding this 3rd process (primary fermentation process) in Claim 3.
That is, after the decontamination in the first step (cleaning step), the compost material and the microbial fungus are added to the dried bark. The compost material is used by selecting one or more from at least livestock manure, straw, litter, lime, and other fertilizer materials. The microorganism is characterized in that one or a plurality of microorganisms are selected from at least Bacillus natto, yeast, lactic acid bacteria, and other bacteria.

About Claim 5, it is as follows.
The manufacturing method of the bark compost of Claim 5 is as follows regarding this 4th process (dispersion homogenization process) in Claim 4.
That is, the aggregated precipitate obtained in the second step (aggregation precipitation step) is added to the bark compost raw material obtained in the third step (primary fermentation step), and the aggregation precipitation is obtained by stirring. The product is characterized by being dispersed, diluted and homogenized in the bark compost material.
About Claim 6, it is as follows.
The manufacturing method of the bark compost of Claim 6 is as follows regarding this 5th process (secondary fermentation process) in Claim 5.
That is, in the obtained bark compost, the cationized radioactive cesium in the aggregated sediment is adhered, covered, adsorbed and retained by the anionized microbial fungus in the bark fungus compost. It is characterized by that.
About Claim 7, it is as follows.
The manufacturing method of the bark compost of Claim 7 is as follows regarding each process in Claim 6.
That is, in the first step (cleaning step), the bark is cut into chips and stored in a basket, and then immersed in the cleaning tank for cleaning water in units of several hours.
In the second step (coagulation sedimentation step), after the straw containing the bark is lifted, the Bacillus natto is added to the contaminated water in the washing tank. In the third step (primary fermentation step), fermentation is performed in units of several months to obtain the bark compost raw material.
In the fourth step (dispersion and homogenization step), stirring is performed in units of several tens of minutes. In the fifth step (secondary fermentation step), fermentation is performed in units of several months, and the obtained bark compost has a radiation dose of 200 Bq / Kg or less.

<About the action>
Since the present invention comprises such means, the following is achieved.
(1) In the first step (cleaning step), the bark to which radioactive cesium as a radioactive substance is attached is cleaned with cleaning water such as active hydrogen water. Thus, radioactive cesium is reduced, separated, and separated from the bark side to the washing water side.
(2) In the second step (coagulation sedimentation step), the washed water containing the separated and separated radioactive cesium is grasped as contaminated water, and an organic polymer flocculant such as Bacillus natto is added. Thus, the contaminated water is separated into an aggregated precipitate made of radioactive cesium, natto, and the like, and supernatant water.
(3) In the third step (primary fermentation step), compost material and microbial fungi are added to bark and fermented, and thus become a bark compost raw material.
(4) In the fourth step (dispersion and homogenization step), the aggregated precipitate is added to the bark compost raw material, and the aggregated precipitate containing radioactive cesium is dispersed, diluted and homogenized by stirring.
(5) In the fifth step (secondary fermentation step), fermentation is further advanced, and thus bark compost is obtained.
(6) In the manufacturing method of the present invention, the bark compost is efficiently manufactured while effectively utilizing each material by sequentially following the first to fifth steps described above.
(7) Bark compost is decontaminated, and the radiation dose of radioactive cesium is 200 Bq / kg or less.
(8) And each process of this manufacturing method consists of simple contents, and can be easily put into practical use.
(9) Furthermore, the bark and compost used in the production method of the present invention are natural natural materials. Activated hydrogen water, organic polymer flocculants such as Bacillus natto, microbial bacteria, etc. are all derived from natural ingredients.
(10) The supernatant water is decontaminated and can be discharged into sewage. Moreover, in the manufactured bark compost, radioactive cesium exists as a cation, and it adheres to, coats, adsorbs and holds on anionic microbial bacteria. Furthermore, many microorganisms have pores that trap radioactive cesium.
(11) Now, the method for producing bark compost of the present invention exhibits the following effects.

<< First effect >>
First, bark is reliably and efficiently decontaminated and composted.
The method for producing bark compost of the present invention comprises a first step (cleaning step) using active hydrogen water and the like, a second step (coagulation sedimentation step) using natto bacteria, etc., and composting material on the decontaminated bark And the 3rd process (primary fermentation process) which adds microbial bacteria and ferment, the 4th process (dispersion homogenization process) which adds and stirs an aggregate sediment to this, and the 5th process (secondary fermentation) further fermented Step).
And by adopting these steps in combination for the first time, the bark is reliably decontaminated and composted, and efficiently composted. Decontaminated bark compost is efficiently commercialized.
In the lumber industry, the situation where the bark is left unattended can be eliminated as the bark cannot be reused or discarded, as in the above-described conventional example. Bark is decontaminated to a level where it can be reused as fertilizer and is therefore reused.

<< Second effect >>
Secondly, this is easily and easily realized with excellent safety.
The manufacturing method of the bark compost of this invention consists of the combination of a process which can be employ | adopted easily on the spot of a lumber industry. Each of the first, second, third, fourth, and fifth steps has a simple content, and is easy to work and can be practically used in the lumber industry.
In addition, bark, active hydrogen water, natto bacteria, compost, microbial bacteria, etc. used in each process are all derived from natural natural materials and natural components, and have no adverse effects on the human body. Thus, highly safe compost can be obtained.
Of course, bark is safely decontaminated. The washing water used for decontamination becomes safe supernatant water.
As described above, the effects exerted by the present invention are remarkably large, such as all the problems existing in this type of conventional example are solved.

It is a process block diagram for the description of the form for implementing invention about the manufacturing method of the bark compost concerning the present invention. It is used for description of the form for implementing this invention, and is front explanatory drawing. And (1) figure shows the bark piled up, (2) figure shows the bark stored in the basket. (3) The figure shows the first step (cleaning step). It is used for description of the form for implementing this invention, and is front explanatory drawing. And (1) figure shows the first half of the 2nd process (aggregation precipitation process), and (2) figure shows the latter half of the 2nd process (aggregation precipitation process). (3) The figure shows the third step (primary fermentation step). It is used for description of the form for implementing this invention, and is front explanatory drawing. And (1) figure shows the 4th process (dispersion homogenization process). (2) The figure shows the fifth step (secondary fermentation step). (3) The figure shows the manufactured bark compost. It is a photograph of the bark etc. which were used for explanation of the form for carrying out the invention, and were piled up.

Hereinafter, embodiments for carrying out the present invention will be described in detail.
<< Outline of the Invention >>
The method for producing bark compost according to the present invention includes a first step (washing step), a second step (coagulation precipitation step), a third step (primary fermentation step), a fourth step (dispersion homogenization step), and a fifth step. It has a process (secondary fermentation process) etc.
Therefore, the bark with radioactive material attached is decontaminated and composted. Hereinafter, these first to fifth will be described.

<< About the outline of the 1st process (cleaning process) >>
First, a 1st process (cleaning process) is demonstrated with reference to (1) figure of FIG. 1, FIG. 2, (2) figure, (3) figure, etc. FIG. The outline is as follows.
In the first process (cleaning process) shown in step 1 of FIG. 1, the bark 1 to which the radioactive substance Cs has adhered is washed with the washing water 2 so that the radioactive substance Cs is separated from the bark 1 into the washing water 2 and separated. Let
The bark 1 is composed of a tree skin obtained as a by-product when the tree skin is peeled off during lumbering, that is, a peeled bark. The radioactive substance Cs consists of oxidized radioactive cesium 134,137. The wash water 2 is typically composed of activated hydrogen water in which hydrogen is injected under high pressure as a reducing agent and is in a high solubility and high saturation state.
Therefore, in the first step (cleaning step), radioactive cesium Cs is reduced in the cleaning water 2 and is separated and separated from the bark 1 side to the cleaning water 2 side by stirring, so that the bark 1 is decontaminated. .
The outline of the first step (cleaning step) is as described above.

<< Details of the first process (cleaning process) >>
The first step (cleaning step) described above will be further described in detail. The bark, or bark 1, is contaminated with radioactive cesium Cs that has diffused in the nuclear accident. Radioactive cesium Cs is made of cesium 134,137, which is an alkali metal, and is known to continue to emit strong radiation for many years. Radioactive cesium Cs is oxidized during the nuclear accident.
On the other hand, the cleaning water 2 functions as a reducing solution, and hydrogen water with enhanced activity is typically used. That is, the wash water 2 is injected under pressure at a high pressure such as 6 atm using solute hydrogen as a reducing agent with respect to the solvent water. Thus, hydrogen is dissolved in a large amount of about 2.2 ppm, and it is in a high solubility and high saturation state, and its reduced state can be maintained for a long time of about 24 hours, for example.
Incidentally, when hydrogen is injected under atmospheric pressure which is not high pressure, a small amount of about 1.6 ppm, low solubility and low saturation state are obtained, and the reduced state is only maintained for about 2 to 4 hours. On the other hand, the washing water 2 used in the present invention is composed of reduced water and hydrogen water with enhanced activity.

The bark 1 is first shredded into chips from the stacked state shown in FIG. 2 (1) and FIG. The chip-formed bark 1 is housed in the basket 3 in the illustrated example shown in FIG. Of course, you may store in another container and net | network with air permeability and water permeability irrespective of the example of illustration. In the illustrated example, about 500 kg is stored in one basket 3.
Then, as shown in FIG. 2 (3), the basket 3 containing the chip-formed bark 1 is in the washing tank 4 filled with the washing water 2 for about 3 hours to 24 hours, It is soaked by dipping and soaked. An activated hydrogen water generator A is attached to the cleaning tank 4. Then, it is soaked for about 4 hours, but if it is less than 3 hours, the cleaning effect is insufficient, but no change is seen in the cleaning effect even if it is immersed for 24 hours or more.

As a result of such immersion and cleaning, the radioactive cesium Cs adhering to the bark 1 is reduced. That is, radioactive cesium Cs is oxidized during the nuclear accident, while cleaning water 2 made of activated hydrogen water has an oxidation (reduction) potential of, for example, an alkali having a reducing power of about −40 mV to −400 mV. Is in a state.
Thus, the oxidized radioactive cesium Cs (metal oxide) is reduced with the washing water 2 (hydrogen). Then, the reduced radioactive cesium Cs is separated and separated from the bark 1 side to the washing water 2 side by stirring, and mixed into the washing water 2. The process during this time is the same as a general rust removal step.
Bark 1 is cleaned and decontaminated in this way. Then, the basket 3 in which the cleaned and decontaminated bark 1 is stored is lifted from the cleaning tank 4 and taken out. At the time of lifting, the crane 3 is vibrated up and down about 50 times using a crane, an excavator car, etc., and thus the radioactive cesium Cs is washed off.
The cleaning water 2 containing the radioactive cesium Cs separated and separated from the bark 1 thus lifted remains in the cleaning tank 4 and contaminated water as shown in FIG. 3 (1). It is grasped as 5. In the contaminated water 5, radioactive cesium Cs is mixed in a suspended state and colloidal particles.
Details of the first step (cleaning step) are as described above.

<< Test data for the first process (cleaning process) >>
When the first step (cleaning step) described above was tested, the measurement data shown in Table 1, Table 2, and Table 3 below were obtained.
Table 1 shows data measured for the hydrogen ion concentration of the cleaning water 2 used for cleaning, and the cleanliness by the BOD value and the COD value. Tables 2 and 3 are data obtained by measuring the value of the radioactive cesium Cs of the bark 1 before and after cleaning and decontamination, that is, the radiation dose.
For the measurements in Tables 2 and 3, a germanium semiconductor detector was used, and a nuclide analysis method by γ-ray spectrometry was used. In Tables 2 and 3, the description “not detected” means that the detection limit value (20 Bq / kg) is not exceeded.
The measurement data in Tables 2 and 3 also confirmed the separation, separation, washing, and decontamination of the radioactive cesium Cs from the bark 1 described above.

The test data for the first step (cleaning step) is as described above.

<< About the outline of the 2nd process (aggregation precipitation process) >>
Next, a 2nd process (coagulation sedimentation process) is demonstrated with reference to (1) figure of FIG. 1, FIG. 3, (2) figure, etc. FIG. First, the outline is as follows.
In the second step (coagulation sedimentation step) shown in step 2 of FIG. 1, the cleaning water 2 containing radioactive cesium Cs, which is the radioactive substance separated and separated in the first step (cleaning step), is used as contaminated water 5. And the organic polymer flocculant 6 is added to the contaminated water 5.
Thus, the contaminated water 5 is separated into an aggregated precipitate 7 mainly composed of radioactive cesium Cs and an organic polymer flocculant 6 and a supernatant water 8. The organic polymer flocculant 6 contains natto bacteria 9 as a main component.
In this way, in the second step (aggregation precipitation step), the contaminated water 5 is an aggregation precipitate mainly composed of organic polymer flocculant 6 such as radioactive cesium Cs and Bacillus natto 9 by accelerating fermentation of Bacillus natto 9. 7 and supernatant water 8.
The outline of the second step (aggregation precipitation step) is as described above.

<< Details of the second step (coagulation sedimentation step) >>
The above-described second step (aggregation precipitation step) will be further described in detail. In the second step (coagulation sedimentation step), as shown in FIG. 3 (1), natto is used as the organic polymer flocculant 6 for the washing tank 4 after the decontaminated bark 1 is lifted. Fungus 9 is typically added.
That is, Bacillus natto against contaminated water 5 in the washing tank 4, that is, against the washed water 2 contaminated with the radioactive cesium Cs separated and separated from the bark 1 in the first step (cleaning step) described above. About 9 kg of 9 is added, added and stirred.
Γ-polyglutamic acid, which is a sticky yarn component of Bacillus natto 9, has a linear structure and a fibrous structure in which glutamic acid is a peptide bond, and as is well known, it is also used for water treatment as a polymer flocculant. Yes. Aggregate flocs, which are aggregates of larger particles, can be formed by firmly crosslinking the particles, and exhibit a powerful aggregation function.

As the fermentation of natto bacteria 9 is promoted, as shown in FIG. 3 (2), the washing water 2 contaminated with the contaminated water 5, that is, radioactive cesium Cs, is solidified into the aggregated precipitate 7 and the supernatant water 8. Liquid separation.
Aggregated sediment 7 is composed of radioactive cesium Cs, Bacillus natto 9, residual bark powder, etc., and aggregates and settles at the bottom of washing tank 4 as a muddy contaminant and is collected by a filter or the like. On the other hand, most of the middle and upper part of the washing tank 4 becomes the supernatant water 8.
In the illustrated second step (coagulation precipitation step), the cleaning tank 4 used in the first step (cleaning process) is used as it is, but of course, the cleaning tank 4 may not be used. That is, it is also possible to transfer the contaminated water 5 from the cleaning tank 4 to another processing tank and to perform the second step (coagulation sedimentation step) in the processing tank.
Details of the second step (aggregation precipitation step) are as described above.

<< Test data for the second step (coagulation sedimentation step) >>
When the second step (aggregation precipitation step) was tested, the measurement data shown in Tables 4 and 5 below were obtained.
That is, the value of radioactive cesium Cs, that is, the radiation dose, was measured for the aggregated precipitate 7 and the supernatant water 8. The description of the measurement method and “not detected” is as described above.
The measurement data in Tables 4 and 5 also confirmed the accumulation and aggregation of radioactive cesium Cs in the aggregated precipitate 7, and the decontamination and safety of the supernatant water 8. As described above, it was confirmed that the supernatant water 8 after removing the bark 1 and the coagulated sediment 7 was decontaminated and purified, and can be discharged to the outside and discharged into the sewage.

The test data for the second step (aggregation precipitation step) is as described above.

<< About the outline of the 3rd process (primary fermentation process) >>
Next, a 3rd process (primary fermentation process) is demonstrated with reference to (3) figure etc. of FIG. 1, FIG. First, the outline is as follows.
In the third process (primary fermentation process) shown in step 3 of FIG. 1, compost 10 and microorganisms are applied to bark 1 from which radioactive cesium Cs, which is a radioactive substance, has been separated and separated in the first process (cleaning process). Bacteria 11 is added and fermented to form a bark compost raw material 12.
That is, after decontamination in the first step (cleaning step), the compost 10 and the microbial fungus 11 are added to the dried bark 1. One or a plurality of compost materials 10 are selected and used from at least livestock manure, straw, litter, lime, and other fertilizer materials. One or a plurality of microbial bacteria 11 are selected and used from at least Bacillus natto, yeast, lactic acid bacteria, and other bacteria.
The outline of the third step (primary fermentation step) is as described above.

<< Details of the third step (primary fermentation step) >>
The 3rd process (primary fermentation process) mentioned above is explained in full detail. In the third step (primary fermentation step), as shown in FIG. 3 (3), the bark 1 that has been first lifted from the washing tank 4 of the first step (cleaning step) and then dried, that is, Compost material 10 and microbial fungus 11 are added to bark 1 from which radioactive cesium Cs has been separated, separated and decontaminated.
In the illustrated example, the third step (primary fermentation step) is performed on the bark 1 in the straw 3, but of course, the bark 1 is transferred from the straw 3 to another container and carried out regardless of the illustrated example. May be.
As compost material 10, pig manure, horse manure, chicken manure, other livestock manure, rice straw, wheat straw, other straw, fallen leaves, lime, nitrogen, phosphorus, rice bran, and other fertilizer materials are selectively used. The As the microorganism 11, Bacillus natto, yeast, lactic acid bacteria, antifungal, other bacteria, and the like are selectively used.
Typically, the bark 1 is about 20% by weight, the compost 10 is about 70% by weight, and the microorganism 11 is about 10% by weight.
Moreover, fermentation is performed for several months, and the bark compost raw material 12 is produced | generated by fermentation acceleration. For example, in a fermentation period of about half a year, the microbial bacteria 11 promote the fermentation, decomposition, and fever of the bark 1 and the compost material 10, thereby generating the bark compost raw material 12.
The details of the third step (primary fermentation step) are as described above.

<< About the outline of the 4th process (dispersion homogenization process) >>
Next, the fourth step (dispersion and homogenization step) will be described with reference to FIGS. 1 and 4 (1) and (2). First, the outline is as follows.
In the fourth step (dispersion homogenization step) shown in Step 4 of FIG. 1, the aggregated precipitate 7 is added to the bark compost raw material 12 and stirred.
That is, the aggregated precipitate 7 obtained in the second step (aggregation precipitation step) is added to the bark compost raw material 12 obtained in the third step (primary fermentation step), and the aggregation precipitate 7 is formed by stirring. Dispersed, diluted and homogenized in bark compost raw material 12.
The outline of the fourth step is as described above.

<< Details of Fourth Step (Dispersion Homogenization Step) >>
The above-described fourth step (dispersion homogenization step) will be further described in detail. In the fourth step (dispersion and homogenization step), first, as shown in FIG. 4A, the bark compost raw material 12 and the aggregated precipitate 7 are charged into the treatment tank 13.
The bark compost raw material 12 is obtained by adding the compost material 10 and the microbial fungus 11 to the bark 1 obtained and decontaminated in the third step (primary fermentation step) and fermenting it. On the other hand, the aggregated precipitate 7 is produced in the second step (aggregated precipitation step), and mainly contains radioactive cesium Cs, natto bacteria 9 and the like.
And with respect to the bark compost raw material 12, the aggregate deposit 7 is used and injected | thrown-in, for example with the following component ratio and weight ratio.
That is, when the aggregated sediment 7 (radioactive cesium Cs, etc.) is 1, a ratio of 20 is used for the bark compost raw material 12 (bark 1, compost 10, microbial fungus 11, etc.) in 20-fold dilution. . In the 30-fold dilution, the bark compost raw material 12 is used at a ratio of 30. In the 40-fold dilution, the bark compost raw material 12 is used at a ratio of 40.

Then, as shown in FIG. 4 (2), in the treatment tank 13, the stirring means 14 is driven in units of several tens of minutes, for example, about 20 minutes, so that the aggregated precipitate 7 is contained in the bark compost raw material 12. To be dispersed, diluted and homogenized.
The agglomerated precipitate 7 containing radioactive cesium Cs is dispersed and diffused in the bark compost raw material 12 by stirring, and is uniformly diluted.
The details of the fourth step (dispersion homogenization step) are as described above.

<< About the outline of the 5th process (secondary fermentation process) >>
Next, the fifth step (secondary fermentation step) of the final step will be described with reference to FIGS. 1 and 4 (3). First, the outline is as follows.
In the fifth step (secondary fermentation step) shown in Step 5 of FIG. 1, the bark compost raw material 12 in which the aggregated precipitate 7 is dispersed, diluted and homogenized in the fourth step (dispersion homogenization step) is further fermented. By doing so, the bark compost 15 is obtained.
In the obtained bark compost 15, the cationized radioactive cesium Cs in the aggregated sediment 7 is adhered, covered, adsorbed and retained by the anionized microbial bacteria 11 in the bark compost raw material 12. .
The outline of the fifth step (secondary fermentation step) is as described above.

<< Details of the fifth step (secondary fermentation step) >>
The fifth step (secondary fermentation step) described above will be further described in detail. In the treatment tank 13, the agglomerated precipitate 7, that is, radioactive cesium Cs, is dispersed, diluted, and homogenized in the bark compost raw material 12 by the stirring in the fourth step (dispersion homogenization step) to a low concentration state.
And in a 5th process (secondary fermentation process), fermentation is implemented for several months, for example about one month, and the bark compost 15 is obtained.
Now, the bark compost 15 manufactured by following the first to fifth steps described above has a value of radioactive cesium Cs in the bark compost 15, that is, a radiation dose of 200 Bq / kg or less, typically 100 Bq / kg or less. ing.

By the way, radioactive cesium Cs exists as a cesium ion irrespective of oxidation and a reduction state. The radioactive cesium Cs in the aggregated sediment 7 constituting the bark compost 15 is oxidized as described above, and exists as a cation charged in a positive state and having a positive charge.
On the other hand, the microbe 11 in the bark compost raw material 12 constituting the bark compost 15 exists as an anion having a negative charge.
As a result, in the bark compost 15, the positive radioactive cesium Cs dispersed, diluted and homogenized in the bark compost raw material 12 is firmly attached, covered, adsorbed and absorbed by the negative microorganism 11 in the bark compost raw material 12. Is retained.
In addition to this, microbial bacteria 11 such as Bacillus natto have many holes that trap radioactive cesium Cs. From this aspect, the radioactive cesium Cs adheres to the microbial bacteria 11 constituting the bark compost 15. , Coated, adsorbed, retained.
The radiation dose of radioactive cesium Cs can also be reduced from both sides. Incidentally, when the bark compost 15 is used as a fertilizer, the amount of radioactive cesium Cs absorbed into the crop is almost the same, because the viscosity in the soil acts in the same manner as the above-mentioned microorganism 11. I guess it is not.
The details of the fifth step (secondary fermentation step) are as described above.

<< Test data for the fifth step (secondary fermentation step) >>
When the bark compost 15 obtained in the fifth step (secondary fermentation step) was tested, the measurement data shown in Table 6, Table 7, and Table 8 below were obtained.
That is, about the manufactured bark compost 15, the value of radioactive cesium Cs, that is, the radiation dose was measured. The description of the measurement method and “not detected” is as described above.
From the measurement data in Table 6, Table 7, and Table 8, it was confirmed that the value of radioactive cesium Cs, that is, the radiation dose, was 100 Bq / kg or less for the manufactured bark compost 15.
That is, in the fourth step (dispersion homogenization step), the component ratio between the aggregated precipitate 7 (radioactive cesium Cs, Bacillus natto 9 etc.) and the bark compost raw material 12 (bark 1, compost material 10, microbial fungus 11 etc.) In the case of 20-fold dilution with a weight ratio of 1:20, the radiation dose was 135.1 Bq / kg. In the case of 30-fold dilution of 1:30, the radiation dose was 72.9 Bq / kg. In the case of 40-fold dilution of 1:40, the radiation dose was 27.9 Bq / kg.

About the test data of the 5th process (secondary fermentation process), it is as above.

《Action etc.》
The manufacturing method of the bark compost 15 of the present invention is configured as described above. Therefore, it becomes as follows.
(1) In the first step (cleaning step), the bark 1 to which radioactive cesium Cs, which is a radioactive substance, is attached is cleaned with cleaning water 2 such as activated hydrogen water (step 1 in FIG. 1, step 2 in FIG. 2). (Refer to (1) Figure, (2) Figure, (3) Figure, etc.)).
Thus, radioactive cesium Cs is reduced and separated and separated from the bark 1 side to the washing water 2 side, and the bark 1 is decontaminated.

(2) In the second step (coagulation sedimentation step), the cleaning water 2 containing the radioactive cesium Cs separated and separated from the bark 1 in the first step (cleaning step) is grasped as the contaminated water 5. Then, an organic polymer flocculant 6 such as Bacillus natto 9 is added to the contaminated water 5 (see step 2 in FIG. 1 and (1) in FIG. 3).
Thus, the contaminated water 5 is decomposed into the aggregated precipitate 7 and the supernatant water 8. It is separated into a flocculated sediment 7 mainly composed of an organic polymer flocculant 6 such as radioactive cesium Cs and natto 9 and a supernatant water 8 (see FIG. 3 (2)).

  (3) In the third step (primary fermentation step), the compost 10 and the microorganism 11 are added to the bark 1 from which the radioactive cesium Cs has been separated, separated and decontaminated in the first step (cleaning step). And it is fermented and it becomes the bark compost raw material 12 (refer step 3 of FIG. 1, (3) figure of FIG. 3, etc.).

(4) In the fourth step (dispersion homogenization step), the aggregated precipitate 7 produced in the second step (aggregation precipitation step) is added to the bark compost raw material 12 produced in the third step (primary fermentation step). (See step 4 in FIG. 1, (1) in FIG. 4, etc.).
Then, the aggregated precipitate 7 containing radioactive cesium Cs is dispersed, diluted, and homogenized in the bark compost raw material 12 (bark 1, compost material 10, microbial fungus 11, etc.) by stirring ((2 in FIG. 4). ) See figure etc.).

  (5) In the fifth step (secondary fermentation step) of the final step, the bark compost raw material 12 that has been dispersed, diluted and homogenized by adding the aggregate precipitate 7 in the fourth step (dispersion homogenization step) is further Fermented. Thus, the bark compost 15 is obtained (see step 5, FIG. 1, (3) in FIG. 4).

(6) Now, in the method for producing bark compost of the present invention, the bark compost 15 is manufactured by sequentially following the first to fifth steps described above.
The bark compost 15 is efficiently manufactured by effectively using not only the bark 1 but also the general compost 10 and the microbial bacteria 11 and the like.

  (7) And the bark compost 15 manufactured in this way is decontaminated. That is, the value of the radioactive cesium Cs of the manufactured bark compost 15 by following the steps of the first step (cleaning step), the third step (primary fermentation step), and the fourth step (dispersion homogenization step), that is, The radiation dose is 200 Bq / kg or less. Typically, it is 100 Bq / kg or less (see Table 2 and Tables 6, 7 and 8 for comparison).

(8) In addition, each step of the production method of the present invention has simple contents and can be easily put into practical use.
That is, the first step (cleaning step) is to clean the bark 1 using the activated hydrogen water of pressurized hydrogen as the cleaning water 2. The content of the second step (aggregation precipitation step) is to add natto 9 or the like to the contaminated water 5.
The third step (primary fermentation step) is to add fertilizer 10 and microbial fungus 11 to bark 1 for fermentation. The fourth step (dispersion and homogenization step) includes adding the aggregated precipitate 7 to the bark compost raw material 12 and stirring. The fifth step (secondary fermentation step) is further fermented. Thus, each process consists of simple contents.

(9) Furthermore, the bark 1 used in the production method of the present invention is bark, and the compost 10 is livestock manure, straw, fallen leaves, etc., all of which are natural natural materials. The organic polymer flocculant 6 is made of natto bacteria 9 and the like, and the microbial bacteria 11 is made of yeast, lactic acid bacteria, natto bacteria, and the like, all of which are derived from natural ingredients. The composition of the activated hydrogen water used as the washing water 2 is also derived from natural components.
Thus, in the production method of the present invention, only natural natural materials, natural component-derived materials, and naturally-derived materials that do not have an adverse effect on the human body are used.

(10) In addition, the supernatant water 8 produced | generated by the 2nd process (coagulation sedimentation process) is decontaminated and purified, can fully clear the environmental standard of water pollution, and can drain sewage (said above) (See Table 5).
In the manufactured bark compost 15, radioactive cesium Cs is present as a cation, and is attached, covered, adsorbed, and retained by the microorganism 11 that functions as an adsorbent as an anion. Furthermore, many microorganisms 11 have a hole for trapping radioactive cesium Cs. The radiation dose of radioactive cesium Cs is also reduced from these both sides.
The operation of the present invention is as described above.

1 Bark 2 Washing water 3 籠 4 Washing tank 5 Contaminated water 6 Organic polymer flocculant 7 Coagulated sediment 8 Supernatant water 9 Natto bacteria 10 Composting material 11 Microorganisms 12 Bark compost raw material 13 Treatment tank 14 Stirring means 15 Bark compost Cs Radioactive Cesium (radioactive material)

Claims (7)

A method for producing bark compost, which decontaminates bark with radioactive material attached, and composts it.
A first step (cleaning step) of washing the bark to which the radioactive substance is attached with washing water, and separating and separating the radioactive substance from the bark to the washing water;
The washed water containing the separated and separated radioactive substance is grasped as contaminated water, and an organic polymer flocculant is added to the contaminated water, so that the contaminated water is separated from the radioactive substance and the organic polymer. A second step (aggregation precipitation step) in which the aggregation precipitate containing a flocculant as a main component and the supernatant water are separated;
The bark from which the radioactive material has been separated and separated is fermented by adding a compost material and a microbial fungus, and thereby a bark compost raw material is used as a third step (primary fermentation step);
Adding the agglomerated precipitate to the bark compost raw material and stirring the fourth step (dispersion homogenization step);
And a fifth process (secondary fermentation process) for further fermenting the bark compost material to which the aggregated precipitate has been added to obtain bark compost. In claim 1, in the first step (washing step), the bark is made of bark obtained as a by-product when peeling the tree skin during lumbering,
The radioactive substance is made of oxidized radioactive cesium 134, 137, and the washing water is made of activated hydrogen water in which hydrogen is pressurized at high pressure as a reducing agent and is highly soluble and highly saturated.
Accordingly, in the first step (washing step), the radioactive cesium is reduced with the washing water, and is peeled and separated from the bark side to the washing water side by stirring to decontaminate the bark. This is a method for producing bark compost. In claim 2, in the second step (aggregation precipitation step), the organic polymer flocculant is mainly composed of Bacillus natto,
Therefore, in the second step (aggregation precipitation step), the contaminated water in the first step (washing step) is the aggregation precipitate containing the radioactive cesium and the natto bacteria as main components by promoting the fermentation of the Bacillus natto. And a method for producing bark compost characterized by being separated into the supernatant water. In Claim 3, in this 3rd process (primary fermentation process), after decontaminating in this 1st process (cleaning process), this compost and this microbial fungus are added to this dried bark. But,
The compost material is selected and used from at least livestock manure, straw, litter, lime, and other fertilizer materials, and the microbial fungus is at least one from natto, yeast, lactic acid, and other fungi. A method for producing bark compost characterized by being selectively used.   In claim 4, in the fourth step (dispersion homogenization step), the bark compost raw material obtained in the third step (primary fermentation step) was obtained in the second step (coagulation precipitation step). A method for producing bark compost, wherein the aggregated precipitate is added, and the aggregated precipitate is dispersed, diluted, and homogenized in the raw material for composting bark by stirring.   6. In the fifth step (secondary fermentation step), in the fifth step (secondary fermentation step), the obtained bark compost is anionized in the bark compost raw material by the cationized radioactive cesium in the aggregated sediment. A method for producing bark compost characterized by being adhered, covered, adsorbed and retained by the microorganisms. In claim 6, in the first step (cleaning step), after the bark is chipped and stored in a basket, it is immersed in the cleaning tank for several hours.
In the second step (coagulation sedimentation step), after the straw containing the bark is lifted, the Bacillus natto is added to the contaminated water in the washing tank, and in the third step (primary fermentation step) , Fermentation is performed in units of several months to obtain the bark compost raw material,
In the fourth step (dispersion homogenization step), stirring is performed in units of several tens of minutes, and in the fifth step (secondary fermentation step), fermentation is performed in units of several months. A method for producing bark compost characterized by having a radiation dose of 200 Bq / Kg or less.