JP2002162394A - Method for measuring maturity degree of compost - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for measuring the maturity degree of a compost capable of judging the maturity degree by operator's visual observation with high reliability and also capable of judging it easily using a machine. SOLUTION: A part of composted material is collected, and a methylene blue pigment is added to a liquid phase acquired by extracting with a solvent. The maturity degree of the compost is judged by estimating a dissolved oxygen amount consumed at organics' microbe decomposition in the solvent based on the change in hue of the methylene blue pigment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the maturity of compost when composting organic matter, and more particularly to a method capable of measuring the maturity by a simple method.

[0002]

2. Description of the Related Art In recent years, organic waste such as cow dung discharged from agriculture and livestock industries and farm households, organic waste such as garbage discharged from households, and further discharged from food processing industry and food service industry. Composting facilities and decomposition facilities have been constructed in various places to collectively process large quantities of organic waste such as leftovers.

[0003] In such a composting facility or a decomposition facility, since the discharged organic waste is treated in a large amount at a time, its treatment efficiency must be emphasized. In other words, the emphasis is on reducing the time required for composting. However, the time required for the fermentation / decomposition period of organic waste is short, and the compost which has a reduced compost production time may generate a bad smell or may be of low quality not suitable for agricultural production (may be).
There is.

Therefore, various indices have been proposed to indicate the progress of composting and the quality of the processed material. Among them, the maturity is an index that is regarded as particularly important, and there are the following measurement methods. (1) C / N of organic waste
Methods for measuring the ratio, (2) determination of nitrogen form, (3) measurement of oxygen consumption, (4) germination test, (5) seedling test, and the like have been reported.

The (1) method for measuring the C / N ratio of organic waste is a method for evaluating the degree of maturity by measuring the ratio of carbon and nitrogen contained in compost. Usually, with the progress of composting, organic matter is decomposed and released into the atmosphere as carbon dioxide (CO ₂ ). As a result, a low C / N ratio is a good compost. That is, C /
When the N value is high, as the microbial decomposition proceeds, the nitrogen content becomes insufficient and the decomposition rate gradually decreases, and the decomposition is easily stopped. For this reason, the time required for composting is long, and it is easy to produce a low-quality compost which deprives soil nitrogen and thins the land. As an analysis method, there are an automatic analysis using an instrument and a manual analysis by titration or the like. The instrumental analysis is basically a kind of elemental analyzer, and the C / N ratio is calculated by measuring CO ₂ and N ₂ gas generated by burning a sample.

In the above (2) method of discriminating nitrogen form, when nitrogen compounds contained therein are decomposed during composting, nitrogen in the form of ammonia is first produced, but as ripening proceeds, nitrogen in the form of nitric acid is produced. To increase. By measuring this, the degree of ripening is determined. As a measuring method, there are many methods such as an ion electrode in addition to the diphenylamine method.

In the method of measuring oxygen consumption (3), since organic matter is not sufficiently decomposed by immature compost, the degree of maturity is determined by measuring the amount of oxygen consumed by the decomposition of organic matter. . As a measuring method, gas generated from compost is directly measured by gas chromatography.

[0008] The germination test (4) was carried out using radish,
The maturity is determined by examining the germination rate and growth amount of seeds such as Komatsuna and Chinese cabbage, and the germination rate is 80%.
If there is no growth inhibition or root abnormality, it is determined that the compost is ripe. There are a planter method using soil and a petri dish method using no soil. Germination when no compost is used is also performed as a control test.

The above (5) seedling test is to confirm the presence or absence of inhibition by actually cultivating plants in soil to which compost has been applied.

[0010]

However, these conventional methods have drawbacks, for example, (4) the germination test and (5) the seedling test require a long period of time (several days) in the measurement process. Was. In addition, (1) measurement of C / N ratio and (3) measurement of oxygen consumption are performed in a decomposition room or an aging room of a treatment facility by using a carbon dioxide concentration meter, an oxygen concentration meter, an ammonia concentration meter, a thermometer, a hygrometer, Various measuring devices such as ion electrodes,
In some cases, expensive equipment such as gas chromatography is provided. For this reason, it is insufficient from the viewpoint of measuring the ripening degree objectively and with high accuracy by a simple and short operation.

Therefore, Japanese Patent Application Laid-Open No. Hei 9-270003 discloses a method for judging the maturity of a composted product which is objective, simple, and capable of judging the maturity with high accuracy. A determination method is disclosed.

In this method, the first absorbance of a liquid phase obtained by extracting a part of the processed material during the composting treatment with a solvent is measured, and the same processing is performed on the obtained part of the processed material obtained by continuing the processing after the collection. Next, the second absorbance is measured, and the change ratio of the first and second absorbances is compared with a standard curve. However, the collected composted product is suspended in distilled water, separated into solid and liquid by centrifugation, and the obtained supernatant is measured by a spectrophotometer. Such a high-sensitivity spectrophotometer is required, and an arithmetic processing unit for comparing the rate of change of the first and second absorbances with a standard curve is also required, resulting in high equipment costs. It is desirable that the degree of maturity can be determined easily and with high accuracy. However, since some operators are unfamiliar with the operation of measuring instruments, reliability can be obtained by visual inspection instead of mechanization. Part should be kept.

The present invention has been made in view of the above problems, and has as its technical object to provide a method for measuring the maturity of compost which can judge the maturity with a high degree of reliability visually by an operator and can easily judge the maturity with a machine. Make it an issue.

[0014]

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention is a method for judging the maturity of a composted product obtained by composting an organic substance. The methylene blue dye is added to the liquid phase obtained by extraction and extraction with a solvent, and the amount of dissolved oxygen consumed by microbial decomposition of organic matter in the solvent is estimated from the change in the hue of the methylene blue dye to obtain a compost. A technical measure was taken to determine the degree of ripening.

A liquid phase obtained by collecting a part of the composted product and extracting it with a solvent contains an easily decomposable organic substance, which is also contained in the liquid phase. Degraded by microorganisms. As this microorganism decomposes organic matter, dissolved oxygen in the liquid phase is consumed,
As the dissolved oxygen decreases, the hue of methylene blue as an indicator changes. The change in hue can be used to determine the degree of maturity of composting. Therefore, carbon dioxide concentration meters, oxygen concentration meters, ammonia concentration meters, thermometers, hygrometers, and arithmetic There is no need to provide various measuring devices such as devices, and the maturity can be measured by a simple method.

Further, since the maturity of the compost can be determined by visually observing the change in hue of the methylene blue dye, the maturity can be determined with high reliability by visual observation by an operator. Then, at the time of visual observation, the maturity of the compost is determined by comparing the change in hue of the methylene blue dye and the maturity of the compost with a colorimetric sample in which the maturity of the compost is previously associated. The degree of ripening can be determined.

Furthermore, since the change in hue of the methylene blue dye is measured by absorbance to determine the maturity of the compost, the maturity can be determined with high accuracy and easily.
Then, at the time of measuring the absorbance, the maturity of the compost is determined by comparing the change in the hue of the methylene blue dye and the maturity of the compost with a standard curve in which the maturity of the compost is previously associated.

The conditions of the methylene blue dye of the present invention are set such that the concentration of the methylene blue dye is 1.5 to 2.5 when irradiated with a wavelength of 650 to 670 nm in the visible region, and the temperature of the added methylene blue dye is , 30 to 40 ° C., and the hue is preferably measured 0 to 24 hours after the addition of the methylene blue dye.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Compost is a mixture containing metabolites obtained by decomposing organic substances by metabolism of microorganisms and microorganisms, and is useful for plants by applying compost to soil. The components are directly or indirectly incorporated into plants through microorganisms and small organisms in the soil to be assimilated. However, depending on the composting conditions, substances harmful to the plant may be generated in the compost or pathogenic bacteria that inhibit the growth of the plant or soil microorganisms may be generated. In other words, not all composts obtained by decomposing organic waste by microorganisms are suitable for growing plants, and in order to obtain an appropriate compost, it is extremely important to adjust the conditions while paying attention to the composting environment.

[0020] Good quality compost is one that does not contain components and microorganisms that inhibit the growth of the plant, and can appropriately provide nutrients necessary for the growth of the plant to the plant. In order to obtain high-quality compost, it is more important that non-degradable decomposition due to depolymerization such as fermentation of organic matter proceeds, rather than decay during the composting process. This does not require an unnatural state in which a specific microorganism species is administered to organic waste and propagates only the organic waste, but can be achieved by appropriately managing the propagation of soil microorganisms. In short, it is important to perform fermentation / decomposition by complex bacteria instead of fermentation by simple bacteria.

Hereinafter, the determination of the degree of maturity of compost according to the present invention will be described with reference to the drawings. FIG. 1 shows a process chart of the method for measuring the maturity of compost according to the present invention.

1 of FIG. ~ 3. Shows the extraction process
I have. The extraction process first includes: Now the compost during the composting process
Part of the chemically treated product (eg, sample extract and methylene blue
-A small amount capable of reacting with the dye is sufficient. ), In this embodiment
Collects and weighs 1.5 g of the composted product in a beaker. Next
And 2. In 1. Sample preparation solution for sample
(KH ₂PO₄/ K₂HPO₄ buffer 100mM pH7.5 [final co
nc 47mM]) and stirred with a stirrer for 3 minutes.
I do. And 3. In 2. Samples and sumps
The filter solution is filtered through a No. 5 filter paper.
And

FIG. ~ 6. Shows the reaction steps. The reaction step is 4. Into a small transparent sealed container shown in (1), add a solution obtained by mixing 0.9 ml of the sample extract with respect to 1.0 ml of the reaction reagent up to the upper limit of the closed container. (Refer to 5. When measuring the absorbance, Select a cell that can be used as a photometer cell). 6. Then, the sealed container is sealed tightly so that air bubbles do not enter, and the sealed container is heated to 35 ° C.
Put in a constant temperature bath.

FIG. 2 shows a measurement step and a judgment step. The measurement was performed visually or using a spectrophotometer for the first measurement 6 hours after the start of the reaction between the sample extract and the reaction reagent, and 24 hours after the start of the reaction, the second measurement was performed visually or using a spectrophotometer. Measurement. The judgment is
In the case of visual measurement, the maturity of the compost is compared with a colorimetric sample in which the maturity of the compost is previously associated, and in the case of measurement using a spectrophotometer, the standard curve in which the maturity of the compost is associated in advance The determination of the degree of maturity is automatically performed as compared with.
Further, the measurement result may be determined according to the following table.

[0025]

[Table 1]

In Table 1, ABS is an abbreviation of absorbance (absorbance: an amount indicating the ratio of a substance absorbing light).
OD is an abbreviation of optical density (optical density: the degree to which a solute in a liquid absorbs light is represented by the logarithm of the reciprocal of the light absorption rate). In the rank column, D is the highest quality. Bad, S is the best quality compost, D, C, B,
The compost quality is ranked in five stages in the order of A and S.

The methylene blue dye serving as the indicator is:
Since the final concentration at the time of mixing is set to be optimal, when the mixing ratio is changed, the concentration must be changed as appropriate. In addition, p of sample preparation solution (buffer)
H is set so that the reaction is optimal in a normal compost, but the pH, concentration, type of sample adjustment liquid, and the like may be changed depending on the target compost.

The extraction conditions in the above extraction step may change the concentration or the like depending on the type of compost. In addition, in the stirring step and the filtration step, in addition to the above, a shaker may be used instead of the stirrer, and a centrifuge may be used instead of the filtration. However, at this time, it is necessary to confirm the correlation with the above-mentioned extraction step.

In the above reaction step, the temperature condition is 35 ° C.
Can be changed, but it will take longer. Further, the judgment is based on the fact that the initial absorbance is around 2.0, and this is not the case when the concentration of the reaction reagent is changed. Then, in the above determination method, the absorbance to be measured is 660 nm, but this is because the instrument used for the measurement is the maximum absorption wavelength of methylene blue 665 nm
This is because there is no filter. For this reason, the wavelength used for the measurement is around 665 nm, and there is no problem as long as the equipment used for the measurement has a sensitivity in the wavelength range near this.

Next, the above determination result will be described with reference to the drawings.

FIG. 2 is a sample color sample used for visual judgment. According to this, as a determination rank, yellowish is 3
Nine kinds of colorimetric labels of three types (columns of judgment ranks D and B), three types of patina (columns of judgment ranks C and A), and three types of dark blue type (judgment and S after 24 hours of judgment rank) The maturity of the compost can be determined accurately and with high accuracy even if it is visually observed.

Next, a determination method based on absorbance will be described.
FIG. 3 shows the results of judging samples having different maturity levels in a certain composting facility. According to FIG. 3, the immature primary fermentation and secondary fermentation samples, and the product with poor fermentation state, have a reduced absorbance at 6 hours after the reaction, and it can be determined that they are immature. Further, after 24 hours, the absorbance of the slightly immature tertiary fermentation sample decreases, and it can be determined that the sample is a good product.

FIG. 4 shows the results obtained by collecting samples of the primary fermentation stepwise and analyzing them. It can be seen that the longer the number of days of composting and the more mature the sample, the slower the decrease in absorbance. As described above, even for the same immature sample, the degree of maturity can be determined by measuring the change over time in absorbance.

Further, the influence of composting is determined based on the conditions of pH and temperature. FIG. 5 shows the effect of using only immature compost and changing only the pH of the reaction conditions. As a result, the standard condition of pH 7.5 has the fastest reaction, and immature compost can be quickly identified.

FIG. 6 shows the same immature compost as in FIG.
This shows the effect of the reaction temperature. As a result, the reaction rate is the fastest at the standard condition of 35 ° C., and immature compost can be quickly identified.

[0036]

As described above, according to the present invention, there is provided a method for judging the maturity of a composted product obtained by composting an organic substance. The methylene blue dye is added to the liquid phase obtained by the extraction treatment in step 2, and the maturity of the compost is determined by estimating the amount of dissolved oxygen consumed by the microbial decomposition of the organic matter in the solvent from the change in the hue of the methylene blue dye. Therefore, it is possible to determine the maturity of composting by using the change in the hue of methylene blue as an indicator, so that a CO2 concentration meter, an oxygen concentration meter, an ammonia concentration meter, There is no need to provide various measuring devices such as a thermometer, a hygrometer and an arithmetic device, and the maturity can be measured by a simple method.

Further, since the maturity of the compost can be determined by visually observing the change in hue of the methylene blue dye, the maturity can be determined with a high degree of reliability by an operator. Then, at the time of visual observation, the maturity of the compost is determined by comparing the change in hue of the methylene blue dye and the maturity of the compost with a colorimetric sample in which the maturity of the compost is previously associated. The degree of ripening can be determined.

Further, since the change in hue of the methylene blue dye is measured by absorbance to determine the maturity of the compost, the maturity can be determined with high accuracy and easily.
Then, at the time of measuring the absorbance, the maturity of the compost is determined by comparing the change in the hue of the methylene blue dye and the maturity of the compost with a standard curve in which the maturity of the compost is previously associated.

The conditions of the methylene blue dye are set such that the absorbance when irradiating a wavelength of 650 to 670 nm in the visible region becomes 1.5 to 2.5, and the temperature of the methylene blue dye to be added is 30. It is preferable to set the temperature to ４０40 ° C. and measure the hue 0 to 24 hours after the addition of the methylene blue dye.

[Brief description of the drawings]

FIG. 1 is a process chart of the method for measuring the maturity of compost according to the present invention.

FIG. 2 is a judgment color sample in the case of visually judging.

FIG. 3 shows the results of judging samples having different maturity levels in a certain composting facility.

FIG. 4 shows the results obtained by collecting samples of the primary fermentation stepwise and analyzing them.

FIG. 5 shows the effect of using only immature compost and changing only the pH of the reaction conditions.

FIG. 6 shows the effect of the reaction temperature using the same immature compost as in FIG.

Claims (9)

[Claims] 1. A method for judging the maturity of a composted product obtained by composting an organic substance, wherein a part of the composted product is collected and extracted with a solvent to form a liquid phase. Adding a methylene blue dye, estimating the amount of dissolved oxygen consumed by microbial decomposition of the organic matter in the solvent from the change in hue of the methylene blue dye to determine the maturity of the compost maturity, Measuring method. 2. The method for measuring the maturity of compost according to claim 1, wherein the maturity of the compost is determined by visually observing a change in hue of the methylene blue dye. 3. The measurement of maturity of the compost according to claim 2, wherein the maturity of the compost is determined by comparing the change in hue of the methylene blue dye with the colorimetric sample in which the maturity of the compost is linked in advance. Method. 4. The method for measuring the maturity of compost according to claim 1, wherein a change in hue of the methylene blue dye is measured by absorbance to determine the maturity of the compost. 5. The method for measuring the maturity of a compost according to claim 4, wherein the maturity of the compost is determined by comparing a change in the hue of the methylene blue pigment with the maturity of the compost in advance with a standard curve. . 6. The method according to claim 1, wherein the concentration of the methylene blue dye added to the liquid phase is set so that the absorbance when irradiating a wavelength of 650 to 670 nm in the visible region becomes 1.5 to 2.5. The method for measuring the maturity of compost according to any of the above. 7. The change in the hue of the methylene blue dye may be measured by adding 0 to 24 hours after adding the methylene blue dye to the liquid phase.
The method for measuring the degree of maturity of compost according to any one of claims 1 to 6, which is performed after a lapse of time. 8. The method according to claim 1, wherein the temperature of the methylene blue dye added to the liquid phase is set at 30 to 40 ° C. 9. The method for measuring the maturity of compost according to claim 1, wherein the pH of the methylene blue dye added to the liquid phase is set at pH 7.0 to pH 8.0.