JPH08277189A - Assesment of compost aging degree - Google Patents

Abstract

PURPOSE: To establish a compost assessment standard in order to supply constant-quality composts with stable aging degree. CONSTITUTION: A compost is subjected to extraction with water, and the ultraviolet-absorbing components in the resultant extract are fractionatingly determined for every molecular weight to determine the rate of low-molecular weight components, and with this rate, the compost aging degree is assessed. It is preferable that the above low-molecular weight components is <=1500 in molecular weight.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to compost (hereinafter referred to as compost) that is fertilized from organic waste such as raw garbage, municipal waste, various agricultural and marine wastes generated at home, and sewage sludge. The present invention relates to a method for evaluating maturity.

[0002]

2. Description of the Related Art As a method for composting (hereinafter referred to as composting), organic substances such as straw, chaff, sawdust, etc., and inorganic substances such as zeolites and porous minerals with huge pores are used as a moisture control agent. A method for ensuring aerobic fermentation and carrying out aerobic fermentation and a method for natural deposition have been conventionally used. In addition, there are known techniques such as turning back in order to promote aerobic fermentation.

However, when an organic substance is used as the water content adjusting material, the carbon / nitrogen ratio (C / N ratio) is high, and there are many cellulosic substances and lignin substances, which are hardly decomposable substances, and therefore, it takes a long time to complete the ripe compost. . Inorganic substances that do not contain difficult-to-decompose substances as water content modifiers, for example, when using zeolite, with the problem that aluminum oxide adsorbs the phosphate content of soil, organic substances that are difficult to ferment by forced aerobic fermentation alone remained Only a mature fermented product can be obtained, and in order to obtain a fully matured fermented product, it is necessary to naturally deposit the obtained middle-aged fermented product for a longer period of time.

Further, in the method of composting by natural deposition, it takes a lot of time to obtain a fully fermented fermented product, and the fermentation is carried out in the vicinity of the surface, which is easily exposed to air due to natural deposition, and the places such as the central part and the lower part. There is a problem that the degree becomes uneven. Furthermore, there is a substance that is relatively easy to ferment and a substance that is difficult to ferment in organic waste regardless of which moisture control material is used, and it takes a long time to ferment and decompose the latter hard to ferment organic matter. There is.

For this reason, various waste treatment devices, food waste treatment devices, high-speed fermentation treatment devices for food waste, methods for composting organic waste, soil conditioners, effective use of excess sludge, etc. have been proposed. However, these technologies propose a high-speed fermentation method and a device and a method for promoting fermentation, and an appropriate index for evaluating compost, which is important for solving these problems, has not been found. It's a reality.

The compost prepared and produced by these high-speed fermentation methods is partially dried, reduced in volume, deodorized, etc.
Easy to handle, but still unfermented ingredients:
Since many components that are easily utilized by soil microorganisms remain, when applied to soil such as fields, the heat generated by secondary fermentation affects the rooting and elongation of roots of plants and crops, which inhibits the growth of plants and crops. However, it is feared that the yield will decrease.

As described above, the composting requires a long period of time, and is a management for judging the maturity of the compost from the viewpoint of producing compost of stable quality and from the technical development of the composting. Items are essential,
A reliable and essential evaluation technique has not been proposed yet. That is, in the past, it was difficult to determine how much the maturity had progressed during composting, the end point was not clear, and experience and skill were required to determine the maturity.

The appearance, which has been conventionally used as an index for evaluating the maturity of agricultural compost, is used as an index for evaluating the maturity.
Although qualitative indicators based on experience and feeling such as odor, water, aging period, color tone, and temperature history during aging period are simple indicators used in actual situations, the aging degree of the compost itself can be quantitatively determined. Not a way to evaluate. As another method of evaluating the maturity of compost, the carbon / nitrogen ratio (C / N
Ratio), amount of ripening components, evaluation by circular filter paper chromatograph, germination test for young plants, growth test and the like. Of these evaluation methods, except for the germination test and growth test for young plants, which directly measure the effects on plants and crops, the measured values fluctuate greatly depending on the raw materials, and they are quantitative indicators. Absent. In addition, the germination test and the growth test evaluate the effects on plants, and do not quantitatively evaluate the compost itself in a short time.

In the conventional agricultural waste compost, C / N is used.
A high correlation between the ratio and the maturity has been proposed, and the C / N ratio has been accepted as a compost evaluation index. However, when various organic wastes are used as a raw material like the recent municipal solid waste compost, the C / N ratio changes greatly depending on the raw material, and the correlation between the C / N ratio and the compost maturity becomes small. ing. Therefore, in this field, in order to evaluate the compost maturity, it is necessary to determine the C / N ratio and the evaluation index for each raw material.

In particular, as composts made from various organic wastes such as municipal solid wastes containing a large amount of cellulosic materials have emerged as in recent years, the conventional evaluation index does not show an accurate maturity of composts. It is difficult and it is strongly desired to determine the evaluation index of compost maturity corresponding to the raw material.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and set and provide a compost evaluation method for supplying a compost of a constant quality with a stable ripening degree.

[0012]

Means for Solving the Problems The present invention is a method of extracting compost from a solvent, fractionating and quantifying the components having absorption in the ultraviolet spectrum in the obtained extract, and determining the ratio of low molecular weight components. Is obtained and the maturity of the compost is evaluated by the ratio, and in the present invention, it is preferable that the low molecular weight component has a molecular weight of 1500 or less.

The ultraviolet spectrum portion in the present invention means a wavelength range of 190 to 350 nm.

[0014]

The function of the present invention is to dispose of domestic garbage, municipal waste,
It is applied to compost that is fertilized from various agricultural and marine wastes and organic wastes such as sewage sludge, and is also applied to all raw materials for composting, compost in the process of composting, and final compost. The aging of compost and the disappearance of food waste, as a first step, the low molecular weight components such as sugars such as glucose and amino acids such as glutamic acid that are easily dissolved in a solvent such as water in the raw materials and used by microorganisms are decomposed and used by the microorganisms, Then, as a second step, a high molecular weight component such as cellulose or hemicellulose is gradually decomposed and utilized to generate a humus component and the like.

It is important to note that low molecular weight sugars such as glucose and sucrose, which are sugar components, are easily utilized by microorganisms and disappear as cell components and energy within a short period of time. Hemicellulose,
The measured value of the low-molecular-weight saccharide does not accurately represent the maturity of compost, because a high-molecular-weight persistent substance such as lignin is gradually decomposed and supplied into compost. Therefore, it has a low correlation with the maturity and is not preferable as an evaluation index of the maturity of compost.

On the other hand, components such as proteins, amino acids, and nucleic acids that have ultraviolet absorption are gradually decomposed unlike the above-mentioned saccharides, and therefore have a high correlation with the maturity and disappearance of the compost, and the maturity of the compost is high. And / or as an index of compost. The solvent used in the present invention, water, ethanol, alcohol such as methanol,
An organic solvent such as acetone or a mixed solution thereof is preferable.

In the present invention, in the process of composting organic waste, by using the ratio of the low molecular weight component having absorption in the ultraviolet spectrum as an index, anyone can quickly obtain it without requiring high skill and experience. It has become possible to easily and quantitatively determine the maturity of compost during aging and fermentation in a short time. Since the method of the present invention makes it possible to clearly determine the completion point of composting, by using the method of the present invention for manufacturing process control, quality control, and product inspection, it becomes possible to supply stable compost of constant quality. It was

For example, when applied to soil, the ratio of low molecular weight components is 5% or less, preferably 2% or less, as a good compost evaluation index that does not affect the crop by secondary fermentation heat. Can be specified.

[0019]

EXAMPLES The present invention will be specifically described below based on examples. (Example 1) 500 g of a treated product under composting (aging) treatment in an urban garbage treatment plant (2 tons / day capacity) was sampled at each elapsed days of composting and sufficiently mixed, and then 10 g was added to a 300 ml triangle. Weighed into a flask. 200 ml of distilled water was added to this, and the water-soluble component was extracted by shaking with a rotary shaker (200 rpm) for 10 minutes at room temperature. After shaking, the extract was filtered and subjected to GPC (Gel-Permeation Chrom
atograph) method.

[GPC analysis conditions] Liquid chromatography: Shimadzu LC-10AD Detector: UV 280 nm Mobile solvent: Distilled water 1 ml / min Carrier gas: Helium He Column: Asahi Pack GS-310 7.6 mm x 500 mm Average particle size 9 ± 0.5 μm (synthetic polymer system) Sample amount: 10 μl Sample filtration: 0.45 μm filter (manufactured by cellulose acetate) FIGS. 3 to 6 show gel chromatogram patterns corresponding to the elapsed days of composting of the treated product.

The detected chromatograms are characteristically divided around a retention time (holding time) of about 18 minutes.
The molecular weight of the component corresponding to a retention time of about 18 minutes is about 1500, and will be expressed as an approximate molecular weight instead of the retention time. The ratio of the total amount of components having a molecular weight of about 1500 or less to the total amount of detected components was used as an evaluation index.

Table 1 shows the measured values of the ratio of components having a molecular weight of 1500 or less, the amount of carbon, the amount of nitrogen, and the carbon / nitrogen ratio (C / N ratio) corresponding to the number of days after composting. 1 and 2 show the relationship between the ratio of components having a molecular weight of 1500 or less and the days after composting. Note that FIG. 1 is a logarithmic plot of the data of FIG.

As shown in FIGS. 1 and 2 and Table 1, a high correlation was observed between the ratio of components having a molecular weight of 1500 or less and the number of days of composting, while the C / N ratio and the number of days of composting were found. It can be seen that the correlation with is small and it is more preferable to use the ratio of the components having a molecular weight of 1500 or less than the C / N ratio as an index of the maturity of compost.

[0024]

[Table 1]

(Example 2) As in Example 1, the treated material under composting was sampled, weighed in an Erlenmeyer flask, the same amount of distilled water was added, and ultrasonic treatment was performed for 10 minutes to extract water-soluble components. did. After the extraction, the extract is filtered and GP
C analysis was performed. Table 2 shows the results. As shown in Table 2, in the case of extraction by ultrasonic treatment, the same result as in the shake extraction was obtained.

[0026]

[Table 2]

Example 3 The same amount of compost as in Example 1 was treated under various extraction conditions, and GPC analysis was performed in the same manner as in Example 1. The results are shown in Table 3. When the extraction time was 10 minutes or more, there was no variation in the ratio of components having a molecular weight of 1500 or less.

[0028]

[Table 3]

(Embodiment 4) The sample amount to be measured is 0.5
g, and treated with the same conditions as in Example 1 except that distilled water was changed to 10 ml, and GPC analysis was performed in the same manner as in Example 1. The results are shown in Table 4. At an extraction time of 10 minutes or longer, no difference from Example 1 was observed in the ratio of components having a molecular weight of 1500 or less.

[0030]

[Table 4]

Example 5 The sample measured by GPC in Example 2 was stored at 10 ° C., and after 5 days, it was measured again in the same manner as in Example 2. The results are shown in Table 5. Molecular weight 15 even after 5 days
Almost no change was observed in the ratio of components of 00 or less.

[0032]

[Table 5]

Example 6 Various kinds of composts such as agricultural compost which is agricultural and marine waste, sewage sludge, purification centers and composts, leftover compost, and ogre powder used as a compost base are treated in the same manner as in Example 1. The water extract thus obtained was analyzed by the GPC method.

The respective gel chromatogram patterns are shown in FIG.
~ Fig. 12 also shows the ratio of the components having a molecular weight of 1500 or less and C / N
The relationship with the ratio is shown in FIG. The ratio of the low molecular weight component, which is the evaluation index of the present invention, was highly correlated with the C / N ratio, which is the evaluation index of the conventional method. As described above, the ratio of the low molecular weight component, which is the evaluation index of the present invention, has a high correlation with both the days after composting and the C / N ratio, and is effective as an evaluation index of the maturity of compost. .

Further, according to the method of the present invention, the sample amount is
It also has an effect that measurement and evaluation can be easily performed even with a small amount of 0.1 to 1.0 g.

[0036]

EFFECT OF THE INVENTION By using the method for evaluating maturity of compost according to the present invention, the compost production process such as the composting period and the quality of compost can be managed, so that the quality of compost can be stabilized and a stable supply can be achieved. became.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the days after composting and the ratio of components having a molecular weight of 1500 or less.

FIG. 2 is a graph showing the relationship between the days after composting and the ratio of components having a molecular weight of 1500 or less.

FIG. 3 is a graph showing the days after composting and gel chromatogram patterns of compost in an urban garbage treatment plant.

FIG. 4 is a graph showing the number of days of composting and gel chromatogram pattern of compost in an urban garbage treatment plant.

FIG. 5 is a graph showing the days after composting and gel chromatogram patterns of compost in an urban food waste treatment plant.

FIG. 6 is a graph showing the days after composting and gel chromatogram patterns of compost in an urban garbage treatment plant.

7A and 7B are graphs showing gel chromatogram patterns of leftover compost.

FIG. 8 (a) is a graph showing a gel chromatogram pattern of fish (tuna) ala compost, and FIG. 8 (b) is a graph showing a gel chromatogram pattern of residual rice compost.

FIG. 9A is a gel chromatogram pattern of bovine dung compost, and FIG. 9B is a graph showing a gel chromatogram pattern of human waste compost.

FIG. 10A is a gel chromatogram pattern of agricultural compost, and FIG. 10B is a graph showing a gel chromatogram pattern of municipal solid waste compost (aged product).

FIG. 11 is a graph showing a gel chromatogram pattern of a purification center / compost.

FIG. 12 is a graph showing a gel chromatogram pattern of a water extract of ogre flour.

FIG. 13 is a graph showing the relationship between the ratio of components having a molecular weight of 1500 or less and the C / N ratio of various composts.

Claims (2)

[Claims] 1. A method of extracting compost with a solvent, fractionating and quantifying the components having absorption in the ultraviolet spectrum of the obtained extract for each molecular weight, obtaining the ratio of low molecular weight components, and calculating the ratio of the compost by the ratio. A method for evaluating maturity of compost, characterized by evaluating maturity. 2. The method for evaluating maturity of compost according to claim 1, wherein the low molecular weight component has a molecular weight of 1500 or less.