JP2001129574A - Method for converting colored fermented waste water into organic fertilizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease environmental pollution caused by coloring ingredients and odorants in a colored fermented waste water by low cost. SOLUTION: A method 1 for treating waste water with a process A wherein a colored fermented waste water generated in a fermentation process and an activated clay are mixed and a process B wherein a mixture obtained by the process A is fermented, a method 2 for converting the colored fermented waste water into an organic fertilizer which additionally has a process for recovering the fermented substance fermented in the process B as an organic fertilizer and the organic fertilizer 3 obtained by the method for making the organic fertilizer, are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for treating wastewater of colored fermentation wastewater. More specifically, the present invention relates to a method of adsorbing coloring components in highly colored wastewater onto activated clay and decomposing the coloring components by fermentation. The present invention relates to a wastewater treatment method capable of reducing environmental pollution caused by colored fermentation wastewater. Further, the present invention relates to a method of converting colored fermentation wastewater into an organic fertilizer using the wastewater treatment method, and an organic fertilizer obtained by the method.

[0002]

2. Description of the Related Art Wastewater generated in the course of baker's yeast fermentation, alcoholic fermentation, amino acid fermentation, etc. is colored fermentation wastewater containing a large amount of black-brown organic substances called humic substances which are not easily susceptible to microbial degradation. At present, it is extremely difficult. Currently, anaerobic microbial treatment by methane fermentation and aerobic microbial treatment using activated sludge, etc., are being used as treatment methods for colored fermentation wastewater. However, since the treated water is still colored blackish brown, there is a problem that it cannot be discharged unless it is diluted with a large amount of water. One of the methods for treating colored fermentation wastewater is to spray the soil as liquid fertilizer. However, since the colored fermentation wastewater contains lower fatty acids and ammonia, when it is sprayed on the soil, it has a problem that it emits a bad smell and pollutes the environment. In addition, since the colored fermentation wastewater contains ammonia and other components that cause plant growth disorders, there was a problem that the soil could not be sprayed. Further, there is a risk that the colored fermentation wastewater sprayed on the soil flows out and causes water pollution, which causes water bodies such as rivers and ponds to be colored brown. One method of treating colored fermentation wastewater is to use organic acid fertilizer by "acid treatment" and "return powder method". Heat treatment at 90-100C using sulfuric acid and coagulation at 500-700C. Must be dried and granulated, which limits the conditions of the processing facility and increases the plant scale.
There was a disadvantage that energy cost was required.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is a method for treating colored fermentation wastewater generated in the course of baker's yeast fermentation, alcoholic fermentation, amino acid fermentation, and the like. An object of the present invention is to reduce environmental pollution at low cost by coloring components and malodorous substances of colored fermentation wastewater.

[0004]

Means for Solving the Problems As a result of various studies to achieve the above object, the present inventors have found that colored fermentation wastewater is produced during the purification of animal and vegetable oils and fats, which can be obtained with activated clay, especially at low cost. It has been found that the fermentation of colored fermentation wastewater by microorganisms becomes possible by adsorbing it on used activated clay (hereinafter referred to as waste clay). Thus, the present invention has been completed.

That is, the gist of the present invention is as follows: [1] Step A:
A step of mixing the colored fermentation wastewater generated in the fermentation process with the activated clay, and a step B: a wastewater treatment method having a step of fermenting the mixture obtained in the step A; [2] Step A: a colored fermentation generated in the fermentation process Colored fermentation wastewater having a step of mixing wastewater and activated clay, a step B: a step of fermenting the mixture obtained in step A, and a step C: a step of recovering the fermented product fermented in step B as an organic fertilizer. The present invention relates to an organic fertilizer method and [3] an organic fertilizer obtained by the organic fertilizer method according to the above [2].

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The wastewater treatment method will be described below with reference to the schematic process diagram of the wastewater treatment method shown in FIG. (1) Step A As the colored fermentation wastewater to be treated in the present invention, baker's yeast fermentation, alcoholic fermentation, amino acid fermentation, organic acid fermentation,
Wastewater generated in fermentation processes such as nucleic acid fermentation, antibiotic fermentation, and methane fermentation can be mentioned. The pH of the colored fermentation wastewater is not particularly limited, but is preferably around 5 to 9 neutral. In the present invention, the colored fermentation wastewater is particularly effective for highly colored fermentation wastewater that is a wastewater containing a humic substance and having a coloring degree of 80 or more.

That is, the treatment method of the present invention is a highly colored wastewater which has been difficult to treat with conventional treatment methods, for example,
Coloring degree: 80 to 50,000, moisture: 50% by weight or more, B
OD (biochemical oxygen demand): 120-50,000m
g / L, COD (chemical oxygen demand): 120-500
00 mg / L, total nitrogen: 120 to 50,000 mg / L,
Lower fatty acid 0-100,000 mg / L, phosphorus: 0-50
000 mg / L, potash: 0 to 50,000 mg / L, which can be preferably applied to wastewater. Among them, the degree of coloring is 1
It can be applied more preferably to wastewater of 00 to 50,000, and particularly preferably to wastewater of 1000 to 20,000.

In the present invention, the degree of coloring of wastewater is a value determined by a dilution method. Such a dilution method is adopted in the ordinances and regulations on the color of wastewater discharged from Wakayama City, and the measurement is performed by the method of Miyoshi et al. (Tokyo Institute of Environmental Science Annual Report, 1991, p.
164).

The activated clay used in the present invention may be a commercially available product or a waste clay. It is more preferable to use waste clay since it can be obtained at low cost. The pH of the activated clay is not particularly limited, but a pH of 1.0 to 12.0 can be preferably used, and a pH of 2.0 to 9.0 can be more preferably used. The water content of the activated clay is not particularly limited, but is preferably 20% by weight or less, more preferably 10% by weight or less. The activated clay may contain fat and ash. The content of fat is preferably 1 to 90% by weight, more preferably 10 to 50% by weight. The ash content is preferably from 1 to 90% by weight, more preferably from 10 to 60% by weight.

In order to control the water content of the mixture of colored fermentation wastewater and activated clay, sawdust, rice husk, bran, rice bran,
Dry feces, compost, pruned branches, chips and the like may be added to the mixture. Further, compost, livestock dung, soil and the like may be added to the mixture. Since high-temperature fermentation bacteria are widely present in nature and multiply spontaneously, fermentation in step B can be performed more reliably. Further, the mixture may be inoculated with a high-temperature fermenter.

In the step A, as shown in FIG. 1, the colored fermentation wastewater, the activated clay, and other components as necessary are mixed. The mixing ratio of the colored fermentation wastewater and the activated clay is not particularly limited, but from the viewpoint of ensuring fermentation, the activated clay is preferably 10 to 300 parts by weight, and more preferably 10 to 100 parts by weight, based on 100 parts by weight of the colored fermentation wastewater. Is more preferable, and 3
Particularly preferred is 0 to 70 parts by weight. In addition, when adding a component for controlling water content such as sawdust, the addition amount is preferably 1 to 300 parts by weight, more preferably 10 to 300 parts by weight, based on 100 parts by weight of the colored fermentation wastewater.
Particularly preferred is 0 to 100 parts by weight. When components such as compost are added, the addition amount is preferably 0.01 to 10 parts by weight, preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the colored fermentation wastewater.
A part by weight is more preferable, and 1 to 10 parts by weight is particularly preferable.

The mixture containing the colored fermentation wastewater and the activated clay obtained in step A preferably has a water content suitable for fermentation. The amount of water suitable for fermentation is preferably 30 to 80% by weight of the mixture, more preferably 40 to 75% by weight, and particularly preferably 60 to 70% by weight. If the water content of the mixture is too high or too low, the fermentation tends not to proceed. The temperature of the mixture is not particularly limited, but is preferably in the range of 10 to 60C, more preferably in the range of 20 to 40C. The pH of the mixture is not particularly limited, but is preferably in the range of 2.0 to 9.0, and is preferably 4.0 to 9.0.
A range of 8.0 is more preferred.

[0013] The colored fermentation wastewater is rich in nitrogen, but high in water, some of which exceed 95% by weight. Therefore, it is difficult to perform fermentation using colored fermentation wastewater alone. Activated clay has low water content, but hardly contains nitrogen, so that it is difficult to ferment it alone. In the present invention, the colored fermentation wastewater and the activated clay are mixed to adsorb the colored fermentation wastewater to the activated clay, whereby the amounts of water and nitrogen are adjusted to enable the fermentation of these mixtures.

(2) Step B As shown in FIG. 1, the mixture obtained in Step A starts to ferment over time. Here, it is preferable that the mixture is put into a container and fermented. As the container, a heat insulating container is more preferable. This is because the influence on the fermentation temperature of the external environment can be reduced. In the present invention, the mixture is fermented at a high temperature of preferably 40 to 80 ° C, more preferably 50 to 70 ° C (referred to as “high temperature fermentation”). High temperature fermentation of the mixture has the advantage that removal of coloring substances and malodorous substances and evaporation of water are performed at low cost and in a short period of time. In order to maintain the fermentation of the mixture, it is preferable to provide, for example, a means for supplementing a nitrogen source such as ammonia, ammonium sulfate, ammonium nitrate, peptone, or for surrounding the periphery with a heat insulating material for keeping the temperature. In addition, microorganisms for causing fermentation of the mixture are many in the natural world such as livestock manure and soil, sewage, rivers and ponds, and fermentation usually occurs spontaneously without particularly adding such microorganisms. Starts with

The time required for fermentation cannot be unconditionally determined because it depends on the amount of the mixture and the like, but is preferably 5 to 40 days, more preferably 10 to 30 days. In the course of fermentation, the fermentation temperature once increased usually drops to the same level as the temperature of the external environment. This time is defined as the time when the process B is completed. In this way, the colored fermentation wastewater can be treated. The degree of coloration of the fermented product obtained as described above is preferably reduced to 30 to 70% before the treatment. Further, the fermented product preferably has a water content of 40
It becomes a solid matter of not more than weight%, and is in a state where it is easy to handle. Further, the fermented product has a reduced amount of malodorous components and components that inhibit plant germination and the like. It is considered that this is because the coloring components and the like in the colored fermentation wastewater were decomposed by fermentation, and the water was evaporated by the fermentation.

2. Organic fertilizer method of colored fermentation wastewater The organic fertilizer method of the present invention is a method including a step of recovering the fermented product fermented in step A, step B, and step C: step B as an organic fertilizer. The specific operation of the recovery is not particularly limited. Fermented products are 1) solids that are easy to collect and handle due to low water content. 2) Colored substances and malodorous substances are reduced. Less, 3) rich in nitrogen,
In addition to this, 4) components that cause plant growth disorders are also removed, so that it can be used as it is as an organic fertilizer. In addition, the resulting fermented product can be used as organic fertilizer,
It is preferable not to contain harmful components such as heavy metals and cyanide compounds. Further, the present invention includes an organic fertilizer obtained by the method of the present invention.

[0017]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. Hereinafter, the baker's yeast fermentation wastewater shown in Table 1 was used as the coloring fermentation wastewater.

[0018]

[Table 1]

The harmful substances of all mercury, cadmium, lead, chromium, arsenic and cyanide were below the detection limit. Appearance, pH, BOD, COD, ammonia nitrogen, phosphorus, potassium, total mercury, cadmium,
Lead, chromium, arsenic, and cyanide were measured by the method described in the Industrial Wastewater Test Method (JIS Handbook Environmental Measurement, Japan Standards Association). For total nitrogen,
It measured by the method described in the sewer test method (Japan Sewer Association). For lower fatty acids (here, propionic acid, butyric acid, and isovaleric acid), ADA was used according to the method of Mori et al. (Journal of the Society of Animal Husbandry, 61: 796-800, 1990).
It was derivatized with M reagent (Funakoshi Co., Ltd., Tokyo) and measured using high performance liquid chromatography. The atmospheric pressure heating and drying method described in the New Food Analysis Method (1996, edited by Japan Society for Food Science and Technology, p.6) was used for the measurement of moisture.
The calorific value is measured by the conversion factor described in the New Food Analysis Method (ibid., P.
/ G). Table 2 shows the moisture, pH, and component composition of the waste clay used below.

[0020]

[Table 2]

The harmful substances cadmium, total cyanide, lead, hexavalent chromium, total chromium, arsenic, total mercury, antimony, polychlorinated biphenyl, trichloroethylene and tetrachloroethylene were below the detection limit. Cadmium, all cyanide, lead, hexavalent chromium, all chromium, arsenic, all mercury, antimony, polychlorinated biphenyl,
Trichloroethylene and tetrachlorethylene were measured by the method of Notification No. 13 of the Environment Agency in 1973. The pH was measured with a pH meter after 5 g of waste clay was placed in 50 mL of distilled water, stirred well, and allowed to stand for 30 minutes. Nitrogen is described in detail in Fertilizer Analysis Method (supervised by Teruo Nakamura, No. 3
It was measured by the sulfuric acid decomposition method described in Ykendo, p.14), published in 1969. Silicon dioxide, aluminum oxide,
Ferric oxide, calcium oxide, magnesium oxide, sulfur trioxide, sodium oxide, potassium oxide, and chlorine were measured in accordance with the Japan Society of Cement Association “Analysis method for siliceous raw materials”. The same method as described above was used for measuring the moisture and the calorific value. The measurement of fat is
The ether extraction method described in the New Food Analysis Method (ibid., Pp. 45-48) was used. The ash was measured using the direct incineration method described in the New Food Analysis Method (ibid., P.99-101).

Test Example 1 The transition of the fermentation temperature in the method of the present invention was examined. The results are shown in FIG. Samples include a mixture of colored fermentation wastewater and waste clay (black triangles in FIG. 2), a mixture of distilled water and waste clay (black squares in FIG. 2), and a mixture of sawdust and colored fermentation wastewater (FIG. 2). (Black circle). About 1.5 kg of a liquid component (colored fermentation wastewater and water) was used, and about 1.5 kg of a solid component (waste clay and sawdust) was used to obtain a mixture. Immediately after mixing, the pH of the mixture of colored fermentation wastewater and waste clay was 3.4.

The mixture of the above combinations was put into a stainless steel tank provided in a room, and the temperature (fermentation temperature) at the approximate center of the mixture was measured. Room temperature was between 20-30 ° C. throughout the measurement period. From the graph of FIG. 2, the mixture of colored fermentation wastewater and waste clay has a fermentation temperature of 5 from the second day.
The temperature rose to 7.6 ° C. and reached 60 ° C. on the third day. The temperature was maintained at 50 ° C. or higher until the 10th day, and was maintained at 30 ° C. until the 25th day. On the other hand, the mixture of waste clay and distilled water and the mixture of colored fermentation wastewater and sawdust did not raise the fermentation temperature at all.
From this, it was found that fermentation was possible by mixing colored fermentation wastewater and waste clay.

Example 1 In the process of treating a mixture of colored fermentation wastewater and waste clay in Test Example 1, changes in moisture, coloring degree and lower fatty acid content as a malodorous substance were examined. Table 3 shows the results. “Before treatment” refers to a stage before receiving the wastewater treatment of the present invention, and here, 5 mL of colored fermentation wastewater before treatment is taken, and 50 mL is taken.
Was extracted with distilled water for 24 hours, and the degree of coloring and the amount of lower fatty acids were measured for the extract obtained. "After waste clay adsorption treatment" refers to a stage immediately after mixing of colored fermentation wastewater and waste clay, and here, a mixture containing 5 mL of colored fermentation wastewater is similarly extracted with 50 mL of distilled water. About the obtained extract, the degree of coloring and the like were measured. "After fermentation"
The term refers to a stage at which the fermentation temperature has become approximately equal to room temperature, that is, a stage at which the fermentation has been completed. In this example, the degree of coloring and the like were measured for a mixture (fermented product) 30 days after mixing, in which the fermentation temperature was almost the same as room temperature. Here, the same amount of fermentation product as the amount of the mixture after the waste clay adsorption treatment was taken, and the degree of coloring and the like were measured for the extract obtained in the same manner as above. The atmospheric pressure drying method described in the New Food Analysis Method (ibid., P. 6) was used for the moisture measurement.

[0025]

[Table 3]

For the colored fermentation wastewater, the mixture, and the fermented product, extracts were obtained three times each for measurement.
Numerical values in Table 3 are shown as an average value of three times ± standard deviation.
The values in parentheses in Table 3 indicate the removal rates as compared with the values before the treatment. In addition, the amount of lower fatty acid is 1 L of the extract.
Per volume. The degree of coloring was measured by the same dilution method as described above. The amount of each lower fatty acid was measured by the above method using high performance liquid chromatography.

As can be seen from Table 3, the coloring degree of the extract of the mixture after the waste clay adsorption treatment was reduced by 33.3% as compared with that of the colored fermentation wastewater extract before the treatment. In addition, the coloring degree of the extract of the obtained fermentation treatment product was reduced by 67% as compared with that of the extract before the treatment. From this, it is understood that the coloring component of the colored fermentation wastewater is decomposed by the fermentation treatment, and environmental pollution due to the colored fermentation wastewater can be reduced.

Changes in the content of lower fatty acids, which are malodorous substances, were also examined. The amounts of propionic acid and butyric acid extracted with distilled water were respectively 16.0 by the waste clay adsorption treatment.
% And 15.0%. The content of propionic acid, butyric acid, and isovaleric acid in the extract of the fermented product was reduced by 70% or more as compared with that of the extract before the treatment. Also,
The colored fermentation wastewater had a water content of 95% by weight and was difficult to handle. On the other hand, after the fermentation treatment, the water content was reduced to 36% by weight, resulting in a solid powder that was easier to handle. From the above, it can be seen that the fermentation treatment evaporates the moisture of the colored fermentation wastewater, decomposes the offensive odor substance, and makes it a solid suitable for handling, thereby reducing the environmental pollution by the colored fermentation wastewater. Was.

Example 2 The possibility of using a solid after fermentation as an organic fertilizer was examined. The fermentation product (solid powder) obtained in Example 1 was analyzed for fertilizer components. Assays were measured for moisture, pH, nitrogen, organics, ash, phosphorus, and potash. For water, pH, ash, and phosphorus (vanado molybdic acid method), fertilizer analysis method (Yokendo, Tokyo, 19
69) was measured by the method described in (69). Nitrogen content was measured using a CN coder. Potassium was measured by the atomic absorption method. Organic matter was obtained by subtracting ash from the amount of dry matter from which water was completely removed from the mixture. Table 4 shows the results.

[0030]

[Table 4]

As can be seen from Table 4, the pH of the fermented product is in a neutral range, contains 50% by weight or more of organic matter, and contains nitrogen, phosphorus and potash necessary for plant growth. It is clear that the mixture can be preferably used as an organic fertilizer.

Example 3 Next, a germination test was performed to confirm the safety of the fermented product against plants. The germination test was performed as follows. 10 g of the mixture and the fermentation product after the waste clay adsorption treatment in Example 1 were taken, and extracted with 100 mL of distilled water at 60 ° C. for 3 hours to obtain an extract. 8 mL of the extract was added to a petri dish from which three filter papers were pulled, and 25 komatsuna (variety name: Osome) seeds were sown thereon, cultured at 25 ° C in the dark, and the germination rate after 3 days was examined. Table 5 shows the results.
Shown in

[0033]

[Table 5]

As shown in Table 5, the extract of the mixture after the adsorption treatment of the waste clay had no germination rate of 0%, and the coloring fermentation wastewater contained a large amount of a component inhibiting germination. I understood. On the other hand, the extract of the fermented product had a germination rate of 97% or more, which was the same as that of distilled water used as a control, and it was found that no component inhibiting germination was contained. From this, it was clarified that the components that inhibit germination in the colored fermentation wastewater were decomposed and removed by the fermentation treatment, and the obtained solid was safe for plants.

Example 4 Next, in order to confirm the effect of the fermented product as an organic fertilizer, a pot cultivation test using Komatsuna was performed. 5 g of the fermented product obtained in Test Example 1 was mixed with 495 g of masago (addition section), and the mixture was placed in a Neubauer pot. 25 seeds of Komatsuna (variety name: Osome) were sowed on this. As a control, 500 g of masago (untreated group) was similarly placed in a Neubauer pot, and seeded with Komatsuna. In both sections, three pots were prepared by the same operation. They were given appropriate water, cultured under dark conditions at 25 ° C. for 3 days, germinated, and then cultivated under natural light for 10 days. After cultivation,
The plant height, leaf diameter and aboveground dry weight of Komatsuna were measured, and the average value for each section was calculated. Table 6 shows the average values.

[0036]

[Table 6]

As shown in Table 6, the plant height of the added group was 24.
At 1 cm, it was 15.3% higher than 2.09 cm in the non-added group, and the growth was good. Leaf diameter of addition section is 1.39cm
As compared with 1.31 cm in the non-added section, a 6% increase effect was recognized. The above-ground dry weight was 10.1
6 mg, 19.2 compared to 8.52 mg in the non-added group.
% Increase effect was recognized. As can be seen from the above, it has been clarified that the fermented product treated by the method of the present invention can be used as an organic fertilizer and promotes plant growth.

[0038]

According to the wastewater treatment method of the present invention utilizing the fermentation of colored fermentation wastewater and activated clay, environmental pollution caused by the colored fermentation wastewater can be reduced with low cost and simple operation, and the handling is easy. Organic fertilizer can be manufactured. Further, the organic fertilizer obtained by the method of the present invention,
Components that inhibit germination and the like have been removed and are useful as fertilizers. The present invention is a method based on the utilization of waste and treatment with microorganisms, and can easily treat colored fermentation wastewater at extremely low cost as compared with the conventional method using a large amount of equipment such as a harmful substance such as sulfuric acid or a drying apparatus. That's how you can.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a wastewater treatment method of the present invention.

FIG. 2 is a graph showing the relationship between fermentation days and fermentation temperature.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Michio Sakimoto, Osaka Prefecture Agriculture and Forestry Research Center, Scale 442, Osaka Prefecture Agriculture and Forestry Research Center (72) Inventor Satoshi Nakaoka 854 Nishijinyoshicho, Kakogawa-shi, Hyogo Pref. (72) Inventor Kimihiko Kono 739-12 Futami-cho, Futami-cho, Akashi-shi, Hyogo F term (reference) 4D027 BA03 BA06 4D038 AA08 AB03 BB19 4D040 DD01 DD11 4H061 AA01 AA02 CC45 CC51 DD20 EE43 GG48 GG56 HH35 HH42

Claims (6)

[Claims] 1. A wastewater treatment method comprising: a step A: a step of mixing colored fermentation wastewater generated in a fermentation process with activated clay; and a step B: a step of fermenting the mixture obtained in step A. 2. The wastewater treatment method according to claim 1, wherein the colored fermentation wastewater is wastewater generated in a baker's yeast fermentation process. 3. The wastewater treatment method according to claim 1, wherein the activated clay is used activated clay generated during refining of animal and vegetable oils and fats. 4. The wastewater treatment method according to claim 1, wherein the colored fermentation wastewater is a wastewater containing a humic substance and having a coloring degree of 80 or more. 5. Step A: a step of mixing colored fermentation wastewater generated in the fermentation process with activated clay, Step B: a step of fermenting the mixture obtained in Step A, and Step C: a fermentation fermented in Step B. A method for converting colored fermentation wastewater into an organic fertilizer, comprising a step of recovering the treated product as an organic fertilizer. 6. An organic fertilizer obtained by the method according to claim 5.