JP2002273473A - Waste water treating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To operate a waste water treating system having a yeast treating section for decomposing the waste water containing organic waste by the yeast while maintaining a proper pH condition where yeast preferentially grows in order to reduce the maintenance load on the waste water treating system and in order to provide a space-saving waste water treating system. SOLUTION: Organic acids are made to be generated in an acid fermentation section and thereby the pH of the waste water flowing in the yeast treating section is maintained at an optimum pH condition for growing the yeast.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wastewater treatment system for treating organic waste such as kitchen garbage generated in apartment houses, business establishments, hospitals and the like.

[0002]

2. Description of the Related Art Conventionally, as a method for treating organic waste such as kitchen garbage, wastewater treatment by an activated sludge method using aerobic bacteria has been known and used. In addition, a relatively high BO such as a place where a disposer, which is a crushing unit for crushing garbage and solubilizing with water at home, is installed.
Where wastewater having a D value is generated, a method of efficiently treating wastewater by attaching flocculent bacteria to a carrier has been taken. However, there is a limit in treating wastewater obtained by subjecting kitchen waste generated in homes and industries to crushing treatment by a disposer in a more space-saving manner because of having a relatively high BOD value.

[0003] In addition, factory wastewater such as brewing and starch plants discharged with a high sugar content, factory wastewater such as a fish surimi factory and a meat processing plant discharged with a high protein content, or restaurants and hotels It is difficult to efficiently treat wastewater containing a large amount of oil discharged by cooking, such as hospitals and office kitchens, due to wastewater having a high BOD value.

As described above, there is a need for a technology and a system for treating wastewater having a high BOD value for any wastewater. A method of treating wastewater having a high BOD value by using yeast having properties has been devised.

[0005]

However, Japanese Patent Laid-Open Publication No.
The treatment method disclosed in Japanese Patent No. 29289 has been improved so as to control the pH with sulfuric acid or the like in order to properly grow the yeast in the yeast treatment section. Regarding the deterioration of the growth conditions in the yeast processing part, the acid solution etc. is dropped periodically, and it is necessary to supply an excess acid solution in order to maintain certain conditions for controlling various bacteria. It had never stopped.

[0006] Further, since an excessive acid solution is supplied, there is a concern that the maintenance load such as periodic replenishment of the acid solution may be increased. There was a problem in designing.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a space-saving wastewater treatment system that operates stably, reduces the load of maintenance, and saves space. And

[0008]

According to a first aspect of the present invention, there is provided a wastewater treatment system containing organic waste according to the present invention, wherein an acid fermentation unit and a yeast treatment unit are combined. Provided, by controlling the pH of the yeast treatment section to a range that is a condition under which yeast can grow as a dominant species,
The operation of the yeast processing unit is controlled.

In order to maintain yeast as the dominant species while suppressing bacterial growth, the optimal and effective conditions are pH
It is known that yeast can efficiently treat wastewater having a high BOD value by maintaining its growth conditions.

[0010] Therefore, in the yeast processing section, in order to maintain appropriate growth conditions for growing yeast,
It is effective to control the pH of the yeast treatment section so that it can be maintained acidic, and it becomes possible by providing an acid fermentation section as the first technical means of the present invention.

According to a second technical means, in the wastewater treatment system according to the first technical means, an acid is used as a means possessed by the pH control means. The acidic water obtained by the decomposition is used to control the operation of the yeast treatment section by controlling the pH of the yeast treatment section in order to maintain more optimal yeast growth conditions while suppressing the growth of various bacteria.

Further, as a fourth technical means, in a wastewater treatment system having the first technical means, by adding and mixing together with a bactericide, the propagation of various germs is suppressed efficiently, and yeast is dominant. Let them grow. p
By installing together with the H control means, the growth conditions of the yeast can be efficiently maintained in an advantageous state.

As a fifth technical means, a solid-liquid separating means is provided by using the first technical means. The solid content in the acid fermentation section is separated, and only the liquid content is treated with yeast to improve the efficiency. It can grow yeast well. In addition, by using this means, most of the solid suspended components are occupied by yeast, and by collecting the solid content, it is possible to obtain sludge having a small amount of impurities and a high protein content.

Further, according to the sixth technical means, in the wastewater treatment system using the fifth technical means, the solid content is recovered by natural sedimentation, which is a simple structure of the solid-liquid separation means. . It is possible to collect solids with low maintenance and to decompose liquids by yeast treatment.

According to the seventh technical means, in the wastewater treatment system using the fifth technical means, the solid-liquid separating means is constituted by a filtration membrane, and the solid-liquid separation is performed in a space-saving manner. Things. By using such a means, it is possible to construct a wastewater treatment system in a more space-saving yeast treatment.

[0016]

DETAILED DESCRIPTION OF THE INVENTION Wastewater containing organic waste is introduced into a yeast treatment section, and yeast predominantly living there undergoes purification treatment by assimilating or decomposing organic compounds. The wastewater containing organic waste that is fed into the acid fermentation unit and the yeast treatment unit can process any wastewater if there is no harmful substance that inhibits the growth of yeast. Not only can be introduced as a system to treat rice washing wastewater, meat washing wastewater, and oil / fat factory washing wastewater, but also a high BO that separates solids and liquids from brewery residues and garbage containing large amounts of solids.
The system can be used as a system for treating the supernatant of wastewater having a D value.

In a system provided with a pulverizing unit for finely pulverizing solids and a disposer for pulverizing kitchen garbage, organic waste mainly composed of kitchen garbage is pulverized by a disposer and transferred to a pipe with water to generate waste. In the vicinity of a place, in a house, a detached house, an urban area unit, or an apartment house unit is transferred, and in a factory, an organic waste treatment system installed in a factory unit or the like is transferred. In this system, the organic waste is stored in the acid fermentation unit to generate organic acids to suppress the growth of various bacteria other than lactic acid bacteria, and then the air is intermittently or continuously supplied to the yeast processing unit by a blower. By blowing, yeast capable of growing together with lactic acid bacteria is grown, solubilized and decomposed by the yeast efficiently, and solubilized and decomposed.

Next, in either a system with or without a pulverizing unit, an acid fermentation unit that generates an organic acid such as lactic acid or acetic acid, and a yeast treatment that stores microorganisms such as yeast. And the solid matter such as yeast contained in the treated water which has been treated by the yeast treatment section and flowed out of the yeast treatment section as it is, is separated by natural sedimentation in the separation section, and the supernatant is discharged as treated water. Yeast has a larger cell size than bacteria and produces sludge that is easier to settle than using the activated sludge method.For example, installing a resin carrier in the separation unit and filtering the sludge to release the supernatant Thus, a more stable system can be constructed.

If a pH meter, an ORP meter, or a DO meter as a water quality detecting means is installed in the yeast processing section,
The pH value, ORP value, etc. of the yeast processing section are always measured. In addition, pH control means is also installed in the yeast processing section, and a pH meter or ORP as a water quality detection means is provided.
It is possible to control the operation of the pH control means according to the output result from the meter.

By controlling the pH, the yeast grows more vigorously, and the surplus yeast grown is aggregated, collected, dried, and crushed to obtain abundant proteins and vitamins including abundant proteins. There is an advantage that it can be used as a high-quality fertilizer containing substances that are effective for the body. Yeast extract as a fertilizer requires many media components including vitamins,
For example, it can be used as a culture medium for microorganisms that ferment and produce mushrooms such as shiitake mushrooms and shimeji mushrooms, or useful substances.

Organic acids such as lactic acid and acetic acid have a lower degree of dissociation than inorganic acids such as hydrochloric acid and sulfuric acid, and are persistent, and work effectively in inhibiting the growth of bacteria. At least as much as possible, it is possible to maintain the yeast-treated portion under appropriate yeast growth conditions. Organic acids are produced when lactic acid bacteria and acetic acid bacteria grow under anaerobic conditions, do not need to be added artificially, and are extremely excellent in maintenance saving.

In a system equipped with a disposer, an organic waste such as kitchen garbage is pulverized and then solubilized, so that lactic acid and acetic acid are generated based on the solubilized components in an acid fermentation section. Lactic acid bacteria and acetic acid bacteria are actively grown, and it is easy to prepare the optimal conditions for operation management of the yeast processing section,
The labor for controlling the water quality to the yeast treatment section can be omitted. A low-maintenance system can be constructed, and an inexpensive and stable system can be provided.

If it becomes possible to operate the system as a stable wastewater treatment system, the capacity of the tank in the yeast treatment section and the separation section can be reduced. The entire wastewater treatment system can be provided in a space-saving manner, and a wastewater treatment system that can be installed in restaurants, small-scale food factories, and the like where installation locations are limited can be provided. As a result of the construction of a system that requires less maintenance, not only the capacity of the wastewater decomposition treatment is improved, but also the growth of yeast that inhabits the yeast processing unit becomes active, and high-quality surplus yeast can be collected.

By providing solid-liquid separation means for solid-liquid separation of the treated water in the acid fermentation section, the solid content obtained in the acid fermentation section can be recovered. By subjecting the recovered material to a drying treatment, the solid content contains a large amount of fiber, and can be secondarily fermented, and a high molecular compound other than fiber can be reduced in molecular weight and composted. As a result, it can be a useful culture base or a soil conditioner having a fertilizer component that is a low molecular weight compound that is easily assimilated and absorbed and has water retention. The base material rich in fiber with high water retention is particularly useful for producing cultivated plants of beans and root vegetables, and it is possible to produce high-quality cultivated plants by adding together with yeast extract obtained from surplus yeast. is there.

In the acid fermentation section, the excess lactic acid produced by the lactic acid bacteria can be recovered, polymerized and converted into resin, and the efficient recycling of garbage can be realized simultaneously with the decomposition treatment of the wastewater.

Since the disposer is installed, the organic waste is treated by the disposer installed in the kitchen in the place where the organic waste is generated, and in the house. There is no need to store organic waste such as kitchen garbage until the garbage collection date of the government, etc.
The hygiene of living space and working space is improved. In addition, when storing garbage in a house, etc., organic waste can be separated in advance, so not only storage of other dry waste becomes sanitary, but also storage place As a premise, it is not necessary to use a closed structure or the like, and storage is easy. In addition, in the process of collecting dried waste other than organic waste into garbage, collecting it, separating it with a machine, etc., and recycling it, this system that provides pre-separation of organic waste Greatly improves workability.

[0027] The system of the present invention not only enables the yeast processing section to be maintained under optimal growth conditions, but also produces high-quality surplus yeast by activating the growth of yeast.
It can be used secondarily as a fertilizer. Further, since a more stable yeast treatment can be performed by installing the disposer, surplus yeast can be obtained more stably, and the wastewater containing the organic waste pulverized by the disposer can be obtained by solid-liquid separation. The solid content can be used effectively. With this system, an efficient recycling system can be provided.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a flow of wastewater treatment including organic waste using the technique of the present invention. The system of the present invention comprises a disposer as a crushing unit 1 and a water supply unit 3 for supplying water for transporting the crushed material, a transfer unit 2 including a pipe or the like for transporting the crushed material, and drainage under anaerobic conditions. Fermentation unit 4 that stores the water, solid-liquid separation means 5 that separates the solid content of the acid fermentation unit, yeast processing unit 6 that inhabits yeast and assimilates and decomposes organic waste, and air installed inside. And a separating section 7 for separating treated water from yeast or solids. In addition, a pH meter 9 for timely measuring the water quality of the yeast processing unit 6 is installed, and a pH control unit 1 for adjusting the pH of the yeast processing unit 6 to an appropriate state.
0 is provided. The acid fermentation unit 4 is provided with a stirring unit 8 for stirring wastewater to promote fermentation.

Organic waste such as garbage generated at home or in a restaurant or food factory is put into the crushing section 1 and crushed, and at the same time washing water such as water and medium water is supplied from the water supply section 3. Supply water. The crushed waste water is transferred to the acid fermentation unit 4 after being transferred through the transfer unit 2 and performs acid fermentation.
The supernatant liquid is transferred to the yeast processing section 6 through the solid-liquid separation means 5, and the air supplied from the air diffuser 11 is obtained to assimilate and decompose wastewater containing organic waste while growing yeast. The treated wastewater flows into the separation unit 7, where the solid content and the yeast are separated from the supernatant, and the supernatant is discharged to the outside. Further, the solid matter and yeast separated in the separation unit 7 are fed into the yeast treatment unit 6 together with the newly-introduced acid-fermented wastewater via the return pipe 12.

During the operation of the present system, the pH of the yeast processing section 6 is adjusted to a range of pH 4 to 6, which is optimum for yeast to grow dominantly. In order to inspect the water quality of the yeast processing section 6, a water quality detecting means is measured at regular intervals by the pH meter 9. If the pH is not within the optimal pH range based on the result obtained by the pH meter, the pH control means 10 is driven to adjust the pH of the yeast treatment unit 6 to an optimal range by adding an acid. The water quality detection means is not limited to a pH value, and may use an instrument for measuring an ORP value or a DO value.

FIG. 2 shows the pH control means 11. Inside, a chemical tank 22 formed of a strong acid-resistant material
Solution tube 23 for dropping the solution and the solution, the solution tank 2
2 is a chemical liquid valve drive unit 24 that opens and closes a valve so that an appropriate amount is dropped onto the yeast processing unit 4 via the chemical liquid tube 23. The chemical tank 22 contains p
It is filled with an acid solution such as sulfuric acid or lactic acid for adjusting H.

The pH control means 11 may be constituted by an electrode which generates an acidic water by applying a voltage in water instead of the one constituted by the chemical liquid tank 22. By supplying the acidic water, the pH of the yeast processing unit 6 can be controlled and managed by an electric signal, so that a very simple system is supplied.

In the present invention, the effect can be enhanced by using the technique according to claim 4 in order for yeast to grow more dominantly. Similar to the pH control means 9 for controlling the pH, the yeast treatment section 9 is provided with a disinfectant injection means filled with a disinfectant for suppressing the growth of bacteria. As a bactericide, an antibiotic such as sodium hypochlorite or chloramphenicol is used. Alternatively, ozone may be generated electrically and injected into the yeast processing unit 6. When a non-selective disinfectant such as sodium hypochlorite or ozone is used, the organic substance is oxidized in the presence of the organic substance and immediately deactivated. By determining and controlling the addition amounts of sodium hypochlorite and ozone according to the organic matter flowing into the system, it is possible to optimize the yeast processing unit 6 more effectively. In particular, it is effective when the pH value increases and bacteria grow.

If the wastewater containing organic waste is anaerobically treated in the acid fermentation section 4, the acid fermentation can be easily performed by the action of lactic acid bacteria producing lactic acid and acetic acid bacteria producing acetic acid. Can be done. In this embodiment, the organic acid is produced by stirring the waste water crushed through the crushing unit 1 by the stirring unit 8. Instead of stirring, a pump for circulating the treated water in the acid fermentation section 4 or a means for intermittently supplying and stirring an inert gas or air may be used. The pH of the treated water of the acid fermentation section 4 is reduced to about 4 in 24 hours due to the generation of organic acids. The optimum yeast growth conditions for the yeast processing section 6 are pH 4 to 6, and the pH can be lowered by the acid fermentation section 4 to allow the yeast to grow very efficiently.

Further, in the present invention, the solid-liquid separating means 5
Is provided, it is possible to separate the solid content of the acid fermentation unit 4 and transfer only the supernatant to the yeast treatment unit 6. Since the lactic acid fermentation and the acetic acid fermentation are performed in the acid fermentation unit 4, the supernatant liquid flowing into the yeast processing unit 6 contains a relatively large amount of lactic acid and acetic acid. The supernatant is composed of microorganisms, such as lactic acid bacteria and acetic acid bacteria, which are extremely limited and cannot coexist with yeast because many bacteria cannot grow. Therefore, it is possible to efficiently perform the decomposition treatment using yeast.

Further, by providing the solid-liquid separation means 5, it is easy to recover solids, and composting is possible by drying and secondary fermentation. It makes recycling easier. The treated water flowing into the solid-liquid separation means 5 is removed by dissolving oil and salt contained in the kitchen waste in the supernatant liquid. As a result, it is optimal as a raw material for producing high-quality compost.

In the present embodiment, a method is employed in which a solid sedimentation separation unit for separating solids by natural sedimentation is incorporated in the solid-liquid separation means 5. The method of solid-liquid separation of the treated water of the acid fermentation unit 4 is not limited to this, and the permeate can be caused to flow into the yeast treatment unit 6 by filtering using a stainless steel net. By using a filtration membrane such as a stainless steel mesh, the separated solid content can be recovered in a state of a small amount of water, which is an optimal method for composting.

As a filtration membrane, an organic membrane made of a polymer resin having a large pore size enough to prevent oil and proteins from being trapped or an inorganic membrane such as ceramics can be used to collect more solids. If installed between the acid fermentation unit 4 and the yeast treatment unit 6, solid-liquid separation can be performed in a smaller space, and a low-cost wastewater treatment system can be supplied.

[0040]

According to the present invention, in order to spread disposers and install small-scale establishments such as restaurants and food factories, it is necessary to save space in a wastewater treatment system. It is considered promising because of its ability to do so. However, there has been a problem that the environment in the tank must be maintained in an acidic environment in order for yeast to grow properly in the yeast processing section. In addition, in order to maintain the environment in the tank, it is necessary to supply an acid solution, and there is a problem in maintainability. In the present invention, it is effective with an easy method to maintain and improve the environment in the yeast processing unit, and it is possible to grow the yeast under optimal conditions. Therefore, the surplus yeast grown in the yeast processing unit is used as a fertilizer. It is also possible to reduce the amount of sludge to be treated. In addition, the yeast processing unit can be designed with a smaller volume, and the system can be provided with less space and less maintenance. In addition, according to the present invention, it is possible to provide a more space-saving system by appropriately controlling the operation of the yeast processing unit. Surplus yeast grown in the yeast processing section can be used as a fertilizer, and the amount of sludge to be treated is reduced. As a result, not only the installation cost of the wastewater treatment system but also the maintenance cost and, at the same time, the contribution to the reduction of the environmental load are also led.

[Brief description of the drawings]

FIG. 1 is a flow chart of wastewater treatment containing organic waste according to one embodiment.

FIG. 2 is a configuration diagram of a pH control unit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... grinding part, 2 ... transfer part, 3 ... water supply part, 4 ... acid fermentation part, 5 ... solid-liquid separation means, 6 ... yeast processing part, 7 ... separation part,
8 stirrer, 9 pH meter, 10 pH control means, 11
Aeration tube, 12 ... return tube, 13 ... crushed material drainage detection unit, 22
... Chemical solution tank, 23 ... Chemical tube, 24 ... Chemical valve drive unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C02F 1/46 C02F 1/46 A 4D050 1/50 510 1/50 510A 4D059 520 520P 4D061 531 531P 4H011 531R 4H061 532 532Z 560 560H 560Z 1/52 1/52 E 1/76 1/76 A 1/78 1/78 11/02 11/02 C05F 7/00 C05F 7/00 C12M 1/00 C12M 1/00 H C12N 1 / 00 C12N 1/00 S // (C12N 1/00 (C12N 1/00 S C12R 1: 645) C12R 1: 645) F-term (reference) 4B029 AA27 BB07 CC01 4B065 AA72X BB38 BC02 CA55 4D006 GA01 KA01 KA72 KB21 MB02 MC01 MC09 PA02 PB08 PC67 4D015 BB01 CA12 EA32 FA01 FA02 FA12 FA23 FA26 FA28 4D040 DD07 DD24 4D050 AA15 AB06 BB02 BB06 BD03 CA12 CA13 CA17 4D059 AA07 AA08 BA00 BA34 BA48 BJ01 CA22 CC01 4D061 DA08 DB07 EA01 FA09 FA10 FA11 FA13 FA15 4H011 AA02 BA01 BB06 BB18 BC18 DA13 DD01 4H061 AA02 AA10 CC47 CC51 DD07 EE66 GG10GG70

Claims (7)

[Claims] In a wastewater treatment system having a yeast treatment section for decomposing wastewater containing organic waste by yeast, an acid fermentation section for acid-fermenting wastewater containing organic waste is provided to perform treatment by acid fermentation. A wastewater treatment system, wherein the wastewater is decomposed by the yeast treatment unit. 2. The wastewater treatment system according to claim 1, wherein the yeast treatment section is provided with water quality detection means for detecting water quality in the yeast treatment section, and pH control means for controlling pH in the yeast treatment section. Wastewater treatment system characterized by supplying acid as a means. 3. The wastewater treatment system according to claim 2, wherein the acid to be supplied is acid water obtained by electrolysis in the yeast treatment section. 4. The wastewater treatment system according to claim 1, further comprising a pH control unit and a disinfectant injection unit for adding a disinfectant to the yeast processing unit. 5. The wastewater treatment system according to claim 1, further comprising solid-liquid separation means for solid-liquid separation of the treated water from the acid fermentation section, and treating the liquid separated by the solid-liquid separation means with the yeast treatment. A wastewater treatment system characterized by being transferred to a section for disassembly. 6. The wastewater treatment system according to claim 5, wherein a natural sedimentation separation in a sediment layer is used as said solid-liquid separation means. 7. The wastewater treatment system according to claim 5, wherein a membrane separation using a filtration membrane is used as said solid-liquid separation means, and a return means for returning separated solids to said fermentation unit is provided. Wastewater treatment system.