JP2002239570A - Apparatus for recycling waste water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste water recycling apparatus capable of reusing waste water, which can produce water with good quality, reusable for toilet, for garden watering in a quantity required at a low cost, require a small installation area, can be easily installed, and can be placed even in a region using a septic tank. SOLUTION: A waste water treatment apparatus comprises a foreign substance removing tank for removing foreign substances in inflow waste water, an activated sludge treatment tank for filtering waste water from the foreign substance removing tank with a separation membrane while aerobically treating the waste water with activated sludge, a storage tank for storing the treated water from the activated sludge treatment tank, a biomembrane treatment tank for aerobically treating the waste water from the foreign substance removing tank with microorganisms fixed on a contact material, a settling tank for precipitating the solid content in the treated water from the biomembrane treatment tank, and a sterilization tank for sterilizing the supernatant liquid from the settling tank. The treated water stored in the storage tank is recycled, and the waste water treated in the biomembrane treatment tank is discharged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wastewater treatment apparatus for reusing wastewater from homes.

[0002]

2. Description of the Related Art Conventionally, domestic wastewater from households is discharged to sewerage or the like without being treated and reused in a sewerage area, or in a septic tank area, treated to a discharge standard in a combined treatment septic tank and then discharged to a river. It is general that the water is discharged to the like. However, in recent years, as the water situation has worsened, a system has been proposed in which domestic wastewater from households, excluding toilet wastewater and kitchen wastewater, is treated with relatively less polluting components and then reused.

For example, Japanese Patent Application Laid-Open No. 2000-279980 discloses that domestic wastewater excluding toilet wastewater and kitchen wastewater having relatively low biological oxygen demand (BOD) and suspended solids (SS) concentration is high. A separation membrane in the shape of a plate or hollow fiber made of a molecular organic compound or ceramic was immersed,
Activated sludge is introduced into a tank containing mud-like microorganisms, and organic matter is decomposed by activated sludge, solid-liquid separation is performed by a separation membrane, and the treated water is sterilized, and then used for toilet flushing water and water sprinkling in gardens. An apparatus for reusing wastewater using a separation membrane and an operation method for reusing wastewater are disclosed.

[0004] However, in order to use this separation membrane-based wastewater recycling apparatus in a septic tank area without a sewer system, the wastewater to be treated by this apparatus is relatively polluted excluding toilet wastewater and kitchen wastewater. Due to the small amount of wastewater, in addition to this equipment, separate septic tanks must be installed for the treatment of toilet drainage and kitchen wastewater, which increases the required installation space and installation work due to complicated piping. There are problems such as an increase in cost.

[0005] Further, since the wastewater to be treated has a small amount of wastewater and relatively little pollution, the total pollutant load is low.
There is a problem that the activated sludge becomes finer and more dispersible due to a lack of organic matter as a nutrient source of the activated sludge, and the separation membrane is more likely to be clogged. Furthermore, the amount of treated water obtained is small because the inflow water is only household wastewater excluding toilet wastewater and kitchen wastewater, and if the reused amount of treated water increases, water shortage will occur. There are problems such as having to secure them.

On the other hand, a membrane type septic tank in which all domestic wastewater is treated by a separation membrane and discharged to a river or the like has been put on the market. A large-area separation membrane is required to treat all domestic wastewater collectively, which increases initial costs and generates a large amount of excess sludge due to the large load of all pollutants in wastewater. However, there is a problem that an increase in the cost and a processing cost for this increase.

[0007]

The waste water treatment apparatus of the present invention is capable of obtaining a required amount of low-cost, high-quality treated water purified to such an extent that it can be reused for toilet flushing water, garden watering, and the like. It can be installed easily and has a small installation area.
The purpose of the present invention is to provide a wastewater treatment apparatus that can be installed in a septic tank area and that can reuse wastewater.

[0008]

According to a first aspect of the present invention, there is provided an apparatus for reusing wastewater, wherein a foreign matter removing tank for removing foreign matter from the inflow wastewater and a wastewater from the foreign matter removing tank are aerobically treated by activated sludge. Activated sludge treatment tank for filtering with a separation membrane while performing the treatment, a storage tank for storing the treated water from the activated sludge treatment tank, and aerobically treated by the microorganism fixed to the contact material with wastewater from the contaminant removal tank A wastewater treatment apparatus, comprising: a biofilm treatment tank that performs, a sedimentation tank that precipitates solids in the treated water from the biofilm treatment tank, and a disinfection tank that disinfects supernatant water from the sedimentation tank, wherein the storage tank Wastewater treated in the biofilm treatment tank is discharged by recycling the treated water stored in the biofilm treatment tank.

[0009] In the wastewater re-use treatment apparatus according to the second aspect, the wastewater is transferred from the contaminant removal tank to the activated sludge treatment tank if the storage tank is not full, and the wastewater is contaminated if the storage tank is full. Transfer from the removal tank to the biofilm treatment tank.

According to a third aspect of the present invention, there is provided a wastewater recycle treatment apparatus, further comprising a disinfecting section after the storage tank for reusing treated water stored in the storage tank.

[0011] In the wastewater reuse treatment apparatus according to the fourth aspect, the contact material in the biofilm treatment tank is a porous carrier to which microorganisms to be aerobicly treated are attached.

(Effect) The wastewater reuse treatment apparatus of the present invention
Since all small households collect and treat the wastewater, the layout of the drainage piping is simplified and the construction cost is reduced.
In addition, a part of the wastewater is purified by an activated sludge treatment tank that is filtered by a separation membrane, and if the storage tank is not full, water purified by the activated sludge treatment is supplied to the storage tank until the storage tank is full. There is no shortage of water required for reuse, and the treated water stored in the storage tank is disinfected before use, so that the reused water has good water quality and is part of the total drainage. Since only the amount of water that is reused is processed, running costs are reduced.

[0013] Further, since the contact material in the biofilm treatment tank is a porous carrier to which microorganisms to be subjected to aerobic treatment are attached, the quality of domestic wastewater is purified to a quality that can be discharged to rivers and the like.
It can be installed in septic tank areas.

Further, since the reuse device and the domestic wastewater purification device are provided in one wastewater treatment device, the wastewater recycling device having a small installation area is smaller than the case where the reuse device and the combined wastewater purification tank are provided together. It becomes a use processing device, and equipment costs are reduced.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a wastewater reusing process according to the present invention will be described with reference to the drawings. FIG. 1 is a process flowchart for explaining the function of the wastewater reuse treatment device of the present invention.

The influent wastewater H is first treated in an activated sludge process B in which relatively large solids are removed in a contaminant removal process A and then filtered through a separation membrane while being aerobically treated with activated sludge. It is transferred to the biofilm treatment step E where it is aerobically treated by the fixed microorganisms. The treated water from the activated sludge treatment tank is stored in a storage step C, and is reused as reuse water I through a disinfection step D. Biofilm treatment process E
From the wastewater is subjected to gravity sedimentation of a small amount of solids contained in the sedimentation step F, and is discharged as effluent water J through the disinfection step G.

FIG. 2 is a sectional view showing an embodiment of the wastewater treatment apparatus according to the present invention. All the waste water from the household is collected and first flowed into the impurity removing tank 3, and the hair, fiber waste, etc. contained in the waste water are settled at the bottom of the impurity removing tank 3 or installed in the intermediate part of the impurity removing tank 3. It is removed by the filter medium 4 to prevent clogging of the separation membrane 5 in the activated sludge treatment tank 7.

Although the size, material, and shape of the filter medium 4 are not particularly limited, a cylindrical resin mesh filter medium is usually preferably used. A part of the contaminant removal tank 3 also serves as the flow rate adjusting unit 6 in a case where a large amount of wastewater suddenly flows. By providing the impurity removal tank 3 with a flow rate adjusting function, it is possible to prevent the wastewater from flowing into the activated sludge treatment tank 7 and the biofilm treatment tank 8 suddenly, and to always perform a stable treatment.

The wastewater from the impurity removing tank 3 is transferred to only one of the activated sludge treatment tank 7 and the biofilm treatment tank 8. As a transfer method, for example, as in the method of the present example, for example, as in the method of the present example, quantitative transfer to the activated sludge treatment tank 7 by an airlift A9 equipped with a measuring device and the biofilm treatment tank 8 by an airlift B10 also equipped with a measuring device. Air lift A9, air lift B
The air pipe to 10 is connected to one blower 1 through a solenoid valve 11.
2 and always connected to the air lift A9 and air lift B10
And operating only one of them.

The control of the solenoid valve 11 is performed by a water level detecting device 13 provided in the storage tank 14, and if the storage tank 14 for storing the processing water from the activated sludge processing tank 7 is not full, the air is blown to the air lift A9. Wastewater is activated sludge treatment tank 7
If the storage tank 14 is full, the air lift B1
And the wastewater is transferred to the biofilm treatment tank 8.

In the activated sludge treatment tank 7, the membrane separation device 15 is immersed in the activated sludge, and is subjected to aerobic treatment and membrane cleaning by bubbling from a diffuser 16 provided at the bottom of the membrane separation device 15. Filtration is performed with a suction pump 17 to obtain treated water. Since the treated water from the activated sludge treatment tank 7 is filtered by the separation membrane 5, the treated water has a good water quality that satisfies the reuse standard.

The membrane separator 15 to be immersed is not particularly limited, but a type in which a plurality of resin flat membranes are arranged in parallel is preferably used. The treated water from the activated sludge treatment tank 7 is stored in the storage tank 14, and the treated water is reused by sucking it up by the pump 18 or the like. In addition, a sanitizing section 19 is provided at the subsequent stage of the storage tank 14 to sterilize and sterilize, so that sanitary reuse water can be obtained.

The wastewater other than transferred to the activated sludge treatment tank 7 is transferred to the biofilm treatment tank 8 for purification. The biofilm treatment tank 8 is filled with a contact material 20, and aerobic treatment is performed by microorganisms attached to the contact material 20 by babbling from an air diffuser 21 provided below the contact material 20.

The contact material 20 has a large specific surface area,
The material is not particularly limited as long as it can adsorb or adhere the organic component, but a porous carrier 24 having a specific gravity of about 1 and having good fluidity and capable of floating in the biofilm treatment tank 8 is preferably used. In this case using the porous carrier, the filling rate of the porous carrier 24 is not particularly limited, but is preferably 1 to 50% of the capacity of the biofilm treatment tank 8. Examples of the material of the porous carrier 24 include a synthetic organic polymer material, a natural organic polymer material, and an inorganic material. When the porous carrier 24 is used as the contact material, the porous carrier 2
The biofilm treatment tank 8 and the sedimentation tank 22
The mesh 25 is installed in the communication part of.

In the sedimentation tank 22, fine solids contained in the treated water from the biofilm treatment tank 8, sludge separated from the contact material 20, and the like are settled by gravity. The treated water from which solids and the like flowing over from the sedimentation tank 22 have been removed is disinfected in the disinfection tank 23 to be discharged water 2 and discharged to rivers, sewers and the like.

[0026]

As described above, the wastewater reuse treatment apparatus of the present invention treats the entire amount of wastewater from homes. Therefore, even in a septic tank area, if there is an installation space for only the wastewater treatment apparatus of the present invention, Good. Further, since all drainage pipes can be put together, the pipe layout can be simplified. In addition, compared to domestic wastewater excluding toilet drainage and kitchen wastewater, the pollutant load is high, so activated sludge can be maintained in a good condition, clogging of the separation membrane can be suppressed, and the amount of inflow water is large For this reason, the treated water is less likely to run out, and the frequency of water supply can be reduced.

Further, the wastewater is treated in the activated sludge treatment tank only when the storage tank is not full, and the water that meets the reuse water quality standard is stored. Since a disinfection unit is provided after the activated sludge treatment tank, sanitary reuse water can be obtained.

In addition, if the storage tank is full, the wastewater is treated in a biofilm treatment tank, and the biofilm treatment tank is filled with a porous carrier having a large specific surface area. To the river. Therefore, compared with the case where the whole amount of wastewater from home is treated using the separation membrane, the required membrane area is small, and the generated excess sludge can be reduced.

[Brief description of the drawings]

FIG. 1 is a flowchart showing processing steps of a wastewater reuse processing apparatus of the present invention.

FIG. 2 is a cross-sectional view showing an example of an embodiment of a wastewater reuse treatment device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inflow 2 Discharge 3 Contaminant removal tank 4 Filter material 5 Separation membrane 6 Flow rate adjustment unit 7 Activated sludge treatment tank 8 Biofilm treatment tank 9 Air lift A 10 Air lift B 11 Electromagnetic valve 12 Blower 13 Water level detection device 14 Storage tank 15 Membrane separation device 16, 21 Air diffuser 17 Suction pump 18 Pump 19 Disinfection unit 20 Contact material 22 Sedimentation tank 23 Disinfection tank 24 Mesh 25 Reuse A Contaminant removal step B Activated sludge treatment step C Storage step D Disinfection step E Biofilm treatment step F Precipitation Process G Disinfection process H Inflow wastewater I Reuse water J Discharge water

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) E03C 1/01 E03C 1/01

Claims (4)

[Claims] 1. An activated sludge treatment tank for removing contaminants from an inflow wastewater, an activated sludge treatment tank for aerobically treating wastewater from the contaminant removal tank and filtering through a separation membrane while activating the activated sludge. A storage tank for storing treated water from the treatment tank, a biofilm treatment tank for aerobically treating wastewater from the contaminant removal tank with microorganisms fixed to the contact material, and treated water from the biofilm treatment tank A wastewater treatment apparatus comprising a sedimentation tank for precipitating solids and a disinfection tank for disinfecting supernatant water from the sedimentation tank, wherein the treated water stored in the storage tank is reused, and the biofilm treatment tank is reused. Wastewater reuse treatment equipment characterized by discharging the wastewater treated in the above. 2. When the storage tank is not full, the wastewater is transferred from the contaminant removal tank to the activated sludge treatment tank, and when the storage tank is full, the wastewater is transferred from the contaminant removal tank to the biofilm treatment tank. The wastewater reuse treatment apparatus according to claim 1, wherein: 3. The wastewater reuse treatment apparatus according to claim 1, further comprising a disinfecting section provided after the storage tank for reusing treated water stored in the storage tank. 4. The wastewater reuse treatment apparatus according to claim 1, wherein the contact material in the biofilm treatment tank is a porous carrier to which microorganisms to be aerobicly treated are attached.