JP2000279980A - Waste water recycling aperture utilizing separation membrane and method for operating the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To assure a stable activated sludge treatment by providing an apparatus having a biological treatment section for purifying waste water and a membrane separation section for filtering the microorganism separating liquid of the biological treatment section 40 with a sludge discharge section capable of maintaining the concentration of the microorganisms in the water held in the biological treatment section and/or the membrane separation section. SOLUTION: The waste water of a bath, washing machine, lavatory, etc., is first introduced through an inflow pipe l into an impurity removal section 2 where the foreign matter, such as hair and fiber scrap, is removed by a bar screen 3. The waste water emerging therefrom is sent to a flow rate section 7. The water is lifted at a specified flow rate by a displacement pump 6 operating on the air supplied from a blower 13 as driving power and is transferred to a biological treatment 8 of a post stage. The organic pollution components, nitrogen and phosphorus in the waste water are stably treated in the biological treatment section 40 and the treated water and microorganisms are separated by a flat membrane 11. The resultant treated water is transferred by a suction pump 24 to a storage section 9 and is thereafter lifted by a pump 25. The treated water is recycled as washing water for a toilet, etc., through an electrolytic sterilization device 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wastewater recycling apparatus using a separation membrane and a method for operating the same, and more particularly to a wastewater recycling apparatus for a detached house and a method for operating the same.

[0002]

2. Description of the Related Art Conventionally, domestic wastewater from homes is generally discharged to a river without being treated, or discharged to a sewer and a combined treatment septic tank without being reused. However, in recent years, as the water situation has worsened, a system has been devised which treats wastewater having relatively low pollutant components among wastewater from homes and then reuses it. As systems for single-family homes, there are systems disclosed in JP-A-9-174072 and JP-A-10-52686, and the former is used for aerobically discharging domestic wastewater and rainwater such as baths, washing and washing surfaces. Treatment is performed by a purification device filled with a ceramic filter bed, and the treated water is electrolytically disinfected and reused.The latter promotes purification by circulating domestic wastewater in a treatment tank, and then treats the treated water. It is to be reused.

Such a conventional system is for a detached house and cannot have a complicated structure, and has a structure in which a ceramic filter bed having a relatively easy structure is provided. However, it is difficult to obtain stable treated water. There was a problem. On the other hand, in the system disclosed in JP-A-6-240711, domestic wastewater including kitchen wastewater excluding toilet wastewater is treated in a septic tank, this treated liquid is further subjected to membrane separation treatment, and after being used as toilet flushing water, it is discharged into sewage. Although there is a system that discharges water, it is large in size and does not have a structure that can be applied to single-family homes, and because of its large size, there are problems that maintenance and cleaning are complicated.

[0004]

However, of the above two inventions, in the former two reports, domestic wastewater and rainwater such as baths, washing and washing surfaces are treated by a purifying device. For this reason, particles having a small particle size may pass through the ceramic filter cylinder and be mixed into the treated water, and the treated water may become turbid. In the latter case, the present inventors have shown the case of a multi-family house, but the drainage reuse device for a single-family house requires a large installation area and a large site area, and is not suitable for installation. Management is difficult.

The present invention has been made to solve the above-mentioned problems. The present invention is made of a high-molecular organic compound or ceramic and has a plate-like, hollow-fiber, or cylindrical shape, and is provided in a tank. An object of the present invention is to provide a wastewater recycling apparatus using a soaking type or an externally installed module type separation membrane and an operation method thereof.

[0006]

In order to solve the above-mentioned conventional problems, the separation membrane-based wastewater recycling apparatus according to any one of claims 1 to 3 of the present application is intended for domestic wastewater having relatively low BOD and SS. The microbial separation solution containing purified water and the purified water is purified by bacteria such as aerobic microorganisms and anaerobic microorganisms. And can be divided into The proliferated microorganisms are stored in the separation unit, and are transported to the outside of the apparatus by a sludge discharge unit for discharging a certain amount of the microorganisms, thereby stabilizing the microorganism concentration in the biological treatment unit or the membrane separation unit by keeping the concentration constant. Processing becomes possible. Furthermore, the biological treatment unit or the membrane separation unit can be pulled out by an air-lift type pump driven by air by discharging the microorganisms above from a certain interface after a certain period of time after stopping the aeration in intermittent aeration. Is simple, can be miniaturized, and is very easy to control microorganisms.

Further, in the present invention, when intermittent operation is performed in the biological treatment section or the membrane separation section, the capacity of the biological treatment section or the membrane separation section is reduced when the inflow wastewater flows directly into the biological treatment section. Need to be bigger. In addition, impurities that are difficult to decompose flow directly in, so that the treatment is not stabilized. Therefore, it is possible to remove impurities that are difficult to decompose by placing a foreign matter removal section, flow rate section, and quantitative transfer section in front, and to quantitatively pump wastewater to the biological treatment section, stabilizing microbial treatment. I do. Further, since the biological treatment section and the membrane separation section do not require more capacity than necessary, the overall capacity is reduced even if the flow rate section and the quantitative transfer section are provided in front, which contributes to downsizing.

Further, in the present invention, it is preferable that the treated water permeated from the membrane separation unit is stored in the storage unit for storing the treated water in order to reuse the treated water in a toilet or water sprinkler, etc. It is possible to sanitarily reuse the treated water by comprising a sterilizing section for treating various bacteria contained in the pumped treated water and the treated water.

[0009] Claims 10 and 11 of the present application.
The water depth and sedimentation curve from the water surface of the biological treatment unit or membrane separation unit to a certain interface, in order to easily discharge microorganisms grown in the biological treatment unit or membrane separation unit out of the system, or
2. The separation membrane according to claim 1, wherein the SV30, which is an index of sedimentation of microorganisms, is used as a control index to easily and stably control the concentration of microorganisms in the biological treatment section or the membrane separation section. This corresponds to the operation method of the wastewater reuse system.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Living wastewater has a fixed amount of a biological material removal section for removing impurities such as hair and lint contained in the wastewater and a flow rate section for storing wastewater from which the foreign matter has been removed. Using a separation membrane, such as a flat membrane or a hollow fiber membrane, that intermittently aerated the microorganisms in the biological treatment section or membrane separation section and dipped the living wastewater pumped from the quantitative transfer section to the treatment section into the separation section, The microorganisms and the treated water are separated, and the treated water is temporarily stored in a storage unit. The permeated treated water has high transparency and is sterilized by a silver electrode or the like, so that propagation of various bacteria does not propagate, and the treated water can be sanitarily reused as toilet flush water.

The microorganisms that have multiplied in the biological treatment section or the membrane separation section are extracted from the extraction pipe at a certain time after sedimentation according to the relationship between the sedimentation curve and the extraction water depth from the water surface to a constant interface or the SV30 and the extraction water depth. Do.
As a result, by automatically discharging the wastewater containing microorganisms in the biological treatment section or membrane separation section to the outside of the system, the concentration of microorganisms in the biological treatment section or membrane separation section can be maintained at a constant level. This eliminates the need for pulling out, thereby greatly improving workability. As described above, the present invention shows a separation membrane-based wastewater recycling apparatus and an operation method that exhibit stable treatment performance and can reduce the burden of manual maintenance.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an overall configuration diagram of a first embodiment of a wastewater treatment system according to the present invention. It is installed buried in the site adjacent to the detached house, and connected to the inflow pipe 1 into which drainage from the bath, washing and lavatory of the house enters, and thread, such as hair and fiber waste contained in the inflowing drainage Impurities and other foreign substances are removed by the bar screen 3 installed in the contaminant removal unit 2. In addition to the bar screen 3, wire mesh, wedge wire, or punching metal can be used, and the mesh width at that time is 0.2 to 5 mm, preferably 0.5 to 2 mm, and air is sent from the bottom of the bar screen 3 to the air diffuser 4. This has the effect of removing what has adhered to the surface and prevents clogging. The removal of the thread-like impurities by the impurity removal unit 2 has an effect of preventing the thread-like impurities from entangled in the flat membrane 11 immersed in the membrane separation unit 8. An overflow port 5 is provided in the impurity removing section 2, and thread-like impurities such as hair and fiber waste accumulated in the tank are removed.
When a large amount of wastewater flows in, it is discharged from the overflow port 5 together with the wastewater to the outside of the system. As a result, it is not necessary to clean the inside of the contaminant removing unit 2, and the sludge can be omitted.

Next, a constant flow rate of the waste water from the contaminant removal section 2 can be pumped by installing a positive displacement pump 6 which is a quantitative transfer section using the air supplied from the blower 13 by a flow section 7 as a driving force. The flow rate of the wastewater is adjusted, and the discharged wastewater is transferred to the biological treatment 8 at the subsequent stage. Further, by pumping water to the biological treatment section 40 at a constant flow rate, organic pollutants, nitrogen and phosphorus contained in the wastewater are stably treated, and microorganisms are treated by the flat membrane 11 immersed in the membrane separation section 8. Water can be separated stably. The flat membrane 11 is
Since the microbes have pores of 0.1 to 1.0 μm and have a size of several hundreds of micrometers or more, the treated water that has passed through the flat membrane 11 contains almost no suspended solids. Very high treated water is obtained.

Further, the flat membrane 11 made of a separation membrane is immersed in the membrane separation section 8 together with the frame 16 for fixing the flat membrane 11 to prevent the flat membrane 11 from floating and moving. . Further, a water intake pipe 20 is provided above the flat membrane 11 installed in the storage section 9, and the pump 10 installed in the storage section 9 through the water collecting box 21 by a rubber or plastic pipe is used as a suction pump composed of an aspirator pipe. By using 24, membrane permeated water can be obtained. By disposing the air diffuser tube 4 directly below the flat membrane 11, it plays a role of cleaning microorganisms attached to the surface of the flat membrane 11 and supplying oxygen to the microorganisms.

The biological treatment section 40 and the membrane separation section 8 are provided with floats 12 for notifying the operation and stop of the pump at the highest water level and the lowest water level, respectively, for adjusting the water level.
And the positive displacement pump 6 installed in the flow section 7
Blower 13 serving as an air driving force for the
In order to suck the treated water from the flat membrane 11 immersed in the water, the operation and stop signals of the suction pump 24 composed of the pump 10 and the aspirator pipe 22 are given and controlled. For example, when drainage flows into the biological treatment unit 40 from the positive displacement pump 6 installed in the flow unit 7, the water level in the membrane separation unit 8 rises, the float 12a having the highest water level floats, and a signal is given through the controller 23. Then, the blower 13 for driving the positive displacement pump 6 stops. When the water level reaches the lowest level, the float 12b gives a signal through the controller 23 to stop the suction pump 10 that sucks the treated water from the flat membrane 11. Further, an overflow port 5 is provided to prevent the biological treatment section 40 and the membrane separation section 8 from flowing out to another tank when the water level in the tank abnormally rises to a position higher than the maximum water level. The sludge concentration in the biological treatment section 40 and the membrane separation section 8 is managed by a method of pulling a certain amount by the air lift pump 14.

Next, the flat membrane 11 installed in the membrane separation section 8
The treated water stored in the storage unit 9 is pumped by the pump 10 and passes through the aspirator tube 22 so that the inside of the flat membrane is reduced in pressure and sucked, whereby the treated water permeates through the membrane, and Water collecting box 21, aspirator tube 2
2 and is stored in the storage unit 9.

Next, the treated water stored in the storage section 9 is pumped by a pump 25, and the pumped treated water is reused as toilet flush water by an electrolysis sterilizer 26 using silver. The properties of this treated water are such that it has a very high degree of transparency and always has a size of 100 cm or more and a BOD of 5 mg /
L or less, SS 5 mg / L or less, COD 10 mg / L
In the following, in the treated water sterilized by the electrolytic sterilizer 26, the coliform group has not been detected. Further, when the water level of the storage section 9 becomes low, the water supply to the toilet from the float 27 through the controller 23 is stopped.

FIG. 2 is an overall configuration diagram of a second embodiment of the intermediate water treatment system according to the present invention. The impurity removing unit 2 and the flow rate unit having different structures in the first embodiment of FIG. 1 will be described. An inflow pipe 1 for receiving drainage from a home bath, washing and lavatory is connected, and a thread-like foreign substance such as hair and fiber waste and other foreign substances contained in the inflowing drainage are removed from the foreign substance removing section 2.
Or ceramic filter media 3 filled in
A value of 0 causes the surface to be supplemented with contaminants, thereby preventing the contaminants from flowing into the downstream flow section 7. The contaminants attached to the surface of the filter medium 30 are pulled out regularly, or
The air diffuser 4 installed at the bottom filled with the filter medium 30 is aerated to separate impurities adhering to the surface of the filter medium 30, and when a large amount of wastewater flows in, flows out of the system through the overflow port 5. Release. Next, the wastewater flowing into the flow section 7 can be pumped to the biological treatment section 40 by the metering pump 31.

FIG. 3 shows the M of the biological treatment section or the membrane separation section 8.
1 shows sedimentation curves of LSS 3,000 mg / L and 8,000 mg / L microorganisms. For example, if the microorganism concentration is MLSS
At 3,000 mg / L, the water surface has settled to 40% of the total water depth after standing for 10 minutes. At this time, withdrawal tube 3
When the inlet 33 of the second is at 20% of the total water depth, the microorganisms are not extracted and only the supernatant water is discharged. Further, when the microorganism concentration is MLSS 8,000 mg / L, the water surface is settled to only 10% of the total water depth when left standing for 10 minutes. At this time, if the extraction pipe 32 is at 20% of the total water depth, the microorganisms are also extracted together with the supernatant water, and the microorganisms in the biological treatment section 40 or the membrane separation section 8 are reduced and settle to a certain concentration.

FIG. 4 shows the biological treatment section 40 or the membrane separation section 8.
2 shows the relationship between the MLSS and the SV 30. In the case where the microorganisms stand still for 30 minutes, as shown in FIG.
V30 increases. For example, when the aeration of the biological treatment section 40 or the membrane separation section 8 is stopped and the apparatus is allowed to stand still for 30 minutes, ML
In order to adjust SS to 3,000 mg / L, the water depth of the inlet 33 of the inlet pipe 32 may be set to 30% of the total water depth. As described above, the management of the MLSS, which is the concentration of microorganisms, depends on the depth of the inlet of the suction pipe and the biological treatment unit 40.
Alternatively, it can be controlled based on the sedimentation time after stopping the aeration of the membrane separation unit 8.

[0022]

As described above, the present invention provides a membrane by removing, by a screen, thread-like contaminants such as hair and fiber waste contained in human wastewater and kitchen wastewater that are generated from a detached house. Activated sludge treatment is carried out stably by preventing the attachment of thread-like contaminants to the separation membrane immersed in the separation unit, and by allowing wastewater to flow into the biological treatment unit at a constant flow rate by the flow unit. -N or T
-P is removed well, and microorganisms and treated water are separated into solid and liquid by a separation membrane immersed in the membrane separation section to obtain highly transparent treated water. There is an effect that it can be used.

Further, the treated water has an effect that the highly transparent treated water can be sanitarily reused as toilet wash water by performing electrolytic sterilization with silver in order to prevent propagation of various bacteria and Escherichia coli.

Further, the control of the concentration of microorganisms in the biological treatment section or the membrane separation section is performed by controlling the microorganism sedimentation curve and S
This can be easily performed by determining the standing time after aeration and the water depth of the suction port of the suction pipe from the relationship with V30. As a result, maintenance and management of the biological treatment section or the separation section becomes easy.

[Brief description of the drawings]

FIG. 1 is an overall structural diagram of a first embodiment of a wastewater reuse device using a separation membrane.

FIG. 2 is an overall structural view of a second embodiment.

Fig. 3 Sedimentation curve of microorganisms (MLSS: 3,000mg / L)

Fig. 4 Sedimentation curve of microorganisms (MLSS: 8,000 mg / L)

FIG. 5: Relationship between MLSS and SV30

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Inflow pipe, 2 ... Contaminant removal part, 4 ... Aeration pipe, 5 ... Overflow port, 6 ... Positive displacement pump, 7 ... Flow rate part, 8 ... Separation part, 9 ... Storage part, 10, 25 ... Pump, 11 … Flat membrane,
12: float, 13: blower, 14: air lift pump, 16: frame, 20: water collecting pipe, 21: water collecting box,
Reference numeral 22: aspirator tube, 23: controller, 24: suction pump, 26: silver electrolytic sterilization, 30: filter medium, 31: metering pump, 32: extraction tube, 33: extraction port, 40: biological treatment section

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D006 GA02 HA01 HA41 HA93 KA12 KA44 KB14 KB22 PA01 PB08 PC65 4D027 AA01 AA14 AA20 4D028 BA00 BC17 BD17 CA05 CA09 CB08 CD05

Claims (11)

[Claims] 1. A wastewater recycling apparatus using a separation membrane, comprising: a biological treatment section for purifying wastewater; and a membrane separation section for filtering a microorganism separation liquid in the biological treatment section and separating the microorganism into treated water. A sludge discharge unit capable of maintaining a concentration of microorganisms in water held in a treatment unit and / or the membrane separation unit is provided. 2. The wastewater recycling apparatus using a separation membrane according to claim 1, further comprising a mechanism for discharging a predetermined amount of microorganisms from the biological treatment section, the membrane separation section, or both. 3. The method according to claim 1, wherein the biological treatment section, the membrane separation section, or both of them are intermittently aerated so as to discharge the upper microorganisms from a certain interface. Wastewater reuse equipment using separation membrane. 4. The wastewater recycling apparatus using a separation membrane according to claim 1, wherein a flow section and a quantitative transfer section required for intermittent operation are provided in front of the biological treatment section. 5. The wastewater recycling apparatus using a separation membrane according to claim 4, further comprising a contaminant removing unit for removing contaminants contained in wastewater flowing into the flow unit. 6. The wastewater reuse system using a separation membrane according to claim 1, wherein a storage unit for storing the treated water permeated through the membrane separation unit is provided downstream of the membrane separation unit. apparatus. 7. The wastewater recycling apparatus using a separation membrane according to claim 1, further comprising a driving unit for pumping up the treated water at a stage subsequent to the storage unit. 8. The wastewater recycling apparatus using a separation membrane according to claim 1, further comprising a sterilizing section for sterilizing the treated water pumped by the driving section. 9. The apparatus for recycling wastewater using a separation membrane according to claim 1, wherein the treated water that has passed through the sterilizing section is reused. 10. The sludge concentration is adjusted based on a relationship between a sedimentation curve of microorganisms and a water depth from a water surface to an interface, in order to control the concentration of microorganisms in the biological treatment section. 4. The method for operating a separation membrane-utilized wastewater recycling apparatus according to 4. 11. In the biological treatment section, SV, which is an index of sedimentation of microorganisms, is used to control the concentration of microorganisms.
The method according to claim 1, wherein the sludge concentration is adjusted based on a relationship between 30 and the water depth from the water surface to the interface. 5.