KR101494398B1 - Apparatus for wastewater treatment with submerged membrane - Google Patents

Abstract

The present invention relates to an apparatus for advanced wastewater treatment using an immersion type membrane that biologically treats wastewater and biologically treats the wastewater and performs solid-liquid separation of the treated wastewater using an immersion type separation membrane without a separate wastewater separation facility. More particularly, An aerobic tank and a membrane separation tank.
In the anoxic tank equipped with the MLSS concentration regulator, the F / M ratio can be freely controlled by performing the denitrification mechanism by performing the buffering action on the impact load of the raw water quality introduced from the flow rate adjusting tank and returning nitrification liquid of the oxic tank, In preparation for the impact load of influent water and cold water in the winter season, phosphorus was removed through phosphorus ingestion in the anaerobic tank and phosphorus ingestion in the aerobic tank and ultimately treated water which separated suspended matter and bacteria from the membrane separation tank equipped with submerged membrane .
In the aerobic tank including the fine bubble supplying device, the oxygen dissolution rate through the fine bubble supplying device and the sludge returning solution including the high dissolved oxygen due to the supercharging air in the membrane separation tank are circulated, thereby minimizing the operation of the fan with high power consumption, The present invention relates to an apparatus for treating wastewater and wastewater using an immersion type membrane capable of automatically coping with fluctuations and minimizing energy consumption.

Description

Technical Field [0001] The present invention relates to an apparatus for treating wastewater with submerged membranes,

The present invention relates to an apparatus and a method for advanced treatment of wastewater using a submerged membrane for biologically treating wastewater generated by human life and industrial activities. More specifically, the anoxic tank, the anaerobic tank, the aerobic tank, and the membrane separation tank are sequentially arranged, and the anoxic tank has a F / M ratio (Food / Microorganism Ratio) freely adjustable so as to cope with load fluctuations of inflow water.
Further, the sludge containing high dissolved oxygen by the supercharging air existing in the membrane separation tank is returned to the aerobic tank including the micro-foam air diffuser to simultaneously supply the dissolved oxygen required for the aerobic tank and the sludge transportation, And the membrane separation tank is separated from the oxic tank so that the untreated water flowing into the oxic tank is prevented from being immediately discharged to the treated water by the membrane filtration action and the effective depth of the membrane separation tank is lowered, The present invention relates to an apparatus for treating wastewater and wastewater which is operated in such a manner as to reduce the blower power, which is the biggest drawback to the membrane bioreactor method.

The present invention relates to an apparatus for treating wastewater and wastewater comprising an anoxic tank, an anaerobic tank, an aerobic tank and a membrane separation tank. More particularly, the present invention relates to a biological treatment apparatus for biologically removing nutrients and organic matters from a wastewater and a wastewater, The present invention relates to an apparatus for advanced wastewater treatment using an MBR to separate and discharge wastewater.

The MBR advanced wastewater treatment system has the advantage that the amount of surplus sludge is small, the site area is small, and the treated water quality is superior to that of the solid-liquid separation sedimentation tank by gravity sedimentation. Therefore, a variety of treatment methods combining a typical A2O method and a membrane are highly used and the treated water quality is very good. Therefore, it has been widely applied to reuse of treated water and heavy water facilities according to recent water reuse policy.

However, when the influent water load fluctuation is high during the advanced treatment process and the C / N ratio is low due to the characteristics of the domestic sewage, the nitrogen treatment efficiency is lowered and the phosphorus removal efficiency is also lowered. The concentration of organic matter, nitrogen and phosphorus in the influent water is biologically treated in the wastewater. Therefore, there is a need for a treatment method for maximizing utilization of organic matters in influent water without supplying a separate carbon source.

In addition, there are some challenges that are required in recent years in the treatment of wastewater.

First, it is a self-sensitive automation system. This is a technology that accurately measures water quality in a biological reactor and controls it according to the operating conditions. For example, it is necessary to optimize the operating conditions according to the water quality of the inflow water by accurately adjusting the dissolved oxygen concentration and MLSS concentration in the bioreactor, which is known to be an important factor in terms of efficiency and economy of treatment. However, most of the water and wastewater treatment methods (DO, MLSS, etc.) are simple monitoring or one to two times a day to manually change the operating conditions. Therefore, It is impossible to measure and cope with the situation.

Second, energy saving type waste water treatment methods are indispensable. Particularly, the most power required for the MBR-based treatment of the waste water and wastewater is based on the cleaning air that is necessary to clean the separation membrane installed in the membrane separating tank or the oxic tank. In order to physically remove the solid material adhering to the surface of the separation membrane during the filtration process of the submerged separation membrane, the cleaning air must be continuously supplied from the outside at the bottom of the separation membrane. In this case, the power of the supplied blower is about 42% of the power ratio required in the entire wastewater treatment process. Generally, the concentration of dissolved oxygen required for nitrification or decomposition of organic matter in an aerobic tank is required to be about 1 to 1.5 mg / L. However, in most MBR processes, dissolved oxygen concentrations of 4 to 6 mg / L have been observed. This is due to the continuously supplied cleaning air to prevent fouling of the membrane.

The disassembly of flocs occurs due to overexcitation of the aerobic tank or the membrane separation tank. Especially, denitrification in anoxic tank requiring dissolved oxygen of 0.1 mg / L or less because of high concentration of dissolved oxygen in the transport sludge transported to the anoxic tank There is a problem that the efficiency is rapidly lowered. To solve these problems, we tried to maximize the denitrification efficiency of the anoxic tank by reducing the concentration of dissolved oxygen in the transport sludge by constructing compartments such as a degassing tank, a stabilization tank, and a dissolved oxygen reducing tank. However, the existing compartment for reducing dissolved oxygen has a problem in that when the hydraulic retention time for stable DO (dissolved oxygen) is insufficient and the DO concentration in the conveyed water is increased to obstruct the stable denitrification process or the hydraulic retention time becomes too long, And it is difficult to reduce the site area, which is an advantage of the present invention, or re-leaching of phosphorus due to a long hydraulic retention time.

Therefore, in the advanced wastewater treatment process using the separation membrane, an energy-saving advanced treatment process capable of coping with the load fluctuation of the influent water and capable of reducing the nitrogen removal rate and operation power due to excessive aeration to prevent separation membrane fouling It is necessary.

The present invention has been made in order to solve the problems of the prior art as described above, and it is an object of the present invention to provide a process configuration different from the existing MBR process, And the efficiency of the advanced treatment was maximized. The aerobic tank and the membrane separation tank were separated from each other, and the aerobic tank was constructed by a time control method such as intermittent aeration or a concentration control method of a dissolved oxygen measuring device (DO meter) Which is supplied to the aerobic tank through the aerobic tank, which is capable of supplying the required amount of oxygen through the aerobic tank and which has a dissolved oxygen dissolution rate in the aerobic tank, and which transports the aerated sludge containing supersaturated dissolved oxygen from the supercharged air in the membrane separation tank to the aerobic tank Provides advanced treatment equipment for wastewater to reduce energy consumption by reducing air volume The main purpose is to do.

In order to solve the above-mentioned problems, the present invention provides an anaerobic tank including an anoxic tank into which raw water as a treatment target water flows, an anaerobic tank through which the effluent discharged from the anoxic tank flows in, an aerobic tank into which effluent discharged from the anaerobic tank flows, Wherein the anoxic tank includes an MLSS concentration adjusting device for adjusting an MLSS concentration of the anoxic tank, wherein the MLSS concentration adjusting device comprises: And the concentration of the sludge is adjusted according to the rotation speed of the concentration adjusting device agitator mounted on the lower part of the MLSS concentration adjusting device to control the settling or floating of the sludge, The MLSS concentration of the anoxic tank is controlled by adjusting the MLSS flow rate, The apparatus stirrer is capable of adjusting the speed by the inverter and adjusting the stirring speed by receiving the signals of the ORP meter and the MLSS meter installed in the anoxic tank to increase or decrease the MLSS concentration in the anoxic tank to cope with the influent load of the raw water, Thereby increasing the efficiency of the waste water treatment apparatus.

The present invention reduces energy consumption by reducing the operation time of the blower for aeration by maintaining the oxygen solubility by the transport of the membrane separation tank mixture to the oxic tank and the fine bubble supplying device installed in the oxic tank, The raw water flowing into the oxic tank is supplied to the microbubble feeder by contacting the microbubble mixture liquid in which the microorganisms of the oxic tank and the outside air are mixed, Oxidative degradation, causal ingestion, and nitrification are promoted.

According to the present invention, the micro-bubble supplying device mixes the micro-bubbles generated from the aeration device, the raw water introduced from the anaerobic tank, and the supercharged air conveyed from the membrane separation tank, thereby minimizing the air supply to the aerobic tank by the blower, And power savings.

The present invention is characterized in that clean air is supplied to prevent separation membrane contamination in the membrane separation tank including the submerged separation membrane and the aerobic tank and the membrane separation tank are separately separated in order to prevent peroxidation due to supercharged air .

The membrane separation tank may be operated at a lower effective water depth of 2 to 2.5 m and lower than the water depth of the oxic tank to lower the wind pressure of the blower during air supply to prevent contamination of the separation membrane to lower the power of the cleaning blower.

The present invention can be characterized in that oxygen in the mixed liquor containing a high dissolved oxygen concentration is used in the oxic tank by providing a line to be transported from the membrane separation tank to the oxic tank.

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According to the sewage / wastewater treatment apparatus using the submerged membrane according to the present invention, since the F / M ratio in the anoxic tank equipped with the MLSS concentration regulating device is adjusted, it is possible to cope with the load fluctuation of the influent water, By separating the separation tank separately and circulating the mixed liquid containing the high dissolved oxygen in the membrane separation tank supplied by the supercharging air for the maintenance and cleaning of the separation membrane for the solid-liquid separation of the treated water into the aerobic tank, the amount of aeration supplied to the aerobic tank is reduced It is very effective for facilities requiring energy-saving type wastewater treatment, which is effective for the treatment of wastewater with heavy load fluctuation by providing the self-sensitive and energy saving type wastewater treatment process required in the wastewater treatment process .

FIG. 1 is a view showing an apparatus for treating wastewater and wastewater using a submerged membrane to maximize the effect of ensuring the stability of water quality, maximizing the altitude treatment efficiency, and energy reduction according to the present invention.
FIG. 2 is a view showing an MLSS concentration adjusting device provided at the downstream end of the anoxic tank.
3 is a view showing a fine bubble supplying device installed in the oxic tank.

Hereinafter, the present invention will be described in detail with reference to the drawings 1 to 3 showing the present invention.
1 is a view showing an apparatus for treating wastewater and wastewater using a separation membrane for maximizing the effect of ensuring the stability of water quality, maximizing the advanced treatment efficiency, and reducing energy consumption according to the present invention.

As shown in FIG. 1, the waste water / wastewater treatment apparatus includes a flow rate adjusting tank 1, an anoxic tank 2, an anaerobic tank 3, an aerobic tank 4, and a membrane separation tank 5. The raw water is supplied to the anoxic tank 2 after the coarse contaminants are removed by the screen 20 and the internal transport liquid whose nitrification has been completed in the oxic tank 4 is returned to the anoxic tank 2 through the sludge return line do. At this time, the raw water and the inner carrier liquid are mixed in baffles (9) provided in the anoxic tank (2), and denitrification occurs in an anaerobic state by the stirrer (7).
In the anaerobic tank 3, the release of phosphorus takes place in the anaerobic state by the detoxifying microorganisms, the removal of residual organic matter and nitrification proceeds in the aerobic tank 4, and the mixed liquor is internally transported to the anoxic tank 2.
In the membrane separation tank 5 provided with the submerged separation membrane 24, treated water is produced by the submerged separation membrane 24 having 0.06 to 0.4 μm pores. Is transferred to the aerobic tank (4) including the micro-bubble supplying device (12) to constitute an energy saving type wastewater treatment device which reduces the blowing amount by replenishing sludge transportation and dissolved oxygen .

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Hereinafter, the sewage / wastewater treatment apparatus of the present invention will be described in detail by each process.

1. Flow control tank (1)

Perform water quality equalization and flow equalization of incoming water. An underwater agitator (6) is installed for decaying the raw water and equalizing the water quality. Further, the screen 20 can be installed at the rear end of the flow rate adjusting tank 1 to protect the downstream equipment such as the pump and the separation membrane by removing impurities in the raw water.

2. Anoxic tank (2)
The raw water introduced from the flow rate adjusting tank 1 flows into the lower portion of the anoxic tank 2 through the baffle 9 and is mixed with the sludge. In addition, some of the sludge is introduced into the lower portion of the anoxic tank 2 through the sludge return line by using the internal transfer pump 14 of the oxic tank 4. [ The main function of the anoxic tank (2) is to treat the nitrogen by the denitrification mechanism of the supply of the raw carbon which is the carbon source by buffering the impact load of the raw water quality and returning the nitrification liquid of the oxic tank (4). Namely, denitrification refers to an action in which nitrate nitrogen is reduced to nitrogen gas (N2) by microorganisms. The denitrification effect is that microorganisms use oxygen contained in nitrate nitrogen (NO3-N) when oxygen is insufficient, nitrate nitrogen loses oxygen and is reduced to nitrogen gas (N2) and released into the atmosphere. An agitator (7) is installed so as to be stirred in the anoxic tank (2).

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The denitrification mechanism in anoxic tank is as follows.

NO ₃ ^- + 1.08 CH ₃ OH + H ⁺

0.065 C ₅ H ₇ O ₂ N + 0.47 N ₂ + 0.76H ₂ O + 2.44H ₂ O

That is, nitrified nitrate nitrogen (NO ₃ ^- ) is reduced to nitrogen (N ₂ ) gas.

As shown in FIGS. 1 and 2, an MLSS concentration adjusting device 11 designed to induce settling and floating of sludge in consideration of a water surface area load is provided at the downstream of the anoxic tank 2. A concentration adjusting device agitator 11a is installed in the lower part of the MLSS concentration adjusting device 11 so as to induce sedimentation or floating of the sludge. In accordance with the rotation speed of the concentration adjusting device 11a, Lt; / RTI > As a result, the MLSS concentration in the anoxic tank 2 is adjusted as needed.
At this time, the stirring speed of the concentration adjusting device 11a is adjusted in the range of 45 to 560 RPM, and when the concentration adjusting device stirrer 11a is not operated, ) Of the anaerobic tank 2 is 70 m 3 / m 2 .day. As only the minimum MLSS is overflowed to the anaerobic tank 3, the F / M ratio in the anoxic tank 2 is lowered so that the microbial impact load It is a difference from the existing process.
At this time, the ORP meter 21 and / or the MLSS meter 22 are installed in the anoxic tank 2 to recognize that the denitrification efficiency is lowered according to the impact load of the influent water, and the concentration adjuster stirrer 11a ) Can control the speed of the agitator by controlling the speed of the agitator, so that the optimum operation condition can be performed, so that the impact load of the influent can be immediately responded to, and in particular, the nitrogen treatment efficiency can be prevented from lowering at the low temperature in the winter. The above description is shown in Table 1.

MLSS concentration control device operation method and concentration control method division Anoxic tank Aerobic tank (bioreactor) MLSS concentration control device Sludge return Sludge pull Inflow water quality Low concentration Operation (high speed) decrease increase High concentration Inactive (low speed) increase decrease

3. Anaerobic tank (3)

The effluent discharged from the anoxic tank 2 flows into the lower portion of the anaerobic tank 3 through the baffle 10 and is mixed with the sludge. An agitator (8) is installed to increase the contact efficiency between the anaerobic microorganism and the substrate to be degraded.
The inflowing source may be divided into the anoxic tank 2 and the anaerobic tank 3 at a ratio of 7: 3 or 8: 2.

The biological phosphorus removal process is carried out by alternately exposing anaerobic and aerobic conditions, releasing phosphorus in anaerobic conditions and releasing more phosphorus than the amount of phosphorus released under aerobic conditions uptake), phosphorus is accumulated in the microorganism body excessively and discharged to the outside of the system to remove phosphorus.

The mechanism in the anaerobic tank (3) is that the microorganisms called PAO (Polyphosphate Accumulating Organism) are converted into VFAs (Volatile fatty acids) form in the source water under anaerobic conditions and absorbed to absorb microorganisms in the form of PHAs (Polyhydroxy alkanoates) . In this metabolic process, PAO releases phosphorus by releasing the orthophosphate from microbial degradation of polyphosphate to the outside of the microorganism. At this time, the phosphorus concentration in the anaerobic tank 3 is increased.

4. The aerobic tank (4)

The effluent from the anaerobic tank 3 flows into the aerobic tank 4 and is mixed with the sludge. The aerobic tank 4 includes an internal return pump 14, an oxic tank blower 18, an aerobic treatment tank 19 and a microbubble feeder 12.

The mechanism that takes place in the aerobic tank 4 is as follows.

First, the main function of the aerobic tank (4) is to oxidize ammonia nitrogen in the incoming raw water to nitrate nitrogen through nitrifying microorganisms.

The nitrification mechanism in the oxic tank 4 is as follows.

^{_{NH 4 + + 1.682O 2 + 0.182CO}} 2 + 0.0455HCO 3 - →

0.0455C ₂ H ₇ O ₂ N + 0.955NO ₃ ^- + 0.909H ₂ O + 1.909H ⁺

That is, ammonia (NH ₄ ⁺ ) in influent water is oxidized to nitrate nitrogen (NO ₃ ^- ). At this time, the nitrification process consumes alkalinity.

The nitrification-completed mixed liquor is transferred to the anoxic tank 2 through the internal return pump 14, and nitrogen is removed by the denitrification mechanism of the anoxic tank.

Second, the residual organic matter used as a carbon source in the anoxic tank (2) and anaerobic tank (3) is removed during the microbial growth under aerobic conditions.

Third, phosphorus released by PAO microorganisms in anaerobic tank (3) was grown and survived by using PHAs that had been stored under anaerobic conditions under aerobic conditions. At the same time, phosphorus released from anaerobic conditions . At this time, the amount of phosphorus absorbed in the aerobic condition absorbs more than the amount of phosphorus released in the anaerobic condition, and the phosphorus concentration in the aerobic tank 4 is excessively consumed in the microorganism body, so that the concentration of phosphorus in the aerobic tank 4 is drastically reduced. The phosphorus is removed by discharging it out (surplus sludge disposal).

In order to maintain the aerobic condition, the aerobic tank blower 18, the aerobic aeration unit 19, and the micro-bubble supplying unit 12 for minimizing the aeration amount and reducing the energy by increasing the oxygen dissolution rate are formed.

The fine bubble supplying device 12 installed at the inlet end of the oxic tank 4 is an aeration device commonly used for purification of water quality such as a lake and a pond, and has a low power consumption and high oxygen solubility.
In the present invention, the raw water flowing from the anaerobic tank 3, the fresh air conveyed from the membrane separation tank 5, and the minute bubbles generated from the aeration device are mixed and circulated to the oxic tank 4 do. At this time, it is possible to supplement the dissolved oxygen additionally by supplying the mixed liquid including the micro-air and the supercharged air conveyed from the membrane separation tank 5. By maintaining the dissolved oxygen concentration in the oxic tank 4 at 1 to 1.5 mg / L, the blowing amount by the oxic tank blower 18 to be supplied from the outside can be minimized. Therefore, it is possible to reduce the energy consumption by reducing the amount of the blower using the most power energy and the use time in the wastewater treatment process.

The oxic tank blower 18 controls the optimum dissolved oxygen using the DO meter 23 provided in the oxic tank 4. [

The fine bubble supplying device 12 supplies air to the circulating pump discharge pipe, and the large air bubbles are converted into fine bubbles by the vortex phenomenon, thereby increasing the dissolution rate and increasing the oxygen transfer efficiency to the mixed liquid with the raw water.

Therefore, the effect of increasing the oxygen dissolution rate and the dissolution duration is generated, and the operation is performed by the intermittent aeration method and the microbubble air dissolution rate is 40% or more according to the oxygen dissolution rate.

5. Membrane separator (5)

The mixed liquid discharged from the aerobic tank 4 flows into the membrane separation tank 5 and the membrane separation tank 5 is connected to the separation membrane 24, the separation membrane suction pump 16, the separation membrane blower 17 and the sludge circulation pump 15, .

The membrane separation tank (5) performs the solid-liquid separation function of the residual organic matter and the sludge mixture. In operating the membrane separator (5), the air is cleaned by using a separator blower (17) in order to reduce the contamination of the separator membrane. . Since the blower of the membrane separation tank 5 continuously maintains the amount of the aeration to clean the separation membrane, the dissolved oxygen amount of the membrane separation tank 5 always tends to be maintained high.

Therefore, the present invention consists of separating the membrane separation tank 5 and the oxic tank 4 to supply the supercharged air from the membrane separation tank 5 to the oxic tank 4 through the sludge circulation pump 15. In addition, the blower required for the membrane separation tank 5 with an effective water depth of 2.0 to 2.5 m of the membrane separation tank 5 has a lower power ratio reduction effect than a conventional membrane separation tank having a water depth of 4 to 5 m . Table 2 shows the power saving effect.

Comparing the general MBR process and the reduction process of the process according to the present invention division Original MBR Invention MBR Biological treatment Required air volume 3.5 ㎥ / min
(Continuous discontinuity, 24 hours operation) 1.2 ㎥ / min
(Intermittent abandonment, 12hr operation) Separation membrane cleaning
Required Air Amount 4.0 ㎥ / min
(Continuous discontinuity, 24 hours operation) 4.0 ㎥ / min
(Continuous discontinuity, 24 hours operation) Total required air volume 7.5 ㎥ / min 4.6 m3 / min Blower selection 11 kW (4,000 mmAq) Exhalation: 2.2 kW (Root's) (4,000 mmAq)
For membrane: 2.2kW (Ring)
(2,000 mmAq) Power Cost (Years) 4,671.53 thousand won 1,401.46 thousand won Reduction cost 3,270.07 thousand won
(About 70% cost reduction effect)

Note 1) Comparison based on 200 ton / day capacity

Note 2) Oxygen transfer efficiency: conventional MBR (8%), MBR (40%) of the present invention,

As shown in the above table, the power cost reduction effect that can be expected in the present invention can be expected to reduce the power cost by about 70% in view of the fan power. According to data from actual academia and other micro-bubble generator manufacturers, the oxygen transfer efficiency of micro-bubbles is about 60 to 70%, and the dissolution duration is longer than that of the existing engine, and the power consumption of the blower in the entire water treatment system Is 40 to 50%, the power reduction effect of the present invention appears to be larger.

1: Flow regulator
2: Anoxic
3: Anaerobic
Four:
5: membrane separation tank
6, 7, 8: stirrer
9, 10: Baffle
11: MLSS concentration control device
11a: concentration adjusting device stirrer
11b:
12: Micro bubble feeder
13: raw water pump
14: Internal return pump
15: sludge circulation pump
16: Membrane suction pump
17: Membrane blower
18: Blower blower
19: aerodynamic engine
20: Screen
21: ORP META
22: MLSS Meta
23: DO meta
24: Submerged membrane

Claims (8)

Anoxic tank 2 into which raw water as a treatment target flows,
An anaerobic tank 3 in which the effluent discharged from the anoxic tank 2 flows over and flows,
An aerobic tank 4 into which effluent discharged from the anaerobic tank 3 flows, and
And a membrane separation tank (5) into which the effluent discharged from the aerobic tank (4) flows are sequentially disposed,
The anoxic tank (2) includes an MLSS concentration adjusting device (11) for adjusting the MLSS concentration of the anoxic tank (2)
The MLSS concentration adjusting device 11 is disposed downstream of the anoxic tank 2 and adjusts the concentration of the sludge depending on the rotation speed of the concentration adjusting device 11a mounted on the lower part of the MLSS concentration adjusting device 11, The MLSS concentration of the anoxic tank 2 is controlled by controlling the amount of MLSS flowing into the anaerobic tank 3 in the upper part of the MLSS concentration control device 11,
The concentration controller 11a is capable of adjusting the speed by the inverter and receives the signals of the ORP meter and the MLSS meter installed in the anoxic tank 2 to adjust the stirring speed,
The MLSS concentration in the anoxic tank 2 is increased or decreased to correspond to the influent load of the raw water and the nitrogen removal efficiency is increased
Advanced wastewater treatment system using submerged membrane
delete delete The method according to claim 1,
The oxygen solubility is maintained by the conveying of the mixed liquid of the membrane separation tank 5 to the oxic tank 4 and the minute bubble supplying device 12 provided in the oxic tank 4 to reduce the operation time of the ventilator blower, However,
The micro-bubble supplying device (12) is installed at an inlet end of the aerobic tank (4)
The raw water flowing into the oxic tank 4 is supplied to the micro-bubble supplying device 12 in contact with the micro-bubble mixture mixed with the microorganisms of the oxic tank and the outside air, circulated to the oxic tank 4, Oxidation and decomposition of the nutrient solution, causative ingestion and nitrification are promoted.
Advanced wastewater treatment system using submerged membrane
5. The method of claim 4,
The fine bubble supplying device (12)
A micro-bubble generated from the aeration device,
The raw water flowing in from the anaerobic tank (3)
By mixing the supercharging air conveyed from the membrane separation tank 5,
Wherein air supply to the oxic tank (4) by the blower is minimized to reduce blower power
Advanced wastewater treatment system using submerged membrane
5. The method of claim 4,
The membrane separation tank 5 including the submerged separation membrane 24 is supplied with cleaning air for preventing separation membrane contamination,
Characterized in that the aerobic tank (4) and the membrane separation tank (5) are separately separated so as to prevent peroxidation due to supercharged air
Advanced wastewater treatment system using submerged membrane
The method according to claim 6,
The membrane separation tank 5 has an effective water depth of 2 to 2.5 m, which is lower than the water depth of the oxic tank to reduce the wind pressure of the blower during air supply for preventing contamination of the separation membrane, thereby lowering the power of the cleaning blower To
Advanced wastewater treatment system using submerged membrane
8. The method of claim 7,
Characterized in that oxygen in the mixed liquor containing dissolved oxygen is provided to the aerobic tank (4) by a line to be transported from the membrane separation tank (5) to the oxic tank (4)
Advanced wastewater treatment system using submerged membrane

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