KR100992321B1 - Wastewater treatment apparatus with membrane module - Google Patents

Abstract

PURPOSE: A device for sewage disposal using a separating film module is provided to enable the treatment target fluid which reduced the dissolved oxygen through dissolved oxygen reducing tub to lower the dissolved oxygen of the treatment target fluid which is initially flown in from the external and enhance the removal process efficiency within the anoxic chamber, thereby enhancing the whole process efficiency of the treatment target fluid. CONSTITUTION: A device for sewage disposal includes an anoxic chamber(100), aversion tub(200), aerobic membrane separation tub(300), oxygen dissolving reduction tub(400), transfer unit(500). The anoxic chamber processes the denitrification of process target fluid. The aversion tub processes the treatment target fluid which is supplied from the anaerobic tub by microorganism. The aerobic membrane separation tub has a separation structure of inhaled filtering method which is design transparent flux 0.33m^3/m^2·day while having the opening size of average 0.4μm and acid organism supplying the oxygen inside and has a separation film which is prepared into one with an acid organism. The aerobic membrane separation tub discharges the treatment target fluid supplied from the aversion tub by oxidizing the nitrifying the fluid. The dissolved oxygen reduction tub discharges the treatment target fluid supplied form one part of the aerobic membrane separation tub after reducing the dissolved oxygen. The transfer unit enables the treatment target fluid from one part within the aerobic membrane separation tub to flow into the dissolved oxygen reduction tub. The transfer unit includes a transfer line(510) connecting the aerobic membrane separation tub and the dissolved reduction tub and a transfer pump which suctions and transfers the treatment target fluid to the dissolved oxygen reduction tub through transfer line.

Description

Wastewater treatment apparatus with membrane module {Wastewater treatment apparatus with membrane module}

The present invention relates to a sewage treatment apparatus using a membrane module and an advanced sewage treatment method using the same, and more specifically, a sewage treatment apparatus using a membrane module for biologically removing organic matter, nitrogen, and phosphorus contained in waste water and separating solid-liquid at the same time. And an advanced sewage treatment method using the same.

Most biological treatment methods for wastewater rely on activated sludge method. However, activated sludge method is very effective for the removal of organic matter, but the processing efficiency of nitrogen and phosphorus is very low, causing eutrophication in natural water system.

Nitrogen in sewage is mostly present in the form of TKN (Total Kjeldahl Nitrogen), and is generally treated by a biological method consisting of two steps of nitrification and denitrification. In the nitrification step, ammonia nitrogen and organic nitrogen are converted to nitrate nitrogen through nitrite nitrogen by aerobic nitrification bacteria. In the denitrification step under anoxic conditions, denitrification microorganisms, which use nitrate nitrogen as an electron acceptor instead of free oxygen, oxidize organic matter, reduce nitrate nitrogen to nitrogen (N ₂ ) gas, and as a result nitrogen is released into the atmosphere. . The denitrification reaction can be carried out without organic matter, and the case where there is no organic matter is called endogeneous denitrification, and the endogenous denitrification reaction has a disadvantage in that the treated water has to stay for a long time due to a slow denitrification rate. That is, the denitrification reaction depends on the concentration and type of organic matter.

Phosphorus component is removed by the microorganism in the anaerobic state to release the phosphorus in the form of phosphate using organic matter, and then, in aerobic state, the microorganism ingested the phosphorus excessively and discharged the microorganism with high phosphorus content in the cell to the excess sludge. On the other hand, in order to release phosphorus by the microorganism in the anaerobic state, the concentration of nitrogen nitrate should be low. This is because the presence of a large amount of nitrate nitrogen inhibits the release of phosphorus due to the bound oxygen of the nitrate nitrogen.

In the method of biologically removing contaminants in the sewage water, the activated sludge is finally precipitated in the sedimentation tank and the treated supernatant is discharged. However, there is a problem that the symbol water contains a large amount of suspended solids due to sludge injuries or bulking due to filamentous fungi, resulting in deterioration of the water quality of the treated water.

Recently, the MBR (Membrane Bio Reactor) method, which installs a membrane in an aerobic tank of a biological treatment device instead of the final sedimentation basin, has been in the spotlight. In particular, since there is no solid substance discharged through the effluent, the discharge of excess sludge In addition to the sludge discharge, there is an advantage that the microbial concentration can be maintained at a high concentration (5,000 to 15,000 mg / L) without any sludge loss.

However, the conventional MBR method completely removes the solids in the water to be treated using a membrane (separation membrane) having a pore size of 0.1 to 0.4 µm, while producing continuous treated water, while the contamination of the membrane proceeds as the operation continues. There is a disadvantage in that the production of. In order to solve the above disadvantages, cleaning air is required to reduce the contamination of the separation membrane. Since the air amount for cleaning the separation membrane is much larger than the amount of air required for nitrification and organic matter removal, peroxidation may occur in the tank. In addition, the dissolved oxygen concentration in the treated water returned internally for the denitrification of nitrate nitrogen is high, so that the dissolved oxygen concentration is high in the whole process and thus can inhibit the denitrification reaction. In addition, the membrane's operating MLSS (Mixed Liquor Suspended Solid) concentration is high, which increases the operating pressure and membrane resistance, which reduces the yield of treated water, which shortens the cleaning cycle of the membrane, and the long SRT (Solids Retention), an advantage of the MBR process. The increase of SMP (Soluble microbial products) or EPS (Extracellular polymeric substances) among the membrane pollutants generated by the time and high sludge concentration has the disadvantage of reducing the life of the membrane and shortening the cleaning cycle. In addition, in the disposal of excess sludge, the aeration tank sludge having a relatively lower concentration than the concentrated sludge is disposed, and thus there is a problem in that a large volume of sludge should be disposed in comparison with the required removal amount.

An object of the present invention is to provide a sewage treatment apparatus using a membrane module and a high sewage treatment method using the same, which allow nitrogen and phosphorus in wastewater to be more efficiently removed and maximize the efficiency of the membrane.

According to an aspect of the present invention, the treatment fluid is introduced from the outside, the oxygen-free tank for denitrifying the introduced fluid to be treated, and the oxygen-free tank is connected to, and the treated fluid supplied from the oxygen-free tank dephosphorized by a microorganism The anaerobic tank to be treated is connected to the anaerobic tank, and an acid pipe and a separator are provided therein to supply oxygen, and the treated fluid supplied from the anaerobic tank is subjected to nitrification and organic oxidation reaction and discharged with sludge removed. And a dissolved oxygen lowering tank connected to the aerobic membrane separation tank and the anoxic tank and receiving a portion of the fluid to be treated from the aerobic membrane separation tank, and then reducing the dissolved oxygen in the fluid to be treated. , Connecting the expiratory membrane separation tank and the dissolved oxygen reduction tank, the expiratory membrane The separation tank in part of the processed fluid provides a sewage treatment apparatus using a separation membrane module including a transport to be introduced twos the dissolved oxygen reduction.

In addition, the separator has a separator structure of the suction filtration method, it can be provided with an diffuser integrally.

In addition, the separator may have a pore size of 0.4 μm.

In addition, the dissolved oxygen in the oxygen-free tank is 0.2mg / L or less, the dissolved oxygen in the dissolved oxygen reduction tank can be maintained to 0.1mg / l or less.

The conveying unit may include a conveying line connecting the aerobic membrane separation tank and the dissolved oxygen reducing tank and a connection line to the conveying line so that the fluid to be treated in the aerobic membrane separation tank passes through the conveying line. It may include a conveying pump for suction transport to the abatement tank.

In addition, the MLSS concentration in the aerobic membrane separation tank may be 4,000 ~ 15,000mg / ℓ.

And, according to another aspect of the invention, the step of flowing the fluid to be treated in the anaerobic tank, the denitrification treatment of the fluid to be treated, the fluid to be treated in the anaerobic tank is introduced into the anaerobic tank, the fluid to be treated Dephosphorizing, filtering the sludge through the separation membrane while nitrifying and organic matters are oxidized while oxygen is supplied to the object to be treated in the anaerobic tank into an aerobic membrane separation tank; After the part of the treated fluid in the membrane separation tank flows into the dissolved oxygen reduction tank through a conveying line, the dissolved oxygen is reduced, and the dissolved fluid in the dissolved oxygen low tank is reduced to the treated fluid. It provides an advanced sewage treatment method comprising introducing an anaerobic tank.

In addition, the MLSS concentration in the aerobic membrane separation tank is 4,000 ~ 15,000mg / ℓ, acid time is 8 ~ 24 hours, F / M ratio is 0.2 ~ 0.3kgBOD / kgMLSS or less, BOD volume load 0.05 ~ 2.64 kg · BOD / m ³ · day or less, the separator may have a pore size of 0.4 μm and a design permeability of 0.33 m ³ / m ² · day.

The sewage treatment apparatus using the membrane module according to the present invention and the advanced sewage treatment method using the same, the treatment target fluid supplied from the outside of the anaerobic tank, anaerobic tank, aerobic membrane separation tank and the denitrification, dephosphorization, nitrification and organic oxidation reaction Organic matter is removed through the process, and some of the fluids to be treated in the aerobic membrane separation tank are re-introduced into the anoxic tank with the dissolved oxygen reduced through the dissolved oxygen reduction tank. Therefore, the treatment fluid in which dissolved oxygen is reduced through the reduction of dissolved oxygen lowers the dissolved oxygen of the treatment fluid flowing into the outside for the first time to increase the denitrification treatment efficiency in the oxygen-free tank, thereby increasing the overall treatment efficiency of the treatment fluid. do.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

1 is a block diagram of a sewage treatment apparatus using a membrane module according to an embodiment of the present invention. Referring to FIG. 1, the wastewater treatment apparatus includes an oxygen-free tank 100, an anaerobic tank 200, an aerobic membrane separation tank 300, a dissolved oxygen reduction tank 400, and a conveying unit 500.

The oxygen-free tank 100 is a fluid to be treated to remove the suspended solids having a large particle state by the settling and screen from the outside. At this time, the fluid to be treated is introduced into the oxygen-free tank 100 flows in accordance with the processing capacity. The anoxic tank 100 denitrates the fluid to be treated. That is, in the anoxic tank 100, the nitric acid in the fluid to be treated is converted to nitrogen gas through a denitrification reaction and released to the atmosphere to be removed. Here, the dissolved oxygen in the oxygen-free tank 100 is maintained to be 0.2 mg / L or less.

The anaerobic tank 200 dephosphorizes the treatment target fluid supplied after being processed from the anaerobic tank 100. The anaerobic tank 200 is connected to the anaerobic tank 100, and microorganisms are introduced therein to release phosphorus up to 3 to 4 times the inflow concentration using the organic material of the processing target fluid. At this time, dissolved oxygen should not be detected in the anaerobic tank 200.

Here, agitators 110 and 210 may be installed inside the anaerobic tank 100 and the anaerobic tank 200 to prevent the microorganisms from rot and to completely mix the microorganisms.

The aerobic membrane separation tank 300 removes sludge as well as allowing nitrification and organic matter oxidation of the treatment target fluid supplied after being treated from the anaerobic tank 200. The aerobic membrane separation tank 300 is installed in connection with the anaerobic tank 200, and has an diffuser 310 for supplying oxygen and a separator 320 for filtering sludge in the fluid to be treated. Here, the diffuser 310 is supplied with oxygen from the outside through the blower 311 installed in the outside to give up in the aerobic membrane separation tank (300). The organic material is processed through biological reactions such as growth of microorganisms in the aerobic membrane separation tank 300 and self oxidation by oxygen supplied from the diffuser 310, and organic nitrogen and ammonia nitrogen are converted into nitrate nitrogen. To be oxidized. That is, as the diffuser 310 is provided in the aerobic membrane separation tank 300, oxygen is supplied to the treated fluid treated in the anaerobic tank 200 in the aerobic membrane separation tank 300. In the state, nitrification and organic matter oxidation proceed.

The separator 320 solid-separates microorganisms and sludge, and then discharges the treated fluid. The separator 320 has a separator structure of suction filtration. In addition, the separation membrane 320 may be provided with an diffuser 321 that allows contamination of the separation membrane 320 to be suppressed while receiving oxygen from the outside of the blower 311 described above. Here, the average pore of the separation membrane 320 is 0.2 ~ 0.5㎛, more preferably the void is 0.4㎛.

The dissolved oxygen reduction tank 400 receives a portion of the fluid to be treated from the aerobic membrane separation tank 300, and then maintains the fluid to be treated with high dissolved oxygen for a predetermined time to reduce dissolved oxygen. It is discharged to the oxygen-free tank (100). The dissolved oxygen reduction tank 400 is connected to the anoxic tank 100 to supply the treated fluid with reduced dissolved oxygen to the anoxic tank 100 so that the dissolved oxygen tank 100 is supplied to the anoxic tank 100 from the outside. By removing the dissolved oxygen of the fluid to be treated having dissolved oxygen, the denitrification reaction can be efficiently performed in the anoxic tank 100 described above. Here, the dissolved oxygen inside the dissolved oxygen reduction tank 400 is maintained to be 0.1 mg / L or less. In addition, an agitator 410 may be installed inside the dissolved oxygen reduction tank 400 to prevent the microorganisms from rot and to completely mix the microorganisms.

The conveyer 500 allows a portion of the fluid to be treated to flow into the dissolved oxygen reduction tank 400 in the aerobic membrane separation tank 300. The conveying unit 500 connects the aerobic membrane separation tank 300 and the dissolved oxygen reduction tank 400. Here, the conveying unit 500 includes a conveying line 510, a conveying pump 520.

The conveying line 510 is a tubular member for connecting the aerobic membrane separation tank 300 and the dissolved oxygen reduction tank 400. Through this conveying line 510, a portion of the fluid to be treated in the aerobic membrane separation tank 300 is guided to the dissolved oxygen reduction tank 400. The conveying pump 520 is connected to one side of the conveying line 510, the fluid to be treated in the aerobic membrane separation tank 300 through the conveying line 510 the dissolved oxygen reduction tank 400 To be transported by suction.

In this way, the conveying line 510 is to convey the fluid to be treated only once in the aerobic membrane separation tank 300 to the dissolved oxygen reduction tank 400, thereby reducing the stress of the microorganisms in the fluid to be treated, The treatment efficiency of the fluid to be treated by the microorganism may be increased. In addition, the sewage treatment apparatus according to an embodiment requires the use of a single pump in the conveying line 510 and reduces the installation cost and maintenance cost while reducing the number of flow meters (not shown) installed accordingly.

2 is a view showing a sewage treatment process according to an embodiment of the present invention. Referring to Figure 2 describes the advanced sewage treatment method as follows.

First, the fluid to be treated is introduced into the anaerobic tank 100 to perform a denitrification treatment of the fluid to be treated. At this time, the dissolved oxygen of the fluid to be treated in the oxygen-free tank 100 is maintained at 0.1mg / L or less, the fluid to be treated from the outside flowing into the stirrer 110, and then the dissolved oxygen reduction tank 400 Mix the fluid to be treated through the mixture. The mixed fluid to be treated is subjected to a denitrification treatment in which nitrogen is reduced by using nitrogen nitrate as an electron acceptor in the oxygen-free tank 100. And, in the oxygen-free tank 100, SDNR is 0.03 ~ 0.11mgNO ₃ -N / mgMLSS · day, HRT is to be 1.5hr or more.

As such, the treated fluid denitrified in the anaerobic tank 100 is introduced into the anaerobic tank 200 and then dephosphorized. At this time, the dissolved oxygen is maintained inside the anaerobic tank 300 so as not to be detected, and microorganisms are introduced into the inside of the anaerobic tank so that the microorganisms are discharged to 3 to 4 times the inflow concentration using the organic material of the fluid to be treated. Here, the stirrer 210 in the anaerobic tank 200 is operated to mix the fluid to be treated with the microorganisms.

Then, the treated fluid dephosphorized in the anaerobic tank 300 is introduced into the aerobic membrane separation tank 300, the growth and self-oxidation of the microorganisms due to the oxygen abandoned through the acid pipe 310 The same biological reaction occurs to treat organic matter in the fluid to be treated. That is, in the aerobic membrane separation tank 300, a process of oxidizing organic nitrogen and ammonia nitrogen to nitrate nitrogen while removing organic substances from the fluid to be treated is performed. At this time, the diffuser 310 uniformly stirs the fluid to be treated in the aerobic membrane separation tank 300 and maintains dissolved oxygen at least 2 ppm.

In addition, the fluid to be treated introduced into the aerobic membrane separation tank 300 solid-separates microorganisms and sludge by the separation membrane 320 and then discharges the treated fluid. At this time, the MLSS concentration in the aerobic membrane separation tank 300 is 4,000 ~ 15,000mg / ℓ, acid time is 8 ~ 24 hours, F / M ratio is 0.2 ~ 0.3kgBOD / kgMLSS or less, BOD volume load 0.05 to 2.64 kg · BOD / m ³ · day or less, the separation membrane has a pore size of 0.4 μm and a design permeability of 0.33 m ³ / m ² · day. In addition, the HRT of the aerobic membrane separation tank 300 is to be 4 ~ 6.0hr.

Thereafter, some of the fluid to be treated in the aerobic membrane separation tank 300 flows into the dissolved oxygen reduction tank 400 through the transport line 510 of the transport unit 500 to reduce dissolved oxygen. . That is, in the dissolved oxygen reduction tank 400, the dissolved oxygen is reduced while the fluid to be treated having high dissolved oxygen stays for a predetermined time from the aerobic membrane separation tank 300. The fluid to be treated introduced into the dissolved oxygen reduction tank 400 maintains dissolved oxygen at 0.1 mg / l, and HRT is maintained at 0.5 hr or more.

The treatment fluid containing low dissolved oxygen through the dissolved oxygen reduction tank 400 is supplied to the anoxic tank 100 as described above, and the denitrification efficiency of the first external fluid to be treated flowing into the oxygen-free tank 100 is reduced. Will increase. That is, when the fluid to be treated in which the dissolved oxygen is reduced in the dissolved oxygen reduction tank 400 flows into the oxygen-free tank 100, nitrogen is added using the nitrate nitrogen in the fluid to be treated first as an electron acceptor. Reduced denitrification proceeds efficiently.

As such, in the sewage treatment apparatus using the membrane module and the sewage treatment method using the same, the treatment target fluid supplied from the outside sequentially the anaerobic tank 100, the anaerobic tank 200, the aerobic membrane separation tank 300 The organic matter is removed through denitrification, dephosphorization, nitrification and organic oxidation reaction, and some of the fluids to be treated in the aerobic membrane separation tank have the dissolved oxygen reduced through the dissolved oxygen reduction tank 400. Is reintroduced to Therefore, by lowering the dissolved oxygen of the treatment target fluid in which the dissolved oxygen is reduced through the dissolved oxygen reduction tank 100 is first introduced to the outside by increasing the denitrification treatment efficiency in the anoxic tank 100. In addition, the overall treatment efficiency of the fluid to be treated is increased.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1 is a block diagram of a sewage treatment apparatus using a membrane module according to an embodiment of the present invention.

2 is a view showing a sewage treatment process according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

100: anaerobic tank 200: anaerobic tank

300: aerobic membrane separation tank 310, 321: diffuser

320: separator 400: dissolved oxygen reduction

500: conveying unit 510: conveying line

520: return pump

Claims (8)

An anoxic tank into which the fluid to be treated is introduced from the outside, and denitrifying the fluid to be treated; An anaerobic tank connected to the anoxic tank and dephosphorizing the fluid to be treated supplied from the anoxic tank by a microorganism; It is connected to the anaerobic tank, and has an acid pipe that supplies oxygen and has an air permeation size of 0.4 μm on average, and has a permeate membrane structure of 0.33m ³ / m ² · day with a permeation filter and a diffuser structure. An aerobic membrane separation tank provided with a separation membrane configured to allow the treatment fluid supplied from the anaerobic tank to undergo nitrification and organic oxidation reaction and to discharge the sludge from the sludge; A dissolved oxygen lowering tank connected to the anoxic tank and receiving a part of the fluid to be treated from the aerobic membrane separation tank and then reducing the dissolved oxygen in the fluid to be treated; And, And a conveying unit connecting the aerobic membrane separation tank and the dissolved oxygen reduction tank so that a part of the fluid to be treated in the aerobic membrane separation tank flows into the dissolved oxygen reduction tank, Dissolved oxygen in the oxygen-free tank is less than 0.2mg / ℓ while SDNR is 0.03 ~ 0.11mgNO ₃ -N / mgMLSS · day, HRT is more than 1.5hr, dissolved oxygen in the dissolved oxygen low reduction tank is 0.1mg / At the same time, the HRT is 0.5hr and the MLSS concentration in the aerobic membrane separation tank is 4,000-15,000mg / l, the acid time is 8-24 hours, and the F / M ratio is 0.2-0.3kgBOD / kg MLSS or less, BOD volume load is 0.05 ~ 2.64kgBOD / m ³ · day or less, HRT is 4 ~ 6hr, The conveying unit, and a conveying line for connecting the aerobic membrane separation tank and the dissolved oxygen reduction tank, The sewage treatment apparatus using a separation membrane module is connected to the conveying line, including a conveying pump for suctioning the fluid to be treated in the aerobic membrane separation tank to the dissolved oxygen reduction tank through the conveying line. delete delete delete delete delete delete delete

Images