KR102108870B1 - Membrane Treatment Device for Eliminating Nitrogen and/or Phosphorus - Google Patents

Abstract

Provided is an advanced treatment device for removing nitrogen and phosphorus. The present invention efficiently removes nitrogen even when a C/N ratio of an influent is low, overcomes the difficulty of dephosphorization due to the long SRT indicated as a disadvantage of an MBR process, and the denitrification reaction of a denitrification tank due to the deaeration of the membrane separation aeration tank. By maximizing the advantages of the MBR process, it is possible to provide the advanced treatment device for removing nitrogen and phosphorus, which is more effective to treat nitrogen and phosphorus, and the supply of filtered wastewater can be stably performed by continuously dewatering sludge in a screen bath.

Description

Nitrogen, phosphorus removal membrane separation advanced treatment device {Membrane Treatment Device for Eliminating Nitrogen and / or Phosphorus}

The present invention relates to an advanced treatment device for removing nitrogen and phosphorus, and more particularly, to an advanced treatment device for removing nitrogen and phosphorus, more specifically, a dephosphorization tank, a first denitrification tank, a second denitrification tank, While passing through an aeration tank, a membrane separation aeration tank, and a stabilization tank, nitrogen, phosphorus, and organic matter in waste water are repeatedly purified to improve treatment efficiency, and sludge is continuously dehydrated in a screen tank to supply filtered waste and waste water. The present invention relates to an advanced treatment device for nitrogen and phosphorus removal membrane separation.

In order to solve the disadvantages of the existing activated sludge process by combining the advantages of the existing activated sludge process and membrane technology, studies have been conducted to replace solid-liquid separation by gravity precipitation with membrane separation. Also called separation process or membrane-bound activated sludge process.

In addition, it is not limited to the activated sludge method, and a general bioreactor combined with a membrane separation process is collectively referred to as a membrane bioreactor (MBR).

The MBR process almost completely separates and removes the target materials (organic, inorganic contaminants, microorganisms, etc.) that are present in raw water, sewage, and waste water depending on the pore size (several mm to several tens of µm) of the separator and the surface charge of the membrane. It is a highly advanced separation process.

Particularly, in accordance with the strengthening of water quality standards in effluents, studies have been actively conducted to combine the advanced sewage treatment process, the Biological Nutrient Removal (BNR) process with the MBR process.

The characteristic of the MBR process is that no sedimentation tank is required and it is possible to maintain the microbial concentration 3 to 4 times higher than the activated sludge method, so that organic matter can be effectively decomposed at a smaller aerobic tank capacity, and the sludge retention time (SRT) It is possible to maximize and induce nitrification, and since the amount of excess sludge is small, the volume of the concentration tank is also reduced, so a compact process is possible.

Also, the advantage of the MBR process is that 100% of suspended solids can be removed, so the treated water can be treated very stably (BOD and SS can be treated with 5 mg / L or less) regardless of sludge sedimentation, and it is more than membrane pore size. Even large bacteria and viruses can be removed, and treated water can be used as heavy water.

In addition, since the membrane unit is additionally installed in the aeration tank in a treatment plant to which the existing activated sludge process is applied, conversion to the membrane separation process is actively increasing from the existing activated sludge process since construction is simple and economical and stable water quality can be obtained.

The MBR process is capable of separating the solid and liquid by a separation membrane more than the conventional activated sludge process, and can maintain a high MLSS concentration (5,000 to 15,000 mg / L) in the reaction tank.

Such a high concentration of microorganisms increases the efficiency of nitrification and increases the sludge residence time (SRT), thereby increasing sludge assetization and reducing the amount of sludge generation.

This, the advantage of the MBR process can be highlighted because the cost of sludge treatment is large and the portion of the wastewater treatment cost is large.

In addition, it is possible to reduce the cost and site required for the sedimentation basin by using a separator instead of the sedimentation basin.

Among the advantages of the MBR process, the most important point is that stable operation is possible.

In other words, there is no need to worry about sludge bulking, foaming, pin floc, etc. occurring in the secondary sedimentation battery. It causes a decrease in processing efficiency.

However, in the MBR, since the sludge expanded by the separation membrane is separated, stable sewage and wastewater treatment is possible.

Existing MBR process is composed of a denitrification tank for denitrifying nitric acid nitrogen using an organic material, and an aerobic tank for converting ammonia nitrogen to nitric acid nitrogen, and the treated water having passed through the membrane module in the aerobic tank to remove organic material is It is transferred to a storage tank, and water mixed with sludge from the exhalation tank is returned to the denitrification tank.

As described above, in order to remove nitrogen biologically, in most processes, the reaction tanks are arranged in order of denitrification tanks and aerobic tanks, and nitric acid nitrogen generated in the exhalation tanks is transferred to a denitrification tank using an internal transfer pump and a pipe.

In addition, since the amount of organic matter in the sewage and waste water is limited, it is generally returned to the inside for the further denitrification treatment only within 3 to 4 times the flow rate, and the rest is discharged to the treated water.

In addition, since the nitrogen removal rate is greatly influenced by the water temperature of the reaction tank, the concentration of microorganisms, the nature of the influent water, the time, and the season, it is very difficult to control the nitrogen concentration of the treated water below a regulated value, so it is 1 when the relief value is exceeded. Subsequently, an external carbon source is additionally added to the denitrification tank to improve denitrification efficiency, and nitrogen is limitedly removed by controlling the amount of internal transport in the exhalation tank.

However, basically, the nitrate nitrogen remaining internally conveyed in the aerobic tank is discharged into the treated water, and thus has limitations in nitrogen removal.

Therefore, if the C / N ratio of the influent is very low, or if nitrogen and phosphorus are required on a more stringent basis, it is difficult to process using the existing method alone, and an additional process is required.

In addition, the MBR process delays occlusion inside the module of the separation membrane unit and reduces membrane contamination, ultimately supplying a higher concentration of DO than the existing activated sludge method to extend the cleaning cycle and membrane life of immersion chemicals. Excess DO (2 ~ 4ppm) is supplied to the mixed solution that is returned to the denitrification tank to interfere with the denitrification reaction in the denitrification tank.

In addition, the MBR process has an advantage in that the hydraulic dwell time (HRT) is shortened when the sludge residence time (SRT) is increased due to high MLSS, but the site area can be reduced, but when it is linked with the sludge activity and advanced treatment This can cause huge problems with phosphorus removal.

That is, long SRT may deteriorate the activity of microorganisms and deteriorate the quality of treatment. In terms of nitrification, it is advantageous to operate SRT for a long time, but it is disadvantageous in terms of phosphorus removal requiring short SRT.

Therefore, the MBR process has a long SRT by high microorganisms, has good nitrification efficiency, and also has an effect of reducing sludge generation due to sludge assetization, but may cause problems of degradation of microorganism activity and phosphorus removal.

In the end, the MBR process was determined by the SRT, and the quality of the treated water and the amount of sludge were determined, and it was difficult to find a driving SRT that could satisfy both nitrification, sludge generation, and phosphorus removal.

KR Patent Registration 10-1018587 B1 (2011.02.22.)

Accordingly, the present invention has been devised to solve the above-mentioned problems, and efficiently removes nitrogen even when the C / N ratio of the influent is low, the difficulty of phosphorus removal due to the long SRT indicated as a disadvantage of the MBR process, and the membrane separation of aerobic tank. Overcoming the difficulties of denitrification reaction of the denitrification tank due to the super aeration, maximizing the advantages of the MBR process to provide a more effective nitrogen, phosphorus-treated nitrogen and phosphorus removal membrane separation device and continuously dewatering sludge in the screen tank It is an object of the present invention to provide an advanced treatment device for removing nitrogen and phosphorus, which is made of stable supply of filtered and filtered wastewater.

In order to achieve this object, the features of the present invention include: a flow rate adjustment tank (1) that receives filtered waste water from the screen tank (10); When the raw water flowing into the flow adjusting tank 1 is higher than a predetermined level, the raw water of the flow adjusting tank 1 is passed through a microfiltration screen 11 by a raw water pump immersed in the flow adjusting tank 1. A dephosphorization tank (2) and a first denitration tank (3) that are supplied at an appropriate ratio through an inflow valve installed in the inflow pipe via V-NOTCH (13a); As the second denitrification tank (4) receiving the raw water of the first denitrification tank (3) when the raw water flowing into the first denitrification tank (3) is above a predetermined level, the mixed liquid in the second denitrification tank (4) And a second denitrification tank (4) for supplying the dephosphorization tank (2) by an internal transfer pump (16) immersed in the second denitration tank; When the mixed liquid stored in the second denitrification tank (4) is a predetermined level or more, an aeration tank (5) for receiving the mixed liquid of the second denitrification tank (4); A membrane separation aeration tank (6) receiving the mixed liquid of the aeration tank (5) when the mixed liquid stored in the aeration tank (5) is a predetermined level or higher; When the mixed solution stored in the membrane separation exhalation tank 6 is a predetermined level or higher, as a stabilization tank 7 receiving the mixed solution of the aeration tank 5, the conveying pump immersed in the stabilization tank in the mixed solution in the stabilization tank 7 (15) through the V-NOTCH (13b) through the inlet valve installed in the inlet pipe and the stabilization tank (7) for supplying the sludge tank (8) or the first denitrification tank (3) at an appropriate ratio; The membrane separation exhalation tank 6 is immersed in the inside, and the mixture outside the separation membrane flows into the separation membrane through the pores of the separation membrane by suction pressure generated by the operation of the suction pump 14 existing outside the membrane separation exhalation tank 6 A plurality of separation membrane units 18 for solid-liquid separation; A flocculant storage tank 19 for storing a flocculant for agglomerating and removing phosphorus components, and supplying the stored flocculant to the aeration tank 5 by a transfer pump 17; When the residue containing the nitric acid component and sludge remaining in the stabilization tank 7 is higher than a predetermined level, when the residue of the stabilization tank 7 is supplied, and the MLSS concentration in the membrane separation aeration tank 6 is high , As the sludge storage tank (8) receiving the sludge in the membrane separation aeration tank (6), the sludge in the sludge storage tank (8) to supply the sludge in the flow rate adjustment tank (1) when a predetermined level using an air lift pump Made, including, the screen tank 10, the lower, the filtration tank 110 in which wastewater is stored, the microfiltration screen 11 installed in the longitudinal direction inside the filtration tank 110, and the microfiltration screen 11 The horizontal screw conveyor 120 and the horizontal screw conveyor 120 which are installed on the bottom of the filtering tank 110 and transfer the sludge filtered by the microfiltration screen 11 and collected downward to one side of the filtering tank 110 and the horizontal screw conveyor 120. Connected, phase sludge It is characterized in that it comprises a dehydration conveyor unit 130 for conveying incense and dehydrating, and a hopper 140 installed above the dewatering conveyor 130 to discharge the dehydrated sludge to the outside of the filtration tank 110.

At this time, the dewatering conveyor 130 is installed on the side wall of the filtration tank 110, the vertical transfer pipe 132 and the vertical transfer pipe (132) formed of a perforated network 131 on the outer peripheral surface corresponding to the inner space of the filtration tank 110 132) It is installed inside and rotated together with the main shaft 134 by the motor 133, the transfer screw 135 for conveying the sludge upwardly, and inserted into the main shaft 134 and transferred in the vertical direction by the cylinder 137 It is characterized in that it comprises a working shaft 136 and a dehydration screw 138 connected to the working shaft 136.

In addition, the cylinder 137 rod rod and the operating shaft 136 is connected by a rotating coupler (136a), it characterized in that the operating shaft 136 is provided to be rotatable in a state connected to the rod rod cylinder 137 .

In addition, the main shaft 134 has a plurality of guide holes (134b) are cut on the outer circumferential surface as the road hole (134a) is formed therein, the dewatering screw (138) and the working shaft (136) through the guide hole (134b) It is characterized in that it is provided to be connected.

In addition, when the sludge collected on the bottom of the filtration tank 110 by the lateral screw conveyor 120 operation collects the dehydration conveyor 130 side, the sludge is returned upward by the dehydration conveyor 130 operation, and the sludge is hopper ( When the dehydration conveyor 130 is stopped by the control unit just before reaching 140, the cylinder 137 is operated and the working shaft 136 is moved downward, the dewatering screw 138 is pressed toward the transfer screw 135 side. As the pressurizes the sludge, the dehydrated screw 138 and the transfer screw 135 dehydrated by the pressing force are re-introduced into the filtration tank 110 through the perforated network 131, and when dehydration is completed, to the operating shaft 136 It is characterized in that the dewatering screw 130 is rotated in a state in which the dewatering screw 138 is returned upward so that the dewatered sludge is discharged through the hopper 140.

In addition, a plurality of separation membrane suction line is installed between the plurality of separation membrane unit 18 and the suction pump 14, a differential pressure gauge for detecting the pressure of the separation membrane unit 18 and a suction valve to control the inflow of the treated water (21) and; A discharge tank (9) for receiving the treated water sucked by the group suction pump (14) and discharging it to the outside by a discharge pump; Air is supplied to the air diffuser disposed under the membrane unit 18 immersed in the membrane separation aerobic tank 6 through the alignment line 22, and the flow rate adjustment tank 1, the aeration tank 5, and the sludge storage tank It comprises a blower (12) for supplying air to each of (8).

In addition, the raw water flowing through the microfiltration screen 11 enables the flow rate flowing through the V-NOTCH 13a to be measured, and the dephosphorization tank 2 and the flow through the inlet valve installed in the inlet pipe. It is configured to be distributed and introduced into one denitrification tank (3).

In addition, the sludge returned from the stabilization tank 7 enables measurement of the flow rate conveyed through the V-NOTCH 13b, and the first denitrification tank 3 at an appropriate ratio through an inlet valve installed in the inlet pipe. Wow, it is configured to be distributed and introduced into the sludge storage tank 8.

According to the above configuration and operation, the present invention consists of two tanks of denitrification tanks, and the first denitrification tank is supplied with sludge containing DO and nitric nitrogen components from a stabilization tank to buffer DO and to a predetermined level. When the level is higher than the level, the mixture is supplied to the second denitrification tank. The DO is supplied in a reduced state to maximize the efficiency of denitrification, and the sludge is continuously dehydrated in the screen tank to supply filtered sewage and wastewater stably. There is an effect made.

In addition, the raw water flowing through the microfiltration screen from the flow adjustment tank flows through the V-NOTCH without directly flowing into the single tank of the rear de-inner or denitrification tank so that the flow rate can be measured. (Example> Dephosphorization tank: Denitrification tank = 3: 7) to remove the nitrogen and phosphorus by controlling the amount of organic substances necessary for phosphorus release in the dephosphorization tank and the amount of organic substances necessary for denitrification in the first denitrification tank. It has the advantage of maximizing efficiency.

In addition, by forming an aeration tank in front of the membrane separation aerobic tank, the concentration of organic matter is reduced to reduce the BOD load of the membrane separation aerobic tank, thereby minimizing the effect on the membrane clogging, and it is possible to more easily maintain the wastewater treatment plant. Can also maximize the lifespan.

1 is a nitrogen, phosphorus removal membrane separation advanced processing apparatus process according to an embodiment of the present invention.
2 to 4 is a block diagram showing a screen tank of a nitrogen, phosphorus removal membrane separation advanced processing apparatus according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present invention, as shown in Figure 1 as a whole screen tank 10, flow adjustment tank (1), de-inking tank (2), the first denitrification tank (3), the second denitrification tank (4), the aeration tank (5) , Membrane separation exhalation tank (6), stabilization tank (7), sludge storage tank (8), discharge tank (9), microfiltration screen (11), blower (12), separation membrane unit (18) provided under the air diffuser, It contains a flocculant storage tank 19, a flocculant transfer pump 17, and VNOTCHs 13a, 13b.

The screen tank 10, as raw water to be treated as waste water and inflow of raw water as waste water, removes contaminants in the waste water, thereby preventing clogging and mechanical failure of the pump in a subsequent process and reducing the load of organic matter.

At this time, the screen tank 10, as shown in FIG. 2, the filtration tank 110 in which wastewater is stored, the microfiltration screen 11 installed in the longitudinal direction inside the filtration tank 110, and the microfiltration screen 11 ) And a horizontal screw conveyor 120 and a horizontal screw conveyor 120 which are installed on the bottom of the filtering tank 110 and transfer the sludge filtered by the microfiltration screen 11 and collected downward to one side of the filtering tank 110. It is connected to, including a dewatering conveyor unit 130 for conveying the sludge upward and dehydrating, and a hopper 140 installed on the dewatering conveyor 130 to discharge the dehydrated sludge to the outside of the filtering tank 110 Is done.

And, the dewatering conveyor 130 is installed on the side wall of the filtration tank 110, the vertical transfer pipe 132 and the vertical transfer pipe (132) formed of a perforated network 131 on the outer circumferential surface corresponding to the inner space of the filtration tank 110 132) It is installed inside and rotated together with the main shaft 134 by the motor 133, the transfer screw 135 for conveying the sludge upwardly, and inserted into the main shaft 134 and transferred in the vertical direction by the cylinder 137 It comprises a working shaft 136 and a dehydration screw 138 connected to the working shaft 136.

Here, the cylinder 137 rod rod and the working shaft 136 are connected by a rotating coupler 136a, the working shaft (136) is provided to be rotatable while being connected to the cylinder 137 rod rod operating shaft ( 136) the linear motion force by the cylinder 137 and the rotational motion force by the motor 133 are transmitted in combination.

At this time, the main shaft 134 has a plurality of guide holes (134b) are cut on the outer circumferential surface while the load hole (134a) is formed therein, the dewatering screw (138) and the working shaft (136) through the guide hole (134b) It is provided to be connected. The guide hole 134b is formed in at least two places on the outer circumferential surface of the main shaft 134 and is cut in the longitudinal direction of the main shaft 134 to control the operation of the dewatering screw 138.

In operation, when the sludge collected on the bottom of the filtration tank 110 by the lateral screw conveyor 120 operation collects the dewatering conveyor 130 side, the sludge is conveyed upward by the dehydration conveyor 130 operation as shown in FIG. 2. When the dewatering conveyor 130 is stopped by the control unit just before the sludge reaches the hopper 140, and the cylinder 137 is operated as shown in FIG. 3 and the working shaft 136 is moved downward, the dewatering screw ( 138) pressurizes the sludge while being pressed toward the conveying screw 135, and the dehydrated screw 138 and the water dehydrated by the pressing screw 135 are re-introduced into the filtration tank 110 through the perforated network 131, When dehydration is completed, the dewatering conveyor 130 is rotated to return to the state in which the dewatering screw 138 is returned upward by the operating shaft 136, as shown in FIG. 4, so that the dewatered sludge is discharged through the hopper 140.

In addition, the flow rate adjustment tank (1) is located at a lower level than the screen tank (10) and receives raw water filtered from the screen tank by natural dropping.

The dephosphorization tank (2) is a microfiltration screen (11) by the raw water pump immersed in the flow rate adjustment tank (1) when the raw water flowing into the flow rate adjustment tank (1) is above a predetermined level or more Through the V-NOTCH (13a), the raw water is supplied at an appropriate ratio through the inlet valve installed in the inlet pipe according to the C / N ratio of the influent water or the nitrogen and phosphorus removal operating conditions.

In addition, the mixed liquid in the second denitrification tank 4 is supplied to the dephosphorization tank 2 by the internal transfer pump 16 immersed in the second denitrification tank.

The first denitrification tank (3), when the raw water flowing into the dephosphorization tank (2) is above a predetermined level, is naturally supplied with the raw water of the dephosphorization tank, and the microfiltration screen (1) in the flow adjustment tank (1) 11) via the V-NOTCH (13a), the raw water is supplied at an appropriate ratio through the inlet valve installed in the inlet pipe according to the C / N ratio of the influent water or nitrogen and phosphorus removal operating conditions.

The second denitrification tank (4), when the mixed liquid flowing into the first denitrification tank (3) is above a predetermined level, is naturally supplied with the mixed solution of the first oxygen free tank, and receives the mixed liquid in the second denitrification tank (4). , It is supplied to the dephosphorization tank (2) by an internal transfer pump (16) immersed in a second denitrification tank.

The aeration tank (5), when the raw water flowing into the second denitrification tank (4) is above a predetermined level, is naturally supplied with the raw water of the second denitrification tank.

In addition, the membrane separation aerobic tank 6, when the mixed liquid stored in the aeration tank 5 is a predetermined level or more, naturally receives the mixed liquid of the aeration tank.

When the mixed solution stored in the membrane separation aerobic tank 6 is above a predetermined level, the stabilization tank 7 naturally receives the mixed liquid of the membrane separation aerobic tank 6.

The stabilization tank 7 is solid-liquid separated by the separation membrane unit 18 immersed in the membrane separation expiration tank 6, so that the residual nitric acid component and the residue containing sludge is above a predetermined level, the stabilization tank 7 ), A certain ratio is supplied to the sludge tank 8 or the first denitrification tank 3 through the inlet valve installed in the inlet pipe according to the field operating conditions through the VNOTCH 13b to the conveying pump 15 immersed in). .

The sludge tank 8 supplies the sludge in the sludge tank 8 to the flow rate adjustment tank 1 using an air lift pump when the sludge flowing from the stabilization tank 6 is above a predetermined level.

Then, the flocculant storage tank 19, in order to remove the untreated phosphorus component in the aeration tank 5, stored a flocculant for agglomerating and removing the phosphorus component, the stored flocculant by the transfer pump 17 It is supplied to the aeration tank (5).

Here, in the screen jaw 10, in order to remove coarse contaminants, a fixed bar screen and an automatic bar screen may be sequentially arranged and provided.

In addition, a water stirrer 20 is disposed in each of the dephosphorization tank 2, the first denitrification tank 3, and the second denitration tank 4, respectively.

The water flow stirrer 20 provided in each of the dephosphorization tank (2), the first denitrification tank (3), and the second denitration tank (4) is to properly mix the inflowing raw water and the conveying water and smoothly denitrification.

Then, the blower 12 supplies air to an air diffuser disposed under the membrane unit 18 immersed in the membrane separation aerobic tank 6 through the air line 22, and the flow rate adjustment tank 1 ), Air is supplied to the aeration tank 5 and the sludge storage tank 8, respectively.

Hereinafter, an advanced nitrogen and phosphorus removal membrane separation apparatus of the present invention configured as described above will be described.

First, the raw water, which is wastewater flowing into the present method, is removed from the coarse contaminant through the fixed bar screen and the automatic bar screen of the screen tank 10 and flows into the flow adjustment tank 1.

The flow rate adjustment tank (1), which supplies a certain amount of raw water to the dephosphorization tank (2) and the first denitrification tank (3), is provided with an inlet valve to control the flow rate of the inflow of lower and waste water in each supply pipe. Supply.

 At this time, the raw water of the flow adjustment tank 1 is filtered once again by the microfiltration screen 11 before being transferred to the dephosphorization tank 2 and the first denitrification tank 3.

The microfiltration screen 11, which is made of a fine mesh screen in a cylindrical shape, is rotated by the driving of a motor to remove fine contaminants.

And, the raw water transferred to the dephosphorization tank (2), the internal transfer pump in the second denitrification tank (4) adjacent to the downstream side, to maintain the MLSS (mixed liquor suspended solids: microorganisms, 5000 to 12000mg / L) concentration It is mixed with the conveyed water conveyed by (16), and the mixture is agitated by the water stirrer 20 immersed in the dephosphorization tank (2), so that it comes into smooth contact with microorganisms, and thus is present in the raw water and conveyed water. Phosphorus components are eluted and released, and some organic substances are removed.

In addition, if the raw water in the dephosphorization tank (2) is above a certain level, it is naturally discharged to the downstream first denitrification tank (3).

 In the first denitrification tank (3), the raw water that is dividedly introduced from the flow rate adjustment tank (1) and the mixture introduced from the dephosphorization tank (2), and the conveyed water conveyed by the transfer pump (15) from the stabilization tank (7) It is mixed with, and the nitrate nitrogen component contained in the raw water and the conveyed water of the dephosphorization tank 2 is removed by a denitrification reaction.

In addition, the nitric acid nitrogen component that has not been removed from the first denitrification tank 3 is sequentially removed while passing through the second denitrification tank 4.

This is because the transported water conveyed by the conveying pump 15 in the downstream stabilization tank 7 contains a large amount of DO components as well as nitrogen components transformed into nitrate nitrogen by nitrifying microorganisms. The first denitrification tank (3) and the second denitrification tank (4) downstream of the unreacted nitric acid nitrogen, which do not properly denitrify, are placed separately, so that denitrification microorganisms can denitrify smoothly in the environment where DO is not present, and nitrogen This is to maximize the removal effect.

At this time, the organic carbon source necessary for the denitrifying microorganisms to act is covered with organic substances in the incoming raw water through the split inflow. During the biometabolism process of the dephosphorization microorganisms in the dephosphorization tank (2) and denitrifying microorganisms in the first denitrification tank (3). This is to maximize the effect of removing phosphorus and nitrogen at the same time by appropriately injecting necessary organic substances (eg, dephosphorization tank: denitrification tank = 3: 7).

As described above, the dephosphorization tank (2), the first denitrification tank (3), the second denitrification tank (4) in order to smoothly release the phosphorus and denitrification by properly mixing the respective mixed liquids, the dephosphorization tank (2), the A water stirrer 20 is installed in each of the 1 denitrification tank 3 and the second denitrification tank 4 to mix raw water and conveyed water.

If the denitrification mixture in the second denitrification tank 4 is equal to or higher than a certain level, it is naturally introduced into the aeration tank 5.

In the mixture introduced into the aeration tank 5, organic contaminants, phosphorus substances, suspended substances, ammonia nitrogen (NH ₃ -N), and nitrite nitrogen (NO ₂ -N) components are present.

The denitrification action refers to an action in which nitric acid nitrogen is reduced to nitrogen gas (N2) by a microorganism, and when the microorganism lacks oxygen, the oxygen contained in nitric acid (NO3) is taken out and used, so nitric acid loses oxygen , It is reduced to nitrogen gas (N2) and released into the atmosphere.

There are many types of microorganisms involved in denitrification, but representative microorganisms include Pseudomonas and Bacillus.

On the other hand, denitrifying microorganisms belong to the heterotrophic bacteria, so they need to be supplied with nutrients (carbon) from outside for growth. Materials that can be used as external carbon sources include organic materials such as methanol, acetic acid, methane, and sewage.

Chemical reaction formula when using methanol

^{_{5CH 3 OH + 6NO 3 - →}} 3N 2 + 5CO 2 + 7H 2 O + 6OH -

Chemical reaction formula when using acetic acid

^{_{5CH 3 COOH + 8NO 3 - →}} 4N 2 + 10CO 2 + 6H 2 O + 8OH -

Chemical reaction formula when methane is used

^{_{5CH 4 + 8 NO 3 - →}} 4N 2 + 5CO 2 + 6H 2 O + 8OH -

Chemical reaction formula when using sewage

_{C 10 H 19 O 3 N +} 10NO 3 - → 5N 2 + 10CO 2 + 3H 2 O + NH 3 + 10OH -

And, in the aeration tank 5, MLSS (mixed liquor suspended solids: microorganism, 5000 to 12000 mg / L) at a concentration suitable for the operating conditions exists, and organic pollutants are consumed and removed as a substrate of MLSS. The BOD load of the membrane separation tank can be reduced, and the membrane pore occlusion can be reduced to extend the cleaning cycle of the membrane and the life of the membrane.

In addition, the components of the ammonia nitrogen (NH ₃ -N) and nitrous nitrogen (NO ₂ -N) contained in the mixture introduced into the aeration tank 5 undergo nitrification in an aerobic state in the aeration tank 5, followed by nitrification to nitrate nitrogen. It is converted into (NO ₃ -N) component, and the phosphorus component material is excessively absorbed and removed by microorganisms in the aeration tank 5.

When the mixture oxidized in the aeration tank 5 is above a certain level, it is naturally introduced into the membrane separation aeration tank 6.

In the mixture introduced into the membrane separation aeration tank 6, the organic contaminants and phosphorus components, suspended matter, ammonia nitrogen (NH ₃ -N), nitrite nitrogen (NO _2- N) The component is present.

And, in the membrane separation tank 6, there is a mixed liquor suspended solids (microorganism, 5000 to 12000 mg / L) at a concentration suitable for the operating condition, and organic pollutants are consumed and removed as a substrate of MLSS. do.

In addition, the components of ammonia nitrogen (NH ₃ -N) and nitrous nitrogen (NO ₂ -N) contained in the mixture introduced into the membrane separation aerobic tank 6 are nitric acid through a nitrification process in an aerobic state in the membrane separation aerobic tank. Nitrogen (NO ₃ -N).

The nitrification action is an action in which ammonia nitrogen (NH ₃ ) is converted into nitrite nitrogen (NO ₂₎ or nitrate nitrogen (NO ₃ ) under aerobic conditions by nitrification bacteria.

Among the nitrifying bacteria, the type that converts ammonia into nitrite nitrogen is mainly Nitrosomonas, and the type that changes into nitrate nitrogen is Nitrobacter.

The process of changing ammonia to nitric acid is represented as follows.

 Nitrosomonas

^{_{NH4 + + 1.5O 2 → NO 2}} - + H 2 O + 2H +

Nitrobacter

^{_{NO2 - + 0.5O 2 → NO 3}} -

The energy generated when the ammonia nitrogen and nitrite nitrogen are oxidized to nitrate nitrogen is used for cell synthesis for growth of nitric acid bacteria.

The cell synthesis reaction scheme by Nitrosomonas and Nitrobacter is as follows.

_{^{NH 4 + + HCO 3 - +}} 4CO 2 + H 2 O → C 5 H 7 O 2 N + 5O 2

The general formula including the cell synthesis of nitric acid bacteria is as follows.

^{_{NH 4 + + 1.83O 2 + 1.98HCO}} 3 - → 0.021C 5 H 7 O 2 N + 0.98NO 3 - + 1.041H 2 O + 1.88H 2 CO 3

In addition, in the removal of biological phosphorus, in the anaerobic condition, PAOs are hydrolyzed to polyphosphoric acid (Poly-P) in microbial cells and released into the mixed solution as static phosphoric acid (PO ₄ -P). At the same time, organic substances in sewage and wastewater are stored in cells as substrates such as PHA mainly composed of glycogen and PHB (poly hydrixybeta Butyrate).

At this time, the release rate of phosphorus is generally higher as the concentration of the organic matter in the mixed liquid is higher, and is usually released up to 3 to 5 times the inlet PO ₄ -P concentration.

As described above, in the aerobic state, the substrate stored in the cell is oxidized and decomposed to decrease.

The PAOs microorganisms re-synthesize the polyphosphoric acid by overtakeing the phosphoric acid released in the anaerobic state at an amount more than necessary for the production of microorganisms using the energy generated at this time.

Phosphorus release dephosphorization conditions Poly -P + VFA PHB + PO ₄ ^3-

Phosphorus intake PHB + PO4 ^3- Poly -P + H ₂ O + CO ₂

Therefore, when the phosphorus component material is removed by the microorganism, only the particulate material such as suspended solids (SS) and MLSS is present in the membrane separation tank (6), which is separated by solid-liquid by the separation membrane unit (18).

The separator unit 18 is capable of performing solid-liquid separation in a state of being coupled to a known separator frame device, which is a suction pump 14 and a suction line 21 existing outside the membrane separator tank 6. Are connected.

Due to the suction pressure generated by the operation of the suction pump 14, a mixture of the outside of the separation membrane flows into the separation membrane through the separation membrane pores, and solid-liquid separation occurs. ).

In order to delay the occlusion occurring on the surface of the separator and to extend the operating time, an air diffuser (not shown because it is known) is installed at the bottom of the separator frame device.

This air diffuser is connected to the membrane separation exhalation tank 6 through the blower 12 and the air line 22, and to supply air to the membrane separation exhalation tank 6 through the operation of the blower 12. do.

Therefore, the water flow in the membrane separation aerobic tank 6 is formed by the air supplied through the blower 12, and the occlusion of the membrane surface is delayed, so that the immersion-type membrane separation advanced treatment facility is smoothly operated for a long period of time.

In addition, the MLSS concentration, SS, and phosphorus substances in the membrane separation exhalation tank 6 are continuously increased while the immersion-type membrane separation advanced treatment facility is operated for a long time.

In order to maintain an appropriate MLSS concentration in the membrane separation aerobic tank 6 and to remove SS and phosphorus-containing substances, solid-liquid separation by the membrane separation unit 18 in the membrane separation aerobic tank 6 leaves the remaining mixture at a certain level or higher. If it is, it is transferred to the stabilization tank 7 and passes through the V-NOTCH 13b by the transfer pump 15 in the stabilization tank, and then through the inlet valve of the inlet pipe, the first denitrification tank 3 and the sludge storage tank 8 Will be divided into

 Then, the flocculant storage tank 19, in order to remove the unprocessed phosphorus component, stores the flocculant for agglomerating and removing the phosphorus component, and then stores the flocculant in the aeration tank 5 by the transfer pump 17. To supply.

An air line 22 connected to the blower 12 is installed in the sludge tank 8 to prevent the sludge from adhering.

The treated water separated by solid-liquid through the membrane separation unit (18) immersed in the membrane separation aerobic tank (6) is sucked by the suction pump (14), supplied to the discharge tank (9), and discharged immersed in the discharge tank It is discharged to the outside by a pump or reused as heavy water.

1: Flow adjustment tank 2: De-intake tank
3: First denitrification tank 4: Second denitrification tank
5: aeration tank 6: membrane separation aeration tank
7: Stabilization tank 8: Onion storage tank
9: Discharge tank 10: Screen tank
11: Microfiltration screen 12: Blower
13a, 13b: V-NOTCH 14: Aspiration pump
15: transfer pump 16: internal transfer pump
17: transfer pump 18: separator unit
19: flocculant injection pump 20: water stirrer
21: suction header 22: air line
110: filtration tank 120: horizontal screw conveyor
130: dewatering conveyor 140: hopper

Claims (4)

A flow rate adjustment tank (1) for receiving lower and waste water filtered by the screen tank (10);
When the raw water flowing into the flow adjusting tank 1 is higher than a predetermined level, the raw water of the flow adjusting tank 1 is passed through a microfiltration screen 11 by a raw water pump immersed in the flow adjusting tank 1. A dephosphorization tank (2) and a first denitration tank (3) that are supplied at an appropriate ratio through an inflow valve installed in the inflow pipe via V-NOTCH (13a);
As the second denitrification tank (4) receiving the raw water of the first denitrification tank (3) when the raw water flowing into the first denitrification tank (3) is above a predetermined level, the mixed liquid in the second denitrification tank (4) And a second denitrification tank (4) for supplying the dephosphorization tank (2) by an internal transfer pump (16) immersed in the second denitration tank;
When the mixed liquid stored in the second denitrification tank (4) is a predetermined level or more, an aeration tank (5) for receiving the mixed liquid of the second denitrification tank (4);
A membrane separation aeration tank (6) receiving the mixed liquid of the aeration tank (5) when the mixed liquid stored in the aeration tank (5) is a predetermined level or higher;
When the mixed solution stored in the membrane separation exhalation tank 6 is a predetermined level or higher, as a stabilization tank 7 receiving the mixed solution of the aeration tank 5, the conveying pump immersed in the stabilization tank in the mixed solution in the stabilization tank 7 (15) through the V-NOTCH (13b) through the inlet valve installed in the inlet pipe and the stabilization tank (7) for supplying the sludge tank (8) or the first denitrification tank (3) at an appropriate ratio;
The membrane separation exhalation tank 6 is immersed in the inside, and the mixture outside the separation membrane flows into the separation membrane through the pores of the separation membrane by suction pressure generated by the operation of the suction pump 14 existing outside the membrane separation exhalation tank 6 A plurality of separation membrane units 18 for solid-liquid separation;
A flocculant storage tank 19 for storing a flocculant for agglomerating and removing phosphorus components, and supplying the stored flocculant to the aeration tank 5 by a transfer pump 17;
When the residue containing the nitric acid component and sludge remaining in the stabilization tank 7 is higher than a predetermined level, when the residue of the stabilization tank 7 is supplied, and the MLSS concentration in the membrane separation aeration tank 6 is high , As the sludge storage tank (8) receiving the sludge in the membrane separation aeration tank (6), the sludge in the sludge storage tank (8) to supply the sludge in the flow rate adjustment tank (1) when a predetermined level using an air lift pump Including,
The screen tank 10 includes a filtration tank 110 in which wastewater is stored, a microfiltration screen 11 installed in the longitudinal direction inside the filtration tank 110, and a filtration tank corresponding to the microfiltration screen 11 ( 110) is installed on the bottom is filtered by the microfiltration screen 11, the horizontal screw conveyor 120 for transferring the sludge collected downward to the filter tank 110, and the horizontal screw conveyor 120 is connected to the end, the sludge It comprises a dewatering conveyor unit 130 for conveying upward and dewatering, and a hopper 140 installed above the dewatering conveyor 130 to discharge the dewatered sludge to the outside of the filtration tank 110,
The dewatering conveyor 130 is installed on the side wall of the filtration tank 110, the vertical transfer pipe 132 and the vertical transfer pipe 132 formed of a perforated network 131 on the outer circumferential surface corresponding to the inner space of the filtration tank 110 It is installed inside and rotated together with the main shaft 134 by the motor 133, and the transfer screw 135 for conveying the sludge upwardly, and inserted into the main shaft 134 and operated in the vertical direction by the cylinder 137 It comprises a shaft 136 and a dewatering screw 138 connected to the operating shaft 136,
The main shaft 134 is formed with a load hole (134a) therein, a plurality of guide holes (134b) are cut in the longitudinal direction on the outer circumferential surface, and the dewatering screw (138) is a working shaft (136) through the guide hole (134b). Nitrogen, phosphorus removal membrane separation advanced treatment device, characterized in that connected to.
According to claim 1,
A plurality of separator suction lines (21) installed between the plurality of separator units (18) and the suction pump (14), and equipped with a differential pressure gauge for sensing the pressure of the separator unit (18) and a suction valve to control the inflow of treated water )and; A discharge tank (9) for receiving the treated water sucked by the group suction pump (14) and discharging it to the outside by a discharge pump; Air is supplied to the air diffuser disposed under the membrane unit 18 immersed in the membrane separation aerobic tank 6 through the alignment line 22, and the flow rate adjustment tank 1, the aeration tank 5, and the sludge storage tank (8) Nitrogen, phosphorus removal membrane separation advanced treatment device characterized in that it comprises a blower (12) for supplying air to each. According to claim 1,
Nitrogen, characterized in that the cylinder 137 rod rod and the working shaft 136 are connected by a rotating coupler (136a), so that the working shaft 136 is rotatably connected to the cylinder 137 rod rod. Advanced phosphorus removal membrane separation device.
According to claim 1,
When the sludge collected on the bottom of the filtration tank 110 by the horizontal screw conveyor 120 is operated and the dewatering conveyor 130 is collected, the sludge is returned upward by the operation of the dewatering conveyor 130, and the sludge is hopper 140. When the dewatering conveyor 130 is stopped by the control unit just before reaching the cylinder, and the cylinder 137 is operated to move the working shaft 136 downward, the dewatering screw 138 is pressurized toward the transfer screw 135, and the sludge Pressurized, and the dehydrated screw 138 and the transfer screw 135 dehydrated by the pressing force are re-introduced into the filtration tank 110 through the perforated network 131, and when dehydration is completed, dehydration is performed by the working shaft 136. Advanced treatment device for removing nitrogen and phosphorus, characterized in that the dewatering conveyor 130 is rotated in a state where the screw 138 is returned upward so that the dewatered sludge is discharged through the hopper 140.

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