KR20200042273A - Membrane combined Advanced wastewater treatment system which applies Trisectional aeration and Changed inflow course and it's operation methods - Google Patents

Abstract

The present invention relates to an immersion type membrane combined advanced wastewater treatment method using trisectional aeration and a flow change method. According to the present invention, provided are a wastewater treatment system comprising: an anaerobic tank; two shift inflow reactors (first and second reactors) arranged in parallel and operated in a trisectional aeration method; an aerobic separation membrane reactor with a membrane immersed; a dissolved oxygen reduction tank; and a sludge storage tank, and a method of operating the same. An advanced wastewater treatment method of the present invention is capable of selectively improving nitrogen and phosphorous removal efficiency and improving removal efficiency of nitrogen and phosphorous by entirely improving availability of an organic matter. In addition, phosphorous removal efficiency is improved compared to the existing MBR technique by operating an MSLL in a reaction tank at a level of 6,000-8,000 mg/L, and an external sludge return amount can be dynamically reduced by a sludge return effect of itself, thereby reducing power costs and operating costs.

Description

{Membrane combined Advanced wastewater treatment system which applies Trisectional aeration and Changed inflow course and it's operation methods}

The present invention relates to an advanced treatment method for immersed membrane-coupled sewage water using a three-part aeration and flow change method, and particularly to an advanced treatment method for sewage water that maximizes the selective removal effect of nitrogen and phosphorus and maximizes the utilization of organic matter as a whole. .

The sewage treatment system (MBR) operated by immersing the membrane in the activated sludge aeration tank is usually arranged with an anaerobic or anoxic tank at the front end and an aerobic reaction tank with the membrane immersed at the rear end, mostly A ² / A membrane similar to O is used as a basic process. This process has a big problem in that organic matter in the influent is lost due to dissolved oxygen in the sludge due to excessive internal and external sludge conveying ranging from 3 to 6 Q, thereby reducing the removal efficiency of nitrogen and phosphorus. In particular, the existing sewage treatment process has been developed to mix the sludge generated in the final sedimentation tank or the exhalation tank with the inflow water or return it to the same reaction tank. In addition, the existing MBR (Membrane Bio Reactor) method has high MLSS (10,000 mg / L) operation, so it has excellent nitrification and organic material removal efficiency, but it has a disadvantage of lowering phosphorus removal efficiency by operating with a long SRT.

In recent years, advanced processing processes have been developed by deviating from existing spatial methods such as A / O, A ² / O, and Bardenpho method, and operating the reactor or changing the inflow direction of the inlet with time. Typical technologies for this temporal method include PID (Phased Isolation Ditch) and DeNiPho (DeniPho intermittent aeration), and improved technologies that change the system configuration or operation method based on these major methods (domestic Published Patent Publication No. 2001-97869, etc.) is also coming out. However, even in such a time method, the reduction in efficiency due to dissolved oxygen in the conveyed sludge cannot be excluded. In particular, when the amount of the conveyed sludge is large, the dissolved oxygen greatly affects the treatment efficiency.

The present invention is to solve the problems of the prior art as described above, in particular, the present invention aims to maximize the utilization of organic matter in consideration of the characteristics of Korea's wastewater with low BOD and to increase the phosphorus removal efficiency, which is a problem of the conventional MBR method. Is done.

In addition, another object of the present invention is to provide a wastewater treatment method capable of selectively removing organic matter, nitrogen, and phosphorus depending on the characteristics of the influent sewage and the target material to be removed.

In addition, the present invention provides an advanced wastewater treatment method that can selectively increase the removal efficiency of organic matter, nitrogen and phosphorus by adjusting the inflow amount, inflow direction, and time setting of the inflow sewage and return sludge according to the characteristics of the influent water and the material to be removed. .

In addition, another object of the present invention is to significantly reduce the amount of sludge return so as to reduce the operating cost by operating the wastewater treatment system more efficiently.

In addition, in the immersion membrane installed in the membrane reaction tank, a membrane having a structure in which membrane fouling is reduced even with a smaller amount of membrane cleaning air is provided, thereby providing an operating method in which membrane fouling is properly controlled even in continuous or intermittent aeration. It is aimed at.

To this end, in the present invention, by reducing the dissolved oxygen, the dissolved oxygen in the conveyed sludge is removed to remove the effect of dissolved oxygen in the anaerobic tank and the alternating inflow reactor to which the conveyed sludge is supplied, so that easily decomposable organic substances in the influent are used in the dephosphorization and denitrification process. At the same time, efficient denitrification and nitrification reactions occur in a single reactor by removing the dissolved oxygen in the sludge by controlling the air supply of the alternating inflow reactor.

In addition, in the present invention, MLSS (mixed liquor suspended solid) in the reactor is operated at a level of 6,000 to 8,000 mg / L to increase the phosphorus removal efficiency by drawing sludge in the reactor.

In addition, in one embodiment of the present invention, the denitrification process is performed by introducing sewage into the sludge blanket layer at the bottom of the reactor so that organic materials can be utilized for maximum denitrification at high MLSS in the reactor.

In order to achieve the above object, in the present invention, the time period is set such that each alternating inflow reaction tank is sequentially deaerated → abandoned → abandoned in a stage in which subsequent inflow is not achieved after passing through a step in which inflow into a non-aeration. It provides an operating method that can significantly reduce the amount of external sludge conveyed by allowing both the nitrification and denitrification processes to occur in the reactor and the self-sludge conveying effect such as the return of sludge from the exhalation tank.

In order to achieve the above object, in the present invention, by using the aeration device configured at the bottom of the separation membrane module arranged in a vertical multi-stage, to prevent contamination of the membrane installed in the separation membrane reactor, continuous aeration or intermittent aeration to suppress adhesion of contaminants and In addition, by controlling the concentration and cycle of chemicals as a method of chemical cleaning according to the pollutant load, and controlling the flow rate of the blower when performing the continuous aeration or intermittent aeration, the membrane contamination is appropriately controlled by supplying a constant amount of air flow in conjunction with the water level. Provides a method of operation.

According to the advanced wastewater treatment method of the present invention, it is possible to selectively increase the efficiency of nitrogen and phosphorus removal by dividing the influent and the return sludge into an anaerobic tank and an alternating inflow reaction tank. By returning the reduced sludge to the reaction tank, the utilization of the organic material was increased so that the easily decomposable organic material in the inflow water could be used for denitrification and dephosphorization. In addition, the alternating inflow reaction tank regulates the air supply with a three-part splitter for a certain period of time after the inflow is stopped, so that nitrification and denitrification reactions occur efficiently within a single reactor, and the internal sludge transfer effect greatly reduces the amount of external sludge transfer, resulting in power cost and Operation costs can be reduced.

In addition, the membrane is installed and operated vertically in multiple stages in a membrane reaction tank, and contaminant adhesion is suppressed by continuous aeration or intermittent aeration. In addition, the concentration and cycle of the chemical are controlled by the method of chemical cleaning according to the pollution load, and the continuous aeration or intermittent In controlling the flow rate of the blower when abandonment is performed, it is possible to reduce the membrane contamination and secure a stable treatment quality and flow rate by supplying a constant amount of blower in connection with the water level.

1 shows a basic configuration of a wastewater treatment system according to an embodiment of the present invention.
Figure 2 shows the effect of the contaminant removal and the flow of aeration air according to the arrangement of the membrane module according to an embodiment of the present invention.
Figure 3 shows a cross-section of the aeration device according to an embodiment of the present invention.
Figure 4 shows the operating principle of the aeration device according to an embodiment of the present invention.
5 schematically shows a method of operating the wastewater treatment system shown in FIG. 1 according to an embodiment of the present invention.
Figure 6 shows the state of the first reaction tank according to each step and the aeration conditions of the present invention.

In the present invention,

Anaerobic tank; Two alternating inflow reactors (first and second reactors) arranged in parallel and operated in three-part aerators; A membrane-immersed aerobic membrane reactor; Reduced dissolved oxygen; Sludge storage tank,

The separation membrane module installed in the separation membrane reaction tank is composed of a plurality of manifolds having a sealed upper end and a plurality of hollow fiber membranes having a free end open and fixed, and a plurality of manifolds are parallel with a predetermined interval. In the arranged state, the separator modules are arranged in vertical multi-stages, and the collecting header communicating with the manifold is configured to be connected to the treated water port, and the water level fluctuates depending on the air inflow and divergence at the bottom of the vertical multi-stage separation membrane modules. Becoming an air chamber; An air accumulating engine configured in the air chamber and allowing compressed air to be compressed by a predetermined volume while pushing the water body in the air chamber; A water body passage configured in the air chamber and having a water body in and out of the air chamber depending on the presence or absence of compressed air; And an aeration device connected to the air accumulation engine and comprising a diffuser having a plurality of pores.

Sewage flows into the anaerobic tank and the alternating inflow reactor at a predetermined rate, so that the flow of sewage becomes the anaerobic tank → alternating inflow reactor → separator membrane reactor or alternating inflow reactor → separator membrane reactor, and the sludge discharged from the separator reactor is transferred to the dissolved oxygen reduction tank to dissolve oxygen. After removal of the wastewater treatment system, which is dividedly returned to the anaerobic tank and the alternating inflow reaction tank, the concentrated sludge of the dissolved oxygen reduction tank is drawn and stored in the sludge storage tank,

Sewage and return sludge flowing into the anaerobic tank are transferred to the alternating inflow reaction tank after undergoing a phosphorus discharge process,

The alternating inflow reaction tank is equipped with a flow change facility that controls the flow of sewage and return sludge introduced through a direct or anaerobic tank, and through this flow change facility, the inflow sewage and return sludge flow only into the first reactor operated as a non-aeration. The second reaction tank includes a first step of operating as aeration-abandonment → abandonment → aeration (three-part aeration); On the contrary, the second reactor is operated as a non-aeration tank with sewage and return sludge flowing. At this time, the first reactor is a second cycle operated with aeration, aeration, and aeration (non-aeration) without inflow of sewage and return sludge. It is provided with a wastewater altitude treatment method characterized in that it is operated repeatedly.

That is, each of the alternating inflow reaction tanks alternately flows into the sewage and return sludge at a predetermined time interval, thereby operating as a non-aeration device when inflow is made, and when the inflow is not made, a three-part aeration device, that is, aeration ( N) → Aeration (A) → Non-aeration (N) (Nonaeration-Aeration-Non aeration, “NAN” method) is performed to perform both denitrification and nitrification in a single reactor and obtain its own sludge transfer effect.

In one embodiment of the present invention, the alternating inflow reaction tank to which the sewage flows is introduced into the sludge blanket layer at the bottom formed in a non-aeration state without agitation equipment, and the sewage and return sludge are introduced to perform denitrification within the sludge blanket. At this time, the sewage and the conveyed sludge are preferably introduced into the reaction tank in a completely mixed state in a flow change facility.

In another embodiment of the present invention, the alternating inflow reaction tank in which the sewage is introduced is provided with a stirring facility to uniformly mix the organic material and sludge introduced in a non-aeration state to proceed with the process.

In the advanced wastewater treatment method of the present invention, MLSS is operated at about 6,000 to 8,000 mg / L to increase the phosphorus removal effect due to sludge disposal.

The advanced wastewater treatment method of the present invention is a dynamic state MBR method that can further improve the treatment efficiency by adjusting the inflow amount, flow direction, and time setting of the inflow sewage and return sludge according to the characteristics of the influent water and the material to be removed.

For example, in order to increase the efficiency of removing phosphorus in sewage, the ratio of sewage flowing into the anaerobic tank is increased and the proportion of the returned sludge flowing into the anaerobic tank is reduced, thereby improving the utilization of easily degradable organic matter in the influent by phosphorus-removing microorganisms. Higher phosphorus removal efficiency.

In addition, in order to increase the removal efficiency of nitrogen in the sewage, the ratio of the sewage and the return sludge flowing into the alternating inflow reaction tank is increased so that the denitrification reaction can be more effectively performed.

In addition, when the C / N ratio and the C / P ratio of the influent sewage are low, an external carbon source (for example, methanol, etc.) can be operated by putting them into an anaerobic tank and an alternate influent reactor.

In addition, when the concentration of phosphorus in the influent sewage is high, a known flocculant such as Alum can be introduced into the anaerobic tank to aggregate the released phosphorus.

In the present specification, "wastewater" and "sewage" include all wastewater, such as sewage, sewage, general wastewater, and livestock wastewater, unless otherwise specified.

Hereinafter, a preferred embodiment of the advanced wastewater treatment method of the present invention and an apparatus used therein will be described with reference to the accompanying drawings. In the configuration of the present invention, a detailed description of the same configuration as that of a conventional wastewater treatment system will be omitted without departing from the scope of the present invention. In addition, in order to facilitate understanding of the present invention, reference numerals in the accompanying drawings are put in parentheses, but the present invention is not limited thereto.

Figure 1 shows the basic configuration of the wastewater treatment system of the present invention. This system consists of an anaerobic tank (2), two alternating inflow reactors (3,4) arranged in parallel, an aerobic reactor with a membrane immersion (separation membrane reactor: 6), and a dissolved oxygen reduction tank for reducing dissolved oxygen in the return sludge ( 7) and sludge storage tank (8) is operated in one set.

The inflowing sewage is supplied to the anaerobic tank 2 and the alternating inflow reaction tanks 3 and 4 in a predetermined ratio after foreign substances are removed from the pre-treatment facility 1 such as a screen. Accordingly, the flow of sewage is in the order of "anaerobic tank (2) → first reactor (3) (or second reactor (4)) → membrane reactor (6)" or "first reactor (3) (or second Reactor (4)) → Membrane Reactor (6) ”. In addition, the return sludge from the dissolved oxygen reduction tank 7 is supplied to the anaerobic tank 2 and the alternate inflow reaction tanks 3 and 4 in a predetermined ratio. In this treatment system, the water treatment effect can be further improved by adjusting the ratio of the sewage and the return sludge divided into the anaerobic tank (2) and the alternating inflow reaction tank (3, 4) according to the characteristics of the incoming sewage. For example, when the phosphorus content in the sewage is high, the ratio of the sewage flowing into the anaerobic tank is increased, and the proportion of the returned sludge flowing into the anaerobic tank is reduced to operate to improve the phosphorus treatment efficiency, and when the nitrogen content in the sewage is high It operates in a way that increases the efficiency of nitrogen treatment by increasing the ratio of both sewage and return sludge flowing into the alternating inflow reactor. In addition, when the C / N ratio and C / P ratio of the influent sewage are low, an external carbon source such as methanol may be supplied to the anaerobic tank and the alternating inflow reactor to increase the organic matter content.

In the anaerobic tank 2 of the present system, the introduced sludge undergoes a phosphorus release process in which phosphorus is released using easily decomposable organic matter in the influent water.

Following the anaerobic tank 2, two alternating inflow reaction tanks 3 and 4 installed in parallel are equipped with a flow change facility 5 to control the flow of sewage and return sludge flowing directly or through the anaerobic tank at a set time interval. The first reactor 3 and the second reactor 4 are alternately supplied. In addition, an air supply device (Blower) for supplying air into the reaction tank and a control facility for controlling air to be supplied to the first reaction tank 3 and the second reaction tank 4 for a predetermined time are provided, and the first reaction tank 3 is provided. And the second reactor (4) are operated under the condition of non-aeration or tripartite aeration depending on the presence or absence of sewage and sludge. This will be described below with reference to FIG. 2.

The flow change facility 5 may be operated in a time setting determined by an automatic control facility such as a timer or PLC in conjunction with an air supply device. The flow change facility selectively supplies inflow sewage and return sludge to the first reaction tank (3) or the second reaction tank (4), and includes the well-known flow change facility to perform the above functions. Any of the various types of flow change equipment that can be used can be used. For example, a water gate is installed toward the first reaction tank 3 and the second reaction tank 4, and an integrated hydrological type flow change facility that controls the flow through the opening and closing of the water gate, or a valve type that controls the flow by opening and closing the valve, etc. Can be used.

The separation membrane reaction tank installed after the alternating inflow reaction tanks 3 and 4 is an aerobic reaction tank in which the membrane is immersed, and treated sewage and sludge introduced through the alternating inflow reaction tank to discharge solid-liquid separated treated water through the separation membrane. In this wastewater treatment system, a subsequent filtration and disinfection process is not required by discharging the treated water through the membrane in an aerobic tank. The sludge discharged from the membrane reaction tank is transferred to the subsequent dissolved oxygen reduction tank 7.

In the reduced oxygen reduction (7), dissolved oxygen in the sludge is removed, and the sludge from which dissolved oxygen is removed is returned to the anaerobic tank (2) and the alternating inflow reaction tank (3, 4) according to the time and the amount of sludge. Then, the concentrated sludge of the dissolved oxygen reduction tank is drawn and stored in the sludge storage tank 8. The sludge storage tank 8 maintains a constant concentration of mixed liquor suspended solid (MLSS) in the reaction tank, and the accumulated phosphorus in the sludge increases the phosphorus removal efficiency by discarding the sludge.

On the other hand, the immersion type membrane installed in the separation membrane reaction tank serves as a solid-liquid separation and produces treated water, and it is necessary to control contamination of the membrane that inevitably occurs. In order to reduce the degree of contamination of the immersed membrane, it is possible to obtain an effect of appropriately desorbing contaminants adhering to the surface of the membrane by giving up cleaning air from the bottom of the membrane. At this time, the supplied air is air that operates the membrane reaction tank as an aerobic tank. If more air is supplied than necessary, the dissolved oxygen in the sludge becomes excessive, which can weaken the function of reducing the dissolved oxygen in the rear stage, increasing the power ratio, dismantling the activated sludge, etc. The disadvantages of will occur.

In order to overcome these disadvantages, as a method for minimizing the amount of air supplied, a structure capable of inhibiting the adhesion of contaminants on the membrane with a small amount of air is obtained, and the effect of easily detaching the adhered contaminants by the supplied air is obtained. The immersion type membrane is preferably in the form of a hollow fiber membrane, and the hollow fiber membrane integration type should have a slim shape rather than a bundle shape to prevent adhesion of contaminants due to vibration or movement of the membrane due to water flow caused by the supplied air.

Figure 2 shows the effect of the contaminant removal and the flow of aeration air according to the arrangement of the membrane module according to an embodiment of the present invention. As shown in (a) of FIG. 2, the separation membrane module installed in the separation membrane reaction tank is composed of a plurality of manifolds in which a plurality of hollow fiber membranes having a free end at which the upper end is sealed and an open free end are concentrated and fixed, and a plurality of manifolds are provided. When a plurality of hollow fiber membranes are arranged in a single manifold in a state where they are arranged in parallel with a predetermined distance and are arranged in parallel, the hollow fiber membranes disposed therein have a disadvantage of relatively increased contamination.

On the other hand, as shown in (b) of FIG. 2, when the separator module is installed in a vertical multi-stage, efficient use of a small amount of air is induced by continuous utilization of air discharged from the lower end of the membrane. In general, the air in the water mainly shows the movement in the upward direction, but it is deflected due to the non-uniformity of the aeration or irregular water flow, so it cannot skim through all parts of the membrane. As the water flow is restarted and uniformly abandoned, the cleaning efficiency of the membrane is increased. That is, in the case of a multi-stage installation membrane, even if water flow channeling occurs, it is redistributed in the buffer space to suppress contamination.

This channeling of water flow (also referred to as drift that occurs only in a certain direction) causes serious membrane contamination along with the knitting machine (also called aeration of a certain portion), and therefore intermittently aeration to eliminate channeling that may occur in continuous aeration. The method of stopping is used, which is mainly implemented by the operation of an automatic valve. However, there are disadvantages such as automatic valve installation cost and frequent failures due to repeated operation.

Therefore, in the present invention, the water level fluctuates depending on the air inflow and divergence at the bottom of the separator module arranged vertically in multiple stages in order to provide the membrane in the water with an aeration device capable of intermittent aeration on / off without the application of such an automatic valve. Becoming an air chamber; An air accumulating engine configured in the air chamber and allowing compressed air to be compressed by a predetermined volume while pushing the water body in the air chamber; A water body passage configured in the air chamber and having a water body in and out of the air chamber depending on the presence or absence of compressed air; And an aeration device connected to the air storage engine and comprising a diffuser having a plurality of pores.

Figure 3 shows a cross-section of the aeration device according to an embodiment of the present invention, Figure 4 shows the operating principle of the aeration device according to an embodiment of the present invention.

 The aeration device according to an embodiment of the present invention is an aeration device that collects and discharges a small amount of air from the water at a time, and a structure capable of blocking air and water and an air supply pipe is installed inside a box provided with the aeration hole. As shown in FIG. 3, when the driving principle is initially filled with water, air is discharged from the air supply pipe, and when it is collected inside the aeration device box, it accumulates while being compressed by water pressure, and compresses at the moment beyond the boundary that blocks water and air. The principle is that the air is released at a time across the boundary (1st step: air volume capture → 2nd step: air accumulation and compression → 3rd step: air mass release). If the air supply amount is greater than the amount of air discharged at one time from the aeration device, the air is continuously abandoned from this time.

As described above, the membrane needs to be periodically cleaned of the chemical according to the reaction effect in each reactor, the organic load of the incoming source water, and the pollutant load. This cycle and the chemical concentration can be adjusted according to the degree, and the cleaning effect can be obtained by injecting the chemical into the membrane.

In addition, in controlling the flow rate of the blower when performing the continuous aeration or intermittent aeration, it is advantageous to provide a more stable treatment of wastewater by supplying a constant amount of blowing in conjunction with the water level.

FIG. 5 schematically shows the operation method of the wastewater treatment system shown in FIG. 1. This operating method is a step feeding method that determines the setting of the flow and inflow of inflow sewage and return sludge in the operation of the anaerobic tank (2) and alternating inflow reaction tank (3,4) according to the characteristics of the influent sewage and the material to be treated. Is applied to selectively control the removal of nitrogen and phosphorus.

In the operation of the shift inflow reactors (3, 4), the sewage and return sludge introduced directly or through the anaerobic tank (2) of the front end into the shift inflow reaction tank are joined at the flow change facility (5), and the first reaction tank or It is supplied to the second reactor. At this time, the reaction tank into which the sewage and return sludge flows is operated as a non-aeration, and the reaction tank that does not flow is operated as a three-part aeration, namely, Nonaeration → Aeration → Noneration.

The alternating inflow reaction tank is operated repeatedly with one cycle of the first step and the second step. In the first step (Phase 1), the first reaction tank is operated as a non-aeration, and the inflow sewage and return sludge flow only into the first reaction tank, At this time, the second reactor is operated as a three-part splitter and no inflow occurs. Conversely, in the second phase (Phase 2), the first reaction tank is operated as a three-part aeration tank without inflow of sewage and return sludge, and no inflow is made, and the second reaction tank is operated with inflow and non-aeration of sewage and return sludge. The status of the reaction tank by stage is summarized as follows.

The first step and the second step are operated repeatedly as one cycle, and the first step and the second step are usually set to the same time so that the inflow time and the inflow stop time are the same in one reactor.

6 shows the state of the first reaction tank according to each step and abandonment conditions. Each reactor maintains a non-aeration → aeration → non-aeration state for a period of time without inflow of sewage and sludge after a certain period of time when sewage and return sludge flow into the aeration state.

6A shows the state of the reaction tank in the first step, that is, the non-aeration state in which inflow is performed. At this stage, an active denitrification reaction occurs due to the incoming sewage, return sludge, and self-sludge (self-sludge return effect in the next step).

B represents the initial aeration (N) state of the second stage. In the initial aeration (N) state after the inflow is stopped, continuous denitrification and phosphorus release occur in the sludge layer. This initial aeration (N) state is to secure a denitrification time so that sufficient denitrification is achieved and serves to increase the utilization of organic matter.

C represents the second stage of abandonment (A). In this aeration (A) state, nitrification proceeds, and the sludge layer and the symbol water are mixed by aeration to solve the sludge injury problem at the top of the sludge layer.

D denotes the last aeration (N) state of the second stage. In this last non-aeration (N) state, the dissolved oxygen in the sludge is depleted and oxygen-free conditions are formed so that the denitrification reaction can be maximized in the subsequent inflow step.

In the N-A-N step, the setting of the condition of abandonment (A) for a certain time brings its own sludge conveying effect as if the sludge is conveyed from the exhalation tank, and thus the amount of conveying of external sludge can be greatly reduced. In addition, the last non-aeration (N) condition is set to completely deplete the dissolved oxygen of the sludge in the reactor before the start of the next cycle, that is, the inflow of sewage and sludge, thereby removing the effect of dissolved oxygen in the sludge in the non-aeration state. It has the effect of maximizing the utilization of organic matter in the denitrification reaction.

The operation of the reactor in which sewage and return sludge flows can be carried out in two ways. The first method is a method using a sludge blanket, and dewatering is performed in the sludge blanket by introducing sewage into the bottom of the reactor. At this time, the sewage and the conveyed sludge are preferably introduced into the reaction tank in a completely mixed state in a flow change facility. This method can use organic materials as much as possible for denitrification at high MLSS, and requires no separate stirring equipment, thereby reducing operating costs. The second method is to use a stirring equipment, which is operated by uniformly mixing the organic matter and sludge introduced in a non-aeration state using a stirring equipment.

1: Pre-treatment facility 2: Anaerobic tank
3: Alternating inflow reaction tank (first reactor) 4: Alternating inflow reaction tank (second reaction tank)
5: Flow change equipment 6: Membrane reactor (MBR)
7: Reduced dissolved oxygen (OER) 8: Sludge storage tank

Claims (10)

Anaerobic tank; Two alternating inflow reactors (first and second reactors) arranged in parallel and operated in three-part aerators; Aerobic membrane reactor; Reduced dissolved oxygen; Sludge storage tank,
The separation membrane module installed in the separation membrane reaction tank is composed of a plurality of manifolds having a sealed upper end and a plurality of hollow fiber membranes having a free end open and fixed, and a plurality of manifolds are parallel with a predetermined interval. In the arranged state, the separator modules are arranged in vertical multi-stages, and the collecting header communicating with the manifold is configured to be connected to the treated water port, and the water level fluctuates depending on the air inflow and divergence at the bottom of the vertical multi-stage separation membrane modules. Becoming an air chamber; An air accumulating engine configured in the air chamber and allowing compressed air to be compressed by a predetermined volume while pushing the water body in the air chamber; A water body passage configured in the air chamber and having a water body in and out of the air chamber depending on the presence or absence of compressed air; And an aeration device connected to the air accumulation engine and comprising a diffuser having a plurality of pores.
Sewage flows into the anaerobic tank and the alternating inflow reactor at a predetermined rate, and the flow of sewage becomes the anaerobic tank → the alternating inflow reactor → the membrane reaction tank or the alternating inflow reaction tank → the membrane reaction tank, and the sludge discharged from the membrane reaction tank is transferred to the dissolved oxygen reduction tank to dissolve dissolved oxygen. After removal of the waste water treatment system, the concentrated sludge of the dissolved oxygen reduction tank is drawn out and stored in the sludge storage tank, after being removed and transferred to the anaerobic tank and the alternating inflow reaction tank.
Sewage and return sludge flowing into the anaerobic tank are transferred to the alternating inflow reaction tank after undergoing a phosphorus discharge process,
The alternating inflow reaction tank is equipped with a flow change facility for controlling the flow of sewage and return sludge introduced through a direct or anaerobic tank, and through this flow change facility, the inflow sewage and return sludge flow only into the first reactor operated as a non-aeration. The second reaction tank includes a first step of operating as aeration-abandonment → abandonment → aeration (three-part aeration); On the contrary, the second reactor is operated as a non-aeration tank with sewage and return sludge flowing. At this time, the first reactor is a second cycle operated with aeration, aeration, and aeration (non-aeration) without inflow of sewage and return sludge. Advanced wastewater treatment method characterized in that it is operated repeatedly. The method according to claim 1,
The alternating inflow reaction tank in which sewage flows in is an advanced wastewater treatment method characterized by performing denitrification in the sludge blanket by introducing sewage and return sludge into the sludge blanket layer at the bottom. The method according to claim 1,
The alternating inflow reaction tank is equipped with an agitation facility, and the advanced wastewater treatment method characterized by uniformly mixing the organic matter and sludge introduced in a non-aeration state. The method according to any one of claims 1 to 3,
Advanced wastewater treatment method characterized by increasing the ratio of sewage and return sludge flowing into the alternating inflow reaction tank to increase the efficiency of nitrogen removal in sewage. The method according to any one of claims 1 to 3,
In order to increase the efficiency of phosphorus removal in the sewage, the advanced wastewater treatment method characterized by increasing the proportion of sewage flowing into the anaerobic tank and reducing the proportion of return sludge flowing into the anaerobic tank. The method according to any one of claims 1 to 3,
When the C / N ratio and the C / P ratio of the influent sewage are low, the advanced wastewater treatment method characterized by operating an external carbon source, such as methanol, in an anaerobic tank and an alternating influent reactor. The method according to any one of claims 1 to 3,
Advanced wastewater treatment method, characterized in that by operating a flocculant in an anaerobic tank to agglomerate the released phosphorus when high-concentration sewage is introduced. The method according to claim 1,
Advanced wastewater treatment method, characterized in that to suppress the adhesion of contaminants by continuous aeration or intermittent aeration to control the membrane installed in the membrane reaction tank. The method according to claim 8,
Advanced wastewater treatment method, characterized in that it is possible to control the concentration and cycle of chemicals as a method of chemical cleaning according to the pollution load, in addition to continuous aeration or intermittent aeration. The method according to claim 8,
A high-level wastewater treatment method characterized by supplying a constant blowing amount in conjunction with the water level in controlling the flow rate of the blower when performing the continuous aeration or intermittent aeration.

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