Advanced Sewage and Wastewater Treatment System with Improved Treatment Efficiency

Abstract

The present invention relates to an advanced wastewater treatment system with improved treatment efficiency, and more specifically, a first anoxic tank, an anaerobic tank, a second anoxic tank, an aerobic tank, a membrane separation tank, and a third anoxic tank are connected and positioned in sequence, and the aerobic tank includes a stirrer equipped with a plurality of blades, and the stirrer includes a plurality of blades coupled to a rotating shaft to form a fluid flow and an angle adjustment unit that adjusts the inclination angle of each blade. According to the present invention as described above, the removal efficiency of high-concentration nitrogen in wastewater and the reduction of sludge can be achieved, so the removal effect of organic matter, nitrogen, and phosphorus in sewage is excellent, and high-concentration nitrogen-containing sewage can be efficiently treated economically through device miniaturization and cost reduction effects.

Description

Technology Field

[0001] The present invention relates to an advanced wastewater treatment system, and more specifically, to a new advanced wastewater treatment system with improved treatment efficiency that can economically treat high-concentration nitrogen-containing sewage by reducing sludge and removing high concentrations of nitrogen in sewage, while also having excellent removal effects of organic matter, nitrogen, and salt in sewage, and by miniaturizing the device and reducing costs. Background Technology

[0002] Generally, pollutants in wastewater consist mainly of organic matter and nutrients such as nitrogen and phosphorus, and accordingly, various attempts are being made to develop devices to purify wastewater by removing nitrogen and phosphorus.

[0003] Conventional purification devices are configured with various types of reactors for biological nitrogen and phosphorus removal processes, such as an aerobic reactor (generally referred to as an aeration tank) for nitrification and phosphorus excess intake, an anoxic reactor for denitrification, and an anaerobic reactor for phosphorus release.

[0004] Here, a conventional wastewater purification device is disclosed as described in Korean Published Patent Application No. 2009-22168 (Title of Invention: Method and apparatus for treating livestock wastewater), Korean Registered Patent Application No. 10-0709456 (Title of Invention: Wastewater treatment apparatus and wastewater treatment method), and Korean Published Patent Application No. 1998-67740 (Title of Invention: Method and apparatus for removing nutrients in sewage and wastewater treatment), etc., wherein an aeration tank, which is mainly in the form of a box, has an air diffuser connected to the bottom, and air supplied from the air diffuser is mixed with the wastewater to promote microorganisms to decompose and purify pollutants.

[0005] However, these conventional wastewater treatment devices have a single internal structure where the reaction takes place, which hinders smooth contact with oxygen as the wastewater passes through the aerobic reaction tank. Consequently, there is a problem in that the ability to decompose pollutants in the wastewater is reduced.

[0006] Furthermore, there is a problem where the loss of influent organic matter is significant, leading to a substantial decrease in the removal efficiency of nitrogen and phosphorus; therefore, there is an urgent need for the development of technologies that can improve treatment efficiency. Prior art literature

[0008] Korean Patent Publication No. 10-2017-0009155 (2017.01.25) The problem to be solved

[0009] Accordingly, the present invention was devised to resolve the above-mentioned problems, and the purpose is to provide an advanced wastewater treatment system with improved treatment efficiency that can economically treat high-concentration nitrogen-containing wastewater efficiently through device miniaturization and cost reduction, while having excellent removal efficiency of organic matter, nitrogen, and phosphorus in wastewater by reducing sludge and high-concentration nitrogen removal efficiency in wastewater. means of solving the problem

[0010] The technical problem of the present invention as described above is achieved by the following means.

[0011] (1) A first anoxic tank (10), an anaerobic tank (20), a second anoxic tank (30), an aerobic tank (40), a membrane separation tank (50), and a third anoxic tank (60) are connected in sequence, and the first anoxic tank is connected to a first split inflow line through which influent wastewater is split and to a first split return line through which return sludge from the third anoxic tank is split and internally returned, the anaerobic tank through which treated water from the first anoxic tank is transferred is connected to a second split inflow line through which influent wastewater is split and transferred, the second anoxic tank through which treated water from the anaerobic tank is transferred is connected to a second split return line through which return sludge from the third anoxic tank is split and internally returned, the aerobic tank through which treated water from the second anoxic tank is transferred is connected to a third anoxic tank through which treated water from the aerobic tank is transferred, and a sludge return line is connected to the third anoxic tank through which treated water from the aerobic tank is transferred.

[0012] The above aeration tank (40) is,

[0013] A chamber (70) having a processing space formed inside; a wastewater supply unit (71) for supplying wastewater to the processing space of the chamber; a wastewater discharge unit (720) for discharging treated water from the processing space; a sediment discharge unit (730) for discharging sediment settled in the processing space; and a stirrer (100) equipped with a plurality of blades; wherein

[0014] The above stirrer (100) is,

[0015] A rotating shaft (110) that transmits rotational force;

[0016] A plurality of blades (120) coupled to the above-mentioned rotating shaft (110) to form a fluid flow: and

[0017] It includes a rotation drive unit (140) that rotates the above rotation shaft (110), and

[0018] The blade (120) has a blade shaft (122) as its central axis, and the blade shaft (122) is installed to be rotatable about the rotation axis (110).

[0019] The above-mentioned stirrer (100) includes an angle adjustment unit (130) that rotates the blade shaft (122) to adjust the inclination angle of the blade (120), and

[0020] The above angle adjustment unit (130) is,

[0021] An operating space (131) formed inside the above-mentioned rotating shaft (110);

[0022] An operating shaft (132) installed to be movable along the above operating space (131);

[0023] A control drive unit (133) that moves the above operating shaft (132) in the longitudinal direction of the operating space;

[0024] A driven gear (134) installed at the end of the blade shaft (122) of the blade (120);

[0025] A drive block (135) coupled to the above-mentioned operating shaft (132) and moved together with it;

[0026] and a rack gear (136) formed in the drive block (135) to mesh with the driven gear (134);

[0027] Each of the above blades (120) is,

[0028] A first blade (124) and a second blade (126) are arranged on both sides based on the blade shaft (122) and formed to be foldable;

[0029] and a blade original position part (128) that returns the folded first blade (124) and second blade (126) to an unfolded state;

[0030] Includes,

[0031] The above-mentioned first blade (124) and second blade (126) are each composed of a first blade piece (125) and a second blade piece (127) that are segmented into multiple parts and formed to be individually foldable, thereby forming an advanced wastewater treatment system with improved treatment efficiency.

[0032] (2) In the above (1),

[0033] The above rotational shaft (110) is composed of a plurality of unit shafts (111) interconnected in series, and

[0034] The above-described operating shaft (132) is characterized by being formed by connecting a plurality of unit shafts (132a) in series, thereby improving the treatment efficiency of the advanced wastewater treatment system.

[0035] (3) In the above (1),

[0036] The above blade original positioning part (128) includes a torsion spring, and one end of the torsion spring is fixed to the blade shaft (122), and the other end is fixed to the first blade (124) or the second blade (126), characterized by an improved high-grade wastewater treatment system. Effects of the invention

[0037] According to the advanced wastewater treatment system with improved treatment efficiency of the present invention, it is a very useful and effective invention that enables the efficient and economical treatment of high-concentration nitrogen-containing wastewater through the miniaturization of the device and cost reduction, while also providing excellent removal effects of organic matter, nitrogen, and phosphorus in the wastewater. Brief explanation of the drawing

[0038] FIG. 1 is a diagram illustrating the overall configuration of an advanced wastewater treatment system with improved treatment efficiency according to the present invention, and FIG. 2 is a drawing illustrating an aerobic tank according to the present invention, and FIG. 3 is a drawing illustrating a stirrer according to the present invention, and FIG. 4 is a drawing illustrating a blade and a blade shaft according to the present invention, and FIG. 5 is a drawing illustrating a rotation axis and an angle adjustment unit according to the present invention, and FIG. 6 is a drawing illustrating the operation state of blade inclination angle adjustment according to the present invention, and FIG. 7 is a drawing illustrating a foldable blade and a blade piece according to the present invention, and FIG. 8 is a drawing illustrating a membrane separation tank according to the present invention. Specific details for implementing the invention

[0039] Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. The detailed description disclosed below, together with the accompanying drawings, is intended to describe exemplary embodiments of the present invention and is not intended to represent the only embodiment in which the present invention may be practiced. The following detailed description includes specific details to provide a complete understanding of the present invention. However, those skilled in the art will know that the present invention may be practiced without such specific details.

[0040] In some cases, to avoid obscuring the concept of the present invention, known structures and devices may be omitted or illustrated in the form of a block diagram focusing on the core functions of each structure and device.

[0041] Throughout the specification, when a part is described as "comprising" or "including" a component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. Furthermore, the term "...part" as used in the specification refers to a unit that performs at least one function or operation. Additionally, "one (a or an)," "one," "the," and similar related terms may be used in the context describing the invention (particularly in the context of the following claims) to include both singular and plural forms, unless otherwise indicated in the specification or clearly contradicted by the context.

[0042] In describing the embodiments of the present invention, specific descriptions of known functions or configurations will be omitted if it is determined that such detailed descriptions could unnecessarily obscure the essence of the invention. Furthermore, the terms described below are defined in consideration of their functions in the embodiments of the present invention, and these definitions may vary depending on the intentions or practices of the user or operator. Therefore, such definitions should be based on the content throughout this specification.

[0043] Hereinafter, preferred embodiments of the present invention will be described with reference to the attached drawings.

[0044] First, referring to FIG. 1, a process according to a preferred embodiment of the present invention is configured in the order of a first anoxic tank (10), an anaerobic tank (20), a second anoxic tank (30), an aerobic tank (40), a membrane separation tank (50), and a third anoxic tank (60), and influent wastewater (1) is divided and introduced into the first anoxic tank (10) and the anaerobic tank (20). In addition, sludge (2) that has undergone endogenous denitrification in the third anoxic tank (60) is divided and internally recirculated to the first anoxic tank (10) and the second anoxic tank (30).

[0045] That is, as shown in FIG. 1, the influent wastewater (1) is introduced into the first anoxic tank (10) through the first divided inflow (11) and into the anaerobic tank (20) through the second divided inflow (12), respectively, and the sludge (2) that has undergone endogenous denitrification in the third anoxic tank (60) is divided and internally recirculated to the first anoxic tank (10) through the first divided internal recirculation (21) and to the second anoxic tank (30) through the second divided internal recirculation (22).

[0046] The following describes each component constituting the processing device according to the present invention in more detail.

[0047] 1) First anaerobic tank (10)

[0048] Heterotrophic microorganisms can utilize both free and bound oxygen for respiration, but they prefer free oxygen respiration. Therefore, for efficient denitrification, the influx of dissolved oxygen (free oxygen) must be prevented, and sufficient organic matter necessary for denitrification must be supplied to establish anaerobic conditions where oxygen within nitrate ions acts as an electron acceptor for the decomposition of organic matter and reduction into nitrogen gas. Consequently, the introduction of dissolved oxygen into the anaerobic tank inhibits denitrification. A wide variety of microorganisms capable of reducing nitrate ions are known, including Aerobacter, Bacillus, and Micrococcus.

[0049] In the present invention, in the first anaerobic tank (10), not only is wastewater introduced in the first divided inflow (11), but the first divided return sludge (21) returned from the third anaerobic tank (60) is also introduced. Therefore, in the first anaerobic tank (10), heteronomous denitrifying microorganisms perform heteronomous denitrification of the remaining nitrate nitrogen in the first divided return sludge (21) from the third anaerobic tank (60) using organic matter introduced through the first divided inflow wastewater (11). The first divided return sludge (21) is sludge in which nitrate nitrogen nitrified through the aerobic tank (40) and membrane separation tank (50) is endogenously denitrified by denitrifying microorganisms without separate organic matter, and since the nitrate nitrogen content is minimized, it becomes a condition in which sufficient organic matter is supplied under optimal denitrification conditions.

[0050] In the third anoxic tank (60), most of the organic matter in the wastewater is consumed as it passes through the first anoxic tank (10), the anaerobic tank (20), the second anoxic tank (30), the aerobic tank (40), and the membrane separation tank (50). Consequently, endogenous denitrification occurs using the substrate within the cell instead of organic matter introduced from the outside, and as a result, nitrate nitrogen can be reduced without consuming organic matter in the wastewater. Accordingly, when the sludge is returned, the nitrate nitrogen load to the first anoxic tank (10) and the second anoxic tank (30) is reduced, which has the advantage of improving the nitrate nitrogen removal rate without the need for separate organic matter input.

[0051] 2) Anaerobic tank (20)

[0052] Phosphorus release in the anaerobic tank (20) occurs when phosphorus-metabolizing microorganisms absorb organic matter and store it in their bodies as PHB under anaerobic conditions where there is no free oxygen or combined oxygen, while simultaneously breaking down ATP and converting it into ADP to obtain energy required for biological metabolism. In this process, phosphorus release occurs in which orthophosphate is expelled from the body, so if nitrate nitrogen is present in the anaerobic tank (20), phosphorus release is inhibited.

[0053] In the present invention, in the anaerobic tank (20), phosphate-metabolizing microorganisms release phosphate using organic matter introduced through the second divided influent wastewater (12), and at this time, as the sludge in which denitrification is completed in the first anoxic tank (10) is transferred to the anaerobic tank (20), nitrate inhibition in the anaerobic tank (20) can be prevented.

[0054] Specifically, phosphorus release proceeds using phosphorus metabolizing microorganisms in the sludge transferred to the anaerobic tank (20) after nitrate nitrogen is removed in the first anoxic tank (10) and volatile organic acid components with a fast phosphorus release rate in the wastewater that is separately divided and introduced (12), thereby satisfying optimal phosphorus release conditions in which volatile organic acids with a fast denitrification rate are sufficiently supplied without nitrate nitrogen.

[0055] 3) Second anaerobic group (30)

[0056] By using the residual organic matter remaining after use in the first anoxic tank (10) and the anaerobic tank (20), the nitrate nitrogen contained in the sludge (22) that is separately divided and returned from the third anoxic tank (60) is denitrified, thereby satisfying the optimal denitrification condition of supplying sufficient organic matter without dissolved oxygen.

[0057] In the second anoxic tank (30), organic matter remaining after being consumed for phosphorus release in the anaerobic tank (20) is used to denitrify the nitrate remaining in the second divided return sludge (22) using heteronomous denitrification microorganisms.

[0058] 4) Exploration group (40)

[0059] Heterotrophic microorganisms remove organic matter remaining after being used for denitrification and phosphorus release while passing through the first anoxic tank (10), the anaerobic tank (20), and the second anoxic tank (30), absorb phosphorus released from the anaerobic tank (20), and nitrify nitrogen (organic nitrogen, ammonia nitrogen) contained in the sewage influent by autotrophic microorganisms.

[0060] Autotrophic microorganisms (nitrification) and heterotrophic microorganisms (organic matter removal) are in a competitive relationship for dissolved oxygen, which is a common substrate, within the aerobic tank (40). Since the growth rate of heterotrophic microorganisms is higher than that of autotrophic microorganisms, excessive organic matter inhibits nitrification. In the present invention, a first anoxic tank (10), an anaerobic tank (20), and a second anoxic tank (30) are located upstream of the aerobic tank (40) so that organic matter in the wastewater is utilized to the maximum extent for denitrification and phosphorus removal. Consequently, organic matter is introduced into the aerobic tank (40) in a state where it is reduced to the maximum extent, thereby minimizing the inflow of organic matter, which is the optimal nitrification condition, and satisfying the optimal nitrification condition where there is no competition for oxygen substrate between autotrophic microorganisms and heterotrophic microorganisms.

[0061] The treatment process within the aerobic tank (40) requires high-efficiency oxygen supply capabilities, but since it must be supplied uniformly throughout, the role of the agitator is particularly important. The present invention provides a structure that replaces a conventional agitator and efficiently responds to changes in the characteristics of the flow within the aerobic tank (40), thereby improving the formation of mixed flow and the uniformity of the mixed liquid. Such an agitator can be controlled through a control unit that controls the operating state of the agitator (100) installed in the aerobic tank (40) according to changes in the characteristics of the incoming wastewater, and preferably, an artificial intelligence control unit (not shown) can be applied.

[0062] A specific embodiment of an aeration tank (40) including a specific stirrer according to the present invention will be described below with reference to FIGS. 2 to 5.

[0063] In the present invention, the aerobic tank (40) includes a chamber (70), a wastewater supply unit (71), a wastewater discharge unit (72), a sediment discharge unit (73), and a stirrer (100), as shown in FIG. 2. A compressor (42) for supplying oxygen and an air diffuser (41) for supplying oxygen supplied through the compressor to the treatment space are installed at the bottom of the chamber (70).

[0064] A chamber (70) has a processing space (70a) formed inside, and a wastewater supply unit (71) supplies wastewater to the processing space (70a) of the chamber (70).

[0065] And the wastewater discharge section (72) is provided to discharge wastewater treated in the treatment space section (70a), and the sediment discharge section (73) discharges sediment settled in the treatment space section (70a).

[0066] As shown in FIG. 3, the agitator (100) includes a plurality of blades (120) and is rotatably provided in the processing space (70a) to uniformly disperse the introduced oxygen and effectively rotate the wastewater introduced into the processing space (70a) to supply a vortex.

[0067] For this purpose, the stirrer (100) includes a rotating shaft (110), a plurality of blades (120) coupled to the rotating shaft (110) to form a fluid flow, and a rotary drive unit (140) that rotates the rotating shaft (110).

[0068] The above-mentioned stirrer (100) improves the uniformity of mixing of the mixture by forming a mixing flow inside the aerobic tank (40) through rotation. Accordingly, the above-mentioned stirrer (100) can perform the function of reducing the variation in activated sludge concentration inside the aerobic tank (40) and suppressing the occurrence of stagnant areas inside the treatment tank.

[0069] As shown in FIGS. 3 and 4, each of the above blades (120) has a blade shaft (122) as its central axis, and the blade shaft (122) is installed so as to be rotatable on a rotation axis (110).

[0070] Preferably, the blade shaft (122) is installed in the center of the blade (120) and can be rotatably supported with respect to the rotation axis (110) by a bearing. Accordingly, the blade (120) rotates as a whole by the rotation of the rotation axis (110), while the angle of inclination can be adjusted around the blade shaft (122).

[0071] The above-described stirrer (100) further includes an angle adjustment unit (130) that adjusts the inclination angle of the blade (120) by rotating the blade shaft (122). The angle adjustment unit (130) may include an operating space (131), an operating shaft (132), an adjustment drive unit (133), a driven gear (134), a drive block (135), and a rack gear (136).

[0072] The above operating space (131) is formed inside the rotation shaft (110), and the rotation shaft (110) may have a plurality of unit shafts (111) of a certain length connected in series, and in this case, the operating space (131) formed inside each unit shaft (111) may be formed to be in communication with each other.

[0073] The above operating shaft (132) is installed to be movable along the operating space (131) and may be formed as a single unit or may be formed by connecting a plurality of unit shafts (132a) having a certain length in series. The upper end of the above operating shaft (132) may be formed to protrude upward from the rotation axis (110), and the control drive unit (133) is installed adjacent to the upper end of the rotation axis (110) and configured to move the above operating shaft (132) in the longitudinal direction (or vertical direction) of the operating space (131).

[0074] The above-mentioned driven gear (134) is installed at the end of the blade shaft (122) of each blade (120) and can be positioned within the operating space (131) of the rotation axis (110). The above-mentioned driving block (135) is coupled to the operating shaft (132) and moves together with the operating shaft (132), and can be positioned at a location corresponding to each blade (120) installed on the rotation axis (110).

[0075] In the above-mentioned drive block (135), block protrusions (135a) may be formed protruding on both sides relative to the driven gear (134), and a rack gear (136) that meshes with the driven gear (134) may be formed on the block protrusions (135a).

[0076] As in one embodiment illustrated in FIG. 4, when a plurality of blades (120) are installed radially with respect to a rotation axis (110), a plurality of block protrusions (135a) corresponding to each blade (120) may be formed on the outer circumference of the drive block (135), and a rack gear (136) formed on each block protrusion (135a) may mesh with a corresponding driven gear (134). Accordingly, the inclination angle of the plurality of blades (120) can be adjusted simultaneously or in conjunction by the movement of a single operating shaft (132).

[0077] When looking at the operating state of the angle adjustment unit (130) as shown in FIG. 5, when the operating shaft (132) moves along the operating space (131) by the adjustment drive unit (133), the drive block (135) coupled to the operating shaft (132) moves together. At this time, the rack gear (136) of the drive block (135) moves linearly, and the driven gear (134) engaged with the rack gear (136) rotates, and the blade shaft (122) rotates according to the rotation of the driven gear (134), thereby adjusting the inclination angle of the blade (120). Accordingly, the agitator (100) can adjust the direction of fluid agitation and the agitation intensity according to changes in the characteristics and flow rate of the wastewater.

[0078] In addition, the blade (120) may be configured to variably form a flow state in response to changes in fluid resistance by means of a folding structure of the first blade (124) and the second blade (126). Accordingly, a stable mixing state can be maintained even when changes in the viscosity of wastewater or the flow velocity of the mixed liquid occur, and the formation of local stagnation areas can be reduced.

[0079] Each of the above blades (120) may include a first blade (124), a second blade (126), and a blade original position portion (128), as shown in FIGS. 4 and 6. The first blade (124) and the second blade (126) may be positioned on both sides relative to the blade shaft (122) and may be formed to be foldable according to fluid resistance.

[0080] The above blade original position part (128) is an elastic configuration and performs the function of returning the folded first blade (124) and second blade (126) to an unfolded state (or restoring the position by restoring force).

[0081] Here, the blade return portion (128) uses a torsion spring as shown in FIG. 4 in one embodiment, and one end of the torsion spring is fixed to the blade shaft (122) and the other end is fixed to the first blade (124) or the second blade (126), and is returned to its original position by a force that returns it to its original state after being folded according to the degree of fluid resistance.

[0082] That is, the first blade (124) and the second blade (126) can repeat folding and returning operations based on the blade shaft (122) according to the flow velocity, viscosity, and sludge concentration of the wastewater when the stirrer (100) rotates. Since the flow state inside the treatment tank can be formed more diversely through this folding and returning operation, it can contribute to improving the uniformity of mixing inside the aerobic tank (40) and reducing localized sludge deposition.

[0083] Additionally, as illustrated in FIG. 7, the first blade (124) and the second blade (126) may be composed of a plurality of blade segments (125, 127). Each of the plurality of blade segments (125, 127) is formed to be individually foldable and can be returned to its original state by the blade original position part (128). Accordingly, instead of the entire blade being deformed uniformly, individual folding and return can be achieved for each part where fluid resistance is significant, thereby improving responsiveness to changes in wastewater characteristics.

[0084] In this way, the stirrer (100) of the present invention can variably form a mixed flow inside a treatment tank by means of a combination of a rotating shaft (110), a blade (120), an angle adjustment part (130), a first blade (124), a second blade (126), and a first blade piece (125) and a second blade piece (127). Accordingly, the present invention can improve the uniformity of mixing inside an aerobic MBR reactor (30) and reduce sludge concentration variation and the occurrence of local stagnation areas.

[0085] 5) Membrane separator

[0086] As shown in FIG. 8, the membrane separation tank (50) is equipped with an immersed membrane module (52) to separate treated water from the sludge received from the aerobic tank (40) and discharge it to the outside. The term "immersed membrane module (52)" refers collectively to flat membranes and hollow fiber membranes designed so that the membrane is directly immersed in water to enable total filtration by suction.

[0087] That is, according to the present invention, in the membrane separation tank (50), solid-liquid separation can be performed using a separation membrane module (52) to obtain treated water in a continuous process.

[0088] These separation membrane modules (52) are installed in a number of parallel at regular intervals on the inside of the support frame (54).

[0089] According to this membrane separation tank (50), only the liquid can be passed through and transported from the water to be treated, thereby easily separating foreign substances.

[0090] For this purpose, the support frame (54) includes a pair of side walls spaced apart from each other, an upper support bar provided on the upper side of the pair of side walls, and a lower support bar provided on the lower side of the pair of side walls.

[0091] In other words, two upper support bars are installed on the upper side of the side wall, spaced apart front and back, and two lower support bars are located below the upper support bars, and two lower support bars are installed on the lower side of the side wall, spaced apart front and back.

[0092] And the membrane modules (52) are installed between a pair of side walls. The membrane modules (52) are supported by an upper support bar and a lower support bar and are installed in a number of parallel. In the illustrated example, a number of membrane modules (52) are installed in a number of parallel spaced apart from each other.

[0093] Each membrane module (52) consists of an upper header and a lower header, a support bar, and a membrane (52a).

[0094] The upper header and the lower header are fixed in a spaced-apart state in the vertical direction by support bars.

[0095] In addition, a separator (52a) with a hollow interior is provided to allow liquid to pass through, wherein the upper part of the separator (52a) is connected to an upper header and the lower part of the separator (52a) is connected to a lower header.

[0096] The upper header is hollow inside, and the upper end of the separator (52a) is inserted into the hollow interior. A connection port is formed in the upper header to which a water collection pipe is connected, and an outlet port is formed in the upper end of the water collection pipe to which a suction line is connected.

[0097] Here, the separator (52a) can be formed from hollow fibers, flat membranes, or membranes, and in one embodiment, the separator (52a) is formed from hollow fibers, and the hollow fiber is a synthetic fiber with a hollow interior.

[0098] 6) Third anaerobic group (60)

[0099] In the third anaerobic tank (60), dissolved oxygen contained in the sludge is removed by the aeration (oxygen supply) of the aerobic tank (40) using the oxygen respiration phenomenon of microorganisms, and the nitrate nitrogen nitrified in the aerobic tank (40) is sequentially denitrified by denitrifying microorganisms without separate organic matter.

[0100] However, in the present invention, a connecting pipe is provided between the membrane separation tank (50) and the third oxygen tank (60), and heat is supplied to the treated water transferred from the membrane separation tank (50) to the third oxygen tank (60) through a heat supply means (e.g., a heat exchanger or a heating jacket) in the connecting pipe. Additionally, a vacuum pump is connected externally to the upper part of the third oxygen tank (60) along with a sealed vacuum pressure reduction chamber, so that dissolved oxygen can be removed using pressure reduction.

[0101] With the above configuration, when sludge from which dissolved oxygen has been almost completely removed is transported and flows into the first anaerobic tank (10) and the second anaerobic tank (30), the inflow of dissolved oxygen is prevented, thereby preventing oxygen inhibition in the first anaerobic tank (10) and the second anaerobic tank (30), and at the same time, the total amount of nitrate nitrogen returned to the first anaerobic tank (10) and the second anaerobic tank (30) is reduced, thereby improving the nitrogen removal rate. Explanation of the symbols

[0103] 10: 1st Anaerobic Tank 20: Anaerobic Tank 30: 2nd Anaerobic Tank 40: Aerobic Tank 50: Membrane separation tank 60: Third anaerobic tank 70: Chamber 71: Wastewater supply unit 72 : Treated water discharge section 73 : Sediment discharge section 100 : Stirrer 110 : Rotating shaft 120 : Blade 122 : Blade shaft 130 : Angle adjustment part 131 : Operating space 132: Actuating shaft 133: Adjusting drive unit 134 : Driven gear 135 : Drive block 136 : Rack gear 140 : Rotary drive unit

Claims

Claim 1 A first anoxic tank (10), an anaerobic tank (20), a second anoxic tank (30), an aerobic tank (40), a membrane separation tank (50), and a third anoxic tank (60) are connected and positioned in sequence. The first anoxic tank (10) is connected to a first split inflow line through which influent wastewater is split and to a first split return line through which return sludge from the third anoxic tank (60) is split and internally returned. The anaerobic tank (20), through which treated water from the first anoxic tank (10) is transferred, is connected to a second split inflow line through which the influent wastewater is split and transferred. The second anoxic tank (30), through which treated water from the anaerobic tank (20) is transferred, is connected to a second split return line through which return sludge from the third anoxic tank (60) is split and internally returned. The aerobic tank (40) receives treated water from the second anoxic tank (30). In an advanced wastewater treatment device in which a sludge return line is connected to the third anoxic tank (60) into which the treated water of the aerobic tank (40) is introduced and transferred, the aerobic tank (40) comprises: a chamber (70) in which a treatment space is formed inside; a wastewater supply unit (71) for supplying wastewater to the treatment space of the chamber (70); a wastewater discharge unit (72) for discharging the treated water treated in the treatment space; a sediment discharge unit (73) for discharging the sediment settled in the treatment space; and a stirrer (100) equipped with a plurality of blades; wherein the stirrer (100) comprises a rotating shaft (110) that transmits rotational force; and a plurality of blades (120) coupled to the rotating shaft (110) to form a fluid flow. and a rotary drive unit (140) for rotating a plurality of blades by rotating the rotary shaft (110); wherein the blade (120) has a blade shaft (122) as a central axis, and the blade shaft (122) is installed to be rotatable with respect to the rotary shaft (110); and the stirrer (100) includes an angle adjustment unit (130) for adjusting the inclination angle of the blade (120), wherein the angle adjustment unit (130) comprises: an operating space (131) formed inside the rotary shaft (110); and an operating shaft (132) installed to be movable along the operating space (131).The device comprises: a control drive unit (133) for moving the operating shaft (132) in the longitudinal direction of the operating space; a driven gear (134) installed at the end of the blade shaft (122) to rotate the blade shaft; a drive block (135) coupled to the operating shaft (132) and moving together with it; and a rack gear (136) formed on the drive block (135) to mesh with the driven gear (134); wherein a plurality of blades (120) are installed radially with respect to the rotation axis (110), and a plurality of block protrusions (135a) corresponding to each blade are formed on the outer circumference of the drive block (135), and the rack gear (136) formed on each block protrusion meshes with the corresponding driven gear (134), and the blades (120) include a first blade (124) that is arranged on both sides with respect to the blade shaft (122) and is formed to be foldable, and Second blade (126); and a blade return section (128) that returns the folded first blade (124) and second blade (126) to an unfolded state; wherein the first blade (124) and second blade (126) are each composed of a first blade section (125) and a second blade section (127) formed to be individually foldable by being segmented into multiple parts, and the blade return section (128) includes a torsion spring, one end of the torsion spring is fixed to the blade shaft (122), and the other end is fixed to the first blade (124) or the second blade (126), and the third anaerobic tank (60) performs endogenous denitrification of nitrate nitrogen nitrified in the aerobic tank (40) without separate organic matter by denitrification microorganisms, and a connecting pipe is provided between the membrane separation tank (50) and the third anaerobic tank (60), and the connecting pipe A high-grade wastewater treatment system with improved treatment efficiency, characterized by having a heat supply means for supplying heat to the treated water transferred from the membrane separation tank (50) to the third anaerobic tank (60), a sealed vacuum depressurization chamber provided at the top of the third anaerobic tank (60), and an external vacuum pump connected to the sealed vacuum depressurization chamber to remove dissolved oxygen using depressurization. Claim 2 delete Claim 3 delete

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