Nitrogen removal and advanced sewage treatment apparatus and method using submerged hollow fiber membrane for sewage treatment

Abstract

The present invention relates to an advanced sewage treatment device comprising a separation membrane module (10) installed to be immersed within a biological reactor (100) of a water treatment facility, wherein a hollow fiber membrane (13) is installed between an upper cover (11) and a lower cover (12) so that treated water is filtered through a suction outlet pipe (20), and an oxygen supply inlet pipe (30) that allows oxygen to be introduced through the hollow fiber membrane (13) installed in the separation membrane module (10) to activate microorganisms attached to the surface of the hollow fiber membrane (13) so that the separation membrane module (10) functions as a carrier of the biological reactor (100), thereby immersing the separation membrane module (10) in the biological reactor (100) of a sewage treatment plant to simultaneously provide the functions of filtration of treated water and carrier, and by reducing the surface area of ​​the biological reactor (100), the construction costs and construction period of the sewage treatment plant installed underground can be reduced.

Description

Technology Field

[0001] The present invention relates to a device and method for nitrogen removal and advanced treatment of sewage using an immersed hollow fiber membrane for sewage treatment, wherein the immersed membrane is used as a carrier in a biological reactor of a sewage treatment plant, thereby allowing the treated water to be filtered while also serving as a carrier. Background Technology

[0003] Wastewater treatment is a process that improves water quality by separating or decomposing pollutants contained in water, transforming them into harmless substances. Generally, wastewater treatment stages include primary, secondary, and tertiary treatment. Primary treatment primarily utilizes physical methods such as sedimentation, flotation, and coagulation, while biological treatment is employed in secondary treatment. Tertiary treatment utilizes chemical methods such as attachment, ion exchange, and reverse osmosis.

[0004] Even if wastewater is treated by physical methods, colloidal and dissolved organic or inorganic substances remain in the wastewater. Biological treatment is a method of removing organic matter and nutrients such as nitrogen and phosphorus from wastewater using microorganisms. Therefore, biological treatment is adopted for the purpose of removing carbon organic matter, denitrification, and stabilization, expressed as BOD (Biological Oxygen Demand), TOC (Total Organic Carbon), and COD (Chemical Oxygen Demand).

[0005] Biological treatment methods are treatment methods that decompose organic matter in wastewater using the metabolic activity of microorganisms. They are classified into aerobic treatment and anaerobic treatment depending on whether oxygen supply is required in microbial metabolism, and into suspension methods and biofilm methods depending on whether microorganisms are used in a suspended state.

[0006] Currently, the most widely used method for treating domestic sewage or general industrial wastewater is the activated sludge method, which is an aerobic suspension process. In this method, wastewater is mixed with an activated microbial community (activated sludge) and aerated in an aeration tank, causing the microorganisms to remain suspended. The activated sludge is separated by sedimentation from the treated wastewater; some of the separated activated sludge is transferred to the aeration tank for reuse, while the remainder is discarded.

[0007] In addition, the activated sludge method has been widely used for the treatment of BOD in domestic sewage and organic industrial wastewater. However, the conventional suspension activated sludge method has problems such as the need for large-scale treatment facilities because the microbial concentration in the treatment reaction tank (aeration tank) is low, resulting in a slow reaction rate and long treatment time, and the disposal of the sludge requires enormous costs due to swelling of the sludge and the generation of a large amount of excess sludge during operation.

[0008] Meanwhile, wastewater treatment methods utilizing microbial reactions with media or MBR processes using membranes are currently being installed underground when constructing large-scale wastewater treatment plants.

[0009] In conventional wastewater treatment using carriers, there is a problem requiring a continuous supply of carriers, and issues such as corroded carriers clogging pipes are occurring.

[0010] Moreover, recently, when constructing underground sewage treatment plants, moving the current above-ground area underground as is results in high civil engineering and construction costs, and consequently, a longer construction period. Prior art literature

[0012] Korean Published Patent Application No. 10-2024-0028012, 'Method for manufacturing an amorphous iron sulfide carrier for underwater nitrogen removal' Korean Published Patent Application No. 10-2014-0066606, 'Method for manufacturing a polyvinylidene fluoride (PVDF) hollow fiber membrane' The problem to be solved

[0013] Therefore, the objective of the present invention is to provide a device and method for nitrogen removal and advanced treatment of sewage using an immersed hollow fiber membrane for sewage treatment, which reduces the installation area of ​​the biological reactor by enabling the biological reactor to have the functions of a filtration body and a filtration function of treated water during sewage treatment, thereby reducing construction costs and construction periods when installing a sewage treatment plant underground. means of solving the problem

[0015] The present invention, according to the above purpose, is characterized in that the advanced treatment device for sewage comprises a separation membrane module (10) installed to be immersed in a biological reactor (100) of a water treatment facility, with a hollow fiber membrane (13) installed between an upper cover (11) and a lower cover (12) so that treated water is filtered through a suction outlet pipe (20), and an oxygen supply inlet pipe (30) that allows oxygen to be introduced through the hollow fiber membrane (13) installed in the separation membrane module (10) so that the separation membrane module (10) functions as a carrier of the biological reactor (100), thereby supplying oxygen to microorganisms attached to the surface of the hollow fiber membrane (13) and activating the microorganisms.

[0016] In addition, the lower part of the membrane module (10) is characterized by having a vortex diffuser (40) configured to remove foreign substances adhering to the surface of the hollow fiber membrane (13) when filtering the treated water by the hollow fiber membrane (13), thereby reducing the number of times the membrane module (10) is washed and allowing the treated water to be filtered smoothly.

[0017] In addition, the inner surface of the bioreactor (100) is characterized by having an air pipe (110) for oxygen supply installed.

[0018] In addition, the hollow fiber membrane is characterized by being composed of PTFE (Polytetrafluoroethylene) material.

[0019] In addition, the present invention is characterized by a method for advanced treatment of sewage, comprising the steps of: installing an immersed separation membrane module in which a hollow fiber membrane (13) is connected between an upper cover (11) and a lower cover (12) within a biological reactor (100); stopping the suction of a suction outlet pipe (20) for filtration of treated water by connecting the separation membrane module (10); using the separation membrane module (10) as a carrier to allow microorganisms to attach to the surface of the hollow fiber membrane (13); supplying oxygen into the separation membrane module (10) through an oxygen supply inlet pipe (30); supplying oxygen to the surface of the hollow fiber membrane (13) to activate microorganisms; stopping the oxygen supply through the oxygen supply inlet pipe (30) to filter the treated water; and sucking the treated water through the suction outlet pipe (20) while the oxygen supply through the oxygen supply inlet pipe (30) is stopped so that it is filtered through the hollow fiber membrane (13). Effects of the invention

[0021] The present invention has the effect of simultaneously providing treated water filtration and carrier functions by immersing a submerged membrane module in the biological reactor of a sewage treatment plant, and has the effect of reducing construction costs and construction time for sewage treatment plants installed underground by reducing the surface area of ​​the biological reactor. Brief explanation of the drawing

[0023] FIG. 1 is a diagram illustrating the configuration of a nitrogen removal and advanced wastewater treatment device using an immersed hollow fiber membrane for wastewater treatment according to the present invention. FIG. 2 is a drawing illustrating the cross-sectional configuration of a membrane module according to an embodiment of the present invention. FIG. 3 is a diagram illustrating a configuration in which a different membrane module is used as a carrier in an embodiment of the present invention. FIG. 4 is a diagram illustrating the configuration of a nitrogen removal and advanced wastewater treatment device using an immersed hollow fiber membrane for wastewater treatment according to another embodiment of the present invention. FIG. 5 is a drawing illustrating another embodiment of the hollow fiber membrane of the present invention. FIG. 6 is a flowchart illustrating a method for nitrogen removal and advanced treatment of sewage using an immersed hollow fiber membrane for sewage treatment according to an embodiment of the present invention. Specific details for implementing the invention

[0024] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0025] FIG. 1 is a diagram illustrating the configuration of a nitrogen removal and advanced wastewater treatment device using an immersed hollow fiber membrane for wastewater treatment according to an embodiment of the present invention, and FIG. 2 to 3 are diagrams illustrating the configuration in which a separation membrane module of the present invention is used as a carrier.

[0026] The nitrogen removal and advanced treatment device for sewage using the immersed hollow fiber membrane (13) of the present invention comprises a separation membrane module (10) installed so as to be immersed within a biological reactor (100) of a water treatment facility, with the hollow fiber membrane (13) installed between an upper cover (11) and a lower cover (12) to filter the treated water through a suction outlet pipe (20), and an oxygen supply inlet pipe (30) that allows oxygen to be introduced through the hollow fiber membrane (13) installed in the separation membrane module (10) so that the separation membrane module (10) functions as a carrier of the biological reactor (100), thereby supplying oxygen to microorganisms attached to the surface of the hollow fiber membrane (13) and activating the microorganisms.

[0027] The above separation membrane module (10) allows treated water to be sucked in and filtered through a hollow fiber membrane (13), and the filtered treated water is discharged through a suction outlet pipe (20). The surface area per unit volume is increased through the hollow fiber membrane (13), which is in the form of a hollow tube with a hollow center, thereby increasing water treatment productivity.

[0028] For example, the hollow fiber membrane (13) can be manufactured from PTFE material so that it can withstand the strong oxidizing action of ozone when installed in a water treatment facility that is treated with ozone, and thus has a lifespan of at least 5 years.

[0029] PTFE (Polytetrafluoroethylene) possesses excellent chemical resistance (alkali and acid resistance) and high tensile strength, along with superior chemical resistance, weather resistance, and heat resistance. This results in excellent durability for membranes, preventing them from easily cracking or tearing even in ozone-based water treatment facilities, thereby extending the maintenance period of membrane filtration devices.

[0030] In addition, a vortex diffuser (40) may be installed at the bottom of the membrane module (10) to remove foreign substances adhering to the surface of the hollow fiber membrane (13) when filtering the treated water by the hollow fiber membrane (13), thereby reducing the number of times the membrane module (10) is washed and allowing the treated water to be filtered smoothly.

[0031] The above-mentioned vortex diffuser (40) allows the air supplied through the air supply pipe (41) to be supplied from the bottom to the top of the membrane module (10) by spraying the air in a vortex manner so that the air is supplied from the bottom of the membrane module (10), thereby enabling foreign substances attached to the surface of the hollow fiber membrane (13) to be removed by the vortexed air.

[0032] As the treated water is also swollen in the form of a vortex by the air that generates the vortex, the hollow fiber membrane (13) is shaken or hits the surface, allowing foreign substances attached to the hollow fiber membrane (13) to fall off.

[0033] If foreign substances adhere to the hollow fiber membrane (13), they become fixed, causing the separation membrane module (10) to need frequent cleaning or take a long time to clean, and in particular, the filtration capacity of the hollow fiber membrane (13) decreases due to the fixed foreign substances.

[0034] To solve this problem, by causing a vortex to be generated in the air sprayed from the bottom of the membrane module (10), foreign substances attached to the hollow fiber membrane (13) can be removed, thereby reducing maintenance costs and improving the filtration capacity of the treated water.

[0035] As an embodiment of the present invention, the hollow fiber membrane (13) installed in the separation membrane module (10) preferably has a pore size of 0.4 to 0.5 μm, an outer diameter of 1.2 to 1.4 mm, an inner diameter of 0.7 to 0.9 mm, and a tensile strength of 70 to 90 N, and preferably has a pore size of 0.45 μm, an outer diameter of 1.3 mm, an inner diameter of 0.8 mm, and a tensile strength of 80 N.

[0036] The separation membrane module (10) of the present invention is installed in a bioreactor (100) and simultaneously has a filtration function for treated water and a carrier function within the bioreactor (100). Since the separation membrane module (10) has two functions, the installation area of ​​the sewage treatment facility can be reduced.

[0037] In order for the above-mentioned membrane module (10) to function as a carrier, an oxygen supply inlet pipe (30) may be installed to supply oxygen into the membrane module (10).

[0038] Referring to FIGS. 2 and 3, microorganisms are attached to the surface of the hollow fiber membrane (13) while the membrane module (10) is immersed in the bioreactor (100), and oxygen supplied through the oxygen supply inlet pipe (30) is supplied into the interior of the membrane module (10) and then supplied to the exterior of the hollow fiber membrane (13), thereby directly supplying oxygen to the microorganisms attached to the hollow fiber membrane (13).

[0039] The supplied oxygen activates microorganisms to enable water treatment, and the large surface area of ​​the hollow fiber membrane (13) allows microorganisms to be activated, so the water treatment efficiency is also excellent.

[0040] In addition, if a hollow fiber membrane (13) is used as a carrier in the anaerobic tank of a water treatment facility, the separation membrane module (10) that would otherwise be discarded after use can be reused, which has the effect of reducing costs.

[0041] FIG. 4 is another embodiment of the present invention, wherein a plurality of membrane modules (10) installed by being immersed in a bioreactor (100) may be installed in a connected manner, and a suction outlet pipe (20) for filtering treated water through the connected membrane modules (10) may be installed, and an air supply pipe (41) for supplying air to a vortex diffuser (40) that allows air to be injected from the bottom of the membrane modules (10) may be installed together.

[0042] Referring again to FIG. 1, an air pipe (110) for oxygen supply is installed on the inner side of the bioreactor (100), and the air pipe (110) is installed together with an air diffuser installed at the bottom of the bioreactor (100) so that oxygen supply can be smoothly provided.

[0043] The above air pipe (110) is preferably installed so that the air hole is not blocked when there is no air supply, and if necessary, a separate mesh net may be installed.

[0045] FIG. 5 is a drawing illustrating another embodiment of the hollow fiber membrane of the present invention.

[0046] In the present invention, a band portion (14) is configured to allow a plurality of hollow fiber membranes (13) to be bundled in a bundle form between upper and lower covers (11) (12), and a microorganism attachment portion (15) is configured such that the hollow fiber membranes (13) are bundled by the band portion (14) and the hollow fiber membranes (13) are closely attached to each other so that the microorganisms attached thereto do not easily fall off.

[0047] The above band portion (14) binds a plurality of hollow fiber membranes (13) at predetermined lengths so that they do not easily shake, and the hollow fiber membranes (13) are bound by the band portion (14) so ​​that the hollow fiber membranes (13) are in close contact with each other.

[0048] With the hollow fiber membrane (13) installed to function as a carrier, oxygen is supplied to the hollow fiber membrane (13) through the oxygen supply inlet pipe (30) while maintaining a constant distance between the hollow fiber membranes (13). In this process, a problem may arise where it becomes difficult for microorganisms to adhere to the surface of the hollow fiber membrane (13) due to the oxygen supplied through the hollow fiber membrane (13).

[0049] If microorganisms do not adhere to the surface of the hollow fiber membrane (13), the hollow fiber membrane (13) cannot function as a carrier. To prevent this, a number of hollow fiber membranes (13) are bundled together with a band portion (14) to form a microorganism attachment portion (15), thereby causing the hollow fiber membranes (13) to clump together so that the microorganisms do not fall off while attached.

[0051] FIG. 6 is a flowchart illustrating a method for nitrogen removal and advanced treatment of sewage using an immersed hollow fiber membrane (13) for sewage treatment according to an embodiment of the present invention.

[0052] A separation membrane module (10) in which a hollow fiber membrane (13) for filtering treated water is connected and installed between an upper cover (11) and a lower cover (12) is immersed in a bioreactor (100) to be used for filtering treated water and as a carrier.

[0053] At this time, the hollow fiber membrane (13) is bound by a band portion (14) in units of a predetermined length so that the hollow fiber membranes are in close contact, thereby forming a microorganism attachment portion (15) where microorganisms can be attached.

[0054] In order to use the membrane module (10) immersed in the bioreactor (100) as a carrier, the suction outflow pipe (20) for filtration of treated water is stopped so that air is not sucked in, and at this time, the filtration of treated water is stopped and does not operate.

[0055] Microorganisms are attached to the surface of the hollow fiber membrane (13) installed in the separation membrane module (10) while the separation membrane module (10) is used as a carrier and the treated water is not filtered.

[0056] With microorganisms attached to the hollow fiber membrane (13), oxygen is supplied into the membrane module (10) through the oxygen supply inlet pipe (30), and the supplied oxygen is supplied through the surface of the hollow fiber membrane (13) installed in the membrane module (10), thereby activating the microorganisms.

[0057] After supplying oxygen so that the microorganisms attached to the surface of the hollow fiber membrane (13) become active, the oxygen supply through the oxygen supply inlet pipe (30) is stopped to filter the treated water through the separation membrane module (10).

[0058] With the oxygen supply through the oxygen supply inlet pipe stopped, the treated water is sucked in through the suction outlet pipe (20) to allow filtration of the treated water through the hollow fiber membrane (13).

[0059] That is, in order to use the membrane module (10) as a carrier, the suction through the suction outlet pipe (20) is stopped, and oxygen is supplied into the membrane module (10) through the oxygen supply inlet pipe (30) to activate the microorganisms attached to the hollow fiber membrane (13). In order to allow the treated water to be filtered through the membrane module (10), the oxygen supply through the oxygen supply inlet pipe (30) is stopped, and suction is allowed through the suction outlet pipe (20) so that the treated water can be filtered through the hollow fiber membrane (13).

[0061] Although specific embodiments have been described in the foregoing description of the present invention, various modifications may be made without departing from the scope of the present invention. Accordingly, the scope of the present invention should not be determined by the described embodiments but by the claims and equivalents thereof. Explanation of the symbols

[0063] (10)-- Separator module (11)-- Top cover (12)-- Lower cover (13)-- Hollow fiber membrane (14)-- band section (15)-- microbial attachment section (20)-- Suction outlet pipe (30)-- Oxygen supply inlet pipe (40)-- Vortex diffuser (41)-- Air supply pipe (100)-- Bioreactor (110)-- air pipe

Claims

Claim 1 A sewage treatment advanced treatment device using an immersed hollow fiber membrane, characterized by comprising: a separation membrane module (10) installed so as to be immersed in a biological reactor (100) of a water treatment facility, wherein a hollow fiber membrane (13) is installed between an upper cover (11) and a lower cover (12) to filter the treated water through a suction outlet pipe (20); and an oxygen supply inlet pipe (30) that allows oxygen to be introduced through the hollow fiber membrane (13) installed in the separation membrane module (10) so as to activate the microorganisms attached to the surface of the hollow fiber membrane (13), thereby activating the microorganisms. Claim 2 A nitrogen removal and advanced treatment device for sewage using an immersed hollow fiber membrane for sewage treatment, characterized in that, in the first paragraph, a vortex diffuser (40) is configured at the bottom of the membrane module (10) to remove foreign substances adhering to the surface of the hollow fiber membrane (13) during the filtration of treated water by the hollow fiber membrane (13), thereby reducing the number of times the membrane module (10) is washed and allowing the treated water to be filtered smoothly. Claim 3 A nitrogen removal and advanced treatment device for sewage using an immersed hollow fiber membrane for sewage treatment, characterized in that, in claim 1, an air pipe (110) for oxygen supply is installed on the inner side of the bioreactor (100). Claim 4 A nitrogen removal and advanced treatment device for sewage using an immersed hollow fiber membrane for sewage treatment, characterized in that, in claim 1, the hollow fiber membrane is composed of PTFE (Polytetrafluoroethylene) material. Claim 5 A method for advanced treatment of sewage, characterized by comprising the steps of: installing an immersed separation membrane module in which a hollow fiber membrane (13) is connected and installed between an upper cover (11) and a lower cover (12) within a biological reactor (100); stopping the suction of a suction outlet pipe (20) for filtration of treated water by connecting and installing the separation membrane module (10); using the separation membrane module (10) as a carrier to allow microorganisms to attach to the surface of the hollow fiber membrane (13); supplying oxygen into the separation membrane module (10) through an oxygen supply inlet pipe (30); supplying oxygen to the surface of the hollow fiber membrane (13) to activate microorganisms; stopping the oxygen supply through the oxygen supply inlet pipe (30) to filter the treated water; and sucking the treated water through the suction outlet pipe (20) while the oxygen supply through the oxygen supply inlet pipe (30) is stopped so that it is filtered through the hollow fiber membrane (13). Nitrogen removal and advanced wastewater treatment method using immersed hollow fiber membranes.

Images