KR101072530B1 - Membrane Coupled Fluidized-Bed Sequencing Batch Reactor - Google Patents

Abstract

The present invention is installed in the bottom of the reactor diffuser for supplying air into the reactor; Immersion type membrane module formed on the top of the diffuser; A baffle for inducing the flow of fluid in the reactor; And it relates to a membrane-bound continuous batch reactor comprising a fluid medium flowing with the air generated in the diffuser and removes the membrane fouling material attached to the surface of the immersion membrane. The present invention is a new type of hybrid reactor technology in which a fluidized medium is added to a membrane-bound continuous batch reactor used in an advanced wastewater treatment method, and more efficiently removes organic substances and nutrients contained in sewage / wastewater. At the same time, there is an advantage that the operation and maintenance costs of the advanced treatment apparatus can be lowered by reducing the contamination of the membrane and extending the membrane replacement and membrane cleaning cycles.

Reactor, wastewater treatment

Description

Membrane Coupled Fluidized-Bed Sequencing Batch Reactor

The present invention relates to a membrane-bound continuous batch reactor for removing contaminants from sewage / wastewater.

In the past, sewage / wastewater treatment (hereinafter, simply referred to as 'wastewater') was mainly concerned with the removal of organic matter and suspended solids, but recently, at home and abroad, various wastewater treatment facilities, including urban and agricultural sewage, have been treated with nitrogen and phosphorus. It is focused on eliminating nutrients. If discharged without removing nutrients, it accelerates eutrophication, lowering the value of valuable water resources and damaging ecosystems.

The biological treatment process for removing nutrients such as nitrogen and phosphorus from wastewater is generally composed of a combination of anoxic stage, anaerobic stage, aerobic stage and precipitation stage. Various advanced treatment methods with different driving methods are applied.

Briefly, these methods are as follows.

SBR (Sequencing Batch Reactor) is a process that operates anaerobic, anaerobic, aerobic and sedimentation step by step in one reactor. It does not need a separate reactor step by step, reducing the required area of wastewater treatment plant. In addition to being able to operate, it has the advantage of being able to operate flexibly according to the characteristics of the sewage. However, the method also has a disadvantage in that the sludge is caused by sludge bulking and pin flop due to the deterioration of microorganisms during the discharge after precipitation, and is discharged together with the discharged water, thereby deteriorating the water quality.

Membrane-coupled bioreactor (MBR) combines the advantages of membrane technology with the general activated sludge process to completely remove not only organic materials but also bacteria and viruses. It has been recognized as the most noticeable and reliable technology in the field.

The membrane-bound bioreactor may be divided into a cross flow type and a submerged type according to a driving method. The cross flow method is a method of obtaining a treated water by circulating a microbial mixed solution through a circulating pump and filtration of the microbial mixture into a membrane module, and the immersion type method is installed through a suction type filtration by a pressure reducing pump by installing a separator inside an aeration tank of activated sludge. This is a method of obtaining treated water. The immersion type method has been applied to the sewage treatment steadily because it is possible to achieve a perfect solid-liquid separation and ensure a stable treatment water.

 However, membrane-bound bioreactors, despite their many advantages, are being pointed out as a limiting factor in their widespread use in wastewater treatment. In general, the life of the separator is shortened due to membrane fouling phenomenon. Therefore, in order to prevent membrane fouling, the surface of the membrane should be periodically cleaned, or backwashing into the membrane pores should remove the contaminants attached to the pores to restore the flux. This washing is performed only with the filtered water or by mixing the cleaning water, such as acid, alkali or organic and inorganic detergents.

Membrane-coupled sequencing batch reactor (MSBR) replaces sedimentation stage and discharge stage with membrane filtration in a continuous batch reaction process that processes wastewater through inflow, reaction, precipitation, discharge and maintenance. In one process, it is a kind of the membrane-bound bioreactor.

In the case of a continuous batch reactor, sludge does not flow out into the effluent when the sludge is perfectly settled, but when the microorganism deteriorates, sludge outflow occurs in the discharged water, and thus an additional filtration device is required.

Therefore, when the membrane-bound continuous batch reactor is used, sludge filtration and pathogenic microorganisms can be almost completely removed by using a separation membrane to overcome the limitations of the continuous batch reaction process, and to be active in the conventional continuous batch reaction process. Although the settling time was required to settle the sludge and discharge the treated water, it is possible to shorten the operation time of the continuous batch reaction process because the precipitation step can be omitted by using the membrane-type continuous batch reactor. There is an advantage to that.

1 is a schematic view showing a conventional membrane-bound continuous batch reactor. As shown in the figure, it is located in the diffuser under the separator, oxygen is supplied through the diffuser and the membrane can be used to remove sludge filtration and pathogenic microorganisms.

However, the membrane-bound continuous batch reaction process having the above-mentioned advantages, like the membrane-bound bioreaction process, still has problems of membrane fouling and pore blocking.

In other words, this is because the production rate of the effluent due to the cake layer developed on the surface of the separator, that is, the flux is reduced. In order to produce stable treated water (or to maintain a constant flux), membrane fouling is required by periodic washing of the membrane, which increases the operation and maintenance costs of the membrane-bound continuous batch reaction process. Acts as.

The present invention relates to a hybrid reactor in which a fluid medium is added to a membrane-bound continuous batch reactor in order to more efficiently remove organic matter and nutrients contained in wastewater. The purpose of the present invention is to provide a membrane-bound continuous batch reactor that extends membrane replacement and membrane cleaning cycles by removing membrane contaminants attached to the membrane surface while reducing the contamination of the membrane.

According to one embodiment of the invention

An diffuser installed at the bottom of the reactor to supply air into the reactor;

Immersion type membrane module formed on the top of the diffuser;

A baffle for inducing the flow of fluid in the reactor; And

Flow media that flows with the air generated from the diffuser and removes membrane contaminants attached to the surface of the immersion type membrane

It provides a membrane-bound continuous batch reactor comprising a.

The membrane-bound continuous batch reactor according to the present invention can increase the concentration of microorganisms with low non-proliferation rate, such as nitrifying bacteria, by using a fluidized medium, and produces less excess sludge than the activated sludge method and is applied to low concentration organic sewage. In addition, the air bubble supplied through the diffuser causes an upward flow between the submerged membrane module and the baffle, causing the flow media to move with the air bubbles, thereby removing membrane contaminants attached to the membrane surface. It is possible to control the membrane fouling effect.

Specific details of other embodiments are included in the detailed description and drawings. Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 2 is a schematic diagram showing a membrane-bound continuous batch reactor according to the present invention.

The present invention is a membrane-bound continuous batch reactor 100, which includes an diffuser 103, an immersion membrane module 102, a baffle plate 104 and a fluid media 105.

The diffuser 103 serves to supply air into the reactor 100. The diffuser 103 is installed below the reactor 100 and is connected to the air pump 40 to supply air generated in the air pump into the reactor.

The submerged membrane module 102 serves to filter out fine particles (pollutants, microorganisms, etc.) in the reactor 100.

The immersion membrane module may be an immersion membrane module having a membrane in the form of hollow fiber, tubular or flat membrane, preferably a membrane in the form of a flat membrane.

When the immersion type membrane module is a separator in the form of a flat membrane, the separator is preferably a MF (micro filtration) membrane having a pore diameter of 0.01 μm to 0.5 μm.

The baffle plate 104 is such that the fluid in the reactor to create a constant flow of the flow after the upflow between the immersion membrane module 102 and the baffle plate 104 by the air supplied from the diffuser 103 Induces a role The baffle plate 104 is located on both sides of the immersion type membrane module 102.

Figure 2 is a schematic diagram showing an example of a membrane-bound continuous batch reactor according to the present invention, the present invention is not limited to this, a large number of submerged membrane module 102 and the baffle plate 104 as needed in the workplace This can be formed alternately. The number of the submerged membrane module 102 and the baffle plate 104 may be adjusted according to the size of the business place.

In the present invention, "fluid media" means a carrier flowing in the reactor.

The flow medium 105 flows together with the carrier and the air generated from the diffuser 103 where microorganisms can inhabit and removes membrane fouling substances attached to the surface of the immersion type separation membrane 102.

The fluid media (105) is preferably formed with pores to inhabit microorganisms having a multi-surface area, activated carbon, plastic (PVA), ceramics, sodium alginate, zeolite, bentonite, shells and polyurethane It may be made of a material containing at least one selected from the group consisting of.

In the membrane-bound continuous batch reactor of the present invention, when a polyurethane-based fluid medium is used, it has a porosity of 95% or more and a density of 0.035 to 0.040 g / cm³. When growing, the density of the flowing media is preferably 0.95 to 1.05 g / cm 3, but is not limited thereto.

In addition, the flow media may vary in size depending on the distance between the membrane module and the baffle plate, and is well circulated by the upward flow to remove the membrane contaminants attached to the surface of the immersed membrane, 2 mm to 20 mm long, and 2 mm. It is preferable to have a diameter of 20mm, it is preferable to have a pellet form, hexahedral, elliptical form or circular shape so as not to damage the material of the separator when contacted with the separator, but is not limited thereto.

The membrane-bound continuous batch reactor 100 of the present invention includes a flow medium 105 having the above characteristics in the reactor, so that air bubbles are immersed through the diffuser 103 and the baffle plate 104. If an upflow occurs between), the activated sludge and the flowing media move along the upflow to remove the membrane contaminants attached to the membrane surface. Therefore, due to the continuous removal of the membrane fouling material, it is possible to extend the membrane replacement and membrane cleaning cycles, and to reduce the operation and maintenance costs of the membrane-bound continuous batch reaction process.

In an aspect of the present invention, the present invention may further include an agitator 101 in addition to the diffuser 103, the submerged membrane module 102, the baffle plate 104, and the fluid media 105.

The stirrer 101 serves to stir the raw water introduced into the reactor 100. The stirrer 101 is installed above the reactor 100 and is driven by the stirring motor 30.

3 is a cross-sectional view taken along line AA ′ of FIG. 2, and shows the state in which the submerged membrane module 102 and the baffle plate 104 according to the present invention are mounted inside the reactor.

According to FIG. 3, a fixing part 120 fixing both ends of the immersion type membrane module 102 and the baffle plate 104 is provided in a case 110 forming an outer wall of the reactor, and the fixing part 120 is Grooves 121-1a, 121-1b, 121-2a, 121-2b, 122a, and 122b are formed, and both ends of the submerged membrane module 102 and the baffle plate 104 are slid.

Figure 4 is a schematic diagram showing a wastewater treatment system using a membrane-bound continuous batch reactor of the present invention.

Referring to Figure 4 in detail, the raw water supply unit is supplied to the raw water in the raw water tank 10 into the membrane-bound continuous batch reactor 100 by the raw water inlet pump 20; A stirrer which is driven by the stirring motor 30 and stirred by the raw water introduced into the reactor 100 for the anaerobic reaction; An air supply unit for supplying air through the diffuser by the air pump 40; A suction unit for separating the suspended solids and permeated water by the separation membrane in the membrane-bound continuous batch reactor 100 by the suction pump 50 connected to the immersion separation membrane to obtain treated water; A controller in which the raw water inflow pump 20, the stirring motor 30, the air pump 40, and the suction pump 50 are controlled by a programmable logical controller (PLC); And a measuring unit for monitoring the pressure generated by the suction pump 50 and the flow rate of the treated water by the computer 70.

When the wastewater is treated using the membrane-bound continuous batch reactor 100 of the present invention, (a) the raw water in the raw water tank is supplied to the membrane-bound continuous batch reactor by the raw water inlet pump; (b) proceeding with denitrification and dephosphorization using microorganisms under anaerobic conditions; (c) circulating the activated sludge and the flowing media in the reactor along the upward flow when air bubbles are caused by the diffuser to continuously raise the airflow between the submerged membrane module and the baffle through the diffuser. ; (d) progressing nitrification and organic oxidation using microorganisms under aerobic conditions; And (e) wastewater is treated through the step of discharging the treated water from which organic matter and nutrients are removed using the immersion membrane.

In the step (c), as the activated sludge and the flowing media moves along the upward flow, the membrane fouling material attached to the membrane surface is removed.

Figure 5 shows the raw water inflow, anaerobic reaction, aerobic reaction and inhaled treated water in each step in the membrane-bound continuous batch reactor of the present invention. In step (1), the raw water in the raw water tank is introduced by the raw water inflow pump, and the stirrer is operated to disperse the raw water into the entire membrane-bound continuous batch reactor. In step (2), there is no more inflow of raw water, and the stirrer is operated in anaerobic state to continuously disperse the raw water throughout the membrane-bound continuous batch reactor, and proceed with denitrification and dephosphorization using microorganisms under anaerobic conditions. In the step (3), continuous aeration by the diffuser causes air bubbles through the diffuser to create an upward flow between the immersion membrane module and the baffle plate, and the active sludge and the active media inside the fluidized media reactor Sludge and flowing media are circulated. At this time, the nitrification process and the organic matter oxidation process are carried out using microorganisms under aerobic conditions. In step (4), the treated water from which the particulate matter and the microorganism are completely removed is discharged through the immersion membrane module.

Figure 6 shows the change in pressure drop per permeate flow rate with time of the membrane-bound continuous batch reactor according to the present invention and the conventional membrane-bound continuous batch reactor. As the permeate flow rate was changed to 20 LMH (unit time, membrane filtration water per unit membrane area: L / m²-hr), 25 LMH and 30 LMH, the membrane-bound continuous batch reactor according to the present invention was operated for a long time. The pressure drop change was found to be insignificant. Through this, the membrane-bound continuous batch reactor according to the present invention was found to effectively control the membrane fouling material attached to the membrane surface.

1 is a schematic diagram showing a conventional membrane-bound continuous batch reactor.

Figure 2 is a schematic diagram showing a membrane-bound continuous batch reactor according to the present invention.

3 is a cross-sectional view taken along line AA ′ of FIG. 2.

Figure 4 is a schematic diagram showing a wastewater treatment system using a membrane-bound continuous batch reactor of the present invention.

Figure 5 shows the raw water inflow, anaerobic reaction, aerobic reaction and inhaled treated water in each step in the membrane-bound continuous batch reactor of the present invention.

Figure 6 shows the change of pressure drop per permeate flow rate with time of the membrane-bound continuous batch reactor and the conventional membrane-bound continuous batch reactor according to the present invention.

<Description of the symbols for the main parts of the drawings>

10: raw water tank

20: raw water inlet pump

30: stirring motor

40: air pump

50: suction pump

60: programmable logical controller

70: monitoring computer

80: digital pressure gauge

90: electronic balance

100, 200: reactor

101: stirrer

102, 202: Immersion type membrane module

103, 203: diffuser

104: baffle

105: floating media

205: air bubbles

110: case

120: fixed part

121-1a, 121-1b, 121-2a, 121-2b, 122a, 122b: fitting groove

Claims (5)

An diffuser installed at the bottom of the reactor to supply air into the reactor; Immersion type membrane module formed on the top of the diffuser; A baffle to induce the flow of fluid in the reactor and located on both sides of the membrane module; And Flow media that flows with the air generated from the diffuser and removes membrane contaminants attached to the surface of the immersion type membrane Membrane-bound continuous batch reactor comprising a. The method of claim 1, Membrane-bound continuous batch reactor characterized in that it further comprises a stirrer installed on the reactor to agitate the raw water. The method of claim 1, The submerged membrane module is a membrane-bound continuous batch reactor having a membrane in the form of a flat membrane. The method of claim 1, The flow medium is a membrane-bound continuous batch reactor, characterized in that having a length and diameter of 2mm to 20mm. The method of claim 1, Membrane-bound continuous batch reactor, characterized in that the fluid medium has a polyurethane material.

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