KR101701215B1 - Polluted river-water purification system - Google Patents

Abstract

Disclosed is a river water purification system capable of increasing available time of the river water purification system by preventing clogging of a separation film. According to the present invention, the polluted river water purification system comprises the following steps: separating raw sludge of initial river water flowing in through a primary settling tank; discharging phosphorous and removing organic matters of the river water through an anaerobic tank; denitrifying the river water and removing the organic matters through an anoxic tank; performing denitrification of the river water and oxidation of the organic matters through an aerobic tank; separating surplus sludge through a secondary settling tank; and converting sludge, transferred from the primary settling tank and the secondary settling tank, into sludge cake through a concentrating and dehydrating facility.

Description

Polluted river-water purification system [0002]

The present invention relates to a purification system, and more particularly, to a polluted river water purification system for purifying polluted river water by installing the polluted river water in a river or a lake to treat sludge or suspended matter contained in polluted river water.

Generally, the rivers themselves operate at midnight. The self-purification process is caused by the decomposition of contaminants by microorganisms, the adsorption and precipitation of particulate pollutants in the process of flowing river water. However, since a considerable distant distance is required to exert the function of the midnight effect, there is a limit to purify the contaminated river water by virtue of the substantially midnight action.

Accordingly, it is known to purify polluted river water by using various methods, and it is known that a hollow fiber membrane (abbreviated as a 'submerged membrane' - membrane) as a purification method is provided in an aerobic tank and is washed by a natural submerged method have.

However, when such a membrane is used, clogging of the membrane due to microbial or foreign matter adherence may occur, which has a problem that it acts as a factor that greatly affects the operation of the membrane process and the lifetime of the membrane. If the separation membrane is contaminated, it is necessary to periodically clean the separation membrane by using air, water, or water containing a small amount of chemical to remove the materials that trap the pores of the separation membrane, or to convert the separation membrane into another separation membrane .

However, in such a case, there are problems such as an increase in manpower and maintenance cost for washing, an increase in the area of the site, and an increase in the burden on the converted membrane.

In order to solve this problem, aeration means for injecting air into an aerobic tank equipped with a separation membrane is provided to supply particles in the form of powder to the separation tank, A method of reducing the clogging of the separation membrane by colliding with the separation membrane due to the influence of the supplied air has been considered.

However, this method has the effect of reducing the clogging of the separation membrane. However, when the size of the aerobic tank is large, since the particles are in a fine powder form, they are not circulated smoothly in the aerobic tank, (Circulation through recovery), it is difficult to continuously supply a large amount of powdery particles continuously or periodically. In addition, powdered activated carbon is used as the particles to be used. However, the activated carbon has a higher cost than the conventional activated carbon because it is made of natural materials such as wood, lignite, and coal.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a contaminated river water purification system capable of increasing the usable time of a river water purification system by preventing clogging of a separation membrane.

According to the present invention, there is provided a contaminated river water purification system for purifying contaminated river water, comprising: separating raw sludge of initial river water introduced through a primary settler; Removing phosphorus release and organic matter from the stream water through an anaerobic tank; Denitrifying the river water and removing organic matter through an anoxic tank; Performing nitrification of the river water and oxidation of organic matter through an aerobic tank; Separating surplus sludge through a second settling tank; And a sludge thickening / dehydrating step of converting the sludge transferred from the primary settling tank and the secondary settling tank into a sludge cake through a condensation / dehydration facility, wherein the aeration tank is provided with aeration means for injecting air into the aerobic tank, And a membrane for solid-liquid separation of the stream water that has passed through the aerobic basin, and an aerobic separating membrane module for circulating the river water supplied to the aerobic tank within the aerobic tank, and capable of vertically moving from the bottom of the aerobic tank to the outside of the water surface A circulation pump for circulating the water in the aerobic tank with the river water by the aeration means and the fluid circulation device, Compressed activated carbon impinging on the compressed activated carbon, Wherein the fluid circulation device includes a crane installed on the outside of the oxic tank, a driving part formed on the crane boom, a guide rail installed along the inner wall of the oxic tank, A transverse mixer coupled to the moving rail; and a controller coupled to the transverse mixer and the driving unit to move the transverse mixer underwater by driving the driving unit, And circulating the compressed activated carbon in the aerobic tank.

At this time, the compressed activated carbon is formed to have a size of 3 mm to 5 mm, and is manufactured using waste materials generated from agricultural and forestry industries such as rice hull, sawdust, and bark.

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According to the present invention, the granular activated carbon is circulated in the aerobic tank to increase the period of washing the separation membrane, thereby minimizing clogging of the separation membrane, thereby prolonging the service life of the separation membrane.

In addition, the amount of heat generated from the sludge produced through the river water purification system can be increased to increase the biofuel utilization, thereby enabling the revitalization of the related industries and improving the profitability of the operators.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic processing diagram for explaining a contaminated stream water purification system according to the present invention. FIG.
2 is a conceptual diagram of an aerobic tank according to the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, and specific details for carrying out the present invention will be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic processing diagram for explaining a contaminated stream water purification system according to the present invention. FIG. 2 is a conceptual diagram of an aerobic tank according to the present invention.

1 and 2, the river water purification system according to the present embodiment includes an anaerobic tank 20, an anoxic tank 30, an oxic tank 40, a secondary settler 30, 50, and a sludge concentration and dewatering facility 60. The filtration tank, the disinfection tank, the discharge water passage, the deodorization facility, the river water sludge storage tank, and the like for filtering the river water through the secondary settler 50 One, this is a generally applicable facility and is omitted for convenience of the city.

The primary settling basin 10 is settled (raw sludge) of the first floater of the river water.

In the anaerobic tank (20), phosphorus emission and organic matter removal are performed in the river water.

In the anoxic tank 30, denitrification and organic matter removal are performed.

The aerobic tank 40 is maintained in an aerobic state by the aeration means 41, and nitrification and oxidation of organic matter are performed. In addition, an immersion separation membrane module 43 is disposed in the oxic tank 40 to perform solid-liquid separation of the river water.

The secondary settling basin (50) is settled (surplus sludge) of surplus suspended substances remaining in the river water through the aerobic tank (40).

The sludge concentration and dewatering facility 60 performs a sludge treatment process for forming a dewatering cake by concentrating and dewatering the sludge (suspended matter) settled in the primary and secondary settling basins 10 and 50.

Specifically, the steps of treating the river water by the primary clarifier 10, the anaerobic tank 20, the anoxic tank 30, the oxic tank 40, and the secondary settler 50 are the same as those used in the conventional river water treatment Therefore, the description of the substance, the reaction formula, and the like in the treatment process will be omitted.

In order to maintain the MLSS of the process constant, the nitrifying nitrate nitrogen in the oxic tank 30 is transferred to the anoxic tank 30 (inner transfer) To the anaerobic tank 20 (outwardly transported). Pipes and pumps for external transfer and internal transfer relate to generally applicable configurations and are thus omitted or simplified in FIG. 1 for ease of illustration.

The present invention will be described mainly with reference to the oxic tank 40 as it has technical features related to the oxic tank 40. [

The aeration means 41 formed in the oxic tank 40 injects air into the oxic tank 40 to make the inside of the oxic tank 40 aerobic and the air bubbles are sucked into the sucker separator module 43 of the oxic tank 40 The clogging of the membrane is minimized by causing it to collide with the membrane.

The activated carbon supplying means 42 supplies granular activated carbon which may collide with the membrane of the submerged membrane module 43 together with the air injected by the aeration means 41.

In this embodiment, compressed activated carbon is used as the granular activated carbon. It has a diameter of about 3 to 5 mm, not a particle close to the powder, and most importantly, it should have a specific gravity similar to that of water. That is, the granular activated carbon has a specific gravity corresponding to the specific gravity of water, and it may be preferable to apply the compressed activated charcoal so as to have a size of 3 to 5 mm.

If the size of the granular activated carbon is smaller than 3 mm, it is difficult to compress and mold the granular activated carbon so as to have a specific gravity corresponding to the specific gravity of water. When the granular activated carbon is 5 mm or more, The efficiency is lowered and the price of activated carbon is increased.

In addition, the granular activated carbon is manufactured in spherical form using waste materials generated from agricultural and forest industries such as rice hull, sawdust, and bark, and can significantly lower the cost of the activated carbon compared to existing activated carbon produced from natural materials .

The amount of the granular activated carbon supplied by the activated carbon supplying means 42 is determined based on the volume of the aerobic tank 40 and the weight of the sludge amount in the entire process. The degree of clogging of the separation membrane or the initial granular activated carbon It can be additionally supplied depending on the amount of activated carbon debris collected separately.

The aerobic tank 40 may further include a fluid circulation device 44. The fluid circulating device 44 circulates the river water in the oxic tank 40 together with the aeration means 41 so that the granular activated carbon can be circulated together with the circulation of the river water. The fluid circulating device 44 includes a crane boom 44a, a driving portion 44b, a guide rail 44c, a moving rail 44d, a horizontal underwater mixer 44e, and a wire 44f.

The crane boom 44a is a support for supporting the horizontal underwater mixer 44e and is installed outside the aerobic tank 40. [ At this time, the crane boom 44a is divided into an upper boom 44a-1 and a lower boom 44a-2. The upper boom 44a-1 is formed in a multi- 44a-2 may be formed so that the bottom surface is fixed to the ground, and the lower end is rotatable 360 degrees. The crane boom 44a having such a structure can be easily operated in the installation, repair, maintenance, and replacement work of the underwater mixer 44e in the aerobic tank 40 in the underwater mixer 44e.

The driving unit 44b is formed in the crane boom 44a and can be constituted by a transmission device such as a winch motor, and a wire 44f is wound around the winch motor.

The guide rails 44c and the movable rails 44d are installed in the oxic tank 40. The guide rails 44c are vertically installed and fixed in the oxic tank 40. The movable rails 44d, And is formed on the rail 44c. At this time, the guide rail 44c is formed with polygonal (EX: hexagonal) columns in cross section, and the movable rail 44d is also formed into a polygon corresponding to the shape of the guide rail 44c. Further, the movable rail 44d is slidable along the guide rail 44c, and a horizontal underwater mixer 44e is fixedly installed. The guide rail 44c and the movable rail 44d can be vertically moved smoothly when the movable rail 44d fixed with the horizontal underwater mixer 44e is slid in the vertical direction along the guide rail 44c At the same time, horizontal (lateral) movement is prevented so that the underwater transverse mixer 44e can maintain the impeller direction of the underwater mixer 44e constantly at all times during vertical movement.

The underwater horizontal mixer 44e has an integral structure of an electric motor and an impeller and serves to direct the flow of the river water toward the center side by driving in the oxic tank 40. [ The wire 44f is connected to the underwater mixer 44e and can be moved to the outside of the oxic tank 40 by vertically moving along the guide rail 44c according to the degree of winding of the wire 44f.

Such a fluid circulation device 44 is formed in pairs in mutually symmetrical positions in the oxic tank 40 so that the flow direction of the river water in the aerobic tank 40 is converged to the center side so that granular activated carbon is continuously collided with the submerged membrane module 43 The river water can be circulated.

In addition, since the horizontal mixer 44e of the fluid circulation apparatus 44 is appropriately moved from the bottom surface of the oxic tank 40 to the outside of the water surface, it is possible to adjust the position (height), thereby facilitating maintenance and replacement, Depending on the amount of incoming stream water, a suitable swirl flow can be generated. Further, even in the winter season, when the amount of the river water flowing into the oxic tank 40 is small and the river water (or the water surface side point) in the oxic tank 40 is frozen, the underwater horizontal mixer 40e is positioned closer to the water surface It is possible to prevent the freezing of the influx of the river water by strengthening the flowing of the river water by making the transversely horizontal mixer 40e move in the predetermined direction in the water surface direction rather than placing the underwater horizontal mixer 40e on the water surface. In addition, the predetermined heat radiating from the underwater horizontal mixer 44e can also help prevent freezing on the water surface side of the oxic tank 40.

The aerobic tank according to the embodiment of the present invention may be constituted by activated carbon collecting units 45a and 45b for collecting the activated carbon debris 46 suspended therein. The activated carbon collecting units 45a and 45b collect the activated carbon debris 46 floated on the water surface of the oxic tank 40 and are formed in the 'b' shape along the wall of the oxic tank 40 having a height similar to that of the water surface An activated carbon conveyance pipe 45b for conveying the activated carbon debris 46 collected at a predetermined point of the collecting frame 45a together with a small amount of river water existing in the collecting frame 45a is connected to the collecting frame 45a.

The particulate activated carbon supplied to the aerobic tank 40 of the present invention has a specific gravity similar to that of water in a size of 3 to 5 mm, The residual debris (material generated from activated carbon such as sculpture, powder, etc.) is generated in the process of circulating the activated carbon. The suspended activated carbon debris 46 is also drifted along the aerobic tank wall by the circulating flow of the river water. Activated carbon debris 46 collected by the activated carbon collection units 45a and 45b is sent to the sludge concentration and dehydration facility 60 where it is concentrated and dehydrated It is possible to obtain an effect of increasing the heat quantity (energy density) of the biofuel produced from the final sludge cake by mixing with the entire sludge.

Hereinafter, the river water purification process using the river water purification system described above will be described.

The contaminated river water purification system according to the present invention is characterized in that the primary settling tank 10, the anaerobic tank 20, the anoxic tank 30, the oxic tank 40 secondary settlement tank 50 and the sludge concentration and dehydration facility 60 shown in FIG. And air is injected into the aerobic oxic tank 40 by the aeration means 41 and the solid-liquid separation by the submerged membrane module 43 can be performed.

The method of purifying the river water by the primary settling tank 10, the anaerobic tank 20, the anoxic tank 30 and the secondary settling tank 50 can be applied to a conventional river water purification facility, And only the treatment method by the aerobic tank 40 and the sludge concentration and dewatering facility 60, which is a characteristic feature of the present invention, will be described.

The river water that has passed through the primary settling tank 10, the anaerobic tank 20 and the anoxic tank 30 is supplied to the oxic tank and the granular activated carbon is supplied to the oxic tank 40 together with the air by the aeration means 41. The granular activated carbon is supplied with compressed activated carbon which can be struck against the membrane of the submerged membrane module 43 together with the air injected by the aeration means 41. Specifically, the activated carbon is 3 to 5 mm in size, And has a corresponding weight.

The amount of particulate activated carbon supplied to the oxic tank 40 is determined on the basis of the volume of the oxic tank 40 and the weight of the sludge amount in the entire process and is determined according to the degree of clogging of the separation membrane or the activated carbon debris 46 to be collected Can supply.

The granular activated carbon supplied to the inside of the oxic tank 40 is circulated in the oxic tank 40 by the aeration means 41 and the fluid circulation device 44 and is separated (tared) from the granular activated carbon during circulation, The activated carbon debris 46 is collected in the activated carbon collection units 45a and 45b. The collected activated carbon debris 46 is transferred to the sludge concentration and dewatering facility 60 through the activated carbon conveying pipe 45b together with some river water present in the collecting section and is conveyed from the primary clarifier 10 existing in the concentrating and dehydrating facility After mixing with the sludge, the sludge cake is mixed with the activated carbon by the dehydration process.

The sludge settled in the secondary settling tank 50 is also transferred to the concentrated dewatering facility 60, and the sludge transferred from the secondary settling tank 50 may partially contain granular activated carbon. This also forms a sludge cake mixed with activated sludge mixed with sludge transferred from the primary sedimentation tank 10 and subjected to a concentration and dehydration process.

As described above, the river water purification method can extend the service life of the separation membrane by minimizing the clogging of the separation membrane by circulating the granular activated carbon in the aerobic tank to increase the separation membrane cleaning cycle.

In addition, the sludge of the activated sludge collected in the aerobic tank and the sludge of the secondary sludge containing some activated carbon are included in the final concentrated sludge dewatering sludge, thereby increasing the energy density of the sludge cake and increasing the biofuel utilization.

While the present invention has been particularly shown and described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, And its operating method.

10: primary sedimentation tank 20: anaerobic tank
30: anoxic tank 40: aerobic tank
41: aeration means 42: activated carbon supply means
43: Deposition membrane module 44: fluid circulation device
45: Activated carbon collection part 46: Activated carbon debris
50: Second settling basin 60: Sludge concentration and dehydration facility

Claims (5)

A stream water purification system for purifying contaminated river water,
Separating the raw sludge of the initial stream water flowing through the primary settling tank;
Removing phosphorus release and organic matter from the stream water through an anaerobic tank;
Denitrifying the river water and removing organic matter through an anoxic tank;
Performing nitrification of the river water and oxidation of organic matter through an aerobic tank;
Separating surplus sludge through a second settling tank; And
And a sludge concentration and dehydration step of converting the sludge transferred from the primary settling tank and the secondary settling tank into a sludge cake through a concentrating and dehydrating facility,
In the oxic tank,
An immersion separation membrane module located at the center of the aerobic tank and including a membrane for solid-liquid separation of the stream water that has passed through the aerobic tank;
Aeration means for injecting air into the oxic tank; aeration means formed in a vertical lower portion of the submerged membrane module at the center side of the oxic tank;
Wherein the aerobic tank is provided at both sides of the inner wall of the aerobic tank with the aeration means therebetween so as to be vertically movable from the bottom of the aerobic tank to the outside of the water surface along the inner wall of the aerobic tank to circulate the stream water containing the compressed activated carbon in the aerobic tank, A strong upward convection flow is generated in the lower part of the submerged membrane module together with the air injected from the aeration unit by converging to the center of the aerobic tank where the aeration unit is located so that the impact force of the compressed activated carbon is increased in the submerged membrane module A pair of fluid circulation devices for generating a flow flow so that the water side water stream converges from the center side to the oxic tank wall side,
Compressed activated carbon which is supplied into the oxic tank and is made of compressed activated carbon having a specific gravity corresponding to water and which collides with the submerged separation membrane while circulating with the river water in the aerobic tank by the aeration means and the fluid circulation means,
Activated carbon supply means for supplying the compressed activated carbon to the aerobic tank, and
And an activated carbon trapping section for trapping compressed activated carbon debris floating on the water surface,
The fluid circulating device includes:
A lower boom which is installed outside the cockpit and is vertically formed and has a lower side fixed to the ground and a lower end rotatable by 360 degrees; a lower boom connected to an upper end of the lower boom and formed in a multi- A crane that is divided into an upper boom capable of adjusting the angle by rotating the connection point between the lower boom and the lower boom by a rotation point,
A drive unit formed on the crane boom,
A guide rail installed along the inner wall of the oxic tank;
A moving rail formed in a polygonal shape so as to be slidable in association with the guide rail;
An underwater horizontal mixer coupled to the moving rail, and
And a wire connected to the transverse mixer and the driving unit for moving the transverse mixer in the vertical direction by driving the driving unit,
The activated carbon collector
A collecting frame having an 'a' type structure formed along the wall of the oxic tank and having a height of water surface of the oxic tank, the debris of the compressed activated carbon floating on the water surface without being circulated through the oxic tank,
And an activated carbon transportation pipe for supplying activated carbon dust collected at a predetermined location of the collection frame to the sludge concentration and dehydration facility so that the amount of the biofuel produced from the sludge cake can be increased by mixing with the sludge cake, And the polluted river water purification system. The method according to claim 1,
Wherein the compressed activated carbon is formed in a size of 3 mm to 5 mm and is manufactured using waste materials generated from agricultural and forestry industries such as rice hull, sawdust, and bark.
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