KR101686484B1 - Method of sewage treatment - Google Patents

Abstract

The present invention discloses a sewage treatment method. The sewage treatment method according to the present invention collects the impurities and sediments contained in the sewage introduced into the geyser by using at least one of a traveling type automatic silencer, a screen, a fine-grain screen, and a desinformer, A sedimentation process in which an object is transferred to a storage container formed on an upper portion of the sedimentation unit with an air pressure conveyor; A primary precipitation step of precipitating and separating solid organic matters contained in the sewage introduced into the primary clarifier through the desalination process; Nitrification and phosphorus uptake during abortion while alternately repeating the sewage of the supernatant discharged through the primary precipitation process by the intermittent aeration contact oxidation unit and denitrification / denitrification are alternately repeated, and the organic carbon source of the inflow sewage is denitrified An intermittent aeration catalytic oxidation process in which simultaneous removal of nitrogen / phosphorus is used in the reaction and biological purification is carried out through the microorganism carrier; In the intermittent aeration contact oxidation tank, the aeration liquid flowing into the secondary settling tank is subjected to solid-liquid separation. The supernatant is discharged to the filtration facility. The sludge collected in the settling hopper is partially returned to the intermittent aeration contact oxidation tank by the pump. To a second settling step; A filtration step for removing residual organic matter in the effluent from the secondary clarifier, adjusting the pH, chemically agglomerating the dissolved phosphorus; And a disinfection process of removing the coliform bacteria and the general bacteria by using the UV disinfection facility through the chemically treated treated water introduced through the filtration process, wherein the intermittent abandonment contact oxidation vessel is subjected to an abandonment / non-abandonment operation , A first to a third type in which at least one pair of submerged horizontal mixers capable of vertically moving along the inner wall are installed and a third type of sewage in a non- And a fourth group in which a plurality of anaerobic devices connected to the blower are formed, wherein the microorganism carrier has a cross-sectional shape of a cross shape, a longitudinal side of which is a hollow cylindrical shape, A contact material made of polyvinylidene chloride (PVDC), a plurality of ribs, and a plurality of ribs formed on the ribs and in contact with the contact material, The womb partition walls are formed can be characterized by being formed of a casing for receiving therein the contact media.

Description

{METHOD OF SEWAGE TREATMENT}

The present invention relates to a sewage treatment method, and more particularly, to a sewage treatment method capable of enhancing denitrification and denitrification efficiency by using an intermittently aerated contact oxidation vessel composed of a plurality of reaction vessels and improving biological purification efficiency through a microorganism carrier .

Currently, the most widely used wastewater treatment process is the A2O process consisting of anaerobic - anoxic tank - membrane separation tank. The biggest limitation of the A2O process is the removal of nitrogen and phosphorus when the concentration of organic matter contained in wastewater is lower than nitrogen and phosphorous The efficiency is lowered. In order to solve these problems, various types of modified altitude treatment processes have been developed, but they have not fundamentally solved problems of deterioration of denitrification and denitrification due to lack of organic matter. In addition, a large number of anaerobic tank, anoxic tank, aeration tank, etc. must be separately separated at high cost, and in spite of a lot of facility investment costs, there is a problem that the capacity to cope with the change of inflow amount and inflow water quality is lacking.

In order to solve the above problems, there has been proposed a so-called intermittent aeration method in which anaerobic or aerobic conditions can be repeatedly performed in one or two or more reaction vessels. The intermittent aeration method repeatedly performs an aerobic state in which oxygen is supplied at a time interval in the same reaction tank and an anaerobic or anoxic state in which oxygen is not supplied. To this end, the reaction tank is provided with aeration device capable of injecting oxygen or air. The intermittent abandonment method has an advantage that the number of reaction tanks for sewage treatment can be reduced, and the facility cost can be reduced.

However, the intermittent aeration method having such an advantage is also difficult to activate microorganisms or bacteria because the change of the aerobic state and the anaerobic state is not clear, and the treatment efficiency of nitrogen and phosphorus may be lowered. Further, the residence time in the treatment tank is long, and there is a problem that a long time is spent for the treatment of nitrogen and phosphorus.

On the other hand, in order to biologically purify wastewater, media or a carrier, which means a material or a material that can be inhabited with microorganisms attached thereto, is dredged in sewage to perform purification. Conventionally, the media include gravel, waste tires, , Waste wood, etc., plastic media made of various shapes instead of microbial media made of plastic foam or fibrous material considering specific surface area have been proposed.

However, in the case of such a plastic medium, it is easy to produce a carrier when plastic is used as a material. However, since the surface of the plastic carrier is dense and smooth, it is difficult to form a biofilm and the surface of the wastewater is in contact with microorganisms in the medium. There is a problem that the decomposition of the contaminant does not occur smoothly.

(0001) Korean Patent Publication No. 10-2002-0089085 (published on November 29, 2002) (0002) Korea Patent No. 10-0935022 (Registered on December 23, 2009)

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a method and apparatus for improving the biological purification efficiency by improving micro- And to provide a sewage treatment method that can be used.

According to the present invention, it is possible to collect the contaminants and sediments contained in the sewage inflowed to the geyser by using a traveling type automatic silencer, a screen, a fine-grain screen, a desolver remover or the like, A sedimentation process for transferring the sediment to a storage container formed on the upper part of the sedimentation bed; A primary precipitation step of precipitating and separating solid organic matters contained in the sewage introduced into the primary clarifier through the desalination process; Nitrification and phosphorus uptake during abortion while alternately repeating the sewage of the supernatant discharged through the primary precipitation process by the intermittent aeration contact oxidation unit and denitrification / denitrification are alternately repeated, and the organic carbon source of the inflow sewage is denitrified An intermittent aeration catalytic oxidation process in which simultaneous removal of nitrogen / phosphorus is used in the reaction and biological purification is carried out through the microorganism carrier; In the intermittent aeration contact oxidation tank, the aeration liquid flowing into the secondary settling tank is subjected to solid-liquid separation, and the supernatant liquid flows out to the filtration facility. The sludge collected in the settling tank hopper is partially returned to the intermittent aeration contact oxidation tank by the pump. To a second settling step; A filtration step for removing residual organic matter in the effluent from the secondary clarifier, adjusting the pH, chemically agglomerating the dissolved phosphorus; And a disinfection process of removing the coliform bacteria and the general bacteria by using the UV disinfection facility through the chemically treated treated water introduced through the filtration process, wherein the intermittent abandonment contact oxidation vessel is subjected to an abandonment / non-abandonment operation And a plurality of perforated axial diffusers connected to a blower, wherein at least one pair of underwater horizontal mixers capable of vertically moving along the inner wall are provided, And a fourth unit in which a plurality of an- alicators connected to the blower are constituted. In the first to fourth groups, an anti-foaming agent for removing bubbles generated in each group is injected The defoaming agent is composed of a defoaming agent injecting device, and the microorganism carrier has a cross-sectional structure of + (+) shape, the longitudinal side being a hollow cylinder, A contact material made of polyvinylidene chloride (PVDC), a polypropylene (PP), and a plurality of ribs formed on the ribs and contacting the contact material, Wherein the upper case and the lower case are permanently joined to each other by heat fusion so that the contact material is received and fixed therein. Can be provided.
In this case, the underwater horizontal mixer includes a rail installed on the inner wall of the first to third groups, a mixer moving part coupled with the underwater horizontal mixer and moving along the rail, and a water horizontal mixer connected with the underwater horizontal mixer, The horizontal mixer is vertically movable from the bottom of the installation tank to the outside of the water surface by a mixer moving device composed of a motor for moving the vertical mixer in the vertical direction.

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According to the present invention, it is possible to improve the response to nitrogen, phosphorus removal efficiency and load fluctuation of sewage through an intermittently aeration contact oxidation vessel formed of a plurality of tanks, and to improve biochemical purification efficiency through expansion of the surface area of the microorganism carrier have.

Further, it is possible to prevent impurity precipitation by a vertically-movable underwater horizontal mixer formed in the intermittently releasing contact oxidation vessel and to improve the ease of maintenance such as replacement repair.

In addition, the quality of the treated water finally discharged by the filtration process and the disinfection process can be further improved.

1 is a process flow chart schematically showing a sewage treatment method according to the present invention.
2 is a schematic view of an intermittently releasing contact oxidation vessel of the intermittent aeration contact oxidation process according to the present invention.
3 is an exploded perspective view of a microorganism carrier according to the present invention.
Fig. 4 is a process flow diagram of a filtration process and a disinfection process according to the present invention.

Hereinafter, specific configurations and effects of the present invention will be described based on the embodiments shown in the drawings.

1 is a process flow chart schematically showing a sewage treatment method according to the present invention. 2 is a schematic view of an intermittently releasing contact oxidation vessel of the intermittent aeration contact oxidation process according to the present invention. 3 is an exploded perspective view of a microorganism carrier according to the present invention. Fig. 4 is a process flow diagram of a filtration process and a disinfection process according to the present invention.

1 to 3, the sewage treatment method according to the present invention can be applied to a sewage treatment process (S100), a primary precipitation process (S200), an intermittent aeration catalytic oxidation process (S300), a secondary precipitation process (S400) S500), and a disinfection process (S600).

At this time, the sewage treatment method according to the present invention may further include a sewage inflow process for inflowing sewage to the geyser, a sludge treatment process for sewage sludge concentration / dehydration, and a discharge process for discharging sewage through the disinfection process Such a process is generally applied and is omitted for convenience of explanation.

First, the silt process (S100) is a process for filtering the contaminants and the sediments contained in the wastewater. The contaminants and the sediments contained in the wastewater flowing into the gypsum are transferred to the traveling silo automatic silencer and screen, And the collected impurities and sediments are transferred to a storage container formed on the upper part of the geyser with an air pressure conveyor.

 The primary precipitation process (S200) is a process for precipitating and separating solid organic matter contained in sewage to reduce the organic matter load of the subsequent nitrification process, thereby enabling effective nitrification. The primary settler (21) is composed of two sheets, and the settler (21) is of gravity type and rectangular. In addition, a distribution tank for decreasing the velocity energy of the inflow sewage and appropriately distributing is formed in the inflow portion of the gravel 21, and an outflow portion is provided with a trough and a V-notch is installed. At this time, the length of the outflow trough can be determined according to the required length of the V-notch, and the overflow load of the V-notch is determined to be 250 m³ / m · day or less from the facility standard. In addition, the sludge immersed in the primary precipitation step (S200) is collected by the sludge collecting facility in the sludge hopper, and the collected sludge is transferred to the pump for the sludge treatment process.

In the intermittent aeration contact oxidation step (S300), the sewage of the supernatant flowing out through the primary precipitation step (S200) is alternately repeated with the intermittent aeration contact oxidation vessel (31) And the simultaneous removal of nitrogen / phosphorus by using the organic carbon source of the inflow sewage in the denitrification reaction in the non-aerobic state.

The intermittently releasing contact oxidation vessel 31 is formed of four tanks 31a, 31b, 31c, and 31d sequentially connected to improve nitrogen and phosphorus removal efficiencies and responsiveness to load fluctuations, The third group 31a, 31b, and 31c are alternately turned ON / OFF for one hour at intervals in which the intermittent aeration contact oxidation is carried out, whereby the aeration / non-aeration is alternately repeated so that the aerobic / anaerobic state of the reactor for removing nitrogen and phosphorus , And the fourth tank (31d) is always abandoned as a tank for catalytic oxidation and aerobic state is maintained.

Specifically, in the first column (3a), the supernatant of the primary clarifier (21) and the activated sludge conveyed from the secondary clarifier (41) are mixedly introduced. By the alternating operation of the aeration / State. At this time, the organic matter is oxidatively decomposed by aerobic microorganisms at the time of abandonment, and ammonia nitrogen is nitrified by the nitrifying microorganism into nitrate form. On the other hand, at the non - refluxing stage, the anaerobic state becomes unoxidized and the nitrate nitrogen in the return sludge is denitrified by the organic matter of the influent sewage and the phosphorus in the microorganism body is released.

Articles 2 and 3 (31b, 31c) are alternating operations of aeration / non-release and change into aerobic and anaerobic conditions over time. In the abandonment, organic matter is decomposed by aerobic microorganisms or nitrification reaction and phosphorus are ingested excessively. In the non-releasing state, nitrogen removal is performed by denitrification.

Since the effluent sewage flowing out from the third tank 31c flows into the third tank 31c in the non-aerated state, the fourth set 31d is in an anaerobic state, so that the sedimentation of the sludge in the secondary settler 41 is reduced, In consideration of the possibility of the release of phosphorus and phosphorus, Article 4 (31d) maintains the aerobic condition at all times to improve sludge sedimentation, to consume excess phosphorus, and to decompose residual organic matter.

The air diffuser 33 connected to the blower 32 for air supply is installed in the first to fourth groups 31a, 31b, 31c, and 31d where the intermittent aeration contact oxidation and the contact oxidation process are performed. It is preferable that the air diffusing device 33 has a high oxygen delivery efficiency, an excellent economy, an excellent wear resistance and impact resistance, and is free from clogging during intermittent aeration.

In addition, the microorganism carriers 34 are filled in the first to fourth groups 31a, 31b, 31c and 31d in order to improve the ability of the inflow sewage to cope with load fluctuations, increase nitrification efficiency and prevent microbial cleaning phenomenon, Is attached to the microorganism carrier or suspended and proliferated.

As shown in FIG. 3, the microorganism carrier 34 is formed into an assembly in which two plastic cases 34a and 34b are filled with a contact material (lock 34c) in the form of a foam (FOAM) do. The cases 34a and 34b have a large porosity and a low water resistance and can flow well in water so that the flow of water and bubbles rising in the reaction tank is guided between the partitions 34e of the cases 34a and 34b, Increases the frequency of contact, and protects the contact material 34c with microorganisms attached thereto.

Specifically, the cases 34a and 34b are equally divided into an upper case 34a and a lower case 34b and are joined by heat fusion and made of polypropylene (PP). In each case 34a and 34b, A plurality of ribs 34d of the shape are formed. In addition, the ribs 34d have a structure in which a sector-shaped partition wall 34e for improving the area to which the microorganisms can be attached in the inward direction of the cases 34a and 34b is formed.

Further, the contact medium 34c is formed of a polyvinylidene chloride (PVDC) having a cross-sectional structure of '+' shape, a hollow cylindrical shape of a longitudinal side, a disk shape of a lateral side and a high biocompatibility do. The structure of the contact filter medium 34c is such that the lateral side and the longitudinal side of the partition wall 34e of the case 34a and 34b come into contact with the contact medium 34c, thereby facilitating the proliferation and attachment of microorganisms to the partition wall 34e, It is possible to minimize the flow of the contact mediums 34c in the cases 34a and 34b. Further, by enlarging the width of the contact medium 34c, it is possible to increase the specific surface area where the microorganisms can multiply and multiply, and at the same time, the buoyancy of the microorganism carrier 34 is increased, 34) can be made similar to water (1.0 ± 0.01). In addition, since the vertical axis is formed into a hollow shape, the flow into the microorganism carrier can be facilitated and the microparticle adhesion and proliferation can be performed in the interior of the filter material, thereby enlarging the specific surface area.

On the other hand, in the first to third groups 31a, 31b, and 31c, which are intermittent contact oxidation vessels, a horizontal type mixer 35 is installed as an agitator for anaerobic stirring in each reaction tank. The underwater horizontal mixer 35 has an integral structure of an electric motor and an impeller and is installed at an underwater corner of the first to third groups 31a, 31b and 31c to generate a swirling flow to prevent sedimentation of impurities in the reaction tank . The underwater horizontal mixer 35 having such a function can be moved in the vertical direction by the mixer moving device 36 installed in each reaction tank. More specifically, the mixer moving device 36 includes a rail 36a provided on the inner walls of the first to third sets 31a, 31b and 31c and a rail 36a to which the underwater mixer 35 is connected, And a motor 36d connected to the transverse mixer 35 provided on the rail 36a by a wire 36c to move the transverse mixer 35 in the vertical direction in the vertical direction . Such a mixer moving device 36 is appropriately moved from the bottom surface of the respective tanks to the outside of the water surface in the vertical direction along the inner wall in each tank to adjust the position (height), thereby facilitating maintenance and replacement, Depending on the amount of sewage flowing into the tank, a suitable swirl flow may be generated.

In addition, in the third tank 31c, a carbon source injection facility 37 composed of a storage tank 37a and an injection pump 37b may be configured to supply an external carbon source, The carbon source may be methanol. At this time, the methanol injected by the carbon source injecting facility 37 is injected in the third tank 31c during non-aerobic stirring.

In addition, in the first to fourth embodiments, a defoaming agent is injected to remove bubbles generated in each tank, and the defoaming agent is supplied by the defoaming agent injection equipment 38.

In the secondary precipitation step (S400), the aeration liquid flowing into the secondary settler 41 from the intermittent aeration contact oxidation vessel 31 is subjected to solid-liquid separation, and the supernatant is discharged to the filtration facility 51. The sludge collected in the hopper is pumped Is partially returned to the contact oxidation vessel (31), and the remaining surplus sludge is transferred to the sludge treatment facility. At the outlet of the secondary settler 41, a treated water trough is provided in a manner similar to the outflow of the primary settler 21 to provide a V-notch at the top of the trough. The sludge of the secondary settler 41 has a small specific gravity, If the weir load is increased, the upflow of the secondary settler 41 causes the floating phenomenon, so that the overflow load is formed within the range of the facility standard of 190 m 3 / m · day.

4, the pH adjustment of the effluent flowing out of the secondary clarifier 41 through the filtration facility 51, the chemical coagulation of the dissolved phosphorus, and the removal of residual organic matter are carried out in the filtration step (S500) The filtration facility 51 may be composed of a rapid mixing tank 52, a full flocculation tank 53, and a filter 54.

The rapid mixing tank 52 is a tank for mixing chemicals such as a disinfectant and a pH adjuster into the supernatant introduced from the secondary settler 41 and mixing the supernatant and the chemicals into the rapid mixing tank 42, A crude stirrer may be constructed. In this way, the treated water that has been stirred with the chemical in the rapid mixing tank 52 is transferred to the slow coagulation tank 53.

The slow flocculation tank 53 is a tank for flocculating the dissolved phosphorus by injecting the flocculant and the flocculant aid into the treated water flowing in the rapid mixing tank 52. The flocculent flocculant tank 53 is provided with a slow flocculation tank stirrer Lt; / RTI > In this way, the rapid mixing tank 52 and the slow aggregation tank 53 are subjected to the chemical treatment with a T-P target water quality of 0.5 mg / L or less.

The filter 54 is provided with a conventional filter for removing residual organic matter of the treated water treated through the slow coagulation bath 53. The treated water having passed through the filter 54 is introduced into the disinfection facility, do.

The disinfection process (S600) is a process of removing Escherichia coli and general bacteria so that the effluent discharged to the public water using the UV disinfection facility (61) meets the discharge water quality standard. The ultraviolet rays are directly irradiated The ultraviolet light is transmitted through the cell membrane of Escherichia coli to damage the nucleic acid (DNA) and sterilize it. The treated water passing through the disinfection facility 61 is discharged through the discharge water channel, and a part of the treated water is supplied as the water for operation in the treatment plant.

INDUSTRIAL APPLICABILITY As described above, the sewage treatment method according to the present invention can improve the response to nitrogen and phosphorus removal efficiency and load fluctuation of sewage through an intermittent aeration contact oxidation vessel formed with a plurality of tanks, The biological purification efficiency can be improved.

In addition, it is possible to prevent impurity precipitation by a vertically movable underwater mixer formed in the intermittent aeration contact oxidation vessel and to improve the ease of maintenance such as replacement repair, and to perform a final discharge treatment by an additional filtration process and a disinfection process The water quality of the water can be further improved.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. The present invention is not limited to the drawings, and all or some of the embodiments may be selectively combined so that various modifications may be made.

21: primary clarifier 31: intermittent aeration contact oxidation vessel
32: blower 33: diffuser
34: Microorganism carrier 35: Underwater horizontal mixer
36: Mixer moving device 37: Carbon source injection equipment
38: vesicle infusion facility 41: secondary clarifier
51: Filtration facility 52: Rapid mixing tank
53: Fast coagulation tank 54: Filter
61: UV disinfection facility

Claims (6)

After collecting the impurities and sediments contained in the sewage inflowed into the geyser by using at least one of a traveling type automatic silencer, a screen, a fine wood screen and a desinformer, the collected contaminants and the precipitate are conveyed to the upper part of the geyser To a formed storage container;
A primary precipitation step of precipitating and separating solid organic matters contained in the sewage introduced into the primary clarifier through the desalination process;
Nitrification and phosphorus uptake during abortion while alternately repeating the sewage of the supernatant discharged through the primary precipitation process by the intermittent aeration contact oxidation unit and denitrification / denitrification are alternately repeated, and the organic carbon source of the inflow sewage is denitrified An intermittent aeration catalytic oxidation process in which simultaneous removal of nitrogen / phosphorus is used in the reaction and biological purification is carried out through the microorganism carrier;
In the intermittent aeration contact oxidation tank, the aeration liquid flowing into the secondary settling tank is subjected to solid-liquid separation, and the supernatant liquid flows out to the filtration facility. The sludge collected in the settling tank hopper is partially returned to the intermittent aeration contact oxidation tank by the pump. To a second settling step;
A filtration step for removing residual organic matter in the effluent from the secondary clarifier, adjusting the pH, chemically agglomerating the dissolved phosphorus;
And disinfecting the chemically treated treated water that has been introduced through the filtering step to remove Escherichia coli and general bacteria using an UV disinfection facility,
The intermittent abrogating contact oxidation vessel
Wherein at least one pair of underwater horizontal mixers capable of vertically moving along the inner wall are installed, wherein the aeration / non-aeration alternating operation is performed, and the air diffusing device is constituted by a plurality of porous- 3, and the third sewer in the non-aerated state is operated to operate in a normally abandoned state, and a plurality of aerators are connected to the blower. In the first to fourth embodiments, The defoaming agent for injecting the defoaming agent for removing the bubbles constituting the defoaming agent is constituted,
The microorganism carrier
A contact material made of polyvinylidene chloride (PVDC), a hollow cylindrical shape having a cross section in the shape of a cross (+), a horizontal side formed in a disc shape,
A plurality of ribs and a plurality of ribs formed on the ribs and having a fan-shaped barrier rib formed by contact with the contactor material and attached to microorganisms adhering to the contactor material to expand and grow, Wherein the upper case and the lower case are permanently coupled to each other by mutual thermal welding so as to be accommodated in and fixed to the lower case. The method according to claim 1,
The underwater horizontal mixer includes a rail installed on the inner wall of the first to third groups, a mixer moving part to which the horizontal underwater mixer is coupled and moves along the rail, and a water horizontal mixer connected to the underwater horizontal mixer, Wherein the horizontal mixer is vertically movable from the bottom of the installation tank to the outside of the water surface by means of a mixer moving device composed of a motor for moving the horizontal mixer in the direction of the water.
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