KR101697025B1 - high-efficient DO supplying system in water treatment process - Google Patents

Abstract

The present invention relates to a dissolved oxygen supply system for a biological wastewater treatment process, in which a fine air supply unit configured to supply high-efficient dissolved oxygen is provided and air, ozone and pure oxygen are supplied into an aerobic tank. The present invention provides the high-efficient dissolved oxygen supply system for a wastewater treatment process, the system comprising: an aerobic tank which accommodates influent water, and which treats the influent water by using microorganisms; a secondary sedimentation tank which separates a mixed liquid, discharged from the aerobic tank, into sludge and treated water by sedimenting the sludge of the mixed liquid; and a fine air supply unit which generates aerated water in which the sludge, separated in the secondary sedimentation tank, or the influent water has been mixed with any one or more of air, ozone and pure oxygen, and which supplies the aerated water to the aerobic tank. According to the present invention, fine bubbles are generated by mixing air, supplied to the aerobic tank, with air, ozone and pure oxygen via natural suction and aerated water forming a vortex is generated and supplied, and thus energy consumed to supply air to the aerobic tank can be effectively reduced. The amounts of air, ozone, pure oxygen, return sludge, influent water and treated water supplied to the aerobic tank are controlled in accordance with conditions of influent water by controlling the former operations in conjunction with the conditions of the influent water, and thus more efficient supply of dissolved oxygen can be performed in a wastewater treatment process.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a high-efficiency dissolved oxygen supply system for a wastewater treatment process,

The present invention relates to a high-efficiency dissolved oxygen supply system for a wastewater treatment process, and more particularly to a fine-oxygen supply system for supplying high-efficiency dissolved oxygen to a biological wastewater treatment process, And more particularly, to a highly efficient dissolved oxygen supply system for a wastewater treatment process that is more economical and efficient.

BACKGROUND ART [0002] Generally, in the treatment of wastewater containing organic substances, biological treatment for decomposing and removing organic matters contained in wastewater and wastewater by microorganisms is widely used. Among them, as the most basic treatment system, There is standard activated sludge method.

This standard activated sludge method was developed in the UK in 1913 and applied to many treatment plants to make the most contribution to the treatment of wastewater containing organic matter. Many modifications as the aid of biological treatment methods are being studied today, It is a very useful method to remove organic materials, colloids and suspended matters. As shown in FIG. 1, the standard activated sludge process is composed of a primary settling tank 20, an aerobic tank 10, and a secondary settling tank 30. The organic activated sludge process decomposes and removes organic substances in the wastewater using an aerobic microorganism do.

That is, the suspended solids are removed from the first settling tank 20, and the soluble organic substances are decomposed by the microorganisms in the aerobic tank 10, and some are synthesized into microbial cells (converted into soluble cells → insoluble substances) 30). It has a high organic removal efficiency and is the most basic process. Due to its application performance, it is easy to operate because it has established operation technology. However, The disadvantage is that the removal of phosphorus is insufficient.

In order to overcome the drawbacks of the standard activated sludge process, many variations have been studied as described above. Typical examples are A / O process and A2 / O process.

The A / O (Anaerobic (anoxic) -Oxic) process was developed by Air Products & Chemicals, Inc. of the United States. It is a treatment method for removing phosphorus, which is a disadvantage of the standard activated sludge process, An anaerobic tank 10c or an anoxic tank 10b is added in front of the aerobic tank 10a of the activated sludge process.

In the anaerobic tank 10c, the return sludge of the second settling tank 30 and the influent water are mixed together, and the organic matter is absorbed by the microorganisms. In order to obtain energy, ATP → ADP is released to release PO4-P.

When phosphorus is released, the next step, the aerobic tank 10a, metabolizes BOD and rapidly absorbs more than the amount required for phosphorus metabolism. Phosphorus absorbs 3 to 4 times phosphorus. This phenomenon is called "luxery uptake", so phosphorus removal is made by disposing of the excess sludge produced and the phosphorus content in the sludge is 4 ~ 6% in dry weight and 2 ~ 3% in standard activated sludge process Includes double phosphorus. Therefore, although the organic material and the phosphorus removal efficiency are high, the nitrogen removal efficiency is low.

To overcome these disadvantages, there is an A2 / 0 (Anaerobic-Anoxic-Oxic) method as shown in FIG. In order to solve the problem of low nitrogen removal efficiency in the AO process, the anaerobic tank 10b is installed between the oxic tank 10a and the anaerobic tank 10c, and the oxic tank 10a is operated to nitrify the A2 / The nitrified inflow water in the oxic tank 10a is returned to the inside of the anoxic tank 10b using the internal transfer pump P as the transfer water to remove nitrogen. Therefore, the F / M ratio in the oxic tank 10a is lower than that of the A / O method, and nitrogen removal is also possible.

1 to 3, conventional biological wastewater treatment systems are required to supply air, i.e., oxygen, necessary for the aerobic microorganisms in the aerobic tank to the aerobic tank 10, so that the aerobic tank 10, 10a is provided with a compressor 15 ) And the like, and it is necessary to continuously supply the air and to return the conveying sludge for adjusting the F / M ratio to the aerobic tank by using a pump or the like, so that the power consumed by the aerobic tank is considerable, Air was not sufficiently supplied to the oxic tank according to the condition. In order to overcome such disadvantages, additional air supply means, surface aeration device or pump 11 are provided to further supply air to the upper part of the oxic tank 10, 10a. In Korean Patent Laid-Open Publication No. 2001-011996, And the water is circulated. However, there is a disadvantage that additional energy is consumed since stirring is required by such an additional apparatus.

Korean Patent Laid-Open Publication No. 2007-0079580 discloses a system for supplying pure oxygen into aeration tank in order to increase the abandonment efficiency of an aerobic tank. This is because the supply efficiency of nitrogen is very high due to the supply of pure oxygen, but pure oxygen itself is expensive , There are many restrictions on the operation.

Korean Patent Laid-Open Publication No. 2002-0068310 discloses a method in which a concentrated sludge is separately transported to a mixing zone to separate the sludge from the sludge, and the sludge is mixed with air, But there is also a disadvantage in that additional energy is consumed in stirring in the mixed region.

Japanese Patent Laid-Open Publication No. 1999-226590 discloses a method in which a part of the influent water to be treated in an aerobic tank is first extracted and then mixed with sludge in order to control the amount of transported sludge to be transferred from the secondary settling tank to the oxic tank, . However, this also has limitations in reducing the energy consumption of the aeration and agitation of the conveying sludge and the drainage.

KR 2001-0111996 A KR 2007-0079580 A KR 2002-0068310 A JP 1999-226590 A

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems occurring in the prior art, and it is an object of the present invention to provide a biological wastewater treatment system including an oxic tank, comprising a supply part for supplying air to the oxic tank in high- And to provide a highly efficient dissolved oxygen supply system of a more economical and efficient wastewater treatment process by supplying pure oxygen.

In order to accomplish the above object, the present invention provides an aerobic tank, comprising: an aerobic tank in which inflow water is received and treated by microorganisms; A second settling tank for settling the mixed liquid flowing out from the aerobic tank and separating the mixed liquid into sludge and treated water; And a fine air supply unit for generating an aeration water mixed with at least one of the sludge separated from the secondary settling tank or the inflow water and air, ozone, and pure oxygen, and supplying the aerated water to the aerobic tank, Supply system.

The fine air supply unit may include an inlet port provided at one side of the second settling tank for introducing the separated sludge or the inflow water into the second settling tank. A mixing portion extending from the inlet; An air inlet provided at one side of the mixing part and through which air flows; An air distribution unit that is divided into a plurality of air inflow portions and communicates with the mixing portion; And an aeration water outlet extending from the mixing portion, wherein the separated sludge introduced into the inlet and the air distributed through the air inlet and the air distributor are mixed in the mixing portion to generate a swirl flow, And is supplied to the aerobic tank through the aeration water outlet.

The air introduced into the air inlet is preferably introduced into the inlet and naturally drawn into the sludge or inflow water passing through the mixing section.

The amount of air, ozone and net oxygen mixed with the sludge or the inflow water preferably varies according to a flow rate, a temperature or a DO value of the inflow water.

And further includes a compressor, an ozone tank, and a pure oxygen tank for supplying the air, ozone, and pure oxygen to the fine air supply unit, respectively.

The compressor, the ozone tank, and the pure oxygen tank are further connected to the oxic tank, and the air, ozone, and pure oxygen are distributed to the fine air supply unit and the oxic tank according to the flow rate, temperature, or DO value of the inflow water, desirable.

And an anoxic tank in which the return water is carried from the oxic tank, wherein the return water is supplied selectively to the fine air supply unit with the sludge or the inflow water, and the aeration number And is preferably supplied to the oxic tank.

As described above, according to the high-efficiency dissolved oxygen supply system of the wastewater treatment process according to the present invention, air, ozone, and pure oxygen supplied to the oxic tank are mixed with the carrier sludge, inflow water, The amount of energy consumed to supply the air to the oxic tank can be effectively reduced and it can be controlled in conjunction with the condition of the influent water so that the air supplied to the oxic tank , It is possible to realize a dissolved oxygen supply system for a more efficient wastewater treatment process by controlling the amount of ozone, pure oxygen, transport sludge, influent water and treated water.

1 to 3 schematically show a wastewater treatment system including a conventional aerobic tank.
4 schematically shows a high-efficiency dissolved oxygen supply system of the wastewater treatment system according to the first embodiment of the present invention.
Fig. 5 schematically shows the configuration of the fine air supply portion of Fig. 4 of the present invention.
Fig. 6 schematically shows a high-efficiency dissolved oxygen supply system of a wastewater treatment system according to a second embodiment of the present invention.
7 schematically shows a high-efficiency dissolved oxygen supply system of a wastewater treatment system according to a third embodiment of the present invention.
Fig. 8 schematically shows a high-efficiency dissolved oxygen supply system of the wastewater treatment system according to the fourth embodiment of the present invention.

These and other objects, features and other advantages of the present invention will become more apparent by describing in detail preferred embodiments of the present invention with reference to the accompanying drawings. In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the intention or custom of the user, the operator. Therefore, the definitions of these terms should be described based on the contents throughout this specification.

In addition, the described embodiments are provided for illustrative purposes and do not limit the technical scope of the present invention.

The components constituting the high-efficiency dissolved oxygen supply system of the wastewater treatment process according to the present invention can be used integrally or individually. In addition, some components may be omitted depending on the usage pattern.

Hereinafter, the high-efficiency dissolved oxygen supply system of the wastewater treatment process according to the first embodiment of the present invention will be described with reference to FIGS. 4 to 5 attached hereto.

4, the high-efficiency dissolved oxygen supply system of the wastewater treatment process according to the first embodiment of the present invention includes an aerobic tank 100, a primary settling tank 200, a secondary settling tank 300, (400).

Some of the organic pollutants in the inflow water are decomposed and taken up by the aerobic microorganisms in the aerobic tank 100, and the remaining part of the organic pollutants are synthesized into microbial cells, do. The pump P1 for transferring the influent water to the oxic tank 100 and the sensor S1 for sensing the temperature, the DO value and the flow rate of the inflow water may be provided on the inflow side of the inflow port, The sensor S2 may be provided inside the sensor 100. [

The primary settling tank 200 is located between the inflow section of the inflow water and the oxic tank 100. The settable suspended solids in the contaminants contained in the inflow water are primarily precipitated and the settled sludge is discharged as a primary sludge .

The second settling tank 300 is connected to the downstream end of the oxic tank 100. As described above, the sludge synthesized from the microbial cells among the organic substances contained in the inflow water and the inflow water is introduced, and after the sludge is finally settled, Thereby discharging the treated water that has been removed.

On the other hand, in order to maintain the F / M ratio in the oxic tank 100, a part of the settled sludge is returned to the oxic tank 100 as the return sludge, and the other part is discarded as the excess sludge. A transfer pump P2 for transferring the transfer sludge to the oxic tank 100 may be provided.

The fine air supply unit 400 is provided on a line conveyed to the oxic tank 100 by the above conveying sludge and supplies the aerated water mixed with the air conveyed from the secondary settling tank 300 to the oxic tank 100, (100). Therefore, the air required for the microorganisms in the oxic tank 100 together with the transport sludge can be supplied at a time by the construction of the line and the transport pump P2 for transporting the transport sludge.

5, the structure of the fine air supply unit 400 will be described in more detail. The fine air supply unit 400 includes an inlet 410, a mixing unit 420, an air inlet 430, (440) and an aeration water outlet (450).

The inlet 410 is located at one side of the fine air supply part 400 and connected to a line for conveying the conveying sludge to the oxic tank 100. The conveying sludge conveyed along the line through the conveying pump P2 is a high- Or the inflow water and / or the return water may be introduced according to each embodiment to be described later.

The mixing portion 420 extends from the inlet 410, and the sludge flowing through the inlet 410 flows.

The air inlet 430 is provided at one side of the mixing unit 420 and air to be supplied to the oxic tank 100 flows through the air inlet 430. At this time, Can be naturally drawn by the negative pressure generated in the mixing portion 420 by the transporting sludge, the influent water and / or the conveying water.

One end of the air distribution unit 440 is branched from the air inlet 430 and connected to the mixing unit 420 so that the air introduced into the air inlet 430 is distributed, The air flowing into the mixing portion 420 is mixed with the transporting sludge passing through the mixing portion 420 and the aeration water containing fine bubbles is generated and flows into the mixing portion 420 through the aeration water outlet (450) and is supplied to the oxic tank (100).

The swirling flow is a flow in which the rotation about the axis and the flow in the axial direction are simultaneously generated when the fluid flows in the tangential direction of the cylindrical tube. The swirling flow passes through the air inlet 430 and the conveying sludge, And the air flowing in the circumferential direction through the air distribution unit 440 are mixed with each other through the mixing unit 420 to generate a swirling flow and the air flowing from the transportation sludge is finely separated and aeration containing minute bubbles And is supplied to the oxic tank 100.

As a result of supplying the aeration tank 100 with the vapors including the minute bubbles to the oxic tank 100, the surface area of the air contained in the aeration tank with the influent water in the aerobic tank 100 is increased, It is possible to shorten the hydraulic retention time (treatment time) in the oxic tank 100 to improve the treatment efficiency.

In addition, air can be naturally aspirated through the air inlet 430 communicated with the conveying sludge passing through the mixing portion 420, so that no additional power is required to supply the air, It is possible to maintain an economical system because there is no energy consumption for supplying air.

4, the air inlet 430 may be provided with a separate air supply unit such as a compressor 150 depending on the condition of the inflow water. In addition, the ozone tank 160 and the pure oxygen The ozone tank 160 and the oxygen inlet 170 are connected to the air inlet 430 by the respective valves V1, V2, and V3 provided on the line connecting the compressor 150, the ozone tank 160, Air, ozone, and pure oxygen may be selectively or separately mixed with each other to be introduced into the air inlet 430, and the air may be supplied from the fine air supplier 400 to the oxic tank 100 to improve the treatment efficiency in the oxic tank .

As described above, even if air is supplied to the compressor 150, the ozone tank 160, and the pure oxygen tank 170 because the aeration air can be naturally introduced by the nature of the aeration water and the return sludge, The energy used for the additional constitution is consumed significantly less than in the prior art, and as shown in Figs. 1 to 3, the air supply means, the surface aeration device, the pump or the impeller It is not necessary to have the configuration of the display device 11 or the like.

Hereinafter, a high-efficiency dissolved oxygen supply system of the wastewater treatment process according to another embodiment of the present invention will be described. However, for the sake of understanding of the invention, the difference between the embodiments and other embodiments will be described. The description thereof will be omitted.

Referring to FIG. 6, the high-efficiency dissolved oxygen supply system of the wastewater treatment process according to the second embodiment of the present invention will be described with reference to an additional compressor 150, an ozone tank 160, a pure oxygen tank 170 The compressor 150, the ozone tank 160, and the ozone tank 160 are connected to each other through a line through which the compressor 150, the ozone tank 160, and the pure oxygen tank 170 are directly connected to the oxic tank 100, S2, S3, S4 (S4, S5, S5, S5, S5, S5, S5, S5, S5, S5, S5, S5) Ozone and pure oxygen supplied from the compressor 150, the ozone tank 160, and the net oxygen tank 170 according to the conditions such as the influent water, the treated water, and the conveying sludge, By adjusting the amount of mixing through each valve (V1, V2, V3) And thus used efficiently manage the energy, it is possible to control may also, for managing the processing efficiency in the aerobic tank (100).

Referring to Fig. 7, a high-efficiency dissolved oxygen supply system of the wastewater treatment process according to the third embodiment of the present invention will be described.

In the present embodiment, the inflow water that is branched by the pump P1 is branched by the valve V4 provided to the fine air supply unit 400 by being branched between the line through which the inflow water flows and the first settling tank 200 It can be mixed with air, ozone and pure oxygen, aerated and supplied to the oxic tank 100.

8, an anaerobic tank 100c and an anoxic tank 100b are additionally provided at the front end of the oxic tank 100. In this case, the transport sludge Can be conveyed to the anaerobic tank 100c by the return pump P2. 8, the anaerobic tank 100c and the aerobic tank 100 are shown in the order of the inflow water inflow direction, the anaerobic tank 100c and the oxic tank 100. However, the order of the anaerobic tank 100c and the anoxic tank 100b may be changed.

In this embodiment, as in the A2 / 0 method, the nitrified inflow water in the oxic tank 100 can be returned to the anoxic tank 100b through the return pump P5 and the valve V6 provided in the return line The line branched from the return line is connected to the fine air supply unit 400 and the return water is supplied to the anoxic tank 100b through a valve V7 provided therein and a valve V6 provided on the return line The air is supplied to the fine air supply unit 400 through the fine air supply unit 400 and then supplied to the oxic tank 100 again.

It is needless to say that the aerobic tank 100, the anaerobic tank 100c and the anoxic tank 100b may be provided in each of the above-described embodiments.

The operation of the high-efficiency dissolved oxygen supply system of the wastewater treatment process according to each embodiment of the present invention will be described below with reference to FIGS. 4 to 8 attached hereto.

The inflow water flows into the primary settling tank 200 through the pump P1 installed in the inflow section and the temperature, the DO value and the flow rate of the inflow water are detected through the sensor S1 provided in the inflow section.

The suspended solids contained in the influent water flowing into the primary settling tank 200 are precipitated and removed, and the suspended solids are discharged as primary sludge and discarded.

The inflow water from which the primary sludge has been removed flows into the oxic tank 100.

The inflow water flowing into the oxic tank 100 is treated according to decomposition by microorganisms in the oxic tank 100. At this time, the temperature of the inflow water in the oxic tank 100, the DO value Etc. can be detected.

The treated inflow water flows into the second settling tank 300 in the form of a mixture of sludge and treated water, and the second settled sludge is precipitated and separated from the mixed solution into sludge and treated water. The separated treated water flows out of the secondary settling tank 300. A portion of the separated sludge for adjusting the F / M ratio in the aerobic tank 100 is introduced into the fine air supply unit 400 as a transport sludge by a pump, According to each of the above embodiments, at least one of the inflow water and the return water may be mixed with at least one of air, ozone, and pure oxygen introduced into the air supply unit 430 of the fine air supply unit 400, , And minute bubbles and is supplied to the oxic tank 100 as aeration water constituting a swirling flow. The temperature and the DO value and the flow rate of the sludge flowing into the sludge and the outflow aeration by the sensors S3 and S4 provided in the respective lines connected to the fine air supply unit 400 are detected.

In biochemical treatment using microorganisms as described above, DO, temperature, flow rate (loading) can be mentioned as major factors affecting the treatment, and further pH and alkalinity can be mentioned.

Influent water and treated water supplied to the fine air supply unit 400 according to the temperature, DO value and flow rate of inflow water, sludge, and aeration water sensed by the sensors S1, S2, S3, And the amount of air, ozone, and pure oxygen supplied from the compressor 150, the ozone tank 160, and the net oxygen tank 170 to the oxic tank 100 and the fine air supply unit 400 The entire system is controlled by the distribution, so that efficient system control is possible.

On the other hand, the remaining part of the sludge by the secondary precipitation flows out of the secondary settling tank 300 as surplus sludge and is discarded, and the inflow water from which such surplus sludge has been removed flows out as treated water.

As described above, according to the wastewater system of the present invention, air, ozone, and pure oxygen supplied to the oxic tank are mixed with the conveying sludge, inflow water, and return water using natural intake, It is possible to effectively reduce the energy consumed to supply air to the oxic tank and to control it in conjunction with the inflow water conditions so that the distribution of air, ozone and pure oxygen supplied to the oxic tank in accordance with the conditions of the influent water And the amount of the transporting sludge, the influent water and the return water can be adjusted to realize a more efficient wastewater system.

Further, since the transfer pump power installed in the conventional wastewater treatment process is used as it is, there is an advantage that there is no additional cost burden.

Although the preferred embodiments of the present invention have been described, the present invention is not limited to the specific embodiments described above. It will be apparent to those skilled in the art that numerous modifications and variations can be made in the present invention without departing from the spirit or scope of the appended claims. And equivalents should also be considered to be within the scope of the present invention.

100:
150: Compressor
160: Ozone tank
170: Oxygen tank
200: primary settling tank
300: secondary settling tank
400: fine air supply
410: inlet
420:
430: Air inlet
440: air distribution portion
450: Aeration water outlet

Claims (7)

An anaerobic tank 100c, an anoxic tank 100b, and an oxic tank 100 that treat inflow water received by the influent pump P1 by microorganisms,
A second settling tank 300 for separating the mixed liquid flowing out of the oxic tank 100 into sludge and treated water; And
A sludge pump P2 for transferring sludge separated from the secondary settling tank 300 to the oxic tank 100; And
And a transfer water pump (P4) for transferring the nitrified inflow water from the oxic tank (100) as the transfer water to the anoxic tank (100b), the system comprising:
And a fine air supply unit (400) into which the influent water, the sludge and the return water are introduced,
The fine air supply unit 400 is configured to supply either one of air, ozone, and pure oxygen to the inflow water, the sludge, and the return water supplied to the fine air supply unit 400 by the pumps P1, P2, The number of the influent aeration, the number of the sludge aeration, and the number of the conveyance water aeration are generated,
The generated aeration numbers are respectively supplied to the oxic tank 100 through the respective pumps P1, P2, and P4,
The amount of the inflow water, the sludge, and the return water that generate the aeration number is determined according to the temperature, the flow rate, and the DO value measured in the oxic tank 100,
High Efficiency Dissolved Oxygen Supply System in Wastewater Treatment Process.
The method according to claim 1,
The fine air supply part (400)
An inlet (410) provided at one side to introduce any one of the influent water, the sludge and the return water;
A mixing portion 420 extending from the inlet 410;
An air inlet 430 provided at one side of the mixing part 420 and through which at least one of the air, ozone, and pure oxygen flows;
An air distribution unit 440 branched from the air inlet 430 and communicating with the mixing unit 420; And
And an aeration water outlet (450) extending from the mixing portion (420)
At least one of the inflow water flowing into the inlet 410, the sludge and the return water, and the air introduced into the air inlet, the ozone, and the pure oxygen are passed through the air distribution unit 440 And is mixed in the mixing part 420 to generate a swirling flow and is supplied to the aerobic tank 100 through the aeration water outlet 450,
High Efficiency Dissolved Oxygen Supply System in Wastewater Treatment Process.
3. The method of claim 2,
The air introduced into the air inlet 430 flows into the inlet 410 and is naturally adsorbed by the sludge passing through the mixing unit 420,
High Efficiency Dissolved Oxygen Supply System in Wastewater Treatment Process.
delete The method according to claim 1,
Further comprising at least one of a compressor (150) for supplying the air, ozone and pure oxygen to the fine air supply unit (400), an ozone tank (160), and a pure oxygen tank (170)
High Efficiency Dissolved Oxygen Supply System in Wastewater Treatment Process.
6. The method of claim 5,
The compressor 150, the ozone tank 160, and the net oxygen tank 170 are further connected to the oxic tank 100, and the air, the ozone, and the pure oxygen, depending on the flow rate, the temperature, or the DO value of the influent water, One or more of which are distributed to the fine air supply unit (400) and the aerobic tank (100)
High Efficiency Dissolved Oxygen Supply System in Wastewater Treatment Process.
delete

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