KR100582988B1 - Advanced sewage water treatment apparatus use of oxidation ditch - Google Patents

Abstract

The present invention is a technique for advanced treatment of sewage using a microbial reaction in the oxidation (ditch) of the sewage treatment plant or wastewater treatment plant.

It is an object of the present invention to provide an advanced treatment apparatus for sewage using oxidizing spheres by improving the oxidizing spheres and treating nitrogen and phosphorus in sewage with organic matter to remove them and increase the treatment capacity.

In order to achieve this purpose, a mixing tank for mixing return sludge and sewage is installed in front of the oxidizing sphere, and the oxidizing sphere in the latter stage is divided into an aerobic denitrification tank, an anaerobic tank, and an aerobic tank. The retention time of the sewage mixture was 8 hours in an aerobic denitrification tank, 6 hours in an anaerobic tank, and 16 hours in 2 hours in an aerobic tank.

In the aerobic denitrification tank, an air diffuser composed of fine diffusers and pipes is installed evenly inside, an inlet branch pipe is installed so that the mixed liquid of sewage and conveying sludge is evenly distributed in the aerobic denitrification tank, and the mixed liquid is circulated in the aerobic denitrification tank. The axial stirrer is installed so that

Dissolved oxygen concentration meter and redox potentiometer (ORP) were installed, and airflow automatic controller was installed to adjust the blower volume of the blower so that the redox potential was maintained at a predetermined value to supply sufficient oxygen to the mixed liquid flowing in the aerobic denitrification tank. Denitrification by nitrogen gas conversion caused by

In the anaerobic tank, an agitator is installed to prevent the mixed solution from settling inside, and a redox potentiometer is installed to prevent precipitation of the mixed liquid flowing from the aerobic denitrification tank, and anaerobic denitrification by residual organic matter occurs.

In the aerobic tank, an aeration machine capable of supplying sufficient air was installed and a dissolved oxygen concentration meter was installed to absorb and remove the phosphorus remaining in the mixed solution flowing from the anaerobic tank by the microorganism.

The sewage mixture discharged from the oxidizing sphere was purified in the next final sedimentation basin, the supernatant water was discharged, and the precipitated sludge was returned to the mixing tank in front of the oxidizing sphere, and some sludge was removed with excess sludge.

The present invention can improve the existing oxidizing spheres can be a high degree of treatment and increase the treatment capacity is economical and excellent treatment effect has the effect of improving the water quality of the effluent.

Description

Advanced sewage water treatment apparatus use of oxidation ditch

1 is a plan view of a common oxide sphere

2 is a plan view showing the structure of the case where the oxidation sphere of the present invention is one branch

Figure 3 is a plan view showing another embodiment when the oxidation sphere of the present invention is one branch

4 is a plan view showing the structure when the oxidizing sphere of the present invention is two

Fig. 5 is a plan view showing the structure of the case where four oxidative spheres of the present invention are four;

6 is a plan view showing the structure of the case where the oxidized sphere of the present invention is eight

Explanation of symbols for important parts of the drawings

1. Mixing tank 2. Inlet pipe

3. Inlet branch pipe 4. Aerobic denitrification tank 4-1. Guide wall

5. Blower 5-1. Airflow automatic controller

6. Air supply line 7. Opening and closing valve.

8. Air diffuser 9. Axial flow stirrer

9-1. Air Supply Axial Agitator

10. Dissolved Oxygen Meter 1 11. Redox Potential (ORP) System 1

12. Separation Wall 1 13. Pathway 1

14. Anaerobic Tank 15. Anaerobic Agitator 15-1. Oxidation sphere Rota

16. Redox Electrometer 2 17 Separation Wall 2

18. Passage 2 19. Exhalation

20. Aeration 21. Dissolved Oxygen Meter 2 22. Outlet

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end. Oxidized sphere b. Oxidized sphere rotor c. Guide wall

la. Sewage Bounce sludge bar. Final sedimentation basin

The present invention relates to a technique for the advanced treatment using the oxidative sphere of the sewage treatment plant or wastewater treatment plant.

Oxidation spheres used in the prior art have a simple structure of the facility and can be operated when only one rotor, which is an aeration device, can be operated, and thus it is widely used in small and medium-sized sewage treatment plants because of easy operation and stable water treatment performance.

Oxidation sphere is a long, donor-shaped quadrilateral cross-section, and it is very simple because it can supply air and oxygen only with the oxidizing sphere rotor. And some of them become anaerobic zone without dissolved oxygen, nitrification occurs in aerobic zone and denitrification in anaerobic zone. The relatively small length makes the distinction between the aerobic and anaerobic zones in the oxidizing zone unclear, making nitrogen removal almost unpredictable, thus making it impossible to process altitudes and long residence times.

Therefore, the residence time of the oxidized spheres was 24 to 36 hours, which was about 8 hours for the standard activated sludge method, 16 to 24 hours for the long-term aeration method, and 12 to 16 hours for the circulating nitrification denitrification method. Water quality tended to be relatively low.

In recent years, however, advanced processing processes have been found to have different microbial metabolic pathways than those of nitrogen removal, which rely on nitrification in conventional aerobic tanks and denitrification in anaerobic tanks.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide an advanced sewage treatment apparatus capable of removing nitrogen, phosphorus, and organic materials at the same time, and increasing the treatment capacity by simply improving some of the existing oxidation spheres.

The present invention to achieve the above technical problem,

A mixing tank 1 for mixing the return sludge and the sewage is installed in front of the oxidizing port, and an inlet pipe 2 is installed so that the sewage mixed liquid flows from the mixing tank 1 into the oxidizing port.

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The inside of the oxidizing sphere (A) is divided into an aerobic denitrification tank (4), an anaerobic tank (14), and an aerobic tank (19) capable of complete mixing. The mixed liquid in (4) is allowed to flow out through the anaerobic tank 14 and the aerobic tank 19 through the passage 1 (13) and the passage 18 provided in the partition 12 and the partition 17 toward the outlet 22. The ratio of the size is 8: 6: 2, respectively, and the residence time of the sewage mixture is 8 hours in the aerobic denitrification tank (4), 6 hours in the anaerobic tank (14), and 2 hours in the aerobic tank (19) for a total of 16 hours. and

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In the aerobic denitrification tank (4), several air diffusers (8) composed of fine diffusers and pipes are uniformly installed at regular intervals in the air supply pipe (6-2) disposed throughout the inner bottom, and the mixed liquid of sewage and conveying sludge An inlet branch pipe 3 connected to the inlet pipe 2 is installed on both sides of the guide wall 4-1 so that the aerobic denitrification tank 4 is evenly distributed. While installing the axial stirrer (9) to circulate toward

Dissolved oxygen concentration meter 1 (10) and redox potential (ORP) 1 (11) by installing the blower (5) and the redox to adjust the blowing amount of the blower (5) to maintain the redox potential at a predetermined value An air flow rate automatic controller 5-1 is provided between the electrometers 1 11 and the dissolved oxygen concentration in the aerobic denitrification tank 4 is maintained at 0.2 to 0.5 mg / l and the redox potential is 330 mV. Denitrification was caused by nitrogen gas conversion by supplying sufficient oxygen to the mixed liquid flowing inside the shell.

The anaerobic tank 14 is equipped with a oxidizer rotor 15-1 or an anaerobic tank stirrer 15 so that the mixed liquid does not settle therein, and a redox potentiometer 2 16 is installed to provide a mixture of the mixed liquid flowing from the aerobic denitrification tank 4. Prevents precipitation and causes anaerobic denitrification by organic residues,

In the aerobic tank 19, a plurality of aeration machines 20 capable of supplying sufficient air are installed in the air supply pipe 6-3, a dissolved oxygen concentration meter 2 (21) is installed, and the dissolved oxygen concentration in the aerobic tank 19 is 2 to. It was maintained at 4 mg / L to remove the phosphorus remaining in the mixed solution flowing from the anaerobic tank 14 to the microorganisms.

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The sewage flowing out of the aerobic tank 19 of the oxidizing sphere (A) is purified at the next final sedimentation basin (bar), the supernatant is discharged and the precipitated sludge is returned to the mixing tank (1) in front of the oxidizing sphere (A) as return sludge. And some sludge provides an advanced treatment of sewage using the oxidizing sphere to remove the excess sludge.

Hereinafter, the embodiments of the present invention will be described in detail as follows, but this does not limit the scope of the present invention, and numerous modifications and applications are included in the scope of the present invention.

A mixing tank (1) is installed in front of the oxidizing sphere (A) in which the inflow sewage (D) and the return sludge (e) are completely mixed with each other, and the inlet pipe (2) is connected to the inlet denitrification tank (4) of the oxidizing sphere. The inlet branch pipe 3 is installed to connect the inlet branch pipe 3 at the rear end of the inlet pipe 2 so that the mixed liquid of sewage and conveying sludge is distributed evenly from the front to the back of the aerobic denitrification tank 4. Evenly distributed and arrange | positioned on both the guide walls 4-1 of the denitrification tank 4, and installed.

An air dispersing device 8 for supplying air to the exhalation denitrification tank 4 is installed near the bottom of the exhalation denitrification tank 4 and provided at the front of the exhalation denitrification tank 4 so that the air can be supplied evenly over the front. It was evenly distributed and spread over the air supply pipe (6) (6-1) to the blower (5).

In the blower 5, the redox potential in the exhalation denitrification tank 4 was maintained at a predetermined value of 330 mV by the air flow automatic controller 5-1.

In order to maintain complete mixing conditions in the aerobic denitrification tank 4, the axial flow stirrer 9 is previously determined such that the mixed liquid of the aerobic denitrification tank 4 is circulated inside to have the same concentration and have the same residence time (about 8 hours). The required number was installed.

In the aerobic denitrification tank 4, a dissolved oxygen concentration meter 1 (10) for measuring the dissolved oxygen concentration and a redox potentiometer 1 (11) for measuring the redox potential are provided, and the output signal of the redox potentiometer 1 (11) is provided. Is connected to the airflow automatic controller 5-1.

The mixed liquid passed through the aerobic denitrification tank (4) was introduced into the anaerobic tank 14, which is the next process, through the passage 1 (13), and in the anaerobic tank 14, the mixed liquid remains anaerobic and prevents precipitation of the mixed liquid. ), A predetermined number of required oxidizing furnace rotors (15-1) and anaerobic tank agitators (15) were installed.

The mixed liquid passed through the anaerobic tank 14 was introduced into the aerobic tank 19 through the passage 2 (18), and the aeration pipe was connected to the air supply pipe (6-3) connected to the blower (5-3) to supply the necessary air to the aerobic tank (19). Several aeration stages 20 were constructed and dissolved oxygen concentration meter 2 (21) was installed for measuring the dissolved oxygen concentration.

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The highly treated mixed liquor passed through the aerobic tank (19) was introduced into the final settling basin (bar) through the outlet 22, and the sludge deposited at the bottom of the final settling basin (bar) was returned to the mixing tank (1). It was allowed to discharge and the remaining sludge was removed with excess sludge.

For example, if there is only one oxidizing sphere (A), the inside of the oxidizing sphere (A) is divided into an aerobic denitrification tank (4), an anaerobic tank (14), and an aerobic tank (19) as shown in FIGS. The area is divided into 8: 6: 2 and the sewage residence time is 8 hours in the aerobic denitrification tank (4), 6 hours in the anaerobic tank (14) and 2 hours in the aerobic tank (19).

In the case where there are several oxidizing spheres (2-8), each oxidizing sphere is divided into an aerobic denitrification tank 4, an anaerobic tank 14, and an aerobic tank 19 as shown in Figs. However, when the water volume was distributed so that its internal volume was 8: 6: 2, and when it was not divided into integers, the inside of some oxidizing spheres was divided into anaerobic tank (14) and aerobic tank (19), and the area was divided and installed to meet the above ratio. The total residence time was 16 hours as in the case of 1 zone of oxidation.

For example, in the case of eight oxidizing spheres, as shown in FIG. 6, four zones are defined as an aerobic denitrification tank (A), three sites as an anaerobic tank (B), and one branch as an aerobic tank (C), and the aerobic tank ( One paper used as C) uses the existing oxidizing sphere and oxidizing sphere rotor (15-1) as aeration.

In the case of four sites of oxidation, as shown in Fig. 5, _two aerobic denitrification tanks (A ₁ : A ₂ ), one anaerobic tank (B ₁ : B ₂ ), and one half of the remaining one branch are anaerobic tanks, The other half is changed to the aerobic tank (C).

In the case of two oxidizing spheres, as shown in FIG. 4, one oxidizing sphere is used as an aerobic denitrification tank 4, and the inside of the remaining one oxidizing sphere is 3/4 as an anaerobic tank 14 and 1/4 as an aerobic tank 19. Change to

And inside each of the aerobic denitrification tank (4), anaerobic tank (14) and the aerobic tank (19) is installed the necessary components, such as an acid apparatus such as described in the case of one branch.

However, in the aerobic denitrification tank 4, since the complete mixing condition is essential, if there are two or more oxidizing spheres used as the aerobic denitrification tank 4 in order to satisfy this condition, the sewage may be disposed in parallel as shown in FIGS. And the inflow of the conveyed sludge mixed liquid and the outflow of the mixed liquid which passed through the aerobic denitrification tank 4 were also collected in one pipe, and then transported to the next anaerobic tank 14 through the pipe.

The operation of the present invention is as follows.

The return sludge (e) returned from the sewage (d) and the final sedimentation basin (bar) is mixed evenly in the mixing tank (1) and then evenly distributed in the aerobic denitrification tank (4) through the inlet pipe (2). It flows into the inflow branch pipe (3), and is distributed and supplied evenly in the aerobic denitrification tank (4).

The air supplied from the blower 5 is supplied to the diffuser 1 8 through the air supply 6 and 6-1 and 6-2, where it is evenly supplied into the aerobic denitrification tank 4 to the mixed liquor. Supply the necessary oxygen.

When the axial agitator 9 installed in the aerobic denitrification tank 4 is operated, the mixed liquid continues to circulate in the aerobic denitrification tank 4 at a rate of about 0.3 m / s by the action of the axial agitator 9. The concentration of the mixed solution in (4), the dissolved oxygen concentration, and the redox potential are equalized to satisfy the complete mixing condition.

Complete mixing conditions generally refer to a condition where the concentration of the mixed liquor or dissolved oxygen concentration is less than 10% in all parts of the aerobic denitrification tank.

Full mixing conditions are necessary for all microbial reactors, but especially in aerobic denitrification tanks where aerobic denitrification occurs because aerobic denitrification occurs only within a limited range of dissolved oxygen concentration.

The conditions under which aerobic denitrification occurs should be maintained at a dissolved oxygen concentration in the range of 0.2 to 0.5 mg / l in a fully mixed state and the redox potential should be maintained accurately at 330 mV (when using a hydrogen comparison electrode).

Therefore, in order to maintain this condition, the circulating flow by the axial flow stirrer 9 makes the concentration of the mixed liquid, the dissolved oxygen concentration, etc. equal, the residence time of the mixed liquid even, and the air flow controller connected to the redox potential 1 11. As a function of -1), the amount of air supplied into the aerobic denitrification tank 4 is automatically controlled so that the redox potential is accurately maintained at a predetermined 330 mV (when a hydrogen comparison electrode is used) so that aerobic denitrification occurs well.

Aerobic denitrification is a new nitrogen removal method that has a microbial metabolism process different from conventional nitrification and anaerobic denitrification, and its reaction rate is relatively slow compared to conventional nitrification and anaerobic denitrification, and aerobic denitrification at the concentration of 3,000 mg / l of mixed liquid solids (MLSS). The residence time required for is about 8 hours.

Nitrogen removal of aerobic denitrification is estimated to occur by microorganisms in the following processes.

When the nitrogen removal effect is calculated by the above equation (1) is as follows.

Above equation, ammonia (NH ₄ -N) 1 molecule and nitrite (NO ₂₎ and 1.26 molecules react with nitrogen gas (N ₂₎ 1 molecule and 0.24NO to the nitrogen of the N ₂ 1 double 0.017N occurs as a molecule with _three sludge Assuming that nitrogen is removed as nitrogen gas and 0.017N is removed as sludge and 0.24NO ₃ is removed by gasification of endogenous or anaerobic denitrification in the anaerobic tank 14 by about 2% + 0.017N + 0.12N = 2.137N), which can remove 2.137 ÷ 2.26 = 0.9455 or 94.5% of the nitrogen in the sewage (NH ₄ -N + 1.26NO ₃ = 2.26N), which is anaerobic due to residual organic matter in the anaerobic tank (14). Considering the denitrification effect, it can be seen that more than 94.5% of nitrogen can be removed, and it is reported that foreign field operation results also have 90-95% of nitrogen removal effect.

The mixed solution treated in the aerobic denitrification tank 4 stays in the next anaerobic tank for about 6 hours while the microorganisms release phosphorus in the anaerobic state and some of the residual nitrite or nitrate denitrates (in the case of FIG. 2 in the anaerobic tank). Is agitated by the action of the guro oxidizer 15-1 submerged in water, and in the case of FIG. 3, the agitation is performed by the action of the anaerobic agitator 15).

The mixed solution passed through the anaerobic tank 14 flows into the aerobic tank 19 and stays for about 2 hours while supplying sufficient air to maintain the dissolved oxygen concentration of about 2 to 4 mg / l, and the microorganism absorbs the phosphorus released in the anaerobic state. At this time, the excess absorption of phosphorus occurs in the microorganisms, so it absorbs 2 to 5 times of normal phosphorus, so the concentration of phosphorus in the mixed solution is very low and some of the untreated organic matter is removed here (FIG. 2, 3, 4). In the case of FIG. 5, the aerobicness is maintained by the air passing through the aeration machine 20, and in the case of FIG.

The mixed liquor having passed through the aerobic tank 19 is then solidified in the mixed liquor in the final settling basin (bar), and the purified supernatant is discharged.

Almost all of the precipitated sludge is returned to the mixing tank 1 as return sludge (e) and the remaining part is removed with excess sludge to remove the phosphorus that the microorganisms have absorbed excessively.

In addition, the residence time in the treatment apparatus is 16 hours, which is smaller than the normal residence time of 24 to 36 hours, so that the sewage can be treated more than 1.5 times more than the capacity of the existing oxidizer. Since the residence time is 8 to 11 hours long, there is enough room, so there is no need for a separate site even if the capacity of the facility increases at the same time as the advanced processing.

In addition, since no sludge is further sent to the aerobic denitrification tank except for the return sludge, the sludge pipe is not required to be changed in principle.

Another embodiment of the present invention is to use an air-fed axial stirrer 9-1 in place of the agitator and agitator of the exhalation denitrification tank.

This allows for high altitude processing without installing diffusers and blowers.

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The advanced treatment apparatus for sewage using the oxidizing sphere of the present invention has a very economical effect by using a conventional oxidizing sphere, which can be highly treated with high nitrogen removal efficiency and can increase the treatment capacity of the facility without a separate site.

Claims (1)

Oxidized sphere (A) with mixing tank (1) installed in front is partitioned into aerobic denitrification tank (4), anaerobic tank (14) and aerobic tank (19), the size of which is in the ratio of 8: 6: 2 and the retention of sewage mixture The total time is 8 hours in the aerobic denitrification tank (4), 6 hours in the anaerobic tank (14), 2 hours in the aerobic tank (19), and in the aerobic denitrification tank (4), the air supply pipes are disposed around the inner bottom. (6-2) Install several acid generators (8) evenly at regular intervals, and install the axial stirrer (9) as many times as necessary for aerobic denitrification. 11), the inlet pipe (2) and the inlet distribution pipe in the mixing tank (1) while maintaining the dissolved oxygen concentration of 0.2 ~ 0.5mg / l, the redox potential of 330mV by the airflow automatic controller (5-1) (3) flows the mixed liquid introduced into the anaerobic tank (14) through passage 1 (13) to return the mixed liquid introduced through (3) to cause denitrification with sufficient oxygen supply. In the anaerobic tank (14), a oxidizer (15-1), an anaerobic tank stirrer (15) and a redox potentiometer (2) were installed in the anaerobic tank (14) to prevent precipitation and oxidation reduction of the mixed solution introduced from the aerobic denitrification tank (4). In the anaerobic state, microorganisms release phosphorus, denitrify residual nitrite or nitrate, and reduce nitric acid contained in the mixed solution by releasing nitrogen gas into the atmosphere. Several aeration machine 20 and dissolved oxygen concentration meter 2 (21) are installed therein to supply sufficient air in the mixed liquid introduced through the passage 2 (18) in the anaerobic tank (14) to obtain a dissolved oxygen concentration of 2 to 4 mg / l. While maintaining this to absorb the phosphorus remaining in the mixed liquid by the action of aerobic microorganisms and then flowing into the final settler (bar) through the outlet 22 to discharge the purified water and precipitated sludge into the mixing tank (1) Bounce and surplus Highly sludge treatment system at a sewage using an oxidation ditch hayeoseo configured to remove processing

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