KR100421114B1 - Nitrogen-Removing Apparatus provided with Fixed-State Media and Swing Reactor and Nitrogen-Removing Process by using the Apparatus - Google Patents

Abstract

PURPOSE: An advanced sewage and wastewater treatment apparatus is provided to increase treatment efficiency, secure operation flexibility and secure adaptability and economic efficiency according to change of temperature and quality of influent, and an advanced sewage and wastewater treatment method by using the same is provided. CONSTITUTION: The advanced biological sewage and wastewater treatment apparatus comprises an anoxic tank(2) for denitrifying raw water to be treated; a compatible tank(5) used as an aerobic tank if denitrified raw water flown in from the anoxic tank has high concentration of organic matter, or ammonia or organic nitrogen and low water temperature or used as an anoxic tank if denitrification efficiency is lowered; an aerobic tank(9) in which nitrification is performed; a sedimentation tank(19) in which solid-liquid separation is performed; and a coagulation reactor(12) chemically coagulating thus removing the remaining residual phosphorus after being biologically eliminated in the anoxic tank, the compatible tank and the aerobic tank and solids temporarily separated from microbial contactor, wherein a return unit is installed between the aerobic tank and the sedimentation tank, a bypass pipe(8) for bypass of the compatible tank is installed between the anoxic tank and the aerobic tank, and a bypass pipe(14) for bypass of the coagulation reactor is installed between the aerobic tank and the sedimentation tank.

Description

Nitrogen-Removing Apparatus provided with Fixed-State Media and Swing Reactor and Nitrogen-Removing Process by using the Apparatus}

The present invention relates to an advanced treatment apparatus having a fixed bed media and a compatible tank, and an advanced treatment method using the same, and more specifically, an oxygen-free tank (2) in which denitrification of a crude treatment solution occurs; ⒝ ⅰ) It is used as an aerobic tank when the organic matter concentration or ammonia or organic nitrogen concentration in the treatment stock solution denitrified and introduced from the anoxic tank (2) is high or the water temperature is low, and ii) used as an anoxic tank when the denitrification efficiency is low. Compatible tanks (5); (Iii) an aerobic tank in which nitrification occurs; 침전 a settling tank 19 in which solid-liquid separation takes place; And (c) a coagulation reaction tank 12 which chemically aggregates and removes the residual phosphorus remaining biologically removed from the anoxic tank 2, the compatible tank 5, and the aerobic tank and the solids temporarily removed from the microbial contact material. A back conveying device is provided in the exhalation tank 9 and the settling tank 19 and between the anaerobic tank 2 and the exhalation tank 9 for bypass of the compatible tank 5 by-pass. The pass pipe 8 and between the exhalation tank 9 and the settling tank 19 are provided with a by-pass piping 14 for bypassing the flocculation reaction tank 12. The present invention relates to a processing apparatus and an advanced processing method using the same.

Generally, in order to remove nitrogen biologically, organic nitrogen and ammonia nitrogen present in sewage and wastewater are oxidized into nitric acid (NO ₂ -N) and nitric acid (NO ₃ -N) by nitrifying bacteria under aerobic conditions. These oxides (NO ₂ -N, NO ₃ -N) are treated by denitrification bacteria under anaerobic or anoxic conditions, and nitrogen gas (N ₂ ) is released from the atmosphere to remove nitrogen from the wastewater and wastewater. .

In addition, the removal of biological phosphorus can be removed through cell synthesis of microorganisms. Specifically, the release of phosphorus starts simultaneously with the storage of organic matter in anaerobic conditions, and the disposal of excess sludge that accumulates cell growth and polyphosphate under aerobic conditions. As removed.

As a component of a general microorganism (BOD: N: P = 100: 5: 1), the phosphorus content in the microorganism is 1.5 to 2%, and if appropriate conditions such as anaerobic and aerobic conditions are formed, the content may be increased. Can be.

Therefore, the formation of anaerobic (aerobic) and aerobic conditions is essential for the batch removal of biological nitrogen and phosphorus, and the A2 / O method, UCT method, VIP, which are currently developed for this purpose VIP method) and SBR (SBR) method. Among these methods, Atoo method, UCT method and VIP method include anaerobic anaerobic-aerobic tank, and nitrogen removal is oxidized to nitric acid by microorganism in aerobic tank at the end of the process, and then internal transfer pump It is made by reducing and removing nitrogen by transporting to an anoxic tank, and the removal of phosphorus is carried out by excessive ingestion of phosphorus released from the anaerobic tank at the front end of the process in an aerobic tank at the rear end and discarding the excess sludge.

However, if the process such as A2O (O2), UCT (VT) and VIP (VIP) is converted to the advanced treatment process for existing activated sludge in Korea, securing the residence time and conveying the sludge Limitation of securing the amount of microorganisms in the reactor through the problem is problematic. In particular, there is a limit to nitrogen removal because it does not achieve proper nitrification in winter when the water temperature is low, and domestic sewage has a low concentration of phosphorus in the influent, so it is easy to comply with the discharge water quality without installing an anaerobic tank, but a residence time of 0.5 to 2.0 hours Since the anaerobic tank having the gas is installed at the front end of the process, an imbalance of C (carbon) / N (nitrogen) ratio is caused, resulting in a problem of lowering of denitrification efficiency and lowering of nitrogen removal rate in an anoxic tank, and an advanced treatment process for an existing treatment plant. In this case, there is a problem that it is difficult to secure the appropriate residence time of the anaerobic tank and the aerobic tank.

Therefore, when retrofitting the devices used in the prior art activated sludge process, long-term aeration method, and catalytic oxidation method into a device capable of removing nitrogen and phosphorus collectively, it is difficult to remodel existing processes due to low utilization of the post-treatment facilities in use. This has been. In particular, when the concentration of suspended microorganisms is increased in order to secure the microbial retention time (SRT) during improvement by the advanced treatment process, the solid matter load (㎏ / ㎡.day) of the final settler may increase and settlement may deteriorate. Facility costs will increase according to the installation of the facility.

In addition, the use of an aerobic tank filled with media in the prior art has the effect of reducing the residence time of the reaction tank due to the securement of adherent microorganisms, but in the case of a change in inflow load or deviation from predetermined operating conditions, the attached microorganisms are detached and the effluent quality is reduced. This may deteriorate and requires a separate filtration facility, which increases the cost of the facility.

Therefore, in the art, it is a sewage and wastewater treatment apparatus that can further remove nitrogen and phosphorus using a device for conventional A2O method, UCT method, VIP method, etc., regardless of treatment conditions and surrounding environment. There has been a need for a microbial advanced treatment apparatus and method for sewage and wastewater which can provide economical treatment with high efficiency by providing operating conditions.

The present inventors have diligently studied to solve the above problems, and as a result, using the apparatus according to the prior art, flocculation for removing compatible solids detached from microorganisms attached to anoxic and aerobic tanks, microorganisms attached to phosphorus and stationary bed media, etc. By adding a bypass pipe for bypassing the reaction tank and the compatible tank and the flocculation reactor, it is confirmed that the treatment apparatus can be optimally operated according to the sewage / wastewater treatment conditions and the surrounding environment. Was done.

As a result, the present invention is to provide a high-treatment apparatus having a high treatment efficiency, ensuring operational flexibility, ensuring responsiveness and economical efficiency due to fluctuations in water temperature and inflow water quality, and an advanced treatment method using the same.

1 is a process diagram showing an embodiment of a high-performance processing apparatus having a compatible tank and a fixed bed media according to the present invention.

Explanation of symbols on the main parts of the drawings

1. Sewage and wastewater 2 ... Anaerobic tank

3, 6, 10 ... stationary media 4, 13 ... agitator

5 ... Compatible baths 7 ... Aeration and agitator

8, 14 By-pass piping 9 ...

11 Aeration system 12 Agglomeration reactor

15, 16 ... flocculants and alkalis 17, 18 ... chemical injection pumps

19 sedimentation tank 20 effluent

21 Internal conveying pump 22 Sludge pump

23 ... surplus sludge 24 ... blower

One aspect of the present invention for this purpose relates to an advanced treatment apparatus having a fixed bed media and a compatible tank, and an advanced treatment method using the same, in more detail, an oxygen-free tank (2) in which denitrification of the treatment stock solution occurs; ⒝ ⅰ) It is used as an aerobic tank when the organic matter concentration, the ammonia or organic nitrogen concentration, or the water temperature is low in the treatment stock solution denitrified and introduced from the anoxic tank (2), and ii) as the anoxic tank when the denitrification efficiency is low. Compatible tanks (5); (Iii) an aerobic tank in which nitrification occurs; 침전 a settling tank 19 in which solid-liquid separation takes place; And (c) a coagulation reaction tank 12 which chemically aggregates and removes the residual phosphorus remaining biologically removed from the anoxic tank 2, the compatible tank 5, and the aerobic tank and the solids temporarily removed from the microbial contact material. A back conveying device is provided in the exhalation tank 9 and the settling tank 19 and between the anaerobic tank 2 and the exhalation tank 9 for bypass of the compatible tank 5 by-pass. The pass pipe 8 and between the exhalation tank 9 and the settling tank 19 are provided with a by-pass piping 14 for bypassing the flocculation reaction tank 12. It relates to a processing apparatus.

Further, another aspect of the present invention relates to an advanced processing method using the advanced processing apparatus.

Hereinafter, the present invention will be described in more detail.

Sewage and wastewater flowing into the anoxic tank (2) are introduced via sedimentation and screening equipment and / or initial settler. Such a pretreatment step is known, and when the coarse sewage / wastewater flows into the anoxic tank (2) by pressure or gravity, the nitrates in the return water returned from the aerobic tank in the downstream stage by using the organic carbon source in the introduced raw stock solution A denitrification process takes place that denitrates nitrogen (NO ₂ -N, NO ₃ -N). The anoxic bath preferably comprises a fixed phase media with microorganisms attached.

Waste water, which has undergone the denitrification process in the anoxic tank (2), is introduced into a compatible reactor (Swing Reactor: (5)). The compatible tank 5 preferably comprises a stationary media with microorganisms attached thereto. If the organic matter concentration and / or the ammonia or organic nitrogen concentration of the feedstock introduced into the compatible tank (5) are high, or the water temperature is low, it is difficult to achieve the planned effluent water quality standard, so that the efficiency of the nitrification process can be improved. Play a role. Specifically, the biochemical oxygen demand (BOD) or chemical oxygen demand (COD) of the effluent 20 is higher than the planned discharge quality standard, or the nitrogen concentration in the influent is higher than the planned influent quality because the concentration of organic matter in the influent is high. When the water temperature is low and the discharged water quality standard is exceeded due to the concentration of ammonia nitrogen and organic nitrogen in the nitrogen (TN) concentration in the effluent 20, the compatible tank is used as an aerobic tank. However, when the denitrification efficiency of the anoxic tank 2 is low, specifically, the denitrification efficiency of the anoxic tank 2 is low and is discharged due to nitrate nitrogen (NO ₃ -N and NO ₂ -N) in the nitrogen (TN) concentration in the effluent 20. When the water quality standard is exceeded, the compatible tank 5 serves as an oxygen-free tank to increase the denitrification efficiency. In some cases, in order to be used as an aerobic tank or anoxic tank, the compatible tank is, for example, equipped with aeration and agitation device. In some cases, if the denitrification process in the anoxic tank (2) and the nitrification process in the aerobic tank (9) occur at a desired efficiency due to the condition of the processing stock solution or the surrounding environment of the processing apparatus, the use of a compatible tank is not necessary. The processed crude solution is directly introduced into the aerobic tank (9) from the anaerobic tank (2) by bypassing the compatible tank (5) through the bypass pipe (8) installed between the anoxic tank (2) and the aerobic tank (9). This can greatly reduce the power in the treatment process.

In the aerobic tank 9, oxidation, ammonia, or organic nitrogen of the remaining organic material used in the denitrification process occurs. The aerobic tank 9 preferably comprises a stationary bed medium to which microorganisms are attached.

The apparatus according to the invention is characterized in that the dephosphorization in the anoxic tank (2), the compatible tank (5) and the aerobic tank (9), residual phosphorus not removed in the nitrification process, and the anoxic tank (2), the compatible tank (5) and the aerobic tank (9) An agglomeration reaction tank 12 for removing suspended solids temporarily detached from the adherent microorganisms in the fixed bed medium of is provided. In the actual treatment step, if desired discharge water quality does not require the operation of the reactor, it is possible to bypass the flocculation reactor 12 through a bypass pipe provided between the aeration tank 9 and the settling tank 19. Can be. More specifically, the effluent 20 is discharged due to residual phosphorus which is not removed in the anoxic tank 2, the compatible tank 5 and the aerobic tank 9 and solids by temporary desorption from microorganisms attached to the media. If the water quality standard is exceeded, it passes through the agglomeration reactor 12, otherwise it is bypassed.

The present invention further provides an advanced treatment method using the aforementioned microbial advanced treatment apparatus for sewage and wastewater.

Hereinafter, the above-described apparatus and method of the present invention will be described in detail with the accompanying exemplary drawings.

1 is a schematic view showing one preferred embodiment of the advanced treatment apparatus for sewage and wastewater according to the present invention. In the figure, the sewage and wastewater 1, which has undergone a predetermined pretreatment (the pretreatment device is not shown in FIG. 1), enters the anoxic tank 2 filled with the stationary phase media 3 and is internally formed in the aerobic tank 9 at the rear stage. The mixed sludge nitrified by the conveying pump 21 and the settling sludge conveyed by the excess sludge pump 22 to maintain the suspended microbial concentration in the anoxic tank are mixed and biologically denitrated.

The denitrified mixed solution flows into the compatible tank 5 filled with the fixed-phase media 6, and the compatible tank 5 has a high concentration of organic matter or high concentration of ammonia nitrogen or organic nitrogen, or low water temperature. If no appropriate nitrification occurs in 9), the air is supplied from the blower 24 to the aeration and stirrer 7 to be used as the aeration tank 9, and if there is no problem in nitrification but the denitrification efficiency is low, the aeration and agitator ( 7) Mix it simply and use it as an oxygen free tank. On the other hand, if the denitrification efficiency and nitrification degree are within the desired range depending on the inflow water quality and external conditions, the denitrification mixture is exchanged through the bypass pipe (8) from the oxygen-free tank (2) to the aerobic tank (9). Bypass (5).

By-pass pipe (8) in the anoxic tank (2) bypassed, or the processing crude liquid passed through the compatible tank (5) flows into the aeration tank (9) filled with the stationary phase media (10) blower (24) Oxygen is supplied from the oxygen through the aeration device 11 to perform the oxidation and nitrification process. A part of the nitrified liquid mixture in the aeration tank 9 is returned to the anoxic tank 2 for denitrification through the internal transfer pump 21.

Nitrified mixed solution in the aerobic tank (9) at the front end flows into the coagulation reaction tank (12), where it is temporarily desorbed from residual phosphorus and media remaining biologically removed from the anoxic tank (2), compatible tank (5), and aerobic tank (9). In order to remove the solids, the flocculant 15 and the alkaline agent 16 for alkaline replenishment are injected into the chemical supply pumps 17 and 18, and the floc floc is separated from the solid solution together with the suspended microorganisms in the settling tank 19. To remove it. The apparatus according to the present invention is configured to be introduced into the settling tank 19 through the bypass (By-pass) pipe 14 in the exhalation tank of the front end, it is possible to ensure the operational flexibility and economics at the same time.

The supernatant separated from the solid solution in the settling tank 19 is discharged and the sludge precipitated is returned or disposed of through the excess sludge pump 22 to maintain the mixed microbial concentration of the reactor.

In the case of the advanced treatment apparatus for sewage and wastewater using the fixed bed media and the compatible tank and the method using the same according to the present invention, the fixed bed media is filled in the reaction tank, thereby reducing the volume of the reaction tank and reducing the solids loading of the final settling tank, thereby increasing the treatment efficiency. In addition, by installing a compatible tank that can be used as an oxygen-free tank and an aerobic tank, it secures flexibility in operation, and by installing a coagulation sedimentation tank at the rear, it reduces the amount of flocculant used by removing the remaining phosphorus and biologically removed. By-pass piping can be configured to allow selective operation to ensure convenience and economy.

While the invention has been shown and described with respect to particular embodiments, it will be understood that various changes and modifications can be made in the art without departing from the spirit or scope of the invention as set forth in the claims below. It will be clear to those skilled in the art that they can easily know.

Claims (5)

An anoxic tank (2) in which denitrification of the processing stock solution takes place; ⒝ ⅰ) It is used as an aerobic tank when the organic matter concentration or the ammonia or organic nitrogen concentration or the water temperature is low in the treatment stock solution denitrified and introduced from the anoxic tank (2), and ii) as the anoxic tank when the denitrification efficiency is low. Being compatible tank 5; 호 an aerobic tank (9) in which nitrification occurs; A sedimentation tank 19 in which solid-liquid separation takes place; And (c) a coagulation reaction tank 12 which chemically coagulates and removes the residual phosphorus remaining biologically removed from the anoxic tank 2, the compatible tank 5, and the aerobic tank and the solids temporarily removed from the microbial contact material. And a back conveying device in the exhalation tank 9 and the settling tank 19, and a by-pass for bypassing the compatible tank 5 between the anaerobic tank 2 and the exhalation tank 9. The pass pipe 8 and between the exhalation tank 9 and the sedimentation tank 19 are provided with a by-pass piping 14 for bypassing the flocculation reaction tank 12, the biological altitude of the sewage and wastewater. Processing unit. 2. An advanced processing apparatus according to claim 1, wherein at least one of the anoxic tank (2), the compatible tank (5), and the aerobic tank (9) further comprises a fixed bed media. 2. The advanced processing apparatus according to claim 1, wherein the compatible tank (5) is provided with aeration and agitation means. An advanced treatment method using the apparatus according to any one of claims 1 to 3, wherein the compatible tank (5) includes: i) organic matter in the treatment stock solution denitrified from the anoxic tank (2) or ammonia or When the organic nitrogen concentration is high or the water temperature is low, it is used as an aerobic tank. Ii) When the denitrification efficiency is lowered, it is used as an anoxic tank. Iii) Bypassing the compatible tank (5) except for the above (iv) and ii). Advanced biological treatment of sewage and wastewater. 5. The effluent 20 according to claim 4, wherein residual phosphate which has not been removed in the anoxic tank 2, the compatible tank 5 and the aerobic tank 9, and solids by temporary desorption from the microorganisms attached to the media are discharged. When the discharged water quality standards are exceeded, the coagulation reactor 12, otherwise, by-pass it.