KR100740579B1 - Advanced wastewater treatment apparatus and method improved from existing waste water treatment process using activated sludge method - Google Patents

Abstract

The present invention includes a reaction tank, a settling tank, a blower for supplying air to the settling tank, and a conveying pump for returning the return water discharged from the settling tank to the reaction tank, wherein one or more diaphragms are provided in the reaction tank, Each divided reactor compartment is equipped with a stirrer as necessary, and the sedimentation tank is equipped with an active sludge process, characterized in that the continuous aeration by air supplied from the blower and an immersion type membrane for performing membrane filtration. Provided is an advanced treatment apparatus and method from sewage treatment processes. According to the present invention, in the improvement of the sewage treatment process using the conventional activated sludge process to a high treatment process capable of treating nitrogen and phosphorus, the cost of improvement to the advanced treatment process is increased because the existing reactor and the equipment are used as it is. It is economical and effective because it is saved and does not require any site for additional reactor installation. In addition, by producing the treated water by membrane filtration process, complete solid-liquid separation is achieved, so it is possible to maintain highly clean treated water without E. coli or pathogenic microorganisms without chemical disinfection process. It can be reused as heavy water such as water, car wash, landscaping water and road cleaning water.

 Advanced treatment, activated sludge, reactor, diaphragm, sedimentation tank, dipping membrane, plug flow

Description

Improved advanced treatment system and method from existing sewage treatment process using activated sludge process TECHNICAL FIELD

1 is a schematic diagram showing an advanced treatment apparatus from an existing sewage treatment process utilizing an activated sludge process according to the present invention.

* Explanation of symbols for main parts of drawings *

10: influent 20: treated water

30: conveying 40: conveying pump

50: blower 60: immersion type membrane

70: reactor 80: diaphragm

90: stirrer 100: excess sludge drawing

110: sedimentation tank

The present invention relates to an advanced treatment apparatus and method that is improved from existing sewage treatment processes using activated sludge processes. Specifically, the present invention relates to an advanced treatment apparatus and method using an existing sewage treatment process for removing organic matter and particulate matter in sewage through an activated sludge process to improve the treatment of nitrogen and phosphorus.

Currently, stricter water quality standards are being applied to prevent eutrophication of rivers and lakes, and this trend will be further strengthened in the future.

In particular, nitrogen and phosphorus contained in sewage and wastewater may cause eutrophication if left untreated and adversely affect water resources and aquatic ecosystems, and cyanosis when infants drink large amounts of nitrate-containing water. This is necessary.

Thus, been devised a variety of processes combine the microfiltration membrane to the existing advanced treatment process to increase the treatment efficiency of the nitrogen and phosphorus, MLE, A ₂ O, MBR was immersed a precision filtration membrane in the process, such as SBR, Phostrip, Badenpho (Membrane Bio-Reactor) is a typical example.

However, the MLE, Phostrip, Badenpho type MBR cannot be expected to remove nitrogen and phosphorus simultaneously, and in case of A ₂ O type, a large site is required, and in the case of the SBR type MBR, the unit throughput is small. .

In addition, most of the processes have a disadvantage in that their biological functions are not exhibited under ideal conditions due to sewage characteristics such as lack of organic carbon sources, fluctuations in sewage properties during summer and winter.

In addition, the processes have a big disadvantage that the structural change is inevitable when applied to the existing sewage treatment facility because the plurality of reactors must be arranged.

One of the conventional treatment methods is a "drainage treatment method" of Japanese Patent Application Laid-open No. Hei 7-100486. In this method, a first treatment tank for inducing nitrification and denitrification through intermittent aeration and an immersion membrane for solid-liquid separation are installed. The second treatment tank is configured to allow nitrogen removal and continuous suction filtration.

However, this method cannot create an anaerobic condition for the removal of phosphorus, so that phosphorus removal cannot be effectively achieved, and a second treatment tank is installed separately for continuous suction filtration to operate to prevent contamination of the separation membrane. There is a drawback that the additional cost of aeration is a double energy cost for aeration.

On the other hand, another conventional method is a "biological nitrogen and phosphorus removal device and method using an immersion membrane" of the Republic of Korea Patent Publication No. 2002-0044820, this method is installed anaerobic tank, anaerobic tank, aerobic tank, degassing tank sequentially It leads to simultaneous removal of nitrogen and phosphorus.

However, this method also requires the addition of anaerobic tanks for phosphorus removal, and in the case of sewage with low C / N ratios, most of the carbon sources are used for denitrification in the anoxic tanks installed at the front end of the tanks. There is a shortcoming such as the limitation of the removal of phosphorus due to lack.

Accordingly, the present invention is to solve the problems of the prior art as described above, an object of the present invention, the existing sewage treatment facility without the addition of additional reactor construction or the introduction of a new facility to the sewage treatment facility of the existing activated sludge process. While it is possible to treat organic matter in sewage and wastewater with maximum use, it can remove nitrogen and phosphorus, which are substances of eutrophication of lakes and streams economically and effectively, and can treat various pathogenic microorganisms such as E. coli without chemical disinfection process. It is to provide an advanced treatment apparatus and method from the existing sewage treatment process using the activated sludge process, which can reuse the produced treated water as heavy water such as toilet water, car wash water, landscaping water and road cleaning water without further treatment. .

In order to achieve the object as described above, the advanced treatment apparatus improved from the existing sewage treatment process using the activated sludge process according to the present invention, the reactor, the settling tank, the blower for supplying air to the settling tank and discharged from the settling tank And a conveying pump for conveying the returned conveyed water to the reactor, wherein one or more diaphragms are provided in the reactor, and each reactor compartment divided by the diaphragm is provided with a stirrer as necessary, and in the settling tank from the blower It is characterized in that the immersion-type separator is installed is a continuous aeration and membrane filtration by the supplied air.

In the advanced processing apparatus according to the present invention, at least two diaphragms are installed in the reactor.

In the advanced processing apparatus according to the present invention, the immersion type separation membrane is characterized in that the flat membrane type, hollow desert type, tubular microfiltration membrane or ultrafiltration membrane.

In order to achieve the above object, the advanced treatment method improved from the existing sewage treatment process using the activated sludge process according to the present invention, the treated water discharged from the reaction tank is introduced into the sedimentation tank and the return water discharged from the sedimentation tank An advanced treatment method for returning the reactor to the reactor, one or more diaphragms are installed in the reactor, and a plug-flow is induced in the inflow and the return water flowing into the reactor, so that the inflow and the return water are sheared in the reactor. Shifting from the anaerobic condition to the anaerobic condition while moving from end to end (S1); And immersing and separating the membrane into the sedimentation tank and supplying air to continuously discharge and filter the membrane permeate water under aerobic conditions, and include nitrate nitrogen generated by nitrification in the returned water to move to the reaction tank. Characterized in that it comprises a; (S2) for drawing excess sludge to the outside of the settling tank in a state in which phosphorus is excessively ingested in aerobic conditions.

Advanced processing method according to the invention, characterized in that to install at least two or more diaphragms in the step S1.

Advanced processing method according to the present invention, characterized in that using a suction pump for suction filtration during membrane filtration using the immersion type membrane in the step S2 or using a natural suction pressure due to water head difference.

Hereinafter, an advanced treatment apparatus and method improved from the existing sewage treatment process using the activated sludge process according to the present invention will be described in detail.

In the present invention, to improve the existing sewage treatment process using the activated sludge process to perform the advanced treatment capable of removing nitrogen and phosphorus, install a diaphragm in the existing aerobic reactor without installing a separate reactor to induce plug flow do.

As a result, an anoxic state due to oxygen depletion and an anaerobic state due to exhaustion of nitrate nitrogen are sequentially formed while the treated water (inflow water and return water) flows to the front end and the rear end of the reaction tank. In the anoxic state, nitrogen is removed by a denitrification reaction in which nitrate nitrogen is reduced to nitrogen gas, and a phosphorus release reaction occurs in the anaerobic state.

Furthermore, in the present invention, the sedimentation tank is connected to the sedimentation tank, and the immersion type separation membrane is installed in the sedimentation tank, and continuous suction filtration is performed without rest period while maintaining aerobic conditions inside the sedimentation tank by supplying air to prevent the contamination of the separation membrane. To drain the permeate. On the other hand, the settling tank can be used as is the existing settling tank.

In addition, excessive intake of phosphorus occurs under the aerobic condition, and sludge disposal is performed while phosphorus is ingested excessively to finally remove phosphorus. In addition to the excessive intake of phosphorus occurs a nitrification reaction and the resulting nitrate nitrogen is returned to the front end to induce an oxygen free state in the front end of the reactor.

1 is a schematic diagram showing an advanced processing apparatus according to the present invention. As shown in FIG. 1, the advanced treatment apparatus according to the present invention includes a reaction tank 70 and a settling tank 110 connected thereto, and returns water 30 between the reactor 70 and the settling tank 110. ) Is provided with a conveying pump 40 for conveying.

The reactor 70 uses an existing aerobic reactor but preferably at least two or more diaphragms 80 are formed therein to form at least three or more compartments. Accordingly, in the first section, the oxygen concentration of the return water returned from the settling tank is reduced, in the second section, anoxic conditions are induced, and in the third section, the anaerobic conditions are induced. In each of the regions within the reaction tank 70 partitioned by the diaphragm 80, a stirrer 90 is provided as necessary to mix the microorganisms with the inflow water or the return water.

The diaphragm 80 is to prevent complete mixing in the entire reaction tank 70, and as will be described in more detail below, the inflow water 10 and the return water 30 introduced into the front end end of the reaction tank 70 from the front end of the reaction tank 70 This is to allow the transition from anaerobic conditions to anaerobic conditions while moving in the form of a plug flow.

An immersion type separation membrane 60 is installed in the settling tank 110, and a blower 50 for supplying air into the settling tank 110 is connected thereto.

Referring to the advanced treatment method according to the present invention, first, the activated sludge mixed liquid which is the return water 30 conveyed by the return pump 40 from the inflow water 10 and the settling tank 110 which is treated water is sheared in the reaction tank 70. Flows into.

At this time, anoxic conditions are formed at the front end of the reaction tank 70 by the nitrate nitrogen present in a large amount in the returned activated sludge mixed liquid, and moved to the rear end, using the organic material in the influent 10 as a carbon source. The denitrification process is carried out to convert to remove the nitrogen gas. In this way, anaerobic state is formed when the nitrate nitrogen remaining in the mixed solution is completely depleted by the continuous denitrification while moving to the rear stage.

When the anaerobic state is formed, phosphorus release by dephosphorous microorganisms occurs using a carbon source included in the influent 10. The treated water flowing out of the reaction tank 70 is introduced into the settling tank 110, in the settling tank 110 to lower the concentration of phosphorus in the mixed solution through the excess intake of the phosphorus of the microorganism under aerobic conditions, and dipping the mixed solution in which the excess phosphorus is ingested Use (60) to discharge continuously without rest periods. At this time, the submerged membrane 60 is a flat membrane, hollow fiber membrane, tubular microfiltration membrane or ultrafiltration membrane, and using a suction pump or suction head for suction filtration during membrane filtration using the submerged membrane 60 Use natural suction pressure by

In the process of supplying air from the blower 50 outside the sedimentation tank 110 to prevent membrane contamination by inducing shear force by air bubbles on the immersion type separation membrane 60, the sedimentation tank 110 maintains an aerobic state. Can be.

Under such an aerobic condition, with the excess intake of phosphorus as described above, a nitrification reaction occurs in which ammonia nitrogen is converted to nitrate nitrogen, and the nitrate nitrogen thus produced is included in the return water 30 to convey pump 40. By the transfer to the front end of the reaction tank (70).

The sedimentation tank 110 induces a state in which phosphorus is excessively ingested in the aerobic condition, and in this state, the excess sludge is drawn to the outside of the sedimentation tank to finally remove phosphorus.

Although the present invention has been described in detail above with reference to the drawings, it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention, and such modifications and variations are included in the appended claims. It is natural to belong.

As described above, according to the present invention, in the improvement of the sewage treatment process using the existing activated sludge process to a high treatment process capable of treating nitrogen and phosphorus, the conventional reactor and the facility are used as it is, so that the advanced treatment It is economical and effective because the cost of retrofitting to the process is reduced and there is no need for additional reactor installation. In addition, by producing the treated water by membrane filtration process, complete solid-liquid separation is achieved, so it is possible to maintain highly clean treated water without E. coli or pathogenic microorganisms without chemical disinfection process. It can be reused as heavy water such as water, car wash, landscaping water and road cleaning water.

Claims (5)

In the advanced treatment apparatus for sewage and wastewater having a reaction tank, a sedimentation tank, and a conveying pump for returning the return water discharged from the settling tank to the reaction tank, The reactor is divided into compartments by at least one diaphragm installed in the reactor, Among the compartments Oxygen-free compartment located in the front end of the reactor, in which wastewater flows in and is connected to the conveying pump to receive the conveyed water, An anaerobic compartment located at the end of the reactor, receiving wastewater and returned water from the anoxic compartment, and passing the treated wastewater and returned water to the settling tank; The settling tank includes an immersion type separation membrane for receiving and continuously filtering the treated water from the reaction tank and a blower for supplying air to the immersion type separation membrane, characterized in that to send a portion of the treated water received to the conveying pump, Advanced treatment device that improves the sewage treatment device of the existing activated sludge process. The method of claim 1, At least two diaphragms are installed in the reactor. The method of claim 1, The immersion type separation membrane is an advanced processing apparatus, characterized in that the flat membrane, hollow fiber membrane, tubular microfiltration membrane or ultrafiltration membrane. In the advanced treatment method for flowing the treated water outflow from the partitioned reaction tank into the settling tank and returning the return water discharged from the settling tank to the partitioned reaction tank, Inflow of wastewater and return water is directed to an anoxic section of the front end of the reaction vessel partitioned by one or more diaphragms installed in the reactor to induce a plug flow by the diaphragm, and the inflow and return water pass through the anaerobic compartment and end portions of the reactor. Depleting oxygen while moving in the anaerobic compartment direction (S1); And Oxygen depletion of the inflow water and the return water from the anoxic compartment in the reaction tank in the anaerobic compartment direction to cause denitrification to remove nitrate nitrogen (S2); The microorganisms in the influent and return water received from the anoxic compartment release phosphorus in the anaerobic compartment and the treated influent and the return water move to the settling tank as treated water (S3); Induced phosphorus excess intake of the microorganisms in the influent, return water and reactor through the aeration tank to remove phosphorus in the treated water and nitrify the ammonia nitrogen in the influent to nitrate nitrogen under aerobic conditions Meanwhile, the treated water is continuously suction-filtered in the sedimentation tank to discharge the final effluent through solid-liquid separation, and the microorganism and the nitrate nitrogen ingested with the phosphorus are included in the returned water to the anoxic compartment of the reactor. Moving step (S4) and Characterized in that it comprises the step (S5) to finally remove the phosphorus by drawing a portion of the excess sludge in excess of phosphorus in the sedimentation tank, Advanced treatment method that improves the sewage treatment process of the existing activated sludge process. The method of claim 4, wherein And a natural suction pressure using a suction pump for suction filtration during membrane filtration using the submerged membrane in the step S4, or water head difference.

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