KR100636340B1 - Sequential batch reactor with anoxic process of biofilm for sewerage and its sewerage methods - Google Patents

Abstract

An apparatus and a method for wastewater treatment which greatly improve removal efficiencies of nitrogen and phosphorous through internal circulation by installing a three-stage aeration structure and a contact media layer within a batch reactor are provided. An apparatus for treating wastewater using an anoxic region of a biofilm in a single reactor comprises: a housing(3) of which an inner part is divided into a flow equalization tank(2), a reaction tank(1), a disinfection/discharge tank(5) and a sludge treatment tank(4); a metering pump(12) installed within the flow equalization tank; a contact media layer(6) installed within the reaction tank in a manner that the contact media layer is distanced from the bottom of the reaction tank to form a predetermined space therebetween; upper, middle and lower aeration nozzle groups(16,17,18) sequentially installed at an upper part of the contact media layer; an air supply device(10) for supplying air to the upper, middle and lower aeration nozzle groups; an electronic valve(11) installed on an air supply pipe for connecting the air supply device and the upper, middle and lower aeration nozzle groups; an internal circulation pump(13) installed in an upper part within the reaction tank; a nonpower floating type discharge pump(14) lifted and lowered along a guide pipe vertically installed within the reaction tank; underwater pumps for agitation(22,23) installed at predetermined locations within the reaction tank; a sludge transfer pump(15) for intermittently transferring excess sludge in a lower part of the contact media layer to the sludge treatment tank; a detection sensor part(41) connected to sensors installed within the reaction tank to detect dissolved oxygen(DO), hydrogen ion concentration(pH), oxidation reduction potential(ORP), mixed liquor suspended solid(MLSS), and water level in the reaction tank; and a control part(40) for controlling the electronic valve, the pumps and the air supply device according to detection signals generated by the detection sensor part.

Description

Sequential batch reactor with anoxic process of biofilm for sewerage and its sewerage methods

1 is an exemplary view showing the overall configuration according to the present invention

2 is a three-stage aeration nozzle distribution in accordance with the present invention

3 is a process chart showing a sewage treatment step according to the present invention.

Figure 4 is an exemplary view showing a cross-sectional configuration of the reaction tank according to the present invention

5 is a block diagram showing a process step according to the present invention;

<Description of the symbols for the main parts of the drawings>

(1): reaction tank (2): flow rate adjusting tank

(3): housing (4): sludge treatment tank

(5): Disinfection / discharge tank (6): Contact media layer

(7): sludge lamination (10): air supply device (blower)

(11): Electronic valve (air supply control device) (12): Metering pump

(13): Internal circulation pump (14): Floating discharge pump

(15): sludge conveying pump (16): upper aeration nozzle group

(17): interrupted aeration nozzle group (18): lower aeration nozzle group

(22): submersible pump for central stirring (23): submersible pump for lower stirring

(24): Raw water supply pipe (25): Internal circulating water transfer pipe

31: buoy 32: floater guide pipe

(33): Hose for discharging treated water 40: Control part

(41): detection sensor unit 50: upper right aeration nozzle

(51): Upper left aeration nozzle (52): Interrupted right aeration nozzle

53: interrupted left aeration nozzle 54: lower right aeration nozzle

(55): Lower left aeration nozzle (80): Air supply pipe

The present invention relates to a sewage treatment apparatus using an anoxic region of a biofilm in a single reactor and a sewage treatment method thereof, and more particularly, to remove nitrogen and phosphorus through internal circulation by providing a three-stage aeration structure and a contact media layer in a batch reactor. The present invention relates to a sewage treatment apparatus and a sewage treatment method which are greatly improved.

In general, nitrogen and phosphorus in biological sewage and wastewater treatment methods act as essential nutrients of protein and nucleic acid synthesis for the activity and growth of microorganisms. However, when nutrients such as nitrogen and phosphorus are contained in the water, eutrophication due to the rapid reproduction of autotrophic organisms, such as algae, may lead to the growth of algae, phytoplankton in the water. This will cause water pollution.

Therefore, nitrogen and phosphorus items were added (TN = 60mg / l, TP = 8mg / l) to the treatment plant effluent water quality standard, and recently, the water quality standards were total nitrogen (TN) = 20mg / l and total phosphorus (TP) = 2mg / It has been lowered to l, and these effects have led to the introduction of advanced biological treatment processes to remove nitrogen and phosphorus in recent sewage treatments.

The biological nitrogen removal process converts organic nitrogen or ammonia nitrogen present in sewage and wastewater into nitric acid through nitrification in aerobic state, and performs denitrification by converting the nitrate nitrogen thus produced into nitrogen gas in anoxic state. In the denitrification reaction, a biosynthetic denitrification method using a hydrogen donor and an endogenous respiratory denitrification method using endogenous respiration of denitrifying microorganisms are used.

In addition, the biosynthetic denitrification can be divided into a method of using organic substances in wastewater as a hydrogen donor and a method of adding drugs such as methanol and acetic acid.

On the other hand, nitrogen present in the sewage and waste water is removed through the two processes.

Biological removal process is based on the microorganism's luxury uptake phenomenon. In activated sludge, there is Acinetobacter species that can ingest excessive phosphorus, and Poly-P microorganism is mainly used. When the aerobic and aerobic states are repeated, the activity of Poly-P microorganisms becomes more active than usual and the intake of phosphorus increases accordingly, and it is possible to increase the phosphorus removal efficiency by removing the microorganisms having high phosphorus content with sludge. Is the principle. For reference, the phosphorus content ratio of general microorganisms in activated sludge is 2 ~ 3%, but the poly-P microorganism is 5 ~ 10% higher than this.

Various treatment methods have been proposed to treat the waste water as described above, but the batch method (SBR) method has been in the spotlight for environmental reasons, installation space, and maintenance / repair costs.

The batch method combines spatially divided reaction tanks into one single reactor so that each reaction proceeds in the order of time. In one reactor, inflow, anaerobic, aerobic, precipitation, and discharge are performed in order of time. The following describes the general function of the SBR reactor.

During the fill period, the sewage is brought into contact with the microorganisms remaining in the reactor and filled to the desired volume. During the inflow period, anaerobic reactions take place, denitrification and phosphorus release.

The reaction period consists of an aerobic reaction time for supplying oxygen and an anaerobic or anoxic reaction time without supplying oxygen. During this time, not only organic matter but also nitrogen and phosphorus can be simultaneously removed. During the reaction period, the aerobic / anaerobic state is repeated periodically.

The settle period is a step of separating solid-liquid from the mixed liquor, and has a high settling efficiency as a static flow with no influent flow during the settling period. SBR is used for the microorganisms in which sedimented sludge is required for the reaction in the next cycle without recycling the sludge.

In the draw period, a fixed discharge pump or a floating discharge pump is used so that there is no shaking of the settling sludge during discharge of the solid-liquid supernatant, and various discharge methods are used.

This batch method has not been activated because it requires a highly automated operation system, but it is widely used as a generalization of recent automation technology and sensor technology. In Korea, various kinds made by changing the machinery or part of the SBR process SBR variants are applied, such as Fluidyne SBR, Jet Tech Omniflo SBR, CASS SBR, KIDEA, ICEAS, Aqua-MSBR, Swirl Vortex-SBR, and Bumyang Continuous Batch Activated Sludge (PSBR). The treatment principles of these methods are all similar, and the biggest difference of each method is the difference between sewage inflow method and machinery.

Meanwhile, the various types of SBR processes effectively remove BOD, COD, and SS, but are difficult to remove nitrogen and phosphorus simultaneously.

In general, phosphorus accumulation microorganisms accumulate in the form of poly-β-hydroxybutyl acid (PHB) and release phosphorus, as well as when nitrogen nitrate (NO _X _N) is released (denitrified) into nitrogen (N ₂ ) gas. Even when organic matter is needed. As such, organic matter plays an important role in the removal of nitrogen and phosphorus contained in the sewage, it is important to properly distribute the limited organic matter to denitrifying microorganisms and condensation microorganisms.

However, when there is a competition between the accumulation of microorganisms and the denitrification microorganisms, the denitrification microorganism becomes a dominant species by first ingesting organic matters compared to the accumulation microorganisms. Therefore, it is necessary to reduce the interference of toxic toxic substances of nitrate nitrogen by supplying the limited organic material to the microorganism as soon as possible, so that the simultaneous treatment of nitrogen and phosphorus can occur by activating the activity of the weaker microorganism, which is relatively weaker than the denitrifying microorganism. .

At present, due to the characteristics of sewage and wastewater in Korea, the concentration of organic matter necessary for removing nitrogen and phosphorus is low, which is disadvantageous in terms of nutrient removal, and there is a lack of a system capable of predominantly growing microorganisms necessary for simultaneous removal of nitrogen and phosphorus. There was a problem that is not suitable as a medium / small sewage treatment system.

The present invention is devised to solve the conventional problems as described above, the object is to form a biofilm by installing a contact media layer in the lower part of the reaction vessel so that the release of phosphorus first when the raw water is injected, the vortex (Vortex) ) It has a three-stage aeration structure for formation to promote the oxidation reaction according to the increase of oxygen utilization efficiency, and the nitrified upper treated water is always managed under the dissolved oxygen concentration of 0.2ppm or less by DO and ORP control. Actively denitrification by circulating to the area, and by increasing the number of repetitions by making the repetition time of anaerobic and aerobic as short as possible, induces the uptake of phosphorus caused by the stress of microorganisms to increase cell synthesis. Improves phosphorus removal efficiency and reduces oxygen reaction time, reducing overall cycle time and residence time Compared with the conventional SBR method, the additional equipment according to the mechanical equipment and treatment functions is greatly reduced, so that the sewage treatment apparatus using the anoxic zone of the biofilm and its sewage treatment method in a single reactor can reduce the equipment and maintenance cost. In providing.

1 is an exemplary view showing the overall configuration according to the present invention, Figure 2 is a three-stage aeration nozzle distribution according to the present invention, Figure 3 is a process diagram showing a sewage treatment step according to the present invention, Figure 4 according to the present invention 5 is a block diagram showing a cross-sectional structure of the reaction vessel, Figure 5 shows a block diagram showing a process step according to the present invention, the present invention is a flow rate adjustment tank (2), reaction tank (1), disinfection / discharge tank (5), The housing 3 is divided into a sludge treatment tank 4, and a contact medium layer 6 is installed at the lower end of the reactor 1 to supply the limited microorganisms to the accumulating microorganisms as soon as possible. By reducing the interference of toxic substances of nitrogen (NO _X _N), it activates the activity of the weaker microorganisms, which are relatively weaker than the denitrifying microorganisms, and also has a high concentration of suspended solids due to the adherent microorganisms fixed in the contact media layer (6). MLSS) to maintain nitrogen and phosphorus It is configured so that simultaneous processing can easily occur.

That is, the present invention is a housing 3 partitioned into a flow adjusting tank 2, a reaction tank 1, a disinfection / discharge tank 5, a sludge treatment tank 4, and the inside of the flow adjusting tank 2; The fixed quantity transfer pump 12 which is installed and supplies the raw water stored in the flow rate adjusting tank 2 to the lower part of the reaction tank 1 through the raw water supply pipe 24, and spaced apart to form a predetermined space from the bottom of the reaction tank 1 And the upper, middle and lower aeration nozzle groups 16, 17, and 18 provided in this order, and the upper, middle and lower aeration nozzle groups 16, respectively. On the air supply pipe (80) for connecting the air supply device 10 for supplying air to the 17, 18, and the air supply device 10 and the upper, middle and lower aeration nozzle group (16, 17, 18) The electronic valve 11 installed above and the supernatant water nitrified in the reaction tank are circulated to the oxygen-free region under the contact media layer through the internal circulation water transfer pipe 25 according to a control signal. A non-powered floating discharge pump 14 which ascends and descends along the inner circulation pump 13 and the guide pipe 32 installed vertically in the reaction tank 1 and discharges the treated water to the disinfection / discharge tank 5; Sludge transfer for feeding the water pump 22, 23 for stirring the sludge and the excess sludge under the contact medium layer 6 intermittently to the sludge treatment tank 4 installed at a predetermined position in the reaction tank 1 The pump 15 and the inside of the reaction tank 1 are installed so that dissolved oxygen concentration (DO), hydrogen ion concentration (pH), redox potential (ORP), suspended solids concentration (MLSS) and water level (WLG) in the reaction tank. A detection sensor unit 41 connected to the detecting sensor and detecting the detection sensor 41, the electronic valve 11, the pumps 12, 13, 14, 15, and air supply according to a detection signal generated by the detection sensor unit 41. It consists of the control part 40 which controls the apparatus 10. FIG.

The housing 3 is made of fiberglass reinforced plastic (FRP) or concrete structure.

Inside the flow rate adjustment tank (2), a fixed quantity feed pump (12) for supplying raw water to the reactor (1) by a predetermined amount is installed, and the raw water supply pipe (24) is connected to the discharge side of the fixed quantity transfer pump (12). It is provided so that the end of this raw water supply pipe 24 is located in the lower part of the reaction tank 1.

The lower portion of the reaction tank 1 is provided with a contact medium layer 6, the upper aeration nozzle group 16, the interrupted aeration nozzle group 17 and the lower aeration nozzle group 18 to the upper portion of the contact media layer (6). ) Is installed sequentially, while detecting to detect dissolved oxygen concentration (DO), hydrogen ion concentration (pH), redox potential (ORP), suspended solids concentration (MLSS), and water level (WLG) in the reactor (1). The sensor unit 41 is provided, and a non-powered floating discharge pump 14 for discharging only the supernatant liquid separated from the reaction tank 1 to the disinfection / discharge tank 5 is provided, and the sludge is stirred during the anaerobic reaction. Agitating submersible pumps 22 and 23 are provided.

After the sewage treatment step is completed, a sludge transfer pump 15 for intermittently discharging only the excess sludge in the reaction tank is provided.

The upper aeration nozzle group 16 is composed of a plurality of aeration nozzles (50, 51) facing the bottom surface of the reaction tank 1, as shown in Figure 2, while being controlled by the air supply regulator 11 It is designed to inject air.

As shown in FIG. 2, the interrupted aeration nozzle group 17 is arranged in a circular arrangement with four nozzles having equal intervals, so that the left aeration nozzle 53 and the right aeration nozzle 52 alternately alternately. It is composed of a structure that operates in such a way as to form a turbulence.

The lower aeration nozzle group 18 is composed of a plurality of aeration nozzles 54, 55 facing the upper portion of the reaction tank (1).

In addition, the upper aeration nozzle group 16, the aeration aeration nozzle group 17 and the lower aeration nozzle group 18 are individually connected to the air supply device 10 by the air supply control device 11 to supply air. Air supply regulator 11 is controlled by a signal from the control unit 40.

In addition, the individual directions of the upper, middle, and lower aeration nozzle groups 16, 17, and 18 are randomly provided, and each stage is alternately operated at random to form a vortex in the reaction tank 1.

The contact medium layer 6 is provided as a filter hanger unit (see FIG. 2), which has been registered and filed by the applicant of the present invention (utility model registration 054905) in an HBC ring structure. The detection sensor unit 41 is dissolved oxygen concentration (DO), hydrogen ion concentration (pH), redox potential (ORP), level gauge (WLG), It consists of a number of sensors that sense each value to detect the temperature.

That is, the contact media layer (6) is mounted on the HBC (Hanging Bio Contactor) ring media is fixed to the media unit, the media is a spring form, usually the upper media hanger plate and the lower media hanger plate and four posts It is mounted on the contact filter layer by hanging on the configured filter unit. The filter hanger unit equipped with the HBC ring is described in detail in the application specification filed by the applicant of December 27, 1996 (Utility Model Registration No. 0154905), the description thereof will be omitted. Next, an example of the specification of the HBC ring which is a contact medium used in the present invention will be described.

Specifications of HBC (Hanging Bio Contactor) Ring:

The material is polyvinylidene chloride fiber (Polyvinylidene Chloride Fiber) is easy to attach microorganisms and has a ring shape with a large specific surface area spread radially in water. The HBC ring has approximately 9,500 rings per meter, the thickness of the thread is 100 denier, the HBC ring twisted 2,850m is about 1m long, and the diameter is 25mm. The HBC ring of the specification is a spring-like thread is fine, so the specific surface area is wide, it is easy to attach a large number of microorganisms in all directions 360 ° angle.

The non-powered floating discharge pump 14 is fixed to the buoy 31 as shown in Figure 2, the buoy 31 is made of a plastic material, a plurality of guide pipes 32 installed vertically in the reactor (1) Supported by, the non-power floating float pump 14 is installed so that the flexible deformable treatment water discharge hose 33 is configured to discharge the treated water to the disinfection / discharge tank (5).

The reactor middle stirred water pump 22 is installed on the upper portion of the contact filtration tank 6 so as to form a vortex from the upper end of the contact medium layer 6 to the upper end of the reaction tank 1 during sludge inflow and anaerobic reaction. It is configured to stir.

The water tank 23 for stirring the lower part of the reactor is installed to be positioned below the contact medium layer 6 so as to stir the sludge of the reaction tank 1 at the bottom of the contact medium layer 6 during the inflow and anaerobic reaction of raw water. have. Here, the agitated submersible pump may be composed of an electric drive pump, or a submerged rotating body and other agitator for agitation of the sludge.

The sludge conveying pump 15 is installed at the lower end of the reaction tank 1, and when a large amount of sludge remains in the reaction tank 1 after the sewage treatment process, the excess sludge sludge treatment tank 4 through the sludge discharge pipe. Configured to discharge).

The control unit 40 combines the various data sensed by the detection sensor unit 41 in the microprocessor, and pumps 12, 13, 14, through the PLC control device in accordance with the current processing state of the sewage of the reactor 1 15), the air supply device 10, the electromagnetic valve 11 and the like are configured to automatically control.

Referring to the operation and operation of the present invention configured as described above are as follows.

Figure 3 is a process diagram showing a sewage treatment step according to the present invention, Figure 6 is a block diagram showing a process step according to the present invention, the present invention is the raw water stored in the flow control tank (2) in the anaerobic reactor bottom By passing through the sludge stack (7) and the contact filter layer (6) in order to first release the phosphorus in the raw water (S1), and through the step (S1) through the contact filter layer (6) Steps to animate nitrification and phosphorus in the aerobic oxidation reaction by intermittently randomly aeration according to the control signal through the upper, middle, lower aeration nozzle group (16, 17, 18) to the injured raw water (S2), During the step (S2), the supernatant treated by sensing the dissolved oxygen concentration (DO) and the redox potential (ORP) at the top and bottom of the reactor is treated with a dissolved oxygen concentration (DO) of 0.2 ppm or less even under an aerobic aeration time. Purification to the anoxic zone In order to dramatically reduce the high dissolved dissolved oxygen in the oxidation reaction in the early stage of the anaerobic reaction time after passing the step (S3) and the step (S2) dramatically to maintain the anaerobic state of the reactor as effectively as possible According to the redox potential (OPR) sensing signal, the lower part of the reaction tank is circulated, and the lower sludge rises by the amount of circulation, while the upper and lower contact medium layers are operated by agitating submersible pumps to form vortices throughout the reaction tank to stir the sludge. While the reaction coagulation is rapidly anaerobic to ensure sufficient anaerobic time required for the reaction (S4), the anaerobic maintained in the step (S4), the step of achieving the release and denitrification of phosphorus in the anaerobic state (S5) and step (S2) ), Step (S3) and step (S4) to occur repeatedly to remove the organic matter, nitrogen and phosphorus (S6), and after the step (S6) Maintaining the sedimentation time to discharge the treated supernatant to the disinfection / discharge tank through a non-power floating pump (S7), and after the step (S7) to transfer the excess sludge in the reactor to the sludge treatment tank (S8) consist of.

The step (S2) forms a vortex in the reaction tank while the upper, middle and lower aeration nozzle groups alternately randomly (Random).

When a certain amount of raw water is introduced into the reaction tank 1 by the quantitative transfer pump 12 in the anaerobic state of the reaction tank 1, the supply of the smooth organic matter of the introduced raw water and the rich organic matter of the activated sludge by the sludge lamination 7 are supplied. It increases the dephosphorization efficiency by activating the activity of the condensed microorganisms, and forms a strong growth condition of the bacteria inducing denitrification attached to the contact filtration tank (6).

In other words, phosphorus compounds (in Acetate and Acetic Acid ions) in the influent raw water are accumulated in the anaerobic sludge stack (7) and the contact material layer (6) while the sufficient accumulation of carbon source (nutrient) The main dominant species of microorganisms (PAOs, Phosphate accumulating organisms, PAOs) are diffused and transferred into cells of Acinetobacter, and the energy (ATP) generated by the decomposition of intracellular phosphate polymers (Poly-P, Poly-phosphate) is anaerobic. used by being changed into acetyl coenzyme (AcCoA, acetyl-CoA), as AcCoA is through the TCA (Tricarboxylic acid) Cycle stored in a state PHB (Poly-β- hydroxybutyrate) actively phosphate ions (P ^-) emits.

The raw water floating to the upper portion of the contact medium layer 6 through the above process removes nitrogen and phosphorus by repeating the aerobic reaction and anaerobic reaction by intermittent random aeration of the aeration nozzle group. At this time, in order to effectively control the reaction time in the reactor 1, a three-stage aeration apparatus, that is, a group of upper, middle and lower aeration nozzles (16, 17, 18) is provided.

In general, in aerobic metabolism, oxygen mainly acts as an electron acceptor for assimilation, and the metabolism of microorganisms determines the required rate of oxygen. According to Fick's law of diffusion, the rate of change of dissolved oxygen concentration during aeration is proportional to the area (A) of the contact interface and the oxygen deficiency (C _S -C, C _S is the saturation concentration of the gas in the liquid, C is the gas concentration in the liquid). And inversely proportional to the thickness of the liquid film. Factors affecting this oxygen transfer are oxygen saturation, temperature, characteristics of waste water, and turbulence. The theory of turbulence in aeration developed by Mancy and Okun is applied to the diffusion in liquid according to the degree of turbulence. As the resistance to the membrane is reduced, the membrane resistance controls the diffusion rate, and when the turbulence increases, the membrane is destroyed, thereby increasing the transfer rate of oxygen to shorten the reaction time as a whole.

In the present invention, the left aeration nozzle 53, the right aeration nozzle 52 and the top aeration nozzle group 16 of the middle aeration nozzle group 17 installed in the middle of the reaction tank 1 to significantly improve the oxygen transfer rate. By randomly operating the lower aeration nozzle group 18 alternately with each other, a vortex is formed in the reactor 1 to significantly improve the uniform concentration in the reactor 1 and the oxygen transfer rate in the gas-liquid boundary membrane. .

In addition, circulation of the supernatant water containing high dissolved oxygen to the lower part of the reaction tank supplies oxygen to the sludge and undergoes sludge self-oxidation process, and carbohydrates of the organic species contained in the sludge are sugars or organic acids, proteins are amino acids, and fats are It breaks down into fatty acids or glycerin and breaks it down into smaller molecules, which actively reduces the volume of sludge (SVI).

In addition, this process, which is repeated continuously, reduces the amount of the sludge cells by self-oxidizing and supplies them to the carbon source and organic matter of the microorganisms used for advanced processing. The remaining sludge (containing phosphorus) used is operated by the sludge conveying pump 15 to be intermittently transferred to the sludge treatment tank 4 for final treatment.

In repeating the anaerobic and aerobic reactions, the repetition time of anaerobic and aerobic cycles is made as short as possible and the number of repetitions is increased to induce excessive intake of phosphorus due to stress of microorganisms to increase cell synthesis, thereby increasing phosphorus removal efficiency. Increased. Hydraulic retention time (4 ~ 6hr) should be kept as short as possible, and the anaerobic and aerobic reactions will be doubled in the time distribution of the anaerobic and aerobic reactions that occur repeatedly within one cycle. If the dissolved oxygen concentration in the reactor (1) is high, the conversion time is long, and the anaerobic reaction time is reduced by that amount. Therefore, the dissolved oxygen concentration exceeds the proper range (2 to 2.5 mg / l) during the aerobic reaction of the reactor (1). In order not to perform the feedback control to control the air supply device 10 and the electronic valve 11 based on the dissolved oxygen concentration detected by the detection sensor unit 41 and transmitted to the control unit 40.

During the anaerobic reaction, agitated submersible pumps 22 and 23 are operated to form a vortex from the top and bottom of the contact media layer 6 to the top of the reactor 1 so that sludge does not precipitate and flows smoothly. The sludge is stirred.

If the reaction according to the removal of nitrogen and phosphorus by the aerobic reaction and anaerobic reaction,

The exhalation of organic matter by aerobic microorganisms in the reactor (1) the reaction time is actively decomposed to obtain the energy to the cell synthesis, the organic matter in the waste water are new cell _{(C 5 H 7 O 2 N} ) of the microorganism, CO _2, etc. Converted and removed. At this time, 0.12kg of nitrogen and 0.025kg of phosphorus are consumed to synthesize 1kg of C ₅ H ₇ O ₂ N. This is expressed as follows.

CHON + O ₂ + Nutrients → C ₅ H ₇ O ₂ N + CO ₂ + NH ₃ + Other products

In the aerobic reaction time, the nitrification reaction takes place actively in the reaction tank (1). Organic Nitrogen and Ammonia Nitrogen (NH ₃ -N) in Sewage Water Decompose Nitrogen Microorganisms (Aerobic Autotrophic Bacteria) such as Nitrosomonas and Nitrobacter To NH ₃ -N. NH ₃ -N is converted to nitrate nitrogen (NO ₃ -N) via nitrite nitrogen (NO ₂ -N) by a microorganism oxidizing it. These microorganisms grow by oxidizing ammonia with oxygen. The nitrification of ammonia in water in the form of ammonia ions (NH ₄ ⁺ ) is as follows.

^{_{22NH 4 + + 37O 2 + 4CO}} 2 + HCO 3 - → C 5 H 7 O 2 N + 21NO 3 - + 20H 2 O + 42H +

In the aerobic reaction time, phosphorus-removing microorganisms (PAOs, phosphate accumulating organisms) in the reaction tank 1 ingest the phosphate ions (orthophosphate) from the outside while decomposing PHB stored in the cells into oxygen in an aerobic state to form cells in poly-phosphate form. Stored within. In order to continue supplying the energy source (ATP) necessary for this synthesis process, the phosphorus intake by PAOs (the main predominant species of PAOs is Acinetobacter) increases from the outside. Is removed.

Treated water after the aerobic reaction time zone is moved to the anaerobic reaction time. The decomposition of organic matter by anaerobic microorganisms can be divided into two stages. The first organic material by the acid producing bacteria in the step of acetic acid (CH ₃ COOH), or as will be converted into an organic acid such as propionic acid (CH ₃ CH ₂ COOH) is ammonia (NH ₃₎ is generated in addition to the organic acid in the course of decomposition in the case of a protein . In the second stage, the organic acid produced in the first stage is converted by the methane producing bacteria into the final products methane and carbon dioxide. Since the growth rate of organic acid producing bacteria is high while the growth rate of methane producing bacteria is slow, the efficiency of wastewater treatment by anaerobic methods is more dependent on the role of methane producing bacteria than organic acid producing bacteria. Organic matter by methanogenic bacteria is converted to C ₅ H ₇ O ₂ N, CH ₄ , CO ₂ and the like. The decomposition process is expressed as follows.

CHON + Organic ₂ + H ₂ O + Nutrients → C ₅ H ₇ O ₂ N + CH ₄ + CO ₂ + NH ₃ + HCO ₃ + Other products

NO ₃ -N produced by nitrification at the anaerobic reaction time is reduced to harmless nitrogen gas (N ₂ ) and released into the atmosphere by a microorganism which reduces it again. Denitrifying microorganisms are facultative heterotrophic bacteria unlike the nitrification reactions described above. When there is sufficient dissolved oxygen, aerobic autotrophic microorganisms (nitrification microorganisms, nitrous oxide microorganisms, etc.) are predominantly active in obtaining oxygen as an electron acceptor, whereas the denitrifying microorganisms in which oxygen and nitrates are energized as nutrient sources. In order to activate the denitrification, an anoxic environment without oxygen supply and sufficient organic matter are absolutely necessary. Representative denitrifying microorganisms include Micrococcus, Pseudomonas, Archomobacter and Bacillus. An example of a denitrification scheme is as follows.

^{_{NO 3 - + 1.08CH 3 OH +}} H + → 0.065C 5 H 7 O 2 N + 0.47N 2 + 0.76C0 2 + 2.44H 2 O

By repeating anaerobic / aerobic / aerobic / aerobic as described above, nitrogen and phosphorus in the sewage are removed. After that, all the equipment is stopped to make the sludge precipitated easily in the reactor (1).

When the sludge is settled as described above, the treated water is discharged to the disinfection / discharge tank 5 by the non-powered floating discharge pump 14, wherein the non-powered floating discharge pump 14 is free of the reaction tank so that the sludge does not shake. It descends according to the water level in (1) and completes the work process by discharging the treated water.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by those skilled in the art without departing from the gist of the present invention as claimed in the claims. Of course, such changes will fall within the scope of the claims.

As described above, in the present invention, the contact medium layer is installed at the lower end of the reaction tank to improve the simultaneous treatment efficiency of nitrogen and phosphorus, and the three stage aeration forms severe turbulence in the reaction tank, which reduces the oxygen reaction time, thereby reducing the overall cycle time and The residence time can be drastically reduced, and there is an oxygen-free zone formed under the contact media layer 6 under DO and ORP control even during the aeration time during the aerobic reaction, circulating the nitrified supernatant to the bottom to undergo an active denitrification process. Maximize nitrogen treatment efficiency.

In addition, the microbial group attached to the contact medium layer 6 installed at the lower end of the reaction tank maintains a high MLSS concentration in the reaction tank 1 so that the BOD load is reduced by applying a low F / M ratio (BOD-SS load, organic matter load). Low efficiency allows for efficient operation.

In addition, it is possible to always know the operating state by the automatic operation in the reaction vessel, easy maintenance and there is no unnecessary effect such as microbial supply.

In addition, compared to the existing SBR method, the additional facilities according to the mechanical equipment and processing functions are greatly reduced and easy to maintain, there is an effect that can reduce the cost in the energy saving problem.

Claims (5)

A housing partitioned into a flow adjusting tank, a reaction tank, a disinfection / discharge tank, and a sludge treatment tank; A fixed quantity transfer pump installed inside the flow rate adjustment tank and supplying raw water stored in the flow rate adjustment tank to the lower portion of the reaction tank through a raw water supply pipe; A contact media layer spaced apart from the bottom of the reactor to form a predetermined space; A plurality of aeration nozzle groups formed in a stage so as to be positioned above the contact media layer; An air supply device for supplying air to the aeration nozzle group; An electronic valve installed on an air supply pipe connecting the air supply device and the aeration nozzle group to control an air supply amount; A floating discharge pump for discharging the treated supernatant to a disinfection / discharge tank according to the water level in the reaction tank; An agitated submersible pump installed at a predetermined position in the reaction tank to stir the sludge, An internal circulation pump installed at an upper portion of the reactor to circulate nitrified supernatant water to an anoxic region below the contact media layer; A sludge transfer pump for intermittently transferring excess sludge under the contact media layer to a sludge treatment tank; Installed inside the reactor, dissolved oxygen concentration (DO), hydrogen ion concentration (pH), redox potential (ORP), water level meter (WLG), A detection sensor unit for detecting a temperature; The sewage treatment apparatus using the oxygen-free region of the biofilm in a single reactor characterized in that the control unit for controlling the electronic valve, the pump and the air supply in accordance with the detection signal generated by the detection sensor. The method of claim 1, The aeration nozzle group is a stop aeration nozzle group is located above the contact media layer and installed to be located in the center of the reaction tank, An upper aeration nozzle group located above the interrupted aeration nozzle group and installed to be positioned above the reaction tank; It is provided with a lower aeration nozzle group located in the lower portion of the interrupted aeration nozzle group and located on the upper contact medium layer, The interrupted aeration nozzle group is provided with a plurality of aeration nozzles are arranged in a circular arrangement so that the four nozzles are equidistant from each other, The upper aeration nozzle group includes a plurality of aeration nozzles facing the bottom surface of the reaction tank, The lower aeration nozzle group is a sewage treatment apparatus using an oxygen-free region of the biofilm in a single reactor characterized in that it comprises a plurality of aeration nozzles facing the upper portion of the reaction tank. Injecting the raw water stored in the flow control tank to the lower part of the anaerobic reaction tank to sequentially discharge the phosphorous in the raw water while passing through the sludge stack and the contact medium layer (S1), The step of ingesting nitrification and phosphorus in an aerobic oxidation reaction by intermittently randomly aeration according to a control signal through the upper, middle, and lower aeration nozzle groups to the raw water floating through the step (S1) and the contact media layer. (S2) and, Sensing dissolved oxygen concentration (DO) and redox potential (ORP) at the top and bottom of the reactor during the step (S2) to circulate the treated supernatant to the anoxic area under the reactor even during aerobic aeration time to induce denitrification (S3). )Wow, After the step (S2), the nitrified supernatant at the beginning of the anaerobic reaction time zone is circulated to the lower part of the reactor according to the redox potential (OPR) sensing signal, and the lower sludge is increased by the circulation amount, and the upper and lower contact media layers Step by operating each of the water pump for stirring to form a vortex throughout the reaction tank and the sludge is stirred while the reaction tank is rapidly anaerobic to ensure sufficient anaerobic time required for the reaction (S4), (S5) and the release and denitrification of phosphorus in the anaerobic, anaerobic state maintained in the step (S4), Step (S6) of removing organic matter, nitrogen and phosphorus by causing step S2, step S3, step S4 and step S5 to occur repeatedly; After maintaining the appropriate settling time after the step (S6) and discharging the treated supernatant to the disinfection / discharge tank through a non-powered floating discharge pump (S7), After the step (S7), the step of transferring the excess sludge in the reaction tank to the sludge treatment tank (S8) characterized in that the sewage treatment method using an oxygen-free region of the biofilm in a single reaction tank. The method of claim 3 The lower part of the reaction tank in step (S3) is a sewage treatment method using an oxygen-free region of the biofilm in a single reactor, characterized in that the oxygen free zone is managed to the dissolved oxygen concentration (DO) to 0.2ppm or less. The method of claim 3; The step (S2) is a sewage treatment method using an oxygen-free region of the biofilm in a single reactor, characterized in that the vortex is formed in the reaction tank is randomly operated by alternating the left and right aeration nozzles of each aeration nozzle group.

Images