WO2016159689A1 - Hybrid biological nutrient salts treatment system - Google Patents

Abstract

The present invention relates to a hybrid biological nutrient salts treatment system, the system arranging one or more organic-matter oxidation tanks at the fore-end of a nitrification tank so that nutrient salts can be effectively removed, even at low winter temperatures, so as to meet actual conditions in Korea, and thereby carrying out a pre-treatment in the one or more organic-matter oxidation tanks prior to treatment in the nitrification tank. The present invention can minimize the amount of organic-matter that flows into the nitrification tank through the organic-matter oxidation tanks in order to maximize growth of nitrifying microorganisms in competition with organic-matter-oxidizing microorganisms. Thus, it is possible to achieve 95% or more nitrification efficiency, even in the case where, as during winter season, sewage/wastewater should be processed at low temperatures or during a short hydraulic retention time, and thus improved total nitrogen (T-N) treatment can be expected. In addition, compared to a conventional two-stage sludge process (for example, Dephanox process) that must comprise two or more settling ponds for independent nitrification, since the treatment system of the present invention has a simpler structure and comprises a single settling pond, it is possible to significantly reduce installation costs, thereby providing a huge economic advantage and, at the same time, enabling minimization of potential operational issues.

Description

[Revision 28.04.2016 by Rule 91] 생물학적 Hybrid Biological Nutrients Treatment System

The present invention relates to a hybrid biological nutrient processing system, and more particularly, to a hybrid biological nutrient processing system for effectively removing nutrients even at a low temperature in winter according to the situation in Korea.

In general, the nutrients contained in the wastewater are inorganic elements, but they flow into rivers, coastal seas, lakes (lakes and reservoirs), etc. to promote algae growth and cause eutrophication.

In addition, when nutrients contained in waste water enter the coastal seas, it causes red tide, and if it is severe, it causes decay and odors at the bottom of the water to promote water pollution. The material to be removed before it is introduced.

In Korea, most sewage treatment and livestock wastewater treatment methods rely on activated sludge. Suspended solids and organics can be easily removed by treatment with activated sludge, but the treatment of nutrients such as nitrogen and phosphorus is not easy to comply with the statutory effluent water quality standards, which are being strengthened by current technology.

Generally, processes for treating nutrients such as nitrogen and phosphorus include physicochemical treatments and biological treatments.

First, in the physicochemical treatment method, ammonia degassing method, ion exchange method using selective adsorption method, method of precipitation of phosphorus using slaked lime and flocculant and method of precipitation of struvite formation which simultaneously precipitates nitrogen and phosphorus Etc. are used. However, such a method has a disadvantage in that the treatment is selectively performed, but sensitive to various influence factors such as temperature and pH, and the treatment cost is high because the chemical is used. In addition, there is a disadvantage in that the environment required for the use of chemicals and operation is characteristic, and therefore, a skilled personnel is necessary for the operation.If the influent concentration of the influent changes, the effluent is unstable due to the change in the amount of chemical injection. Is reluctant.

On the other hand, in the biological treatment method, in the case of nitrogen, ammonia nitrogen and organic nitrogen in the dissolved state are nitrified by nitrifying bacteria (for example, Nitrosomonas & Nitrobacter) under aerobic conditions (ammonia is transformed into nitrate form), and nitrate is denitrified. Oxidized bacteria (eg, Pseudomonas, Paracoccus denitrifiers) are used as electron acceptors instead of oxygen under anoxic conditions, converted to nitrogen gas, released into the atmosphere (denitrification) and removed.

In the case of phosphorus, wastewater is alternately maintained under anaerobic and aerobic conditions to release phosphorus from phosphorus-removing microorganisms (eg, Acinetobacter) under anaerobic conditions, and in subsequent aerobic conditions, the microorganisms overtake phosphorus. The phosphorus in the wastewater is then removed by removing a certain amount of microorganisms. The degree of ingestion of the phosphorus of the microorganism in the aerobic condition depends on the amount and type of organic matter introduced into the anaerobic condition, especially in the case of maintaining a pure anaerobic state and in the case of a large amount of organic acid salts such as acetate in pure anaerobic condition The amount of phosphorus released is enhanced, and the intake of phosphorus in the subsequent exhaled state is improved, thereby increasing the throughput.

Therefore, the biological nitrogen and phosphorus removal process properly arranges anaerobic-aerobic-anaerobic-aerobic reactors to induce organic oxidation and nitrification reactions and intake of microorganisms in the aerobic reactors according to the characteristics of each reactor, and anaerobic and anoxic reactors. Induces the release of phosphorus and the denitrification reaction which converts nitrate nitrogen into nitrogen gas and releases it into the atmosphere.

In the above-described general process of treating biological nutrients, an aerobic reactor is disposed before the precipitation tank to improve the sludge settling property and suppress the release of phosphorus. An example of such a method is the Ludzack-Ettinger process, which is designed so that the most common process can make the best use of denitrification of the influent sewage without introducing a separate organic source. In this process, the aerobic and anaerobic tanks are divided into aberrations so that the anaerobic and aerobic tanks are not clearly distinguished. The use of organic matter in sewage instead of methanol is a method in which ammonia is oxidized in an aerobic tank and nitrate is transported to an oxygen-free tank through a conveying sludge carried by aberration to induce denitrification. However, the process has the disadvantage that the nitrogen removal efficiency is very low.

To compensate for these drawbacks, the rate of return from an aerobic tank to an anaerobic tank was increased to improve the total nitrogen removal rate by about 90%. Later, based on the Modifide Ludzack-Ettinger process concept, processes such as A2 / O process, 4-stage 5-stage Bardenpho process, and University Cape town were developed. However, since the above process is a process proposed for a foreign country with a large site, it is difficult to apply it in sewage characteristics and various matters that have a small site and low C / N ratio as in Korea due to a long hydraulic stay. In particular, the domestic sewage treatment technology has been advanced significantly at the same time to treat organic material, nitrogen and phosphorus, but most of these processes are performed at the same time in the reaction of the removal of organic matter and nitrification in one reactor, due to the inhibition of nitrification by organic matter Nitrogen treatment efficiency is not effectively performed in the low temperature winter or short hydraulic residence time (6-8 hours).

Therefore, in order to successfully treat nutrients in the hydraulic retention time (6-8 hours) of the existing treatment plant, it is necessary to develop a process that can effectively treat nutrients even if the hydraulic retention time is short. . In addition, in the case of Korea where the temperature is low in winter, when applied directly to the site without design change or process improvement of the system, there is a problem that the nitrification efficiency is lowered and ultimately the nitrogen treatment efficiency of the system is reduced.

The process developed to overcome the denitrification deterioration due to the low C / N ratio and the reduction of nitrification efficiency caused by low temperature or short hydraulic residence time includes the Dephanox process developed in Italy. See FIG. 1). In this process, anaerobic contacting tanks and separation tanks are used for the microorganisms to adsorb organic matter and induce the release of phosphorus in the anaerobic contacting tank, the organic matter and microorganisms adsorbed in the separation tank are separated into the subsequent denitrification tank and the nitrogen is not adsorbed. The compound is nitrified in a separate reactor and sent to a subsequent denitrification tank for denitrification by the microorganisms that adsorb the organics. That is, the depanox process is a process in which denitrification and nitrification are carried out in separate sludges and reactors, and the phosphorus is excessively ingested by microorganisms in a subsequent aerobic reactor. In addition, as described above, the Depanox process adopts an independent nitrification method in which nitrification is performed in a separate reaction tank, and nitrifying bacteria predominate because nitrifying bacteria are attached and grown by filling the medium and nitrification in the nitrification reaction tank. It can be effectively nitrification at low temperature or short hydraulic residence time.

However, despite these advantages of the depanox process, the organic nitrogen and ammonia nitrogen flowing into the denitrification tank from the separation tank during the subsequent treatment after the nitrification process are discharged without being sufficiently decomposed or nitrified, and the single subsequent to the nitrification reactor. Since denitrification is performed only in the denitrification reactor, it has a disadvantage that high nitrogen removal efficiency cannot be expected.

In addition, the Depanox process, including the Depanox process, is a two-stage sludge process that is somewhat complicated in structure and has two sedimentation basins, resulting in economic and operational aspects such as operational costs and maintenance of sedimentation basins. The disadvantage is that it is inefficient in terms of.

Therefore, there is an urgent need for the development of a wastewater treatment system that can minimize the problems in the field operation due to its simple structure and simple nitrification more effectively in the cold winter or short hydraulic conditions.

In order to solve the above problems, the present invention can obtain a high nitrification efficiency even under a short hydraulic residence time and low temperature conditions, it is composed of a single settling basin can simplify the structure and greatly reduce the installation cost The aim is to provide a nutrient processing system that can minimize operational problems.

In order to achieve the above object, the present invention in the nutrient processing system including an anaerobic reactor, an oxygen-free reactor and nitrification reaction tank, by minimizing the amount of organic matter flowing into the nitrification reaction tank to promote the growth of nitrification microorganisms in the nitrification reactor In order to be concentrated and cultured, one or more organic oxidizing tank is placed in front of the nitrification tank, to provide a hybrid biological nutrient processing system characterized in that the pre-treatment in one or more organic oxidizing tank prior to the nitrification tank treatment.

In addition, the present invention provides an anaerobic reaction tank for releasing phosphorus and adsorbing organic substances by using organic substances contained in the incoming wastewater; An oxygen-free reaction tank for removing nitrogen by using an organic material contained in the wastewater introduced from the anaerobic reactor; An organic material oxidizing tank for oxidizing the organic matter remaining after nitrogen removal in the anoxic reaction tank (partial nitrification reaction occurs due to adherent growth nitrification microorganisms in the organic oxidizing tank); A nitrification reactor for nitrifying the ammonia nitrogen of the exhausted organic matter from the organic oxidation tank; It provides a hybrid biological nutrient processing system comprising a; and the final sedimentation tank for the solid-liquid separation of the sludge treated in the nitrification reaction tank to discharge the treated water from which the suspended matter is removed.

Also preferably, the inside of the nitrification tank may perform nitrification only by floating growth.

Also preferably, the inside of the nitrification tank may be filled with any one of a rotating disc and a fluidized bed attachment medium.

Also, the nitrate may be denitrated by using an organic material introduced into the anoxic reaction tank by returning the nitrate and sludge nitrified in the nitrification tank to the anoxic reaction tank.

Also preferably, the nitrate transfer from the nitrification tank to the anoxic oxidation tank may use a metering pump.

In addition, the present invention provides an anaerobic reaction tank for releasing phosphorus and adsorbing organic substances by using organic substances contained in the incoming wastewater; An oxygen-free reaction tank for removing nitrogen by using an organic material contained in the wastewater introduced from the anaerobic reactor; An organic material oxidizing tank for oxidizing the organic material remaining after nitrogen removal in the anoxic reaction tank; And a nitrification reaction tank for nitrifying the ammonia nitrogen of the effluent with reduced organic matter from the organic oxidation tank, wherein the separator is provided in the organic oxidation tank, and any one of a rotating disc and a fluidized bed adhesion medium is attached to the nitrification reactor. It provides a hybrid biological nutrient processing system characterized in that the filling.

Also preferably, the separator may be in the form of a rod or disc.

Also preferably, the nitrates and sludges nitrified in the nitrification tank may be returned from the nitrification tank to the organic oxidizing tank, the organic oxidizing tank to the anoxic reaction tank, and the anoxic reactor to the anaerobic reactor.

Also preferably, the nitrate transfer from the nitrification reaction tank to the organic oxidation tank may use any one of a metering pump and a natural oil drop method.

As described above, the present invention minimizes the amount of organic matter introduced into the nitrification tank through the organic oxidizing tank to maximize the growth of the nitrifying microorganisms in competition with the organic oxidizing microorganisms, so that the temperature is low or short as in winter. It is expected that nitrification efficiency of more than 95% can be achieved even if the wastewater has to be treated under hydraulic residence time.

In addition, this can result in improved total nitrogen (T-N) treatment from the wastewater treatment system of the present invention.

In addition, the process proposed in the present invention is simpler in structure than the two-stage sludge process (for example, the Dephanox process) that requires two or more sedimentation basins for independent nitrification. It can be installed to save a lot of installation cost, so it can be economically significant and minimize the problems that can be exposed to operation.

In addition, it is easy to apply to the existing sewage treatment facility without the construction of a separate reaction tank, and when the membrane is used, it can be applied to reuse of sewage by removing suspended solids due to complete solid-liquid separation.

Figure 1 shows a schematic of the Dephanox process used in the prior art.

2 shows a schematic diagram of an A2 / O process conventionally used.

Figure 3 is a conceptual diagram of a process for receiving less interference of the organic matter in the nitrification reaction of the nitrification reaction tank according to the present invention.

4 is a schematic diagram of a hybrid biological nutrient processing system for performing nitrification only with suspended growth without using microbial adhesion media according to one embodiment of the present invention.

 5 is a system for improving the phosphorus treatment efficiency and uniformly adjusting the sludge concentration of the treatment system by returning the sludge from the final settling tank to the anaerobic reactor in the final settling tank according to the embodiment of the present invention and back to the anaerobic reactor. Schematic diagram.

6 is a schematic diagram of a hybrid biological nutrient processing system applying a fixed microorganism attachment medium and a rotating disc method to a nitrification reaction tank according to an embodiment of the present invention.

Figure 7 is a schematic diagram of a hybrid biological nutrient processing system applying the fluidized bed adhesion medium to the nitrification reaction tank according to an embodiment of the present invention.

8 is a schematic diagram of a hybrid biological nutrient processing system applying a separation membrane to a nitrification reaction tank according to an embodiment of the present invention.

9 is a schematic diagram of a biological nutrient treatment system applying a separation membrane to an organic material oxidation tank according to an embodiment of the present invention and applying a rotating disc method to a nitrification reactor.

10 is a graph showing the removal efficiency of organic nitrogen and ammonia nitrogen of the nutrient processing system according to water temperature in one embodiment and one comparative example of the present invention.

11 is a graph showing the ammonia nitrogen removal efficiency according to the winter temperature and the reaction tank water temperature of the nutrient processing system according to an embodiment and one comparative example of the present invention.

12 illustrates microbial analysis results when the nutrient processing system according to one embodiment and one comparative example of the present invention is operated at a low temperature.

FIG. 13 shows the concentration of organics flowing into the nitrification tank (aerobic tank) in the nutrient processing system according to one embodiment and one comparative example of the present invention.

14 is a graph showing the effect of temperature on suspended growth and adherent growth nitrifying bacteria.

15 is a graph showing the effect of organic influx on the nitrification reaction.

Hereinafter, with reference to the accompanying drawings, the present invention will be described in detail.

The present invention provides a nutrient processing system including an anaerobic reactor, an anoxic reactor, and a nitrification tank, in which a nitrification microorganism is grown in a nitrification tank so that the nitrification microorganisms can be grown and concentrated in a nitrification tank. It provides a hybrid biological nutrient processing system characterized in that the pre-treatment in one or more organic oxidizing tank prior to nitrification tank treatment by placing at least one organic oxidizing tank in the front end.

In general, when the temperature is low, the growth of heterotrophs that oxidize organic matter when organic matter is introduced is relatively larger than that of autotrophs, which are nitrifying microorganisms. At the outer surface, organic oxidative heterotrophic microorganisms are located. Both heterotrophs and autotrophs require O ₂ to grow, and the heterotrophs that cover the exterior of the biofloc first consume the O _{2 so} that the interior of the biofloc is independent. In the case of trophic microorganisms (Autotroph) it is difficult to contact with O ₂ and the nitrification reaction is prevented, so the vicious cycle of growth decreases. In order to support this, as a result of experiments to investigate the effect of organic inflow on the nitrification reaction, as shown in Figure 14, even if the amount of organic matter is increased by about 2 mg / L that the nitrification efficiency is reduced to about 40% Could know. Therefore, in order to perform smooth nitrification even at a low temperature of 10 ° C. or less, it is necessary to minimize the influence on organic matter in the nitrification reaction tank. For this purpose, as shown in FIG. It is preferable to arrange one or more organic oxidizing baths to perform pretreatment on the organics.

In one embodiment of the present invention, the hybrid biological nutrient treatment system, as shown in Figures 4 to 7, anaerobic reactor (1), anoxic reactor (2), organic matter oxidation tank (4), nitrification reactor (5) And a final settling tank 6.

By the structure and configuration as described above, the hybrid biological nutrient treatment system is first introduced into the anaerobic reactor (1), the wastewater is introduced into the anaerobic reactor (2) when the inflow of wastewater, nitrification The nitrates and sludges returned from the reactor 5 remove the nitrate nitrogen and sludges in the wastewater.

Next, the organic matter oxidizing tank 4 minimizes the amount of organic matter introduced into the nitrification reactor 5 by oxidizing and decomposing organic matter in the wastewater, so that the nitrifying microorganisms can be grown in the nitrification reaction vessel 5 to be concentrated and cultured. Provide an environment. Specifically, in the organic oxidizing tank (4), the organic material is oxidized, and the organic material load flowing into the nitrification reaction tank (5) is reduced, thereby reducing the growth of the organic oxidizing heterotrophic microorganism and smoothly by the nitrifying microorganisms, which are independent nutrients. Since the nitrification reaction can be induced, it is possible to create an environment favorable for the nitrification reaction in the nitrification reaction tank 5 arranged at the rear stage. This is because organic oxidizing microorganisms have an advantage over nitrifying microorganisms in competition between nitrifying microorganisms and organic oxidizing microorganisms, so that organic oxidizing microorganisms are controlled in subsequent nitrification reactors 5 by consuming organic matter in the organic oxidizing tank 4. will be.

The wastewater that has passed through the organic oxidizing tank 4 is transferred to the nitrification tank 5. The nitrification reaction tank 5 may perform the nitrification reaction only by floating growth without using the microorganism attachment medium, or may be filled with the microorganism attachment medium. However, in order to concentrate the nitrifying microorganisms with relatively low growth in the nitrification tank, it is preferable to fill the microorganism attachment media. It is desirable to effectively induce nitrification through the growth of adhesion of microorganisms. In this case, as the microorganism adhesion medium in which nitrifying microorganisms are relatively concentrated, the fluid media 100 that is flowed by a brower for maintaining an aerobic state may be used, and the rotating disc 102 may be easily desorbed by a rotational force. In this case, the shape and shape of the reactor can be varied according to the conditions of the site to be applied. In addition, in order to minimize the land area of the wastewater treatment system may be configured in the form of a process that can be separated completely by applying the separation membrane 101 instead of the sedimentation tank.

The nitrates and sludges nitrated from the nitrification microorganisms attached to the medium of the nitrification reactor 5 are returned to the anoxic reactor 2 and the organic matter nitrate introduced into the anoxic reactor 2 from the anaerobic reactor 1. Denitrate.

When the amount of organic matter in the wastewater is low, the external organic carbon source 10 may be injected into the oxygen-free reactor 2 to maintain the treatment efficiency. The injection position of the external organic carbon source 10 may be injected not only into the oxygen-free reactor 2 but also into another reactor depending on the situation.

In one embodiment of the present invention, when the separation membrane 101 is used in the present invention as shown in Figs. 8 and 9, dissolved oxygen is introduced into the anaerobic reactor 1 in which phosphorus is released during the phosphorus removal mechanism, thereby preventing the release of phosphorus. It acts as a factor and tends to reduce phosphorus removal efficiency. So, in order to prevent this when the membrane 101 is used in a normal activated sludge process, a stabilizing tank is provided at the rear of the membrane tank to reduce dissolved oxygen, and then the sludge is returned to the anaerobic reactor 1, but the present invention is used. Rather than adding a single reactor, the sludge conveyed from the nitrification tank 5 to the organic oxidizing tank 4 and the organic oxidizing tank 4 to the anoxic reaction tank 2 is finally used. In the anaerobic reactor 1 to the anaerobic reactor 1. In addition, when the separation membrane 101 is applied, the conditions such as whether the injection time of the air through the blower, suction and rest time, cleaning, etc. will vary depending on the material of the membrane 101 and the shape of the module. In addition, the application of the separator 101 in relation to the illustrated embodiment may be diversified into an immersion type and a pressure type.

Sludge conveyance from the nitrification reaction tank (5) to the organic material oxidation tank (4) requires a higher dissolved oxygen amount than the conventional activated sludge process when the separation membrane (101) is applied, and when the internal transport method described above is applied, the organic oxidation tank ( In 4), sludge with sufficient dissolved oxygen is transferred to reduce the oxygen demand, thus reducing maintenance costs.

The internal transport from the nitrification reactor (5) to the organic matter oxidization tank (4) can be carried out using a metering pump, and the sludge can be transported in a natural flow method by using a water level rise by air injection depending on the site conditions. have.

Hybrid biological nutrient processing system according to the present invention by maximizing the growth of nitrifying microorganisms in competition with organic oxidizing microorganisms by minimizing the amount of organic matter flowing into the nitrification reactor through the organic oxidizing tank, low temperature as in winter High nitrification efficiency can be achieved even if the wastewater has to be treated at short or short hydraulic residence times, compared to a two-stage sludge process that requires two or more settling basins for independent nitrification. , Dephanox process), simple structure and single sedimentation basin can greatly reduce installation cost, which has great economic advantages and minimizes problems that can be revealed in operation. It is easy to apply without the construction of a separate reactor in the facility, and it uses a separator If it can be applied to the reuse of sewage by removing the suspended solids due to complete solid-liquid separation, it can be usefully used in place of the conventional sewage treatment system.

In addition, Figure 5 shows a schematic diagram according to an embodiment of the present invention, the sludge concentration of the treatment system by uniformly conveying the sludge from the final settling tank to the anaerobic reactor and back to the anaerobic reactor. A schematic diagram of a system that fits and improves phosphorus treatment efficiency is shown, and this process is not limited to FIG. 5 but is applicable to all of the systems of the present invention.

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are intended to illustrate the present invention more specifically, but the scope of the present invention is not limited to these examples.

Comparative Example Conventional A2 / O Process

As shown in FIG. 2, the influent water is discharged by being treated through an anaerobic reactor 200, an anoxic reactor 300, an aerobic reactor 400, and a secondary precipitation tank 500, and dissolved in the anoxic reactor 300. Nitrogen nitrate and nitrite chemically bonded oxygen is introduced from the aerobic reactor (400), but the nitrogen removal process is performed by denitrification of nitrate nitrogen, and phosphorus released from the anaerobic reactor (200). In the latter stage, the aerobic reactor 400 is excessively absorbed to remove phosphorus through sludge disposal, and in the anaerobic reactor 200, the return sludge is conveyed from the secondary settling tank 500.

Example 1 A2 / O2 Process According to the Present Invention

The aerobic reactor (400), which acts as a nitrification reactor in the A2 / O process, is divided into an organic material oxidizer, which focuses on organic matter oxidation, and a nitrification reactor, which enhances nitrification and microbial growth and nitrification reaction. I named it.

Example 2 A2 / O2 with RBC process according to the present invention

Wastewater treatment was performed by filling a rotating disc (RBC) in the aerobic reactor in the A2 / O2 process of Example 1. This process was named A2 / O2 with RBC process.

Experimental Example 1 Measurement of Treatment Efficiency of Organic Nitrogen (TKN) and Ammonia Nitrogen According to Temperature

In order to prove the usefulness of the hybrid biological nutrient processing system according to the present invention, the A2 / O process which is most commonly applied as an advanced treatment method, and the organic oxidizing tank installed in front of the nitrification tank (aerobic reactor) according to the present invention A comparative experiment on sewage treatment efficiency against temperature was conducted using the processes of Examples 1 and 2.

It took about 30 days for the acclimatization period to stabilize the initial processing efficiency and evaluated the processing efficiency by operating the process for 360 days. The hydraulic retention time (HRT) of the process was 6 hours and the microbial retention time (SRT) was 12 days. The temperature of the thermostat was operated at 7 ~ 20 ℃ during the experiment. Quantitative pumps were used for supplying raw water and returning activated sludge from the anaerobic tank to internal recycle and from the final settling tank to the anaerobic contact tank. The return sludge feed flow from the final settling tank to the anaerobic contacting tank was maintained at 1Q. Endogenous circulation from the anoxic tank to the denitrification tank was operated at 1Q to improve the nitrogen removal efficiency. In addition, the carrier used for the growth of microorganisms in the nitrification tank was fixed by using a polyethylene honeycomb-shaped filter medium having a diameter of 120 mm and a thickness of 25 mm and six pieces of stainless steel shaft having a diameter of 10 mm and a length of 300 mm. RBC rpm was maintained at 2-3 rpm. In order to maintain aerobic conditions, two disc type diffusers were used to operate the average DO concentration at 2-3 mg / L. The MLSS concentration in each reactor was maintained at 3500-4500 mg / L and the VSS / TSS ratio was maintained at an average of about 75 ± 5%.

The main items analyzed in this study were TCOD _cr (5220-COD-D, HACH), SCOD _cr (5220-COD-D, HACH), NH ₄ ⁺ -N (Nessler method, HACH), NO ₂ ^-- N ( 4500-NO ₂ ^-- B, HACH), NO ₃ ^-- N (4500-NO ₃ ^-- B, HACH), PO ₄ ^3- -P (4500-PE, HACH), TP, etc., double TCOD _cr , SCOD _cr was measured according to Standard Methods (APHA, 2005) and HACH DR-4000, and NH ₄ ⁺ -N, TP was measured using the Nessler method and the HACH phospho Ver 3 method of the HACH manual, respectively. In addition, TKN was measured using VELP (UDKCO30) manufactured in Milano, Italy. SCOD _cr , NH ₄ ⁺ -N were measured by filtration on GF / C filter paper (Whatmann) with a pore size of 1.2㎛, NO ₂ ^-- N, NO ₃ ^-- N is 0.45㎛ pore size to prevent organic interference It was measured by filtration on membrane filter paper.

The results are shown in FIG.

As shown in FIG. 10, according to the present invention, the A2 / O2 process in which an organic oxidizing tank is disposed in front of the nitrification tank and the A2 / O2 with RBC process in which a rotating disc (RBC) is filled in the nitrification tank in the A2 / O2 process are TKN. (Total Kjeldahl Nitrogen; total of organic nitrogen <org-N> and ammonia nitrogen <NH ₄ -N>) and removal efficiency of ammonia nitrogen showed more than 90% at 10 ℃, low temperature below 10 ℃ Also showed much higher nitrogen removal efficiency than the conventional single sludge A2 / O process. In particular, it was observed that the tendency of nitrogen removal was very noticeable when the temperature reached 7-8 ° C.

This is because the organic matter is removed from the organic oxidation tank to minimize the organic matter flowing into the nitrification tank to promote the growth of nitrifying microorganisms in the nitrification tank, which is believed to be because the nitrification proceeded effectively even at low temperatures.

Therefore, the hybrid biological nutrient processing system according to the present invention provides an environment capable of promoting the growth of nitrification microorganisms in the nitrification tank even at low temperatures in winter, thereby effectively performing nitrification by placing an organic oxidizing tank in front of the nitrification tank. Nitrogen removal can be performed more effectively than the method.

<Experimental Example 2> Measurement of ammonium nitrogen removal efficiency in the pilot scale (Pilot-scale) in the winter temperature

The hybrid biological nutrient treatment system according to the present invention was operated on a pilot scale to measure winter ammonia nitrogen treatment efficiency.

Specifically, the pilot scale treatment capacity was 7 tons / day, the hydraulic residence time was 6 hours, and the internal and sludge transport were operated at 1Q, respectively, and the treatment efficiency was observed according to the actual water temperature and the room temperature. .

The results are shown in FIG.

As shown in FIG. 11, even though the room temperature dropped below -10 ° C., the water temperature of the reactor did not drop below 10 ° C., and the treatment efficiency of ammonia nitrogen was maintained at about 95% or more. The results were in agreement with. In conclusion, in the case of the process proposed in the present invention, the nitrification can be performed perfectly at 10 ° C., and thus it is judged to be advantageous in winter nitrogen treatment than the existing process.

Experimental Example 3 Analysis of Microorganisms in Nitrification Tank

12 shows the types and amounts of microorganisms in the nitrification reactor after operating the hybrid biological nutrient treatment system according to the present invention. Wherein 16S rRNA is an indicator indicating the presence of microorganisms and amoA is an indicator indicating the gene of the microorganisms on the path (oxidation) of ammonia oxidizing ammonia monoixgenase gene subunit A.

As shown in FIG. 12, in the case of A2 / O2 with RBC using a carrier, the ratio of amoA was 9% compared to that of other 16S rRNA, and A2 / O2 was 3% and A2 / O was 4%. This means that the growth of adhesion using carriers is about three times more than the growth of suspended solids, and the process of minimizing the nitrification efficiency of organic materials by placing the organic oxidation tank proposed in the present invention in front of the nitrification tank is performed at low temperature. The results prove to be advantageous for the treatment of ammoniacal nitrogen.

Experimental Example 4 Analysis of the Amount of Organics Inflowed into the Nitrification Reactor

13 shows the concentration of organic material flowing into the nitrification tank (aerobic tank) of the hybrid biological nutrient treatment system according to the present invention.

As shown in FIG. 13, when the organic oxidizing tank is placed in front of the nitrification tank according to the present invention (A2 / O2), the amount of organic matter flowing into the aerobic tank is lower than that of the organic oxidizing tank (A2 / O). It can be seen that the lower half.

Therefore, in the hybrid biological nutrient processing system according to the present invention, by placing an organic oxidizing tank in front of the nitrification tank, the organic matter is removed from the organic oxidizing tank, thereby minimizing organic substances flowing into the nitrification tank, thereby minimizing organic matter in the nitrification tank even at a low temperature in winter. By promoting the growth of the nitrification can be effectively carried out nitrogen removal compared to the conventional method.

Experimental Example 5 Effect of Temperature on Nitrifying Bacteria

In the nutrient processing system according to the present invention, in order to smoothly process nitrogen at low temperatures in winter, the temperature is indeed suspended in growth (method of growing in suspension without media in water) and adhesion growth (carrier in water). Method to attach and grow microorganisms) The following experiment was conducted to see how it affects nitrifying bacteria.

Specifically, the experiment was carried out using concentrated cultured nitrifying bacteria while collecting activated sludge from C municipal sewage treatment plant and giving 2 L of tap water (18 L) and activated sludge (MLSS 1200 mg / L) in a 20 L reactor. . NH ₄ Cl was used as a substrate and NaHCO ₃ was used as a buffer for the smooth growth of nitrifiers.

 Activation energy (Ea) of Nitrosomonas in suspension growth and adhesion growth using sponge-like media was calculated using the concentrated nitrifier, and the results converted into graphs are shown in FIG. 14.

As shown in Fig. 14, in the case of suspended growth, the Ea value at 4-11 ° C was 169.5 KJ / mol, and the Ea value at 11-34 ° C was 20.4 KJ / mol. However, adhesion growth was 32 KJ / mol above 8 ℃ and 283 KJ / mol below 8 ℃.

In conclusion, it can be seen that the suspended growth and adhesion growth nitrifiers had different activation energy values based on 11 and 8 ° C, respectively. This shows that the adhesion growth has the activity of suspended growth even at a temperature as low as 3 ℃, indicating that it is more advantageous to attach the nitrifying microorganism at low temperature.

In addition, under relatively good conditions of activity of microorganisms (above 10 ° C.), activation energy is low to easily cover the energy required for the reaction. High, indicating slow reaction under the same energy generation conditions.

In addition, it was observed that the activation energy of nitrifying bacteria attached to the media was about 1.6 times higher than that of suspended growth. This was influenced by the rate of substrate diffusion into cells. In the case of suspended growth, substrate diffusion into cells was faster than that of adherent growth nitride, and substrate decomposition could be easily progressed. The substrate diffusion rate was slower than that of suspended growth, suggesting that the substrate decomposition was relatively slow.

Experimental Example 6 Effect of Organic Matter Influence on Nitrification

At low temperatures, the growth of heterotrophs that oxidize organic matters is relatively greater than that of autotrophs, which are nitrifying microorganisms. do. Both heterotrophs and autotrophs require O ₂ to grow. However, when organic material is injected at low temperature, heterotrophs covering the outside of the biofloc first consume O _2, and in the case of autotrophs located inside the biofloc, the contact with O ₂ is difficult, resulting in nitrification. There is a vicious cycle in which growth slows down.

FIG. 15 shows that the nitrification efficiency is reduced to about 40% even when the amount of organic matter is increased by about 2 mg / L as a result of the effect of organic inflow on the nitrification reaction.

Therefore, in order to efficiently perform nitrification reaction, it is considered advantageous to minimize the effect on organic matter and to minimize the competition by attaching and growing nitrifying microorganisms.

So far I looked at the center of the preferred embodiment for the present invention. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the present invention.

Claims (10)

1. In a nutrient processing system including an anaerobic reactor, an anoxic reactor, and a nitrification reactor, at the front of the nitrification reactor, the nitrification microorganisms can be grown and concentrated in the nitrification reactor by minimizing the amount of organic matter introduced into the nitrification reactor. A hybrid biological nutrient processing system, wherein the organic oxidizing tank is disposed, and pretreatment is performed in at least one organic oxidizing tank before the nitrification tank treatment.
2. An anaerobic reactor (1) for releasing phosphorus and adsorbing organic substances by using organic substances contained in the incoming wastewater; An oxygen-free reaction tank (2) for removing nitrogen by using an organic material contained in the wastewater introduced from the anaerobic reactor; An organic material oxidizing tank (4) which mainly oxidizes the remaining organic materials after nitrogen removal in the anoxic reaction tank; A nitrification reaction tank (5) aiming at nitrifying the ammonia nitrogen of the exhausted organic matter from the organic oxidation tank; And a final sedimentation tank (6) for solid-liquid separation of the sludge treated in the nitrification reactor to discharge the treated water from which the suspended solids have been removed.
3. The method according to claim 1 or 2,

   The interior of the nitrification tank is a hybrid biological nutrient processing system, characterized in that to perform the nitrification reaction only in the floating growth.
4. The method according to claim 1 or 2,

   The interior of the nitrification tank is a hybrid biological nutrient processing system, characterized in that the filling of any one of the rotating disk, the fixed bed and the fluidized bed adhesion medium.
5. The method according to claim 1 or 2,

   Hybrid nutrient processing system, characterized in that the nitrified nitrate and sludge in the nitrification tank is returned to the anoxic reactor to denitrate the organic nitrate flowing into the anoxic reactor.
6. The method of claim 5,

   Hybrid biological nutrient processing system, characterized in that the returning sludge is injected into the anaerobic reactor (2) and a portion of the anaerobic reactor sludge is introduced into the anaerobic reactor to improve the phosphorus treatment efficiency.
7. An anaerobic reactor (1) for releasing phosphorus and adsorbing organic substances by using organic substances contained in the incoming wastewater; An oxygen-free reaction tank (2) for removing nitrogen by using an organic material contained in the wastewater introduced from the anaerobic reactor; An organic material oxidizing tank (4) for oxidizing the organic material remaining after nitrogen removal in the anoxic reaction tank; And a nitrification reaction tank (5) for nitrifying the ammonia nitrogen of the discharged organic matters from the organic oxidation tank, wherein the organic oxidation tank is provided with a separator, and the rotating disc (102) and the flow medium are attached to the nitrification reaction tank. Hybrid biological nutrient processing system, characterized in that any one of the phase attachment medium (100) is filled.
8. The method of claim 7, wherein

   The separation membrane is a hybrid biological nutrient processing system, characterized in that the rod or disk form.
9. The method of claim 7, wherein

   Nitrified nitrates and sludges from the nitrification tank are converted from the nitrification tank (5) to the organic oxidizing tank (4), from the organic oxidizing tank (4) to the anoxic reactor (2), and from the anoxic reactor (2) to the anaerobic reactor (1). Hybrid biological nutrient processing system, characterized in that the return in order.
10. The method of claim 9,

    The nitrate transfer from the nitrification tank to the organic oxidizing tank is a hybrid biological nutrient processing system, characterized in that using any one of a metering pump and a natural load method.

Images