KR20030086227A - Treating method of sewage and wastewater - Google Patents

Abstract

PURPOSE: Provided an advanced wastewater treatment method for the removal of nitrogen and phosphorus. CONSTITUTION: The system comprises an anoxic chamber(20) into which a raw wastewater(40) containing nitrate and nitrite ammonia is introduced; an aeration chamber(22) in which a microorganism media is packed; tapered aeration tanks(24,26); a final settling basin(30); and a return pipe(52) through which a portion of sludge is returned to the anoxic chamber.

Description

Wastewater Treatment Method {TREATING METHOD OF SEWAGE AND WASTEWATER}

The present invention relates to a method for treating sewage, and more specifically, to predominantly treat Bacillus bacteria, and to process organic sewage, sewage, and wastewater containing nitrogen (N) and phosphorus (P), but with nitrite nitrogen and quality. The present invention relates to a wastewater treatment method for effectively treating acidic nitrogen.

Patent No. 0151928 discloses a wastewater treatment apparatus and method for treating wastewater using Bacillus, which is known to have excellent treatment of organic wastewater, as well as to remove nitrogen and phosphorus. have. The present applicant has developed such a patent invention under the trade name of B3 method (Bio-Best-Bacillus System) and is carrying out in the field, and improving and applying the problems caused through continuous technology development.

The wastewater treatment system and method according to the present invention has been proven to be excellent in various treatment facilities, but it does not effectively treat nitrite nitrogen (NO ₂ -N) and nitrate nitrogen (NO ₃ -N) generated during the treatment of wastewater. The reality is that you can't. Patent No. 0151928 treats nitrogen by predominantly Bacillus bacteria, but the main subject is ammonia nitrogen, which is difficult to treat nitrite nitrogen and nitrate nitrogen. In other words, the present invention proceeds to a process to prevent nitrification of ammonia nitrogen by using concentrated aeration and abatement aeration, but effectively removes nitrite and nitrate nitrogen present in the influent or in process such as industrial wastewater. There is a problem that can not be.

The present invention has been made to solve the above problems, and an object thereof is to provide a new type of wastewater treatment method capable of effectively removing nitrite nitrogen and nitrate nitrogen present in the influent or generated in the process.

1 is a view showing an example of a wastewater treatment system to which the wastewater treatment method of the present invention is applied;

2 is an explanatory diagram for explaining the wastewater treatment method according to the present invention.

* Explanation of symbols for the main parts of the drawings

10 reactor 20 first chamber

22: second room 24: third room

26: 4th chamber 30: 1st settling tank

40: influent 50: internal return

52: external conveyance 70: motor

90: media

According to a feature of the present invention for achieving the above object, there is provided a sewage treatment method for treating the influent by predominantly Bacillus bacteria having a reaction tank divided into a plurality of chambers and a precipitation tank for receiving the effluent through the reaction tank. . The wastewater treatment method includes the steps of: supplying the influent while maintaining the first chamber of the reactor in anoxic conditions; Intensive aeration of the second yarn following the first yarn and attenuating the remaining yarn after the first yarn; Conveying a predetermined amount of sludge from the final chamber of the reactor to the first chamber; And returning a predetermined amount of sludge from the sedimentation tank to the first chamber to treat nitrous nitrogen or nitrate nitrogen generated during treatment of the influent with the organics of the influent.

In the wastewater treatment method according to the present invention, the reaction tank is divided into first to fourth chambers, and the third and fourth chambers may be attenuated. At this time, the dissolved oxygen amount (DO) of the first chamber may be maintained below 0.2, the second chamber 0.5 to 1.5, the third chamber 0.3 to 0.5, the fourth chamber 0.3 or less.

In the wastewater treatment method according to the present invention as described above, further comprising the step of applying each of the above-described method to the Bacillus-coated media in the second room, so as to maintain a stable uniformity of the Bacillus bacteria to be stable can do.

Bacillus bacteria hydrolyze not only organic substances but also hardly degradable cellulose, proteins, starches and fats, and directly ingest the ammonia, hydrogen sulfide, and amines, which are odors generated during the treatment of wastewater. Decompose to remove odor. Since Bacillus bacteria have endogenous spores, they can adapt to changes in environmental conditions compared to the microbial group applied to the treatment of wastewater, even if the surrounding environmental conditions change. → Survival is repeated for the same process as spores, so it is possible to maintain high concentration of cells. Since the surface of Bacillus bacteria is covered with a sticky substance, adsorption and aggregation occur well, and the formed floc has good precipitation. In addition, nitrogen or phosphorus contained in the sludge is known to be present in the cells of the spores Bacillus bacteria is not likely to be eluted from the sedimentation basin or sludge concentration tank.

1 is a view showing a wastewater treatment system of Patent No. 0519928 to which the wastewater treatment method according to the present invention can be applied. At this time, the illustration of FIG. 1 is similar to the drawing of the patent registration publication of Patent No. 0151928, and a detailed description of parts that can be easily predicted and understood or implemented by those skilled in the art from the description of the patent is omitted. It will be described based on the part related to the present invention.

First, Patent No. 0151928 proposes a system and method for treating sewage water by predominantly culturing Bacillus bacteria described above. Bacillus bacteria are predominantly cultured in a reaction tank (digestion tank) 10 divided into four threads 20, 22, 24, and 26, which are formed by the differential aeration, the inner conveyance 50, and the outer conveyance 52, which are made for each thread. By sludge conveying. In order to maintain the first chamber 20 of the reactor 10 in anoxic conditions, only the stirring is carried out, and the second chamber 22 is concentrated aerated with about 70% of the total amount of aeration of the reactor 10 and the third chamber The yarn 24 is aerated with the remaining 20% air volume and the fourth yarn 26 is divided by 15% to allow attenuation.

Therefore, the amount of dissolved oxygen can maintain a certain concentration of only the second chamber 22, and the remaining three chambers 20, 24, and 26 have only a very low level of dissolved oxygen. It is difficult, and instead, breeding fungi that can grow well under low oxygen concentrations. Then, the sludge of the final chamber 26 of the reaction tank 10 is recycled (100% to 300%) (inner bounce), and further 50% to 100% is returned from the primary settling tank 30 (52, external bounce). It is a method of selecting and culturing strains that can grow while enduring in such an environment by operating at a return rate of 150% to 400%.

In other words, the present invention is difficult to grow absolute anaerobic microorganisms due to the presence of dissolved oxygen in a certain concentration (about 0.5 to 1.5 ppm) in the second chamber 22 and lack of organic matter in the third to fourth chambers 24 and 26. And because dissolved oxygen is very low, the growth of absolute aerobic microorganisms is suppressed. In addition, the present invention is repeated through this environment through the inner conveying 50 and the outer conveying (52, sludge conveying), the proliferation of absolute anaerobic, absolute aerobic microorganisms is suppressed and the proliferation of the anaerobic microorganisms such as Bacillus is relatively advantageous advantage Is maintained.

Existing wastewater treatment process (B3) maintains the first chamber as aerobic, so that the growth of microorganisms in the first chamber is vigorous, decomposing most organic materials and oxidizing part of TKN to nitrate nitrogen (NO ³ -N). Flows into the second chamber. Therefore, the existing B3 process is often the cause of TN is increased by the charge claim 2-4 yarn end TN is 70~80% nitrate nitrogen (NO ³ -N) of the discharged water by being denitrification is not caused after discharging the organic material is low in do. However, in the present invention, the fourth chamber 26 in which the nitrogen is mostly removed in the form of ammonia nitrogen (NH ₃ -N) from the second chamber 22 and inevitably generated nitrate nitrogen (NO ³ -N) which is inevitably generated The TN in the treated water is reduced by returning and denitrifying the first chamber 20 which is an oxygen free tank.

Therefore, the present invention can be easily applied to the wastewater treatment system to effectively treat nitrite nitrogen and nitrate nitrogen as well as ammonia nitrogen when treating wastewater.

Nitrous acid nitrogen and nitrate nitrogen are removed as organic medium as follows.

NO ₂ -N, NO ₃ -N + Organics → N ₂ ↑

The present invention provides a wastewater treatment method as shown in FIG. 2 using the principle of removing nitrous and nitrate nitrogen.

The wastewater treatment method according to the present invention provides a method for effectively treating ammonia nitrogen, nitrite nitrogen and nitrate nitrogen which are generated during treatment or present in the influent 40 and supplied to the reaction tank 10. To this end, the present invention has developed a sewage treatment method that can be applied to the sewage treatment system of Patent No. 0151928, which is being used by the applicant for the B3 method. Of course, the present invention is not limited to such a wastewater treatment system, but may be applied to various forms within the technical scope.

Referring to Figure 2, the wastewater treatment method according to the present invention comprises a reaction tank 10 divided into four chambers (20, 22, 24, 26) and a settling tank 30 for receiving the effluent through the reaction tank (10) It can be applied to the sewage treatment system that treats the influent 40 by predominantly Bacillus bacteria. The greatest feature of the wastewater treatment method according to the present invention is to supply the inflow water 40 while maintaining the first chamber 20 in anoxic conditions, the second chamber 22, the third chamber 24 and the fourth chamber ( 26) while performing the differential aeration and at the same time performing the inner conveying (50) and the outer conveying (52), such wastewater treatment method is the first chamber (Nitrite nitrogen and nitrate nitrogen generated in the wastewater treatment process) 20) to be decomposed by the organic material introduced in. At this time, in the embodiment of the present invention, the reactor 10 has been described as a configuration consisting of four chambers 20, 22, 24, 26, the number of the divided chambers of the reactor 10 is not limited. For example, when divided into three rooms, the first room operates under the same conditions as the first room 20 of the embodiment, the second room operates under the same conditions as the second room 22 of the embodiment, and the third room 24 ) May be operated in the same manner as in the third chamber 24 of the embodiment. If it is divided into five rooms, the fifth room becomes the final room, and its operation is performed under the same conditions as the fourth room 26 of the present embodiment, and internal transfer is made from the fifth room.

In the present invention, the first chamber 20 is maintained under anoxic conditions, and the second chamber 22, the third chamber 24, and the fourth chamber 26 are subjected to differential aeration. In other words, the second chamber 22 attenuates the concentrated aeration, the third chamber 24 and the fourth chamber 26. At this time, the dissolved oxygen content of each chamber is kept below 0.2 for the first chamber 20, 0.5 to 1.5 for the second chamber 22, 0.3 to 0.5 for the third chamber 24, and 0.3 or less for the fourth chamber 26. Be sure to In the present invention, the differential aeration of the second chamber 22, the third chamber 24 and the fourth chamber 26 is different from that of the first chamber, the second chamber and the third chamber in the wastewater treatment method of Patent No. 0151928. It may be possible to implement the corresponding method.

As described above, the present invention performs the inner conveyance 50 and the outer conveyance 52. That is, the inflow water 40 is carried out by conveying a predetermined amount of sludge from the fourth chamber 26 to the first chamber 20 and conveying a predetermined amount of sludge from the settling tank 30 to the first chamber 20. The nitrite nitrogen or nitrate nitrogen generated in the treatment process of the treatment using the organic material of the influent 40.

Meanwhile, in a preferred embodiment of the present invention, the media 90 coated with Bacillus bacteria in the second chamber 22 is stably and uniformly stabilized in order to optimize treatment efficiency of wastewater. Can be kept. This method is very useful when the concentration is low, such as sewage. This media 90 solves the problem of difficult concentration when providing a simple space (room). That is, the median 90 is to provide a space for Bacillus bacteria. The media 90 is placed in a space for activating Bacillus bacteria as in the second chamber 22 of the present invention. The contact material of the media 90 may be a net, a ceramic, an organic polymer compound, a yogurt bottle, a sponge, a porous material (activated carbon, zeolite, etc.), calcined mud, or the like.

Such the present invention was able to verify the effect through the following experiment.

First, in the wastewater treatment system used in the experiment, the reactor 10 was made of iron, and the reaction tank volume was 12.5 m 3, divided into four chambers, and the first chamber 20 was operated by the motor 70 with an oxygen-free tank. The stirrer was installed and the diffuser was installed in the lower part from the 2nd chamber 22 to the 4th chamber 26 so that air may be supplied from a blower. And the effluent treated in the reaction tank 10 was introduced to the settling tank 30 and the outer conveying 52 was made to be made in the settling tank 30, the inner conveying 50 in the fourth chamber 26 of the reaction tank 10 This was done. In addition, the inflow of the reaction tank and the sludge internal and external transport were performed using a metering pump.

Looking at the characteristics of the influent (urban sewage) used in this experiment, the influent BOD 52 ~ 433 mg / L (average 160 mg / L), COD 42-248 mg / L (average 87 mg / L), SS 42 ~ 1050 mg / L (average 187 mg / L), TN 12-68 mg / L (average 35 mg / L), and TP 1-18 mg / L (average 4 mg / L).

In the treatment of such sewage, it was operated for 6 months for the comparison between the conventional B3 method and the method according to the present invention, and the analysis of each sample was conducted twice a week.

Mean value of each water quality according to the experiment of the present invention B3 and the present invention is shown in Table 1 below.

division Original invention The present invention Remarks B3 Processing efficiency Anaerobic + B3 Processing efficiency BOD 5.7 96.4 5.6 96.5 COD 10.1 88.4 9.8 88.7 SS 4.3 97.7 4.1 97.8 TN 10.4 70.3 6.8 80.5 TP 0.6 85.0 0.5 87.5

As shown in Table 1, the treated water concentration and the removal efficiency of the present invention were 5.6 mg / L and 96.5% in the case of BOD as a result of comparative operation with the existing method (B3) using the treatment process of the present invention. , COD was 9.8 mg / L, 88.7%, SS was 4.1 mg / L, 97.8%, TN was 6.8 mg / L, 80.5%, and TP was 0.5 mg / L, 87.5%.

Therefore, the wastewater treatment method according to the present invention was able to obtain better treatment results than the conventional B3 method, and in particular, the treatment efficiency of TN was 80.5%, which is considerably superior to the existing method.

Meanwhile, in the present invention, an experiment was performed for four months with and without the media 90 in the second chamber 22 in treating sewage using the sewage treatment method, and the treatment results are shown in Table 2 below. It was. At this time, the treated water showed only the treated water quality for the inflow and outflow of the biological treatment reactor.

As shown in Table 2, according to the present invention, the treated water concentration and the removal efficiency in the experiments in which the media of the present invention were put in the comparative operation in treating sewage showed 4.8 mg / L and 96.1% for BOD. COD was 10.1 mg / L, 89.4%, SS was 4.3 mg / L, 97.7%, TN was 5.6 mg / L, 81.1%, and TP was 0.5 mg / L, 90.2%.

Therefore, the present invention was able to obtain a better treated water quality by adding a media even when a low concentration of influent water is introduced.

Table 3 is a result of contrasting Bacillus population and dominance rate when the media is put in the present invention.

As such, when using the media in the present invention, it can be seen that the stable dominance ratio of Bacillus is maintained. Therefore, even when a low concentration of influent flows in, it is possible to maintain stable dominance of Bacillus by adding media.

As described above, the wastewater treatment method according to a preferred embodiment of the present invention has been described, but this is merely an example, and various changes and modifications can be made without departing from the technical spirit of the present invention. Those skilled in the art will appreciate.

According to the wastewater treatment method according to the present invention, the first chamber is operated as an anaerobic tank in the reactor divided into four chambers, and the sludge is transferred back to the first chamber through the inner and outer conveying, so that the wastewater is present in the influent or in the process of treating the wastewater. The generated nitrite nitrogen or nitrate nitrogen can be effectively treated by reacting with the organics of the influent.

Claims (4)

In the wastewater treatment method for treating the influent water by having a reaction tank divided into a plurality of chambers and a precipitation tank for receiving the effluent through the reaction tank and predominantly Bacillus bacteria, Supplying the influent while maintaining the first chamber of the reactor in anoxic conditions; Intensive aeration of the second yarn following the first yarn and attenuating the remaining yarn after the first yarn; Conveying a predetermined amount of sludge from the final chamber of the reactor to the first chamber; And returning a predetermined amount of sludge from the sedimentation tank to the first chamber to treat nitrous nitrogen or nitrate nitrogen generated during treatment of the influent using the organic material of the influent. . The method of claim 1, The reactor is divided into first chambers and fourth chambers, and the third chamber and the fourth chamber are tapered and attenuated. The method of claim 2, Dissolved oxygen amount (DO) of the first chamber is less than 0.2, the second chamber is 0.5 to 1.5, the third chamber is 0.3 to 0.5, the fourth chamber is characterized in that it is maintained below 0.3. The method according to any one of claims 1 to 4, And further comprising the step of putting the media coated with Bacillus bacteria in the second room, sewage treatment method characterized in that to maintain a stable uniformity of the Bacillus bacteria to be stable.