KR100483305B1 - Biological Nutrient Removal Device Using Rotating Biological Contactor Package system - Google Patents

Abstract

The present invention relates to a wastewater package treatment apparatus using a rotating disc, and more specifically, to an oxygen-free rotating disc reactor, a nitrification rotary disc reactor, an internal circulation tank, a precipitation tank, a chemical input device, and the like, and are integrally manufactured. The present invention relates to a wastewater package treatment apparatus using an original plate. The wastewater package treatment device according to the present invention is unified, and is suitable for small scale wastewater treatment facilities, small-scale village sewage treatment facilities (nitrogen / phosphorus removal), etc., and also 50 tons / day based on daily treatment capacity, 100 ton / day, 200 ton / day, 500 ton / day can be divided into production can be standardized equipment. Wastewater package treatment apparatus according to the present invention can remove the organic matter within a short residence time by using the attached microorganism, and can be purified almost completely by the highly treated nitrogen, phosphorus.

Description

Biological Nutrient Removal Device Using Rotating Biological Contactor Package system}

The present invention relates to a wastewater package treatment apparatus using a rotating disc, and more specifically, to an oxygen-free rotating disc reactor, a nitrification rotary disc reactor, an internal circulation tank, a precipitation tank, a chemical input device, and the like, and are integrally manufactured. The present invention relates to a wastewater package treatment apparatus using an original plate. The wastewater package treatment device according to the present invention is unified, and is suitable for small scale wastewater treatment facilities, small-scale village sewage treatment facilities (nitrogen / phosphorus removal), etc., and also 50 tons / day based on daily treatment capacity, 100 ton / day, 200 ton / day, 500 ton / day can be divided into production can be standardized equipment.

The rotating disc method for wastewater treatment is by attaching microorganisms to the rotating disc to alternately circulate water and air to transfer oxygen in the air to remove water and remove pollutants through nitrification. As a general method for purifying oil, it is easy and easy to manage, and it is a kind of economical wastewater treatment method due to the small amount of sludge generated and low power cost due to the deposition growth process. A general wastewater and wastewater treatment process using a rotating disc is briefly shown in FIG.

This rotational disk method attaches and treats microorganisms to a disk, which is a media, and rotates the disk instead of by a conventional blower, thereby transferring oxygen in the air to the water, thereby making a mechanical device for rotating motion. Its durability, corrosion resistance, and chemical resistance are more important than any other methods, and since it is necessary to operate the disc with microorganisms attached to it by a certain power source such as a power source, power transmission method, Disc fabrication, disc coupling, and the complex configuration of disc coupling are important design factors in the advanced treatment of wastewater and wastewater. In addition, there is a need for a technology that simplifies and integrates the system to facilitate installation and maintenance. However, there have been no examples in which an oxygen-free rotary disc reactor is integrated and applied, and the design criteria also depend on the characteristics of each disc and the characteristics of the influent wastewater. Accordingly, an object of the present invention is to propose a standard specification and design criteria of a wastewater package treatment apparatus using a rotating disc as an example of design criteria and target wastewater obtained through experiments.

 Hereinafter, the features of the waste water treatment apparatus using the conventional rotating disc will be described in more detail.

First, in the conventional processing apparatus, since the rotating disc is mainly used under aerobic conditions, the deposition rate under the surface is about 40% nitrification rotary disc reactor, and the design criteria for anoxic rotary disc reactor are not established. There is no method for manufacturing a rotating disc reactor integrally and driving a single shaft from a single shaft. Therefore, there is no detailed data on the sealing part of the connection part when fabricating the oxygen-free rotary disc reactor and the nitric oxide rotary disc reactor. Sealing is generally aimed at preventing the leakage of the connecting part when the rotating body is driven, and is divided into mechanical seal packing method and grand packing method according to the shaft rod method. The mechanical seal packing method has excellent watertightness and airtightness, but it has high installation and maintenance costs, has the disadvantage of having to remove the entire shaft when repairing or replacing it, and the wear of the seal when idling the rotor. Therefore, the low-speed rotating body does not need to apply expensive mechanical seals, and may use a grand packing method.

Second, the conventional rotary disk reactor is composed of a floating phase anoxic tank and a nitrate rotary disk tank for removing nitrogen, and at this time, the stirrer and the denitrification tank rotating disk of the anoxic tank cannot be driven at the same time. do. The conventional rotary disk reactor also maintains the suspended microbial concentration in the floating phase anoxic tank at about 2,000 to 4,000 mg / L, so that the suspended microbial concentration in the rotary disk reactor, which is a nitrification tank, is also maintained at a high concentration, resulting in a large amount of sludge. In order to maintain a constant microbial concentration, the sludge conveyance has to maintain up to 50-100% of the inflow flow rate.

Third, since the rotating disc should have a form that can quickly and easily attach a large amount of microorganisms, the surface of the rotating disc used in the conventional rotating disc method is composed of an uneven type, a unit fan shape, and a SARAN ROCK attachment type, and most of the surface Is rough and the specific surface area is formed as large as possible. However, such a conventional rotational disc method not only keeps the attached microorganisms thick, but also causes nitrification, organic matter removal, and denitrification reactions to proceed in a single nitrification rotational disc reactor, resulting in temporary anaerobicization of the attached large amount of microbial layer. Desorption may occur, and centrifugal dropping of microorganisms by centrifugal force during the rotation of the disc may also occur, causing a large amount of solids to be caused in the effluent. In addition, since the microorganisms are excessively attached to the unit disc surface, the weight per unit disc area is relatively high, and when the microorganisms are excessively attached, the rotating shaft is broken, and the attached microorganism layer is thick inactive microorganisms except for the outer surface. Because it is a layer, it is difficult for oxygen to be sufficiently diffused to the inside, so that oxygen in the atmosphere is not sufficiently transferred into the suspended sludge system during the rotation of the disc, and thus the oxygen transfer efficiency to the water is also lowered.

Fourth, in recent years, a method of adding elements such as ceramics and transition metals to the original plate to increase the microbial adhesion rate to the original plate has been proposed, and PVC, PE, HDPE, expanded polystyrene, etc. have been used as representative materials. However, this type of disk has a low nitrogen surface area load, so the advanced treatment for nitrogen removal is not efficient, and the initial investment costs naturally increase. In addition, when the disc diameter is 3m or more, the disc is divided into six equal parts or more in the shape of a fan, and the left and right of these unit pieces are bound together and assembled into discs, and then overlapped with each other to overlap the disc coupling portions (as long as multiple discs are combined). The unit is cumbersome because it is produced and utilized. The related technology is disclosed in Korean Patent Application No. 94-5063.

Fifth, the conventional rotating disc method attaches an excessive amount of microorganisms to the surface of the unit disc, so that the weight per unit disc area is relatively high. Therefore, when the disks are continuously bonded, the number of disks that can be attached in a single volume is small, which not only lowers the efficiency of the disks for inducing nitrification reactions, but also causes an overload on the central axis after bonding, and at the same time Since more than 12 coupling rods (tubes or heavy-loaded metal rods) must support the disc, the load (self-weight) becomes larger, and when the microorganisms are excessively attached, the rotating shaft may be damaged. As such, the conventional rotating disc needs to be provided with a high-load rotating bearing to withstand high loads, so a bearing made of a high strength material is required, which increases the manufacturing cost, and the bearing may be easily corroded by the scattering liquid made by the rotation of the disc. Since the bearings are not prefabricated, it was cumbersome to lift the entire disc during maintenance.

Sixth, in the existing wastewater treatment process, phosphorus released from the anaerobic tank is excessively ingested into the microorganisms in the aerobic tank in which dissolved oxygen is present, so that the phosphorus content in the sludge increases, and thus it is contained in the excess sludge. Phosphorus is processed during the exhalation process. Therefore, there was a problem to install the anaerobic tank.

The present invention is designed to solve the above problems, the object of the present invention is as follows.

The first object of the present invention, the oxygen-free rotary disk reactor and the nitric oxide rotary disk reactor is made of a single shaft and a drive shaft, compared to the existing rotary disk device, less power consumption and waste water using the rotating disk has a simple structure It is to provide a package processing apparatus. In addition, in the case of a large capacity, it can be composed of a rotating disc device that connects several discs simply by coupling the disc coupling unit, and there is no mechanical noise and corrosion during operation, and the overall structure is simple and easy to install, and when rotating the disc It is to provide a wastewater package treatment apparatus using a rotating disc to prevent the warpage phenomenon.

The second object of the present invention is to compare the anoxic rotary disc reactor with the anoxic tank, which is composed of suspended aeration which requires sludge return (50%) in order to maintain a certain amount of microorganism concentration (2,000-4,000 mg / L) in the anoxic tank. Since the microorganisms are attached to the rotating disk rotating microorganisms in water, the microorganism concentration (7,000-10,000 ㎎ / L) can be increased, and it can have a strong advantage in the impact load according to the inflow load condition which is characteristic of the attached microorganisms. It is possible to provide a wastewater package treatment apparatus using a rotating disc, which does not require a separate underwater stirrer, since only a rotating disc rotating in the water is possible.

The third object of the present invention is to easily detach and attach the microorganisms in the rotating disk by using the nitrification rotating disk reactor, so that the thickness of the rotating disk is maintained only by the microorganisms with strong activity, so that the number of disks per unit volume is reduced. It is possible to provide a wastewater package treatment device that enables a high compact design, and consequently increases oxygen transfer efficiency and reduces unit load, thereby greatly reducing the load and power required on the shaft.

The present invention relates to a wastewater package treatment apparatus for advanced treatment using a rotating disc, and more specifically, an oxygen-free rotating disc reactor (2), a nitric oxide rotating disc reactor (4), an internal circulation tank (6), and a precipitation tank ( 8), and relates to a wastewater package treatment device composed of a chemical injection device (10). A single manufacturing process of the oxygen-free rotary disc reactor and the nitrification rotary disc reactor is disclosed in Korean Patent Application No. 2001-0015261 "Sewage Treatment System Using Polypropylene Spinning Disc".

The material of the rotary discs used in the oxygen-free rotary disc reactor 2 and the nitrification rotary disc reactor 4 of the present invention is preferably polypropylene (PP), and the surface shape is preferably free from irregularities and bends. The thickness is preferably about 2 mm. As described above, the polypropylene rotating disc having a surface state without irregularities and bends exhibits a self cleaning function in which microorganisms to be attached are easily attached and detached, and only strong microorganisms are formed to be attached to the disc thinly. The load can be minimized, and the power required can be reduced by about one third compared to the existing installation, even if the motor, reducer, coupling, plastic bearing and disc coupling are configured on a single drive shaft.

In this way, the number of original plates can be increased, the interval can be minimized, and oxygen is rapidly delivered to the thin microbial layer formed on the surface of the original plate because it does not adhere to inactive microorganisms thickly (Korea Application No.: 10-2001-0015261 Reference).

For reference, the physical and chemical properties of the polypropylene are described as follows (refer to Republic of Korea Application No. 10-2001-0015261).

<Polypropylene; PP>

⊙ Chemical Name: 1-Propene homopolymer

⊙ Melting point: 165 ℃ (Actual, solid at room temperature, recording at 155 ℃)

Specific gravity: 0.90 to 0.92

⊙ Features:

-Low flammability and insoluble in organic solvents.

-Very strong against acid and alkali and high frictional resistance.

-Robust

The treatment apparatus according to the present invention connects the anaerobic rotary disc reactor 2 and the nitric oxide rotary disc reactor 4 to a single shaft to manufacture a single body, and seals the connection using a grand packing method. Thus, unlike conventional rotary disc reactors, the sludge agitation and denitrification reaction of the oxygen-free rotary disc reactor 2 and the oxygen of the nitric oxide rotary disc reactor 4 are driven by a single motor power driven from a single shaft central axis. The transfer and nitrification reactions can be carried out simultaneously. The sealing aims at the smooth running of the rotating disc and the secondary purpose is to prevent leakage between the shafts. In the processing apparatus according to the present invention, a rotary disc device rotating at a low speed is used, and thus maintenance is easy, replacement is easy, and watertightness is applied to the grand packing method to have economical efficiency.

In the treatment apparatus according to the present invention, it is preferable that the coupling portion of the oxygen free rotary disc reactor 2 and the nitric oxide rotary disc reactor 4 is configured to be axially arranged by a bidirectional metal coupling. This is because the bidirectional coupling not only facilitates installation and operation of the disc coupling portion, but also facilitates maintenance. In addition, by inserting the plastic packing between the two-way metal coupling, the friction, wear and noise of the coupling can be hardly generated between the disc coupling portions, and the noise and corrosion phenomenon by supporting the rotary shaft with the plastic bearing and the bearing buffer support. It can prevent, and can mitigate the impact caused by the rapid instantaneous drive and axial shaking of the rotating disc.

In addition, the oxygen-free rotary disc reactor (2) is usually produced in two stages (Stage), the first stage is 30 ~ 40㎜ disc installation interval to prevent the closing phenomenon of the disc due to the excessive adhesion of microorganisms during the initial inflow of raw water inflow It is preferable to manufacture a wide range of two stages, and to install and install a disc installation interval of 10 to 20 mm according to the inflow load conditions (see FIG. 3). In general, when the inflow load is low, maintain an interval of about 15mm, and when the inflow load is a high load, maintain an interval of about 20mm.

The reason why the original disc shear interval of the original disk shear interval is 40 mm in the disc installation of the oxygen-free rotating disc reactor 2 is to reduce dissolved oxygen in the internal circulation liquid returned from the internal circulation tank 6 and maintain the quasi-aerobic state. This is to reduce dissolved oxygen in the oxygen-free rotary disc reactor 2.

Oxygen-free rotary disc reactor (2) is where the inflow water is introduced for the first time in the waste water package treatment apparatus according to the present invention, the upper and lower rotary disc is preferably configured to have a spacing of 15 cm or more. In addition, the upper part is preferably maintained at a distance of 15cm away from the water surface, the left and right spaces of the disc is made more than 15cm to ensure that the mixing of the sludge in the oxygen-free rotating disk reactor during the drive by the driving force of the rotating disc smoothly. desirable.

In the apparatus according to the invention, the nitrification rotary disc reactor 4 is preferably composed of two stages. In this case, the front end is a BOD removal disk reactor for removing organic substances remaining after the denitrification reaction occurs in the oxygen-free rotary disc reactor, and the rear end is oxidizing ammonia nitrogen to nitrate nitrogen after the remaining organic substances are oxidized. It is a rotating disc reactor for the disc, unlike the previous disc installation method, the number of discs is large and the interval is narrow.

In addition, unlike the oxygen-free rotary disc reactor 2, the nitrification rotary disc reactor 4 has a small amount of microorganisms attached to the disc. In other words, heterotrophic microorganisms for fast removal of organic matter grow only in the BOD removal rotary disc reactor, which is the front end of the anoxic rotary disc reactor (2) or nitrate rotary disc reactor (4), and thus the slow growth rate Nitric oxide rotary disc reactors predominantly nitrifying bacteria have few microorganisms in appearance. In order for the nitrifying bacteria to function normally, the dissolved oxygen acts as a limiting factor in addition to the temperature, so the dissolved oxygen concentration must be maintained high.

In addition, the rotational speed of the rotating disk is relatively fast at 18.85m / min (circumferential speed) to maintain the contact time of the wastewater and air, and the dissolved oxygen concentration (DO) in the nitric oxide rotating disk reactor is 2-6 mg / L. It is desirable to maintain.

Since the rotating disk method is a deposition growth process, the amount of sludge generated is generally low and the suspended sludge concentration is low. When the inner disk is returned to the denitrification tank from the rear end of the nitrification rotary disk reactor (4), a high concentration of dissolved oxygen is returned along with the nitrate nitrogen to denitrification tank. There is a problem of lowering the denitrification efficiency in the bar, the internal circulation tank 6 in the treatment apparatus according to the present invention is to solve this.

Inflow water is first denitrified in an oxygen-free rotary disc reactor (2), and then introduced into the nitrification rotary disc reactor (4), in which nitrification of ammonia nitrogen in the influent source occurs.

The nitrified symbolized water in the nitrification rotary disc reactor (4) is introduced into the oxygen-free rotary disc reactor (2) by an internal circulation pump in an internal circulation tank, and a part is transferred to the settling tank (8). In the settling tank (8), sludge and suspended microorganisms detached from the rotating disc are separated from the supernatant and solid-liquid, and the sludge is transferred to an oxygen-free tank, and some are disposed of by sludge dewatering.

In the treatment apparatus according to the present invention, the dissolved oxygen concentration (DO) flowing out of the nitric oxide rotating disc reactor using an inverter motor or a variable speed as a drive motor for adjusting the oxygen transfer efficiency of the rotating disc. Can be properly maintained and controlled. In general, when different conditions (reactor microbial concentration, inflow source concentration, temperature, etc.) are the same, the dissolved oxygen concentration in the nitrate rotating disc reactor is related to the driving speed (circumferential speed) of the rotating disc, and the driving speed of the rotating disc is As early as possible, the dissolved oxygen concentration in the nitrate rotating disc reactor tends to be high. The dissolved oxygen concentration in the treated water flowing out of the nitrate rotating disc reactor may be high, resulting in the loss of the function of the anoxic tank when entering the anoxic tank, thereby lowering the denitrification efficiency. The treatment apparatus according to the present invention uses an inverter motor or a variable motor to change the driving speed (circumferential speed) of the nitrification rotating disc reactor according to the operating conditions (change in inflow water, change in microbial concentration). It is possible to keep the dissolved oxygen concentration in the nitrate rotating disc reactor effluent constant.

In the treatment apparatus according to the present invention, phosphorus may be removed using an anaerobic tank, but in a small treatment plant, it may be more economic to remove phosphorus by chemical treatment.

Processing apparatus according to the invention is also the soluble phosphate in the coagulant property alum (Al ³⁺⁾ or iron (Fe ³⁺⁾ in the final sedimentation tank through a shear drug input device 10, the raw water (soluble PO ₄ ^3- -P) By introducing a ratio of 1: 1 to the concentration, it promotes sludge formation, which not only shortens the residence time but also prevents excessive phosphorus load.In the case of a small treatment plant, the removal rate is fast and the amount of sludge generated is small. There is an advantage to minimize the required site.

Hereinafter, the present invention will be described in detail through examples. These examples are for illustrative purposes only, and the present invention is not limited thereto.

Example 1

 The design criteria of a general floating anaerobic tank and anoxic rotary disc reactor are shown in Table 1 below, and the target water was compared based on living sewage.

<Table 1> Comparison of Floating Anaerobic Tank and Anaerobic Rotary Disc Reactor

division Floating anaerobic tank Anaerobic Rotary Disc Reactor Microbial concentration 2,000 to 4,000 mg / L (based on floating microbial concentration) 7,000-10,000 mg / L (approximate concentration of attached microorganism) Residence time About 1.5 ~ 3 hr Around 2.5 hr Design load SDNR: 0.008gNO ₃ -N / g.MLSSday NO ₃ -N Load: ₃ ~ 5g NO ₃ -N / ㎡ ・ day Denitrification efficiency 60% average Around 70% Sludge Transfer Around 50% Less than 30% Accessories Stirrer required No agitator required Temperature change Weak against temperature change in winter because of microbial metabolism by suspended microorganisms It is resistant to temperature change in winter because of microbial metabolism by adherent microorganism

Example 2

In order to examine the correlation between the driving speed (circumferential speed) of the rotating disk and the dissolved oxygen concentration in the nitrate rotating disk reactor, the rotational disk of the rotating disk under the same operating conditions (the same conditions of microorganism concentration in the reactor, inlet water concentration, temperature, etc.) The dissolved oxygen concentration in the effluent of the nitrate rotating disc reactor was measured while reducing the rotational speed from 25 m / min to 15 m / min.

As a result, the dissolved oxygen concentration was 5-6 mg / L when the rotational speed was 25 m / min, while the dissolved oxygen concentration was 3-4 mg / L when the rotational speed was reduced to 15 m / min. The phenomenon did not occur.

Example 3

As shown in Fig. 2, the rotary disc according to the present invention includes an oxygen-free rotary disc reactor 2, a nitrification rotary disc reactor 4, an internal circulation tank 6, a final precipitation tank 8 and a chemical injection device 10. Wastewater package treatment device using the wastewater treatment system, the average biological oxygen demand (SBOD) of raw water 73mg / l, chemical oxygen demand (COD) 138mg / l, suspended solids (SS) 60mg / l, total nitrogen (TN) 27.8 Results of treatment of municipal sewage with mg / l and total phosphorus (TP) of 3.1 mg / l are shown in Table 2 below.

Table 2. Influent and treated water quality of this example

Item Influent Quality (mg / l) Treatment water quality (mg / l) Remarks Biological Oxygen Demand (SBOD) 73 8 or less Chemical oxygen demand (COD) 138 23 or less Suspended solids (SS) 60 7 or less Total nitrogen (TN) 27.8 8 or less Total Person (TP) 3.1 1.0 or less

According to the above configuration, the present invention can achieve the following effects.

Wastewater package treatment apparatus according to the present invention, the oxygen-free rotary disc reactor and the nitric oxide rotary disc reactor is made of a single shaft and a drive shaft, compared to the conventional rotary disc device, the power consumption is less, simple structure and installation It is easy and can prevent the distortion during the rotation of the disc, and can be agitated only by the rotating disc that rotates in the water, there is no need for a separate agitator.

Wastewater package treatment apparatus according to the present invention, unlike the anaerobic tank consisting of suspended premature, it is possible to maintain a high concentration of adherent microorganisms to 7,000 ~ 10,000 ㎎ / L, excellent response to temperature changes, features of adherent microorganisms It has a strong advantage in impact load according to phosphorus inflow load condition.

The wastewater package treatment apparatus according to the present invention also facilitates the detachment and attachment of microorganisms in the rotating disc using a nitrification rotary disc reactor, and the number of discs per unit volume is maintained by keeping the thickness thin with only active microorganisms. ), A compact design is possible, so oxygen transmission efficiency is high, and unit load is reduced, which greatly reduces the load and power required on the shaft.

The wastewater package treatment apparatus according to the present invention also uses a flat and smooth polypropylene as a material for anoxic and nitric oxide rotating discs, so that the microorganisms do not adhere excessively, and the mechanism of detachment and attachment occurs naturally. One effect.

In addition, since the wastewater package treatment apparatus according to the present invention uses a disc having a thickness of about 2 mm, the unit load can be minimized as compared with a conventional rotating disc, and a motor, a reducer, a coupling, a plastic bearing, Even if the disk coupling portion is configured, the required power can be reduced by about one third of that of the conventional equipment.

1 is a flow chart schematically showing a general sewage and wastewater treatment process by a rotating disc,

2 is an overall process configuration of the wastewater package treatment apparatus according to the present invention,

3 is a detailed cross-sectional view of an oxygen-free rotary disc reactor according to the present invention,

4 is a detailed cross-sectional view of the nitrification rotary disc reactor according to the present invention;

5 is a view showing a sealing portion of the oxygen-free rotary disk reactor and the nitric oxide rotary disk reactor according to the present invention.

* Explanation of symbols used in drawings

2: oxygen-free rotary disc reactor 4: nitric oxide rotary disc reactor

6: internal circulation tank 8: final settling tank

10: Chemical input device (for phosphorus removal)

12: conveying line of nitric oxide mixture from internal circulation tank to oxygen-free rotary disc reactor

14: conveying line of sludge from the final settling tank to the anaerobic rotary disc reactor

16: surplus sludge disposal line settled by chemical injection

Claims (7)

Oxygen-free rotary disc reactor (2), nitric oxide rotary disc reactor (4), internal circulation tank (6), sedimentation tank (8) and chemical injection device (10), the oxygen-free rotary disc reactor (2) has a disc installation interval It consists of one stage of 30-40mm and two stages of disc installation interval of 10-20mm. The oxygen-free rotary disc reactor (2) and the nitric oxide rotary disc reactor (4) consist of a single shaft, and the oxygen-free rotary disc reactor (2) And the nitrification rotary disc reactor (4) is sealed in a grand packing method, the wastewater package treatment apparatus using a rotary disc, characterized in that driven by a single drive motor. The method of claim 1, wherein the drive motor of the rotating disc is an inverter motor or a variable speed (Varied Speed), dissolved oxygen concentration (DO) flowing out of the nitric oxide rotating disc reactor by adjusting the drive speed (circumferential speed) of the rotating disc (DO) ) Can be appropriately maintained and controlled. According to claim 1 or 2, the oxygen-free rotary disk reactor 2 has a space between the top and bottom of the rotary disk 15cm or more, the upper portion maintains a distance of 15cm from the water surface, the space of 15cm or more on the left and right of the disk Processing apparatus characterized in that it has a. delete The method of claim 1 or 2, wherein the coupling portion of the oxygen-free rotary disc reactor (2) and the nitric oxide rotary disc reactor (4) is axially arranged by a bidirectional metal coupling, and a plastic packing is inserted between the bidirectional metal couplings. , The rotating shaft is supported by a plastic bearing and the bearing buffer support. 3. The treatment apparatus according to claim 1 or 2, wherein the nitric oxide rotary disc reactor 4 is composed of two stages: a front end which is a rotary disc reactor for removing BOD and a rear stage that is a rotary disc reactor for ammonia nitrogen oxidation. . The processing apparatus according to claim 1 or 2, wherein the rotating disc of the oxygen-free rotating disc reactor (2) or the nitric oxide rotating disc reactor (4) is made of polypropylene having a thickness of about 2 mm.