KR0140446B1 - Sewage treatment equipment - Google Patents

Abstract

The present invention relates to a sewage treatment apparatus for arranging reaction tanks in an anaerobic-anaerobic-aerobic order and discharging influent into an anaerobic tank and an anaerobic tank when removing nitrogen and phosphorus in sewage, and organic materials consumed during denitrification in anoxic tank. Due to this, in case of lack of organic matter required for phosphorus release in anaerobic tank, inflow of water is distributed to anaerobic and anaerobic tank to compensate for the shortage of organic matter.

Description

Sewage treatment equipment

1 is a schematic view showing the configuration of the sewage treatment apparatus of the present invention.

2 is a view showing a reactor outlet of the present invention.

* Explanation of symbols for main parts of the drawings

1: ware 2: influent distribution equipment

3: anaerobic tank 4: anaerobic tank

5: Aeration tank 6: Media filling part

7: Precipitator 8: Internal circulation device

9: sludge conveying equipment 11: anoxic tank outlet

12: anaerobic tank outlet portion 13: aeration tank outlet portion

The present invention relates to a sewage treatment apparatus for disposing nitrogen and phosphorus in sewage in an anaerobic-anaerobic-aerobic order and distributing the influent into an anaerobic and anaerobic tank.

In the conventional sewage treatment apparatus, the reaction tank is disposed in the anaerobic-oxygen-aerobic order and the entire influent is introduced into the anaerobic tank, so that organic matters are insufficient when the anaerobic tank is discharged.

An object of the present invention is to provide a sewage treatment apparatus configured to arrange the reaction tank in the order of anaerobic tank, anaerobic tank, aeration tank in order to solve the above drawbacks and the influent is distributed to the anaerobic tank and anaerobic tank by the influent distribution facility. .

The present invention is described below with reference to the accompanying drawings.

The sewage treatment apparatus of the present invention forms a reaction tank arrangement of an anaerobic tank, anaerobic tank, and aeration tank in order to maximize the efficiency of general nitrogen and phosphorus removal. Therefore, the performance of the sewage treatment system can be improved by first, denitrification efficiency of nitrate nitrogen when empty coagulation tanks are installed in anoxic, anaerobic-aerobic tank order. In preparation for this shortage, if the inflow (Q) is divided into Q / 2 and flowed into the anaerobic and anaerobic tanks respectively, can the denitrification and phosphorus release reactions occur smoothly? Is it possible to improve the phosphorus release of cells of macroorganisms and the denitrification efficiency of anoxic nitrogen and the nitrification efficiency of the aeration tank? Third, the media filled in the aeration tank increases the nitrification and denitrification efficiency. Inside the medial can be an anaerobic part to help with denitrification and outside the medial To Identify etc. Can promote nitrification phenomenon.

The sewage treatment apparatus of the present invention comprises a treatment system as shown in FIG. 1 to treat the primary sedimentation cell effluent in the sewage treatment plant actually discharged, and the reaction tank and the aftertreatment facilities of the present invention are the wear (1), influent water Distribution equipment (2), anaerobic tank (3), anaerobic tank (4), aeration tank (5), filter medium (6) and settling tank (7), etc., and internal circulation system (8) for denitrification of nitrate nitrogen In order to maintain the microbial concentration of the aeration tank properly, the sludge conveying facility 9 conveyed from the settling tank is installed.

In the primary sedimentation battery of the sewage treatment plant, the effluent from which small amounts of organic matter and suspended solids are removed is passed through the ware (1) installed higher than the position of the reaction tank and introduced into the reaction tanks (3) to (6) by using the influent distribution system (2). . The introduced sewage denitrifies nitrate nitrogen internally circulated in the aeration tank (5) by using denitrification microorganisms as an organic material in an anaerobic tank (3) through denitrification reaction and in the anaerobic tank (4) using the remaining organic matter. Release extracellularly. In this case, inflow of 50% of the influent into the anaerobic tank (3) and the anaerobic tank (4) is prepared in case the organic matter consumed in the anaerobic tank (4) is insufficient due to the organic matter consumed in the denitrification reaction (3). It is designed to make up for the shortage of organic matter.

For the denitrification in the anoxic tank, the outside oxygen supply should be blocked and the outflow part of the anoxic tank should be drained down for smooth contact between the denitrifying microorganism and the organics. In addition, in the aeration tank, it is possible to reduce the possibility of a short-circuit phenomenon when the mixture of microorganisms and sewage passes through each aeration tank by staggering the outlets from side to side.

The filter medium filling unit 6 increases the nitrification and denitrification efficiency by using a high concentration of microorganisms accumulated in the filter medium, and also installs an internal circulation device of nitrate nitrogen for the denitrification reaction. In order to maintain the proper concentration of microorganisms in the aeration tank, a certain amount is transferred from the settling tank to the anaerobic tank using a conveying facility (9). This facility is a process that can make nitrogen and phosphorus components treatable by simple modification of aeration tank and installation of internal circulation facility, which is difficult to process by standard activated sludge method, which is currently operated in domestic sewage treatment plant. Design, manufacture in a method that can be applicable to new and expanded sewage treatment plants.

The capacity of the reactor is 2.5m ³ hydraulic retention time in the aeration tank as (0.6m × 3.6m × 1.16m): and (the HRT) six hours, the daily sewage throughput of 10m ³ / day, F / M ratio (FMR) 0.1 to 0.25 kg BOD / kg MLSS. d, the organic matter volume loading ratio (OLR) is to be 0.3 ~ 0.5kg BOD / m ³ d.

Inflow of sewage into the anoxic tank (3) causes the denitrification reaction of nitrate nitrogen by denitrification bacteria using organic matter in the inflow water. Referring to FIG. 2, in order to induce an effective denitrification reaction in anoxic tank. While mixing the stirrer at a low speed of the reaction tank at 30 RPM at a low speed, the pure nitrate nitrogen in the aeration tank 5 was reduced to nitrogen gas to remove nitrogen. In order to create a denitrification reaction condition of the mixed solution of microorganism and organic matter in the anoxic tank (3), the organic acid flows into the upper part of the anaerobic tank (4) from the lower part of the reactor through the anoxic tank outlet (12), and in the anaerobic tank (4), Phosphorus Removal Releases phosphorus extracellularly in microorganisms.

At this time, the influent is distributed in order to assist the denitrification and phosphorus release phenomenon, and are respectively distributed by Q / 2 into the anaerobic tank (4) and the anaerobic tank (3). On the other hand, in order to prevent the short circuit phenomenon (Short Circuit) of the mixed liquid flowing into the aeration tank by installing the aeration tank outlet portion 12 in the anaerobic tank, the mixed liquid flows out from the reaction tank bottom and flows into the aeration tank (5). Since the short-circuit phenomenon may occur continuously while passing through the aeration tank 5, the circumference tank outlet 13 of the aeration tank may be staggered from side to side to prevent this phenomenon. The installation of the filter filling unit (6) increases the oxidation and denitrification reaction by about 15-25%, thereby reducing the pumping cost by reducing the circulation amount of nitrate nitrogen circulated internally and increasing the concentration of nitrate nitrogen. Maximum denitrification can be induced.

On the other hand, the total volume of the reaction tank was 2.5m ³ and the anaerobic tank (3), anaerobic tank (4) and aeration tank (5) were set at 420L, respectively. The outlet 11 of 10 cm x 100 cm x 1180 cm is installed in the anaerobic tank so that the treated water undergoing denitrification is introduced into the anaerobic tank 4 from the bottom to the top. After inducing phosphorus release by phosphorus-removing microorganisms, phosphorus is removed by phosphorus intake in the next aeration tank. The lower part of the anoxic tank was stirred at 30 RPM at low speed and 10cm × 100cm × 1170cm outlets were made to prevent short circuit and maximize contact between microorganisms and minerals. In addition, the mixed solution introduced into the aeration tank has a residence time of 4 hours, and phosphorus released from the anaerobic tank is absorbed into the cells of the microorganism under aerobic conditions, causing a phosphorus removal stoppage. At this time, when the mixed solution is passed from the first aeration tank (5) to the next aeration tank (50) to prevent the smooth contact and short circuit phenomenon of microorganisms and organic matter, the outlet portion 13 of the first aeration tank (5) is 25cm × 400cm bottom right The second aeration tank was installed at the center of the left side with the same size, and the third aeration tank was installed at the bottom right side with the same size. To increase the nitrification and denitrification efficiency, the filled media was 5 cm x 5 cm x 5 cm, filling 15% of the total volume of the reactor and incorporating microorganisms into the media at a high concentration.

The filter filler (6) designed to increase the efficiency of nitrogen and phosphorus removal is described in detail in the same patent application. The filter filler is filled with 5cm × 5cm × 5cm sized media with 15% of the volume of the reactor 420 L and the media is poly It is a urethane foam and has a resource of 98% porosity and 20m ² / m ³ of specific surface area. On the other hand, in order to prevent the filter medium in the filter filling part is lost to the left and right aeration tank, 0.5cm × 0.5cm size screen is installed in the inlet and outlet respectively.

EXAMPLE

(1) Device name: DNR PROCESS-2

(Daewoo Nutrient Removal Process) -2

(2) Applicable sewage treatment plant: Glpocheon sewage treatment plant (bucheon-si, Gyeonggi-do)

(3) Application sewage: 1st sedimentation effluent

(4) Scale: (reactor)

Cross section (60cm × 60cm × 6EA): 21600 cm ²

Height: 1160cm

Volume: 2.5cm ³

Material: acrylic plate

(5) Operation period: 1994. 2.- 1994. 12.

(6) How to operate

In order to evaluate the efficiency of the sewage treatment plant of the present invention, empirical experiments were carried out using primary sedimentation effluent at representative Popocheon sewage treatment plant in Korea. After seeding the return water of the sewage treatment plant and the sludge in the aeration tank in the reactors (3) to (6), start the operation with HRT 20 hr (3.3day) with an adaptor for about 15 days before the initial trial run. When the removal rate was shown, the influent sewage was gradually increased.

The raw sewage flowing into the weir (1) is to flow into the anaerobic tank (3) by natural flow. The sewage flow into the anaerobic tank (4) was adjusted according to the operating conditions based on the analysis data table 1, Table 2. Growth indicators of anaerobic microorganisms were based on the release rate of phosphorus in the anaerobic tank, nitrifier microorganisms began to be active according to the number of reaction days in the aeration tank, and anoxic tank to induce denitrification at the time of nitrification increase. Nitric acid nitrate mixture is transferred using the internal circulation (8).

Under normal conditions, anoxic tanks denitrify nitrous nitrogen from sources of incoming sewage. In anaerobic tanks, point phosphoric acid is released into the cells of the phosphorus-removing microorganisms by using the organic matter that has been consumed at the front end. In addition, in order to increase the efficiency during the denitrification reaction, the influent is distributed in equal amounts to the anaerobic tank and the anaerobic tank. Phosphorus released from the anaerobic tank (4) is absorbed into the cells of the phosphorus removal bacteria using dissolved oxygen in the aeration tank (5).

In addition, the filter filler 6 installed to increase the removal efficiency of nitrogen and phosphorus is important to mix for smooth contact between the filter medium and the sewage so that a high concentration of microorganisms can be directly into the filter medium. Therefore, by adjusting the amount of aeration to inject air to the extent that the media does not sink.

All of the above reactors and substrates were designed to be automatically controlled in the device.

The microorganism of the treatment plant conveying sludge and the aeration tank in the reaction tank of the sewage treatment apparatus of the present invention is 0.4m After seeding, the adaptor was placed for about 10 days before the initial commissioning and the operation was started with HRT 24hr (4day), and the inflow sewage was gradually increased when the BOD removal rate was maintained above 80%. Approximately 50 days have passed since the start of operation. / d) was introduced and the internal circulation from the aeration tank to the anaerobic tank was gradually changed from 80% of the internal circulation ratio to 80% after about 40 days after the start of operation for the denitrification of nitrate nitrogen. As the inflow sewage increased and the denitrification rate increased with the increase of nitrification rate, BOD removal rate was 85 ~ 95%, SS was more than 95%, T-N was more than 68% and T-P was more than 88%.

The pH of the influent was 6, 4-7, 3, and after treatment, the pH was stable at pH 7, 1-7, 3, and the water temperature in the reactor was maintained at 14-29 ℃. The effect of phosphorus removal rate on temperature was not significant, but it affected the nitrification rate and the temperature effect on the specific gravity rate μmax of nitrifying microorganisms showed the form of μ = μmax (T-Tref). The resulting microbial saturation constant (KS, 1) is 0.047e K, 1 appeared.

Considering the cost of changing the existing facility to evaluate the economic feasibility of this device, the cost of simple modification of the aeration tank (diaphragm installation) and the pump installation for the internal circulation of nitrate nitrogen are insignificant. It is very economical compared to the cost of additional reactor, pump and chemicals needed for the installation.

The outflow device installed in the anaerobic and anaerobic tanks inside the reactor creates an anaerobic and a complete anaerobic tank, resulting in effective denitrification of nitrogen nitrate and phosphorus release of phosphorus-removing microorganisms. Therefore, it is possible to treat nitrogen and phosphorus that are difficult to treat in low concentration sewage as in Korea, and there are various problems such as the installation of additional reactors required for the existing nitrogen and phosphorus removing process, the weekly cost of chemicals and sludge generation after treatment. It is proved that the present invention is excellent. In addition, the media filled in the aeration tank can increase the efficiency of nitrogen and phosphorus removal in the open anaerobic process by 15-25%, and the aeration tank, sedimentation tank, and sludge swelling phenomena due to the load shock that may occur in the existing sewage treatment plant. It can be seen that it is very effective in the operation of the process because it can be reduced.

Applicable sewage treatment plant of sewage treatment apparatus of the present invention is a large scale (5000m / d) sewage treatment plant, low concentration sewage treatment plant with BOD 70mg / L, sewage treatment plant with sludge swelling frequently, high sewage treatment plant with BOD 140mg / L, sewage treatment plant with high nitrogen and phosphorus concentration, sewage with high BOD load fluctuation Treatment plant, packaged small wastewater treatment plant.

Claims (2)

Ware (1), influent distribution equipment (2), anoxic tank (3), anaerobic tank (4), aeration tank (5), filter medium (6), sedimentation tank (7), internal circulation (8) and sludge conveying equipment ( 9) and the influent distribution system (2) is a sewage treatment device configured to inject 50% of the influent water through the weir (1) to the anaerobic tank (3) and anaerobic tank (4). The sewage treatment according to claim 1, wherein the inflow water flows from the anaerobic tank (3) to the upper part of the anaerobic tank (4) through the anaerobic tank outlet (12) and the outlets (13) of the aeration tank (5) are staggered from side to side. Device.