KR100481885B1 - Advanced treatment apparaters and method of sewage water by flow distribution ratio use of NO3 and NH4-N. - Google Patents

Abstract

The present invention is to dominate the specific microorganisms in each sewage treatment plant or wastewater treatment plant by each process and to accurately set the necessary conditions by the ratio distribution using nitric acid and ammonia to remove nitrogen and phosphorus in the sewage or wastewater highly by biological treatment method. The present invention relates to an advanced treatment system and method for sewage treatment using different anaerobic, aerobic, and denitrifying microorganisms in growth and growth conditions, and using submerged biofilm devices to achieve mass retention by predominance and adhesion of specific microorganisms. It is to effectively remove organic substances and nutrients such as nitrogen by maintaining the required nitrification rate and denitrification condition.

To this end, an anaerobic tank is installed at the front of the process, and a submerged biofilm device is installed to mass-proliferate microorganisms suitable for anaerobic conditions to remove organic matter in anaerobic state, and then, an aerobic tank is installed to supply air and remove residual organic matter. And oxidize the ammonia and organic nitrogen in the sewage with nitric acid (NO ₃ ), about 42% of the sewage flowing out of the first anaerobic tank is introduced into the aerobic tank (nitrification tank), and about 58% is the anaerobic denitrification tank installed after the aerobic tank. By sending directly, the aerobic tank completely oxidizes 42% of the ammonia in the total incoming sewage to nitric acid. In the next anaerobic denitrification tank, a submerged biofilm is installed to mass-proliferate microorganisms suitable for anaerobic depletion of organic matter, so that ammonia and nitric acid can be directly converted to nitrogen gas to remove most nitrogen and not removed in this process. Some nitric acid (NO ₃ ) is an advanced treatment system and method for sewage treatment that allows for the denitrification in the anaerobic tank by internal return, and nitridates the ammonia accurately and stably with nitric acid only in the required ratio. By maintaining the ratio of nitric acid accurately, it is possible to effectively remove organic matter and nutrients such as nitrogen and phosphorus in sewage, which have lower C / N ratio than the conventional high-treatment method. No sludge decay, no smell, altitude There is an effect that it is possible to obtain a discharge water quality.

Description

Advanced treatment apparaters and method of sewage water by flow distribution ratio use of NO3 and NH4-N.}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for treating sewage by ratio distribution using nitric acid and ammonia for effectively removing nutrients such as nitrogen and phosphorus together with organic matter in a water treatment process using microorganisms such as a sewage treatment plant or a wastewater treatment plant.

As a method of removing organic substances, nitrogen, and phosphorus from sewage, there is a conventional method of treating sewage using anaerobic and aerobic tanks to perform denitrification and nitrification. In recent years, the process conditions are controlled so that specific microorganisms become dominant species. The treatment method is also used, such as domestic patent 10-0203050 (1999.3.22) or 10-0276096 (2000.9.26).

In this method, in order to cultivate bacteria in Bacillus as dominant species, the aerobic conditions are maintained at the front stage of the process, and anaerobic and unaerobic conditions are returned at the end of the process, and the sludge is returned. Dominates.

The introduction technology of A ₂ / O, which is a conventional advanced treatment method, is a method of denitrification after nitrification. An anaerobic denitrification tank is installed at the front end of the treatment process, and an aerobic aeration tank is installed at the rear end, and a large amount of mixed solution is returned after nitrification to anaerobic shear. Denitrification is performed in a denitrification tank (this method is called pre-denitrification).

However, in such a conventional method, it is difficult to dominate only bacteria of Bacillus, and it is economically burdened by the use of artificial microorganisms, which are inadequately controlled and expensive, and there is a limit in the dominance rate of bacteria of Bacillus and denitrification is in Bacillus genus. The effect was limited because it was not only caused by bacteria, and in the conventional high-treatment method, the denitrification effect was low in the case of sewage with low C / N ratio, such as lower nitrification rate at low water temperature and sewage inflow quality of most sewage treatment plants in Korea. Even if there is a problem and the C / N ratio is high, a large amount of internal return water (typically 300 to 400% of the influent sewage) is required to increase the denitrification effect. There was a problem in that the number of conveying equipment is required to increase the conveying equipment and power costs.

The present invention relates to another embodiment of the present invention (Application No. 10-2002-0072894) as a high processing method for solving this problem.

The technical problem to be achieved by the present invention consists of anaerobic and aerobic parts of sewage treatment process, each bacterium acting in advanced treatment of various kinds of sewage such as Bacillus, Sedonas, independent chemical and nutritional bacteria using hydrogen for each predetermined process during the treatment process. Maintain proper conditions and predominantly inject the sewage into 42% of the aerobic tank and 58% of the anaerobic denitrification tank to oxidize 42% of the total ammonia in the sewage to nitric acid (NO ₃ ) and maintain the correct ratio. By the conversion of ammonia and nitric acid to nitrogen gas in anaerobic denitrification tank and anaerobic denitrification by some organic substances, nutrients such as nitrogen and phosphorus in sewage at low C / N ratio without the use of special microbial culture agent and also with small internal return. It is to provide an advanced treatment apparatus and method for sewage for effectively removing the organic matter and organic matter.

The present invention to achieve the above technical problem,

The front anaerobic tank into which the pretreated sewage with debris and sand is removed, and the submerged biofilm unit is installed and kept anaerobic, decomposing organic matter in the anaerobic state and denitrifying some lines;

A first aerobic tank for discarding some of the sewage introduced from the anaerobic tank by an aerobic device to maintain aerobic and remove residual organic matter;

A second tank for oxidizing ammonia in the sewage to nitric acid (NO ₃ ) while maintaining the dissolved oxygen concentration in the range suitable for nitrification by introducing the sewage flowing out of the first tank;

An anaerobic denitrification tank, in which an immersion type biofilm device is installed and maintained under anaerobic or anoxic conditions, and mainly denitrifies by directly converting ammonia and nitric acid into nitrogen gas; A distribution channel and water gate capable of distributing about 42% of the sewage flowing out of the foremost anaerobic tank and about 58% to the anaerobic denitrification tank;

A third tank for maintaining the sewage flowing out of the anaerobic denitrification tank to oxidize and remove residual pollutants and to oxidize untreated ammonia (NH ₄ -N) to nitric acid in the previous step;

A final sedimentation basin separating sewage solids and symbolic water from the third vessel;

An internal conveying apparatus for conveying sludge to the anaerobic tank at the rear end of the third tank and a sludge conveying apparatus for conveying the sludge of the final sedimentation basin to the anaerobic tank and the first vessel of the front;

Sewage diffuser configured to control the aeration amount in order to maintain the dissolved oxygen concentration within an appropriate range so that ammonia in the second tank can be oxidized and maintained with nitric acid (NO ₃ );

A sludge storage tank and a sludge refilling device capable of replenishing and supplying sludge to the first vessel according to the needs of the process;

In order to maintain the required F / M ratio and SRT even when the flow rate fluctuates, each reactor acts as a set of reactors in a series direction and is blocked in parallel to each other in a series of independent series. The series of is connected to the common distribution channel, and the inlet of the anaerobic tank in front of each series is equipped with an electric inflow gate to calculate the number of series of reactors that operate automatically according to the inflow flow. A driving sequence number control device and method for controlling; And

Each reactor includes a flow meter and a measuring instrument necessary to measure ORP, DO, MLSS, etc., as well as a process control panel that automatically controls each process based on the measurement information. Provided is an advanced treatment apparatus and method for sewage by proportional distribution using nitric acid and ammonia to check the identification from time to time to maintain optimal process conditions.

Hereinafter, the present invention will be described in detail as follows, but the scope of the present invention is not limited to the following examples, but numerous modifications are possible, but in view of the contents of the present invention, the similarity or contradiction to the concept violates the rights of the present invention. do.

An embodiment of the present invention is as follows.

After the sewage pipe enters the sewage treatment plant, sewage and sand are removed from the pretreatment unit, and the sewage pipe (1) and the inflow flow meter (1-1) are distributed evenly in the inflow distribution channel (B) through the sewage inlet pipe (B). ORP to be introduced into the front anaerobic tank (3) through the inlet sluice (2) and the submerged biofilm device (4) in the anaerobic tank (3) and to measure the anaerobic degree of the mixed solution in the anaerobic tank (3) The measuring instrument 6 was installed.

A ratio distribution channel (5) is installed at the rear end of the anaerobic tank (3), and the effluent of the anaerobic tank (3) passes through the inflow gate (7-1) of the first tank (7) installed at the rear end of the anaerobic tank (3). About 42% of the effluent flowed in through the bottom of the first vessel (7) is installed in the air dispersing device 1 (8) to control the air supply amount dissolved oxygen concentration (DO) to measure the dissolved oxygen concentration of the mixed liquid The measuring instrument 9 was installed.

The second unit 10 is connected to the rear end of the first unit (7) and installed in the lower portion of the second unit 10, the diffuser type diffuser device 2 (11) installed in the flow rate control device that can adjust the air supply amount ( 13) and a dissolved oxygen concentration (DO) measuring device 12 for measuring the dissolved oxygen concentration of the mixed solution.

The anaerobic denitrification tank 14 was connected to the rear end of the second tank 10 and installed on the front side of the anaerobic denitrification tank 14 to install the inlet gate 14-1 connected to the ratio distribution channel 5 to the anaerobic tank ( About 58% of the sewage discharged from 3) was introduced, and at the same time, the total amount of sewage from the second tank was introduced.

In the anaerobic denitrification tank 14, an immersion type biofilm apparatus 15 was installed, and an ORP measuring instrument 16 for measuring the anaerobic degree of the mixed solution was installed.

At the rear end of the anaerobic denitrification tank 14, a third tank 17 was installed and the lower part of the third tank 17 was installed with an aerobic device 3 (18) to supply air for maintaining aerobic. A dissolved oxygen concentration (DO) measuring instrument 19 was installed to measure the concentration.

The final sedimentation basin (20) was installed at the rear end of the third basin (17), and a portion of the mixed liquid from the third basin (17) was introduced into the final settler, and the sludge precipitated in the final sedimentation basin (20) was the sludge drawing pipe (24). ), And the symbolic water was discharged through the next common discharge channel.

Part of the mixed liquid from the third tank 17 is divided into the internal conveying pump 22 through the inner conveying pipe 21 installed to be connected to the common water channel (C) installed at the rear end of the third bath 17. It was transferred to the drainage path (B) and installed to be conveyed to the inlet of the foremost anaerobic tank 3 through the inlet sluice 2, and an inner conveying flowmeter 23 was installed in the middle of the inner conveying pipe 21.

The sludge precipitated in the final sedimentation basin (20) was installed to connect the sludge return pipe (26) branched from the sludge drawing pipe (24) to the inlet distribution channel (b) and the inlet of the first tank (7) The sludge conveying pump 25 was connected to the feeder, and the sludge conveying flow meter 27 was installed in the middle of the sludge conveying pipe 26.

Part of the sludge precipitated in the final sedimentation basin 20 is to be transferred to the sludge storage tank 29 by the excess sludge conveying pump 28 installed in connection with the sludge drawing pipe 24 and the sludge of the sludge storage tank 29 is necessary. In order to supply the sludge to the inlet of the first tank (7), the sludge replenishment pipe (30) was connected between them, and the sludge replenishment pump (31) was transferred to the replenishment sludge flowmeter (32). Made it possible.

In order to remove the remaining sludge from the sludge stored in the sludge storage tank 29, the sludge storage tank 29 is connected between the excess sludge thickener 38 to the excess sludge pipe 35, and transferred to the excess sludge pump 36, and the excess sludge flowmeter The amount can be measured by (37).

The sludge concentrated in the excess sludge concentrator 38 is temporarily stored in the excess concentrated sludge storage tank 39 through a pipe to allow for dehydration.

A phase contrast microscope (33) was installed to identify the microorganisms in the sewage and treatment processes. The microorganisms of each process can be identified and information about the microorganisms in each process can be checked. The process control panel 34 was installed to allow automatic control.

Such action of the present invention is as follows.

In order to remove organic substances and nutrients (mainly nitrogen and phosphorus) by microorganisms such as bacteria, there are cases of using anaerobic microorganisms and aerobic microorganisms. Various kinds of aerobic and anaerobic microorganisms are used together in sewage treatment. Anaerobic microorganisms are slow to decompose, but less sludge is produced after treatment, and aerobic microorganisms decompose faster, but sludge is relatively higher.

Aerobic microorganisms can be divided into absolute aerobic and breathable anaerobic microorganisms, but absolute aerobic microorganisms require oxygen for growth and growth, so proliferation and growth is impossible without oxygen, and aerobic microorganisms can grow without oxygen and proliferate with oxygen. It is a microorganism that grows better.

Anaerobic microorganisms can be divided into oxygen-resistant and absolute anaerobic. Absolute anaerobic microorganisms are killed when oxygen exists, and oxygen-resistant microorganisms can grow and grow even with oxygen.

In addition, the removal of nitrogen, which is one of the nutrients, has been traditionally oxidized to ammonia in the water with nitric acid (NO ₃ ) by the action of nitrifying bacteria in the aerobic state, and then reduced to nitrogen by the action of denitrifying bacteria in the anaerobic state. The removal of nitrogen by releasing gas was the traditional removal method, which required a large amount of organic carbon sources for denitrification, requiring a high C / N ratio (usually 8-12 times the ratio of organics and nitrogen).

However, some independent chemical nutrient microorganisms are known to convert ammonia (NH ₄ -N) directly to nitrogen gas under anaerobic conditions using hydrogen or nitric acid (NO ₃ ) as an alternative to the above example. It is not known.

For example, in an anaerobic condition, when nitric acid (NO ₃ ) is present and hydrogen gas is present as an electron donor, it is known that an independent chemotrophic microorganism (bacteria) using hydrogen is denitrified.

The denitrification process of this microorganism is expressed as follows.

0.5 H ₂ + 0.1773 NO ₃ + 0.0246 CO ₂ + 0.1773 H = 0.0862 N ₂ +0.00493 C ₅ H ₇ O ₂ N + 0.5714 H ₂ O. … … … … … … … … … … … … … … … … … … … … … … … [I]

When hydrogen gas (H ₂ ) is replaced with ammonia (NH ₄ -N) in the above formula [I], the following formula [II] is obtained.

0.25 NH ₄ -N + 0.1773 NO ₃ + 0.0246 CO ₂ + 0.1773 H = 0.211 N ₂ +0.00493 C ₅ H ₇ O ₂ N +0.5714 H ₂ O. … … … … … … … … … … … … … … … … … … … … … … … [II]

As can be seen from the formula [II], some independent chemical nutrient denitrification bacteria use hydrogen as an electron donor, and hydrogen bound to ammonia can also be used as an electron donor. According to formula [II], the total amount of nitrogen contained in sewage (organic nitrogen and ammonia coexist in sewage, but organic nitrogen is converted to ammonia in the process of decomposing in anaerobic or aerobic process, so total nitrogen in sewage is equal to total ammonia) With respect to nitric acid (NO ₃ ) of 0.1773 / (0.25 + 0.1773) = 0.42 = about 42%, it can be seen that ammonia (NH ₄ -N) and nitric acid are converted directly to nitrogen gas (N ₂ ) and removed.

In addition, as already known, bacteria in Bacillus are capable of directly denitrifying by converting ammonia into nitrogen gas without undergoing nitrification, and denitrification occurs because of conversion of ammonia to nitrogen gas by other unknown microorganisms. Nitrogen is also used in the substrate synthesis of the microorganisms that proliferate in the process, and nitrogen is removed through the discharge of excess sludge, which discards the remaining microorganisms.

The present invention takes full advantage of the characteristics of various microorganisms required to remove such nitrogen, and each microorganism forms an environment and a habitat suitable for proliferation and growth of each microorganism, and in a predetermined process, the specific microorganism predominates and the amount of the microorganisms is retained. Maximize the removal of organics and nitrogen and phosphorus effectively.

In general, organic matters are known to be effective in aerobic removal, but a large amount of microorganisms grown by the method of the present invention have been shown to be capable of removing a large amount of organic matter (over 70% or more) without supplying oxygen in an anaerobic state. The microorganisms are attached to the submerged biofilm device (4) in the anaerobic tank (3) installed at the front of the process to proliferate and grow, and selectively dominate anaerobic or communicable bacteria which have good growth and growth under anaerobic conditions rich in organic matter. Most of the organic matter in the sewage is removed by maximizing its retention.In the anaerobic condition, some of the organic matter is removed by acid fermentation and methanation by anaerobic microorganisms (bacteria), and the rest is removed by the anaerobic microorganisms (bacteria). carbon dioxide (CO ₂₎ which abundantly present in the bicarbonate contained in the (HCO _3), etc. It is expected to remove organic materials and breath using the oxygen bond.

In the first aeration tank (7), about 42% of the sewage from which most organic matter is removed from the anaerobic tank (3) flows to maintain a high MLSS concentration in aerobic state and a relatively low dissolved oxygen concentration (DO) (about 0.5 to 1.0 mg). / l) to remove the remaining organic matter by aerobic microorganisms (bacteria), and in the second vessel (10) by adjusting the air supply amount according to the state to maintain the dissolved oxygen concentration in a predetermined range in a predetermined range of nitro sorbnase and The ammonia (NH ₄ -N) in the sewage introduced by the action of nitrobacter or the like is oxidized to the total amount of nitric acid (NO ₃ ).

The dissolved oxygen concentration suitable for nitrification requires at least 1.0 mg / l, but more than 2.0 mg / l is known for the process.

Therefore, in the second vessel, about 42% of the total ammonia amount is oxidized to nitric acid (NO ₃ ).

In the anaerobic denitrification tank 14, 58% of the sewage flows directly from the anaerobic tank 3, and the remaining 42% flows from the second aeration tank.

In this case, 58% of ammonia (NH ₄ -N) introduced from the anaerobic tank (3) and 42% of nitric acid (NO ₂ ) introduced from the second tank (10) exist in the anaerobic denitrification tank (14). As it is very small, the ratio of ammonia and nitric acid is 0.25: 0.1773 as shown in the formula [II], which is the most ideal condition for denitrification.

In the anaerobic denitrification tank 14, a submerged biofilm device 15 is installed to allow microorganisms to attach and proliferate and grow, thereby proliferating and growing under anaerobic conditions in which a small amount of organic carbon is present and ammonia and nitric acid are present at an appropriate ratio. Good microorganisms, for example, dominate the independent chemical and nutritional bacteria using hydrogen that directly convert ammonia to nitrogen gas and denitrify it, and maximize its retention to remove ammonia and nitrogen from sewage as described in formula [II]. do.

This is because submerged biofilms can secure much more microorganisms than suspended growth reactors and maintain high microbial concentrations of about 15,000 to 30,000 mg / l based on MLSS concentrations.

Microorganisms that directly denitrate ammonia have been commonly used because they require long SRT, anaerobic conditions (oxygen deficiency), non-reducing nitrates (organic depletion) and stable operation for growth and growth. In the growth method, it is impossible to dominate these microorganisms and increase their retention due to the lack of SRT and microbial load, competition with other mixed microorganisms, and changes in MLSS concentrations that are changed frequently. This condition can be satisfied.

In addition, in the anaerobic denitrification tank 14, as described above, ammonia is directly converted to nitrogen gas for denitrification, and in the process, most of the nitric acid is removed, and at the same time, a small amount of organic matter is present in the anaerobic state, so that the action of the denitrification bacteria mixed in the sewage. As with pre-nitrification, traces of nitric acid (NO ₃ ) are reduced to nitrogen gas, resulting in additional denitrification.

In the above explanation, the ratio of sewage to the sewage ratio is about a few percent. In an ideal state, the ratio of ammonia and nitric acid should be exactly 58%: 42%, but the rate of oxidation to nitric acid due to changes in water temperature, water quality and quantity. Since this cannot always be 100%, the distribution ratio must be adjusted for these variations with slight changes to the site conditions.

When the nitrogen removal effect of the present invention by the above formula [I] is calculated as follows. In the above equation, 0.25 molecules of ammonia (NH ₄ -N) and 0.1773 molecules of nitric acid (NO ₂ ) react to generate nitrogen gas (N ₂ ) 0.211 molecules and 0.00493N of nitrogen as sludge, of which N ₂ 0.211 molecules are removed as nitrogen gas. And 0.00493N is removed as sludge, so the removed nitrogen is (0.211 × 2N + 0.00493N = 0.42693N), which is 0.42693 ÷ 0.4273 = 0.999 for nitrogen (0.25NH ₄ -N + 0.1773NO ₃ = 0.4273N) in the sewage. In other words, 99.9% of nitrogen can be removed. (This difference is theoretically 100% of nitrogen as a difference by cutting the decimal point.)

In addition, the amount of oxygen required for sewage treatment in the present invention can be calculated as follows.

The amount of oxygen required for sewage treatment is the amount of oxygen required to oxidize 42% of the total ammonia present in the sewage to nitric acid (NO ₃ ) and the organic matter in the sewage (generally expressed as BOD) according to the above formula [Ⅰ]. It can be seen that the amount of oxygen required for the removal is combined.

The amount of oxygen needed to oxidize ammonia to nitric acid can be obtained from the following equation.

NH ₄ -N +2.0 O ₂ → NO ₃ + H ₂ O + 2H... … … … … … … … … … … … … … [III]

According to the above equation [Ⅲ] Oxygen is required two molecules relative to include nitrogen per molecule oxidation of ammonia nitrate and the molecular weight of the molecular weight (N) of nitrogen was 14, and oxygen (O ₂₎ of 32 randomly 2 × 32 ÷ 14 = 4.573, i.e., 4.57 times the amount of nitrogen in ammonia is required.

In general, it is known that about 1 mg of oxygen is required to remove 1 mg of organic matter (BOD).

Comparing the required amount of oxygen of the conventional pre-denitrification process with the present invention is as follows.

Conditions: BOD: 120 mg / L. TN: 30 mg / l (Nitrogen in the influent sewage is mostly ammonia, so TN = NH ₄ -N.)

In the conventional denitrification process, ammonia is first oxidized to nitric acid (NO ₃ ), which requires 4.57 times the oxygen amount of ammonia and BOD of 3 times the amount of ammonia is removed in the anaerobic state without oxygen because it is oxidized and removed. The amount of organic matter is equal to the amount of incoming BOD minus three times the amount of ammonia.

Therefore, the amount of oxygen required for the denitrification process is as follows.

(BOD-3 × T-N) × 1 + 4.57 × T-N = (120-30 × 3) × 1 + 4.57 × 30 = 167.1 mg / l

In the denitrification process according to the present invention, since 70% of the inflow BOD is removed in anaerobic state and only 42% of ammonia is oxidized, the amount of oxygen required is as follows.

(Inflow BOD-inflow BOD × 0.7) × 1 + 0.42 × 4.57 × T-N = 36 + 57.6 = 93.6 mg / l

According to the above calculation results, it can be seen that the amount of oxygen required for organic matter removal and denitrification in the present invention is very small because only 56% of the amount of oxygen required for the conventional denitrification process is required.

The sewage treatment method of the present invention will be described in detail as follows.

The sewage from which fine contaminants and sand are removed in the pretreatment facility (a) is passed through the sewage inlet pipe (1) and the amount is measured in the inflow flowmeter (2) and then flows into the anaerobic tank (3).

Anaerobic tank (3) is maintained in the anaerobic state without oxygen supply, and submerged biofilm device (4) installed in the anaerobic tank (3), anaerobic bacteria and denitrifying bacteria, Bacillus (Bacillus) suitable for organic matter rich state over time As microorganisms such as anaerobic bacteria, such as aerobic bacteria, are attached, multiply and grow, the amount is increased and the equilibrium is maintained at a certain level, and the state is maintained and converted to MLSS concentration. Quantity can be retained.

The microorganisms attached in such a large amount decompose about 70% of organic matter in sewage and denitrify at the same time to reduce nitric acid (NO ₃ ) contained in the internal return water to release nitrogen gas to the atmosphere to remove nitrogen.

The ORP measuring apparatus 6 installed in the anaerobic tank 3 is a measuring instrument for judging whether the anaerobic degree of the anaerobic tank is appropriate. The appropriate ORP value is -150 to -300 mV.

The sewage through the anaerobic tank (3) flows through the ratio distribution channel (5), only 42% of the sewage flows to the first process (7), the next process, and the remaining about 58% flows into the anaerobic denitrification tank (14).

The first aeration tank (7) is an organic substance remaining by the action of aerobic microorganisms in water while maintaining an aerobic state of dissolved oxygen concentration (DO) of 0.5 to 1.0 mg / l by supplying an appropriate amount of air by the aeration device 1 (8). And the MLSS concentration and dissolved oxygen concentration (DO) are controlled to prevent the generation of nitric acid or nitrous acid, and the sewage is transferred to the second process (10), which is the next process. The ammonia in the sewage is oxidized and converted into nitric acid (NO ₃ ). In this process, it is very important to maintain the dissolved oxygen concentration (DO) at 2.0 to 4.0 mg / l depending on the conditions. The amount of air supplied to (11) should be adjusted by the flow control device 13 to maintain the air supply properly.

In Unit 2 (10), it is important to change only about 42% of the total ammonia to nitric acid according to the formula [II]. Since only about 42% of the total sewage is introduced by ratio distribution, the introduced ammonia is converted into nitric acid. Only by% nitrification, this ratio is obtained automatically, so it is very easy to maintain the ratio of nitric acid accurately, and this can cope with some degree of fluctuations in flow rate or water quality, and thus a stable treatment effect can be obtained.

However, even in the first vessel (7), a small amount of ammonia is removed to some extent by the action of bacteria in Bacillus, and the ratio of ammonia to nitric acid in the second vessel may not always be 100%. The amount of sewage produced is based on 42%, but to some extent, the inflow rate may be adjusted according to site conditions.

The sewage (about 42% of the total amount) passed through the second tank (10) and about 58% of the sewage flowing out of the anaerobic tank (3) are transferred to the anaerobic denitrification tank (14), which is the next process, and the anaerobic denitrification tank (14). Is maintained in anoxic or anaerobic state to satisfy the growth conditions of microorganisms required for direct denitrification, such as hydrogen-independent chemical nutrition bacteria, and almost all organic matters in sewage are removed in the previous step, thus reducing the nitric acid even under anaerobic conditions. Due to this lack, heterotrophic bacteria are proliferated and deteriorated, so that independent chemical and nutritional bacteria using hydrogen multiply into dominant species, and the submerged biofilm device (15) is installed as a means for the independent chemical nutrition using a large amount of hydrogen on the surface. By attaching and growing bacteria, etc., the action of these bacteria causes denitrification by direct nitrogen gas conversion of ammonia and most of nitric acid in the process. Ring by denitrification by most of the nitrogen is removed from here.

The sewage through the anaerobic denitrification tank (14) is transferred to the third tank (17) to remove residual contaminants in aerobic state and nitrify some of the ammonia that may have been untreated. Nitric acid (NO ₃ ) and third tank (17), which are transferred to the inlet of the anaerobic tank (3) by an internal conveying pump (22) and may be partially untreated in the denitrification process to the anaerobic denitrification tank (14) by equation [I]. ), The nitric acid generated in the anaerobic state is reduced and removed by nitrogen gas, and the internal return ratio is based on about 100% of the inflow sewage, but the return ratio is 0% if necessary, such as when the ammonia concentration in the inflow sewage is low. You can also

Phosphorus in the sewage is removed by removing excess phosphorus from the final sedimentation basin (20) as excess sludge when a part of the phosphorus is used to synthesize the substrate of the microorganism and changed from anaerobic to aerobic state in the third vessel (17). do.

The remaining portion of the sewage through the third vessel 17 is transferred to the final sedimentation basin 20, the sludge settles to the bottom and sinks, and the symbol water in the upper portion is discharged to the outside.

The sludge settled at the bottom of the final settling basin 20 is drawn through the sludge drawing pipe 24 and then part of the sludge conveying pipe 26 and the sludge conveying pump 25 as necessary through the inlet portion of the anaerobic tank (3). It is returned to the inlet of the first vessel (7) at about 20 to 100% of the flow rate and used to maintain an appropriate MLSS concentration.

There are various types of bacteria in this return sludge, which are grown in the reaction tank of the process described above that are suitable for them, and are used to maintain the required MLSS concentration in the sewage. .

When the sludge becomes excessive in the operating series, some sludge in the final sedimentation basin 20 is transferred to and stored in the sludge storage tank 29 by the excess sludge conveying pump 28 installed by being connected to the sludge drawing pipe 24 and the sludge storage tank ( Residual sludge other than the amount required in 29) is transferred to the excess sludge concentrator 38 by the excess sludge pump 36, concentrated to about 4%, and then transferred to the excess concentrated sludge storage tank 39 for temporary storage and then dewatering equipment. Dehydration treatment at

The sludge reservoir 29 should be kept in aerobic state to prevent the release of phosphorus.

In addition, among the combined sewage treatment systems that occupy most of our country, there is no flow control tank in the medium and large treatment plants, so that the inflow of sewage fluctuates greatly during the day and the discharge water quality also fluctuates.

Changes in inflow sewage are not constant for each location of the treatment plant, but in general it is excessively inflowed at 130-150% of the capacity during the daytime and 30-70% of the capacity at the nighttime. When operating in the daytime, the quality of the treated water deteriorates during the daytime and the microbial condition deteriorates due to the underload of the nighttime time, which affects the next daytime time again. In the process of the present invention, the ratio of nitrous acid is very important. If this occurs, the rate of nitrogen removal can be greatly reduced.

In the present invention, in order to solve this problem, the reactors from the anaerobic tank 3 of the treatment plant to the final sedimentation basin 20 are one series in a series direction and are blocked in parallel to each other so that these series are independently connected in parallel. After installation, install a common distribution channel (B) which penetrates each other at the front of several series, and install an inflow gate (2) that can be electrically operated remotely at the inlet of each anaerobic tank (3). Open the inlet sluice (2) by the required number to increase the number of series to operate, and if the inflow sewage is reduced, close the inflow sluice (2) as needed and program it to the process control panel 31 to reduce the number of series to operate. It is possible to determine the number of series driving with.

In addition, the capacity of inflow sewage and the number of operating series can be different, which is significant in small and medium sized sewage treatment plants.

If the operating conditions fluctuate, the amount of sludge present in the operating system is fixed, so even if the operation is carried out by changing the internal return ratio or sludge return ratio, it is often impossible to immediately maintain the required sludge concentration according to the changes. The sludge stored in the reservoir 29 (this sludge is a highly active sludge) is operated by the sludge replenishment pump 31 to convey the required amount of sludge to the first reactor 7 to maintain the required sludge concentration.

In addition, there are cases where excessive sludge exists in the operating series due to fluctuating operation conditions, resulting in a higher MLSS concentration than necessary. In this case, the sludge transfer pump 28 is operated to transfer and store the sludge in the sludge storage tank 29. Eliminate excess sludge in the series and prepare for lack of sludge in the operating series.

The volume of the sludge storage tank 29 is supplemented with sludge only until the inflow of sewage from the first vessel 7 to the third vessel 17 passes, and then the sludge required by the internal and sludge conveyance without additional sludge supplementation. Since the concentration can be maintained, the amount of sludge to be stored is determined.

Although there is some variation in size, the volume of the sludge storage tank is about 10-15% of the volume required when installing the flow regulating tank, which is more economical than the construction of the flow regulating tank.

In this way, even if the sewage inflow fluctuates, the proper load ratio (F / M ratio, BOD volume load, etc.) can be maintained at all times, improving the water treatment effect, stabilizing the discharge water quality, and maintaining the proper activity of microorganisms. The microorganisms of the land remain stationary for a while, but only about 6 to 8 hours of operation stops, and there is no problem in the operation of the process because no microorganisms are killed or weakened.

In addition, the influence of the deviation between the inflow sewage and the operating series may be partially mitigated by the action of microorganisms inhabiting the submerged biofilm devices installed in the anaerobic tank (3) and anaerobic denitrification tank (14).

Submerged biofilm devices installed in the anaerobic tank 3 and anaerobic denitrification tank 14 can be used in various ways, one embodiment is to use a rotary biofilm device (RBC).

The submerged rotary biofilm device is very effective because it can maintain the anaerobic state and at the same time can achieve microbial adhesion proliferation and complete mixing of sewage in the reaction vessel with one device.

In addition, the type of submerged rotary biofilm device may be a revolving or sponge-type rotary biofilm device having a large amount of microorganisms, rather than a conventional uneven plate type. It is good to consist of a biofilm of hydrophilic synthetic resin.

Another embodiment of the submerged biomembrane device is to use a fixed biofilm device such as a ciliated phase in combination with a stirring device for complete mixing in the reactor.

Another embodiment of the submerged biofilm device may use a granular biofilm-filled layer composed of granular material with a diameter of 3 to 5 mm, in which case the retention of microorganisms can be much higher than in the previous two examples. Although the volume can be very small, it is necessary to periodically wash the packed layer, which makes the maintenance slightly difficult. (The devices of the above examples are well known per se, so the specific structure is not shown.)

The phase contrast microscope 33 is attached with an enlarged screen so that process managers can directly check the status and identification of microorganisms so that they can immediately take effective measures necessary for process management, and the process control panel 34 provides various methods for optimizing treatment processes. The operating conditions are set to automatically control and operate various pumps and equipment according to predetermined conditions by receiving information from various flow meters and water quality data installed during the process.

In addition, the microorganisms used in the present invention are anaerobic and breathable anaerobic microorganisms predominantly do not rot easily even if the excess sludge is anaerobic, so there is almost no odor generated, and the smell from the concentrated sludge storage tank or inflow sewage, etc. If it is blown into the first tank (7), the microorganisms in the sewage decomposes the odor, so there is no need to install a separate odor removing device.

Another embodiment of the present invention is as follows.

The construction and function of another embodiment of the present invention is the same as in the above embodiment, but the ratio distribution channel 5 is installed at the rear end of the first tank 7 and the inflow sewage is passed through the anaerobic tank 3 to the first tank 7. And the outflow of the first tank (7) flows into the ratio distribution channel (5), then about 42% to the second tank (10) and about 58% to the anaerobic denitrification tank (14) and the second The outflow of the aerobic tank 10 was introduced into the anaerobic denitrification tank 14.

The operation of another embodiment of the present invention is the same as the above embodiment.

The present invention enables the microorganisms involved in the advanced treatment of sewage treatment plant or wastewater treatment plant to dominate according to the characteristics of each process, and the ratio of the sewage flowing into the first and the anaerobic denitrification tanks is about 42% to 58%. It is possible to keep the conditions suitable for denitrification accurately and easily stably by inflow to water, so it is highly efficient to remove organic matter and nutrients such as nitrogen and phosphorus without using special microbial activator, especially C / N like our country's sewage. High removal effect of organic matter and nutrients even in low sewage water, improves discharge water quality and environmental protection effect, low internal return cost and very small amount of oxygen required, so the cost of equipment needed for return and oxygen supply is low, consumption power is reduced, and sewage inflow fluctuates. Water quality can be maintained stably and the treatment plant of the existing activated sludge process There is an effect that can be easily applied.

1 is a schematic diagram showing a configuration of the present invention

2 is a plan view showing the configuration of the present invention

Explanation of symbols for important parts of the drawings

1. Sewage Inlet Pipe 1-1. Inflow flowmeter 2. inflow sluice 3. anaerobic tank

4. Submerged Biofilm Device

5. Ratio Distribution 6. ORP Meter 7. Unit 1 7-1. Inflow Gate

8. Apparatus 1 9. Dissolved Oxygen Concentration (DO) Measuring Device 10. Unit 2 11. 11. Apparatus 2

12. DO meter 13. Flow control device 14. Anaerobic denitrification tank 14-1. Inflow Gate

15. Submerged Biofilm Apparatus 16. ORP Meter 17. Unit 3

18. diffuser 3 19. DO meter 20. final sedimentation basin

21. Internal return piping 22. Internal return pump 23. Internal return flow meter

24. Sludge drawing piping 25. Sludge conveying pump 26. Sludge conveying piping

27. Sludge Return Flow Meter 28. Sludge Transfer Pump

29. Sludge Storage Tank 30. Sludge Filling Pipe 31. Sludge Filling Pump

32. Supplemental sludge flowmeter 33. Phase contrast microscope 34. Process control panel

35. Surplus sludge piping 36. Surplus sludge pump 37. Surplus sludge flowmeter

38. Surplus sludge thickener 39. Surplus concentrated sludge reservoir

end. Pretreatment unit; C) the inflow distribution; D. Discharge channel

Claims (4)

The front anaerobic tank into which the pretreated sewage with debris and sand is removed, and the submerged biofilm unit is installed and kept anaerobic to anaerobicly decompose organic matter and perform some pre-denitrification; A first aerobic tank for discarding some of the sewage introduced from the anaerobic tank by an aerobic device to maintain aerobic and remove residual organic matter; A second tank for oxidizing the ammonia in the sewage with nitric acid (NO ₃ ) while maintaining the dissolved oxygen concentration in a predetermined range of the sewage introduced into the first tank; An anaerobic denitrification tank in which a part of the effluent of the second tank and an effluent of the anaerobic tank flow in together and install a submerged biofilm device and are maintained in anaerobic or anoxic conditions, and mainly denitrification by directly converting ammonia and nitric acid into nitrogen gas; A ratio distribution channel capable of distributing about 42% of the sewage discharged from the foremost anaerobic tank and about 58% to the anaerobic denitrification tank and flowing in; A third tank for maintaining the sewage flowing out of the anaerobic denitrification tank to oxidize and remove residual pollutants and to oxidize untreated ammonia (NH ₄ -N) to nitrous acid or nitric acid in the previous step; A final sedimentation basin separating sewage solids and symbolic water from the third vessel; An internal conveying device for conveying the sludge to the anaerobic tank at the rear end of the third tank and a sludge conveying device for conveying the sludge of the final settler to the anaerobic tank and the first tank of the front; Sewage diffuser 1 configured to control the aeration amount in order to maintain the dissolved oxygen concentration within an appropriate range so that ammonia in the second tank can be oxidized and maintained with nitric acid (NO ₃ ); A second air tank installed with an air diffuser 2 and a flow regulator to maintain an appropriate amount of air at all times; A sludge storage tank and a sludge refilling device capable of replenishing and supplying sludge to the first vessel according to the needs of the process; In order to maintain the required F / M ratio and SRT even when the flow rate fluctuates, each reactor acts as a set of reactors in the series direction and blocks them in parallel to form a series of independent units each in parallel. The series of is connected to the common distribution channel, and the inlet of the anaerobic tank in front of each series is equipped with an electric inflow gate to calculate the number of series of reactors that operate automatically according to the inflow flow. Driving series number control unit and Each reactor can measure flow meter, ORP, DO, MLSS, etc. as needed, and includes a process control panel that automatically controls each process based on the measurement information, and check the microorganism status and identification of each process from time to time using a phase contrast microscope. An advanced treatment system for sewage by the ratio distribution of sewage using nitric acid and ammonia to maintain optimal process conditions. The internal conveyance ratio for conveying a part of the mixed solution from the third vessel of the present invention through the inner conveying pipe to the inlet distribution channel (b) is 0 to 100%, and the sludge conveying pipe to the inlet distribution channel and the first unit tank from the final settler. The sludge conveyance ratio returned through the process is 20 to 100%, the dissolved oxygen concentration in the first vessel is about 0.5 to 1.0 mg / l, and the dissolved oxygen concentration in the second vessel is about 2.0 to 4.0 mg / l. A method for advanced treatment of sewage by rate distribution using nitric acid and ammonia, characterized in that 42% nitric acid (NO ₃ ) is denitrated in an anaerobic denitrification tank. The method of nitrifying about 42% of the total ammonia in claim 2, about 42% of the sewage from the anaerobic tank is introduced into the first tank and then passed through the second tank, and about 58% of the sewage from the anaerobic tank and from the second tank The denitrification by introducing the sewage into the anaerobic denitrification tank, but the ammonia contained in the sewage introduced into the first tank is oxidized to nitric acid in the second tank, the advanced treatment method of sewage by the ratio distribution using nitric acid and ammonia. In claim 3, about 42% of total ammonia is nitrified and the sewage from the anaerobic tank is introduced into the first tank, and about 42% of the sewage from the first tank is introduced into the second tank and the sewage from the first tank is Sewage from 58% and No. 2 tank is introduced into the anaerobic denitrification tank to denitrify, but the altitude of the sewage by the ratio distribution using nitric acid and ammonia is characterized by oxidizing ammonia contained in the sewage flow into the No. 2 tank to nitric acid. Treatment method.