KR100239804B1 - System and its operation method for disposing of livestock waste biologically - Google Patents

Abstract

The present invention relates to a biological livestock wastewater treatment system and a method of operation, and in particular, the arrangement of the reaction tank in the livestock wastewater treatment system in the order of anaerobic reaction tank-first intermittent aeration tank-second intermittent aeration tank-aerobic tank-sedimentation tank By effectively conducting nitrification, denitrification, and internal circulation in the reactor, it is possible to effectively treat organic substances from livestock wastewater such as nitrogen, phosphorus, etc. at low cost, and prevent the environmental pollution caused by the waste water. Technology.

Description

Biological Livestock Wastewater Treatment System and Operation Method

The present invention relates to a biological livestock wastewater treatment system and a method of operation, and in particular, to remove the organic and nutrients nitrogen and phosphorus generated from the livestock wastewater at a low cost and efficiently at the same time to prevent the environmental pollution due to wastewater discharge The present invention relates to a wastewater treatment system and a method of operating the same.

In general, nitrogen and phosphorus, which are nutrients from urban sewage, livestock waste and industrial wastewater, should be properly disposed of for the conservation of rivers and lakes. If not properly treated, it can be an important factor in the abnormal growth of algae that cause eutrophication, and can also be a major obstacle to the management of water resources such as rivers and lakes. This can be a factor that causes many economic losses, such as an increase in production costs.

In particular, livestock wastewater contains high concentrations of organic substances and large amounts of nutrients such as nitrogen and phosphorus, which cause eutrophication and produce green algae. For example, when 1 kg of nitrogen is released into the environment, it can produce about 16 kg of algae. Has the potential. When converted into chemical oxygen demand (COD), it corresponds to about 20 kg. Due to this, major domestic appeals, including Soyang Lake, are suffering from over-nutrition, and the rest of the coast except Jeju coastal area is in an nutrient-rich state or an ongoing process of nutrient-nutrition. . In particular, special management is necessary considering the fact that the discharge point of livestock wastewater is scattered upstream of the dam.

Generally, there are physicochemical and biological methods for treating nutrients in water, but biological methods are mainly used for large-scale treatment facilities.

As a sewage treatment method mainly used in Korea, the standard activated sludge method is aerated for 24 hours, and more than 98% is the situation using the standard activated sludge method, and the livestock waste water treatment method is a long-term aeration that continuously supplies air for 24 hours. Activated sludge method is mainly used.

However, in the wastewater treatment method as described above, in the case of nitrogen, organic and ammonia nitrogen is changed to the form of nitrite or nitrate nitrogen, and the final treatment cannot be expected to be completed. Also has very poor problems.

In addition, there are various methods for biological treatment of nitrogen and phosphorus depending on the operation type, but commonly used methods include Bardenpho, A / O, and A ² / O. ) There are methods.

However, the conventional methods as described above have been pointed out as a problem in use because of the large economic burden because the organic material must be continuously supplied from the outside for nitrogen removal.

In addition, in recent years, as an operating method of changing the inflow direction of the influent and the operation of the reaction tank over time as described above, an intermittent aeration type treatment method, which is particularly effective for nitrogen treatment, has been developed. When it is introduced, there is still a problem that the processing thereof is difficult.

Therefore, in order to solve the above problems, the present invention provides a biological livestock wastewater that can effectively remove organic matter, nitrogen, phosphorus, etc. generated from the livestock wastewater by appropriately implementing the arrangement of the reactor and the operating method of the arranged reactor. Its purpose is to provide a treatment system and a method of operation thereof.

1 is a view showing the structure of a biological livestock wastewater treatment system according to the method of the present invention.

* Explanation of symbols for main parts of the drawings

1: anaerobic tank 2: first intermittent aeration tank

3: second intermittent aeration tank 4: aerobic tank

5: sedimentation basin 6: internal conveying

7: Sludge External Transfer 8: Paddle

9: Sludge Disposal 10: Blower

11, 12: pump 13: solenoid valve

14 motor 15 enemies

16: treated water 17: diffuser

The wastewater treatment system of the present invention for achieving the above object comprises the steps of performing a denitrification reaction, phosphorus release and organic decomposition in an anaerobic tank into which wastewater is first introduced; In the first intermittent aeration tank and the second intermittent aeration tank in which aeration and non-aeration are alternately performed, performing nitrification and phosphorus intake during aeration, denitrification, release of phosphorus, and organic decomposition during the aeration; Performing nitrification in the aerobic tank connected to the intermittent aeration tank and controlling phosphorus concentration by ingesting phosphorus, and separating the microorganisms grown by ingesting contaminants in the precipitation tank connected to the aerobic tank; Comprising the step of discarding the microorganisms ingested a large amount of contaminants, and in addition to the step of transferring the nitrate nitrogen formed in the aerobic tank to the first anaerobic tank to the nitrogen gas through the deoxidation reaction; The sludge of the sedimentation tank is returned to the second intermittent aeration tank to maintain a constant microbial concentration in each reaction tank, and a small amount of nitrate nitrogen present in the sludge is denitrified in the second intermittent aeration tank during non-aeration. Depleting is further included.

As described above, the biological treatment method and apparatus for livestock wastewater according to the present invention by appropriately adjusting the arrangement and operation of the reactor can be effectively applied to treat organic matter, nitrogen and phosphorus generated from the livestock wastewater. This is because the concentration of organic matter is relatively low while the concentration of nitrogen is relatively high, that is, the ratio of total nitrogen (TN) to organic matter (TN) (TN / BOD) is high, and livestock containing organic matter, nitrogen and phosphorus It can be effectively applied to the treatment of waste water.

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

In general, in order to treat nitrogen, organic nitrogen or ammonia nitrogen must be converted to the state of nitrous nitrogen or nitrate through nitrification in one step; In the second step, the converted nitrous nitrogen or nitrate nitrogen is denitrified in anoxic state and converted into nitrogen gas.

1 is a view showing the structure of a biological livestock wastewater treatment system according to the method of the present invention.

Referring to the drawings, the arrangement of the reaction tank in the biological livestock wastewater treatment system of the present invention is anaerobic tank (1)-first intermittent aeration tank (2)-second intermittent aeration tank (3)-aerobic tank (4)-sedimentation tank (5) In order.

In the anaerobic tank (1) disposed at the first position, denitrification reaction occurs in an airless state in which no air is supplied into the tank to convert nitrous nitrogen or nitrate nitrogen into nitrogen gas and release it into the atmosphere. The paddle 8 is installed in the tank 1 to prevent the sludge from stagnation.

In the first intermittent aeration tank 2 installed at the next position of the anaerobic tank 1, a reaction tank in which a reaction of various substances such as ammonia, nitrogen nitrate, organic matter, and phosphorus introduced from raw water (influent water 15) is combined. A paddle (8) is also installed in the bath (2) to prevent sedimentation of the sludge.

The second intermittent aeration tank 3 in the third position is an aeration tank which is operated in the same manner as the first intermittent aeration tank 2 but is alternately operated. That is, when the first intermittent aeration tank 2 is in the aeration state, the second intermittent aeration tank 3 is operated in the non-aeration state, and the period of the aeration and the non-aeration time is the same as the first intermittent aeration tank 2.

The aerobic tank 4 installed in the fourth position is a reaction tank installed for two purposes.

First, since the nitrification may not proceed smoothly when the concentration of nitrogen is high, this tank (4) serves to maintain an aerobic state so that nitrification can occur sufficiently.

The second is to stably control the concentration of phosphorus by reliably ingesting phosphorus dynamically released due to the movement of phosphorus in the second intermittent aeration tank 3.

On the other hand, the period of time for supplying air from the first intermittent aeration tank 2 and the second intermittent aeration tank 3 and the time for not supplying air is 40 minutes to 1 hour 30 minutes.

The sedimentation tank (5) located at the end is a reaction tank for effectively separating the microorganisms grown by ingesting contaminants, and is installed for solid-liquid separation, and by installing a paddle to prevent sludge accumulation in the tank (5), about 1 to 2 rev / Rotate at min speed.

When the sludge is accumulated in the settling tank (5) to become an anaerobic state because the concentration of phosphorus can be discharged high so that the sludge does not accumulate and is smoothly conveyed and discarded.

The path 6 shown in FIG. 1 is an internal transport path, which is circulated to the anaerobic tank 1 rich in organic matter in order to denitrify the nitrogen component which has been changed into nitrate nitrogen through nitrification in the aerobic tank 4. will be. At this time, the conveyed amount is 250 to 300% of the influent based on the volume ratio, but may be up to 100 to 400% depending on the nitrogen treatment concentration.

The path 7 of FIG. 1 is a path for externally transporting the sludge, and is composed of the sedimentation tank 5 and the second intermittent aeration tank 3, and is also about 100% of the influent based on the volume ratio. This is done to maintain a constant microbial concentration in each reactor, to deplete trace amounts of nitrate nitrogen present in the sludge by denitrification, and to achieve phosphorus intake.

The paddle 8 is installed in the anaerobic tank 1, the first intermittent aeration tank 2, and the second intermittent aeration tank 3, respectively, and rotates at a constant rotational speed, for example, 10 to 20 rev / min so that sludge does not accumulate in each reaction tank. .

Path 9 is a path to dispose of sludge. If the contaminated microorganisms stay in the reactor for too long, the microorganisms age and reduce the removal efficiency, and the removal efficiency is unstable. To control microorganisms.

Unexplained reference numerals 10, 11, 12, 13, 14, and 17 are accessory components used in the treatment system of the present invention, wherein reference numeral 10 is a blower. , 11 and 12 are pumps, 13 are valves, and 14 are motors for operating the paddles 8.

In addition, reference numerals 15 and 16 show the inflow and outflow of raw water and treated water in the wastewater treatment system of the present invention.

As described above, according to the method of the present invention, the arrangement of the reaction tanks in the biological livestock wastewater treatment system is performed in the order of anaerobic tank-first intermittent aeration tank-second intermittent aeration tank-aerobic tank-precipitation tank, and nitrification in each reaction tank. By effectively conducting operations such as reaction, denitrification, internal transport, and sludge external transport, environmental pollution can be prevented by effectively treating organic matter, nitrogen, and phosphorus from livestock wastewater at low cost.

Claims (3)

(Secondary correction) A wastewater treatment method in which the flow of wastewater is in the order of anaerobic tank, aeration / non-aeration tank, aerobic tank, and sedimentation tank, wherein the aeration / non-aeration tank is a first intermittent aeration tank in which aeration and non-aeration reaction are alternately performed. And a second intermittent aeration tank; Internally transferring the nitrate nitrogen in the aerobic tank to the anaerobic tank to convert the nitrate nitrogen formed in the aerobic tank into nitrogen gas through a deoxidation reaction; Animal husbandry comprising externally transporting sludge in the settling tank to the second intermittent aeration tank to maintain a constant microbial concentration in each reactor and to deplete trace amounts of nitrate nitrogen present in the sludge through denitrification during non-aeration. Biological treatment of wastewater. (Secondary correction) The method according to claim 1, wherein in the first intermittent aeration tank and the second intermittent aeration tank, aeration and non-aeration are not performed at the same time, but are operated opposite to each other, and a period of time for supplying air and time for not supplying is 40 minutes to The treatment method is 1 hour 30 minutes. (Secondary correction) The treatment method according to claim 1 or 2, wherein the amount of wastewater returned from the aerobic tank to the anaerobic tank in the inner conveying step is 100 to 400% of the influent.

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