KR20110045812A - Anaerobic Digestion Tissue Nitrogen Removal Device and Nitrogen Removal Method for Anaerobic Digestion Tissue - Google Patents

Abstract

The present invention provides a degreasing solution storage tank (10) for storing a stripping filtrate generated by solid-liquid separation of anaerobic digestion sludge after any anaerobic digestion of any one selected from the group consisting of food waste stripping liquid, livestock wastewater and manure; Denitrification by converting nitrite (NO ₂ ⁻ ) or nitrate (NO ₃ ⁻ ) from the desorption filtrate introduced from the desorption liquor 10 into nitrogen gas (N ₂ ) by denitrifying microorganisms using nitrite or nitrate as an electron acceptor A first anaerobic tank 20; A first aeration tank 30 for oxidizing ammonia (NH ₃ ) of the desorption filtrate introduced from the first anoxic tank 20 to nitrite or nitrate by the action of nitrite or nitrifying bacteria and returning it to the first anoxic tank 20; A heat exchanger 40 which maintains the internal temperature of the first aeration tank 30 at 34 to 40 ° C. to promote growth of nitrous oxide and inhibit growth of nitrifier; And an anaerobic digestion and desorbent nitrogen removal apparatus including a precipitation tank (50) or a pressurized floatation tank (60) for separating solids from the first aeration tank (30) to remove solids from the desorption filtrate, and anaerobic digestion using the same. It relates to a nitrogen removal method of the desorption liquid.

According to the present invention, the anaerobic digestion leachate nitrogen removal of the present invention is carried out to remove the high concentration nitrogen of the leachate filtrate generated by solid-liquid separation of anaerobic digestion sludge after anaerobic digestion of food waste leachate, livestock wastewater or manure showing low C / N ratio When using the device and the nitrogen removal method of anaerobic digestion leachate using the same, it is possible to provide high nitrogen removal effect without supplying additional organic carbon source unlike the conventional nitrogen removal method that requires supplying organic carbon source such as A ₂ O process. Will be.

Anaerobic Digestion, Nitrogen Removal, Nitrite, Nitrifier

Description

Anaerobic Digestional Denitrification Nitrogen Removal Apparatus and Method for Removing Nitrogen from Anaerobic Digestional Detachment Using the Same

The present invention relates to an anaerobic digestion leachate nitrogen removal apparatus and a method for removing nitrogen from the anaerobic digestion leachate using the same, more specifically anaerobic digestion sludge after any anaerobic digestion of any one selected from the group consisting of food waste leachate, livestock wastewater and manure A desorption solution storage tank (10) for storing a desorption filtrate generated by solid-liquid separation; Denitrification by converting nitrite (NO ₂ ⁻ ) or nitrate (NO ₃ ⁻ ) from the desorption filtrate introduced from the desorption liquor 10 into nitrogen gas (N ₂ ) by denitrifying microorganisms using nitrite or nitrate as an electron acceptor A first anaerobic tank 20; A first aeration tank 30 for oxidizing ammonia (NH ₃ ) of the desorption filtrate introduced from the first anoxic tank 20 to nitrite or nitrate by the action of nitrite or nitrifying bacteria and returning it to the first anoxic tank 20; A heat exchanger 40 which maintains the internal temperature of the first aeration tank 30 at 34 to 40 ° C. to promote growth of nitrous oxide and inhibit growth of nitrifier; And an anaerobic digestion and desorbent nitrogen removal apparatus including a precipitation tank (50) or a pressurized floatation tank (60) for separating solids from the first aeration tank (30) by solid-liquid separation to remove solids from the desorption filtrate, and anaerobic digestion using the same. It relates to a nitrogen removal method of the desorption liquid.

The forms of nitrogen present in nature are ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, atmospheric nitrogen, etc. Nitrogen is essential for the growth of microorganisms, and contains about 12 to 14% in cells. Nitrogen in domestic sewage is a protein ingested by humans and is mostly released as urea (NH ₂ -CO-NH ₂ ) and various organic nitrogen compounds.

Nitrogen removal by biological method can be basically classified into three categories, which are easier to maintain and economically than physical or chemical treatment, and are widely used to remove nitrogen from sewage and wastewater. It can be used for the simultaneous removal of organics and nitrogen by partial remodeling of existing sewage and wastewater treatment plants to remove organics.

Nitrogen removal by biological method

1) Use as cell constituents through cell synthesis metabolic pathway

2) Conversion of ammonia nitrogen to nitrate nitrogen by nitrifying microorganisms

3) Converting nitrate nitrogen to nitrogen gas by denitrification microorganism

Most of the nitrogen in the wastewater is composed of organic nitrogen and ammonia nitrogen (NH ₃ -N), which are nitrite nitrogen (NO ₂ -N) and nitrate by hydrolysis and nitrification. After being converted to nitrogen (NO ₃ -N), it is removed by being released into the atmosphere as nitrogen gas (N ₂ ) through denitrification. Denitrification requires anoxic conditions with no carbon source and dissolved oxygen.

In nature, nitrification is known to act as a chemical synthetic autotrophic microorganism that sequentially oxidizes ammonia (NH ₃ ) to nitrous acid (NO ₂ ⁻ ) and nitric acid (NO ₃ ⁻ ).

{Formula 1}

^{_{NH 4 + + 1.5 O 2 →}} NO 2 - + 2H + + H 2 O + 240 ~ 350KJ (Nitrosomonas)

{Formula 2}

^{_{NO 2 - + 0.5 O 2 →}} NO 3 - + 65 ~ 90KJ (Nitrobacter)

Energy generated here nitrifying microorganisms CO _2, HCO ₃ ^- it is used to synthesize the organic material they need from the inorganic carbon source, such as, CO ₃ ^2-, so that itself has a very closely related to the growth of nitrifying micro-organisms. In the reaction of Chemical Formulas 1 and 2, the first reaction in which ammonia is oxidized to nitrous acid is mainly performed by microorganisms of the genus Nitrosomonas and Nitrosococcus. Nitrosomonas, in particular, N. europaea, is the most easily found in the environment for wastewater treatment. The second reaction, nitrous acid oxidation, is carried out by a microorganism classified as Nitrobacter.

The dissolved oxygen sufficient state organisms obtain the energy using the dissolved oxygen as an electron acceptor, but the dissolved oxygen shortage in the other hand, NO ₃ ^to-the oxygen-free state in which the forms of the compounds such as the presence NO ₃ ^- and NO ₂ ^- Or NO ₂ ^- is used as the electron acceptor.

Preferred conditions for denitrification are low DO concentrations and sufficient nitrates. The term anaerobic denitrification may be used depending on the presence of DO, but the biochemical reaction pathway is not anaerobic, but is merely a slightly modified aerobic reaction pathway. Therefore, the term “anaerobic denitrification” is preferred, and microorganisms can perform denitrification if the microorganism has an electron transport system that can use nitric acid or nitrous acid as the final electron acceptor instead of oxygen. Denitrification usually occurs in two stages: the first stage is the conversion of nitric acid to nitrite, and the second stage is the conversion of nitrite to N ₂ gas through two intermediates. These two stages are commonly called breathing.

Microorganisms need oxidant to reduce to N ₂ gas. Examples of electron donors for denitrification include acetic acid, acetone and methanol. The waste water itself is the most economical and reliable source of organic carbon, and when it is used for denitrification, some ammonia is resynthesized and a significant amount of soluble BOD is removed.

In the case of digestive liquids in which food waste is decomposed by anaerobic microorganisms, that is, anaerobic digestion liquids, the available organic matter is converted to methane through anaerobic digestion, and thus has a very low C / N (carbon / nitrogen) ratio. For anaerobic digestion of food, BOD (biological oxygen demand) is about 5,000 mg / l and nitrogen is 2,000 to 3,000 mg / l. Therefore, it has an appropriate C / N ratio of 3.5 to 5, which is required to remove nitrogen, and a C / N ratio of about 2.0, and thus lacks an organic carbon source for denitrification. Therefore, it is necessary to supply methanol, which is an alternative carbon source, which requires a lot of maintenance costs.

In addition, anaerobic digestion is difficult to nitrify and denitrate because of its high nitrogen concentration. Anaerobic digestion of foods is converted to NH ₄ ⁺ -N by the hydrolysis of organic nitrogen components of TKN components, so when analyzing the water quality of anaerobic digested digestion, NH ₄ ⁺ -N accounts for more than 90% of TN. . It is also characterized by maintaining a concentration high enough that most of the nitrogen is equal to the influent water quality. Therefore, in the case of Nitrosomonas or Nitrobacter nitrifying bacteria growth is inhibited at a high concentration of NH ₄ ⁺ -N concentration it is necessary to make conditions that allow nitrification without being inhibited by these microorganisms. In addition to NH ₄ ⁺ -N, the microbial nitrification conditions need to properly control NO ₂ -N, NO ₃ -N, temperature and pH.

In the case of livestock wastewater with a C / N ratio of around 3.0, various construction methods have been applied in Korea, but it is difficult to meet the quality of the discharged water, even though the facility cost is about 50,000 ~ 60 million won per ton. Therefore, it is necessary to construct an optimal economic treatment process and apply economical methods.

Domestic biological nitrogen removal technology can be largely divided into A ₂ O series, SBR series, carrier and MEDIA series, and there are about 30 developed technologies. However, most of the technology applied to sewage is considered to be inappropriate for the treatment of anaerobic digested wastewater. Most of the TN removal capacity is also up to 70%, which limits the treatment of high concentration nitrogen wastewater.

Domestic biological treatment technology applied to advanced nitrogen treatment has the following limitations.

1) The nitrification process requires a lot of air.

2) Denitrification after nitrification requires a large amount of organic matter, but anaerobic digestion is difficult to apply in the present state due to the small amount of organic matter.

3) Nitrification Low growth rate of microorganisms requires long SRT (treatment time) for nitrification.

4) High concentration wastewater with nitrogen concentration above 1,000mg / ℓ is difficult to nitrate and denitrification due to NH ₃ Free Ammonia Inhibition action, so HRT is often taken up to 20-30 days depending on the concentration. Hard. In particular, in the domestic livestock wastewater treatment process, the A ₂ O process with a long HRT is the majority.

Domestic and foreign low C / N ratio high concentration nitrogen containing wastewater treatment method is as follows.

1) Membrane application method

Although it is composed of a process that increases the concentration of microorganisms to facilitate nitrification and denitrification by applying membrane, wastewater treatment is not properly performed due to the fouling phenomenon of membrane.

2) ANAMMOX (Anaerobic ammonium oxidation)

It is an autotrophic denitrification process that uses nitrite as an electron acceptor to oxidize ammonia to nitrogen gas. The ANAMMOX process is based on the conversion of half ammonia to nitrite and the SHARON process must be applied at all stages.

The disadvantage is that the sludge doubled time is stabilized to about 11 days, but it takes about 120 days at the laboratory scale and about 200 days at the commercial plant, and it takes a lot of time to recover or recover when the sludge is leaked due to abnormal symptoms. This may not be the case. In addition, the theoretical ratio of NO ₂ -N and NH ₄ ⁺ -N is about 1: 1.3, but the ratio varies depending on the type of researcher or wastewater, making it difficult to calculate the correct ratio. Therefore, the classical nitrification and denitrification process must be added to the rear stage to treat high concentration nitrogen wastewater with concentration of NH ₄ ⁺ -N up to 5000m / l up to the effluent “I” standard. In addition, since the nitrified nitrogen ratio is not constant according to the efficiency of SHARON process, the concentration of treated water is considered to be severe, and even in foreign countries, the commercialization is not made and it is still at the research stage in Korea.

3) OLAND (Oxygen limited autotrophic nitrification denitrification)

The process was developed at Ghent University and used to cultivate autotrophic nitrifiers and use microorganisms as biocatalysts to treat ammonium-rich sewage. However, in the case of livestock wastewater, landfill leachate, and refluxed water having high inflow ammonia, it is necessary to additionally supply an external carbon source such as methanol to satisfy the discharged water quality standard and has a disadvantage of requiring long-term air supply.

4) SHARON-ANAMMOX

The process was the first successful laboratory-scale cultivation by Muller et al. At Delft University and then conducted an ANAMMOX study using a continuous batch reactor. In 1998, fluoridated bed reactors were used to achieve more than twice the efficiency of conventional nitrogen removal. In Japan, Kumamoto University recently collaborated with PAQUES, the Netherlands, in 2000. In Korea, in 2007, the Korea Institute of Science and Technology conducted the study to remove high concentration nitrogen using granular sludge.

However, even in the case of foreign countries that are developing all of the above high concentration nitrogen treatment, there is a case that is applied to wastewater treatment of high concentration low C / N ratio with the same characteristics as domestic food waste water, that is, ammonia concentration of 4,000 ~ 5,000mg / ℓ. I do not know.

In Korea, livestock wastewater, a kind of high-density nitrogen wastewater, is treated mainly by the A ₂ O-based method, but it has not been successfully applied to the treatment of anaerobic digestion fluid with low C / N ratio. This is because dumping at sea, rather than treating high concentrations of wastewater, is more convenient in terms of maintenance and because the cost of dumping at sea is relatively low, there is no need for treatment. However, it was not without attempt at all.

Therefore, it is urgent to secure a technology for treating high concentration nitrogen wastewater having a low C / N ratio. At present, as a method of treating high concentration of nitrogen, technology development using nitrite oxidation has been applied in the laboratory scale of each university, and it is applied to treating sludge digested water containing low concentration of nitrogen (1,000mg / ℓ). For example, it is considered insufficient to establish a technique for treating high concentration wastewater with a concentration of 4,000 to 5,000 mg / l such as food wastewater.

Accordingly, the present inventors have made diligent research efforts to overcome the problems of the prior art, in the nitrogen removal method using Nitrosomonas involved in nitrous oxidation and Nitrobacter involved in nitrification, when using a relatively high temperature of 34 to 40 ℃ As the growth of Nitrobacter is suppressed and the growth of Nitrosomonas is doubled and nitrous oxidation is mainly performed, it is confirmed that the requirement of organic carbon source is reduced more than 35% and the required air amount is more than 25% than the nitrous and nitrification process. The present invention has been completed.

Therefore, the main object of the present invention is to provide a large amount of organic carbon source, such as A ₂ O process, compared to the conventional nitrogen removal method that must be blown by using a large amount of air, more than 25% of air volume saving and 35% or more organic The present invention provides an anaerobic digestive sorbent nitrogen removal apparatus capable of providing a reduction in the amount of carbon source (methanol), and a nitrogen removal method of the anaerobic digestive leachate using the same.

According to an aspect of the present invention, the present invention is an anaerobic digestion of any one selected from the group consisting of food waste stripping liquid, livestock wastewater and manure after the anaerobic digestion sludge solids to store the stripping filtrate generated by the solid-liquid separation (10) ;

Denitrification by converting nitrite (NO ₂ ⁻ ) or nitrate (NO ₃ ⁻ ) from the desorption filtrate introduced from the desorption liquor 10 into nitrogen gas (N ₂ ) by denitrifying microorganisms using nitrite or nitrate as an electron acceptor A first anaerobic tank 20;

A first aeration tank 30 for oxidizing ammonia (NH ₃ ) of the desorption filtrate introduced from the first anoxic tank 20 to nitrite or nitrate by the action of nitrite or nitrifying bacteria and returning it to the first anoxic tank 20;

A heat exchanger 40 which maintains the internal temperature of the first aeration tank 30 at 34 to 40 ° C. to promote growth of nitrous oxide and inhibit growth of nitrifier; And

It provides an anaerobic digestion desorption nitrogen removal apparatus including a settling tank 50 or a pressurized floatation tank 60 to remove the solids in the desorption filtrate by separating the desorption filtrate introduced from the first aeration tank 30 (FIG. 1). And FIG. 2).

In the present invention, the anaerobic digestion stripping solution refers to a stripping filtrate which is produced by solid-liquid separation of anaerobic digestion sludge after anaerobic digestion of food wastes, livestock wastewater or manure.

According to another aspect of the present invention, the present invention is an anaerobic digestion of any one selected from the group consisting of food waste stripping liquid, livestock wastewater and manure after the anaerobic digestion sludge solids to separate the desorption storage tank (10) ;

Denitrification by converting nitrite (NO ₂ ⁻ ) or nitrate (NO ₃ ⁻ ) from the desorption filtrate introduced from the desorption liquor 10 into nitrogen gas (N ₂ ) by denitrifying microorganisms using nitrite or nitrate as an electron acceptor A first anaerobic tank 20;

A first aeration tank 30 for oxidizing ammonia (NH ₃ ) of the desorption filtrate introduced from the first anoxic tank 20 to nitrite or nitrate by the action of nitrite or nitrifying bacteria and returning it to the first anoxic tank 20;

A heat exchanger 40 which maintains the internal temperature of the first aeration tank 30 at 34 to 40 ° C. to promote growth of nitrous oxide and inhibit growth of nitrifier;

A second anoxic tank (70) for converting the nitrate of the desorption filtrate introduced from the first aeration tank (30) into nitrogen gas by denitrifying microorganisms using nitrate as an electron acceptor;

A second aeration tank (80) for oxidizing ammonia (NH ₃ ) of the desorption filtrate introduced from the second anoxic tank (70) to nitrate by the action of nitrifying bacteria and returning it to the second anoxic tank (70); And

It provides an anaerobic digestion desorption nitrogen removal apparatus including a settling tank 50 or a pressurized tank 60 to remove the solids in the desorption filtrate by separating the desorption filtrate introduced from the second aeration tank (80) (Fig. 3). And FIG. 4).

According to another aspect of the present invention, the present invention is a) produced by anaerobic digestion of any one selected from the group consisting of food waste degreasing solution, livestock wastewater and manure, which has passed through the desorption liquid storage tank (10), is produced by solid-liquid separation of anaerobic digestion sludge A first denitrification step of introducing a desorption filtrate to be introduced into the first anoxic tank 20 to reduce the nitrite or nitrate of the desorption filtrate to nitrogen gas by a denitrification microorganism using nitrite or nitrate as an electron acceptor;

b) flowing the desorption filtrate passed through the first denitrification step into the first aeration tank 30 and maintaining the desorption filtrate temperature in the first aeration tank 30 at 34 to 40 ° C. in the first aeration tank 30. Nitrite oxidation step of oxidizing the nitrite bacteria growth rate and inhibiting the nitrification bacteria growth rate so that the ammonia of the deaerated filtrate in the first aeration tank 30 is more oxidized with nitrite than nitrate;

c) a first internal transfer and denitrification step of re-injecting the desorption filtrate through the nitrite oxidation step into the first anaerobic tank 20 through internal transfer to denitrify with nitrogen gas; And

d) transferring the denitrified denitrification filtrate to the settling tank 50 or the pressure flotation tank 60 to separate the treated water and sludge, and returning a portion of the sludge to the first anaerobic tank 20. Provided is a method for removing nitrogen from an anaerobic digestion leachate using an anaerobic digestion waste nitrogen removal device.

In the method for removing nitrogen from the anaerobic digestive leachate of the present invention, between the steps c) and d), e) the releasing filtrate after the first nitrite oxidation step is introduced into a second anoxic tank (70) to obtain nitrate of the releasing filtrate. A second denitrification step of reducing nitrate to nitrogen gas by using a denitrification microorganism using an electron acceptor;

f) a nitrification step of introducing the desorption filtrate after the second denitrification step into the second aeration tank 80 and oxidizing ammonia (NH ₃ ) remaining after the second denitrification step to nitrate by the action of nitrifying bacteria; And

g) It is preferable to further include a second internal transfer and denitrification step of re-injecting the denitration filtrate passed through the nitrification step into the second anoxic tank 70 through an internal transport to denitrify with nitrogen gas.

Hereinafter, the present invention will be described more specifically.

Ammonia nitrogen is generally subjected to the nitridation and nitrification process according to the following Chemical Formulas 3 and 4 by the nitrifying microorganisms of Nitrosomonas and Nitrobacter.

Nitrous Oxidation

NH ₄ ⁺ + 1.5O ₂ → NO ₂ + H ₂ O + 2H ⁺ (Nitrosomonas)

Nitrification

NO ₂ + 0.5 O ₂ → NO ₃ (Nitrobacter)

The present invention is to increase the growth rate of Nitrosomonas involved in nitrification during nitrification process, artificially inhibit the growth rate of Nitrobacter involved in nitrification, proceeds nitrification only to the nitrite stage and wash out Nitrobacter, An essential factor is to inhibit the growth of nitrobacter, a nitrifying microorganism, from the reactor, and the anaerobic digestive fluid and the microorganisms can be enhanced because nitrosomonas, a nitrite microorganism, usually has a higher growth rate at high temperatures (34-40 ° C) and pH. The reaction aeration tank is characterized by maintaining at 34 ~ 40 ℃.

Denitrification of Nitrite

6NO ^2- + 3CH ₃ OH → 3N ₂ + 6HCO ^3- + 3H ₂ O

Denitrification of Nitrate

6NO ^3- + 5CH ₃ OH → 3N ₂ + 6HCO ^3- + 7H ₂ O

As shown in Chemical Formulas 5 to 6, when an organic carbon source such as methanol is used to remove nitrite or nitrate, denitrification of nitrite requires 40% less methanol than denitrification of nitrate. That is, the nitrite pathway in nitrogen removal requires 25% less oxygen than the nitrate pathway, and 40% less methanol when methanol is used as the organic carbon source.

Therefore, as described above, since the present invention suppresses nitrification reaction and activates nitrous oxidation reaction, it requires less amount of organic carbon source and oxygen than the nitrogen removal method through the conventional nitrification reaction.

In addition, since the consumption of alkaline substances is less than that of the conventional nitrogen removal method, the decrease in pH is reduced, which is an advantageous condition for the survival of the microorganisms, so that the ammonia nitrogen can be converted into nitrite nitrogen or nitrate nitrogen more efficiently. It is a method that can be applied to high concentration nitrogen wastewater because of the fast denitrification rate.

Hereinafter, the present invention will be described in more detail with reference to Examples. These embodiments are only for illustrating the present invention, and thus the scope of the present invention is not construed as being limited by these embodiments.

Anaerobic digestion desorption nitrogen removal apparatus of the present invention for removing high concentration nitrogen of the desorption filtrate produced by separating anaerobic digestion sludge after anaerobic digestion of food waste stripping liquid, livestock wastewater or manure showing low C / N ratio When the nitrogen removal method of the anaerobic digestion leachate is used, it is possible to provide a high nitrogen removal effect without supplying an additional organic carbon source unlike the conventional nitrogen removal method, which requires supplying an organic carbon source such as an A ₂ O process.

Comparative Example 1 Existing A ₂ Nitrogen removal using O process

Using the system as shown in Figure 5 was carried out for nitrogen removal of anaerobic digestion desorption filtrate of food waste desorption liquid for 46 days, methanol was injected into the anaerobic tank at 2.5kgMeOH / kgNO ₃ -N _Re ratio per day, daily The pH and dissolved oxygen concentration (DO) of the anaerobic and anaerobic tanks were measured, and the pH, temperature and dissolved oxygen concentrations of the aeration tank were measured (Table 1).

{Table 1}

 Count Anaerobic tank Anaerobic Aeration tank pH DO pH DO pH Temperature DO One 6.65 0 6.75 0 6.08 25.0 4.25 2 6.47 0 6.70 0 6.39 25.6 4.95 3 6.53 0 6.75 0 6.41 26.3 4.38 4 6.63 0 6.82 0 6.50 27.0 4.12 5 6.61 0 6.57 0 6.23 24.9 3.50 6 6.62 0 6.56 0 6.31 24.8 4.09 7 6.71 0 6.64 0 6.54 25.2 4.73 8 6.41 0 6.30 0 6.08 26.6 3.95

 Count Anaerobic tank Anaerobic Aeration tank pH DO pH DO pH Temperature DO 9 6.41 0 6.30 0 6.08 26.6 3.95 10 6.38 0 6.51 0 6.25 25.3 3.48 11 7.86 0 7.76 0 6.72 24.1 2.98 12 7.96 0 7.93 0 7.51 25.6 1.22 13 8.14 0 8.05 0 6.74 26.0 3.14 14 8.22 0 8.14 0 7.48 26.6 2.50 15 8.25 0 8.17 0 7.21 26.1 2.78 16 8.06 0 8.05 0 7.07 26.4 3.03 17 8.05 0 8.03 0 7.07 27.5 2.56 18 8.16 0 8.13 0 7.20 27.7 4.25 19 8.13 0 8.10 0 7.30 29.1 4.21 20 8.15 0 8.09 0 7.17 28.0 3.96 21 8.09 0 8.04 0 6.86 27.4 3.92 22 6.75 0 7.77 0 6.45 26.9 5.80 23 7.87 0 7.33 0 5.82 26.2 6.93 24 7.80 0 7.57 0 6.22 25.7 6.10 25 7.93 0 7.71 0 6.19 29.2 4.90 26 7.95 0 7.78 0 6.22 27.2 5.13 27 7.96 0 7.76 0 6.28 28.7 5.43 28 7.95 0 7.82 0 6.17 28.0 4.72 29 8.01 0 7.89 0 6.03 25.7 4.95 30 7.99 0 7.79 0 5.84 26.3 4.22 31 7.94 0 7.85 0 5.77 27.4 4.51 32 7.92 0 7.80 0 5.51 27.0 4.23 33 7.81 0 7.69 0 5.37 27.1 4.04 34 7.86 0 7.74 0 5.29 26.5 4.05 35 7.99 0 7.81 0 5.08 27.9 4.62 36 8.02 0 7.86 0 5.29 29.1 5.40 37 8.01 0 7.81 0 5.47 28.8 5.14 38 7.96 0 7.78 0 5.58 28.4 5.02 39 7.99 0 7.74 0 5.81 28.6 5.22 40 8.04 0 7.85 0 6.14 28.5 5.22 41 8.02 0 7.81 0 5.94 27.9 5.64 42 7.93 0 7.75 0 5.80 27.8 6.33 43 7.98 0 7.84 0 6.18 28.1 1.92 44 7.96 0 7.83 0 6.23 28.3 2.22 45 7.94 0 7.78 0 6.05 28.6 2.41 46 7.88 0 7.74 0 5.74 28.7 1.85 47 7.82 0 7.67 0 5.46 28.8 1.36 Average 7.69 0 7.62 0 6.26 27.1 4.09

Anaerobic Digestion of Food Waste Desorbents COD, BOD, SS, TN, TP, NH ₃ -N, NO ₂ -N and NO ₃ -N were measured before nitrogen removal of the desorption filtrate, and the COD inside the aeration tank was , BOD, SS, TN, TP, NH ₃ -N, NO ₂ -N and NO ₃ -N were measured and COD, BOD, SS, TN, TP, NH ₃ -N, NO _2- N and NO ₃ -N were measured (Table 2).

{Table 2} (Unit: mg / l)

Item Digestive Tissue Desorption Aeration tank Effluent 1 time Episode 2 1 time Episode 2 1 time Episode 2 COD 262 380 - - 179 105 BOD 420 247 - - 99.4 49.7 SS 270 138 1,980 - 11.7 13.0 T-N 886 1,100 530 - 303 295 T-P 24.3 21.7 36.2 - 22.4 10.3 NH ₃ -N 795 897 135 55.1 146 56.3 NO ₂ -N 0.24 0.10 39.6 0.25 77.6 0.02 NO ₃ -N Not detected 0.15 312 409 196 221

Example 1 Nitrogen Removal Using System of the Invention

Nitrogen removal of the anaerobic digestion and desorption filtrate of food waste desorption liquid was carried out for 37 days using the system as shown in FIG. The pH, temperature and dissolved oxygen concentration of the first aeration tank were measured (Table 3).

{Table 3}

Count
First anaerobic tank First aeration tank (nitrous oxide tank) Second anaerobic Second Aeration Tank pH DO pH Temperature DO pH DO pH DO One 7.58 0 6.84 36.9 6.09 6.77 0 6.42 2 7.32 0 6.75 34.8 6.53 6.41 0 6.38 6.95 3 8.32 0 8.16 36.0 5.72 7.40 0 7.01 7.09 4 8.60 0 8.54 38.0 6.90 7.59 0 6.73 5 8.57 0 8.22 35.3 6.08 7.68 0 7.05 6 8.52 0 8.16 35.4 6.34 7.84 0 7 8.56 0 8.23 35.6 6.84 8.22 0 8 8.64 0 8.32 37.1 7.00 8.55 0 7 6.9 9 8.68 0 8.58 32.8 7.30 8.46 0 6.7 7.2 10 8.62 0 8.52 34.9 7.08 8.16 0 11 8.62 0 8.55 34.2 5.12 8.55 0 7.98 5.15 12 8.73 0 8.02 39.6 3.08 8.21 0 7.05 5.58 13 8.93 0 7.35 36.3 3.26 8.31 0 7.1 7.2 14 8.86 0 7.51 35.8 3.84 8.24 0 15 8.93 0 7.35 36.0 3.80 7.20 0 7.05 7.26 16 9.11 0 8.09 38.8 4.30 8.00 0 8.04 7.8 17 8.97 0 7.79 37.5 1.05 8.03 0 8.1 6.8 18 8.81 0 8.14 35.1 3.80 8.16 0 8.23 6.6 19 9.11 0 8.04 34.1 5.14 8.43 0 8.4 6.22 20 8.94 0 8.13 35.5 4.28 8.11 0 21 8.95 0 8.11 35.2 4.07 8.13 0 22 9.09 0 8.16 34.9 3.55 8.41 0 8.47 6.2 23 8.80 0 8.47 34.6 5.94 8.52 0 8.57 6.7 24 8.84 0 8.26 35.9 5.82 8.42 0 25 8.96 0 8.15 33.7 5.66 8.32 0 8.51 6.8 26 8.91 0 8.27 34.8 4.95 8.39 0 27 8.90 0 8.22 36.6 4.54 8.40 0 8.5 6.63 28 8.55 0 8.16 35.2 4.28 8.42 0 29 8.27 0 8.34 35.3 4.69 8.52 0 30 8.19 0 8.57 35.5 4.61 8.69 0 8.77 6.6 31 9.32 0 8.85 33.1 6.13 8.82 0 8.84 6.9 32 9.34 0 8.75 34.5 6.22 8.78 0 8.86 6.9 33 8.93 0 8.55 34.9 5.42 8.66 0 34 8.27 0 7.98 35.3 4.09 8.13 0 6.38 4.7 35 8.19 0 7.84 35.7 4.53 8.09 0 36 8.26 0 7.58 36.1 4.82 7.84 0 37 8.34 0 7.63 35.4 4.59 7.69 0 5.5 6.5 Average 8.66 0 8.09 35.6 5.07 8.12 0 7.64 6.62

Anaerobic Digestion of Food Waste Desorbents The COD, BOD, SS, TN, TP, NH ₃ -N, NO ₂ -N and NO ₃ -N of the desorption filtrate were measured prior to the nitrogen removal of the desorption filtrate. COD, BOD, SS, TN, T-P, NH ₃ -N, NO ₂ -N and NO ₃ -N in the first aeration tank, the second anoxic tank and the second aeration tank were measured. , SS, TN, TP, NH ₃ -N, NO ₂ -N and NO ₃ -N were measured (Table 4).

{Table 4} (Unit: mg / L)

Item Digestive Liquid
Desorption First anaerobic tank First Aeration Tank Second anaerobic Second Aeration Tank Effluent 1 time Episode 2 1 time Episode 2 1 time Episode 2 1 time Episode 2 1 time Episode 2 1 time Episode 2 COD 949 740 - - - - - - - - 23.0 323 BOD 1,860 1,710 - - - - - - - - 26.4 13.0 SS 1,180 950 - - - - - - - - 7.8 9.2 T-N 1,060 1,100 - - - - - - - - 287 297 T-P 23.8 29.0 - - - - - - - - 17.8 15.9 NH ₃ -N 838 767 128 159 130 7.68 96.5 4.39 41.9 1.18 26.1 1.28 NO ₂ -N 0.22 0.08 0.83 5.20 3.15 180 0.65 228 0.94 234 201 235 NO ₃ -N 1.27 0.61 26.0 0.40 16.8 3.10 56.4 7.27 97.3 7.96 45.4 15.0

As a result of Comparative Example 1 and Example 1, the effluent TN concentration in the A ₂ O process was 303 and 295 mg / L, and the process of the present invention was 287 and 297 mg / L, although methanol was not injected into the process of the present invention. And water similar to A ₂ O process.

The concentration of ammonia nitrogen in the effluent water of the A ₂ O process is 146 and 56.3 mg / l, and despite the high air flow, the nitrification (NO ₃ -N) is not sufficiently achieved, resulting in low nitrogen removal. Nitrogen concentrations were 26.1 and 1.28 mg / l, and nitrite nitrogen concentrations were 201 and 235 mg / l.

As described above, the anaerobic digestion leachate nitrogen removal of the present invention is carried out to remove the high concentration nitrogen of the leachate filtrate produced by solid-liquid separation of anaerobic digestion sludge after anaerobic digestion of food waste leachate, livestock wastewater or manure showing low C / N ratio When using the apparatus and the nitrogen removal method of anaerobic digestion leachate using the same, unlike the conventional nitrogen removal method that requires the supply of organic carbon sources such as A ₂ O process, it is possible to provide high nitrogen removal effect without additional organic carbon sources. Will be.

1 is a schematic representation of one embodiment of the system of the present invention.

2 is a schematic representation of one embodiment of a system of the present invention.

3 is a schematic representation of one embodiment of a system of the present invention.

4 is a schematic representation of one embodiment of the system of the present invention.

Figure 5 shows a schematic of the system of the existing A ₂ O process.

Claims (4)

A stripping solution storage tank (10) for storing a stripping filtrate generated by anaerobic digestion of any one selected from the group consisting of food waste stripping liquid, livestock wastewater and manure and then solid-liquid separation of anaerobic digestion sludge; Denitrification by converting nitrite (NO ₂ ⁻ ) or nitrate (NO ₃ ⁻ ) from the desorption filtrate introduced from the desorption liquor 10 into nitrogen gas (N ₂ ) by denitrifying microorganisms using nitrite or nitrate as an electron acceptor A first anaerobic tank 20; A first aeration tank 30 for oxidizing ammonia (NH ₃ ) of the desorption filtrate introduced from the first anoxic tank 20 to nitrite or nitrate by the action of nitrite or nitrifying bacteria and returning it to the first anoxic tank 20; A heat exchanger 40 which maintains the internal temperature of the first aeration tank 30 at 34 to 40 ° C. to promote growth of nitrous oxide and inhibit growth of nitrifier; And Anaerobic digestion desorption nitrogen removal apparatus comprising a settling tank (50) or a pressurized flotation tank (60) for removing solid matter from the desorption filtrate by solid-separating the desorption filtrate introduced from the first aeration tank (30). A stripping solution storage tank (10) for storing a stripping filtrate generated by anaerobic digestion of any one selected from the group consisting of food waste stripping liquid, livestock wastewater and manure and then solid-liquid separation of anaerobic digestion sludge; Denitrification by converting nitrite (NO ₂ ⁻ ) or nitrate (NO ₃ ⁻ ) from the desorption filtrate introduced from the desorption liquor 10 into nitrogen gas (N ₂ ) by denitrifying microorganisms using nitrite or nitrate as an electron acceptor A first anaerobic tank 20; A first aeration tank 30 for oxidizing ammonia (NH ₃ ) of the desorption filtrate introduced from the first anoxic tank 20 to nitrite or nitrate by the action of nitrite or nitrifying bacteria and returning it to the first anoxic tank 20; A heat exchanger 40 which maintains the internal temperature of the first aeration tank 30 at 34 to 40 ° C. to promote growth of nitrous oxide and inhibit growth of nitrifier; A second anoxic tank (70) for converting the nitrate of the desorption filtrate introduced from the first aeration tank (30) into nitrogen gas by denitrifying microorganisms using nitrate as an electron acceptor; A second aeration tank (80) for oxidizing ammonia (NH ₃ ) of the desorption filtrate introduced from the second anoxic tank (70) to nitrate by the action of nitrifying bacteria and returning it to the second anoxic tank (70); And Anaerobic digestion desorption nitrogen removal apparatus comprising a settling tank (50) or a pressurized flotation tank (60) for removing the solids from the desorption filtrate by solid-liquid separation of the stripping filtrate introduced from the second aeration tank (80). a) anaerobic digestion of any one selected from the group consisting of food waste stripping liquor, livestock wastewater and manure, which has passed through the stripping liquor storage tank 10, and the stripping filtrate produced by solid-liquid separation of anaerobic digestion sludge is introduced into the first anaerobic tank 20 A first denitrification step of reducing nitrite or nitrate in the denitrification filtrate to nitrogen gas by a denitrification microorganism using nitrite or nitrate as an electron acceptor; b) flowing the desorption filtrate passed through the first denitrification step into the first aeration tank 30 and maintaining the desorption filtrate temperature in the first aeration tank 30 at 34 to 40 ° C. in the first aeration tank 30. Nitrite oxidation step of oxidizing the nitrite bacteria growth rate and inhibiting the nitrification bacteria growth rate so that the ammonia of the deaerated filtrate in the first aeration tank 30 is more oxidized with nitrite than nitrate; c) a first internal transfer and denitrification step of re-injecting the desorption filtrate through the nitrite oxidation step into the first anaerobic tank 20 through internal transfer to denitrify with nitrogen gas; And d) transferring the denitrified denitrification filtrate to the settling tank 50 or the pressure flotation tank 60 to separate the treated water and sludge, and returning a portion of the sludge to the first anoxic tank 20. Nitrogen removal method of anaerobic digestion leachate using the anaerobic digestion waste nitrogen removal apparatus of Claim 1 or 2. According to claim 3, between step c) and step d) e) the denitrification filtrate through the first nitrite oxidation step is introduced into the second anoxic tank 70 to use the nitrate of the desorbed filtrate, nitrate as an electron acceptor A second denitrification step of reducing the nitrogen gas by the denitrification microorganism; f) a nitrification step of introducing the desorption filtrate after the second denitrification step into the second aeration tank 80 and oxidizing ammonia (NH ₃ ) remaining after the second denitrification step to nitrate by the action of nitrifying bacteria; And g) nitrogen removal of the anaerobic digestion and releasing fluid further comprising a second internal transfer and denitrification step of re-injecting the denitration filtrate through the nitrification step into the second anoxic tank 70 through internal transport and denitrifying with nitrogen gas. Way.

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