Wastewater treatment apparatus for shortcut nitrogen removal using anaerobic ammonium oxidation and partial nitritation using ammonium oxidizing bacteria granules

Abstract

The present invention relates to a wastewater treatment apparatus for shortcut nitrogen removal using anaerobic ammonium oxidation (ANAMMOX) and partial nitritation using ammonium oxidizing bacteria (AOB) granules. High-purity AOB granules are formed by means of AOB predominance using a side stream generated during a sludge treatment process. Moreover, the formed AOB granules are supplied to a partial nitritation tank (130) of a main treatment process and thus the partial nitritation is efficiently performed and nitrogen is quickly removed, and thus oxygen and an organic material is reduced compared to an existing method.

Claims

1. A wastewater treatment apparatus, comprising: a main treatment processing part including a first sedimentation tank for removing particulate organic matter of wastewater, a bio-reaction tank for removing dissolved organic matter of the first sedimented wastewater, and a second sedimentation tank for solid-liquid separating the organic matter-removed wastewater; and a sludge treatment processing part including a concentrating part to concentrate the solids separated in the first and second sedimentation tanks, an anaerobic digestion tank to anaerobically digest the concentrated solids, and a dehydrator to solid-liquid separate the solids anaerobically digested, wherein the main treatment processing part further includes a partial nitritation reaction tank using ammonium oxidation bacteria (AOB) granules, a granule recovery tank recovering granules in the partially nitritated wastewater, and an anaerobic ammonia oxidation (ANAMMOX) reaction tank, wherein the wastewater treatment apparatus comprises an AOB granulation tank reproducing granules reentered from the granule recovery tank into high-purity AOB granules, producing the AOB granules using a side stream from the dehydrator using an air lift-type reactor, and providing the AOB granules to the partial nitritation reaction tank included in the main treatment processing part, and wherein the side stream from the dehydrator is relatively high in concentration and temperature of ammonia nitrogen than in the main treatment processing part.

2. The wastewater treatment apparatus of claim 1, comprising another granule recovery tank, wherein the two granule recovery tanks separate the AOB granules into good granules and poor granules.

3. The wastewater treatment apparatus of claim 1, wherein the ANAMMOX reaction tank includes a sludge granule process or an biofilm process and is operated in an upflow and fluidized bed, and wherein an upper portion of the ANAMMOX reaction tank is filled with floating media to prevent leakage of anaerobic ammonium oxidation bacteria.

4. The wastewater treatment apparatus of claim 1, wherein the granules produced in the AOB granulation tank are recovered and stored in a storage tank and, when the partial nitritation reaction tank further included in the main treatment processing part is subjected to low efficiency, are supplied.

5. A wastewater treatment apparatus, comprising: a main treatment processing part including a first sedimentation tank for removing particulate organic matter of wastewater, a bio-reaction tank for removing dissolved organic matter of the first sedimented wastewater, and a second sedimentation tank for solid-liquid separating the organic matter-removed wastewater; and a sludge treatment processing part including a concentrating part to concentrate the solids separated in the first and second sedimentation tanks, an anaerobic digestion tank to anaerobically digest the concentrated solids, and a dehydrator to solid-liquid separate the solids anaerobically digested, wherein the main treatment processing part further includes: a partial nitritation reaction tank using AOB granules; a granule recovery tank recovering granules in the partially nitritated wastewater; and an ANAMMOX reaction tank, wherein the wastewater treatment apparatus further comprises: an AOB granulation tank reproducing granules reentered from the granule recovery tank into high-purity AOB granules, producing the AOB granules using a side stream from the dehydrator using an air lift-type reactor, and providing the produced AOB granules to the partial nitritation reaction tank included in the main treatment processing part; and another ANAMMOX reaction tank, and wherein the side stream from the dehydrator is relatively high in concentration and temperature of ammonia nitrogen than in the main treatment processing part.

6. The wastewater treatment apparatus of claim 5, wherein the ANAMMOX reaction tank for processing the side stream includes any one of a completed mixed or fluidized bed biofilm process.

7. The wastewater treatment apparatus of claim 6, wherein the fluidized bed biofilm process includes putting a fluidized bed carrier with a specific gravity of 0.94 to 0.96 and a specific surface area of 500 m2/m3 to 800 m2/m3 in 40 volume % to 50 volume % of the reaction tank, a stirrer for smooth fluidity of the fluidized bed carrier, and a non-powered buoyant discharger for preventing leakage of the carrier and bacteria.

8. The wastewater treatment apparatus of claim 5, wherein the ANAMMOX reaction tank includes a flotation-type solid separator to minimize influence by particulate matter discharged from the dehydrator, and wherein floating sludge is carried back to a front end of the dehydrator.

9. The wastewater treatment apparatus of claim 5, wherein a slope plate-type sedimentation tank is included between the granulation tank and the ANAMMOX reaction tank.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a view illustrating a conventional nitrogen treatment process;

(2) FIG. 2 is a view illustrating a short-cut nitrogen removal process in a main treatment process according to an embodiment of the present invention;

(3) FIG. 3 is a view illustrating a process of returning and recovering granules in a granule recovering tank according to an embodiment of the present invention;

(4) FIG. 4 is a view illustrating a short-cut nitrogen removal process of side stream using an ANAMMOX process and an AOB granulation tank according to an embodiment of the present invention;

(5) FIG. 5 shows photos for comparing variations in the size of AOB granules over time as an AOB granulation tank is operated according to an embodiment of the present invention;

(6) FIG. 6 is a graph illustrating the amount of AOB granules produced per ammonia removal amount under a nitrogen influx load condition in an AOB granulation tank according to an embodiment of the present invention;

(7) FIG. 7 is a graph illustrating a ratio of nitrite nitrogen to ammonia nitrogen in treated water in a nitrification reaction tank of a main treatment part according to an embodiment of the present invention;

(8) FIG. 8 is a graph illustrating the maximum nitrogen removal rate as per ANAMMOX reaction tank operation days using nitrified water in a main treatment part according to an embodiment of the present invention.

DESCRIPTION OF REFERENCE CHARACTERS

(9) 110: main treatment processing part 111: first sedimentation tank 112: bio-reaction tank 113: second sedimentation tank 120: sludge treatment processing part 121: concentration part 122: anaerobic digestion tank 123: dehydrator 130: partial nitrification reaction tank 140: granule recovery tank 150: ANAMMOX reaction tank 160: AOB granulation tank 170: ANAMMOX reaction tank

MODE FOR CARRYING OUT THE INVENTION

(10) Hereinafter, the present invention is described in detail with reference to embodiments thereof. The present invention is not limited to embodiments set forth herein but may rather be embodied in other various forms. The embodiments set forth herein are provided to fully convey the spirit of the present invention to one of ordinary skill in the art to which the present invention pertains. Thus, the present invention should not be limited by the following embodiments and it should be appreciated that all modifications, equivalents, or replacements which belong to the technical spirit and scope of the present invention are included.

(11) Various changes may be made to the present invention, and the present invention may come with a diversity of embodiments. Some embodiments of the present invention are shown and described in connection with the drawings. Relative sizes between the components in the drawings may be slightly exaggerated for a clear understanding of the present invention. Slight changes may also be made to the shape of the components in the drawings due to, e.g., variations in manufacturing process. Thus, unless explicitly stated otherwise, the embodiments set forth herein should not be limited to the shapes shown in the drawings and it should be appreciated that some changes may be made thereto.

(12) Meanwhile, various embodiments of the present invention may be combined with any other embodiments unless indicated otherwise. In particular, some features indicated as preferable or advantageous may be combined with other features indicated as preferable or advantageous.

(13) When determined to make the subject matter of the present invention unclear, the detailed description of the known art or functions may be skipped.

Embodiment 1. Wastewater Treatment Apparatus

(14) FIG. 2 is a view illustrating a short-cut nitrogen removal process in a main treatment process according to an embodiment of the present invention;

(15) The wastewater treatment apparatus includes a main treatment processing part 110, a sludge treatment processing part 120, a partial nitritation reaction tank 130, a granule recovery tank 140, an ANAMMOX reaction tank 150, and an AOB granulation tank 160. However, the present invention is not limited thereto.

(16) The main treatment processing part 110 includes, but is not limited to, a first sedimentation tank 111 for removing particulate organic matter of wastewater, a bio-reaction tank 112 for removing dissolved organic matter of the first sedimented wastewater, and a second sedimentation tank 113 for solid-liquid separating the organic matter-removed wastewater.

(17) The main treatment processing part 110 may further include, but is not limited to, the partial nitritation reaction tank 130, the granule recovery tank 140, and the ANAMMOX reaction tank 150.

(18) The sludge treatment processing part 120 includes, but is not limited to, a concentrating part 121 to concentrate the solids separated in the first and second sedimentation tanks, an anaerobic digestion tank 122 to anaerobically digest the concentrated solids, and a dehydrator 123 to solid-liquid separate the solids anaerobically digested.

(19) The sludge treatment processing part 120 may further include, but is not limited to, the AOB granulation tank 160.

(20) The wastewater goes through partial nitritation in the partial nitritation reaction tank 130.

(21) The partial nitritation reaction tank 130 measures 2 m horizontally, 2 m in length, and 2.5 m in effective depth of water and may be made a block whose effective volume is 10 m.sup.3. The partial nitritation reaction tank 130 may be operated in continuous flow and completed mixed forms but is not limited thereby.

(22) The wastewater which has undergone partial nitritation is introduced into the granule recovery tank 140.

(23) The granule recovery tank 140 may recover AOB granules discharged along with the wastewater.

(24) The granule recovery tank 140 includes a granule recovering part, preferably two granule recovering parts, but not limited to two.

(25) The recovered granules are separated into good granules and poor granules.

(26) The granule recovery tank 140 may allow granules which have a poor condition and low settleability to reenter the AOB granulation tank 160.

(27) FIG. 3 is a view illustrating a process of returning and recovering granules in a granule recovering tank according to an embodiment of the present invention;

(28) The ANAMMOX reaction tank 150 removes nitrogen in the wastewater, which has undergone partial nitritation, without consuming organic matter. The ANAMMOX reaction tank 150 may include, but is not limited to, any one of a sludge granule process or a biofilm process.

(29) The ANAMMOX reaction tank 150 may be configured as a circular reactor which measures 0.5 m in diameter, 3.7 m in effective depth of water, and 0.72 m.sup.3 in effective volume. The ANAMMOX reaction tank 150 may be operated in an upflow and fluidized bed but is not limited thereby.

(30) An upper portion of the ANAMMOX reaction tank 150 may be filled with floating media, thereby preventing loss of ANAMMOX microorganisms and securing a concentration of suspended solids in the discharged water.

(31) The AOB granulation tank 160 performs partial nitritation on the side stream produced in the dehydrator 123 using an airlift-type reactor while simultaneously producing AOB granules.

(32) The AOB granulation tank 160 may reproduce poor granules which have been reentered from the granule recovery tank 140 into good granules, i.e., high-purity AOB granules.

(33) The AOB granulation tank 160 may recover and store the produced AOB granules in a storage tank and, as the efficiency of the partial nitritation reaction tank 130 is lowered, may supply the granules to the partial nitritation reaction tank 130.

(34) The AOB granules produced by the AOB granulation tank 160 are supplied to the partial nitritation reaction tank 130.

MODE FOR CARRYING OUT THE INVENTION

Embodiment 2. Wastewater Treatment Apparatus

(35) FIG. 4 is a view illustrating a short-cut nitrogen removal process of side stream using an ANAMMOX process and an AOB granulation tank according to an embodiment of the present invention;

(36) The wastewater treatment apparatus of <Embodiment 1> includes a main treatment processing part 110, a sludge treatment processing part 120, a partial nitritation reaction tank 130, a granule recovery tank 140, an ANAMMOX reaction tank 150, and an AOB granulation tank 160 and may further include, but is not limited to, an ANAMMOX reaction tank 170.

(37) The sludge treatment processing part 120 may further include, but is not limited to, the ANAMMOX reaction tank 170.

(38) The ANAMMOX reaction tank 170 may include, but is not limited to, any one of a completed mixed or moving bed biofilm process.

(39) In the fluidized bed biofilm process, a fluidized bed carrier formed with a specific gravity of 0.94 to 0.96 and a specific surface area of 500 to 800 m.sup.2/m.sup.3 may be put in 40 to 50% of the volume of the ANAMMOX reaction tank 170, but is not limited thereto.

(40) The fluidized bed biofilm process may include, but is not limited to, a stirrer for smooth fluidity of the fluidized bed carrier and a non-powered buoyant discharger for preventing leakage of the carrier and bacteria.

(41) To minimize influence by particulate matter discharged from the dehydrator 123, the ANAMMOX reaction tank 170 includes a flotation-type solid separator, and floating sludge is carried back to the front end of the dehydrator.

(42) To minimize influence by particulate matter flowing out of the airlift-type reactor of the AOB granulation tank 160, a slope plate-type sedimentation tank may be added between the AOB granulation tank 160 and the ANAMMOX reaction tank 170, but without limited thereto.

Embodiment 3. Method of Producing AOB Granules

(43) As an AOB granulation reactor used according to the present invention, a known one was used.

(44) The AOB granulation reactor may include, but is not limited to, a sequencing batch reactor including a stainless reactor shaped as a circular pipe and including an inner circular pipe to form spherical granules by the internal hydraulic shearing force, a pump to inject ammonia-containing wastewater, a motorized valve for discharging treated water, a motorized valve for discharging granules, a blower for supplying air, a chemical pump, and an automatic operation control panel.

(45) The AOB granulation reactor measures 0.86 m in diameter, 3.45 m in effective depth of water, and 2 m.sup.3 in effective volume, and the motorized valve for discharging treated water after sedimentation may be installed in the middle of the height of the reactor and the motorized valve for discharging granules may be installed at the bottom of the reactor, but without limited thereto or thereby.

(46) Regarding the amount of air in the AOB granulation reactor, operation may be performed as the adjusting valve is adjusted in a range from 0.01 m/s to 0.2 m/s, and preferably, as it is operated in a range from 0.05 m/s to 0.15 m/s, operation may be performed, but without limited thereto.

(47) The area of the inner circular pipe and outer circular pipe in the reaction tank is set to allow the flow speed of air to be the same in the inner circular pipe and the outer circular pipe, and the area of the upper portion of the reaction tank where a hydraulic shearing force is produced for producing granules is set to be able to reduce the flow speed of air to .

(48) The diameter-to-effective water depth height ratio of the reaction tank is preferably maintained to be minimally 1:3 to 4.

(49) AOB-containing extra sludge is inoculated into the reactor and high-concentration ammonia-containing wastewater is injected to the reactor, thereby performing the operation.

(50) The operation of the reactor repeats the step of injecting ammonia wastewater, the step of nitritation and forming granules, the step of sedimentation, and the step of discharging microorganisms with poor settleability and treated water in the order thereof.

(51) As the influent wastewater, anaerobically digested leachate of first sedimented sludge and second sedimented sludge was used. At this time, operation may be performed until the ammonia concentration of the influent wastewater is 100 to 2,500 mg/L, preferably 500 to 2,000 mg/L, but without limited thereto.

(52) The time taken for introducing wastewater, aeration, sedimentation, and discharge may be varied depending on the concentration of introduced ammonia nitrogen, and three to 24 hours may be consumed for one cycle, but without limited thereto.

(53) Keeping the time of sedimentation short upon operation of the AOB granulation reactor allows a good amount of AOB granules with good settleability to settle in the lower portion of the reactor. However, the AOB granulation reactor fails to form AOB granules, and suspended microorganisms which have low settleability are washed out in the discharging step. If such manipulation is repeated, the AOB granulation reactor selectively exerts pressure, thus forming good-settleability AOB granules and making them dominance species. However, embodiments of the present invention are not limited thereto.

(54) According to the present invention, operation may be performed to allow AOB granules to selectively accumulate while maintaining the sedimentation speed of the sequencing batch reactor to be 10 to 60 m/h, but without limited thereto.

Experimental Example 1: Identify the Characteristic of AOB Granulation in Side Stream

(55) An experiment for AOB granulation and partial nitritation was performed in the side stream using the AOB granulation reactor of <Embodiment 3>.

(56) As one cycle, side stream was introduced into the AOB granulation reactor for five minutes, aeration and partial nitritation was performed for 140 to 155 minutes, the AOB granulation reactor was subjected to sedimentation for about 15 minutes to about 30 minutes, and the treated water was discharged for five minutes.

(57) Further, eight cycles were performed for a day, with each cycle taking three hours.

(58) 1 m.sup.3 of the treated water which is of the volume of the overall reactor was discharged, and the overall retention time was maintained as 6 hours. (The tester) stepwise shortened the sedimentation time depending on the degree of formation and sedimentation of granules and increased aeration time.

(59) The ammonia nitrogen in wastewater used for the experiment was 500 mg/L on the average, and the pH and temperature of the reactor were maintained to be 7.3 to 7.5 and 282 C., respectively. Oxygen which was needed for partial nitritation was injected by a diffuser inside the reaction tank, and dissolved oxygen was maintained to be about 2 mg/L or less.

(60) FIG. 5 shows photos for comparing variations in the size of AOB granules over time as an AOB granulation tank is operated according to an embodiment of the present invention.

(61) Referring to FIG. 5, it can be identified that the size of granules per period in a reactor was observed under a microscope. It can be shown that the size of microorganisms in active sludge is about 10 m to 50 m, 20 days after the operation, granules with a size of about 100 m formed, and 60 days after the operation, the size of granules was increased up to 800 m to 1,200 m.

(62) It can be shown that 60 days after in the reactor of <Embodiment 3>, spherical and elliptical granules formed.

(63) FIG. 6 is a graph illustrating the amount of AOB granules produced per ammonia removal amount under a nitrogen influx load condition in an AOB granulation tank according to an embodiment of the present invention.

(64) Referring to FIG. 6, as organic matter are mostly removed from the anaerobic digestion tank, the substrates available to the microorganisms exist mostly in the form of ammonia nitrogen. Thus, it can be shown that as autotrophic microorganisms spread and grow, 0.13 Kg to 0.18 Kg of OB granules, 0.16 Kg on the average, are produced for 1 Kg of influent ammonia nitrogen.

Experimental Example 2: Assess Variations in Microorganism Distribution Ratio in AOB Granulation Reactor

(65) To figure out variations in microorganism distribution ratio in an AOB granulation reactor, the amount and sequence listing of microorganisms and the community distribution of microorganisms in the AOB granules were identified using pyrosequencing analysis during the period of operation of the AOB granulation reactor of <Embodiment 3>.

(66) Table 1 shows the types and distributions of microorganisms in the reactor.

(67) TABLE-US-00001 TABLE 1 Nitrosomonas Nitrosospira Nitrobacter Types and periods SPP. SPP. SPP. Early stage of operation 1 1.5% 0.2 0.3%.sup. .sup.3 0.4% 20 days of operation 6 3.0% 2 0.5% 1.5 1.3% 60 days of operation 23 2.5% 4 0.5% 0.5 0.5%

(68) Referring to Table 1, Nitrosomonas SPP. which belong to the AOB increased from about 1% at the early stage of the operation to about 23% 60 days later the operation, and Nitrosospira SPP. increased from about 0.2% at the early stage of the operation to about 4% 60 days later.

(69) In contrast, Nitrobacter SPP. which belong to the NOB decreased from about 3% at the early stage of the operation to about 0.5% 60 days later.

(70) In other words, heterotrophic microorganisms grow very fast, thus forming low-density flocs.

(71) Influenced by free ammonia (FA) which has a high concentration in the reaction tank, NOB become less active and are mostly washed out of the reactor, and AOB, which grow slow but are sedimented and left in the reactor despite quick sedimentation, have a strong and durable structure with relatively high density and form granules.

(72) Thus, whereas the AOB distribution in the nitrification tank in the conventional active sludge process is 2% to 5% of all the microorganisms, the concentration of AOB according to the present invention is four times or more high as compared with the conventional active sludge. Further, use of AOB granules produced in the granule reactor increases nitritation efficiency in the same microorganism quantity by two to four times to the minimum as compared with the conventional active sludge process.

(73) Processing high-concentration ammonia wastewater using the conventional active sludge process requires a high microorganism concentration, large reactor volume, and long retention time, consuming initial construction costs and lots of maintenance costs. Meanwhile, if high-concentration ammonia wastewater is treated using AOB granules produced in the AOB granulation reactor of the present invention, the amount of microorganisms required may be reduced by 30% or more and, despite the short retention time, the volume required may be reduced to a maximum of .

Experimental Example 3: Assess Partial Nitritation in Main Process Using AOB Granules

(74) Partial nitritation was performed in the partial nitritation reaction tank 130 of <Embodiment 1> or <Embodiment 2> using AOB granules produced in the AOB granulation reactor of <Embodiment 3>.

(75) The partial nitritation reaction tank 130 measures 2 m horizontally, 2 m in length, and 2.5 m in effective depth of water and may be made a block whose effective volume is 10 m.sup.3. The partial nitritation reaction tank 130 is operated in continuous flow and completed mixed forms.

(76) organic matter are previously removed from the wastewater used for the experiment, and about 42 mg/L to about 49 mg/L of ammonia nitrogen are used. The daily treatment amount of wastewater is 220 m.sup.3/day, and the hydraulic retention time is about 1 hour.

(77) 1 to 2 mg/L of dissolved oxygen are retained as required for partial nitritation, and the dried AOB granule weight in the reactor remains about 3,000 mg/L.

(78) FIG. 7 is a graph illustrating a ratio of nitrite nitrogen to ammonia nitrogen in treated water in a nitrification reaction tank of a main treatment part according to an embodiment of the present invention.

(79) Referring to FIG. 7, as the ratio of nitrite nitrogen to ammonia nitrogen in the wastewater is 1:1 on the average as a result of the operation, it can be shown that partial nitritation has succeeded.

(80) In particular, the activity of NOB remained low until part of the ammonia nitrogen is oxidized into nitrite nitrogen, and about 3 mg/L of nitrate nitrogen was produced.

(81) In other words, since a high density of AOB exist in the granules, ammonia oxidizing was rapidly performed, and the subsequent step, i.e., nitrous oxidizing was not done due to the short retention time.

(82) As a result of feeding an amount of oxygen necessary for partial nitritation to transform only half of the ammonia nitrogen into nitrite nitrogen, 5% or less of nitrate nitrogen was obtained. This save oxygen consumption by 60% as compared with full nitrification of ammonia nitrogen into nitrate nitrogen.

(83) The activity lowering in NOB in the partial nitritation reaction tank 130 may be described as follows.

(84) First, since the number of NOB is smaller than the number of AOB, the activity of NOB may be relatively low.

(85) Second, in the distribution of nitrification microorganisms in granules, NOB are distributed mainly inside the granules as compared with AOB and, thus, NOB have a lower chance to use oxygen supplied from the outside of the granules than AOB.

(86) Further, since NOB are lower in substrate affinity for oxygen than AOB and, as compared with AOB, are thus disadvantageous in competition for using oxygen under the same condition.

(87) The nitrite accumulation property may be identified as the concentration of dissolved oxygen remains 2 mg/L or less. As set forth above, after ammonia is oxidized into nitric acid so that the oxidation of ammonia is complete, it is oxidized into nitrate nitrogen. Accordingly, the retention time of AOB in the reactor remains short, and as the amount of oxygen supplied to AOB is limited, ammonia may mostly transform into nitrite nitrogen.

Experimental Example 4: Assess ANAMMOX Process Using Partial Nitritation Treated Water in Main Process

(88) (The tester) assessed an ANAMMOX process using partial nitritation treated water.

(89) The ANAMMOX reaction tank 150 of <Embodiment 1> or <Embodiment 2> was used.

(90) The ANAMMOX reaction tank 150 may be configured as a circular reactor which measures 0.5 m in diameter, 3.7 m in effective depth of water, and 0.72 m.sup.3 in effective volume. Floating media fills the upper portion of the ANAMMOX reaction tank 150 in the depth of 0.2 m to 0.3 m. The floating media may prevent leakage of AOB while simultaneously controlling the concentration of suspended materials in the discharged water.

(91) As anaerobic AOB in the form of granules are positioned under the floating media, operation is performed, and the amount of microorganisms is configured to take up about 10% to about 20% of the volume of the reaction tank.

(92) The reaction tank was operated in an upflow and fluidized form, and 75 days after the operation, the operation was performed with partial nitritation treated water injected.

(93) FIG. 8 is a graph illustrating the maximum nitrogen removal rate as per ANAMMOX reaction tank operation days using nitrified water in a main treatment part according to an embodiment of the present invention.

(94) It may be identified from FIG. 8 that the removal rate of ANAMMOX process before partial nitritation was complete was very low and, as partial nitritation was then complete stepwise, nitrogen was removed.

(95) (The tester) increased the nitrogen inflow load rate by gradually increasing the amount of inflow into the ANAMMOX reaction tank 150. As a result of the operation, it was identified that 90% or more of the influent nitrogen was removed and a maximum nitrogen removal rate (NRR) of 4.5 KgN/m.sup.3/d was achieved.

(96) As such, the treatment apparatus of the present invention may save oxygen consumption by 60% and organic matter necessary for denitrification by 100% by sufficiently performing partial nitritation on wastewater as compared with the conventional nitrification-denitrification process.

INDUSTRIAL AVAILABILITY

(97) The present invention relates to a short-cut nitrogen removal wastewater treatment apparatus using an ANAMMOX process and partial nitritation using AOB granules. The present invention regards a short-cut nitrogen removal process which oxidizes only half of ammonia nitrogen up to the nitritation step and removing nitrogen using denitrification, thereby saving oxygen and organic matter consumption as compared with the conventional method and thus making it industrially applicable.