Apparatus for low ammonia-nitrogen wastewater short-cut nitrification-anammox treatment and method of using same

Abstract

The application relates to the technical field of wastewater treatment, in particular to a device for short-path nitrification-anammox treatment of low-ammonia-nitrogen wastewater and a method for short-path nitrification-anammox treatment of low-ammonia-nitrogen wastewater by using the device. The device comprises a reaction tank, an intermittent aeration system and a sulfur ion slow-release system based on the reaction tank. The intermittent aeration system can control the alternating change of the dissolved oxygen concentration through a preset intermittent aeration program, thereby realizing the inhibition of NOB. The sulfur ion slow-release system releases sulfur ions through the sulfur ion slow-release suspension ball to long-term inhibit NOB. Therefore, the device can inhibit NOB with different growth characteristics through the coupling of the two inhibition modes, avoid the loss of inhibition effect caused by the adaptability of some types of NOB to environmental conditions due to a single inhibition mode, and realize the rapid start and long-term stable operation of the short-path nitrification-anammox of the low-ammonia-nitrogen wastewater.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to an apparatus for short-cut nitrification-anaerobic ammonia oxidation treatment of low-ammonia nitrogen wastewater, and a method for using the apparatus for short-cut nitrification-anaerobic ammonia oxidation treatment of low-ammonia nitrogen wastewater. Background Technology

[0002] The short-cut nitrification-anaerobic ammonia oxidation process has advantages such as low aeration energy consumption, no need for external carbon sources, low sludge production, and small footprint, making it a promising green and low-carbon wastewater treatment technology. However, this process has not yet achieved large-scale application, especially in mainstream low-ammonia-nitrogen municipal wastewater treatment. The main reason is the difficulty in controlling the conversion of nitrite to nitrate during actual treatment, making it impossible to guarantee stable nitrite accumulation, thus hindering short-cut nitrification and affecting subsequent processes.

[0003] Currently, the main methods for achieving short-cut nitrification involve creating environmental conditions unfavorable to the growth of nitrite-oxidizing bacteria (NOB) through hydraulic parameter adjustments such as high free ammonia (FA), high free nitrite (FNA), mesophilic conditions, low dissolved oxygen (DO), low sludge retention time (SRT), and intermittent aeration, or by adding inhibitors, thereby leading to nitrite accumulation. However, in practical applications, urban wastewater generally does not possess conditions such as mesophilic conditions and high concentrations of FA and FNA. Therefore, strategies such as continuous low-oxygen aeration and intermittent aeration have become commonly used methods for achieving short-cut nitrification.

[0004] However, the inventors found that continuous low-oxygen aeration and intermittent aeration strategies are difficult to achieve long-term NOB suppression, with poor suppression effects. Furthermore, the time required for short-cut nitrification initiation under these suppression methods is relatively long. NOB bacteria exhibit rich population structures and diverse growth characteristics. Research by Fu Kunming et al. shows that some dominant populations can gradually adapt to long-term aerobic suppression environments through population replacement, and selectively enrich some Nitrospira bacteria with better DO affinity, which is detrimental to the stability of selective suppression of AOB and NOB under long-term low-DO continuous aeration strategies. In addition, studies on intermittent aeration show that excessively low DO concentrations during the aeration phase easily lead to poor aerobic-anoxic alternation environments, allowing NOB bacteria with strong DO affinity to adapt to the low-DO environment; while excessively high DO concentrations during the aeration phase, although achieving a better aerobic-anoxic alternation environment, also accelerate the recovery of NOB activity.

[0005] Adding chemical inhibitors is a method to achieve rapid start-up and stable operation of short-cut nitrification by inhibiting NOB enzyme activity. Related literature reports that adding inhibitors such as p-chloro-m-dimethylphenol, chlorate, and hydroxylamine can rapidly start short-cut nitrification. However, these methods all involve directly adding a certain concentration of inhibitor solution to the reactor to inhibit NOB. Firstly, these substances have a limited time to exert their effects in the reactor, thus requiring frequent additions. Secondly, most of these chemical agents have some degree of biotoxicity; unused or undecomposed inhibitors are directly discharged into receiving water bodies, resulting in resource waste and adverse environmental impacts. In conclusion, these inhibitors are not suitable for large-scale production and use. Summary of the Invention

[0006] In view of this, the present invention provides an apparatus for short-cut nitrification-anaerobic ammonia oxidation treatment of low ammonia nitrogen wastewater, and a method for short-cut nitrification-anaerobic ammonia oxidation treatment of low ammonia nitrogen wastewater using the apparatus, in order to solve the problems of poor inhibition effect and long start-up time of short-cut nitrification when using continuous low-oxygen aeration and intermittent aeration strategies to inhibit NOB in related technologies.

[0007] In a first aspect, the present invention provides an apparatus for short-cut nitrification-anaerobic ammonia oxidation treatment of low-ammonia nitrogen wastewater, the apparatus comprising a reaction tank, and an intermittent aeration system and a sulfur ion slow release system configured based on the reaction tank; wherein...

[0008] The intermittent aeration system can introduce air into the reaction tank according to a preset aeration program, which includes a repeating "low-frequency aeration - stop aeration - high-frequency aeration - stop aeration" program.

[0009] The sulfur ion slow-release system is capable of reciprocating within the reaction tank and continuously releasing sulfur ions into the reaction tank.

[0010] The device provided by this invention includes a reaction tank and an intermittent aeration system and a sulfur ion slow release system based on the reaction tank. The intermittent aeration system can control the alternating changes in dissolved oxygen concentration through a preset intermittent aeration program, thereby inhibiting NOB. The sulfur ion slow release system releases sulfur ions through sulfur ion slow release suspension balls to inhibit NOB for a long time. Therefore, this device can inhibit NOB with different growth characteristics through the coupling of two inhibition methods, avoiding the loss of inhibition effect of a single inhibition method due to the adaptation of some types of NOB to environmental conditions. This enables the rapid start-up and long-term stable operation of short-cut nitrification-anaerobic ammonia oxidation for low ammonia nitrogen wastewater.

[0011] In one alternative embodiment, the device further includes a controller connected to both the intermittent aeration system and the sulfur ion slow-release system.

[0012] The controller can instruct the intermittent aeration system to introduce air into the reaction tank according to the preset aeration program;

[0013] And / or, the controller can instruct the sulfur ion slow-release system to move back and forth within the reaction tank according to a preset movement program.

[0014] In one optional embodiment, when the intermittent aeration system introduces air into the reaction tank according to the preset aeration program, the duration of the low-frequency aeration phase is controlled to be 15-20 minutes. Furthermore, the dissolved oxygen content in the reactor during the low-frequency aeration phase is controlled to be 0.3-0.5 mg / L by adjusting the aeration frequency, and the aeration stops when the dissolved oxygen content in the reactor is higher than 0.5 mg / L.

[0015] And / or, control the duration of the aeration cessation phase to be 10–15 min;

[0016] And / or, control the duration of the high-frequency aeration stage to be 5 to 10 minutes, and control the dissolved oxygen content in the reactor during the high-frequency aeration stage to be 0.8 to 1.2 mg / L by adjusting the aeration frequency, and enter the stop aeration stage when the dissolved oxygen content in the reactor is higher than 1.2 mg / L.

[0017] In one optional embodiment, the intermittent aeration system includes an air intake pump, an air intake pipe, an air distribution device, and a flow meter.

[0018] The air pump is connected to the controller and is used to introduce air into the reaction tank according to the preset aeration program based on the instructions of the controller.

[0019] And / or, the air pump, the air inlet pipe, and the air distribution device are connected in sequence, the flow meter is installed on the air inlet pipe, and the air distribution device is installed inside the reaction tank.

[0020] In one optional embodiment, the sulfur ion slow-release system includes a movable support frame, a drive device, and at least one sulfur ion slow-release suspension ball; wherein,

[0021] The drive device is connected to the controller and is used to drive the movable support frame to reciprocate within the reaction tank according to the preset movement program based on the instructions of the controller.

[0022] And / or, at least one of the sulfur ion slow-release suspension balls is strung together on the movable support frame and extends into the reaction tank;

[0023] Optionally, the sulfur ion slow-release suspension balls are filled to a density of 40-60% in the reaction tank.

[0024] In one optional embodiment, the sulfide ion slow-release suspension ball comprises a porous hollow ball and a slow-release filler filling the interior of the porous hollow ball; the slow-release filler comprises sulfide, sponge iron, foaming agent, binder and pH buffer.

[0025] In one optional embodiment, the porous hollow sphere has a diameter of 6-8 cm and a surface pore diameter of 5-8 mm.

[0026] In one optional embodiment, based on the total weight of the slow-release filler, the weight percentage of the sulfide is 45-55%, the weight percentage of the sponge iron is 10-15%, the weight percentage of the foaming agent is 10-15%, the weight percentage of the binder is 12-18%, and the weight percentage of the pH buffer is 6-10%.

[0027] In one alternative embodiment, the sulfide includes at least one of sodium sulfide nonahydrate, ammonium sulfide, potassium sulfide, calcium sulfide, and magnesium sulfide.

[0028] And / or, the foaming agent includes at least one of calcium carbonate, magnesium carbonate, and ammonium bicarbonate;

[0029] And / or, the adhesive comprises sodium alginate and / or polyvinyl alcohol; preferably, the adhesive is a combination of sodium alginate and polyvinyl alcohol;

[0030] And / or, the pH buffer comprises calcium carbonate and / or magnesium carbonate; preferably, the pH buffer is a combination of calcium carbonate and magnesium carbonate.

[0031] In one optional embodiment, the driving device drives the movable support frame to reciprocate within the reaction tank according to the preset movement program, including:

[0032] When the intermittent aeration system performs low-frequency aeration, the drive device drives the movable support frame to reciprocate within the reaction tank at a speed of 5 to 10 m / min.

[0033] When the intermittent aeration system stops aeration, the drive device drives the movable support frame to move back and forth in the reaction tank at a speed of 10 to 20 m / min.

[0034] When the intermittent aeration system performs high-frequency aeration, the drive device drives the movable support frame to reciprocate within the reaction tank at a speed of 5 to 10 m / min.

[0035] Secondly, the present invention provides a method for short-cut nitrification-anaerobic ammonia oxidation treatment of low-ammonia nitrogen wastewater using the above-mentioned apparatus, the method comprising the following steps:

[0036] (1) Preparations before processing:

[0037] Low ammonia nitrogen wastewater is introduced into the reaction tank and inoculated with residual sludge from the secondary sedimentation tank;

[0038] (2) Short-range nitration start-up:

[0039] Using the intermittent aeration system, air is introduced into the reaction tank according to the preset aeration program. At the same time, the sulfur ion slow release system moves back and forth in the reaction tank and continuously releases sulfur ions until the accumulation rate of nitrite ions in the effluent of the reaction tank is not less than 90%, thus confirming that the short-cut nitrification has been successfully started.

[0040] (3) Short-cut nitrification-anaerobic ammonium oxidation start-up:

[0041] After the short-cut nitrification operation is stable, a portion of the short-cut nitrification sludge is discharged from the reaction tank, and anaerobic ammonium oxidation sludge is added; when the TN removal rate in the reaction tank reaches more than 80%, the short-cut nitrification-anaerobic ammonium oxidation is considered to have started successfully.

[0042] (4) Treatment of low ammonia nitrogen wastewater:

[0043] After the short-cut nitrification-anaerobic ammonia oxidation operation is stable, sulfur-iron autotrophic denitrification sludge is inoculated into the reaction tank; when the TN removal rate in the reaction tank reaches more than 85% and the sulfur ion detection rate in the effluent of the reaction tank is 0, the low ammonia nitrogen wastewater treatment begins.

[0044] In one optional embodiment, in the pretreatment preparation step, after inoculating the residual sludge in the secondary sedimentation tank, the concentration of activated sludge in the reaction tank is 4-5 mg / L.

[0045] In one optional embodiment, during the short-cut nitrification-anaerobic ammonium oxidation start-up step, a portion of the short-cut nitrification sludge is discharged, resulting in an activated sludge concentration of 2–3 mg / L in the reaction tank; and the anaerobic ammonium oxidation sludge is added, so that the concentration ratio of the short-cut nitrification sludge to the anaerobic ammonium oxidation sludge is 1:(1–1.25).

[0046] In one optional embodiment, in the low ammonia nitrogen wastewater treatment step, the sulfur-iron autotrophic denitrification sludge is inoculated into the reaction tank so that the weight of the sulfur-iron autotrophic denitrification sludge is 8 to 12% of the total weight of the sludge in the reaction tank.

[0047] Thirdly, the present invention provides the use of the above-described apparatus in short-cut nitrification-anaerobic ammonia oxidation treatment of low ammonia nitrogen wastewater. Attached Figure Description

[0048] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0049] Figure 1 An exemplary three-dimensional structural schematic diagram of an apparatus for short-cut nitrification-anaerobic ammonia oxidation treatment of low ammonia nitrogen wastewater according to the present invention is shown.

[0050] Figure 2 An exemplary schematic diagram of a planar structure of an apparatus for short-cut nitrification-anaerobic ammonia oxidation treatment of low ammonia nitrogen wastewater according to the present invention is shown.

[0051] Figure 3 Exemplary illustrations show a top view (left) and a side view (right) of an apparatus for short-cut nitrification-anaerobic ammonia oxidation treatment of low ammonia nitrogen wastewater according to the present invention;

[0052] Figure 4 An exemplary schematic diagram of a driving device and a movable support frame according to an embodiment of the present invention is shown;

[0053] Figure 5 An exemplary schematic diagram of a sulfur ion slow-release suspension ball is shown in an embodiment of the present invention.

[0054] Explanation of reference numerals in the attached figures:

[0055] 0. Reaction tank; 1. Inlet / outlet water system; 2. Intermittent aeration system; 3. Controller; 4. Sulfate ion slow-release system; 5. Drive unit; 1.1. Inlet pipe; 1.2. Inlet pump; 1.3. Water distribution device; 1.4. Outlet pipe; 1.5. Sludge discharge pipe; 2.1. Air pump; 2.2. Flow meter; 2.3. Air inlet pipe; 2.4. Air distribution device; 4.1. Sulfate ion slow-release suspended balls; 4.1.1. Upper shell of suspended balls; 4.1.2. Slow-release packing material inside suspended balls; 4.1.3. Lower shell of suspended balls; 4.2. Movable support frame; 4.3. Dissolved oxygen online monitor; 4.4. pH online monitor; 5.1. Gear motor; 5.2. Drive sprocket; 5.3. Drive shaft; 5.4 Driven sprocket; 5.5. Traveling track; 5.6. Traveling wheels. Detailed Implementation

[0056] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0057] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0058] The reason why the inhibition effect of NOB by low DO control and intermittent aeration strategy is poor and the time required for short-range nitrification start-up is long in the relevant technologies is as follows: (1) When in a long-term low-oxygen environment, NOB can gradually adapt to the long-term low-oxygen inhibition environment through the replacement of dominant species, and specifically enrich some Nitrospira bacteria with better DO affinity, so that the inhibition effect is weakened or even ineffective; (2) Under the conventional intermittent aeration strategy, due to the rich population structure and diverse growth characteristics of NOB bacteria, different NOB bacteria have different affinity for oxygen, such as active Among the common NOB bacteria in sludge, Nitrospira bacteria, which prefer low DO environment, are less adaptable to sudden high DO environment, while Nitrobacter bacteria are more adaptable to high intermittent aeration conditions. However, the existing intermittent aeration mode is relatively simple and it is difficult to achieve the inhibition of different types of NOB. (3) Using only low DO control and intermittent aeration strategy to inhibit NOB is a simple inhibition method, which makes it easy for NOB to adapt and recover its activity. Moreover, the simple NOB inhibition method makes the system less resistant to shocks, so it is difficult to maintain the long-term inhibition state of NOB.

[0059] To address the problems existing in the aforementioned related technologies, according to a first aspect of the present invention, an apparatus for short-cut nitrification-anaerobic ammonia oxidation treatment of low-ammonia nitrogen wastewater is provided. Wherein, Figure 1 An exemplary three-dimensional structural schematic diagram of an apparatus for short-cut nitrification-anaerobic ammonia oxidation treatment of low ammonia nitrogen wastewater according to the present invention is shown. Figure 2 An exemplary schematic diagram of a planar structure of an apparatus for short-cut nitrification-anaerobic ammonia oxidation treatment of low ammonia nitrogen wastewater according to the present invention is shown. Figure 3 Exemplary illustrations show a top view (left) and a side view (right) of an apparatus for short-cut nitrification-anaerobic ammonia oxidation treatment of low-ammonia nitrogen wastewater according to the present invention. Figure 1-3 As shown, the device includes a reaction tank 0, and an intermittent aeration system 2 and a sulfur ion slow release system 4 based on the reaction tank 0; wherein,

[0060] The intermittent aeration system 2 can introduce air into the reaction tank 0 according to a preset aeration program, which includes a repeated "low-frequency aeration - stop aeration - high-frequency aeration - stop aeration" program.

[0061] The sulfur ion slow release system 4 is capable of reciprocating within the reaction tank 0 and continuously releasing sulfur ions into the reaction tank 0.

[0062] The device provided by this invention includes a reaction tank and an intermittent aeration system and a sulfur ion slow release system based on the reaction tank. The intermittent aeration system can control the alternating changes in dissolved oxygen concentration through a preset intermittent aeration program, thereby inhibiting NOB. The sulfur ion slow release system releases sulfur ions through sulfur ion slow release suspension balls to inhibit NOB for a long time. Therefore, this device can inhibit NOB with different growth characteristics through the coupling of two inhibition methods, avoiding the loss of inhibition effect of a single inhibition method due to the adaptation of some types of NOB to environmental conditions. This enables the rapid start-up and long-term stable operation of short-cut nitrification-anaerobic ammonia oxidation for low ammonia nitrogen wastewater.

[0063] In addition, the above-mentioned device can also realize a new intermittent aeration mode. Through intermittent aeration of low oxygen-anoxic-high oxygen-anoxic, it can suppress NOB with different DO affinities. This can significantly improve the effectiveness and long-term effect of NOB suppression, thereby improving the stability of the short-cut nitrification system.

[0064] In one optional embodiment, the device further includes a controller 3, which is connected to the intermittent aeration system 2 and the sulfur ion slow release system 4, respectively.

[0065] The controller 3 can instruct the intermittent aeration system 2 to introduce air into the reaction tank 0 according to the preset aeration program;

[0066] And / or, the controller 3 can instruct the sulfur ion slow release system 4 to move back and forth within the reaction tank 0 according to a preset movement program.

[0067] In one optional embodiment, when the intermittent aeration system introduces air into the reaction tank according to the preset aeration program, the duration of the low-frequency aeration phase is controlled to be 15-20 minutes. Furthermore, the dissolved oxygen content in the reactor during the low-frequency aeration phase is controlled to be 0.3-0.5 mg / L by adjusting the aeration frequency, and the aeration stops when the dissolved oxygen content in the reactor is higher than 0.5 mg / L.

[0068] And / or, control the duration of the aeration cessation phase to be 10–15 min;

[0069] And / or, control the duration of the high-frequency aeration stage to be 5 to 10 minutes, and control the dissolved oxygen content in the reactor during the high-frequency aeration stage to be 0.8 to 1.2 mg / L by adjusting the aeration frequency, and enter the stop aeration stage when the dissolved oxygen content in the reactor is higher than 1.2 mg / L.

[0070] In one optional embodiment, the intermittent aeration system 2 includes an air intake pump 2.1, an air intake pipe 2.3, an air distribution device 2.4, and a flow meter 2.2;

[0071] The air pump 2.1 is connected to the controller 3 and is used to introduce air into the reaction tank 0 according to the preset aeration program based on the instruction of the controller 3.

[0072] And / or, the air pump 2.1, the air pipe 2.3 and the air distribution device 2.4 are connected in sequence, the flow meter 2.2 is installed on the air pipe 2.3 and the air distribution device 2.4 is installed in the reaction tank 0.

[0073] In one optional embodiment, the sulfur ion slow-release system 4 includes a movable support frame 4.2, a drive device 5, and at least one sulfur ion slow-release suspension ball 4.1; wherein,

[0074] The driving device 5 is connected to the controller 3 and is used to drive the movable support frame 4.2 to reciprocate within the reaction tank 0 according to the preset movement program based on the instructions of the controller 3.

[0075] And / or, at least one of the sulfur ion slow-release suspension balls 4.1 is strung together and hung on the movable support frame 4.2 and extends into the reaction tank 0;

[0076] Optionally, the sulfur ion slow-release suspension ball 4.1 is filled to a rate of 40-60% in the reaction tank 0.

[0077] In the device provided by the present invention, the sulfur ion slow release system includes a movable support frame, a driving device, and at least one sulfur ion slow release suspended ball. The driving device can drive the movable support frame to move. Therefore, the movable support frame can be used as a stirring device to achieve uniform mixing of activated sludge and wastewater during the aeration stop stage by moving the frame left and right.

[0078] In an optional embodiment, the sulfur ion slow-release system 4 further includes an online dissolved oxygen monitor 4.3 and an online pH monitor 4.4. The sulfur ion slow-release suspension ball 4.1 is fixed to a movable support frame 4.2 by ropes, and the upper end of the movable support frame 4.2 is connected to the drive device 5.

[0079] Figure 4An exemplary schematic diagram of a driving device and a movable support frame according to an embodiment of the present invention is shown. Figure 4 As shown, the drive device 5 includes a geared motor 5.1, a drive sprocket 5.2, a drive shaft 5.3, a driven sprocket 5.4, a travel track 5.5, and travel wheels 5.6. The drive device 5 operates as follows: under the instruction of the controller 3, the geared motor 5.1 is slowly started by frequency conversion. The geared motor 5.1 drives the drive sprocket 5.2 to rotate, which in turn drives the drive shaft 5.3 and travel wheels 5.6 to rotate. The driven sprocket 5.4 is mounted on the drive shaft 5.3, thus transmitting power to the second, third, fourth, and fifth sets of rotating shafts and travel wheels 5.6, ultimately achieving synchronous rotation and movement of all travel wheels 5.6. The travel wheels have a central groove and a rim; the central groove precisely engages with the travel track 5.5 to prevent the rim from deviating. The entire movable support frame 4.2 moves along the track under the drive of the geared motor 5.1, simultaneously causing the sulfur ion slow-release suspended balls 4.1 below to move left and right.

[0080] In one optional embodiment, the sulfide ion slow-release suspension ball 4.1 includes a porous hollow ball (4.1.1+4.1.3) and a slow-release filler 4.1.2 filled inside the porous hollow ball; the slow-release filler includes sulfide, sponge iron, foaming agent, binder and pH buffer. Figure 5 An exemplary schematic diagram of a sulfur ion slow-release suspension ball is shown in an embodiment of the present invention.

[0081] In one optional embodiment, the porous hollow sphere has a diameter of 6-8 cm and a surface pore diameter of 5-8 mm. Furthermore, the material of the porous hollow sphere can be selected within a certain range; for example, the material of the porous hollow sphere can be polyethylene.

[0082] In the device provided by this invention, the sulfur ion slow-release suspension ball comprises a porous hollow sphere and a slow-release filler filled inside the porous hollow sphere. This suspension ball can slowly release sulfur ions, continuously providing sulfur ions to the short-cut nitrification system to inhibit NOB activity, achieving rapid start-up and stable operation of the short-cut nitrification system, and avoiding frequent addition of inhibitors; simultaneously, the encapsulated S... 2- It acts on microorganisms in a heterogeneous manner in water bodies, compared to the direct addition of S. 2- The homogeneous action mode of aqueous solution, this heterogeneous action mode can significantly reduce the amount of sulfide used; moreover, S 2- It can also act as an electron acceptor for sulfur-autotrophic denitrifying bacteria, participating in the denitrification reaction and ultimately producing SO4. 2- Discharged into water bodies.

[0083] In addition, the slow-release filler of this sulfur ion slow-release suspension ball also contains sponge iron, which does not affect the sulfur content. 2-In the case of slow release, sponge iron can act as an oxygen buffer, reducing the impact of oxygen on sulfur dioxide in the system. 2- On the one hand, it can act as an oxidation process, and on the other hand, it can act as an electron acceptor for certain autotrophic microorganisms in the sulfur autotrophic denitrification reaction. Moreover, the Fe generated during the reaction process 2+ It can also be used as a phosphorus precipitant to remove some of the soluble phosphorus from water.

[0084] In one optional embodiment, based on the total weight of the slow-release filler, the weight percentage of the sulfide is 45-55%, the weight percentage of the sponge iron is 10-15%, the weight percentage of the foaming agent is 10-15%, the weight percentage of the binder is 12-18%, and the weight percentage of the pH buffer is 6-10%.

[0085] In one alternative embodiment, the sulfide includes at least one of sodium sulfide nonahydrate, ammonium sulfide, potassium sulfide, calcium sulfide, and magnesium sulfide.

[0086] And / or, the foaming agent includes at least one of calcium carbonate, magnesium carbonate, and ammonium bicarbonate;

[0087] And / or, the adhesive comprises sodium alginate and / or polyvinyl alcohol; preferably, the adhesive is a combination of sodium alginate and polyvinyl alcohol;

[0088] And / or, the pH buffer comprises calcium carbonate and / or magnesium carbonate; preferably, the pH buffer is a combination of calcium carbonate and magnesium carbonate.

[0089] The method for preparing the sulfide ion slow-release suspension balls can be selected within a certain range. For example, the sulfide ion slow-release suspension balls can be prepared by the following method:

[0090] ① Weigh out the sulfide, sponge iron, foaming agent, and pH buffer, and grind them into powders with particle sizes of 100-150 mesh, 100-200 mesh, 100-200 mesh, and 50-100 mesh, respectively; ② Weigh out the binder and dissolve it to prepare an aqueous solution with a mass concentration of 4-5%; ③ Mix the ground powders, add the binder aqueous solution to the mixed powders, stir and mix evenly, granulate to obtain filler particles, and soak the shaped filler in a 2-3% calcium chloride solution for 6 hours; ④ Dry the filler particles in a vacuum for 8-10 hours at a vacuum drying temperature of 120-140℃, and after cooling, obtain sulfide slow-release filler with a particle size of 10-12 mm; ⑤ Fill the above slow-release filler into porous hollow spheres.

[0091] In one optional embodiment, the driving device 5 drives the movable support frame 4.2 to reciprocate within the reaction tank 0 according to the preset movement program, including:

[0092] When the intermittent aeration system 2 performs the low-frequency aeration, the drive device 5 drives the movable support frame 4.2 to reciprocate within the reaction tank 0 at a speed of 5 to 10 m / min.

[0093] When the intermittent aeration system 2 stops aeration, the drive device 5 drives the movable support frame 4.2 to move back and forth in the reaction tank 0 at a speed of 10 to 20 m / min;

[0094] When the intermittent aeration system 2 is performing high-frequency aeration, the drive device 5 drives the movable support frame 4.2 to reciprocate within the reaction tank 0 at a speed of 5 to 10 m / min.

[0095] In one optional embodiment, the device further includes an inlet / outlet water system 1, which includes an inlet pipe 1.1, an inlet pump 1.2, a water distribution device 1.3, an outlet pipe 1.4, and a sludge discharge pipe 1.5. The inlet / outlet water system 1 is connected to the inlet and outlet ends of the reaction tank 0 via the inlet pipe 1.1 and the outlet pipe 1.4, wherein the inlet end is located at the lower end of one side of the reaction tank 0, the outlet end is located at the upper end of the other side of the reaction tank 0, and the sludge discharge pipe 1.5 is located at the lower end of one side of the outlet pipe 1.4.

[0096] Secondly, the present invention provides a method for short-cut nitrification-anaerobic ammonia oxidation treatment of low-ammonia nitrogen wastewater using the above-mentioned apparatus, the method comprising the following steps:

[0097] (1) Preparations before processing:

[0098] Low ammonia nitrogen wastewater is introduced into the reaction tank and inoculated with residual sludge from the secondary sedimentation tank;

[0099] (2) Short-range nitration start-up:

[0100] Using the intermittent aeration system, air is introduced into the reaction tank according to the preset aeration program. At the same time, the sulfur ion slow release system moves back and forth in the reaction tank and continuously releases sulfur ions until the accumulation rate of nitrite ions in the effluent of the reaction tank is not less than 90%, thus confirming that the short-cut nitrification has been successfully started.

[0101] (3) Short-cut nitrification-anaerobic ammonium oxidation start-up:

[0102] After the short-cut nitrification operation is stable, a portion of the short-cut nitrification sludge is discharged from the reaction tank, and anaerobic ammonium oxidation sludge is added; when the TN removal rate in the reaction tank reaches more than 80%, the short-cut nitrification-anaerobic ammonium oxidation is considered to have started successfully.

[0103] (4) Treatment of low ammonia nitrogen wastewater:

[0104] After the short-cut nitrification-anaerobic ammonia oxidation operation is stable, sulfur-iron autotrophic denitrification sludge is inoculated into the reaction tank; when the TN removal rate in the reaction tank reaches more than 85% and the sulfur ion detection rate in the effluent of the reaction tank is 0, the low ammonia nitrogen wastewater treatment begins.

[0105] In one optional embodiment, in the pretreatment preparation step, after inoculating the residual sludge in the secondary sedimentation tank, the concentration of activated sludge in the reaction tank is 4-5 mg / L.

[0106] In one optional embodiment, during the short-cut nitrification-anaerobic ammonium oxidation start-up step, a portion of the short-cut nitrification sludge is discharged, resulting in an activated sludge concentration of 2–3 mg / L in the reaction tank; and the anaerobic ammonium oxidation sludge is added, so that the concentration ratio of the short-cut nitrification sludge to the anaerobic ammonium oxidation sludge is 1:(1–1.25).

[0107] In one optional embodiment, in the low ammonia nitrogen wastewater treatment step, the sulfur-iron autotrophic denitrification sludge is inoculated into the reaction tank so that the weight of the sulfur-iron autotrophic denitrification sludge is 8 to 12% of the total weight of the sludge in the reaction tank.

[0108] In one optional embodiment, the short-cut nitrification start-up step may be as follows: Start the intermittent aeration system and the sulfide ion slow-release system, operating as follows: low-frequency aeration for 15-20 minutes, controlling the movable support frame to move back and forth at a low speed (5-10 m / min) to maintain the DO in the reaction tank at 0.3-0.5 mg / L; stop aeration when the DO exceeds 0.5 mg / L; stop aeration for 10-15 minutes, controlling the movable support frame to move back and forth at a medium speed (10-15 m / min); high-frequency aeration for 5-10 minutes, controlling the movable support frame to move back and forth at a low speed (5-10 m / min) to maintain the DO in the reaction tank at 0.8-1.2 mg / L; stop aeration when the DO exceeds 1.2 mg / L; stop aeration for 10-15 minutes, controlling the movable support frame to move at a medium speed (10-20 m / min); alternate between the above operating modes, and periodically monitor the NH4 in the effluent from the reaction tank. + NO2 - NO3 - and TN concentration, up to NO2 in the effluent from the reaction tank. - When the accumulation rate reaches 90% or more, short-cut nitrification is considered to have started successfully.

[0109] In one optional implementation, the short-cut nitrification-anammox start-up step may be as follows: after the short-cut nitrification is running stably, a portion of the short-cut nitrification sludge is discharged from the system, and acclimated anammox sludge is added to the device. The mass ratio of short-cut nitrification sludge to anammox sludge is controlled at 1:(1-1.25). No sludge is discharged during the initial operation phase. When the system's TN removal rate reaches more than 20%, a 300-500 micrometer screen is set at the sludge discharge port to screen the sludge and retain anammox granular sludge. The short-cut nitrification-anammox system is considered to have been successfully started up when the system's effluent TN removal rate reaches more than 80%.

[0110] In one optional embodiment, the low ammonia nitrogen wastewater treatment step may be as follows: after the short-cut nitrification-anaerobic ammonia oxidation system is operating stably, a portion of sulfur-iron autotrophic denitrification sludge is inoculated into the system, controlling the sulfur-iron autotrophic denitrification sludge to account for 8% to 12% of the system sludge, until the TN removal rate of the system effluent stably reaches more than 85%, and the effluent S 2- If no detection is detected, the device is considered to have met the operating requirements.

[0111] Thirdly, the present invention provides the use of the above-described apparatus in short-cut nitrification-anaerobic ammonia oxidation treatment of low ammonia nitrogen wastewater.

[0112] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. An apparatus for short-cut nitrification-anaerobic ammonia oxidation treatment of low-ammonia nitrogen wastewater, characterized in that, The device includes a reaction tank, and an intermittent aeration system and a sulfur ion slow release system based on the reaction tank; wherein, The intermittent aeration system can introduce air into the reaction tank according to a preset aeration program, which includes a repeatedly executed "low-frequency aeration - stop aeration - high-frequency aeration - stop aeration" program. The duration of the low-frequency aeration stage is controlled to be 15-20 minutes. The dissolved oxygen content in the reaction tank during the low-frequency aeration stage is controlled to be 0.3-0.5 mg / L by adjusting the aeration frequency. When the dissolved oxygen content in the reaction tank is higher than 0.5 mg / L, the aeration is stopped. The duration of the aeration cessation phase should be controlled to be 10–15 minutes; The duration of the high-frequency aeration stage is controlled to be 5 to 10 minutes. The dissolved oxygen content in the reaction tank during the high-frequency aeration stage is controlled to be 0.8 to 1.2 mg / L by adjusting the aeration frequency. When the dissolved oxygen content in the reaction tank is higher than 1.2 mg / L, the aeration is stopped. The sulfur ion slow-release system is capable of reciprocating within the reaction tank and continuously releasing sulfur ions into the reaction tank.

2. The apparatus according to claim 1, characterized in that, The device also includes a controller, which is connected to the intermittent aeration system and the sulfur ion slow release system respectively; The controller can instruct the intermittent aeration system to introduce air into the reaction tank according to the preset aeration program; And / or, the controller can instruct the sulfur ion slow-release system to move back and forth within the reaction tank according to a preset movement program.

3. The apparatus according to claim 2, characterized in that, The intermittent aeration system includes an air intake pump, an air intake pipe, an air distribution device, and a flow meter; The air pump is connected to the controller and is used to introduce air into the reaction tank according to the preset aeration program based on the instructions of the controller. And / or, the air pump, the air inlet pipe, and the air distribution device are connected in sequence, the flow meter is installed on the air inlet pipe, and the air distribution device is installed inside the reaction tank.

4. The apparatus according to claim 2, characterized in that, The sulfur ion slow-release system includes a movable support frame, a drive device, and at least one sulfur ion slow-release suspension ball; wherein... The drive device is connected to the controller and is used to drive the movable support frame to reciprocate within the reaction tank according to the preset movement program based on the instructions of the controller. And / or, at least one of the sulfur ion slow-release suspension balls is strung together on the movable support frame and extends into the reaction tank.

5. The apparatus according to claim 4, characterized in that, The sulfur ion slow-release suspension balls have a filling rate of 40-60% in the reaction tank.

6. The apparatus according to claim 4, characterized in that, The sulfide ion slow-release suspension ball comprises a porous hollow ball and a slow-release filler filling the interior of the porous hollow ball; the slow-release filler comprises sulfide, sponge iron, foaming agent, binder and pH buffer.

7. The apparatus according to claim 6, characterized in that, The porous hollow sphere has a diameter of 6-8 cm and a surface pore diameter of 5-8 mm.

8. The apparatus according to claim 6, characterized in that, Based on the total weight of the slow-release filler, the weight percentage of the sulfide is 45-55%, the weight percentage of the sponge iron is 10-15%, the weight percentage of the foaming agent is 10-15%, the weight percentage of the binder is 12-18%, and the weight percentage of the pH buffer is 6-10%.

9. The apparatus according to claim 6, characterized in that, The sulfide includes at least one of sodium sulfide nonahydrate, ammonium sulfide, potassium sulfide, calcium sulfide, and magnesium sulfide; And / or, the foaming agent includes at least one of calcium carbonate, magnesium carbonate, and ammonium bicarbonate; And / or, the adhesive comprises sodium alginate and / or polyvinyl alcohol; And / or, the pH buffer includes calcium carbonate and / or magnesium carbonate.

10. The apparatus according to any one of claims 4 to 9, characterized in that, The driving device drives the movable support frame to reciprocate within the reaction tank according to the preset movement program, including: When the intermittent aeration system performs low-frequency aeration, the drive device drives the movable support frame to reciprocate within the reaction tank at a speed of 5 to 10 m / min. When the intermittent aeration system stops aeration, the drive device drives the movable support frame to move back and forth in the reaction tank at a speed of 10 to 20 m / min. When the intermittent aeration system performs high-frequency aeration, the drive device drives the movable support frame to reciprocate within the reaction tank at a speed of 5 to 10 m / min.

11. A method for short-cut nitrification-anaerobic ammonia oxidation treatment of low-ammonia nitrogen wastewater using the apparatus according to any one of claims 1 to 10, characterized in that, The method includes the following steps: (1) Preparations before processing: Low ammonia nitrogen wastewater is introduced into the reaction tank and inoculated with residual sludge from the secondary sedimentation tank; (2) Short-range nitrification start-up: Using the intermittent aeration system, air is introduced into the reaction tank according to the preset aeration program. At the same time, the sulfur ion slow release system moves back and forth in the reaction tank and continuously releases sulfur ions until the accumulation rate of nitrite ions in the effluent of the reaction tank is not less than 90%, thus confirming that the short-cut nitrification has been successfully started. (3) Short-cut nitrification-anaerobic ammonium oxidation start-up: After the short-cut nitrification operation is stable, a portion of the short-cut nitrification sludge is discharged from the reaction tank, and anaerobic ammonium oxidation sludge is added; when the TN removal rate in the reaction tank reaches more than 80%, the short-cut nitrification-anaerobic ammonium oxidation is considered to have started successfully. (4) Treatment of low ammonia nitrogen wastewater: After the short-cut nitrification-anaerobic ammonia oxidation operation is stable, sulfur-iron autotrophic denitrification sludge is inoculated into the reaction tank; when the TN removal rate in the reaction tank reaches more than 85% and the sulfur ion detection rate in the effluent of the reaction tank is 0, the low ammonia nitrogen wastewater treatment begins.

12. The method according to claim 11, characterized in that, In the pretreatment preparation step, after inoculating the residual sludge in the secondary sedimentation tank, the concentration of activated sludge in the reaction tank is 4-5 g / L.

13. The method according to claim 11, characterized in that, In the short-cut nitrification-anaerobic ammonium oxidation start-up step, a portion of the short-cut nitrification sludge is discharged, resulting in an activated sludge concentration of 2-3 g / L in the reaction tank; and the anaerobic ammonium oxidation sludge is added, so that the concentration ratio of the short-cut nitrification sludge to the anaerobic ammonium oxidation sludge is 1:1-1.

25.

14. The method according to claim 11, characterized in that, In the low ammonia nitrogen wastewater treatment step, the sulfur-iron autotrophic denitrification sludge is inoculated into the reaction tank so that the weight of the sulfur-iron autotrophic denitrification sludge is 8 to 12% of the total weight of the sludge in the reaction tank.

15. Use of the apparatus according to any one of claims 1 to 10 in short-cut nitrification-anaerobic ammonia oxidation treatment of low ammonia nitrogen wastewater.

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