Short-cut nitrification-anaerobic ammonia oxidation integrated reactor

Abstract

The utility model particularly relates to a short-cut nitrification-anaerobic ammonia oxidation integrated reactor. The reactor comprises a short-cut nitrification area, a sponge iron area, an anaerobic ammonia oxidation area and an autotrophic denitrification area. According to the growth characteristics of different bacteria, environment control is performed in a targeted manner, so that the different bacteria are in respective optimal growth conditions, the activity of the bacteria is ensured, and the system is more efficient. In addition, nitrite nitrogen in the reactor is consumed while being generated, the concentration of the nitrite nitrogen in the system is low, and the problem of inhibition of high nitrite nitrogen concentration on anaerobic ammonium oxidation bacteria is solved. According to the reactor, the short-cut nitrification reaction and the anaerobic ammonia oxidation reaction are arranged in the same system, the anaerobic ammonia oxidation reaction can supplement needed alkalinity for the short-cut nitrification reaction, consumption of extra chemical agents is reduced, cost is saved, and the reactor has high practical value.

Description

Technical Field

[0001] This utility model relates to the field of wastewater biological treatment technology, and in particular to a short-cut nitrification-anaerobic ammonium oxidation integrated reactor. Background Technology

[0002] The short-cut nitrification-anaerobic ammonium oxidation (ATAO) process combines the advantages of both short-cut nitrification and anaerobic ammonium oxidation. It partially oxidizes ammonia nitrogen in wastewater into nitrite nitrogen, while the remaining ammonia nitrogen reacts with the generated nitrite nitrogen to produce nitrogen gas and water in the reactor. This process can save 50% on aeration, requires 100% of the external carbon source, reduces carbon dioxide release by 100%, and decreases sludge production, demonstrating excellent development prospects.

[0003] Currently, short-cut nitrification-anammox biological treatment often employs a two-stage process, where short-cut nitrification and anammox occur in separate reactors. In this process, short-cut nitrification consumes alkalinity, causing a decrease in the system's pH. To maintain the environment for microbial growth, alkalinity needs to be replenished into the short-cut nitrification system. Anammox, on the other hand, consumes acid, causing an increase in the system's pH. To maintain the environment for microbial growth in this system, acid needs to be added to adjust the pH. This two-stage process cannot meet the system's self-regulating pH requirements, necessitating the addition of chemical agents for adjustment, increasing costs. Furthermore, because short-cut nitrification and anammox are conducted in separate reactors, the higher concentration of nitrite nitrogen produced in the upstream short-cut nitrification reactor inhibits the growth of anammox bacteria in the downstream stage, making system stability difficult.

[0004] In a short-cut nitrification-anammox integrated reactor, ammonia-oxidizing bacteria and anammox bacteria coexist in one system. This combined short-cut nitrification and anammox technologies enables self-denitrification, allowing for pH self-regulation. The acidity generated by short-cut nitrification replenishes the acid consumed by anammox. Furthermore, the simultaneous production and consumption of nitrite nitrogen ensures its concentration is not likely to inhibit anammox bacteria, thus achieving stable system operation. However, when ammonia-oxidizing bacteria, anammox bacteria, and some denitrifying bacteria are mixed together in the integrated reactor, targeted cultivation based on their growth characteristics becomes impossible, easily leading to competition and making reactor operation difficult.

[0005] This invention provides a short-path nitrification-anaerobic ammonia oxidation integrated reactor, which achieves pH self-regulation and environmental control based on the growth characteristics of the microorganisms, thus ensuring stable system operation. Utility Model Content

[0006] To address the issues that two-stage short-cut nitrification-anaerobic ammonium oxidation reactors cannot achieve self-regulation of pH value, and that integrated reactors cannot be used for the cultivation of specific microorganisms, this invention provides an integrated short-cut nitrification-anaerobic ammonium oxidation reactor, taking into account the aforementioned background technology.

[0007] The reactor consists of four sections: a short-cut nitrification zone, a sponge iron zone, an anaerobic ammonium oxidation zone, and an autotrophic denitrification zone.

[0008] The short-cut nitrification zone is located at the bottom of the reactor, the anaerobic ammonium oxidation zone is located in the middle of the reactor, the autotrophic denitrification zone is located at the top of the reactor, and the sponge iron zone is located between the short-cut nitrification zone and the anaerobic ammonium oxidation zone.

[0009] The short-cut nitrification zone is equipped with short-cut nitrification packing material, which is polyethylene packing material. There are 2-10 packing chambers, and each packing chamber is filled with 1 / 3-4 / 5 of the packing material. The short-cut nitrification reaction takes place in this zone. The dissolved oxygen and pH value are controlled in this zone, with dissolved oxygen less than 1.5 mg / L and pH value 6.5-8.5.

[0010] The anaerobic ammonia oxidation zone is equipped with anaerobic ammonia oxidation packing material, which is polyurethane packing material. There are 1-5 packing compartments, and each compartment is filled with 1 / 3-4 / 5 of the packing material. Anaerobic ammonia oxidation reaction takes place in this zone.

[0011] The autotrophic denitrification zone is equipped with autotrophic denitrification packing material; the packing material is sulfur, and there are 1-3 packing compartments, each filled with 1 / 3-4 / 5 of the packing material volume, where the denitrification reaction takes place.

[0012] The sponge iron zone is filled with sponge iron to remove dissolved oxygen from the effluent of the short-cut nitrification zone.

[0013] The upper part of the sponge iron zone is equipped with an ammonia nitrogen probe, a nitrite nitrogen probe, and a dissolved oxygen probe. The short-range nitrification zone is equipped with a pH probe and a dissolved oxygen probe. Based on the data feedback from each probe, the dissolved oxygen and pH value of the reactor are adjusted by a programmable logic controller (PLC).

[0014] The integrated reactor is also equipped with a corresponding dosing pump and dosing tank.

[0015] The integrated reactor is equipped with an air outlet and a sludge discharge outlet at the top.

[0016] The device operates as follows: High ammonia nitrogen wastewater enters the bottom of the reactor via an influent pump. It first enters the short-cut nitrification zone, where microorganisms on the short-cut nitrification packing convert some ammonia nitrogen into nitrite nitrogen. Then, it enters the sponge iron zone to remove dissolved oxygen before entering the anaerobic ammonia oxidation zone. Microorganisms on the anaerobic ammonia oxidation packing remove the remaining ammonia nitrogen and nitrite nitrogen, while producing some nitrate nitrogen. The water containing nitrate nitrogen then enters the upper autotrophic denitrification zone, where microorganisms on the autotrophic denitrification packing remove nitrate nitrogen. The clean water is discharged from the drain outlet at the top of the reactor. The aeration rate at the bottom of the reactor is adjusted by a PLC.

[0017] The ammonia nitrogen concentration of the high ammonia nitrogen wastewater is 100-1000 mg / L.

[0018] The key feature of this invention is that traditional short-cut nitrification-anammox processes are two-stage. The initial short-cut nitrification reaction produces acid, causing a decrease in pH, while the subsequent anammox reaction consumes acid, causing an increase in pH. Both require additional chemicals for pH adjustment. Dissolved oxygen in the initial short-cut nitrification zone flows into the subsequent anammox zone, impacting the anammox bacteria. Furthermore, a high concentration of nitrite nitrogen in the initial short-cut nitrification effluent inhibits the subsequent anammox reaction, causing the system to malfunction. This invention provides an integrated short-cut nitrification-anammox reactor, placing both reactions in the same system. This allows for self-regulation of the system's pH, eliminating the need for additional chemical reagents and saving costs. The nitrite nitrogen produced by short-cut nitrification serves as the substrate for anammox, being produced and consumed simultaneously. The low concentration of nitrite nitrogen in the system does not inhibit the anammox reaction. Furthermore, a sponge iron zone connects the short-cut nitrification and anammox zones, eliminating dissolved oxygen in the short-cut nitrification zone and providing an anaerobic environment for the anammox zone, thus making the entire system more stable. In addition, this invention provides an integrated short-cut nitrification-anammox reactor with targeted environmental control based on the growth characteristics of different bacteria, ensuring optimal growth conditions for each bacteria and maintaining their activity, making the system more efficient. Moreover, the multi-layer packing design not only allows for more flexible design of the reactor height based on water quality characteristics, improving reactor utilization, but also ensures uniform water distribution, preventing short-circuiting and clogging common in fixed-bed reactors, and improving mass transfer between microorganisms on the packing and substances in the water. This invention also includes a denitrification zone at the top of the short-cut nitrification-anammox reactor to remove nitrate nitrogen produced by anammox, ensuring the effluent meets discharge standards. Attached Figure Description

[0019] Figure 1 is a schematic diagram of a short-path nitrification-anaerobic ammonium oxidation reactor.

[0020] Figure Labels

[0021] 1-Short-cut nitrification zone; 2-Anaerobic ammonia oxidation zone; 3-Autotrophic denitrification zone; 4-Short-cut nitrification packing; 5-Anaerobic ammonia oxidation packing; 6-Autotrophic denitrification packing; 7-Sponge iron; 8-Sampling port; 9-Air outlet; 10-Sludge inlet; 11-Inlet pump; 12-Aeration pump; 13-Inlet tank; 14-Dosing tank 1; 15-Dosing tank 2; 16-Outlet tank; 17-Nitrite nitrogen probe; 18-Ammonia nitrogen probe; 19-Dissolved oxygen probe; 20-Dissolved oxygen probe in short-cut nitrification zone; 21-pH probe in short-cut nitrification zone; 22-Dosing pump; 23-Dosing pump. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and examples:

[0023] Figure 1 shows a short-path nitrification-anaerobic ammonium oxidation reactor.

[0024] The reaction apparatus is shown in Figure 1. The operation process of this apparatus is described as follows:

[0025] Reactor Operation Flow Description: After biofilm formation, high-ammonia nitrogen wastewater from inlet tank 13 enters the bottom of the reactor via inlet pump 11. It undergoes short-cut nitrification via microorganisms on short-cut nitrification packing 4 in short-cut nitrification zone 1, where some ammonia nitrogen is oxidized to nitrite. The water then flows through sponge iron zone 7 to remove dissolved oxygen before entering anaerobic ammonia oxidation zone 2. In anaerobic ammonia oxidation zone 2, anaerobic ammonia oxidation occurs via anaerobic ammonia oxidation bacteria on anaerobic ammonia oxidation packing 5, removing ammonia nitrogen and nitrite nitrogen in proportion. The water then flows into autotrophic denitrification zone 3, where autotrophic denitrification occurs via autotrophic microorganisms on autotrophic denitrification packing 6, removing nitrate nitrogen. The treated water is discharged from the top outlet, and the gas generated by the system is discharged from the top of the reactor through gas outlet 9. Dissolved oxygen probe 20 in the short-cut nitrification zone detects dissolved oxygen, and the flow rate of aeration pump 12 is controlled by PLC to adjust the aeration rate at the bottom of the reactor. A pH probe 21 in the short-cut nitrification zone detects the pH value and monitors the reaction status. Nitrite nitrogen probe 17 and ammonia nitrogen probe 18 detect the nitrite nitrogen and ammonia nitrogen concentrations in the short-cut nitrification zone, respectively. The flow rates of dosing pumps 22 and 23 are then controlled by a PLC to adjust the ammonia nitrogen and nitrite nitrogen concentrations in the reactor.

[0026] Example 1

[0027] This invention utilizes a short-cut nitrification-anaerobic ammonia oxidation integrated reactor to treat simulated fertilizer plant wastewater. The reactor has a total volume of 48 L, with four packing chambers measuring 30 cm long, 20 cm wide, and 10 cm high. Two chambers are for short-cut nitrification, using commercially available polyethylene packing material (filled to 1 / 3 capacity); one chamber is for anaerobic ammonia oxidation, using polyurethane packing material (filled to 1 / 3 capacity); and one chamber is for denitrification, using sulfur packing material (filled to 1 / 3 capacity). Acclimated sludge is inoculated onto the packing material in batches. After inoculation, simulated fertilizer plant wastewater is pumped into the reactor through the inlet. The influent ammonia nitrogen concentration is 100 mg / L, nitrite nitrogen is less than 1.0 mg / L, and the hydraulic retention time in the reactor is 10 h. The total nitrogen content is measured to be less than 2.0 mg / L, and the total nitrogen removal rate is greater than 98%. The test data are shown in Table 1.

[0028] Example 2

[0029] This invention utilizes a short-cut nitrification-anaerobic ammonia oxidation integrated reactor to treat simulated fertilizer plant wastewater. The reactor has a total volume of 75 L, with eight packing chambers measuring 30 cm long, 20 cm wide, and 10 cm high. Four chambers are for short-cut nitrification, using commercially available polyethylene packing material at 3 / 5 capacity; two chambers are for anaerobic ammonia oxidation, using polyurethane packing material at 3 / 5 capacity; and one chamber is for denitrification, using sulfur packing material at 3 / 5 capacity. Acclimated sludge is inoculated onto the packing material in batches. After inoculation, simulated fertilizer plant wastewater is pumped into the reactor through the inlet. The influent ammonia nitrogen concentration is 300 mg / L, nitrite nitrogen is less than 1.0 mg / L, and the hydraulic retention time in the reactor is 10 h. The effluent total nitrogen content is measured to be less than 5.0 mg / L, and the total nitrogen removal rate is greater than 98%. The test data are shown in Table 2.

[0030] Example 3

[0031] This invention utilizes a short-cut nitrification-anaerobic ammonia oxidation integrated reactor to treat simulated fertilizer plant wastewater. The reactor has a total volume of 132 L, with each packing chamber measuring 30 cm long, 20 cm wide, and 10 cm high, comprising 18 chambers. Ten chambers are for short-cut nitrification using commercially available polyethylene packing material, filled to 4 / 5 capacity. Five chambers are for anaerobic ammonia oxidation using polyurethane packing material, also filled to 4 / 5 capacity. Three chambers are for denitrification using sulfur packing material, filled to 4 / 5 capacity. Acclimated sludge is inoculated onto the packing material in batches. After inoculation, simulated fertilizer plant wastewater is pumped into the reactor through the inlet. The influent ammonia nitrogen concentration is 1000 mg / L, nitrite nitrogen is less than 1.0 mg / L, and the hydraulic retention time in the reactor is 10 h. The effluent total nitrogen content is measured to be below 15.0 mg / L, with a total nitrogen removal rate greater than 98%. The test data are shown in Table 3.

[0032] As described above, although the embodiments illustrate the present invention, they should not be construed as limiting the present invention.

Claims

1. A short-cut nitrification-anammox integrated reactor, characterized in that: The reactor comprises four parts, a short-range nitrification zone (1), an anaerobic ammonia oxidation zone (2), an autotrophic denitrification zone (3) and a sponge iron zone (7), the short-range nitrification zone (1) is located at the bottom of the reactor, the anaerobic ammonia oxidation zone (2) is located in the middle of the reactor, the autotrophic denitrification zone (3) is located at the top of the reactor, and the sponge iron zone (7) is located between the short-range nitrification zone (1) and the anaerobic ammonia oxidation zone (2); The short-range nitrification zone (1) is provided with short-range nitrification fillers (4), the anaerobic ammonia oxidation zone (2) is provided with anaerobic ammonia oxidation fillers (5), and the autotrophic denitrification zone (3) is provided with autotrophic denitrification fillers (6).

2. The short-cut nitrification-anammox integrated reactor according to claim 1, characterized in that: The number of filler spaces in the short-range nitrification zone (1) is 2-10, and 1 / 3-4 / 5 volume of short-range nitrification fillers (4) is filled in each filler space, and the short-range nitrification fillers (4) are polyethylene fillers.

3. The short-cut nitrification-anammox integrated reactor according to claim 1, characterized in that: The number of filler spaces in the anaerobic ammonia oxidation zone (2) is 1-5, and 1 / 3-4 / 5 volume of anaerobic ammonia oxidation fillers (5) is filled in each filler space, and the anaerobic ammonia oxidation fillers (5) are polyurethane fillers.

4. The short-cut nitrification-anammox integrated reactor according to claim 1, characterized in that: The number of filler spaces in the autotrophic denitrification zone (3) is 1-3, and 1 / 3-4 / 5 volume of autotrophic denitrification fillers (6) is filled in each filler space, and the autotrophic denitrification fillers (6) are sulfur.

5. The short-cut nitrification-anammox integrated reactor according to claim 1, characterized in that: The top of the reactor is provided with a gas outlet (9) and a mud inlet (10).

6. The short-cut nitrification-anammox integrated reactor according to claim 1, characterized in that: The upper part of the sponge iron zone (7) is provided with a nitrite nitrogen probe (17), an ammonia nitrogen probe (18) and a dissolved oxygen probe (19).

7. The short-cut nitrification-anammox integrated reactor according to claim 1, characterized in that: The short-range nitrification zone (1) is provided with a short-range nitrification zone dissolved oxygen probe (20) and a short-range nitrification zone pH probe (21).

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