Method and device for treating wastewater by coupling autotrophic heterotrophic and anammox denitrification

Abstract

The present application relates to a wastewater treatment method and device for synchronous autotrophic-heterotrophic coupled anaerobic ammonia oxidation denitrification, the device comprising a SBR reactor and an aeration pump; the aeration pump is connected with the SBR reactor, used for adjusting the aeration intensity in the SBR reactor; a partition is arranged inside the SBR reactor; the partition divides the inside of the SBR reactor into two communicating parts along the longitudinal direction, a micro-aerobic functional area and a limited-oxygen functional area, so that the substances in the micro-aerobic functional area and the limited-oxygen functional area can flow to each other; the micro-aerobic functional area is used for oxygen-demanding bacteria metabolism, and the limited-oxygen functional area is used for anoxic bacteria metabolism. The present application realizes the cycle of NO2 ‑ -N by adjusting the aeration intensity, using the micro-aerobic and limited-oxygen environment, and the influent organic matter and nitrate by-products in the synchronous autotrophic-heterotrophic metabolism process, reduces the difficulty of NOB inhibition, and strengthens the anammox performance, and efficiently removes nitrogen.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of industrial wastewater treatment, and particularly relates to a wastewater treatment method and device for simultaneous autotrophic heterotrophic coupled anaerobic ammonia oxidation and denitrification. BACKGROUND

[0002] In view of the increasing urgency of energy-saving sewage treatment, promoting the development and application of new biological denitrification technology is the trend of mainstream municipal sewage denitrification treatment. The advantage of anaerobic ammonia oxidation (Anammox) process in realizing autotrophic biological denitrification without additional carbon source has attracted widespread attention. However, due to the lack of long-term stable NOB inhibition strategy, the accumulation of nitrate by-products seriously affects the denitrification efficiency, and due to the particularity of denitrification, the shortage of substrate NO2--N limits the application of anammox in mainstream municipal sewage. The coupling process of short-cut nitrification (PN), short-cut denitrification (PD) and endogenous short-cut denitrification (EPD) NO2--N supply route and anammox has become a hot topic.

[0003] PN coupled anammox (PN / A) is a completely autotrophic denitrification process, which has been widely used in the treatment of high-strength wastewater such as flow measurement liquid and landfill leachate. Compared with nitrification / denitrification, 100% organic matter is reduced, 90% sludge production is reduced, and 62.5% aeration energy consumption is reduced, which is considered to be the most potential application way of mainstream anammox. However, the relative growth rate of NOB will be accelerated at low temperature, and low NH4+-N concentration cannot produce high level of FA to effectively inhibit NOB. The stable maintenance of mainstream PN is more challenging under long-term operation. In addition, nitrate (NO3--N) is an inevitable by-product of the PN / A process. Theoretically, PN / A will produce 11.0% of nitrate, and the mainstream PN / A process will produce more without a stable NOB inhibition strategy. Therefore, effective strategies are needed to eliminate nitrate accumulation to ensure stable and efficient denitrification performance of the system.

[0004] Partial denitrification (PD) coupled with anammox (PD / A) has become a research hotspot in recent years, which can reduce nitrate to NO2--N with limited carbon source. PN / A and PD / A have complementary advantages, and the nitrate produced by PN / A can be converted to NO2--N by PD. The dual-channel nitrite supply of PN and PD is conducive to maintaining system stability and preserving anammox bacteria, which provides a feasible direction for the optimization of mainstream PN / A systems. In order to realize the synergistic metabolism of autotrophic and heterotrophic bacteria and fully utilize the influent organic matter and anammox for denitrification, some studies have coupled PN, PD and anammox by spatial distribution of aerobic / anaerobic in a step-feed reactor. Some studies have also sequentially coupled PN / A and PD / A by time distribution of aerobic / anaerobic in a single-stage sequencing batch reactor (SBR). At present, the coupling methods are roughly divided into two categories: one is to divide a reactor into multiple time-end batches, and the other is to divide multiple reactors into step feeds. Batch operation and step feed strategy have strict requirements for automatic control system, and multi-stage combined process undoubtedly increases construction space, operation difficulty and cost. At the same time, in practical application, the autotrophic bacteria in the aerobic stage will be adversely affected by the influent organic matter, and inevitably cause waste of organic matter. SUMMARY

[0005] To this end, the technical problem to be solved by the present application is to overcome the problems of lack of long-term stable NOB inhibition strategy in the prior art, serious accumulation of nitrate by-product affecting denitrification efficiency, high operation difficulty and high cost. In order to solve the above technical problems, the present application provides a wastewater treatment method and device for simultaneous autotrophic-heterotrophic coupled anaerobic ammonia oxidation denitrification, which optimizes system denitrification while eliminating the adverse effects of influent organic matter and by-product nitrate through the synergistic effect of simultaneous autotrophic-heterotrophic microorganisms.

[0006] In order to achieve the above purpose, the main technical solutions adopted by the present application include:

[0007] In a first aspect, the present application provides a wastewater treatment device for autotrophic and heterotrophic coupled anaerobic ammonia oxidation denitrification, comprising: an SBR reactor and an aeration pump; the aeration pump is connected with the SBR reactor, and is used for adjusting the aeration intensity in the SBR reactor; the SBR reactor is provided with an inlet and an outlet; wherein the wastewater to be treated enters the SBR reactor through the inlet, and the effluent in the SBR reactor is discharged through the outlet; the SBR reactor is inoculated with sludge; the sludge is used to bring the bacteria required for wastewater treatment into the SBR reactor; the SBR reactor is internally provided with a partition plate; the partition plate divides the interior of the SBR reactor into two communicating parts along the longitudinal direction, i.e. a micro-aerobic functional area and a limited-oxygen functional area, so that the substances in the micro-aerobic functional area and the limited-oxygen functional area can flow into each other; the micro-aerobic functional area is used for metabolism of oxygen-demanding bacteria, and the limited-oxygen functional area is used for metabolism of anoxic bacteria.

[0008] In an embodiment of the present application, the partition plate is connected with the inner wall of the SBR reactor on both sides, and a distance of a preset length is provided between the bottom of the partition plate and the bottom of the SBR reactor, and the top end of the partition plate is lower than the height of the liquid in the interior of the SBR reactor.

[0009] In an embodiment of the present application, the partition plate divides the interior of the SBR reactor into two areas with a volume ratio of 2:1 along the longitudinal direction where the partition plate is located, the micro-aerobic functional area is in the larger-volume area, and the limited-oxygen functional area is in the smaller-volume area.

[0010] In an embodiment of the present application, the inlet is connected with a peristaltic pump, and the wastewater to be treated enters the SBR reactor from the inlet through the peristaltic pump; the outlet is connected with the electromagnetic valve, and the electromagnetic valve is used to control the effluent time.

[0011] In an embodiment of the present application, the inlet is connected with a peristaltic pump, and the wastewater to be treated enters the SBR reactor from the inlet through the peristaltic pump; the outlet is connected with the electromagnetic valve, and the electromagnetic valve is used to control the effluent time.

[0012] In an embodiment of the present application, a porous aeration stone is arranged in the micro-aerobic functional area.

[0013] In one embodiment of the present application, the micro-aerobic functional area and the limited-oxygen functional area are provided with measuring instruments; the measuring instruments comprise a collection end and a display; the collection end is arranged in the liquid in the micro-aerobic functional area and the limited-oxygen functional area; the display is arranged outside the SBR reactor and is used for reading the values collected by the collection end; the measuring instruments comprise a PH measuring instrument and a DO measuring instrument; the PH measuring instrument is used for monitoring the PH value, and the DO measuring instrument is used for monitoring the DO value.

[0014] In a second aspect, the present application provides a wastewater treatment method for simultaneous autotrophic heterotrophic coupled anaerobic ammonia oxidation denitrification, which is applied to the wastewater treatment device for simultaneous autotrophic heterotrophic coupled anaerobic ammonia oxidation denitrification, and comprises the following steps: in a first preset time, the aeration flow rate in the SBR reactor is controlled to be 100-150 mL / min, the DO values in the micro-aerobic functional area and the limited-oxygen functional area are measured, and the DO values in the micro-aerobic functional area and the limited-oxygen functional area are less than 0.20 mg / L; the first preset time is 40 days; in a second preset time, the aeration flow rate in the SBR reactor is adjusted to 200-250 mL / min, and the aeration time is 5 h; the second preset time is 60 days; in a third preset time, the aeration flow rate in the SBR reactor is increased to 300-320 mL / min, and the aeration time is maintained at 5 h; and the third preset time is 60 days.

[0015] In one embodiment of the present application, in the first preset time, the water residence time in the SBR reactor is 7 hours; in the second preset time, the water residence time in the SBR reactor is 5 hours; and in the third preset time, the water residence time in the SBR reactor is 5 hours.

[0016] In one embodiment of the present application, four cycles are carried out in the SBR reactor every day, and each cycle comprises five stages of feeding, continuous aeration, sedimentation, water discharge and idling in sequence; the feeding stage lasts for 10 minutes, the continuous aeration stage lasts for 5 hours, the sedimentation stage lasts for 20 minutes, the water discharge stage lasts for 15 minutes and the liquid discharge rate is 50%, and the idling stage lasts for 15 minutes.

[0017] The above technical scheme of the present application has the following advantages compared with the prior art:

[0018] The wastewater treatment method and device for simultaneous autotrophic heterotrophic coupled anammox denitrification provided by the application are improved based on a baffle gas-lift reactor in an SBR reactor, a micro-aerobic functional area and a limited oxygen functional area are formed in the SBR reactor, and the micro-aerobic / limited oxygen alternating environment creates more suitable conditions for the synergistic metabolism of autotrophic-heterotrophic functional microorganisms; the application establishes an anammox system in the micro-aerobic / limited oxygen SBR reactor to treat municipal wastewater, adopts a continuous aeration operation mode, realizes the synergistic metabolism of autotrophic and heterotrophic bacteria through the regulation of aeration intensity and water retention time and the common induction of limited organic matter, fully utilizes the organic matter in the influent and anammox for denitrification, long-term and stable inhibits NOB, through the synergistic effect of simultaneous autotrophic-heterotrophic microorganisms, optimizes the denitrification performance while eliminating the adverse effects of the influent organic matter and byproduct nitrate; the application realizes the cycle of NO2 - -N in the process of simultaneous autotrophic-heterotrophic metabolism by using the influent organic matter and the byproduct nitrate, reduces the difficulty of NOB inhibition while strengthening the anammox performance, and realizes efficient denitrification. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to make the content of the application more easily and clearly understood, the application will be further described in detail below according to specific embodiments of the application and in combination with the drawings, in which

[0020] Figure 1 is a schematic diagram of the overall structure of the simultaneous autotrophic-heterotrophic coupled anammox denitrification device of the preferred embodiment of the application;

[0021] Figure 2 is Figure 1 a difference analysis diagram of internal microbial alpha diversity index of the simultaneous autotrophic-heterotrophic coupled anammox denitrification device;

[0022] Figure 3 is Figure 1 a denitrification pathway analysis diagram of the simultaneous autotrophic-heterotrophic coupled anammox denitrification device;

[0023] Figure 4 is Figure 1 an internal nitrogen transformation mechanism analysis diagram of the simultaneous autotrophic-heterotrophic coupled anammox denitrification device;

[0024] Figure 5 is a schematic diagram of the overall process of the simultaneous autotrophic-heterotrophic coupled anammox denitrification method of another embodiment of the application.

[0025] The description of the drawings is as follows: 1, first sampling port; 2, second sampling port; 3, third sampling port; 4, fourth sampling port; 5, fifth sampling port; 6, sixth sampling port; 7, SBR reactor; 8, water inlet tank; 9, water outlet tank; 10, aeration pump; 11, PH measuring instrument; 12, DO measuring instrument; 13, peristaltic pump; 14, electromagnetic valve; 15, partition. DETAILED DESCRIPTION

[0026] In order to better explain the present application, in order to facilitate understanding, the following specific embodiments are combined with the drawings, and the present application is described in detail. Although the exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a clearer, more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0027] In the first aspect, with reference to Figure 1 A preferred embodiment of the present application provides a synchronous autotrophic heterotrophic coupled anaerobic ammonia oxidation denitrification wastewater treatment device, comprising: an SBR reactor 7 and an aeration pump 10;

[0028] The aeration pump 10 is connected with the SBR reactor 7, which is used to adjust the aeration intensity in the SBR reactor 7; the SBR reactor 7 is provided with a water inlet and a water outlet; wherein the wastewater to be treated enters the SBR reactor 7 through the water inlet, and the effluent in the SBR reactor 7 is discharged through the water outlet; the SBR reactor 7 is inoculated with sludge; the sludge is used to bring the bacteria required for wastewater treatment into the SBR reactor 7; the SBR reactor 7 is internally provided with a partition 15; the partition 15 divides the inside of the SBR reactor 7 into two communicating parts along the longitudinal direction, i.e. a micro-aerobic functional area and a limited oxygen functional area, so that the substances in the micro-aerobic functional area and the limited oxygen functional area can flow to each other; the micro-aerobic functional area is used for oxygen-demanding bacteria metabolism, and the limited oxygen functional area is used for anoxic bacteria metabolism.

[0029] The partition 15 is connected with the inner wall of the SBR reactor 7 on both sides, and a distance of a predetermined length is provided between the bottom of the partition 15 and the bottom of the SBR reactor 7, and the top end of the partition 15 is lower than the height of the liquid inside the SBR reactor 7. The partition 15 divides the inside of the SBR reactor 7 into two areas with a volume ratio of 2:1 along the longitudinal direction where the partition 15 is located, the micro-aerobic functional area is in the larger volume area, and the limited oxygen functional area is in the smaller volume area.

[0030] The water inlet is connected with the peristaltic pump 13, and the sewage to be treated enters the SBR reactor 7 from the water inlet through the peristaltic pump 13; the water outlet is connected with the electromagnetic valve 14, and the electromagnetic valve 14 is used for controlling the water outlet time. The SBR reactor 7 is surrounded by a constant temperature part, and the constant temperature part is connected with a constant temperature controller, and the constant temperature controller is used for controlling the constant temperature part to maintain the temperature of the SBR reactor 7 at 30±1℃. The micro-aerobic functional area is provided with porous aeration stones. The micro-aerobic functional area and the oxygen-limited functional area are both provided with measuring instruments; the measuring instruments include collection ends and displays; the collection ends are arranged in the liquid in the micro-aerobic functional area and the oxygen-limited functional area; the displays are arranged outside the SBR reactor 7 and are used for reading the values collected by the collection ends; the measuring instruments include a PH measuring instrument 11 and a DO measuring instrument 12; the PH measuring instrument 11 is used for monitoring the PH value, and the DO measuring instrument 12 is used for monitoring the DO value.

[0031] In the embodiment, the SBR reactor 7, the water inlet pool 8, the aeration pump 10 and the water outlet pool 9 are arranged.

[0032] The water inlet pool 8, the aeration pump 10 and the water outlet pool 9 are connected with the SBR reactor 7 respectively; the SBR reactor 7 is provided with inoculated sludge; the SBR reactor 7 is provided with a partition plate 15; the partition plate 15 is connected with the inner wall of the SBR reactor 7 on both sides, and the internal space of the SBR reactor 7 is divided into a micro-aerobic functional area and an oxygen-limited functional area along the longitudinal direction; the micro-aerobic functional area is used for culturing aerobic bacteria, and the oxygen-limited functional area is used for culturing anoxic bacteria; the volume ratio of the micro-aerobic functional area to the oxygen-limited functional area is 2:1; the micro-aerobic functional area is provided with porous aeration stones; the micro-aerobic functional area and the oxygen-limited functional area are both provided with a PH measuring instrument 11 and a DO measuring instrument 12; the PH measuring instrument 11 is used for monitoring the PH value, and the DO measuring instrument 12 is used for monitoring the DO value. A distance of a preset length is arranged between the bottom of the partition plate 15 and the bottom of the SBR reactor 7, and the top end of the partition plate 15 is lower than the height of the liquid in the SBR reactor 7. The SBR reactor 7 is provided with a water inlet and a water outlet; the water inlet is connected with the water inlet pool 8, and the water outlet is connected with the water outlet pool 9; the water inlet and the water inlet pool 8 are provided with a peristaltic pump 13; the water outlet and the water outlet pool 9 are provided with an electromagnetic valve 14. The SBR reactor 7 is surrounded by a constant temperature part connected with a constant temperature controller, and the constant temperature controller is used for maintaining the temperature of the SBR reactor 7 at 30±1℃.

[0033] Specifically, in this embodiment, a modified SBR reactor 7 with a reaction volume of 21L is used for long-term operation in continuous aeration mode. The SBR reactor 7 has a height of 130cm and an inner diameter of 15cm. An internal partition 15, made of plexiglass, is installed inside the SBR reactor 7, with both sides embedded in the inner wall of the reactor. This partition divides the internal space of the SBR reactor 7 longitudinally into a microaerobic functional zone and an oxygen-limited functional zone. The microaerobic functional zone cultivates aerobic bacteria, while the oxygen-limited functional zone cultivates anaerobic bacteria. The volume ratio of the microaerobic functional zone to the oxygen-limited functional zone is 2:1 to ensure the synchronous and coordinated metabolism of autotrophic and heterotrophic microorganisms. The microaerobic functional zone of the SBR reactor 7 utilizes porous aeration stones to fully distribute air bubbles, ensuring oxygen mass transfer and fluidization of the reactor substrate. Both the microaerobic and oxygen-limiting functional zones are equipped with a pH meter 11 and a DO meter 12. The pH meter 11 is used to monitor the pH value, and the DO meter 12 is used to monitor the DO value. The DO value is the dissolved oxygen value. This application utilizes aeration power instead of mechanical stirring to mix the reaction substrate, further reducing operating energy consumption and process operation difficulty.

[0034] In this embodiment, a certain distance is maintained between the bottom of the baffle 15 and the bottom of the SBR reactor 7, and a certain distance is also maintained between the top of the baffle 15 and the liquid surface inside the SBR reactor 7, allowing the substances in the micro-aerobic functional zone and the oxygen-limited functional zone to circulate. In this embodiment, a distance of 10 cm is maintained between the bottom of the baffle 15 and the bottom of the SBR reactor 7.

[0035] The SBR reactor 7 is equipped with an inlet and an outlet. The inlet is connected to the inlet tank 8, and the outlet is connected to the outlet tank 9. A peristaltic pump 13 is installed between the inlets, and a solenoid valve 14 is installed between the outlet and the outlet tank 9. The solenoid valve 14 is used to control the water discharge time. The SBR reactor 7 is also connected to an aeration pump 10, which adjusts the aeration flow rate. A thermostat surrounds the SBR reactor 7 and is connected to a thermostat controller, which maintains the temperature of the SBR reactor 7 at 30±1℃. In this embodiment, the thermostat is a heating plate.

[0036] The SBR reactor 7 also contains inoculated sludge. In this embodiment, the inoculated sludge is a mixed activated sludge, comprising 500 mL of Anammox activated sludge and 2500 mL of ordinary activated sludge. The 500 mL of Anammox activated sludge was taken from an Anammox bioreactor that had been stably operating for 200 days prior, and the 2500 mL of ordinary activated sludge was taken from the Suzhou Fuxing Wastewater Treatment Plant. The initial MLSS and MLVSS of the sludge in the SBR reactor 7 are as follows: Figure 2 As shown in (b) of the diagram.

[0037] Synthetic influent, which is simulated domestic wastewater prepared by NH4Cl, sodium acetate and mineral elements, was fed into the tank 8. Sodium acetate, as the only source of COD, was introduced into the SBR reactor 7 by a peristaltic pump 13. The composition of the mineral elements was ( / L): KH2PO40.03g, MgSO4·7H2O 0.16g, CaCl20.08g and trace element solutions A and B 1mL. The pH was not controlled during the operation of the device and was stable at 7.4-8.2.

[0038] In a second aspect, referring to Figure 5 Another embodiment of the present application provides a wastewater treatment method for simultaneous autotrophic heterotrophic coupled anaerobic ammonia oxidation and denitrification, comprising:

[0039] S1, in the first preset time, the aeration flow rate in the SBR reactor is controlled to be 100-150mL / min, the DO values in the micro-aerobic functional area and the limited oxygen functional area are measured, and the DO values in the micro-aerobic functional area and the limited oxygen functional area are both less than 0.20mg / L; the first preset time is 40 days;

[0040] S2, in the second preset time, the aeration flow rate in the SBR reactor is adjusted to 200-250mL / min, and the aeration time is 5h; the second preset time is 60 days;

[0041] S3, in the third preset time, the aeration flow rate in the SBR reactor is increased to 300-320mL / min, and the aeration time is maintained at 5h; the third preset time is 60 days.

[0042] In the first preset time, the hydraulic retention time in the SBR reactor is 7 hours; in the second preset time, the hydraulic retention time in the SBR reactor is 5 hours; in the third preset time, the hydraulic retention time in the SBR reactor is 5 hours. In the first preset time, the hydraulic retention time in the SBR reactor is 7 hours; in the second preset time, the hydraulic retention time in the SBR reactor is 5 hours; in the third preset time, the hydraulic retention time in the SBR reactor is 5 hours.

[0043] Specifically, this application divides the entire operation cycle into three stages by controlling DO (dissolved oxygen) and continuous aeration time: Start-up stage (stage 1, days 1-40): Aeration flow rate is maintained at a low intensity, within the range of 100-150 mL / min. DO values ​​in both the microaerobic and oxygen-limiting zones are kept at low levels, ensuring that both are less than 0.20 mg / L to limit NOB proliferation. The hydraulic retention time is 7 hours. Optimization stage (stage 2, days 41-100): Aeration flow rate is optimized to 200-250 mL / min to enhance ammonia nitrogen removal performance. Aeration time is shortened to 5 hours to avoid excessive nitrification. The hydraulic retention time is also 5 hours. Stabilization stage (stage 3, days 101-160): Aeration flow rate is increased to 300-320 mL / min, aeration duration is maintained at 5 hours, and the hydraulic retention time is 7 hours.

[0044] For ease of description, this application will hereafter be referred to as "synchronous autotrophic-heterotrophic coupling anammox".

[0045] In this embodiment, the operating parameters at different stages during the entire operation of the device are shown in Table 1. Among them, DO... L The DO value of the microaerobic functional zone, DO R The DO value represents the oxygen-limiting functional zone, and the Aerobic duration represents the hydraulic retention time.

[0046] Table 1 Operating parameters at different stages

[0047]

[0048] Specifically, in each stage, the microaerobic and oxygen-limiting functional zones within SBR reactor 7 undergo four cycles per day. Each cycle includes a feeding stage, a continuous aeration stage, a settling stage, an effluent stage, and a rest stage. Specifically, the effluent stage has a discharge rate of 50%, the feeding stage lasts 10 minutes, the continuous aeration stage lasts 5 hours, the settling stage lasts 20 minutes, the effluent stage lasts 15 minutes with a discharge rate of 50%, and the rest stage lasts 15 minutes.

[0049] During the entire operation of the device, the synthetic feedwater in the inlet tank 8 enters the SBR reactor 7 through the peristaltic pump 13, the aeration pump 10 controls the aeration flow rate in the SBR reactor 7, the pH meter 11 in the micro-aerobic functional zone and the oxygen-limited functional zone monitors the pH value in the two functional zones respectively, the DO meter 12 in the micro-aerobic functional zone and the oxygen-limited functional zone monitors the DO value in the two functional zones respectively, and the effluent in the SBR reactor 7 enters the effluent tank 9 through the solenoid valve 14.

[0050] NH4 + -N is converted to NO2 - -N, NO2 - -N is converted to NO3 - -N, NO3 - -N is converted to N2 by anoxic bacteria in the limited oxygen zone, thus achieving the goal of denitrification; NO3 - -N is converted to NO2 - -N becomes the raw material of the micro-aerobic zone and is recycled, thus reducing the accumulation of nitrates and enabling the simultaneous and synergistic metabolism of autotrophic and heterotrophic functional microorganisms, which optimizes denitrification performance while eliminating the adverse effects of influent organic matter and byproduct nitrates.

[0051] In this embodiment, batch tests are conducted periodically to determine the specific biological activity of the sludge in each stage of the SBR reactor, including short-term nitrification, nitrite oxidation, anaerobic ammonia oxidation, denitrification, and nitrite reduction. Specifically, the tests include:

[0052] Specific Ammonia Oxidation Activity (SAOA): 100 mL of sludge is removed from the reactor and washed three times with deionized water to remove residual substrates. The gas flow is maintained at 500 mL / min to provide sufficient oxygen (DO > 3.5 mg / L). The initial pH is 7.5 ± 0.5. The influent NH4 + -N concentration is 50 mg / L. The test temperature is maintained at 30.0 ± 1.0°C during the test. The test is conducted three times, and water samples are collected periodically to determine the NH4 + -N concentration. The specific activity is represented by the maximum NH4 + -N degradation rate.

[0053] Specific Nitrite Oxidation Activity (SNOA): The test steps and methods are the same as the SAOA batch test, with the influent changed to 50 mg / L of NO2 - -N. Water samples are collected periodically to determine the NO2 - -N concentration. The specific activity is represented by the maximum NO2 - -N degradation rate.

[0054] Specific Anaerobic Ammonia Oxidation Activity (SAA): 100 mL of sludge is removed from the reactor and washed three times with deionized water to remove residual substrates. The initial pH is 7.5 ± 0.5. Prior to the test, high-purity N2 gas (> 99.99%) is used to wash out the oxygen in the sludge-water mixture to ensure anoxic conditions. The influent NH4 + -N concentration is 50 mg / L, corresponding to a NO2 - -N concentration of NH4 +1.32 times of the initial NH4 + -N concentration. The whole experiment was conducted in a water bath constant temperature shaker at 30.0±1.0℃ for three times, and water samples were collected periodically to determine NH4 + -N concentration. The specific activity was represented by the maximum NH4 - -N degradation rate.

[0055] Short-term denitrification activity (SDAA): The experimental steps and pretreatment method were the same as the SAA batch experiment, and the influent was 50mg / L of NO3 - -N and COD, corresponding to a COD concentration of 150mg / L. Water samples were collected periodically to determine NO3 - -N concentration. The specific activity was represented by the maximum NO3 - -N degradation rate.

[0056] Nitrite reduction activity (SNRA): The experimental steps and pretreatment method were the same as the SAA batch experiment, and the influent was 50mg / L of NO2 - -N and COD, corresponding to a COD concentration of 150mg / L. Water samples were collected periodically to determine NO2 - -N concentration. The specific activity was represented by the maximum NO2 + -N degradation rate.

[0057] After the end of the experiment, MLVSS was measured to calculate the specific reaction rate, and the remaining sludge was recovered to the reactor.

[0058] In this embodiment, in the stable stage (the third stage), the autotrophic and heterotrophic synergistic metabolic characteristics of the application were studied by in-situ experiment to determine the potential denitrification pathway; specifically including:

[0059] (1) In-situ experiment I: Micro-aerobic / limited oxygen SBR was carried out for 3 times in-situ experiment under continuous aeration mode. No heterotrophic metabolism was shown under the condition of influent without organic matter, and the autotrophic metabolic characteristics of the application were explored.

[0060] (2) In-situ experiment II: The reactor operating conditions were the same as in-situ experiment I, and 3 in-situ experiments were also carried out. The influent was increased with organic matter (COD / NH4 - -N=3.0), and the autotrophic-heterotrophic synergistic metabolism of the application was studied.

[0061] In this embodiment, the nitrite conversion rate and denitrification efficiency were calculated, and the nitrite conversion rate (NTR) and denitrification efficiency (NRE) were calculated by formula (1), (2):

[0062] NTR=NO2 - -N eff / (NO3 - -N inf –NO3 - -Neff ) x 100% (1)

[0063] NRE= (TIN inf -TIN eff ) / TIN inf x 100% (2)

[0064] where NO2 - -N eff is the effluent nitrite concentration (mg / L), NO3 - -N inf and NO3 - -N eff are the influent and effluent nitrate concentrations (mg / L), respectively. TIN inf and TIN eff are the influent and effluent total nitrogen concentrations (mg / L), respectively.

[0065] In this example, in order to understand the nitrogen and carbon conversion pathways in the device, the mass balance was determined according to the substrate degradation rate of each stable stage obtained from the batch experiment. Briefly, a small amount of sludge was taken from the SBR reactor 7 for substrate degradation rate batch test. The test steps are the same as the ex-situ activity batch test. The nitrification ammonia nitrogen degradation rate is set as V1; the nitrite oxidation nitrite degradation rate is set as V2; the anaerobic ammonia oxidation ammonia nitrogen degradation rate is set as V3; the denitrification nitrate degradation rate is set as V4; and the nitrite reduction rate is set as V5.

[0066] It is assumed that the reaction in the SBR reactor 7 ignores the biomass production, and the theoretical stoichiometric relationship of several biological activities in the reactor is shown in equations (3), (4), (5), (6), and (7):

[0067] Partial nitrification:

[0068] NH4 + + 1.238O2+ 0.04HCO3 - + 0.161CO2→ 0.96NO2 - + 0.04C5H7NO2+ 0.919H2O+ 1.919H + (3)

[0069] Nitrite oxidation:

[0070] NO2 - + 0.01NH4 + + 0.45O2+ 0.01HCO3 - + 0.01H2O+ 0.04CO2→ NO3 - + 0.01C5H7NO2 (4)

[0071] Anammox:

[0072] NH4 + +1.32NO2 - +0.066HCO3 - +0.13H + →1.02N2+0.26NO3 - +0.066CH2O 0.5 N 0.15 +2.03H2O(5)

[0073] Partial denitrification (PD):

[0074] 0.048NH4 + +NO3 - +0.37CH3COO - +0.32H + →NO2 - +0.048C5H7NO2+0.64H2O+0.5CO2 (6)

[0075] Nitrite reduction:

[0076] 0.12NH4 + +NO2 - +0.68CH3COO - +1.57H + →0.5N2+0.12C5H7NO2+1.62H2O+0.75CO2 (7)

[0077] Based on the above reactions and apparent reaction rates, the nitrogen conversion rates are calculated as shown in equations (8) to (18):

[0078] Ammonia nitrogen conversion:

[0079] R1 = (NH4 + -N Inf –NH4 + -N Eff ) x V1 / (V1 + V3) (8)

[0080] R2 = (NH4 + -N Inf –NH4 + -N Eff ) x V3 / (V1 + V3) (9)

[0081] Nitrite conversion:

[0082] R3 = R1 (10)

[0083] R4 = 1.32 x R2 (11)

[0084] R5 = (R3 - R4 - NO2 - -N Eff ) x V2 / (V2 + V5) (12)

[0085] R6 = (R3 - R4 - NO2 - -N Eff ) x V5 / (V2 + V5) (13)

[0086] R7 = R3 - R5 - R6 (14)

[0087] Denitrification:

[0088] R8 = R5 (15)

[0089] R9 = 0.26 x R2 (16)

[0090] R10 = R8 + R9 (17)

[0091] R11 = R4 - R7 (18)

[0092] wherein R1 is the consumption of NH4 + -N by partial nitrification; R2 is the consumption of NH4 + -N by anammox; R3 is the production of NO2 - -N by nitrification; R4 is the consumption of NO2 - -N by anammox; R5 is the consumption of NO2 - -N by nitrite oxidation; R6 is the consumption of NO2 - -N by nitrite reduction (NO2 - -N produced by nitrification); R7 is the supply of NO2 - -N by partial nitrification to anammox; R8 is the production of NO3 - -N by nitrite oxidation; R9 is the production of NO3 - -N by anammox; R10 is the consumption of NO3 - -N by denitrification; R11 is the supply of NO2 - -N by PD to anammox; NH4 + -N Inf and NH4 + -N Eff are the NH4 + -N concentrations of the influent and effluent; NO2 - -N Eff is the effluent NO2 - -N concentration.

[0093] In this example, the daily influent and effluent samples were analyzed for conventional carbon and nitrogen concentration indicators to evaluate the nutrient removal performance of the present application. NH4 + -N, NO2 - -N, NO3 - -N, COD, MLSS and MLVSS were measured as described in previous studies, and DO, temperature and pH were monitored by a pH / Oxi 340i analyzer (WTW, Germany).

[0094] Sludge samples were collected from the reactors on day 1, 40, 100 and 160 for high-throughput 16S rRNA sequencing analysis. To avoid the non-mixing difference of the samples in space, the first sampling port 1, the second sampling port 2, the third sampling port 3, the fourth sampling port 4, the fifth sampling port 5 and the sixth sampling port 6 were sampled from left to right on the SBR reactor 7, respectively, as shown in FIG. 1. In addition, the microbial correlation network was visualized by Cytoscape 3.10.1 to understand the cooperation and competition relationship between functional bacteria. Figure 1

[0095] In this example, the second sampling port 2 was used as the influent port, and the fifth sampling port 5 was used as the effluent port.

[0096] In the first stage (1-40 days), the present application was started with low aeration intensity (100-150 mL / min), and the DO R and DO L were 0.18 mg / L and 0.11 mg / L, respectively. Studies have shown that under DO limited conditions, the oxygen affinity of AOB is better than that of NOB. Therefore, starting with a lower DO level (<0.2 mg / L) is beneficial to limit the growth of NOB. After 20 days of operation, the effluent NH4 + -N and NO3 - -N concentrations were stabilized at 16.49±2.50 mg / L and 3.14±1.00 mg / L, respectively. The NRE was only 60.68±2.56%. The large amount of NH4 + -N present in the effluent was the main reason for the low NRE of the present application. The weak NH4 + -N removal performance indicates that the activity of AOB and AnAOB in the present application is low, and the growth is inhibited. The growth kinetics of aerobic heterotrophic bacteria (0.4-0.6 g VSS / g COD) and AOB (0.11-0.2 g VSS / g COD) shows that under the condition of high COD, the proliferating aerobic heterotrophic bacteria will compete with AOB for oxygen, inhibiting the activity of AOB, thereby affecting part of the nitrification performance. In addition, the proliferation of anoxic heterotrophic microorganisms increases the substrate competition, squeezing the survival space of slow-growing AnAOB.

[0097] ​To enhance the NH4 of this application + -N removal performance, in the second stage (41-100 days), the aeration intensity is increased to 200-250 mL / min. DO R With DO L The concentrations reached 0.27 mg / L and 0.12 mg / L respectively, and the increase in aeration intensity had no significant effect on DO in the oxygen-limited zone. After 35 days of operation, the NH4 in the effluent of this application was [data missing]. + -N decreased to 4.93±1.76 mg / L, NH4 + -N removal rate increased to 89.30±1.86%. Effluent NO3 - -N increased to 4.48±1.38 mg / L, effluent COD decreased to 22.23±3.86 mg / L, and NRE reached 80.44±1.53%. Increased aeration intensity optimized the ammonia oxidation performance of this application. Anaerobic ammonia oxidation and heterotrophic denitrification were not adversely affected by increased aeration intensity; on the contrary, their functional activity was enhanced by the stimulation of more substrate, which is consistent with the results of non-in-situ specific activity measurements.

[0098] In this embodiment, to further explore the autotrophic-heterotrophic synergistic metabolic potential of this application and improve the TIN removal rate, the aeration intensity was increased to 300-320 mL / min in the third stage (days 101-160). During the stable operation period from day 123 to day 160, the DO... R With DO L The concentrations were increased to 0.35 mg / L and 0.15 mg / L, respectively. DO L The NH4 level remains low, providing a suitable metabolic environment for anoxic microorganisms such as AnAOB. ​​The average effluent NH4 in this application... + -N as low as 0.17 mg / L, NO3 in effluent - -N remained stable at 4.26±0.73 mg / L, and the removal rates of NRE and COD were as high as 90.77±1.82% and 92.82±1.24%, respectively.

[0099] The above results demonstrate that, by controlling the aeration intensity, this application successfully achieved stable and efficient nitrogen removal via simultaneous autotrophic-heterotrophic coupling of Anammox in a microaerobic / oxygen-limited SBR. Throughout the experiment, DO... L All levels were at low levels (<0.2 mg / L), ensuring stable synergistic metabolism of aerobic and hypoxic microorganisms during continuous aeration.

[0100] In this embodiment, the microbial characteristics of this application were studied. After stable operation, the Shannon index decreased and the Simpson index increased, such as... Figure 2(a) and (b) showed. The start-up strategy of continuous low DO and micro-aerobic / limited oxygen operation led to the selective enrichment of species, and the microorganisms that were not adapted were gradually eliminated, and the microbial diversity of the present application decreased significantly. The Chao and Ace indices of microbial richness decreased significantly as shown in Figure 2 (c) and (d) showed that autotrophic and heterotrophic functional microorganisms in the present application proliferated synergistically and further dominated. This is consistent with the changes of MLSS and MLVSS during the operation of the present application.

[0101] Proteobacteria (25.59%-38.58%), Bacteroidota (14.72%-21.08%), Armatimonadota (1.35%-21.70%), Chloroflexi (6.34%-8.26%) and Nitrospirota (5.74%-8.30%) accounted for more than 75% of the microbial species at the phylum level in the present application. Proteobacteria was always the best phylum-level microorganism in the present application, which was not only closely related to nitrogen transformation and organic matter degradation in the present application, but also could provide secondary metabolites such as molybdenum cofactor and folic acid for the growth of AnAOB. Chloroflexi could degrade complex compounds, which meant that there was a release of biomass products in the present application. The abundance of Planctomycetota related to AnAOB showed relative stability, indicating that the system had stable and effective AnAOB retention potential. It is worth noting that Armatimonadota was involved in the ammonia oxidation process, and its abundance increased significantly from 1.35% to 21.70%, which meant the potential recovery of ammonia oxidation performance in the present application, which was consistent with the ex situ biological activity in the present application.

[0102] In the present application, AOB genus was the first nitrogen metabolism genus, which could provide key inter-species substrate NO2 - for autotrophic and heterotrophic denitrification processes. Nitrosomonas was a typical AOB genus detected in the present application, and its relative abundance was relatively stable, decreasing slightly from 0.94% (Day 1) to 0.81% (Day 160). In addition, another nitrifying bacteria genus Nitrospira dominated the NO2 -- N oxidation metabolism, which decreased significantly from 8.29% (Day 1) to 5.72% (Day 160). The low DO start-up and micro-aerobic / limited oxygen environment mediated autotrophic-heterotrophic metabolism. The present application effectively inhibited NOB during the operation of gradually increasing aeration intensity. Candidatus Brocadia and Candidatus Jettenia were the genera of AnAOB detected in the present application. The relative abundance of AnAOB increased significantly from 0.40%+0.0023% (Day 1) to 0.44%+0.23% (Day 160), and the present application had potential enrichment retention ability of AnAOB. Thauera (7.66%), Denitratisoma (1.18%), unclassified f Comamonadaceae (0.45%), and Ignavibacterium (0.33%) were the genera of exogenous denitrifying bacteria detected in the present application. The relative abundance of Thauera decreased from 12.29% (Day 1) to 7.66% (Day 160). The relative abundance of polyphosphate-accumulating organisms (PAOs) Dechloromonas decreased from 1.818% to 0.75%, and the relative abundance of glycogen-accumulating organisms (GAOs) Candidatus Competibacter increased significantly from 0.93% (Day 1) to 7.98% (Day 160). The high abundance of GAOs represented the excellent intracellular carbon source storage capacity and NO X - - N reduction capacity. In addition, GAOs have lower biomass production, and lower heterotrophic growth production has no negative effect on autotrophic bacteria, which is well supported by the change of MLVSS in the present application.

[0103] In the present embodiment, in order to further understand the changes of the coexistence relationship and interaction of functional microorganisms in the present application, network analysis was performed on the key functional bacterial genera at each stage.

[0104] During start-up, the interaction between key functional bacteria genera was enhanced, from 27 nodes and 30 edges to 30 nodes and 43 edges. And the symbiotic network showed stronger positive interaction, with the proportion of positive correlation increasing significantly from 56.67% to 88.37%. This shows that low DO start-up is an effective strategy to realize autotrophic-heterotrophic coupled Anammox. In addition, the number of nodes of AOB sub-network decreased, while the number of edges and the proportion of positive correlation increased, indicating that low DO limited AOB, but also stimulated the synergistic effect of AOB and other functional bacteria. The NOB sub-network was only associated with AOB after start-up, and NOB was successfully inhibited at low DO. It is worth noting that the AnAOB sub-network was enhanced, and the interaction object changed to GAOs (endogenous denitrifying bacteria genus). This is consistent with the potential multi-channel supply of nitrite in the application.

[0105] In the optimization phase, the increase of aeration intensity restored the strength of the autotrophic bacteria genus sub-network and stimulated the heterotrophic functional bacteria sub-network. Therefore, the key functional bacteria genus network of autotrophic-heterotrophic was enhanced. In addition, the decrease of the proportion of positive correlation and the increase of the clustering coefficient indicate that the interaction between autotrophic and heterotrophic functional bacteria genera becomes more balanced and close. This is the main reason for the significant improvement of the denitrification performance of the application.

[0106] In the stable operation phase, the nodes and edges of the key functional bacteria genus network of autotrophic-heterotrophic decreased. The increase of aeration intensity again caused a certain interspecific selection in the application, and the sub-networks of some functional bacteria genera (AOB, NOB, denitrifying bacteria genus) were challenged. This is consistent with the analysis of microbial community. However, the interaction between each functional bacteria genus in the key functional bacteria genus network became closer, and the stability and robustness of the network were improved. The synergistic metabolic potential of autotrophic-heterotrophic microorganisms in the application was stimulated. It is worth mentioning that the size, complexity and stability of the AnAOB sub-network were enhanced, which was due to the multiple interactions of AnAOB autotrophic-heterotrophic. In general, the strengthening of interspecific interaction of key functional bacteria genera is conducive to the function optimization and stability of the application. The dynamic balance between competition and cooperation of functional bacteria genera maintains the stability of microbial community, while realizing the efficient and stable nutrient removal performance of the application.

[0107] In this embodiment, in the synchronous autotrophic-heterotrophic coupled Anammox system of the application, the substrate NO2 -The primary source of nitrogen (N) is the nitrification process (PN), and the activity of key functional bacteria AOB and NOB affects PN stability. In the first stage, the reactor was started up with low DO (0.18 / 0.11 mg / L). NOB and AOB activities were significantly inhibited. SAOA and SAA were both higher than SNOA, with SAA increasing from 3.85 mgN / gVSS / h (Phase 0) to 5.15 mgN / gVSS / h (Phase I). Denitrification performance decreased slightly but still showed good activity. The relative abundance of the key AOB bacterium, *Candidatus Brocadia*, increased from 0.40% to 0.78%. Furthermore, in the batch tests of PD efficiency in this application, the NTR consistently remained above 45%, reaching a maximum of 50.67%. Figure 3 As shown, where, Figure 3 In the diagram, (a) represents Phase I (day 40), (b) represents Phase II (day 100), and (c) represents Phase III (day 160). These results indicate that the system has a multi-channel potential supply of nitrite.

[0108] During the optimization phase, the aeration intensity was increased to enhance oxygen mass transfer and improve the nitrification efficiency of this application. SAOA and SAA were significantly enhanced, both far exceeding SNOA. SAOA increased from 4.62 mg N / g VSS / h to 12.51 mg N / g VSS / h, and SAA significantly increased from 5.15 mg N / g VSS / h to 12.74 mg N / g VSS / h. The relative abundance of the relevant functional bacteria genus Nitrosomonas increased from 0.79% to 0.89%, indicating enhanced PN efficiency. However, the optimized PN process implies low NO3. - -N production, substrate stimulation caused a significant decrease in SDAA. The NTR of PD efficacy decreased to 24.87%-30.78%, as... Figure 3 As shown in (b) of this application, the denitrification supply pathway for nitrite is suppressed. However, with optimized autotrophic denitrification and good synergy of denitrification SNRA, the TIN removal rate of this application is further improved.

[0109] During the stable operation phase, oxygen supply was increased again to stimulate the autotrophic-heterotrophic metabolic potential of this application. Due to substrate limitation, the relative abundance of AOB remained stable at 0.81%-0.88%, and SAOA remained relatively stable. Sufficient oxygen stimulated NOB activity, with SNOA increasing from 5.96 mg N / g VSS / h to 8.77 mg N / g VSS / h. The increase in NOB activity increased NO3-. - -N production stimulated the denitrification supply pathway of nitrite, with SDAA significantly increasing to 13.20 mgN / gVSS / h. PD efficiency reached its peak, with NTR reaching a maximum of 69.42%, and consistently remaining above 60%. Figure 3Thauera (7.67%) and highly enriched endogenous denitrifier Candidatus Competibacter (7.98%) are the guarantee of excellent PD performance. The autotrophic-heterotrophic nitrite multi-channel supply reduces the requirement for NOB control and the threat of unstable NOB control, strengthens the Anammox performance, and enhances the stability of the mainstream anammox denitrification system.

[0110] To further understand the nitrogen conversion pathway and mechanism in the present application, the typical cycle analysis of the influent / outflow nitrogen concentration in the stable stage was carried out, and the mass balance of nutrients in the present application was evaluated based on the degradation rate and theoretical stoichiometric ratio obtained from batch tests. The analysis results show that Anammox and denitrification construct a simultaneous autotrophic-heterotrophic denitrification system. The dual coupling of PN and PD strengthens the Anammox denitrification contribution to 57.17%. The nitrite contribution of PN and PD is 39.12% and 60.88% respectively. At the same time, the contributions of aerobic oxidation and heterotrophic denitrification to COD removal are 53.29% and 46.71% respectively. Among them, the COD consumption ratio of nitrite reduction is 27.35%, and the COD consumption of PD process is 19.36%.

[0111] It is worth noting that the micro-aerobic / limited oxygen alternating environment adopted in the present application realizes the enrichment of endogenous denitrifier. The denitrifier in the present application changes from exogenous denitrifier to endogenous denitrifier, which changes the metabolic pathway of organic matter in the present application. Compared with exogenous denitrifier, the proliferation rate of endogenous denitrifier is lower, which can convert into slow-degradation organic matter such as PHAs, reducing the consumption of organic matter by aerobic oxidation. The enrichment of GAOs increases the organic matter input in the denitrification process, realizes the stable stage NO X - -N and COD removal. In addition, in the stable stage, PN / A without carbon source participation only removes 30.67% of TIN, and the nitrate accumulation amount is as high as 19.23 mg / L, which is undoubtedly the main reason limiting the successful implementation of the mainstream PN / A. After the introduction of carbon source, the present application successfully realizes the degradation of nitrate, and realizes higher ammonia nitrogen degradation (ΔNH4 + -N X ) during nitrate degradation. This further confirms the denitrification strengthening of anammox performance in the present application. Overall, in the present application, the introduction of organic matter does not have an inhibitory effect on autotrophic bacteria. On the contrary, the denitrifier uses organic matter and nitrate byproducts to strengthen the induction of anammox, which provides an optimization direction for the mainstream PN / A, and the synergy and symbiosis of autotrophic-heterotrophic microorganisms can realize the deep removal of nutrients.

[0112] The application realizes efficient denitrification of mainstream municipal wastewater by synchronous autotrophic-heterotrophic coupled anammox, and provides a new green and efficient path for mainstream municipal wastewater treatment, wherein the process is induced by limited organic matter and adjustment of aeration intensity. Based on anammox-mediated various new combined processes have been developed, and have been successfully applied to high NH4 + -N wastewater treatment. However, low temperature and low NH4 + -N mainstream conditions increase the difficulty of NOB inhibition, increase the potential negative impact of byproduct nitrate in long-term operation, and the application of mainstream anammox process still faces challenges. In the application, the synchronous autotrophic-heterotrophic metabolic process realizes the cycle of NO2 - -N by using influent organic matter and nitrate byproduct, reduces the difficulty of NOB inhibition, and strengthens the anammox performance. The synchronous autotrophic-heterotrophic induced anammox provides an optimization strategy for mainstream PN / A, and fully utilizing limited organic matter combined with strengthening anammox denitrification may be a promising way for mainstream application.

[0113] Reference Figure 4 As shown in the figure, the application establishes a device of synchronous autotrophic-heterotrophic coupled anammox in a micro-aerobic / limited oxygen SBR by aeration regulation and limited organic matter induction method, realizes stable and efficient denitrification of mainstream municipal wastewater, and the TIN removal rate is as high as 90.77±1.82%. The multi-channel supply of nitrite of autotrophy and heterotrophy strengthens the Anammox performance, realizes the enrichment and reservation of AnAOB, reduces the inhibition requirement of NOB and the threat of unstable control of NOB. The closer interaction between various functional bacteria is beneficial to stimulating the synergistic metabolic potential of autotrophic-heterotrophic microorganisms, and improving the performance and stability of the application. In general, the application can provide a stable optimization strategy for mainstream PN / A, and provide a potential technology for stable, green and efficient treatment of mainstream municipal wastewater.

[0114] Those skilled in the art will appreciate that embodiments of the application can be provided as methods, systems or computer program products. Accordingly, the application can be embodied in the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the application can be embodied in the form of a computer program product on one or more computer-usable storage media (including, but not limited to, disk memory, CD-ROM, optical memory, etc.) having computer usable program code embodied therein.

[0115] Obviously, various modifications and changes can be made to the present application by those skilled in the art without departing from the spirit and scope of the present application. Accordingly, it is intended that the present application encompass all such modifications and changes as fall within the scope of the claims and their equivalents.

[0116] Although the embodiments of the present application have been shown and described above, it is to be understood that the above-described embodiments are merely exemplary and are not to be taken in a limiting sense, but the scope of the present application is not to be understood to be limited to the above-described embodiments but can be variously modified, changed, replaced and altered by those skilled in the art within the scope of the present application.

Claims

1. A wastewater treatment method based on simultaneous autotrophic-heterotrophic coupled anaerobic ammonia oxidation denitrification, wherein the wastewater treatment device comprises: SBR reactor and aeration pump; The aeration pump is connected to the SBR reactor and is used to adjust the aeration intensity in the SBR reactor. The SBR reactor is provided with an inlet and an outlet; wherein, the wastewater to be treated enters the SBR reactor through the inlet, and the effluent from the SBR reactor is discharged through the outlet. The SBR reactor is inoculated with sludge; the sludge is used to introduce bacteria required for wastewater treatment into the SBR reactor. The SBR reactor is internally equipped with a baffle plate; the baffle plate longitudinally divides the interior of the SBR reactor into two interconnected parts: a microaerobic functional zone and an oxygen-limited functional zone, allowing substances to circulate between the two zones; the microaerobic functional zone is used for the metabolism of aerobic bacteria, and the oxygen-limited functional zone is used for the metabolism of anoxic bacteria; the wastewater treatment method is characterized by comprising: Within a first preset time period, the aeration flow rate in the SBR reactor is controlled at 100-150 mL / min, and the DO values ​​in the microaerobic functional zone and the oxygen-limited functional zone are measured, ensuring that the DO values ​​in both the microaerobic functional zone and the oxygen-limited functional zone are less than 0.20 mg / L; the first preset time period is 40 days. Within a second preset time period, the aeration flow rate in the SBR reactor is adjusted to 200-250 mL / min, and the aeration time is 5 hours; the second preset time period is 60 days. Within a third preset time period, the aeration flow rate in the SBR reactor is increased to 300-320 mL / min, and the aeration time is maintained at 5 hours; the third preset time period is 60 days. Within the first preset time period, the hydraulic retention time in the SBR reactor is 7 hours; within the second preset time period, the hydraulic retention time in the SBR reactor is 5 hours; within the third preset time period, the hydraulic retention time in the SBR reactor is 5 hours. The SBR reactor operates four cycles per day, and each cycle includes five stages in sequence: feeding, continuous aeration, settling, effluent, and idle. The feeding stage lasts for 10 minutes, the continuous aeration stage lasts for 5 hours, the settling stage lasts for 20 minutes, the effluent stage lasts for 15 minutes with a discharge rate of 50%, and the idle stage lasts for 15 minutes.

2. The wastewater treatment method for simultaneous autotrophic-heterotrophic coupled anaerobic ammonia oxidation denitrification according to claim 1, characterized in that: The baffle is connected to the inner wall of the SBR reactor on both sides, and there is a predetermined distance between the bottom of the baffle and the bottom of the SBR reactor. The top of the baffle is lower than the height of the liquid inside the SBR reactor.

3. The wastewater treatment method for simultaneous autotrophic-heterotrophic coupled anaerobic ammonia oxidation denitrification according to claim 2, characterized in that: The partition divides the interior of the SBR reactor into two regions with a volume ratio of 2:1 along the longitudinal direction of the partition. The micro-aerobic functional zone is located in the larger volume region, and the oxygen-limiting functional zone is located in the smaller volume region.

4. The wastewater treatment method for simultaneous autotrophic-heterotrophic coupled anaerobic ammonia oxidation denitrification according to claim 3, characterized in that: The inlet is connected to a peristaltic pump, through which the wastewater to be treated enters the SBR reactor; the outlet is connected to a solenoid valve, which is used to control the outlet time.

5. The wastewater treatment method for simultaneous autotrophic-heterotrophic coupled anaerobic ammonia oxidation denitrification according to claim 4, characterized in that: The SBR reactor is surrounded by a temperature-regulating element, which is connected to a temperature controller. The temperature controller is used to control the temperature-regulating element to maintain the temperature of the SBR reactor at 30±1℃.

6. The wastewater treatment method for simultaneous autotrophic-heterotrophic coupled anaerobic ammonia oxidation denitrification according to claim 4, characterized in that: The micro-aerobic functional zone is equipped with porous aeration stones.

7. The wastewater treatment method for simultaneous autotrophic-heterotrophic coupled anaerobic ammonia oxidation denitrification according to claim 5, characterized in that: Measuring instruments are installed in both the microaerobic functional zone and the oxygen-limiting functional zone; each measuring instrument includes a data acquisition terminal and a display; the data acquisition terminal is located inside the liquid in the microaerobic functional zone and the oxygen-limiting functional zone; the display is located outside the SBR reactor and is used to read the values ​​collected by the data acquisition terminal. The measuring instrument includes a pH meter and a DO meter; the pH meter is used to monitor the pH value, and the DO meter is used to monitor the DO value.

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