A device and method for continuous flow optimization determination of anaerobic ammonium oxidation activity

Abstract

The present invention relates to a device and method for continuously optimizing the determination of anaerobic ammonia oxidation activity, the device comprising: a temperature control unit, including a temperature control tank; a liquid inlet unit located in the temperature control tank; a reaction unit located in the temperature control tank, including an upflow columnar reactor, the liquid inlet unit being connected to the liquid inlet at the bottom of the upflow columnar reactor; a liquid outlet unit located on the side of the temperature control tank, the liquid outlet unit being connected to the liquid outlet on the side of the upflow columnar reactor; the determination method is based on the above-mentioned device. Compared with the prior art, the present invention simulates the continuous flow operation mode of the original reactor where the sludge is located, and belongs to an in-situ activity determination method. The present invention effectively avoids the impact inhibitory effect of the initial high substrate concentration on the sludge during the activity determination of anaerobic ammonia oxidation sludge in a continuous flow reactor, thereby improving the accuracy of the determination. In addition, the present invention can also adapt to the determination of anaerobic ammonia oxidation sludge with different activities by flexibly adjusting the hydraulic retention time and the influent substrate concentration, thereby having both flexibility and accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of biological denitrification treatment of sewage and wastewater, and in particular to a device and a method for continuously optimizing the determination of anaerobic ammonia oxidation activity. Background Art

[0002] The anaerobic ammonium oxidation process has attracted widespread attention in the field of biological denitrification of sewage and wastewater due to its characteristics such as high denitrification rate, low energy consumption and low greenhouse gas production. Its functional microorganisms, anaerobic ammonium oxidizing bacteria, use nitrite as an electron acceptor to oxidize ammonia into nitrogen gas under anoxic conditions. In the actual process treatment process, the activity of anaerobic ammonium oxidizing bacteria is easily inhibited by components such as organic matter, heavy metals and antibiotics in sewage and wastewater, thereby affecting the overall denitrification performance of the process. The denitrification performance of anaerobic ammonium oxidizing bacteria is usually characterized by measuring the specific anaerobic ammonium oxidation activity. Specific anaerobic ammonium oxidation activity (SAA) refers to the amount of nitrogen that can be denitrified per day by a unit concentration of anaerobic ammonium oxidation sludge, and the unit is gN·g-VSS. -1 ·d -1 Specific ANAMMOX activity is typically determined using a batch experiment. This involves injecting a substrate solution containing ammonia and nitrite at a specific concentration into a serum bottle containing the ANAMMOX sludge to be tested. The concentrations of the three nitrogen species (ammonia, nitrite, and nitrate) are then measured over the course of the reactor. The specific ANAMMOX activity is calculated from the ratio of the maximum total nitrogen removal rate to the sludge concentration.

[0003] Nitrogen in wastewater usually exists in the form of ammonia nitrogen, and the nitrite nitrogen content is relatively low. To solve the problem of the source of nitrite nitrogen, a short-cut nitrification-anaerobic ammonium oxidation coupled process (Partial Nitrification / Anammox, PN / A) is usually adopted. The front-end short-cut nitrification provides nitrite for anaerobic ammonium oxidation. In the actual scale PN / A process, nearly half of the reactors adopt the continuous flow operation mode due to the advantages of simple operation control, strong resistance to water quality fluctuations and high denitrification rate. In a continuous flow reactor (such as the expanded granular sludge bed EGSB), the influent is immediately diluted by the reflux after entering the reactor due to the backflow effect, making the substrate concentration in the reactor close to the effluent concentration, and the anaerobic ammonium oxidizing bacteria operate under low substrate conditions for a long time. However, the existing specific anaerobic ammonium oxidation activity determination mode (batch experiment) is similar to the substrate concentration variation pattern of the sequencing batch reactor (SBR) during the water inlet stage and the reaction stage, that is, a large amount of substrate is added at one time during the water inlet stage, and the substrate concentration in the reactor gradually decreases from high to low during the reaction stage. This is significantly different from the long-term low-substrate operation environment of anaerobic ammonium oxidation sludge under continuous flow. The use of batch experiments to determine the anaerobic ammonium oxidation activity in a continuous flow reactor is likely to cause the shock inhibitory effect of high substrate concentration on anaerobic ammonium oxidation bacteria, thereby affecting the accurate determination of anaerobic ammonium oxidation activity, and even causing the determination to fail, ultimately affecting the operation and regulation of the reactor. In addition, the difference in reactor operation mode may also cause the measured activity to be somewhat different from the actual activity under the continuous flow operation environment. Summary of the Invention

[0004] The present invention aims to overcome the drawback of batch experiments measuring anaerobic ammonium oxidizing (ANAMMOX) bacterial activity in a continuous flow reactor, where sludge is susceptible to shock inhibition by high substrate concentrations. The present invention provides a device and method for optimizing continuous flow ANAMMOX activity measurement. This device simulates the continuous flow operation mode of the original reactor containing the sludge, representing an in-situ activity measurement method. This effectively avoids the shock inhibitory effect of initial substrate concentration on ANAMMOX sludge, improving measurement accuracy. Furthermore, flexible adjustments to the hydraulic retention time and influent substrate concentration allow for measurement of ANAMMOX sludge with varying activity levels. This provides both flexibility and accuracy.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] One of the purposes of the present invention is to provide a device for continuously optimizing the determination of anaerobic ammonium oxidation activity, the device comprising:

[0007] A temperature control unit consisting of a temperature controller, a temperature control pool and a heating rod;

[0008] A liquid inlet unit located in the temperature-controlled tank;

[0009] The reaction unit located in the temperature-controlled pool includes an upflow column reactor (UCR) operating in a continuous flow mode, and the liquid inlet unit is connected to the liquid inlet at the bottom of the upflow column reactor;

[0010] The liquid outlet unit is located on the side of the temperature control pool, and the liquid outlet unit is connected to the liquid outlet on the side of the upflow column reactor.

[0011] Furthermore, the liquid inlet unit includes:

[0012] Liquid inlet container;

[0013] The liquid inlet pump is inserted into the liquid inlet container below the liquid level through one end of the liquid inlet pipe, and the other end is connected to the liquid inlet at the bottom of the upflow column reactor.

[0014] Furthermore, the liquid inlet unit is also provided with a first gas collecting assembly connected to the top of the liquid inlet container.

[0015] Furthermore, the reaction unit is further provided with a second gas collecting assembly connected to the top of the upflow columnar reactor.

[0016] Furthermore, the liquid outlet unit includes:

[0017] Discharge container;

[0018] The liquid discharge pump is connected to the liquid outlet on the side of the upflow columnar reactor through one end of the liquid discharge pipe, and the other end is inserted into the liquid discharge container.

[0019] Furthermore, the temperature control unit controls the temperature of the heating rod through a temperature controller to keep the temperature in the temperature control pool constant, thereby maintaining the temperature in the liquid inlet container and the upflow column reactor constant.

[0020] A second object of the present invention is to provide a method for determining anaerobic ammonium oxidation activity by continuous flow optimization, using the above-mentioned device for determining anaerobic ammonium oxidation activity by continuous flow optimization, comprising the following steps:

[0021] Step 1: Add the matrix solution into the liquid inlet container, add the anaerobic ammonium oxidation sludge to be tested that has been washed with the matrix-free solution and the matrix-free solution into the upflow column reactor, and preheat the temperature control tank to the specified temperature;

[0022] Step 2: Determine the hydraulic retention time in the initial stage, adjust the feed pump to the corresponding speed, and adjust the outlet pump speed to be slightly higher than the feed pump speed to ensure a constant liquid level in the upflow column reactor;

[0023] Step 3: taking out the collected liquid from the liquid outlet container at equal intervals, and measuring the pH, liquid volume, and concentrations of ammonia nitrogen, nitrite nitrogen, and nitric nitrogen;

[0024] Step 4: Calculate the actual hydraulic retention time based on the hourly liquid output and the effective volume of the upflow column reactor; then calculate the total nitrogen removal rate based on the ammonia nitrogen, nitrite nitrogen and nitrate nitrogen concentrations in the inlet and outlet liquids and the actual hydraulic retention time;

[0025] Step 5: After a hydraulic retention time, adjust the speed of the inlet pump and the outlet pump to shorten the hydraulic retention time, increase the total nitrogen load of the influent, and repeat steps 3 and 4;

[0026] Step 6: Repeat step 5 until the calculated total nitrogen removal rate begins to decrease, that is, the total nitrogen removal rate reaches an inflection point;

[0027] Step 7: Take out the measured anaerobic ammonium oxidation sludge in the upflow column reactor and use the national standard weight method to obtain the sludge concentration; the ratio of the maximum total nitrogen removal rate to the sludge concentration is the specific anaerobic ammonium oxidation activity of the measured anaerobic ammonium oxidation sludge.

[0028] Furthermore, in step one:

[0029] The matrix solution is a mixed solution of ammonium chloride, sodium nitrite and potassium bicarbonate that has been aerated with nitrogen to remove dissolved oxygen;

[0030] The matrix-free solution is a potassium bicarbonate solution that has been aerated with nitrogen to remove dissolved oxygen;

[0031] The concentration of potassium bicarbonate in the matrix solution and the matrix-free solution was equal.

[0032] Furthermore, a continuous flow optimization method for determining anaerobic ammonium oxidation activity comprises the following steps:

[0033] Step 1: Add the specified amount of ammonium chloride, sodium nitrite and potassium bicarbonate to prepare the matrix solution, and aerate with nitrogen to remove dissolved oxygen. Then add it to the liquid inlet container;

[0034] Step 2: Add a specified amount of potassium bicarbonate to prepare a matrix-free solution and aerate with nitrogen to remove dissolved oxygen;

[0035] Step 3: Take a certain amount of the anaerobic ammonium oxidation sludge to be tested, and wash it three times with a matrix-free solution to remove the matrix remaining on the anaerobic ammonium oxidation sludge to be tested;

[0036] Step 4: Add the cleaned anaerobic ammonium oxidation sludge to be tested into the upflow column reactor, then fill the upflow column reactor with the matrix-free solution, and then aerate with nitrogen to lower the liquid level to the liquid outlet to ensure that the headspace is an oxygen-free environment;

[0037] Step 5: Set the temperature controller to the specified temperature, turn on the heating rod, and heat the temperature control pool;

[0038] Step 6: Determine the initial hydraulic retention time and adjust the feed pump to the corresponding speed. Adjust the outlet pump speed slightly higher than the feed pump speed to ensure a constant liquid level in the upflow column reactor.

[0039] Step 7: Take out the collected liquid from the liquid outlet container at equal intervals, and measure the pH, liquid volume, and concentrations of ammonia nitrogen, nitrite nitrogen, and nitric nitrogen;

[0040] Step 8: Calculate the actual hydraulic retention time based on the hourly liquid output and the effective volume of the upflow column reactor, as shown in the following formula 1:

[0041]

[0042] Where: HRT is hydraulic retention time, h; V w is the effective volume of the upflow column reactor, mL; V eff is the liquid output per hour, mL.

[0043] Step 9: Calculate the total nitrogen load, total nitrogen removal rate, and total nitrogen removal efficiency based on the inlet and outlet liquid ammonia nitrogen, nitrite nitrogen, and nitrate nitrogen concentrations and the actual hydraulic retention time, as shown in the following equations 2 to 4:

[0044]

[0045]

[0046]

[0047] Where: NLR is the total nitrogen load, kg-N·m -3 ·d -1 ;c TINinf is the total nitrogen concentration of the matrix solution in the liquid inlet container, that is, the sum of the concentrations of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen, mg-N·L -1 ; NRR is the total nitrogen removal rate, kg-N·m -3 ·d -1 ;c TINeff The total nitrogen concentration of the liquid collected in the liquid outlet container, that is, the sum of the concentrations of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen, mg-N·L -1 ; NRE is total nitrogen removal rate, %.

[0048] Step 10: After a hydraulic retention time, adjust the speed of the inlet pump and the outlet pump to shorten the hydraulic retention time, and repeat steps 7, 8, and 9;

[0049] Step 11, repeating step 10 until the calculated total nitrogen removal rate begins to decrease, i.e., an inflection point appears;

[0050] Step 12: Take out the measured anaerobic ammonium oxidation sludge in the upflow column reactor, use the national standard weight method to obtain the dry sludge mass, and calculate the sludge concentration as shown in the following formula 5:

[0051]

[0052] Where: MLVSS is the sludge concentration, g-VSS·L -1 ;m d It is the dry sludge mass measured by the national standard weight method, g-VSS.

[0053] Step 13: The ratio of the maximum total nitrogen removal rate to the sludge concentration is the specific anaerobic ammonium oxidation activity of the measured anaerobic ammonium oxidation sludge, as shown in Formula 6 below;

[0054]

[0055] Where: SAA is the specific anaerobic ammonium oxidation activity, gN·g-VSS -1 ·d -1 ;NRR max is the maximum total nitrogen removal rate, kg-N·m -3 ·d -1 .

[0056] The temperature of the temperature controller is further set at 30-37°C, preferably 35°C.

[0057] Furthermore, the mass concentration ratio of ammonia nitrogen to nitrite nitrogen in the matrix solution is 1:1 to 1:1.3, preferably 1:1.2, and the mass concentration of potassium bicarbonate is 0.5 to 1.5 g·L -1 , preferably 1 g·L -1 .

[0058] Furthermore, the dissolved oxygen of the matrix solution and the matrix-free solution is controlled at 0.1 mg·L -1 The following is to avoid the inhibition of anaerobic ammonia-oxidizing bacteria by dissolved oxygen, which will affect the accuracy of the measurement.

[0059] Furthermore, the pH of the matrix solution and the matrix-free solution is controlled at 7 to 7.6, preferably at 7.

[0060] Compared with the prior art, the present invention has the following advantages:

[0061] 1) In the present invention, an upflow columnar reactor is used to simulate the continuous flow operation mode of the original reactor where the sludge is located. This is an in-situ measurement method, and the measured activity can better reflect the actual activity in the original reactor.

[0062] 2) The present invention utilizes a gentler and more stable water inlet method, effectively mitigating the impact of the influent substrate. Batch experiments are equivalent to injecting all nitrogen into the reaction unit at once, which can easily lead to impact inhibition due to high substrate concentrations and a long adaptation lag before the anaerobic ammonia-oxidizing bacteria react. This assay method, however, does not inject nitrogen into the system all at once. Instead, it is temporarily stored in a liquid inlet container and then sequentially injected into the system via a liquid inlet pump, effectively avoiding the impact of substrate concentration on the anaerobic ammonia-oxidizing sludge.

[0063] 3) In the present invention, a more stringent anaerobic environment can be provided for anaerobic ammonia oxidizing bacteria. Anaerobic ammonia oxidizing bacteria are anaerobic bacteria and are sensitive to dissolved oxygen. Since batch experiments need to be shaken on a shaker, the headspace gas above the serum bottle is in frequent contact with the matrix solution. Therefore, the headspace needs to be strictly anaerobic, otherwise the anaerobic ammonia oxidizing bacteria in the matrix solution will be inhibited. In contrast, the upflow column reactor used in this continuous flow experiment does not require a shaker to oscillate, which can significantly reduce the diffusion rate of the headspace gas into the liquid phase, and the nitrogen produced by the anaerobic ammonia oxidizing bacteria themselves also helps to discharge the gas in the liquid phase, thereby ensuring a more stringent anaerobic environment.

[0064] 4) In the present invention, sampling has a smaller impact on the reaction unit. Batch experiments require frequent sampling from the reaction unit (serum bottle), and each sampling will reduce the total volume of the matrix solution and change the mud-water ratio. Therefore, frequent sampling will affect the accurate determination of the three nitrogens, and ultimately the accurate determination of activity. On the other hand, the maximum total nitrogen removal rate in the batch experiment is obtained by linear regression fitting, and the sampling frequency needs to be increased to improve the fitting accuracy. In contrast, the water sample of this continuous flow determination method is removed from the liquid outlet container, which has no impact on the three nitrogen determination in the reaction unit (UCR reactor), thus having better accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 Schematic diagram of the device for continuous flow optimization determination of anaerobic ammonium oxidation activity in the present invention;

[0066] Figure 2 Graphs showing changes in NLR, NRR, NRE, and HRT at different stages in a) UCR10, b) UCR20, c) UCR30, and d) UCR50 reactors in Example 1;

[0067] Figure 3 NH4 in a) BT1 and b) BT2 in Example 2 + 、NO2 - 、NO3 - and TIN concentration versus time;

[0068] Figure 4The NRR, average NRR, pH and NO3 at different stages in a) UCR1 and b) UCR2 reactors in Example 3 are shown in Table 3. - Concentration change graph;

[0069] Numbers in the figure are as follows: 1-temperature controller, 2-temperature control tank, 3-heating rod, 4-first gas collecting assembly, 5-liquid inlet pipe, 6-liquid inlet container, 7-liquid inlet pump, 8-upflow column reactor, 9-anaerobic ammonia oxidation sludge to be tested, 10-second gas collecting assembly, 11-liquid outlet pump, 12-liquid outlet pipe, 13-liquid outlet container. DETAILED DESCRIPTION

[0070] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0071] Examples 1-3 were implemented by optimizing the apparatus and method for measuring anaerobic ammonium oxidation activity using continuous flow as described below.

[0072] 1. A device for continuous flow optimization determination of anaerobic ammonium oxidation activity, see Figure 1 , the device comprises:

[0073] A temperature control unit consisting of a temperature controller 1, a temperature control pool 2 and a heating rod 3;

[0074] A liquid inlet unit located in the temperature-controlled tank;

[0075] The reaction unit located in the temperature control tank includes an upflow column reactor 8, a second gas collection assembly 10 connected to the top of the upflow column reactor 8, and a liquid inlet unit connected to the liquid inlet at the bottom of the upflow column reactor 8;

[0076] The liquid outlet unit is located on the side of the temperature control pool, and the liquid outlet unit is connected to the liquid outlet on the side of the upflow column reactor 8.

[0077] The liquid inlet unit includes a liquid inlet container 6 and a liquid inlet pump 7. The liquid inlet pump 7 is inserted below the liquid level of the liquid inlet container 6 through a liquid inlet pipe 5 at one end and connected to the liquid inlet at the bottom of the upflow columnar reactor 8 at the other end. The liquid inlet unit also includes a first gas collection assembly 4 connected to the top of the liquid inlet container 6.

[0078] The liquid discharge unit includes: a liquid discharge container 13; a liquid discharge pump 11, wherein one end of the liquid discharge pump 11 is connected to the liquid outlet on the side of the upflow column reactor 8 through a liquid discharge pipe 12, and the other end is inserted into the liquid discharge container 13.

[0079] The temperature control unit controls the temperature of the heating rod 3 through the temperature controller 1 to keep the temperature in the temperature control pool 2 constant, thereby maintaining the temperature in the liquid inlet container 6 and the upflow column reactor 8 constant.

[0080] 2. A method for determining anaerobic ammonium oxidation activity by continuous flow optimization, using the above-mentioned apparatus for determining anaerobic ammonium oxidation activity by continuous flow optimization, comprises the following steps:

[0081] Step 1: Add the specified amount of ammonium chloride, sodium nitrite and potassium bicarbonate to prepare the matrix solution, and aerate with nitrogen to remove dissolved oxygen. Then add it to the liquid inlet container;

[0082] Step 2: Add a specified amount of potassium bicarbonate to prepare a matrix-free solution and aerate with nitrogen to remove dissolved oxygen;

[0083] Step 3: Take a certain amount of anaerobic ammonium oxidation sludge to be tested and wash it three times with a matrix-free solution to remove the matrix remaining on the anaerobic ammonium oxidation sludge;

[0084] Step 4: Add the cleaned anaerobic ammonium oxidation sludge to be tested into the upflow column reactor, then fill the upflow column reactor with the matrix-free solution, and then aerate with nitrogen to lower the liquid level to the liquid outlet to ensure that the headspace is an oxygen-free environment;

[0085] Step 5: Set the temperature controller to the specified temperature, turn on the heating rod, and heat the temperature control pool;

[0086] Step 6: Determine the initial hydraulic retention time and adjust the feed pump to the corresponding speed. Adjust the outlet pump speed slightly higher than the feed pump speed to ensure a constant liquid level in the upflow column reactor.

[0087] Step 7: Take out the collected liquid from the liquid outlet container at equal intervals, and measure the pH, liquid volume, and concentrations of ammonia nitrogen, nitrite nitrogen, and nitric nitrogen;

[0088] Step 8: Calculate the actual hydraulic retention time based on the hourly liquid output and the effective volume of the upflow column reactor, as shown in the following formula 1:

[0089]

[0090] Where: HRT is hydraulic retention time, h; V w is the effective volume of the upflow column reactor, mL; V eff is the liquid output per hour, mL.

[0091] Step 9: Calculate the total nitrogen load, total nitrogen removal rate, and total nitrogen removal efficiency based on the inlet and outlet nitrogen concentrations and the actual hydraulic retention time, as shown in the following equations 2 to 4:

[0092]

[0093]

[0094]

[0095] Where: NLR is the total nitrogen load, kg-N·m -3 ·d -1 ;c TINinf is the total nitrogen concentration of the matrix solution in the liquid inlet container, that is, the sum of the concentrations of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen, mg-N·L -1 ; NRR is the total nitrogen removal rate, kg-N·m -3 ·d -1 ;c TINeff The total nitrogen concentration of the liquid collected in the liquid outlet container, that is, the sum of the concentrations of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen, mg-N·L -1 ; NRE is total nitrogen removal rate, %.

[0096] Step 10: After a hydraulic retention time, adjust the speed of the inlet pump and the outlet pump to shorten the hydraulic retention time, and repeat steps 7, 8, and 9;

[0097] Step 11, repeating step 10 until the calculated total nitrogen removal rate begins to decrease, i.e., an inflection point appears;

[0098] Step 12: Take out the measured anaerobic ammonium oxidation sludge in the upflow column reactor, use the national standard weight method to obtain the dry sludge mass, and calculate the sludge concentration as shown in the following formula 5:

[0099]

[0100] Where: MLVSS is the sludge concentration, g-VSS·L -1 ;m d It is the dry sludge mass measured by the national standard weight method, g-VSS.

[0101] Step 13: The ratio of the maximum total nitrogen removal rate to the sludge concentration is the specific anaerobic ammonium oxidation activity of the measured anaerobic ammonium oxidation sludge, as shown in Formula 6 below;

[0102]

[0103] Where: SAA is the specific anaerobic ammonium oxidation activity, gN·g-VSS -1 ·d -1 ;NRR max is the maximum total nitrogen removal rate, kg-N·m -3 ·d -1 .

[0104] The mass concentration ratio of ammonia nitrogen to nitrite nitrogen in the matrix solution is 1:1.2, and the mass concentration of potassium bicarbonate is 1 g·L-1 After nitrogen aeration, the dissolved oxygen in both the matrix solution and the matrix-free solution was controlled at 0.1 mg·L -1 To prevent dissolved oxygen from inhibiting anaerobic ammonium oxidizing bacteria and affecting the accuracy of the assay, both the matrix solution and the matrix-free solution were adjusted to pH 7.0 with hydrochloric acid, and the temperature of the thermostat was set to 35°C.

[0105] The upflow column reactor (UCR) in continuous flow operation mode has an inner diameter of 40 mm, a total height of 160 mm, a liquid outlet height of 120 mm, and an effective volume of 150.8 mL.

[0106] Example 1:

[0107] NRR max The acquisition of is the key to calculate SAA, NRR max The acquisition of depends on selecting the appropriate amount of sludge. This example reflects the effect of different sludge amounts on the determination of the maximum total nitrogen removal rate under a given operating mode (influent substrate concentration and HRT fixation, i.e., NLR fixation).

[0108] The anaerobic ammonium oxidation sludge to be tested was taken from the EGSB reactor with an effective volume of 70L in the laboratory. The dominant bacterial genus was unclassified_f_Brocadiaceae with an abundance of 50.81%. The inlet container was filled with a substrate solution with a composition of NH4Cl (100mg-N·L -1 )、NaNO2(120mg-N·L -1 ) and KHCO3 (1g·L -1 ), after nitrogen aeration, the dissolved oxygen is less than 0.1 mg·L -1 , hydrochloric acid (3M) solution was added to adjust the pH to 7.0. Four identical UCR reactors were added with 10g, 20g, 30g and 50g of anaerobic ammonia oxidation wet sludge (washed three times with matrix-free solution), respectively, and named UCR10, UCR20, UCR30 and UCR50. The temperature of the temperature controller was controlled at 35°C. The four UCR reactors were operated in five stages. Before operation, matrix-free solution was first pumped into the UCR reactor, and then the inlet was switched to the matrix solution in the inlet container. From stage I to stage V, the HRT was gradually shortened and the influent nitrogen load (NLR) was increased. The HRT of the five stages and the corresponding influent flow rate and NLR are shown in Table 1 below. The duration of one HRT corresponding to the operation of each stage, that is, 0 to 3h is stage I (HRT = 3h, influent flow rate = 50.3mL·h -1 ); 3 to 5.5 h is stage II (HRT = 2.5 h, inlet flow rate = 60.3 mL·h -1); 5.5 to 7.5 hours is the third stage (HRT = 2 hours, liquid flow rate = 75.4 mL·h -1 ); 7.5 to 9 hours is the fourth stage (HRT = 1.5h, liquid flow rate = 100.5mL·h -1 ); 9-10h is stage V (HRT = 1h, liquid flow rate = 150.8mL·h -1 The effluent was collected every half hour, and the effluent volume and pH were measured. The concentrations of ammonia nitrogen, nitrite nitrogen, and nitrate nitrogen in the effluent were also determined. The actual HRT, NLR, NRR, and NRE were calculated using equations 1 to 4, respectively.

[0109] Table 1: Five-stage preset hydraulic retention time, corresponding inlet flow rate and total nitrogen load in continuous flow experiment

[0110]

[0111] The changes of NLR, NRR, NRE and HRT at different stages in UCR10, UCR20, UCR30 and UCR50 reactors are shown in the figure. Figure 2 a~d are shown. The average NLR and average NRR changes in each stage are shown in Table 2. In the UCR10 reactor, as the NLR increases, the NRR gradually decreases, indicating that the NLR in stage I exceeds the NRR of the measured anaerobic ammonium oxidation sludge max Since the NRR showed a gradual downward trend and no NRR inflection point was found, the average NRR of stage I cannot be used as the NRR. max , so the NRR cannot be derived max Similarly, in the UCR30 and UCR50 reactions, as the NLR increased, the NRR gradually increased, and no inflection point appeared even in the V stage, indicating that the NLR in the V stage had not yet exceeded the NRR of the measured anaerobic ammonium oxidation sludge. max Therefore, the NRR of stage V cannot be used as the NRR max In the UCR20 reactor, NRR gradually increases with the increase of NLR in stages I to IV. When NLR increases to stage V, NRR begins to decrease, and the NRR inflection point appears in stage V. Therefore, the NRR of the sludge measured in the UCR20 reactor is max 2.64 kg-N·m -3 ·d -1 .

[0112] According to the calculation of 95% moisture content of anaerobic ammonium oxidizing bacteria, the amount of dry sludge corresponding to 20g wet sludge is 1g-VSS. According to formulas 5 and 6, the SAA of the measured anaerobic ammonium oxidizing bacteria can be estimated to be 0.398gN·g-VSS -1 ·d -1 .

[0113] Table 2 Changes of average NLR and average NRR at each stage in UCR10, UCR20, UCR30 and UCR50 reactors

[0114]

[0115] Example 2:

[0116] The apparatus and method for optimizing continuous flow anaerobic ammonium oxidation (ANAMMOX) activity in this example are designed to overcome the drawback of batch experiments, which often result in inhibition by high-concentration substrates, when measuring ANAMMOX activity in a continuous flow reactor, thereby improving the accuracy of activity measurements. In this example, both continuous flow and batch experiments were used to measure ANAMMOX sludge activity in the same continuous flow reactor, and the results obtained by the two methods were compared.

[0117] Table 3 Preset hydraulic retention time, corresponding liquid flow rate and nitrogen load of the six stages in the continuous flow experiment

[0118]

[0119] The anaerobic ammonium oxidation (ANAMMOX) sludge was collected from a 70L EGSB reactor in the laboratory. The dominant bacterial genus was unclassified_f_Brocadiaceae, with an abundance of 50.81%. The continuous flow experiment was conducted using two identical UCR reactors, each containing 20g of wet sludge (washed three times without substrate solution). These reactors were designated UCR1 and UCR2. The substrate solution consisted of the same NH4Cl (100mg-N·L -1 )、NaNO2(120mg-N·L -1 ) and KHCO3 (1g·L -1 ), after nitrogen aeration, the dissolved oxygen is less than 0.1 mg·L -1 3 M hydrochloric acid solution was added to adjust the pH to 7.0. The temperature controller was set to 35°C. To shorten the total duration of the continuous flow experiment, the UCR1 and UCR2 reactors were operated in six stages. The initial HRT was reduced from 3 hours to 2.5 hours, and two additional stages with HRT = 1.25 hours and HRT = 0.75 hours were added. The HRTs for the six stages, along with the corresponding inlet flow rates and NLRs, are shown in Table 3. Before the run, the UCR reactors were again initially pumped with a substrate-free solution, followed by the inlet solution from the inlet container. From stage I to stage VI, the HRT was gradually shortened, increasing the inlet nitrogen load (NLR). The total experimental duration was shortened to 9 hours. The effluent was collected every half hour from stages I to III, and every 25, 20, and 15 minutes from stages IV, V, and VI, respectively. The effluent volume and pH were measured, and the concentrations of ammonia nitrogen, nitrite nitrogen, and nitrate nitrogen in the effluent were determined. The actual HRT, NLR, NRR and NRE were calculated according to formulas 1 to 4 respectively.

[0120] The average NLR and average NRR changes in each stage of the UCR1 and UCR2 reactors are shown in Table 4. The average NRR in UCR1 and UCR2 showed a trend of increasing first and then decreasing. Therefore, the NRR of UCR1 max 1.81 kg-N·m -3 ·d -1 , while the NRR of UCR2 max 1.93 kg-N·m -3 ·d -1 .

[0121] According to the national standard weight method and formula 5, the sludge concentrations MLVSS of UCR1 and UCR2 are 9.11 g-VSS·L -1 and 9.06g-VSS·L -1 According to formula 6, NRR max The SAA of the anaerobic ammonium oxidation sludge was calculated to be 0.206±0.010gN·g-VSS by using MLVSS. -1 ·d -1 .

[0122] Table 4 Changes of average NLR and average NRR in each stage of UCR1 and UCR2 reactors

[0123]

[0124]

[0125] The batch experiment was conducted using two identical serum bottles (BT1 and BT2) with an effective volume of 150.8 mL (total volume 200 mL). The configuration of the matrix solution and the matrix-free solution was exactly the same as that of the continuous flow experiment. BT1 and BT2 were also added with 20 g of wet sludge (washed three times with the matrix-free solution). The serum bottles were then filled with matrix solution and aerated with nitrogen until the liquid level in the serum bottles dropped to 150.8 mL to ensure an oxygen-free headspace. Finally, BT1 and BT2 were placed in a shaker with a preset temperature of 35°C and a rotation speed of 190 rpm. Water samples were taken from the serum bottles every half hour using a syringe to determine the concentrations of ammonia nitrogen, nitrite nitrogen, and nitrate nitrogen.

[0126] NH4 in BT1 and BT2 + ,NO2 - ,NO3 - The TIN concentration changes are shown in the figure Figure 3 As shown in a~b. In BT1 and BT2, the first 8 hours are in the adaptation lag period, and NH4 + and NO2 -The removal rates of anaerobic ammonium oxidizing bacteria are relatively slow. This is because the anaerobic ammonium oxidizing sludge is affected by the substrate shock inhibition. The anaerobic ammonium oxidizing sludge measured comes from the EGSB reactor in continuous flow operation. The anaerobic ammonium oxidizing bacteria operate in a low-concentration substrate and high-load environment in the EGSB reactor. Therefore, transferring the anaerobic ammonium oxidizing bacteria to a high-concentration substrate environment may be inhibited and require a certain adaptation period. After an 8-hour adaptation lag period, the anaerobic ammonium oxidizing bacteria enter the reaction period, and NH4 + and NO2 - The removal rate of BT1 was significantly improved, and the maximum total nitrogen removal rate appeared in 11-12h ( Figure 3 a), while BT2 appears at 8.5-9.5h( Figure 3 b) Linear regression analysis of the two TIN curves revealed that the maximum total nitrogen removal rates for BT1 and BT2 were 32.84 mg-N·L -1 ·h -1 and 45.76mg-N·L -1 ·h -1 According to the national standard weight method, the sludge concentrations of BT1 and BT2 were 8.47 g-VSS·L -1 and 8.36g-VSS·L -1 , which was significantly lower than the sludge concentration measured in UCR1 and UCR2 (p < 0.01). This suggests that during the first 8 hours (adaptation lag period), some anaerobic ammonia-oxidizing bacteria may have been inhibited, leading to sludge decay. According to Equation 6, the SAA measured in the batch experiment was 0.112 ± 0.027 gN·g-VSS. -1 ·d -1 , which was significantly lower than the SAA measured in the continuous flow experiment (p<0.05). Therefore, the use of batch experiments is likely to cause substrate shock inhibition, resulting in inaccurate or even underestimated anaerobic ammonia oxidizing bacteria activity, ultimately affecting the regulation and operation of the reactor.

[0127] Example 3:

[0128] The success of continuous flow experiments depends on NRR max The NRR in the UCR reactor needs to go through a trend of increasing first and then decreasing before the NRR can be obtained. max Therefore, it is necessary to timely control the trend of NRR. However, NRR requires the determination of NH4 + , NO2 - and NO3 - It can be calculated later, but it is difficult to monitor in real time. Therefore, it is necessary to find a more convenient and easy-to-measure alternative indicator to reflect the changing trend of NRR. Anaerobic ammonia oxidizing bacteria produce alkali and nitrate. In this embodiment, the pH or NO3 of the effluent is measured. - To determine the NRR change trend.

[0129] Based on Example 2, the pH and NO3 of the effluent were measured. - .like Figure 4 As shown, the pH and NO3 in UCR1 and UCR2 - The trend of change is highly consistent with that of NRR. In UCR1, the maximum values ​​of average NRR and pH both appeared in stage II, while NO3 - The highest concentration value appeared in stage III, slightly later than the average NRR ( Figure 4 a). In UCR2, the average NRR and NO3 - The maximum concentration of α appeared in stage III, while the maximum pH appeared in stage II, slightly earlier than the average NRR ( Figure 4 b) Considering pH measurement is better than NO3 - It is more convenient and recommended to determine the trend of NRR by measuring the pH change of the effluent. In actual continuous flow experiments, if the pH of the effluent decreases, the measurement can be stopped after one or two more stages, thus saving measurement time.

[0130] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other manner. Any person skilled in the art may utilize the above-disclosed technical content to modify or modify the present invention into equivalent embodiments. However, any simple modifications, equivalent variations, and modifications to the above embodiments that do not depart from the technical content of the present invention and are based on the technical essence of the present invention remain within the scope of protection of the present invention.

Claims

1. A method for determining anaerobic ammonium oxidation activity by continuous flow optimization, characterized in that: The continuous flow optimized anaerobic ammonium oxidation activity determination device includes: A temperature control unit consisting of a temperature controller (1), a temperature control pool (2) and a heating rod (3); A liquid inlet unit located in the temperature control pool (2); The reaction unit located in the temperature control pool (2) includes an upflow column reactor (8), and the liquid inlet unit is connected to the liquid inlet at the bottom of the upflow column reactor (8); A liquid outlet unit located on the side of the temperature control pool (2), the liquid outlet unit being connected to a liquid outlet on the side of the upflow columnar reactor (8); The liquid inlet unit comprises: Liquid inlet container (6); A liquid inlet pump (7), wherein one end of the liquid inlet pump (7) is inserted below the liquid level of the liquid inlet container (6) through a liquid inlet pipe (5), and the other end is connected to the liquid inlet at the bottom of the upflow column reactor (8); The liquid outlet unit comprises: Discharge container (13); A liquid outlet pump (11), wherein one end of the liquid outlet pump (11) is connected to the liquid outlet on the side of the upflow column reactor (8) through a liquid outlet pipe (12), and the other end is inserted into the liquid outlet container (13); The method for determining anaerobic ammonium oxidation activity includes the following steps: Step 1: Add the matrix solution into the liquid inlet container (6), add the anaerobic ammonia oxidation sludge to be tested (9) washed with the matrix-free solution and the matrix-free solution into the upflow column reactor (8), and preheat the temperature control tank to a specified temperature; Step 2: Determine the hydraulic retention time in the initial stage, adjust the feed pump (7) to the corresponding speed, adjust the speed of the discharge pump (11) to be slightly greater than the speed of the feed pump (7), and ensure that the liquid level in the upflow column reactor (8) is constant; Step 3: taking out the effluent collected in the effluent container (13) at equal intervals, and measuring the pH, effluent volume, and concentrations of ammonia nitrogen, nitrite nitrogen, and nitric nitrogen; Step 4: Calculate the actual hydraulic retention time based on the liquid output and the effective volume of the upflow column reactor (8); then calculate the total nitrogen removal rate based on the ammonia nitrogen, nitrite nitrogen and nitrate nitrogen concentrations of the inlet and outlet liquids and the actual hydraulic retention time; Step 5: After a hydraulic retention time, adjust the speed of the inlet pump (7) and the outlet pump (11) to shorten the hydraulic retention time, increase the total nitrogen load of the inlet water, and repeat steps 3 and 4; Step 6: Repeat step 5 until the calculated total nitrogen removal rate begins to decrease, that is, the total nitrogen removal rate reaches an inflection point; Step 7: Take out the anaerobic ammonium oxidation sludge (9) in the upflow column reactor (8), and use the national standard weight method to obtain the sludge concentration; the ratio of the maximum total nitrogen removal rate to the sludge concentration is the specific anaerobic ammonium oxidation activity of the anaerobic ammonium oxidation sludge.

2. The method for determining anaerobic ammonium oxidation activity by continuous flow optimization according to claim 1, characterized in that: The liquid inlet unit is further provided with a first gas collecting assembly (4) connected to the top of the liquid inlet container (6).

3. The method for determining anaerobic ammonium oxidation activity by continuous flow optimization according to claim 1, characterized in that: The reaction unit is further provided with a second gas collecting assembly (10) connected to the top of the upflow columnar reactor (8).

4. The method for determining anaerobic ammonium oxidation activity by continuous flow optimization according to claim 1, wherein: In step one: The temperature of the temperature controller is set at 30-37°C.

5. The method for determining anaerobic ammonium oxidation activity by continuous flow optimization according to claim 1, characterized in that: In step one: The matrix solution is a mixed solution of ammonium chloride, sodium nitrite and potassium bicarbonate that has been aerated with nitrogen to remove dissolved oxygen; The matrix-free solution is a potassium bicarbonate solution that has been aerated with nitrogen to remove dissolved oxygen; The concentration of potassium bicarbonate in the matrix solution and the matrix-free solution was equal.

6. The method for determining anaerobic ammonium oxidation activity by continuous flow optimization according to claim 5, characterized in that: The mass concentration ratio of ammonia nitrogen to nitrite nitrogen in the matrix solution is 1:1-1:1.3, and the mass concentration of potassium bicarbonate is 0.5-1.5 g·L -1 .

7. The method for determining anaerobic ammonium oxidation activity by continuous flow optimization according to claim 5, characterized in that: The dissolved oxygen in the matrix solution and the matrix-free solution was controlled at 0.1 mg·L -1 The pH of the matrix solution and the matrix-free solution is controlled at 7 to 7.6.

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