A method and device for real-time online in-situ determination of heterotrophic bacteria yield coefficient

Abstract

The present invention provides a method and device for real-time online in-situ determination of heterotrophic bacteria yield coefficient, comprising the following steps: S1: placing the device in a biological pond, and performing cleaning, rinsing, and sludge feeding within the device; S2: aerating the device and feeding sludge within the device. After a period of time, the aeration is turned off, a dissolved oxygen versus time curve is plotted, the sludge concentration is measured, and the specific respiration rate is calculated. When the specific respiration rate is less than or equal to 1 mgO2 / gMLVSS·h, step S3 is performed; otherwise, step S2 is repeated; S3: the aeration device within the device is turned on, and when the dissolved oxygen concentration is greater than or equal to 6 mg / L, the aeration is turned off. When the dissolved oxygen concentration is less than or equal to 6 mg / L, the device is dosed; S4: during the measurement phase, continuous monitoring is performed, and the specific respiration rate is calculated. If the specific respiration rate is less than or equal to 1 mgO2 / gMLVSS·h, the measurement process is terminated, and the heterotrophic bacteria yield coefficient is calculated. This method performs online in-situ detection within the biological pond, and the measurement results are accurate, with a small difference between the measured results and the true value.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage biological treatment, and in particular relates to a method and a device for real-time online in-situ determination of heterotrophic bacteria yield coefficient. Background Art

[0002] In the design and operation of sewage treatment plants, the sludge yield coefficient is a very important parameter. According to the research results of the International Water Association, the heterotrophic bacteria yield coefficient (Y H ) plays a major role in the calculation of sludge yield coefficient. H ) is the proportional constant between the growth rate of heterotrophic microorganisms and the degradation rate of substrates, and is defined as the amount of cell COD formed per 1g COD oxidized in wastewater. Therefore, the heterotrophic bacteria yield coefficient (Y H The accuracy of the value of ) is not only directly related to the calculation of sludge yield and oxygen demand, but also has a significant impact on the calculation of some wastewater component ratios and kinetic parameters. H It depends on the nature of the substrate and also on the microorganisms that perform the degradation. H There may be significant differences, so the heterotrophic bacteria yield coefficient Y of each sewage treatment plant was determined. H It is very necessary.

[0003] In addition, with the construction of smart sewage treatment plants, sewage treatment plant modeling and simulation technology has continued to develop. The ASM series of models published by the International Water Association has become the preferred mechanism model for most modeling workers. When using the ASM series of models for simulation, it is usually necessary to select parameters that have a significant impact on the reaction process for measurement, including the yield coefficient of heterotrophic bacteria (Y H ), so the yield coefficient of heterotrophic bacteria (Y H ) has important practical significance for the construction of smart sewage treatment plants.

[0004] Conventional heterotrophic bacteria yield coefficient Y H Most methods use laboratory tests, including the intermittent activated sludge method and the respirometry method. Laboratory tests are manual operations with complicated steps. Yield coefficients determined by different laboratories and different testers vary. It is difficult for general sewage treatment plants to meet the above monitoring conditions, and accuracy is difficult to guarantee, and the process is relatively complicated. In addition, the time from sampling to laboratory measurement is long, the biological pond environment cannot be restored, and real-time online in-situ measurement cannot be achieved. There is a gap between the measurement results and the true value. Summary of the Invention

[0005] In view of this, the present invention proposes a method and device for real-time online in-situ determination of heterotrophic bacteria yield coefficient, which has a simple method, accurate measurement, and low equipment technical requirements.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] A method for real-time online in-situ determination of heterotrophic bacteria yield coefficient comprises the following steps:

[0008] S1: Place the device in the biological pool mixed liquid to be measured, and clean, rinse, and add mud into the device;

[0009] S2: Aeration and sludge are introduced into the device. After a period of time, aeration is turned off, a dissolved oxygen versus time curve is plotted, sludge concentration is measured, and specific respiration rate is calculated. When the specific respiration rate is less than or equal to 1 mgO2 / gMLVSS·h, step S3 is performed, otherwise step S2 is repeated;

[0010] S3: The aeration device in the device is turned on. When the dissolved oxygen concentration is greater than or equal to 6 mg / L, the aeration is turned off. When the dissolved oxygen concentration is less than or equal to 6 mg / L, the device is dosing.

[0011] S4: During the measurement continuation phase, continuous monitoring is performed and the specific respiratory rate is calculated. If the specific respiratory rate is less than or equal to 1 mgO2 / gMLVSS·h, the measurement process is terminated and the heterotrophic bacteria yield coefficient is calculated.

[0012] A device for use with a method for real-time online in-situ determination of heterotrophic bacteria yield coefficient, comprising a reactor, a controller, a dissolved oxygen electrode, a sludge concentration electrode, an aeration device, a spraying device, a sodium acetate dosing device, a propenylthiourea dosing device, and a stirring device;

[0013] The reactor and the sludge concentration electrode are both arranged in the mixed liquid of the biological pool, and the sludge concentration electrode is electrically connected to the controller;

[0014] A tortuous exhaust pipe is provided at the bottom of the reactor;

[0015] The dissolved oxygen electrode is arranged in the reactor, and the dissolved oxygen electrode is electrically connected to the controller;

[0016] The aeration device is electrically connected to the controller, and the gas outlet end of the aeration device is arranged in the reactor;

[0017] The spray device is electrically connected to the controller, and the spray end of the spray device is arranged in the reactor;

[0018] The stirring device is electrically connected to the controller, and the stirring device is arranged in the reactor;

[0019] The sodium acetate dosing device and the propylene thiourea dosing device are electrically connected to the controller, and the dosing ends of the sodium acetate dosing device and the propylene thiourea dosing device are arranged in the reactor.

[0020] Furthermore, the equipment cleaning in step S1 includes the following steps: turning on the aeration component switch of the aeration device, closing the mud inlet pump valve on the reactor, and when the liquid inside the reactor is completely replaced by air, turning on the spray device switch of the spray device and the stirring device, and then starting to clean the dissolved oxygen electrode, the aeration head of the aeration device and the stirring device. After a period of time, the aeration device, the spray device and the stirring device are turned off;

[0021] And / or the rinsing and mud feeding in step S1 further include opening the mud feeding pump valve, and after the sludge liquid level is at the designated mud feeding port scale, the mud feeding pump valve is closed.

[0022] Furthermore, after the aeration assembly switch of the aeration device in step S2 is turned off, the dissolved oxygen electrode performs real-time detection and records the dissolved oxygen concentration in the reactor every 10 seconds. After recording 6 dissolved oxygen concentrations, a dissolved oxygen vs. time curve is plotted and the slope of the curve is calculated. The calculated slope value is the respiration rate.

[0023] The specific respiration rate is the ratio of the respiration rate to the volatile sludge concentration;

[0024] After continuous monitoring for 1 minute, the aeration component switch of the aeration device is turned on again. When the specific respiratory rate is less than or equal to 1 mgO2 / gMLVSS·h, step S3 is performed, otherwise step S2 is repeated.

[0025] Furthermore, the dosing in step S3 further includes starting a sodium acetate dosing pump and a propylene thiourea dosing pump;

[0026] And / or the drugs added in step S3 include sodium acetate and allylthiourea;

[0027] And / or the concentration of the device after the addition of propylene thiourea is 20 mg / L, and the F / M range after the addition of sodium acetate is 0.02-0.05 kgBOD / (kgMLVSS·d);

[0028] F is the COD concentration of soluble and easily degradable organic matter, in mg / L;

[0029] M is the volatile sludge concentration, in mg / L;

[0030] And / or the calculation formula of F / M is: ;

[0031] Where: F is the COD concentration of soluble and easily degradable organic matter, in mg / L;

[0032] M and MLVSS are both volatile sludge concentrations, expressed in mg / L;

[0033] C NaAc is the concentration of sodium acetate solution, in mg / L;

[0034] V NaAc is the volume of sodium acetate solution in ml;

[0035] V is the effective volume of the reactor, in L;

[0036] And / or the calculation formula of M and MLVSS is: MLVSS=MLSS*K;

[0037] M and MLVSS are both volatile sludge concentrations, expressed in mg / L;

[0038] K is the volatility ratio;

[0039] And / or where: F is the concentration of soluble degradable organic matter COD, in mg / L;

[0040] M and MLVSS are both volatile sludge concentrations, expressed in mg / L;

[0041] C NaAc is the concentration of sodium acetate solution, in mg / L;

[0042] V NaAc is the volume of sodium acetate solution in ml;

[0043] V is the effective volume of the reactor, in L;

[0044] And / or the calculation formula of M and MLVSS is: MLVSS=MLSS*K;

[0045] M and MLVSS are both volatile sludge concentrations, expressed in mg / L;

[0046] K is the volatility ratio;

[0047] and / or ;

[0048] C ATU is the concentration of allylthiourea solution, in mg / L;

[0049] V ATU is the volume of allylthiourea solution, in ml.

[0050] Furthermore, the continuing phase of step S4 includes the following steps:

[0051] A1: When the dissolved oxygen concentration is less than or equal to 2 mg / L, record the time and respiratory rate;

[0052] A2: Turn on the aeration component switch of the aeration device. When the dissolved oxygen concentration is greater than or equal to 6 mg / L, the aeration device is turned off. When the dissolved oxygen concentration is less than or equal to 6 mg / L, record the time and respiration rate after a period of time. When the dissolved oxygen concentration is less than or equal to 2 mg / L, repeat step A2. If the specific respiration rate is less than or equal to 1 mgO2 / gMLVSS·h, the measurement process is completed.

[0053] If the dissolved oxygen concentration is greater than 6 mg / L, it will lead to a waste of oxygen and increase operating costs. If the dissolved oxygen concentration is limited to less than or equal to 6 mg / L, it will result in too many aeration and oxygenation times during the measurement process, or cause the aerobic reaction process to be atypical. If the dissolved oxygen concentration is less than or equal to 2 mg / L, the aerobic conditions cannot be met.

[0054] Furthermore, and / or in step S4, continuously monitoring and recording the dissolved oxygen concentration further comprises:

[0055] The time when the measurement process ends is recorded as t n , the calculated OUR value is recorded as OURn;

[0056] The heterotrophic bacteria productivity coefficient is calculated as:

[0057] ;

[0058] Y H : heterotrophic bacteria productivity coefficient;

[0059] COD: COD equivalent of added sodium acetate;

[0060] OUR: The detection value during the measurement process; after the drug is added in step S3, this time is recorded as time 0, 60s later, the respiratory rate is recorded as OUR1, and the time is recorded as t1; the time when the measurement process ends is recorded as t n , the calculated OUR value is recorded as OURn;

[0061] OUR1 to OUR n The OUR values ​​between them are recorded as OUR1, OUR2, OUR n , the corresponding times are recorded as t1, t2...t n , during the period when the aeration equipment is turned on, the OUR value and SOUR value are not calculated;

[0062] t1: measurement start time;

[0063] t n : Measurement end time;

[0064] And / or after step S4, the equipment is also cleaned, the aeration component switch of the aeration device is turned on, the mud pump valve on the reactor is closed, and when the liquid inside the reactor is completely replaced by air, the spray device switch of the spray device is turned on, and the stirring device is turned on. At this time, the dissolved oxygen electrode, the aeration head of the aeration device and the stirring device are cleaned. After a period of time, the spray device is turned off, the stirring device is turned off, and the aeration device is turned off.

[0065] Furthermore, the aeration device includes an aeration component, an aeration component switch, and an aeration head. The aeration component is electrically connected to the controller, the aeration component is connected to the aeration head through a pipeline, and the aeration head is arranged in the reactor; the aeration component switch is arranged on the pipeline between the aeration component and the aeration head;

[0066] And / or the spray device includes a clean water pump, a spray device switch, a spray head, and a water inlet pipe. The clean water pump and the spray device switch are arranged on the water inlet pipe in sequence. One end of the water inlet pipe is connected to the water source, and the other end of the water inlet pipe is connected to the spray head. The spray head is arranged in the reactor, and the spray device switch is electrically connected to the controller.

[0067] Furthermore, the stirring device includes a stirrer, the stirrer is arranged in the reactor, and the stirrer is electrically connected to the controller;

[0068] And / or a mud inlet pipe is provided on one side of the reactor, a mud inlet pump valve is provided on the mud inlet pipe, and the mud inlet pump valve is electrically connected to the controller;

[0069] And / or the reactor is provided with a mud inlet scale.

[0070] And / or the controller is provided with a display, and the controller is electrically connected to the display.

[0071] Furthermore, the sodium acetate dosing device includes a sodium acetate solution storage tank and a sodium acetate dosing pump, the sodium acetate solution storage tank is connected to the reactor through a first drug inlet pipeline, and the sodium acetate dosing pump is arranged on the first drug inlet pipeline;

[0072] And / or the propylene thiourea dosing device includes a propylene thiourea solution storage tank and a propylene thiourea dosing pump. The propylene thiourea solution storage tank is connected to the reactor through a second drug inlet pipeline, and the propylene thiourea dosing pump is arranged on the second drug inlet pipeline.

[0073] Compared with the prior art, the method and device for real-time online in-situ determination of heterotrophic bacteria yield coefficient described in the present invention have the following advantages:

[0074] 1. This method performs online in-situ detection in the biological pool, the measurement results are accurate, and the overall operation is simple, which reduces the sampling steps and the difference between the measurement results and the true value is small.

[0075] 2. The test method of this patent is to combine a closed waterproof reactor with a computer system, based on the metabolic mechanism of heterotrophic microorganisms, to measure the heterotrophic bacteria yield coefficient Y H To achieve real-time, online, in-situ measurement, accurate "measurement start" and "measurement end" times must be set. Improper timing settings can result in the monitored OUR values ​​not representing the full OUR values ​​that should be monitored between the start and complete degradation of sodium acetate by heterotrophic microorganisms. This application is based on the same microbial state (endogenous respiration, with a respiration rate of less than or equal to 1 mgO₂ / gMLVSS·h). When the sludge in the reactor is in the endogenous respiration state, no soluble, readily degradable COD is present. At this point, sodium acetate is added and measurement begins. The microorganisms rapidly degrade the added sodium acetate, and catabolic and anabolic reactions occur in the reactor. When the microorganisms have completely degraded the sodium acetate, the sludge returns to the endogenous respiration state, meaning that no soluble, readily degradable COD is present in the reactor, and measurement ends. Throughout this process, the activated sludge microorganisms have completely degraded the added sodium acetate, and the reaction is complete. The OUR values ​​monitored by the system represent the full OUR values ​​that should be monitored between the start and complete degradation of sodium acetate by heterotrophic microorganisms. During the measurement process, aeration and oxygenation are used to ensure that the system is always in an aerobic state, thereby ensuring that the heterotrophic bacteria can completely and thoroughly degrade organic matter. In this application, the measurement process ends when the specific respiration rate is less than or equal to 1mgO2 / gMLVSS·h. This application uses the specific respiration rate to determine whether the measurement has ended, which can be more accurate.

[0076] 3. The COD value used in the calculation of the results of this application is the COD equivalent value of AaAc added to the reaction device at the beginning of the measurement. This value is a theoretical calculation value, and its accuracy is not affected by the experimental operation. When calculating the heterotrophic bacteria yield coefficient, the COD equivalent of sodium acetate is used for calculation. The COD value used in the calculation result is the laboratory measurement value of the samples taken before and after the test. The pretreatment of this application will be in the endogenous respiration state when the specific respiration rate in the reactor is less than or equal to 1mgO2 / gMLVSS·h. When the specific absorption rate value of the activated sludge is less than or equal to 1mgO2 / gMLVSS·h, it can fully explain that the activated sludge microorganisms at this time are in the endogenous respiration state, and there is no soluble and easily degradable COD in the activated sludge mixed liquor. The determination accuracy of the COD value has a very significant impact, so it has a very significant impact on the final Y H The calculation of will also have a significant impact. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0078] Figure 1 This is a schematic diagram of a process for real-time online in-situ determination of heterotrophic bacteria yield coefficient according to an embodiment of the present invention;

[0079] Figure 2 Schematic diagram of a device for real-time online in-situ determination of heterotrophic bacteria yield coefficient according to an embodiment of the present invention;

[0080] Figure 3 This is a schematic diagram of the respiratory rate curve described in Example 1 of the present invention.

[0081] Description of reference numerals:

[0082] 1. Reactor; 2. Mud feed pump valve; 3. Mud feed pump; 4. Dissolved oxygen electrode; 5. Sludge concentration electrode; 6. Agitator; 7. Aeration head; 8. Aeration component switch; 9. Aeration component; 10. Spray head; 11. Spray device switch; 12. Clean water pump; 13. Sodium acetate dosing pump; 14. Sodium acetate solution storage tank; 15. Propylene thiourea dosing pump; 16. Propylene thiourea solution storage tank; 17. Controller; 18. Display; 19. Maze drain pipe; 20. Biological pool mixed liquid. DETAILED DESCRIPTION

[0083] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0084] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0085] like Figure 1 As shown, the entire workflow is divided into six stages, and the work content of each stage is as follows:

[0086] Phase 1: Equipment Cleaning Phase—The aeration assembly switch 8 of the aeration device is turned on, and the mud pump valve 2 is closed. After T1, the liquid inside the reactor 1 is completely replaced with air. The spray device switch 11 of the spray device is turned on, and the stirring device is turned on. At this time, the dissolved oxygen electrode 4, aeration head 7, and stirrer 6 are cleaned. After T2, the spray device switch 11 of the spray device is turned off. Entering Phase 2.

[0087] The agitator 6 is a submersible agitator, and the agitator adopts the existing technology.

[0088] The second stage: equipment rinsing and mud feeding stage - mud feeding pump valve 2 is opened, and mud feeding pump valve 2 is closed after T3 time. At this time, the sludge liquid level is at the designated mud inlet scale (the flow setting of the mud feeding pump valve: the suction volume within T3 time is greater than 4L 。 ) enters the third stage.

[0089] The second stage is the equipment rinsing and mud filling stage. The suction volume is greater than 4L to ensure that the equipment can be rinsed three times before mud filling. Good rinsing effect is conducive to ensuring the accuracy of the measurement process.

[0090] Stage 3: Pretreatment—The aeration system's aeration switch 8 is turned on, and the mud pump valve 2 is opened. After time t4, the aeration system is shut down, and the dissolved oxygen electrode 4 begins real-time monitoring, recording the dissolved oxygen concentration (DO) in the reactor every 10 seconds. After every six DO values, the system plots a DO vs. time curve and uses linear regression analysis to calculate the slope. The calculated slope is the single respiration rate (OUR), and the ratio of the OUR to the volatile sludge concentration (MLVSS) is the specific respiration rate (SOUR). Monitoring continues for one minute, and the aeration system is turned on again. This process repeats until the monitored specific respiration rate (SOUR) is less than or equal to 1 mgO2 / gMLVSS·h. This enters Stage 4.

[0091] Draw a dissolved oxygen vs. time curve every 6 DO records to get a OUR value: H According to the measurement principle, generally speaking, the higher the recording frequency of OUR values, the more ideal the final OUR integral curve will be, and the OUR value is the rate of change of DO values ​​within a period of time. If this period of time is too long, the number of OUR values ​​obtained will be too small, which is not conducive to the accurate calculation of the final parameters. On the contrary, if this period of time is too short, the dissolved oxygen DO may not change significantly in the slow reaction stage, and the OUR calculation may have a large error. In this method, the OUR value is calculated once every 6 DO values ​​are recorded, which means that this method takes this period of time as 1 minute, which means that the changes in the respiration rate of activated sludge microorganisms in each minute are examined. Our long-term test verification shows that this time not only ensures that the data volume of OUR values ​​is sufficient, but also avoids the problem of large OUR calculation errors in the slow reaction stage.

[0092] Stage 4: Measurement Start—Open the aeration assembly switch 8 of the aeration device until the dissolved oxygen concentration (DO) reaches 6 mg / L or higher. Then, close the aeration assembly switch 8. When the dissolved oxygen concentration (DO) reaches 6 mg / L or lower, start the sodium acetate dosing pump 13 and the propylene thiourea dosing pump 15 to simultaneously add propylene thiourea (ATU) and sodium acetate. (The ATU concentration after addition is 20 mg / L, and the F / M ratio after sodium acetate addition is in the range of 0.02-0.05 kgBOD / (kgMLVSS·d) (F / M = BOD / MLVSS). This time is recorded as time 0, the start of the measurement. The respiration rate (OUR) after 60 seconds is recorded as OUR1, and the time is recorded as t1, marking the beginning of the fifth stage.

[0093] The fifth stage: continuous measurement stage - continuous monitoring and automatic recording by the computer of changes in dissolved oxygen concentration (DO value), sludge concentration, respiration rate (OUR value) and specific respiration rate (SOUR value). When the dissolved oxygen concentration (DO value) is less than or equal to 2 mg / L, the time t at this time is recorded, and the respiration rate (OUR value) at this time is calculated. The aeration and oxygenation stage begins, that is, the aeration device is turned on and the calculation of the respiration rate (OUR value) is stopped. When the dissolved oxygen concentration is greater than or equal to 6 mg / L, the aeration device is turned off. When the dissolved oxygen concentration (DO value) drops to less than or equal to 6 mg / L, the time t is recorded 60 seconds after this moment, and the respiration rate (OUR value) is calculated. 。 Continue to monitor continuously and the computer will automatically record the changes in dissolved oxygen concentration (DO value), respiration rate (OUR value) and specific respiration rate (SOUR value). If the dissolved oxygen concentration (DO value) monitored by the system is less than or equal to 2 mg / L, a new round of aeration and oxygenation process will begin. During the real-time monitoring process of the system, if the specific respiration rate (SOUR value) monitored by the system at a certain moment is less than or equal to 1 mgO2 / gMLVSS·h, the measurement process ends and the time at this time is recorded as t n The calculated OUR value is recorded as OUR n . (From OUR1 to OUR n The OUR values ​​between them are recorded as OUR1, OUR2, OUR n , the corresponding times are recorded as t1, t2...t n . During the period when the aeration equipment is turned on, the OUR value and SOUR value are not calculated. ) Enter the sixth stage.

[0094] Stage 6: Equipment Cleaning—The aeration unit's aeration switch 8 is turned on, and the mud pump valve 2 is closed. After time T1, the liquid inside reactor 1 is completely replaced with air. The spray unit's spray switch 11 is turned on, and the agitator is turned on. Cleaning of the dissolved oxygen electrode 4, aeration head 7, and agitator 6 begins. After time T2, the spray unit's spray switch 11 is turned off, and the agitator and aerator are turned off. After time T0, the next round of testing begins, entering Stage 1 (T0 is the equipment idle time, generally set to 1 hour).

[0095] like Figure 2 As shown, a device used in conjunction with a method for real-time online in-situ determination of heterotrophic bacteria yield coefficient includes a reactor 1, a controller 17, a dissolved oxygen electrode 4, a sludge concentration electrode 5, an aerator, a spraying device, a sodium acetate dosing device, a propylene thiourea dosing device, and a stirring device; the reactor 1 and the sludge concentration electrode 5 are both arranged below the biological pool mixed liquid 20, and the sludge concentration electrode 5 is electrically connected to the controller 17; a maze-shaped drain pipe 19 is provided at the bottom of the reactor 1; the dissolved oxygen electrode 4 is arranged in the reactor 1, and the dissolved oxygen electrode 4 is electrically connected to the controller 17; the aerator is electrically connected to the controller 17, and the air outlet end of the aerator is arranged in the reactor 1; the spraying device is electrically connected to the controller 17, and the spraying end of the spraying device is arranged in the reactor 1; the stirring device is electrically connected to the controller 17, and the stirring device is arranged in the reactor 1; the sodium acetate dosing device and the propylene thiourea dosing device are electrically connected to the controller 17, and the dosing ends of the sodium acetate dosing device and the propylene thiourea dosing device are arranged in the reactor 1.

[0096] The aeration device includes an aeration component 9, an aeration component switch 8, and an aeration head 7. The aeration component 9 is electrically connected to the controller 17. The aeration component 9 is connected to the aeration head 7 through a pipe. The aeration head 7 is arranged in the reactor 1; the aeration component switch 8 is arranged on the pipe between the aeration component 9 and the aeration head 7; the spray device includes a clean water pump 12, a spray device switch 11, a spray head 10, and a water inlet pipe. The clean water pump 12 and the spray device switch 11 are arranged on the water inlet pipe in sequence. One end of the water inlet pipe is connected to the water source, and the other end of the water inlet pipe is connected to the spray head 10. The spray head 10 is arranged in the reactor 1, and the spray device switch 11 is electrically connected to the controller 17.

[0097] The stirring device includes an agitator 6, which is disposed within the reactor 1 and electrically connected to a controller 17. A mud inlet pipe is provided on one side of the reactor 1, which is equipped with a mud pump 3 and a valve 2, which are electrically connected to the controller 17. A mud inlet scale is provided on the reactor 1. A display 18 is provided on the controller 17, which is electrically connected to the display 18. The sodium acetate dosing device includes a sodium acetate solution storage tank 14 and a sodium acetate dosing pump 13, which are connected to the reactor 1 via a first drug inlet pipe and are located on the first drug inlet pipe. The propylene thiourea dosing device includes a propylene thiourea solution storage tank 16 and a propylene thiourea dosing pump 15, which are connected to the reactor 1 via a second drug inlet pipe and are located on the second drug inlet pipe. In the specific implementation process, the waterproof grade of the whole device is IPX-8, the material of the reactor 1 can be metal or plastic with good thermal conductivity, the dissolved oxygen electrode 4 adopts a HANIC optical dissolved oxygen sensor, and the controller 17 adopts the existing PLC technology.

[0098] Example 1

[0099] Measurement object: Heterotrophic bacteria yield coefficient in the aeration tank of a sewage treatment plant.

[0100] Test process:

[0101] In the first step, a sodium acetate solution with a concentration of 20 mg / mL and an allylthiourea (ATU) solution with a concentration of 20 mg / mL were prepared and placed in a storage tank.

[0102] The second step is to turn on the controller 17 and the display 18, and set the system parameters: set F / M to 0.025, V to 1, C NaAc and C ATU Set them to 20 and 20 respectively. K is set to 0.5. The MLSS detected by the sludge concentration electrode 5 probe is 4000 mg / L. After the above parameters are set, V NaAc and V ATU The concentrations of T1, T2, T3, T4 and T0 were set to 2 min, 2 min, 8 min, 30 min and 60 min respectively.

[0103] In the third step, the aeration component switch 8 of the aeration device is turned on, the mud pump valve 2 is closed, and after 2 minutes, the liquid inside the reactor is replaced by air, the spray device switch 11 of the spray device is turned on, the stirring device is turned on, and the equipment cleaning begins. After 2 minutes, the spray device switch 11 of the spray device is turned off to complete the equipment cleaning.

[0104] In the fourth step, the mud feed pump is turned on. After 8 minutes, the mud feed pump is turned off, completing the equipment rinsing and mud feeding stage.

[0105] In the fifth step, the aeration device is turned on, the mud pump valve 2 is opened, and the pretreatment stage begins. Every 30 minutes, the equipment automatically stops aeration and monitors the specific respiratory rate (SOUR value). After repeating this process twice, the system monitors the specific respiratory rate (SOUR value) to be 0.95mgO2 / gMLVSS·h (less than or equal to 1mgO2 / gMLVSS·h), and the pretreatment stage is completed.

[0106] In step six, the aeration assembly switch 8 of the aeration device is turned on. When the system-monitored dissolved oxygen (DO) value rises to 6.2 mg / L (greater than or equal to 6 mg / L), the aeration assembly switch 8 is turned off. At this point, the system-monitored dissolved oxygen (DO) value first rises and then falls. When the system-monitored dissolved oxygen (DO) value drops again to 5.8 mg / L (less than or equal to 6 mg / L), the sodium acetate dosing pump 13 and the propylene thiourea dosing pump 15 are turned on. The system-monitored dissolved oxygen concentration (DO) value at this point is the first DO value after the measurement begins. Ten seconds later, the system-calculated respiratory rate (OUR) and specific respiratory rate (SOUR) are the first OUR and SOUR values ​​after the measurement begins. Monitoring continues until the DO value drops to less than or equal to 2 mg / L, at which point aeration and oxygenation are resumed. Aeration and oxygenation occurred twice during this measurement: the first at 11 minutes after the measurement begins, and the second at 35 minutes after the measurement begins. The measurement lasted a total of 77 minutes from start to finish.

[0107] Step 7: After the measurement is completed, the data is processed. The display records the respiratory rate curve with time as the horizontal axis and OUR value as the vertical axis. By integrating the curve, the area of ​​the area enclosed by the respiratory rate curve, the vertical axis corresponding to the first OUR value, and the horizontal axis corresponding to the last OUR value is calculated. The calculation results are as follows: Figure 3 and is calculated as follows.

[0108] COD=K×MLSS×(F / M)=0.5×4000×0.025=50mg / L;

[0109] ;

[0110] ;

[0111] After the above calculations, the heterotrophic bacteria productivity coefficient was calculated to be 0.76.

[0112] In step 8, the aeration unit's aeration switch 8 is turned on, and the mud pump valve 2 is closed. After time T1, the liquid inside reactor 1 is completely replaced with air. The sprayer switch 11 of the sprayer is turned on, and the agitator is turned on. Cleaning of the dissolved oxygen electrode 4, aeration head 7, and agitator 6 begins. After time T2, the sprayer switch 11 of the sprayer is turned off, and the agitator and aerator are turned off. After time T0, the next round of testing begins, entering the first stage (T0 is the equipment idle time, generally set to 1 hour).

[0113] In the prior art, the measurement end time is determined by stopping recording when the dissolved oxygen concentration drops to the anoxic concentration, and taking samples to measure the change in COD concentration before and after the test. H The accuracy of the existing technology is affected by two aspects: (1) Since there is no "supplementary aeration stage" in the measurement process, the easily degradable COD put into the reactor is not completely degraded during the entire measurement process, which means that the microorganisms have not undergone a complete metabolic process. In this case, the growth rate of heterotrophic bacteria examined is not representative. (2) The COD value used in the calculation results is the laboratory measurement value of the samples taken before and after the test. Combining these two aspects, the influence of Y H calculation accuracy.

[0114] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for real-time online in-situ determination of heterotrophic bacteria yield coefficient, characterized by: The steps include: S1: Place the device in the biological pool mixed liquid to be measured, and clean, rinse, and add mud into the device; S2: Aeration and sludge are introduced into the device. After a period of time, aeration is turned off, and a dissolved oxygen vs. time curve is plotted. The slope of the curve is calculated, and the calculated slope value is the respiration rate OUR; the sludge concentration is measured, and the specific respiration rate is calculated. The specific respiration rate is the ratio of the respiration rate to the volatile sludge concentration; When the specific respiratory rate is less than or equal to 1 mgO2 / gMLVSS·h, proceed to step S3, otherwise, repeat step S2; S3: The aeration device in the device is turned on. When the dissolved oxygen concentration is greater than or equal to 6 mg / L, the aeration is turned off. When the dissolved oxygen concentration is less than or equal to 6 mg / L, the device is dosing. The drugs dosed in step S3 include sodium acetate and propylene thiourea. S4: During the measurement phase, continuous monitoring is performed and the specific respiratory rate is calculated. If the specific respiratory rate is less than or equal to 1 mgO2 / gMLVSS·h, the measurement process is terminated and the heterotrophic bacteria productivity coefficient is calculated. The continuing phase of step S4 includes the following steps: A1: When the dissolved oxygen concentration is less than or equal to 2 mg / L, record the time and respiratory rate; A2: Start aeration. When the dissolved oxygen concentration is greater than or equal to 6 mg / L, stop aeration. When the dissolved oxygen concentration is less than or equal to 6 mg / L, record the time and respiration rate after a period of time. When the dissolved oxygen concentration is less than or equal to 2 mg / L, repeat step A2. If the specific respiration rate is less than or equal to 1 mgO2 / gMLVSS·h, the measurement process ends. The time when the measurement process ends is recorded as tn, and the calculated OUR value is recorded as OURn; The calculation formula for heterotrophic bacteria productivity coefficient is: ； YH: heterotrophic bacteria productivity coefficient; COD: COD equivalent of added sodium acetate; OUR: The measured value during the measurement process; after the drug is added in step S3, this time is recorded as time 0, the respiratory rate after 60 seconds is recorded as OUR1, and the time is recorded as t1; the time when the measurement process ends is recorded as tn, and the calculated OUR value is recorded as OURn; The OUR values ​​between OUR1 and OURn are recorded as OUR1, OUR2, ... OURn in sequence, and the corresponding times are recorded as t1, t2, ... tn, respectively. During the period when the aeration equipment is turned on, the OUR value and SOUR value are not calculated; t1: measurement start time; tn: measurement end time.

2. The method for real-time online in-situ determination of heterotrophic bacteria productivity coefficient according to claim 1, characterized in that: The equipment cleaning in step S1 includes the following steps: starting aeration, stopping the mud from entering the device, and when all the liquid inside the device is replaced by air, starting spraying in the device and stirring. After a period of time, stopping spraying, stirring and aeration.

3. The method for real-time online in-situ determination of heterotrophic bacteria productivity coefficient according to claim 1, characterized in that: After the aeration is turned off in step S2, the dissolved oxygen concentration is detected in real time and the dissolved oxygen concentration in the reactor is recorded every 10 seconds. A dissolved oxygen vs. time curve is drawn every 6 dissolved oxygen concentrations recorded; After continuous monitoring for 1 minute, aeration is turned on again. When the specific respiratory rate is less than or equal to 1 mgO2 / gMLVSS·h, step S3 is performed; otherwise, step S2 is performed again.

4. The method for real-time online in-situ determination of heterotrophic bacteria productivity coefficient according to claim 1, characterized in that: After step S4, the equipment cleaning in step S1 includes the following steps: starting aeration, stopping mud feeding into the device, and when all the liquid inside the device is replaced by air, starting spraying in the device and stirring. After a period of time, stopping spraying, stirring and aeration.

Images