An online wastewater toxicity monitoring device and method based on nitrifying bacteria biofilm

Abstract

The application belongs to the technical field of wastewater monitoring, and particularly relates to an online wastewater toxicity monitoring device and method based on nitrifying bacteria biofilm, which comprises a sample storage bottle, a nutrient solution pool, a buffer pool, a mixing and dissolved oxygen pool, an ultraviolet sterilization lamp, a gas-liquid mixing nozzle, a biofilm reactor, and a conveying pump for pumping liquid and gas, and valves and pumps for controlling the opening and closing of the conveying pipeline. The online wastewater toxicity monitoring device and method based on nitrifying bacteria biofilm have the advantages of high detection efficiency and detection accuracy, flexible and convenient use, simple structure, and low manufacturing cost.

Description

Technical Field

[0001] This invention belongs to the field of wastewater monitoring technology, and particularly relates to an online wastewater toxicity monitoring device and method based on nitrifying bacteria biofilm. Background Technology

[0002] Activated sludge is the most commonly used wastewater treatment process, which efficiently and cost-effectively removes pollutants such as carbon, nitrogen, and phosphorus from wastewater through the synergistic effect of microbial colonies. However, the stability of activated sludge is highly dependent on the quality of the influent. Changes in water quality can significantly impact the biological system. For example, thiourea is a reducing electrolyte commonly used in electroplating companies to replace cyanide, with an industrial concentration of approximately 10 mg / L. If this electroplating wastewater is illegally discharged into a wastewater treatment plant, it will significantly inhibit the activity of nitrifying bacteria (e.g., a thiourea concentration of 0.075 mg / L inhibits nitrifying bacteria by 75%). Another example is chlorophenol, a typical pollutant in wastewater discharged from pharmaceutical, chemical, pesticide, and plastics processing companies. The concentration of this substance in industrial wastewater is often thousands of times higher than the concentration that inhibits nitrifying bacteria. If this type of wastewater is discharged into an activated sludge wastewater treatment system, it will strongly inhibit or even toxicize nitrifying bacteria, leading to the failure of the biological system. Currently, my country's standards for industrial wastewater discharge are often based on COD concentration. Although my country's national standard GB-18918, "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants," stipulates discharge limits for various characteristic pollutants, effective monitoring is difficult due to the lack of online monitoring technology. In addition, some pollutants, such as chlorophenol and thiourea, are not yet included in the key pollutant monitoring list. In practical applications, to ensure the stable operation of the wastewater treatment plant's biological treatment system, real-time monitoring of influent toxicity is necessary to guide on-site operations.

[0003] Currently, wastewater toxicity testing is typically conducted in laboratories, using model organisms such as algae, water fleas, zebrafish embryos, and luminescent bacteria to detect acute toxicity, chronic toxicity, and teratogenicity in wastewater in situ. These methods are generally time-consuming and cumbersome, making them difficult to apply at wastewater treatment plants. Oxygen consumption, a key parameter for assessing the inhibition of aerobic microorganisms, has been widely used in microbial respiration toxicity testing in recent years. Currently, methods for evaluating the inhibition rate of microorganisms by measuring dissolved oxygen consumption are widely applied, reducing toxicity testing time from several hours to just a few minutes. Several domestic and international equipment manufacturers currently sell and use online wastewater toxicity testing equipment for activated sludge; however, these devices often suffer from technical deficiencies such as poor repeatability of test results and low sensitivity in toxicity detection. For example, ToxAlarm, an online wastewater toxicity monitoring device based on suspended nitrifying bacteria developed by the German company Lahr, suffers from poor stability of toxicity detection results and is difficult to apply to treated industrial wastewater effluent. Sentry's device for evaluating wastewater toxicity based on the electrical signals of microbial biofilms is suitable for evaluating the biodegradability of municipal sewage or low-toxicity industrial wastewater, but it is insufficient to meet the technical requirements for online monitoring of industrial wastewater toxicity. Of particular note is the patent application (publication number CN115818859B) submitted by Professor Zhang Yongjun's team at Nanjing University of Technology in my country, entitled "An Online Wastewater Toxicity Detection System and Method Based on Nitrifying Bacterial Biofilm." This patent application uses nitrifying bacteria as a model organism, maintains bacterial concentration through a biofilm, and avoids interference from other bacteria through ultraviolet sterilization. Intermittent rinsing with nutrient solution protects the biological activity of nitrifying bacteria, providing a highly sensitive and stable method and device for wastewater toxicity detection. It assesses wastewater toxicity by detecting the dissolved oxygen concentration in the solution flowing into and out of the nitrifying bacterial biofilm reactor. This method enables rapid and highly stable online detection of wastewater toxicity, providing a new approach to evaluating the microbial inhibition rate of wastewater by detecting dissolved oxygen consumption. However, the online wastewater toxicity monitoring technology disclosed in this patent is mainly based on laboratory conditions. When applied to actual wastewater testing, the following issues still need to be overcome:

[0004] First, there is the problem of low real-time detection: In this type of online wastewater toxicity monitoring system, because the proportion of wastewater sample entering the feed tank is very small, taking the preferred example given in the patent, "in the detection stage, wastewater, nutrient solution, and pure water are mixed in a ratio of 13.8:11:525.2" and "the volume of the feed tank is 5L," calculations show that: during the detection stage, the wastewater, nutrient solution, and pure water entering the feed tank are 125mL, 100mL, and 4775mL, respectively. In the mixed solution in the feed tank, the proportions of wastewater, nutrient solution, and pure water are 2.5%, 2%, and 95.5%, respectively. Therefore, the proportion of wastewater and nutrient solution used during detection is very small. At the same time, the content of chlorophenol and thiourea in the wastewater is also very low. The concentration is generally 0.1~10mg / L. For laboratory simulation testing, the wastewater tank, nutrient solution tank, pure water tank, and other components are relatively small in size and close in location. Therefore, the amount of residual liquid in the system is small. For example, the residual wastewater in the pipe between the wastewater tank and the feed tank is unlikely to have a significant impact on the test results. However, in practical applications, the wastewater tank is very large, and it is also affected by the installation environment, or there is a need for multiple sampling points. The pipe between the sampling point on the wastewater tank and the feed tank is long. In this case, the residual wastewater in the pipe between the wastewater tank and the feed tank will have a significant impact on the test results. In some cases, the water sample being tested may not have been taken from the current wastewater tank, resulting in the test results not reflecting the real-time changes in the toxicity of the wastewater.

[0005] Secondly, poor liquid-liquid and gas-liquid mixing can easily lead to increased time required for the solution in the feed tank to reach dissolved oxygen saturation, longer detection cycles, uneven sample concentration, and poor detection accuracy. In this type of wastewater toxicity online monitoring system, the mixing of water from the wastewater tank, nutrient solution tank, and pure water tank, as well as gas from the air pump, mainly relies on the aeration device at the bottom of the feed tank and the self-diffusion of various fluid media through Brownian motion. Due to environmental limitations, microporous aerators laid at the bottom of the feed tank are often used to refine the air input from the blower into tiny bubbles and evenly diffuse them into the water, achieving rapid oxygen dissolution. Since the diameter of the aeration membrane on the microporous aerator is generally 0.1~1.0 mm, if it is too large, it will affect the air refinement effect and reduce oxygen dissolution efficiency. Therefore, this type of aeration device... Microbubbles rise slowly, are small in size, and have a large specific surface area. Although they can achieve efficient oxygen transfer, the small bubble size and slow buoyancy result in weak disturbance and shear force during the ascent. Furthermore, microbubbles are released locally at the bottom of the pool, and the airflow mainly rises vertically, making it difficult to form a horizontal circulation flow or complete water turbulence within the pool. Therefore, their effect on promoting liquid mixing is relatively weak. However, if mechanical equipment is used to assist in stirring, it requires a large amount of energy input and is prone to generating large bubbles due to stirring and the input air. This can cause light refraction and scattering in the ultraviolet sterilization lamp, reduce the penetration depth of ultraviolet light, reduce the sterilization effect, and prolong the sterilization time.

[0006] Third, the application scenarios and usage methods are not flexible enough. This online wastewater toxicity detection system can only directly detect wastewater in wastewater ponds. However, in actual use, enterprises often need to conduct separate sampling tests on individual samples, such as when toxicity alarms or toxicity values ​​are abnormal, when equipment is malfunctioning, when processes are switching, when emissions are abnormal or in emergency situations, when periodic sampling or calibration is performed, or when environmental protection departments, industrial parks, or units conduct spot checks and sampling of key discharge outlets. Therefore, the online wastewater toxicity monitoring device needs to be able to conduct separate sampling tests on directly collected samples.

[0007] Fourth, the large number of power components not only leads to a complex system structure and equipment malfunctions, but also results in high equipment manufacturing costs and high energy consumption during operation.

[0008] Fifth, in the process of chemical testing and sampling, in-situ direct sampling is preferred, and the use of pumps and other power equipment for transportation should be avoided as much as possible. Some high-precision testing standards even explicitly prohibit the use of pumps or transfer media for sampling or transporting samples. When conducting toxicity testing on industrial wastewater containing components such as thiourea and chlorophenol, thiourea is chemically reactive and easily oxidized into urea or other byproducts. Thiourea is also sensitive to environmental conditions such as pH and temperature. In addition, thiourea can easily undergo complexation reactions with metal ions (such as copper and iron in the pump body), reducing its concentration. Ultimately, it will decompose or transform during the pumping process due to metal catalysis, leading to an underestimation of its toxicity. Furthermore, chlorophenol is a volatile and semi-volatile organic pollutant. During the pumping process, the violent agitation of the water sample can easily cause the volatilization loss of chlorophenol. At the same time, the pump body material may adsorb pollutants, and oxygen and metal surfaces can promote its oxidative degradation, leading to a decrease in the concentration of chlorophenol in the sample and an underestimation of its toxicity. Therefore, in the process of online wastewater toxicity monitoring, the use of pumps to transport the water sample to be tested should be avoided as much as possible.

[0009] In view of this, the present invention provides an improved online wastewater toxicity monitoring device and method based on nitrifying bacteria biofilm, so as to optimize the adaptability of the online wastewater toxicity monitoring device to the environment and detection requirements, detection efficiency and detection accuracy in actual use. Summary of the Invention

[0010] The purpose of this invention is to address the aforementioned technical problems by providing an online wastewater toxicity monitoring device and method based on nitrifying bacteria biofilm, thereby optimizing the adaptability, detection efficiency, and detection accuracy of the online wastewater toxicity monitoring device in practical use to meet environmental and detection requirements.

[0011] In view of this, the present invention provides an online wastewater toxicity monitoring device based on a nitrifying bacteria biofilm, comprising: a sample storage bottle for storing a wastewater sample to be tested; a nutrient solution tank for storing nutrient solution; a buffer tank for temporarily storing the wastewater sample discharged from the sample storage bottle, or the nutrient solution discharged from the nutrient solution tank; a mixing and dissolved oxygen tank, in which oxygen, pure water, nutrient solution, and the wastewater sample are mixed to obtain a curing solution for the curing stage or a test solution for the testing stage; an ultraviolet sterilization lamp disposed in the mixing and dissolved oxygen tank; a gas-liquid mixing nozzle disposed in the mixing and dissolved oxygen tank for promoting liquid mixing and oxygen dissolution in the mixing and dissolved oxygen tank; a biofilm reactor disposed therein with packing material, on the surface of which a nitrifying bacteria biofilm mainly composed of nitrifying bacteria is formed; and a conveying pipe connecting the various components, a valve for controlling the opening and closing of the pipe, and a pump for pumping liquid and gas.

[0012] In use, the wastewater sample from the sample storage bottle or the nutrient solution from the nutrient solution pool is first input into the buffer pool. Then, the wastewater sample or nutrient solution temporarily stored in the buffer pool is flushed into the mixing and dissolved oxygen pool with pure water and mixed with oxygen therein to obtain a maintenance solution or a test solution. The maintenance solution or test solution is then transported to the biofilm reactor for nitrifying bacteria biofilm maintenance or wastewater toxicity testing.

[0013] Furthermore, the volume of the buffer pool is greater than or equal to the maximum amount of wastewater sample required for a single preparation of the maintenance solution or test solution, and the volume of the buffer pool is greater than or equal to the maximum amount of nutrient solution required for a single preparation of the maintenance solution or test solution.

[0014] Furthermore, the cache pool has a tubular structure.

[0015] Furthermore, the gas-liquid mixing nozzle includes: a converging section, which is a trumpet-shaped structure with a cross-section that gradually decreases from bottom to top; an injection section, which is a tubular structure disposed at the upper end of the converging section, and the inner diameter of the injection section is equal to the inner diameter of the upper end of the converging section; a baffle tube, which is a cylindrical structure suspended above the injection section, and the inner diameter of the baffle tube is larger than the inner diameter of the injection section; and a first injection port, which is formed by the gap between the injection section and the baffle tube.

[0016] Furthermore, the baffle tube includes:

[0017] The sidewall and the top surface located at its upper end, and a second injection port disposed on the upper part of the baffle tube, wherein there are multiple second injection ports, which are evenly spaced along the circumference on the baffle tube.

[0018] Furthermore, the delivery pipeline includes: a first sample delivery pipeline disposed between the second port of the buffer pool and the liquid inlet on the gas-liquid mixing nozzle; a pure water input pipeline connected between an external pure water inlet pipeline and the first sample delivery pipeline; a second sample delivery pipeline connecting the first port of the buffer pool to the first sample delivery pipeline; the connection point between the pure water input pipeline and the first sample delivery pipeline is located between the second port of the buffer pool and the connection point between the second sample delivery pipeline and the first sample delivery pipeline; an air input pipeline connected to the external atmosphere and the gas inlet on the gas-liquid mixing nozzle; and a flow meter is installed on the first sample delivery pipeline, the flow meter being located at the rear end of the connection point between the second sample delivery pipeline and the first sample delivery pipeline.

[0019] Furthermore, the valve includes: a first control valve disposed on the pure water input pipe for controlling the on / off state of the pure water input pipe; a second control valve disposed on the first sample delivery pipe for controlling the on / off state of the first sample delivery pipe, and the second control valve being located between the connection point of the first sample delivery pipe and the pure water input pipe and the connection point of the first sample delivery pipe and the second sample delivery pipe; and a third control valve having four interconnected ports, the four ports being respectively connected to the outlet of the sample storage bottle, the outlet of the nutrient solution pool, the first port of the buffer pool, and the inlet of the second sample delivery pipe, for regulating the liquid flow direction among the sample storage bottle, the nutrient solution pool, and the buffer pool.

[0020] Furthermore, the sample storage bottle is provided with a connection mechanism for quick connection with the sampling bottle, which includes:

[0021] A sandwich panel is formed inside the sample storage bottle, which divides the internal space of the bottle into a main chamber for containing liquid and a secondary chamber for gas passage, wherein the main chamber is located on the side away from the bottle opening and the secondary chamber is located on the side closer to the bottle opening.

[0022] An inner bottle opening and an outer bottle opening are fitted together, wherein the inner bottle opening and the outer bottle opening are both located on the side surface of the interlayer plate near the secondary chamber, and the outer bottle opening surrounds the outer periphery of the inner bottle opening.

[0023] A first air inlet is provided on the body of the sample storage bottle, and the first air inlet is located on the side wall of the secondary chamber;

[0024] A second air inlet and a third air inlet are provided on the outer bottle opening, wherein the second air inlet is located at the end of the outer bottle opening near the interlayer plate, and the third air inlet is located at the end of the outer bottle opening away from the interlayer plate.

[0025] Furthermore, the outer diameter of the outer bottle opening is equal to the inner diameter of the bottle opening on the sampling bottle. When the bottle opening of the sampling bottle is inserted into the outer bottle opening of the storage bottle, the side wall of the bottle opening of the sampling bottle is located between the second air inlet and the third air inlet.

[0026] An online wastewater toxicity monitoring method based on nitrifying bacteria biofilm, wherein the online wastewater toxicity monitoring method is used in the aforementioned online wastewater toxicity monitoring device based on nitrifying bacteria biofilm, and the online wastewater toxicity monitoring method includes an intermittent phase and a detection phase:

[0027] The intermittent phase includes: a nutrient solution input program, a pure water input program, and a maintenance program;

[0028] The detection phase includes: nutrient solution input procedure, wastewater sample input procedure, pure water input procedure, and detection procedure;

[0029] The nutrient solution or wastewater sample input procedure during the intermittent and detection phases includes:

[0030] First, the outlet of the nutrient solution tank or sample storage bottle is connected to the first port of the buffer tank through the third control valve, so that the nutrient solution in the nutrient solution tank or the wastewater sample in the sample storage bottle can enter the buffer tank for temporary storage through the third control valve. At this time, the second control valve is opened so that the pure water pre-stored in the buffer tank can enter the mixing and dissolved oxygen tank through the second control valve. At the same time, the pure water flowing through it is measured by the flow meter, so the amount of pure water flowing through it is equal to the amount of nutrient solution or wastewater sample entering the buffer tank.

[0031] The pure water input procedure during the intermittent and detection phases includes:

[0032] The first port of the buffer tank is connected to the inlet of the second sampling pipeline via the third control valve. Then, the pure water delivery pump and the first control valve are turned on, and the second control valve is turned off. External pure water is pumped into the pure water input pipeline through the pure water delivery pump, and then enters the buffer tank through the first sampling pipeline. The pure water is used to fill the nutrient solution or wastewater sample temporarily stored in the buffer tank into the mixing and dissolved oxygen tank through the second sampling pipeline and the gas-liquid mixing nozzle. At the same time, the pure water flowing through it is measured by the flow meter. During this period, the total amount of liquid flowing through it is equal to the amount of pure water entering the buffer tank. At the same time as the first control valve is turned on, the gas delivery pump is turned on to pump clean air or oxygen into the gas-liquid mixing nozzle.

[0033] The beneficial effects of this invention are:

[0034] First, in the online wastewater toxicity monitoring method based on nitrifying bacteria biofilm described in this invention, nutrient solution or wastewater samples are first introduced into the buffer tank and the mixing and dissolved oxygen tank during both the intermittent and detection phases. This allows for the direct flushing of nutrient solution or wastewater samples into the mixing and dissolved oxygen tank using pure water, avoiding the need for a power pump and resulting in more accurate detection results. Furthermore, prioritizing the introduction of nutrient solution or wastewater samples into the mixing and dissolved oxygen tank extends the mixing time under the influence of pure water and oxygen, as well as the time spent under the ultraviolet sterilization lamp, optimizing the gas-liquid and liquid-liquid mixing and sterilization effects. Moreover, this sampling method significantly reduces the number of pumps required, substantially lowering equipment manufacturing costs.

[0035] Secondly, in addition, after each time the nutrient solution or wastewater sample is flushed into the mixing and dissolved oxygen tank with pure water, the pipeline system of the online wastewater toxicity monitoring device is temporarily filled with pure water, which will not affect the operation of the next stage, making the detection results more accurate.

[0036] Third, before inputting wastewater samples into the sample storage bottle, the sixth control valve on the sample storage bottle can be opened for a period of time to drain the wastewater in the water sampling pipeline between the sampling point and the sample storage bottle, as well as the wastewater in the sample storage bottle. Then, the sixth control valve can be closed to obtain the water sample for testing, thus achieving real-time acquisition of water samples.

[0037] Fourth, by setting a connection mechanism on the sample storage bottle for quick connection with the sampling bottle, individual sampling and testing of individual samples can be achieved;

[0038] Fifth, by setting up the gas-liquid mixing nozzle, a high-frequency oscillating fluid is formed in the mixing and dissolved oxygen pool. This oscillating fluid with a high oscillation frequency and a certain deflection angle can increase the disturbance and rotation intensity of the fluid, effectively promoting the mixing of gas and liquid and liquid and liquid in the mixing and dissolved oxygen pool, especially the rapid mixing of the fluid in the lower part of the mixing and dissolved oxygen pool. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the online wastewater toxicity monitoring device based on nitrifying bacteria biofilm in this invention;

[0040] Figure 2 This is a schematic diagram of the upper structure of the online wastewater toxicity monitoring device based on nitrifying bacteria biofilm in this invention;

[0041] Figure 3 This is a schematic diagram of the lower structure of the online wastewater toxicity monitoring device based on nitrifying bacteria biofilm described in this invention;

[0042] Figure 4This is a schematic diagram of the internal structure of the cache unit described in this invention;

[0043] Figure 5 This is a schematic diagram of the gas-liquid mixing nozzle described in this invention;

[0044] Figure 6 This is another structural schematic diagram of the gas-liquid mixing nozzle described in this invention;

[0045] Figure 7 This is a schematic diagram of the assembly method of the sample storage bottle and the sampling bottle described in this invention;

[0046] Figure 8 This is a schematic cross-sectional view of the assembly structure of the sample storage bottle and the sampling bottle described in this invention;

[0047] Figure 9 This is a schematic cross-sectional view of the sample storage bottle described in this invention;

[0048] Figure 10 This is a schematic cross-sectional view of the sampling bottle described in this invention;

[0049] The markings in the diagram are as follows:

[0050] 1. Sample storage bottle; 101. Bottle body; 102. Spliced ​​plate; 103. Outer bottle mouth; 104. Inner bottle mouth; 105. First air inlet; 106. Second air inlet; 107. Third air inlet; 108. Cap; 109. Fourth air inlet; 2. Nutrient solution tank; 3. Buffer tank; 301. Buffer unit; 4. Mixing and dissolved oxygen tank; 5. Ultraviolet sterilization lamp; 6. Gas-liquid mixing nozzle; 601. Converging section; 602. Spray section; 603. Baffle tube; 604. Premixing section; 605. First spray nozzle; 606. Second spray nozzle; 7. Delivery pipeline; 701. Pure water input pipeline; 702. Air input pipeline; 703. First 704. Sample delivery pipeline; 705. Second sample delivery pipeline; 706. Sample inlet pipeline; 707. Wastewater discharge pipeline; 708. Residual sample discharge pipeline; 709. Gas discharge pipeline; 7000. Exhaust pipeline; 8. Valves; 801. First control valve; 802. Second control valve; 803. Third control valve; 804. Fourth control valve; 805. Fifth control valve; 806. Sixth control valve; 9. Transfer pump; 901. Gas transfer pump; 902. Pure water transfer pump; 10. Biofilm reactor; 1001. Liquid distributor; 1002. Nitrifying bacteria biofilm; 11. Sampling bottle; 1101. Plastic sealing film; 12. Outer shell; 13. Flow meter. Detailed Implementation

[0051] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0052] In the description of this application, it should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. For ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn to actual scale.

[0053] It should be noted that the terms "first," "second," etc., in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or sequence.

[0054] It should be noted that in the description of this application, the directional terms such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description.

[0055] It should be noted that, in this application, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0056] like Figures 1-10 As shown, an online wastewater toxicity monitoring device based on nitrifying bacteria biofilm includes:

[0057] Sample bottle 1 is used to store wastewater samples to be tested;

[0058] Nutrient solution tank 2, which is used to store nutrient solution;

[0059] Buffer pool 3 is used to temporarily store wastewater samples discharged from the sample storage bottle 1, or nutrient solution discharged from the nutrient solution pool 2.

[0060] In the mixing and dissolved oxygen tank 4, oxygen or oxygen-containing air, pure water, nutrient solution from the nutrient solution tank 2, and wastewater sample from the sample storage bottle 1 can be mixed to obtain a curing solution for the curing stage or a detection solution for the detection stage.

[0061] A gas-liquid mixing nozzle 6 is disposed in the mixing and dissolved oxygen tank 4 to promote liquid mixing and oxygen dissolution in the mixing and dissolved oxygen tank 4;

[0062] An ultraviolet sterilization lamp 5 is installed in the mixing and dissolved oxygen tank 4 to sterilize the liquid in the mixing and dissolved oxygen tank 4.

[0063] A biofilm reactor 10 is provided inside, and a nitrifying bacteria biofilm 1002, mainly composed of nitrifying bacteria, is formed on the surface of the packing material.

[0064] In addition, there are conveying pipes 7 connecting the various components, valves 8 controlling the opening and closing of the pipes, and conveying pumps 9 for pumping liquids and gases;

[0065] In use, the wastewater sample in the sample storage bottle 1 or the nutrient solution in the nutrient solution pool 2 is first input into the buffer pool 3. Then, the wastewater sample or nutrient solution temporarily stored in the buffer pool 3 is flushed into the mixing and dissolved oxygen pool 4 with pure water and mixed with oxygen therein to obtain a maintenance solution or a test solution. Then, the maintenance solution or test solution is transported to the biofilm reactor 10 for the maintenance of the nitrifying bacteria biofilm 1002 or wastewater toxicity testing.

[0066] Those skilled in the art will know that the maintenance solution in the maintenance stage is a mixture of pure water and nutrient solution, and the detection solution in the detection stage is a mixture of pure water, nutrient solution and wastewater sample.

[0067] The proportions of each component in the maintenance solution and the mixture can be found in Chinese patent application CN115818859B, or can be adjusted according to the concentration of nutrients or pollutants in the nutrient solution or wastewater sample.

[0068] The main components of the online wastewater toxicity monitoring device based on nitrifying bacteria biofilm are described below:

[0069] Sample bottle 1

[0070] In this invention, the main function of the sample storage bottle 1 is to obtain real-time fresh water samples from the wastewater pool online. The sample storage bottle 1 is connected to one or more sampling points through a sampling pipe. The wastewater at the sampling point enters the sample storage bottle 1 by gravity or negative pressure attraction. Under different methods, corresponding matching structures can be set on the sample storage bottle 1.

[0071] As a preferred example of the present invention, the height of the sample storage bottle 1 can be set below the sampling point. In this case, the wastewater at the sampling point can spontaneously enter the sample storage bottle 1 by gravity.

[0072] At this point, an air inlet and a drainage channel can be provided on the sample storage bottle 1. The air inlet is generally located at the top of the sample storage bottle 1 and is used to introduce air into the sample storage bottle 1 while the water sample is being discharged, thus balancing the air pressure inside the sample storage bottle 1. The drainage channel is used to promptly drain any remaining water sample from the sample storage bottle 1, ensuring that the next water sample entering the sample storage bottle 1 is fresh at the current moment. Alternatively, the sample storage bottle 1 can be designed with an open top, in which case the air inlet can be omitted.

[0073] Specifically, as some examples of the present invention, such as Figures 1-2 As shown, a drainage channel for the sample storage bottle 1 is formed by a wastewater discharge pipe 706 located at the bottom of the sample storage bottle 1 and a sixth control valve 806 located on the wastewater discharge pipe 706. Residual water samples in the sample storage bottle 1 can be discharged through the wastewater discharge pipe 706. Simultaneously, a fourth air inlet 109 can be formed on the sample storage bottle 1 through a through hole located at the top of the bottle body 101. Preferably, the through hole is located at the top of the sample storage bottle 1 in the vertical direction.

[0074] In addition, in order to enable the online wastewater toxicity monitoring device based on nitrifying bacteria biofilm of the present invention to perform individual sampling and testing on individual samples, the sample storage bottle 1 is also provided with a connection mechanism for quick connection with the sampling bottle 11.

[0075] As a preferred example of the present invention, such as Figures 7-10 As shown, the connection mechanism provided on the sample storage bottle 1 for quick connection with the sampling bottle 11 specifically includes:

[0076] A sandwich panel 102 is formed inside the sample bottle 1. The sandwich panel 102 divides the internal space of the bottle body 101 into a main chamber for containing liquid and a secondary chamber for gas passage. The volume of the main chamber is much larger than the volume of the secondary chamber. The main chamber is located on the side away from the bottle opening of the sample bottle 1, and the secondary chamber is located on the side closer to the bottle opening of the sample bottle 1.

[0077] The inner bottle opening 104 and the outer bottle opening 103 are nested together, wherein the inner bottle opening 104 and the outer bottle opening 103 are both disposed on the side surface of the interlayer plate 102 near the secondary chamber, and the outer bottle opening 103 surrounds the outer periphery of the inner bottle opening 104.

[0078] A first air inlet 105 is provided on the bottle body 101 of the sample storage bottle 1, and the first air inlet 105 is located on the side wall of the secondary chamber.

[0079] The second air inlet 106 and the third air inlet 107 are provided on the outer bottle opening 103, wherein the second air inlet 106 is located at the end of the outer bottle opening 103 near the interlayer plate 102, and the third air inlet 107 is located at the end of the outer bottle opening 103 away from the interlayer plate 102.

[0080] When it is necessary to connect the sampling bottle 11 to the storage bottle 1, the mouth of the sampling bottle 11 can be inserted into the outer periphery of the outer bottle mouth 103 on the storage bottle 1. At this time, the side wall of the mouth of the sampling bottle 11 is located between the second air inlet 106 and the third air inlet 107. In this way, the first air inlet 105 can connect the external atmosphere with the secondary chamber, the second air inlet 106 can connect the secondary chamber with the annular gap between the inner bottle mouth 104 and the outer bottle mouth 103, and the third air inlet 107 can connect the annular gap with the internal space of the sampling bottle 11. Finally, the internal space of the sampling bottle 11 is connected with the external atmosphere, so as to achieve continuous and stable discharge of the water sample in the sampling bottle 11 and prevent the water sample in the sampling bottle 11 from not being discharged smoothly due to pressure.

[0081] In addition, when it is not necessary to conduct individual sampling tests on individual samples, the cap 108 can be used to cover the outer bottle opening 103 to achieve the closure of the connecting mechanism on the sample storage bottle 1.

[0082] Furthermore, to ensure that the wastewater sample in the sample storage bottle 1 can spontaneously enter the buffer tank 3 under gravity, the installation position of the sample storage bottle 1 should also be higher than that of the buffer tank 3. Additionally, it is understood that the installation position of the sample storage bottle 1 should also be higher than the upper surface of the gas-liquid mixing nozzle 6.

[0083] It should be noted that when selecting from the above-mentioned multiple options for sample storage bottle 1, attention should be paid to the synergistic effect between the various structures to avoid conflicts between different options.

[0084] As some examples of the present invention, the shape of the sample storage bottle 1 can be set as needed. Preferably, the bottom surface of the sample storage bottle 1 can be set to gradually tilt towards the water outlet on the sample storage bottle 1, so as to achieve the purpose of rapid and complete discharge of water sample in the sample storage bottle 1.

[0085] As some examples of the present invention, the outer diameter of the outer bottle opening 103 is equal to the inner diameter of the bottle opening on the sampling bottle 11.

[0086] As some examples of the present invention, the connecting mechanism provided on the sample storage bottle 1 for quick connection with the sampling bottle 11 can be vertical or inclined, preferably with the bottle mouth inclined upward on the sample storage bottle 1. In this case, the sampling bottle 11 can be inserted into the connecting mechanism at a downward inclination, which facilitates rapid sample injection.

[0087] In addition, after obtaining the wastewater sample to be tested using the sampling bottle 11, a soft plastic sealing film 1101 can be used to seal the mouth of the sampling bottle 11 to facilitate the transportation and transfer of the sampling bottle 11 and avoid contamination. When in use, the mouth of the sampling bottle 11 can be directly inserted into the outer mouth 103 of the storage bottle 1 along with the plastic sealing film 1101. At this time, the outer mouth 103 can be used to seal the mouth of the sampling bottle 11 while breaking the plastic sealing film 1101 on the sampling bottle 11 and opening its mouth, thus preventing leakage at the connection between the two.

[0088] Nutrient solution tank 2

[0089] The nutrient solution tank 2 in this invention is mainly used to store the prepared nutrient solution. Therefore, it should be equipped with at least an inlet for the nutrient solution to enter and an outlet for the nutrient solution to exit. Furthermore, to ensure the smooth discharge of the nutrient solution from the nutrient solution tank 2, the nutrient solution tank 2 should also be able to communicate with the external atmosphere.

[0090] In addition, in order to enable the nutrient solution in the nutrient solution tank 2 to spontaneously enter the buffer tank 3 by gravity, the installation position of the nutrient solution tank 2 should also be higher than that of the buffer tank 3.

[0091] Cache pool 3

[0092] The buffer pool 3 in this invention is mainly used to temporarily store the wastewater sample discharged from the sample storage bottle 1 or the nutrient solution discharged from the nutrient solution pool 2. Therefore, the size of the buffer pool 3 needs to be determined according to the amount of wastewater sample and nutrient solution required each time during use. Specifically, it is advisable that the volume of the buffer pool 3 is greater than or equal to the maximum amount of wastewater sample and the maximum amount of nutrient solution required for a single preparation of maintenance solution or test solution. The shape of the buffer pool 3 can be set as needed.

[0093] As some examples of the present invention, when the volume of the buffer pool 3 is set to be small, the buffer pool 3 can be a tubular structure, which can be served by a section of the first sample delivery pipe 703, without any other specific structural components.

[0094] As further examples of the present invention, when the volume of the cache pool 3 is set to be large, the cache pool 3 includes at least one cache unit 301, such as... Figure 4 As shown, the buffer unit 301 is a spiral tube, and the two ends of the spiral tube form the inlet and outlet of the buffer pool 3.

[0095] Furthermore, when the cache pool 3 includes multiple cache units 301, the multiple cache units 301 can be connected in series to further increase the volume of the cache pool 3 and meet the caching needs.

[0096] Preferably, the diameter of the pipe structure within the buffer pool 3 is less than or equal to 20 mm. More preferably, the diameter of the pipe structure within the buffer pool 3 is less than or equal to 15 mm, such as 5-10 mm.

[0097] Mixed and dissolved oxygen tank 4

[0098] The main function of the mixing and dissolved oxygen tank 4 in this invention is to provide a place for mixing and sterilizing oxygen, pure water, wastewater and nutrient solution. Its function is mainly achieved by the gas-liquid mixing nozzle 6 and ultraviolet sterilization lamp 5 installed therein.

[0099] Specifically, such as Figures 5-6 As shown, the gas-liquid mixing nozzle 6 includes:

[0100] The tapering section 601 is a trumpet-shaped structure whose cross-section gradually decreases from bottom to top;

[0101] The spray section 602 is a tubular structure disposed at the upper end of the tapered section 601, and the inner diameter of the spray section 602 is equal to the inner diameter of the upper end of the tapered section 601.

[0102] The baffle 603 is a cylindrical structure suspended above the jet section 602, and the inner diameter of the baffle 603 is slightly larger than the inner diameter of the jet section 602.

[0103] The first injection port 605 is formed by the gap between the injection section 602 and the baffle 603;

[0104] The fluid ejected from the jet section 602 continues to move upward, and after hitting the baffle tube 603, it turns back and is then sprayed into the mixing and dissolved oxygen pool 4 through the first jet port 605.

[0105] Preferably, the inner diameter of the baffle 603 is 1 to 1.5 times the inner diameter of the spray section 602.

[0106] Preferably, the distance between the baffle 603 and the spray section 602 is 10~50mm.

[0107] Preferably, the baffle 603 includes a side wall and a top surface located at its upper end. The fluid ejected from the jet 602 is deflected back after hitting the side wall or top surface of the baffle 603, mainly the top surface.

[0108] As some examples of the present invention, the baffle 603 can be connected to the side wall of the mixing and dissolved oxygen pool 4 via a connecting bracket or the like, so as to achieve the purpose of being suspended above the spray section 602.

[0109] Furthermore, the gas-liquid mixing nozzle 6 also includes a premixing section 604, which is a cylindrical structure with a uniform cross-section; the premixing section 604 is located below the tapering section 601, with its lower end forming a gas and / or liquid inlet, and its upper end connected to the tapering section 601.

[0110] Furthermore, the gas-liquid mixing nozzle 6 also includes: a second injection port 606 disposed on the upper part of the baffle 603, wherein there are multiple second injection ports 606, which are evenly spaced along the circumference on the baffle 603; the arrangement of the second injection ports 606 allows some of the fluid entering the baffle 603 to be discharged through the second injection ports 606.

[0111] In the gas-liquid mixing nozzle 6, the gas-liquid mixing system entering the nozzle 6 is accelerated and pressurized when passing through the tapering section 601 due to its reduced cross-section, forming a high-speed gas-liquid mixing jet with higher velocity and pressure. After being ejected by the injection section 602, most of this high-speed gas-liquid mixing jet continues to move, enters the baffle tube 603 and is compressed. After contacting the inner wall of the baffle tube 603, it rebounds and expands outward, causing lateral deflection and flow field vibration of the high-speed gas-liquid mixing jet through the first injection port 605, forming a high-frequency oscillating fluid, which ultimately increases the disturbance and rotation intensity of the fluid. After being discharged from the first injection port 605, this oscillating fluid with a high oscillation frequency and a certain deflection angle enters the chamber formed by the mixing and dissolved oxygen pool 4, first moving downward, and then moving upward after hitting the bottom of the mixing and dissolved oxygen pool 4, thereby driving the gas-liquid and liquid-liquid mixtures, especially the fluid in the lower part of the mixing and dissolved oxygen pool 4, to mix rapidly.

[0112] Furthermore, when the gas-liquid mixing nozzle 6 is also provided with a second injection port 606, part of the fluid entering the baffle 603 can be discharged through the second injection port 606, and the lateral deflection of the fluid by the second injection port 606 will generate radial and circumferential secondary disturbances to the solution in the upper part of the mixing and dissolved oxygen pool 4, further enhancing the mixing effect of gas-liquid and liquid-liquid within it.

[0113] This method, which utilizes the initial kinetic energy of the fluid and optimizes the flow channel, enables comprehensive energy utilization and structural simplification, achieving efficient fluid mixing without increasing additional energy consumption.

[0114] As some examples of the present invention, the liquid inlet and the gas inlet on the gas-liquid mixing nozzle 6 may be respectively provided on the bottom or side wall of the gas-liquid mixing nozzle 6.

[0115] Furthermore, in actual operation, the amount of liquid delivered to the mixing and dissolved oxygen tank 4 through the gas-liquid mixing nozzle 6 is determined based on the amount of curing solution or detection solution. The amount and time of gas delivery to the mixing and dissolved oxygen tank 4 are determined based on the dissolved oxygen in the curing solution or detection solution. Generally speaking, the time for delivering gas to the mixing and dissolved oxygen tank 4 can be equal to or greater than the time for delivering liquid to the mixing and dissolved oxygen tank 4. That is, after the liquid delivery is completed, gas can continue to be delivered to the mixing and dissolved oxygen tank 4 to achieve dissolved oxygen saturation.

[0116] Preferably, the ultraviolet sterilization lamp 5 is positioned directly above the gas-liquid mixing nozzle 6, which is an area where fluid movement is relatively weak. This avoids the impact of fluid on the ultraviolet sterilization lamp 5, improves its service life and operational stability, and provides a good fluid environment for the ultraviolet sterilization lamp 5 to achieve its sterilization function.

[0117] Pipeline 7 and valve 8

[0118] In this invention, the main function of the conveying pipe 7 is to connect the various components in the online wastewater toxicity monitoring device to realize the material conveying between them; while the valve 8 is specifically set at a specific position of the conveying pipe 7 to regulate the opening and closing of the conveying pipe 7.

[0119] Specifically, the delivery pipeline 7 includes: a first sample delivery pipeline 703, which is disposed between the second port of the buffer pool 3 and the liquid inlet on the gas-liquid mixing nozzle 6; a pure water input pipeline 701, which is connected between the external pure water inlet pipeline and the first sample delivery pipeline 703, through which pure water can be delivered to the first sample delivery pipeline 703; and a second sample delivery pipeline 704, which connects the first port of the buffer pool 3 to the first sample delivery pipeline 703; the connection point between the pure water input pipeline 701 and the first sample delivery pipeline 703 is located between the second port of the buffer pool 3 and the connection point between the second sample delivery pipeline 704 and the first sample delivery pipeline 703.

[0120] Furthermore, the conveying pipe 7 also includes:

[0121] The sample inlet pipe 705 connects the mixing and dissolved oxygen pool 4 to the biofilm reactor 10, so that the detection solution in the mixing and dissolved oxygen pool 4 can enter the biofilm reactor 10 through the sample inlet pipe 705.

[0122] In addition, the conveying pipeline 7 also includes: a residual sample discharge pipeline 707, which is located at the bottom of the mixing and dissolved oxygen tank 4, for discharging the remaining liquid in the mixing and dissolved oxygen tank 4; a gas discharge pipeline 708, which is located at the top of the mixing and dissolved oxygen tank 4, for connecting the mixing and dissolved oxygen tank 4 with the external atmosphere, providing a channel for gas overflow from the mixing and dissolved oxygen tank 4; an emptying pipeline 709, which is located at the bottom of the biofilm reactor 10, for discharging the liquid in the biofilm reactor 10; an air input pipeline 702, which connects the external atmosphere with the gas inlet on the gas-liquid mixing nozzle 6; and the aforementioned wastewater discharge pipeline 706, which is located at the bottom of the sample storage bottle 1, for discharging the remaining liquid in the sample storage bottle 1.

[0123] Furthermore, a flow meter 13 is installed on the first sample delivery pipe 703. The flow meter is located at the rear end of the connection point between the second sample delivery pipe 704 and the first sample delivery pipe 703. In this way, by setting a flow meter 13, the amount of wastewater sample discharged from the sample storage bottle 1, the amount of nutrient solution discharged from the nutrient solution tank 2, and the amount of pure water entering the mixing and dissolved oxygen tank 4 can be measured separately, reducing the number of flow meters 13 used and simplifying the equipment structure.

[0124] Specifically, the valve 8 includes: a first control valve 801, which is disposed on the pure water input pipe 701 and used to control the opening and closing of the pure water input pipe 701; a second control valve 802, which is disposed on the first sample delivery pipe 703 and used to control the opening and closing of the first sample delivery pipe 703, and the second control valve 802 is located between the connection point of the first sample delivery pipe 703 and the pure water input pipe 701 and the connection point of the first sample delivery pipe 703 and the second sample delivery pipe 704; and a third control valve 803, which has four interconnected ports, which are respectively connected to the outlet of the sample storage bottle 1, the outlet of the nutrient solution pool 2, the first port of the buffer pool 3, and the inlet of the second sample delivery pipe 704, for regulating the liquid flow direction among the sample storage bottle 1, the nutrient solution pool 2, and the buffer pool 3.

[0125] In addition, the valve 8 also includes:

[0126] The fourth control valve 804 is installed on the sample inlet pipe 705 to control the opening and closing of the sample inlet pipe 705; the fifth control valve 805 is installed on the residual sample discharge pipe 707 to control the opening and closing of the residual sample discharge pipe 707; and the sixth control valve 806 is installed on the wastewater discharge pipe 706 to control the opening and closing of the wastewater discharge pipe 706.

[0127] Transfer pump 9

[0128] In this invention, the main function of the delivery pump 9 is to input water or air into the online wastewater toxicity monitoring device to prepare the detection solution required for wastewater detection.

[0129] Specifically, the delivery pump 9 includes a gas delivery pump 901, which is connected to the air input pipe 702 to input air into the mixing and dissolved oxygen pool 4 to prepare a detection solution with dissolved oxygen saturation.

[0130] In addition, the delivery pump 9 also includes a pure water delivery pump 902, which is connected to the pure water input pipe 701 to input pure water into the pure water input pipe 701 and provide a certain water pressure for the pure water to be smoothly sprayed into the mixing and dissolved oxygen pool 4.

[0131] Of course, when the pressure of the incoming pure water is high, the pure water delivery pump 902 may not be installed, and the pure water may be directly delivered to the mixing and dissolved oxygen tank 4 by utilizing the pressure of the incoming water.

[0132] Biofilm reactor 10

[0133] The principle of the biofilm reactor 10 described in this invention for toxicity testing of wastewater is the same as that of Chinese Patent No. CN115818859B, which uses nitrifying bacteria as model organisms and assesses the toxicity of wastewater by detecting the rate of dissolved oxygen consumption in the solution of the biofilm reactor 10 during the detection and intermittent phases. This will not be described in detail here.

[0134] It should be noted that in industrial production, when the size of the biofilm reactor 10 is increased, the detection liquid can be uniformly introduced onto the nitrifying bacteria biofilm 1002 by adding a liquid distributor 1001.

[0135] Furthermore, when continuous monitoring of wastewater is required, multiple sets of online wastewater toxicity monitoring devices can be installed, and real-time, online continuous monitoring of wastewater can be achieved through the alternation of intermittent and monitoring phases.

[0136] Furthermore, the online wastewater toxicity monitoring device also includes an outer casing 12, and the pipe in the conveying pipeline 7 that needs to discharge gas or liquid extends out of the outer casing 12 to realize its function.

[0137] Furthermore, the present invention also provides an online wastewater toxicity monitoring method based on nitrifying bacteria biofilm. This online wastewater toxicity monitoring method is used in the aforementioned online wastewater toxicity monitoring device based on nitrifying bacteria biofilm. The online wastewater toxicity monitoring method includes an intermittent phase and a detection phase.

[0138] The process of the intermittent phase is as follows:

[0139] Nutrient solution input procedure: First, the outlet of the nutrient solution tank 2 is connected to the first port of the buffer tank 3 through the third control valve 803, so that the nutrient solution in the nutrient solution tank 2 can enter the buffer tank 3 for temporary storage through the third control valve 803. At this time, the second control valve 802 is opened so that the pure water pre-stored in the buffer tank 3 can enter the mixing and dissolved oxygen tank 4 through the second control valve 802. At the same time, the pure water flowing through it is measured by the flow meter 13, so that the amount of pure water flowing through it is equal to the amount of nutrient solution entering the buffer tank 3.

[0140] Pure water input procedure: When the amount of nutrient solution temporarily stored in the buffer tank 3 reaches the amount required for preparing the maintenance solution, switch the connection state of the third control valve 803, connecting the first port of the buffer tank 3 to the inlet of the second sample delivery pipe 704 through the third control valve 803; then turn on the pure water delivery pump 902 and the first control valve 801, and close the second control valve 802, pumping external pure water into the pure water input pipe 701 through the pure water delivery pump 902, and then into the buffer tank through the first sample delivery pipe 703. Pool 3 uses pure water to fill the nutrient solution temporarily stored in the buffer pool 3 into the mixing and dissolved oxygen pool 4 through the second sampling pipe 704 and the gas-liquid mixing nozzle 6. At the same time, the pure water flowing through it is measured by the flow meter 13. During this period, the amount of pure water flowing through it and the total amount of nutrient solution are equal to the amount of pure water entering the buffer pool 3. At the same time as the first control valve 801 is opened, the gas delivery pump 901 is turned on to pump clean air or oxygen into the gas-liquid mixing nozzle 6.

[0141] Maintenance procedure: In the gas-liquid mixing nozzle 6, liquid and gas are sprayed out from the spray section 602 of the gas-liquid mixing nozzle 6 by the pressure of the delivery pump 9, and the gas and liquid are fully mixed under the action of the baffle 603 to obtain a uniformly mixed maintenance solution with dissolved oxygen saturation; then the fourth control valve 804 is opened to deliver the test solution into the biofilm reactor 10 at the set flow rate and make full contact with the nitrifying bacteria biofilm 1002. At the same time, the dissolved oxygen concentration of the liquid flowing into and out of the biofilm reactor 10 is measured by the dissolved oxygen detector.

[0142] The testing phase process is as follows:

[0143] Nutrient solution input procedure: During the detection phase, the nutrient solution input procedure is the same as that during the intermittent phase, and will not be described again here;

[0144] Wastewater sample input procedure: First, the outlet of the sample storage bottle 1 is connected to the first port of the buffer tank 3 through the third control valve 803, so that the wastewater sample in the sample storage bottle 1 can enter the buffer tank 3 for temporary storage through the third control valve 803. At this time, the second control valve 802 is opened so that the pure water pre-stored in the buffer tank 3 can enter the mixing and dissolved oxygen tank 4 through the second control valve 802. At the same time, the pure water flowing through it is measured by the flow meter 13, so the amount of pure water flowing through it is equal to the amount of wastewater sample entering the buffer tank 3.

[0145] Pure water input procedure: During the detection phase, the pure water input procedure is the same as that during the intermittent phase, and will not be described again here;

[0146] Detection procedure: In the gas-liquid mixing nozzle 6, liquid and gas are sprayed out from the injection section 602 of the gas-liquid mixing nozzle 6 by the pressure of the delivery pump 9, and the gas and liquid are fully mixed under the action of the baffle 603 to obtain a uniformly mixed test liquid with dissolved oxygen saturation. Then, the fourth control valve 804 is opened to deliver the test liquid into the biofilm reactor 10 at the set flow rate and make full contact with the nitrifying bacteria biofilm 1002. At the same time, the dissolved oxygen concentration of the liquid flowing into and out of the biofilm reactor 10 is measured by the dissolved oxygen detector, and the biotoxicity of the wastewater is calculated using the dissolved oxygen concentration of the liquid. The detailed calculation process is referred to Chinese Patent No. CN115818859B, which will not be repeated here.

[0147] It should be noted that if the buffer pool 3 has a large volume, sufficient to hold both nutrient solution and wastewater sample at the same time, then the nutrient solution input program and the wastewater sample input program can be performed continuously, followed by a pure water input program. However, if the buffer pool 3 has a slightly smaller volume, only able to hold one of the nutrient solution or wastewater sample at the same time, then a pure water input program can be performed after the nutrient solution input program and the wastewater sample input program.

[0148] In addition, before each intermittent or detection phase, the liquid remaining in the mixing and dissolved oxygen tank 4 from the previous phase must be drained through the fifth control valve 805.

[0149] In addition, in order to obtain real-time water samples of the water body being tested, before inputting wastewater samples into sample storage bottle 1, the sixth control valve 806 on sample storage bottle 1 can be opened for a period of time to drain the wastewater in the water sampling pipeline between the sampling point and sample storage bottle 1, as well as the wastewater in sample storage bottle 1. Then, the sixth control valve 806 is closed to obtain the water sample for testing, thereby achieving real-time acquisition of water samples.

[0150] In the online wastewater toxicity monitoring method based on nitrifying bacteria biofilm described in this invention, nutrient solution or wastewater samples are first introduced into the buffer tank 3 and the mixing and dissolved oxygen tank 4 during both the intermittent and detection phases. Firstly, pure water can be used to directly flush the nutrient solution or wastewater samples into the mixing and dissolved oxygen tank 4, avoiding the use of a power pump to directly deliver the nutrient solution or wastewater samples, thus making the detection results more accurate. Secondly, the nutrient solution or wastewater samples can be preferentially delivered to the mixing and dissolved oxygen tank 4, extending the mixing time under the subsequent action of pure water and oxygen, as well as the time spent under the action of the ultraviolet sterilizing lamp 5, optimizing the gas-liquid and liquid-liquid mixing effect and the sterilization treatment effect. Furthermore, this sampling method greatly reduces the number of delivery pumps used, significantly reducing equipment manufacturing costs.

[0151] In addition, after each time the nutrient solution or wastewater sample is flushed into the mixing and dissolved oxygen tank 4 with pure water, the pipeline system of the online wastewater toxicity monitoring device will temporarily contain pure water, which will not affect the operation of the next stage and make the detection results more accurate.

[0152] In addition, during the use of the online wastewater toxicity monitoring device, the equipment can be thoroughly cleaned at regular intervals. The cleaning procedure is as follows:

[0153] First, turn on the pure water delivery pump 902, the first control valve 801, and the second control valve 802, and connect the first port of the buffer tank 3 to the inlet of the second sample delivery pipe 704. Pump external pure water into the pure water input pipe 701 through the pure water delivery pump 902, and then enter the gas-liquid mixing nozzle 6 through the first sample delivery pipe 703 and the second control valve 802, and then spray it into the mixing and dissolved oxygen tank 4. After a set time, open the fifth control valve 805 to discharge the liquid in the mixing and dissolved oxygen tank 4 from the residual sample discharge pipe 707.

[0154] The embodiments of this application have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. This application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. An online wastewater toxicity monitoring device based on nitrifying bacteria biofilm, characterized in that, include: Sample storage bottle (1), which is used to store wastewater samples to be tested; Nutrient solution tank (2), which is used to store nutrient solution; The buffer pool (3) is used to temporarily store the wastewater sample discharged from the sample bottle (1) or the nutrient solution discharged from the nutrient solution pool (2); the buffer pool (3) is a tubular structure, with the two ends of the pipe forming the inlet and outlet of the buffer pool (3), and the diameter of the pipe structure inside the buffer pool (3) is less than or equal to 20 mm. In the mixing and dissolved oxygen tank (4), oxygen, pure water, nutrient solution and wastewater sample are mixed to obtain the curing solution for the curing stage or the test solution for the testing stage. Ultraviolet sterilization lamp (5) is installed in the mixing and dissolved oxygen pool (4); A gas-liquid mixing nozzle (6) is provided in the mixing and dissolved oxygen pool (4) to promote liquid mixing and oxygen dissolution in the mixing and dissolved oxygen pool (4); A biofilm reactor (10) is provided with packing material, and a nitrifying bacteria biofilm (1002) mainly composed of nitrifying bacteria is formed on the surface of the packing material. In addition, there are conveying pipes (7) connecting the various components, valves (8) controlling the opening and closing of the pipes, and conveying pumps (9) for pumping liquids and gases. The gas-liquid mixing nozzle (6) includes: The tapering section (601) is a trumpet-shaped structure whose cross-section gradually decreases from bottom to top; The spray section (602) is a tubular structure provided at the upper end of the tapered section (601), and the inner diameter of the spray section (602) is equal to the inner diameter of the upper end of the tapered section (601). The baffle (603) is a cylindrical structure suspended above the jet (602), and the inner diameter of the baffle (603) is larger than the inner diameter of the jet (602). The first injection port (605) is formed by the gap between the injection part (602) and the baffle (603), and the distance between the baffle (603) and the injection part (602) is 10~50mm; The baffle tube (603) includes a side wall and a top surface located at its upper end. The fluid ejected from the jet (602) is deflected back after hitting the side wall or top surface of the baffle tube (603). The conveying pipeline (7) includes: The first sample delivery pipe (703) is connected between the second port of the buffer pool (3) and the liquid inlet on the gas-liquid mixing nozzle (6); A pure water inlet pipe (701) is connected between an external pure water inlet pipe and a first sample delivery pipe (703); The second sample delivery pipe (704) connects the first port of the buffer pool (3) to the first sample delivery pipe (703); The connection point between the pure water input pipe (701) and the first sample delivery pipe (703) is located between the second port of the buffer pool (3) and the connection point between the second sample delivery pipe (704) and the first sample delivery pipe (703); An air input pipe (702) is connected to the external atmosphere and the gas inlet on the gas-liquid mixing nozzle (6); A flow meter (13) is installed on the first sample delivery pipe (703), and the flow meter is located at the rear end of the connection point between the second sample delivery pipe (704) and the first sample delivery pipe (703); In use, firstly, the wastewater sample in the sample storage bottle (1) or the nutrient solution in the nutrient solution pool (2) is input into the buffer pool (3). Then, the wastewater sample or nutrient solution temporarily stored in the buffer pool (3) is flushed into the mixing and dissolved oxygen pool (4) with pure water and mixed with oxygen therein to obtain the maintenance solution or test solution. Then, the maintenance solution or test solution is transported to the biofilm reactor (10) for the maintenance of nitrifying bacteria biofilm (1002) or wastewater toxicity testing.

2. The online wastewater toxicity monitoring device based on nitrifying bacteria biofilm according to claim 1, characterized in that, The volume of the buffer pool (3) is greater than or equal to the maximum amount of wastewater sample required for a single preparation of maintenance solution or test solution, and the volume of the buffer pool (3) is greater than or equal to the maximum amount of nutrient solution required for a single preparation of maintenance solution or test solution.

3. The online wastewater toxicity monitoring device based on nitrifying bacteria biofilm according to claim 1, characterized in that, The baffle (603) includes: The second injection port (606) is provided on the upper part of the baffle (603). There are multiple second injection ports (606), which are evenly spaced along the circumference on the baffle (603).

4. The online wastewater toxicity monitoring device based on nitrifying bacteria biofilm according to claim 1, characterized in that, The valve (8) includes: The first control valve (801) is installed on the pure water input pipe (701) and is used to control the opening and closing of the pure water input pipe (701); The second control valve (802) is installed on the first sample delivery pipe (703) and is used to control the opening and closing of the first sample delivery pipe (703). The second control valve (802) is located between the connection point of the first sample delivery pipe (703) and the pure water input pipe (701) and the connection point of the first sample delivery pipe (703) and the second sample delivery pipe (704). The third control valve (803) has four interconnected ports, which are respectively connected to the outlet of the sample bottle (1), the outlet of the nutrient solution pool (2), the first port of the buffer pool (3), and the inlet of the second sample delivery pipe (704) to regulate the liquid flow direction between the sample bottle (1), the nutrient solution pool (2), and the buffer pool (3).

5. The online wastewater toxicity monitoring device based on nitrifying bacteria biofilm according to claim 1, characterized in that, The sample storage bottle (1) is provided with a connection mechanism for quick connection with the sampling bottle (11), which includes: A sandwich panel (102) is formed inside the sample bottle (1), the sandwich panel (102) dividing the internal space of the bottle body (101) into a main chamber for containing liquid and a secondary chamber for gas passage, wherein the main chamber is located on the side away from the bottle opening of the sample bottle (1), and the secondary chamber is located on the side close to the bottle opening of the sample bottle (1). The inner bottle opening (104) and the outer bottle opening (103) are fitted together, wherein the inner bottle opening (104) and the outer bottle opening (103) are both located on the side surface of the sandwich plate (102) near the secondary chamber, and the outer bottle opening (103) surrounds the outer periphery of the inner bottle opening (104). A first air inlet (105) is provided on the body (101) of the sample storage bottle (1), and the first air inlet (105) is located on the side wall of the secondary chamber; The second air inlet (106) and the third air inlet (107) are provided on the outer bottle opening (103), wherein the second air inlet (106) is located at the end of the outer bottle opening (103) near the interlayer plate (102), and the third air inlet (107) is located at the end of the outer bottle opening (103) away from the interlayer plate (102).

6. The online wastewater toxicity monitoring device based on nitrifying bacteria biofilm according to claim 5, characterized in that, The outer diameter of the outer bottle opening (103) is equal to the inner diameter of the bottle opening on the sampling bottle (11). When the bottle opening of the sampling bottle (11) is inserted into the outer bottle opening (103) of the storage bottle (1), the side wall of the bottle opening of the sampling bottle (11) is located between the second air inlet (106) and the third air inlet (107).

7. A method for online wastewater toxicity monitoring based on nitrifying bacteria biofilm, characterized in that, The online wastewater toxicity monitoring method is used in the online wastewater toxicity monitoring device based on nitrifying bacteria biofilm as described in any one of claims 1-6, and the online wastewater toxicity monitoring method includes an intermittent phase and a detection phase: The intermittent phase includes: a nutrient solution input program, a pure water input program, and a maintenance program; The detection phase includes: nutrient solution input procedure, wastewater sample input procedure, pure water input procedure, and detection procedure; The nutrient solution or wastewater sample input procedure during the intermittent and detection phases includes: First, the outlet of the nutrient solution tank or sample storage bottle is connected to the first port of the buffer tank through the third control valve, so that the nutrient solution in the nutrient solution tank or the wastewater sample in the sample storage bottle can enter the buffer tank for temporary storage through the third control valve. At this time, the second control valve is opened so that the pure water pre-stored in the buffer tank can enter the mixing and dissolved oxygen tank through the second control valve. At the same time, the pure water flowing through it is measured by the flow meter, so the amount of pure water flowing through it is equal to the amount of nutrient solution or wastewater sample entering the buffer tank. The pure water input procedure in the intermittent and detection phases includes: connecting the first port of the buffer tank to the inlet of the second sample delivery pipe via the third control valve; then turning on the pure water delivery pump and the first control valve, and closing the second control valve to pump external pure water into the pure water input pipe via the pure water delivery pump, and then into the buffer tank via the first sample delivery pipe. Using pure water, the nutrient solution or wastewater sample temporarily stored in the buffer tank is filled into the mixing and dissolved oxygen tank through the second sample delivery pipe and the gas-liquid mixing nozzle. At the same time, the pure water flowing through it is measured by the flow meter. During this period, the total amount of liquid flowing through it is equal to the amount of pure water entering the buffer tank. At the same time as the first control valve is turned on, the gas delivery pump is turned on to pump clean air or oxygen into the gas-liquid mixing nozzle via the gas delivery pump.

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