Biodegradation reactor based detection system, and method therefor

Abstract

The present invention relates to the technical field of water quality monitoring. Specifically, disclosed are a biodegradation reactor based detection system, and a method therefor. The biodegradation reactor based detection system of the present invention comprises a plug flow type microbial film reactor, a power system, a detection system, and a flow system for storing and conveying fluid. Detection and analysis of a target pollutant is realized by detecting consumption of reactants or generation of products in a biodegradation reaction process, and the present invention can be applied to water environment pollutant detection. In the present invention, a biodegradation reactor is constructed by using various microorganisms having a specific biodegradation function in a water body, and a specific biodegradation function of a microbial film reactor is realized by means of domestication for a specific pollutant, thereby avoiding tedious processes such as microbial separation and purification and culture in conventional methods; and the method involves a simple operation, and has a wide application range, strong anti-interference capability and high biodegradation efficiency, and the analysis method has high sensitivity.

Description

A biodegradation reactor detection system and method Technical Field

[0001] The invention belongs to the technical field of water quality monitoring, and in particular relates to a biodegradation reactor detection system and a method thereof. Background Art

[0002] Nature is rich in microbial resources. Long-term induction by multiple environmental factors has domesticated microorganisms capable of biodegrading various environmental pollutants, maintaining the self-purification and material circulation of ecosystems. The unique degradation capabilities of microorganisms have been widely applied in the treatment and detection of water pollutants. Water quality testing technologies developed using microorganisms primarily rely on immobilized microbial membranes to construct microbial sensors and microbial fuel cells.

[0003] Microbial sensors typically use a purified, cultured single bacterial species or multiple bacterial species, which are then embedded in an immobilized material to form a membrane, which is then covered on the surface of a dissolved oxygen (DO) sensor probe. These sensors are typically used to measure the biochemical oxygen demand (BOD) of water. Microbial sensors require isolation, purification, culture, and immobilization, which is a complex process. Immobilized microorganisms must be maintained in a phosphate buffer solution to maintain their biological activity. The immobilized microbial population is small and single, with limited biodegradation capacity. In actual applications, environmental water samples are complex in composition, artificially selected strains have poor adaptability, and the embedding material is prone to clogging and swelling, leading to microbial inactivation.

[0004] The activated sludge aeration method uses activated sludge as a microbial reaction unit to degrade organic pollutants in water samples. The BOD content in the water is quantified by measuring the change in chemical oxygen demand (COD) before and after biodegradation. In practice, the decomposition of pollutants by activated sludge is inevitably accompanied by microbial proliferation, which can easily lead to sludge bulking. Furthermore, this sludge proliferation can render the original standard curve inapplicable, resulting in poor test result stability.

[0005] A microbial fuel cell (MFC) is an electrochemical system that converts biochemical reactions into electrical energy. Electrochemically active bacteria are enriched on the anode surface of the fuel cell, forming a biofilm. The electrogenic microorganisms on the biofilm convert the chemical energy in organic matter into electrical energy. It is commonly used to measure water quality parameters such as BOD and COD. Because MFCs convert biochemical reactions into electrical energy, electrons generated by the anaerobic metabolism of organic matter by electroactive bacteria must permeate the biofilm to reach the anode and then be transferred through an external circuit to the cathode, completing a closed circuit. Operation requires strict control of anaerobic conditions in the anode chamber. In practice, the metabolism of organic pollutants by electroactive bacteria inevitably leads to proliferation, increasing the biofilm thickness and directly limiting the efficiency of electron transfer to the anode. Consequently, the increased biodegradation efficiency of the biofilm is accompanied by a gradual decrease in electron transfer efficiency, resulting in suboptimal performance in practice. The complex composition of organic pollutants in wastewater, as well as the conductivity and pH of the solution, can affect the MFC's power generation and microbial activity, leading to suboptimal performance in practice.

[0006] Current water quality testing technologies based on microorganisms still face challenges such as cumbersome manual microbial screening and cultivation, poor stability in practical applications of immobilized methods, and low anti-interference capabilities of biorecognition elements. Therefore, there is a need for efficient, accurate, stable, and sensitive water quality testing methods.

[0007] Summary of the Invention

[0008] In response to the above-mentioned defects of water quality detection in the prior art, the present invention will provide a method for constructing a biodegradation reactor, as well as a method for realizing the detection of multiple water quality parameters using this biodegradation reactor. The biodegradation reactor is constructed using various microorganisms with specific biodegradation functions in the water body, and the specific biodegradation function of the microbial membrane reactor is realized through the domestication of specific pollutants. The detection and analysis of target pollutants are realized by detecting the consumption of reactants or the generation of products in the biodegradation reaction process.

[0009] To achieve the above objectives, the following technical solutions are specifically included:

[0010] A plug flow microbial membrane reactor comprises a plug flow reactor and a microbial membrane, wherein the plug flow reactor is a through-tube structure, and the microbial membrane is attached to the inner surface of the plug flow reactor;

[0011] The method for constructing the microbial membrane reactor comprises the following steps:

[0012] (1) placing an environmental water sample and a plug flow reactor in a constant temperature water bath, aerating the environmental water sample, and then continuously transporting the environmental water sample to the plug flow reactor through a pipeline. During the environmental water sample flowing in the plug flow reactor and contacting the inner surface of the plug flow reactor, microorganisms in the environmental water sample adhere to and grow on the inner surface of the plug flow reactor to form a microbial film;

[0013] (2) adding an acclimation agent to an environmental water sample, and then transporting the water sample containing the acclimation agent to a plug flow reactor for a microbial film acclimation culture process to obtain the microbial film reactor; the acclimation agent includes at least one of biodegradable organic matter, inorganic ammonium salt, inorganic carbonate, and inorganic nitrite.

[0014] As a preferred embodiment of the present invention, the microbial film acclimation and cultivation process further includes a method for monitoring the microbial film acclimation and cultivation process, which includes the following steps:

[0015] (2-1) A blank water sample is delivered to a plug flow reactor, and the outflowing water sample is detected by a detection system to obtain an initial signal;

[0016] (2-2) Then, a pollutant standard solution of known concentration is added to the blank water sample, and the water sample containing the pollutant standard solution of known concentration is transported to the plug flow reactor. The outflowing water sample is detected by the detection system to obtain a water sample signal, and the difference between the water sample signal and the initial signal is used as the response signal of the water sample;

[0017] (2-3) The growth status of the microbial membrane is determined by the change of the response signal. When the response signal of the water sample is measured to no longer change, the microbial membrane reactor is obtained.

[0018] As a preferred embodiment of the present invention, in the pollutant standard solution in step (2-2), when the biodegradation reactor is used for water quality biochemical oxygen demand detection, the pollutant standard solution is a biodegradable organic matter solution, and the five-day biochemical oxygen demand (BOD5) concentration of the biodegradable organic matter is 2-500 mg / L; when the biodegradation reactor is used for water quality ammonia nitrogen detection, the pollutant standard solution is an inorganic ammonium salt solution, and the ammonia nitrogen concentration of the inorganic ammonium salt is 0.5-10 mg / L in terms of N; when used for simultaneous detection of water quality biochemical oxygen demand and ammonia nitrogen, the pollutant standard solution is a mixed solution of the above two solutions.

[0019] As a preferred embodiment of the present invention, it also includes subjecting the microbial membrane reactor to a second microbial membrane acclimation and culture process, specifically including the following steps: adding an acclimation agent to the water sample in the already constructed microbial membrane reactor, and then transporting the water sample containing the acclimation agent to a plug flow reactor for a second microbial membrane acclimation and culture process to obtain the microbial membrane reactor; the acclimation agent used in the second microbial membrane acclimation and culture process is different from the acclimation agent used in the previous microbial membrane acclimation and culture process. The acclimation of different acclimation agents can dynamically adjust the microbial population structure on the microbial membrane reactor and achieve different biodegradation capabilities of the plug flow microbial membrane reactor. The microbial membrane reactor obtained by culturing the above steps can be acclimated and cultured again using another acclimation agent to obtain a microbial membrane reactor with another biodegradation function.

[0020] The present invention provides a microbial membrane reactor in a biodegradation reactor constructed by colonizing environmental microorganisms on the surface of a substrate. The reactor utilizes the directional domestication of specific pollutants to realize the conduction of specific biological reactions in the reactor, and detects the consumption of reactants and the generation of products (conservation of matter transformation) during the biodegradation reaction process to realize the detection and analysis of target pollutants.

[0021] Specifically, first, a plug flow reactor is constructed by connecting a central tubular structure to a flow system. During the continuous flow of the water sample in the reactor, it comes into contact with the substrate in a stepwise manner, and the microbial film in the confined space can only grow in layers. The surface adhesion of the microorganisms is utilized to achieve adsorption, layered growth, and film formation of environmental microorganisms in the water sample on the surface of the substrate, thereby constructing a biodegradation reactor with a broad spectrum of microbial populations and a large number of microorganisms. Then, when there is obvious microbial adsorption on the surface of the reactor, specific pollutants are added to the water sample for microbial film acclimation and cultivation. A signal detection unit is connected to the end of the plug flow reactor, and a standard solution of the pollutant to be tested is passed into the plug flow reactor. The response of the signal detection unit is used to determine whether the biochemical degradation reaction is proceeding. The response signal of the microbial film to the same concentration of standard solution is regularly tracked to determine the growth status of the microbial film. When the response signal no longer changes after repeated measurements of the same concentration of standard solution, the microbial film cultivation is complete. In this process, continuous and frequent standard sample testing also acclimates the microorganisms on the microbial film. The continuous acclimation process gradually selects the dominant microbial strains under these conditions, achieving efficient degradation of pollutants and accurately quantifying the pollutant content.

[0022] The growth status of the microbial film is judged by the change of the response signal. When the response signal of the water sample is measured to no longer change, the microbial film reactor is obtained; when the response signal of the water sample is measured to still change, the process of steps (2), (2-1) and (2-2) is repeated multiple times, and the time interval between each step (2) and steps (2-1) and (2-2) is 1-4 hours.

[0023] As a preferred embodiment of the present invention, the process of repeating steps (2), (2-1) and (2-2) in sequence multiple times is specifically as follows: the interval time is 4 hours each time, when the response signal of two consecutive measurements is less than 0.2 mg / L, the interval time is changed to 1 hour each time, and when the response signal obtained after three consecutive measurements no longer changes, the microbial membrane reactor is obtained.

[0024] The present invention utilizes various microorganisms with specific biodegradation functions in water bodies to construct a biodegradation reactor, realizes the specific biodegradation function of microorganisms through the targeted domestication of specific environmental pollutants, avoids the tedious processes of microbial separation, purification and cultivation in conventional methods, and is simple to operate; different environmental pollutants can be used to domesticate biological reaction units that can specifically degrade different pollutants, and the method has a wide range of applications; through domestication technical means, the composition of the microbial population on the microbial membrane reactor can be adjusted to achieve switching / simultaneous online monitoring of different environmental pollutants; the naturally domesticated microbial population has excellent environmental adaptability and strong anti-interference ability, and accurate measurement of actual water samples can be achieved without pretreatment; the construction of the plug flow reactor realizes step-by-step contact between pollutants and microbial reaction units, high biodegradation efficiency, and high sensitivity of the analysis method.

[0025] As a preferred embodiment of the present invention, the biodegradable organic matter includes at least one of biodegradable sugars, amino acids, aliphatic hydrocarbons, organic acids, and alcohols; the inorganic ammonium salt includes an inorganic matter containing ammonium ions; the inorganic carbonate includes an inorganic matter containing carbonate ions; and the inorganic nitrite includes an inorganic matter containing nitrite ions.

[0026] As a preferred embodiment of the present invention, the five-day biochemical oxygen demand (BOD5) concentration of the biodegradable organic matter is 2-500 mg / L, the ammonia nitrogen concentration of the inorganic ammonium salt is 0.5-50 mg / L in terms of N, the mass concentration of the inorganic carbonate is 0.004-0.4 g / L, and the nitrite nitrogen concentration of the inorganic nitrite is 0.05-5 mg / L in terms of N.

[0027] As a preferred embodiment of the present invention, the detection system includes at least one of a dissolved oxygen analysis system, a total organic carbon (TOC) analysis system, a chemical oxygen demand (COD) analysis system, and a pH analysis system.

[0028] As a preferred embodiment of the present invention, the blank water sample includes tap water or an uncontaminated water sample.

[0029] As a preferred embodiment of the present invention, the environmental water sample includes at least one of natural water and sewage.

[0030] As a preferred embodiment of the present invention, the water sample includes at least one of river water, effluent from a primary sedimentation tank of a domestic sewage treatment plant, pond water, and lake water.

[0031] As a preferred embodiment of the present invention, the material of the plug flow reactor includes at least one of polyurethane, polylactic acid, and glass.

[0032] As a further preferred embodiment of the present invention, the plug flow reactor is a hollow multi-channel cylindrical pipe with a length of 75 cm and an outer diameter of 2.4 cm, wherein the inner diameter of each channel is 1-3 mm, or a spiral tubular pipe with a wall thickness of 0.5 mm, an inner diameter of 1-4 mm, and a total length of 100-200 cm.

[0033] Using biocompatible materials such as polyurethane and polylactic acid as the substrate, important parameters such as the cross-sectional shape of the reactor structure cavity, channel size, hydraulic flow direction and reactor volume are designed. The reactor is designed through heat setting and 3D printing, connected to the flow system, and constructed as a plug flow reactor.

[0034] As a preferred embodiment of the present invention, the temperature of the constant temperature water bath is 25-37°C.

[0035] As a preferred embodiment of the present invention, the flow rate of the environmental water sample is 0.5-5 mL / min.

[0036] After aeration, the water sample is continuously introduced into the plug flow reactor. The water sample flows at a constant speed within the plug flow reactor. During contact with the substrate surface, microorganisms attach and grow on the substrate surface, gradually forming a biofilm. This uniform, progressive contact ensures uniform microbial attachment within the reactor.

[0037] A biodegradation reactor detection system, comprising the plug-flow microbial membrane reactor, a power system, a detection system, and a flow system for storing and transporting fluids;

[0038] One side of the plug flow microbial membrane reactor is connected to the pipeline and the power system to form a closed system. The fluid in the flow system is transported to the plug flow reactor through the pipeline and the power system. After passing through the plug flow microbial membrane reactor, the fluid flows out from the other side, and the outflowing fluid is detected by the detection system.

[0039] As a preferred embodiment of the present invention, the power system includes a peristaltic pump.

[0040] The power system provides power for the fluid and is used to control the inflow and outflow of the fluid in the flow system; the plug flow microbial membrane reactor is used for the biodegradation of environmental pollutants. In the process of acclimating the microbial membrane, a specific type of acclimator is acclimated to obtain a plug flow microbial membrane reactor with a specific biodegradation function. This specific degradation function degrades the pollutants passing through it. Combined with the detection function of the effluent of the detection system, the purpose of detecting the pollutant concentration is achieved through degradation-detection.

[0041] A detection method for a biodegradation reactor detection system comprises the following steps:

[0042] (1) Using a blank water sample as a fluid, the blank water sample is detected by the biodegradation reactor detection system to obtain an initial signal;

[0043] (2) Then, the signal of the water sample to be tested is detected by the biodegradation reactor detection system to obtain the water sample signal to be tested, and the difference between the water sample signal to be tested and the initial signal is used as the response signal of the water sample to be tested.

[0044] As a preferred embodiment of the present invention, the following steps are also included:

[0045] (1) Drawing of a standard curve: using standard samples containing pollutants at different concentrations as standard solutions, the standard solutions are tested using the biodegradation reactor detection system to obtain response signals of different standard solutions, and a standard curve is drawn with the concentration of the standard solution as the abscissa and the response signal of the standard solution as the ordinate;

[0046] (2) Detection of the water sample to be tested: The water sample to be tested is detected using the biodegradation reactor detection system to obtain a response signal of the water sample to be tested, and the detection result of the water sample to be tested is calculated using a standard curve.

[0047] When used for water quality biochemical oxygen demand (BOD) detection, the acclimatizer is biodegradable organic matter, and the detection system is a dissolved oxygen analysis system, a total organic carbon (TOC) analysis system or a chemical oxygen demand (COD) analysis system.

[0048] When used for detecting ammonia nitrogen concentration in water, the acclimatizer is an inorganic ammonium salt, an inorganic carbonate and / or an inorganic nitrite, and the detection system is a pH analysis system or a dissolved oxygen analysis system.

[0049] When used for simultaneous detection of water quality BOD and ammonia nitrogen, the acclimatizer is biodegradable organic matter, inorganic ammonium salt, inorganic carbonate and / or inorganic nitrite, and the detection system is a dissolved oxygen analysis system.

[0050] When using the biodegradation reactor for water quality testing, an uncontaminated water sample, such as a background solution of tap water, is first used, placed under constant temperature conditions, and continuously introduced into the reactor after aeration. Signal detection is then performed on the water outlet from the reactor. At this time, the signal response is a blank signal of the microbial membrane. When the sample to be tested flows through the reactor, a biodegradation reaction occurs, and this process is accompanied by material transformation. The difference between the response signal and the blank signal measured by the signal detection unit is the degree of biochemical degradation reaction of the microbial membrane in the reactor to the pollutant. This signal corresponds to the concentration of the pollutant.

[0051] By testing the response signals of multiple standard samples of known concentrations, a standard curve is drawn, and the pollutant concentration of the water sample to be tested is calculated based on the corresponding relationship of the standard curve. After a single test is completed, the uncontaminated water sample is continuously passed through the reactor to discharge the residual sample before the next measurement can be carried out.

[0052] The application of the biodegradation reactor in water quality detection can utilize the specific biodegradation function to achieve alternating / synchronous monitoring of water quality parameters BOD and ammonia nitrogen.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] (1) The biodegradation reactor of the present invention is constructed with a plug flow reactor with a through-tube structure, so that the environmental microorganisms can uniformly adhere to form a film during the contact process between the water sample and the substrate. The microbial film reactor can be constructed without the use of embedding materials and expensive carriers. The microbial film in the confined space can only grow in layers. Due to the limitation of the mass transfer efficiency of substances in the microbial film, only the surface microbial film participates in the biodegradation reaction. The biodegradation efficiency is not affected by the proliferation of the microbial film, and the long-term stability of the microbial film performance is achieved.

[0055] (2) In the biodegradation reactor of the present invention, the environmental microorganisms contained in the natural water body itself are the product of natural domestication and survival competition, and are generally the microbial population most suitable for degrading pollutants contained in the water body. They are colonized on the surface of the substrate to form a microbial film, and at the same time, the specific biodegradation ability of the microbial film is achieved by further domestication of environmental pollutants. This microbial film is then used to determine pollutants in water samples, which best reflects the intrinsic biochemical reaction process of the microbial population in the water body. At the same time, the naturally domesticated microbial population environment has excellent environmental adaptability, strong anti-interference ability, and efficient and stable biodegradation. The water quality detection and analysis method developed based on this has high sensitivity.

[0056] (3) In the biodegradation reactor of the present invention, environmental pollutants are used to acclimate environmental microorganisms to achieve biodegradation specialization, avoiding the tedious process of microbial separation, purification and cultivation. No buffer system is required during the application process, and tap water can be used to maintain microbial activity.

[0057] (4) The biodegradation reactor of the present invention is taken from the environment and used in the environment, is simple to operate, does not consume reagents, and is green and environmentally friendly. At the same time, the water quality detection process also achieves partial degradation of pollutants.

[0058] (5) The present invention can adjust the composition of the microbial population on the microbial membrane reactor by means of domestication, realize the switching / simultaneous online monitoring of different environmental pollutants, and can monitor BOD or ammonia nitrogen separately in a targeted manner or simultaneously.

[0059] (6) The microbial population structure on the microbial membrane reactor can be dynamically adjusted by domestication with different domestication agents, thereby realizing different biodegradation capabilities of the plug-flow microbial membrane reactor. If the domestication agent is changed and the reactor is domesticated and cultured again, a microbial membrane reactor with another biodegradation function can be obtained. The present invention can change the detection signal and the microbial membrane reactor to realize the detection of different pollutants. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] FIG1 is a structural diagram of an environmental pollutant biodegradation reactor according to an embodiment.

[0061] Figures 2A, 2B and 2C are schematic diagrams of a multi-channel plug flow reactor according to an embodiment, wherein Figure 2A is a front view of the reactor, Figure 2B is a schematic diagram of the hollow multi-channel cylindrical pipeline of the reactor, and Figure 2C is a cross-sectional view of the reactor.

[0062] FIG3 is a BOD standard curve diagram of Example 1.

[0063] FIG4 is a relationship curve diagram of ΔTOC and BOD in Example 2.

[0064] FIG5 is ammonia nitrogen (NH + 4-N) Standard curve graph.

[0065] FIG6 is a BOD standard curve diagram of Example 4.

[0066] FIG7 is ammonia nitrogen (NH + 4-N) Standard curve. DETAILED DESCRIPTION

[0067] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below through specific embodiments.

[0068] Example 1

[0069] The biodegradation reactor of this embodiment uses a dissolved oxygen electrode as a signal detection unit and is applied to the detection of biochemical oxygen demand (BOD) of water quality.

[0070] The method for constructing the biodegradation reactor comprises the following steps:

[0071] (1) Plug flow reactor design

[0072] A hollow multi-channel cylindrical tube with a length of 7.5 cm and an outer diameter of 2.4 cm was prepared using polylactic acid (PLA) material using 3D printing technology, as shown in Figures 2A, 2B, and 2C (the multi-channel design is to provide more adsorption surface area for microorganisms). Each channel has an inner diameter of 2 mm and is connected to the power system using a hose.

[0073] (2) Microbial membrane reactor culture

[0074] (2-1) Microbial Adsorption: A plug flow reactor was placed in a 37°C constant temperature water bath. A water sample (river water sample) collected from the Tiansha River was saturated with air via an aeration pump and then placed in a 37°C constant temperature water bath. A peristaltic pump was used to continuously deliver the water sample to the plug flow reactor at a flow rate of 3 mL / min and then discharge it. Simultaneously, the influent water sample was continuously replenished. During this process, the water sample came into contact with the substrate in a stepwise manner, and environmental microorganisms in the water sample gradually adsorbed and colonized on the substrate surface.

[0075] (2-2) Acclimation of the Microbial Film: When microbial flocs are clearly visible on the reactor's inner surface, add acclimation solution to the water sample until the BOD concentration reaches 100 mg / L and continue to flow through the plug flow reactor to acclimate the microbial film. The acclimation solution is composed of a mixture of glucose solution, glutamic acid solution, galactose solution, sucrose solution, benzoic acid solution, malic acid solution, and asparagine solution, all with a BOD concentration of 1000 mg / L. During acclimation, add the solution to the water sample at a ratio of 1:10.

[0076] (2-3) Monitoring of the microbial film acclimation process: A dissolved oxygen electrode was connected to the end of the plug flow reactor as a signal detection unit. Tap water was placed in a water sample cup, placed in a 37°C constant temperature water bath and saturated with air. The tap water was delivered to the plug flow reactor at a flow rate of 3 mL / min using a peristaltic pump. The dissolved oxygen electrode was used as a signal detection system to detect the oxygen content of the water sample when it reached the oxygen electrode. When the dissolved oxygen signal reached a steady state, the signal was recorded as DO. b ; A GGA standard solution with a BOD concentration of 10 mg / L is introduced. When the GGA solution enters the reactor, the microorganisms on the microbial membrane degrade the organic matter in the solution during contact. At the same time, the dissolved oxygen in the water is consumed in this process, and the dissolved oxygen content reaching the surface of the oxygen electrode is reduced. When the signal reaches a steady state again, the signal is recorded as DO s ,DO b With DO sThe difference ΔDO is the signal response of the reactor to the GGA solution. Step (2-3) is also the test process when the biodegradation reactor is used to detect water pollutants.

[0077] (2-4) Test with a GGA standard solution with a BOD concentration of 10 mg / L every 4 hours. The specific steps are: repeat the above-mentioned microbial film cultivation and standard sample testing steps (i.e., repeat steps 2-2 and 2-3) until the difference ΔDO between the signal response values ​​of two consecutive measurements is less than 0.2 mg / L. The standard sample test interval is changed to once an hour. When the signal no longer changes after three consecutive measurements, it indicates that a stable microbial film has been formed on the inner wall of the reactor, thereby determining that the microbial film reactor formed by environmental microbial colonization is complete.

[0078] (3) Drawing of standard curve

[0079] Referring to the steps (2-3) above, GGA standard solutions with BOD concentrations of 0.0, 5.0, 10.0, 15.0, and 20.0 mg / L were passed into the above-mentioned microbial membrane reactor, and the GGA standard solutions were tested. The steady-state signal ΔDO of the oxygen electrode was recorded when the tap water and the standard solution reached the oxygen electrode after passing through the microbial membrane. The results are shown in Table 1. The standard curve was drawn with the BOD concentration as the horizontal axis and the corresponding dissolved oxygen signal difference ΔDO as the vertical axis. The results showed that the equation of the standard curve was y = 0.200x-0.016, the linear range was 0-20 mg / L, and the correlation coefficient r 2 =0.9996, as shown in Figure 3.

[0080] Table 1 BOD standard curve data

[0081] (4) River water sample testing

[0082] Tap water and river water samples were taken in beakers respectively, placed together in a constant temperature water bath at 37°C and saturated with air at 3.5 L / min. The tap water was continuously transported to the reactor at a flow rate of 3 mL / min using a peristaltic pump and then flowed through the oxygen electrode. When the output signal of the oxygen electrode reached stability, the dissolved oxygen signal was recorded. After that, the river water sample was continuously passed into the reactor. When this solution passed through the microbial membrane and reached the dissolved oxygen electrode, the electrode detected that the output signal gradually decreased and reached a new steady state. The dissolved oxygen change value of this process was calculated, and the BOD value of the water sample was calculated according to the standard curve.

[0083] (5) Testing river water samples using the national standard method (obtaining the true BOD value of water samples)

[0084] The river water sample in step (4) was biochemically cultured for 5 days using the national standard dilution inoculation method (HJ 505-2009) to obtain the BOD value of the river water sample.

[0085] (6) Test results

[0086] The test results of steps (4) and (5) on the water samples are shown in Table 2.

[0087] Table 2 Comparison of BOD value test results of river water samples

[0088] Example 2

[0089] The biodegradation reactor of this embodiment is used to quickly determine the BOD value of a water sample by measuring the difference in total organic carbon (TOC) before and after the biodegradation reaction.

[0090] The construction method of the biodegradation reactor is shown in Example 1, and the difference from Example 1 is that the design of the plug flow reactor adopts a polyurethane pipe with an inner diameter of 3mm and a length of 110cm, and the microbial film grows on the inner wall of the pipe; the environmental water sample used to cultivate the microbial film is the effluent of the primary sedimentation tank of the domestic sewage treatment plant; the acclimatization agent used for acclimating the microbial film is a glucose-glutamic acid (abbreviated as GGA) solution; the sample flow rate in the plug flow reactor is 1.5mL / min. When performing BOD detection, the detection system is a TOC analyzer. First, the TOC analyzer is used to detect the water sample to obtain the initial TOC value of the water sample. Then, the water sample is transported to the plug flow reactor, and the effluent flowing out of the reactor is collected and TOC measurement is performed to obtain the TOC value of the water sample after the biodegradation reaction. The corresponding relationship between the TOC difference before and after the biodegradation reaction and the BOD value is used to perform water quality BOD determination. The ΔTOC and BOD relationship curve is shown in Figure 4. The test results of the domestic sewage sample are shown in Table 3.

[0091] Table 3 Comparison of BOD value test results of domestic sewage samples

[0092] Example 3

[0093] The biodegradation reactor of this embodiment uses a dissolved oxygen electrode as a signal detection unit and is applied to the detection of ammonia nitrogen in water quality.

[0094] The method for constructing the biodegradation reactor comprises the following steps:

[0095] (1) Plug flow reactor design

[0096] Using glass as the raw material, a spiral tubular structure with a wall thickness of 0.5 mm and an inner diameter of 2.4 mm was fired. The total length was 150 cm. After rinsing, a 10% HF solution was passed through the glass to etch the inner wall to roughen the surface. After 15 minutes, the etchant was drained, and the remaining solution was rinsed with pure water before drying. A silicone hose was used to connect it to the power system.

[0097] (2) Microbial membrane reactor culture

[0098] (2-1) Microbial Adsorption: The plug flow reactor was placed in a 30°C constant temperature water bath. A water sample (pond water) collected from the pond was saturated with air via an aeration pump and then placed in a 30°C constant temperature water bath. A peristaltic pump was used to continuously deliver the water sample to the plug flow reactor at a flow rate of 3.5 mL / min and then discharge the sample. Simultaneously, the influent sample was continuously replenished. During this process, the water sample came into contact with the substrate in a stepwise manner, and the environmental microorganisms in the water sample gradually adsorbed and colonized on the substrate surface.

[0099] (2-2) Acclimation of the Microbial Film: When microbial flocs are clearly visible on the reactor surface, acclimation solution is added to the water sample to acclimate the microbial film. The acclimation solution consists of a mixture of 3.819 g / L ammonium chloride solution, 7.638 g / L sodium bicarbonate solution, and 0.492 g / L sodium nitrite solution. During acclimation, it is added to the water sample at a ratio of 1:50. After long-term acclimation with the acclimation solution, nitrifying bacteria on the microbial film gradually proliferate, while heterotrophic microorganisms gradually lose activity due to the long-term lack of nutrient sources such as organic matter.

[0100] (2-3) Monitoring of microbial film acclimation process: A dissolved oxygen electrode was connected to the end of the plug flow reactor as a signal detection unit. Tap water was placed in a water sample cup, placed in a 30°C constant temperature water bath and saturated with air. The tap water was delivered to the plug flow reactor at a flow rate of 3.5 mL / min using a peristaltic pump. The dissolved oxygen electrode was used as a signal detection system to detect the oxygen content of the water sample when it reached the oxygen electrode. When the dissolved oxygen signal reached a steady state, the signal was recorded as DO. b Then, an NH4Cl solution with an ammonia nitrogen concentration of 1 mg / L is introduced. When the NH4Cl solution enters the reactor, nitrification reaction occurs during the contact between the microorganisms on the microbial membrane and the ammonia nitrogen in the solution. At the same time, the dissolved oxygen in the water is consumed in this process, and the dissolved oxygen content reaching the surface of the oxygen electrode is reduced. When the signal reaches a steady state again, the signal is recorded as DO s ,DO b With DO s The difference ΔDO is the signal response of the reactor to the NH4Cl solution.

[0101] (2-4) The test was performed every 4 hours using an NH4Cl solution with an ammonia nitrogen concentration of 1 mg / L. The specific steps were as follows: the above-mentioned microbial film culture and standard sample test steps were repeated until the difference ΔDO between the signal response values ​​of two consecutive measurements was less than 0.2 mg / L. The standard sample test interval was changed to once an hour. When the signal no longer changed after three consecutive measurements, it was indicated that a stable microbial film had been formed on the inner wall of the reactor, thereby determining that the microbial film reactor culture formed by the colonization of environmental microorganisms was complete.

[0102] (3) Drawing of standard curve

[0103] According to the steps (2-3), NH + NH4-N concentrations of 0.0, 0.25, 0.5, 0.75, 1.0, 1.25, and 1.5 mg / L + 4-N standard solution was introduced into the above-mentioned microbial membrane reactor to + 4-N standard solution was used for ΔDO detection, and the difference in steady-state dissolved oxygen signal ΔDO between tap water and standard sample after passing through the microbial membrane and reaching the oxygen electrode was recorded. The results are shown in Table 4. + The concentration of 4-N was used as the horizontal axis, and the corresponding dissolved oxygen difference ΔDO was used as the vertical axis to draw a standard curve. The results showed that the equation was y = 2.679x + 0.031, the linear range was 0 ~ 1.5 mg / L, and the correlation coefficient r 2 =0.9971, as shown in Figure 5.

[0104] Table 4 Ammonia nitrogen standard curve data

[0105] (4) Pond water sample testing

[0106] Tap water and pond water samples were taken in beakers respectively, placed together in a constant temperature water bath at 30℃ and saturated with air. The tap water was continuously transported to the reactor at a flow rate of 3.5mL / min using a peristaltic pump and then flowed through the oxygen electrode. When the output signal of the oxygen electrode reached stability, the dissolved oxygen signal was recorded. After that, the pond water sample was continuously passed into the reactor. When this solution reached the dissolved oxygen electrode through the microbial membrane, the electrode detected that the output signal gradually decreased and reached a new steady state. The dissolved oxygen change value of this process was calculated, and the ammonia nitrogen value of the water sample was calculated according to the standard curve.

[0107] (5) Testing pond water samples using the national standard method (obtaining the true ammonia nitrogen value of the water sample)

[0108] The water sample was tested using the national standard salicylic acid spectrophotometry method (HJ 536-2009) to obtain the ammonia nitrogen value.

[0109] (6) Test results

[0110] The test results of steps (4) and (5) on the water samples are shown in Table 5.

[0111] Table 5 Comparison of ammonia nitrogen value test results of water samples

[0112] Example 4

[0113] The biodegradation reactor of this embodiment uses a dissolved oxygen electrode as a signal detection unit for simultaneous determination of water quality BOD and ammonia nitrogen.

[0114] The biodegradation reactor is obtained by re-acclimating the microbial membrane reactor used in Example 3, and comprises the following steps:

[0115] (1) Reacclimation of microbial membrane reactor

[0116] (1-1) Acclimation of the microbial membrane: The plug flow reactor was placed in a constant temperature water bath at 35°C. The water sample (sewage) collected from the effluent of the primary sedimentation tank of the domestic sewage treatment plant was saturated with air through an aeration pump and also placed in a constant temperature water bath at 35°C. A mixed solution of GGA and NH4Cl was added to the water sample to a BOD concentration of 100 mg / L and an ammonia nitrogen concentration of 10 mg / L. The solution was passed into the plug flow reactor at a flow rate of 4 mL / min to acclimate the microbial membrane so that the aerobic microorganisms and nitrifying bacteria therein could obtain sufficient nutrient sources to maintain biodegradation activity and proliferate.

[0117] (1-2) Monitoring of the microbial film acclimation process: A dissolved oxygen electrode was connected to the end of the plug flow reactor as a signal detection unit, and tests were performed using a GGA solution with a GGA concentration of 10 mg / L and an NH4Cl solution with an ammonia nitrogen concentration of 1 mg / L, respectively. The specific test steps were the same as those in Example 1 above.

[0118] (1-3) Repeat the above-mentioned microbial film cultivation and standard sample testing steps at intervals of 4 hours until the difference in the signal response values ​​of two consecutive measurements is less than 0.2 mg / L. The standard sample testing interval is changed to once an hour. When the signal no longer changes after three consecutive measurements, it indicates that a stable microbial film has been formed on the inner wall of the reactor, thereby determining that the microbial film reactor formed by environmental microbial colonization is complete.

[0119] (2) Drawing of standard curve

[0120] According to the above process, the BOD standard curve and the ammonia nitrogen standard curve were drawn respectively. The results are shown in Figures 6 and 7.

[0121] (3) Sewage sample testing

[0122] Take tap water and sewage samples separately in beakers, place them together in a constant temperature water bath at 35℃ and saturate them with air. Then, continuously deliver tap water to the reactor at a flow rate of 4mL / min and flow through the oxygen electrode. When the output signal of the oxygen electrode reaches stability, record the dissolved oxygen signal. Then, continuously pass the sewage sample into the reactor. When the solution passes through the microbial membrane and reaches the dissolved oxygen electrode, the electrode detects that the output signal gradually decreases and reaches a new steady state. The dissolved oxygen change value of this process is calculated as DO. t , which represents the amount of dissolved oxygen consumed by the biodegradation of organic matter and ammonia nitrogen in the water sample by the microbial film. Afterwards, 0.02 mg / L propylene thiourea (ATU) solution was added to the sewage sample and the above steps were measured. The dissolved oxygen change value during the process is DO BOD , represents the amount of dissolved oxygen consumed by the biodegradation of organic matter in the water sample by the microbial film. It should be noted that propylene thiourea solution is usually used as a nitrification inhibitor to inhibit nitrification. It is a non-competitive inhibitor and will not inhibit the activity of microorganisms in the reactor under the concentration conditions used in this example. BOD Calculate the BOD value of water sample with DO NH+4-N =DO t -DO BOD Calculate the NH+4-N value of the water sample.

[0123] (4) Test sewage samples using the national standard method (obtaining the true BOD and NH + 4-N value)

[0124] The sewage sample in step (4) was biochemically cultured for 5 days using the national standard BOD5 method to obtain the BOD value of the river water sample.

[0125] Use national standard method to measure NH + 4-N value.

[0126] (5) Test results

[0127] The test results of steps (4) and (5) on the water samples are shown in Table 6.

[0128] Table 6 BOD and NH of sewage samples + Comparison of 4-N value test results

[0129] As demonstrated in Examples 1-4, the present invention constructs a biodegradation reactor by colonizing environmental microorganisms on a substrate surface. This utilizes targeted acclimation of specific pollutants to achieve specific biological reactions within the reactor. By monitoring the consumption of reactants and the generation of products during the biodegradation reaction, the target pollutant can be detected and analyzed. This method is simple to operate, has a wide range of applications, and offers high analytical sensitivity without reagent consumption, making it a green and environmentally friendly method for analyzing and detecting environmental pollutants.

[0130] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A plug flow microbial membrane reactor, characterized in that: It includes a plug flow reactor and a microbial membrane, wherein the plug flow reactor is a through-tube structure, and the microbial membrane is attached to the inner surface of the plug flow reactor; The method for constructing the microbial membrane reactor comprises the following steps: (1) placing an environmental water sample and a plug flow reactor in a constant temperature water bath, aerating the environmental water sample, and then continuously transporting the environmental water sample to the plug flow reactor through a pipeline. The environmental water sample flows in the plug flow reactor. During the process of contacting the inner surface of the plug flow reactor, microorganisms in the environmental water sample adhere to and grow on the inner surface of the plug flow reactor to form a microbial film; (2) adding a domesticating agent to an environmental water sample, and then transporting the water sample containing the domesticating agent to a plug flow reactor for a microbial membrane domestication culture process to obtain the microbial membrane reactor; the domesticating agent includes at least one of biodegradable organic matter, inorganic ammonium salt, inorganic carbonate, and inorganic nitrite.

2. The plug flow microbial membrane reactor according to claim 1, characterized in that: The microbial film acclimation and cultivation process also includes a method for monitoring the microbial film acclimation and cultivation process, which includes the following steps: (2-1) A blank water sample is transported to a plug flow reactor, and the outflowing water sample is detected by a detection system to obtain an initial signal; (2-2) Then, a pollutant standard solution of known concentration is added to the blank water sample, and the water sample containing the pollutant standard solution of known concentration is transported to the plug flow reactor. The outflowing water sample is detected by the detection system to obtain a water sample signal, and the difference between the water sample signal and the initial signal is used as the response signal of the water sample; (2-3) The growth status of the microbial membrane is determined by the change of the response signal. When the response signal of the water sample is measured to no longer change, the microbial membrane reactor is obtained.

3. The plug flow microbial membrane reactor according to claim 1, characterized in that: Include any of the following: The biodegradable organic matter includes at least one of biodegradable sugars, amino acids, aliphatic hydrocarbons, organic acids, and alcohols; The inorganic ammonium salt includes an inorganic substance containing ammonium ions; The inorganic carbonate includes inorganic substances containing carbonate ions; the inorganic nitrite includes inorganic substances containing nitrite ions; It also includes a process of subjecting the microbial membrane reactor to a second microbial membrane acclimation and cultivation process, which specifically includes the following steps: adding an acclimator to a water sample in the constructed microbial membrane reactor, and then transporting the water sample containing the acclimator to a plug flow reactor for a second microbial membrane acclimation and cultivation process to obtain the microbial membrane reactor; the acclimator used in the second microbial membrane acclimation and cultivation process is different from the acclimator used in the previous microbial membrane acclimation and cultivation process.

4. The plug flow microbial membrane reactor according to claim 1, characterized in that: The five-day biochemical oxygen demand concentration of the biodegradable organic matter is 2-500 mg / L, the ammonia nitrogen concentration of the inorganic ammonium salt is 0.5-50 mg / L in terms of N, the mass concentration of the inorganic carbonate is 0.004-0.4 g / L, and the nitrite nitrogen concentration of the inorganic nitrite is 0.5-5 mg / L in terms of N.

5. The plug flow microbial membrane reactor according to claim 2, characterized in that: The detection system includes at least one of a dissolved oxygen analysis system, a total organic carbon analysis system, a chemical oxygen demand analysis system, and a pH analysis system; the blank water sample includes tap water or an uncontaminated water sample.

6. The plug flow microbial membrane reactor according to claim 1, characterized in that: The environmental water sample includes at least one of natural water and sewage; the material of the plug flow reactor includes at least one of polyurethane, polylactic acid, and glass; the flow rate of the environmental water sample is 0.5-5mL / min; the temperature of the constant temperature water bath is 25-37°C.

7. A biodegradation reactor detection system, characterized in that: It comprises the plug flow microbial membrane reactor according to any one of claims 1 to 6, a power system, a detection system and a flow system for storing and transporting fluids; One side of the plug flow microbial membrane reactor is connected to the pipeline and the power system to form a closed system. The fluid in the flow system is transported to the plug flow reactor through the pipeline and the power system. The fluid flows out from the other side after passing through the plug flow microbial membrane reactor, and the outflowing fluid is detected by the detection system.

8. A detection method for a biodegradation reactor detection system, characterized in that: The steps include: (1) Using a blank water sample as the fluid, the biodegradation reactor detection system of claim 7 is used for detection. Blank water sample to obtain the initial signal; (2) Then, the signal of the water sample to be tested is detected by the biodegradation reactor detection system described in claim 7 to obtain the signal of the water sample to be tested, and the difference between the signal of the water sample to be tested and the initial signal is used as the response signal of the water sample to be tested.

9. The detection method of the biodegradation reactor detection system according to claim 8, characterized in that: The steps include: (1) Drawing of standard curve: using standard samples containing pollutants of different concentrations as standard solutions, using the biodegradation reactor detection system to detect the standard solutions, obtaining response signals of different standard solutions, and drawing a standard curve with the concentration of the standard solution as the abscissa and the response signal of the standard solution as the ordinate; (2) Detection of the water sample to be tested: The water sample to be tested is tested using the biodegradation reactor detection system to obtain a response signal of the water sample to be tested, and the detection result of the water sample to be tested is calculated using a standard curve.

10. The detection method of the biodegradation reactor detection system according to claim 8 or 9, characterized in that: When used for water quality biochemical oxygen demand detection, the acclimatizer is a biodegradable organic matter, and the detection system is a dissolved oxygen analysis system, a total organic carbon analysis system or a chemical oxygen demand analysis system; When used for detecting ammonia nitrogen concentration in water, the acclimatizer is an inorganic ammonium salt, an inorganic carbonate and / or an inorganic nitrite, and the detection system is a pH analysis system or a dissolved oxygen analysis system; When used for the simultaneous detection of water quality biochemical oxygen demand and ammonia nitrogen, the acclimatizer is biodegradable organic matter, inorganic ammonium salt, inorganic carbonate and / or inorganic nitrite, and the detection system is a dissolved oxygen analysis system.

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