Heavy metal pollution early warning method and system based on microbial electrochemical sensor

Abstract

The invention relates to the technical field of microbial electrochemical sensors, in particular to a heavy metal pollution early warning method and system based on a microbial electrochemical sensor, and the method comprises the following steps: detecting the Cr < 6 + > concentration of a water body to be detected based on the prepared microbial electrochemical sensor, the microbial electrochemical sensor is prepared through a single-chamber microbial electrolytic tank, and the Cr < 6 + > concentration is obtained through a quantitative relation model obtained through linear fitting of normalized electrochemical parameters and the Cr < 6 + > concentration; and judging the pollution degree of the to-be-detected water body based on the Cr < 6 + > concentration, and sending a pollution early warning instruction. The prepared microbial electrochemical sensor can quickly and accurately identify Cr < 6 + > concentration change, the sensitivity and accuracy of the sensor for early warning Cr < 6 + > pollution in a water body are remarkably improved, and the microbial electrochemical sensor has real-time monitoring and early warning capabilities.

Description

Technical Field

[0001] The present invention relates to the technical field of microbial electrochemical sensors, and particularly to a heavy metal pollution early warning method and system based on a microbial electrochemical sensor. Background Art

[0002] The global water environmental pollution is intensifying, seriously endangering human health. The online real-time water quality early warning technology is an effective means to ensure water body safety. The commonly used water environmental pollution early warning systems mainly carry out physical and chemical analysis and early warning through large-scale instrument equipment. This method cannot achieve online real-time monitoring, and there is a large deviation between the early warning concentration and the real concentration. In order to improve the real-time performance and accuracy of water quality early warning technology, biological analysis methods have gradually emerged. The microbial electrochemical early warning technology is a new type of biological early warning technology developed by using microbial electrochemical technology. The core of this technology is the electroactive microbial membrane, and the unique extracellular electron transfer characteristics of electroactive microorganisms establish a natural connection between cell activity and electrical signals. Any factor that can affect the activity of microbial cells can be directly fed back in the form of changes in electrical signals. Based on this, the presence of toxic substances or a sharp change in the surrounding environment will inhibit the metabolism and electricity generation process of electrochemically active microorganisms, causing changes in electrical signal output. When a certain threshold is reached, an alarm signal can be triggered, meeting the requirements of online real-time monitoring.

[0003] The existing microbial electrochemical sensors for monitoring toxic substances mainly establish a certain correlation between the concentration of toxic substances and single values such as peak current / voltage, current density, Coulomb quantity, change amount of CV peak, and inhibition rate, so as to achieve the purpose of early warning. Such methods are often limited to the simple numerical analysis of electrical signals, lacking the extraction and comprehensive utilization of multi-dimensional electrical signal characteristics. At the same time, during the toxicity test process, the sensor often needs to run a complete operation cycle to obtain the above electrochemical parameters, resulting in the fact that this method often takes several hours or even dozens of hours to obtain the results, making it difficult to quickly and accurately identify the concentration of pollutants and achieve effective early warning. Therefore, it is urgent to improve the selection and calculation method of early warning signals of microbial electrochemical sensors to provide a fast and accurate solution for the high-sensitivity early warning of heavy metals in water bodies. Summary of the Invention

[0004] The purpose of the present invention is to solve the problems of low sensitivity and slow response speed of existing microbial electrochemical sensors in early warning heavy metal chromium pollution in water bodies, and to provide a heavy metal pollution early warning method and system based on a microbial electrochemical sensor, which accurately analyzes the electrochemical response characteristics of electroactive microbial membranes through multi-dimensional electrical signal analysis, enhances the detection sensitivity and realizes rapid early warning.

[0005] To achieve the above purpose, the present invention provides the following solutions:

[0006] A heavy metal pollution warning method based on a microbial electrochemical sensor, comprising:

[0007] Detecting the Cr concentration of the water body to be measured based on the prepared microbial electrochemical sensor, wherein the microbial electrochemical sensor is prepared by a single-chamber microbial electrolytic cell, and the Cr concentration is obtained by linearly fitting the normalized electrochemical parameters and the Cr concentration to obtain a quantitative relationship model; 6+ Detecting the Cr concentration of the water body to be measured based on the prepared microbial electrochemical sensor, wherein the microbial electrochemical sensor is prepared by a single-chamber microbial electrolytic cell, and the Cr concentration is obtained by linearly fitting the normalized electrochemical parameters and the Cr concentration to obtain a quantitative relationship model; 6+ Detecting the Cr concentration of the water body to be measured based on the prepared microbial electrochemical sensor, wherein the microbial electrochemical sensor is prepared by a single-chamber microbial electrolytic cell, and the Cr concentration is obtained by linearly fitting the normalized electrochemical parameters and the Cr concentration to obtain a quantitative relationship model; 6+ Detecting the Cr concentration of the water body to be measured based on the prepared microbial electrochemical sensor, wherein the microbial electrochemical sensor is prepared by a single-chamber microbial electrolytic cell, and the Cr concentration is obtained by linearly fitting the normalized electrochemical parameters and the Cr concentration to obtain a quantitative relationship model;

[0008] Judging the pollution degree of the water body to be measured based on the Cr concentration and issuing a pollution warning instruction. 6+ Judging the pollution degree of the water body to be measured based on the Cr concentration and issuing a pollution warning instruction.

[0009] Optionally, preparing the microbial electrochemical sensor by the single-chamber microbial electrolytic cell includes:

[0010] Using a single-chamber microbial electrolytic cell with a carbon fiber brush as the anode, a stainless steel mesh as the cathode, and the effluent of the microbial fuel cell as the inoculation source, wherein the culture solution in the single-chamber microbial electrolytic cell is a phosphate buffer solution and the carbon source is sodium acetate;

[0011] Operating the single-chamber microbial electrolytic cell by chronoamperometry in a two-electrode mode by applying a constant voltage to form an electroactive biofilm and obtain the microbial electrochemical sensor.

[0012] Optionally, linearly fitting the normalized electrochemical parameters and the Cr concentration to obtain the quantitative relationship model includes: 6+ Optionally, linearly fitting the normalized electrochemical parameters and the Cr concentration to obtain the quantitative relationship model includes:

[0013] Detecting different concentrations of Cr solutions based on the microbial electrochemical sensor to obtain the normalized electrochemical parameters and various warning indicators; 6+ Detecting different concentrations of Cr solutions based on the microbial electrochemical sensor to obtain the normalized electrochemical parameters and various warning indicators;

[0014] Linearly fitting the normalized electrochemical parameters with the concentration of the Cr solution to establish a quantitative relationship model corresponding to each warning indicator. 6+ Linearly fitting the normalized electrochemical parameters with the concentration of the Cr solution to establish a quantitative relationship model corresponding to each warning indicator.

[0015] Optionally, judging the pollution degree of the water body to be measured based on the Cr concentration and issuing a pollution warning instruction includes: 6+ Optionally, judging the pollution degree of the water body to be measured based on the Cr concentration and issuing a pollution warning instruction includes:

[0016] Presetting the concentration intervals corresponding to each warning indicator;

[0017] Judging the pollution degree of the water body to be measured according to the concentration interval where the Cr concentration is located and issuing a corresponding pollution warning instruction. 6+ Judging the pollution degree of the water body to be measured according to the concentration interval where the Cr concentration is located and issuing a corresponding pollution warning instruction.

[0018] To further achieve the above object, the present invention also provides a heavy metal pollution early warning system based on a microbial electrochemical sensor, including: a concentration detection module and a warning judgment module;

[0019] The concentration detection module is used to detect the Cr concentration of the water body to be measured based on the prepared microbial electrochemical sensor. 6+ Among them, the microbial electrochemical sensor is prepared by a single-chamber microbial electrolytic cell, and the Cr concentration is obtained by a quantitative relationship model obtained by linear fitting of the normalized electrochemical parameters and the Cr concentration. 6+ The concentration is obtained by linear fitting of the normalized electrochemical parameters and the Cr concentration to obtain a quantitative relationship model; 6+

[0020] The warning judgment module is used to judge the pollution degree of the water body to be measured based on the Cr concentration and issue a pollution warning instruction. 6+

[0021] Optionally, preparing the microbial electrochemical sensor by the single-chamber microbial electrolytic cell includes:

[0022] A single-chamber microbial electrolytic cell with a carbon fiber brush as the anode, a stainless steel mesh as the cathode, and the effluent of the microbial fuel cell as the inoculation source is used. Among them, the culture solution in the single-chamber microbial electrolytic cell is a phosphate buffer solution, and the carbon source is sodium acetate;

[0023] The single-chamber microbial electrolytic cell is operated by chronoamperometry in a two-electrode mode by applying a constant voltage to form an electroactive biofilm to obtain the microbial electrochemical sensor.

[0024] Optionally, obtaining the quantitative relationship model by linear fitting of the normalized electrochemical parameters and the Cr concentration includes: 6+

[0025] Based on the microbial electrochemical sensor, solutions with different Cr concentrations are detected to obtain the normalized electrochemical parameters and various warning indicators; 6+

[0026] The normalized electrochemical parameters are linearly fitted with the concentration of the Cr solution to establish a quantitative relationship model corresponding to each warning indicator. 6+

[0027] Optionally, the warning judgment module judging the pollution degree of the water body to be measured based on the Cr concentration and issuing a pollution warning instruction includes: 6+

[0028] Preset the concentration intervals corresponding to each warning indicator;

[0029] According to the Cr 6+Based on the concentration range where the concentration is located, determine the pollution degree of the water body to be measured and issue a corresponding pollution warning instruction.

[0030] The beneficial effects of the present invention are as follows:

[0031] Based on the highly stable and parallel microbial electrochemical sensor, the present invention uses an innovative multi-dimensional electrical signal calculation method to improve the analysis accuracy of electrical signal characteristics, enabling the sensor to quickly and accurately identify the Cr 6+ concentration change, significantly improving the sensitivity and accuracy of the sensor to warn of Cr 6+ pollution in the water body, having the ability of real-time monitoring and warning, and meeting the requirements of water quality warning. Brief Description of the Drawings

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0033] Figure 1 Schematic diagram of the warning mechanism of the microbial electrochemical sensor according to the embodiment of the present invention;

[0034] Figure 2 Variation curve of the maximum value I'(t) of the first derivative of the time-current curve and its corresponding current value I(t) according to the embodiment of the present invention;

[0035] Figure 3 Variation and fitting curve of the normalized electrochemical parameter NES(I') according to the embodiment of the present invention;

[0036] Figure 4 Variation and fitting curve of the normalized electrochemical parameter NES(I) according to the embodiment of the present invention;

[0037] Figure 5 Schematic diagram of the response time of the microbial electrochemical sensor according to the embodiment of the present invention;

[0038] Figure 6 Flowchart of a heavy metal pollution warning method based on a microbial electrochemical sensor according to the embodiment of the present invention. Detailed Embodiments

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0040] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] This embodiment provides a heavy metal pollution early warning method based on a microbial electrochemical sensor, as Figure 6 shown, including:

[0042] Detecting the Cr 6+ concentration of the water body to be measured based on the prepared microbial electrochemical sensor, wherein the microbial electrochemical sensor is prepared by a single-chamber microbial electrolytic cell, and the Cr 6+ concentration is obtained by a quantitative relationship model obtained by linearly fitting the normalized electrochemical parameters and the Cr 6+ concentration;

[0043] Judging the pollution degree of the water body to be measured based on the Cr 6+ concentration and issuing a pollution early warning instruction.

[0044] Specifically, this embodiment is based on a highly stable and parallel microbial electrochemical sensor, and uses an innovative multi-dimensional electrical signal calculation method to improve the analysis accuracy of electrical signal characteristics, enabling the sensor to quickly and accurately identify changes in Cr 6+ concentration, significantly improving the sensitivity and accuracy of the sensor to early warn of Cr 6+ pollution in the water body, having the ability of real-time monitoring and early warning, and meeting the requirements of water quality early warning.

[0045] Furthermore, preparing the microbial electrochemical sensor through the single-chamber microbial electrolytic cell includes:

[0046] Using a single-chamber microbial electrolytic cell with a carbon fiber brush as the anode, a stainless steel mesh as the cathode, and the effluent of the microbial fuel cell as the inoculation source. Among them, the culture solution in the single-chamber microbial electrolytic cell is a phosphate buffer solution, and the carbon source is sodium acetate;

[0047] Operating the single-chamber microbial electrolytic cell by applying a constant voltage in a two-electrode mode using chronoamperometry to form an electroactive biofilm and obtain the microbial electrochemical sensor.

[0048] Specifically, in this embodiment, the sensor uses a single-chamber microbial electrolytic cell (MEC), which is a cube made of plexiglass with a cylindrical cavity inside. The anode is a carbon fiber brush, and the cathode is a stainless steel mesh. The effluent of a long-term domesticated microbial fuel cell is used as the inoculation source, and the culture solution is a 50 mM phosphate buffer solution with sodium acetate added as the sole carbon source. The sensor operates in a two-electrode mode by applying a constant voltage and uses chronoamperometry, and an electroactive biofilm is formed after operating for 3 - 10 days.

[0049] Further, obtaining the quantitative relationship model through linear fitting of the normalized electrochemical parameters and the concentration of Cr 6+ includes:

[0050] Based on the microbial electrochemical sensor detecting solutions with different concentrations of Cr 6+ to obtain the normalized electrochemical parameters and a variety of early warning indicators;

[0051] Performing linear fitting on the normalized electrochemical parameters and the concentration of the Cr 6+ solution to establish a quantitative relationship model corresponding to each early warning indicator.

[0052] Specifically, in this embodiment, a solution with a concentration of 1 - 11 mg / L of Cr 6+ is added to the above-mentioned electrochemical reactor that has formed a stable electroactive biofilm. The maximum value of the current growth rate, that is, the maximum value of the first derivative I'(t) of the time-current curve and its corresponding current value I(t), are used to determine the response ability of the electroactive biofilm to different Cr 6+ concentrations, thereby reflecting the level of Cr 6+ concentration in the water body. Linear fitting is performed between the normalized electrochemical parameters NES(I') and NES(I) generated by the electroactive biofilm and the Cr 6+ concentration in the water, and a standard curve is plotted to establish a quantitative relationship model between the electrochemical signal and the Cr 6+ concentration, and the response time is determined.

[0053] Further, judging the pollution degree of the water body to be measured based on the Cr 6+ concentration and issuing a pollution early warning instruction includes:

[0054] Presetting the concentration intervals corresponding to each early warning indicator;

[0055] According to the concentration interval where the Cr 6+ concentration is located, judging the pollution degree of the water body to be measured and issuing a corresponding pollution early warning instruction.

[0056] Specifically, in this embodiment, the Cr 6+Concentration. Based on the changes in the normalized electrochemical parameters NES(I') and NES(I) generated thereby, combined with the standard curve, the Cr in the water to be measured is inversely deduced using the quantitative relationship model 6+ Concentration, to determine whether it reaches the preset warning concentration range, and corresponding pollution warning instructions are issued according to the concentration value.

[0057] The following combines Figures 1-6 A heavy metal pollution warning method based on a microbial electrochemical sensor proposed in this embodiment will be described in detail as follows:

[0058] (1) Preparation of a highly stable and parallel microbial electrochemical sensor:

[0059] The single-chamber microbial electrolysis cell (MEC) reactor is a cube made of plexiglass, with a cylindrical cavity inside, a volume of 28 mL, the cathode is a 100-mesh 304 stainless steel mesh, and the anode is a carbon fiber brush with a diameter of 3 cm. A programmable DC power supply (RIGOL DP800) is used to apply a voltage of 0.9 V, and at the same time, a multi-channel data recorder (Keithley 2700) is used to monitor the current change in the circuit, and the electrical signal is recorded every 5 s. All reactors operate at 30 ± 1 °C. It is cultured for 3 - 10 days to form a sensor electrode biofilm.

[0060] In the startup stage, using the effluent of a long-term domesticated microbial fuel cell as the inoculation source, the sensor is fed in a batch mode, and the culture solution contains 50 mM phosphate buffer solution (PBS, Na 2 HPO 4 , 4.58 g / L; NaH 2 PO 4 , 2.13 g / L; NH 4 Cl, 0.31 g / L; KCl, 0.13 g / L), 12.5 mL / L mineral solution, 5 mL / L vitamin solution, and 0.385 g / L sodium acetate (COD 300 mg / L). When the current drops below 0.1 mA, the culture solution is replaced, and the culture solution is deoxygenated by continuous aeration with N 2 / CO 2 (4:1) for 30 minutes to remove the dissolved oxygen in the solution. When three consecutive cycles with repeated maximum current output are observed, the activation process is considered complete.

[0061] (2) Construct a quantitative relationship model based on the response of the microbial electrochemical sensor to Cr 6+ :

[0062] The warning mechanism of the microbial electrochemical sensor is as Figure 1As shown in the figure, add Cr solutions with concentrations of 1, 3, 5, 7, 9, and 11 mg / L to the electrochemical reactor that has already formed a stable electroactive biofilm. 6+ As Figure 2 shown, the maximum value of the current growth rate, that is, the maximum value of the first derivative I'(t) of the time-current curve and the change in its corresponding current value I(t) are used to quantify the impact of Cr pollution on the output electrical signal of the sensor. To avoid interference with the sensing signal due to the non-parallel performance between sensors, the warning indicators are converted into normalized electrochemical parameters NES(I') and NES(I), and the calculation methods are as follows: 6+

[0063] NES(I') = I'(t) n / I'(t) 0 ;

[0064] NES(I) = I(t) n / I(t) 0 ;

[0065] where I'(t) 0 is the maximum value of the first derivative of the time-current curve before the toxicity test, and I'(t) n after the toxicity test. I(t) 0 is the current value corresponding to the maximum value of the first derivative before the toxicity test, and I(t) n after the toxicity test.

[0066] After the electroactive biofilm contacts different concentrations of Cr 6+ 6+ , the changes in the electrical signal parameters are as Figure 3 , Figure 4 shown. Establish the dose-response relationship between the normalized electrochemical parameters NES(I') and NES(I) and the Cr concentration gradient. The Cr 6+ concentration is used as the independent variable x, and NES(I') and NES(I) are used as the dependent variable y. By fitting the linear relationship between the independent variable and the dependent variable, the linear fitting equation y = kx + b is obtained, and the sensitivity of the microbial electrochemical sensor is represented by the k value. The fitting equation of the NES(I') warning indicator and the Cr 6+ gradient concentration is y = -0.105x + 1.015, and R 2 is 0.994. The effective warning concentration range of Cr 6+ is 0 - 7 mg / L; the fitting equation of the NES(I) warning indicator and the Cr 6+ gradient concentration is y = -0.073x + 1.045, and R 2 is 0.992. The effective warning concentration range of Cr 6+ is 0 - 11 mg / L.

[0067] ​​The microbial electrochemical sensor responds to different concentrations of Cr 6+ pollution as shown in Figure 5 the figure. When the Cr 6+ concentration is 7 mg / L, the longest response time is 1125.6 ± 320.9 s. When the Cr 6+ concentration is 9 mg / L, the shortest response time is only 662.2 ± 123.9 s.

[0068] Both NES(I') and NES(I) can be used for the early warning of Cr 6+ pollution, but they focus on different performances. From the fitting equation, it can be seen that the sensitivity of the NES(I') early warning index is higher. In the range of 0 - 7 mg / L Cr 6+ concentration, it can sensitively capture the appearance of pollutants and ensure an early warning before the pollution spreads. The linear interval of the NES(I) early warning index and the Cr 6+ concentration is wider (0 - 11 mg / L), which means that it can still maintain an effective linear response in a larger Cr 6+ concentration range. Therefore, NES(I') is more suitable for pollution scenarios with high sensitivity requirements and the need to quickly capture weak signal changes. NES(I) can cover a higher concentration range and maintain better accuracy and stability in a relatively wide chromium concentration range. The differential design of the two early warning indicators ensures accurate and rapid early warning and judgment of Cr 6+ pollution at different concentration levels.

[0069] (3) Prediction and early warning of the Cr 6+ concentration in the water sample to be measured:

[0070] In actual on-line monitoring, when encountering a water sample polluted by Cr 6+ with an unknown concentration, introduce the unknown water sample to be measured into the microbial electrochemical sensor, and synchronously record the electrochemical signal response values NES(I') and NES(I) on-line. Assume that the measured normalized electrochemical parameters NES(I') and NES(I) are y 未知 , substitute them into the established fitting equations (NES(I') early warning index y = -0.105x + 1.015, NES(I) early warning index y = -0.073x + 1.045), and obtain the corresponding chromium concentration x 未知 . According to the obtained chromium concentration x 未知 , judge the pollution degree of the Cr 6+ in the water sample to be measured and issue a targeted pollution early warning instruction.

[0071] Set 4 groups of standard Cr 6+The detection accuracy and precision of a microbial electrochemical sensor were verified using water samples to be tested with concentrations of 1.4 mg / L, 2.5 mg / L, 4.3 mg / L, and 6.4 mg / L. The microbial electrochemical sensor was used to detect Cr in the water samples to be tested. 6+ concentration and the standard Cr 6+ concentration. The relative error range of the linear fitting model of the NES(I') warning index was 1.57%-4.67%, and the RSD (relative standard deviation) range was 2.70%-5.99%. The relative error range of the linear fitting model of the NES(I) warning index was 1.73%-8.38%, and the RSD range was 2.66%-7.70%. The electrical signal generated by the bioelectrochemical sensor in the presence of chromium pollutants was not only responsive but also had good accuracy and precision.

[0072] To further optimize the technical solution, this embodiment also provides a heavy metal pollution warning system based on a microbial electrochemical sensor, including: a concentration detection module and a warning judgment module;

[0073] The concentration detection module is used to detect the Cr 6+ concentration of the water sample to be tested based on the prepared microbial electrochemical sensor. The microbial electrochemical sensor is prepared by a single-chamber microbial electrolytic cell, and the Cr 6+ concentration is obtained by a quantitative relationship model linearly fitted by normalized electrochemical parameters and Cr 6+ concentration;

[0074] The warning judgment module is used to judge the pollution degree of the water sample to be tested based on the Cr 6+ concentration and issue a pollution warning instruction.

[0075] Further, the preparation of the microbial electrochemical sensor by the single-chamber microbial electrolytic cell includes:

[0076] A single-chamber microbial electrolytic cell with a carbon fiber brush as the anode, a stainless steel mesh as the cathode, and the effluent of the microbial fuel cell as the inoculation source is used. The culture solution in the single-chamber microbial electrolytic cell is a phosphate buffer solution, and the carbon source is sodium acetate;

[0077] The single-chamber microbial electrolytic cell is operated by chronoamperometry in a two-electrode mode by applying a constant voltage to form an electroactive biofilm and obtain the microbial electrochemical sensor.

[0078] In this embodiment, the sensor uses a single-chamber microbial electrolytic cell (MEC), which is a cube made of plexiglass with a cylindrical cavity inside. The anode is a carbon fiber brush, and the cathode is a stainless steel mesh. The effluent of a long-term domesticated microbial fuel cell is used as the inoculation source, and the culture solution is a 50 mM phosphate buffer solution, with sodium acetate added as the sole carbon source. The sensor operates in a two-electrode mode using chronoamperometry by applying a constant voltage, and an electroactive biofilm is formed after operating for 3 - 10 days.

[0079] Further, obtaining the quantitative relationship model by linearly fitting the normalized electrochemical parameters and the concentration of Cr 6+ includes:

[0080] Based on the microbial electrochemical sensor detecting solutions with different concentrations of Cr 6+ to obtain the normalized electrochemical parameters and a variety of early warning indicators;

[0081] Linearly fitting the normalized electrochemical parameters with the concentration of the Cr 6+ solution to establish a quantitative relationship model corresponding to each early warning indicator.

[0082] Specifically, in this embodiment, a solution with a concentration of 1 - 11 mg / L of Cr 6+ is added to the above-mentioned electrochemical reactor that has already formed a stable electroactive biofilm. By the maximum value of the current growth rate, that is, the maximum value of the first derivative I'(t) of the time-current curve and its corresponding current value I(t), the response ability of the electroactive biofilm to different Cr 6+ concentrations is determined, thereby reflecting the level of Cr 6+ concentration in the water body. The normalized electrochemical parameters NES(I') and NES(I) generated by the electroactive biofilm are linearly fitted with the Cr 6+ concentration in the water to draw a standard curve, establishing a quantitative relationship model between the electrochemical signal and the Cr 6+ concentration, and determining the response time.

[0083] Further, the early warning judgment module judging the pollution degree of the water body to be measured based on the Cr 6+ concentration and issuing a pollution early warning instruction includes:

[0084] Presetting the concentration intervals corresponding to each early warning indicator;

[0085] According to the concentration interval where the Cr 6+ concentration is located, judging the pollution degree of the water body to be measured and issuing a corresponding pollution early warning instruction.

[0086] Specifically, in this embodiment, the Cr 6+Concentration. Based on the changes in the normalized electrochemical parameters NES(I') and NES(I) generated thereby, combined with the standard curve, the Cr in the water to be measured is inversely deduced using the quantitative relationship model. 6+ Concentration is determined to see if it reaches the preset early warning concentration range, and corresponding pollution early warning instructions are issued according to the concentration value.

[0087] This embodiment is based on the microbial electrolysis cell sensor technology, uses an electroactive microbial membrane as the sensitive element, and proposes a new method for calculating electrical signals and multi-dimensional signal analysis. The maximum value of the current growth rate, that is, the maximum value of the first derivative of the time-current curve I'(t) and its corresponding current value I(t), are used to construct the normalized electrochemical parameters NES(I') and NES(I). The differential design of the two early warning indicators ensures high-sensitivity detection in the Cr concentration range of 0 - 7 mg / L, and at the same time maintains a stable linear response in the higher concentration range of 0 - 11 mg / L, enabling this method to quickly and accurately give early warnings for Cr pollution at different concentration levels. 6+ Concentration range, and maintain a stable linear response in the higher concentration range of 0 - 11 mg / L, so that this method can quickly and accurately give early warnings for Cr pollution at different concentration levels. 6+ Pollution for rapid and accurate early warning.

[0088] The embodiments described above are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A heavy metal pollution early warning method based on microbial electrochemical sensor, characterized in that: include: Detection of Cr in the water body based on the prepared microbial electrochemical sensor 6+ concentration, wherein the microbial electrochemical sensor is prepared by a single-chamber microbial electrolysis cell, and the Cr 6+ The concentration was normalized by electrochemical parameters and Cr 6+ The quantitative relationship model was obtained by linear fitting of concentration; Based on the Cr 6+ The concentration determines the pollution degree of the water body to be tested and issues a pollution warning instruction.

2. The heavy metal pollution early warning method based on microbial electrochemical sensor according to claim 1 is characterized in that: The preparation of the microbial electrochemical sensor by the single-chamber microbial electrolysis cell comprises: A single-chamber microbial electrolysis cell is used, in which the anode is a carbon fiber brush, the cathode is a stainless steel mesh, and the effluent of a microbial fuel cell is used as an inoculation source, wherein the culture solution in the single-chamber microbial electrolysis cell is a phosphate buffer solution, and the carbon source is sodium acetate; The single-chamber microbial electrolysis cell is operated by applying a constant voltage in a two-electrode mode using a chronoamperometry method to form an electroactive biofilm and obtain the microbial electrochemical sensor.

3. The heavy metal pollution early warning method based on microbial electrochemical sensor according to claim 1 is characterized in that: By normalizing the electrochemical parameters and Cr 6+ The concentration linear fitting to obtain the quantitative relationship model includes: Based on the microbial electrochemical sensor for different concentrations of Cr 6+ The solution is tested to obtain the normalized electrochemical parameters and a variety of early warning indicators; The normalized electrochemical parameters were compared with the Cr 6+ The concentration of the solution is linearly fitted to establish a quantitative relationship model corresponding to each early warning indicator.

4. The heavy metal pollution early warning method based on microbial electrochemical sensor according to claim 3 is characterized in that: Based on the Cr 6+ The concentration determines the pollution degree of the water body to be tested and issues a pollution warning instruction, including: Preset the concentration range corresponding to each warning indicator; According to the Cr 6+ The concentration range in which the concentration lies is used to judge the pollution degree of the water body to be tested and issue corresponding pollution warning instructions.

5. A heavy metal pollution early warning system based on microbial electrochemical sensors, characterized in that: include: Concentration detection module, early warning judgment module; The concentration detection module is used to detect the Cr concentration of the water body to be tested based on the prepared microbial electrochemical sensor. 6+ concentration, wherein the microbial electrochemical sensor is prepared by a single-chamber microbial electrolysis cell, and the Cr 6+ The concentration was normalized by electrochemical parameters and Cr 6+ The quantitative relationship model was obtained by linear fitting of concentration; The early warning judgment module is used to 6+ The concentration determines the pollution degree of the water body to be tested and issues a pollution warning instruction.

6. The heavy metal pollution early warning system based on microbial electrochemical sensor according to claim 5 is characterized in that: The preparation of the microbial electrochemical sensor by the single-chamber microbial electrolysis cell comprises: A single-chamber microbial electrolysis cell is used, in which the anode is a carbon fiber brush, the cathode is a stainless steel mesh, and the effluent of a microbial fuel cell is used as an inoculation source, wherein the culture solution in the single-chamber microbial electrolysis cell is a phosphate buffer solution, and the carbon source is sodium acetate; The single-chamber microbial electrolysis cell is operated by applying a constant voltage in a two-electrode mode using a chronoamperometry method to form an electroactive biofilm and obtain the microbial electrochemical sensor.

7. The heavy metal pollution early warning system based on microbial electrochemical sensor according to claim 5 is characterized in that: By normalizing the electrochemical parameters and Cr 6+ The concentration linear fitting to obtain the quantitative relationship model includes: Based on the microbial electrochemical sensor for different concentrations of Cr 6+ The solution is tested to obtain the normalized electrochemical parameters and a variety of early warning indicators; The normalized electrochemical parameters were compared with the Cr 6+ The concentration of the solution is linearly fitted to establish a quantitative relationship model corresponding to each early warning indicator.

8. The heavy metal pollution early warning system based on microbial electrochemical sensor according to claim 7 is characterized in that: The early warning judgment module is based on the Cr 6+ The concentration determines the pollution degree of the water body to be tested and issues a pollution warning instruction, including: Preset the concentration range corresponding to each warning indicator; According to the Cr 6+ The concentration range in which the concentration lies is used to judge the pollution degree of the water body to be tested and issue corresponding pollution warning instructions.

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