A device and method for detecting the content of organic matter in a water body

Abstract

This invention relates to the field of water body detection technology, and more particularly to a device and method for detecting the organic matter content in water. The detection device includes: a detector; the detector includes a reference electrode, a counter electrode, and a working electrode; the working electrode is a microbial membrane modified electrode; a data acquisition, processing, and display unit connected to the detector; a first standard sample container, a second standard sample container, and a water sample container to be tested; the first standard sample container, the second standard sample container, and the water sample container to be tested are all connected to the inlet of the detector via a first switching valve; the outlet of the detector is connected to the first standard sample container and the water sample container to be tested via a second switching valve. The detection device provided by this invention has a simple structure, is easy to operate, has strong anti-pollution capabilities, and provides high accuracy and reliability of the detection results.

Description

Technical Field

[0001] This invention relates to the field of water body detection technology, and in particular to a device and method for detecting the organic matter content in water. Background Technology

[0002] The detection of organic matter content in water bodies is of great significance for water quality assessment, environmental protection policy formulation, wastewater treatment, and aquatic life protection. Currently, commonly used methods for detecting organic matter content in water bodies include electrochemical oxidation, photoelectrochemical oxidation, chemical oxidation, and biological oxidation.

[0003] Chemical oxidation methods rely on toxic and harmful chemical reagents, posing a risk of secondary environmental pollution. Electrochemical oxidation methods offer high detection concentrations, but the electrode surface easily adsorbs organic matter, leading to electrode contamination and affecting the reproducibility and reliability of the results. Photoelectrochemical oxidation methods suffer from low detection concentrations and narrow linear ranges, and are also prone to electrode contamination.

[0004] Biological oxidation methods offer advantages such as mild conditions and no secondary pollution, thus possessing promising market prospects. In biological oxidation testing, dissolved oxygen in water is typically used as the electron acceptor in the biological oxidation process of organic matter. However, the concentration detected by the biological oxidation method for organic matter in water using oxygen as the electron acceptor, as described in patent 201210103635.5, is usually below 20 mg / L. Although patent 201210308355.8 proposes using potassium ferricyanide as an electron mediator instead of oxygen as the electron acceptor, which could raise the upper limit of organic matter content testing to 1000 mg / L, this device has a complex structure, and the electrodes in the detector directly contact the water sample, easily causing significant pollution. Furthermore, the reliability and reproducibility of the detection results cannot be guaranteed.

[0005] Therefore, the disadvantages of bio-oxidation technology are:

[0006] (1) When dissolved oxygen in water is used as the electron medium, the concentration of dissolved oxygen in the water limits the concentration of microorganisms that can be used. Therefore, the detection of organic matter content in water can only be achieved in a low concentration range, with an upper limit of about 20 mg / L. To achieve the detection of samples with higher concentrations, a dilution component needs to be added to the device, which increases the structural complexity of the instrument. In addition, fluctuations in the oxygen concentration in the water can also interfere with the detection results.

[0007] (2) When potassium ferricyanide electron mediator is used instead of dissolved oxygen in the water as the electron acceptor in the process of organic matter degradation by microorganisms, the working electrode in the detector is in direct contact with the water sample. The adsorption of substances in the water on the electrode surface will cause electrode contamination, which seriously affects the reliability and reproducibility of the detection results. Summary of the Invention

[0008] In view of this, the technical problem to be solved by the present invention is to provide a device and method for detecting the organic matter content in water, which has a simple structure, strong anti-pollution ability, and high accuracy and reliability of detection results.

[0009] This invention provides a device for detecting the organic matter content in water, comprising:

[0010] The detector includes a reference electrode, a counter electrode, and a working electrode; the working electrode is a microbial membrane modified electrode.

[0011] The data acquisition, processing, and display unit is connected to the detector;

[0012] The system comprises a first standard sample container, a second standard sample container, and a water sample container to be tested; all three containers are connected to the inlet of the detector via a first switching valve.

[0013] The detector's outlet is connected to the first standard sample container and the water sample container to be tested via a second switching valve.

[0014] Preferably, the method for preparing the working electrode includes the following steps:

[0015] a) Mix deionized water, peptone, yeast extract powder and sodium chloride, sterilize, and obtain a sterilized solution;

[0016] b) Mix the target water or bacterial strain with the sterilized solution and incubate at a constant temperature of 30-40°C. When the OD600 value of the microorganisms in the solution is 3-6, a microbial solution is obtained.

[0017] c) After centrifuging the microbial solution and removing the supernatant, mix it with sodium chloride solution and disperse by shaking to obtain a microbial solution with low extracellular polymer content.

[0018] d) The microbial solution with low extracellular polymer content is coated on the surface of the ITO electrode and dried to obtain the working electrode.

[0019] Preferably, the mass ratio of peptone, yeast extract powder and sodium chloride is 4-10:4-10:7-12;

[0020] The sterilization temperature is 115–125°C, and the time is 10–20 minutes.

[0021] Preferably, the volume ratio of the sterilizing solution to the target water is 1-5:4000;

[0022] The centrifugation speed is 4500-5500 rpm, and the time is 3-7 min;

[0023] The concentration of the sodium chloride solution is 0.005–0.01 g / mL;

[0024] The volume ratio of the microbial solution to the sodium chloride solution after removing the supernatant is 1:9 to 19;

[0025] The OD600 value of the microbial concentrate was 60-100.

[0026] Preferably, the coating amount of the microbial solution with low extracellular polymeric content on the ITO electrode surface is 70–90 μL / cm. 2 .

[0027] Preferably, a peristaltic pump is also provided between the outlet of the detector and the second switching valve.

[0028] The present invention also provides a method for detecting the organic matter content in water using the detection device described above, comprising the following steps:

[0029] a) Add the first standard sample to the first standard sample container, add the second standard sample to the second standard sample container, and add the water sample to be tested to the water sample container;

[0030] The first standard sample comprises water, organic matter, and potassium ferricyanide; the organic matter comprises glucose and glutamic acid; in the first standard sample, the content of organic matter is C1 = 0-100 mg / L, and the concentration of potassium ferricyanide is 5-50 mmol / L;

[0031] The second standard sample includes water, organic matter, and potassium ferricyanide; the organic matter includes glucose and glutamic acid; in the second standard sample, the content of organic matter is C2 = 10-200 mg / L, and the concentration of potassium ferricyanide is 5-50 mmol / L;

[0032] Furthermore, the difference in organic matter content between the second standard sample and the first standard sample shall not be less than 10 mg / L;

[0033] The water sample to be tested includes the water body to be tested and potassium ferricyanide; the concentration of potassium ferricyanide in the water sample to be tested is 5-50 mmol / L;

[0034] b) Adjust the first switching valve and the second switching valve to form a loop with the first standard sample container, the first switching valve, the detector, the peristaltic pump and the second switching valve, so that the first standard sample circulates through the detector.

[0035] The potential difference between the reference electrode and the working electrode is controlled to be 0.40 to 0.50V using a data acquisition, processing, and display unit. The current value flowing through the working electrode is acquired, and the current value i1 flowing through the working electrode at time t1 is recorded.

[0036] Adjust the first switching valve and the second switching valve so that the second standard sample flows through the second standard sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container. Then adjust the first switching valve and the second switching valve so that the second standard sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the water sample container to be tested form a loop, and the second standard sample circulates through the detector.

[0037] The potential difference between the reference electrode and the working electrode is controlled to be 0.40 to 0.50V using a data acquisition, processing, and display unit. The current value flowing through the working electrode is acquired, and the current value i2 flowing through the working electrode at time t2 is recorded.

[0038] Adjust the first switching valve and the second switching valve so that the water sample to be tested flows through the water sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container. Then adjust the first switching valve and the second switching valve so that the water sample container, the first switching valve, the detector, the peristaltic pump and the second switching valve form a loop, and the water sample to be tested circulates through the detector.

[0039] The potential difference between the reference electrode and the working electrode is controlled to be 0.40 to 0.50V using a data acquisition, processing, and display unit, and the current value flowing through the working electrode is acquired and the current value i3 flowing through the working electrode at time t3 is recorded.

[0040] c) Use two points (C1, i1) and (C2, i2) to plot a first-order linear regression curve as the working curve of the detection device; then substitute the i3 value into the working curve to calculate the organic matter content C value of the water sample to be tested.

[0041] Preferably, the volume of the first standard sample added to the first standard sample container is 2 to 5 mL;

[0042] The volume of the second standard sample added to the second standard sample container is 1 mL larger than the volume of the first standard sample in the first standard sample container;

[0043] The volume of the water sample to be tested added to the water sample container is 1 mL more than the volume of the first standard sample in the first standard sample container;

[0044] The concentrations of potassium ferricyanide in the first standard sample, the second standard sample, and the water sample to be tested are the same.

[0045] Preferably, t1 = 600~1200s, t2 = 2×t1, t3 = 3×t1.

[0046] Preferably, during the process of the second standard sample flowing through the second standard sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container, the time for the second standard sample to flow through the first switching valve does not exceed 60 seconds, and the volume of the second standard sample is 1 mL.

[0047] During the process of the water sample to be tested flowing through the water sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container, the time for the water sample to flow through the first switching valve shall not exceed 60 seconds, and the volume of the water sample to be tested is 1 mL.

[0048] This invention provides a device for detecting the organic matter content in water, comprising: a detector; the detector including a reference electrode, a counter electrode, and a working electrode; the working electrode being a microbial membrane modified electrode; a data acquisition, processing, and display unit connected to the detector; a first standard sample container, a second standard sample container, and a water sample container to be tested; the first standard sample container, the second standard sample container, and the water sample container to be tested are all connected to the inlet of the detector via a first switching valve; the outlet of the detector is connected to the first standard sample container and the water sample container to be tested via a second switching valve, respectively. The detection device provided by this invention has a simple structure, is easy to operate, has strong anti-fouling ability, and low solution consumption. By using a microbial membrane modified electrode, in-situ testing of the microbial degradation process of organic matter is achieved, eliminating the need for a separate reaction tank, thus simplifying the device structure. Simultaneously, using a microbial membrane modified electrode avoids direct contact between highly adsorbent colloids and polymers in the water and the working electrode, solving the electrode contamination problem caused by the water sample and improving the accuracy and reliability of the test results. The circulating flow of the water sample reduces the amount of solution used and consumed. Attached Figure Description

[0049] Figure 1 A diagram of a device for detecting the organic matter content in water provided in an embodiment of the present invention. Detailed Implementation

[0050] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0051] This invention provides a device for detecting the organic matter content in water, comprising:

[0052] The detector includes a reference electrode, a counter electrode, and a working electrode; the working electrode is a microbial membrane modified electrode.

[0053] The data acquisition, processing, and display unit is connected to the detector;

[0054] The system comprises a first standard sample container, a second standard sample container, and a water sample container to be tested; all three containers are connected to the inlet of the detector via a first switching valve.

[0055] The detector's outlet is connected to the first standard sample container and the water sample container to be tested via a second switching valve.

[0056] Figure 1 This diagram illustrates a device for detecting the organic matter content in water according to an embodiment of the present invention. In the diagram, 1 is a first standard sample container, 2 is a second standard sample container, 3 is a water sample container to be tested, 4 is a first switching valve, 5 is a peristaltic pump, 6 is a detector, 7 is a reference electrode, 8 is a counter electrode, 9 is a working electrode, 10 is a second switching valve, 11 is a waste liquid recovery container, and 12 is a data acquisition, processing, and display unit.

[0057] The device for detecting the organic matter content in water provided by this invention includes a detector 6. The detector 6 includes a reference electrode 7, a counter electrode 8, and a working electrode 9. The detector is provided with an inlet and an outlet.

[0058] The detector is used to hold the water sample to be tested. In some embodiments of the present invention, the detector is a flow cell.

[0059] The present invention does not impose any special restrictions on the arrangement of the reference electrode 7, counter electrode 8, and working electrode 9 in the detector; any corresponding electrode arrangement method well known to those skilled in the art can be used. Specifically, the detector is provided with a first electrode interface, a second electrode interface, and a third electrode interface, and the reference electrode 7, counter electrode 8, and working electrode 9 are fixed to the first electrode interface, the second electrode interface, and the third electrode interface, respectively. The function of the first electrode interface, the second electrode interface, and the third electrode interface is to fix the reference electrode 7, the counter electrode 8, and the working electrode 9, and to adjust the distance between each electrode.

[0060] The reference electrode 7 and the counter electrode 8 are electrodes well known to those skilled in the art. In some embodiments of the present invention, the reference electrode is an Ag / AgCl electrode, and the reference electrode filling solution is 3 mol / L KCl. In some embodiments of the present invention, the counter electrode is a titanium wire electrode, a stainless steel wire electrode, a gold wire electrode, or a platinum wire electrode.

[0061] In some embodiments of the present invention, the working electrode is a microbial membrane-modified electrode, which is prepared by drop-coating cultured microorganisms onto the surface of an ITO electrode or a carbon-printed electrode. The principle is to utilize the extracellular polymers secreted by the microorganisms as an adhesive to directly bond the microorganisms to the surface of the ITO electrode or the carbon-printed electrode.

[0062] In some embodiments of the present invention, the method for preparing the working electrode includes the following steps:

[0063] a) Mix deionized water, peptone, yeast extract powder and sodium chloride, sterilize, and obtain a sterilized solution;

[0064] b) Mix the target water or bacterial strain with the sterilized solution and incubate at a constant temperature of 30-40°C. When the OD600 value of the microorganisms in the solution is 3-6, a microbial solution is obtained.

[0065] c) After centrifuging the microbial solution and removing the supernatant, mix it with sodium chloride solution and disperse by shaking to obtain a microbial solution with low extracellular polymer content.

[0066] d) The microbial solution with low extracellular polymer content is coated on the surface of the ITO electrode and dried to obtain a microbial membrane modified electrode, which is the working electrode.

[0067] In step a):

[0068] The mass ratio of peptone, yeast extract powder and sodium chloride is 4-10:4-10:7-12, for example 1.6:4:4 (i.e. 4:10:10).

[0069] The ratio of the total mass of peptone, yeast extract powder, and sodium chloride to the amount of secondary water is 5-15g:300-500mL, for example, 9.6g:400mL.

[0070] The sterilization temperature is 115–125°C, for example, 121°C; the time is 10–20 minutes, for example, 15 minutes. Sterilization is carried out in an autoclave.

[0071] In step b):

[0072] The volume ratio of the sterilizing solution to the target water is 1–5:4000, for example, 1:4000. The target water can be tap water. The bacterial strain can be a commercially available BOD seed.

[0073] In some embodiments, the isothermal incubation is carried out at a temperature of 30°C for 14–18 hours, such as 16 hours.

[0074] In some embodiments, the OD600 value of the microorganisms in the solution is 3.

[0075] In step c):

[0076] The centrifugation speed is 4500-5500 rpm, for example 5000 rpm; the time is 3-7 minutes, for example 5 minutes. The centrifugation is carried out in centrifuge tubes.

[0077] The concentration of the first sodium chloride solution is 0.08 to 0.012 g / mL, for example, 0.01 g / mL.

[0078] The volume ratio of the microbial solution after removing the supernatant to the sodium chloride solution is 1:9 to 19, for example, 1:12.

[0079] Shaking dispersion is used to disperse microorganisms at the bottom of centrifuge tubes.

[0080] In step d):

[0081] The amount of the microbial solution with low extracellular polymeric content coated on the ITO electrode surface is 70–90 μL / cm. 2 For example, 80 μL / cm 2 .

[0082] The drying temperature is 40–60°C, and the time is 10–20 minutes.

[0083] The device for detecting the organic matter content in water also includes a data acquisition, processing, and display unit 11 connected to the detector, comprising a data acquisition module, a processing module, and a display module. The data acquisition module in the data acquisition, processing, and display unit 11 uses an electrochemical device model uECS-pro, manufactured by the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences; or an electrochemical device model HY-EW100, manufactured by Guangzhou Yuandian Technology Co., Ltd. The processing and display modules in the data acquisition, processing, and display unit 11 can use an industrial all-in-one computer, such as a touchscreen industrial all-in-one computer, specifically a 7-inch Guangyingke model with 1900 / 4G / 64G storage.

[0084] In some embodiments of the present invention, the data acquisition, processing, and display unit 11 is connected to each electrode in the detector. The reference electrode 7, the counter electrode 8, and the working electrode 9 can detect the current value of the water sample to be tested, and acquire and display the data through the data acquisition, processing, and display unit 11, thereby detecting the organic matter content in the water.

[0085] In this invention, the device for detecting the organic matter content in water further includes a first standard sample container 1, a second standard sample container 2, and a water sample container to be tested 3; the first standard sample container 1, the second standard sample container 2, and the water sample container to be tested 3 are all connected to the inlet of the detector 6 through a first switching valve 4.

[0086] In some embodiments of the present invention, the first standard sample container 1 is connected to the first inlet of the first switching valve 4; the second standard sample container 2 is connected to the second inlet of the first switching valve 4; and the water sample container 3 to be tested is connected to the third inlet of the first switching valve 4.

[0087] The present invention does not impose any special restrictions on the structure, material and type of the first standard sample container, the second standard sample container and the water sample container to be tested. The first standard sample container can hold the first standard sample, the second standard sample container can hold the second standard sample, and the water sample container to be tested can hold the water sample to be tested.

[0088] In this invention, the outlet of the detector 6 is connected to the first standard sample container 1 and the water sample container to be tested 3 via the second switching valve 10.

[0089] In some embodiments of the present invention, the outlet of the detector 6 is connected to the first standard sample container 1 through the first outlet of the second switching valve 10, and the outlet of the detector 6 is connected to the water sample container 3 to be tested through the second outlet of the second switching valve 10.

[0090] In some embodiments of the present invention, a peristaltic pump 5 is also provided between the outlet of the detector 6 and the second switching valve 10. This pump is used to draw the solution from the detector into the second switching valve, and then into subsequent processing equipment.

[0091] In some embodiments of the present invention, the device for detecting the organic matter content in the water further includes a waste liquid recovery container 11. The waste liquid recovery container 11 is connected to the third outlet of the second switching valve 10. The waste liquid recovery container is used to recover waste liquid.

[0092] In some embodiments of the present invention, both the first switching valve and the second switching valve are rotary switching valves, specifically four-channel rotary switching valves, using three of the channels. Rotary switching valves have a small cavity volume, saving components, but commercially available models typically have at least four channels; the present invention only requires three. The interface of the four-channel rotary switching valve includes a common port C and four selective ports. By rotating the valve body, four channels (C-1, C-2, C-3, and C-4) can be formed.

[0093] This invention provides a method for detecting the organic matter content in water using the detection device described above, comprising the following steps:

[0094] a) Add the first standard sample to the first standard sample container, add the second standard sample to the second standard sample container, and add the water sample to be tested to the water sample container;

[0095] The first standard sample comprises water, organic matter, and potassium ferricyanide; the organic matter comprises glucose and glutamic acid; in the first standard sample, the content of organic matter is C1 = 0-100 mg / L, and the concentration of potassium ferricyanide is 5-50 mmol / L;

[0096] The second standard sample includes water, organic matter, and potassium ferricyanide; the organic matter includes glucose and glutamic acid; in the second standard sample, the content of organic matter is C2 = 10-200 mg / L, and the concentration of potassium ferricyanide is 5-50 mmol / L;

[0097] Furthermore, the difference in organic matter content between the second standard sample and the first standard sample shall not be less than 10 mg / L;

[0098] The water sample to be tested includes the water body to be tested and potassium ferricyanide; the concentration of potassium ferricyanide in the water sample to be tested is 5-50 mmol / L;

[0099] b) Adjust the first switching valve and the second switching valve to form a loop with the first standard sample container, the first switching valve, the detector, the peristaltic pump and the second switching valve, so that the first standard sample circulates through the detector.

[0100] The potential difference between the reference electrode and the working electrode is controlled to be 0.40 to 0.50V using a data acquisition, processing, and display unit. The current value flowing through the working electrode is acquired, and the current value i1 flowing through the working electrode at time t1 is recorded.

[0101] Adjust the first switching valve and the second switching valve so that the second standard sample flows through the second standard sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container. Then adjust the first switching valve and the second switching valve so that the second standard sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the water sample container to be tested form a loop, and the second standard sample circulates through the detector.

[0102] The potential difference between the reference electrode and the working electrode is controlled to be 0.40 to 0.50V using a data acquisition, processing, and display unit. The current value flowing through the working electrode is acquired, and the current value i2 flowing through the working electrode at time t2 is recorded.

[0103] Adjust the first switching valve and the second switching valve so that the water sample to be tested flows through the water sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container. Then adjust the first switching valve and the second switching valve so that the water sample container, the first switching valve, the detector, the peristaltic pump and the second switching valve form a loop, and the water sample to be tested circulates through the detector.

[0104] The potential difference between the reference electrode and the working electrode is controlled to be 0.40 to 0.50V using a data acquisition, processing, and display unit, and the current value flowing through the working electrode is acquired and the current value i3 flowing through the working electrode at time t3 is recorded.

[0105] c) Use two points (C1, i1) and (C2, i2) to plot a first-order linear regression curve as the working curve of the detection device; then substitute the i3 value into the working curve to calculate the organic matter content C value of the water sample to be tested.

[0106] In step a):

[0107] In some embodiments of the present invention, the method for preparing the first standard sample includes the following steps:

[0108] After mixing water, organic matter, and potassium ferricyanide, the first standard sample was obtained.

[0109] The water includes at least one of deionized water, recycled water, and tap water.

[0110] In some embodiments of the present invention, the method for preparing the second standard sample includes the following steps:

[0111] After mixing water, organic matter, and potassium ferricyanide, a second standard sample was obtained.

[0112] The water includes at least one of deionized water, recycled water, and tap water.

[0113] In some embodiments of the present invention, the method for preparing the water sample to be tested includes the following steps:

[0114] The water sample is obtained by mixing the water to be tested with potassium ferricyanide.

[0115] In some embodiments of the present invention, the volume of the first standard sample added to the first standard sample container is 2 to 5 mL.

[0116] In some embodiments of the present invention, the volume of the second standard sample added to the second standard sample container is 1 mL larger than the volume of the first standard sample in the first standard sample container.

[0117] In some embodiments of the present invention, the volume of the water sample to be tested added to the water sample container is 1 mL larger than the volume of the first standard sample in the first standard sample container.

[0118] In some embodiments of the present invention, the concentrations of potassium ferricyanide in the first standard sample, the second standard sample, and the water sample to be tested are the same.

[0119] In step b):

[0120] In some embodiments of the present invention, t1 = 600~1200s.

[0121] In some embodiments of the present invention, during the process of the second standard sample flowing through the second standard sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container, the time for the second standard sample to flow through the first switching valve does not exceed 60 seconds, and the volume of the second standard sample is 1 mL.

[0122] In some embodiments of the present invention, t2 = 2 × t1.

[0123] In some embodiments of the present invention, during the process of the water sample to be tested flowing through the water sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container, the time for the water sample to be tested to flow through the first switching valve does not exceed 60 seconds, and the volume of the water sample to be tested is 1 mL.

[0124] In some embodiments of the present invention, t3 = 3 × t1.

[0125] The present invention does not impose any special restrictions on the source of the raw materials used above, and they can be commercially available.

[0126] This invention directly immobilizes a microbial membrane on the electrode surface. This allows for real-time detection of microbial degradation of organic matter in water, thus obtaining information on the organic matter content. Furthermore, it fully utilizes the porous structure of the biofilm, solving the electrode contamination problem caused by direct electrode contact with the test water sample. This technical method retains the advantages of organic matter bio-oxidation detection methods based on potassium ferricyanide electron mediators in detecting samples with high organic matter content, while simplifying the related device structure, eliminating the need for a separate reactor and electrode cleaning unit.

[0127] To further illustrate the present invention, the following detailed description of a device and method for detecting the organic matter content in water provided by the present invention is provided in conjunction with embodiments, but it should not be construed as limiting the scope of protection of the present invention.

[0128] In this embodiment, the method for preparing the working electrode is as follows:

[0129] 1) Add 1.6g peptone, 4g yeast extract and 4g sodium chloride to 400mL of secondary water, put the solution into an autoclave and place it at 121℃ for 15min to obtain a sterilized solution;

[0130] 2) Add tap water to the sterilized solution obtained in step 1) (the volume ratio of sterilized solution to tap water is 1:4000), place it in a shaker, rotate at 200 rpm, and incubate at 30℃ for 16 hours. When the OD600 value of the microorganisms in the solution is 3, the microbial solution is obtained.

[0131] 3) Pour 10 mL of the microbial solution obtained in step 2) into a centrifuge tube, centrifuge at 5000 rpm for 5 min, pour out the supernatant from the centrifuge tube, add 0.01 g / mL sodium chloride solution to the centrifuge tube (the volume ratio of the microbial solution after removing the supernatant to the sodium chloride solution is 1:12), shake to disperse the microorganisms at the bottom of the centrifuge tube, and obtain a microbial solution with low extracellular polymer content;

[0132] 4) The microbial solution with low extracellular polymeric content was prepared at a concentration of 80 μL / cm³. 2 A certain amount of material was drop-coated onto the surface of the ITO electrode and dried at 50°C for 15 minutes to obtain a microbial membrane modified electrode, which is the working electrode.

[0133] Example 1

[0134] Adopting such Figure 1 The analytical apparatus shown represents a method for analyzing water toxicity, comprising the following steps:

[0135] 1) Preparation of the first standard sample:

[0136] After mixing the deionized water, organic matter, and potassium ferricyanide, a first standard sample is obtained; the organic matter includes glucose and glutamic acid; in the first standard sample, the content of organic matter is C1 = 3 mg / L, and the concentration of potassium ferricyanide is 5 mmol / L; 2 mL of the first standard sample is added to the first standard sample container.

[0137] Preparation of the second standard sample:

[0138] After mixing the deionized water, organic matter, and potassium ferricyanide, a second standard sample is obtained; the organic matter includes glucose and glutamic acid; in the second standard sample, the content of organic matter is C1 = 15 mg / L, and the concentration of potassium ferricyanide is 5 mmol / L; 3 mL of the second standard sample is added to the container of the second standard sample.

[0139] Preparation of water samples for testing:

[0140] The water to be tested (river water) and potassium ferricyanide were mixed to obtain the water sample to be tested; the concentration of potassium ferricyanide in the water sample to be tested was 5 mmol / L; 3 mL of the water sample to be tested was added to the water sample container.

[0141] 2) Adjust the first switching valve and the second switching valve so that the first standard sample container, the first switching valve, the detector, the peristaltic pump and the second switching valve form a loop, and the first standard sample circulates through the detector;

[0142] The potential difference between the reference electrode and the working electrode is controlled to be 0.50V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i1 flowing through the working electrode at time t1 (1200s) is recorded.

[0143] Adjust the first switching valve and the second switching valve so that the second standard sample flows through the second standard sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container. When the time for 1 mL of the second standard sample to flow through the first switching valve does not exceed 60 s, adjust the first switching valve and the second switching valve so that the second standard sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the water sample container to be tested form a loop, and the second standard sample circulates through the detector.

[0144] The potential difference between the reference electrode and the working electrode is controlled to be 0.50V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i2 flowing through the working electrode at time t2 (2400s) is recorded.

[0145] Adjust the first switching valve and the second switching valve so that the water sample to be tested flows through the water sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container. When the time for 1 mL of water sample to be tested to flow through the first switching valve does not exceed 60 s, adjust the first switching valve and the second switching valve so that the water sample container, the first switching valve, the detector, the peristaltic pump and the second switching valve form a loop, and the water sample to be tested circulates through the detector.

[0146] The potential difference between the reference electrode and the working electrode is controlled to be 0.50V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i3 flowing through the working electrode at time t3 (3600s) is recorded.

[0147] 3) Use two points (C1, i1) and (C2, i2) to plot a first-order linear regression curve as the working curve of the detection device; then substitute the i3 value into the working curve to calculate the organic matter content C value of the water sample to be tested = 2.2 mg / L.

[0148] Example 2

[0149] Adopting such Figure 1 The analytical apparatus shown represents a method for analyzing water toxicity, comprising the following steps:

[0150] 1) Preparation of the first standard sample:

[0151] After mixing the deionized water, organic matter, and potassium ferricyanide, a first standard sample is obtained; the organic matter includes glucose and glutamic acid; in the first standard sample, the content of organic matter is C1 = 40 mg / L, and the concentration of potassium ferricyanide is 25 mmol / L; 3 mL of the first standard sample is added to the first standard sample container.

[0152] Preparation of the second standard sample:

[0153] After mixing the deionized water, organic matter, and potassium ferricyanide, a second standard sample is obtained; the organic matter includes glucose and glutamic acid; in the second standard sample, the content of organic matter is C1 = 150 mg / L, and the concentration of potassium ferricyanide is 25 mmol / L; 4 mL of the second standard sample is added to the container of the second standard sample.

[0154] Preparation of water samples for testing:

[0155] The water sample to be tested (a type of domestic sewage) was mixed with potassium ferricyanide to obtain the water sample to be tested; the concentration of potassium ferricyanide in the water sample to be tested was 25 mmol / L; 4 mL of the water sample to be tested was added to the water sample container.

[0156] 2) Adjust the first switching valve and the second switching valve so that the first standard sample container, the first switching valve, the detector, the peristaltic pump and the second switching valve form a loop, and the first standard sample circulates through the detector;

[0157] The potential difference between the reference electrode and the working electrode is controlled to be 0.40V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i1 flowing through the working electrode at time t1 (600s) is recorded.

[0158] Adjust the first switching valve and the second switching valve so that the second standard sample flows through the second standard sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container. When the time for 1 mL of the second standard sample to flow through the first switching valve does not exceed 60 s, adjust the first switching valve and the second switching valve so that the second standard sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the water sample container to be tested form a loop, and the second standard sample circulates through the detector.

[0159] The potential difference between the reference electrode and the working electrode is controlled to be 0.40V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i2 flowing through the working electrode at time t2 (1200s) is recorded.

[0160] Adjust the first switching valve and the second switching valve so that the water sample to be tested flows through the water sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container. When the time for 1 mL of water sample to be tested to flow through the first switching valve does not exceed 60 s, adjust the first switching valve and the second switching valve so that the water sample container, the first switching valve, the detector, the peristaltic pump and the second switching valve form a loop, and the water sample to be tested circulates through the detector.

[0161] The potential difference between the reference electrode and the working electrode is controlled to be 0.40V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i3 flowing through the working electrode at time t3 (1800s) is recorded.

[0162] 3) Use two points (C1, i1) and (C2, i2) to plot a first-order linear regression curve as the working curve of the detection device; then substitute the i3 value into the working curve to calculate the organic matter content C value of the water sample to be tested = 123.6 mg / L.

[0163] Example 3

[0164] Adopting such Figure 1 The analytical apparatus shown represents a method for analyzing water toxicity, comprising the following steps:

[0165] 1) Preparation of the first standard sample:

[0166] After mixing the deionized water, organic matter, and potassium ferricyanide, a first standard sample is obtained; the organic matter includes glucose and glutamic acid; in the first standard sample, the content of organic matter is C1 = 100 mg / L, and the concentration of potassium ferricyanide is 25 mmol / L; 4 mL of the first standard sample is added to the first standard sample container.

[0167] Preparation of the second standard sample:

[0168] After mixing the deionized water, organic matter, and potassium ferricyanide, a second standard sample is obtained; the organic matter includes glucose and glutamic acid; in the second standard sample, the content of organic matter is C1 = 200 mg / L, and the concentration of potassium ferricyanide is 25 mmol / L; 5 mL of the second standard sample is added to the container of the second standard sample.

[0169] Preparation of water samples for testing:

[0170] The water to be tested (river water) and potassium ferricyanide were mixed to obtain the water sample to be tested; the concentration of potassium ferricyanide in the water sample to be tested was 25 mmol / L; 5 mL of the water sample to be tested was added to the water sample container.

[0171] 2) Adjust the first switching valve and the second switching valve so that the first standard sample container, the first switching valve, the detector, the peristaltic pump and the second switching valve form a loop, and the first standard sample circulates through the detector;

[0172] The potential difference between the reference electrode and the working electrode is controlled to be 0.40V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i1 flowing through the working electrode at time t1 (700s) is recorded.

[0173] Adjust the first switching valve and the second switching valve so that the second standard sample flows through the second standard sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container. When the time for 1 mL of the second standard sample to flow through the first switching valve does not exceed 60 s, adjust the first switching valve and the second switching valve so that the second standard sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the water sample container to be tested form a loop, and the second standard sample circulates through the detector.

[0174] The potential difference between the reference electrode and the working electrode is controlled to be 0.40V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i2 flowing through the working electrode at time t2 (1400s) is recorded.

[0175] Adjust the first switching valve and the second switching valve so that the water sample to be tested flows through the water sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container. When the time for 1 mL of water sample to be tested to flow through the first switching valve does not exceed 60 s, adjust the first switching valve and the second switching valve so that the water sample container, the first switching valve, the detector, the peristaltic pump and the second switching valve form a loop, and the water sample to be tested circulates through the detector.

[0176] The potential difference between the reference electrode and the working electrode is controlled to be 0.40V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i3 flowing through the working electrode at time t3 (2100s) is recorded.

[0177] 3) Use two points (C1, i1) and (C2, i2) to plot a first-order linear regression curve as the working curve of the detection device; then substitute the i3 value into the working curve to calculate the organic matter content C value of the water sample to be tested = 263.8 mg / L.

[0178] Example 4

[0179] Adopting such Figure 1 The analytical apparatus shown represents a method for analyzing water toxicity, comprising the following steps:

[0180] 1) Preparation of the first standard sample:

[0181] After mixing the deionized water, organic matter, and potassium ferricyanide, a first standard sample is obtained; the organic matter includes glucose and glutamic acid; in the first standard sample, the content of organic matter is C1 = 0 mg / L, and the concentration of potassium ferricyanide is 30 mmol / L; 5 mL of the first standard sample is added to the first standard sample container.

[0182] Preparation of the second standard sample:

[0183] After mixing the deionized water, organic matter, and potassium ferricyanide, a second standard sample is obtained; the organic matter includes glucose and glutamic acid; in the second standard sample, the content of organic matter is C1 = 10 mg / L, and the concentration of potassium ferricyanide is 30 mmol / L; 6 mL of the second standard sample is added to the container of the second standard sample.

[0184] Preparation of water samples for testing:

[0185] The water sample to be tested (groundwater) was mixed with potassium ferricyanide to obtain the water sample to be tested; the concentration of potassium ferricyanide in the water sample to be tested was 30 mmol / L; 6 mL of the water sample to be tested was added to the water sample container.

[0186] 2) Adjust the first switching valve and the second switching valve so that the first standard sample container, the first switching valve, the detector, the peristaltic pump and the second switching valve form a loop, and the first standard sample circulates through the detector;

[0187] The potential difference between the reference electrode and the working electrode is controlled to be 0.43V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i1 flowing through the working electrode at time t1 (800s) is recorded.

[0188] Adjust the first switching valve and the second switching valve so that the second standard sample flows through the second standard sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container. When the time for 1 mL of the second standard sample to flow through the first switching valve does not exceed 60 s, adjust the first switching valve and the second switching valve so that the second standard sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the water sample container to be tested form a loop, and the second standard sample circulates through the detector.

[0189] The potential difference between the reference electrode and the working electrode is controlled to be 0.43V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i2 flowing through the working electrode at time t2 (1600s) is recorded.

[0190] Adjust the first switching valve and the second switching valve so that the water sample to be tested flows through the water sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container. When the time for 1 mL of water sample to be tested to flow through the first switching valve does not exceed 60 s, adjust the first switching valve and the second switching valve so that the water sample container, the first switching valve, the detector, the peristaltic pump and the second switching valve form a loop, and the water sample to be tested circulates through the detector.

[0191] The potential difference between the reference electrode and the working electrode is controlled to be 0.43V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i3 flowing through the working electrode at time t3 (2400s) is recorded.

[0192] 3) Use two points (C1, i1) and (C2, i2) to plot a first-order linear regression curve as the working curve of the detection device; then substitute the i3 value into the working curve to calculate the organic matter content C value of the water sample to be tested = 0.3 mg / L.

[0193] Example 5

[0194] Adopting such Figure 1 The analytical apparatus shown represents a method for analyzing water toxicity, comprising the following steps:

[0195] 1) Preparation of the first standard sample:

[0196] After mixing the deionized water, organic matter, and potassium ferricyanide, a first standard sample is obtained; the organic matter includes glucose and glutamic acid; in the first standard sample, the content of organic matter is C1 = 0 mg / L, and the concentration of potassium ferricyanide is 35 mmol / L; 4 mL of the first standard sample is added to the first standard sample container.

[0197] Preparation of the second standard sample:

[0198] After mixing the deionized water, organic matter, and potassium ferricyanide, a second standard sample is obtained; the organic matter includes glucose and glutamic acid; in the second standard sample, the content of organic matter is C1 = 10 mg / L, and the concentration of potassium ferricyanide is 35 mmol / L; 5 mL of the second standard sample is added to the container of the second standard sample.

[0199] Preparation of water samples for testing:

[0200] The water to be tested (tap water) and potassium ferricyanide were mixed to obtain the water sample to be tested; the concentration of potassium ferricyanide in the water sample to be tested was 35 mmol / L; 5 mL of the water sample to be tested was added to the water sample container.

[0201] 2) Adjust the first switching valve and the second switching valve so that the first standard sample container, the first switching valve, the detector, the peristaltic pump and the second switching valve form a loop, and the first standard sample circulates through the detector;

[0202] The potential difference between the reference electrode and the working electrode is controlled to be 0.45V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i1 flowing through the working electrode at time t1 (900s) is recorded.

[0203] Adjust the first switching valve and the second switching valve so that the second standard sample flows through the second standard sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container. When the time for 1 mL of the second standard sample to flow through the first switching valve does not exceed 60 s, adjust the first switching valve and the second switching valve so that the second standard sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the water sample container to be tested form a loop, and the second standard sample circulates through the detector.

[0204] The potential difference between the reference electrode and the working electrode is controlled to be 0.45V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i2 flowing through the working electrode at time t2 (1800s) is recorded.

[0205] Adjust the first switching valve and the second switching valve so that the water sample to be tested flows through the water sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container. When the time for 1 mL of water sample to be tested to flow through the first switching valve does not exceed 60 s, adjust the first switching valve and the second switching valve so that the water sample container, the first switching valve, the detector, the peristaltic pump and the second switching valve form a loop, and the water sample to be tested circulates through the detector.

[0206] The potential difference between the reference electrode and the working electrode is controlled to be 0.45V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i3 flowing through the working electrode at time t3 (2700s) is recorded.

[0207] 3) Use two points (C1, i1) and (C2, i2) to plot a first-order linear regression curve as the working curve of the detection device; then substitute the i3 value into the working curve to calculate the organic matter content C value of the water sample to be tested = 0.2 mg / L.

[0208] Example 6

[0209] Adopting such Figure 1 The analytical apparatus shown represents a method for analyzing water toxicity, comprising the following steps:

[0210] 1) Preparation of the first standard sample:

[0211] After mixing the deionized water, organic matter, and potassium ferricyanide, a first standard sample is obtained; the organic matter includes glucose and glutamic acid; in the first standard sample, the content of organic matter is C1 = 0 mg / L, and the concentration of potassium ferricyanide is 45 mmol / L; 4 mL of the first standard sample is added to the first standard sample container.

[0212] Preparation of the second standard sample:

[0213] After mixing the deionized water, organic matter, and potassium ferricyanide, a second standard sample is obtained; the organic matter includes glucose and glutamic acid; in the second standard sample, the content of organic matter is C1 = 20 mg / L, and the concentration of potassium ferricyanide is 45 mmol / L; 5 mL of the second standard sample is added to the container of the second standard sample.

[0214] Preparation of water samples for testing:

[0215] The water to be tested (tap water) and potassium ferricyanide were mixed to obtain the water sample to be tested; the concentration of potassium ferricyanide in the water sample to be tested was 45 mmol / L; 5 mL of the water sample to be tested was added to the water sample container.

[0216] 2) Adjust the first switching valve and the second switching valve so that the first standard sample container, the first switching valve, the detector, the peristaltic pump and the second switching valve form a loop, and the first standard sample circulates through the detector;

[0217] The potential difference between the reference electrode and the working electrode is controlled to be 0.47V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i1 flowing through the working electrode at time t1 (1100s) is recorded.

[0218] Adjust the first switching valve and the second switching valve so that the second standard sample flows through the second standard sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container. When the time for 1 mL of the second standard sample to flow through the first switching valve does not exceed 60 s, adjust the first switching valve and the second switching valve so that the second standard sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the water sample container to be tested form a loop, and the second standard sample circulates through the detector.

[0219] The potential difference between the reference electrode and the working electrode is controlled to be 0.47V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i2 flowing through the working electrode at time t2 (2200s) is recorded.

[0220] Adjust the first switching valve and the second switching valve so that the water sample to be tested flows through the water sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container. When the time for 1 mL of water sample to be tested to flow through the first switching valve does not exceed 60 s, adjust the first switching valve and the second switching valve so that the water sample container, the first switching valve, the detector, the peristaltic pump and the second switching valve form a loop, and the water sample to be tested circulates through the detector.

[0221] The potential difference between the reference electrode and the working electrode is controlled to be 0.47V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i3 flowing through the working electrode at time t3 (3300s) is recorded.

[0222] 3) Use two points (C1, i1) and (C2, i2) to plot a first-order linear regression curve as the working curve of the detection device; then substitute the i3 value into the working curve to calculate the organic matter content C value of the water sample to be tested = 7.5 mg / L.

[0223] Example 7

[0224] Adopting such Figure 1 The analytical apparatus shown represents a method for analyzing water toxicity, comprising the following steps:

[0225] 1) Preparation of the first standard sample:

[0226] After mixing the deionized water, organic matter, and potassium ferricyanide, a first standard sample is obtained; the organic matter includes glucose and glutamic acid; in the first standard sample, the content of organic matter is C1 = 0 mg / L, and the concentration of potassium ferricyanide is 40 mmol / L; 4 mL of the first standard sample is added to the first standard sample container.

[0227] Preparation of the second standard sample:

[0228] After mixing the deionized water, organic matter, and potassium ferricyanide, a second standard sample is obtained; the organic matter includes glucose and glutamic acid; in the second standard sample, the content of organic matter is C1 = 100 mg / L, and the concentration of potassium ferricyanide is 40 mmol / L; 5 mL of the second standard sample is added to the container of the second standard sample.

[0229] Preparation of water samples for testing:

[0230] After mixing the secondary water, organic matter, and potassium ferricyanide, a water sample to be tested is obtained; the organic matter content in the water sample to be tested is 50 mg / L, and the potassium ferricyanide concentration is 40 mmol / L; 5 mL of the water sample to be tested is added to the water sample container.

[0231] 2) Adjust the first switching valve and the second switching valve so that the first standard sample container, the first switching valve, the detector, the peristaltic pump and the second switching valve form a loop, and the first standard sample circulates through the detector;

[0232] The potential difference between the reference electrode and the working electrode is controlled to be 0.47V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i1 flowing through the working electrode at time t1 (1000s) is recorded.

[0233] Adjust the first switching valve and the second switching valve so that the second standard sample flows through the second standard sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container. When the time for 1 mL of the second standard sample to flow through the first switching valve does not exceed 60 s, adjust the first switching valve and the second switching valve so that the second standard sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the water sample container to be tested form a loop, and the second standard sample circulates through the detector.

[0234] The potential difference between the reference electrode and the working electrode is controlled to be 0.47V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i2 flowing through the working electrode at time t2 (2000s) is recorded.

[0235] Adjust the first switching valve and the second switching valve so that the water sample to be tested flows through the water sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container. When the time for 1 mL of water sample to be tested to flow through the first switching valve does not exceed 60 s, adjust the first switching valve and the second switching valve so that the water sample container, the first switching valve, the detector, the peristaltic pump and the second switching valve form a loop, and the water sample to be tested circulates through the detector.

[0236] The potential difference between the reference electrode and the working electrode is controlled to be 0.47V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i3 flowing through the working electrode at time t3 (3000s) is recorded.

[0237] 3) A first-order linear regression curve was plotted using two points (C1, i1) and (C2, i2) as the working curve of the detection device; then, the value of i3 was substituted into the working curve to calculate the organic matter content C value of the water sample. The C values ​​of the sample after seven repeated tests were 48.3 mg / L, 48.4 mg / L, 50.0 mg / L, 49.2 mg / L, 48.5 mg / L, 48.1 mg / L, and 47.9 mg / L, respectively. The average value of the measured results was 48.6 mg / L, and the relative standard deviation (RSD) was <3%.

[0238] The organic matter content in the water sample from Example 7 was modified to 20 mg / L. Using the same method, seven tests were conducted, yielding results of 19.6 mg / L, 19.1 mg / L, 18.3 mg / L, 19.4 mg / L, 20.1 mg / L, 19.2 mg / L, and 19.2 mg / L. The average value of the measured results was 19.3 mg / L, and the relative standard deviation (RSD) was <3%.

[0239] The organic matter content in the water sample from Example 7 was modified to 70 mg / L. Using the same method, seven tests were conducted, yielding results of 66.9 mg / L, 68.1 mg / L, 69.8 mg / L, 66.8 mg / L, 68.9 mg / L, 69.0 mg / L, and 68.5 mg / L. The average value of the measured results was 68.3 mg / L, and the relative standard deviation (RSD) was <3%.

[0240] The RSD of the test was 5% using the TE-2015 fully automatic rapid BOD analyzer manufactured by Tianer Analytical Instruments (Tianjin) Co., Ltd.; the RSD of the test was 5% using the JC-50 microbial electrode method BOD analyzer (Qingdao Juchuang Environmental Protection Group Co., Ltd.).

[0241] Furthermore, when using the TE-2015 fully automated rapid BOD analyzer manufactured by Tianer Analytical Instruments (Tianjin) Co., Ltd., the testing volume for a single sample is 50 mL; when using the JC-50 microbial electrode method BOD analyzer (Qingdao Juchuang Environmental Protection Group Co., Ltd.), the testing volume for a single sample is also 50 mL. The testing volume is relatively high. In contrast, in this invention, the testing volume for a single sample does not exceed 6 mL, resulting in lower solution consumption.

[0242] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A device for detecting the organic matter content in water, comprising: Detector; The detector includes a reference electrode, a counter electrode, and a working electrode; The working electrode is a microbial membrane modified electrode; The method for preparing the working electrode includes the following steps: a) Mix deionized water, peptone, yeast extract powder and sodium chloride, sterilize, and obtain a sterilized solution; b) Mix the target water or bacterial strain with the sterilized solution and incubate at a constant temperature of 30-40°C. When the OD600 value of the microorganisms in the solution is 3-6, a microbial solution is obtained. c) After centrifuging the microbial solution and removing the supernatant, mix it with sodium chloride solution and disperse by shaking to obtain a microbial solution with low extracellular polymer content; d) The microbial solution with low extracellular polymer content is coated onto the surface of the ITO electrode and dried to obtain the working electrode; The data acquisition, processing, and display unit is connected to the detector; The system comprises a first standard sample container, a second standard sample container, and a water sample container to be tested; all three containers are connected to the inlet of the detector via a first switching valve. The detector's outlet is connected to the first standard sample container and the water sample container to be tested via a second switching valve. The first standard sample comprises water, organic matter, and potassium ferricyanide; the organic matter comprises glucose and glutamic acid; the second standard sample comprises water, organic matter, and potassium ferricyanide; the organic matter comprises glucose and glutamic acid.

2. The detection device according to claim 1, characterized in that, The mass ratio of peptone, yeast extract powder and sodium chloride is 4~10:4~10:7~12; The sterilization temperature is 115~125℃ and the time is 10~20 min.

3. The detection device according to claim 1, characterized in that, The volume ratio of the sterilization solution to the target water body is 1~5:4000; The centrifugation speed is 4500~5500 rpm, and the time is 3~7 min; The concentration of the sodium chloride solution is 0.005~0.01 g / mL; The volume ratio of the microbial solution to the sodium chloride solution after removing the supernatant is 1:9~19; The OD600 value of the microbial solution with low extracellular polymer content was 60~100.

4. The detection device according to claim 1, characterized in that, The amount of the microbial solution with low extracellular polymeric content coated on the ITO electrode surface is 70~90 µL / cm. 2 .

5. The detection device according to claim 1, characterized in that, A peristaltic pump is also installed between the outlet of the detector and the second switching valve; The detection device also includes a waste liquid recovery container.

6. A method for detecting the organic matter content in water using the detection device according to claim 5, comprising the following steps: a) Add the first standard sample to the first standard sample container, add the second standard sample to the second standard sample container, and add the water sample to be tested to the water sample container; The first standard sample comprises water, organic matter, and potassium ferricyanide; the organic matter comprises glucose and glutamic acid; in the first standard sample, the content of organic matter is C1=0~100 mg / L, and the concentration of potassium ferricyanide is 5~50 mmol / L; The second standard sample includes water, organic matter, and potassium ferricyanide; the organic matter includes glucose and glutamic acid; in the second standard sample, the content of organic matter is C2=10~200 mg / L, and the concentration of potassium ferricyanide is 5~50 mmol / L; Furthermore, the difference in organic matter content between the second standard sample and the first standard sample shall not be less than 10 mg / L; The water sample to be tested includes the water body to be tested and potassium ferricyanide; the concentration of potassium ferricyanide in the water sample to be tested is 5~50 mmol / L; b) Adjust the first switching valve and the second switching valve to form a loop with the first standard sample container, the first switching valve, the detector, the peristaltic pump and the second switching valve, so that the first standard sample circulates through the detector. The potential difference between the reference electrode and the working electrode is controlled to be 0.40~0.50V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i1 flowing through the working electrode at time t1 is recorded. Adjust the first switching valve and the second switching valve so that the second standard sample flows through the second standard sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container. Then adjust the first switching valve and the second switching valve so that the second standard sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the water sample container to be tested form a loop, and the second standard sample circulates through the detector. The potential difference between the reference electrode and the working electrode is controlled to be 0.40~0.50V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i2 flowing through the working electrode at time t2 is recorded. Adjust the first switching valve and the second switching valve so that the water sample to be tested flows through the water sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container. Then adjust the first switching valve and the second switching valve so that the water sample container, the first switching valve, the detector, the peristaltic pump and the second switching valve form a loop, and the water sample to be tested circulates through the detector. The potential difference between the reference electrode and the working electrode is controlled to be 0.40~0.50V using the data acquisition, processing and display unit, and the current value flowing through the working electrode is collected and the current value i3 flowing through the working electrode at time t3 is recorded. c) Use two points (C1, i1) and (C2, i2) to plot a first-order linear regression curve as the working curve of the detection device; then substitute the i3 value into the working curve to calculate the organic matter content C value of the water sample to be tested.

7. The method according to claim 6, characterized in that, Add 2 to 5 mL of the first standard sample to the first standard sample container; The volume of the second standard sample added to the second standard sample container is 1 mL larger than the volume of the first standard sample in the first standard sample container; The volume of the water sample to be tested added to the water sample container is 1 mL more than the volume of the first standard sample in the first standard sample container; The concentrations of potassium ferricyanide in the first standard sample, the second standard sample, and the water sample to be tested are the same.

8. The method according to claim 6, characterized in that, t1=600~1200 s, t2=2×t1, t3=3×t1.

9. The method according to claim 6, characterized in that, During the process of the second standard sample flowing through the second standard sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve, and the waste liquid recovery container, the time for the second standard sample to flow through the first switching valve shall not exceed 60 seconds, and the volume of the second standard sample shall be 1 mL. During the process of the water sample to be tested flowing through the water sample container, the first switching valve, the detector, the peristaltic pump, the second switching valve and the waste liquid recovery container, the time for the water sample to flow through the first switching valve shall not exceed 60 seconds, and the volume of the water sample to be tested is 1 mL.

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