Water quality detection concentration calculation method and system

Abstract

The application provides a water quality detection concentration calculation method and system, and relates to the field of water quality concentration detection. The method comprises the following steps: after sequentially performing sampling, quantification, mixing of preset reagents, transfer and centrifugal color development, continuously performing photoelectric detection on the target water sample for a preset number of times to obtain the total phosphorus concentration, total nitrogen concentration, COD concentration and ammonia nitrogen concentration of the target water sample for the preset number of times; determining the actual total phosphorus concentration of the target water sample and the actual ammonia nitrogen concentration of the target water sample; calculating the actual total nitrogen concentration matrix according to the initial total nitrogen concentration matrix and the total nitrogen hidden transfer matrix, and determining the actual total nitrogen concentration of the target water sample; and calculating the actual COD concentration matrix according to the initial COD concentration matrix and the COD hidden transfer matrix, and determining the actual COD concentration of the target water sample. The application integrates multiple different index detections in the same chip at the same time, ensures the accuracy of the detection results of the total nitrogen concentration, COD concentration, total phosphorus concentration and ammonia nitrogen concentration, shortens the detection time, and improves the detection efficiency.

Description

Technical Field

[0001] This invention relates to the field of water quality concentration detection, and in particular to a method and system for calculating water quality concentration. Background Technology

[0002] After undergoing processes such as injection molding, bonding, and hot pressing, the microfluidic chip forms a sealed chip body. If the water quality concentration detection for each indicator is performed on an independent microfluidic chip, it can fully meet the requirements of different indicators. For example, for total nitrogen, the cleanliness of the quartz plate surface is sufficient; for COD, as long as the water sample can be quickly transferred to the detection chamber after digestion for photoelectric detection, the reaction rate of the reagent with the microfluidic chip material is extremely low in a short time; relatively speaking, the chemical reagents for ammonia nitrogen and total phosphorus have the lowest sensitivity to the microfluidic chip material, and as long as the inner cavity is clean and free of impurities, the changes in water sample deterioration are very stable. However, once the microfluidic chip has been tested, its internal chemical molecules are altered, and it cannot be cleaned and retested like traditional laboratory equipment.

[0003] To improve the efficiency of microfluidic chips, integrating multiple different indicators onto a single chip is crucial. However, the integrated detection of four indicators prolongs the contact time between the chemical reagents and the microfluidic chip material. This leads to distortion in the photoelectric detection of COD and total nitrogen after all four indicators have completed transfer and color development. This distortion in the photoelectric detection signal results in inaccurate concentration calculations. How to achieve compatibility between the detection processes of different indicators while ensuring the detected concentration is the same as that obtained with four independent microfluidic chips is a pressing technical problem that needs to be solved in multi-indicator microfluidic water quality detection. Currently, there is no technical solution that can solve this problem, nor is there a method or system for calculating water quality detection concentrations based on microfluidic chips. Summary of the Invention

[0004] This invention provides a method and system for calculating water quality concentration. After the conversion and integration from single-index detection to multi-index detection, the method utilizes an implicit transition matrix to improve the accuracy of total nitrogen and COD detection results, addressing the impact of compatibility issues between different index processes on the accuracy of total nitrogen and COD detection results.

[0005] In a first aspect, the present invention provides a method for calculating water quality concentration, comprising:

[0006] For the target water sample, after sequentially performing injection, quantification, mixing of pre-prepared reagents, transfer, and centrifugation for color development, the target water sample is continuously subjected to photoelectric detection for a preset number of times to obtain the total phosphorus concentration, total nitrogen concentration, COD concentration, and ammonia nitrogen concentration for the preset number of times. Different wavelengths correspond to photoelectric detection of different water quality indicators.

[0007] The actual total phosphorus concentration of the target water sample is determined based on the average concentration of total phosphorus concentration from a preset number of tests, and the actual ammonia nitrogen concentration of the target water sample is determined based on the average concentration of ammonia nitrogen concentration from a preset number of tests.

[0008] An initial total nitrogen concentration matrix is ​​constructed based on the total nitrogen concentration of a preset number of cycles. An actual total nitrogen concentration matrix is ​​calculated based on the initial total nitrogen concentration matrix and the total nitrogen implicit transfer matrix. The actual total nitrogen concentration of the target water sample is determined based on the maximum value in the actual total nitrogen concentration matrix. Similarly, an initial COD concentration matrix is ​​constructed based on the COD concentration of a preset number of cycles. An actual COD concentration matrix is ​​calculated based on the initial COD concentration matrix and the COD implicit transfer matrix. The actual COD concentration of the target water sample is determined based on the maximum value in the actual COD concentration matrix.

[0009] The total nitrogen hidden transfer matrix is ​​obtained by performing photoelectric detection on water samples at different concentrations a preset number of times, resulting in a total nitrogen concentration matrix constructed from the total nitrogen concentrations of the samples at different concentrations a preset number of times. The matrix is ​​determined by calculation based on the total nitrogen concentration matrix and the total nitrogen standard solution matrix at different concentrations.

[0010] The COD hidden transfer matrix is ​​obtained by performing photoelectric detection on sample water quality at different concentrations a preset number of times, resulting in a sample COD concentration matrix constructed from the sample COD concentrations at different concentrations and a preset number of times. The COD concentration matrix is ​​determined by calculation based on the sample COD concentration matrix and the COD standard solution matrix at different concentrations.

[0011] According to the water quality detection concentration calculation method provided by the present invention, before calculating the actual total nitrogen concentration matrix based on the initial total nitrogen concentration matrix and the total nitrogen latent transfer matrix, the total nitrogen latent transfer matrix is ​​determined by calculation based on the sample total nitrogen concentration matrix and the total nitrogen standard solution matrix at different concentrations:

[0012]

[0013] in, P is the total nitrogen hidden transfer matrix. T Let Q be the transpose of P, where P is the total nitrogen concentration matrix of the sample, and Q is the total nitrogen standard solution matrix at different concentrations.

[0014] According to the water quality detection concentration calculation method provided by the present invention, the total nitrogen concentration matrix P of the sample is:

[0015]

[0016] The total nitrogen standard solution matrix Q at different concentrations is:

[0017]

[0018] The total nitrogen hidden transfer matrix for:

[0019]

[0020] M represents the preset number of times, and Z represents the number of different concentrations.

[0021] According to the water quality detection concentration calculation method provided by the present invention, before calculating the actual COD concentration matrix based on the initial COD concentration matrix and the COD implicit transition matrix, the COD implicit transition matrix is ​​determined by calculation based on the sample COD concentration matrix and the COD standard solution matrix at different concentrations:

[0022]

[0023] The degree matrix, where H is the COD standard solution matrix at different concentrations.

[0024] According to the water quality detection concentration calculation method provided by the present invention, the sample COD concentration matrix C is:

[0025]

[0026] The COD standard solution matrix H at different concentrations is:

[0027]

[0028] The COD hidden transition matrix ω is:

[0029]

[0030] M represents the preset number of times, and Z represents the number of different concentrations.

[0031] According to the water quality detection concentration calculation method provided by the present invention, after determining the actual COD concentration of the target water sample based on the maximum value in the actual COD concentration matrix, the method further includes:

[0032] The variance of the target total phosphorus concentration is calculated based on the total phosphorus concentration of the preset number of times, and the variance of the target ammonia nitrogen concentration is calculated based on the ammonia nitrogen concentration of the preset number of times.

[0033] If the variance of the target total phosphorus concentration is within a preset total phosphorus concentration variance range, and the variance of the target ammonia nitrogen concentration is within a preset ammonia nitrogen concentration variance range, then the actual total nitrogen concentration and actual COD concentration of the target water sample are determined to be valid calculation results; otherwise, the actual total nitrogen concentration and actual COD concentration of the target water sample are determined to be invalid calculation results.

[0034] According to the water quality detection concentration calculation method provided by the present invention, before calculating the target total phosphorus concentration variance based on the total phosphorus concentration of a preset number of tests and the target ammonia nitrogen concentration variance based on the ammonia nitrogen concentration of a preset number of tests, the method further includes:

[0035] The water sample was subjected to photoelectric detection a preset number of times to obtain the total phosphorus concentration of the sample at different concentrations for a preset number of times. The water sample was subjected to photoelectric detection a preset number of times to obtain the ammonia nitrogen concentration of the sample at different concentrations for a preset number of times.

[0036] For each concentration, calculate the variance of total phosphorus concentration based on the total phosphorus concentration of all samples at that concentration, iterate through all concentrations, determine the variance of total phosphorus concentration at each concentration, and determine the preset total phosphorus concentration variance interval based on the maximum and minimum values ​​of the variance of total phosphorus concentration at all concentrations.

[0037] For each concentration, the variance of the ammonia nitrogen concentration is calculated based on the ammonia nitrogen concentration of all samples at that concentration. All concentrations are iterated over to determine the variance of the ammonia nitrogen concentration at each concentration. The preset ammonia nitrogen concentration variance interval is determined based on the maximum and minimum values ​​of the variance of the ammonia nitrogen concentration at all concentrations.

[0038] According to the water quality detection concentration calculation method provided by the present invention, the water quality indicators include total phosphorus concentration, total nitrogen concentration, COD concentration, and ammonia nitrogen concentration, and the different wavelengths correspond to the photoelectric detection of different water quality indicators, including:

[0039] The photoelectric detection of total phosphorus corresponds to a wavelength of 700 nm;

[0040] The photoelectric detection of total nitrogen corresponds to a wavelength of 220 nm;

[0041] The photoelectric detection of COD corresponds to a wavelength of 440nm;

[0042] The photoelectric detection of ammonia nitrogen corresponds to a wavelength of 700 nm.

[0043] According to the water quality detection concentration calculation method provided by the present invention, before constructing an initial total nitrogen concentration matrix based on the total nitrogen concentration of a preset number of tests, the method further includes:

[0044] Photoelectric detection was performed on total nitrogen standard solutions at different concentrations a preset number of times, with each photoelectric detection lasting a preset duration. The concentration of the photoelectric signal corresponding to the photoelectric detection was determined as the total nitrogen concentration, until the total nitrogen concentration of the preset number of times was obtained.

[0045] The different concentrations are different concentrations that are taken uniformly.

[0046] Secondly, a water quality detection concentration calculation system is provided, wherein the water quality detection concentration calculation system is a microfluidic chip, and the microfluidic chip is used for:

[0047] For the target water sample, after sequentially performing injection, quantification, mixing of pre-prepared reagents, transfer, and centrifugation for color development, the target water sample is continuously subjected to photoelectric detection for a preset number of times to obtain the total phosphorus concentration, total nitrogen concentration, COD concentration, and ammonia nitrogen concentration for the preset number of times. Different wavelengths correspond to photoelectric detection of different water quality indicators.

[0048] The actual total phosphorus concentration of the target water sample is determined based on the average concentration of total phosphorus concentration from a preset number of tests, and the actual ammonia nitrogen concentration of the target water sample is determined based on the average concentration of ammonia nitrogen concentration from a preset number of tests.

[0049] An initial total nitrogen concentration matrix is ​​constructed based on the total nitrogen concentration of a preset number of cycles. An actual total nitrogen concentration matrix is ​​calculated based on the initial total nitrogen concentration matrix and the total nitrogen implicit transfer matrix. The actual total nitrogen concentration of the target water sample is determined based on the maximum value in the actual total nitrogen concentration matrix. Similarly, an initial COD concentration matrix is ​​constructed based on the COD concentration of a preset number of cycles. An actual COD concentration matrix is ​​calculated based on the initial COD concentration matrix and the COD implicit transfer matrix. The actual COD concentration of the target water sample is determined based on the maximum value in the actual COD concentration matrix.

[0050] The total nitrogen hidden transfer matrix is ​​obtained by performing photoelectric detection on water samples at different concentrations a preset number of times, resulting in a total nitrogen concentration matrix constructed from the total nitrogen concentrations of the samples at different concentrations a preset number of times. The matrix is ​​determined by calculation based on the total nitrogen concentration matrix and the total nitrogen standard solution matrix at different concentrations.

[0051] The COD hidden transfer matrix is ​​obtained by performing photoelectric detection on sample water quality at different concentrations a preset number of times, resulting in a sample COD concentration matrix constructed from the sample COD concentrations at different concentrations and a preset number of times. The COD concentration matrix is ​​determined by calculation based on the sample COD concentration matrix and the COD standard solution matrix at different concentrations.

[0052] To improve the efficiency of microfluidic chips, this invention integrates the detection of multiple different indicators onto a single chip. However, during the simultaneous centrifugal transfer and mixing of pre-prepared reagents for multiple indicators, the varying sensitivities of different chemical reagents to the microfluidic chip material cause abnormal distortions in the detected water concentration. To ensure compatibility with the detection processes of different indicators and to make the final concentration result as accurate as when detected by four independent microfluidic chips individually, this invention proposes a calculation method that uses an implicit transfer matrix to reconstruct the actual water concentration, improving the accuracy of total nitrogen and COD concentration detection results. Since the detection of total phosphorus and ammonia nitrogen involves a color development process, extending the photoelectric detection time extends the color development process, which has no impact on these two indicators.

[0053] The reason why this invention can use the errors of ammonia nitrogen and total phosphorus to determine whether the actual total nitrogen concentration and actual COD concentration of the target water sample are valid calculation results is that this invention can solve the distortion problem when upgrading from single-index detection to multi-index detection. If the materials and processes of this microfluidic chip itself have problems, it is impossible to achieve accurate calculation of water quality concentration through this invention. This is the boundary range of the problem that this invention can solve. Ultimately, when the detection of multiple different indicators is integrated into the same chip, the detection results of total nitrogen concentration, COD concentration, total phosphorus concentration and ammonia nitrogen concentration are all very accurate, shortening the detection time and improving the detection efficiency. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0055] Figure 1 This is a flowchart illustrating the water quality detection concentration calculation method provided by the present invention;

[0056] Figure 2 This is one of the structural schematic diagrams of the water quality detection concentration calculation system provided by the present invention;

[0057] Figure 3 This is the second schematic diagram of the water quality detection concentration calculation system provided by the present invention;

[0058] Figure 4 This is a trend diagram of the changes in different standard solution points provided by the present invention;

[0059] Figure 5 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0061] Traditional chemical reagent-based water quality testing methods integrate complex and cumbersome water quality testing procedures—digestion, titration, mixing, colorimetry, and calculation—onto a micrometer-scale chip, automating the entire analysis process. Microfluidic chips offer advantages such as compact size, small sample and reagent usage, low energy consumption, fast reaction speed, large-scale parallel processing, and disposable functionality. However, the application of microfluidic chips in analytical chemistry for water quality testing of indicators such as ammonia nitrogen, total phosphorus, total nitrogen, and COD is still limited. This is mainly due to the limitations of the material properties and bonding processes of microfluidic chips. While many different materials are available, including silicon, metals, polymers, glass, and quartz, few can meet the COD requirements. Furthermore, the molding and bonding processes for polymers or quartz are crucial factors affecting the accuracy and validity of water quality test results.

[0062] The entire manufacturing process of microfluidic chips involves several main steps, including injection molding, sensor bonding, pressure-sensitive membrane hot pressing, and pre-assembled reagents. This differs from traditional water quality testing equipment, which can be pre-cleaned, dried according to national standards, and stored in a clean environment for regular inspection and maintenance. Upgrading microfluidic chip detection from single-index to simultaneous detection of four water quality concentrations can save significant time. This is because the execution of four indicators involves many overlapping processes, such as sample introduction, transfer, and photoelectric detection. Furthermore, four indicators can more comprehensively represent the water quality characteristics of a single sampling point.

[0063] This invention aims to design a method for water quality detection using a multi-index microfluidic chip, such as... Figure 2 As shown, the detection carrier is a microfluidic chip as the main body. The chip is circular and contains fan-shaped chips containing four different water quality parameters: total phosphorus, total nitrogen, COD, and ammonia nitrogen. The initial values ​​of the four indicators are obtained by multiple photoelectric detections and a preset model algorithm, and the true concentration values ​​are estimated. The preset model algorithm includes the least squares method and the fusion discrimination of different indicators.

[0064] Figure 1 This is a flowchart illustrating the water quality detection concentration calculation method provided by the present invention, which includes:

[0065] Step 101: For the target water sample, after sequentially performing injection, quantification, mixing of pre-prepared reagents, transfer, and centrifugation and color development, the target water sample is continuously subjected to photoelectric detection for a preset number of times to obtain the total phosphorus concentration, total nitrogen concentration, COD concentration, and ammonia nitrogen concentration for the preset number of times. Different wavelengths correspond to photoelectric detection of different water quality indicators.

[0066] Step 102: Determine the actual total phosphorus concentration of the target water sample based on the average concentration of total phosphorus concentration over a preset number of tests, and determine the actual ammonia nitrogen concentration of the target water sample based on the average concentration of ammonia nitrogen concentration over a preset number of tests.

[0067] Step 103: Construct an initial total nitrogen concentration matrix based on the total nitrogen concentration of a preset number of cycles; calculate the actual total nitrogen concentration matrix based on the initial total nitrogen concentration matrix and the total nitrogen implicit transfer matrix; determine the actual total nitrogen concentration of the target water sample based on the maximum value in the actual total nitrogen concentration matrix; construct an initial COD concentration matrix based on the COD concentration of a preset number of cycles; calculate the actual COD concentration matrix based on the initial COD concentration matrix and the COD implicit transfer matrix; determine the actual COD concentration of the target water sample based on the maximum value in the actual COD concentration matrix.

[0068] The total nitrogen hidden transfer matrix is ​​obtained by performing photoelectric detection on water samples at different concentrations a preset number of times, resulting in a total nitrogen concentration matrix constructed from the total nitrogen concentrations of the samples at different concentrations a preset number of times. The matrix is ​​determined by calculation based on the total nitrogen concentration matrix and the total nitrogen standard solution matrix at different concentrations.

[0069] The COD hidden transfer matrix is ​​obtained by performing photoelectric detection on sample water quality at different concentrations a preset number of times, resulting in a sample COD concentration matrix constructed from the sample COD concentrations at different concentrations and a preset number of times. The COD concentration matrix is ​​determined by calculation based on the sample COD concentration matrix and the COD standard solution matrix at different concentrations.

[0070] In step 101, the water quality indicators include total phosphorus concentration, total nitrogen concentration, COD concentration, and ammonia nitrogen concentration. The different wavelengths correspond to photoelectric detection of different water quality indicators, including: photoelectric detection of total phosphorus corresponds to a wavelength of 700 nm; photoelectric detection of total nitrogen corresponds to a wavelength of 220 nm; photoelectric detection of COD corresponds to a wavelength of 440 nm; and photoelectric detection of ammonia nitrogen corresponds to a wavelength of 700 nm.

[0071] For the target water sample, the following steps are performed sequentially, followed by a preset number of photoelectric detections: First, the target water sample is introduced into the detection cell of the microfluidic chip. The volume of the water sample is precisely controlled within the detection cell. A predetermined amount of chemical reagent is mixed with the water sample to produce a detectable reaction. The mixed water sample is then transferred to an appropriate detection area, and centrifugation is used to develop the color of the chemical substances in the water sample for optical detection. After centrifugation and color development, four light sources of different wavelengths (total phosphorus: 700nm; total nitrogen: 220nm; COD: 440nm; ammonia nitrogen: 700nm) are used to continuously perform photoelectric detection on the target water sample. The preset number of detections is M. The corresponding absorbance value is recorded for each detection, thereby obtaining the total phosphorus concentration, total nitrogen concentration, COD concentration, and ammonia nitrogen concentration for the preset number of detections.

[0072] In an optional embodiment, an unknown target water sample is digested, transferred, mixed with pre-prepared reagents, and developed in four independent chips, and then subjected to M consecutive photoelectric detections. The concentration values ​​of the signals after photoelectric detection are recorded. The matrix p of the total nitrogen concentration value is [1*M], and the matrix is ​​[p1 p2...pM]. The matrix c of the COD concentration value is [1*M], and the matrix is ​​[c1c2...cM]. The matrix v of the ammonia nitrogen concentration value is [1*M], and the matrix is ​​[v1 v2...vM]. The matrix b of the total phosphorus concentration value is [1*M], and the matrix is ​​[b1 b2...bM].

[0073] In step 102, for the total phosphorus concentration, the total phosphorus concentration values ​​of a preset number of times are arithmetically averaged to obtain the average concentration, which is used as the actual total phosphorus concentration of the target water sample; for the ammonia nitrogen concentration, the ammonia nitrogen concentration values ​​of a preset number of times are also arithmetically averaged to obtain the average concentration, which is used as the actual ammonia nitrogen concentration of the target water sample.

[0074] In step 103, the total nitrogen concentration values ​​of the preset number of tests are used to form an initial total nitrogen concentration matrix. Based on the known concentration change data determined by multiple tests of the standard water sample at different concentrations, the total nitrogen implicit transition matrix is ​​calculated by iterative reweighted least squares method. Using the initial total nitrogen concentration matrix and the total nitrogen implicit transition matrix, the actual total nitrogen concentration matrix is ​​calculated by mathematical transformation. The maximum value is selected from the actual total nitrogen concentration matrix as the actual total nitrogen concentration of the target water sample.

[0075] Furthermore, the COD concentration values ​​of a preset number of times are used to form an initial COD concentration matrix. Similarly, based on the known concentration change data, the COD implicit transition matrix is ​​calculated by iterative reweighted least squares method. Using the initial COD concentration matrix and the COD implicit transition matrix, the actual COD concentration matrix is ​​calculated by mathematical transformation. The maximum value in the actual COD concentration matrix is ​​selected as the actual COD concentration of the target water sample.

[0076] Those skilled in the art understand that after completing the digestion, quantification, pre-prepared reagent mixing, and color development processes for different water quality indicators, and continuously performing photoelectric detection on the detection cell of the microfluidic chip multiple times, the influencing factors for different indicators differ during the detection of total phosphorus, ammonia nitrogen, total nitrogen, and COD. For total nitrogen, because it is detected under a 220nm light source, and 220nm has strong penetrability, any errors in the microfluidic chip manufacturing process, the surface process of the inner cavity flow channel, and the degree of quartz plate cleaning will ultimately be detected by the 220nm light source and superimposed on the total nitrogen absorbance, thus causing concentration distortion. For COD, the influence comes from the fact that potassium dichromate (K2Cr2O7) in the COD reagent will continuously react with the microfluidic chip material, causing the absorbance detected under a 440nm light source to continuously decrease. However, the microfluidic processes for total phosphorus and ammonia nitrogen are the same as those for single-indicator microfluidic chips, and therefore have no effect.

[0077] To further illustrate the technical problem this application aims to solve, a detailed analysis is conducted here, combining the similarities and differences between single-index detection and multi-index simultaneous detection:

[0078] In conducting single-index testing:

[0079] Total phosphorus detection includes: injection -- quantification -- mixing pre-prepared reagent A -- mixing pre-prepared reagent B -- transfer -- centrifugation and color development -- photoelectric detection; ammonia nitrogen detection includes: injection -- quantification -- mixing pre-prepared reagent A -- mixing pre-prepared reagent B -- transfer -- centrifugation and color development -- photoelectric detection; total nitrogen detection includes: injection -- quantification -- mixing pre-prepared reagent A -- transfer -- photoelectric detection; COD detection includes: injection -- transfer -- photoelectric detection.

[0080] The process of simultaneous detection of multiple indicators includes: sample injection, quantification, mixing of pre-prepared reagent A, mixing of pre-prepared reagent B, transfer, centrifugation and color development, and photoelectric detection.

[0081] As can be seen from the above, the above detection methods have the greatest impact on total nitrogen and COD indicators, prolonging the contact time between total nitrogen and COD and the disk chip material, thus making the detection results of total nitrogen and COD indicators less accurate. Regarding the problems in the process of detecting water quality parameters using microfluidic chips, such as... Figure 2As shown, this invention uses a circular microfluidic chip as a carrier, containing four independent sector-shaped chips for total phosphorus, total nitrogen, COD, and ammonia nitrogen. It employs four different wavelength light emission / reception channels as multi-source synchronous detection hardware: total phosphorus: 700nm; total nitrogen: 220nm; COD: 440nm; ammonia nitrogen: 700nm. Based on pre-set concentration change data for different indicators, a multi-indicator synchronous detection process is run to calculate the implicit transfer matrix. After each of the four water samples independently completes digestion, transfer, pre-set reagent mixing, and color development, multiple photoelectric detections are performed, and the photoelectric detection signal values ​​are recorded. Based on the measured unknown water sample, the true estimate of the unknown water sample is calculated using the implicit transfer matrix. By analyzing the absorbance change rate of the insensitive chemical reagents for total phosphorus and ammonia nitrogen, it is determined whether the current estimated value originates from errors in the multi-indicator process synchronization. If the change rate is large, the error source is not due to error distortion in the process of integrating multiple indicators from a single indicator.

[0082] Optionally, before calculating the actual total nitrogen concentration matrix based on the initial total nitrogen concentration matrix and the total nitrogen latent transfer matrix, the total nitrogen latent transfer matrix can be determined by calculating based on the sample total nitrogen concentration matrix and the total nitrogen standard solution matrix at different concentrations:

[0083]

[0084] Matrix, Q is the total nitrogen standard solution matrix at different concentrations.

[0085] Optionally, the total nitrogen concentration matrix P of the sample is:

[0086]

[0087] The total nitrogen standard solution matrix Q at different concentrations is:

[0088]

[0089] The total nitrogen hidden transfer matrix for:

[0090]

[0091] M represents the preset number of times, and Z represents the number of different concentrations.

[0092] Optionally, before constructing the initial total nitrogen concentration matrix based on the total nitrogen concentration of a preset number of times, the method further includes: performing photoelectric detection on the total nitrogen standard solution at different concentrations a preset number of times, with each photoelectric detection lasting for a preset duration, and determining the concentration of the photoelectric signal corresponding to the photoelectric detection as the total nitrogen concentration, until the total nitrogen concentration of the preset number of times is obtained; the different concentrations are different concentrations with uniform values. In an optional embodiment, standard water samples with uniform total nitrogen concentration are taken, and the hidden transfer matrix of total nitrogen is calculated. Taking a range of 0-5 mg / L as an example, the following are examples of uniformly selected concentrations Z: 0.5 mg / L, 1.0 mg / L, 1.5 mg / L, 2 mg / L, 2.5 mg / L, 3 mg / L, 3.5 mg / L, 4 mg / L, 4.5 mg / L, and 5 mg / L. M sets of continuous photoelectric detection are performed on the standard solution at each concentration point, and the photoelectric detection time of each set lasts for t seconds. The concentration of each set of photoelectric signals is calculated by calculating the arithmetic mean. The number of concentration values ​​calculated for each set is M, and the different concentration points are Z. Finally, the concentration values ​​P of Z×M sets can be measured, and the size of the P matrix is ​​[Z×M]. The concentrations of the Z sets of standard solutions are stored on the diagonal, and the size of the total nitrogen standard solution matrix Q is [Z×Z]. The total nitrogen hidden transfer matrix is ​​obtained using the iterative reweighted least squares method.

[0093] Optionally, before calculating the actual COD concentration matrix based on the initial COD concentration matrix and the COD implicit transfer matrix, the COD implicit transfer matrix can be determined by calculating the sample COD concentration matrix and the COD standard solution matrix at different concentrations.

[0094]

[0095] The degree matrix, where H is the COD standard solution matrix at different concentrations.

[0096] Optionally, the sample COD concentration matrix C is:

[0097]

[0098] The COD standard solution matrix H at different concentrations is:

[0099]

[0100] The COD hidden transition matrix ω is:

[0101]

[0102] M represents the preset number of times, and Z represents the number of different concentrations.

[0103] Optionally, a standard water sample with a uniform COD concentration distribution can be taken, and the COD implicit transition matrix ω can be calculated using the same method, with the matrix size [M×Z].

[0104] Optionally, after determining the actual COD concentration of the target water sample based on the maximum value in the actual COD concentration matrix, the method further includes:

[0105] The variance of the target total phosphorus concentration is calculated based on the total phosphorus concentration of the preset number of times, and the variance of the target ammonia nitrogen concentration is calculated based on the ammonia nitrogen concentration of the preset number of times.

[0106] If the variance of the target total phosphorus concentration is within a preset total phosphorus concentration variance range, and the variance of the target ammonia nitrogen concentration is within a preset ammonia nitrogen concentration variance range, then the actual total nitrogen concentration and actual COD concentration of the target water sample are determined to be valid calculation results; otherwise, the actual total nitrogen concentration and actual COD concentration of the target water sample are determined to be invalid calculation results.

[0107] Optionally, the variance of the target total phosphorus concentration can be calculated using a preset variance formula. and the variance of the target ammonia nitrogen concentration The estimates of total nitrogen and COD are valid if the following conditions are met simultaneously:

[0108]

[0109]

[0110] in, This represents the minimum variance of the total phosphorus concentration in the sample. This represents the maximum variance of the total phosphorus concentration in the sample. This represents the minimum variance of the sample ammonia nitrogen concentration. This represents the maximum variance of the ammonia nitrogen concentration in the sample.

[0111] Optionally, before calculating the target total phosphorus concentration variance based on the total phosphorus concentration of a preset number of times, and before calculating the target ammonia nitrogen concentration variance based on the ammonia nitrogen concentration of a preset number of times, the method further includes:

[0112] The water sample was subjected to photoelectric detection a preset number of times to obtain the total phosphorus concentration of the sample at different concentrations for a preset number of times. The water sample was subjected to photoelectric detection a preset number of times to obtain the ammonia nitrogen concentration of the sample at different concentrations for a preset number of times.

[0113] For each concentration, calculate the variance of total phosphorus concentration based on the total phosphorus concentration of all samples at that concentration, iterate through all concentrations, determine the variance of total phosphorus concentration at each concentration, and determine the preset total phosphorus concentration variance interval based on the maximum and minimum values ​​of the variance of total phosphorus concentration at all concentrations.

[0114] For each concentration, the variance of the ammonia nitrogen concentration is calculated based on the ammonia nitrogen concentration of all samples at that concentration. All concentrations are iterated over to determine the variance of the ammonia nitrogen concentration at each concentration. The preset ammonia nitrogen concentration variance interval is determined based on the maximum and minimum values ​​of the variance of the ammonia nitrogen concentration at all concentrations.

[0115] Optionally, standard water samples with uniform concentration distributions of total phosphorus and ammonia nitrogen are taken, and the maximum and minimum variance ranges of the standard solution concentrations are calculated. The matrix of ammonia nitrogen concentrations for a preset number of samples at different concentrations is then defined as follows:

[0116]

[0117] The formula for calculating the variance of the first row of data is:

[0118]

[0119] Among them, V ar1 V represents the variance of the first row of data. 1.i For the i-th data in the first row, Let M be the mean of the first row of data, and M be the number of data points in the first row (i.e., the preset number of times). Iterate through all rows to obtain the variance for each row.

[0120]

[0121] Where Z is the number of rows in the matrix of sample ammonia nitrogen concentrations for a predetermined number of times at different concentrations, the minimum variance of the total phosphorus concentration in the samples is determined from the above data. and the maximum variance of total phosphorus concentration in the sample. The preset total phosphorus concentration variance interval is determined based on the maximum and minimum variances of total phosphorus concentrations across all concentrations. Similarly, determine the minimum variance of the sample ammonia nitrogen concentration. and the maximum variance of sample ammonia nitrogen concentration The preset ammonia nitrogen concentration variance interval is determined based on the maximum and minimum variances of ammonia nitrogen concentrations across all concentrations.

[0122] Figure 4This is a trend chart of different standard solution points provided by the present invention. The present invention aims to upgrade the detection of single-index microfluidic chip to the detection of water quality concentration of four indices. In the execution of the four indices, there are many overlapping actions, such as sample injection, transfer, and photoelectric detection. Moreover, the four indices can more completely represent the water quality characteristics of a sampling point. However, the integration of these four indices also has its drawbacks. The COD and total nitrogen indices prolong the contact time between the chemical reagents and the microfluidic chip material. This causes the photoelectric detection of COD and total nitrogen to be distorted after all four indices have been transferred and developed. The photoelectric detection signal value is distorted, then the absorbance value is distorted, and the converted concentration value is also distorted.

[0123] To address this technical problem, this invention estimates the true concentration value by analyzing multiple photoelectric detection values. The duration of these multiple photoelectric detections effectively extends the implicit change process, allowing the calculation of the initial true value by observing subsequent changes. Experiments show that the longer COD and total nitrogen remain within the chip, the higher their concentrations gradually become. Furthermore, the changes are more pronounced at lower concentrations than at higher concentrations, eventually converging to a certain concentration value and then ceasing to change.

[0124] In contrast, the changes in total phosphorus and ammonia nitrogen are not significant, remaining relatively stable as a straight line. Since the process for multiple indicators is exactly the same as that for single indicators (total phosphorus and ammonia nitrogen), the changes in absorbance of total phosphorus and ammonia nitrogen can be used to reflect the rationality of the calculation for multiple indicators. If the concentration values ​​of total phosphorus and ammonia nitrogen deviate significantly in multiple photoelectric detections, it indicates the influence of other introduced variables (disk chip material, cleanliness, light signal contamination, etc.), and this calculation method cannot meet the requirements. This invention can analyze the impact deviation caused by the extended contact time between COD and total nitrogen and microfluidic chip material during the process of moving from single-indicator to multi-indicator synchronous detection.

[0125] like Figure 4 As shown, the larger the Z value, the closer the estimated concentration value is to the actual concentration value; the larger the M value, the more stable the calculated numerical change. For example, Z = 10, M = 8, the actual concentration is 1.25 mg / L, and the estimated concentration is 1.30–1.4; Z = 15, M = 8, the actual concentration is 1.25 mg / L, and the estimated concentration is 1.265–1.365; Z = 15, M = 12, the actual concentration is 1.25 mg / L, and the estimated concentration is 1.265–1.295. To ensure that no singular values ​​appear when inverting the matrix, Z ≥ M is set. In an optional embodiment, Z = 6, M = 6.

[0126]

[0127]

[0128] Total nitrogen hidden transfer matrix

[0129]

[0130] To improve the efficiency of microfluidic chips, this invention integrates the detection of multiple different indicators onto a single chip. When using microfluidic chips to detect water concentration, the varying sensitivities of different chemical reagents to the microfluidic chip material during the simultaneous centrifugal transfer and mixing of pre-prepared reagents can cause abnormal distortions in the detected water concentration. To ensure compatibility with the detection process of different indicators and make the final concentration result as accurate as when detected by four independent microfluidic chips individually, this invention proposes a calculation method that uses an implicit transfer matrix to reconstruct the actual water concentration. This improves the accuracy of total nitrogen and COD concentration detection results. Since the sensitivity of total phosphorus and ammonia nitrogen concentrations to the microfluidic chip material is not significant during detection, there is no need to consider the impact of photoelectric detection time variations on the detection results. Ultimately, when multiple different indicators are integrated into a single chip, the detection results for total nitrogen, COD, total phosphorus, and ammonia nitrogen concentrations are all highly accurate, shortening the detection time and improving detection efficiency.

[0131] Figure 2 This is one of the structural schematic diagrams of the water quality detection concentration calculation system provided by the present invention. The water quality detection concentration calculation system is a microfluidic chip, and the microfluidic chip is used for:

[0132] For the target water sample, after sequentially performing injection, quantification, mixing of pre-prepared reagents, transfer, and centrifugation for color development, the target water sample is continuously subjected to photoelectric detection for a preset number of times to obtain the total phosphorus concentration, total nitrogen concentration, COD concentration, and ammonia nitrogen concentration for the preset number of times. Different wavelengths correspond to photoelectric detection of different water quality indicators.

[0133] The actual total phosphorus concentration of the target water sample is determined based on the average concentration of total phosphorus concentration from a preset number of tests, and the actual ammonia nitrogen concentration of the target water sample is determined based on the average concentration of ammonia nitrogen concentration from a preset number of tests.

[0134] An initial total nitrogen concentration matrix is ​​constructed based on the total nitrogen concentration of a preset number of cycles. An actual total nitrogen concentration matrix is ​​calculated based on the initial total nitrogen concentration matrix and the total nitrogen implicit transfer matrix. The actual total nitrogen concentration of the target water sample is determined based on the maximum value in the actual total nitrogen concentration matrix. Similarly, an initial COD concentration matrix is ​​constructed based on the COD concentration of a preset number of cycles. An actual COD concentration matrix is ​​calculated based on the initial COD concentration matrix and the COD implicit transfer matrix. The actual COD concentration of the target water sample is determined based on the maximum value in the actual COD concentration matrix.

[0135] The total nitrogen hidden transfer matrix is ​​obtained by performing photoelectric detection on water samples at different concentrations a preset number of times, resulting in a total nitrogen concentration matrix constructed from the total nitrogen concentrations of the samples at different concentrations a preset number of times. The matrix is ​​determined by calculation based on the total nitrogen concentration matrix and the total nitrogen standard solution matrix at different concentrations.

[0136] The COD hidden transfer matrix is ​​obtained by performing photoelectric detection on sample water quality at different concentrations a preset number of times, resulting in a sample COD concentration matrix constructed from the sample COD concentrations at different concentrations and a preset number of times. The COD concentration matrix is ​​determined by calculation based on the sample COD concentration matrix and the COD standard solution matrix at different concentrations.

[0137] Figure 3 This is the second schematic diagram of the water quality detection concentration calculation system provided by the present invention, as shown below. Figure 2 as well as Figure 3 As shown, in order to realize the calculation of water quality concentration by multiple index detection, the present invention designs a circular microfluidic disk chip. The overall manufacturing process of the microfluidic chip is divided into mold injection molding parts, PMMA detection sheet upper part, PMMA detection sheet lower part, quartz detection sheet upper part, quartz detection sheet lower part, circular pressure-sensitive film, bonding double-sided adhesive, etc.

[0138] Based on existing designs, this application combines single sector-shaped chips into a circular chip. The seven materials mentioned above will be shared in different indicator processes. Specifically, the PMMA detection sheet is bonded to the upper and lower layers of three detection cavities of the microfluidic chip using double-sided adhesive, for the detection of ammonia nitrogen, total phosphorus, and COD concentrations. The quartz plate detection sheet is bonded to one of the detection cavities of the microfluidic chip using double-sided adhesive, for the detection of total nitrogen concentration. The pressure-sensitive film at the bottom of the microfluidic chip is sealed by hot pressing. Optionally, four different wavelength light emission / reception channels constitute multi-source asynchronous detection hardware: total phosphorus 700nm; total nitrogen 220nm; COD 440nm; ammonia nitrogen 700nm. Based on existing technology, a single indicator is expanded into four different indicators, and the implicit transition matrix is ​​calculated from preset concentration change data of different types.

[0139] To improve the efficiency of microfluidic chips, this invention integrates the detection of multiple different indicators onto a single chip. When using microfluidic chips to detect water concentration, the varying sensitivities of different chemical reagents to the microfluidic chip material during the simultaneous centrifugal transfer and mixing of pre-prepared reagents can cause abnormal distortions in the detected water concentration. To ensure compatibility with the detection process of different indicators and make the final concentration result as accurate as when detected by four independent microfluidic chips individually, this invention proposes a calculation method that uses an implicit transfer matrix to reconstruct the actual water concentration. This improves the accuracy of total nitrogen and COD concentration detection results. Since the sensitivity of total phosphorus and ammonia nitrogen concentrations to the microfluidic chip material is not significant during detection, there is no need to consider the impact of photoelectric detection time variations on the detection results. Ultimately, when multiple different indicators are integrated into a single chip, the detection results for total nitrogen, COD, total phosphorus, and ammonia nitrogen concentrations are all highly accurate, shortening the detection time and improving detection efficiency.

[0140] Figure 5 This is a schematic diagram of the structure of the electronic device provided by the present invention. For example... Figure 5As shown, the electronic device may include: a processor 510, a communication interface 520, a memory 530, and a communication bus 540, wherein the processor 510, the communication interface 520, and the memory 530 communicate with each other through the communication bus 540. The processor 510 can call logic instructions in the memory 530 to execute a water quality detection concentration calculation method. This method includes: for a target water sample, sequentially performing sample injection, quantification, mixing of pre-prepared reagents, transfer, and centrifugation for color development; continuously performing photoelectric detection on the target water sample a preset number of times to obtain the total phosphorus concentration, total nitrogen concentration, COD concentration, and ammonia nitrogen concentration for the preset number of times, wherein different wavelengths correspond to photoelectric detection of different water quality indicators; determining the actual total phosphorus concentration of the target water sample based on the average concentration of total phosphorus from the preset number of times; determining the actual ammonia nitrogen concentration of the target water sample based on the average concentration of ammonia nitrogen from the preset number of times; constructing an initial total nitrogen concentration matrix based on the total nitrogen concentration from the preset number of times; calculating the actual total nitrogen concentration matrix based on the initial total nitrogen concentration matrix and the total nitrogen implicit transfer matrix; and determining the actual total nitrogen concentration of the target water sample based on the maximum value in the actual total nitrogen concentration matrix. The method involves: constructing an initial COD concentration matrix based on COD concentrations from a predetermined number of COD tests; calculating the actual COD concentration matrix based on the initial COD concentration matrix and the COD latent transfer matrix; and determining the actual COD concentration of the target water sample based on the maximum value in the actual COD concentration matrix. The total nitrogen latent transfer matrix is ​​obtained by performing photoelectric detection on sample water quality at different concentrations a predetermined number of times, resulting in a sample total nitrogen concentration matrix constructed from the sample total nitrogen concentrations at different concentrations. The COD latent transfer matrix is ​​also obtained by performing photoelectric detection on sample water quality at different concentrations a predetermined number of times, resulting in a sample COD concentration matrix constructed from the sample COD concentrations at different concentrations. The COD latent transfer matrix is ​​determined based on the sample COD concentration matrix and the COD standard solution matrix at different concentrations.

[0141] Furthermore, the logical instructions in the aforementioned memory 530 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0142] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute a water quality detection concentration calculation method provided by the above methods. The method includes: for a target water sample, sequentially performing sample injection, quantification, mixing of pre-prepared reagents, transfer, and centrifugation for color development, and then continuously performing photoelectric detection on the target water sample a preset number of times to obtain the total phosphorus concentration, total nitrogen concentration, COD concentration, and ammonia nitrogen concentration for the preset number of times, wherein different wavelengths correspond to photoelectric detection of different water quality indicators; determining the actual total phosphorus concentration of the target water sample based on the average concentration of the total phosphorus concentration for the preset number of times, and determining the actual ammonia nitrogen concentration of the target water sample based on the average concentration of the ammonia nitrogen concentration for the preset number of times; constructing an initial total nitrogen concentration matrix based on the total nitrogen concentration for the preset number of times, and calculating the actual total nitrogen based on the initial total nitrogen concentration matrix and the total nitrogen implicit transfer matrix. The concentration matrix is ​​used to determine the actual total nitrogen concentration of the target water sample based on the maximum value in the actual total nitrogen concentration matrix. An initial COD concentration matrix is ​​constructed based on the COD concentration from a preset number of COD tests. The actual COD concentration matrix is ​​calculated based on the initial COD concentration matrix and the COD latent transfer matrix. The actual COD concentration of the target water sample is determined based on the maximum value in the actual COD concentration matrix. The total nitrogen latent transfer matrix is ​​obtained by performing photoelectric detection on the sample water quality at different concentrations a preset number of times, resulting in a sample total nitrogen concentration matrix constructed from the sample total nitrogen concentrations at different concentrations. This matrix is ​​calculated based on the sample total nitrogen concentration matrix and the total nitrogen standard solution matrix at different concentrations. The COD latent transfer matrix is ​​obtained by performing photoelectric detection on the sample water quality at different concentrations a preset number of times, resulting in a sample COD concentration matrix constructed from the sample COD concentrations at different concentrations. This matrix is ​​calculated based on the sample COD concentration matrix and the COD standard solution matrix at different concentrations.

[0143] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon. When executed by a processor, the computer program implements a water quality detection concentration calculation method provided by the methods described above. This method includes: for a target water sample, sequentially performing sample injection, quantification, mixing of pre-prepared reagents, transfer, and centrifugation for color development, and then continuously performing photoelectric detection on the target water sample a preset number of times to obtain the total phosphorus concentration, total nitrogen concentration, COD concentration, and ammonia nitrogen concentration for the preset number of times, wherein different wavelengths correspond to photoelectric detection of different water quality indicators; determining the actual total phosphorus concentration of the target water sample based on the average concentration of total phosphorus concentration from the preset number of times, and determining the actual ammonia nitrogen concentration of the target water sample based on the average concentration of ammonia nitrogen concentration from the preset number of times; constructing an initial total nitrogen concentration matrix based on the total nitrogen concentration from the preset number of times; calculating the actual total nitrogen concentration matrix based on the initial total nitrogen concentration matrix and the total nitrogen implicit transfer matrix; and calculating the actual total nitrogen concentration matrix based on the actual total nitrogen concentration matrix. The maximum value in the matrix determines the actual total nitrogen concentration of the target water sample; an initial COD concentration matrix is ​​constructed based on the COD concentration from a preset number of COD tests; the actual COD concentration matrix is ​​calculated based on the initial COD concentration matrix and the COD implicit transfer matrix; the actual COD concentration of the target water sample is determined based on the maximum value in the actual COD concentration matrix; the total nitrogen implicit transfer matrix is ​​obtained by performing photoelectric detection on the sample water quality at different concentrations a preset number of times, resulting in a sample total nitrogen concentration matrix constructed from the sample total nitrogen concentration from a preset number of tests; the COD implicit transfer matrix is ​​obtained by performing photoelectric detection on the sample water quality at different concentrations a preset number of times, resulting in a sample COD concentration matrix constructed from the sample COD concentration from a preset number of tests; the COD implicit transfer matrix is ​​determined based on the sample COD concentration matrix and the COD standard solution matrix at different concentrations.

[0144] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0145] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0146] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for calculating water quality concentration, characterized in that, include: For the target water sample, after sequentially performing injection, quantification, mixing of pre-prepared reagents, transfer, and centrifugation for color development, the target water sample is continuously subjected to photoelectric detection for a preset number of times to obtain the total phosphorus concentration, total nitrogen concentration, COD concentration, and ammonia nitrogen concentration for the preset number of times. Different wavelengths correspond to photoelectric detection of different water quality indicators. The actual total phosphorus concentration of the target water sample is determined based on the average concentration of total phosphorus concentration from a preset number of tests, and the actual ammonia nitrogen concentration of the target water sample is determined based on the average concentration of ammonia nitrogen concentration from a preset number of tests. An initial total nitrogen concentration matrix is ​​constructed based on the total nitrogen concentration of a preset number of cycles. An actual total nitrogen concentration matrix is ​​calculated based on the initial total nitrogen concentration matrix and the total nitrogen implicit transfer matrix. The actual total nitrogen concentration of the target water sample is determined based on the maximum value in the actual total nitrogen concentration matrix. Similarly, an initial COD concentration matrix is ​​constructed based on the COD concentration of a preset number of cycles. An actual COD concentration matrix is ​​calculated based on the initial COD concentration matrix and the COD implicit transfer matrix. The actual COD concentration of the target water sample is determined based on the maximum value in the actual COD concentration matrix. The total nitrogen hidden transfer matrix is ​​obtained by performing photoelectric detection on water samples at different concentrations a preset number of times, resulting in a total nitrogen concentration matrix constructed from the total nitrogen concentrations of the samples at different concentrations a preset number of times. The matrix is ​​determined by calculation based on the total nitrogen concentration matrix and the total nitrogen standard solution matrix at different concentrations. The COD hidden transfer matrix is ​​obtained by performing photoelectric detection on sample water quality at different concentrations a preset number of times, resulting in a sample COD concentration matrix constructed from the sample COD concentrations at different concentrations a preset number of times. The COD concentration matrix is ​​determined by calculation based on the sample COD concentration matrix and the COD standard solution matrix at different concentrations. Before calculating the actual total nitrogen concentration matrix based on the initial total nitrogen concentration matrix and the total nitrogen latent transfer matrix, the total nitrogen latent transfer matrix is ​​determined by calculating based on the sample total nitrogen concentration matrix and the total nitrogen standard solution matrix at different concentrations: ； in, The total nitrogen hidden transfer matrix, for transpose, This is the total nitrogen concentration matrix of the sample. This is a matrix of total nitrogen standard solutions at different concentrations; The total nitrogen concentration matrix of the sample for: ； The total nitrogen standard solution matrix at different concentrations for: ； The total nitrogen hidden transfer matrix for: ； For the preset number of times, For different concentrations; Before calculating the actual COD concentration matrix based on the initial COD concentration matrix and the COD implicit transfer matrix, the COD implicit transfer matrix is ​​determined by calculating the sample COD concentration matrix and the COD standard solution matrix at different concentrations. ； in, This is the COD implicit transition matrix. for transpose, This is the COD concentration matrix of the samples. This is a matrix of COD standard solutions at different concentrations.

2. The method for calculating water quality concentration according to claim 1, characterized in that, The sample COD concentration matrix for: ； The COD standard solution matrix at different concentrations for: ； The COD hidden transition matrix for: ； For the preset number of times, For different concentrations, the quantities are listed below.

3. The method for calculating water quality concentration according to claim 1, characterized in that, After determining the actual COD concentration of the target water sample based on the maximum value in the actual COD concentration matrix, the method further includes: The variance of the target total phosphorus concentration is calculated based on the total phosphorus concentration of the preset number of times, and the variance of the target ammonia nitrogen concentration is calculated based on the ammonia nitrogen concentration of the preset number of times. If the variance of the target total phosphorus concentration is within a preset total phosphorus concentration variance range, and the variance of the target ammonia nitrogen concentration is within a preset ammonia nitrogen concentration variance range, then the actual total nitrogen concentration and actual COD concentration of the target water sample are determined to be valid calculation results; otherwise, the actual total nitrogen concentration and actual COD concentration of the target water sample are determined to be invalid calculation results.

4. The method for calculating water quality concentration according to claim 3, characterized in that, Before calculating the target total phosphorus concentration variance based on the total phosphorus concentration from a preset number of tests, and before calculating the target ammonia nitrogen concentration variance based on the ammonia nitrogen concentration from a preset number of tests, the method further includes: The water sample was subjected to photoelectric detection a preset number of times to obtain the total phosphorus concentration of the sample at different concentrations for a preset number of times. The water sample was subjected to photoelectric detection a preset number of times to obtain the ammonia nitrogen concentration of the sample at different concentrations for a preset number of times. For each concentration, calculate the variance of total phosphorus concentration based on the total phosphorus concentration of all samples at that concentration, iterate through all concentrations, determine the variance of total phosphorus concentration at each concentration, and determine the preset total phosphorus concentration variance interval based on the maximum and minimum values ​​of the variance of total phosphorus concentration at all concentrations. For each concentration, the variance of the ammonia nitrogen concentration is calculated based on the ammonia nitrogen concentration of all samples at that concentration. All concentrations are iterated over to determine the variance of the ammonia nitrogen concentration at each concentration. The preset ammonia nitrogen concentration variance interval is determined based on the maximum and minimum values ​​of the variance of the ammonia nitrogen concentration at all concentrations.

5. The method for calculating water quality concentration according to claim 1, characterized in that, The water quality indicators include total phosphorus concentration, total nitrogen concentration, COD concentration, and ammonia nitrogen concentration. The different wavelengths correspond to the photoelectric detection of different water quality indicators, including: The photoelectric detection of total phosphorus corresponds to a wavelength of 700 nm; The photoelectric detection of total nitrogen corresponds to a wavelength of 220 nm; The photoelectric detection of COD corresponds to a wavelength of 440nm; The photoelectric detection of ammonia nitrogen corresponds to a wavelength of 700 nm.

6. The method for calculating water quality concentration according to claim 1, characterized in that, Before constructing an initial total nitrogen concentration matrix based on the total nitrogen concentration of a preset number of times, the method further includes: Photoelectric detection was performed on total nitrogen standard solutions at different concentrations a preset number of times, with each photoelectric detection lasting a preset duration. The concentration of the photoelectric signal corresponding to the photoelectric detection was determined as the total nitrogen concentration, until the total nitrogen concentration of the preset number of times was obtained. The different concentrations are different concentrations that are taken uniformly.

7. A water quality detection concentration calculation system, used to execute the water quality detection concentration calculation method as described in any one of claims 1-6, characterized in that, The water quality detection concentration calculation system is a microfluidic chip, which is used for: For the target water sample, after sequentially performing injection, quantification, mixing of pre-prepared reagents, transfer, and centrifugation for color development, the target water sample is continuously subjected to photoelectric detection for a preset number of times to obtain the total phosphorus concentration, total nitrogen concentration, COD concentration, and ammonia nitrogen concentration for the preset number of times. Different wavelengths correspond to photoelectric detection of different water quality indicators. The actual total phosphorus concentration of the target water sample is determined based on the average concentration of total phosphorus concentration from a preset number of tests, and the actual ammonia nitrogen concentration of the target water sample is determined based on the average concentration of ammonia nitrogen concentration from a preset number of tests. An initial total nitrogen concentration matrix is ​​constructed based on the total nitrogen concentration of a preset number of cycles. An actual total nitrogen concentration matrix is ​​calculated based on the initial total nitrogen concentration matrix and the total nitrogen implicit transfer matrix. The actual total nitrogen concentration of the target water sample is determined based on the maximum value in the actual total nitrogen concentration matrix. Similarly, an initial COD concentration matrix is ​​constructed based on the COD concentration of a preset number of cycles. An actual COD concentration matrix is ​​calculated based on the initial COD concentration matrix and the COD implicit transfer matrix. The actual COD concentration of the target water sample is determined based on the maximum value in the actual COD concentration matrix. The total nitrogen hidden transfer matrix is ​​obtained by performing photoelectric detection on water samples at different concentrations a preset number of times, resulting in a total nitrogen concentration matrix constructed from the total nitrogen concentrations of the samples at different concentrations a preset number of times. The matrix is ​​determined by calculation based on the total nitrogen concentration matrix and the total nitrogen standard solution matrix at different concentrations. The COD hidden transfer matrix is ​​obtained by performing photoelectric detection on sample water quality at different concentrations a preset number of times, resulting in a sample COD concentration matrix constructed from the sample COD concentrations at different concentrations and a preset number of times. The COD concentration matrix is ​​determined by calculation based on the sample COD concentration matrix and the COD standard solution matrix at different concentrations.

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