Determination method of heavy metal wastewater containing ammonia

Abstract

The present invention provides a method for determining ammonia-containing heavy metal wastewater, including: providing standard copper-ammine complex solutions of different concentrations, measuring them respectively using an ultraviolet-visible spectrophotometer to generate a first ultraviolet-visible spectrum; collecting first spectral data of the first ultraviolet-visible spectrum in a band of 500 to 800 nm, and establishing a concentration prediction model based on the spectral data; measuring the copper-ammine complex solution sample to be tested under the same measurement conditions as the standard copper-ammine complex solution to generate a second ultraviolet-visible spectrum; collecting second spectral data of a band of 500 to 800 nm in the second ultraviolet-visible spectrum; standardizing the second spectral data in turn, performing principal component regression analysis, and determining the concentration of the copper-ammine complex solution sample to be tested based on the concentration prediction model. Compared with the prior art, the method for detecting copper-ammine complex ions in water bodies realizes rapid and accurate monitoring of the actual copper-ammine complex ion concentration in each treatment link.

Description

Technical Field

[0001] The invention relates to the field of wastewater treatment, and in particular to a method for determining ammonia-containing heavy metal wastewater. Background Art

[0002] The use of ammonia water results in the generation of a large amount of ammonia-containing heavy metal wastewater in the ammonia leaching section of non-ferrous metal hydrometallurgy and the ammonia saponification section of rare earth smelting. Therefore, it is necessary to monitor and measure such wastewater in a targeted manner.

[0003] The current mainstream treatment process is still guided by the total amount of pollutants in the emission standards. The method of measuring the concentration of major pollutants in the combined specific wastewater is to measure the emission concentration of copper, ammonia and other substances separately. Due to the large differences in water quality and water volume of wastewater from different sources, it is difficult to monitor the actual concentration of major pollutants in ammonia-containing heavy metal wastewater, which leads to the implementation of a square peg in the round hole, and the treatment effect may be unsatisfactory.

[0004] In view of this, it is necessary to provide a method for determining ammonia-containing heavy metal wastewater, so as to determine the actual concentration of the main pollutants in the ammonia-containing heavy metal wastewater in each treatment link, so as to achieve targeted removal of the main pollutants in the ammonia-containing heavy metal wastewater and improve the shortcomings of the existing technology. Summary of the invention

[0005] The main purpose of the present invention is to provide a method for detecting copper ammonia complex ions in water, aiming to solve the problems that the prior art does not specifically detect copper ammonia complex ions in water and the detection results are inaccurate.

[0006] To achieve the above object, the present invention provides a method for detecting copper ammonia complex ions in water, comprising the steps of:

[0007] S1, providing standard copper-ammonia complex solutions of different concentrations, and measuring them respectively using a UV-visible spectrophotometer to generate a first UV-visible spectrum.

[0008] S2, collecting first spectrum data of the first ultraviolet-visible spectrum in a wavelength range of 500-800 nm, and establishing a concentration prediction model according to the spectrum data.

[0009] S3, measuring the copper-ammine complex solution sample to be tested under the same measurement conditions as the standard copper-ammine complex solution to generate a second ultraviolet-visible spectrum.

[0010] S4, collecting the second spectral data of the 500-800nm ​​band in the second ultraviolet-visible spectrum in step S3; standardizing and principal component regression analysis the second spectral data in turn, and determining the concentration of the copper-ammonia complex solution sample to be tested based on the concentration prediction model.

[0011] Further, in step S2, establishing a concentration prediction model according to the spectral data includes:

[0012] S21, performing SG least square smoothing preprocessing on the first spectrum data in the wavelength band of 500-800 nm.

[0013] S22, performing matrix standardization processing on the preprocessed data to obtain a spectral data standardization matrix; and extracting principal components to obtain the principal components and the cumulative contribution rates corresponding to the principal components.

[0014] S23, multiplying the spectral data standardization matrix by the eigenvector matrix of the principal component to obtain the principal component score.

[0015] S24, performing multivariate linear regression processing on the obtained data of the principal component and the standard copper-ammine complex solutions of different concentrations to obtain a concentration calculation formula C=79.999+3.7916*F1, wherein C is the concentration of the copper-ammine complex ion, and F1 is the principal component score.

[0016] Furthermore, after step S24, the step further includes performing accuracy verification on the concentration prediction model to determine the accuracy of the concentration prediction model.

[0017] Furthermore, the accuracy verification process specifically includes: respectively calculating the correlation coefficient, root mean square error, mean absolute percentage error, detection limit of the method and quantitative limit of the method of the concentration calculation formula C=79.999+3.7916*F1 in the step S24, so as to evaluate the degree of fit of the concentration prediction model.

[0018] Furthermore, in step S1, the copper element concentration gradient of the standard copper ammonia complex solution of different concentrations is 5 mg / L, 10 mg / L, 15 mg / L, 20 mg / L, 35 mg / L, 50 mg / L, 75 mg / L, 100 mg / L, 125 mg / L, 150 mg / L, 175 mg / L, and 200 mg / L.

[0019] Furthermore, the pH values ​​of the standard copper-ammonia complex solutions of different concentrations are all 8.8-9.2, and the molar ratio of copper element to ammonia molecule is all in the range of 1:128-1:256.

[0020] Furthermore, in the step S4, the steps of sequentially standardizing and principal component regression analyzing the second spectral data respectively use the spectral data standardization matrix in the step S22 and the eigenvector matrix in the step S23.

[0021] Furthermore, in the steps S1 and S4, the measurement process specifically includes: selecting an absorption cell with a width of 1 cm, scanning with ultrapure water as a reference, a scanning speed of 0.5 nm / s, and scanning each solution sample 3 times.

[0022] The present invention has the following beneficial effects:

[0023] The above method for detecting copper-ammine complex ions in water is to determine that the copper-ammine complex ion solution has an obvious absorption peak in the visible light band through a standard copper-ammine complex solution, and it is found that the absorption peak intensity is positively correlated with the concentration of the copper-ammine complex ions. Since there is a linear dependency between the applied variables, a concentration prediction model is established for the spectral data measured by an ultraviolet-visible spectrophotometer using a principal component regression analysis method. In this way, the spectral data of the copper-ammine complex solution sample to be measured by the ultraviolet-visible spectrophotometer can be accurately and directly calculated through the concentration prediction model to obtain the concentration of the copper-ammine complex ions in the sample to be measured.

[0024] The above-mentioned method for detecting copper-ammine complex ions in water bodies was applied to determine the actual concentrations of major pollutants in ammonia-containing heavy metal wastewater in each treatment link, which is accurate and direct, and is no longer affected by problems such as different water quality and large differences in water volume of ammonia-containing heavy metal wastewater from different sources.

[0025] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail below. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0027] Figure 1 A first ultraviolet-visible spectrum of an embodiment of the present application;

[0028] Figure 2 A spectrum of first spectrum data of a first ultraviolet-visible spectrum in a wavelength range of 500 to 800 nm according to an embodiment of the present application;

[0029] Figure 3 This is a diagram of predicted concentration and confidence interval of a concentration prediction model according to an embodiment of the present application.

[0030] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with the implementation methods and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. It should also be understood that the terms used in the embodiments of the present invention are intended to describe specific embodiments rather than to limit the scope of protection of the present invention.

[0033] Unless otherwise defined, all technical and scientific terms used in the present invention are consistent with the prior art knowledge of the technicians in this technical field and the description of the present invention. The present invention can also be implemented using any prior art methods, equipment and materials similar or equivalent to the methods, equipment and materials in the embodiments of the present invention. It should be noted that as an explanation of the present application document, without affecting the actual understanding of the technical solution of the present application, R 2 is the correlation coefficient, AdjustedR 2 is the corrected correlation coefficient, RMSE is the root mean square error, MAPE is the mean percentage error, LOD is the limit of detection of the method, and LOQ is the limit of quantification of the method.

[0034] When the embodiments give numerical ranges, it should be understood that unless otherwise specified in the present invention, both endpoints of each numerical range and any value between the two endpoints can be selected. The test methods in the following embodiments without specifying specific conditions are usually carried out under conventional conditions or under conditions recommended by the manufacturers. The materials or reagents required in the following embodiments are commercially available unless otherwise specified.

[0035] In the process of measuring ammonia-containing heavy metal wastewater, it was found that ammonia molecules in wastewater have the ability to form stable complexes with heavy metals such as Cu, Co, and Ni, so that the main pollutants in ammonia-containing heavy metal wastewater often exist as complex pollutants such as copper ammonia complex ions. Copper ammonia complex ions are more difficult to separate from water than heavy metal ions, and because the absorption peaks of the ultraviolet-visible light spectra of copper ammonia complex ions of different concentrations shift with the change of concentration, it is difficult to directly and accurately measure the concentration of copper ammonia complex ions in wastewater samples based on existing technologies.

[0036] In order to solve the problems that the prior art does not specifically detect copper-ammine complex ions in water and the detection results are indirect and inaccurate, the present invention provides a method for detecting copper-ammine complex ions in water, comprising the steps of:

[0037] S1, providing standard copper-ammonia complex solutions of different concentrations, and measuring them respectively using a UV-visible spectrophotometer to generate a first UV-visible spectrum.

[0038] In this step, the ultraviolet-visible spectrophotometer may be a SHIMADZU UV-1780 ultraviolet-visible spectrophotometer.

[0039] S2, collecting first spectrum data of a first ultraviolet-visible spectrum in a wavelength range of 500-800 nm, and establishing a concentration prediction model according to the spectrum data.

[0040] The spectral data in the selected band of 500-800 nm can just cover the standard copper-ammonia complex solutions of different concentrations, so as to achieve the universality of concentration detection after modeling. Therefore, the spectral data in this band is collected.

[0041] S3, measuring the copper-ammine complex solution sample to be tested under the same measurement conditions as the standard copper-ammine complex solution to generate a second ultraviolet-visible spectrum.

[0042] S4, collecting the second spectral data of the 500-800nm ​​band in the second ultraviolet-visible spectrum in step S3; standardizing and principal component regression analysis the second spectral data in turn, and determining the concentration of the copper ammonia complex solution sample to be tested based on the concentration prediction model.

[0043] Further, in step S2, establishing a concentration prediction model using spectral data includes:

[0044] S21, performing SG least square smoothing preprocessing on the first spectrum data in the wavelength band of 500-800 nm.

[0045] Specifically, a corresponding absorbance is measured every 0.5 nm wavelength, and a total of 601 spectral data are obtained, which is sufficient to support subsequent modeling. The SG least squares smoothing preprocessing can make the spectral data in the 500-800 nm band obtained linearly fit, which is convenient for subsequent processing.

[0046] S22, performing matrix standardization processing on the preprocessed data to obtain a spectral data standardization matrix; and extracting the principal components to obtain the principal components and the corresponding cumulative contribution rates of the principal components.

[0047] Specifically, the SLSTAT plug-in of the spreadsheet software (Microsoft Office Excel) was used to perform matrix standardization on the preprocessed data obtained in S21 to obtain the spectral data standardization matrix, principal components, and the cumulative contribution rates corresponding to the principal components.

[0048] S23, multiplying the spectral data standardization matrix by the eigenvector matrix of the principal component to obtain the principal component score.

[0049] S24, performing multiple linear regression processing on the obtained principal component and the data of standard copper-ammine complex solutions of different concentrations to obtain a concentration calculation formula C=79.999+3.7916*F1, wherein C is the concentration of the copper-ammine complex ion, and F1 is the principal component score.

[0050] From step S22, it can be obtained that the cumulative contribution rate of the first principal component is greater than 85% and F1>1. It should be noted that if this standard is met, multiple linear regression processing can be performed according to F1 to obtain the concentration calculation formula C=79.999+3.7916*F1.

[0051] Furthermore, after step S24, the concentration prediction model is further included in the process of performing accuracy verification to determine the accuracy of the concentration prediction model.

[0052] Furthermore, the precision verification process specifically includes: respectively calculating the correlation coefficient, root mean square error, mean absolute percentage error, detection limit of the method and quantitative limit of the method of the concentration calculation formula C=79.999+3.7916*F1 in step S24, so as to evaluate the degree of fit of the concentration prediction model.

[0053] Specifically, R was calculated based on the actual concentration, predicted concentration and residual of 12 standard copper-ammonia complex solutions. 2 、AdjustedR 2 , RMSE, MAPE, LOD and LOQ to determine whether the obtained concentration prediction model meets the accuracy requirements and can be used for calculations.

[0054] Further, in step S1, the copper element concentration gradient of the standard copper ammonia complex solution of different concentrations is 5 mg / L, 10 mg / L, 15 mg / L, 20 mg / L, 35 mg / L, 50 mg / L, 75 mg / L, 100 mg / L, 125 mg / L, 150 mg / L, 175 mg / L, and 200 mg / L.

[0055] Furthermore, the pH values ​​of standard copper-ammonia complex solutions of different concentrations are all between 8.8 and 9.2, and the molar ratio of copper element to ammonia molecule is all within the range of 1:128 to 1:256.

[0056] Furthermore, in step S4, the steps of sequentially performing standardization and principal component regression analysis on the second spectral data use the spectral data standardization matrix in step S22 and the eigenvector matrix in step S23 respectively.

[0057] The use of the same spectral data normalization matrix and eigenvector matrix reduces variable interference in the modeling process, making the analysis and processing of the second spectral data more accurate.

[0058] Furthermore, in steps S1 and S4, the measurement process specifically includes: selecting the width of the absorption cell as 1 cm, scanning with ultrapure water as a reference, scanning speed of 0.5 nm / s, and scanning each solution sample 3 times.

[0059] Controlling the injection scanning speed and the three scans in this way can avoid the randomness of the injection measurement process, thereby reducing modeling errors.

[0060] For further understanding of the present invention, examples are given below:

[0061] Example 1

[0062] Establishment of a prediction model for copper-ammonia complex ion concentration

[0063] 1. Provide standard copper-ammonia complex solutions of different concentrations and use UV-visible spectrophotometer to measure:

[0064] (1) Ammonia water was injected into the copper sulfate solution, and the pH was controlled at 8.8-9.2. A series of standard copper-ammonia complex solutions with concentrations of 5 mg / L, 10 mg / L, 15 mg / L, 20 mg / L, 35 mg / L, 50 mg / L, 75 mg / L, 100 mg / L, 125 mg / L, 150 mg / L, 175 mg / L, and 200 mg / L were prepared. The spectrum of the standard solution was then collected immediately, and the spectrum data of each sample was collected three times.

[0065] (2) The standard copper-ammonia complex solution prepared in the above step (1) was poured into a quartz cuvette with a width of 1 cm and a height of 3.5 cm. The sample was scanned using a SHIMADZU UV-1780 ultraviolet-visible spectrophotometer with ultrapure water as a reference at a scanning speed of 0.5 nm / s. Each sample was scanned 3 times to obtain an average value, and the absorbance value at room temperature was collected. Figure 1 The first UV-visible spectrum is shown in FIG. Due to space constraints, only part of the spectrum of the standard solution is marked.

[0066] 2. Establish a concentration prediction model

[0067] (1) According to the calculation results of copper ammonia complex ions by density functional theory, the first ultraviolet-visible spectrum of copper ammonia complex ions in water is obtained, and the spectral data in the band of 500-800 nm are selected as the first spectral data, and the first spectral data are preprocessed by SG least squares smoothing.

[0068] The spectrum of the first spectrum data of the first ultraviolet-visible spectrum in the wavelength range of 500 to 800 nm is as follows: Figure 2 As shown. Figure 2 In the figure, the directions indicated by the arrows are the spectra of 5mg / L, 10mg / L, 15mg / L, 20mg / L, 35mg / L, 50mg / L, 75mg / L, 100mg / L, 125mg / L, 150mg / L, 175mg / L, and 200mg / L. Figure 2 It can be seen that the absorption peak corresponding to the copper-ammine complex solution of 5 mg / L to the copper-ammine complex solution of 200 mg / L gradually shifts from 630 nm to 660 nm.

[0069] (2) Perform matrix normalization on the preprocessed data to obtain a spectral data normalization matrix; and extract the principal components to obtain the principal components and the cumulative contribution rates corresponding to the principal components. The obtained principal component eigenvalues ​​and their corresponding contribution rates and cumulative contribution rates are shown in Table 1.

[0070] Table 1 The eigenvalues ​​of each principal component and their corresponding contribution rate and cumulative contribution rate

[0071]

[0072] It can be seen from Table 1 that the cumulative contribution rate of principal component 1 is 99.97%, which has met most of the characteristics of the selected data.

[0073] (3) The spectral data standardization matrix is ​​multiplied with the eigenvector matrix of the principal component to obtain the principal component score, and the relationship between the copper ammonia complex ion concentration and the principal component score is obtained after multiple linear regression. The concentration function is simplified to C = 79.999 + 3.7916 * F1, where C is the concentration of the copper ammonia complex ion and F1 is the principal component score. The scores of each principal component are shown in Table 2.

[0074] Table 2 Principal component scores

[0075]

[0076]

[0077] Among them, F1, F2, F3...F12 are the scores of principal component 1, principal component 2, principal component 3...principal component 12 respectively.

[0078] (4) The predicted concentrations and residuals of different standard copper-ammonia complex solution concentrations were obtained. The specific values ​​are shown in Table 3.

[0079] Table 3 Standard copper-ammonia complex solution concentrations and their corresponding predicted concentrations and residuals

[0080]

[0081] (5) Accuracy verification of concentration prediction model

[0082] Based on the above data, the accuracy of the concentration prediction model can be obtained as shown in Table 4.

[0083] Table 4 Accuracy of concentration prediction model

[0084]

[0085] in, Where y is the actual value and f is the predicted value. is the average of the actual values;

[0086]

[0087] (6) The predicted concentrations and confidence intervals of 12 standard copper-ammonia complex solutions were calculated using the concentration prediction model. Figure 3 As shown. Figure 3 The shaded area shows the 95% confidence interval. Figure 3 It can be seen that within the selected concentration range of 5 to 200 mg / L, the concentration prediction model has extremely high accuracy in predicting the concentration of copper ammine complex ions in water.

[0088] Example 2

[0089] A method for detecting copper-ammonia complex ions in water

[0090] (1) Prepare sample A

[0091] Dissolve 0.0315 g of copper sulfate pentahydrate in 100 mL of water to obtain a copper sulfate solution; measure 9.8 mL of 28% ammonia water and add it to the copper sulfate solution, adjust the pH to 9.0, add water to make the volume to 200 mL, obtain a 40 mg / L (in terms of copper) copper-ammonia complex solution, and perform three parallel experiments.

[0092] (2) Obtaining the second UV-visible spectrum of sample A

[0093] Measure 2.5 mL of the 40 mg / L copper-ammine complex solution prepared in step (1) above, slowly add it to a quartz cuvette with a width of 1 cm and a height of 3.5 cm, and carefully expel bubbles until the solution is uniform. Use a SHIMADZU UV-1780 ultraviolet-visible spectrophotometer at a wavelength range of 220 to 800 nm, with ultrapure water as a reference, a scanning speed of 0.5 nm / s, scan each sample 3 times, and collect the absorbance value at room temperature. Obtain the second ultraviolet-visible spectrum of the sample A to be tested.

[0094] (3) Apply the concentration prediction model to obtain the concentration of the sample to be tested

[0095] The second spectrum data of the second ultraviolet-visible spectrum of the sample A to be tested obtained in the above step (2) in the wavelength band of 500-800 nm is selected and standardized together with the first spectrum data of the standard copper-ammonia complex solution; the standardized data of the sample A to be tested is multiplied with the eigenvector matrix of the main component to obtain the main component eigenvalue F1 of the sample A to be tested. Substituting into the concentration calculation formula: C=79.999+3.7916*F1, the concentration of the copper-ammonia solution to be tested is obtained as 41.21±0.64 mg / L.

[0096] Example 3

[0097] A method for detecting copper-ammonia complex ions in water

[0098] (1) Prepare sample B

[0099] Dissolve 0.0630 g of copper sulfate pentahydrate in 100 mL of water to obtain a copper sulfate solution; measure 19.6 mL of 28% ammonia water and add it to the copper sulfate solution, adjust the pH to 9.0, add water to make the volume to 200 mL, obtain 80 mg / L (in terms of copper) copper-ammonia complex solution, and perform 3 parallel experiments.

[0100] (2) Obtaining the second UV-visible spectrum of sample B

[0101] Measure 2.5 mL of the 80 mg / L copper-ammine complex solution prepared in step (1) above, slowly add it to a quartz cuvette with a width of 1 cm and a height of 3.5 cm, and carefully expel bubbles until the solution is uniform. Use a SHIMADZU UV-1780 ultraviolet-visible spectrophotometer at a wavelength range of 220 to 800 nm, with ultrapure water as a reference, a scanning speed of 0.5 nm / s, and scan each sample 3 times to collect the absorbance value at room temperature. Obtain the second ultraviolet-visible spectrum of the sample B to be tested.

[0102] (3) Apply the concentration prediction model to obtain the concentration of the sample to be tested

[0103] The second spectrum data of the second ultraviolet-visible spectrum of the sample B to be tested obtained in the above step (2) in the wavelength band of 500-800 nm is selected and standardized together with the first spectrum data of the standard copper-ammonia complex solution; the standardized data of the sample B to be tested is multiplied by the eigenvector matrix of the main component to obtain the main component eigenvalue F1 of the sample B to be tested. Substituting into the concentration calculation formula: C=79.999+3.7916*F1, the concentration of the copper-ammonia solution to be tested is obtained as 81.24±0.55 mg / L.

[0104] Example 4

[0105] A method for detecting copper-ammonia complex ions in water

[0106] (1) Prepare the sample C to be tested

[0107] Dissolve 0.0945 g of copper sulfate pentahydrate in 100 mL of water to obtain a copper sulfate solution; measure 29.4 mL of 28% ammonia water and add it to the copper sulfate solution, adjust the pH to 9.0, add water to make the volume to 200 mL, and obtain a 120 mg / L (in terms of copper) copper-ammonia complex solution. Perform three parallel experiments.

[0108] (2) Obtaining the second UV-visible spectrum of the sample C to be tested

[0109] Measure 2.5 mL of the 80 mg / L copper-ammine complex solution prepared in step (1) above, slowly add it to a quartz cuvette with a width of 1 cm and a height of 3.5 cm, and carefully expel bubbles until the solution is uniform. Use a SHIMADZU UV-1780 ultraviolet-visible spectrophotometer in the wavelength range of 220 to 800 nm, with ultrapure water as a reference, and a scanning speed of 0.5 nm / s. Scan each sample 3 times and collect the absorbance value at room temperature. Obtain the second ultraviolet-visible spectrum of the sample C to be tested.

[0110] (3) Apply the concentration prediction model to obtain the concentration of the sample to be tested

[0111] The second spectrum data of the second ultraviolet-visible spectrum of the sample C to be tested obtained in the above step (2) in the wavelength band of 500-800 nm is selected and standardized together with the first spectrum data of the standard copper-ammonia complex solution; the standardized data of the sample C to be tested is multiplied by the eigenvector matrix of the main component to obtain the main component eigenvalue F1 of the sample C to be tested. Substitute into the concentration calculation formula: C=79.999+3.7916*F1, and the concentration of the copper-ammonia solution to be tested is obtained as 120.10±0.50 mg / L.

[0112] Analysis example 1

[0113] Analysis of the Accuracy of the Measurement Results of the Samples to be Tested in Example 2, Example 3 and Example 4

[0114] The detection concentrations and relative standard deviations corresponding to the measurement results of the samples to be tested in Example 2, Example 3 and Example 4 are shown in Table 5.

[0115] Table 5 Analysis of measurement results of each sample to be tested

[0116]

[0117] As can be seen from Table 5, the concentration determination results of sample A, sample B and sample C all have good reproducibility.

[0118] It can be seen that the method for detecting copper ammine complex ions in water bodies can achieve rapid and accurate monitoring of the actual copper ammine complex ion pollutant concentration in each treatment link.

[0119] In summary, the above technical solutions of the present invention are only preferred embodiments of the present invention, and the patent scope of the present invention is not limited thereto. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for detecting copper ammonia complex ions in water, characterized in that: Includes steps: S1, providing standard copper-ammonia complex solutions of different concentrations, and measuring them respectively using a UV-visible spectrophotometer to generate a first UV-visible spectrum; The pH values ​​of the standard copper-ammonia complex solutions of different concentrations are all 8.8-9.2, and the molar ratio of copper element to ammonia molecule is in the range of 1:128-1:256; S2, collecting first spectrum data of the first ultraviolet-visible spectrum in the wavelength range of 500-800 nm, and establishing a concentration prediction model according to the spectrum data; The establishing of a concentration prediction model according to the spectral data comprises: S21, performing SG least squares smoothing preprocessing on the first spectrum data in the wavelength band of 500-800 nm; S22, performing matrix standardization processing on the preprocessed data to obtain a spectral data standardization matrix; and extracting principal components to obtain the principal components and the cumulative contribution rates corresponding to the principal components; S23, multiplying the spectral data standardization matrix by the eigenvector matrix of the principal component to obtain a principal component score; S24, performing multiple linear regression processing on the obtained data of the main component and the standard copper-ammonia complex solution of different concentrations to obtain a concentration calculation formula C=79.999+3.7916 F1, wherein C is the concentration of copper ammonia complex ions and F1 is the principal component score; S3, measuring the copper-ammine complex solution sample to be tested under the same measurement conditions as the standard copper-ammine complex solution to generate a second UV-visible spectrum; S4, collecting the second spectrum data of the wavelength band of 500-800 nm in the second ultraviolet-visible spectrum in step S3; performing standardization and principal component regression analysis on the second spectrum data in sequence, and determining the concentration of the copper-ammonia complex solution sample to be tested based on the concentration prediction model; The steps of sequentially standardizing and principal component regression analyzing the second spectral data respectively use the spectral data standardization matrix in step S22 and the eigenvector matrix in step S23.

2. The method for detecting copper ammonia complex ions in water according to claim 1, characterized in that: After step S24, the concentration prediction model is further verified for accuracy to determine the accuracy of the concentration prediction model.

3. The method for detecting copper ammonia complex ions in water according to claim 2, characterized in that: The precision verification process specifically includes: respectively calculating the concentration calculation formula C=79.999+3.7916 in step S24. The correlation coefficient of F1, root mean square error, mean absolute percentage error, detection limit of the method and quantification limit of the method were used to evaluate the fit of the concentration prediction model.

4. The method for detecting copper-ammine complex ions in water according to claim 1, characterized in that: In step S1, the copper element concentration gradient of the standard copper ammonia complex solution of different concentrations is 5 mg / L, 10 mg / L, 15 mg / L, 20 mg / L, 35 mg / L, 50 mg / L, 75 mg / L, 100 mg / L, 125 mg / L, 150 mg / L, 175 mg / L, and 200 mg / L.

5. The method for detecting copper-ammine complex ions in water according to claim 1, characterized in that: In the steps S1 and S4, the measurement process specifically includes: selecting the width of the absorption cell as 1 cm, scanning with ultrapure water as a reference, scanning speed of 0.5 nm / s, and scanning each solution sample 3 times.

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