Water sample hardness detection device and method based on Raman spectrum

Abstract

The invention discloses a water sample hardness detection device and method based on Raman spectroscopy, and relates to the technical field of water sample hardness detection.The water sample hardness detection device comprises a machine box and a machine cover arranged on one side of the machine box, and a partition plate layer is arranged in the machine box and divides the machine box into a front part and a rear part; a laser light source, a Raman detector, a spectrograph, a data processing module and a power supply module are arranged in the front part, a cavity is formed in the rear part, an ion concentration measuring bracket is arranged in the cavity, a water sample pool is arranged above the ion concentration measuring bracket, one side, far away from the partition plate layer, of the front part is an inclined plane, and a touch display module is arranged on the inclined plane; a power switch is arranged below the touch display module, and the power module is connected with the power switch. The water sample hardness detection device and method based on the Raman spectrum have the advantages that the device is integrated, the detection speed is high, the detection accuracy is high, low-concentration hardness components can be detected, multiple hardness components can be detected at the same time, and an interaction function is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of water sample hardness detection, and in particular to a water sample hardness detection device and method based on Raman spectroscopy. Background Art

[0002] Water sample hardness testing has an important impact in areas such as daily life and industrial production. Testing water hardness is mainly to understand the content of calcium and magnesium ions in water. The right amount of calcium and magnesium ions in drinking water is beneficial to the human body, but too high water hardness can cause problems such as kidney stones, which affects human health. At the same time, high-hardness water is prone to scale formation in industrial cooling systems, increasing energy consumption, shortening equipment life, and causing equipment failure. Water sample hardness is evaluated by the total concentration of calcium and magnesium ions contained in the water. The higher the concentration, the higher the water sample hardness. The ideal concentration range of drinking water is 60mg / L-120mg / L. A hardness exceeding 200mg / L may affect the taste of water and household water equipment, and a hardness exceeding 500mg / L may cause damage to the human digestive system. Traditional water sample hardness testing usually uses chemical reagent titration, such as EDTA (Ethylenediaminetetraacetic acid disodium salt) solution.

[0003] The Chinese patent "CN202311501272.5 A device and method for online measurement of water hardness" first adds the water sample to be tested into the reaction tank, and respectively adds the first combined liquid and the second combined liquid to the water sample through the reaction liquid group to form a first mixed liquid and a second mixed liquid. The two mixed liquids are titrated with a titration standard solution until the first titration end point and the second titration end point are reached respectively. The detection component is used to monitor the color change during the titration process to determine whether the titration has reached the endpoint. The control component is connected to the reaction component and the detection component, and is used to measure the hardness of the water sample online and detect whether the component is faulty. However, it is impossible to detect multiple hardness components at the same time, such as calcium ions, magnesium ions, etc., and there are difficulties in detecting low-concentration hardness components.

[0004] The Chinese patent "CN202110167084.8 A water hardness detector and its detection method" introduces the water sample to be tested into the detection container through the water inlet module, and adds reagents to the detection container through the reagent input module to form a mixed liquid. The detection container is used to hold the mixed liquid, and the water hardness detection module determines the hardness value of the water to be tested based on the color information of the mixed liquid. The system adopts the reagent method and combines machine vision technology to achieve high-precision and fully automatic detection of water hardness, and has the ability of remote control. However, the addition of reagents during the detection process destroys the water sample, and the detection speed is not fast enough to achieve online real-time monitoring.

[0005] Raman spectroscopy is a method for detecting the hardness of water samples. It has the advantages of low-concentration hardness component detection, simultaneous detection of multiple hardness components, no addition of chemical reagents to damage water samples, fast detection speed, etc. The detection device is integrated and suitable for on-site real-time detection. Summary of the invention

[0006] The purpose of the present invention is to provide a device and method for detecting hardness of water samples based on Raman spectroscopy to solve the problems raised in the above background technology.

[0007] To achieve the above-mentioned purpose, the present invention provides a water sample hardness detection device based on Raman spectroscopy, comprising a chassis and a cover arranged on one side of the chassis, a partition layer is arranged in the chassis, the partition layer divides the chassis into a front part and a rear part, the front part is provided with a laser light source, a Raman detector, a spectrometer, a data processing module and a power module, the rear part is provided with a cavity, an ion concentration measurement bracket is arranged in the cavity, a water sample pool is arranged above the ion concentration measurement bracket, a side of the front part away from the partition layer is arranged as an inclined surface, a touch display module is arranged on the inclined surface, a power switch is arranged below the touch display module, and the power module is connected to the power switch through a power data line.

[0008] Preferably, the ion concentration measurement bracket includes a metal bracket, a square groove is formed on the metal bracket, through holes 1 are formed on both sides of the square groove, a focusing lens is arranged in the through hole 1, the focusing lens is connected to a fiber optic adapter, two fiber optic adapters are provided, and the two fiber optic adapters are respectively connected to the laser light source and the Raman detector through fiber 1 and fiber 2; the water sample pool is arranged in the square groove.

[0009] Preferably, the partition layer is provided with a through hole 2 for the optical fiber 1 and the optical fiber 2 to pass through.

[0010] Preferably, the laser light source, the Raman detector and the spectrometer are respectively connected to the power module, and are powered by the power module, and the spectrometer is connected to the data processing module via a USB cable;

[0011] The laser light source is provided with a light output port, which is connected to the optical fiber one; the Raman detector is provided with a light input port, which is connected to the optical fiber two through the focusing lens, and the Raman detector is connected to the spectrometer through the optical fiber three.

[0012] Preferably, the wavelength of the laser light source is 785 nm.

[0013] Preferably, the water sample pool is a quartz water sample pool, and the inner wall of the water sample pool is provided with an anti-reflection coating and a black light-absorbing coating.

[0014] Preferably, the touch display module is used to display the water quality test results and the operation interface in real time, the touch display module is provided with a UI of a graphical interface software written by JavaFx software, and the operation interface is provided with an operation button control and a result display control.

[0015] Preferably, the cover is hingedly connected to the chassis.

[0016] A method for detecting water sample hardness based on Raman spectroscopy, comprising the following steps:

[0017] Step 1: Connect the power module cable and press the power switch to power the laser light source, spectrometer, Raman detector, touch display module and data processing module;

[0018] Step 2: Use calcium carbonate, magnesium chloride and deionized water to prepare standard solutions of 0 mg / L-600 mg / L respectively, and prepare solutions every 10 mg / L. Put the standard solutions of different concentrations into the water sample pool respectively, place it on the ion concentration measurement bracket, click the start button on the touch display module, use a laser light source to excite Raman scattering, drive the Raman detector through the optical fiber and drive the spectrometer through the USB line, measure standard solutions of different concentrations, establish standard curves for calcium ions and magnesium ions, record the intensity of the Raman characteristic peaks of these standard solutions, identify and quantify the characteristic Raman peaks of calcium ions and magnesium ions, determine their concentrations in the water sample according to the standard curve, plot the intensity of the characteristic Raman peak and the concentration of the standard solution, record and save the data, and this step will not be repeated in subsequent measurements;

[0019] Step 3: Inject the water sample to be tested into the water sample pool and click the start button on the interface;

[0020] Step 4: The laser light source excites Raman scattering, records the Raman spectrum, and uses the standard curve saved in step 2 to automatically calculate the concentration of ions in the sample to be tested. The system uses Python to perform curve fitting based on the characteristic Raman peak intensity of the sample and the corresponding relationship in the standard curve to obtain the concentration value;

[0021] Step 5: Use the data processing module to substitute the magnesium ion and calcium ion concentration values ​​into the formula to calculate the water sample hardness value, and the touch display module displays the corresponding water sample hardness value.

[0022] Preferably, the water sample hardness value calculation formula in step 5 is as follows:

[0023]

[0024] Where A is the calcium hardness equivalent, 2.5 is the equivalent factor of CaCO3, and 40 is the molar mass of calcium ions;

[0025]

[0026] Where B is the magnesium hardness equivalent, 4.1 is the equivalent factor of CaCO3, and 24 is the molar mass of magnesium ions;

[0027] C=A+B

[0028] Among them, C is the total hardness. This formula converts the concentration of calcium ions and magnesium ions in water into the equivalent concentration of calcium carbonate, and expresses it by adding the two together.

[0029] Therefore, the present invention adopts the above-mentioned water sample hardness detection device and method based on Raman spectroscopy, which has the following beneficial effects:

[0030] (1) Raman spectroscopy is used to measure the ion concentration of water samples to avoid water sample contamination caused by the use of chemical reagents;

[0031] (2) The water sample hardness detection device has high integration, simple overall structure, simple measurement steps, short waiting time for water sample detection, and can be detected quickly and in real time. The touch screen interaction makes the measurement results more intuitive and the detection results can be directly output.

[0032] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a system framework diagram of an embodiment of a water sample hardness detection device and method based on Raman spectroscopy of the present invention;

[0034] Figure 2 This is a schematic diagram of the chassis structure of the water sample hardness detection device according to an embodiment of the present invention;

[0035] Figure 3 A schematic diagram of the structure of a water sample pool according to an embodiment of the present invention;

[0036] Figure 4 This is a schematic structural diagram of an ion concentration measurement bracket according to an embodiment of the present invention;

[0037] Figure numerals: 1. chassis; 2. partition layer; 3. touch display module; 4. power switch; 5. cover; 6. power connection line; 7. water sample pool; 8. anti-reflective coating; 9. black light-absorbing coating; 10. ion concentration measurement bracket; 11. focusing lens; 12. fiber optic adapter; 13. optical fiber one; 14. optical fiber two. DETAILED DESCRIPTION

[0038] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0039] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0040] Example

[0041] Reference Figure 1 and Figure 2 A water hardness detection device based on Raman spectroscopy includes a chassis 1 and a cover 5, the cover 5 is arranged at the rear side of the chassis 1, and the chassis 1 and the cover 5 are hingedly connected, the front side of the chassis 1 is arranged as an inclined surface, a touch display module 3 is arranged on the inclined surface, a power switch 4 is arranged below the touch display module 3, a partition layer 2 is arranged in the chassis, the partition layer 2 divides the chassis 1 into two parts, a front part and a back part, a laser light source, a Raman detector, a spectrometer, a data processing module and a power module are arranged at the front of the partition layer 2, the power module is connected to the power switch 4 through a power connection line 6, a cavity is arranged at the rear of the partition layer 2, and an ion concentration measurement bracket 10 is arranged in the cavity, as shown in FIG. Figure 4 As shown, a water sample pool 7 is arranged above the ion concentration measurement bracket 10; the ion concentration measurement bracket 10 includes a metal bracket, a square groove is opened on the metal bracket, through holes 1 are opened on both sides of the square groove, a focusing lens 11 is arranged in the through hole 1, and an optical fiber adapter 12 is connected to the outer side of the focusing lens 11. Two optical fiber adapters 12 are provided, and the two optical fiber adapters 12 are connected to the laser light source and the Raman detector through optical fiber 1 13 and optical fiber 2 14 respectively; the water sample pool 7 is arranged in the square groove, as shown in FIG. Figure 3 As shown, the water sample pool 7 is a quartz water sample pool, and the inner wall contains an anti-reflection coating 8 and a black light-absorbing coating 9, which can improve the accuracy and reliability of the detection, reduce measurement errors, and improve the experimental efficiency and stability of the results when testing the hardness of water samples. The partition layer 2 is provided with a through hole 2 for the optical fiber 13 and the optical fiber 2 14 to pass through.

[0042] The laser light source is provided with a light output port, which is connected to an optical fiber 13; the Raman detector is provided with a light input port, which is connected to an optical fiber 2 14; the Raman detector is connected to a spectrometer via an optical fiber 3; the laser light source has a wavelength of 785nm, has the advantages of small fluorescence interference, good penetration depth, etc., and is suitable for high-precision water sample hardness detection.

[0043] The power module is respectively connected to the laser light source, the Raman detector and the spectrometer for power supply. The spectrometer is connected to the data processing module via a USB cable. The data processing module is a mainboard of an ARM processor, and the operating system running on it is a Linux kernel operating system.

[0044] The spectrometer is a small USB spectrometer with a measurable wavelength range of 200nm-850nm and a high resolution. It is driven by a USB device driver framework under the Linux kernel system.

[0045] The touch display module 3 is used to display the water sample hardness test results and operation interface in real time, and improve the user experience through the graphical interface and touch operation. The UI of the graphical interface set on the touch display module 3 is written using JavaFx software, and the operation interface is provided with operation button controls and result display controls.

[0046] A detection method of a water sample hardness detection device based on Raman spectroscopy comprises the following steps:

[0047] Step 1: Connect the power module cable and press the power switch to power the laser light source, spectrometer, Raman detector, touch display module and data processing module;

[0048] Step 2: Use calcium carbonate, magnesium chloride and deionized water to prepare standard solutions of 0mg / L-600mg / L (prepare a solution every 10mg / L), respectively, put the standard solutions of different concentrations into the water sample pool, place it on the ion concentration measurement bracket, click the start button on the touch display module, use a laser light source to excite Raman scattering, drive the Raman detector through the optical fiber and drive the spectrometer through the USB cable, measure standard solutions of different concentrations, establish standard curves for calcium ions and magnesium ions, record the intensity of the Raman characteristic peaks of these standard solutions, identify and quantify the characteristic Raman peaks of calcium ions and magnesium ions, and determine their concentrations in the water sample according to the standard curve. Plot the intensity of the characteristic Raman peak (vertical axis) and the concentration of the standard solution (horizontal axis), record and save the data, and this step will not be repeated in subsequent measurements;

[0049] Step 3: Inject the water sample to be tested into the water sample pool and click the start button on the interface;

[0050] Step 4: The laser light source excites Raman scattering, records the Raman spectrum, and uses the previously saved standard curve to automatically calculate the concentration of ions in the sample to be tested. The system will use Python to perform curve fitting based on the characteristic Raman peak intensity of the sample and the corresponding relationship in the standard curve to obtain the concentration value.

[0051] Step 5: Use the data processing module to substitute the magnesium ion and calcium ion concentration values ​​into the formula to calculate the water sample hardness value. The touch display module displays the corresponding water sample hardness value. The water sample hardness value formula is as follows:

[0052]

[0053] Where A is the calcium hardness equivalent, 2.5 is the equivalent factor of CaCO3, and 40 is the molar mass of calcium ions;

[0054]

[0055] Where B is the magnesium hardness equivalent, 4.1 is the equivalent factor of CaCO3, and 24 is the molar mass of magnesium ions;

[0056] C=A+B

[0057] Among them, C is the total hardness. This formula converts the concentration of calcium ions and magnesium ions in water into the equivalent concentration of calcium carbonate, and expresses it by adding the two together.

[0058] Therefore, the present invention adopts the above-mentioned Raman spectroscopy-based water sample hardness detection device and method, and uses Raman spectroscopy to measure the ion concentration of water samples, avoiding the use of chemical reagents for determination and causing water sample contamination. The detection device has high integration, simple overall structure, simple measurement steps, short waiting time for water sample detection, and can be detected in real time and quickly. The touch screen interaction makes the measurement results more intuitive and the detection results can be directly output.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A water sample hardness detection device based on Raman spectroscopy, characterized in that: It includes a chassis and a cover arranged on one side of the chassis, a partition layer is arranged in the chassis, the partition layer divides the chassis into a front part and a rear part, the front part is provided with a laser light source, a Raman detector, a spectrometer, a data processing module and a power module, the rear part is provided with a cavity, an ion concentration measurement bracket is arranged in the cavity, a water sample pool is arranged above the ion concentration measurement bracket, a side of the front part away from the partition layer is arranged as an inclined surface, a touch display module is arranged on the inclined surface, a power switch is arranged below the touch display module, and the power module is connected to the power switch through a power data line.

2. The water sample hardness detection device based on Raman spectroscopy according to claim 1 is characterized in that: The ion concentration measurement bracket includes a metal bracket, a square groove is opened on the metal bracket, through holes are opened on both sides of the square groove, a focusing lens is arranged in the through hole, the focusing lens is connected to a fiber optic adapter, two fiber optic adapters are arranged, and the two fiber optic adapters are respectively connected to the laser light source and the Raman detector through fiber 1 and fiber 2; the water sample pool is arranged in the square groove.

3. The water sample hardness detection device based on Raman spectroscopy according to claim 2 is characterized in that: The partition layer is provided with a through hole 2 for the optical fiber 1 and the optical fiber 2 to pass through.

4. The water sample hardness detection device based on Raman spectroscopy according to claim 3 is characterized in that: The laser light source, the Raman detector and the spectrometer are respectively connected to the power module, and the spectrometer is connected to the data processing module via a USB cable; The laser light source is provided with a light output port, which is connected to the optical fiber one; the Raman detector is provided with a light input port, which is connected to the optical fiber two through the focusing lens, and the Raman detector is connected to the spectrometer through the optical fiber three.

5. The water sample hardness detection device based on Raman spectroscopy according to claim 4 is characterized in that: The wavelength of the laser light source is 785nm.

6. The water sample hardness detection device based on Raman spectroscopy according to claim 1, characterized in that: The water sample pool is a quartz water sample pool, and the inner wall of the water sample pool is provided with an anti-reflection coating and a black light-absorbing coating.

7. The water sample hardness detection device based on Raman spectroscopy according to claim 1 is characterized in that: The touch display module is used to display the water quality test results and the operation interface in real time. The touch display module is provided with a UI of a graphical interface software written by JavaFx software, and the operation interface is provided with an operation button control and a result display control.

8. The water sample hardness detection device based on Raman spectroscopy according to claim 1, characterized in that: The machine cover is hingedly connected to the machine chassis.

9. A method for detecting water sample hardness based on Raman spectroscopy according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: Connect the power module cable and press the power switch to power the laser light source, spectrometer, Raman detector, touch display module and data processing module; Step 2: Use calcium carbonate, magnesium chloride and deionized water to prepare standard solutions of 0 mg / L-600 mg / L respectively, and prepare solutions every 10 mg / L. Put the standard solutions of different concentrations into the water sample pool respectively, place it on the ion concentration measurement bracket, click the start button on the touch display module, use a laser light source to excite Raman scattering, drive the Raman detector through the optical fiber and drive the spectrometer through the USB line, measure standard solutions of different concentrations, establish standard curves for calcium ions and magnesium ions, record the intensity of the Raman characteristic peaks of these standard solutions, identify and quantify the characteristic Raman peaks of calcium ions and magnesium ions, determine their concentrations in the water sample according to the standard curve, plot the intensity of the characteristic Raman peak and the concentration of the standard solution, record and save the data, and this step will not be repeated in subsequent measurements; Step 3: Inject the water sample to be tested into the water sample pool and click the start button on the interface; Step 4: The laser light source excites Raman scattering, records the Raman spectrum, and uses the standard curve saved in step 2 to automatically calculate the concentration of ions in the sample to be tested. The system uses Python to perform curve fitting based on the characteristic Raman peak intensity of the sample and the corresponding relationship in the standard curve to obtain the concentration value; Step 5: Use the data processing module to substitute the magnesium ion and calcium ion concentration values ​​into the formula to calculate the water sample hardness value, and the touch display module displays the corresponding water sample hardness value.

10. The method for detecting water sample hardness based on Raman spectroscopy according to claim 9, characterized in that: The calculation formula for the water sample hardness value in step 5 is as follows: Where A is the calcium hardness equivalent, 2.5 is the equivalent factor of CaCO3, and 40 is the molar mass of calcium ions; Where B is the magnesium hardness equivalent, 4.1 is the equivalent factor of CaCO3, and 24 is the molar mass of magnesium ions; C=A+B Among them, C is the total hardness. This formula converts the concentration of calcium ions and magnesium ions in water into the equivalent concentration of calcium carbonate, and expresses it by adding the two together.

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