Method for determining total alkalinity, carbonate and bicarbonate content of geothermal water

Abstract

The invention discloses a method for determining the total alkalinity, carbonate and bicarbonate content of geothermal water, electronic equipment and a medium. The method comprises the following steps: step 1, taking two terrestrial heat horizontal samples and two blank samples; 2, recording V1 for the first geothermal level row sample; 3, repeating the operation in the step 2 for the first blank sample, and recording V01; 4, recording V2 and V3 for a second geothermal level row sample; 5, repeating the operation in the step 4 for the second blank sample, and recording V02; and 6, calculating the total alkalinity, the carbonate content and the bicarbonate content according to V1, V01, V2, V3 and V02. According to the method, result deviation caused by improper titration modes is avoided by selecting the titration modes, the practical operability is high, and compared with a manual titration mode, the method has better precision and standard addition recovery rate.

Description

Technical Field

[0001] The present invention relates to the field of analysis and detection of geothermal water of hydrothermal geothermal resources, and more specifically, to a method for determining the total alkalinity, carbonate and bicarbonate contents of geothermal water, electronic equipment and a medium. Background Art

[0002] Geothermal energy is a valuable renewable clean energy. The development and utilization of geothermal resources are of great significance to the development of the new energy industry. Geothermal resources usually use water as a medium to bring heat to the surface to form geothermal water. The composition of geothermal water in different regions is different. Before developing and utilizing geothermal resources, we should measure the quality of geothermal water in the development area. The total alkalinity, carbonate and bicarbonate content of geothermal water are some of the important basic indicators. Geothermal water alkalinity refers to the ability of geothermal water to accept hydrogen ions, which represents the strength of the reaction between geothermal water and acid. Its amount determines the scaling and corrosion tendency of geothermal water to a certain extent. Carbonate and bicarbonate are the main forms of carbonate compounds in natural water. Their content can reflect the geochemical behavior and carbon cycle characteristics of the region.

[0003] The current method for determining the total alkalinity, carbonate and bicarbonate content of geothermal water is mainly the acid-base indicator titration method, which uses methyl orange and phenolphthalein as indicators, uses hydrochloric acid standard titration solution for titration, and determines the titration endpoint based on the change in the color of the water sample. As a manual titration method, the acid-base indicator titration method has problems such as complex operation, easy to produce human errors, and many interference factors. In particular, the temperature of geothermal water itself is relatively high, and the color of the water body often becomes darker after cooling. This will interfere with the color change of the indicator, making it difficult to judge the endpoint. Therefore, for geothermal water, the accuracy and stability of the acid-base indicator titration method are poor, and it is difficult to achieve ideal measurement results.

[0004] Potentiometric titration is an electrochemical analysis method. It indicates the titration endpoint by the sudden jump of the electrode potential. Before and after the titration reaches the endpoint, the concentration of the ion to be measured in the sample often changes continuously by n orders of magnitude, and the content of the measured component is calculated by the amount of titrant consumed. In potentiometric titration, the two factors that have a greater impact on the analysis results are mainly the endpoint judgment and the titration mode. Most water quality analyses can use a fixed pH value method (i.e., SET method) to determine the titration endpoint. This method has a fast titration speed and can avoid excessive titration of reagents. However, due to the large difference in the content of carbonate and bicarbonate in geothermal water itself, and the presence of symbiotic ions (such as silicate, phosphate, sulfite, etc.) in geothermal water, especially the presence of sulfite, it will cause deviations in the titration endpoint, thereby affecting the titration results. In terms of titration mode, there are mainly two types: dynamic titration (DET) and equal volume titration (MET). The volume of reagent added in each step of the DET method is variable, and the change in the volume of liquid added in each step is a function of the slope of the curve. The MET method adds a constant volume of reagents in each step, and can be used for relatively large signal fluctuations, sudden potential changes, slower titrations, or electrodes with slower responses. At present, both titration modes are used in geothermal water quality determination, but after comparison, it is found that the determination results of the two titration modes have large deviations. In the process of titrating geothermal water in the MET mode, the first equivalence point is often unrecognizable. If the volume increment is reduced, the titration time will be too long. The DET method often cannot find the titration end point when titrating blank samples.

[0005] Therefore, it is necessary to develop a method, electronic equipment and medium for determining the total alkalinity, carbonate and bicarbonate contents of geothermal water.

[0006] The information disclosed in the background technology section of the present invention is only intended to deepen the understanding of the general background technology of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to those skilled in the art. Summary of the invention

[0007] The present invention proposes a method, electronic equipment and medium for determining the total alkalinity, carbonate and bicarbonate contents of geothermal water. The method can avoid result deviation caused by improper titration method by selecting a titration mode, has strong practicability and has better precision and spike recovery rate than a manual titration method.

[0008] In a first aspect, the present disclosure provides a method for determining the total alkalinity, carbonate and bicarbonate content of geothermal water, comprising:

[0009] Step 1: Take two parallel geothermal water samples and two blank samples;

[0010] Step 2: For the first geothermal water parallel sample, use a hydrochloric acid standard titration solution to titrate to a first pH value, and record the volume V1 of the consumed hydrochloric acid standard titration solution;

[0011] Step 3: Repeat step 2 for the first blank sample and record the volume V of the hydrochloric acid standard titration solution consumed. 01 ;

[0012] Step 4: For the second geothermal water parallel sample, KMnO4 is dripped until the solution turns into light purple, and the hydrochloric acid standard titration solution is used for titration, and the volume V2 of the hydrochloric acid standard titration solution consumed during the first potential jump and the volume V3 of the hydrochloric acid standard titration solution consumed during the second potential jump are recorded;

[0013] Step 5: Repeat step 4 for the second blank sample and record the volume V of the hydrochloric acid standard titration solution consumed. 02 ;

[0014] Step 6: According to V1, V 01 , V2, V3, V 02 Calculate total alkalinity, carbonate content, and bicarbonate content.

[0015] Preferably, the step 1 comprises:

[0016] Return the sample to room temperature, take two parallel samples of geothermal water of 30 to 100 mL and place them in 200 mL beakers respectively. If the sample volume is less than 100 mL, add CO2-free water to make it up to 100 mL.

[0017] A rod-shaped spiral stirrer is used for stirring;

[0018] Take two 100 mL portions of de-CO2 water as blank samples.

[0019] Preferably, the rotation speed of the rod-shaped spiral agitator is 6.

[0020] Preferably, the first pH is pH 4.4.

[0021] Preferably, the total alkalinity is:

[0022]

[0023] Where, JD is the total alkalinity of the sample, c(HCl) is the concentration of the standard hydrochloric acid titration solution, V s is the volume of geothermal water sample.

[0024] Preferably, the carbonate content is:

[0025]

[0026] Among them, c(CO3 2- ) is the carbonate content in the sample, c(HCl) is the concentration of the standard hydrochloric acid titration solution, V s is the volume of geothermal water sample.

[0027] Preferably, the bicarbonate content is:

[0028]

[0029] Among them, c(HCO3 - ) is the bicarbonate content in the sample, c(HCl) is the concentration of the standard hydrochloric acid titration solution, V s is the volume of geothermal water sample.

[0030] Preferably, the step 4 further comprises:

[0031] If the sample does not contain carbonate, there is only one potential jump in the entire titration process, that is, V2 is zero, and the volume V3 of the standard hydrochloric acid titration solution consumed during the jump is recorded.

[0032] In a second aspect, an embodiment of the present disclosure further provides an electronic device, the electronic device comprising:

[0033] A memory storing executable instructions;

[0034] A processor runs the executable instructions in the memory to implement the method for determining the total alkalinity, carbonate and bicarbonate content of geothermal water.

[0035] In a third aspect, the embodiments of the present disclosure further provide a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the method for determining the total alkalinity, carbonate, and bicarbonate content of geothermal water.

[0036] The methods and apparatus of the present invention have other features and advantages that will be apparent from, or will be described in detail in, the accompanying drawings and subsequent detailed descriptions incorporated herein, which together serve to explain the specific principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0038] Figure 1A flow chart showing the steps of a method for determining the total alkalinity, carbonate and bicarbonate contents of geothermal water according to an embodiment of the present invention. DETAILED DESCRIPTION

[0039] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0040] Figure 1 A flow chart showing the steps of a method for determining the total alkalinity, carbonate and bicarbonate contents of geothermal water according to an embodiment of the present invention.

[0041] like Figure 1 As shown, the present invention provides a method for determining the total alkalinity, carbonate and bicarbonate contents of geothermal water, comprising:

[0042] Step 1: Take two parallel geothermal water samples and two blank samples;

[0043] Step 2: For the first geothermal water parallel sample, use a hydrochloric acid standard titration solution to titrate to a first pH value, and record the volume V1 of the consumed hydrochloric acid standard titration solution;

[0044] Step 3: Repeat step 2 for the first blank sample and record the volume V of the hydrochloric acid standard titration solution consumed. 01 ;

[0045] Step 4: For the second geothermal water parallel sample, KMnO4 is dripped until the solution turns to light purple, and a hydrochloric acid standard titration solution is used for titration, and the volume V2 of the hydrochloric acid standard titration solution consumed during the first potential jump and the volume V3 of the hydrochloric acid standard titration solution consumed during the second potential jump are recorded;

[0046] Step 5: Repeat step 4 for the second blank sample and record the volume V of the hydrochloric acid standard titration solution consumed. 02 ;

[0047] Step 6: According to V1, V 01 , V2, V3, V 02 Calculate total alkalinity, carbonate content, and bicarbonate content.

[0048] In one example, step 1 includes:

[0049] Return the sample to room temperature, take two parallel samples of geothermal water of 30 to 100 mL and place them in 200 mL beakers respectively. If the sample volume is less than 100 mL, add CO2-free water to make it up to 100 mL.

[0050] A rod-shaped spiral stirrer is used for stirring;

[0051] Take two 100 mL portions of de-CO2 water as blank samples.

[0052] In one example, the rod-shaped screw agitator has a rotation speed of 6.

[0053] In one example, the first pH is pH 4.4.

[0054] In one example, the total alkalinity is:

[0055]

[0056] Where, JD is the total alkalinity of the sample, c(HCl) is the concentration of the standard hydrochloric acid titration solution, V s is the volume of geothermal water sample.

[0057] In one example, the carbonate content is:

[0058]

[0059] Among them, c(CO3 2- ) is the carbonate content in the sample, c(HCl) is the concentration of the standard hydrochloric acid titration solution, V s is the volume of geothermal water sample.

[0060] In one example, the bicarbonate content is:

[0061]

[0062] Among them, c(HCO3 - ) is the bicarbonate content in the sample, c(HCl) is the concentration of the standard hydrochloric acid titration solution, V s is the volume of geothermal water sample.

[0063] In one example, step 4 further includes:

[0064] If the sample does not contain carbonate, there is only one potential jump in the entire titration process, that is, V2 is zero, and the volume V3 of the standard hydrochloric acid titration solution consumed during the jump is recorded.

[0065] Specifically, prepare the potentiometric titrator and electrode according to the instruction manual. The electrode should be calibrated with a pH standard buffer solution before use. As shown in Table 1, prepare a 0.025-0.1 mol / L hydrochloric acid standard titration solution according to the predicted total alkalinity of the sample to be tested and calibrate it. Alternatively, you can directly purchase a hydrochloric acid standard titration solution with a certificate.

[0066] Table 1 Selection of concentration of hydrochloric acid standard titration solution

[0067] <![CDATA[Alkalinity (mg / L, CaCO3)]]> Hydrochloric acid standard titration solution (mol / L) ＜150 0.025 150～300 0.025 300～500 0.025 500～1000 0.05 ＞1000 0.1

[0068] The total alkalinity, carbonate and bicarbonate content calculation formula, titrant type and titrant concentration are set into the potentiometric titrator.

[0069] The calculation formula is as follows:

[0070]

[0071]

[0072]

[0073] Where:

[0074] JD----total alkalinity of the sample (measured in CaCO3), in milligrams per liter (mg / L);

[0075] c(HCl)----Concentration of standard hydrochloric acid titration solution, in moles per liter (mol / L);

[0076] c(CO3 2- )----Carbonate content in the sample, in milligrams per liter (mg / L);

[0077] c(HCO3 - )----The bicarbonate content in the sample, in milligrams per liter (mg / L);

[0078] V 01 ----The volume of hydrochloric acid standard titration solution consumed when titrating the first blank sample to the endpoint, in milliliters (mL);

[0079] V 02 ----The volume of hydrochloric acid standard titration solution consumed when titrating the second blank sample to the endpoint, in milliliters (mL);

[0080] V1----The volume of hydrochloric acid standard titration solution consumed when titrating the first sample to the endpoint, in milliliters (mL);

[0081] V2----The volume of hydrochloric acid standard titration solution consumed at the first jump point when titrating the second sample, in milliliters (mL);

[0082] V3----The volume of hydrochloric acid standard titration solution consumed at the final jump point when titrating the second sample, in milliliters (mL);

[0083] V s ----Geothermal water sample volume, in milliliters (mL);

[0084] 50.044----The molar mass of the basic unit calcium carbonate (i.e. 1 / 2CaCO3), g / mol.

[0085] 30.005----Basic unit carbonate (i.e. 1 / 2CO3 2- ) molar mass, g / mol

[0086] 60.017----Basic unit bicarbonate (i.e. HCO3 - ) molar mass, g / mol

[0087] Before the experiment, the sample should be restored to room temperature. As shown in Table 2, take two parallel samples of geothermal water of 30 to 100 mL and put them into 200 mL beakers respectively. If the sample volume is less than 100 mL, add CO2-free water to 100 mL;

[0088] Table 2 Selection of sample volume

[0089] <![CDATA[Alkalinity (mg / L, CaCO3)]]> Sample volume (mL) ＜150 100 150～300 50 300～500 30 500～1000 30 ＞1000 30

[0090] The experiment uses a rod-shaped spiral stirrer. If the stirring speed is too fast, the solution will easily splash out or produce bubbles. If the stirring speed is too slow, it will cause incomplete local reaction. The speed should be set to 6 during the experiment.

[0091] Determination of total alkalinity of samples: The first sample uses SET mode, sets the instrument parameters, and directly uses hydrochloric acid standard titration solution to titrate the sample. Endpoint titration to pH4.4, record the volume V1 of the consumed hydrochloric acid standard titration solution; instrument test parameters: titration mode: SET pH; end point pH: 4.40; maximum speed: 10.0mL / min; minimum speed: 25.0μL / min; signal drift: 50mV / min; pre-added volume: 4mL; liquid addition speed: maximum; liquid aspiration speed: maximum; pause: 5s; stop volume: 20mL, and the others are default values.

[0092] The pH value determination method is used as the basis for judging the titration endpoint of the total alkalinity determination of geothermal water, which avoids the interference of water color on the titration endpoint, saves titration reagents, and improves the detection speed and accuracy.

[0093] Determination of carbonate and bicarbonate content in samples: The second sample uses the DET mode, sets the instrument parameters, drips 1-2 drops of KMnO4 into the sample, stirs for half a minute until the solution turns pale purple, and then titrates it with a standard hydrochloric acid solution. Record the volume V2 of the standard hydrochloric acid solution consumed during the first potential jump, continue to titrate the sample with the standard hydrochloric acid solution, and record the volume V3 of the standard hydrochloric acid solution consumed during the second potential jump. If the sample does not contain carbonate, there will only be one potential jump in the entire titration process, that is, V2 is zero, and record the volume V3 of the standard hydrochloric acid solution consumed during the jump.

[0094] Instrument test parameters: titration mode: DET U; measurement point density: 4; minimum volume increment: 10.0 μL / min; liquid addition rate: maximum; signal drift: 50 mV / min; maximum waiting time: 20 s; stop volume: 20 mL; stop equivalence point: 2; equivalence point evaluation criteria: 5; others are default values.

[0095] Using potential jump as the basis for judging the titration end point of the carbonate and bicarbonate content determination in geothermal water avoids interference on the titration end point caused by the dark color of geothermal water and the large difference in carbonate and bicarbonate content, thereby improving the accuracy of the measurement results.

[0096] Determination of blank samples:

[0097] Use MET mode to measure the blank sample and set the instrument parameters. Take two 100mL portions of CO2-free water, titrate the first portion directly with hydrochloric acid standard titration solution, and record the volume V of the hydrochloric acid standard titration solution consumed. 01 ; Add the same number of drops of KMnO4 as the second sample to the second blank sample, titrate it with a standard hydrochloric acid solution, and record the volume V of the standard hydrochloric acid solution consumed 02 .

[0098] Instrument test parameters: Titration mode: MET U; Volume increment: 0.01 mL; Adding speed: Maximum; Signal drift: 20 mV / min; Maximum waiting time: 20 s; Stop volume: 1 mL; Stop equivalence point: 1; Equivalence point evaluation criteria: 5; Others are default values.

[0099] The blank sample is titrated in MET mode to avoid the situation where the titration endpoint cannot be found due to low sample blank.

[0100] The method uses a redox reaction to remove the influence of the associated ion sulfite on the determination of carbonate and bicarbonate contents by dropping a low-concentration KMnO4 solution.

[0101] Determination of the precision of this method:

[0102] Determination of total alkalinity precision: Take more than 6 parallel samples of geothermal water for determination. The specific test steps and instrument parameter settings refer to the determination of total alkalinity of the above samples.

[0103] Determination of the precision of carbonate and bicarbonate content: Take more than 6 parallel samples of geothermal water for determination. The specific test steps and instrument parameter settings refer to the determination of carbonate and bicarbonate content in the above samples.

[0104] The relative standard deviation (RSD) is used to express the precision of the test results:

[0105]

[0106]

[0107]

[0108] In the formula: n----number of parallel measurements of samples;

[0109] x k ----The kth measurement result of the sample, mg / L;

[0110] ----The average value of n measurements of the sample, mg / L;

[0111] S----standard deviation of n measurements of the sample;

[0112] RSD----Relative standard deviation of n measurements of a sample.

[0113] Determination of the accuracy of this method:

[0114] Determination of total alkalinity accuracy: Take two parallel samples of geothermal water, add standard substance to one of them, and then test the two samples in the same way. The specific test steps and instrument parameter settings refer to the determination of total alkalinity of the above samples.

[0115] Determination of the accuracy of carbonate and bicarbonate content: Take two parallel samples of geothermal water, add standard substance to one of them, and then test the two samples in the same way. The specific test steps and instrument parameter settings refer to the determination of carbonate and bicarbonate content in the above samples.

[0116] The spike recovery rate was used to express the accuracy of the test results.

[0117]

[0118] Where: P----spike recovery rate;

[0119] c1----sample concentration before spike, mg / L;

[0120] c2----sample concentration after spike, mg / L;

[0121] c3----Spike concentration, mg / L.

[0122] The present invention also provides an electronic device, which includes: a memory storing executable instructions; a processor, which runs the executable instructions in the memory to implement the above-mentioned method for determining the total alkalinity, carbonate and bicarbonate content of geothermal water.

[0123] The present invention also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the above-mentioned method for determining the total alkalinity, carbonate and bicarbonate content of geothermal water is implemented.

[0124] To facilitate understanding of the solutions and effects of the embodiments of the present invention, four specific application examples are given below. Those skilled in the art should understand that the examples are only for facilitating understanding of the present invention, and any specific details thereof are not intended to limit the present invention in any way.

[0125] Example 1

[0126] This embodiment includes the following steps:

[0127] (1) Prepare the potentiometric titrator according to the instruction manual and use an aqueous pH composite electrode. Calibrate the electrode with buffer solutions of pH 4.00, 7.00, and 10.00.

[0128] (2) Prepare 0.05 mol / L hydrochloric acid standard titration solution and calibrate it to a value of 0.04992 mol / L.

[0129] (3) Set the total alkalinity, carbonate and bicarbonate content calculation formula, titrant type hydrochloric acid and titrant concentration 0.04992 mol / L into the potentiometric titrator.

[0130] (4) Before the experiment, the sample should be restored to room temperature. Take two 30 mL geothermal water samples and place them in 200 mL beakers respectively, and add CO2-free water to 100 mL.

[0131] (5) Set the speed of the rod-shaped spiral stirrer to 6.

[0132] (6) Determination of total alkalinity of samples

[0133] The first sample was titrated using the SET mode, the instrument parameters were set, and the sample was titrated directly using the hydrochloric acid standard titration solution. The endpoint was titrated to pH 4.4, and the volume of the hydrochloric acid standard titration solution consumed, V1, was recorded as 7.6820 mL.

[0134] (7) Determination of carbonate and bicarbonate content in samples

[0135] The second sample was titrated in DET mode. The instrument parameters were set. One drop of KMnO4 was dripped into the sample. The purple color did not disappear. Then the sample was titrated with standard hydrochloric acid solution. The volume V2 of standard hydrochloric acid solution consumed during the first potential jump was recorded as 1.6821 mL. The sample was titrated with standard hydrochloric acid solution. The volume V3 of standard hydrochloric acid solution consumed during the second potential jump was recorded as 7.4207 mL.

[0136] (8) Determination of blank samples

[0137] Use MET mode to measure the blank sample and set the instrument parameters. Take two 100mL portions of CO2-free water, titrate the first portion directly with hydrochloric acid standard titration solution, and record the volume V of the hydrochloric acid standard titration solution consumed. 01 0.1110mL; add 1 drop of KMnO4 to the second blank sample, titrate it with hydrochloric acid standard titration solution, and record the volume V of the hydrochloric acid standard titration solution consumed 02 It is 0.1120mL.

[0138] (9) According to the formula, the total alkalinity of the sample is 630.46 mg / L, the carbonate content is 78.39 mg / L, and the bicarbonate content is 582.65 mg / L.

[0139] Example 2

[0140] This embodiment includes the following steps:

[0141] (1) Prepare the potentiometric titrator according to the instruction manual and use an aqueous pH composite electrode. Calibrate the electrode with buffer solutions of pH 4.00, 7.00, and 10.00.

[0142] (2) Prepare 0.025 mol / L hydrochloric acid standard titration solution and calibrate it to a value of 0.02494 mol / L.

[0143] (3) Set the total alkalinity, carbonate and bicarbonate content calculation formula, titrant type hydrochloric acid and titrant concentration 0.02494 mol / L into the potentiometric titrator.

[0144] (4) Before the experiment, the sample should be restored to room temperature. Take two 30 mL geothermal water samples and place them in 200 mL beakers respectively, and add CO2-free water to 100 mL.

[0145] (5) Set the speed of the rod-shaped spiral stirrer to 6.

[0146] (6) Determination of total alkalinity of samples

[0147] The first sample was titrated using the SET mode, instrument parameters were set, and the sample was titrated directly using the hydrochloric acid standard titration solution. The endpoint was titrated to pH 4.4, and the volume of the hydrochloric acid standard titration solution consumed, V1, was recorded as 10.4580 mL.

[0148] (7) Determination of carbonate and bicarbonate content in samples

[0149] The second sample uses the DET mode, sets the instrument parameters, drips 1 drop of KMnO4 into the sample, the lavender color does not disappear, and then uses the hydrochloric acid standard titration solution to titrate it. Record the volume V2 of the hydrochloric acid standard titration solution consumed during the first potential jump as 3.4600mL, continue to use the hydrochloric acid standard titration solution to titrate the sample, and record the volume V3 of the hydrochloric acid standard titration solution consumed during the second potential jump as 9.9124mL.

[0150] (8) Determination of blank samples

[0151] Use MET mode to measure the blank sample and set the instrument parameters. Take two 100mL portions of CO2-free water, titrate the first portion directly with hydrochloric acid standard titration solution, and record the volume V of the hydrochloric acid standard titration solution consumed. 01 0.2000mL; add 1 drop of KMnO4 to the second blank sample, titrate it with hydrochloric acid standard titration solution, and record the volume V of the hydrochloric acid standard titration solution consumed 02 It is 0.2230mL.

[0152] (9) According to the formula, the total alkalinity of the sample is 426.77 mg / L, the carbonate content is 80.74 mg / L, and the bicarbonate content is 321.94 mg / L.

[0153] Example 3

[0154] The precision of the determination method of total alkalinity, carbonate and bicarbonate content of geothermal water was tested by using a potentiometric titrator, and the magnitude of the random error existing in the present invention, that is, the reproducibility of the method, was detected by the degree of proximity of multiple measurement results.

[0155] Table 3 lists the results of the precision test of the determination method of total alkalinity, carbonate and bicarbonate content in geothermal water.

[0156] Table 3 Precision test results of the determination methods for total alkalinity, carbonate and bicarbonate content of geothermal water

[0157]

[0158] As shown in Table 3, the maximum relative standard deviation of the total alkalinity of geothermal water is 0.44%, the maximum relative standard deviation of the carbonate content is 0.52%, and the maximum relative standard deviation of the bicarbonate content is 0.43%. It can be seen that the method for determining the total alkalinity, carbonate and bicarbonate content of geothermal water according to the present invention has good reproducibility.

[0159] Example 4

[0160] The method for determining the total alkalinity, carbonate and bicarbonate content of geothermal water was tested by adding a spike recovery test using sodium carbonate and sodium bicarbonate standard substances using a potentiometric titrator. The accuracy of the present invention was tested by examining the degree of proximity between the test results of the present invention and the reference value.

[0161] Table 4 lists the results of the spike recovery test for the determination of total alkalinity, carbonate, and bicarbonate contents in geothermal water.

[0162] Table 4 Results of spike recovery test for determination of total alkalinity, carbonate and bicarbonate content in geothermal water

[0163]

[0164] As shown in Table 4, the recovery rate of the total alkalinity of geothermal water is 98.02% to 100.93%, the recovery rate of the carbonate content is 99.45% to 102.46%, and the recovery rate of the bicarbonate content is 97.94% to 101.88%. Therefore, the accuracy of the total alkalinity, carbonate and bicarbonate contents of geothermal water determined according to the present invention is high.

[0165] Those skilled in the art should understand that the purpose of the above description of the embodiments of the present invention is only to exemplarily illustrate the beneficial effects of the embodiments of the present invention, and is not intended to limit the embodiments of the present invention to any given examples.

[0166] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for determining the total alkalinity, carbonate and bicarbonate content of geothermal water, characterized in that: include: Step 1: Take two parallel geothermal water samples and two blank samples; Step 2: For the first geothermal water parallel sample, use a hydrochloric acid standard titration solution to titrate to a first pH value, and record the volume V1 of the consumed hydrochloric acid standard titration solution; Step 3: Repeat step 2 for the first blank sample and record the volume V of the hydrochloric acid standard titration solution consumed. 01 ; Step 4: For the second geothermal water parallel sample, KMnO4 is dripped until the solution turns into light purple, and the hydrochloric acid standard titration solution is used for titration, and the volume V2 of the hydrochloric acid standard titration solution consumed during the first potential jump and the volume V3 of the hydrochloric acid standard titration solution consumed during the second potential jump are recorded; Step 5: Repeat step 4 for the second blank sample and record the volume V of the hydrochloric acid standard titration solution consumed. 02 ; Step 6: According to V1, V 01 , V2, V3, V 02 Calculate total alkalinity, carbonate content, and bicarbonate content.

2. The method for determining the total alkalinity, carbonate and bicarbonate content of geothermal water according to claim 1, wherein: The step 1 comprises: Return the sample to room temperature, take two parallel samples of geothermal water of 30 to 100 mL and place them in 200 mL beakers respectively. If the sample volume is less than 100 mL, add CO2-free water to make it up to 100 mL. A rod-shaped spiral stirrer is used for stirring; Take two 100 mL portions of de-CO2 water as blank samples.

3. The method for determining the total alkalinity, carbonate and bicarbonate content of geothermal water according to claim 2, wherein: The rotation speed of the rod-shaped spiral stirrer is 6.

4. The method for determining the total alkalinity, carbonate and bicarbonate content of geothermal water according to claim 1, wherein: The first pH is pH 4.

4.

5. The method for determining the total alkalinity, carbonate and bicarbonate contents of geothermal water according to claim 1, wherein: The total alkalinity is: Where, JD is the total alkalinity of the sample, c(HCl) is the concentration of the standard hydrochloric acid titration solution, V s is the volume of geothermal water sample.

6. The method for determining the total alkalinity, carbonate and bicarbonate contents of geothermal water according to claim 1, wherein: The carbonate content is: Among them, c(CO3 2- ) is the carbonate content in the sample, c(HCl) is the concentration of the standard hydrochloric acid titration solution, V s is the volume of geothermal water sample.

7. The method for determining the total alkalinity, carbonate and bicarbonate contents of geothermal water according to claim 1, wherein: The bicarbonate content is: Among them, c(HCO3 - ) is the bicarbonate content in the sample, c(HCl) is the concentration of the standard hydrochloric acid titration solution, V s is the volume of geothermal water sample.

8. The method for determining the total alkalinity, carbonate and bicarbonate contents of geothermal water according to claim 1, wherein: The step 4 also includes: If the sample does not contain carbonate, there is only one potential jump in the entire titration process, that is, V2 is zero, and the volume V3 of the standard hydrochloric acid titration solution consumed during the jump is recorded.

9. An electronic device, characterized in that: The electronic device comprises: A memory storing executable instructions; A processor, wherein the processor runs the executable instructions in the memory to implement the method for determining the total alkalinity, carbonate and bicarbonate content of geothermal water according to any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for determining the total alkalinity, carbonate and bicarbonate content of geothermal water according to any one of claims 1 to 8 is implemented.

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