Method for determining operating parameters of electrodialysis device

Abstract

The invention discloses a method for determining operating parameters of an electrodialysis device, which belongs to the technical field of electrodialysis, and comprises the following steps: calculating the resistance of an ion exchange membrane, and if the resistance of the ion exchange membrane is smaller than the resistance of the ion exchange membrane in the specification of an ion exchange membrane product, carrying out subsequent steps; in the first mode, the required operation time is estimated according to the concentration of the solution to be treated, the set flow rate, the volume of the solution to be treated and the selected operation voltage, and the volume of the solution to be treated is estimated according to the concentration of the solution to be treated, the set operation time and the selected operation voltage. In the second mode, the required operation time is estimated according to the concentration of the to-be-treated solution, the set flow rate, the volume of the to-be-treated solution and the selected operation current, and the volume of the to-be-treated solution is estimated according to the concentration of the to-be-treated solution, the set operation time and the selected operation current. Therefore, the problems that an existing electrodialysis mass transfer model is too complex and operation parameters of an electrodialysis device cannot be rapidly determined are solved.

Description

Technical Field

[0001] The invention relates to the technical field of electrodialysis devices, and in particular to a method for determining operating parameters of an electrodialysis device. Background Art

[0002] Electrodialysis (ED) is an electrically driven membrane separation technology widely used in separation, concentration and purification, especially in water treatment, desalination, food processing, chemical separation and other fields. The electrodialysis device applies an electric field to allow charged ions in water to pass through a selectively permeable ion exchange membrane, thereby achieving the migration of ions from the solution and removing salts or other charged solutes. During the electrodialysis operation, the working efficiency and operating cost of the equipment are affected by multiple operating parameters, such as voltage, current, flow rate, solution concentration, etc. Therefore, determining the appropriate operating parameters is the key to the electrodialysis process.

[0003] In current research, relevant researchers have tried to design many mathematical models to simulate the material separation process based on electrodialysis, and explore the transfer laws of ions and other uncharged substances in combination with flow state, current density, etc., and determine the optimal separation operation strategy on this basis. There are mainly Maxwell-Stefan model, Nernst-Planck model, Kedem-Katchalsky model, fuzzy logic model, artificial neural network model and semi-empirical model. These electrodialysis process mass transfer modeling studies provide theoretical guidance for electrodialysis structure design and operation process optimization, which helps to guide the improvement of electrodialysis separation efficiency. However, these methods lack universality and simplicity. The formulas are complex and require the help of programming and related software for calculation and simulation.

[0004] To operate an electrodialysis device, the volume of solution to be processed and the duration of operation need to be clearly determined. However, there is currently no simple and universal method to accurately determine the volume of solution and the duration of operation that the device can process for different solutions and flow rates. Summary of the invention

[0005] The purpose of the present invention is to provide a method for determining the operating parameters of an electrodialysis device. For the set target concentration required for solution treatment, the volume of solution that can be treated by the electrodialysis device within an ideal time can be quickly determined by the change law of voltage and current under different solutions and different flow rates, and the time required to treat a quantitative solution can be estimated. This solves the problem that the current electrodialysis mass transfer model is too complicated and the operating parameters of the electrodialysis device cannot be quickly determined. The present invention is achieved through the following technical solutions.

[0006] In a first aspect, the present invention provides a method for determining operating parameters of an electrodialysis device, comprising:

[0007] Determine the maximum voltage at which an electrodialysis unit can operate ;

[0008] Obtaining the starting voltage based on an electrodialysis device without an ion exchange membrane and device resistance ;

[0009] Obtaining the system resistance of an electrodialysis system based on a complete electrodialysis device containing an ion exchange membrane , and calculate the resistance of the ion exchange membrane based on the device resistance and system resistance , if the resistance of the ion exchange membrane If the resistance of the ion exchange membrane is less than the standard value, the following steps are performed: represents the concentration of the solution, The serial number indicating the concentration, represents the solution flow rate, Ordinal number indicating flow rate:

[0010] In the first mode, according to the concentration of the solution to be treated , Planned flow rate , required volume of treatment solution and the selected operating voltage , estimate the time required for the operation , or according to the concentration of the solution to be treated , Planned flow rate , set operation time and the selected operating voltage , estimate the volume of solution that can be processed .

[0011] Alternatively, in the second mode, according to the concentration of the solution to be treated , Planned flow rate , required volume of treatment solution and the selected operating current , estimate the time required for the operation , or according to the concentration of the solution to be treated , Planned flow rate , set operation time and the selected operating current , estimate the volume of solution that can be processed .

[0012] In practical applications, it is necessary to first calculate the resistance of the ion exchange membrane in the electrodialysis device. , the calculated membrane resistance The membrane resistance is different from the membrane resistance in the ion exchange membrane product manual provided by the membrane manufacturer. Under different solution ion concentrations or flow rates, the measured Should be less than If it is greater than or equal to this value, it means that there is a problem with the measurement or the membrane is damaged, and it is necessary to check and troubleshoot. Only after it is confirmed that there is no problem, can the subsequent steps be carried out.

[0013] Since the working state of the electrodialysis device can be selected in constant voltage mode and constant current mode, the resistance of the ion exchange membrane in the electrodialysis device used in the experiment is determined. After there are no problems, calculate the volume of solution to be treated in the constant voltage mode. From the concentration Dilute to concentration Total time And at this time, the solution to be treated is in the set operation time Next, from the concentration Dilute to concentration The maximum volume that can be processed is ; Calculate the volume of solution to be treated in the constant current mode From the concentration Dilute to concentration Total time And at this time, the solution to be treated is in the set operation time Next, from the concentration Dilute to concentration The maximum volume that can be processed is The calculation methods in the above two modes can respectively enable the electrodialysis device to estimate the volume of solution that can be processed within the ideal time, or estimate the time required to process a quantitative solution, thereby solving the problem that the current electrodialysis mass transfer model is too complicated.

[0014] Optionally, the maximum voltage that the electrodialysis device can withstand is According to the number of ion exchange membranes Decide: ,and , is the voltage corresponding to the limiting current density.

[0015] Optionally, the device resistance is obtained based on the electrodialysis device without ion exchange membrane The method comprises: applying a voltage from 0 V to 1 V step by step to the electrodialysis device without an ion exchange membrane. , each level increases The voltage is kept for thirty seconds to two minutes until the current value is stable, and the device current at each voltage level is recorded, and a current-voltage curve is drawn. Based on the current-voltage curve, the device resistance of the electrodialysis device without an ion exchange membrane is obtained. .

[0016] Optionally, the system resistance of the electrodialysis system is obtained based on a complete electrodialysis device containing an ion exchange membrane. , including: for a specified solution from low concentration to high concentration, and at a specified flow rate, the complete electrodialysis device containing the ion exchange membrane gradually increases the voltage from 0 V to , each level increases The voltage is kept for thirty seconds to two minutes until the current value stabilizes. The device current at each voltage level is recorded and the current-voltage curve is drawn;

[0017] Change the flow rate to record the current-voltage curve at different flow rates, and obtain the system resistance at different flow rates and different concentrations through the current-voltage curve at different flow rates ;

[0018] The resistance of the ion exchange membrane is calculated based on the device resistance and the system resistance. Calculated by the following formula:

[0019] .

[0020] Optionally, calculate the resistance of the ion exchange membrane After that, if the resistance of the ion exchange membrane If it is greater than or equal to the standard value of the ion exchange membrane resistance, it is determined that there is a problem with the measurement or the ion exchange membrane is damaged. After troubleshooting the measurement process or inspecting the ion exchange membrane and confirming that there is no problem, execute the subsequent steps.

[0021] Optionally, in the first mode, according to the concentration of the solution to be treated , Planned solution flow rate , required volume of treatment solution and the selected operating voltage , , estimate the time required for the operation include:

[0022] Proposed solution flow rate is the measured value within the measured flow rate range, and the concentration of the solution to be treated The concentration range before dilution is , is the solution concentration serial number of the measured current-voltage curve;

[0023] Device current before dilution , The concentration of the solution is Solution flow rate The slope of the current-voltage curve is The concentration of the solution is Solution flow rate The slope of the current-voltage curve is

[0024] Calculate the concentration of the solution to be treated from Dilute to concentration Time required , ,

[0025] Calculate the concentration of the solution to be treated from Dilute to concentration Time required ,in,

[0026] In the above formula, N A is Avogadro's constant,

[0027] The volume of solution to be treated is the volume of solution required for dilution Next, from the concentration Dilute to concentration The total time is , calculated by the following formula:

[0028] .

[0029] Optionally, in the first mode, according to the concentration of the solution to be treated , Planned flow rate , set operation time and the selected operating voltage , , estimate the volume of solution that can be processed include:

[0030] Proposed solution flow rate is the measured value within the measured flow rate range, and the concentration of the solution to be treated c a The concentration range before dilution is , is the solution concentration serial number of the measured current-voltage curve;

[0031] Device current before dilution , The concentration of the solution is Solution flow rate The slope of the current-voltage curve is The concentration of the solution is Solution flow rate The slope of the current-voltage curve is

[0032] The solution to be treated is kept for the set operation time. Next, from the concentration Dilute to concentration The maximum volume that can be processed is , calculated by the following formula:

[0033] , where N A is Avogadro's constant.

[0034] Optionally, in the second mode, according to the concentration of the solution to be treated , Planned flow rate , required volume of treatment solution and the selected operating current , estimate the time required for the operation include:

[0035] Proposed solution flow rate is the measured value within the measured flow rate range, and the concentration of the solution to be treated The concentration range before dilution is , is the solution concentration serial number of the measured current-voltage curve;

[0036] Calculate the concentration of the solution to be treated from Dilute to concentration Time required , ,

[0037] Calculate the concentration of the solution to be treated from Dilute to concentration Time required , ,in,

[0038] In the above formula, N A is Avogadro's constant,

[0039] The volume of solution required for treatment is the volume of solution required for dilution Next, from the concentration Dilute to concentration The total time is , calculated by the following formula:

[0040] , .

[0041] Optionally, in the second mode, according to the concentration of the solution to be treated , Planned flow rate , set operation time and the selected operating current , estimate the volume of solution that can be processed include:

[0042] Proposed solution flow rate is the measured value within the measured flow rate range, and the concentration of the solution to be treated The concentration range before dilution is , is the solution concentration serial number of the measured current-voltage curve;

[0043] The solution to be treated is kept for the set operation time. Next, from the concentration Dilute to concentration The maximum volume that can be processed is , calculated by the following formula:

[0044] , where N A is Avogadro's constant.

[0045] Optionally, the first mode is a constant voltage mode, and the second mode is a constant current mode.

[0046] Beneficial Effects

[0047] (1) The present invention calculates the current-voltage curve by calculating the device with and without membrane and injecting solutions of different concentrations and flow rates into the device, thereby calculating the resistance of the ion exchange membrane based on the current-voltage curve, and then comparing it with the membrane resistance in the ion exchange membrane product manual provided by the membrane manufacturer to eliminate the problem of ion exchange membrane damage. This is conducive to providing accurate experimental results for subsequent experimental steps.

[0048] (2) The present invention combines the actual situation of the electrodialysis device to introduce the electrodialysis device in two modes to respectively calculate the estimated volume of solution that can be processed by the electrodialysis device within an ideal time, or to estimate the time required to process a quantitative solution, thereby solving the problem that the current electrodialysis mass transfer model is too complicated and the operating parameters of the electrodialysis device cannot be quickly determined. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 FIG. 1 is a schematic flow chart of a method for determining operating parameters of an electrodialysis device according to an embodiment of the present invention;

[0050] Figure 2 Shown is a current-voltage curve diagram of the electrodialysis device of the present invention when no ion exchange membrane is provided;

[0051] Figure 3 The current-voltage curve diagram of the ion exchange membrane in the electrodialysis device of the present invention at the same flow rate and different concentrations is shown;

[0052] Figure 4 Shown is a current-voltage curve diagram during the determination of the limiting current density of the electrodialysis device of the present invention;

[0053] Figure 5 The figure shows a schematic diagram of the change of the conductivity of the diluent over time during the electrodialysis process of the electrodialysis device of the present invention. DETAILED DESCRIPTION

[0054] The following is a further description in conjunction with the accompanying drawings and specific embodiments. In the description of the present invention, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features.

[0055] Example 1

[0056] This embodiment introduces a method for determining operating parameters of an electrodialysis device, including:

[0057] Determine the maximum voltage at which an electrodialysis unit can operate ;

[0058] Obtaining the starting voltage based on an electrodialysis device without an ion exchange membrane and device resistance ;

[0059] Obtaining the system resistance of an electrodialysis system based on a complete electrodialysis device containing an ion exchange membrane , and calculate the resistance of the ion exchange membrane based on the device resistance and system resistance , if the resistance of the ion exchange membrane If the resistance of the ion exchange membrane is less than the standard value, the following steps are performed: represents the concentration of the solution, The serial number indicating the concentration, represents the solution flow rate, Ordinal number indicating flow rate:

[0060] In the first mode, according to the concentration of the solution to be treated , Planned flow rate , required volume of treatment solution and the selected operating voltage , estimate the time required for the operation , or according to the concentration of the solution to be treated , Planned flow rate , set operation time and the selected operating voltage , estimate the volume of solution that can be processed .

[0061] Alternatively, in the second mode, according to the concentration of the solution to be treated , Planned flow rate , required volume of treatment solution and the selected operating current , estimate the time required for the operation , or according to the concentration of the solution to be treated , Planned flow rate , set operation time and the selected operating current , estimate the volume of solution that can be processed .

[0062] In this embodiment, the method proposed in this embodiment is applicable to a brackish water desalination laboratory electrodialysis device, and the conductivity of the solution is less than 32 mS / cm. This is because if the conductivity concentration exceeds this upper limit, it does not belong to the brackish water range and some rules do not apply.

[0063] In practical applications, it is necessary to first calculate the resistance of the ion exchange membrane in the electrodialysis device. , the calculated membrane resistance The membrane resistance is different from the membrane resistance in the ion exchange membrane product manual provided by the membrane manufacturer. Under different solution ion concentrations or flow rates, the measured Should be less than If it is greater than or equal to this value, it means that there is a problem with the measurement or the membrane is damaged, and it is necessary to check and troubleshoot. Only after it is confirmed that there is no problem, can the subsequent steps be carried out.

[0064] Since the working state of the electrodialysis device can be selected in constant voltage mode and constant current mode, the resistance of the ion exchange membrane in the electrodialysis device used in the experiment is determined. After there are no problems, calculate the volume of solution to be treated in the constant voltage mode. From the concentration Dilute to concentration Total time And at this time, the solution to be treated is in the set operation time Next, from the concentration Dilute to concentration The maximum volume that can be processed is ; Calculate the volume of solution to be treated in the constant current mode From the concentration Dilute to concentration Total time And at this time, the solution to be treated is in the set operation time Next, from the concentration Dilute to concentration The maximum volume that can be processed is The calculation methods in the above two modes can respectively enable the electrodialysis device to estimate the volume of solution that can be processed within the ideal time, or estimate the time required to process a quantitative solution, thereby solving the problem that the current electrodialysis mass transfer model is too complicated.

[0065] Example 2

[0066] Based on Example 1, this example introduces a specific implementation process of a method for determining operating parameters of an electrodialysis device, such as Figure 1 As shown, specifically including the following:

[0067] 1. Calculate the resistance of ion exchange membrane

[0068] First, determine the voltage range in which the electrodialysis device of this embodiment can operate. In this embodiment, the maximum voltage that the electrodialysis device can withstand is The number of ion exchange membranes It is determined that the voltage that a pair of ion exchange membranes can withstand is 1.5V, and . Different solution concentrations Or different flow rates Under this condition, the voltage corresponding to the limiting current density of the device is , which can be determined by the current-voltage method or the pH method and When the electrodialysis device without ion exchange membrane can detect current, the corresponding voltage is determined as the starting voltage of the device. When the electrodialysis device containing an ion exchange membrane can detect the current, the voltage is consistent with or not much different from the starting voltage of the membraneless device, which is also recorded as .

[0069] After determining the voltage range in which the electrodialysis device can operate, an electrodialysis device without an ion exchange membrane is assembled. At this time, the electrodialysis device only includes electrodes and a separator. In this example, a 0.5 mol / L sodium sulfate solution Na2SO4 is continuously introduced at a flow rate of 5 cm / s, and voltages are applied to the device step by step from 0 V to , each level increases The voltage is kept for thirty seconds to two minutes until the current value stabilizes. Record the device current at each voltage level and draw a current-voltage curve, such as Figure 2 As shown, when the voltage is small, the current may be 0. When it increases to a certain voltage When the voltage increases step by step, the current can be detected in the device. As the voltage increases step by step, the current increases approximately linearly with the voltage. Through curve fitting, the slope of the fitting curve is , the device resistance is In the actual experiment, the starting voltage of some devices is zero, and the starting voltage of some devices is non-zero. If the device cannot remove and replace the membrane, this step can be omitted.

[0070] Then the current-voltage curve of the complete electrodialysis device was measured. Under certain conditions, determine the solution that is passed into the device, such as NaCl, KCl, etc. After determining the type of solution that is passed into the device, for different concentrations The solution was changed from low concentration to high concentration, and the voltage was gradually increased from 0V to , each level increases The voltage is kept at this level for thirty seconds to two minutes until the current value stabilizes. The device current at each voltage level is recorded and a current-voltage curve is drawn, such as Figure 3 As shown, Figure 3 The electrodialysis device contains ion exchange membranes at the same flow rate. Different concentrations In actual experiments, it is necessary to change multiple flow rate values ​​to obtain multiple Figure 3 The current-voltage curve is shown. The slope of the straight line at different flow rates and concentrations is obtained. , and then the device resistance at different flow rates and different feed solution concentrations is obtained , In the actual experiment, the current-voltage curve can be fitted based on different concentrations and flow rates as needed. Then the resistance of the ion exchange membrane under different flow rates and concentrations can be estimated. , .

[0071] The calculated membrane resistance The membrane resistance is different from the membrane resistance in the ion exchange membrane product manual provided by the membrane manufacturer. Under different solution ion concentrations or flow rates, the measured Should be less than If it is greater than this value, it means that there is a problem with the measurement or the membrane is damaged, and it is necessary to check and troubleshoot. Only after it is confirmed that there is no problem, can the subsequent steps be carried out.

[0072] 2. Calculate the operation time and solution volume that the electrodialysis device can handle under different modes

[0073] 2.1 Calculation of the operating time and solution volume that the electrodialysis device can handle in the first mode

[0074] In this embodiment, the first mode is a constant voltage mode.

[0075] In the process of measuring the current-voltage curve, when it is found that the voltage is increased but the current no longer increases linearly, such as Figure 4 As shown, at this time the device reaches the limiting current density state. At this time, the intersection of the fitting lines at both ends is the limiting current, and the corresponding voltage is Generally speaking, for the case where the number of membrane groups is small, ,therefore However, when there are many membrane groups, ,at this time .

[0076] In constant voltage mode, according to the concentration of the solution to be treated , Planned solution flow rate , required volume of treatment solution and the selected operating voltage , , estimate the time required for the operation include:

[0077] Proposed solution flow rate is the measured value within the measured flow rate range, and the concentration of the solution to be treated The concentration range before dilution is , is the solution concentration serial number of the measured current-voltage curve;

[0078] Device current before dilution , The concentration of the solution is Solution flow rate The slope of the current-voltage curve is The concentration of the solution is Solution flow rate The slope of the current-voltage curve is

[0079] Calculate the concentration of the solution to be treated from Dilute to concentration Time required , ,

[0080] Calculate the concentration of the solution to be treated from Dilute to concentration Time required ,in,

[0081] In the above formula, N A is Avogadro's constant,

[0082] The volume of solution to be treated is the volume of solution required for dilution Next, from the concentration Dilute to concentration The total time is , calculated by the following formula:

[0083] .

[0084] In constant voltage mode, according to the concentration of the solution to be treated , Planned flow rate , set operation time and the selected operating voltage , , estimate the volume of solution that can be processed include:

[0085] Proposed solution flow rate is the measured value within the measured flow rate range, and the concentration of the solution to be treated The concentration range before dilution is , is the solution concentration serial number of the measured current-voltage curve;

[0086] Device current before dilution , The concentration of the solution is Solution flow rate The slope of the current-voltage curve is The concentration of the solution is Solution flow rate The slope of the current-voltage curve is

[0087] At this time, the solution to be treated is in the set operation time Next, from the concentration Dilute to concentration The maximum volume that can be processed is , calculated by the following formula:

[0088] ,

[0089] Where N A is Avogadro's constant.

[0090] This calculation method is based on the relationship between the conductivity of the diluent and time in a constant voltage electrodialysis experiment, such as Figure 5 As shown in the figure: In the first 95% of the time period, the conductivity and time are linearly related, and the amount of ions that the device can transmit per unit time is almost constant. In the last 5% of the time period, the current in the device is gradually decreasing, and the transmission amount of the device is gradually decreasing, that is, the volume of solution that can be diluted is almost negligible. Therefore, the maximum volume that can be processed can be inferred with a constant current.

[0091] 2.2 Calculation of the operating time and solution volume that the electrodialysis device can handle in the second mode

[0092] In this embodiment, the second mode is a constant current mode.

[0093] In constant current mode, according to the concentration of the solution to be treated , Planned flow rate , required volume of treatment solution and the selected operating current , estimate the time required for the operation include:

[0094] Proposed solution flow rate is the measured value within the measured flow rate range, and the concentration of the solution to be treated The concentration range before dilution is , is the solution concentration serial number of the measured current-voltage curve;

[0095] Calculate the concentration of the solution to be treated from Dilute to concentration Time required , ,

[0096] Calculate the concentration of the solution to be treated from Dilute to concentration Time required , ,in,

[0097] In the above formula, N A is Avogadro's constant,

[0098] The volume of solution required for treatment is the volume of solution required for dilution Next, from the concentration Dilute to concentration The total time is , calculated by the following formula:

[0099] , .

[0100] In constant current mode, according to the concentration of the solution to be treated , Planned flow rate , set operation time and the selected operating current , estimate the volume of solution that can be processed include:

[0101] Proposed solution flow rate is the measured value within the measured flow rate range, and the concentration of the solution to be treated The concentration range before dilution is , is the solution concentration serial number of the measured current-voltage curve;

[0102] At this time, the solution to be treated is in the set operation time Next, from the concentration Dilute to concentration The maximum volume that can be processed is , calculated by the following formula:

[0103] , where N A is Avogadro's constant.

[0104] Figure 1 1 is a flow chart of a method for determining operating parameters of an electrodialysis device. This flow chart only shows the logical sequence of the method described in this embodiment. In other possible embodiments of the present invention, different methods may be used without conflict. Figure 1 The steps shown or described are accomplished in the order shown.

[0105] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which all fall within the protection of the present invention.

Claims

1. A method for determining operating parameters of an electrodialysis device, characterized in that: include: Determine the maximum voltage at which an electrodialysis unit can operate ; Obtaining the starting voltage based on an electrodialysis device without an ion exchange membrane and device resistance ; Obtaining the system resistance of an electrodialysis system based on a complete electrodialysis device containing an ion exchange membrane , and calculate the resistance of the ion exchange membrane based on the device resistance and system resistance , if the resistance of the ion exchange membrane If the resistance of the ion exchange membrane is less than the standard value, the following steps are performed: represents the concentration of the solution, The serial number indicating the concentration, represents the solution flow rate, Ordinal number indicating flow rate: In the first mode, according to the concentration of the solution to be treated , Planned flow rate , required volume of treatment solution and the selected operating voltage , estimate the time required for the operation , or according to the concentration of the solution to be treated , Planned flow rate , set operation time and the selected operating voltage , estimate the volume of solution that can be processed ; Alternatively, in the second mode, according to the concentration of the solution to be treated , Planned flow rate , required volume of treatment solution and the selected operating current , estimate the time required for the operation , or according to the concentration of the solution to be treated , Planned flow rate , set operation time and the selected operating current , estimate the volume of solution that can be processed .

2. The method for determining operating parameters of an electrodialysis device according to claim 1, wherein: The maximum voltage that the electrodialysis device can withstand According to the number of ion exchange membranes Decide: ,and , is the voltage corresponding to the limiting current density.

3. The method for determining the operating parameters of an electrodialysis device according to claim 2, wherein: The device resistance is obtained based on the electrodialysis device without ion exchange membrane The method comprises: applying a voltage from 0 V to 1 V step by step to the electrodialysis device without an ion exchange membrane. , each level increases The voltage is kept for thirty seconds to two minutes until the current value is stable, and the device current at each voltage level is recorded, and a current-voltage curve is drawn. Based on the current-voltage curve, the device resistance of the electrodialysis device without an ion exchange membrane is obtained. .

4. The method for determining the operating parameters of an electrodialysis device according to claim 3, wherein: The method of obtaining the system resistance of the electrodialysis system based on a complete electrodialysis device containing an ion exchange membrane , including: for a specified solution from low concentration to high concentration, and at a specified flow rate, the complete electrodialysis device containing the ion exchange membrane gradually increases the voltage from 0 V to , each level increases The voltage is kept for thirty seconds to two minutes until the current value stabilizes. The device current at each voltage level is recorded and the current-voltage curve is drawn; Change the flow rate to record the current-voltage curve at different flow rates, and obtain the system resistance at different flow rates and different concentrations through the current-voltage curve at different flow rates ; The resistance of the ion exchange membrane is calculated based on the device resistance and the system resistance. Calculated by the following formula: 。 5. The method for determining the operating parameters of an electrodialysis device according to claim 1, wherein Calculate the resistance of the ion exchange membrane After that, if the resistance of the ion exchange membrane If it is greater than or equal to the standard value of the ion exchange membrane resistance, it is determined that there is a problem with the measurement or the ion exchange membrane is damaged. After troubleshooting the measurement process or inspecting the ion exchange membrane and confirming that there is no problem, execute the subsequent steps.

6. The method for determining the operating parameters of an electrodialysis device according to claim 1, wherein: In the first mode, according to the concentration of the solution to be treated , Planned solution flow rate , required volume of treatment solution and the selected operating voltage , , estimate the time required for the operation include: Proposed solution flow rate is the measured value within the measured flow rate range, and the concentration of the solution to be treated The concentration range before dilution is , is the solution concentration serial number of the measured current-voltage curve; Device current before dilution , The concentration of the solution is Solution flow rate The slope of the current-voltage curve is The concentration of the solution is Solution flow rate The slope of the current-voltage curve is Calculate the concentration of the solution to be treated from Dilute to concentration Time required , , Calculate the concentration of the solution to be treated from Dilute to concentration Time required ,in, , In the above formula, N A is Avogadro's constant, The volume of solution to be treated is the volume of solution required for dilution Next, from the concentration Dilute to concentration The total time is , calculated by the following formula: 。 7. The method for determining operating parameters of an electrodialysis device according to claim 1, wherein: In the first mode, according to the concentration of the solution to be treated , Planned flow rate , set operation time and the selected operating voltage , , estimate the volume of solution that can be processed include: Proposed solution flow rate is the measured value within the measured flow rate range, and the concentration of the solution to be treated c a The concentration range before dilution is , is the solution concentration serial number of the measured current-voltage curve; Device current before dilution , The concentration of the solution is Solution flow rate The slope of the current-voltage curve is The concentration of the solution is Solution flow rate The slope of the current-voltage curve is The solution to be treated is kept for the set operation time. Next, from the concentration Dilute to concentration The maximum volume that can be processed is , calculated by the following formula: , where N A is Avogadro's constant.

8. The method for determining operating parameters of an electrodialysis device according to claim 1, wherein: In the second mode, according to the concentration of the solution to be treated , Planned flow rate , required volume of treatment solution and the selected operating current , estimate the time required for the operation include: Proposed solution flow rate is the measured value within the measured flow rate range, and the concentration of the solution to be treated The concentration range before dilution is , is the solution concentration serial number of the measured current-voltage curve; Calculate the concentration of the solution to be treated from Dilute to concentration Time required , , Calculate the concentration of the solution to be treated from Dilute to concentration Time required , ,in, , In the above formula, N A is Avogadro's constant, The volume of solution required for treatment is the volume of solution required for dilution Next, from the concentration Dilute to concentration The total time is , calculated by the following formula: ， 。 9. The method for determining operating parameters of an electrodialysis device according to claim 1, wherein: In the second mode, according to the concentration of the solution to be treated , Planned flow rate , set operation time and the selected operating current , estimate the volume of solution that can be processed include: Proposed solution flow rate is the measured value within the measured flow rate range, and the concentration of the solution to be treated The concentration range before dilution is , is the solution concentration serial number of the measured current-voltage curve; The solution to be treated is kept for the set operation time. Next, from the concentration Dilute to concentration The maximum volume that can be processed is , calculated by the following formula: , where N A is Avogadro's constant.

10. The method for determining operating parameters of an electrodialysis device according to claim 1, characterized in that: The first mode is a constant voltage mode, and the second mode is a constant current mode.

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