Nanofiltration and electric field coupled ion separation device

Abstract

The invention belongs to the technical field of ion separation, and particularly relates to a nanofiltration and electric field coupled ion separation device, and a dead end filtering device comprises a nanofiltration membrane used for preliminarily filtering large-particle impurities in a solution; the upper and lower porous electrode plates are respectively positioned above and below the nanofiltration membrane and are respectively connected with a positive electrode and a negative electrode of a power supply, and the power supply applies an electric field on the surfaces of the porous electrode plates; and an air compressor is arranged above the dead-end filtering device and is used for providing pressure for the dead-end filtering device so as to push a solution to pass through the dead-end filtering device and the porous electrode plate. The nanofiltration membrane provided by the invention has the capability of selectively separating ions, and the electric field device further enhances the separation effect and improves the separation efficiency and selectivity. The device is simple in structure and convenient to operate, and can effectively solve the problems of low efficiency, poor selectivity and the like in a traditional separation method.

Description

Technical Field

[0001] The present invention belongs to the technical field of ion separation, and specifically relates to an ion separation device coupled with nanofiltration and electric field, which is used to achieve efficient separation of cations with different valences in a salt solution with the assistance of an electric field. Background Art

[0002] In the fields of chemical analysis, materials science, and environmental science, the separation of cations of different valences is an important technical requirement. Traditional cation separation methods usually rely on technologies such as chemical precipitation and ion exchange resins, but these methods have limitations such as low separation efficiency, insufficient selectivity, complex operation, and the potential generation of large amounts of waste liquid. In recent years, nanofiltration technology has received widespread attention in the field of ion separation due to its advantages such as high efficiency and energy saving. However, nanofiltration membranes still face the trade-off between selectivity and flux during the separation process, and concentration polarization is easily generated on the membrane surface, resulting in limited separation efficiency. In order to overcome these shortcomings, researchers have begun to explore new methods of coupling electric fields with nanofiltration technology in order to achieve more efficient and precise ion separation. Summary of the Invention

[0003] The present invention aims to provide an ion separation device that couples nanofiltration with an electric field. Through a rationally designed structure and electric field configuration, it can efficiently and accurately separate cations of different valences while overcoming the problems existing in traditional nanofiltration technology. The specific technical solution is as follows:

[0004] An ion separation device coupled with nanofiltration and electric field, comprising a dead-end filter device and two upper and lower porous electrode sheets;

[0005] The dead-end filtration device includes a nanofiltration membrane for preliminary filtration of large particle impurities in the solution;

[0006] The upper and lower porous electrode sheets are respectively located above and below the nanofiltration membrane. The upper and lower porous electrode sheets are respectively connected to the positive and negative poles of the power supply, and the power supply applies an electric field on the surface of the porous electrode sheets.

[0007] An air compressor is provided above the dead-end filtering device, and the air compressor provides pressure for the dead-end filtering device to push the solution through the dead-end filtering device and the porous electrode sheet.

[0008] When the device is activated, the pressure generated by the air compressor pushes the solution through the dead-end filter, removing large impurities. The filtered solution then flows to the porous electrode sheet, where the electric field provided by the power supply separates the ions in the solution according to their charge and valence. The selectivity of the nanofiltration membrane, combined with the driving force of the electric field, effectively separates cations of different valences. The separation effect can be further optimized by adjusting the voltage and current of the power supply, as well as the pressure of the air compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a structural schematic diagram of the present invention;

[0010] Figure 2 The effects of the NF1 membrane of the embodiment on the retention performance of NaCl, MgCl2, and AlCl3 under no electric field conditions are shown;

[0011] Figure 3 The effects of the MOF membrane of the embodiment on the retention performance of NaCl, MgCl2, and AlCl3 under the condition of no electric field are shown;

[0012] Figure 4 The effects of the NF1 membrane of the embodiment on the retention performance of NaCl, MgCl2, and AlCl3 under the forward electric field condition are shown;

[0013] Figure 5 The effects of the MOF membrane of the embodiment on the retention performance of NaCl, MgCl2, and AlCl3 under the condition of a positive electric field are shown;

[0014] Figure 6 The effects of the NF1 membrane of the embodiment on the retention performance of NaCl, MgCl2, and AlCl3 under reverse electric field conditions are shown;

[0015] Figure 7 The effects of the MOF membrane of the embodiment on the retention performance of NaCl, MgCl2, and AlCl3 under reverse electric field conditions are shown;

[0016] Figure 8 Schematic diagram of the forward electric field of the embodiment

[0017] Figure 9 Schematic diagram of the reverse electric field of the embodiment. DETAILED DESCRIPTION

[0018] The specific technical solutions of the present invention are described with reference to the accompanying drawings.

[0019] like Figure 1 As shown, a nanofiltration and electric field coupled ion separation device includes a dead-end filter device 2 and two upper and lower porous electrode sheets 3;

[0020] The dead-end filtering device 2 is provided with a nanofiltration membrane 4 for preliminarily filtering large particles of impurities in the solution; protecting the subsequent nanofiltration membrane from being blocked, and ensuring that the solution can smoothly pass through the nanofiltration membrane for ion separation.

[0021] The upper and lower porous electrode sheets 3 are located above and below the nanofiltration membrane 4 and are used to apply an electric field during the nanofiltration process.

[0022] An air compressor 1 is provided above the dead-end filter device 2, and the air compressor 1 provides pressure for the dead-end filter device 2, pushing the solution through the dead-end filter device 2 and the porous electrode sheet 3;

[0023] The two porous electrode sheets 3 are connected to the positive and negative terminals of a power supply, which applies an electric field to their surfaces. The porous electrode sheets 3 are designed to allow solution to pass through while simultaneously applying an electric field to enhance ion migration and separation. The porous structure helps evenly distribute the electric field, improving the efficiency of electric field-assisted separation.

[0024] The power supply provides a stable electric field for the porous electrode sheet 3. The power supply needs to be designed to provide sufficient voltage and current to ensure the stability and effectiveness of the electric field. The power supply is a DC power supply to provide a continuous electric field.

[0025] The device provided by the present invention was subjected to an effect comparison experiment, and the experimental results were as follows:

[0026] 1. Effects of NF1 membrane and MOF membrane on the retention performance of NaCl, MgCl2, and AlCl3 under no electric field conditions (pressure 3 bar)

[0027] Depend on Figure 2 and Figure 3 As shown in the figure, under no electric field conditions, the NF1 membrane and MOF membrane all promote the retention of sodium chloride, magnesium chloride, and aluminum chloride. Under no electric field conditions, the MOF membrane has a significantly lower retention effect on sodium chloride than the NF1 membrane, and has no significant effect on magnesium chloride and aluminum chloride.

[0028] 2. NF1 membrane and MOF membrane in Figure 8 The effects of the forward electric field on the retention performance of NaCl, MgCl2, and AlCl3 (pressure 3 bar) are shown.

[0029] Depend on Figure 4 and Figure 5 As shown in the figure, under the condition of positive electric field, compared with NF1 membrane, MOF membrane has a promoting effect on the retention of sodium chloride, and has an inhibitory effect on the retention of magnesium chloride and aluminum chloride. And the retention rate of sodium chloride in the positive electric field of MOF membrane is 40.78%, which is significantly improved compared with the retention rate under the condition of no electric field, while the retention rates of magnesium chloride and aluminum chloride are both less than -100%, indicating that the positive electric field in MOF membrane has a significant effect on the retention of sodium chloride. + The interception promotion effect is more obvious, and the effect on Mg 2+ and Al 3+ The inhibitory effect is more obvious, and the Mg 2+ The inhibitory effect is stronger than that of Al 3+ .

[0030] 3. NF1 membrane and MOF membrane in Figure 9The effects of reverse electric field on the retention performance of NaCl, MgCl2, and AlCl3 (pressure 3 bar)

[0031] Depend on Figure 6 and Figure 7 As shown in the figure, under the reverse electric field condition, compared with the NF1 membrane, the MOF membrane has a promoting effect on the retention of magnesium chloride and aluminum chloride, and the promoting effect on the retention of aluminum chloride is more obvious, and it has an inhibitory effect on the retention of sodium chloride. The sodium chloride retention rate of the MOF membrane under the reverse electric field is -8.74%, indicating that the MOF membrane has a strong effect on the retention of sodium chloride under the reverse electric field. + The retention rates of magnesium chloride and aluminum chloride are both greater than 60%, which are significantly improved compared with no electric field and positive electric field, indicating that the retention rate of Mg 2+ and Al 3+ It promotes penetration.

Claims

1. An ion separation device coupled with nanofiltration and electric field, characterized in that: It comprises a dead-end filtering device (2) and two upper and lower porous electrode sheets (3); The dead-end filtering device (2) includes a nanofiltration membrane (4) for preliminarily filtering large particles of impurities in the solution; The upper and lower porous electrode sheets (3) are respectively located above and below the nanofiltration membrane (4), and the upper and lower porous electrode sheets (3) are respectively connected to the positive and negative poles of a power supply, and the power supply applies an electric field on the surface of the porous electrode sheets (3); An air compressor (1) is provided above the dead-end filter device (2), and the air compressor (1) provides pressure for the dead-end filter device (2), pushing the solution through the dead-end filter device (2) and the porous electrode sheet (3).

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