Preparation method of BMED anti-pollution ion exchange conducting membrane for treating acid crystal water

Abstract

The invention discloses a preparation method of a BMED anti-pollution ion exchange conducting membrane for treating acid crystal water, and belongs to the field of wastewater treatment. The invention aims to solve the problems of poor anti-pollution performance, poor ion selectivity, low ion transmission efficiency and increased energy consumption of the existing ion exchange membrane caused by membrane pollution of the existing ion exchange membrane. The invention provides an innovative ion exchange membrane surface modification strategy, graphene oxide is doped into sulfonated polyethersulfone, meanwhile, a conductive material polypyrrole is introduced, and specifically, the introduction of GO not only optimizes the hydrophilic-hydrophobic balance of the membrane surface, but also improves the surface roughness and the distribution of fixed charge density. PPy is introduced as a conductive material, the conductivity of the whole membrane is improved, pollutant electrophoresis separation is adopted under the participation of an external electric field, and the scaling phenomenon on the surface of the membrane is effectively relieved through the multi-layer surface modification strategy, so that the anti-pollution performance of the membrane is greatly improved.

Description

Technical Field

[0001] The present invention belongs to the field of wastewater treatment, and particularly relates to a preparation method of a BMED anti-pollution ion exchange conductive membrane for treating acid crystal water. Background Art

[0002] Electrodialysis (ED) and bipolar membrane electrodialysis (BMED) are usually used for the recycling and reuse of acid crystal wastewater in pharmaceutical factories. In the BMED technology, the optimal selection of membrane materials, energy consumption, membrane fouling, and membrane life are important factors affecting the sustainability of the process. During the process of treating acid crystal water, the BMED process is sustainable because of its cost-effectiveness, high recovery rate, and good service life. The BMED process using ion exchange membranes is suitable for removing salts in pharmaceutical factories, recovering the effective acid and alkali components in acid crystal water, and improving the process efficiency. However, membrane fouling is very sensitive to the BMED process. This is because chemical and physical interactions form a fouling layer on the membrane surface, resulting in scaling phenomena that increase the resistance of the ion exchange membrane and reduce the selectivity of the lithium ion exchange membrane, thus significantly increasing energy consumption. The degree of fouling of the ion exchange membrane depends on the surface charge characteristics, the density of charged functional groups, and the nature of the fouling.

[0003] In order to reduce the influence of membrane fouling, surface modification of ion exchange membranes has been proposed by controlling the hydrophilic-hydrophobic balance, fixed charge density, and surface roughness. Based on the bipolar membrane electrodialysis technology, the present invention further proposes surface modification of ion exchange membranes, aiming to improve ion transport efficiency and anti-pollution performance, so as to better meet the urgent requirements of pharmaceutical factories for reuse. Summary of the Invention

[0004] The object of the present invention is to solve the problems of poor anti-pollution performance of existing ion exchange membranes, poor ion selectivity, low ion transport efficiency, and increased energy consumption caused by membrane fouling of existing ion exchange membranes, and to provide a preparation method of a BMED anti-pollution ion exchange conductive membrane for treating acid crystal water.

[0005] The present invention proposes an innovative surface modification strategy for ion exchange membranes. By incorporating graphene oxide (GO) into sulfonated polyethersulfone (SPES) and simultaneously introducing the conductive material polypyrrole (PPy), specifically, the introduction of GO not only optimizes the hydrophilic-hydrophobic balance on the membrane surface but also improves the surface roughness and the distribution of fixed charge density. The introduction of PPy as a conductive material, by enhancing the conductive performance of the overall membrane, enables the electrophoretic detachment of pollutants with the participation of an external electric field. This multi-level surface modification strategy effectively alleviates the fouling phenomenon on the membrane surface, thereby significantly enhancing the anti-fouling performance of the membrane. Compared with traditional ion exchange membranes, the BMED anti-fouling ion exchange conductive membrane for treating acid crystal water prepared by the present invention exhibits significant performance advantages in the bipolar membrane electrodialysis (BMED) process. The successful implementation of the present invention not only provides new ideas for the surface modification of ion exchange membranes but also lays a solid foundation for the wide application of bipolar membrane electrodialysis technology in fields such as industrial wastewater treatment and resource recovery.

[0006] A preparation method of a BMED anti-fouling ion exchange conductive membrane for treating acid crystal water is specifically completed according to the following steps:

[0007] I. Preparation of graphene oxide:

[0008] Mix H2SO4 and H3PO4 in a certain volume ratio to obtain a mixed solution; add graphite powder and KMNO4 powder to the mixed solution, stir for a period of time, then add hydrogen peroxide dropwise, stir, cool to room temperature, add HCl solution dropwise, centrifuge, wash the obtained solid material several times, and finally dry it to obtain graphene oxide powder;

[0009] II. Preparation of sulfonated polyethersulfone:

[0010] ①. Add polyethersulfone to chloroform at 30 °C - 40 °C with stirring until completely dissolved. Under stirring conditions, use a low-temperature funnel to dropwise add HSO3Cl and CHCl3 to the polyethersulfone chloroform solution. After the addition is completed, a precipitate is formed. Filter it, wash the obtained precipitate with water several times, and dry it under vacuum to obtain a reaction product;

[0011] ②. Under the conditions of 30 °C - 40 °C and stirring, add the reaction product to N-methylpyrrolidone, stir for a period of time to obtain a viscous solution; pour the viscous solution onto a clean glass plate and dry it under vacuum. The membrane falls off the glass plate to obtain a sulfonated polyethersulfone film;

[0012] III. Preparation of PPy / GO powder:

[0013] Graphene oxide was added to absolute ethanol, stirred for a period of time, then pyrrole was added, ultrasonicated for a period of time, and then FeCl3 solution was added. The reaction was carried out for a period of time under ice bath conditions. Finally, it was washed with hydrochloric acid and dried to obtain PPy / GO powder;

[0014] IV. Preparation of SPES-PPy / GO ion exchange membrane:

[0015] The sulfonated polyethersulfone film was dissolved in N-methylpyrrolidone and heated and stirred for a period of time to obtain a sulfonated polyethersulfone solution; the PPy / GO powder was added to the sulfonated polyethersulfone solution, ultrasonicated for a period of time, and then evenly dispersed on a clean glass plate using a spatula, and vacuum dried. The membrane peeled off from the glass plate, and then the membrane was immersed in HCl solution for a period of time to obtain the SPES-PPy / GO ion exchange membrane, which is the BMED anti-pollution ion exchange conductive membrane for treating acid crystal water.

[0016] Principle of the present invention:

[0017] In the present invention, by introducing nanomaterials into the polymer matrix, the thermomechanical stability and oxidation stability of the ion exchange membrane are significantly improved. The physical interaction between the nanomaterials and the polymer matrix forms an efficient ion conductive channel, thereby optimizing the ion transport performance. Among them, graphene oxide (GO) is used as a non-resistant material. By precisely regulating the ratio of its hydrophobic and hydrophilic regions, the problems of membrane dehydration and reduction of ion conductivity at high temperatures are effectively solved. The charge functionalization of GO not only endows the material with excellent thermal stability, but also provides a high dielectric constant, and significantly reduces the risk of membrane pollution and fouling by adjusting hydrophilicity and hydrophobicity. At the same time, by incorporating the conductive material PPy, the pollutants are electrophoretically detached by applying an electric field. Therefore, by modifying the surface of the ion exchange membrane, the precise regulation of the hydrophilic-hydrophobic balance, surface roughness and fixed charge density is realized, combined with the dynamic anti-pollution technology to achieve the purpose of reducing membrane pollution and improving stability.

[0018] Beneficial effects of the present invention:

[0019] I. In the present invention, the anti-pollution property of the membrane is synergistically increased by the modified membrane technology and the dynamic anti-pollution technology;

[0020] II. The present invention introduces the conductive material PPy, which can increase the conductivity of the membrane and improve the anti-pollution performance of the membrane with the participation of an external electric field;

[0021] III. The bipolar membrane electrodialysis technology has a strong treatment effect and can efficiently treat the salt components in water to form corresponding acids and alkalis, and complete the treatment and use of acid crystal wastewater;

[0022] IV. The conductivity and hydrophilicity of GO improve the anti-pollution performance of the membrane, and at the same time, the ion conductivity is improved by the dual functional groups of SPES-PPy / GO. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 For the conductivity of the SPES-PPy / GO ion exchange membranes prepared in Comparative Example 1 and Examples 1-5, and the SPES-GO ion exchange membranes prepared in Comparative Examples 2-7. SPECIFIC EMBODIMENTS

[0024] Specific Embodiment 1: A method for preparing a BMED anti-pollution ion exchange conductive membrane for treating acid crystal water is specifically completed according to the following steps:

[0025] I. Preparation of graphene oxide:

[0026] Mix H2SO4 and H3PO4 in a certain volume ratio to obtain a mixed solution; add graphite powder and KMNO4 powder to the mixed solution, stir for a period of time, then add hydrogen peroxide, stir, cool to room temperature, add HCl solution, centrifuge, wash the obtained solid material several times, and finally dry to obtain graphene oxide powder;

[0027] II. Preparation of sulfonated polyethersulfone:

[0028] ①. Add polyethersulfone to chloroform at 30°C - 40°C under stirring until completely dissolved. Under stirring conditions, use a low-temperature funnel to dropwise add HSO3Cl and CHCl3 to the polyethersulfone chloroform solution drop by drop. After the addition is completed, a precipitate is formed. Filter, wash the obtained precipitate with water several times, and dry in vacuum to obtain a reaction product;

[0029] ②. Add the reaction product to N-methylpyrrolidone at 30°C - 40°C under stirring for a period of time to obtain a viscous solution; pour the viscous solution onto a clean glass plate and dry in vacuum. The membrane falls off the glass plate to obtain a sulfonated polyethersulfone thin film;

[0030] III. Preparation of PPy / GO powder:

[0031] Add graphene oxide to absolute ethanol, stir for a period of time, then add pyrrole, perform ultrasonic treatment for a period of time, then add FeCl3 solution, react for a period of time under ice bath conditions, and finally wash with hydrochloric acid and dry to obtain PPy / GO powder;

[0032] IV. Preparation of SPES-PPy / GO ion exchange membrane:

[0033] Dissolve the sulfonated polyethersulfone film in N-methylpyrrolidone, heat and stir for a period of time to obtain a sulfonated polyethersulfone solution; add the PPy / GO powder to the sulfonated polyethersulfone solution, ultrasonicate for a period of time, and then evenly disperse it on a clean glass plate using a spatula, followed by vacuum drying. The film is peeled off from the glass plate, and then the film is immersed in the HCl solution for a period of time to obtain the SPES-PPy / GO ion exchange membrane, which is the BMED anti-fouling ion exchange conductive membrane for treating acid crystal water.

[0034] Specific Embodiment 2: The difference between this embodiment and Specific Embodiment 1 is that the volume ratio of H2SO4 to H3PO4 described in Step 1 is 9:1; the mass fraction of H2SO4 described in Step 1 is 98%; the mass fraction of H3PO4 described in Step 1 is 95%. Other steps are the same as those in Specific Embodiment 1.

[0035] Specific Embodiment 3: The difference between this embodiment and one of Specific Embodiments 1 or 2 is that the mass-volume ratio of the graphite powder, KMNO4 powder and the mixed solution described in Step 1 is (2g - 3g):(13g - 14g):(280mL - 320mL); the mass fraction of the HCl solution described in Step 1 is 5% - 8%; the mass-volume ratio of hydrogen peroxide, HCl solution and the mixed solution described in Step 1 is (15mL - 20mL):(95mL - 105mL):(280mL - 320mL). Other steps are the same as those in Specific Embodiment 1 or 2.

[0036] Specific Embodiment 4: The difference between this embodiment and one of Specific Embodiments 1 to 3 is that in Step 1, graphite powder and KMNO4 powder are added to the mixed solution, stirred for 6h - 7h, then hydrogen peroxide is added dropwise, stirred for 10min - 20min, cooled to room temperature, HCl solution is added dropwise, centrifuged for 10min - 15min, the obtained solid substance is washed 3 to 5 times, and finally dried at 80°C - 100°C to obtain graphene oxide powder. Other steps are the same as those in Specific Embodiments 1 to 3.

[0037] Specific Embodiment 5: The difference between this embodiment and one of Specific Embodiments 1 to 4 is that the mass-volume ratio of polyethersulfone, chloroform, HSO3Cl and CHCl3 described in Step 2① is 30g:200mL:10mL:200mL; the temperature of the low-temperature funnel described in Step 2① is 0°C - 5°C; the obtained precipitate is washed 3 to 5 times with water and then vacuum dried at 50°C - 70°C for 20h - 24h. Other steps are the same as those in Specific Embodiments 1 to 4.

[0038] Specific Embodiment Six: The difference between this embodiment and any one of Specific Embodiments One to Five is as follows: In step 2②, the mass ratio of the reaction product to the volume of N-methylpyrrolidone is 2 g : (15 mL - 16 mL); the stirring time in step 2② is 10 min - 15 min; the temperature of vacuum drying in step 2② is 80 °C - 90 °C, and the vacuum drying time is 10 h - 12 h. Other steps are the same as those in Specific Embodiments One to Five.

[0039] Specific Embodiment Seven: The difference between this embodiment and any one of Specific Embodiments One to Six is as follows: In step 3, the mass-volume ratio of graphene oxide, pyrrole, FeCl3 solution, and absolute ethanol is (0 g - 0.3 g) : (0.5 mL - 1 mL) : (15 mL - 25 mL) : (20 mL - 80 mL); the concentration of the FeCl3 solution in step 3 is 1 mol / L; the concentration of hydrochloric acid in step 3 is 1 mol / L. Other steps are the same as those in Specific Embodiments One to Six.

[0040] Specific Embodiment Eight: The difference between this embodiment and any one of Specific Embodiments One to Seven is as follows: In step 3, graphene oxide is added to absolute ethanol, stirred for 20 min - 40 min, then pyrrole is added, ultrasonic treatment is carried out for 5 min - 10 min, then the FeCl3 solution is added, and the reaction is carried out for 8 h - 12 h under ice bath conditions. Finally, it is washed with hydrochloric acid and dried to obtain PPy / GO powder. Other steps are the same as those in Specific Embodiments One to Seven.

[0041] Specific Embodiment Nine: The difference between this embodiment and any one of Specific Embodiments One to Eight is as follows: In step 4, the temperature of heating and stirring is 70 °C - 80 °C, and the stirring time is 3 h - 4 h; the mass fraction of the sulfonated polyether sulfone solution in step 4 is 10% - 15%; the mass fraction of graphene oxide in the SPES-PPy / GO ion exchange membrane in step 4 is 2% - 10%. Other steps are the same as those in Specific Embodiments One to Eight.

[0042] Specific Embodiment Ten: The difference between this embodiment and any one of Specific Embodiments One to Nine is as follows: The ultrasonic time in step 4 is 40 min - 50 min; the temperature of vacuum drying in step 4 is 80 °C - 90 °C, and the vacuum drying time is 10 h - 12 h; in step 4, the membrane is immersed in a 1 mol / L HCl solution for 10 h - 12 h. Other steps are the same as those in Specific Embodiments One to Nine.

[0043] The following examples are used to verify the beneficial effects of the present invention:

[0044] Example 1: A preparation method of a BMED anti-pollution ion exchange conductive membrane for treating acid crystal water, which is specifically completed according to the following steps:

[0045] I. Preparation of graphene oxide:

[0046] Mix H2SO4 and H3PO4 evenly according to a certain volume ratio to obtain a mixed solution; add graphite powder and KMNO4 powder to the mixed solution, stir for 6 h, then add hydrogen peroxide dropwise, stir for 10 min, cool to room temperature, add 5% HCl solution dropwise, centrifuge for 10 min at a speed of 8000 r / min, wash the obtained solid material with water 3 times, and finally dry it at 80 °C to obtain graphene oxide powder;

[0047] In step I, the volume ratio of H2SO4 to H3PO4 is 9:1;

[0048] In step I, the mass fraction of H2SO4 is 98%; the mass fraction of H3PO4 is 95%;

[0049] In step I, the mass-volume ratio of graphite powder, KMNO4 powder and the mixed solution is 2.25 g: 13.2 g: 300 mL;

[0050] In step I, the mass-volume ratio of hydrogen peroxide, HCl solution and the mixed solution is 15 mL: 100 mL: 300 mL;

[0051] II. Preparation of sulfonated polyethersulfone:

[0052] ① Add 30 g of polyethersulfone to 200 mL of chloroform at 30 °C with stirring, stir until completely dissolved, and dropwise add 10 mL of HSO3Cl and 200 mL of CHCl3 to the polyethersulfone chloroform solution through a funnel at 5 °C with stirring. After the addition, a precipitate is formed. Filter, wash the obtained precipitate with water 3 times, and then vacuum dry it at 65 °C for 24 h to obtain a reaction product;

[0053] ② Add 2 g of the reaction product to 15 mL of N-methylpyrrolidone at 30 °C with stirring, stir for 10 min to obtain a viscous solution; pour the viscous solution onto a clean glass plate and vacuum dry it at 80 °C for 12 h. The film falls off the glass plate to obtain a sulfonated polyethersulfone film;

[0054] III. Preparation of PPy / GO powder:

[0055] Add 0.2 g of graphene oxide to 80 mL of absolute ethanol, stir for 30 min, then add 0.5 mL of pyrrole, ultrasonically treat for 5 min, then add 15.15 mL of FeCl3 solution, react under ice bath conditions for 8 h, and finally wash it 3 times with hydrochloric acid and dry it at 50 °C to obtain PPy / GO powder;

[0056] The concentration of the FeCl3 solution described in step three is 1 mol / L;

[0057] The concentration of the hydrochloric acid described in step three is 1 mol / L;

[0058] IV. Preparation of SPES-PPy / GO ion exchange membrane:

[0059] Dissolve the sulfonated polyethersulfone film in N-methylpyrrolidone, heat and stir at 70 °C for 4 h to obtain a sulfonated polyethersulfone solution; add the PPy / GO powder to the sulfonated polyethersulfone solution, ultrasonicate for 45 min, and then evenly disperse it on a clean glass plate with a scraper. Vacuum dry at 80 °C for 12 h, the film will fall off from the glass plate, and then immerse the film in a 1 mol / L HCl solution for 12 h to obtain the SPES-PPy / GO-2% ion exchange membrane, which is the BMED anti-fouling ion exchange conductive membrane for treating acid crystal water;

[0060] The mass fraction of the sulfonated polyethersulfone solution described in step four is 11.5%;

[0061] The mass fraction of graphene oxide in the SPES-PPy / GO ion exchange membrane described in step four is 2%.

[0062] Example 2: The difference between this example and Example 1 is that: the mass fraction of graphene oxide in the SPES-PPy / GO ion exchange membrane described in step four is 4%; the SPES-PPy / GO-4% ion exchange membrane is obtained in step four. Other steps and parameters are the same as those in Example 1.

[0063] Example 3: The difference between this example and Example 1 is that: the mass fraction of graphene oxide in the SPES-PPy / GO ion exchange membrane described in step four is 6%; the SPES-PPy / GO-6% ion exchange membrane is obtained in step four. Other steps and parameters are the same as those in Example 1.

[0064] Example 4: The difference between this example and Example 1 is that: the mass fraction of graphene oxide in the SPES-PPy / GO ion exchange membrane described in step four is 8%; the SPES-PPy / GO-8% ion exchange membrane is obtained in step four. Other steps and parameters are the same as those in Example 1.

[0065] Example 5: The difference between this example and Example 1 is that: the mass fraction of graphene oxide in the SPES-PPy / GO ion exchange membrane described in step four is 10%; the SPES-PPy / GO-10% ion exchange membrane is obtained in step four. Other steps and parameters are the same as those in Example 1.

[0066] Comparative Example 1: Preparation method of SPES-PPy / GO-0% ion exchange membrane, which is specifically completed according to the following steps:

[0067] I. Preparation of sulfonated polyethersulfone:

[0068] ①. At 30 °C and under stirring, add 30 g of polyethersulfone to 200 mL of chloroform, stir until completely dissolved, and dropwise add 10 mL of HSO3Cl and 200 mL of CHCl3 to the polyethersulfone chloroform solution drop by drop using a funnel at 5 °C under stirring. After the addition is completed, a precipitate is formed. Filter, wash the obtained precipitate with water 3 times, and then vacuum dry at 65 °C for 24 h to obtain the reaction product;

[0069] ②. At 30 °C and under stirring, add 2 g of the reaction product to 15 mL of N-methylpyrrolidone, stir for 10 min to obtain a viscous solution; pour the viscous solution onto a clean glass plate and vacuum dry at 80 °C for 12 h. The membrane peels off from the glass plate to obtain a sulfonated polyethersulfone film;

[0070] II. Preparation of SPES-PPy / GO-0% ion exchange membrane:

[0071] Dissolve the sulfonated polyethersulfone film in N-methylpyrrolidone, heat and stir at 70 °C for 4 h to obtain a sulfonated polyethersulfone solution; add 0.5 g of pyrrole (PPy) powder to 50 mL of the sulfonated polyethersulfone solution, ultrasonicate for 45 min, then evenly disperse it on a clean glass plate using a spatula and vacuum dry at 80 °C for 12 h. The membrane peels off from the glass plate, and then immerse the membrane in a 1 mol / L HCl solution for 12 h to obtain the SPES-PPy / GO-0% ion exchange membrane;

[0072] The mass fraction of the sulfonated polyethersulfone solution described in step four is 11.5%.

[0073] Comparative Example 2: Preparation method of SPES-GO-0% ion exchange membrane, which is specifically completed according to the following steps:

[0074] I. Preparation of graphene oxide:

[0075] Mix H2SO4 and H3PO4 in a certain volume ratio to obtain a mixed solution; add graphite powder and KMNO4 powder to the mixed solution, stir for 6 h, then dropwise add hydrogen peroxide, stir for 10 min, cool to room temperature, dropwise add a 5% mass fraction HCl solution, centrifuge for 10 min at a speed of 8000 r / min, wash the obtained solid material with water 3 times, and finally dry at 80 °C to obtain graphene oxide powder (GO powder);

[0076] In Step 1, the volume ratio of H2SO4 to H3PO4 is 9:1;

[0077] In Step 1, the mass fraction of H2SO4 is 98%; the mass fraction of H3PO4 is 95%;

[0078] In Step 1, the mass-volume ratio of graphite powder, KMNO4 powder and the mixed solution is 2.25 g: 13.2 g: 300 mL;

[0079] In Step 1, the mass-volume ratio of hydrogen peroxide, HCl solution and the mixed solution is 15 mL: 100 mL: 300 mL;

[0080] II. Preparation of sulfonated polyethersulfone:

[0081] ①. Under the conditions of 30 °C and stirring, add 30 g of polyethersulfone to 200 mL of chloroform, stir until completely dissolved, and dropwise add 10 mL of HSO3Cl and 200 mL of CHCl3 to the polyethersulfone chloroform solution drop by drop using a funnel at 5 °C under stirring conditions. After the dropping is completed, a precipitate is generated. Filter, wash the obtained precipitate with water 3 times, and then vacuum dry at 65 °C for 24 h to obtain a reaction product;

[0082] ②. Under the conditions of 30 °C and stirring, add 2 g of the reaction product to 15 mL of N-methylpyrrolidone, stir for 10 min to obtain a viscous solution; pour the viscous solution onto a clean glass plate and vacuum dry at 80 °C for 12 h. The film peels off from the glass plate to obtain a sulfonated polyethersulfone film;

[0083] III. Dissolve the sulfonated polyethersulfone film in N-methylpyrrolidone, heat and stir at 70 °C for 4 h to obtain a sulfonated polyethersulfone solution; add 0 g of GO powder to 50 mL of the sulfonated polyethersulfone solution, ultrasonicate for 45 min, and then evenly disperse it on a clean glass plate using a spatula. Vacuum dry at 80 °C for 12 h. The film peels off from the glass plate, and then immerse the film in a 1 mol / L HCl solution for 12 h to obtain a SPES-GO-0% ion exchange membrane;

[0084] In Step 3, the mass fraction of the sulfonated polyethersulfone solution is 11.5%.

[0085] Comparative Example 3: The difference in the preparation method of the SPES-GO-2% ion exchange membrane in this comparative example from that of Comparative Example 2 is as follows: In Step 3, the sulfonated polyethersulfone film was dissolved in N-methylpyrrolidone, heated and stirred at 70 °C for 4 h to obtain a sulfonated polyethersulfone solution; 0.041 g of GO powder was added to 50 mL of the sulfonated polyethersulfone solution, sonicated for 45 min, and then evenly dispersed on a clean glass plate using a spatula, vacuum dried at 80 °C for 12 h, the film peeled off from the glass plate, and then the film was immersed in a 1 mol / L HCl solution for 12 h to obtain the SPES-GO-2% ion exchange membrane. Other steps and parameters are the same as those in Comparative Example 2.

[0086] Comparative Example 4: The difference in the preparation method of the SPES-GO-4% ion exchange membrane in this comparative example from that of Comparative Example 2 is as follows: In Step 3, the sulfonated polyethersulfone film was dissolved in N-methylpyrrolidone, heated and stirred at 70 °C for 4 h to obtain a sulfonated polyethersulfone solution; 0.083 g of GO powder was added to 50 mL of the sulfonated polyethersulfone solution, sonicated for 45 min, and then evenly dispersed on a clean glass plate using a spatula, vacuum dried at 80 °C for 12 h, the film peeled off from the glass plate, and then the film was immersed in a 1 mol / L HCl solution for 12 h to obtain the SPES-GO-4% ion exchange membrane. Other steps and parameters are the same as those in Comparative Example 2.

[0087] Comparative Example 5: The difference in the preparation method of the SPES-GO-6% ion exchange membrane in this comparative example from that of Comparative Example 2 is as follows: In Step 3, the sulfonated polyethersulfone film was dissolved in N-methylpyrrolidone, heated and stirred at 70 °C for 4 h to obtain a sulfonated polyethersulfone solution; 0.128 g of GO powder was added to 50 mL of the sulfonated polyethersulfone solution, sonicated for 45 min, and then evenly dispersed on a clean glass plate using a spatula, vacuum dried at 80 °C for 12 h, the film peeled off from the glass plate, and then the film was immersed in a 1 mol / L HCl solution for 12 h to obtain the SPES-GO-6% ion exchange membrane. Other steps and parameters are the same as those in Comparative Example 2.

[0088] Comparative Example 6: The difference in the preparation method of the SPES-GO-8% ion exchange membrane in this comparative example from that of Comparative Example 2 is as follows: In Step 3, the sulfonated polyethersulfone film was dissolved in N-methylpyrrolidone, heated and stirred at 70 °C for 4 h to obtain a sulfonated polyethersulfone solution; 0.174 g of GO powder was added to 50 mL of the sulfonated polyethersulfone solution, sonicated for 45 min, and then evenly dispersed on a clean glass plate using a spatula, vacuum dried at 80 °C for 12 h, the film peeled off from the glass plate, and then the film was immersed in a 1 mol / L HCl solution for 12 h to obtain the SPES-GO-8% ion exchange membrane. Other steps and parameters are the same as those in Comparative Example 2.

[0089] Comparative Example 7: The difference in the preparation method of the SPES-GO-10% ion exchange membrane in this comparative example from that of Comparative Example 2 is as follows: In Step 3, the sulfonated polyethersulfone film was dissolved in N-methylpyrrolidone, heated and stirred at 70 °C for 4 h to obtain a sulfonated polyethersulfone solution; 0.222 g of GO powder was added to 50 mL of the sulfonated polyethersulfone solution, sonicated for 45 min, and then evenly dispersed on a clean glass plate using a spatula, and vacuum-dried at 80 °C for 12 h. The membrane peeled off from the glass plate, and then the membrane was immersed in a 1 mol / L HCl solution for 12 h to obtain the SPES-GO-10% ion exchange membrane. Other steps and parameters are the same as those in Comparative Example 2.

[0090] Anti-fouling property test:

[0091] The SPES-PPy / GO ion exchange membranes prepared in Comparative Example 1 and Examples 1 to 5 and the SPES-GO ion exchange membranes prepared in Comparative Examples 2 to 7 were respectively immersed in a solution containing 100 ppm of cation (CPC), 100 ppm of anion (SDS), and 100 ppm of bovine serum albumin (BSA) fouling for 12 parts, and the membrane conductivity test was carried out under the condition that the equilibrium time to 0.1 M NaCl was 12 h; the CPC cation was cetylpyridinium, and the SDS anion was dodecyl sulfate.

[0092] Figure 1 is the conductivity of the SPES-PPy / GO ion exchange membranes prepared in Comparative Example 1 and Examples 1 to 5 and the SPES-GO ion exchange membranes prepared in Comparative Examples 2 to 7.

[0093] Figure 1 In SPES-PPy / GO, the abscissa GO-0% is Comparative Example 1, GO-2% is Example 1, GO-4% is Example 2, GO-6% is Example 3, GO-8% is Example 4, and GO-10% is Example 5;

[0094] Figure 1 In the SPES-GO curve, the abscissa GO-0% is Comparative Example 2, GO-2% is Comparative Example 3, GO-4% is Comparative Example 4, GO-6% is Comparative Example 5, GO-8% is Comparative Example 6, and GO-10% is Comparative Example 7.

[0095] The surface charge characteristics of the membrane directly determine the pollutant adsorption behavior and significantly affect the conductivity. The anti-fouling membrane maintains a stable ion transport channel by inhibiting pollutant accumulation, thereby maintaining high conductivity. As Figure 1As shown, with the increase of GO doping amount, the conductivity is significantly improved. In particular, the conductivity of SPES-PPy / GO increases more than that of SPES-GO, which is due to the electrophoretic repulsion formed by the PPy conductive material in the presence of an external electric field. The peak conductivity appears at a GO doping amount of 6%-8%. Excessive doping leads to a slight decrease in performance due to the aggregation of GO.

Claims

1. A preparation method of a BMED anti-pollution ion exchange conductive membrane for treating acid crystal water, characterized in that The preparation method is specifically completed according to the following steps: I. Preparation of graphene oxide: Mix H2SO4 and H3PO4 evenly according to a certain volume ratio to obtain a mixed solution; add graphite powder and KMNO4 powder to the mixed solution, stir for a period of time, then add hydrogen peroxide dropwise, stir, cool to room temperature, add HCl solution dropwise, centrifuge, wash the obtained solid material several times, and finally dry to obtain graphene oxide powder; II. Preparation of sulfonated polyethersulfone: ①. Add polyethersulfone to chloroform at 30°C - 40°C under stirring until completely dissolved. Under stirring conditions, use a low-temperature funnel to dropwise add HSO3Cl and CHCl3 to the polyethersulfone chloroform solution drop by drop. After the addition is completed, a precipitate is generated. Filter, wash the obtained precipitate with water several times, and dry it under vacuum to obtain a reaction product; ②. Add the reaction product to N-methylpyrrolidone at 30°C - 40°C under stirring for a period of time to obtain a viscous solution; Cast the viscous solution onto a clean glass plate and dry it under vacuum. The film peels off from the glass plate to obtain a sulfonated polyethersulfone film; III. Preparation of PPy / GO powder: Add graphene oxide to absolute ethanol, stir for a period of time, then add pyrrole, perform ultrasonic treatment for a period of time, then add FeCl3 solution, react for a period of time under ice bath conditions, and finally wash with hydrochloric acid and dry to obtain PPy / GO powder; IV. Preparation of SPES-PPy / GO ion exchange membrane: Dissolve the sulfonated polyethersulfone film in N-methylpyrrolidone, heat and stir for a period of time to obtain a sulfonated polyethersulfone solution; add the PPy / GO powder to the sulfonated polyethersulfone solution, perform ultrasonic treatment for a period of time, then use a spatula to evenly disperse it on a clean glass plate, dry it under vacuum, the film peels off from the glass plate, and then immerse the film in HCl solution for a period of time to obtain the SPES-PPy / GO ion exchange membrane, which is the BMED anti-pollution ion exchange conductive membrane for treating acid crystal water.

2. The preparation method of a BMED anti-pollution ion exchange conductive membrane for treating acid crystal water according to claim 1, characterized in that In step I, the volume ratio of H2SO4 to H3PO4 is 9:1; the mass fraction of H2SO4 in step I is 98%; the mass fraction of H3PO4 is 95%.

3. The preparation method of a BMED anti-pollution ion exchange conductive membrane for treating acid crystal water according to claim 1, characterized in that In step I, the mass-volume ratio of the graphite powder, KMNO4 powder and the mixed solution is (2g - 3g):(13g - 14g):(280mL - 320mL); the mass fraction of the HCl solution in step I is 5% - 8%; the mass-volume ratio of the hydrogen peroxide, HCl solution and the mixed solution is (15mL - 20mL):(95mL - 105mL):(280mL - 320mL).

4. The preparation method of a BMED anti-pollution ion exchange conductive membrane for treating acid crystal water according to claim 1, characterized in that In step I, add graphite powder and KMNO4 powder to the mixed solution, stir for 6h - 7h, then add hydrogen peroxide dropwise, stir for 10min - 20min, cool to room temperature, add HCl solution dropwise, centrifuge for 10min - 15min, wash the obtained solid material 3 - 5 times, and finally dry at 80°C - 100°C to obtain graphene oxide powder.

5. The preparation method of a BMED anti-pollution ion exchange conductive membrane for treating acid crystal water according to claim 1, characterized in that In Step 2①, the mass-volume ratio of the polyethersulfone, chloroform, HSO3Cl, and CHCl3 is 30 g: 200 mL: 10 mL: 200 mL; the temperature of the low-temperature funnel in Step 2① is 0 °C to 5 °C; in Step 2①, the obtained precipitate is washed with water 3 to 5 times, and then vacuum dried at a temperature of 50 °C to 70 °C for 20 h to 24 h.

6. The preparation method of a BMED anti-pollution ion exchange conductive membrane for treating acid crystal water according to claim 1, characterized in that In Step 2②, the mass-volume ratio of the reaction product to N-methylpyrrolidone is 2 g: (15 mL to 16 mL); the stirring time in Step 2② is 10 min to 15 min; the temperature of the vacuum drying in Step 2② is 80 °C to 90 °C, and the vacuum drying time is 10 h to 12 h.

7. The preparation method of a BMED anti-pollution ion exchange conductive membrane for treating acid crystal water according to claim 1, characterized in that In Step 3, the mass-volume ratio of the graphene oxide, pyrrole, FeCl3 solution, and absolute ethanol is (0 g to 0.3 g): (0.5 mL to 1 mL): (15 mL to 25 mL): (20 mL to 80 mL); the concentration of the FeCl3 solution in Step 3 is 1 mol / L; the concentration of the hydrochloric acid in Step 3 is 1 mol / L.

8. The preparation method of a BMED anti-pollution ion exchange conductive membrane for treating acid crystal water according to claim 1, characterized in that In Step 3, the graphene oxide is added to the absolute ethanol, stirred for 20 min to 40 min, then pyrrole is added, ultrasonically treated for 5 min to 10 min, then the FeCl3 solution is added, reacted under ice bath conditions for 8 h to 12 h, and finally washed with hydrochloric acid and dried to obtain the PPy / GO powder.

9. The preparation method of a BMED anti-pollution ion exchange conductive membrane for treating acid crystal water according to claim 1, characterized in that In Step 4, the temperature of the heating and stirring is 70 °C to 80 °C, and the stirring time is 3 h to 4 h; the mass fraction of the sulfonated polyethersulfone solution in Step 4 is 10% to 15%; the mass fraction of the graphene oxide in the SPES-PPy / GO ion exchange membrane in Step 4 is 2% to 10%.

10. The preparation method of a BMED anti-pollution ion exchange conductive membrane for treating acid crystal water according to claim 1, characterized in that In Step 4, the ultrasonic time is 40 min to 50 min; the temperature of the vacuum drying in Step 4 is 80 °C to 90 °C, and the vacuum drying time is 10 h to 12 h; in Step 4, the membrane is immersed in a 1 mol / L HCl solution for 10 h to 12 h.

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