Nanofiltration-electrodialysis coupling device for separating ADP and phosphate and application of nanofiltration-electrodialysis coupling device

Abstract

The invention relates to a nanofiltration-electrodialysis coupling device for separating ADP and phosphate and application of the nanofiltration-electrodialysis coupling device, the nanofiltration-electrodialysis coupling device is an electrodialyzer inserted with an organic nanofiltration membrane, and the nanofiltration-electrodialysis coupling device comprises a membrane stack composed of at least two separation units; each separation unit comprises a first ion exchange membrane assembly, a first organic nanofiltration membrane assembly, a second organic nanofiltration membrane assembly and a second ion exchange membrane assembly which are sequentially arranged in parallel. The nanofiltration-electrodialysis coupling device provided by the invention can be used for separating the charged target product from the salt and realizing efficient separation of the charged target product, and the device and the use method thereof can be used for separating charged substances and the salt in a mixed system. Particularly, a novel method is provided for separation and purification of the cofactor ADP in a multienzyme catalysis system synthesis system, the recovery rate level is very considerable, and the salt removal effect is very good.

Description

Technical Field

[0001] The invention belongs to the field of industrial biotechnology and relates to a nanofiltration-electrodialysis coupling device for separating ADP and phosphate and application of the device in separating and recovering ADP and phosphate. Background Art

[0002] The core content of cell-free synthetic biology is to construct a multi-enzyme catalytic system in vitro, mimic the metabolic pathways in vivo, and combine a series of enzymes and coenzymes in vitro to form a complex biochemical metabolic network to obtain the target product. One difficulty of the cell-free in vitro multi-enzyme synthesis method is the reuse of cofactors. ATP, as one of the two common cofactors, participates in most enzymatic reactions. Expensive cofactors increase production costs. If the cofactor ADP (adenosine diphosphate) in the conversion liquid system can be separated and purified and regenerated to synthesize ATP (adenosine triphosphate), the production cost can be greatly reduced. In addition, high concentrations of phosphate also inhibit the enzyme activity of the multi-enzyme system. Therefore, the separation of ADP and phosphate is of great significance to the multi-enzyme catalytic system.

[0003] Electrodialysis is a commonly used desalination device in membrane separation. However, when the target product is charged, it will pass through the anion and cation exchange membrane along with the impurities during the electrodialysis process, resulting in product loss or even inability to effectively separate the impurities. Conventional electrodialysis desalination devices cannot separate the charged target product and salt.

[0004] CN 216024146 U discloses an electrodialysis desalination device for amino acid separation. The amino acid stock solution enters the inside of the dialysis tank, and the ion exchange membrane separates the amino acid stock solution into a cationic solution and an anionic solution. In this way, the anionic and cationic separation can be carried out quickly when the amino acid stock solution enters the inside of the dialysis tank, which fundamentally reduces the formation of salt. At its isoelectric point, the amino acid is electrically neutral in the solution, but as the electrodialysis proceeds, the pH of the solution will change, and the amino acid will migrate due to the charge.

[0005] Therefore, it is necessary to develop a device and a method for separating ADP from phosphate to overcome the disadvantage that the target product with charge migrates into the concentration chamber during conventional electrodialysis operation, resulting in the loss of the target product. Summary of the invention

[0006] In view of the deficiencies in the prior art, the object of the present invention is to provide a nanofiltration-electrodialysis coupling device for separating ADP and phosphate and its application in separating and recovering ADP and phosphate.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] In the first aspect, the present invention provides a nanofiltration-electrodialysis coupling device for separating ADP from phosphate, wherein the nanofiltration-electrodialysis coupling device is an electrodialyzer inserted with an organic nanofiltration membrane, and comprises a membrane stack composed of at least two separation units; each separation unit comprises a first ion exchange membrane assembly, a first organic nanofiltration membrane assembly, a second organic nanofiltration membrane assembly, and a second ion exchange membrane assembly arranged in parallel in sequence. The schematic diagram thereof is shown in FIG. Figure 1 shown.

[0009] The nanofiltration-electrodialysis coupling device involved in the present invention can separate the charged target product from the salt, thereby realizing the efficient separation of the charged target product. The device and the use method thereof can be used to separate the charged substances and salts in a mixed system, and in particular, provide a new method for the separation and purification of the cofactor ADP in a multi-enzyme catalytic system synthesis system, with a very impressive recovery rate and a very good salt removal effect.

[0010] Preferably, the number of the separation units is 3-9, such as 3, 4, 5, 6, 7, 8 or 9, preferably 3-6.

[0011] Preferably, the first ion exchange membrane component is selected from a single anion exchange membrane, a single cation exchange membrane, and anion exchange membranes and cation exchange membranes arranged alternately in parallel;

[0012] The second ion exchange membrane component is selected from a single anion exchange membrane, a single cation exchange membrane, and anion exchange membranes and cation exchange membranes arranged alternately in parallel;

[0013] Furthermore, the first ion exchange membrane assembly and the second ion exchange membrane assembly together constitute 1-3 pairs (eg, 1 pair, 2 pairs or 3 pairs) of anion and cation exchange membranes.

[0014] Preferably, the first organic nanofiltration membrane assembly comprises 1-3 (e.g., 1, 2 or 3) organic nanofiltration membrane sheets arranged in parallel;

[0015] Preferably, the second organic nanofiltration membrane assembly comprises 1-3 (eg, 1, 2 or 3) organic nanofiltration membrane sheets arranged in parallel.

[0016] Preferably, the material of the organic nanofiltration membrane is independently selected from cellulose acetate, polyamide, sulfonated polysulfone, sulfonated polyethersulfone, polyethersulfone, polyacrylonitrile or polyvinylidene fluoride; more preferably polyamide, polyethersulfone or polyvinylidene fluoride.

[0017] Compared with other materials, choosing polyamide, polyethersulfone or polyvinylidene fluoride as the material of organic nanofiltration membrane has better separation effect.

[0018] Preferably, the molecular weight cutoff of the organic nanofiltration membrane is independently selected from 100-1000Da, such as 100Da, 200Da, 300Da, 400Da, 500Da, 600Da, 700Da, 800Da, 900Da, 1000Da, etc., more preferably 400-1000Da.

[0019] Preferably, the anion exchange membranes are each independently selected from polyacrylic acid exchange membranes, quaternized polyarylethersulfone exchange membranes, polybenzimidazole ion exchange membranes or polyvinyl alcohol ion exchange membranes; more preferably quaternized polyarylethersulfone exchange membranes and polyvinyl alcohol ion exchange membranes.

[0020] Compared with other anion exchange membranes, the separation effect of the device is better when quaternary ammonium polyarylethersulfone exchange membrane and polyvinyl alcohol ion exchange membrane are selected as anion exchange membrane.

[0021] Preferably, the cation exchange membranes are each independently selected from perfluorosulfonic acid ion exchange membranes, perfluorocarboxylic acid ion exchange membranes, polybenzimidazole ion exchange membranes or polyvinyl alcohol ion exchange membranes; more preferably perfluorosulfonic acid ion exchange membranes and polyvinyl alcohol ion exchange membranes.

[0022] Compared with other cation exchange membranes, the separation effect of the device is better when perfluorosulfonic acid ion exchange membrane and polyvinyl alcohol ion exchange membrane are selected as cation exchange membranes.

[0023] In a second aspect, the present invention provides a method for separating ADP from phosphate, the method being performed using the nanofiltration-electrodialysis coupling device described in the first aspect, and specifically comprising the following steps:

[0024] The mixed solution containing ADP and phosphate is circulated into and out of the dilute chamber between the first organic nanofiltration membrane assembly and the second organic nanofiltration membrane assembly, and the low-concentration phosphate solution is simultaneously circulated into and out of the concentrated chamber between the first ion exchange membrane assembly and the first organic nanofiltration membrane assembly and the concentrated chamber between the second ion exchange membrane assembly and the second organic nanofiltration membrane assembly; after the treatment is completed, the ADP concentrated solution is output from the dilute chamber.

[0025] All membranes in the nanofiltration-electrodialysis coupling device of the present invention are arranged parallel to each other. The space between the first organic nanofiltration membrane assembly and the second organic nanofiltration membrane assembly is used as a dilute chamber, the space between the first ion exchange membrane assembly and the first organic nanofiltration membrane assembly is used as a concentrate chamber, and the space between the second organic nanofiltration membrane assembly and the second ion exchange membrane assembly is also used as a concentrate chamber.

[0026] When the mixed solution containing ADP and phosphate enters the dilute chamber, ADP cannot pass through the nanofiltration membrane, but phosphate can, so ADP concentrated solution is recovered from the dilute chamber; further, the cations of phosphate can pass through the anion exchange membrane, and the anions can pass through the cation exchange membrane, so that alkaline solution and phosphoric acid solution as well as phosphate concentrated solution can be recovered separately.

[0027] Preferably, the operation mode of the nanofiltration-electrodialysis coupling device is constant current electrodialysis or constant voltage electrodialysis.

[0028] Preferably, the voltage of the nanofiltration-electrodialysis coupling device is set to 5-30V, such as 5V, 8V, 10V, 12V, 15V, 20V, 25V, 30V, etc., more preferably 10-20V.

[0029] Preferably, the current of the nanofiltration-electrodialysis coupling device is set to 10-30 mA / cm 2 , for example 10mA / cm 2 , 12mA / cm 2 , 15mA / cm 2 , 18mA / cm 2 , 20mA / cm 2 , 22mA / cm 2 , 25mA / cm 2 、30mA / cm 2 etc., more preferably 10-20 mA / cm 2 .

[0030] Preferably, the flow rate of the dilute chamber liquid is 0.2-0.6 L / min, for example, 0.2 L / min, 0.3 L / min, 0.4 L / min, 0.5 L / min, 0.6 L / min, etc., more preferably 0.4-0.6 L / min.

[0031] Preferably, the flow rate of the concentrated chamber liquid is 0.2-0.6 L / min, such as 0.2 L / min, 0.3 L / min, 0.4 L / min, 0.5 L / min, 0.6 L / min, etc., more preferably 0.4-0.6 L / min.

[0032] Preferably, the concentration of the low concentration phosphate solution is 0.1-0.8 M, such as 0.1 M, 0.2 M, 0.3 M, 0.4 M, 0.5 M, 0.6 M, 0.7 M, 0.8 M, etc.

[0033] Other specific point values ​​within the above numerical ranges can be selected and are all within the protection scope of the present invention. Due to space limitations, they will not be described one by one here.

[0034] In a third aspect, the present invention provides use of the nanofiltration-electrodialysis coupling device described in the first aspect or the method described in the second aspect in separating charged compounds and salts.

[0035] In a fourth aspect, the present invention provides the use of the nanofiltration-electrodialysis coupling device described in the first aspect or the method described in the second aspect in recovering ADP from a cell-free in vitro multi-enzyme catalytic conversion solution.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The nanofiltration-electrodialysis coupling device involved in the present invention can separate the charged target product from the salt, thereby realizing the efficient separation of the charged target product. The device and the use method thereof can be used to separate the charged substances and salts in a mixed system, and in particular, provide a new method for the separation and purification of the cofactor ADP in a multi-enzyme catalytic system synthesis system, with a very impressive recovery rate and a very good salt removal effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of a membrane stack in a nanofiltration-electrodialysis coupling device involved in the present invention. DETAILED DESCRIPTION

[0039] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0040] Example 1

[0041] The present embodiment provides a nanofiltration-electrodialysis coupling device, which includes 4 separation units, each of which includes 2 organic nanofiltration membranes, both of which are made of polyethersulfone with a molecular weight cutoff of 400-500. An anion exchange membrane and a cation exchange membrane are respectively arranged on both sides of the organic nanofiltration membrane, wherein the anion exchange membrane is a polyvinyl alcohol ion exchange membrane and the cation exchange membrane is a perfluorosulfonic acid ion exchange membrane. The 4 separation units form a complete membrane stack, and its schematic diagram is as shown in FIG. Figure 1 shown.

[0042] This embodiment also provides a method for separating ADP and phosphate using the nanofiltration-electrodialysis coupling device, which is as follows:

[0043] A mixed solution of 1 mM ADP and 10 g / L sodium phosphate at an initial concentration was circulated and pumped into the dilute chamber of the nanofiltration-electrodialysis device, and a 0.3 M phosphate solution was simultaneously circulated and pumped into the concentrate chambers on both sides of the dilute chamber. Constant voltage operation was adopted, the voltage was 10 V, and the flow rates in the dilute chamber and the concentrate chamber were both 0.4 L / min. After 4.5 hours of treatment, the dilute chamber liquid obtained a concentrated solution containing ADP.

[0044] The results showed that the removal rate of phosphate was 43.56% and the recovery rate of ADP was 88.69%.

[0045] Example 2

[0046] The present embodiment provides a nanofiltration-electrodialysis coupling device, which includes three separation units, each of which includes two organic nanofiltration membranes, both of which are made of polyethersulfone with a molecular weight cutoff of 500-600. A pair of alternating anion and cation exchange membranes are arranged on both sides of the organic nanofiltration membrane, wherein the anion exchange membrane is a polyvinyl alcohol ion exchange membrane and the cation exchange membrane is a polyvinyl alcohol ion exchange membrane. The three separation units form a complete membrane stack.

[0047] This embodiment also provides a method for separating ADP and phosphate using the nanofiltration-electrodialysis coupling device, which is as follows:

[0048] A mixed solution of 1 mM ADP and 10 g / L sodium phosphate at an initial concentration was circulated and pumped into the dilute chamber of the nanofiltration-electrodialysis device, and a 0.2 M phosphate solution was simultaneously circulated and pumped into the concentrate chambers on both sides of the dilute chamber. Constant voltage operation was adopted, the voltage was 20 V, and the flow rates of the dilute chamber and the concentrate chamber were both 0.6 L / min. After 3 hours of treatment, the dilute chamber liquid obtained a concentrated solution containing ADP.

[0049] The results showed that the removal rate of phosphate was 45.26% and the recovery rate of ADP was 85.36%.

[0050] Example 3

[0051] The present embodiment provides a nanofiltration-electrodialysis coupling device, which includes 6 separation units, each of which includes 2 organic nanofiltration membranes, both of which are made of polyamide with a molecular weight cutoff of 700-800, and a pair of alternating anion and cation exchange membranes are arranged on both sides of the organic nanofiltration membrane, wherein the anion exchange membrane is a quaternary ammonium polyarylethersulfone ion exchange membrane, and the cation exchange membrane is a perfluorosulfonic acid ion exchange membrane, and the 6 separation units constitute a complete membrane stack.

[0052] This embodiment also provides a method for separating ADP and phosphate using the nanofiltration-electrodialysis coupling device, which is as follows:

[0053] A mixed solution of 1 mM ADP and 10 g / L sodium phosphate was circulated into the dilute chamber of the nanofiltration-electrodialysis device, and a 0.5 M phosphate solution was simultaneously circulated into the concentrated chambers on both sides of the dilute chamber; constant current operation was adopted, and the current was 20 mA / cm 2 The flow rates of the dilute chamber and the concentrated chamber were both 0.6 L / min; after 2.5 hours of treatment, the dilute chamber liquid obtained a concentrated solution containing ADP.

[0054] The results showed that the removal rate of phosphate was 56.38% and the recovery rate of ADP was 82.56%.

[0055] Example 4

[0056] The present embodiment provides a nanofiltration-electrodialysis coupling device, which includes three separation units, each of which includes a first organic nanofiltration membrane assembly composed of two parallel arranged organic nanofiltration membrane sheets, and a second organic nanofiltration membrane assembly composed of two parallel arranged organic nanofiltration membrane sheets, the membrane sheets are made of polyvinylidene fluoride, and the retention molecular weight is 800-900, and one anion exchange membrane and one cation exchange membrane are respectively arranged on the outer sides of the first organic nanofiltration membrane assembly and the second organic nanofiltration membrane assembly, wherein the anion exchange membrane is a polyvinyl alcohol ion exchange membrane, and the cation exchange membrane is a perfluorosulfonic acid ion exchange membrane, and the three separation units constitute a complete membrane stack.

[0057] This embodiment also provides a method for separating ADP and phosphate using the nanofiltration-electrodialysis coupling device, which is as follows:

[0058] A mixed solution of 1 mM ADP and 10 g / L sodium phosphate was circulated into the dilute chamber of the nanofiltration-electrodialysis device, and a 0.3 M phosphate solution was simultaneously circulated into the concentrated chambers on both sides of the dilute chamber; constant current operation was adopted, and the current was 15 mA / cm 2 The flow rates of the dilute chamber and the concentrated chamber were both 0.5 L / min; after 3 hours of treatment, the dilute chamber liquid obtained a concentrated solution containing ADP.

[0059] The results showed that the removal rate of phosphate was 68.59% and the recovery rate of ADP was 79.26%.

[0060] Example 5

[0061] The present embodiment provides a nanofiltration-electrodialysis coupling device, which includes 5 separation units, each of which includes 2 organic nanofiltration membranes, the membrane materials are polyamide and polyvinylidene fluoride, and the retention molecular weight is 900-1000. A pair of alternating anion and cation exchange membranes are arranged on both sides of the organic nanofiltration membrane, wherein the anion exchange membrane is a quaternary ammonium polyarylethersulfone ion exchange membrane, and the cation exchange membrane is a polyvinyl alcohol ion exchange membrane. The 5 separation units constitute a complete membrane stack.

[0062] This embodiment also provides a method for separating ADP and phosphate using the nanofiltration-electrodialysis coupling device, which is as follows:

[0063] A mixed solution of 1 mM ADP and 10 g / L sodium phosphate was circulated into the dilute chamber of the nanofiltration-electrodialysis device, and a 0.5 M phosphate solution was simultaneously circulated into the concentrated chambers on both sides of the dilute chamber; constant current operation was adopted, and the current was 20 mA / cm2 The flow rates of the dilute chamber and the concentrated chamber were both 0.6 L / min; after 2.5 hours of treatment, the dilute chamber liquid obtained a concentrated solution containing ADP.

[0064] The results showed that the removal rate of phosphate was 79.33% and the recovery rate of ADP was 77.25%.

[0065] Example 6

[0066] This embodiment provides a nanofiltration-electrodialysis coupling device, which differs from the device in Example 1 only in that the material of the organic nanofiltration membrane is replaced with cellulose acetate, and other conditions remain unchanged.

[0067] This embodiment also provides a method for separating ADP and phosphate using the nanofiltration-electrodialysis coupling device, which is specifically consistent with Example 1.

[0068] The results showed that the removal rate of phosphate was 40.26% and the recovery rate of ADP was 70.39%.

[0069] Example 7

[0070] This embodiment provides a nanofiltration-electrodialysis coupling device, which differs from the device in Example 1 only in that the material of the organic nanofiltration membrane is replaced with polyacrylonitrile, and other conditions remain unchanged.

[0071] This embodiment also provides a method for separating ADP and phosphate using the nanofiltration-electrodialysis coupling device, which is specifically consistent with Example 1.

[0072] The results showed that the removal rate of phosphate was 35.69% and the recovery rate of ADP was 65.36%.

[0073] Example 8

[0074] This embodiment provides a nanofiltration-electrodialysis coupling device, which differs from the device in Example 1 only in that the material of the organic nanofiltration membrane is replaced with sulfonated polysulfone, and other conditions remain unchanged.

[0075] This embodiment also provides a method for separating ADP and phosphate using the nanofiltration-electrodialysis coupling device, which is specifically consistent with Example 1.

[0076] The results showed that the removal rate of phosphate was 38.26% and the recovery rate of ADP was 75.23%.

[0077] Example 9

[0078] This embodiment provides a nanofiltration-electrodialysis coupling device, which differs from the device in Example 1 only in that the cation exchange membrane is replaced by a perfluorocarboxylic acid ion exchange membrane, and other conditions remain unchanged.

[0079] This embodiment also provides a method for separating ADP and phosphate using the nanofiltration-electrodialysis coupling device, which is specifically consistent with Example 1.

[0080] The results showed that the removal rate of phosphate was 33.18% and the recovery rate of ADP was 72.69%.

[0081] Example 10

[0082] This embodiment provides a nanofiltration-electrodialysis coupling device, which differs from the device in Example 1 only in that the anion exchange membrane is replaced by a polybenzimidazole ion exchange membrane, and other conditions remain unchanged.

[0083] This embodiment also provides a method for separating ADP and phosphate using the nanofiltration-electrodialysis coupling device, which is specifically consistent with Example 1.

[0084] The results showed that the removal rate of phosphate was 38.91% and the recovery rate of ADP was 74.64%.

[0085] Comparative Example 1

[0086] This comparative example provides an electrodialysis device, which includes 4 separation units, each of which includes a group of parallel arranged anion exchange membranes and a cation exchange membrane, wherein the anion exchange membrane is a polyvinyl alcohol ion exchange membrane, and the cation exchange membrane is a perfluorosulfonic acid ion exchange membrane, and the 4 separation units constitute a complete membrane stack.

[0087] This comparative example also provides a method for separating ADP and phosphate using the electrodialysis device, which is as follows:

[0088] A mixed solution with an initial concentration of 1mM ADP and 10g / L sodium phosphate was pumped into the dilute chamber of the electrodialysis device, and a 0.5M phosphate solution was pumped into the concentrate chamber at the same time; constant voltage operation was adopted, the voltage was 10V, and the flow rates in the dilute chamber and the concentrate chamber were both 0.4L / min; after 5h of treatment, a concentrated solution containing ADP was obtained in the dilute chamber.

[0089] The results showed that the removal rate of phosphate was 89.36% and the recovery rate of ADP was 15.33%.

[0090] In summary, compared with the electrodialysis device of Comparative Example 1, the nanofiltration-electrodialysis coupling device of the present invention can efficiently separate ADP from phosphate and recover ADP.

[0091] The applicant declares that the present invention illustrates the technical solution of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0092] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0093] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A nanofiltration-electrodialysis coupling device for separating ADP and phosphate, characterized in that: The nanofiltration-electrodialysis coupling device is an electrodialyzer inserted with an organic nanofiltration membrane, including a membrane stack composed of at least two separation units; each separation unit includes a first ion exchange membrane component, a first organic nanofiltration membrane component, a second organic nanofiltration membrane component, and a second ion exchange membrane component arranged in parallel in sequence.

2. The nanofiltration-electrodialysis coupling device according to claim 1, characterized in that: The number of the separation units is 3-9, more preferably 3-6.

3. The nanofiltration-electrodialysis coupling device according to claim 1 or 2, characterized in that: The first ion exchange membrane component is selected from a single anion exchange membrane, a single cation exchange membrane, and anion exchange membranes and cation exchange membranes arranged alternately in parallel; The second ion exchange membrane component is selected from a single anion exchange membrane, a single cation exchange membrane, and anion exchange membranes and cation exchange membranes arranged alternately in parallel; Furthermore, the first ion exchange membrane assembly and the second ion exchange membrane assembly together constitute 1-3 pairs of anion and cation exchange membranes.

4. The nanofiltration-electrodialysis coupling device according to any one of claims 1 to 3, characterized in that: The first organic nanofiltration membrane assembly comprises 1 to 3 organic nanofiltration membrane sheets arranged in parallel; Preferably, the second organic nanofiltration membrane assembly comprises 1 to 3 organic nanofiltration membrane sheets arranged in parallel.

5. The nanofiltration-electrodialysis coupling device according to claim 4, characterized in that: The material of the organic nanofiltration membrane is independently selected from cellulose acetate, polyamide, sulfonated polysulfone, sulfonated polyethersulfone, polyethersulfone, polyacrylonitrile or polyvinylidene fluoride; more preferably polyamide, polyethersulfone or polyvinylidene fluoride; Preferably, the molecular weight cutoff of the organic nanofiltration membrane is independently selected to be 100-1000Da, more preferably 400-1000Da.

6. The nanofiltration-electrodialysis coupling device according to claim 3, characterized in that: The anion exchange membranes are each independently selected from polyacrylic acid ion exchange membranes, quaternized polyarylethersulfone ion exchange membranes, polybenzimidazole ion exchange membranes or polyvinyl alcohol ion exchange membranes; more preferably quaternized polyarylethersulfone ion exchange membranes and polyvinyl alcohol ion exchange membranes; Preferably, the cation exchange membranes are each independently selected from perfluorosulfonic acid ion exchange membranes, perfluorocarboxylic acid ion exchange membranes, polybenzimidazole ion exchange membranes or polyvinyl alcohol ion exchange membranes; more preferably perfluorosulfonic acid ion exchange membranes and polyvinyl alcohol ion exchange membranes.

7. A method for separating ADP and phosphate, characterized in that: The method is carried out using the nanofiltration-electrodialysis coupling device according to any one of claims 1 to 6, and specifically comprises the following steps: A mixed solution containing ADP and phosphate is circulated into and out of the dilute chamber between the first organic nanofiltration membrane assembly and the second organic nanofiltration membrane assembly, and a low-concentration phosphate solution is simultaneously circulated into and out of the concentrate chamber between the first ion exchange membrane assembly and the first organic nanofiltration membrane assembly and the concentrate chamber between the second ion exchange membrane assembly and the second organic nanofiltration membrane assembly for treatment; after the treatment, an ADP concentrated solution is output from the dilute chamber.

8. The method according to claim 7, characterized in that The operation mode of the nanofiltration-electrodialysis coupling device is constant current electrodialysis or constant voltage electrodialysis; Preferably, the voltage of the nanofiltration-electrodialysis coupling device is set to 5-30V, more preferably 10-20V; Preferably, the current of the nanofiltration-electrodialysis coupling device is set to 10-30 mA / cm 2 , more preferably 10-20 mA / cm 2 ; Preferably, the flow rate of the dilute chamber liquid is 0.2-0.6 L / min, more preferably 0.4-0.6 L / min; Preferably, the flow rate of the concentrate liquid is 0.2-0.6 L / min, more preferably 0.4-0.6 L / min; Preferably, the concentration of the low concentration phosphate solution is 0.1-0.8M.

9. Use of the nanofiltration-electrodialysis coupling device according to any one of claims 1 to 6 or the method according to any one of claims 7 to 9 in separating charged compounds and salts.

10. Use of the nanofiltration-electrodialysis coupling device according to any one of claims 1 to 6 or the method according to any one of claims 7 to 9 for recovering ADP from a cell-free in vitro multi-enzyme catalytic conversion solution.

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