A method for treating high-concentration saline organic wastewater

Abstract

The present invention discloses a method for treating high-concentration saline organic wastewater, belonging to the technical field of wastewater treatment, and is used to solve the technical problems that both the separation degree of components in the existing high-salt organic matter solution and the performance of ion exchange membranes in the electrodialysis method need to be improved. The present invention includes the following steps: pretreating the high-salt and high-organic wastewater to obtain a low-salt and low-organic matter solution, preparing activated CNTs / TiO2-CuO, preparing modified cation exchange membrane precursors and modified anion exchange membrane precursors, and applying plating to obtain modified cation exchange membranes and modified anion exchange membranes, and subjecting the low-salt and low-organic matter solution to electrodialysis to obtain a high-salt solution and drainable water. The present invention uses surface-modified ion exchange membranes to enhance the catalytic ability of oxidants for organic matter, and uses chemical plating to provide a uniform deposition layer, ultimately achieving the purpose of efficiently and highly purifying saline organic wastewater.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial wastewater treatment, and particularly relates to a method for treating high-concentration saline organic wastewater. Background Art

[0002] In industrial production, high-salt organic wastewater contains a large amount of organic matter and salts. If directly discharged or improperly treated, it is likely to cause serious environmental pollution, such as having a long-term impact on soil and groundwater. While effectively recovering and treating high-salt organic wastewater, protecting natural resources and recycling high-salt organic wastewater is also one of the important aspects of achieving sustainable development.

[0003] Patent application CN2016110952679 discloses a method for treating high-salt organic wastewater. This method performs repeated dehydration and crystallization treatment on high-salt organic wastewater to achieve the purpose of separating inorganic salts and organic matter. However, this method ignores the influence of salt ion effect and colligative properties of solutes on the crystallization of water molecules in the solution, and the extraction effect of repeated crystallization on inorganic salts needs to be further improved.

[0004] Patent application CN2019110771785 discloses a method for treating high-salt organic wastewater by electrodialysis. This method first uses a flocculant to preliminarily separate the organic matter in high-salt organic wastewater, and then uses a plated ion exchange membrane for electrodialysis. While performing electrodialysis, an oxidant is introduced to catalyze the decomposition of residual organic matter in the solution to achieve the purpose of separating inorganic salts and removing organic matter. However, this method ignores the influence of the inorganic salt composition on the performance of the flocculant in precipitating organic matter, does not modify the ion exchange membrane, cannot guarantee the service life of the plated ion exchange membrane, and does not introduce a catalyst with strong promoting performance for the oxidant to oxidize organic matter in the ion exchange membrane, over-optimistically estimating the catalytic performance of the oxidant on the organic matter in the solution.

[0005] In view of the technical deficiencies in this regard, a solution is now proposed. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for treating high-concentration saline organic wastewater to solve the technical deficiencies presented in the background art.

[0007] The purpose of the present invention can be achieved through the following technical solutions: A method for treating high-concentration saline organic wastewater includes the following steps:

[0008] S1. Pretreat the high-salt organic solution to obtain a high-salt low-organic matter solution;

[0009] S2. Assemble a modified cation exchange membrane and a modified anion exchange membrane into an electrodialysis device, and use the electrodialysis device to treat the high-salt low-organic matter solution to obtain a high-salt solution and water that can be discharged;

[0010] Among them, the preparation method of the modified cation exchange membrane is as follows: Add activated CNTs / TiO2-CuO and a 10-20 wt% polyvinylidene chloride solution to a reaction kettle, raise the temperature of the reaction kettle to 30-40 °C, keep warm and ultrasonic for 1-2 h, perform post-treatment to obtain modified polyvinylidene chloride, perform coupling modification on the modified polyvinylidene chloride to obtain a modified cation exchange membrane precursor, apply plating to the modified cation exchange membrane precursor using an electroless plating solution, and perform post-treatment to obtain the modified cation exchange membrane;

[0011] The preparation method of the modified anion exchange membrane is as follows: Add activated CNTs / TiO2-CuO and a 10-20 wt% polyethersulfone solution to a reaction kettle, raise the temperature of the reaction kettle to 30-40 °C, keep warm and ultrasonic for 1-2 h, perform post-treatment to obtain a composite polyethersulfone membrane, perform modification treatment on the composite polyethersulfone membrane to obtain a modified anion exchange membrane precursor, apply plating to the modified anion exchange membrane precursor using an electroless plating solution, and perform post-treatment to obtain the modified anion exchange membrane.

[0012] Furthermore, the pretreatment operation includes the following steps:

[0013] A1. Add a high-salt organic solution and deionized water to a reaction kettle and stir. Stir at room temperature for 5-15 min to obtain a diluted solution;

[0014] A2. Lower the temperature of the reaction kettle containing the diluted solution to 0-5 °C, stir for 3-5 h, and perform suction filtration to obtain inorganic salt crystals and a low-salt high-organic matter solution;

[0015] A3. Add the low-salt high-organic matter solution and an extractant to a reaction kettle and stir. Stir at room temperature for 20-30 min, let it stand for liquid separation to obtain an organic solution and a low-salt low-organic matter solution.

[0016] Among them, in step A1, the volume ratio of deionized water to the high-salt organic solution is 2:1, and the stirring rate is 120 rpm; in step A3, the extractant is one or more of ethyl acetate, dichloromethane, and diethyl ether, the volume ratio of the extractant to the mixed solution is 0.5:1, and the stirring rate is 120 rpm.

[0017] Reaction principle:

[0018] Dilute the high-salt and high-organic matter solution with deionized water. Excessively high concentrations of salt ions can affect the arrangement of water molecules, making the process of forming large ice crystals more complex. At the same time, due to the colligative properties of solute molecules, excessive organic solutes can also cause the freezing point of the solution to decrease, making it more difficult to freeze. Organic components are excluded during the crystallization of water molecules due to their low solubility and poor affinity with salts, resulting in the formation of ice crystals mainly composed of inorganic components of salts. High concentrations of salt ions can affect the extraction performance of the extractant. Using the crystallization method to remove some inorganic salt components is more conducive to the extraction of organic substances.

[0019] Furthermore, the activated CNTs / TiO2-CuO is prepared by the following steps:

[0020] B1. Add single-walled carbon nanotubes, amide compounds, and dichloromethane into a reaction kettle. Raise the temperature of the reaction kettle to 40 - 60 °C, keep the temperature for reaction for 6 - 8 h, and perform post-treatment to obtain modified carbon nanotubes;

[0021] B2. Mix nano-TiO2, nano-CuO, and modified carbon nanotubes in N,N-dimethylformamide to obtain a mixed solution. Add the mixed solution into an ultrasonic device for ultrasonic treatment. Set the ultrasonic device at 60 - 80 °C and a frequency of 40 - 60 kHz, keep the temperature for ultrasonic treatment for 3 - 5 h, and perform post-treatment to obtain CNTs / TiO2-CuO;

[0022] B3. Add CNTs / TiO2-CuO, silane coupling agent, and organic solvent into a reaction kettle and stir. Raise the temperature of the reaction kettle to 40 - 60 °C, keep the temperature for reaction for 6 - 8 h, and perform post-treatment to obtain activated CNTs / TiO2-CuO.

[0023] Furthermore, in step B1, the dosage ratio of single-walled carbon nanotubes, amide compounds, and dichloromethane is 1 g:2 g:15 mL. The amide compound is one or more of acetamide, benzoyl, and aminocysteine. The post-treatment operation is: suction filtration, and place the filter cake in a drying oven at 80 °C for vacuum drying until the filter cake reaches a constant weight to obtain modified carbon nanotubes;

[0024] In step B2, the dosage ratio of nano-TiO2, nano-CuO, modified carbon nanotubes, and N,N-dimethylformamide is 2 g:1 g:5 g:40 mL. The post-treatment operation is: suction filtration, and place the filter cake in a drying oven at 80 °C for vacuum drying until the filter cake reaches a constant weight to obtain CNTs / TiO2-CuO;

[0025] In step B3, the dosage ratio of CNTs / TiO2-CuO, organic solvent and silane coupling agent is 1 g: 20 mL: 4 g. The organic solution is one or more of toluene, xylene and dichloromethane. The silane coupling agent is one or more of 3-aminopropyltriethoxysilane, aminophenyltrimethoxysilane, γ-aminobutyltrimethoxysilane. The post-treatment operation is: suction filtration, and the filter cake is placed in a drying oven at 80 °C for vacuum drying until the filter cake reaches a constant weight to obtain activated CNTs / TiO2-CuO.

[0026] Reaction principle: Amidation treatment can introduce carboxyl (-COOH) or amino (-NH2) groups to the surface of carbon nanotubes, making them have better affinity and enhanced interfacial compatibility with nano metal particles. The functionalization treatment of the carbon nanotube surface can improve its electrochemical performance. Especially in electrocatalytic reactions, the composite material of metal nanoparticles and functionalized carbon nanotubes can exhibit higher conductivity and electrochemical activity, which helps to improve the efficiency and response speed of catalytic materials.

[0027] Silanization treatment can endow the carbon fiber tube surface with certain anti-biofouling properties. Silanization can introduce silicon-containing organic groups to the surface of the carbon fiber tube. These groups can effectively bind to the matrix molecules of the adsorbed ion exchange membrane, enhancing the interfacial binding force and stability, and preventing the loosening or peeling of the interface during use.

[0028] Furthermore, the dosage ratio of activated CNTs / TiO2-CuO and 10-20 wt% partially polyvinyl chloride solution is 1 g: 10 ml, and the ultrasonic frequency is 20-80 kHz.

[0029] Furthermore, the coupling modification of modified partially polyvinyl chloride includes the following steps:

[0030] C1. Immerse the modified partially polyvinyl chloride in a 30-50 wt% sulfuric acid solution and a 1-5 wt% hydrogen peroxide solution at an immersion temperature of 60-80 °C, keep the temperature for reaction for 2-4 h, and perform post-treatment to obtain sulfonated partially polyvinyl chloride.

[0031] The synthesis reaction formula of sulfonated partially polyvinyl chloride is:

[0032]

[0033] The synthesis reaction principle of sulfonated polyvinylidene chloride is as follows: Sulfuric acid acts as a catalyst in the reaction. Sulfuric acid is a strong acid that can provide protons for the formation of reaction intermediates. Sulfuric acid first reacts with the vinyl chloride groups in the polyvinylidene chloride molecule to form an intermediate sulfate compound. Under the action of sulfuric acid, the chlorine atom in the vinyl chloride group is substituted or added with a sulfonic acid group (-SO3H) to form a sulfuric acid sulfonic acid compound. In this process, a part of the vinyl chloride groups will be converted into sulfonic acid groups. After the reaction, some vinyl chloride units in the polyvinylidene chloride chain will be sulfonated by sulfuric acid to form sulfonated polyvinylidene chloride.

[0034] C2. Immerse the sulfonated polyvinylidene chloride in a mixed solution composed of 20 - 30 wt% sodium hydroxide solution and 30 - 50 wt% ammonia water solution at an immersion temperature of 30 - 50 °C, keep the temperature for reaction for 2 - 4 h, and perform post-treatment to obtain sulfonated and ammoniated polyvinylidene chloride. Dissolve the sulfonated and ammoniated polyvinylidene chloride in ethylene glycol monomethyl ether acetate to prepare a sulfonated and ammoniated polyvinylidene chloride solution;

[0035] The synthesis reaction formula of sulfonated and ammoniated polyvinylidene chloride is:

[0036]

[0037] The reaction principle of the sulfonated and ammoniated polyvinylidene chloride solution is as follows: The sulfonic acid group is a strong acidic functional group and will undergo a neutralization reaction under strong alkaline conditions. The negative charge on the sulfonic acid group is neutralized by sodium ions to form sodium sulfonate (-SO3Na). After the formation of sodium sulfonate, it contacts with ammonia water and undergoes a displacement reaction to form the corresponding sulfonated and ammoniated group (-SO3NH2).

[0038] C3. Spin-coat the sulfonated and ammoniated polyvinylidene chloride solution on the surface of silanized glass fabric to form a coating with a thickness of 150 - 200 μm to obtain a coated glass fabric. Place the coated glass fabric in a drying oven at 80 °C for vacuum heat treatment for 1 h to obtain a modified glass fabric;

[0039] C4. Immerse the modified glass fabric in a 20 - 30 wt% glutaraldehyde solution at an immersion temperature of 40 - 50 °C, keep the temperature for reaction for 3 - 5 h, and perform post-treatment to obtain a modified cation exchange membrane precursor.

[0040] The synthesis reaction formula of the modified cation exchange membrane precursor is:

[0041]

[0042] The synthesis reaction principle of the modified cation exchange membrane precursor is as follows: The carbonyl group of acetaldehyde is opened by the nucleophilic attack of the amino group, forming an intermediate iminium ion. Valeraldehyde and amino compounds can undergo a Schiff base reaction. In this reaction, the carbonyl group of the aldehyde undergoes a nucleophilic addition reaction with the amino group. The mechanism is: RCHO + NH2R' → RCH=NR' + H2O, where R represents the pentyl group (the carbon chain part of valeraldehyde), and R' represents the carbon chain part of the amino compound. The product formed is an intermediate containing a C=N bond, and this intermediate further reacts to form a stable Schiff base.

[0043] Furthermore, in step C1, the dosage ratio of the modified polyvinylidene chloride, 30 - 50 wt% sulfuric acid solution, and 1 - 5 wt% hydrogen peroxide solution is 1 g:4 mL:1 mL. The post-treatment operation is: suction filtration, and the filter cake is placed in a drying oven at 80 °C for vacuum drying until the filter cake reaches a constant weight, obtaining sulfonated polyvinylidene chloride.

[0044] In step C2, the dosage ratio of the sulfonated polyvinylidene chloride, 0 - 30 wt% sodium hydroxide solution, and 30 - 50 wt% ammonia water solution is 1 g:1 mL:4 mL. The post-treatment operation is: suction filtration, and the filter cake is placed in a drying oven at 80 °C for vacuum drying until the filter cake reaches a constant weight, obtaining sulfonated and aminated polyvinylidene chloride.

[0045] Furthermore, in step C3, the silanized glass fabric is prepared by the following steps: A glass fabric with a thickness of 0.05 - 0.10 mm and a 0.5% - 5 wt% silane coupling agent solution are placed in a stirring kettle for reaction. The temperature is set at 60 - 80 °C, the heat preservation time is 2 - 3 h, and the stirring rate is 120 rpm. After the reaction kettle is cooled to room temperature, the silanized glass fabric precursor is taken out, rinsed 3 - 5 times with cold ethanol at a temperature of 10 °C, and then placed in a drying oven for vacuum baking at 110 - 120 °C for 1 - 2 h, obtaining the silanized glass fabric.

[0046] The synthesis reaction formula of the silanized glass fabric is:

[0047]

[0048] The synthesis reaction principle of the silanized glass fabric is as follows: The 3-aminopropyltrimethoxysilane molecule first undergoes hydrolysis under the action of water, and its methoxy (-OCH3) group is replaced by a water molecule to form a hydroxyl group (-OH). The hydroxyl group (-OH) of the silane in the hydrolyzed 3-aminopropyltrihydroxysilane forms a silicon-oxygen bond (Si-O-Si) with the hydroxyl group (-OH) on the glass surface. The newly formed siloxane bond firmly connects the 3-aminopropyl group to the glass surface.

[0049] Furthermore, It represents a glass fabric network structure, and the silane coupling agent is selected as 3-aminopropyltrimethoxysilane with the structure of .

[0050] Furthermore, the silane coupling agent is one or more of 3-aminopropyltrimethoxysilane, aminophenyltrimethoxysilane, and γ-aminobutyltrimethoxysilane. Preferably, it is 3-aminopropyltrimethoxysilane. The dosage ratio of the glass fabric to the silane coupling agent is 1 g:5 mL; in step C4, the dosage ratio of the modified glass fabric with a thickness of 0.05 - 0.10 mm to the 20 - 30 wt% glutaraldehyde solution is 1 g:5 mL. The post-treatment operation is: suction filtration, and the filter cake is placed in a drying oven at 80 °C for vacuum drying until the filter cake reaches a constant weight, obtaining the precursor of the modified cation exchange membrane.

[0051] Furthermore, the dosage ratio of the activated CNTs / TiO2-CuO to the 10 - 20 wt% polyethersulfone solution is 1 g:10 ml, and the ultrasonic frequency is 20 - 80 kHz.

[0052] Furthermore, the modification treatment of the composite polyethersulfone membrane includes the following steps:

[0053] D1. Immerse the composite polyethersulfone membrane in a mixed solution containing 5 - 10 wt% chloromethane and 20 - 30 wt% aluminum chloride at an immersion temperature of 50 - 70 °C, keep the temperature for reaction for 1 - 3 h to obtain an impregnated membrane, and perform post-treatment to obtain a halogenated membrane;

[0054] The synthesis equation of the halogenated membrane is:

[0055]

[0056] The synthesis principle of the halogenated membrane is: Aluminum chloride, as a Lewis acid, can form a coordination compound with the halogen atoms in the benzene ring. This coordination will make the π-electron system of the benzene ring more electrophilic and more easily accept electrophilic attack. The chloride ion (Cl - ) in chloromethane will attack the activated benzene ring. AlCl3 acts as a catalyst and can catalyze the intermediate to eliminate hydrogen chloride (HCl) at the end of the reaction, generating the final halogenated aromatic compound.

[0057] D2. Immerse the halogenated membrane in a 20 - 30 wt% trimethylamine solution at an immersion temperature of 40 - 60 °C, keep the temperature for reaction for 2 - 4 h to obtain a quaternized membrane, and perform post-treatment to obtain the precursor of the modified anion exchange membrane.

[0058] The synthesis equation of the precursor of the modified anion exchange membrane is:

[0059]

[0060] The synthesis principle of the modified anion exchange membrane precursor is as follows: Trimethylamine, as an electrophilic reagent, has a lone pair of electrons on its nitrogen atom, so it has strong nucleophilicity. In the reaction, the nitrogen atom of trimethylamine will attack the chlorine group in the halogenated polyethersulfone molecule, causing the chloride ion to detach from the halogenated polyethersulfone molecule, forming an intermediate in a transition state. This intermediate will then lose a proton to form trimethylamine salt, and finally a compound with a quaternary ammonium salt group is introduced into the halogenated polyethersulfone molecule.

[0061] Furthermore, in step D1, the dosage ratio of the composite polyethersulfone, 5 - 10 wt% chloromethane, and 20 - 30 wt% aluminum chloride is 1 g:5 mL:3 mL. The post-treatment operation is as follows: Take out the impregnated membrane, place the impregnated membrane in a drying oven at 80 °C and vacuum dry it until the filter cake reaches a constant weight to obtain the halogenated membrane; In step D2, the dosage ratio of the halogenated membrane soaking and 20 - 30 wt% trimethylamine solution is 1 g:5 mL. The post-treatment operation is as follows: Take out the quaternized membrane, place the quaternized membrane in a drying oven at 80 °C and vacuum dry it until the filter cake reaches a constant weight to obtain the halogenated membrane modified anion exchange membrane precursor.

[0062] Furthermore, the plating includes the following steps: Place the membrane substrate in the electroless plating solution, keep it warm and plate for 1 - 2 h at a temperature of 20 - 40 °C. After the plating is completed, rinse the plated ion exchange membrane with deionized water until it is neutral to obtain the modified ion exchange membrane, where the membrane substrate is a modified cation exchange membrane or a modified anion exchange membrane;

[0063] The composition of the electroless plating solution consists of a metal ion source, a reducing agent, a complexing agent, a surfactant, a stabilizer, a buffer, and deionized water in a weight ratio of 0.1 - 5:1 - 10:2 - 12:0.001 - 0.2:0.01 - 0.1:0.01 - 0.1:10 - 60;

[0064] The metal ion source is selected from one or more of nickel chloride, nickel sulfate, zinc chloride, zinc sulfate, chromium chloride, chromium sulfate, and chromium anhydride; The reducing agent is selected from one or more of sodium hypophosphite, formaldehyde, and hydrazine; The complexing agent is selected from one or more of ethylenediaminetetraacetic acid, sodium citrate, sodium pyrophosphate, diethanolamine, triethanolamine, diethylenetriaminepentaacetic acid, polyacrylic acid, and citric acid; The surfactant is selected from one or more of sodium dodecylbenzenesulfonate, sodium octyl sulfate, and sodium dodecyl sulfate; The stabilizer is selected from lead nitrate or sodium thiosulfate; The buffer is selected from boric acid or sodium acetate.

[0065] Reaction principle: Electroless plating can provide a very uniform deposition layer and can form a uniform and dense thin film on the surface of the ion exchange membrane. It is applicable to substrates of various sizes and shapes. Whether it is a flat surface or a curved surface, electroless plating can form a continuous and uniform thin film on these surfaces;

[0066] Reducing agents provide electrons to metal ions in the solution to reduce them to corresponding metal atoms; complexing agents can complex metal ions and usually have a more uniform deposition rate and more uniform surface coverage during the plating process; stabilizers can help maintain a stable concentration of metal ions in the plating solution, prevent premature precipitation or over-reduction, and maintain the uniformity and long-term stability of the plating solution; buffering agents can optimize the chemical environment of the plating solution, contribute to the uniformity and consistency of metal deposition, and stable pH conditions can make the deposition rate of metal ions more controllable, thus producing a uniform and well-crystallized deposition layer.

[0067] Further, in step S2, the wastewater treatment includes the following steps: set the voltage of the electrodialysis device to 20 - 80V, introduce ozone into the ion exchange membrane at a rate of 10 L / h, set the electrodialysis time to 6 - 7h, after taking out the electrodialyzed water and the salt-collecting solution, repeat the electrodialysis operation on the electrodialyzed water 2 - 3 times, and obtain a high-salt solution and drainable water after concentration respectively.

[0068] Reaction principle: Under the drive of an electric field, anions are attracted to the positive electrode and cations are attracted to the negative electrode among the ions in the waste liquid. The ion exchange membrane selectively permeates, causing the inorganic salt components in the wastewater to accumulate in the electrode area, obtaining drainable water and a high-salt solution.

[0069] The present invention has the following beneficial effects:

[0070] 1. During the pretreatment process of the high-salt and high-organic matter solution in the present invention, deionized water is first used to reduce the inorganic salt concentration and organic matter concentration in the solution, effectively reducing the salt effect and solute colligative properties in the system on the solution freezing process. Due to the low solubility and poor affinity with salts of the organic components, the organic components will be excluded during the crystallization of water molecules, resulting in the formation of ice crystals mainly composed of inorganic components of salts, separating most of the inorganic salts in the solution system, effectively reducing the influence of the salt effect on the extraction of organic matter, and making the extraction of organic matter more sufficient. During the preparation of activated CNTs / TiO2-CuO, an amide compound is used to modify the surface of the single-walled carbon fiber tube to fix the amide group on the surface of the carbon nanotube, which can provide active sites and help with the subsequent coating and stabilization of metal particles. The amide group usually has a nitrogen atom, which can provide additional coordination sites and form strong coordination bonds with metal ions. This coordination not only helps with the adsorption and fixation of metal ions on the surface of the carbon nanotube, but also reduces the dissolution and migration of metal particles in the environment, helps the carbon nanotubes to disperse and uniformly coat on the surface of the metal particles, thus ensuring the activity and stability of the metal particles in catalysis or other applications. Using single-walled carbon nanotubes to coat metal copper particles with catalytic oxidation and metal oxide particles titanium dioxide helps to improve the catalytic performance of the particles and their stability in the electrodialysis process. Using a silane coupling agent to modify CNTs / TiO2-CuO can silylate it, which is beneficial for subsequent stable combination with polyvinylidene chloride and polysulfone, making the ion exchange membrane have the function of catalytic oxidation of organic matter. The silylation treatment can adjust the surface of the carbon fiber tube, thereby optimizing the surface properties of the adsorbed ion exchange membrane.

[0071] 2. During the preparation of the modified ion exchange membrane in the present invention, activated CNTs / TiO2-CuO is first used to combine with polyvinylidene chloride and polysulfone respectively, enriching the functions of the ion exchange membrane. During the preparation of the modified cation exchange membrane, a modified glass fabric is introduced as the substrate material to enhance the mechanical strength of the cation exchange membrane. Among them, by silylating the glass fabric and sulfonating the modified polyvinylidene chloride, the two can be combined through glutaraldehyde to form a tight organic structure, improving the mechanical strength of the modified cation exchange membrane while preventing the modified polyvinylidene chloride from falling off, and extending the service life of the modified cation exchange membrane. During the preparation of the modified anion exchange membrane, formaldehyde is used to introduce halogen groups under acidic conditions to prepare a halomethyl membrane, and then trimethylamine is used to further quaternize the halomethyl membrane to generate a positively charged quaternary ammonium salt, further enhancing the selectivity of the ion exchange membrane.

[0072] 3. During the plating process of the modified ion exchange membrane substrate in the present invention, electroless plating solution is used instead of the electroplating method. Electroless plating can provide a very uniform deposition layer, and a uniform and dense thin film can be formed on the surface of the ion exchange membrane. It is applicable to substrates of various sizes and shapes. Whether it is a flat surface or a curved surface, electroless plating can form a continuous and uniform thin film on these surfaces; the reducing agent provides electrons to the metal ions in the solution to reduce them to the corresponding metal atoms; the complexing agent can coordinate with the metal ions and usually has a more uniform deposition rate and a more uniform surface coverage during the plating process; the stabilizer can help maintain the stable concentration of metal ions in the plating solution, prevent their premature precipitation or over-reduction, and maintain the uniformity and long-term stability of the plating solution; the buffer can optimize the chemical environment of the plating solution, contribute to the uniformity and consistency of metal deposition, and the stable pH condition can make the deposition rate of metal ions more controllable, thereby producing a uniform and well-crystallized deposition layer. Detailed implementation mode

[0073] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope of protection of the present invention. Embodiment 1

[0074] This embodiment provides a method for treating high-concentration saline organic wastewater, including the following steps:

[0075] S1. Pretreat the waste liquid

[0076] Mix the high-salt organic solution and deionized water in a volume ratio of 1:2 in a reaction kettle and stir. The stirring rate of the stirring kettle is 120 rpm, and stir at room temperature for 5 min to obtain a diluted solution;

[0077] Lower the temperature of the reaction kettle containing the diluted solution to 5°C, keep it warm and stand for 3 h, then separate the solid-liquid mixture to obtain high-salt ice and low-salt high-organic matter solution;

[0078] Mix the low-salt high-organic matter and dichloromethane in a volume ratio of 0.5:1 to obtain a mixed solution. Add the mixed solution to the reaction kettle and stir at a rotation speed of 120 rpm. Stir at room temperature for 1 h, stand for 20 min, and collect the organic solution and the low-salt low-organic matter solution.

[0079] S2. Prepare activated CNTs / TiO2-CuO

[0080] Add single-walled carbon nanotubes, acetamide, and an organic solvent to a reaction kettle in a dosage ratio of 1 g: 2 g: 15 mL. Raise the temperature of the reaction kettle to 40 °C, hold the temperature for reaction for 6 h, perform suction filtration, and place the filter cake in a drying oven at 80 °C for vacuum drying until the filter cake reaches a constant weight to obtain modified carbon nanotubes;

[0081] Mix 2 g of nano-TiO₂, 1 g of nano-CuO, and 5 g of modified carbon nanotubes with 40 mL of N,N-dimethylformamide to obtain a mixed solution. Add the mixed solution to an ultrasonic device for ultrasonic treatment. Set the ultrasonic device at 60 °C and a frequency of 40 kHz, hold the temperature for ultrasonic treatment for 3 h, perform suction filtration, and place the filter cake in a drying oven at 80 °C for vacuum drying until the filter cake reaches a constant weight to obtain CNTs / TiO₂-CuO;

[0082] Add CNTs / TiO₂-CuO, dichloromethane, and 3-aminopropyltriethoxysilane to a reaction kettle in a dosage ratio of 1 g: 20 mL: 4 g and stir. Raise the temperature of the reaction kettle to 40 °C, hold the temperature for reaction for 6 h, perform suction filtration, and place the filter cake in a drying oven at 80 °C for vacuum drying until the filter cake reaches a constant weight to obtain activated CNTs / TiO₂-CuO.

[0083] S3. Prepare a modified cation exchange membrane precursor

[0084] Add activated CNTs / TiO₂-CuO and a 10 wt% solution of partially hydrolyzed polyvinyl chloride to a reaction kettle in a dosage ratio of 1 g: 10 mL. Raise the temperature of the reaction kettle to 30 °C and a frequency of 40 kHz, hold the temperature for ultrasonic treatment for 1 h, perform suction filtration, and place the filter cake in a drying oven at 80 °C for vacuum drying until a constant weight is reached to obtain modified partially hydrolyzed polyvinyl chloride;

[0085] Soak the modified partially hydrolyzed polyvinyl chloride in a 30 wt% sulfuric acid solution and a 1 wt% hydrogen peroxide solution. The dosage ratio of the modified partially hydrolyzed polyvinyl chloride, the 30 wt% sulfuric acid solution, and the 1 wt% hydrogen peroxide solution is 1 g: 4 mL: 1 mL. The soaking temperature is 60 °C, hold the temperature for reaction for 2 h, perform suction filtration, and place the filter cake in a drying oven at 80 °C for vacuum drying until a constant weight is reached to obtain sulfonated partially hydrolyzed polyvinyl chloride;

[0086] Soak the sulfonated partially hydrolyzed polyvinyl chloride in a 20 wt% sodium hydroxide solution and a 30 wt% ammonia water solution. The dosage ratio in the sulfonated partially hydrolyzed polyvinyl chloride, the 20 wt% sodium hydroxide solution, and the 30 wt% ammonia water solution is 1 g: 1 mL: 4 mL. The soaking temperature is 30 °C, hold the temperature for reaction for 2 h, perform suction filtration, and place the filter cake in a drying oven at 80 °C for vacuum drying until a constant weight is reached to obtain sulfonated and aminated partially hydrolyzed polyvinyl chloride. Dissolve the sulfonated and aminated partially hydrolyzed polyvinyl chloride in ethylene glycol monomethyl ether acetate to prepare a sulfonated and aminated partially hydrolyzed polyvinyl chloride solution;

[0087] Put the glass fabric with a thickness of 0.05 mm and a 2.5 wt% silane coupling agent solution into a stirring kettle for reaction. The dosage ratio of the glass fabric with a thickness of 0.05 mm to the 2.5 wt% silane coupling agent is 1 g:5 mL. Set the temperature to 60 °C, keep the temperature for reaction for 2 h, and the stirring rate is 120 rpm. After the reaction kettle is cooled to room temperature, take out the silanized glass fabric precursor, rinse it 3 times with cold ethanol at a temperature of 10 °C, and then place it in a drying oven for vacuum baking at 110 °C for 1 h to obtain the silanized glass fabric;

[0088] Spin-coat the sulfonated polyvinylidene chloride solution on the surface of the silanized glass fabric to form a coating with a thickness of 150 μm to obtain the coated glass fabric. Place the coated glass fabric in a drying furnace at 80 °C for vacuum heat treatment for 1 h to obtain the modified glass fabric;

[0089] Immerse the modified glass fabric in a 20 wt% glutaraldehyde solution. The dosage ratio of the modified glass fabric to the 20 wt% glutaraldehyde solution is 1 g:5 mL. The soaking temperature is 40 °C, keep the temperature for reaction for 3 h, take out the modified glass fabric, and place the post-modified glass fabric in a drying oven at 80 °C for vacuum drying to constant weight to obtain the modified cation exchange membrane precursor.

[0090] S4. Prepare the modified anion exchange precursor

[0091] Add the activated CNTs / TiO2-CuO and 10 wt% polyethersulfone solution to the reaction kettle according to the dosage ratio of 1 g:10 ml. Raise the temperature of the reaction kettle to 30 °C, the frequency is 20 kHz, keep the temperature for ultrasonic treatment for 1 h, the frequency is 20 kHz, perform suction filtration, and place the filter cake in a drying oven at 80 °C for vacuum drying to constant weight to obtain the composite polyethersulfone membrane;

[0092] Immerse the composite polyethersulfone membrane in a mixed solution composed of 5 wt% chloroform and 20 wt% aluminum chloride. The dosage ratio of the composite polyethersulfone, 5 wt% chloroform and 20 wt% aluminum chloride is 1 g:5 mL:3 mL. The soaking temperature is 50 °C, keep the temperature for reaction for 1 h, perform suction filtration, and place the filter cake in a drying oven at 80 °C for vacuum drying to constant weight to obtain the halogenated membrane;

[0093] Immerse the halogenated membrane in a 20 wt% trimethylamine solution. The dosage ratio of the halogenated membrane to the 20 wt% trimethylamine solution is 1 g:5 mL. The soaking temperature is 40 °C, react for 2 h, and perform post-treatment to obtain the modified anion exchange membrane precursor.

[0094] S5. Chemical plating

[0095] Mix nickel chloride, sodium hypophosphite, sodium citrate, sodium dodecylbenzenesulfonate, sodium thiosulfate, sodium acetate and deionized water according to the weight ratio of 0.1:1:2:0.001:0.01:0.01:10 to prepare an electroless plating solution;

[0096] Place the modified cation exchange membrane precursor and the modified anion exchange membrane precursor in the electroless plating solution, keep the temperature at 20 °C for 1 h during plating, and after the plating is completed, rinse the plated ion exchange membrane with deionized water until it is neutral to obtain a modified ion exchange membrane.

[0097] S6. Electrodialysis

[0098] Assemble the cation exchange membrane and the anion exchange membrane into an electrodialysis device: set the voltage of the electrodialysis device to 20 V, introduce ozone into the ion exchange membrane at a rate of 10 L / h, set the electrodialysis time to 6 h, after taking out the electrodialysis water and the salt-collecting solution, repeat the electrodialysis operation of the electrodialysis water 2 times, and concentrate them respectively to obtain a high-salt solution and drainable water. Example 2

[0099] This example provides a method for treating high-concentration saline organic wastewater, including the following steps:

[0100] S1. Pretreat the high-salt and high-organic matter solution

[0101] Mix the high-salt organic solution and deionized water in a volume ratio of 1:2 in a reaction kettle and stir. The stirring rate of the stirring kettle is 120 rpm, and stir at room temperature for 10 min to obtain a diluted solution;

[0102] Lower the temperature of the reaction kettle containing the diluted solution to 3 °C, keep it warm and static for 4 h, then separate the solid-liquid mixture to obtain high-salt ice and low-salt high-organic matter solution;

[0103] Mix the low-salt high-organic matter and dichloromethane in a volume ratio of 0.5:1 to obtain a mixed solution. Add the mixed solution to the reaction kettle and stir. Set the rotation speed to 120 rpm, stir at room temperature for 1.5 h, and let it stand for 20 min to collect the organic solution and the low-salt low-organic matter solution.

[0104] S2. Prepare activated CNTs / TiO2-CuO

[0105] Add single-walled carbon nanotubes, acetamide and organic solvent to the reaction kettle according to the dosage ratio of 1 g:2 g:15 mL and stir. Raise the temperature of the reaction kettle to 50 °C, keep it warm and react for 7 h, then filter by suction. Place the filter cake in a drying oven at 80 °C and vacuum dry it until the filter cake reaches a constant weight to obtain modified carbon nanotubes;

[0106] Mix 2 g of nano-TiO₂, 1 g of nano-CuO, and 5 g of modified carbon nanotubes with 40 mL of N,N-dimethylformamide to obtain a mixed solution. Add the mixed solution to an ultrasonic device and ultrasonicate. The ultrasonic device is set at 70 °C, with a frequency of 50 kHz. Keep the temperature and ultrasonicate for 4 h. Then, perform suction filtration. Place the filter cake in a drying oven at 80 °C and vacuum dry it until the filter cake reaches a constant weight to obtain CNTs / TiO₂-CuO;

[0107] Add CNTs / TiO₂-CuO, dichloromethane, and 3-aminopropyltriethoxysilane to a reaction kettle in a dosage ratio of 1 g:20 mL:4 g and stir. Raise the temperature of the reaction kettle to 50 °C and keep the temperature for reaction for 7 h. Then, perform suction filtration. Place the filter cake in a drying oven at 80 °C and vacuum dry it until the filter cake reaches a constant weight to obtain activated CNTs / TiO₂-CuO.

[0108] S3. Prepare a modified cation exchange membrane precursor

[0109] Add activated CNTs / TiO₂-CuO and a 15 wt% solution of partial polyvinyl chloride to a reaction kettle in a dosage ratio of 1 g:10 ml. Raise the temperature of the reaction kettle to 35 °C and set the frequency to 40 kHz. Keep the temperature and ultrasonicate for 1.5 h. Then, perform suction filtration. Place the filter cake in a drying oven at 80 °C and vacuum dry it until it reaches a constant weight to obtain modified partial polyvinyl chloride;

[0110] Soak the modified partial polyvinyl chloride in a 40 wt% sulfuric acid solution and a 3 wt% hydrogen peroxide solution. The dosage ratio of the modified partial polyvinyl chloride, the 40 wt% sulfuric acid solution, and the 3 wt% hydrogen peroxide solution is 1 g:4 mL:1 mL. The soaking temperature is 70 °C. Keep the temperature and react for 3 h. Then, perform suction filtration. Place the filter cake in a drying oven at 80 °C and vacuum dry it until it reaches a constant weight to obtain sulfonated partial polyvinyl chloride;

[0111] Soak the sulfonated partial polyvinyl chloride in a 25 wt% sodium hydroxide solution and a 40 wt% ammonia water solution. The dosage ratio of the sulfonated partial polyvinyl chloride, the 25 wt% sodium hydroxide solution, and the 40 wt% ammonia water solution is 1 g:1 mL:4 mL. The soaking temperature is 40 °C. Keep the temperature and react for 3 h. Then, perform suction filtration. Place the filter cake in a drying oven at 80 °C and vacuum dry it until it reaches a constant weight to obtain sulfonated and aminated partial polyvinyl chloride. Dissolve the sulfonated and aminated partial polyvinyl chloride in ethylene glycol monomethyl ether acetate to prepare a sulfonated and aminated partial polyvinyl chloride solution;

[0112] Put the glass fabric with a thickness of 0.10 mm and a 5 wt% silane coupling agent solution into a stirring kettle for reaction. The dosage ratio of the glass fabric with a thickness of 0.10 mm to the 5 wt% silane coupling agent is 1 g:5 mL. Set the temperature at 70 °C, keep the temperature for reaction for 3 h, and the stirring rate is 120 rpm. After the reaction kettle is cooled to room temperature, take out the silanized glass fabric precursor, rinse it 5 times with cold ethanol at a temperature of 10 °C, and then place it in a drying oven for vacuum baking at 120 °C for 2 h to obtain the silanized glass fabric;

[0113] Spin-coat the sulfonated polyvinylidene chloride solution on the surface of the silanized glass fabric to form a coating with a thickness of 200 μm to obtain the coated glass fabric. Place the coated glass fabric in a drying furnace at 80 °C for vacuum heat treatment for 1 h to obtain the modified glass fabric;

[0114] Immerse the modified glass fabric in a 25 wt% glutaraldehyde solution. The dosage ratio of the modified glass fabric to the 25 wt% glutaraldehyde solution is 1 g:5 mL. The soaking temperature is 45 °C, keep the temperature for reaction for 4 h, take out the modified glass fabric, and place the post-modified glass fabric in a drying oven at 80 °C for vacuum drying to constant weight to obtain the modified cation exchange membrane precursor.

[0115] S4. Prepare the modified anion exchange precursor

[0116] Add the activated CNTs / TiO2-CuO and a 15 wt% polyethersulfone solution into the reaction kettle according to the dosage ratio of 1 g:10 ml. Raise the temperature of the reaction kettle to 35 °C, set the frequency at 40 kHz, keep the temperature for ultrasonic treatment for 1 h, set the frequency at 40 kHz, carry out suction filtration, and place the filter cake in a drying oven at 80 °C for vacuum drying to constant weight to obtain the composite polyethersulfone membrane;

[0117] Immerse the composite polyethersulfone membrane in a mixed solution composed of 8 wt% chloromethane and 25 wt% aluminum chloride. The dosage ratio of the composite polyethersulfone, 8 wt% chloromethane and 25 wt% aluminum chloride is 1 g:5 mL:3 mL. The soaking temperature is 60 °C, keep the temperature for reaction for 2 h, carry out suction filtration, and place the filter cake in a drying oven at 80 °C for vacuum drying to constant weight to obtain the halogenated membrane;

[0118] Immerse the halogenated membrane in a 25 wt% trimethylamine solution. The dosage ratio of the halogenated membrane to the 25 wt% trimethylamine solution is 1 g:5 mL. The soaking temperature is 50 °C, keep the temperature for reaction for 3 h, carry out suction filtration, and place the filter cake in a drying oven at 80 °C for vacuum drying to constant weight to obtain the modified anion exchange membrane precursor.

[0119] S5. Chemical plating

[0120] Mix nickel chloride, sodium hypophosphite, sodium citrate, sodium dodecylbenzenesulfonate, sodium thiosulfate, sodium acetate and deionized water in a weight ratio of 3:5:6:0.01:0.05:0.05:30 to prepare an electroless plating solution;

[0121] Place the modified cation exchange membrane precursor and the modified anion exchange membrane precursor in the electroless plating solution, keep it warm at 30 °C for 2 h for plating, and after the plating is completed, rinse the plated ion exchange membrane with deionized water until it is neutral to obtain a modified ion exchange membrane.

[0122] S6. Electrodialysis

[0123] Assemble the cation exchange membrane and the anion exchange membrane into an electrodialysis device: set the voltage of the electrodialysis device to 60 V, introduce ozone into the ion exchange membrane at a rate of 10 L / h, set the electrodialysis time to 6 h, take out the electrodialysis water and the salt-collecting solution, and repeat the electrodialysis operation of the electrodialysis water 2 times. After concentration, a high-salt solution and drainable water are obtained respectively. Example 3

[0124] This example provides a method for treating high-concentration saline organic wastewater, including the following steps:

[0125] S1. Pretreat the high-salt and high-organic matter solution

[0126] Mix the high-salt organic solution and deionized water in a volume ratio of 1:2 in a reaction kettle and stir. The stirring rate of the stirring kettle is 120 rpm, and stir at room temperature for 15 min to obtain a diluted solution;

[0127] Lower the temperature of the reaction kettle containing the diluted solution to 0 °C, keep it warm and stand for 5 h, then separate the solid-liquid mixture to obtain high-salt ice and a low-salt and high-organic matter solution;

[0128] Mix the low-salt and high-organic matter with dichloromethane in a volume ratio of 0.5:1 to obtain a mixed solution. Add the mixed solution to the reaction kettle and stir. Set the rotation speed to 120 rpm, keep it warm and stir for 2 h, stand for 30 min, collect the organic solution and the low-salt and low-organic matter solution. After the high-salt ice melts, mix it with the low-salt and low-organic matter solution to obtain a high-salt and low-organic matter solution.

[0129] S2. Prepare activated CNTs / TiO2-CuO

[0130] Add single-walled carbon nanotubes, acetamide and organic solvent in a dosage ratio of 1 g:2 g:15 mL to a reaction kettle and stir. Raise the temperature of the reaction kettle to 60 °C, keep it warm and react for 8 h, then filter by suction. Place the filter cake in a drying oven at 80 °C and vacuum dry it until the filter cake reaches a constant weight to obtain modified carbon nanotubes;

[0131] Mix 2 g of nano-TiO₂, 1 g of nano-CuO, and 5 g of modified carbon nanotubes with 40 mL of N,N-dimethylformamide to obtain a mixed solution. Add the mixed solution to an ultrasonic device and ultrasonicate. The ultrasonic device is set at 80 °C with a frequency of 60 kHz, and keep warm and ultrasonicate for 5 h. Then, perform suction filtration. Place the filter cake in a drying oven at 80 °C and vacuum dry it until the filter cake reaches a constant weight to obtain CNTs / TiO₂-CuO;

[0132] Add CNTs / TiO₂-CuO, dichloromethane, and 3-aminopropyltriethoxysilane to a reaction kettle in a dosage ratio of 1 g:20 mL:4 g and stir. Raise the temperature of the reaction kettle to 60 °C, keep warm and react for 8 h, and then perform post-treatment to obtain activated CNTs / TiO₂-CuO.

[0133] S3. Prepare a precursor of a modified cation exchange membrane

[0134] Add activated CNTs / TiO₂-CuO and a 20 wt% solution of partially hydrolyzed polyvinyl chloride to a reaction kettle. Raise the temperature of the reaction kettle to 40 °C, set the frequency at 80 kHz, keep warm and ultrasonicate for 2 h. Then, perform suction filtration. Place the filter cake in a drying oven at 80 °C and vacuum dry it until it reaches a constant weight to obtain modified partially hydrolyzed polyvinyl chloride;

[0135] Soak the modified partially hydrolyzed polyvinyl chloride in a 50 wt% sulfuric acid solution and a 5 wt% hydrogen peroxide solution. The dosage ratio of the modified partially hydrolyzed polyvinyl chloride, the 50 wt% sulfuric acid solution, and the 5 wt% hydrogen peroxide solution is 1 g:4 mL:1 mL. The soaking temperature is 80 °C, keep warm and react for 4 h. Then, perform suction filtration. Place the filter cake in a drying oven at 80 °C and vacuum dry it until it reaches a constant weight to obtain sulfonated partially hydrolyzed polyvinyl chloride;

[0136] Soak the sulfonated partially hydrolyzed polyvinyl chloride in a 30 wt% sodium hydroxide solution and a 50 wt% ammonia water solution. The dosage ratio of the sulfonated partially hydrolyzed polyvinyl chloride, the 30 wt% sodium hydroxide solution, and the 50 wt% ammonia water solution is 1 g:1 mL:4 mL. The soaking temperature is 50 °C, keep warm and react for 4 h. Then, perform suction filtration. Place the filter cake in a drying oven at 80 °C and vacuum dry it until it reaches a constant weight to obtain sulfonated and aminated partially hydrolyzed polyvinyl chloride. Dissolve the sulfonated and aminated partially hydrolyzed polyvinyl chloride in ethylene glycol monomethyl ether acetate to prepare a sulfonated and aminated partially hydrolyzed polyvinyl chloride solution;

[0137] Put a glass fabric with a thickness of 0.75 mm and a 5 wt% silane coupling agent solution into a stirring kettle for reaction. The dosage ratio of the glass fabric with a thickness of 0.75 mm and the 5 wt% silane coupling agent is 1 g:5 mL. Set the temperature at 80 °C, keep warm and react for 3 h, and the stirring rate is 120 rpm. After the reaction kettle cools to room temperature, take out the precursor of the silylated glass fabric, rinse it 5 times with cold ethanol at 10 °C, and then place it in a drying oven and vacuum bake it at 120 °C for 2 h to obtain silylated glass fabric;

[0138] Spin-coat the sulfonated polyvinylidene chloride solution on the surface of the silanized glass fabric to form a coating with a thickness of 175 μm, obtaining a coated glass fabric. Place the coated glass fabric in a drying oven at 80 °C for vacuum heat treatment for 1 h to obtain a modified glass fabric;

[0139] Immerse the modified glass fabric in a 30 wt% glutaraldehyde solution, where the dosage ratio of the modified glass fabric to the 30 wt% glutaraldehyde solution is 1 g:5 mL, the soaking temperature is 50 °C, keep warm and react for 5 h, take out the modified glass fabric, and place the post-modified glass fabric in a drying oven at 80 °C for vacuum drying to constant weight to obtain a modified cation exchange membrane precursor.

[0140] S4. Prepare a modified anion exchange precursor

[0141] Add the activated CNTs / TiO2-CuO and 20 wt% polyethersulfone solution to the reaction kettle according to the dosage ratio of 1 g:10 ml, raise the temperature of the reaction kettle to 40 °C, set the frequency to 80 kHz, keep warm and ultrasonicate for 2 h, perform suction filtration, and place the filter cake in a drying oven at 80 °C for vacuum drying to constant weight to obtain a composite polyethersulfone membrane;

[0142] Immerse the composite polyethersulfone membrane in 10 wt% chloromethane and 30 wt% aluminum chloride, where the dosage ratio of the composite polyethersulfone, 10 wt% chloromethane and 30 wt% aluminum chloride is 1 g:5 mL:3 mL, the soaking temperature is 70 °C, the reaction time is 3 h, perform suction filtration, and place the filter cake in a drying oven at 80 °C for vacuum drying to constant weight to obtain a halomethylated membrane;

[0143] Immerse the halomethylated membrane in a 30 wt% trimethylamine solution, where the dosage ratio of the halogenated membrane to the 30 wt% trimethylamine solution is 1 g:5 mL, the soaking temperature is 60 °C, keep warm and react for 4 h, perform suction filtration, and place the filter cake in a drying oven at 80 °C for vacuum drying to constant weight to obtain a modified anion exchange membrane precursor.

[0144] S5. Chemical plating

[0145] Prepare a chemical plating solution by mixing nickel chloride, sodium hypophosphite, sodium citrate, sodium dodecylbenzenesulfonate, sodium thiosulfate, sodium acetate and deionized water according to the weight ratio of 5:10:12:0.2:0.1:0.1:60;

[0146] Place the modified cation exchange membrane precursor and the modified anion exchange membrane precursor in the chemical plating solution and keep warm for plating at 40 °C for 2 h. After the plating is completed, rinse the plated ion exchange membrane with deionized water until it is neutral to obtain a modified ion exchange membrane.

[0147] S6. Electrodialysis

[0148] Assemble a cation exchange membrane and an anion exchange membrane into an electrodialysis device. Set the voltage of the electrodialysis device to 80 V, introduce ozone into the ion exchange membrane at a rate of 10 L / h, set the electrodialysis time to 7 h. After taking out the electrodialyzed water and the salt-collecting solution, repeat the electrodialysis operation on the electrodialyzed water 3 times, and then concentrate them respectively to obtain a high-salt solution and water that can be discharged.

[0149] Comparative Example 1

[0150] The difference between this comparative example and Example 3 is that the pretreatment of the high-salt and high-organic matter solution is as follows: Add 1 g / L of the flocculant polyaluminum chloride to the wastewater, let it stand for 0.5 h, and then filter it with activated carbon.

[0151] Comparative Example 2

[0152] The difference between this comparative example and Example 3 is that step S2 is cancelled, and the use of activated CNTs / TiO2-CuO in the subsequent steps is cancelled.

[0153] Comparative Example 3

[0154] The difference between this comparative example and Example 3 is that in step S3, the modification process of the glass fabric is cancelled, and the glass fabric is not used as the matrix for modifying the cation exchange.

[0155] According to the standard GB 8978-1996 "Integrated Wastewater Discharge Standard", the water that can be discharged obtained from Examples 1-3 and Comparative Examples 1-2 is detected: After repeating the electrodialysis operation on the ion exchange membranes prepared in Example 3 and Comparative Example 3, the water that can be discharged in different batches is inspected according to the standard GB 8978-1996 "Integrated Wastewater Discharge Standard", and the inspection data results are shown in Tables 1-2.

[0156] Table 1 - Data Sheet for Content Detection of Water that can be Discharged

[0157] Table 2 - Data Sheet for Cyclic Electrodialysis Detection of Ion Exchange Membranes

[0158] Data Analysis:

[0159] Analyze the data in Table 1 above. In the method for treating high-concentration saline organic wastewater, by comparing Example 3 and Comparative Example 1, it can be found that compared with directly using a flocculant for treatment, the pretreatment method of the present invention separates organic matter more fully;

[0160] By comparing Example 3 and Comparative Example 2, it can be found that using activated CNTs / TiO2-CuO to treat the ion exchange membrane can effectively promote the oxidation of organic matter by the oxidant during the electrodialysis process and thus meet the discharge standard;

[0161] Analyze the data in Table 2 above. When preparing the ion exchange membrane, silanized glass fabric is introduced, and effective component separation of wastewater can still be achieved after ten times of electrodialysis treatment.

[0162] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation manners. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification in order to better explain the principle and practical application of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A method for treating high-concentration saline organic wastewater, characterized in that: The following steps are involved: S1, pre-treating the high-salt organic solution to obtain a low-salt and low-organic solution; S2, assembling the modified cation exchange membrane and the modified anion exchange membrane into an electrodialysis device, and using the electrodialysis device to treat the high-salt and low-organic solution to obtain a high-salt solution and dischargeable water; The preparation method of the modified cation exchange membrane is as follows: adding activated CNTs / TiO2-CuO and 10-20wt% polyvinylidene chloride solution into a reactor and stirring, raising the temperature of the reactor to 30-40°C, keeping the temperature and ultrasonicating for 1-2h, post-treating to obtain modified polyvinylidene chloride, coupling-modifying the modified polyvinylidene chloride to obtain a modified cation exchange membrane precursor, and plating the modified cation exchange membrane precursor with a chemical plating solution to obtain a modified cation exchange membrane, wherein the amount ratio of activated CNTs / TiO2-CuO and 10-20 wt% polyvinylidene chloride solution is 1g:10ml, and the ultrasonic frequency is 20-80kHz; The coupling modification of the modified polyvinylidene chloride comprises the following steps: C1, soaking the modified polyvinylidene chloride in a mixed solution consisting of 30-50wt% sulfuric acid solution and 1-5wt% hydrogen peroxide solution, the mixed solution temperature is 60-80°C, and the mixture is soaked for 2-4 hours, and post-processed to obtain sulfonated polyvinylidene chloride; C2, soaking the sulfonated polyvinylidene chloride in a mixed solution consisting of 20-30wt% sodium hydroxide solution and 30-50wt% ammonia solution, the mixed solution temperature is 30-50°C, and the mixture is soaked for 2-4h, post-processed to obtain sulfonated polyvinylidene chloride, and the sulfonated polyvinylidene chloride is dissolved in ethylene glycol monomethyl ether acetate to prepare a sulfonated polyvinylidene chloride solution; C3, spin coating the sulfonated polyvinylidene chloride solution on the surface of the silanized glass fabric to form a coating with a thickness of 150-200 μm to obtain a coated glass fabric, placing the coated glass fabric in a drying oven at 80° C. for vacuum heat treatment for 1 h to obtain a modified glass fabric; C4, immersing the modified glass fabric in a 20-30wt% glutaraldehyde solution at a soaking temperature of 40-50°C, keeping the solution warm for 3-5h, and post-treating to obtain a modified cation exchange membrane precursor; The preparation method of the modified anion exchange membrane is as follows: adding activated CNTs / TiO2-CuO and 10-20 wt% polyethersulfone solution into a reactor and stirring, raising the temperature of the reactor to 30-40°C, keeping the temperature and ultrasonicating for 1-2 hours, post-treating to obtain a composite polyethersulfone membrane, modifying the composite polyethersulfone membrane to obtain a modified anion exchange membrane precursor, and plating the modified anion exchange membrane precursor with a chemical plating solution to obtain a modified anion exchange membrane, wherein the amount ratio of activated CNTs / TiO2-CuO and 10-20 wt% polyethersulfone solution is 1g:10ml, and the ultrasonic frequency is 20-80kHz; The composite polyethersulfone membrane is modified, comprising the following steps: D1, soaking the composite polyethersulfone membrane in 5-10wt% methyl chloride and 20-30wt% aluminum chloride at a temperature of 50-70°C, keeping the temperature for reaction for 1-3h to obtain an impregnated membrane, and post-treating to obtain a halogenated membrane; D2. Soak the halogenated membrane in a 20-30 wt% trimethylamine solution at a soaking temperature of 40-60°C, keep the solution warm for 2-4 hours, and post-treat to obtain a modified anion exchange membrane precursor.

2. The method for treating high-concentration saline organic wastewater according to claim 1, characterized in that: In step S1, the pre-processing operation includes the following steps: A1. Add high-salt organic solution and deionized water into a reactor and stir for 5-15 minutes at room temperature to obtain a diluted solution; A2. Lower the temperature of the reactor containing the diluted solution to 0-5°C, stir for 3-5 hours, and filter to obtain inorganic salt crystals and a low-salt, high-organic matter solution; A3. Add the low-salt high-organic matter solution and the extract into a reaction kettle and stir. Stir for 20-30 minutes at room temperature. Allow to stand and separate the liquids to obtain an organic solution and a low-salt low-organic matter solution.

3. The method for treating high-concentration saline organic wastewater according to claim 2, characterized in that: In step A1, the volume ratio of deionized water to high-salt organic solution is 2:1, and the stirring rate is 120 rpm; in step A3, the extractant is one or more of ethyl acetate, dichloromethane, and ether, the volume ratio of the extractant to the mixed solution is 0.5:1, and the stirring rate is 120 rpm.

4. The method for treating high-concentration saline organic wastewater according to claim 1, characterized in that: Activated CNTs / TiO2-CuO was prepared by the following steps: B1, adding single-walled carbon nanotubes, amide compounds and dichloromethane into a reactor, raising the temperature of the reactor to 40-60°C, keeping the temperature for 6-8h, and post-treating to obtain modified carbon nanotubes; B2, mixing nano-TiO2, nano-CuO and modified carbon nanotubes in N,N-dimethylformamide to obtain a mixed solution, adding the mixed solution to an ultrasonic device for ultrasonication, the ultrasonic device is set at 60-80°C, the frequency is 40-60kHz, the temperature is kept for reaction for 3-5h, and post-processing is performed to obtain CNTs / TiO2-CuO; B3. Add CNTs / TiO2-CuO, silane coupling agent and organic solvent into a reactor and stir. Raise the temperature of the reactor to 40-60°C and keep the reaction for 6-8h. Post-treat to obtain activated CNTs / TiO2-CuO.

5. The method for treating high-concentration saline organic wastewater according to claim 1, characterized in that: The silanized glass fabric is prepared by the following steps: a glass fabric with a thickness of 0.05-0.10 mm and a 0.5-5wt% silane coupling agent solution are placed in a stirring kettle and stirred, the temperature of the reactor is increased to 60-80°C, the stirring rate is set to 120rpm, and the reaction is kept warm for 2-3 hours. After the reaction is completed, the reactor is cooled to room temperature, the silanized glass fabric precursor is taken out, rinsed with cold ethanol at a temperature of 10°C for 3-5 times, and then placed in a drying oven and vacuum baked at 110-120°C for 1-2 hours to obtain the silanized glass fabric.

6. The method for treating high-concentration saline organic wastewater according to claim 1, characterized in that: The plating includes the following steps: placing the membrane substrate in a chemical plating solution, keeping the plating at a temperature of 20-40°C for 1-2 hours, and after the plating is completed, using deionized water to rinse the plated ion exchange membrane to neutrality to obtain a modified ion exchange membrane, wherein the membrane substrate is a modified cation exchange membrane precursor or a modified anion exchange membrane precursor.

7. The method for treating high-concentration saline organic wastewater according to claim 1, characterized in that: In step S2, the wastewater treatment includes the following steps: setting the voltage of the electrodialysis equipment to 20-80V, introducing ozone into the ion exchange membrane at a rate of 10L / h, setting the electrodialysis time to 6-7h, taking out the electrodialysis water and the salt solution, repeating the electrodialysis operation 2-3 times, and concentrating them to obtain a high salt solution and dischargeable water.

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