A method for removing inert organic substances from a high-salinity chemical wastewater split mother liquor

Abstract

A method for removing inert organic matters from chemical high-salinity wastewater, comprising the following steps: pretreatment, reacting the chemical high-salinity wastewater under the action of a micro electric field and catalyst A, and controlling the process elements of the reaction to obtain pretreated wastewater; re-treatment, successively reacting the pretreated wastewater under the action of a micro electric field and catalyst B, and controlling the process elements of the successive reaction to obtain re-treated wastewater; filtration, precisely filtering the re-treated wastewater, and controlling the process elements of the precise filtration to obtain filtered water; and adsorption treatment, adsorbing the filtered water to obtain the chemical high-salinity wastewater from which the inert organic matters are removed. The method has the advantages of short process flow, stable and reliable process, low treatment cost, and the ability to meet the requirements of non-heterogeneous treatment of the chemical high-salinity wastewater and lay the foundation for the resource recycling of the purified mother liquor.

Description

Technical Field

[0001] This invention belongs to the field of chemical high-salt wastewater desalination mother liquor treatment technology and water resource comprehensive utilization technology, specifically involving a method for removing inert organic matter from chemical high-salt wastewater desalination mother liquor. Background Technology

[0002] High-salt chemical wastewater refers to: ① large amounts of high-COD, high-salt, and toxic wastewater generated during the production of chemical products such as coal chemical, petrochemical, metallurgical, fine chemical, dye, and pesticide products, due to incomplete chemical reactions or chemical byproducts; ② wastewater treatment, including mineralization resulting from the addition of water treatment agents, acids, and alkalis, as well as concentrated liquid generated from the recovery of most of the "freshwater".

[0003] After passing through a "zero-discharge system," high-salt chemical wastewater yields concentrated water with a total dissolved solids (TDS) content exceeding 5%, which is difficult to treat biochemically. This concentrated water is further treated using a salt separation and crystallization process to obtain recyclable byproduct salts, namely sodium sulfate (Na₂SO₄) and sodium chloride (NaCl). However, the residual inert COD in the concentrated water causes the salt separation and crystallization process to generate some mother liquor. Currently, the common practice in the chemical industry is to evaporate and crystallize this mother liquor to produce mixed salts (i.e., hazardous waste, accounting for 15-20% of the total salt content). The disposal cost of these mixed salts is 2000-5000 yuan / ton, placing a significant economic burden on chemical enterprises.

[0004] The inert organic compounds remaining in the aforementioned mother liquor include nearly 40 kinds such as humin, fulvic acid, dimethylpyridine, acetophenone, acetone, glutaraldehyde, citric anhydride, methyl thiocyanate, and ethylacetamide. Due to the characteristics of complex composition, small relative molecular weight (generally less than 150 Da), high biotoxicity, and difficulty in degradation, it is very difficult to remove them using conventional techniques.

[0005] There are several existing methods for removing inert COD from the aforementioned mother liquor, mainly including: ① electrocoagulation oxidation; ② electrocatalytic oxidation; ③ photocatalysis + Fenton oxidation; ④ ozone oxidation. The disadvantage of electrocoagulation oxidation is its lack of safety, as the mother liquor contains a high amount of sodium chloride. Upon energization, hydrogen (H2) and chlorine (Cl2) are generated at the cathode and anode, respectively. If not separated and collected promptly, this can lead to chlorine poisoning or even an explosion of the mixed gas. The disadvantages of electrocatalytic oxidation are high investment costs and unsuitability for high-salinity wastewater. Similar to electrocoagulation, high sodium chloride content in the wastewater poses a safety hazard. The disadvantages of photocatalysis + Fenton oxidation include a narrow ultraviolet light absorption range, low light energy utilization, and the dark color of the wastewater affecting light transmittance. Additionally, Fenton oxidation requires the addition of ferrous sulfate, generating a large amount of sludge. The disadvantages of ozone oxidation are high investment costs, high operating costs, and unsatisfactory removal of inert COD.

[0006] Currently, the concentrated wastewater from the "zero discharge" treatment of high-salt chemical wastewater in my country is mainly treated with salt separation and crystallization processes, producing sodium sulfate and sodium chloride as byproducts. Due to the difficulty in removing inert organic matter from this concentrated wastewater, the mother liquor produced by the salt separation and crystallization process cannot be utilized as a resource, resulting in 2-3 million tons of mixed salts per year. These mixed salts are classified as hazardous waste, and with a hazardous waste disposal fee of 3,000 yuan per ton, this places a heavy economic burden on the chemical industry. Therefore, effectively removing the inert organic matter from the mother liquor and turning waste into treasure has both immediate economic and social benefits.

[0007] Therefore, it is of positive significance to explore methods for removing residual inert organic matter from mother liquor of high-salt wastewater. More specifically, how to simplify the process, reduce the treatment cost, achieve the elimination of impurities in the mother liquor of high-salt wastewater treatment, and ensure the resource reuse of the mother liquor are the technical problems that urgently need to be solved in this field. Summary of the Invention

[0008] The objective of this invention is to provide a method for removing inert organic matter from the mother liquor of high-salt chemical wastewater. This method features a simple and stable process, low processing cost, and can meet the requirements for the non-hybridization treatment of the mother liquor of high-salt chemical wastewater, laying the foundation for the resource-based reuse of the purified mother liquor.

[0009] The objective of this invention is achieved by providing a method for removing inert organic matter from a mother liquor containing high-salt chemical wastewater, comprising the following steps:

[0010] (1) Pretreatment: The mother liquor of high-salt chemical wastewater is reacted under the action of a micro-electric field and catalyst A, and the process elements of the reaction are controlled to obtain pretreated wastewater;

[0011] (2) Reprocessing: The pretreated wastewater obtained in step (1) is then reacted under the action of a micro-electric field and catalyst B, and the process elements of the subsequent reaction are controlled to obtain reprocessed wastewater;

[0012] (3) Filtration: The retreated wastewater obtained in step (2) is subjected to precision filtration, and the process elements of precision filtration are controlled to obtain filtered water.

[0013] (4) Adsorption treatment: The filtered water obtained in step (3) is subjected to adsorption treatment to obtain a high-salt chemical wastewater desalination mother liquor from which inert organic matter has been removed.

[0014] In a specific embodiment of the present invention, the process element for controlling the reaction in step (1) refers to: firstly, pumping the desalination mother liquor of high-salt chemical waste into the first regulating tank, which serves as a primary reaction unit, and adjusting the water temperature and pH value of the water in the first regulating tank; after the water temperature and pH value adjustment is completed, introducing it into the first micro-electric field reaction tank for aeration reaction; then overflowing it into the second micro-electric field reaction tank, adding catalyst A into the second micro-electric field reaction tank, continuing the aeration reaction; and finally pumping it into the first clarification tank for clarification. The supernatant in the first clarification tank serves as the pretreated wastewater obtained in step (1), while the bottom sludge in the first clarification tank is returned to the second micro-electric field reaction tank; the process element for controlling the subsequent reaction in step (2) refers to: firstly, pumping the pretreated wastewater obtained in step (1) from the first clarification tank into the second regulating tank, which serves as a secondary reaction unit, and adjusting the water temperature and pH value of the pretreated wastewater in the second regulating tank; after the water temperature and pH value adjustment is completed, introducing it into the third micro-electric field reaction tank. Furthermore, hydrogen peroxide is added to the third micro-electric field reaction tank for aeration, and then catalyst B is added. Under the action of the third micro-electric field and catalyst B, aeration continues. Then, it is pumped into the third regulating tank for regulation, and finally pumped into the second clarification tank. The supernatant in the second clarification tank is the retreated wastewater obtained in step (2). The process elements of controlling precision filtration in step (3) refer to: first, the retreated wastewater obtained in step (2) is pumped from the second clarification tank into a multi-media filter, which serves as a precision filtration unit. After filtration by the multi-media filter, it is pumped into a security filter. The water obtained after filtration by the security filter is the filtered water. The adsorption treatment of the filtered water obtained in step (4) is: first, the filtered water is pumped into the fourth regulating tank, which serves as a mesoporous separation unit, for regulation. Then, the regulated filtered water is pumped into the mesoporous separation system. Finally, the product water separated by the mesoporous separation system is pumped into a storage tank. The water in the storage tank is the chemical high-salt wastewater desalination mother liquor from which inert organic matter has been removed in step (4).

[0015] In another specific embodiment of the present invention, the water temperature and pH adjustment in the first regulating tank mentioned in step (1) are to adjust the water temperature in the first regulating tank to 15-45℃ and the pH value to pH=3-6. The aeration reaction time introduced into the first micro-electric field reaction tank is 20-40 min, and the continued aeration reaction time is 60-90 min. The clarification method in the first clarification tank is natural clarification, and the clarification time is 110-130 min. The air-water volume ratio of the aeration reaction is 2-10:1, and the air-water volume ratio of the continued aeration reaction is also 2-10:1.

[0016] In another specific embodiment of the present invention, the water temperature and pH adjustment of the pretreated wastewater in the second equalization tank in step (2) are as follows: the water temperature is adjusted to 25-45℃ and the pH value is adjusted to pH=3-6; the aeration reaction time of adding hydrogen peroxide is 20-40 min; the aeration reaction time under the action of the third micro-electric field and catalyst B is 60-90 min; the aeration reaction time of adding hydrogen peroxide to the third micro-electric field reaction tank is 20-40 min; the adjustment of the water in the third equalization tank by pumping into the third equalization tank is as follows: the water temperature in the third equalization tank is adjusted to 25-45℃ and the pH value is adjusted to pH=8-8.5℃; the air-water volume ratio of the aeration reaction and the subsequent aeration reaction is 3-15:1.

[0017] In another specific embodiment of the present invention, the multi-media filter described in step (3) is filled with filter media, which is refined quartz sand. The refined quartz sand is filled in three layers, and the particle size of the quartz sand in the three layers decreases from bottom to top. The security filter filters through filter cartridges. The filter cartridges are deep filter cartridges with acid and alkali resistance, uniform pore size, and a high filtration efficiency due to their open outer layer and dense inner layer.

[0018] In another specific embodiment of the present invention, the step (4) of pumping the filtered water into the fourth regulating tank, which serves as a mesoporous separation unit, involves adjusting the water temperature to 35-45°C and the pH value to neutral. The mesoporous separation system consists of one or more groups, with each group consisting of 3-5 adsorption tanks connected in series. The adsorption tanks are filled with mesoporous adsorption material, and inert organic matter is adsorbed and separated at a flow rate of 0.5-2.5 BV.

[0019] In a more specific embodiment of the present invention, the mass ratio of the amount of catalyst A added to the content of inert organic matter is 0.1-0.5:1; the mass ratio of the amount of catalyst B added to the content of inert organic matter is also 0.1-0.5:1; and the mass ratio of the amount of hydrogen peroxide added to the content of inert organic matter is 0.1-0.5:1.

[0020] In a further specific embodiment of the present invention, the material used in the micro-electric field is any one or a combination of iron electrode plates, aluminum electrode plates, graphite electrode plates, diamond electrode plates, titanium-ruthenium-iridium alloy electrode plates, titanium-iridium-tantalum alloy electrode plates, and titanium-tin-tantalum alloy electrode plates; the electrode material used in the micro-electric field is a combination of the following materials A and B: material A includes aluminum and / or iron electrode plates, while material B includes at least one of graphite, diamond, titanium-ruthenium-iridium alloy, titanium-iridium-tantalum alloy electrode plates, and titanium-tin-tantalum alloy electrode plates, wherein, in the first micro-electric field reaction cell, the aluminum electrode area accounts for 10% to 20% of the total electrode area. The iron electrode area accounts for 10% to 20% of the total electrode area, with the remainder being at least one of the materials B; wherein, in the second micro-electric field reaction cell, the iron electrode area accounts for 10% to 20% of the total electrode area, with the remainder being at least one of the materials B; wherein, in the third micro-electric field reaction cell, the electrode plate used is at least one of the materials B, including graphite, diamond, titanium-ruthenium-iridium alloy, titanium-iridium-tantalum alloy electrode plate, and titanium-tin-tantalum alloy electrode plate; the input voltage of the micro-electric field is 1 to 2.5V; the input current is 1 to 3A; and the electrode plate current density is 0.01 to 0.1 mA / cm². 2 The electrode spacing is 5–25 cm.

[0021] In yet another specific embodiment of the present invention, the catalyst A is one or a combination of nonacarbonyl diferric [Fe2(CO)9], diborane (B2H6), boric acid (H3BO3), sulfur trioxide (SO3), boron trichloride (BCl3), boron trifluoride (BF3), aluminum trichloride (AlCl3), dichlorocarbene (CCl2), chloroform (CHCl3), silicon tetrafluoride (SiF4), ferric chloride (FeCl3), and ferric bromide (FeBr3).

[0022] In yet another specific embodiment of the present invention, the catalyst B is methylamine (CH3NH2), aniline (C6H5NH2), ethylenediamine (C2H8N2), or diisopropylamine (C6H5NH2). 15 N), formamide (CH3NO), trifluoroacetic acid (C2HF3O2), dimethyl sulfoxide (C2H6OS), dimethylformamide (C3H7NO), methanol (CH3OH), ethanol (C2H5OH), triethanolamine (C6H 15 NO3), tetrabutylammonium chloride (C 16 H 36 One or more combinations of ClN).

[0023] The technical advantages of the solution provided by this invention are as follows: Since the removal of inert organic matter from the water-deionized mother liquor of high-salt chemical waste is completed by only four steps—pretreatment, retreatment, filtration, and adsorption—it has the advantages of a short process flow, stable and reliable process, low treatment cost, meeting the requirements for hybridization-free treatment of water-deionized mother liquor of high-salt chemical waste, and laying the foundation for the resource-based reuse of the purified mother liquor. Attached Figure Description

[0024] Figure 1 This is a flowchart illustrating an embodiment of the method for removing inert organic matter from the mother liquor of high-salt coal chemical wastewater, as described in this invention. Detailed Implementation

[0025] The following description of the embodiments will not only further illustrate the technical essence of the present invention, but also more comprehensively reveal the following advantages of the present invention: The method for removing inert organic matter from the mother liquor of high-salt coal chemical wastewater, exemplified by the present invention, involves using a micro-electric field and catalysis technology to activate small-molecule inert organic matter in the mother liquor. A micro-electric field is applied to the organic phase nanoparticles to adjust the motion state of their outer electrons. Then, a catalyst is used to further apply ionization energy to the electron cloud of the inert organic matter, causing changes in the bond energy of the inert organic matter in an independent microscopic system, thereby achieving a rearrangement reaction and enabling the activated inert particles to... The wastewater is in a metastable state, thus meeting the separation conditions. After the above two-stage catalytic reaction, the inertness of the organic matter is activated, that is, the organic phase particles in the mother liquor are adjusted from the ground state to the excited state to achieve molecular rearrangement. Finally, the wastewater is pumped into a mesoporous separation system, where mesoporous materials are used for adsorption separation to separate small molecule (molecular diameter <1nm) inert organic matter in the water. Due to the above two-stage catalytic reaction, the inert organic matter can be effectively adsorbed by the mesoporous material, thus ensuring the removal of inert organic matter. The treated mother liquor meets the requirements and standards of subsequent resource chemical processes, and can be further utilized for high-value purposes.

[0026] Depend on Figure 1The flowchart shows that by setting up a primary reaction unit 1, a secondary reaction unit 2, a precision filtration unit 3, and a mesoporous separation unit 4, the process is as follows: First, in the primary reaction unit 1, micro-electric field and catalysis technology are used to activate the activity of small-molecule inert COD, applying a micro-electric field to the organic phase nanoparticles to adjust the motion state of the outer electrons. Second, the wastewater treated in the primary reaction unit 1 is input into the secondary reaction unit 2. In the third micro-electric field reaction tank 22, micro-electric field and catalysis technology are used to further apply ionization energy to the electron cloud of the inert organic matter, causing the bond energy of the inert organic matter to change in an independent microscopic system, thus achieving molecular regeneration. The process involves two stages of catalytic reaction, which activates the inertness of organic matter, causing the organic phase particles in the mother liquor to rearrange from their ground state to an excited state. The effluent from the secondary reaction unit 2 is then filtered through a precision filtration unit 3 to remove fine impurities. Finally, the filtered wastewater is pumped into a mesoporous separation unit 4, where it is adjusted and then adsorbed using mesoporous materials. This process effectively removes inert organic matter, ensuring that the mother liquor meets the requirements and standards of subsequent resource chemical processing, thus clearing obstacles for further high-value utilization.

[0027] Example 1:

[0028] Please see Figure 1 ,according to Figure 1 The process shown describes a method for removing inert organic matter from the mother liquor of high-salt coal chemical wastewater, comprising the following steps:

[0029] (1) Pretreatment: The high-salt wastewater mother liquor from coal chemical industry is reacted under the action of a micro-electric field and catalyst A, and the process elements of the reaction are controlled to obtain pretreated wastewater. The process elements of the reaction controlled in this step are: firstly, the high-salt wastewater mother liquor from coal chemical industry is pumped into the first regulating tank 11, which is the first-stage reaction unit 1, and the water temperature in the first regulating tank 11 is adjusted to 25℃ and the pH value is adjusted to 5. After the water temperature and pH value are adjusted, it is introduced into the first micro-electric field reaction tank 12 for aeration reaction. The aeration reaction time is 35 minutes and the air-to-water volume ratio of the aeration reaction is 10:1. Then, it overflows into the second micro-electric field reaction tank 13, and an inert organic matter content of 0 is added to the second micro-electric field reaction tank 13. The nonacarbonyl ferric [Fe2(CO)9] in a 2:1 ratio as catalyst A is aerated for 90 min, and the gas-to-water volume ratio is 2:1. Finally, it is pumped into the first clarification tank 14 for clarification. The clarification time in the first clarification tank 14 is controlled at 130 min. The supernatant in the first clarification tank 14 is used as the pretreated wastewater obtained in step (1), while the bottom sludge of the first clarification tank 14 is returned to the second micro-electric field reaction tank 13. In the first micro-electric field reaction tank 12 mentioned above, the aluminum electrode area accounts for 20% of the total electrode area, the iron electrode area accounts for 10% of the total electrode area, and the remainder is graphite and diamond. In the second micro-electrode reaction tank 13 mentioned above, the iron electrode area accounts for 20% of the total electrode area, and the remainder is titanium-tin-tantalum alloy electrode plate.

[0030] (2) Reprocessing: The pretreated wastewater obtained in step (1) is further reacted under the action of a micro-electric field and catalyst B. The process elements of the subsequent reaction are controlled to obtain reprocessed wastewater. The process elements of the subsequent reaction mentioned in this step are: first, the pretreated wastewater obtained in step (1) is pumped from the first clarifier 14 into the second regulating tank 21, which is the secondary reaction unit 2. The water temperature and pH value of the pretreated wastewater in the second regulating tank 21 are adjusted to 45°C and pH value is adjusted to pH=4. After the water temperature and pH value are adjusted, it is introduced into the third micro-electric field reaction tank 22 and hydrogen peroxide is added to the third micro-electric field reaction tank 22 for aeration reaction for 30 minutes. Then, catalyst B is added, and the reaction is further aerated for 60 minutes under the action of the third micro-electric field and catalyst B. Then, it is pumped into the third regulating tank 23 for adjustment. Finally, it is pumped... The wastewater is introduced into the second clarification tank 24. The supernatant in the second clarification tank 24 is the retreated wastewater obtained in step (2). In this step, the mass percentage of hydrogen peroxide added (i.e., added) to the inert organic matter content is 0.5:1, and the mass percentage of catalyst B added to the inert organic matter content is 0.1:1. The catalyst B is a mixture of methylamine (CH3NH2), aniline (C6H5NH2), and ethylenediamine (C2H8N2) in any proportion. The adjustment in the third regulating tank 23 is to adjust the water temperature in the third regulating tank 23 to 45°C and adjust the pH value to pH=8-8.5. The electrode plates used in the third micro-electric field reaction tank 22 in this step are graphite and titanium-tin-tantalum alloy electrode plates. The gas-water volume ratio of the aeration reaction and the subsequent aeration reaction is 10:1.

[0031] (3) Filtration: The retreated wastewater obtained in step (2) is subjected to precision filtration, and the process elements of precision filtration are controlled to obtain filtered water. The process elements of precision filtration mentioned in this step refer to: first, the retreated wastewater obtained in step (2) is pumped from the second clarifier 24 into a multi-media filter 31, which serves as the precision filtration unit 3; after filtration by the multi-media filter 31, it is pumped into a security filter 32; and the water obtained after filtration by the security filter 32 is the filtered water. The multi-media filter 31 is filled with filter media, which is refined quartz sand. The refined quartz sand is filled in three layers, and the particle size of the quartz sand in the three layers decreases from bottom to top (i.e., becomes coarser from top to bottom). The security filter 32 is filtered by a filter element. The filter element is a deep filter element structure that is acid and alkali resistant, has uniform pore size, and is sparse on the outside and dense on the inside, thus exhibiting high filtration efficiency.

[0032] (4) Adsorption treatment: The filtered water obtained in step (3) is subjected to adsorption treatment to obtain a chemical high-salt wastewater desalination mother liquor from which inert organic matter has been removed. In this step, the filtered water is pumped into the fourth conditioning tank 41, which is the mesoporous separation unit 4, to adjust the water temperature to 45°C and the pH value to neutral. The aforementioned mesoporous separation system 42 consists of one or more groups, and each group consists of 3-5 adsorption tanks connected in series. The adsorption tanks are filled with mesoporous adsorption material, and inert organic matter is adsorbed and separated at a flow rate of 0.5-2.5 BV. The product water separated by the mesoporous separation system 42 is pumped into the storage tank 43. The water in the storage tank 43 is the chemical high-salt wastewater desalination mother liquor from which inert organic matter has been removed as described in step (4).

[0033] In this embodiment, the input voltage of the micro-electric field mentioned in steps (1) and (2) is 1-2.5V, the input current is 1-3A, and the plate current density is 0.01-0.1mA / cm². 2 The electrode spacing is 5-25cm.

[0034] Example 2:

[0035] Please see Figure 1 ,according to Figure 1 The process shown describes a method for removing inert organic matter from the mother liquor of high-salt coal chemical wastewater, comprising the following steps:

[0036] (1) Pretreatment: The high-salt coal chemical wastewater desalination mother liquor is reacted under the action of a micro-electric field and catalyst A, and the process elements of the reaction are controlled to obtain pretreated wastewater. The process elements of the reaction controlled in this step are: firstly, the high-salt coal chemical wastewater desalination mother liquor is pumped into the first regulating tank 11, which is the first-stage reaction unit 1, and the water temperature in the first regulating tank 11 is adjusted to 15℃ and the pH value is adjusted to 4.5. After the water temperature and pH value are adjusted, it is introduced into the first micro-electric field reaction tank 12 for aeration reaction. The aeration reaction time is 30 min, and the air-to-water volume ratio of the aeration reaction is 6:1. Then, it overflows into the second micro-electric field reaction tank 13, and boric acid (H3B4) as catalyst A is added to the second micro-electric field reaction tank 13 at a mass ratio of 0.5:1 to the inert organic matter content. A mixture of O3, boron trifluoride (BF3), and boron trichloride (BCl3) in any proportion is aerated and reacted for 60 minutes. The gas-to-water volume ratio during the aeration reaction is 5:1. Finally, the mixture is pumped into the first clarification tank 14 for clarification. The clarification time in the first clarification tank 14 is controlled to be 110 minutes. The supernatant in the first clarification tank 14 is used as the pretreated wastewater obtained in step (1). The bottom sludge of the first clarification tank 14 is returned to the second micro-electric field reaction tank 13. In the first micro-electric field reaction tank 12 mentioned above, the aluminum electrode area accounts for 18% of the total electrode area, the iron electrode area accounts for 13% of the total electrode area, and the remainder is titanium-iridium-tantalum alloy plate. In the second micro-electrode reaction tank 13 mentioned above, the iron electrode area accounts for 15% of the total electrode area, and the remainder is aluminum electrode plate, graphite electrode plate, and diamond electrode plate.

[0037] (2) Reprocessing: The pretreated wastewater obtained in step (1) is further reacted under the action of a micro-electric field and catalyst B. The process elements of the subsequent reaction are controlled to obtain retreated wastewater. The process elements of the subsequent reaction controlled in this step are: first, the pretreated wastewater obtained in step (1) is pumped from the first clarifier 14 into the second regulating tank 21, which is the secondary reaction unit 2. The water temperature and pH value of the pretreated wastewater in the second regulating tank 21 are adjusted to 25°C and pH value is adjusted to pH=3. After the water temperature and pH value are adjusted, it is introduced into the third micro-electric field reaction tank 22, and hydrogen peroxide is added to the third micro-electric field reaction tank 22 for aeration reaction for 20 minutes. Then, catalyst B is added, and the reaction is further aerated for 70 minutes under the action of the third micro-electric field and catalyst B. Then, it is pumped into the third equalization tank 23 for adjustment, and finally pumped into the second clarification tank 24. The supernatant in the second clarification tank 24 is the retreated wastewater obtained in step (2). In this step, the mass percentage of hydrogen peroxide added (i.e., added) to the inert organic matter content is 0.4:1, and the mass percentage of catalyst B added to the inert organic matter content is 0.2:1. The catalyst B is dimethylformamide (C3H7NO). The adjustment in the third equalization tank 23 is to adjust the water temperature in the third equalization tank 23 to 30°C and adjust the pH value to pH=8-8.5. The electrode plate used in the third micro-electric field reaction tank 22 in this step is a titanium-ruthenium-iridium alloy electrode plate. The air-water volume ratio of the aeration reaction and the subsequent aeration reaction is 3:1.

[0038] (3) Filtration: The retreated wastewater obtained in step (2) is subjected to precision filtration, and the process elements of precision filtration are controlled to obtain filtered water. The process elements of precision filtration mentioned in this step refer to: first, the retreated wastewater obtained in step (2) is pumped from the second clarifier 24 into a multi-media filter 31, which serves as the precision filtration unit 3; after filtration by the multi-media filter 31, it is pumped into a security filter 32; and the water obtained after filtration by the security filter 32 is the filtered water. The multi-media filter 31 is filled with filter media, which is refined quartz sand. The refined quartz sand is filled in three layers, and the particle size of the quartz sand in the three layers decreases from bottom to top (i.e., becomes coarser from top to bottom). The security filter 32 is filtered by a filter element. The filter element is a deep filter element structure that is acid and alkali resistant, has uniform pore size, and is sparse on the outside and dense on the inside, thus exhibiting high filtration efficiency.

[0039] (4) Adsorption treatment: The filtered water obtained in step (3) is subjected to adsorption treatment to obtain a chemical high-salt wastewater desalination mother liquor from which inert organic matter has been removed. In this step, the filtered water is pumped into the fourth conditioning tank 41, which is the mesoporous separation unit 4, to adjust the water temperature to 35°C and the pH value to neutral. The aforementioned mesoporous separation system 42 consists of one or more groups, and each group consists of 3-5 adsorption tanks connected in series. The adsorption tanks are filled with mesoporous adsorption material, and inert organic matter is adsorbed and separated at a flow rate of 0.5-2.5 BV. The product water separated by the mesoporous separation system 42 is pumped into the storage tank 43. The water in the storage tank 43 is the chemical high-salt wastewater desalination mother liquor from which inert organic matter has been removed as described in step (4).

[0040] In this embodiment, the input voltage of the micro-electric field mentioned in steps (1) and (2) is 1-2.5V, the input current is 1-3A, and the plate current density is 0.01-0.1mA / cm². 2 The electrode spacing is 5-25cm.

[0041] Example 3:

[0042] Please see Figure 1 ,according to Figure 1 The process shown describes a method for removing inert organic matter from the mother liquor of high-salt coal chemical wastewater, comprising the following steps:

[0043] (1) Pretreatment: The high-salt coal chemical wastewater desalination mother liquor is reacted under the action of a micro-electric field and catalyst A, and the process elements of the reaction are controlled to obtain pretreated wastewater. The process elements of the reaction controlled in this step are: firstly, the high-salt coal chemical wastewater desalination mother liquor is pumped into the first regulating tank 11, which is the first-stage reaction unit 1, and the water temperature in the first regulating tank 11 is adjusted to 35℃ and the pH value is adjusted to 3. After the water temperature and pH value are adjusted, it is introduced into the first micro-electric field reaction tank 12 for aeration reaction. The aeration reaction time is 20 minutes, and the air-to-water volume ratio of the aeration reaction is 2:1. Then, it overflows into the second micro-electric field reaction tank 13, and a mixture of inert organic matter with a mass ratio of 0.3:1 is added to the second micro-electric field reaction tank 13. The mixture of ferric chloride (FeCl3) and ferric bromide (FeBr3) as catalyst A is aerated for 80 minutes, and the gas-to-water volume ratio during the aeration reaction is 10:1. Finally, it is pumped into the first clarification tank 14 for clarification. The clarification time in the first clarification tank 14 is controlled to be 120 minutes. The supernatant in the first clarification tank 14 is used as the pretreated wastewater obtained in step (1), while the bottom sludge of the first clarification tank 14 is returned to the second micro-electric field reaction tank 13. In the first micro-electric field reaction tank 12 mentioned above, the aluminum electrode area accounts for 13% of the total electrode area, the iron electrode area accounts for 18% of the total electrode area, and the remainder is titanium-ruthenium-iridium alloy plate. In the second micro-electrode reaction tank 13 mentioned above, the iron electrode area accounts for 10% of the total electrode area, and the remainder is titanium electrode plate.

[0044] (2) Reprocessing: The pretreated wastewater obtained in step (1) is further reacted under the action of a micro-electric field and catalyst B. The process elements of the subsequent reaction are controlled to obtain reprocessed wastewater. The process elements of the subsequent reaction mentioned in this step are: first, the pretreated wastewater obtained in step (1) is pumped from the first clarifier 14 into the second regulating tank 21, which is the secondary reaction unit 2. The water temperature and pH value of the pretreated wastewater in the second regulating tank 21 are adjusted to 30°C and pH value is adjusted to pH=6. After the water temperature and pH value are adjusted, it is introduced into the third micro-electric field reaction tank 22 and hydrogen peroxide is added to the third micro-electric field reaction tank 22 for aeration reaction for 40 minutes. Then, catalyst B is added, and the reaction is further aerated for 90 minutes under the action of the third micro-electric field and catalyst B. Finally, it is pumped into the third regulating tank 2. 3. After adjustment, the water is finally pumped into the second clarification tank 24. The supernatant in the second clarification tank 24 is the retreated wastewater obtained in step (2). In this step, the mass percentage of hydrogen peroxide added (i.e., added) to the inert organic matter content is 0.1:1, and the mass percentage of catalyst B added to the inert organic matter content is 0.3:1. The catalyst B is a mixture of methanol (CH3OH) and ethanol (C2H5OH) in any proportion. The adjustment in the third adjustment tank 23 is to adjust the water temperature in the third adjustment tank 23 to 25℃ and adjust the pH value to pH=8-8.5. The electrode plate used in the third micro-electric field reaction tank 22 in this step is a titanium-iridium-tantalum alloy electrode plate. The gas-water volume ratio of the aeration reaction and the subsequent aeration reaction is 15:1.

[0045] (3) Filtration: The retreated wastewater obtained in step (2) is subjected to precision filtration, and the process elements of precision filtration are controlled to obtain filtered water. The process elements of precision filtration mentioned in this step refer to: first, the retreated wastewater obtained in step (2) is pumped from the second clarifier 24 into a multi-media filter 31, which serves as the precision filtration unit 3; after filtration by the multi-media filter 31, it is pumped into a security filter 32; and the water obtained after filtration by the security filter 32 is the filtered water. The multi-media filter 31 is filled with filter media, which is refined quartz sand. The refined quartz sand is filled in three layers, and the particle size of the quartz sand in the three layers decreases from bottom to top. The security filter 32 is filtered by a filter element. The filter element is a deep filter element structure that is acid and alkali resistant, has uniform pore size, and is sparse on the outside and dense on the inside, thus exhibiting high filtration efficiency.

[0046] (4) Adsorption treatment: The filtered water obtained in step (3) is subjected to adsorption treatment to obtain a chemical high-salt wastewater desalination mother liquor from which inert organic matter has been removed. In this step, the filtered water is pumped into the fourth conditioning tank 41, which serves as the mesoporous separation unit 4, to adjust the water temperature to 40°C and the pH value to neutral. The aforementioned mesoporous separation system 42 consists of one or more groups, and each group consists of 3-5 adsorption tanks connected in series. The adsorption tanks are filled with mesoporous adsorption material, and inert organic matter is adsorbed and separated at a flow rate of 0.5-2.5 BV. The product water separated by the mesoporous separation system 42 is pumped into the storage tank 43. The water in the storage tank 43 is the chemical high-salt wastewater desalination mother liquor from which inert organic matter has been removed as described in step (4).

[0047] In this embodiment, the input voltage of the micro-electric field mentioned in steps (1) and (2) is 1-2.5V, the input current is 1-3A, and the plate current density is 0.01-0.1mA / cm². 2 The electrode spacing is 5-25cm.

[0048] Example 4:

[0049] Please see Figure 1 ,according to Figure 1 The process shown describes a method for removing inert organic matter from the mother liquor of high-salt coal chemical wastewater, comprising the following steps:

[0050] (1) Pretreatment: The high-salt coal chemical wastewater desalination mother liquor is reacted under the action of a micro-electric field and catalyst A, and the process elements of the reaction are controlled to obtain pretreated wastewater. The process elements of the reaction controlled in this step are: firstly, the high-salt coal chemical wastewater desalination mother liquor is pumped into the first regulating tank 11, which is the first-stage reaction unit 1, and the water temperature in the first regulating tank 11 is adjusted to 25℃ and the pH value is adjusted to 6. After the water temperature and pH value are adjusted, it is introduced into the first micro-electric field reaction tank 12 for aeration reaction. The aeration reaction time is 40 minutes, and the air-to-water volume ratio of the aeration reaction is 8:1. Then, it overflows into the second micro-electric field reaction tank 13, and an inert organic matter content of a certain mass ratio is added to the second micro-electric field reaction tank 13. Silicon tetrafluoride (SiF4) at a ratio of 0.4:1 as catalyst A is aerated for 70 minutes, and the gas-to-water volume ratio during the aeration reaction is 7:1. Finally, it is pumped into the first clarification tank 14 for clarification. The clarification time in the first clarification tank 14 is controlled at 115 minutes. The supernatant in the first clarification tank 14 is used as the pretreated wastewater obtained in step (1), while the bottom sludge of the first clarification tank 14 is returned to the second micro-electric field reaction tank 13. In the first micro-electric field reaction tank 12 mentioned above, the aluminum electrode area accounts for 10% of the total electrode area, the iron electrode area accounts for 20% of the total electrode area, and the remainder is titanium-tin-tantalum alloy plate. In the second micro-electrode reaction tank 13 mentioned above, the iron electrode area accounts for 18% of the total electrode area, and the remainder is titanium-ruthenium-iridium alloy plate.

[0051] (2) Reprocessing: The pretreated wastewater obtained in step (1) is further reacted under the action of a micro-electric field and catalyst B. The process elements of the subsequent reaction are controlled to obtain reprocessed wastewater. The process elements of the subsequent reaction controlled in this step are: first, the pretreated wastewater obtained in step (1) is pumped from the first clarifier 14 into the second regulating tank 21, which is the secondary reaction unit 2. The water temperature of the pretreated wastewater in the second regulating tank 21 is adjusted to 25°C and the pH value is adjusted to pH=5. After the water temperature and pH value are adjusted, it is introduced into the third micro-electric field reaction tank 22 and the third micro-electric field is applied to the reaction tank. Hydrogen peroxide was added to reaction tank 22 for aeration for 15 minutes, then catalyst B was added, and the reaction was continued for 80 minutes under the action of the third micro-electric field and catalyst B. The mixture was then pumped into the third equalization tank 23 for adjustment, and finally into the second clarification tank 24. The supernatant in the second clarification tank 24 is the retreated wastewater obtained in step (2). In this step, the mass percentage of hydrogen peroxide added to the inert organic matter content is 0.25:1, and the mass percentage of catalyst B added to the inert organic matter content is 0.5:1. The catalyst B is tetrabutylammonium chloride (C14). 16 H 36 ClN), the pumping into the third regulating tank 23 for regulation is to adjust the water temperature in the third regulating tank 23 to 30℃ and adjust the pH value to pH=8-8.5. The electrode plate used in the third micro electric field reaction tank 22 in this step is diamond. The air-water volume ratio of the aeration reaction and the subsequent aeration reaction is 9:1.

[0052] (3) Filtration: The retreated wastewater obtained in step (2) is subjected to precision filtration, and the process elements of precision filtration are controlled to obtain filtered water. The process elements of precision filtration mentioned in this step refer to: first, the retreated wastewater obtained in step (2) is pumped from the second clarifier 24 into a multi-media filter 31, which serves as the precision filtration unit 3; after filtration by the multi-media filter 31, it is pumped into a security filter 32; and the water obtained after filtration by the security filter 32 is the filtered water. The multi-media filter 31 is filled with filter media, which is refined quartz sand. The refined quartz sand is filled in three layers, and the particle size of the quartz sand in the three layers decreases from bottom to top. The security filter 32 is filtered by a filter element. The filter element is a deep filter element structure that is acid and alkali resistant, has uniform pore size, and is sparse on the outside and dense on the inside, thus exhibiting high filtration efficiency.

[0053] (4) Adsorption treatment: The filtered water obtained in step (3) is subjected to adsorption treatment to obtain a chemical high-salt wastewater desalination mother liquor from which inert organic matter has been removed. In this step, the filtered water is pumped into the fourth conditioning tank 41, which is the mesoporous separation unit 4, to adjust the water temperature to 45°C and the pH value to neutral. The aforementioned mesoporous separation system 42 consists of one or more groups, and each group consists of 3-5 adsorption tanks connected in series. The adsorption tanks are filled with mesoporous adsorption material, and inert organic matter is adsorbed and separated at a flow rate of 0.5-2.5 BV. The product water separated by the mesoporous separation system 42 is pumped into the storage tank 43. The water in the storage tank 43 is the chemical high-salt wastewater desalination mother liquor from which inert organic matter has been removed as described in step (4).

[0054] In this embodiment, the input voltage of the micro-electric field mentioned in steps (1) and (2) is 1-2.5V, the input current is 1-3A, and the plate current density is 0.01-0.1mA / cm². 2 The electrode spacing is 5-25cm.

[0055] Comparative Example 1:

[0056] Electrocoagulation oxidation refers to the process of oxidizing and degrading organic pollutants using hydroxyl radicals and other oxidizing agents generated by an anodic electrochemical reaction. The efficiency of electrochemical oxidation depends to some extent on the mass transfer efficiency of pollutants migrating from the solution system to or near the anode surface. The oxidative degradation process of organic pollutants is generally considered to be divided into direct oxidation and indirect oxidation.

[0057] In direct oxidation, organic pollutants are oxidized and destroyed at the anode through direct electron transfer, without involving other active substances. This process is mainly controlled by the mass transport and electron transfer rates at the electrode / solution interface. Generally, the reaction rate of direct oxidation is relatively slow, which depends on the electrocatalytic activity of the anode material.

[0058] In indirect oxidation, high-redox-potential active oxides, such as ·OH, O3, H2O2, and other strong oxidizing agents, are generated in situ at the electrode. Pollutants then react with these strong oxidizing agents, being oxidized into smaller molecules or directly mineralized into CO2 and H2O. This process involves multiple factors, including the spatiotemporal generation rate of strong oxidizing agents, the interaction between ·OH and the anode, and the oxygen evolution reaction. Generally, in practical electrochemical oxidation systems, both direct and indirect oxidation processes coexist and contribute to the removal of organic pollutants.

[0059] Electrocoagulation: During the electrolysis process, a soluble anode made of aluminum or iron is used. When a direct current is applied, the anode material dissolves during the electrolysis process, forming metal cations such as Fe3+ and Al3+. These cations form colloidal substances with flocculation effects in the solution. These substances can promote the flocculation and precipitation of colloidal impurities in the water, thereby achieving the removal of pollutants.

[0060] Technical advantages:

[0061] (1) The reaction conditions are mild, and the electrochemical oxidation equipment can be operated at room temperature and pressure;

[0062] (2) It has strong controllability. The reaction conditions can be adjusted at any time by changing the applied voltage, current and other means.

[0063] (3) High cost performance: As a wastewater treatment process, electrochemical oxidation has the advantages of high equipment integration, low treatment cost and small footprint.

[0064] (4) The treatment method is flexible. The electrochemical oxidation process can improve the biodegradability of wastewater as a pretreatment and ensure that the effluent meets the standards as a deep treatment. It can be used as a standalone treatment or combined with other treatments, making the process very flexible.

[0065] Technical disadvantages:

[0066] (1) The cost is relatively high. Because the electrolytic resistor is relatively small, it is easy to cause the current density to be too high, resulting in greater losses.

[0067] (2) The operation is complicated. The process will produce pollutant sedimentation, which will block the cleaning tank. Different parameters need to be adjusted for different pollutants.

[0068] (3) It is not suitable for wastewater with chloride ion concentrations above 20,000 mg / L, otherwise chlorine gas will be generated, or even an explosion may occur;

[0069] (4) It can only remove large molecular organic matter in wastewater, but cannot remove inert small molecular organic matter.

[0070] Comparative Example 2:

[0071] Electrocatalytic oxidation is a form of advanced oxidation. Compared with direct ozone oxidation, the hydroxyl radicals (·HO) generated in the electrocatalytic oxidation system have a reaction rate 105 times higher. It has no selectivity and can react with most macromolecular organic compounds, so the advanced oxidation is effective.

[0072] The operating principle of electrocatalytic oxidation technology mainly utilizes a metal oxide electrode with catalytic properties to generate hydroxyl radicals or other free radicals and groups with strong oxidizing capabilities, which attack organic pollutants in the solution, causing them to be completely decomposed into harmless H2O and CO2. This degradation pathway makes the decomposition of organic matter more thorough and less likely to produce toxic intermediate products. In the reaction, electrons are the main reactants, achieving the purification of pollutants in water through chemical and physical actions.

[0073] Table 1 compares several conventional advanced oxidation technologies.

[0074]

[0075] In China, high-salt wastewater treatment projects in industries such as petrochemicals and pharmaceuticals often use electrocatalytic oxidation technology to degrade high molecular weight COD, which has a relatively good effect. However, the COD in the mother liquor described in this invention is an inert organic particle, and the treatment rate of electrocatalytic oxidation technology is very low (often less than 30%). This can be seen from the miscellaneous salts (hazardous waste) generated annually by petrochemical and pharmaceutical companies.

[0076] Comparative Example 3:

[0077] Photocatalytic oxidation combined with Fenton oxidation utilizes photo-excited oxidation to combine oxidants such as O2 and H2O2 with light radiation. The light used is primarily ultraviolet light, including processes such as UV-H2O2 and UV-O2, which can be used to treat recalcitrant organic matter in wastewater. Simultaneously, in the Fenton system with ultraviolet light, a synergistic effect exists between ultraviolet light and iron ions, significantly accelerating the rate of hydroxyl radical generation from H2O2 decomposition, thus promoting the oxidative removal of organic matter.

[0078] In this reaction, molecules absorb light energy and are excited to a high-energy state. Then, the electronically excited molecules undergo a chemical reaction. The activation energy of the photochemical reaction comes from the energy of the photon.

[0079] Photocatalysis combined with Fenton degradation can generally be divided into two types: homogeneous and heterogeneous. Homogeneous photocatalytic degradation mainly uses Fe2+ or Fe3+ and H2O2 as a medium, and degrades pollutants through a photo-Fenton reaction. This type of reaction can directly utilize visible light. Heterogeneous photocatalytic degradation involves adding a certain amount of photosensitive semiconductor material to the pollution system, combined with light radiation of a certain energy. Under light irradiation, the photosensitive semiconductor is excited to generate electron-hole pairs. Dissolved oxygen, water molecules, etc., adsorbed on the semiconductor interact with electrons and holes to generate highly oxidizing free radicals such as ·OH. These free radicals then mineralize all or nearly all of the pollutants through bonding with hydroxyl groups, substitution, and electron transfer, ultimately generating CO2, H2O, and other ions such as NO3-, PO43-, SO42-, Cl-, etc.

[0080] advantage:

[0081] (1) Environmentally friendly: The Fenton process does not produce toxic substances such as chlorinated organic matter that are easily generated by bleach (sodium hypochlorite) and cause damage to the environment;

[0082] (2) Small footprint: Due to the fast oxidation rate of organic matter, the required residence time is short (about 1 to 2 hours), which is much faster than the tens of hours of general biological treatment, thus saving time. In addition, the volume of the reaction tank is small, thus saving space.

[0083] (3) High operational flexibility: The operating conditions can be adjusted according to the quality of the influent water to increase the treatment capacity, which is difficult for general biological treatment to achieve such flexible operation.

[0084] shortcoming:

[0085] (1) The absorption range of ultraviolet light is narrow and the light energy utilization rate is low. Its efficiency is also limited by the properties of the catalyst, the wavelength of ultraviolet light and the reactor. Short-wave ultraviolet light (wavelength less than 1700A) is more effective than long-wave ultraviolet light, but short-wave ultraviolet light is difficult to obtain.

[0086] (2) Photocatalysis needs to solve the problem of light transmittance, because the dark color of some wastewater is not conducive to the transmission of light, which will affect the photocatalytic effect;

[0087] (3) High cost and large amount of sludge: The cost of hydrogen peroxide is high, and a large amount of sludge will be generated during the Fenton treatment process, which increases the treatment cost and the burden of sludge treatment.

[0088] (4) Easy to revert to color: If the dosage and ratio of hydrogen peroxide and ferrous sulfate are not well controlled, the wastewater may turn slightly yellow or yellowish-brown.

[0089] (5) Difficult to control: The reaction conditions of Fenton treatment are quite sensitive, such as pH value, the ratio of hydrogen peroxide to ferrous sulfate, etc., which need to be precisely controlled, otherwise the treatment effect will be affected.

[0090] In China, high-salt wastewater treatment projects in the fine chemical industry often use photocatalysis + Fenton oxidation to remove COD, which is effective for large molecular organic matter. However, for the inert COD in the mother liquor described in this invention, the removal effect is very limited (removal rate <40%), as can be seen from the amount of mixed salts (hazardous waste) generated by fine chemical enterprises every year.

[0091] Comparative Example 4:

[0092] The ozone oxidation process for removing inert COD mainly includes steps such as chemical dosing and mixing, reaction, sedimentation, and discharge. This process is also known as ozonation treatment or ozone catalytic oxidation. It is a commonly used radius flow process that removes organic matter from wastewater by catalytically oxidizing COD with ozone. The specific process flow is as follows:

[0093] (1) Chemically mixed wastewater

[0094] After ozone gas is mixed with wastewater, it enters a mixing tank. Inside the mixing tank, the ozone gas reacts with the organic matter in the wastewater. The reaction produces oxides, particulate matter, etc., which exist in the wastewater in dissolved or suspended form and are carried into the reactor along with the mixture.

[0095] (2) Reaction

[0096] After a period of residence and mixing in the mixing tank, the mixture enters the reaction tank. The reaction tank is equipped with UV lamps, whose function is to induce the conversion of oxygen into ozone molecules. Under UV light irradiation, ozone molecules further decompose into highly oxidized free radicals. In the reaction tank, these free radicals react with organic pollutants to form corresponding oxidation products. Simultaneously, oxygen may need to be added to the reactor to meet the required amount of oxidant for the reaction.

[0097] (3) Precipitation

[0098] The reaction produces particulate matter and suspended matter, so the mixture must be allowed to settle and precipitate after the reaction is complete.

[0099] (4) Discharge clean water

[0100] After treatment and sedimentation, the COD concentration in the wastewater is reduced. Therefore, the clean water can be discharged into wastewater treatment plants, rivers, or reused.

[0101] Because the inert organic matter in the mother liquor has a very small molecular weight, mainly consisting of carbon-hydrogen bonds (CH bonds), and the electronegativity difference of these covalent single bonds is very small (0.35), they are particularly stable. The free radicals generated by ozone have very limited effect on them. Using this process, inert COD in wastewater can be reduced to a small extent, but it cannot achieve the desired effect. For example, most domestic coal chemical high-salt wastewater treatment projects use ozone oxidation to remove inert COD, but the removal rate is often less than 30%, as can be seen from the amount of mixed salts (hazardous waste) generated annually by coal chemical enterprises.

[0102] Table 2 Comparison of Removal Efficiency of Inert Organic Matter

[0103] serial number Inert COD removal rate Experimental Example 1 91％ Experimental Example 2 90.5％ Experimental Example 3 93.3％ Experiment Example 4 92％ Comparative Example 1 ＜30％ Comparative Example 2 ＜30％ Comparative Example 3 ＜30％ Comparative Example 4 ＜30％

[0104] As shown in Table 2, the comparative examples above demonstrate that, compared to traditional methods for removing inert organic matter, the method provided by this invention employs an innovative process to treat the mother liquor, significantly shortening the process flow, saving a large amount of specialized equipment, simplifying operation, and utilizing skid-mounted equipment with low energy consumption. Furthermore, the method provided by this invention achieves a removal efficiency of up to 90% for inert organic matter. Compared to methods used in related technologies, the method and system of this invention greatly improve the removal efficiency of inert organic matter, representing a significant advancement.

[0105] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for removing inert organic matter from the mother liquor of high-salt chemical wastewater, characterized in that: Includes the following steps: (1) Pretreatment: The mother liquor of high-salt chemical wastewater is reacted under the action of a micro-electric field and catalyst A, and the process elements of the reaction are controlled to obtain pretreated wastewater; (2) Reprocessing: The pretreated wastewater obtained in step (1) is then reacted under the action of a micro-electric field and catalyst B, and the process elements of the subsequent reaction are controlled to obtain reprocessed wastewater; (3) Filtration: The retreated wastewater obtained in step (2) is subjected to precision filtration, and the process elements of precision filtration are controlled to obtain filtered water. (4) Adsorption treatment: The filtered water obtained in step (3) is subjected to adsorption treatment to obtain a high-salt chemical wastewater desalination mother liquor from which inert organic matter has been removed. The process elements for controlling the reaction mentioned in step (1) refer to: firstly, the mother liquor of the high-salt chemical wastewater is pumped into the first regulating tank (11), which is the first-stage reaction unit (1), and the water temperature and pH value of the water in the first regulating tank (11) are adjusted. After the water temperature and pH value are adjusted, it is introduced into the first micro-electric field reaction tank (12) for aeration reaction. Then, it overflows into the second micro-electric field reaction tank (13) and catalyst A is added into the second micro-electric field reaction tank (13) for continued aeration reaction. Finally, it is pumped into the first clarification tank (14) for clarification. The supernatant in the first clarification tank (14) is used as the pretreated wastewater obtained in step (1), while the bottom sludge in the first clarification tank (14) is returned to the first clarification tank (14). The wastewater is led to the second micro-electric field reaction tank (13); the process elements for controlling the reaction in step (2) refer to: first, the pretreated wastewater obtained in step (1) is pumped from the first clarifier (14) into the second regulating tank (21) which is the secondary reaction unit (2), and the water temperature and pH value of the pretreated wastewater in the second regulating tank (21) are adjusted. After the water temperature and pH value are adjusted, the wastewater is introduced into the third micro-electric field reaction tank (22) and hydrogen peroxide is added to the third micro-electric field reaction tank (22) for aeration reaction. Then, catalyst B is added, and aeration reaction is carried out under the action of the third micro-electric field and catalyst B. Then, the wastewater is pumped into the third regulating tank (23) for adjustment, and finally pumped into the third regulating tank (23). The second clarification tank (24) contains supernatant, which is the reprocessed wastewater obtained in step (2). The process elements for controlling precision filtration in step (3) refer to: first, pumping the reprocessed wastewater obtained in step (2) from the second clarification tank (24) into a multi-media filter (31) which is a precision filtration unit (3); after filtration by the multi-media filter (31), pumping it into a security filter (32); and the water obtained after filtration by the security filter (32) is the filtered water. The adsorption treatment of the filtered water obtained in step (4) refers to: first, pumping the filtered water into the fourth regulating tank (41) which is a mesoporous separation unit (4) for regulation; and then, after regulation... After the holiday, the filtered water is pumped into the mesoporous separation system (42), and the product water separated by the mesoporous separation system (42) is pumped into the storage tank (43). The water in the storage tank (43) is the chemical high-salt wastewater desalination mother liquor with inert organic matter removed as described in step (4). The catalyst A is one or more of the following: nonacarbonyl ferric, diborane, boric acid, sulfur trioxide, boron trichloride, boron trifluoride, aluminum trichloride, dichlorocarbene, chloroform, silicon tetrafluoride, ferric chloride, and ferric bromide. The catalyst B is one or more of the following: methylamine, aniline, ethylenediamine, diisopropylamine, formamide, trifluoroacetic acid, dimethyl sulfoxide, dimethylformamide, methanol, ethanol, triethanolamine, and tetrabutylammonium chloride.

2. The method for removing inert organic matter from the mother liquor of high-salt chemical wastewater according to claim 1, characterized in that: The water temperature and pH adjustment in the first regulating tank (11) mentioned in step (1) are to adjust the water temperature in the first regulating tank to 15-45℃ and adjust the pH value to pH=3-6. The aeration reaction time in the first micro electric field reaction tank (12) is 20-40min, and the aeration reaction time is 60-90min. The clarification method in the first clarification tank (14) is natural clarification, and the clarification time is 110-130min. The air-water volume ratio of the aeration reaction is 2-10:1, and the air-water volume ratio of the continued aeration reaction is also 2-10:

1.

3. The method for removing inert organic matter from the mother liquor of high-salt chemical wastewater according to claim 1, characterized in that: The water temperature and pH adjustment of the pretreated wastewater in the second regulating tank (21) in step (2) are to adjust the water temperature to 25-45℃ and the pH value to pH=3-6. The time for adding hydrogen peroxide for aeration reaction is 20-40 min. The time for continuing aeration reaction under the action of the third micro electric field and catalyst B is 60-90 min. The time for adding hydrogen peroxide to the third micro electric field reaction tank (22) for aeration reaction is 20-40 min. The time for pumping into the third regulating tank (23) for regulation is to adjust the water temperature in the third regulating tank (23) to 25-45℃ and the pH value to pH=8-8.

5. The air-water volume ratio of the aeration reaction and the subsequent aeration reaction is 3-15:

1.

4. The method for removing inert organic matter from the mother liquor of high-salt chemical wastewater according to claim 1, characterized in that: The multi-media filter (31) mentioned in step (3) is filled with filter media, which is refined quartz sand. The refined quartz sand is filled in three layers, and the particle size of the quartz sand in the three layers decreases from bottom to top. The security filter (32) filters by a filter element. The filter element is a deep filter element structure that is acid and alkali resistant, has uniform pore size, and is sparse on the outside and dense on the inside, thus exhibiting high filtration efficiency.

5. The method for removing inert organic matter from the mother liquor of high-salt chemical wastewater according to claim 1, characterized in that: In step 4, the filtered water is pumped into the fourth conditioning tank (41), which is the mesoporous separation unit (4), to adjust the water temperature to 35-45℃ and the pH value to neutral. The mesoporous separation system (42) consists of one or more groups, and each group consists of 3-5 adsorption tanks connected in series. The adsorption tanks are filled with mesoporous adsorption materials and adsorb and separate inert organic matter at a flow rate of 0.5-2.5 BV.

6. The method for removing inert organic matter from the mother liquor of high-salt chemical wastewater according to claim 1, characterized in that: The mass ratio of the amount of catalyst A added to the content of inert organic matter is 0.1-0.5:1; the mass ratio of the amount of catalyst B added to the content of inert organic matter is also 0.1-0.5:1; the mass ratio of the amount of hydrogen peroxide added to the content of inert organic matter is 0.1-0.5:

1.

7. The method for removing inert organic matter from the mother liquor of high-salt chemical wastewater according to claim 1, characterized in that: The micro-electric field uses any one or more of the following materials: iron electrode plate, aluminum electrode plate, graphite electrode plate, diamond electrode plate, titanium-ruthenium-iridium alloy electrode plate, titanium-iridium-tantalum alloy electrode plate, and titanium-tin-tantalum alloy electrode plate. The electrode plate material used in the micro-electric field is a combination of the following materials A and B: material A includes aluminum and / or iron electrode plates, while material B includes at least one of graphite, diamond, titanium-ruthenium-iridium alloy, titanium-iridium-tantalum alloy electrode plate, and titanium-tin-tantalum alloy electrode plate. In the first micro-electric field reaction cell (12), the aluminum electrode area accounts for 10% to 20% of the total electrode area, and the iron electrode area accounts for 10% to 20% of the total electrode area. The area of ​​the iron electrode accounts for 10% to 20% of the total electrode area, with the remainder being at least one of the materials B; wherein, in the second micro-electric field reaction cell (13), the iron electrode area accounts for 10% to 20% of the total electrode area, with the remainder being at least one of the materials B; wherein, in the third micro-electric field reaction cell (22), the electrode plate used is at least one of the materials B, namely graphite, diamond, titanium-ruthenium-iridium alloy, titanium-iridium-tantalum alloy electrode plate, and titanium-tin-tantalum alloy electrode plate; the input voltage of the micro-electric field is 1 to 2.5V; the input current is 1 to 3A; and the electrode plate current density is 0.01 to 0.1mA / cm. 2 The electrode spacing is 5–25 cm.

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