Resource utilization method of semi-coke wastewater

Abstract

The invention relates to a resource utilization method of semi-coke wastewater, which comprises the steps of oil separation and precipitation, pressure filtration and phenol removal, resin oil removal and phenol removal, electrolytic oxidation, evaporation and concentration, spray drying and recrystallization and purification of ammonium sulfate, and is characterized in that sulfuric acid and ammonia water are added into the semi-coke wastewater to regulate the pH value of the wastewater, so that COD and BOD in the wastewater are reduced through a scientific experimental method; the problems of difficult phenol recovery, impure byproduct ammonium sulfate and the like caused by the defects in the oil and phenol removal treatment process of the original semi-coke wastewater treatment technology are improved, the pH is adjusted to a lower level by adding sulfuric acid in advance, most phenols are precipitated and recovered, and then oil and phenols are further recovered by adopting resin; according to the method, ammonia and phenolic substances in the wastewater are respectively recovered while pH is regulated and controlled by sulfuric acid and ammonia water, so that a phenolic product and a byproduct ammonium sulfate product are obtained, resource recovery is realized, good economic benefits are generated, and meanwhile, distilled water is treated by adopting biochemical-MBR (Membrane Bioreactor), so that water recycling is realized.

Description

Technical Field

[0001] The present invention belongs to the field of blue coke wastewater treatment, and relates to a blue coke wastewater resource utilization method, and in particular to a blue coke wastewater reuse and comprehensive treatment method and treatment system. Background Art

[0002] Coal-based lignite, also known as semi-coke, is a new type of carbon material made from high-quality clean coal through medium and low temperature dry distillation. It has the characteristics of high fixed carbon, high chemical activity, high specific resistivity, and low content of impurities such as ash, sulfur, phosphorus, and moisture. Therefore, it has gradually replaced the application of coke in the production of calcium carbide and ferroalloys.

[0003] Semi-coke wastewater, also known as semi-coke wastewater, refers to a type of industrial wastewater generated during the medium- and low-temperature dry distillation (about 600-800°C) of low-metamorphic coal (non-caking coal, weakly caking coal, and long-flame coal) and the gas purification process. This type of wastewater has a complex composition and contains a large number of difficult-to-degrade and highly toxic pollutants, such as organic pollutants such as benzene, phenols, polycyclic aromatic hydrocarbons, nitrogen-oxygen heterocyclic compounds, and inorganic pollutants such as sulfides, cyanides, and thiocyanates. It is a typical highly polluted and highly toxic industrial wastewater.

[0004] The phenol and petroleum substances contained in the lignite wastewater are highly toxic and poorly degradable organic substances. Long-term accumulation in the environment can cause serious harm to human health and ecological balance. At present, the common technologies for treating lignite wastewater in China include steam stripping, electro-Fenton technology, wet oxidation technology, etc. These commonly used lignite wastewater treatment technologies have the following problems: (1) The removal rate of tar substances in lignite wastewater is low, resulting in a large load on subsequent process treatment and prone to collapse; (2) The organic matter contained in the wastewater is highly toxic and has a high content, making it difficult for the biochemical process to operate stably; (3) The treatment depth of lignite wastewater is not deep enough, and the reuse rate of ammonia and phenol substances in the wastewater is low, which needs further improvement. Summary of the invention

[0005] In view of this, the present invention provides a method for resource utilization of blue carbon wastewater in order to solve the above-mentioned problems existing in the blue carbon wastewater treatment process. Ammonia and phenol in the blue carbon wastewater are fully recycled and utilized through reasonable physicochemical treatment to obtain two products, phenolic tar and by-product ammonium sulfate. In the subsequent process, a biochemical-MBR process is used to make the evaporated water meet the emission standard, thereby realizing the purification and reuse of the evaporated water and improving the reuse rate of the wastewater.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A method for resource utilization of blue carbon wastewater comprises the following steps:

[0008] S1, oil separation and sedimentation: pump the raw water of semi-coal wastewater into the oil separation and sedimentation tank, and add demulsifier to initially achieve oil-water separation, and take the lower layer of wastewater to enter the next treatment process;

[0009] S2, filter press treatment: the deoiled wastewater obtained in step S1 is placed in a flocculation sedimentation tank, and sulfuric acid is added to adjust the pH of the wastewater to 6-8, and if necessary, a sewage treatment flocculant such as PAC is added to fully stir and obtain flocculated solids, and then solid-liquid separation is performed in a filter press to obtain flocculated wastewater;

[0010] S3, filter press to remove phenol: add sulfuric acid to the wastewater obtained in step S2, adjust the pH of the wastewater to 0-1.5, and remove phenolic substances in the wastewater in advance through a filter press after standing, so that the subsequent device can work better;

[0011] S4, resin deoiling and phenol removal: the wastewater obtained in step S3 is passed through the columns of deoiling resin and phenol removal resin in sequence to further remove the oil and phenol substances in the wastewater and finally obtain relatively clear wastewater;

[0012] S5, electrolytic oxidation: adding ammonia water to the wastewater obtained in step S4, adjusting the pH value of the wastewater to 2-3, and then performing electrolytic oxidation under the condition of a current in the range of 3-8A, standing and separating the liquid, further removing the organic matter in the wastewater, and oxidizing and activating the organic matter in the wastewater, thereby increasing the BOD / COD value of the subsequent distilled water, and facilitating the biochemical treatment of the distilled water;

[0013] S6, evaporation concentration: adding ammonia water to the wastewater obtained in step S5 to adjust the pH value of the wastewater to 4-5, and then entering the evaporation concentrator for evaporation concentration to obtain ammonium sulfate concentrate, and the condensate after the evaporated water is condensed is subjected to biochemical treatment to reach the industrial water standard for reuse; the ammonium sulfate concentrate enters the concentrate transfer tank;

[0014] S7, spray drying-rotary kiln: the ammonium sulfate concentrate obtained in step S6 is pumped into a spray drying tower, and water is evaporated by hot air at 200-400°C. The tail gas is discharged into a VOC treatment system, and the obtained solid enters a rotary kiln, where the ammonium sulfate solid is heat-insulated by hot air at 250-300°C in the rotary kiln to make the organic matter adhering to the surface of the ammonium sulfate solid become insoluble in water; this step obtains crude ammonium sulfate;

[0015] S8, dissolving-filtering: adding the crude ammonium sulfate obtained in step S7 into a dissolving and stirring tank, and then using a filter press to remove water-insoluble organic and inorganic substances to obtain an ammonium sulfate solution with a low impurity content;

[0016] S9, evaporation crystallization-drying: the ammonium sulfate solution obtained in step S8 is evaporated-centrifuged-dried to obtain by-product ammonium sulfate;

[0017] S10, biochemical-MBR treatment: The distilled water obtained in step S9 and step S6 is subjected to biochemical treatment and testing, and is recycled after meeting the standards.

[0018] Furthermore, in step S1, the raw water of the semi-coke wastewater is allowed to stand for 24 hours before deslagging to promote full aggregation of solid impurities in the wastewater.

[0019] Furthermore, sulfuric acid is added in step S3 to adjust the pH to 0-1.5, thereby removing phenols from the wastewater at a low cost.

[0020] Furthermore, in step S4, the wastewater is cleaned before being treated with the oil-removing resin and the phenol-removing resin. During the resin cleaning process, steam and an organic solvent (such as methanol, ethanol, etc.) are successively introduced into the resin column to remove organic matter adsorbed on the resin, and a mixture containing oil-phenol and organic matter is obtained for recycling as tar.

[0021] Furthermore, in step S5, the electrolytic oxidation time is 2-4 min, the current is adjusted to 4-7 A, and the pH is adjusted to 2-3. Under these parameters, the activity of the electrolytic reaction is improved, which helps to enhance the efficiency of the electrolytic oxidation, and the BOD / COD of the subsequently evaporated water is increased to above 0.3.

[0022] Further, in step S6, an evaporator such as a multiple-effect evaporator, an MVR evaporator, etc. is used to evaporate and concentrate the aforementioned wastewater until the ammonium sulfate concentration reaches 20-40%. Before the wastewater enters the evaporator, the pH of the feed liquid is controlled at 4-5 to reduce ammonia escape.

[0023] Further, step S7 adopts spray drying-rotary kiln, and uses 200-400° C. hot air to evaporate the water of the concentrated liquid obtained in step S6 to obtain crude ammonium sulfate solid, and the crude ammonium sulfate solid is subsequently kept warm at 200-300° C. in a rotary kiln for 1-3 hours.

[0024] Furthermore, step S8 and step S9 adopt dissolution-evaporation crystallization-drying to finally obtain the by-product ammonium sulfate product.

[0025] Furthermore, the phenolic substance collected in step S3 and the mixture of oil-phenol and organic matter collected in step S4 are recycled as phenolic tar. After steps S1-S9, the phenols and ammonium sulfate in the blue carbon wastewater are separated to obtain by-product phenolic tar and by-product ammonium sulfate, respectively.

[0026] Furthermore, in step S10, the biochemical-MBR system is used to treat the distilled water to remove ammonia nitrogen and organic matter in the distilled water so that the distilled water can be reused.

[0027] The beneficial effects of the present invention are:

[0028] 1. A method for resource utilization of semi-coke wastewater disclosed in the present invention comprises the steps of oil separation precipitation, phenol removal by pressure filtration, oil and phenol removal by resin, electrolytic oxidation, evaporation concentration, spray drying and recrystallization purification. In the phenol removal by pressure filtration process, an appropriate amount of sulfuric acid is added to the wastewater to reduce the pH, so that hydrogen ions react with phenolic substances in the wastewater to obtain phenolic precipitates, and phenols are removed in advance, which can effectively reduce the pressure on equipment in subsequent processes; and the sulfate ions introduced in this process will be used as raw materials for generating ammonium sulfate in subsequent processes to achieve the purpose of reuse.

[0029] The cleaned resin in the resin deoiling and phenol process can treat wastewater 50 times its own volume each time. Compared with the common extraction dephenolization, this process is not only efficient but also can effectively reduce costs. Steam and organic solvents are introduced into the used resin to wash away the organic matter adsorbed on the resin to obtain a tar precursor; and the content of phenolic substances in the wastewater treated by the filter pressing dephenolization process is very low, which greatly improves the efficiency of resin dephenolization, reduces the frequency of resin cleaning, improves the stability of the process and reduces costs.

[0030] In the electrolytic oxidation process, the pH of the wastewater is adjusted to 2-3 in the previous phenol removal process by filter pressing. The clarified wastewater obtained by the phenol removal process by filter pressing has good stability, which avoids the precipitation caused by pH fluctuation during the electrolytic oxidation process and reduces the electrolytic efficiency; and the pH of the wastewater is adjusted to 2-3 in the electrolytic oxidation process, and the current is set to 5.6A. Under this parameter, the activity of the electrolytic reaction is improved, which helps to enhance the efficiency of electrolytic flotation. In particular, dense bubbles can be clearly observed during the electrolytic process, which is very helpful to improve the flotation effect and facilitate the removal of pollutants. This is because when direct current passes through the wastewater, a series of electrochemical reactions will occur, such as a reduction reaction at the cathode, which produces bubbles with a smaller diameter, and thus has a larger specific surface area, which can adsorb tiny particles, colloidal substances and charged particles in the wastewater. These bubbles will drive the adsorbed pollutants to float together during the rising process, and finally form scum, thereby achieving the separation of pollutants from water. A series of substances with oxidizing or reducing properties may also be produced during the electrolysis process, such as hydroxyl radicals, which can oxidize and decompose organic matter in the wastewater, thereby reducing the COD and BOD of the wastewater.

[0031] The pH of the wastewater is adjusted to 4-5 in the evaporation and concentration process, mainly to promote the formation of ammonium sulfate. In an environment with a pH of 4-5, ammonia nitrogen exists in the form of ammonium ions, which is conducive to combining with sulfuric acid introduced in the filter press to remove phenol to form ammonium sulfate. Within this pH range, ammonia gas escapes less, which is helpful for subsequent biological or chemical treatment, making the entire wastewater treatment process more efficient. The condensed water generated during evaporation in this step is subjected to biochemical-MBR treatment and recycled again if it meets the standards. The water vapor generated in the spray drying tower-fluidized bed is introduced into the VOC treatment system for harmless treatment and then discharged.

[0032] 2. The resource utilization method of a kind of blue carbon wastewater disclosed in the present invention is to adjust the pH of the wastewater by adding sulfuric acid and ammonia water to the blue carbon wastewater, and then reduce the COD and BOD in the wastewater by scientific experimental methods, thereby improving the shortcomings of the original blue carbon wastewater treatment technology in the oil removal treatment process, and adjusting the pH to a lower level by adding a large amount of sulfuric acid in advance, so that phenolic substances are precipitated in advance, thereby reducing the potential safety hazards in the subsequent process, and improving the system's blue carbon wastewater treatment efficiency. At the same time, sulfuric acid and ammonia water can recycle ammonia and phenolic substances in the wastewater while regulating the pH, and obtain phenolic tar and ammonium sulfate by-products, thereby realizing resource recovery and generating good economic benefits. At the same time, the distilled water is treated with biochemical-MBR to achieve water reuse.

[0033] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0035] Figure 1 This is a framework diagram of the blue carbon wastewater treatment process of the present invention;

[0036] Figure 2 This is a process flow chart of the blue carbon wastewater treatment process of the present invention. DETAILED DESCRIPTION

[0037] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0038] like Figure 1~2 The resource utilization method of semi-coke wastewater shown in the figure includes oil separation sedimentation, filter pressing to remove phenol, resin oil removal and phenol removal, electrolytic oxidation, evaporation concentration, spray drying and recrystallization purification steps, and the treatment system involved includes an oil separation sedimentation tank, a flocculation sedimentation tank, a filter press, a transfer tank, a resin oil removal and phenol device, an electrolytic oxidation device, an evaporation concentrator, a centrifuge, a spray drying tower-rotary kiln, a dissolving stirring tank, a VOC treatment system, an evaporation crystallizer, and a cake dryer. Specifically:

[0039] S1. Oil separation and sedimentation

[0040] In the oil separation sedimentation tank, add demulsifier and let it stand, and the lower layer will get wastewater with less oil content;

[0041] S2. Filter Press Treatment

[0042] The deslagging wastewater obtained in step S1 is placed in a flocculation sedimentation tank, sulfuric acid is added to adjust the pH to 6-8, and then polyaluminium chloride (PAC) flocculant is added for sufficient stirring, and solid-liquid separation is performed in a filter press to finally obtain wastewater from which flocculent pollutants are removed;

[0043] S3, phenol removal by filtration

[0044] The wastewater obtained in step S2 is adjusted to a pH of 0-1.5 by adding sulfuric acid, and after standing to precipitate phenol, solid phenol and liquid wastewater are separated by a filter press;

[0045] Experiments have confirmed that when the pH is 0-1.5, hydrogen ions react with phenolic substances in wastewater to obtain phenolic precipitates. Removing more phenols in advance can reduce the pressure on equipment in subsequent processes.

[0046] S4, resin oil removal and phenol removal, the wastewater obtained in step S3 is passed through oil removal resin and phenol removal resin columns in sequence to further remove oil and phenol substances in the wastewater, and finally relatively clear wastewater is obtained.

[0047] In this step, the efficiency of the resin is greatly improved due to the early removal of phenolic substances in the S3 process. The cleaned resin can process wastewater 50 times its own volume each time. Compared with the common extraction dephenolization, this process is not only efficient but also can effectively reduce costs. During the resin cleaning process, steam and organic solvents need to be introduced into the resin column in sequence to remove organic matter adsorbed on the resin. The eluent is then obtained as a tar byproduct.

[0048] S5. Electrolytic oxidation

[0049] Add an appropriate amount of ammonia water to the wastewater obtained in step S4 to adjust the pH value to 2-3, then perform electrolytic oxidation at a current of 5.6A, let the solution stand to separate, and further remove organic matter in the wastewater.

[0050] In some embodiments, after repeated experiments to find the optimal parameter conditions, we adjusted the pH to 2-3 and set the current to 5.6A. Under this parameter, the activity of the electrolytic reaction is improved, which helps to enhance the efficiency of electrolytic flotation. In particular, dense bubbles can be clearly observed during the electrolysis process, which is very helpful to improve the flotation effect and facilitate the removal of pollutants. This is because when a direct current passes through the wastewater, a series of electrochemical reactions will occur, such as a reduction reaction at the cathode, which produces bubbles with a smaller diameter, and thus has a larger specific surface area, which can adsorb tiny particles, colloidal substances and charged particles in the wastewater. These bubbles will drive the adsorbed pollutants to float together during the rising process, and finally form scum, thereby achieving the separation of pollutants from water. A series of substances with oxidizing or reducing properties may also be produced during the electrolysis process, such as hydroxyl radicals, which can oxidize and decompose organic matter in the wastewater, thereby reducing the COD and BOD of the wastewater and increasing the BOD / COD ratio.

[0051] S6. Evaporation and concentration

[0052] Ammonia water is added to the wastewater obtained in step S5 to adjust the pH to 4-5, and then the wastewater is introduced into an evaporation concentrator to obtain a concentrated solution of ammonium sulfate.

[0053] In some examples, we adjust step S5 to make the wastewater pH value to 4-5. In an environment with a pH value of 4-5, ammonia nitrogen exists in the form of ammonium ions, and ammonia gas escapes less, which is helpful for subsequent biological-MBR treatment and makes the entire wastewater treatment process more efficient. While obtaining ammonium sulfate, the condensed water generated during evaporation and crystallization in this step is also subjected to biochemical treatment and testing, and is recycled again if it meets the standard.

[0054] S7, spray drying-rotary kiln treatment

[0055] The ammonium sulfate concentrate obtained in step S6 is pumped into a spray drying tower, and water is evaporated by hot air at 200-400°C. The tail gas is discharged into a VOC treatment system. The obtained solid enters a rotary kiln, and the ammonium sulfate solid is heat-insulated in the rotary kiln by hot air at 250-300°C, so that the organic matter adhering to the surface of the ammonium sulfate solid becomes insoluble in water. This step obtains crude ammonium sulfate; the water vapor generated in the spray drying tower-fluidized bed is introduced into the VOC treatment system for harmless treatment before discharge.

[0056] S8, dissolution-filtration

[0057] The crude ammonium sulfate obtained in step S7 is added to a dissolving and stirring tank, and then a filter press is used to remove organic and inorganic substances insoluble in water to obtain an ammonium sulfate solution with a low impurity content;

[0058] S9, evaporation crystallization-drying

[0059] The ammonium sulfate solution obtained in step S8 is evaporated, centrifuged and dried to obtain by-product ammonium sulfate. Wet ammonium sulfate solid is obtained in a centrifuge, and then dried in a rake dryer to obtain by-product ammonium sulfate solid.

[0060] S10, Biochemical-MBR treatment

[0061] The distilled water obtained in step S8 and step S6 is treated by biochemical-MBR to meet the reuse water standard.

[0062] The resource utilization method of the semi-coke wastewater can adjust the pH to a lower level by adding an appropriate amount of sulfuric acid in advance, so that phenolic substances can be precipitated in advance, reducing the safety hazards in the subsequent process, improving the system's efficiency in treating semi-coke wastewater, and improving the deficiencies in the original semi-coke wastewater treatment technology in the oil removal process. Sulfuric acid and ammonia water are added to the semi-coke wastewater to adjust the pH of the wastewater, and then the COD and BOD in the wastewater are reduced by a simple experimental method. While adjusting the pH by sulfuric acid and ammonia water, ammonia and phenolic substances in the wastewater can be recovered to obtain two by-products, tar and ammonium sulfate, which produces good economic benefits. At the same time, the evaporated water is treated by biochemical-MBR to meet the reuse water standard, realize water reuse, and save resources.

[0063] This application adds sulfuric acid, PAC, ammonia and other substances to the blue carbon wastewater to explore the optimal pH for removing pollutants, and then reduces the concentration of pollutants such as COD in the wastewater through experimental methods, improves the shortcomings of the original blue carbon wastewater treatment technology oil removal process, and reduces the potential safety hazards during the operation of the system. At the same time, sulfuric acid and ammonia can recycle ammonia and phenolic substances in the wastewater while regulating the pH, and obtain two by-products, tar and ammonium sulfate, to achieve resource recovery and produce good economic benefits. At the same time, the distilled water is treated with biochemical-MBR to meet the reuse water standard, realize water reuse, and save resources.

[0064] Example

[0065] Weigh 18.3g of solid and keep it at 250℃ for 2 hours to obtain 15.9241g of solid, dissolve it in 300ml of distilled water, ultrasonicate it for 2 hours and let it stand overnight, filter it to obtain a light yellow solution, and then recrystallize it. Put the solution on a heater and stir and heat it. As the solution evaporates, the light yellow solution becomes darker in color, and no floating matter is precipitated. Stop heating when crystals are precipitated, cool it to room temperature and filter it to obtain about 9.3g of white solid. This method can effectively purify ammonium sulfate.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A method for resource utilization of blue carbon wastewater, characterized in that: The steps include: S1, oil separation and sedimentation: pump the raw water of semi-coal wastewater into the oil separation and sedimentation tank, and add demulsifier to initially achieve oil-water separation, and take the lower layer of wastewater to enter the next treatment process; S2, filter press treatment: the deoiled wastewater obtained in step S1 is placed in a flocculation sedimentation tank, sulfuric acid is added to adjust the pH of the wastewater to 6-8, and then a sewage treatment flocculant is added, and the mixture is fully stirred to obtain flocculated solids, and then solid-liquid separation is performed in a filter press to obtain flocculated wastewater; S3, filter press to remove phenol: add sulfuric acid to the wastewater obtained in step S2, adjust the pH value of the wastewater to ≤1.5, and remove the phenolic substances in the wastewater in advance through a filter press after standing, so that the subsequent device can work better; S4, resin deoiling and phenol removal: the wastewater obtained in step S3 is passed through the columns of deoiling resin and phenol removal resin in sequence to further remove the oil and phenol substances in the wastewater and finally obtain relatively clear wastewater; S5, electrolytic oxidation: adding ammonia water to the wastewater obtained in step S4, adjusting the pH value of the wastewater to 2-3, and then performing electrolytic oxidation under the condition of a current in the range of 3-8A, standing and separating the liquid, further removing the organic matter in the wastewater, and oxidizing and activating the organic matter in the wastewater, thereby increasing the BOD / COD value of the subsequent distilled water, and facilitating the biochemical treatment of the distilled water; S6, evaporation concentration: adding ammonia water to the wastewater obtained in step S5 to adjust the pH value of the wastewater to 4-5, and then entering the evaporation crystallizer for evaporation concentration to obtain ammonium sulfate concentrate, and the condensate after the evaporated water is condensed is subjected to biochemical treatment to reach the industrial water standard for reuse, and the ammonium sulfate concentrate enters the concentrate transfer tank; S7, spray drying-rotary kiln: the ammonium sulfate concentrate obtained in step S6 is pumped into a spray drying tower, and water is evaporated by hot air at 200-400°C. The tail gas is discharged into a VOC treatment system, and the obtained solid enters a rotary kiln, where the ammonium sulfate solid is heat-insulated in the rotary kiln by hot air at 250-300°C, so that organic matter adhering to the surface of the ammonium sulfate solid becomes insoluble in water, thereby obtaining crude ammonium sulfate; S8, dissolving-filtering: adding the crude ammonium sulfate obtained in step S7 into a dissolving and stirring tank, and then using a filter press to remove water-insoluble organic and inorganic substances to obtain an ammonium sulfate solution with a low impurity content; S9, evaporation crystallization-drying: the ammonium sulfate solution obtained in step S8 is evaporated-centrifuged-dried to obtain by-product ammonium sulfate; S10, biochemical-MBR treatment: The distilled water obtained in step S9 and step S6 is subjected to biochemical treatment to meet the reuse water standard and then reused.

2. The method for resource utilization of blue carbon wastewater according to claim 1, characterized in that: In step S1, the raw semi-coke wastewater is left to stand for more than 24 hours for deslagging, so as to promote full agglomeration of solid impurities in the wastewater.

3. The method for resource utilization of blue carbon wastewater according to claim 1, characterized in that: In step S3, sulfuric acid is added to adjust the pH to 0-1.5, so as to precipitate the phenols in the water and remove as much phenols as possible from the wastewater.

4. The method for resource utilization of blue carbon wastewater according to claim 1, characterized in that: In step S4, wastewater is treated by oil removal resin and phenol removal resin. During the resin cleaning process, steam and organic solvent are introduced into the resin column in sequence to remove organic matter adsorbed on the resin, and a mixture of organic matter and phenols is obtained as a tar by-product for recycling, wherein the organic solvent is one of methanol and ethanol.

5. The method for resource utilization of blue carbon wastewater according to claim 1, characterized in that: In step S5, the electrolytic oxidation time is 2-4 minutes, the current is adjusted to 4-7A, and the pH is adjusted to 2-3. Under these parameters, the activity of the electrolytic reaction is high, which helps to enhance the efficiency of the electrolytic oxidation, and the BOD / COD of the subsequently evaporated water is increased to above 0.

3.

6. The method for resource utilization of blue carbon wastewater according to claim 1, characterized in that: The evaporator used in step S6 is a multiple-effect evaporator or an MVR evaporator, and the wastewater in step S5 is evaporated and concentrated to an ammonium sulfate concentration of 20-40%. Before the wastewater enters the evaporator, the pH of the feed liquid is controlled at 4-5 to reduce ammonia escape.

7. The method for resource utilization of blue carbon wastewater according to claim 1, characterized in that: Step S7 uses spray drying-rotary kiln, and uses hot air at 200-400° C. to evaporate water to obtain ammonium sulfate solid. The ammonium sulfate solid is subsequently kept warm at 200-300° C. in a rotary kiln for 1-3 hours.

8. The method for resource utilization of blue carbon wastewater according to claim 1, characterized in that: Step S8 and step S9 adopt dissolution-evaporation crystallization-drying to finally obtain the by-product ammonium sulfate product.

9. The method for resource utilization of blue carbon wastewater according to claim 1, characterized in that: The phenolic substance collected in step S3 and the mixture of oil-phenol and organic matter collected in step S4 are recycled as phenolic tar. After steps S1-S9, the phenols and ammonium sulfate in the blue carbon wastewater are separated to obtain by-product phenolic tar and by-product ammonium sulfate, respectively.

10. The method for resource utilization of blue carbon wastewater according to claim 1, characterized in that: Step S10 uses a biochemical-MBR system to treat the evaporated water, removes ammonia nitrogen and organic matter in the evaporated water, and recycles the evaporated water for reuse.

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