Method for advanced treatment of salt-containing wastewater

Abstract

The application discloses a method for deep treatment of salt-containing sewage. The method comprises the following steps: (1) loading activated carbon according to 30%-70% of the effective volume of the reactor; (2) carrying out wall breaking treatment on the remaining activated sludge to release intracellular substances, removing impurities by precipitation or filtration, and then reserving the liquid above to be added into the reactor in step (1), and then carrying out 12-24h stewing and aeration treatment by using large air bubbles; (3) adding halomonas to the reaction system in step (2), and continuously carrying out aeration treatment by using large air bubbles and micro air bubbles in an alternating mode for 5-7 days, and then carrying out sewage treatment according to the set hydraulic retention time; wherein, the activated carbon is periodically treated by cyclone to be regenerated during the sewage treatment process. The method can greatly improve the use efficiency of activated carbon and the treatment effect of organic pollutants and nitrogen-containing pollutants in the sewage, and simultaneously realizes high-efficiency and stable operation of the high-salt sewage system.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, specifically relating to a method for deep treatment of saline wastewater. Background Technology

[0002] Refining and chemical enterprises discharge large amounts of saline wastewater from their circulating water systems, boiler drainage systems, and recycled water treatment systems. This wastewater is characterized by high inorganic salt content, along with small amounts of recalcitrant organic matter and nitrogenous pollutants. Direct discharge into natural water bodies without treatment will inevitably cause significant harm to aquatic life, drinking water, and industrial and agricultural water use, placing immense pressure on the ecological environment. Therefore, advanced treatment is essential. Existing advanced industrial wastewater treatment technologies mainly include membrane treatment, ozone oxidation, and activated carbon treatment. Membrane treatment technology produces high-quality effluent but suffers from high operating costs and difficulties in properly disposing of concentrated wastewater. Ozone treatment technology effectively treats the main pollutants in the effluent but has drawbacks such as complex processes and the risk of secondary byproduct pollution. The commonly used ozone + BAF (biological aerated filter) advanced treatment process still fails to achieve the expected treatment results.

[0003] CN201910665816.9 discloses a method and equipment for advanced wastewater treatment based on activated carbon technology. The method includes the following steps: 1) injecting a wastewater sample into a culture device, then adding powdered activated carbon and a culture medium; 2) adding the cultured biological activated carbon to a biological activated carbon water treatment device; 3) introducing the wastewater to be treated into the biological activated carbon water treatment device for a first aeration treatment to obtain biodegradable wastewater; 4) introducing the biodegradable wastewater into a multifunctional wastewater treatment device, adding wastewater treatment agents, and performing a second aeration treatment; 5) filtering the multifunctional wastewater through an ultrafiltration membrane to obtain dischargeable wastewater that meets emission standards. This method first involves adding powdered activated carbon and a culture medium for aeration and cultivation to obtain biological activated carbon with microorganisms parasitizing its surface; then, aerating the wastewater with the cultured biological activated carbon, where the microorganisms on the biological activated carbon consume some of the biodegradable organic matter in the wastewater, converting it into carbon dioxide for degradation and elimination; finally, adding wastewater treatment agents to the biodegradable wastewater, and filtering it through an ultrafiltration membrane to obtain dischargeable wastewater that meets emission standards. This method separates the loading of microorganisms on the surface of powdered activated carbon from the treatment of wastewater biodegradation. Although it achieves the treatment of effluent to meet standards, it still requires the replenishment of new activated carbon and involves high-temperature regeneration. It cannot achieve dynamic regeneration of activated carbon and will still increase operating costs.

[0004] Existing advanced wastewater treatment technologies using activated carbon as a carrier utilize the physical adsorption capacity of activated carbon in conjunction with microorganisms attached to its surface for treatment. While achieving good decolorization and deodorization effects and showing significant removal of major pollutants in effluent, their effectiveness in treating pollutants in saline wastewater is less than ideal. This is due to two main issues: activated carbon saturation and the reduction in biological activity caused by high concentrations of inorganic salts. When the osmotic pressure balance inside and outside microbial cells is disrupted, the wastewater treatment effect decreases, and even long-term operational stability is affected. In particular, existing advanced treatment systems using activated carbon as a carrier essentially lack the ability to remove nitrogenous pollutants. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for the advanced treatment of saline wastewater. This method significantly improves the efficiency of activated carbon utilization and the treatment effect on organic and nitrogenous pollutants in wastewater, while simultaneously achieving efficient and stable operation of high-salinity wastewater systems.

[0006] This invention provides a method for advanced treatment of saline wastewater, comprising the following steps:

[0007] (1) Activated carbon is filled into the reactor at 30% to 70% of its effective volume, preferably 40% to 60%;

[0008] (2) The remaining activated sludge is subjected to cell wall breaking treatment to release the intracellular substances. After removing impurities by precipitation or filtration, the liquid on the surface is retained and added to the reactor in step (1). Then, large bubble aeration is used for simmering treatment for 12 to 24 hours. The dissolved oxygen concentration is controlled above 5 mg / L, preferably 5 to 7 mg / L.

[0009] (3) Add Halomonas bacteria to the reaction system in step (2), and use alternating large bubble aeration and micro bubble aeration to continuously aerate for 5 to 7 days under the conditions of pH 7 to 9 and temperature 25 to 40°C. Then, treat the wastewater according to the set hydraulic retention time. During the wastewater treatment process, the activated carbon is periodically cycloneedled to regenerate it.

[0010] In this invention, after the activated carbon is filled in step (1), it can be washed with water 2 to 3 times. The water used for washing the activated carbon can be tap water, fire-fighting water, and / or qualified sewage.

[0011] In this invention, in step (1), the activated carbon is coal-based activated carbon with a particle size of 2-8 mm and a specific surface area of ​​600-1000 m². 2 / g, iodine value 600~1000mg / g, methylene blue adsorption value 90~120mg / g.

[0012] In this invention, in step (2), preferably, the amount of liquid added is sufficient to submerge the activated carbon. Generally, it is added to the reactor at 100% to 120% of the volume of activated carbon in the reactor.

[0013] In this invention, the cell wall breaking process described in step (2) is well known to those skilled in the art and can be achieved by at least one of the following methods: over-aeration, mechanical stirring, ultrasonic crushing, or chemical permeation with surfactant.

[0014] In this invention, the residual activated sludge in step (2) can be taken from the activated sludge in the secondary sedimentation tank of a saline wastewater treatment plant, i.e., sludge that has not undergone flocculation and dewatering treatment. The MLSS of the residual activated sludge is 5–25 g / L.

[0015] In this invention, the large bubble aeration in step (2) refers to aeration through a porous pipe or a porous diffuser, with a bubble diameter of more than 3 mm, generally 3-5 mm.

[0016] In this invention, the halomonas mentioned in step (3) is Halomonas nigrificans N2-2, which was deposited on March 18, 2024 at the China General Microbiological Culture Collection Center, with accession number CGMCC No. 30065; deposit address: Institute of Microbiology, Chinese Academy of Sciences, No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing.

[0017] In this invention, the Halomonas nigrificans N2-2 described in step (3) has a rod-shaped morphology, with milky white, opaque colonies, regular edges, a raised surface, no halo, and a diameter of 1-2 mm. Its biological characteristics are: Gram-negative, catalase-positive, oxidase-positive, and urease-positive. This bacterium is a heterotrophic nitrifying bacterium capable of utilizing various carbon sources, with citrate being the preferred one.

[0018] In this invention, the cultivation method for Halomonas nigrificans N2-2 uses citrate culture medium and is cultured under aerobic conditions until the stationary phase. The citrate is at least one of sodium citrate, potassium citrate, etc. The culture medium also contains potassium nitrate, potassium dihydrogen phosphate, calcium chloride, etc. The culture medium may further contain ammonium sulfate, sodium chloride, peptone, etc. The cultivation conditions are: pH 6-9, temperature 20-40℃, dissolved oxygen 0.5-5.0 mg / L, and cultivation time 18-36 h. The bacterial culture that has reached the stationary phase can be directly used as inoculum or prepared into a formulation by adding nutrient solution, preservatives, and protective agents.

[0019] In this invention, the reactor refers to any reactor with an aeration function and a support layer at the bottom. Microbubble aeration refers to bubble diameters below 100 micrometers (generally 50-100 micrometers), which increases dissolved oxygen levels, promotes microbial growth, and accelerates pollutant degradation. Large bubble aeration refers to bubble diameters above 3 mm (generally 3-5 mm), which has a stirring function, allowing the packed activated carbon to vibrate slightly.

[0020] In step (3) of this invention, the alternation of large bubble aeration and micro bubble aeration means that the hydraulic retention time is used as a cycle, and the micro bubble aeration time in each cycle is 20-40 minutes, with the remainder being large bubble aeration time. Specifically, micro bubble aeration is performed first and then large bubble aeration is performed in each cycle.

[0021] In this invention, the inoculation amount of the bacterial agent is 0.01% to 0.05% of the volume of the bacterial agent to the effective volume of the sewage treatment device.

[0022] In this invention, the wastewater can be at least one of the following: saline wastewater, effluent from a biological treatment unit, RO (reverse osmosis) concentrate, or circulating water discharge. Specifically, the water quality is as follows: ammonia nitrogen concentration of 20–30 mg / L, total nitrogen of 50–100 mg / L, COD concentration of 80–150 mg / L, and B / C ratio less than 0.3. Further, the salt content in the wastewater can be 15,000–20,000 mg / L.

[0023] In this invention, the advanced wastewater treatment refers to the treatment of effluent with ammonia nitrogen concentration of less than 1 mg / L, total nitrogen concentration of less than 15 mg / L, and COD concentration of less than 30 mg / L.

[0024] In this invention, the set hydraulic retention time refers to a hydraulic retention time of 2–8 hours, preferably 3–6 hours. The wastewater treatment conditions are: dissolved oxygen controlled at 0.5–5.0 mg / L, pH value of 7–9, and temperature of 25–40°C.

[0025] In this invention, the hydrocyclone used for the hydrocyclone treatment can be any hydrocyclone well known in the art. It can be a hydrocyclone that removes substances adsorbed on the surface or pores of a solid and can achieve solid-liquid separation. Under the action of the swirling flow field, the solid moves downward along the axial direction and is discharged from the underflow port, while the liquid moves upward along the central axis and is discharged from the overflow port, thus ultimately achieving solid-liquid separation.

[0026] In this invention, activated carbon is subjected to periodic cyclone treatment during wastewater treatment. The volume of activated carbon subjected to each cyclone treatment accounts for 5% to 10% of the total activated carbon loading. The cyclone treatment is performed 2 to 7 times per week. The first treatment is performed 20 to 30 days after the wastewater treatment device has been running. The interval between two consecutive treatments is 24 to 84 hours, and the treatment time for each treatment is 10 to 40 minutes.

[0027] A second aspect of the present invention provides a device for the above-mentioned advanced treatment of saline wastewater, the device mainly comprising a wastewater treatment system and a monitoring system;

[0028] The wastewater treatment system is filled with activated carbon and inoculated with activated sludge and Haloxylon ammonium bacteria for wastewater treatment.

[0029] The monitoring system is used to monitor the system's effluent.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] (1) This invention uses activated carbon as a carrier and Haloxylon ammodendron as a core strain, and through the cooperation of different aeration methods, it greatly improves the efficiency of activated carbon use and the treatment effect of organic pollutants and nitrogen-containing pollutants in sewage, so as to achieve efficient and stable operation of high-salt sewage system.

[0032] (2) This invention employs two oxygen supply methods simultaneously, which is beneficial to both the growth of the core strain and the microbial regeneration of activated carbon, allowing macromolecules to reach adsorption-desorption equilibrium with the help of enzymes. Regular microbubble aeration is beneficial to the growth and reproduction of Halomonas, while large bubble aeration is beneficial to the secretion of compatible solutes by Halomonas, protecting the biofilm from detachment and improving treatment efficiency; and further enhancing the overall system's resistance to adverse environments and its buffering capacity against salinity.

[0033] (3) In particular, by inoculating Halomonas nigrificans N2-2 as the core strain, this invention can simultaneously carry out heterotrophic nitrification and aerobic denitrification under high salt conditions, enhance the operational stability of the high salt system, and protect the degradation activity of other microorganisms, thereby further improving the wastewater treatment effect. Detailed Implementation

[0034] The following examples further illustrate the method and effects of the present invention in detail. These examples are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following examples.

[0035] Unless otherwise specified, the experimental methods used in the following examples are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following examples can be purchased from biochemical reagent stores.

[0036] In this embodiment of the invention, COD concentration was determined using GB11914-89 "Water Quality - Determination of Chemical Oxygen Demand - Dichromate Method"; ammonia nitrogen concentration was determined using GB7478-87 "Water Quality - Determination of Ammonium - Distillation and Titration Method"; total nitrogen concentration was determined using GB11894-89 "Water Quality - Determination of Total Nitrogen - Ultraviolet Spectrophotometry"; and salt content was determined using HJ / T 51-1999 "Water Quality - Determination of Total Salt Content - Gravimetric Method".

[0037] Example 1: Culture of Halomonas nigrificans N2-2 strain

[0038] Prepare citrate culture medium: sodium citrate 2 g / L, peptone 0.1 g / L, ammonium sulfate 1.0 g / L, potassium nitrate 0.5 g / L, potassium dihydrogen phosphate 0.1 g / L, calcium chloride 5 g / L, sodium chloride 5 g / L, and adjust the pH to 7.5.

[0039] The pure strain of Halomonas nigrificans N2-2 was inoculated into citrate culture medium and cultured in a shaker at 30℃, pH 7.0-7.5, under aerobic conditions for 24 h to obtain activated bacterial solution.

[0040] Inoculate the activated bacterial solution into fresh citrate culture medium at an inoculum volume of 5v%. Incubate for at least 20 hours at 25-30℃, pH 7.0-7.5, and dissolved oxygen 1-3 mg / L. Take samples to detect OD. 660 A bacterial solution with a pH of 0.8 or higher is considered usable.

[0041] Example 2

[0042] The saline wastewater treated in this example was RO concentrate, with the following specific water quality: ammonia nitrogen concentration of 20 mg / L, total nitrogen of 50 mg / L, COD concentration of 80 mg / L, B / C ratio of less than 0.3, and salt content of 15000 mg / L.

[0043] A cylindrical aeration reactor with an effective volume of 10L was used for the advanced treatment of saline wastewater. First, pebbles of varying particle sizes were loaded into the reactor as a support layer. Then, coal-based activated carbon with a particle size of 2–8mm (specific surface area of ​​900 m²) was filled into the reactor, filling 50% of its effective volume. 2 / g, iodine value 900mg / g, methylene blue adsorption value 90mg / g), and then rinse the activated carbon twice with tap water.

[0044] Take 100L of residual activated sludge from a saline wastewater treatment plant (MLSS of 10g / L), mechanically stir for 4 hours, filter to remove impurities, add the liquid to the reactor loaded with activated carbon and immerse the activated carbon, use large bubble (bubble diameter of 3-5mm) aeration method, and simmer for 24 hours under dissolved oxygen concentration of 6mg / L.

[0045] Then, the bacterial solution from Example 1 was inoculated into the reactor at a volume of 0.03% of the effective volume of the wastewater treatment device. Continuous aeration was performed under conditions of pH 7.5–7.8 and temperature 28–30°C, with each aeration cycle lasting 4 hours. Within each cycle, microbubbles (50-100 micrometers in diameter) were used for 30 minutes, followed by large bubbles (3-5 mm in diameter) for 210 minutes, alternating between the two aeration methods. After 5 days, wastewater was treated according to the set hydraulic retention time of 4 hours, with dissolved oxygen concentration controlled at 4–5 mg / L, pH 7–8, and temperature 25–30°C. During the wastewater treatment process, the activated carbon was subjected to cyclone treatment four times per week. The first cyclone treatment was performed on the 25th day of operation of the wastewater treatment device, with an interval of 42 hours between each treatment. Each treatment lasted 30 minutes to regenerate the activated carbon, and the amount of activated carbon treated each time was 10% of the total activated carbon content.

[0046] During reactor operation, effluent samples were collected daily for pollutant concentration analysis. After 5 months of continuous operation, the average effluent ammonia nitrogen concentration was 0.63 mg / L, the average total nitrogen concentration was 12.97 mg / L, and the average COD concentration was 25.96 mg / L, indicating stable treatment performance.

[0047] Example 3

[0048] The saline wastewater treated in this example was RO concentrate, with the following specific water qualities: ammonia nitrogen concentration of 25 mg / L, total nitrogen of 80 mg / L, COD concentration of 100 mg / L, B / C ratio of less than 0.3, and salt content of 15000 mg / L.

[0049] A cylindrical aeration reactor with an effective volume of 10L was used for the advanced treatment of saline wastewater. First, pebbles of varying particle sizes were loaded into the reactor as a support layer. Then, coal-based activated carbon with a particle size of 2–8mm (specific surface area of ​​900 m²) was filled into the reactor, filling 50% of its effective volume. 2 / g, iodine value 900mg / g, methylene blue adsorption value 90mg / g), and then rinse the activated carbon twice with tap water.

[0050] Take 100L of residual activated sludge from a saline wastewater treatment plant (MLSS of 10g / L), mechanically stir for 4 hours, filter to remove impurities, add the liquid to the reactor loaded with activated carbon and immerse the activated carbon, use large bubble (bubble diameter of 3-5mm) aeration method, and simmer for 12 hours under dissolved oxygen concentration of 6mg / L.

[0051] Then, the bacterial solution from Example 1 was inoculated into the reactor at a volume of 0.01% of the effective volume of the wastewater treatment device. Continuous aeration was performed under conditions of pH 7.5–7.8 and temperature 28–30°C, with each aeration cycle lasting 3 hours. Within each cycle, microbubbles (50-100 micrometers in diameter) were used for 20 minutes, followed by large bubbles (3-5 mm in diameter) for 160 minutes, alternating between the two aeration methods. After 6 days, wastewater treatment was carried out according to the set hydraulic retention time of 3 hours, with dissolved oxygen concentration controlled at 4–5 mg / L, pH 7–8, and temperature 25–30°C. During the wastewater treatment process, the activated carbon was subjected to cyclone treatment 6 times per week. The first cyclone treatment was performed on the 20th day of operation of the wastewater treatment device, with an interval of 28 hours between each treatment. Each treatment lasted 20 minutes to regenerate the activated carbon, and the amount of activated carbon treated each time accounted for 5% of the total activated carbon loading.

[0052] During reactor operation, effluent samples were collected daily for pollutant concentration analysis. After 5 months of continuous operation, the average effluent ammonia nitrogen concentration was 0.69 mg / L, the average total nitrogen concentration was 13.14 mg / L, and the average COD concentration was 26.11 mg / L, indicating stable treatment performance.

[0053] Example 4

[0054] The saline wastewater treated in this example is a mixture of circulating water discharge and RO concentrate. The specific water quality is as follows: ammonia nitrogen concentration of 30 mg / L, total nitrogen of 100 mg / L, COD concentration of 150 mg / L, B / C ratio of less than 0.3, and salt content of 20,000 mg / L.

[0055] A cylindrical aeration reactor with an effective volume of 10L was used for the advanced treatment of saline wastewater. First, pebbles of varying particle sizes were loaded into the reactor as a support layer. Then, coal-based activated carbon with a particle size of 2–8mm (specific surface area of ​​900 m²) was filled into the reactor, filling 50% of its effective volume. 2 / g, iodine value 900mg / g, methylene blue adsorption value 90mg / g), and then rinse the activated carbon twice with tap water.

[0056] Take 100L of residual activated sludge from a saline wastewater treatment plant (MLSS of 10g / L), mechanically stir for 4 hours, filter to remove impurities, add the liquid to the reactor loaded with activated carbon and immerse the activated carbon, use large bubble (bubble diameter of 3-5mm) aeration method, and simmer for 24 hours under dissolved oxygen concentration of 6mg / L.

[0057] Then, the bacterial solution from Example 1 was inoculated into the reactor at a volume of 0.05% of the effective volume of the wastewater treatment device. Continuous aeration was performed under conditions of pH 7.5–7.8 and temperature 28–30°C, with each aeration cycle lasting 6 hours. Within each cycle, microbubbles (50-100 micrometers in diameter) were used for 40 minutes, followed by large bubbles (3-5 mm in diameter) for 320 minutes, alternating between the two aeration methods. After 6 days, wastewater was treated according to the set hydraulic retention time of 6 hours, with dissolved oxygen concentration controlled at 4–5 mg / L, pH 7–8, and temperature 25–30°C. During the wastewater treatment process, the activated carbon was subjected to cyclone treatment twice a week. The first cyclone treatment was performed on the 30th day of operation of the wastewater treatment device, with an interval of 84 hours between each treatment. Each treatment lasted 40 minutes to regenerate the activated carbon, with each treatment involving 10% of the total activated carbon content.

[0058] During reactor operation, effluent samples were collected daily for pollutant concentration analysis. After 5 months of continuous operation, the average effluent ammonia nitrogen concentration was 0.89 mg / L, the average total nitrogen concentration was 13.43 mg / L, and the average COD concentration was 27.07 mg / L, indicating stable treatment performance.

[0059] Comparative Example 1

[0060] The only difference from Example 2 is that the bacterial culture of the highly salt-tolerant bacterium (Halomonasnigrificans) GXNYJ-DL-1 disclosed in CN202011623087.X was used as the inoculum.

[0061] During reactor operation, effluent samples were collected daily for pollutant concentration analysis. After 5 months of continuous operation, the effluent ammonia nitrogen concentration was between 10-15 mg / L, total nitrogen concentration was between 22-25 mg / L, and COD concentration was between 56-64 mg / L, indicating unstable treatment performance.

[0062] Comparative Example 2

[0063] The only difference from Example 2 is that no bacterial agent is used.

[0064] During reactor operation, effluent samples were collected daily for pollutant concentration analysis. After 5 months of continuous operation, the effluent ammonia nitrogen concentration was between 15-18 mg / L, total nitrogen concentration was between 35-41 mg / L, and COD concentration was between 69-77 mg / L, indicating unstable treatment performance.

[0065] Comparative Example 3

[0066] Compared with Example 2, the only difference is that after inoculating the bacterial solution of Example 1, only large air bubbles (3-5 mm in diameter) are used for aeration.

[0067] During reactor operation, effluent samples were collected daily for pollutant concentration analysis. After 5 months of continuous operation, the effluent ammonia nitrogen concentration ranged from 9 to 16 mg / L, total nitrogen concentration from 30 to 38 mg / L, and COD concentration from 66 to 70 mg / L, indicating unstable treatment performance.

[0068] Comparative Example 4

[0069] The only difference from Example 2 is that the activated carbon is not regenerated using a hydrocyclone, but is backwashed weekly using reactor effluent.

[0070] During reactor operation, effluent samples were collected daily for pollutant concentration analysis. After 5 months of continuous operation, the effluent ammonia nitrogen concentration ranged from 11 to 16 mg / L, total nitrogen concentration from 29 to 37 mg / L, and COD concentration from 52 to 59 mg / L, indicating unstable treatment performance.

Claims

1. A method for advanced treatment of saline wastewater, comprising the following steps: (1) Activated carbon is filled into the reactor at 30% to 70% of its effective volume, preferably 40% to 60%; (2) The remaining activated sludge is subjected to cell wall breaking treatment to release the intracellular substances. After removing impurities by precipitation or filtration, the liquid on the surface is retained and added to the reactor in step (1). Then, large bubble aeration is used for simmering treatment for 12 to 24 hours. The dissolved oxygen concentration is controlled above 5 mg / L, preferably 5 to 7 mg / L. (3) Add Halomonas bacteria to the reaction system in step (2), and use alternating large bubble aeration and micro bubble aeration to continuously aerate for 5 to 7 days under the conditions of pH 7 to 9 and temperature 25 to 40°C. Then, treat the wastewater according to the set hydraulic retention time. During the wastewater treatment process, the activated carbon is periodically cycloneedled to regenerate it.

2. The method according to claim 1, characterized in that, In step (1), after the activated carbon is filled, it is washed with water 2 to 3 times; And / or, in step (1), the activated carbon is coal-based activated carbon with a particle size of 2-8 mm and a specific surface area of ​​600-1000 m². 2 / g, iodine value 600~1000mg / g, methylene blue adsorption value 90~120mg / g.

3. The method according to claim 1, characterized in that, In step (2), the amount of liquid added is sufficient to submerge the activated carbon; And / or, the cell wall breaking treatment in step (2) is performed by at least one of the following: over-aeration, mechanical stirring, ultrasonic crushing, or chemical permeation with surfactant. And / or, the residual activated sludge in step (2) is taken from the activated sludge in the secondary sedimentation tank of the refining and chemical saline wastewater treatment plant; wherein, the MLSS of the residual activated sludge is 5-25 g / L.

4. The method according to claim 1, characterized in that, In the large bubble aeration described in step (2), the bubble diameter is above 3 mm, preferably 3-5 mm.

5. The method according to claim 1, characterized in that, The halomonas mentioned in step (3) is Halomonas nigrificans N2-2, which was deposited at the China General Microbiological Culture Collection Center on March 18, 2024, with the accession number CGMCC No. 30065.

6. The method according to claim 5, characterized in that, The cultivation method for Halomonas nigrificans N2-2 involves using citrate broth and culturing under aerobic conditions until the stationary phase. Preferably, the citrate is at least one of sodium citrate and potassium citrate; Preferably, the culture medium also contains potassium nitrate, potassium dihydrogen phosphate, and calcium chloride; Preferably, the culture conditions in the culture method are: pH value of 6-9, temperature of 20-40℃, dissolved oxygen of 0.5-5.0 mg / L, and culture time of 18-36 h.

7. The method according to claim 1, characterized in that, In step (3), the microbubble aeration refers to bubble diameter less than 100 micrometers, preferably 50-100 micrometers; the large bubble aeration refers to bubble diameter greater than 3mm, preferably 3-5mm.

8. The method according to claim 1 or 7, characterized in that, In step (3), the alternation of large bubble aeration and micro bubble aeration means that the hydraulic retention time is used as a cycle, the micro bubble aeration time in each cycle is 20-40 minutes, and the rest is the large bubble aeration time; in each cycle, micro bubble aeration is performed first and then large bubble aeration is performed.

9. The method according to claim 1, characterized in that, The inoculation amount of the bacterial agent is 0.01% to 0.05% of the volume of the bacterial agent to the effective volume of the sewage treatment device.

10. The method according to claim 1, characterized in that, The wastewater is saline wastewater or at least one of the following: effluent from a biological treatment unit, RO concentrate, or circulating water discharge. Specifically, the water quality is as follows: ammonia nitrogen concentration of 20–30 mg / L, total nitrogen of 50–100 mg / L, COD concentration of 80–150 mg / L, B / C ratio less than 0.3, and salt content of 15,000–20,000 mg / L.

11. The method according to claim 1, characterized in that, The aforementioned advanced wastewater treatment refers to effluent with ammonia nitrogen concentration less than 1 mg / L, total nitrogen concentration less than 15 mg / L, and COD concentration less than 30 mg / L after treatment.

12. The method according to claim 1 or 8, characterized in that, In step (3), the hydraulic retention time is set to 2 to 8 hours, preferably 3 to 6 hours; the wastewater treatment conditions are: dissolved oxygen controlled at 0.5 to 5.0 mg / L, pH value at 7 to 9, and temperature at 25 to 40°C.

13. The method according to claim 1, characterized in that, During the wastewater treatment process, activated carbon is subjected to periodic cyclone treatment. The volume of activated carbon in each cyclone treatment accounts for 5% to 10% of the total activated carbon loading. The cyclone treatment is carried out 2 to 7 times per week. The first treatment time is between 20 and 30 days after the wastewater treatment device has been running. The interval between two consecutive treatments is 24 to 84 hours, and the treatment time for each treatment is 10 to 40 minutes.