Method for treating seawater culture tail water mediated by mangrove ammonia-oxidizing archaea and nirS type denitrifying bacteria

Abstract

The application provides a mangrove sediment domesticated DAT-IAT pool, a mangrove sediment domesticated upflow denitrification filter pool and a seawater aquaculture tail water treatment method mediated by mangrove sediment domesticated DAT-IAT pool and nirS type denitrifying bacteria. The seawater aquaculture tail water treatment method comprises the following steps: pretreating seawater aquaculture tail water to remove large-particle impurities in the seawater aquaculture tail water; introducing the pretreated seawater aquaculture tail water into the DAT-IAT pool domesticated by the mangrove sediment to perform heterotrophic nitrification treatment; introducing the seawater aquaculture tail water subjected to the heterotrophic nitrification treatment into the upflow denitrification filter pool domesticated by the mangrove sediment to perform aerobic denitrification treatment; and performing disinfection treatment on the seawater aquaculture tail water subjected to the aerobic denitrification treatment to remove pathogens in the seawater aquaculture tail water. The application focuses on the nitrification function of mangrove ammonia-oxidizing archaea and the denitrification function of nirS type denitrifying bacteria, and constructs a seawater aquaculture tail water treatment process, which can efficiently reduce the high-concentration nitrogen content in seawater aquaculture tail water and can maintain long-time operation.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a method for treating marine aquaculture tailwater mediated by mangrove ammonia-oxidizing archaea and nirS-type denitrifying bacteria. Background Technology

[0002] Marine products are a major source of "food" for China's aquatic products. my country has a long history of mariculture, and in the past 40 years, marine fisheries, with a focus on mariculture, have developed rapidly, playing a pivotal role in the global mariculture industry. Aquatic products provide significantly more protein than ordinary grains, thus playing a crucial role in the nation's protein supply. Against the backdrop of China's rapid economic growth, residents' purchasing power has continued to increase. Simultaneously, the continuous upgrading of key infrastructure such as transportation and cold chain logistics, along with the growing desire for a healthy lifestyle, have jointly driven the continuous rise in demand for high-quality aquatic products in the Chinese market and the sustained release of consumption potential.

[0003] However, wastewater discharge in mariculture has become a major obstacle to its sustainable development. Nitrogen plays a vital role in the conversion of matter and energy and the growth of farmed organisms in aquaculture ecosystems, but direct discharge of wastewater causes marine pollution and ecological damage. High concentrations of nitrogenous nutrients such as ammonia nitrogen, nitrates, and phosphates are the main factors causing pollution and damage. In particular, excessive ammonia nitrogen levels can inhibit the growth of aquatic animals, even leading to the death of farmed organisms, and polluting the surrounding water environment. Therefore, ammonia nitrogen has become one of the key pollutants that need to be addressed in the treatment of aquaculture wastewater.

[0004] The traditional "large-scale water intake and discharge" model commonly used in aquaculture has resulted in significant water resource waste. Physical, chemical, and biological treatment technologies are the main methods for treating aquaculture wastewater. Biological treatment technology is widely adopted as the primary treatment technology due to its high efficiency and environmental friendliness, supplemented by physical and chemical treatment technologies to achieve a more comprehensive purification effect. However, marine aquaculture wastewater has a high salinity, while salt-tolerant microorganisms are relatively scarce, thus hindering the biological treatment process of marine aquaculture wastewater. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a method for treating marine aquaculture wastewater mediated by mangrove ammonia-oxidizing archaea and nirS-type denitrifying bacteria. This treatment method is simple and low in cost, and can not only meet the national first-class discharge standard for total nitrogen content in marine aquaculture wastewater, but also maintain long-term operation.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A method for treating marine aquaculture wastewater mediated by mangrove ammonia-oxidizing archaea and nirS-type denitrifying bacteria includes the following steps:

[0008] S1: Pre-treat the wastewater from marine aquaculture to remove large particulate impurities.

[0009] S2: The pretreated effluent from marine aquaculture is introduced into a DAT-IAT tank acclimated with mangrove sediments for heterotrophic nitrification treatment;

[0010] S3: The seawater aquaculture tailwater that has undergone heterotrophic nitrification is introduced into an upflow denitrification filter acclimated with mangrove sediments for aerobic denitrification treatment;

[0011] S4: Disinfect the effluent from aquaculture that has undergone aerobic denitrification treatment to remove pathogens from the effluent.

[0012] Preferably, in step S2, the process of acclimatizing mangrove sediments in the DAT-IAT pool is as follows:

[0013] Mangrove sediments were inoculated into the bottom of the DAT-IAT reaction tank, and the simulated seawater NH4 levels were first increased in stages. + The method of -N concentration was used to acclimatize mangrove sediments in the DAT-IAT reactor to ammonia nitrogen tolerance, until the NH4+ concentration in the DAT-IAT reactor was similar to that of seawater. + -N concentration was 30-50 mg / L; then, the mangrove sediments in the DAT-IAT reactor were subjected to the first salt tolerance acclimatization by gradually increasing the salinity of the simulated seawater until the salinity of the simulated seawater in the DAT-IAT reactor was 3%-3.5%.

[0014] Preferably, the method of using staged increases in simulated seawater NH4 + The method of N concentration for acclimation of mangrove sediments in the DAT-IAT reactor to ammonia nitrogen tolerance specifically includes:

[0015] Simulated seawater with an ammonia nitrogen concentration of 1-3 mg / L was used as the culture medium for the first stage of ammonia nitrogen tolerance acclimatization. The ammonia nitrogen concentration of the simulated seawater in subsequent stages of ammonia nitrogen tolerance acclimatization was increased by 4-6 mg / L. The simulated seawater for each stage of ammonia nitrogen tolerance acclimatization was introduced into the DAT-IAT reactor in sequence, and the hydraulic retention time was controlled at 15-24 h. The water quality monitoring data after each stage of ammonia nitrogen tolerance acclimatization was monitored. When the water quality monitoring data stabilized, the culture for the next stage of ammonia nitrogen tolerance acclimatization was started. During the ammonia nitrogen tolerance acclimatization process, intermittent aeration was used, with aeration every 3-5 h, an aeration rate of 0.5-1.5 L / min each time, and a stirring intensity of 100-200 r / min.

[0016] Preferably, after inoculating the bottom of the DAT-IAT reaction tank with mangrove sediments, the simulated seawater NH4 content is increased in stages. + Before using the -N concentration method to acclimatize mangrove sediments in the DAT-IAT reactor to ammonia nitrogen tolerance, the following steps were also taken:

[0017] Simulated seawater with an ammonia nitrogen concentration of 1-3 mg / L was introduced into the DAT-IAT reactor, and the hydraulic retention time was controlled at 24-48 h for initial ammonia nitrogen tolerance acclimatization. The initial ammonia nitrogen tolerance acclimatization was completed when the water quality monitoring data of the effluent from the DAT-IAT reactor stabilized. During the initial ammonia nitrogen tolerance acclimatization process, continuous aeration was used with an aeration rate of 0.4-0.6 L / min and a stirring intensity of 80-120 r / min.

[0018] Preferably, the method of gradually increasing the salinity of simulated seawater to conduct the first salt tolerance acclimatization of mangrove sediments in the DAT-IAT reactor specifically includes:

[0019] With a salinity of 0.8%-1.2% and NH4+ + Simulated seawater with an ammonia nitrogen concentration of 30-50 mg / L was used as the culture medium for the first stage of the first salt tolerance acclimatization. In subsequent stages of the first salt tolerance acclimatization, the salinity of the simulated seawater increased by 0.1%-0.3% sequentially, while the ammonia nitrogen concentration remained constant. The simulated seawater from each stage of the first salt tolerance acclimatization was introduced into the DAT-IAT reaction tank in sequence, and the hydraulic retention time was controlled at 15-24 h. The water quality monitoring data after each stage of treatment was monitored. When the water quality monitoring data stabilized, the next stage of cultivation began. During the first salt tolerance acclimatization, intermittent aeration was used, with aeration every 3-5 h, an aeration rate of 0.5-1.5 L / min each time, and a stirring intensity of 100-200 r / min.

[0020] Preferably, before performing the first salt tolerance acclimatization on the mangrove sediments in the DAT-IAT reactor using a method of gradually increasing simulated seawater salinity, the method further includes:

[0021] With a salinity of 0.8%-1.2%, NH4 + Simulated seawater with a -N concentration of 30-50 mg / L was introduced into the DAT-IAT reactor for the first initial salt tolerance acclimatization until the water quality monitoring data of the effluent from the DAT-IAT reactor stabilized. During the first initial salt tolerance acclimatization process, continuous aeration was used with an aeration rate of 0.4-0.6 L / min and a stirring intensity of 80-120 r / min.

[0022] Preferably, step S3, the process of acclimating mangrove sediments in an upflow denitrification filter, includes:

[0023] Mangrove sediments were inoculated onto the bottom of an upflow denitrification filter, and the simulated seawater NO3 levels were initially increased in stages. - The method of NO3- concentration was used to acclimate mangrove sediments to nitrate in an upflow denitrification filter, simulating the NO3 concentration in seawater in the upflow denitrification filter. - -N concentration is 200-300 mg / L; then, the mangrove sediments in the upflow denitrification filter are subjected to a second salt tolerance acclimatization by gradually increasing the salinity of the simulated seawater until the salinity of the simulated seawater in the upflow denitrification filter is 3%-3.5%.

[0024] Preferably, the method of using staged increases in simulated seawater NO3 - The method of N concentration for nitrate tolerance acclimation of mangrove sediments in upflow denitrification filters specifically includes:

[0025] With NO3 - Simulated seawater with an NO3- concentration of 50-100 mg / L was used as the culture medium for the first stage of nitrate tolerance acclimatization. Subsequent stages of nitrate tolerance acclimatization involved using simulated seawater with NO3- concentrations... - The concentration of -N was increased by 50 mg / L in sequence. Simulated seawater for each stage of nitrate tolerance acclimatization was introduced into an upflow denitrification filter in sequence, and the hydraulic retention time was controlled to be 24-48 h. Water quality monitoring data after each stage of nitrate tolerance acclimatization was monitored. When the water quality monitoring data stabilized, the cultivation of the next stage of nitrate tolerance acclimatization was started. The nitrate tolerance acclimatization process adopted the suffocation cultivation method.

[0026] Preferably, after inoculating the mangrove sediments onto the bottom of the upflow denitrification filter, a phased increase in simulated seawater NO3 is adopted. - Before using the -N concentration method to acclimate mangrove sediments to nitrate tolerance in upflow denitrification filters, an initial nitrate tolerance acclimatization process is also included. The specific process of the initial nitrate tolerance acclimatization is as follows:

[0027] Using a closed-air cultivation method, NO3 - Simulated seawater with a nitrogen concentration of 50-100 mg / L was introduced into an upflow denitrification filter, and the hydraulic retention time was controlled at 48-60 h for initial nitrate tolerance acclimatization. After the water quality monitoring data of the effluent from the upflow denitrification filter stabilized, the aeration culture method was switched to aeration culture mode with an aeration rate of 0.1-0.2 L / min and a stirring intensity of 40-60 r / min. The initial nitrate tolerance acclimatization was completed when the water quality monitoring data of the effluent from the upflow denitrification filter stabilized.

[0028] Preferably, the method of gradually increasing the simulated seawater salinity to conduct a second salt tolerance acclimatization of mangrove sediments in an upflow denitrification filter specifically includes:

[0029] With a salinity of 0.8%-1.2% and NO3... - Simulated seawater with a NO3- concentration of 200-300 mg / L was used as the culture medium for the first stage of the second salt tolerance acclimatization. In subsequent stages of the second salt tolerance acclimatization, the salinity of the simulated seawater increased sequentially by 0.4%-0.6%. - With the -N concentration kept constant, simulated seawater from each stage of the second salt tolerance acclimatization was sequentially introduced into an upflow denitrification filter. The hydraulic retention time was controlled to be 12–20 h. Water quality monitoring data after each stage of treatment were detected. When the water quality monitoring data stabilized, the next stage of cultivation began. The second salt tolerance acclimatization process adopted a simmering cultivation method.

[0030] Preferably, the hydraulic retention time for heterotrophic nitrification is 30-40 hours, and the heterotrophic nitrification is carried out by intermittent aeration, with aeration once every 2-4 hours, an aeration rate of 1.0-1.5 L / min each time, and a stirring intensity of 150-200 r / min.

[0031] Preferably, the hydraulic retention time for aerobic denitrification is 25-30 hours, and the aerobic denitrification process employs a simmering and aeration method.

[0032] Preferably, the amount of mangrove sediment inoculum is 75%-85% of the volume of the DAT-IAT reaction tank.

[0033] Preferably, the amount of mangrove sediment inoculum is 75%-85% of the volume of the upflow denitrification filter.

[0034] Preferably, the disinfection process specifically includes: introducing the seawater aquaculture tailwater treated by the DAT-IAT process into the disinfection tank, turning on the chlorine dioxide generator in the disinfection tank, and the residence time of the seawater aquaculture tailwater in the disinfection tank is 5-10 hours.

[0035] Preferably, the pretreatment specifically includes: passing the marine aquaculture wastewater through a process of interception, sedimentation, homogenization and equalization, and coagulation sedimentation.

[0036] Compared with the prior art, the advantages of the present invention are as follows:

[0037] This invention focuses on the nitrification function of ammonia-oxidizing archaea (AOA) and the denitrification function of nirS-type denitrifying bacteria in mangroves, and constructs a marine aquaculture wastewater treatment process to reduce the high concentration of nitrogen in the wastewater. The marine aquaculture wastewater treatment method of this invention mainly includes three stages: pretreatment, main treatment, and advanced treatment, wherein a continuous aeration tank-intermittent aeration tank (Demand Aeration Tank-Intermittent) is used. The DAT-IAT (Damage-Oxygenation Tank) process is the primary ammonia nitrogen treatment process. Mangrove sediments are added to the DAT-IAT reactor and undergo a special gradient acclimation process to enrich the ammonia-oxidizing archaea (AOA) in the mangrove sediments. This process heterotrophically nitrifies the high-concentration ammonia nitrogen effluent from marine aquaculture, converting it into nitrates and nitrites. The upflow denitrification filter is the primary nitrate nitrogen treatment process. Mangrove sediments are added to the upflow denitrification filter and undergo a special gradient acclimation process to enrich the NiRS-type denitrifying bacteria in the mangrove sediments. This process efficiently converts harmful environmental substances in aquaculture effluent—nitrates and nitrites—into harmless nitrogen gas, significantly reducing the adverse impact on the surrounding marine ecosystem and protecting the aquatic environment. Practice has shown that this invention can achieve NH4+ treatment. + -N, NO3 - It effectively removes nitrogen, COD, and other pollutants, and can maintain long-term operation. Attached Figure Description

[0038] Figure 1 This is a process flow diagram of the marine aquaculture wastewater treatment method mediated by mangrove ammonia-oxidizing archaea and nirS-type denitrifying bacteria of the present invention.

[0039] Figure 2 Phylogenetic tree of amoA genes, based on major OTUs, for the bottom sediments of domesticated DAT-IAT reaction tanks.

[0040] Figure 3 Phylogenetic tree of the nirS gene of denitrifying bacteria from the bottom sediments of a domesticated upflow denitrifying filter. Detailed Implementation

[0041] The present invention will be further described below with reference to specific preferred embodiments, but this does not limit the scope of protection of the present invention.

[0042] The initial simulated seawater composition of this embodiment is shown in Table 1:

[0043] Table 1 Initial Simulated Seawater Mixture

[0044]

[0045] Example 1:

[0046] like Figure 1 As shown, this embodiment provides a method for treating marine aquaculture wastewater mediated by mangrove ammonia-oxidizing archaea and nirS-type denitrifying bacteria, including the following steps:

[0047] S1: Pre-treat the wastewater from marine aquaculture to remove large particulate impurities.

[0048] S2: The pretreated effluent from marine aquaculture is introduced into a DAT-IAT tank acclimated with mangrove sediments for heterotrophic nitrification treatment;

[0049] S3: The seawater aquaculture tailwater that has undergone heterotrophic nitrification is introduced into an upflow denitrification filter acclimated with mangrove sediments for aerobic denitrification treatment;

[0050] S4: Disinfect the effluent from aquaculture that has undergone aerobic denitrification treatment to remove pathogens from the effluent.

[0051] In this embodiment, the pretreatment specifically includes: passing the marine aquaculture tailwater through a process of interception, sedimentation, homogenization and equalization, and coagulation sedimentation.

[0052] 1.1) Pollution interception

[0053] The primary function of trash racks is to intercept large, suspended, or floating pollutants in wastewater. If these pollutants are not intercepted, they can clog or damage subsequent treatment equipment such as pumps and pipes. Trash racks are generally classified into two types: coarse and fine. Fine-screen trash racks, in addition to intercepting coarse debris, also remove suspended solids.

[0054] 1.2) Settled Sand

[0055] The working principle of grit settling is based on gravity separation. Therefore, it is necessary to control the influent flow rate of the grit settling tank so that the heavier inorganic particles sink, while the suspended organic particles are carried away by the water flow. In aquaculture wastewater treatment, grit settling tanks are mainly used to remove sand particles from the wastewater to protect pipes, valves, and other facilities from wear and blockage.

[0056] Two parallel grit chambers are typically required for alternating cleaning. The efficiency of a grit chamber is directly proportional to its surface area and independent of its width, depth, flow velocity, and shape. Settled sand and gravel often contain organic matter, making them prone to decomposition. Aerated grit chambers have relatively flexible flow velocity control requirements; abnormal changes in flow rate do not significantly affect the settling effect. Due to the aeration effect, sand and gravel can be treated without washing, and the effluent also has a pre-aeration effect. The chamber design is similar to that of an activated sludge process aeration tank, except that an additional grit hopper approximately 90cm deep is needed for sludge collection.

[0057] 1.3) Homogenization and uniformity

[0058] In wastewater treatment processes, equalization tanks primarily serve two functions: homogenization and flow equalization. Homogenization within the equalization tank helps control the concentration of harmful substances in the wastewater within a specific range, ensuring effective treatment. Flow equalization within the equalization tank helps control the wastewater volume within a specific range, thus reducing the design and operating costs of the wastewater treatment facility. If the wastewater volume fluctuates significantly, the wastewater treatment facility needs to be designed to handle the maximum flow rate.

[0059] A submersible mixer needs to be installed at the bottom of the equalization tank. It plays a crucial role in wastewater treatment plants, effectively agitating suspended solids in the wastewater to ensure uniform mixing of the effluent, thereby improving the treatment effect and efficiency. Selecting the right submersible mixer is a complex task, and the correct selection directly affects the normal operation of the equipment.

[0060] 1.4) Coagulation and sedimentation

[0061] The purpose of a sedimentation tank is to remove suspended solids through settling. When water flows into a large-section tank, the flow velocity decreases, and the water becomes almost still. Under the influence of gravity, particles with higher mass density will move downwards, while particles with lower mass density will move upwards. Therefore, the effluent will be divided into two parts: scum on the surface and sludge at the bottom of the tank. This separation of mud and water achieves the purpose of setting up a sedimentation tank.

[0062] Coagulation can cause suspended particles in effluent to aggregate into large flocs, making them easier to settle. It removes some organic matter, heavy metals, and substances that reduce the transparency of the water. It is usually used in conjunction with sedimentation tanks. Coagulation is carried out through the following steps: (1) In order to shorten the reaction time, the coagulant can quickly and evenly penetrate into the effluent, promoting the balanced distribution of the coagulant in the entire effluent system; (2) The slow mixing process aims to promote the formation of large-particle sediment flocs in the water through slow mixing for 20-30 minutes. To achieve this goal, multiple slow mixing tanks are arranged in sequence. These tanks gradually slow down the water flow to prevent the flocs from breaking due to the shearing effect of the water flow; (3) In order to enhance the aggregation effect between particles, negatively charged or uncharged polymers are introduced. In the actual addition process, the required polymer dosage and the optimal pH conditions should be accurately determined through field tests; (4) During the coagulation process, if the flocs formed in the subsequent sedimentation tank can be circulated to the slow mixing zone, it will help to speed up the coagulation process and reduce the amount of coagulant required.

[0063] In this embodiment, the process of collecting mangrove sediments is as follows:

[0064] The study area was selected as the mangrove ecological reserve in Yangjiang City, Guangdong Province (21°45'18"-21°46'1"N, 111°44'26"-111°45'3"E). Sediment samples were collected on-site and packaged in sterile sealed bags, then placed in a 4°C refrigerator.

[0065] The DAT-IAT process is a variation of the SBR process and is commonly used in wastewater treatment. The DAT-IAT reactor consists of a continuous aeration tank (DAT) and an intermittent aeration tank (IAT) connected in series. During continuous influent, continuous aeration, and continuous effluent flow, the effluent from the DAT flows into the IAT through a distribution baffle wall, and its dissolved oxygen concentration is typically controlled within the range of 1.5–2.5 mg / L. High nitrogen removal efficiency can be achieved by adjusting operating parameters. The continuous influent, aeration, sedimentation, and decanting process of the IAT is a three-stage cycle, typically a 3-hour cycle, with each stage lasting 1 hour. Mixed liquor is recirculated during the aeration and sedimentation stages at a recirculation ratio of 1:200–1:400.

[0066] In this embodiment, the process of acclimatizing mangrove sediments in the DAT-IAT pond in step S2 is as follows:

[0067] 2.1 Gradually increase ammonia nitrogen levels to acclimatize mangrove sediments, thereby enhancing AOA's ability to degrade ammonia nitrogen.

[0068] (1) Initial ammonia nitrogen tolerance acclimatization process: Mangrove sediments were inoculated into the DAT-IAT reactor, with the inoculation amount accounting for 80% of the reactor volume. Simulated marine aquaculture tailwater with an ammonia nitrogen concentration of 3 mg / L was introduced into the DAT-IAT reactor. The hydraulic retention time was controlled at 24–48 h, and continuous aeration was maintained in the reactor. The initial aeration rate was 0.5 L / min, and the stirring intensity was 100 r / min to ensure that the mangrove sediments could fully contact the acclimatization water to degrade organic matter and ammonia nitrogen. The NH4 content of the treated water was measured. + -N, NO2 - -N, COD, and pH, until the data stabilizes, complete the DAT-IAT startup; this step takes 15–20 days to run.

[0069] (2) Gradual increase of ammonia nitrogen concentration: Based on the initial ammonia nitrogen tolerance acclimatization, the concentration of NH4+ was gradually increased. +The -N concentration method was used to acclimatize AOA in the DAT-IAT reactor to ammonia nitrogen tolerance, and intermittent aeration was adopted, i.e., aeration once every 4 hours, aeration rate of 1L / min, and stirring intensity of 150r / min. The culture medium for the first stage was seawater aquaculture tailwater with the same composition and ratio as the start-up stage. The NH4 in the tailwater was synthesized in each stage. + The concentration of -N increases sequentially, and the concentration of NH4+ in the wastewater decreases in the later stage. + The concentration of -N was 5 mg / L higher than that of the previous stage. Simulated seawater from each stage of ammonia nitrogen tolerance acclimation was sequentially introduced into the DAT-IAT reactor, with the hydraulic retention time controlled at 15–24 h. The NH4+ concentration of the treated water at each stage was measured. + -N, NO2 - -N, COD, and pH, each stage lasts 8-9 days. Once the water quality monitoring data stabilizes, the next stage of acclimatization is carried out until the NH4 in the marine aquaculture wastewater... + The concentration of -N was 30-50 mg / L, completing the initial adjustment of AOA in the DAT-IAT sediments. Based on the adaptation of AOA in mangrove sediments and the ammonia nitrogen degradation efficiency (maintained above 80%), it was ensured that AOA in mangrove sediments could efficiently degrade the gradually increasing ammonia nitrogen concentration.

[0070] (3) Stabilization and acclimatization stage: Once the AOA in the mangrove sediments has adapted to the current ammonia nitrogen concentration (30-50 mg / L), this concentration should be maintained for 5-10 days to consolidate the acclimatization results and further improve the degradation capacity of AOA.

[0071] 2.2 First step of salt tolerance acclimatization

[0072] (1) First initial salt tolerance acclimatization stage: The salinity is 1% and NH4+ is used. + Simulated seawater with a nitrogen concentration of 30-50 mg / L was introduced into the DAT-IAT reactor. The initial salinity of the reactor was close to that of the original mangrove sediments (around 1%). The hydraulic retention time was controlled at 24-48 h. The DAT reactor was started for continuous aeration with an initial aeration rate of 0.5 L / min and a stirring intensity of 100 r / min to ensure full contact between the mangrove sediments and the wastewater. The changes in the mangrove sediment sludge were observed to ensure that AOA could grow and reproduce normally in a low-salinity environment.

[0073] (2) Gradually increase salinity: After the microorganisms adapt to the low salinity environment, the salinity of the wastewater in the DAT-IAT reactor is gradually increased. The salinity is controlled at 1% in the first stage, and then increased by 0.2% each time. The salinity content of each stage increases sequentially. During the acclimation period, intermittent aeration is adopted, that is, aeration is carried out once every 4 hours, the aeration rate is 1L / min, and the stirring intensity is 150r / min. The NH4 content of the water after treatment at each stage is measured. + -N, NO2 - The cultivation process involves adjusting nitrogen (N), COD, and pH, with each stage lasting 8–10 days. Once the data stabilizes, the next stage begins, simulating a seawater salinity of 3%–3.5% in the DAT-IAT reactor. The hydraulic retention time for each stage is 15–24 hours. The degradation efficiency of ammonia nitrogen in mangrove sediments is closely monitored (maintained above 80%) to ensure that the ammonia oxygenate (AOA) in the mangrove sediments can adapt to the new salinity level, until the simulated seawater salinity in the DAT-IAT reactor reaches 3% and the water quality monitoring data stabilizes. If the ammonia nitrogen degradation efficiency in mangrove sediments decreases during this period, the rate of salinity increase should be appropriately reduced, and more time should be given for the mangrove sediment AOA to adapt to the salinity change.

[0074] (3) Stabilization phase: After the mangrove sediments have adapted to the current salinity level, the salinity should be maintained for 5-10 days to consolidate the acclimatization results. During this period, the ammonia nitrogen concentration (30-50 mg / L) in the DAT-IAT reactor should remain stable to stabilize the ammonia nitrogen treatment capacity of the DAT-IAT reactor.

[0075] After the mangrove sediments in the DAT-IAT pond were acclimatized, sediment samples were taken from the bottom of the pond. In a clean bench, approximately 0.25g of the sample was randomly selected and placed in a Lysis Tube. Genomic DNA of microorganisms in the sediments was extracted according to the instructions of the MagicPure Soil Genomic DNA Kit.

[0076] Using microbial DNA from sediments as a template, the functional gene amoA of AOA was amplified by PCR. The amoA gene was amplified using the forward-specific primer Arch-amoAF (5'-STAATGGTCTGGCTTAGACG-3') modified with an 8bp barcode sequence and the reverse-specific primer Arch-amoAR (5'-GCGGCCATCCATCTGTATGT-3'). The PCR amplification conditions for amoA were as follows: 95℃ pre-denaturation for 3 min, 95℃ denaturation for 45 s, 52℃ annealing for 45 s, 72℃ extension for 1 min, for 35 cycles, followed by a final extension at 72℃ for 10 min. dd H2O was used as a negative control. The PCR amplification system for the AOA amoA gene is shown in Table 2.

[0077] Table 2 PCR amplification system of AOAamoA gene

[0078] reagents Volume / μL Taq enzyme 12.5 <![CDATA[ddH2O]]> 9.5 Primer Arch-amoAF 1 Primer Arch-amoAR 1 template 1 Total 25

[0079] After PCR amplification, in order to detect the presence of the target gene, 5 μL of the amplification product was subjected to agarose gel electrophoresis, stained with Goldview staining agent, and the electrophoretic bands were observed in a gel imaging system. Subsequently, the target DNA was purified by gel recovery.

[0080] The PCR products of the samples were thoroughly mixed and subjected to agarose gel electrophoresis. The target band was then excised using a blue light gel cutter, and DNA was purified by gel extraction according to the SteadyPure DNA Gel Extraction Kit instructions. After DNA gel extraction and purification, 5 μL of the purified sample was mixed with 1 μL of Loading Buffer and subjected to agarose gel electrophoresis. The electrophoresed samples were observed using a gel imaging system to detect the target gene. Finally, the purified products were sent to a testing company for analysis.

[0081] The phylogenetic tree of mangrove AOA drawn based on major OTUs is as follows: Figure 2As shown: According to the phylogenetic tree, the main OTUs are divided into 4 clusters. Among them, cluster 1 accounts for 6.83% with 1618 sequences, which is the lowest percentage; cluster 2 accounts for 11.11% with 2634 sequences; cluster 3 accounts for 17.94% with 4254 sequences; and cluster 4 accounts for 50.00% with 11853 sequences, which is the highest percentage. OTU2, OTU13, OTU18, and OTU24 belong to cluster 1 and are similar to the archaea (FJ601574.1) found on the west coast of central India; OTU21, OTU9, OTU6, OTU22, OTU1084, and OTU1169 belong to cluster 2 and are similar to the archaea (KF286684.1) found in the coastal wetlands of the Mai Po Nature Reserve in Hong Kong; OTU25, OTU37, OTU17, OTU59, OTU5, OTU4, OTU14, OTU58, OTU12, OTU47, OTU31, OTU55, and OTU3 belong to cluster 1. 3. Similar to *DQ148594.1* found in the Gulf of California, *FJ601570.1* found in marine estuary sediments on the west coast of central India, archaea (ON113396.1, MF566733.1) found in mangrove sediments, *JQ345908.1* found in intertidal sediments in eastern Chongming, China, and *FJ227851.1* found in estuary sediments; OTU29, OTU40, OTU19, OTU33, OTU7, OTU441 OTU11, OTU16, OTU20, OTU8, OTU34, OTU10, OTU32, and OTU28 belong to cluster 4 and are similar to archaea (MH919267.1) found in sediments of the Liaohe River estuary in China, sediment spring archaea (DQ148816.1) found in California, USA, archaea (MK487181.1) found in salt marsh sediments in the Gulf of Mexico, and archaea (MF566559.1, KJ778402.1) found in mangrove sediments. This indicates a relatively rich diversity of amoA-type AOA types in the Yangjiang mangrove sediments.

[0082] The final microbial composition and percentage of mangrove sediments after acclimatization in the DAT-IAT pond were determined as follows: Thaumarcchaeota accounted for 31.2%, Nitrosoarchaeum koreensisMY1 (HQ331117) accounted for 22.7%, and Nitrosoarchaeum limnia accounted for 46.2%.

[0083] After the DAT-IAT pond is acclimated with mangrove sediments, the pretreated marine aquaculture tailwater can be introduced into the DAT-IAT pond acclimated with mangrove sediments for heterotrophic nitrification. The hydraulic retention time for heterotrophic nitrification is 30-40 hours. The heterotrophic nitrification is carried out by intermittent aeration, with aeration every 2-4 hours, an aeration rate of 1.0-1.5 L / min each time, and a stirring intensity of 150-200 r / min.

[0084] In this process, the DAT-IAT reactor plays a central role. After mangrove sediment is introduced into the DAT-IAT reactor, it undergoes gradient acclimatization by gradually increasing ammonia nitrogen and salinity. This process allows for the selection of a group of highly efficient ammonia nitrogen-treating microorganisms. These microorganisms can survive and metabolize in high-salinity and high-ammonia nitrogen environments, adapting to and degrading these high-concentration pollutants. They primarily convert ammonia nitrogen into nitrite and nitrate, a process called nitrification, mainly completed by mangrove AOA (autoclave oxygenation). The acclimatization process is a crucial step, enhancing the tolerance and transformation capacity of the sludge microbial community to specific pollutants. AOA can more efficiently oxidize ammonia nitrogen into nitrate, thus completing the first step of the denitrification process.

[0085] Denitrification filters are wastewater treatment processes that integrate biological nitrogen removal and filtration. They combine biofilm treatment and physical treatment technologies. The water flow direction in denitrification filters is either upflow or downflow. Upflow denitrification filters have influent from the bottom and effluent from the top, while downflow denitrification filters have the opposite influent and effluent directions. Upflow biological filters can achieve higher filtration rates, require less space, are more resistant to hydraulic load shocks, and allow for higher filter media packing heights.

[0086] The main function of the filter media in a biological filter is as a biological carrier and to intercept suspended solids. The choice of filter media is a crucial factor affecting the treatment efficiency of a denitrification filter. Currently, commonly used filter media include ceramsite and quartz sand. In terms of nitrogen removal efficiency, ceramsite is superior to quartz sand. Ceramsite has a larger specific surface area and higher adsorption capacity than quartz sand, thus allowing for a larger biofilm to adhere and resulting in better nitrogen removal. However, in terms of filtration efficiency, quartz sand is superior to ceramsite. Considering nitrogen removal efficiency, this design selects ceramsite as the filter media for the denitrification filter.

[0087] The denitrification filter employs inoculation with biofilm to acclimate Nirs-type denitrifying bacteria to nitrate tolerance. The acclimatization process is divided into three stages:

[0088] (1) The first stage is biological inoculation and initial cultivation. Mangrove soil sediment is introduced into the denitrification filter, with the mangrove sediment accounting for 80% of the denitrification filter volume. The mangrove soil sediment contains denitrifying bacteria. To promote the growth and reproduction of denitrifying bacteria, simulated marine aquaculture effluent is passed into the filter, which contains NO3. - The -N concentration is 50 mg / L, the hydraulic retention time is 48-60 h, and the reactor is kept in a low-oxygen state without any agitation.

[0089] (2) The second stage is the adaptation stage of Nirs-type denitrifying bacteria, and the influent NO3 - The nitrogen concentration is kept constant, providing a small amount of oxygen to the denitrifying bacteria. The initial aeration rate is 0.2 L / min, and the stirring intensity is 50 r / min, allowing the denitrifying bacteria to adapt and proliferate. Once the denitrifying bacteria have proliferated to a certain level, targeted acclimatization is initiated to make them more adaptable to high salinity and high NO3. - -N wastewater treatment environment;

[0090] (3) The third stage involves increasing the nitrate treatment load of the denitrifying filter, understanding the community structure of Nirs-type denitrifying bacteria through high-throughput sequencing, and then adjusting the nutrient dosage, gradually increasing the potassium nitrate concentration to synthesize the potassium nitrate concentration in the marine aquaculture effluent, and then increasing the NO3 concentration in the marine aquaculture effluent. - The NO3- concentration increased by 50 mg / L in each stage compared to the previous stage. Simulated seawater from each stage of nitrate tolerance acclimation was sequentially introduced into the denitrification filter reactor, maintaining a controlled aeration and aeration method, with a hydraulic retention time of 24–48 h. The NO3- concentration in the treated water was measured at each stage. - -N, COD, and pH, each stage lasts 10-15 days. Once the water quality monitoring data stabilizes, the next stage of acclimatization begins, until NO3 in the effluent from marine aquaculture is reduced. + The concentration of -N is 200-300 mg / L, NO3 + The operation period for the N-N concentration increase phase is 50–60 days. Based on the adaptation of Nirs-type denitrifying bacteria in mangrove sediments and the nitrate degradation efficiency (maintained above 70%), it is ensured that Nirs-type denitrifying bacteria in mangrove sediments can efficiently degrade the gradually increasing nitrate concentration, thereby improving the nitrate nitrogen removal efficiency of the denitrification filter.

[0091] The denitrification filter uses inoculation with biofilm to acclimate Nirs-type denitrifying bacteria to high salinity.

[0092] The main purpose of salinity acclimatization is to improve the adaptability of denitrifying bacteria in high-salt environments and their ability to remove nitrate nitrogen, so as to ensure that the upflow denitrification filter can maintain stable and efficient operation when treating high-salt wastewater.

[0093] (1) First stage: The initial salt concentration is 1%, NO3 - Simulated seawater with a nitrogen concentration of 200-300 mg / L was introduced into an upflow denitrification filter. The filter was operated under low-oxygen conditions, without aeration or stirring. The growth of denitrifying bacteria and the nitrate removal effect in the sediment were observed. If the denitrifying bacteria could adapt and stably remove 90% of the nitrate nitrogen, the process would proceed to the next stage.

[0094] (2) Second stage: Gradually increase the salt concentration in the simulated seawater aquaculture tailwater, increasing by 0.5% each time, NO 3- With the -N concentration kept constant, observe for 5-10 days to ensure that the denitrifying bacteria can adapt to the new salinity environment, and test the NO3 content in the water after each stage of treatment. - -N, COD, and pH are adjusted until the water quality monitoring data stabilizes, then the next stage of cultivation begins. If the removal effect decreases or the growth of denitrifying bacteria is inhibited, the salt concentration is appropriately reduced and observation continues.

[0095] (3) Third stage: When the denitrifying bacteria can adapt to the high salt concentration of 3-3.5% and stably remove nitrate nitrogen, continuously monitor the NO3 in the effluent. - The acclimatization process is considered complete when the denitrifying bacteria adapt to the final salt concentration and stably remove nitrate nitrogen, based on the levels of nitrogen (N), COD, pH, and the growth of denitrifying bacteria. At this point, the upflow denitrifying filter can operate stably at higher salt concentrations.

[0096] The phylogenetic tree of the nirS gene, constructed based on the OUT level from 50 core OTUs selected from the bottom sediments of the aforementioned acclimatized upflow denitrification filter, is as follows: Figure 3 As shown, the tree structure is subdivided into 10 different clusters based on sequence clustering. Cluster 1 has the largest number of sequences, totaling 29,303, accounting for 19.88% of the total, while cluster 8 contains the fewest sequences, with only 3,810, accounting for 2.58%. The remaining clusters cover sequences ranging from 3.49% to 16.78%.

[0097] Cluster 1 comprised OTU1, OTU7, OTU13, OTU16, OTU27, OTU30, OTU39, OTU48, and OTU49, indicating a close association with nirS-type denitrifying bacteria sequences (HQ882414 and HQ882417.1) from Pearl River Estuary sediments. On the other hand, OTU5 and OTU33 were grouped into cluster 3, similar to the aforementioned Pearl River Estuary sequences. Cluster 2 included OTU10, OTU33, and OTU40, which showed high similarity to denitrifying bacteria sequences (KU995374.1) found in native coastal wetlands. Furthermore, cluster 4 comprised OTU2, OTU3, OTU15, and OTU20, matching known nirS-type denitrifying bacteria sequences (JX002733) in mangrove ecosystems. Cluster 5 includes OTUs 19 through 47, which are highly similar to denitrifying bacteria sequences from various environments, such as potato fields (FJ853966.1), the South China Sea (HQ666561), New England salt marshes (KF896049), and Bahia del Tobal, Mexico (KC614388.1). Cluster 6 includes OTUs 8, 21, 29, 32, and 44, which show a genetic relationship to nirS-type denitrifying bacteria sequences (such as KC2934453, DQ676190, and KX388846.1) from oil-bearing salt marsh environments along the Chesapeake Bay and Gulf Coast. Members of cluster 7, OTU6, OTU9, OTU22, OTU41, and OTU46, show high sequence identity with nirS-type strains (e.g., KT444053, JX941775) found in intertidal marshes and river sediments in Fujian. In cluster 8, OTU11 and OTU45 are associated with denitrifying bacteria sequences (KX510628) derived from beach sediments; while cluster 9, including OTU4 and OTU23, is similar to nirS-type strain sequences (KX389087) found in oil-bearing salt marshes along the Gulf Coast. This reveals the high diversity and widespread distribution of nirS-type denitrifying bacteria in mangrove ecosystems.

[0098] The final determination of the microbial composition and percentage content of mangrove sediments after acclimation treatment in an upflow denitrification filter was as follows: Proteobacteria 85.22%, Chlorophyta 10.22%, Aquatic Bacteria 3.45%, and other phyla, including Actinobacteria, Planctomycetes, and Bacteroidetes, accounting for 1.11% of the total.

[0099] After the upflow denitrification filter has been acclimated with mangrove sediments, the seawater effluent that has undergone heterotrophic nitrification can be introduced into the upflow denitrification filter acclimated with mangrove sediments for aerobic denitrification. The hydraulic retention time for aerobic denitrification is 25-30 hours, and the aerobic denitrification process adopts a simmering culture method.

[0100] In this embodiment, the disinfection process specifically includes: introducing the effluent from marine aquaculture treated by the DAT-IAT process into the disinfection tank, turning on the chlorine dioxide generator in the disinfection tank, and the residence time of the effluent from marine aquaculture in the disinfection tank is 5-10 hours.

[0101] Chlorine dioxide disinfection technology, after years of development, has proven to be a stable and effective treatment method, widely used in various fields, and favored for its simple operation and management. This technology excels in eliminating bacteria such as E. coli, typhoid bacilli, and tubercle bacilli, as well as viruses, including hepatitis A and B viruses. Furthermore, the economic efficiency of chlorine dioxide disinfection is a major advantage, as it is not only affordable as a disinfectant but also consumes little electricity during operation, thus reducing overall operating costs. In terms of equipment, it also boasts advantages such as simple structure, reliability, durability, and low cost, and has achieved complete domestic production, making maintenance and repair more convenient. Finally, the disinfection characteristics of chlorine dioxide also include a special residual chlorine effect, ensuring that treated water retains its disinfection effect after discharge, effectively preventing secondary pollution.

[0102] The treatment effect of the seawater aquaculture wastewater treated in this embodiment is shown in Table 3. It can be seen that the treatment process of this embodiment can achieve NH4+ treatment. + -N、NO 3- It effectively removes nitrogen, COD, and other pollutants, and can stably and continuously treat marine aquaculture wastewater for about 100-120 days.

[0103] Table 3. Treatment effect of marine aquaculture tailwater

[0104] tailwater indicators Influent concentration (mg / L) Effluent concentration (mg / L) Removal rate (%) Remark <![CDATA[NH4 + -N]]> 20.3～30.3 3.8～6.2 80.2～81.3 Good removal effect <![CDATA[NO2 - -N]]> 10.5～13.5 1.0～2.2 83.7～90.5 Good removal effect <![CDATA[NO3 - -N]]> 115.5～150.5 13.5～20.5 86.4～88.3 Good removal effect COD 101.8～120.9 15.5～18.8 84.4～84.8 Good removal effect pH 7.5～7.8 7.2～7.5 - Stable water quality

[0105] The above description is merely a preferred embodiment of this application and does not constitute any limitation on this application. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any modifications or alterations made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for treating marine aquaculture wastewater mediated by mangrove ammonia-oxidizing archaea and nirS-type denitrifying bacteria, characterized in that, Includes the following steps: S1: Pre-treat the wastewater from marine aquaculture to remove large particulate impurities. S2: The pretreated effluent from marine aquaculture is introduced into a DAT-IAT tank acclimated with mangrove sediments for heterotrophic nitrification treatment; S3: The seawater aquaculture tailwater that has undergone heterotrophic nitrification is introduced into an upflow denitrification filter acclimated with mangrove sediments for aerobic denitrification treatment; S4: Disinfect the effluent from aquaculture that has undergone aerobic denitrification treatment to remove pathogens from the effluent. In step S2, the process of acclimatizing mangrove sediments in the DAT-IAT pool is as follows: Mangrove sediments were inoculated into the bottom of the DAT-IAT reaction tank, and the simulated seawater NH4 levels were first increased in stages. + The method of -N concentration was used to acclimatize mangrove sediments in the DAT-IAT reactor to ammonia nitrogen tolerance, until the NH4+ concentration in the DAT-IAT reactor was similar to that of seawater. + -N concentration was 30-50 mg / L; then, the mangrove sediments in the DAT-IAT reactor were subjected to the first salt tolerance acclimatization by gradually increasing the salinity of the simulated seawater until the salinity of the simulated seawater in the DAT-IAT reactor was 3%-3.5%. In step S3, the process of acclimating mangrove sediments in an upflow denitrification filter includes: Mangrove sediments were inoculated onto the bottom of an upflow denitrification filter, and the simulated seawater NO3 levels were initially increased in stages. - The method of NO3- concentration was used to acclimate mangrove sediments to nitrate in an upflow denitrification filter, simulating the NO3 concentration in seawater in the upflow denitrification filter. - -N concentration is 200-300 mg / L; then, the mangrove sediments in the upflow denitrification filter are subjected to a second salt tolerance acclimatization by gradually increasing the salinity of the simulated seawater until the salinity of the simulated seawater in the upflow denitrification filter is 3%-3.5%.

2. The method for treating marine aquaculture wastewater mediated by mangrove ammonia-oxidizing archaea and NirS-type denitrifying bacteria according to claim 1, characterized in that, The stage of improving simulated seawater NH4 + The method of N concentration for acclimation of mangrove sediments in the DAT-IAT reactor to ammonia nitrogen tolerance specifically includes: Simulated seawater with an ammonia nitrogen concentration of 1-3 mg / L was used as the culture medium for the first stage of ammonia nitrogen tolerance acclimatization. The ammonia nitrogen concentration of the simulated seawater in subsequent stages of ammonia nitrogen tolerance acclimatization was increased by 4-6 mg / L. The simulated seawater for each stage of ammonia nitrogen tolerance acclimatization was introduced into the DAT-IAT reactor in sequence, and the hydraulic retention time was controlled at 15-24 h. The water quality monitoring data after each stage of ammonia nitrogen tolerance acclimatization was monitored. When the water quality monitoring data stabilized, the culture for the next stage of ammonia nitrogen tolerance acclimatization was started. During the ammonia nitrogen tolerance acclimatization process, intermittent aeration was used, with aeration every 3-5 h, an aeration rate of 0.5-1.5 L / min each time, and a stirring intensity of 100-200 r / min.

3. The method for treating marine aquaculture wastewater mediated by mangrove ammonia-oxidizing archaea and NirS-type denitrifying bacteria according to claim 2, characterized in that, After inoculating the bottom of the DAT-IAT reactor with mangrove sediments, the simulated seawater NH4 levels were increased in stages. + Before using the -N concentration method to acclimatize mangrove sediments in the DAT-IAT reactor to ammonia nitrogen tolerance, the following steps were also taken: Simulated seawater with an ammonia nitrogen concentration of 1-3 mg / L was introduced into the DAT-IAT reactor, and the hydraulic retention time was controlled at 24-48 h for initial ammonia nitrogen tolerance acclimatization. The initial ammonia nitrogen tolerance acclimatization was completed when the water quality monitoring data of the effluent from the DAT-IAT reactor stabilized. During the initial ammonia nitrogen tolerance acclimatization process, continuous aeration was used with an aeration rate of 0.4-0.6 L / min and a stirring intensity of 80-120 r / min.

4. The method for treating marine aquaculture wastewater mediated by mangrove ammonia-oxidizing archaea and NirS-type denitrifying bacteria according to claim 1, characterized in that, The method of gradually increasing the simulated seawater salinity to conduct the first salt tolerance acclimatization of mangrove sediments in the DAT-IAT reactor specifically includes: With a salinity of 0.8%-1.2% and NH4+ + Simulated seawater with an ammonia nitrogen concentration of 30-50 mg / L was used as the culture medium for the first stage of the first salt tolerance acclimatization. In subsequent stages of the first salt tolerance acclimatization, the salinity of the simulated seawater increased by 0.1%-0.3% sequentially, while the ammonia nitrogen concentration remained constant. The simulated seawater from each stage of the first salt tolerance acclimatization was introduced into the DAT-IAT reaction tank in sequence, and the hydraulic retention time was controlled at 15-24 h. The water quality monitoring data after each stage of treatment was monitored. When the water quality monitoring data stabilized, the next stage of cultivation began. During the first salt tolerance acclimatization, intermittent aeration was used, with aeration every 3-5 h, an aeration rate of 0.5-1.5 L / min each time, and a stirring intensity of 100-200 r / min.

5. The method for treating marine aquaculture wastewater mediated by mangrove ammonia-oxidizing archaea and NirS-type denitrifying bacteria according to claim 4, characterized in that, Prior to the initial salt tolerance acclimatization of mangrove sediments in the DAT-IAT reactor using a phased increase in simulated seawater salinity, the following steps were also included: With a salinity of 0.8%-1.2%, NH4 + Simulated seawater with a -N concentration of 30-50 mg / L was introduced into the DAT-IAT reactor for the first initial salt tolerance acclimatization until the water quality monitoring data of the effluent from the DAT-IAT reactor stabilized. During the first initial salt tolerance acclimatization process, continuous aeration was used with an aeration rate of 0.4-0.6 L / min and a stirring intensity of 80-120 r / min.

6. The method for treating marine aquaculture wastewater mediated by mangrove ammonia-oxidizing archaea and NirS-type denitrifying bacteria according to claim 1, characterized in that, The stage of increasing simulated seawater NO3 - The method of N concentration for nitrate tolerance acclimation of mangrove sediments in upflow denitrification filters specifically includes: With NO3 - Simulated seawater with an NO3- concentration of 50-100 mg / L was used as the culture medium for the first stage of nitrate tolerance acclimatization. Subsequent stages of nitrate tolerance acclimatization involved using simulated seawater with NO3- concentrations... - The concentration of -N was increased sequentially by 45-55 mg / L. Simulated seawater for each stage of nitrate tolerance acclimatization was introduced into an upflow denitrification filter in sequence, and the hydraulic retention time was controlled at 24-48 h. Water quality monitoring data after each stage of nitrate tolerance acclimatization was monitored. When the water quality monitoring data stabilized, the cultivation of the next stage of nitrate tolerance acclimatization was started. The nitrate tolerance acclimatization process adopted the suffocation cultivation method.

7. The method for treating marine aquaculture wastewater mediated by mangrove ammonia-oxidizing archaea and NirS-type denitrifying bacteria according to claim 6, characterized in that, After inoculating the bottom of an upflow denitrification filter with mangrove sediments, a phased increase in simulated seawater NO3 was employed. - Before using the -N concentration method to acclimate mangrove sediments to nitrate tolerance in upflow denitrification filters, an initial nitrate tolerance acclimatization process is also included. The specific process of the initial nitrate tolerance acclimatization is as follows: Using a closed-air cultivation method, NO3 - Simulated seawater with a nitrogen concentration of 50-100 mg / L was introduced into an upflow denitrification filter, and the hydraulic retention time was controlled at 48-60 h for initial nitrate tolerance acclimatization. After the water quality monitoring data of the effluent from the upflow denitrification filter stabilized, the aeration culture method was switched to aeration culture mode with an aeration rate of 0.1-0.2 L / min and a stirring intensity of 40-60 r / min. The initial nitrate tolerance acclimatization was completed when the water quality monitoring data of the effluent from the upflow denitrification filter stabilized.

8. The method for treating marine aquaculture wastewater mediated by mangrove ammonia-oxidizing archaea and NirS-type denitrifying bacteria according to claim 1, characterized in that, The method of gradually increasing simulated seawater salinity to conduct a second salt tolerance acclimatization of mangrove sediments in an upflow denitrification filter specifically includes: With a salinity of 0.8%-1.2% and NO3... - Simulated seawater with a NO3- concentration of 200-300 mg / L was used as the culture medium for the first stage of the second salt tolerance acclimatization. In subsequent stages of the second salt tolerance acclimatization, the salinity of the simulated seawater increased sequentially by 0.4%-0.6%. - With the -N concentration kept constant, simulated seawater from each stage of the second salt tolerance acclimatization was sequentially introduced into an upflow denitrification filter. The hydraulic retention time was controlled to be 12–20 h. Water quality monitoring data after each stage of treatment were detected. When the water quality monitoring data stabilized, the next stage of cultivation began. The second salt tolerance acclimatization process adopted a simmering cultivation method.

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