Mangrove forest ammonia oxidizing archaea and nirS type denitrifying bacterium mediated mariculture tail water treatment method

Abstract

The invention provides a mangrove forest ammonia oxidizing archaea and nirS type denitrifying bacterium mediated mariculture tail water treatment method which comprises the following steps: pretreating mariculture tail water to remove large-particle impurities in the mariculture tail water; the pretreated mariculture tail water is guided into a DAT-IAT pool subjected to mangrove forest sediment domestication to be subjected to heterotrophic nitrification treatment; the mariculture tail water subjected to heterotrophic nitrification treatment is guided into an up-flow denitrification filter tank subjected to mangrove forest sediment domestication to be subjected to aerobic denitrification treatment; and carrying out disinfection treatment on the mariculture tail water subjected to aerobic denitrification treatment so as to remove pathogens in the mariculture tail water. The invention focuses on the nitrification function of mangrove forest ammonia-oxidizing archaea and the denitrification function of nirS-type denitrifying bacteria to construct a set of mariculture tail water treatment process, so that the high-concentration nitrogen content in mariculture tail water can be efficiently reduced; and long-time operation can be maintained.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, and in particular to a method for treating seawater aquaculture tail water mediated by mangrove ammonia oxidizing archaea and nirS type denitrifying bacteria. Background Art

[0002] Marine products are the main source of "food" for Chinese aquatic products. my country's marine aquaculture industry has a long history. In the past 40 years, marine fisheries with a focus on marine aquaculture have developed rapidly and played a pivotal role in the world's marine aquaculture industry. Aquatic products can provide a much higher protein supply than ordinary grains, so aquatic products play a huge role in the national protein supply. Against the backdrop of China's rapid economic growth, residents' purchasing power continues to increase. At the same time, the continuous upgrading of key facilities such as transportation and cold chain logistics, as well as the people's growing desire for a healthy lifestyle, have jointly promoted the continuous increase in the Chinese market's demand for high-quality aquatic products and the continuous release of consumption potential.

[0003] However, the discharge of tailwater in marine aquaculture has become a major problem that hinders its sustainable development. Nitrogen content plays a very important role in the transformation of material energy and the growth of cultured organisms in aquaculture ecosystems, but the direct discharge of tailwater will cause marine pollution and ecological damage. High concentrations of nitrogen nutrients such as ammonia nitrogen, nitrates, and phosphates are the main factors causing pollution and damage. In particular, excessive ammonia nitrogen content will inhibit the growth of aquatic animals, even cause the death of aquaculture objects, and pollute the surrounding water environment. Therefore, ammonia nitrogen has become one of the pollutants that need to be addressed in the process of aquaculture tailwater treatment.

[0004] The "large-scale drainage" model commonly used in aquaculture in the past has also caused a large amount of water resources to be consumed. Physical treatment, chemical treatment and biological treatment technology are the main treatment methods for aquaculture tail water. Biological treatment technology is widely adopted as the main treatment technology due to its high efficiency and environmental protection, and is partially supplemented by physical and chemical treatment technologies to achieve a more comprehensive purification effect. However, the salinity of marine aquaculture tail water is relatively high, and there are relatively few salt-tolerant microorganisms, which restricts the biological treatment process of marine aquaculture tail water. 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 tail water mediated by mangrove ammonia oxidizing archaea and nirS-type denitrifying bacteria. The treatment method has a simple process and low cost. Not only can the total nitrogen content of marine aquaculture tail water meet the national first-level emission standards, but it can also maintain long-term operation.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A method for treating seawater aquaculture tail water mediated by mangrove ammonia-oxidizing archaea and nirS-type denitrifying bacteria comprises the following steps:

[0008] S1: Pre-treat the tail water of marine aquaculture to remove large particles of impurities in the tail water of marine aquaculture;

[0009] S2: The pre-treated marine aquaculture tailwater was introduced into the DAT-IAT pool acclimated with mangrove sediments for heterotrophic nitrification treatment;

[0010] S3: introducing the marine aquaculture tail water treated with heterotrophic nitrification into an upflow denitrification filter tank acclimated with mangrove sediments for aerobic denitrification treatment;

[0011] S4: The aquaculture tail water treated by aerobic denitrification is disinfected to remove pathogens in the aquaculture tail water.

[0012] Preferably, in step S2, the process of acclimatizing mangrove sediment 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 NH 4 + -N concentration method was used to acclimate the mangrove sediments in the DAT-IAT reaction tank to ammonia nitrogen tolerance. 4 + -N concentration is 30-50mg / L; and then the mangrove sediment in the DAT-IAT reaction pool is first acclimated to salt tolerance by increasing the salinity of the simulated seawater in stages until the salinity of the simulated seawater in the DAT-IAT reaction pool is 3%-3.5%.

[0014] Preferably, the adoption stage increases the simulated seawater NH 4 + The mangrove sediments in the DAT-IAT reaction tank were acclimated to ammonia nitrogen tolerance by using the -N concentration method, which specifically includes:

[0015] The simulated seawater with an ammonia nitrogen concentration of 1-3 mg / L is used as the culture medium for the first stage of ammonia nitrogen resistance acclimation. The ammonia nitrogen concentration of the simulated seawater in the subsequent ammonia nitrogen resistance acclimation stages is increased by 4-6 mg / L in sequence. The simulated seawater in each stage of ammonia nitrogen resistance acclimation is sequentially introduced into the DAT-IAT reaction tank, and the hydraulic retention time is controlled to be 15-24 hours. The water quality monitoring data after each stage of ammonia nitrogen resistance acclimation is detected. When the water quality monitoring data is stable, the cultivation of the next stage of ammonia nitrogen resistance acclimation is started. Intermittent aeration is adopted during the ammonia nitrogen resistance acclimation process, with aeration every 3-5 hours, an aeration volume of 0.5-1.5 L / min each time, and a stirring intensity of 100-200 r / min.

[0016] Preferably, after inoculating mangrove sediments into the bottom of the DAT-IAT reaction tank, the simulated seawater NH 4 + Before acclimatizing the mangrove sediment in the DAT-IAT reaction tank to ammonia nitrogen tolerance, the method also includes:

[0017] Introduce simulated seawater with an ammonia nitrogen concentration of 1-3 mg / L into the DAT-IAT reaction tank, control the hydraulic retention time to 24-48 hours, and carry out initial ammonia nitrogen resistance acclimation. When the water quality monitoring data of the effluent from the DAT-IAT reaction tank is stable, the initial ammonia nitrogen resistance acclimation is completed. Continuous aeration is used during the initial ammonia nitrogen resistance acclimation process, with an aeration volume of 0.4-0.6 L / min and a stirring intensity of 80-120 r / min.

[0018] Preferably, the method of increasing the salinity of simulated seawater in stages to perform the first salt tolerance acclimatization on the mangrove sediment in the DAT-IAT reaction tank specifically includes:

[0019] With salinity of 0.8%-1.2%, NH 4 + The simulated seawater with a -N concentration of 30-50 mg / L is used as the culture medium for the first stage of the first salt tolerance acclimation. The salinity of the simulated seawater in the subsequent stages of the first salt tolerance acclimation is increased by 0.1%-0.3% in sequence, and the ammonia nitrogen concentration remains unchanged. The simulated seawater in each stage of the first salt tolerance acclimation is sequentially introduced into the DAT-IAT reaction tank, and the hydraulic retention time is controlled to be 15-24 hours. The water quality monitoring data after treatment in each stage is detected, and the next stage of culturing is started when the water quality monitoring data is stable; intermittent aeration is adopted during the first salt tolerance acclimation process, and aeration is performed once every 3-5 hours, the aeration volume is 0.5-1.5 L / min each time, and the stirring intensity is 100-200 r / min.

[0020] Preferably, before the method of increasing the simulated seawater salinity in stages to perform the first salt tolerance acclimatization on the mangrove sediment in the DAT-IAT reaction tank, the method further comprises:

[0021] The salinity is 0.8%-1.2%, NH 4 + -N concentration of 30-50 mg / L simulated seawater was introduced into the DAT-IAT reaction tank for the first initial salt tolerance acclimation until the water quality monitoring data of the effluent from the DAT-IAT reaction tank was stable; during the first initial salt tolerance acclimation, continuous aeration was adopted with an aeration volume of 0.4-0.6 L / min and a stirring intensity of 80-120 r / min.

[0022] Preferably, in step S3, the process of acclimatizing mangrove sediment in the upflow denitrification filter includes:

[0023] Mangrove sediments were inoculated into the bottom of the upflow denitrification filter tank, and the simulated seawater NO was first increased in stages. 3 - -N concentration method was used to acclimate the mangrove sediments in the upflow denitrification filter to nitrate tolerance. 3 - -N concentration is 200-300 mg / L; and then the mangrove sediment in the upflow denitrification filter is subjected to a second salt tolerance acclimatization by a method of increasing the salinity of the simulated seawater in stages, until the salinity of the simulated seawater in the upflow denitrification filter is 3%-3.5%.

[0024] Preferably, the adoption stage increases the simulated seawater NO 3 - The mangrove sediments in the upflow denitrification filter were acclimated to nitrate tolerance by using a -N concentration method, which specifically includes:

[0025] with NO 3 - -N concentration of 50-100 mg / L simulated seawater was used as the culture medium for the first stage of nitrate tolerance acclimation. 3 - The -N concentration was increased by 50 mg / L successively, and the simulated seawater at each stage of nitrate resistance acclimation was introduced into the upflow denitrification filter in sequence. The hydraulic retention time was controlled at 24 to 48 h. The water quality monitoring data after each stage of nitrate resistance acclimation was tested. When the water quality monitoring data was stable, the next stage of nitrate resistance acclimation was started. The aeration culture method was adopted in the nitrate resistance acclimation process.

[0026] Preferably, after inoculating the mangrove sediment to the bottom of the upflow denitrification filter, the simulated seawater NO is increased in stages. 3 - Before the mangrove sediment in the upflow denitrification filter is acclimated to nitrate tolerance using the -N concentration method, it also includes initial nitrate tolerance acclimation. The specific process of initial nitrate tolerance acclimation is as follows:

[0027] Using the air-drying culture method, NO 3 --N concentration of 50-100 mg / L simulated seawater is introduced into the upflow denitrification filter, and the hydraulic retention time is controlled at 48-60h for initial nitrate tolerance acclimation. After the water quality monitoring data of the effluent from the upflow denitrification filter is stable, the aeration culture mode is switched to an aeration volume of 0.1-0.2L / min and a stirring intensity of 40-60r / min. After the water quality monitoring data of the effluent from the upflow denitrification filter is stable, the initial nitrate tolerance acclimation is completed.

[0028] Preferably, the method of increasing the salinity of simulated seawater in stages to perform the second salt tolerance acclimatization on the mangrove sediment in the upflow denitrification filter specifically comprises:

[0029] With salinity of 0.8%-1.2%, NO 3 - The simulated seawater with a NO concentration of 200-300 mg / L was used as the culture medium for the first stage of the second salt tolerance acclimation. The salinity of the simulated seawater in the subsequent stages of the second salt tolerance acclimation was increased by 0.4%-0.6%, and NO 3 - -N concentration remains unchanged, and the simulated seawater of each stage of the second salt tolerance acclimation is sequentially introduced into the upflow denitrification filter. The hydraulic retention time is controlled to be 12 to 20 hours. The water quality monitoring data after each stage of treatment is tested. When the water quality monitoring data is stable, the next stage of cultivation is started. The second salt tolerance acclimation process adopts the air-drying cultivation method.

[0030] Preferably, the hydraulic retention time of heterotrophic nitrification treatment is 30-40h, and the heterotrophic nitrification treatment adopts intermittent aeration, aeration once every 2-4h, each aeration volume is 1.0-1.5L / min, and the stirring intensity is 150-200r / min.

[0031] Preferably, the hydraulic retention time of aerobic denitrification treatment is 25-30 hours, and aerobic denitrification treatment adopts aeration culture method.

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

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

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

[0035] Preferably, the pretreatment specifically comprises: subjecting the marine aquaculture tail water to pollution interception, sand settling, homogenization and equalization, and coagulation and sedimentation treatment in sequence.

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

[0037] The present invention focuses on the nitrification function of mangrove ammonia oxidizing archaea (AOA) and the denitrification function of nirS type denitrifying bacteria, and constructs a set of marine aquaculture tail water treatment process to reduce the high concentration of nitrogen in marine aquaculture tail water; the marine aquaculture wastewater treatment method of the present invention mainly includes three stages: pretreatment, main treatment and deep treatment, wherein the continuous aeration tank-intermittent aeration tank (Demand Aeration Tank-Intermittent Aeration Tank) is used to treat the aquaculture wastewater. The main ammonia nitrogen treatment process is the Direct Aeration Tank (DAT-IAT) process. Mangrove sediments are placed in the DAT-IAT reaction tank and subjected to a special gradient acclimation process to enrich ammonia oxidizing archaea (AOA) in the mangrove sediments. The aquaculture tail water with high ammonia nitrogen concentration is subjected to heterotrophic nitrification treatment to convert it into nitrate and nitrite. The upflow denitrification filter is the main nitrate nitrogen treatment process. Mangrove sediments are placed in the upflow denitrification filter and subjected to a special gradient acclimation process to enrich the nirS type denitrifying bacteria in the mangrove sediments. The environmentally harmful substances in the aquaculture tail water, nitrate and nitrite, are efficiently converted into harmless nitrogen gas for release, thereby significantly reducing the adverse effects on the surrounding marine ecological environment and protecting the aquatic ecological environment. Practice has shown that the present invention can achieve NH 4 + -N, NO 3 - -N, COD, etc., and can maintain long-term operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The present invention is a process flow chart of the method for treating seawater aquaculture tail water mediated by mangrove ammonia oxidizing archaea and nirS-type denitrifying bacteria.

[0039] Figure 2 This is the phylogenetic tree of amoA genes of ammonia-oxidizing archaea based on major OTUs in the bottom sediment of the domesticated DAT-IAT reactor.

[0040] Figure 3 This is the phylogenetic tree of the nirS gene of denitrifying bacteria from the bottom sediment of the domesticated upflow denitrifying filter. DETAILED DESCRIPTION

[0041] The present invention is further described below in conjunction with specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

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

[0043] Table 1 Initial simulated seawater ratio

[0044]

[0045] Embodiment 1:

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

[0047] S1: Pre-treat the tail water of marine aquaculture to remove large particles of impurities in the tail water of marine aquaculture;

[0048] S2: The pre-treated marine aquaculture tailwater was introduced into the DAT-IAT pool acclimated with mangrove sediments for heterotrophic nitrification treatment;

[0049] S3: introducing the marine aquaculture tail water treated with heterotrophic nitrification into an upflow denitrification filter tank acclimated with mangrove sediments for aerobic denitrification treatment;

[0050] S4: The aquaculture tail water treated by aerobic denitrification is disinfected to remove pathogens in the aquaculture tail water.

[0051] In this embodiment, the pretreatment specifically includes: subjecting the seawater aquaculture tail water to pollution interception, sand settling, homogenization and quantity equalization, and coagulation and sedimentation treatment in sequence.

[0052] 1.1) Pollution control

[0053] The main function of the trash rack is to intercept large suspended or floating pollutants in sewage. If these pollutants are not intercepted, they may cause blockage or damage to subsequent water pumps, pipelines and other treatment equipment. Trash racks can generally be divided into two types: coarse screen type and fine screen type. In addition to intercepting coarse debris, fine screen type trash racks also have the function of removing suspended solids.

[0054] 1.2) Grit

[0055] The working principle of grit is based on gravity separation, so it is necessary to control the water flow rate of the grit chamber so that inorganic particles with high specific gravity sink, while organic suspended particles can be carried away with the water flow. The grit chamber in aquaculture tailwater treatment is mainly used to remove sand from sewage to protect pipes, valves and other facilities from wear and blockage.

[0056] Usually two parallel grit chambers are required for alternate cleaning. The efficiency of the grit chamber is proportional to the surface area, and has nothing to do with the width, depth, flow rate and shape. The settled sand and gravel are often mixed with organic matter and are easy to corrupt. The aerated grit chamber has a wider control requirement for the flow rate, and abnormal changes in flow rate do not have a great impact on the sedimentation effect. Due to the aeration effect, the sand and gravel do not need to be cleaned for treatment, and it also has a pre-aeration effect on the tail water. The tank body design is similar to the aeration tank of the activated sludge method, except that a grit chamber about 90cm deep needs to be added to collect mud.

[0057] 1.3) Homogeneity and uniformity

[0058] The main functions of the regulating tank in the sewage treatment process are homogenization and equalization. Through the homogenization of the regulating tank, the concentration of harmful substances in the sewage can be controlled within a certain range, thereby ensuring the effect of sewage treatment; through the equalization of the regulating tank, the amount of sewage can be controlled within a certain range, thereby reducing the design and operation costs of sewage treatment facilities. If the amount of sewage fluctuates too much, then the sewage treatment facility needs to be designed larger to be able to cope with the maximum sewage flow.

[0059] A submersible agitator needs to be installed at the bottom of the adjustment tank. It plays a vital role in the sewage treatment plant. It can effectively stir the suspended matter in the sewage to make the tail water evenly mixed, and improve the effect and efficiency of sewage treatment. The selection of a submersible agitator is a relatively complicated task. The correctness of the selection directly affects the normal use of the equipment.

[0060] 1.4) Coagulation and sedimentation

[0061] The purpose of a sedimentation tank is to remove suspended solids by sedimentation. When water flows into a large-section pool, the water velocity decreases and the pool water is almost static. Under the influence of gravity, particles with higher mass density will move downward, and conversely, particles with lower mass density will move upward. Therefore, the tail water solution will be divided into two parts: scum on the liquid surface and mud at the bottom of the pool. In this way, the mud and water are separated, and the purpose of setting up a sedimentation tank can be achieved.

[0062] Coagulation can aggregate suspended particles in tailwater into large flocs that are easy to precipitate, remove some organic matter, heavy metals and substances that reduce the transparency of the water body, and is usually used in combination 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 tailwater and promote the balanced distribution of the coagulant in the entire tailwater 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 speed of the water flow to prevent the flocs from being broken by the shearing effect of the water flow; (3) In order to enhance the coagulation 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 experiments; (4) During the coagulation process, if the flocs formed in the subsequent sedimentation tank can be circulated to the slow mixing area, this will help to speed up the coagulation process and reduce the amount of coagulant required.

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

[0064] The mangrove ecological protection area of ​​Yangjiang City, Guangdong Province (21°45'18"-21°46'1"N, 111°44'26"-111°45'3"E) was selected as the study area for sediment sample collection. The sediment samples collected on site were packed in sterilized sealed bags and then placed in a 4°C refrigerator.

[0065] The DAT-IAT process is a variant of the SBR process and is often used in sewage treatment. The DAT-IAT reaction tank is composed of a continuous aeration tank (Demand Aeration Tank, DAT) and an intermittent aeration tank (Intermitten Aeration Tank, IAT) in series. During the continuous water inlet, continuous aeration and continuous water outlet, the effluent of the DAT will flow into the IAT through the water distribution diversion wall, and its dissolved oxygen concentration is usually controlled within the range of 1.5-2.5 mg / L; by adjusting the operating parameters, a higher denitrification effect can be achieved. The continuous water inlet, aeration, sedimentation and decanting of IAT is a three-stage cycle process, usually a 3-hour cycle, each stage lasting 1 hour, and the mixed liquid is refluxed during the aeration and sedimentation stages, with a reflux ratio of 1:200-1:400.

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

[0067] 2.1. Gradually increase ammonia nitrogen and acclimate mangrove sediments to improve the ability of AOA to degrade ammonia nitrogen

[0068] (1) Initial ammonia nitrogen tolerance acclimation process: mangrove sediments were inoculated into the DAT-IAT reaction tank, with the mangrove sediment inoculation amount accounting for 80% of the volume of the DAT-IAT reaction tank. Simulated seawater aquaculture tail water with an ammonia nitrogen concentration of 3 mg / L was introduced into the DAT-IAT reaction tank. The hydraulic retention time was controlled to be 24-48 h. The reactor was continuously aerated, with an initial aeration volume of 0.5 L / min and a stirring intensity of 100 r / min to ensure that the mangrove sediments could fully contact with the acclimation water, degrade organic matter and ammonia nitrogen, and detect the NH3+ of the treated water. 4 + -N, NO 2 - -N, COD and pH, and when the data are stable, complete the DAT-IAT startup; the running time of this step is 15 to 20 days.

[0069] (2) Gradually increase the concentration of ammonia nitrogen: Based on the initial ammonia nitrogen tolerance acclimatization, the concentration of NH 4 + The AOA in the DAT-IAT reaction tank was acclimated to ammonia nitrogen tolerance by using the method of -N concentration, and intermittent aeration was used, that is, aeration was performed once every 4 hours, the aeration volume was 1L / min, the stirring intensity was 150r / min, and the seawater aquaculture tail water with the same composition and ratio as the start-up stage was used as the culture medium in the first stage. The NH 4 + The concentration of -N increases gradually, and the NH 4 + -N concentration was 5 mg / L higher than that in the previous stage; the simulated seawater in each stage of ammonia nitrogen tolerance acclimation was introduced into the DAT-IAT reaction tank in sequence, and the hydraulic retention time was controlled at 15 to 24 hours. The NH 4 + -N, NO 2 - -N, COD and pH. Each stage lasts for 8 to 9 days. When the water quality monitoring data tends to be stable, the next stage of acclimatization will be carried out until the NH 4 + -N concentration is 30-50mg / L, completing the preliminary adjustment of sediment species AOA in DAT-IAT. According to the adaptability of AOA in mangrove sediments and the ammonia nitrogen degradation efficiency (maintained at more than 80%), ensure that AOA in mangrove sediments can efficiently degrade the gradually increasing ammonia nitrogen concentration.

[0070] (3) Stabilization acclimation stage: After the AOA in 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 acclimation results and further improve the degradation capacity of AOA.

[0071] 2.2. The first step of salt tolerance acclimatization

[0072] (1) The first initial salt tolerance acclimatization stage: the salinity was 1%, NH 4 + -N concentration of 30-50 mg / L simulated seawater was introduced into the DAT-IAT reaction tank. The initial salinity content in the tank was close to the original salinity of the mangrove sediments (about 1%). The hydraulic retention time was controlled at 24 to 48 hours. The DAT tank was started for continuous aeration with an initial aeration volume of 0.5 L / min and a stirring intensity of 100 r / min to ensure that the mangrove sediments were in full contact with the sewage. 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 DAT-IAT reactor wastewater is gradually increased. The salinity in the first stage is controlled at 1%, and then the salinity is increased by 0.2% each time. The salinity content of each stage increases successively. During the acclimatization period, intermittent aeration is used, that is, aeration is performed once every 4 hours, the aeration volume is 1 L / min, and the stirring intensity is 150 r / min. The NH 4 + -N, NO 2 - -N, COD and pH, each stage lasts for 8 to 10 days. When the data is stable, the next stage of cultivation begins, until the salinity of the simulated seawater in the DAT-IAT reaction tank is 3%-3.5%. The hydraulic retention time of each stage is 15 to 24 hours. The degradation efficiency of ammonia nitrogen in mangrove sediments is closely monitored (maintained at more than 80%) to ensure that the AOA in mangrove sediments can adapt to the new salinity level, until the salinity of the simulated seawater in the DAT-IAT reaction tank reaches 3% and the water quality monitoring data is stable. If the degradation efficiency of ammonia nitrogen in mangrove sediments decreases during this period, the rate of salinity increase should be appropriately reduced, and the AOA in mangrove sediments should be given more time to adapt to the salinity changes.

[0074] (3) Stabilization stage: After the mangrove sediment AOA adapts 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 reaction pool remains stable to stabilize the ammonia nitrogen treatment capacity of the DAT-IAT reaction pool.

[0075] After the DAT-IAT pool was subjected to mangrove sediment acclimation treatment, the bottom sediment samples were taken from the pool. About 0.25 g of the samples were randomly selected and placed in a Lysis Tube in an ultra-clean workbench. The genomic DNA of the microorganisms in the sediments was extracted according to the operating instructions of the MagicPure Soil Genomic DNA Kit.

[0076] Using the DNA of microorganisms in the sediment as a template, PCR amplification of the functional gene amoA of AOA was performed. The forward specific primer Arch-amoAF (5'-STAATGGTCTGGCTTAGACG-3') and the reverse specific primer Arch-amoAR (5'-GCGGCCATCCATCTGTATGT-3') modified with the 8bp barcode sequence were used to amplify the functional gene of DNA. The PCR amplification conditions of the amoA functional gene are as follows: 95℃ pre-denaturation for 3min, 95℃ denaturation for 45s, 52℃ annealing for 45s, 72℃ extension for 1min, run 35 cycles, and finally extend at 72℃ for 10min. dd H 2 O was used as a template as a negative control, and the PCR amplification system of the AOAamoA gene was shown in Table 2.

[0077] Table 2 AOAamoA gene PCR amplification system

[0078] Reagents Volume / μL Taq enzyme 12.5 <![CDATA[ddH 2 The]]> 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 amplified product was taken for agarose gel electrophoresis, stained with Goldview dye, and the electrophoresis bands were observed in a gel imaging system, and then the target DNA was purified using gel recovery.

[0080] Mix the PCR products of the samples evenly for agarose gel electrophoresis, then use a blue light gel cutter to cut the target band, and then perform DNA gel recovery and purification according to the operating instructions of the SteadyPure DNA gel recovery kit. After DNA gel recovery and purification, take 5μL of the purified sample and mix it evenly with 1μL of Loading Buffer, and perform agarose gel electrophoresis. Use a gel imaging system to observe the samples after electrophoresis and detect the target gene. Finally, send the purified product to the testing company for testing.

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

[0082] The final microbial components and their percentages in the mangrove sediments after acclimation treatment in the DAT-IAT pool were determined as follows: Thaumarchaeota accounted for 31.2%, Nitrosoarchaeum koreensisMY1 (HQ331117) accounted for 22.7%, and Nitrosoarchaeum limnia accounted for 46.2%.

[0083] After the DAT-IAT pool is acclimated with mangrove sediments, the pretreated seawater aquaculture tail water can be introduced into the DAT-IAT pool acclimated with mangrove sediments for heterotrophic nitrification treatment. The hydraulic retention time of the heterotrophic nitrification treatment is 30-40h. The heterotrophic nitrification treatment adopts intermittent aeration, which is aerated once every 2-4h. The aeration volume each time is 1.0-1.5L / min and the stirring intensity is 150-200r / min.

[0084] In this process step, the DAT-IAT reactor plays a core role. After the mangrove sediments are added to the DAT-IAT reactor, the mangrove sediments are gradually domesticated by gradually increasing ammonia nitrogen and salinity. In this way, a group of microorganisms that can efficiently treat ammonia nitrogen can be screened out. These microorganisms can survive and carry out metabolic activities in high salinity and high ammonia nitrogen environments, adapt to and degrade these high concentrations of pollutants, and mainly convert ammonia nitrogen into nitrite and nitrate. This process is called nitrification, which is mainly completed by mangrove AOA. The domestication process is a key step that can enhance the tolerance and conversion capacity of sludge microbial communities to specific pollutants. AOA can more efficiently oxidize ammonia nitrogen into nitrates, thereby completing the first step of the denitrification process.

[0085] The denitrification filter is a sewage treatment process that integrates biological denitrification and filtration functions. It is a combination of biofilm treatment technology and physical treatment technology. The water flow direction of the denitrification filter is divided into upward flow and downward flow. The water inlet of the upward denitrification filter is from the bottom of the pool and the water outlet is from the top of the pool. The inlet and outlet directions of the downward denitrification pool are opposite. The upward flow biological filter can adopt a higher filtration rate and occupy a small area. It is more resistant to hydraulic load impact and has a higher filter material filling height.

[0086] The main function of the filter material filled in the biological filter is to act as a biological carrier and intercept and filter suspended solids. The choice of filter material is an important factor affecting the treatment efficiency of the denitrification filter. At present, ceramsite and quartz sand are commonly used as the filling filter material. From the perspective of denitrification effect, ceramsite has a better denitrification effect than quartz sand. The specific surface area and adsorption performance of ceramsite filter material are stronger than quartz sand, so more biofilm can be attached, and the denitrification effect is better. From the perspective of filtration effect, quartz sand filter material is better than ceramsite. Considering the denitrification efficiency, this design uses ceramsite as the filling filter material for the denitrification filter.

[0087] The denitrification filter uses the method of inoculation and biofilm to domesticate NIRS type denitrifying bacteria to tolerate nitrate. The domestication is divided into three stages:

[0088] (1) The first stage is biological inoculation and initial cultivation. Mangrove soil sediments are added to the denitrification filter. The mangrove sediment inoculation volume accounts for 80% of the denitrification filter volume. Mangrove soil sediments contain denitrifying bacteria. In order to promote the growth and reproduction of denitrifying bacteria, simulated seawater aquaculture tail water is passed into the filter, in which NO 3 - -N concentration is 50mg / L, hydraulic retention time is 48-60h, 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 NO 3 - -N concentration remains unchanged, providing a small amount of oxygen for denitrifying bacteria, with an initial aeration rate of 0.2L / min and a stirring intensity of 50r / min, so that the denitrifying bacteria can adapt and proliferate. When the denitrifying bacteria proliferate to a certain amount, they will be directional domesticated to make them more adaptable to high salinity and high NO 3 - -N sewage treatment environment;

[0090] (3) The third stage is to increase the nitrate treatment load of the denitrification filter, understand the community structure of NIRS-type denitrifying bacteria through high-throughput sequencing, and then adjust the amount of nutrient addition to increase the potassium nitrate concentration in stages. The concentration of potassium nitrate in the synthetic seawater aquaculture tail water increases successively, and the NO in the seawater aquaculture tail water increases. 3 - The concentration of -N increased by 50mg / L compared with the previous stage. The simulated seawater of each stage of nitrate tolerance acclimation was introduced into the denitrification filter reaction tank in sequence. The aeration culture method was maintained and the hydraulic retention time was controlled to be 24-48h. The NO of the water treated in each stage was detected. 3 - -N, COD and pH, each stage lasts for 10 to 15 days. When the water quality monitoring data tends to be stable, the next stage of acclimatization will be carried out until the NO in the tail water of marine aquaculture is 3 + The concentration of -N is 200-300 mg / L, NO 3 + -The operation time of the N concentration increase stage is 50 to 60 days. According to the adaptability of NIRS-type denitrifying bacteria in mangrove sediments and the nitrate degradation efficiency (maintained at more than 70%), it is ensured that NIRS-type denitrifying bacteria in mangrove sediments can efficiently degrade the gradually increasing nitrate concentration to improve the nitrate nitrogen removal efficiency of the denitrification filter.

[0091] The denitrification filter uses the inoculation biofilm method to acclimate NIRS-type denitrifying bacteria to high salinity

[0092] The main purpose of salt acclimation 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) The first stage: the initial salt concentration is 1%, NO 3 - -N concentration of 200-300 mg / L simulated seawater is introduced into the upflow denitrification filter. The filter is operated and maintained under low oxygen conditions without ventilation and stirring. The growth of denitrifying bacteria in the sediment and the nitrate removal effect are observed. If the denitrifying bacteria can adapt and stably remove 90% of the nitrate nitrogen, it will enter the next stage.

[0094] (2) The second stage: gradually increase the salt concentration in the simulated seawater aquaculture tail water by 0.5% each time, NO 3- -N concentration remains unchanged, observe for 5-10 days to ensure that the denitrifying bacteria can adapt to the new salt concentration environment, and detect NO in the water after each stage of treatment. 3 - -N, COD and pH. When the water quality monitoring data stabilize, start the next stage of cultivation. If the removal effect decreases or the growth of denitrifying bacteria is hindered, reduce the salt concentration appropriately and continue to observe.

[0095] (3) The third stage: When the denitrifying bacteria can adapt to the higher salt concentration of 3-3.5% and stably remove nitrate nitrogen, the effluent NO is continuously monitored. 3 - -N, COD and pH as well as the growth of denitrifying bacteria. When the denitrifying bacteria can adapt to the final salt concentration and stably remove nitrate nitrogen, the acclimation process can be considered complete. At this point, the upflow denitrification filter can operate stably at a higher salt concentration.

[0096] The phylogenetic tree of nirS gene constructed based on OUT level of 50 core OTUs selected from the bottom sediment of the upflow denitrification filter after the above acclimation treatment is shown in Figure 2. Figure 3 As shown in the figure, the tree structure is subdivided into 10 different clusters based on sequence clustering, among which cluster 1 has the largest number of sequences, 29,303, accounting for 19.88% of the total, while cluster 8 has the least number of sequences, only 3,810, accounting for 2.58%. The remaining clusters cover a range of sequence proportions from 3.49% to 16.78%.

[0097] Cluster 1 brings together OTU1, OTU7, OTU13, OTU16, OTU27, OTU30, OTU39, OTU48, and OTU49, indicating that they are closely related to the nirS-type denitrifying bacterial sequences (HQ882414 and HQ882417.1) from the sediments of the Pearl River Estuary. On the other hand, OTU5 and OTU33 are included in cluster 3, which are similar to the above-mentioned Pearl River Estuary sequences; cluster 2 contains OTU10, OTU33, and OTU40, which have high similarity with the denitrifying bacterial sequences (KU995374.1) found in local coastal wetlands. In addition, cluster 4 brings together OTU2, OTU3, OTU15, and OTU20, which match the known nirS-type denitrifying bacterial sequences (JX002733) in mangrove ecosystems. Cluster 5 includes OTU19 to OTU47, which are highly similar to denitrifying bacterial sequences in different environments, such as potato fields (FJ853966.1), the South China Sea (HQ666561), New England salt marshes (KF896049), and Bahia del Tobar, Mexico (KC614388.1). Cluster 6 includes OTU8, OTU21, OTU29, OTU32, and OTU44, which show a genetic relationship with nirS-type denitrifying bacterial sequences (such as KC2934453, DQ676190, and KX388846.1) in oily salt marsh environments along the Chesapeake Bay and the Gulf of Mexico. The members of cluster 7, OTU6, OTU9, OTU22, OTU41, and OTU46, have high sequence identity with nirS-type strains (e.g., KT444053 and JX941775) in intertidal marshes and Fujian river sediments. In cluster 8, OTU11 and OTU45 are associated with denitrifying bacterial sequences (KX510628) from beach sediments, while cluster 9, including OTU4 and OTU23, is similar to the nirS-type strain sequence (KX389087) from oily salt marshes along the Gulf of Mexico. This reveals the high diversity and widespread distribution of nirS-type denitrifiers in mangrove ecosystems.

[0098] The final microbial components and their percentages in mangrove sediments after acclimation treatment in the upflow denitrification filter were determined as follows: Proteobacteria 85.22%, Chloroflexi 10.22%, Aquatic bacteria 3.45%, and other phyla, including Actinobacteria, Planctomyces, and Bacteroidetes, accounting for 1.11% of the total.

[0099] After the upflow denitrification filter has been acclimated with mangrove sediments, the seawater aquaculture tail water that has been treated with heterotrophic nitrification can be introduced into the upflow denitrification filter pool that has been acclimated with mangrove sediments for aerobic denitrification treatment. The hydraulic retention time of aerobic denitrification treatment is 25-30h, and the aerobic denitrification treatment adopts the aeration culture method.

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

[0101] After years of development, chlorine dioxide disinfection technology has been proven to be a stable and effective treatment method. It is widely used in many fields and is favored for its simple operation and management process. The technology performs well in eliminating bacteria such as Escherichia coli, Salmonella typhi, Mycobacterium tuberculosis, and viruses, including hepatitis A and B viruses. In addition, the economy of chlorine dioxide disinfection is also a major advantage, because it is not only affordable as a disinfectant, but also has low power consumption during operation, thereby reducing the overall operating cost. In terms of equipment, it also has the advantages of simple structure, reliability and durability, low cost, and has achieved comprehensive localization, making maintenance and overhaul more convenient. Finally, the disinfection characteristics of chlorine dioxide also include a special residual chlorine effect, which can ensure that the treated water body still maintains the disinfection effect after discharge, effectively preventing the occurrence of secondary pollution.

[0102] The treatment effect of the marine aquaculture tail water treated by this embodiment is shown in Table 3. It can be seen that the treatment process of this embodiment can achieve NH 4 + -N, NO 3- -N, COD, etc. can be removed efficiently, and the marine aquaculture tail water can be treated stably and continuously for about 100-120 days.

[0103] Table 3 Treatment effect of marine aquaculture tail water

[0104] Tail water index Influent concentration (mg / L) Outlet concentration (mg / L) Removal rate (%) Remark <![CDATA[NH 4 + -N]]> 20.3～30.3 3.8～6.2 80.2～81.3 Good removal effect <![CDATA[NO 2 - -N]]> 10.5～13.5 1.0～2.2 83.7～90.5 Good removal effect <![CDATA[NO 3 - -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 is only a preferred embodiment of the present application and does not constitute any form of limitation to the present application. Although the present application is disclosed as a preferred embodiment as above, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for treating marine aquaculture tail water mediated by mangrove ammonia-oxidizing archaea and nirS-type denitrifying bacteria, characterized in that: The following steps are involved: S1: Pre-treat the tail water of marine aquaculture to remove large particles of impurities in the tail water of marine aquaculture; S2: The pre-treated marine aquaculture tailwater was introduced into the DAT-IAT pool acclimated with mangrove sediments for heterotrophic nitrification treatment; S3: introducing the marine aquaculture tail water treated with heterotrophic nitrification into an upflow denitrification filter tank acclimated with mangrove sediments for aerobic denitrification treatment; S4: The aquaculture tail water treated by aerobic denitrification is disinfected to remove pathogens in the aquaculture tail water.

2. The method for treating seawater aquaculture tailwater mediated by mangrove ammonia oxidizing archaea and nirS-type denitrifying bacteria according to claim 1, characterized in that: In step S2, the process of acclimatizing mangrove sediment in the DAT-IAT pool is as follows: The mangrove sediment was inoculated into the bottom of the DAT-IAT reaction tank, and the simulated seawater NH4 + -N concentration method was used to acclimate the mangrove sediments in the DAT-IAT reaction tank to ammonia nitrogen tolerance, until the NH4 + -N concentration is 30-50mg / L; and then the mangrove sediment in the DAT-IAT reaction pool is first acclimated to salt tolerance by increasing the salinity of the simulated seawater in stages until the salinity of the simulated seawater in the DAT-IAT reaction pool is 3%-3.5%.

3. The method for treating seawater aquaculture tailwater mediated by mangrove ammonia oxidizing archaea and nirS-type denitrifying bacteria according to claim 2, characterized in that: The adoption stage increases the simulated seawater NH4 + The mangrove sediments in the DAT-IAT reaction tank were acclimated to ammonia nitrogen tolerance by using the -N concentration method, which specifically includes: The simulated seawater with an ammonia nitrogen concentration of 1-3 mg / L is used as the culture medium for the first stage of ammonia nitrogen resistance acclimation. The ammonia nitrogen concentration of the simulated seawater in the subsequent ammonia nitrogen resistance acclimation stages is increased by 4-6 mg / L in sequence. The simulated seawater in each stage of ammonia nitrogen resistance acclimation is sequentially introduced into the DAT-IAT reaction tank, and the hydraulic retention time is controlled to be 15-24 hours. The water quality monitoring data after each stage of ammonia nitrogen resistance acclimation is detected. When the water quality monitoring data is stable, the cultivation of the next stage of ammonia nitrogen resistance acclimation is started. Intermittent aeration is adopted during the ammonia nitrogen resistance acclimation process, with aeration every 3-5 hours, an aeration volume of 0.5-1.5 L / min each time, and a stirring intensity of 100-200 r / min.

4. The method for treating seawater aquaculture tailwater mediated by mangrove ammonia oxidizing archaea and nirS-type denitrifying bacteria according to claim 3, characterized in that: After inoculating mangrove sediments into the bottom of the DAT-IAT reactor, the simulated seawater NH4 + Before acclimatizing the mangrove sediment in the DAT-IAT reaction tank to ammonia nitrogen tolerance, the method also includes: Introduce simulated seawater with an ammonia nitrogen concentration of 1-3 mg / L into the DAT-IAT reaction tank, control the hydraulic retention time to 24-48 hours, and carry out initial ammonia nitrogen resistance acclimation. When the water quality monitoring data of the effluent from the DAT-IAT reaction tank is stable, the initial ammonia nitrogen resistance acclimation is completed. Continuous aeration is used during the initial ammonia nitrogen resistance acclimation process, with an aeration volume of 0.4-0.6 L / min and a stirring intensity of 80-120 r / min.

5. The method for treating seawater aquaculture tailwater mediated by mangrove ammonia oxidizing archaea and nirS-type denitrifying bacteria according to claim 2, characterized in that: The method of increasing the simulated seawater salinity in stages to perform first salt tolerance acclimatization on the mangrove sediment in the DAT-IAT reaction tank specifically includes: With salinity of 0.8%-1.2%, NH4 + The simulated seawater with a -N concentration of 30-50 mg / L is used as the culture medium for the first stage of the first salt tolerance acclimation. The salinity of the simulated seawater in the subsequent stages of the first salt tolerance acclimation is increased by 0.1%-0.3% in sequence, and the ammonia nitrogen concentration remains unchanged. The simulated seawater in each stage of the first salt tolerance acclimation is sequentially introduced into the DAT-IAT reaction tank, and the hydraulic retention time is controlled to be 15-24 hours. The water quality monitoring data after treatment in each stage is detected, and the next stage of culturing is started when the water quality monitoring data is stable; intermittent aeration is adopted during the first salt tolerance acclimation process, and aeration is performed once every 3-5 hours, the aeration volume is 0.5-1.5 L / min each time, and the stirring intensity is 100-200 r / min.

6. The method for treating seawater aquaculture tailwater mediated by mangrove ammonia-oxidizing archaea and nirS-type denitrifying bacteria according to claim 5, characterized in that: Before the first salt tolerance acclimatization of the mangrove sediment in the DAT-IAT reaction tank by the method of increasing the simulated seawater salinity in stages, it also includes: The salinity is 0.8%-1.2%, NH4 + -N concentration of 30-50 mg / L simulated seawater was introduced into the DAT-IAT reaction tank for the first initial salt tolerance acclimation until the water quality monitoring data of the effluent from the DAT-IAT reaction tank was stable; during the first initial salt tolerance acclimation, continuous aeration was adopted with an aeration volume of 0.4-0.6 L / min and a stirring intensity of 80-120 r / min.

7. The method for treating seawater aquaculture tailwater mediated by mangrove ammonia oxidizing archaea and nirS-type denitrifying bacteria according to any one of claims 1 to 6, characterized in that: In step S3, the process of acclimatizing mangrove sediment in the upflow denitrification filter includes: The mangrove sediment was inoculated into the bottom of the upflow denitrification filter, and the simulated seawater NO3 - -N concentration method was used to acclimate the mangrove sediments in the upflow denitrification filter to nitrate tolerance, until the NO3 - -N concentration is 200-300 mg / L; and then the mangrove sediment in the upflow denitrification filter is subjected to a second salt tolerance acclimatization by a method of increasing the salinity of the simulated seawater in stages, until the salinity of the simulated seawater in the upflow denitrification filter is 3%-3.5%.

8. The method for treating seawater aquaculture tailwater mediated by mangrove ammonia oxidizing archaea and nirS-type denitrifying bacteria according to claim 7, characterized in that: The adoption stage increases the simulated seawater NO3 - The mangrove sediments in the upflow denitrification filter were acclimated to nitrate tolerance by using a -N concentration method, which specifically included: NO3 - -N concentration of 50-100 mg / L simulated seawater was used as the culture medium for the first stage of nitrate tolerance acclimation, and the NO3 - The -N concentration was increased by 45-55 mg / L in sequence, and the simulated seawater at each stage of nitrate resistance acclimation was introduced into the upflow denitrification filter in sequence. The hydraulic retention time was controlled at 24-48 h. The water quality monitoring data after each stage of nitrate resistance acclimation was tested. When the water quality monitoring data was stable, the next stage of nitrate resistance acclimation was started. The nitrate resistance acclimation process adopted the air-drying culture method.

9. The method for treating seawater aquaculture tailwater mediated by mangrove ammonia-oxidizing archaea and nirS-type denitrifying bacteria according to claim 8, characterized in that: After inoculating mangrove sediments into the bottom of the upflow denitrification filter, the simulated seawater NO3 - Before the mangrove sediment in the upflow denitrification filter is acclimated to nitrate tolerance using the -N concentration method, it also includes initial nitrate tolerance acclimation. The specific process of initial nitrate tolerance acclimation is as follows: Using the air-breathing culture method, NO3 - -N concentration of 50-100 mg / L simulated seawater is introduced into the upflow denitrification filter, and the hydraulic retention time is controlled at 48-60h for initial nitrate tolerance acclimation. After the water quality monitoring data of the effluent from the upflow denitrification filter is stable, the aeration culture mode is switched to an aeration volume of 0.1-0.2L / min and a stirring intensity of 40-60r / min. After the water quality monitoring data of the effluent from the upflow denitrification filter is stable, the initial nitrate tolerance acclimation is completed.

10. The method for treating seawater aquaculture tailwater mediated by mangrove ammonia-oxidizing archaea and nirS-type denitrifying bacteria according to claim 7, characterized in that: The method of increasing the salinity of simulated seawater in stages to perform the second salt tolerance acclimatization on the mangrove sediment in the upflow denitrification filter specifically includes: With salinity of 0.8%-1.2%, NO3 - The simulated seawater with a concentration of 200-300 mg / L of NO was used as the culture medium for the first stage of the second salt tolerance acclimation. The salinity of the simulated seawater in the subsequent stages of the second salt tolerance acclimation was increased by 0.4%-0.6%. 3- -N concentration remains unchanged, and the simulated seawater of each stage of the second salt tolerance acclimation is sequentially introduced into the upflow denitrification filter. The hydraulic retention time is controlled to be 12 to 20 hours. The water quality monitoring data after each stage of treatment is tested. When the water quality monitoring data is stable, the next stage of cultivation is started. The second salt tolerance acclimation process adopts the air-drying cultivation method.

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