Biological fluidized bed tower type water treatment method

Abstract

The invention relates to a biological fluidized bed tower type water treatment method and belongs to the technical field of sewage treatment.The biological fluidized bed tower type water treatment method highly integrates an anoxic tank, an aerobic tank and a secondary sedimentation tank, and the occupied area is reduced; a sludge reflux pump and a nitrification liquid reflux pump are omitted, so that the daily operation and maintenance workload is reduced; a gas stripping technology, an aerobic fluidized bed technology and a deep well aeration technology are utilized, so that the oxygen utilization efficiency is greatly improved, and the operation energy consumption is reduced; according to the method, the sludge concentration is higher (can reach 8000 mg / L), meanwhile, large-proportion sludge and nitrification liquid circulation is achieved through the gas stripping technology (the circulation proportion can reach 500%-900%), the load impact resistance is greatly improved, the sludge load is higher (0.05-0.3 kg COD / kg MLVSS.d), and the good effect is achieved on high-salt wastewater, high-COD wastewater, high-nitrogen wastewater and the like.

Description

Technical Field

[0001] The present application relates to the technical field of biological fluidized beds, and in particular to a biological fluidized bed tower water treatment method. Background Art

[0002] At present, with the advancement of industrialization, China's industrial wastewater discharge has shown an increasing trend year by year. The increase in industrial wastewater discharge has not only aggravated the shortage of water resources, but may also lead to environmental problems such as water pollution and soil pollution, which in turn poses a potential threat to human survival and development.

[0003] In the existing sewage treatment method, aerobic pools, anoxic pools and sedimentation pools are set up in the sewage treatment site. The sewage to be treated flows between the various pools, degrading the organic matter in the sewage and causing nitrification and denitrification reactions. The flow of sewage between the various pools is achieved by water pump lifting or gravity flow. In addition, the existing sewage treatment method has low efficiency in treating high-salt, high-COD, and high-nitrogen wastewater.

[0004] In the actual sewage treatment process, the whole process of transportation by water pumps has the defect of high energy consumption. If gravity flow is used, a large site and a high-drop pool are required, which has the defects of large equipment size and high cost. In addition, the high-salt and high-COD treatment efficiency is low and the treatment cycle is long. Summary of the invention

[0005] In order to reduce the energy consumption of equipment operation, reduce the size of equipment, facilitate operation and maintenance, improve the treatment efficiency of high-salt, high-COD, and high-nitrogen wastewater, and shorten the start-up period of bacterial strain acclimatization, the present application provides a biological fluidized bed tower water treatment method.

[0006] The present application provides a biological fluidized bed tower water treatment method using the following technical solutions: A biological fluidized bed tower water treatment method, comprising: S1, the wastewater to be treated enters the anoxic zone through the water inlet pipe; S2, the wastewater to be treated undergoes a reaction in the anoxic zone where organic matter is decomposed into small molecular organic matter, and organic nitrogen undergoes an ammonia reaction, and then becomes anoxic zone produced water, and the anoxic zone produced water enters the aerobic zone through a gas lift pipe; S3, start the aeration pipe, the aeration pipe is used to provide oxygen for the aerobic zone and provide power for the water flow in the aerobic zone; the water produced in the anoxic zone enters the aerobic zone and is guided by the guide plate to form an aerobic circulating fluidized bed; the water produced in the anoxic zone undergoes organic matter degradation reaction and nitrification reaction in the aerobic zone to form water produced in the aerobic zone; S4. The water produced in the aerobic zone is powered by the aeration pipe. A part of it flows back to the anoxic zone, where it undergoes denitrification and denitrification reactions and eventually generates nitrogen gas for discharge. The other part enters the sedimentation zone, where it undergoes sedimentation to generate sludge and supernatant. The supernatant is discharged through the effluent weir, and the sludge falls back to the anoxic zone for discharge. Excess sludge is discharged through the sludge discharge pipe.

[0007] By adopting the above technical solution, the aeration pipe pumps air into the aerobic zone, so that the aeration pipe can achieve the effect of transporting oxygen into the aerobic zone. While transporting the gas, the gas fully merges with the liquid in the aerobic zone to form a gas-liquid mixture. The density of the gas-liquid mixture is lower than that of the original pure liquid, thereby forming a pressure difference. The fluid with low density will be subject to upward buoyancy in the gravity field, while the fluid with high density will produce downward pressure on the fluid with low density, so that a pressure difference is formed at both ends of the lifting pipe, so that the water produced in the anoxic zone enters the aerobic zone through the gas lifting pipe, part of the water produced in the aerobic zone flows back to the anoxic zone, and part of the water produced in the aerobic zone flows back to the sedimentation zone. Air lifting replaces the nitrification liquid return and the sludge return, which not only reduces the number of equipment, but also greatly reduces the operating energy consumption, which is more than 30% lower than the traditional process. It improves the treatment efficiency of high-salt, high-COD, and high-nitrogen wastewater, and shortens the start-up period of strain acclimatization. The bubbles generated by the aeration tube will drive the surrounding sewage upward during the rising process. The design of the guide plate can guide this part of the upward-moving sewage to flow along a specific path. For example, the guide plate can guide the rising sewage to the side of the aerobic zone away from the anoxic zone, and then let the sewage flow downward or in other directions along the shape of the guide plate, thereby forming a circulating flow. The guide plate is cleverly used to achieve aerobic zone circulation, further improving the oxygen utilization rate and the system's ability to resist load impact. The overall effect of reducing equipment operation energy consumption, reducing equipment volume, and saving costs is achieved.

[0008] Optionally, the wastewater to be treated includes high-salt petrochemical wastewater, electronic wastewater, coking wastewater, printing and dyeing wastewater, high COD and high nitrogen wastewater.

[0009] By adopting the above technical solution, the application scope of the present application is expanded, achieving the effects of wide application and impact resistance.

[0010] Optionally, according to the type of high-salt petrochemical wastewater to be treated, a corresponding biological carrier is added, and the biological carrier includes powdered activated carbon, magnetic powder, micro sand and bentonite.

[0011] By adopting the above technical solutions, the treatment efficiency of the system can be further improved and the equipment volume can be reduced. For example, activated carbon can be used as an attachment carrier for microorganisms. Microorganisms grow and reproduce on the surface of activated carbon to form a biofilm; for example, magnetic powder can be recovered and recycled through an external magnetic field. After adding magnetic powder, some microorganisms can attach to the surface of magnetic powder and grow, and the presence of magnetic powder can improve the sedimentation performance of the mixed liquid. When it is necessary to separate the microorganisms from the treated wastewater, the magnetic powder with microorganisms can be quickly precipitated through the magnetic field to improve the efficiency of mud-water separation; such as bentonite, bentonite has good adsorption and dispersibility. Adding bentonite in the aerobic zone can adsorb some heavy metal ions and organic matter in the wastewater, and can also improve the rheological properties of the mixed liquid, which is conducive to the transfer of oxygen and the uniform distribution of microorganisms.

[0012] Optional, volumetric load range 0.5-2.5 kg CODcr / m³.d, control influent COD 0-4000mg / L, TDS 0-30000 mg / L and pH 6~9 when treating high-salinity petrochemical wastewater.

[0013] By adopting the above technical solutions, the COD removal rate is increased by 23.4% compared with the traditional biochemical process.

[0014] Optional, volumetric load range 0.1-0.3 kg TN / m³.d, control COD 0-1000mg / L, total nitrogen 0-400mg / L, ammonia nitrogen 0-300mg / L and pH 6~9 when treating high-nitrogen wastewater.

[0015] By adopting the above technical solutions, the total nitrogen removal rate is increased by 15.3% compared with the traditional biochemical process.

[0016] Optionally, the sewage circulation ratio is controlled to 500%-900%.

[0017] By adopting the above technical solutions, using gas lift technology, aerobic fluidized bed technology and deep well aeration technology, a large proportion of sewage circulation (the circulation ratio can reach 500%-900%) can be achieved, thereby improving the sewage treatment efficiency.

[0018] Optionally, control the sludge concentration to 5000-8000 mg / L.

[0019] By adopting the above technical solution, the sludge concentration of the traditional method is only 4000 mg / L, while the sludge concentration of the present application can be even higher, up to 8000 mg / L, thereby improving the sewage treatment load and treatment efficiency.

[0020] Optionally, special high-salt-tolerant bacteria can be used for bio-augmentation to shorten the start-up time of microbial acclimation by about 1 / 3.

[0021] Optionally, a debugging phase is added, which includes an initial startup phase, a process optimization phase and a trial operation phase. The debugging phase is used to add special biological strains; the debugging phase is established before step S1.

[0022] By adopting the above technical solutions, the initial startup stage is the preparation period before the sewage treatment system and method are officially put into operation. The addition of special high-salt-tolerant biological strains is to quickly establish an effective microbial treatment system. In the process optimization stage, after adding special biological strains, it is necessary to observe and adjust various parameters, such as dissolved oxygen concentration, temperature, pH value, hydraulic retention time, etc., to ensure that the special biological strains can exert the best treatment efficiency. The trial operation stage is for the sewage treatment system and method to operate under conditions close to the actual operation to test the stability and treatment effect of the system and method.

[0023] In summary, the present application includes at least one of the following beneficial technical effects: 1. High integration and small footprint: The biological fluidized bed integrates aerobic decarbonization, anoxic denitrification and sludge sedimentation, with a compact structure and small footprint; 2. High efficiency and energy saving: three channels and large-scale circulation, good mass transfer effect and high oxygen utilization rate; the stripping technology is used to synchronously return sludge and nitrification liquid, which greatly reduces operating energy consumption; 3. Wide application and impact resistance: Suitable for various difficult wastewater treatments such as high COD, high salt, high ammonia nitrogen and total nitrogen; the large flow reflux technology system has high operating stability and strong impact resistance; 4. Short construction period and fast start-up: Adopting integrated steel structure, the installation period is short; the system is domesticated with high-efficiency strains and auxiliary agents, and the start-up cycle is short; 5. Fewer equipment and simple operation and maintenance: There is no sludge return and nitrification liquid return pump, the equipment cost is low, and the workload of operation and maintenance personnel is greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of a biological fluidized bed tower water treatment system of the present application; Figure 2 This is a continuous experimental diagram of high-salinity petrochemical wastewater; Figure 3 This is a continuous experimental diagram of high nitrogen content wastewater.

[0025] In the figure, 1, tower body; 11, anoxic zone; 12, aerobic zone; 13, sedimentation zone; 2, inner tube wall; 3, guide wall; 4, mud bucket wall; 41, water outlet weir; 42, mud discharge pipe; 5, guide plate; 6, water inlet pipe; 7, gas lift pipe; 8, aeration pipe. DETAILED DESCRIPTION

[0026] The following is combined with Figure 1-Figure 3 This application is described in further detail.

[0027] To facilitate understanding of a biological fluidized bed tower water treatment method, the present application first discloses a biological fluidized bed tower water treatment system.

[0028] refer to Figure 1 A biological fluidized bed tower water treatment system includes a tower body 1, in which an inner cylinder wall 2, a guide wall 3 and a mud bucket wall 4 are arranged, the top of the tower body 1 is connected to a water outlet weir 41, the middle of the tower body 1 is connected to a water inlet pipe 6, and the bottom of the tower body 1 is connected to a mud discharge pipe 42.

[0029] refer to Figure 1 The bottom of the inner cylinder wall 2 is fixed on the inner wall at the bottom of the tower body 1, the inner wall at the bottom of the inner cylinder wall 2 is concave at the center, the top of the inner cylinder wall 2 is fixedly connected to the bottom of the guide wall 3, there is a distance between the top of the guide wall 3 and the inner wall at the top of the tower body 1, and the bottom of the guide wall 3 is connected to the inside of the inner cylinder wall 2. The inner area of ​​the inner cylinder wall 2 is anoxic zone 11, and there is a distance between the outer wall of the inner cylinder wall 2 and the inner wall of the tower body 1 and this area is aerobic zone 12.

[0030] refer to Figure 1 The mud bucket wall 4 is located inside the guide wall 3. Both the guide wall 3 and the mud bucket wall 4 are funnel-shaped with an opening at the bottom, and the top of the mud bucket wall 4 is higher than the top of the guide wall 3. There is a distance between the outer wall of the mud bucket wall 4 and the inner wall of the guide wall 3. The bottom of the mud bucket wall 4 is connected to the inside of the inner cylinder wall 2. There is a distance between the top of the mud bucket wall 4 and the inner wall of the top of the tower body 1, and there is a distance between the guide wall 3 and the vertical inner wall of the tower body 1. The inner area of ​​the mud bucket wall 4 is the sedimentation area 13.

[0031] refer to Figure 1 A guide plate 5, an aeration pipe 8 and a gas lifting pipe 7 are arranged in the tower body 1. The guide plate 5 is vertically fixed inside the tower body 1. The guide plate 5 is located in the aerobic zone 12. There is a distance between the guide plate 5 and the inner cylinder wall 2 and the inner wall of the tower body 1. There is also a distance between the bottom of the guide plate 5 and the inner wall of the bottom of the tower body 1. The aeration pipe 8 is located near the bottom of the tower body 1 and in the aerobic zone 12. The aeration pipe 8 is located between the guide plate 5 and the inner cylinder wall 2 and the height is below the guide plate 5. The setting of the positions of the aeration pipe 8 and the guide plate 5 allows the liquid to form an aerobic circulating fluidized bed in the aerobic zone 12.

[0032] refer to Figure 1, the water outlet weir 41 is located at the top of the tower body 1 and is connected to the sedimentation zone 13. The water inlet pipe 6 is connected to the anoxic zone 11. The mud discharge pipe 42 is located at the bottom of the tower body 1 and is connected to the bottom of the anoxic zone 11. The exhaust pipe is connected to the anoxic zone 11 and is located at the center of the depression at the bottom of the inner cylinder wall 2. A gas lift pipe 7 is arranged in the tower body 1. One end of the gas lift pipe 7 is connected to the inside of the anoxic zone 11, and the other end is connected to the inside of the aerobic zone 12 and is located above the aeration pipe 8. The height of the end of the gas lift pipe 7 in the aerobic zone 12 is higher than the height of the end of the gas lift pipe 7 in the anoxic zone 11, and the position of the gas lift pipe 7 at the end of the aerobic zone 12 is lower than the position of the top of the guide plate 5.

[0033] The inner tube wall 2, the guide wall 3, the mud bucket wall 4 and the guide plate 5 can be fixedly connected in the tower body 1 by connecting rods, which are not unique and are no longer shown in the figure. The biological fluidized bed tower water treatment system is made of steel structure.

[0034] The embodiment of the present application discloses a biological fluidized bed tower water treatment method.

[0035] refer to Figure 1 , a biological fluidized bed tower water treatment method comprises: The debugging phase includes the initial startup phase, the process optimization phase and the trial operation phase. The debugging phase is used to add special biological strains. The initial startup phase is the preparation period before the sewage treatment system and method are officially put into operation. The addition of special biological strains is to quickly establish an effective microbial treatment system. In the process optimization phase, after adding special biological strains, it is necessary to observe and adjust various parameters, such as dissolved oxygen concentration, temperature, pH value, hydraulic retention time, etc., to ensure that the special biological strains can exert the best treatment efficiency. The trial operation phase is for the sewage treatment system and method to operate under conditions close to the actual operation to test the stability and treatment effect of the system and method.

[0036] By using special high-salt-tolerant bacteria for bio-augmentation, the start-up time of microbial domestication can be shortened by about 1 / 3. Special biological bacteria include digestive bacteria, denitrifying bacteria, yeast, photosynthetic bacteria, etc., and no more examples are given here.

[0037] Start the acclimation method: Add concentrated activated sludge to the tower body, accounting for 10%-25% of the total tank volume, and then add 2-10% of the mixed bacterial solution of high-salt nitrification strains, high-salt denitrification strains, and high-salt decarbonation strains. Control the dissolved oxygen in the aerobic zone at 2-4mg / L, the air stripping circulation ratio at 500%-900%, the water temperature at 20-30℃, pH 7-8.5, and the nutrient ratio CODcr: N: P = 200~300:5:1; after one week, introduce high salt water, and the salt concentration slowly increases from 3000mg / L to 20000mg / L, quickly establish an effective microbial treatment system, and achieve the effect of shortening the start-up period of strain acclimatization.

[0038] S1, the wastewater to be treated enters the anoxic zone 11 through the water inlet pipe 6; S2. The wastewater to be treated undergoes a reaction in the anoxic zone 11 where organic matter is decomposed into small molecular organic matter, and organic nitrogen undergoes an ammonia reaction, and then becomes water produced in the anoxic zone 11. The water produced in the anoxic zone 11 enters the aerobic zone 12 through the gas lift pipe 7. In the anoxic zone 11, microorganisms will use organic matter in the sewage for anaerobic fermentation, and complex organic matter in the sewage (such as protein, carbohydrates, fat, etc.) will be decomposed into small molecular organic matter by microorganisms. Organic nitrogen in sewage (such as nitrogen present in protein) will undergo an ammonia reaction, and microorganisms will convert organic nitrogen into ammonia nitrogen through hydrolysis and deamination. Taking protein as an example, protein is first hydrolyzed into amino acids under the action of protease, and amino acids are then converted into ammonia nitrogen through deamination.

[0039] S3. Before starting the aeration tube 8, place the aeration tube 8 near the inner wall of the bottom of the aerobic zone 12. Start the aeration tube 8, the aeration tube 8 provides oxygen to the aerobic zone 12 and power to the water flow in the aerobic zone 12, the gas and the liquid in the aerobic zone 12 are fully integrated to form a gas-liquid mixture, the density of the gas-liquid mixture is lower than that of the original pure liquid, and the fluid with low density will be subject to upward buoyancy in the gravity field. After the water produced in the anoxic zone 11 enters the aerobic zone 12, it is guided by the guide plate 5 to form an aerobic circulating fluidized bed. The bubbles generated by the aeration pipe 8 will drive the surrounding sewage to move upward during the rising process. The design of the guide plate 5 can guide this part of the upwardly moving sewage to flow along a specific path, such as: the guide plate 5 can guide the rising sewage to the side of the aerobic zone 12 away from the anoxic zone 11, and then let the sewage flow downward or in other directions along the shape of the guide plate 5, thereby forming a circulating flow. The guide plate 5 is cleverly used to realize the circulation flow of the aerobic zone 12, further improving the oxygen utilization rate and the system's ability to resist load shock. The water produced in the anoxic zone 11 undergoes organic matter degradation reaction and nitrification reaction in the aerobic zone 12 to form the water produced in the aerobic zone 12.

[0040] S4. The water produced in the aerobic zone 12 is powered by the aeration pipe 8. A part of the water flows back to the anoxic zone 11, where it undergoes denitrification and denitrification reaction and finally generates nitrogen gas for discharge. The other part of the water flows into the sedimentation zone 13, where it undergoes sedimentation to generate sludge and supernatant. The supernatant is discharged through the outlet weir 41, and the sludge falls back to the anoxic zone 11. The excess sludge is discharged through the sludge discharge pipe 42.

[0041] According to the type of wastewater to be treated, the corresponding biological carrier is added, and the biological carrier includes activated carbon, magnetic powder and bentonite. The wastewater to be treated includes high-salt petrochemical wastewater, electronic wastewater, coking wastewater, printing and dyeing wastewater, high COD and high nitrogen wastewater. For example: the volume load range is 0.5-2.5 kg CODcr / m³.d, and the influent COD is controlled to be 0-4000mg / L, TDS 0-30000 mg / L and pH 6~9 when treating high-salt petrochemical wastewater; the volume load range is 0.1-0.3 kg TN / m³.d, and the COD is controlled to be 0-1000mg / L, total nitrogen 0-400mg / L, ammonia nitrogen 0-300mg / L and pH6~9 when treating high-nitrogen wastewater.

[0042] The following is experimental data proof: Experiment 1: Treatment of high-salt petrochemical wastewater: The main components of high-salt petrochemical wastewater are ethylene glycol, phenol acetone, ethylene waste alkali solution, dilution water, etc.; the water quality indicators are COD 3364mg / L, TDS 16000mg / L, pH 6~9.

[0043] Experimental control: effective volume 500L, sludge concentration in a biological fluidized bed tower water treatment system of the present application is 8g / L, and sludge concentration in a traditional biochemical device is 4g / L.

[0044] Experimental steps: During the microbial debugging and acclimation stage, the water inlet and outlet volume was 50L / d, and the load was increased every 6 days, in the order of 50L / d, 100L / d, 150L / d, 200L / d, and 250L / d, and finally stabilized at 250L / d to enter the test stage.

[0045] refer to Figure 2 The experimental results show that the COD removal of high-salinity petrochemical wastewater can be improved by 23.4% compared with the traditional biochemical process by applying the biological fluidized bed tower water treatment method to the biological fluidized bed tower water treatment system.

[0046] Experiment 2: Apply the biological fluidized bed tower water treatment method to treat high-nitrogen wastewater in a biological fluidized bed tower water treatment system.

[0047] The main components of high-nitrogen wastewater are acrylonitrile, ABS production wastewater, etc. The water quality indicators are COD of 753mg / L, total nitrogen of 290mg / L, ammonia nitrogen of 250mg / L, and pH 6~9.

[0048] Experimental control: effective volume 500L, sludge concentration in a biological fluidized bed tower water treatment system of the present application is 8g / L, and sludge concentration in a traditional biochemical device is 4g / L.

[0049] Experimental steps: During the microbial debugging and acclimation stage, the water inlet and outlet volume was 50L / d, and the load was increased every 6 days, in the order of 50L / d, 100L / d, 150L / d, 200L / d, and 250L / d, and finally stabilized at 250L / d to enter the test stage.

[0050] refer to Figure 3 The experimental results show that the total nitrogen removal of high-nitrogen wastewater can be increased by 15.3% compared with the traditional biochemical process by applying the biological fluidized bed tower water treatment method to the biological fluidized bed tower water treatment system.

[0051] The embodiments of this specific implementation method are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, all equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A biological fluidized bed tower water treatment method, characterized in that: include: S1, the wastewater to be treated enters the anoxic zone (11) through the water inlet pipe (6); S2, the wastewater to be treated undergoes a reaction in the anoxic zone (11) where organic matter is decomposed into small molecular organic matter, and organic nitrogen undergoes an ammonia reaction, and then becomes water produced in the anoxic zone (11). The water produced in the anoxic zone (11) enters the aerobic zone (12) through the gas lift pipe (7); S3, starting the aeration pipe (8), the aeration pipe (8) is used to provide oxygen to the aerobic zone (12) and provide power for the water flow in the aerobic zone (12); the water produced in the anoxic zone (11) enters the aerobic zone (12) and is guided by the guide plate (5) to form an aerobic circulating fluidized bed; the water produced in the anoxic zone (11) undergoes organic matter degradation reaction and nitrification reaction in the aerobic zone (12) to form water produced in the aerobic zone (12); S4. The water produced in the aerobic zone (12) is powered by the aeration pipe (8), and a portion of the water flows back to the anoxic zone (11), where it undergoes denitrification and denitrification reactions and eventually generates nitrogen gas and is discharged. The other portion of the water flows into the sedimentation zone (13), where it undergoes sedimentation to generate sludge and supernatant. The supernatant is discharged through the outlet weir (41), and the sludge falls back to the anoxic zone (11). The excess sludge is discharged through the sludge discharge pipe (42).

2. A biological fluidized bed tower water treatment method according to claim 1, characterized in that: The wastewater to be treated includes high-salt petrochemical wastewater, electronic wastewater, coking wastewater, printing and dyeing wastewater, high COD and high nitrogen wastewater.

3. A biological fluidized bed tower water treatment method according to claim 2, characterized in that: According to the type of high-salt petrochemical wastewater to be treated, corresponding biological carriers are added, and the biological carriers include powdered activated carbon, magnetic powder, micro sand and bentonite.

4. A biological fluidized bed tower water treatment method according to claim 2, characterized in that: The volumetric load range is 0.5-2.5 kg CODcr / m³.d. When treating high-salt petrochemical wastewater, the influent COD is controlled at 0-4000mg / L, TDS at 0-30000mg / L and pH at 6-9.

5. A biological fluidized bed tower water treatment method according to claim 2, characterized in that: The volumetric load range is 0.1-0.3 kg TN / m³.d. When treating high-nitrogen wastewater, the COD is controlled at 0-1000mg / L, the total nitrogen is 0-400mg / L, the ammonia nitrogen is 0-300mg / L and the pH is 6~9.

6. A biological fluidized bed tower water treatment method according to claim 1, characterized in that: Control the sewage circulation ratio to 500%-900%.

7. A biological fluidized bed tower water treatment method according to claim 1, characterized in that: Control the sludge concentration to 5000-8000mg / L.

8. A biological fluidized bed tower water treatment method according to claim 1, characterized in that: The use of special high-salt-tolerant bacteria for bio-augmentation can shorten the start-up time of microbial domestication by about 1 / 3.

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