Aquaculture tail water treatment system based on membrane aeration bio-membrane reactor

Abstract

The utility model discloses a culture tail water treatment system based on a membrane aeration bio-membrane reactor, which comprises a grit chamber and a high-efficiency air flotation device connected with the grit chamber, the high-efficiency air flotation device is connected with a primary membrane bioreactor, the primary membrane bioreactor is connected with a secondary membrane aeration bio-membrane reactor, and the secondary membrane aeration bio-membrane reactor is connected with the high-efficiency air flotation device. The secondary membrane aeration bio-membrane reactor is connected with a multi-medium filter, and the multi-medium filter is connected with a clean water tank; sludge of the high-efficiency air flotation device, the primary membrane bioreactor and the secondary membrane aeration bio-membrane reactor is discharged into a sludge concentration tank. The aquaculture tail water treatment device effectively reduces the content of protein, suspended solids and nitrogen and phosphorus in the tail water, greatly improves the transparency of a water body and improves the treatment efficiency of the aquaculture tail water.

Description

Technical Field

[0001] The utility model relates to the technical field of sewage treatment, in particular to an aquaculture tail water treatment system based on a membrane aeration biofilm reactor. Background Art

[0002] Selecting appropriate technology to treat aquaculture tail water and make it meet discharge standards has become one of the current research hotspots.

[0003] Aquaculture tailwater is characterized by high protein content (due to feed, excrement, and other factors), high suspended solids content, high nitrogen and phosphorus levels, and low water transparency. Discharging untreated or substandard aquaculture tailwater directly can lead to a range of ecological and environmental problems, including eutrophication, excessive algae growth, and deteriorating water quality.

[0004] Aquaculture tailwater treatment can be primarily categorized into biological, physical, and chemical methods, with biological methods considered the most cost-effective way to remove tailwater pollutants. The membrane bioreactor (MBR) is a novel water treatment device that combines a membrane separation unit with a biological treatment unit. It leverages the advantages of membrane and biological treatment technologies to achieve efficient water purification and mud-water separation. The membrane aerated biofilm reactor (MABR) is a novel wastewater treatment device that combines gas separation membrane technology with biofilm water treatment technology. It uses hollow fiber membranes to supply oxygen to the biofilm, achieving wastewater purification and stable biofilm growth.

[0005] At present, most of the biological methods for treating aquaculture tailwater use MBR or MABR alone, which has low treatment efficiency. Even if the two are used in combination, the process is relatively complicated. For example, Chinese patent ZL202310291402.0 discloses a skid-mounted aquaculture tailwater treatment system based on the coupling of MABR and MBR. Although the system comprehensively utilizes MBR and MABR to improve the tailwater treatment efficiency, its structure is relatively complex, and the organic matter, especially the total nitrogen index in the treated tailwater, still has the technical problem of exceeding the discharge standard.

[0006] Therefore, there is an urgent need for an aquaculture tailwater treatment system that is high-efficiency, low-energy-consuming, and can effectively reduce organic matter emission indicators. Utility Model Content

[0007] To address the above technical issues, this utility model proposes a treatment system based on a high-efficiency flotation and membrane aeration biofilm reactor. By combining high-efficiency flotation and membrane aeration biofilm reactors with traditional biochemical treatment, this system effectively reduces the protein, suspended matter, and nitrogen and phosphorus content in tailwater, significantly improving water clarity, and increasing aquaculture tailwater treatment efficiency, saving energy, and reducing carbon emissions.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0009] A breeding tailwater treatment system based on a membrane aeration biofilm reactor comprises a grit chamber, a high-efficiency flotation device connected to the grit chamber, the high-efficiency flotation device connected to a primary membrane bioreactor, the primary membrane bioreactor connected to a secondary membrane aeration biofilm reactor, the secondary membrane aeration biofilm reactor connected to a multi-media filter, and the multi-media filter connected to a clear water tank; sludge from the high-efficiency flotation device, the primary membrane bioreactor and the secondary membrane aeration biofilm reactor is discharged into a sludge thickening tank.

[0010] According to a further technical solution, the first-level membrane bioreactor and the second-level membrane aeration biofilm reactor are equipped with Roots blowers to provide oxygen.

[0011] According to a further technical solution, the high-efficiency air flotation device is connected to an air compressor, which provides an air flotation carrier for it.

[0012] According to a further technical solution, the grit chamber and the clear water tank are provided with liquid level control devices to monitor and control the water level.

[0013] In a further technical solution, the sludge concentration tank is provided with a PAM automatic dosing device, which can timely and quantitatively dose PAM, and the PAM plays a flocculation and sedimentation role, effectively improving the sludge concentration efficiency in the sludge tank.

[0014] In a further technical solution, a first lift pump is provided between the grit chamber and the high-efficiency flotation device. A second lift pump is provided between the secondary membrane aeration biofilm reactor and the multi-media filter. The lift pump facilitates pumping sewage / treated sewage into the device for the next process. Beneficial effects

[0015] Compared with the prior art, the advantages of the present invention are:

[0016] 1. The high-efficiency flotation device in this utility model generates a large number of small-diameter bubbles in the sewage. The large contact area between the bubbles and the suspended particles in the sewage greatly improves adsorption efficiency. The bubbles adhere to the surface of the suspended particles and quickly float them to the water surface, effectively removing free protein and suspended matter from the sewage. Simultaneously, nitrification and denitrification occur simultaneously in the membrane aeration biofilm reactor, improving oxygen utilization and total nitrogen removal efficiency.

[0017] 2. The high-efficiency flotation of the utility model has the advantages of high efficiency in removing suspended matter, strong adaptability, small footprint, energy saving and environmental protection, simple operation, convenient maintenance and stable and reliable treatment effect. For aquaculture tail water with high organic components and high solid suspended matter content, it can effectively improve the free protein content and suspended matter removal rate of aquaculture tail water.

[0018] 3. This utility model achieves bubble-free aeration and efficient oxygen transfer through the integration of a two-stage membrane aeration biofilm reactor. During operation, oxygen is transferred from the inner membrane through micropores or a dense membrane structure to the outer membrane, supplying oxygen to the biofilm attached to the outer membrane. During this process, the oxygen pressure remains below the bubble point pressure of the membrane assembly. Therefore, oxygen does not form bubbles during transfer, but rather diffuses directly into the biofilm in molecular form, achieving bubble-free aeration. Bubble-free aeration reduces resistance to oxygen transfer and increases the oxygen transfer rate, allowing oxygen to more efficiently enter the biofilm and promote microbial metabolic activity. Due to this high oxygen transfer efficiency, the MABR has a large aeration membrane area per unit volume, resulting in relatively low energy consumption. The membrane bioreactor combines the advantages of membrane technology and biological treatment technology, achieving highly efficient nitrogen and phosphorus removal. The aerobic biofilm (dominated by nitrifying bacteria) in the aerated biofilm reactor and the denitrifying bacteria growing in suspension in the anoxic zone achieve simultaneous nitrification and denitrification, further enhancing the removal of total nitrogen and ammonia nitrogen from wastewater. Oxygen-permeable membranes have a higher oxygen utilization rate, which can more effectively reduce total nitrogen concentration when pollutant concentrations are low, complementing membrane bioreactors. They can simultaneously achieve nitrification and denitrification, achieving high pollutant removal efficiency and excellent treatment effects.

[0019] 4. The service life of the MABR membrane fibers in this invention is as long as 10 years; the hydraulic impact loss is small. Even in the typhoon season or when multiple ponds are fished at the same time, the water quantity and quality can stably meet the standards when the impact load is generated, and the safety performance is high.

[0020] 5. This utility model combines high-efficiency flotation, a membrane bioreactor, and a membrane aerated biofilm reactor. On the one hand, it has high treatment efficiency and simultaneously performs nitrification and denitrification, achieving the goal of highly efficient removal of ammonia nitrogen, total nitrogen, COD, etc., and can effectively reduce the content of protein and total nitrogen in the effluent, improving the effluent quality. On the other hand, the bubble-free aeration and dual-mode design have low energy consumption, high oxygen transfer efficiency, and energy conservation. It has the advantages of high efficiency, low energy consumption, and small footprint. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural diagram of the present utility model.

[0022] Markings in the figure: 1. Grit chamber, 2. First lifting pump, 3. High-efficiency flotation device, 4. First-stage membrane bioreactor, 5. Second-stage membrane aeration biofilm reactor, 6. Fan, 7. Fan, 8. Second lifting pump, 9. Multi-media filter, 10. Clear water tank, 11. Sludge thickening tank, 12. Air compressor. DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Example

[0024] like Figure 1 As shown, an aquaculture tailwater treatment system based on a membrane aeration biofilm reactor includes a grit chamber 1, a high-efficiency flotation device 3 connected to the grit chamber, the high-efficiency flotation device 3 is connected to a primary membrane bioreactor 4, the primary membrane bioreactor 4 is connected to a secondary membrane aeration biofilm reactor 5, the secondary membrane aeration biofilm reactor 5 is connected to a multi-media filter 9, and the multi-media filter 9 is connected to a clear water tank 10; the sludge from the high-efficiency flotation device 3, the primary membrane bioreactor 4 and the secondary membrane aeration biofilm reactor 5 is discharged into a sludge thickening tank 11.

[0025] The primary membrane bioreactor 4 and the secondary membrane aeration biofilm reactor 5 are provided with Roots blowers 6 and 7 to provide oxygen.

[0026] The high-efficiency flotation device 3 is connected to the air compressor 12, which provides it with an air flotation carrier. The grit chamber and the clear water tank are provided with a liquid level control device to monitor and control the water level.

[0027] The sludge thickening tank 11 is provided with a PAM automatic dosing device. The device can regularly and quantitatively add PAM reagent, which plays a flocculation and sedimentation role, effectively improving the sludge concentration efficiency in the sludge tank.

[0028] A first lift pump 2 is provided between the grit chamber 1 and the high-efficiency flotation device 3. A second lift pump 8 is provided between the secondary membrane aeration biofilm reactor 5 and the multi-media filter 9. The lift pump facilitates pumping sewage / treated sewage into the device of the next process.

[0029] The working method of the utility model is:

[0030] The tail water of aquaculture first enters the grit chamber 1 with a liquid level control device to regulate the grit chamber. The grit chamber will remove large particles with a specific gravity greater than water in the tail water. Then, it is pumped into the high-efficiency flotation device 3 through the pipeline via the first lifting pump 2. The air compressor 12 delivers high-pressure air to the high-efficiency flotation device 3 through the air pressure pipe. Tiny bubbles adhere to the free protein and suspended matter in the tail water, float to the water surface, form a scum layer, and then are removed. The sludge enters the sludge thickening tank 11; then the sewage enters the primary membrane bioreactor 4. The primary membrane bioreactor effectively intercepts the suspended matter in the tail water and degrades pollutants such as total nitrogen in the water through nitrification. The roots blower 6 blows air to the primary membrane bioreactor 4. Compressed air is provided, and the sludge is intercepted and collected and enters the sludge thickening tank 11; the tail water overflows and enters the secondary membrane aeration biofilm reactor 5, and nitrification and denitrification are carried out at the same time to further degrade pollutants such as total nitrogen in the water, and the small amount of sludge produced enters the sludge thickening tank 11; the treated tail water is pumped into the multi-media filter 9, which can filter suspended matter and adsorb excess pollutants, reducing chemical oxygen demand, total phosphorus and total nitrogen content; the tail water that meets the treatment standards flows into the clear water tank 10 with a liquid level control device and is then pumped into the discharge pipe network; the sludge from the high-efficiency flotation device 3 and the secondary membrane aeration biofilm reactor 5 enters the sludge thickening tank, and is discharged after the sludge is concentrated.

Claims

1. A system for treating aquaculture tailwater based on a membrane aerated biofilm reactor, comprising a grit chamber, characterized in that: It also includes a high-efficiency flotation device connected to the grit chamber, the high-efficiency flotation device is connected to the primary membrane bioreactor, the primary membrane bioreactor is connected to the secondary membrane aeration biofilm reactor, the secondary membrane aeration biofilm reactor is connected to a multi-media filter, and the multi-media filter is connected to the clear water tank; the sludge from the high-efficiency flotation device, the primary membrane bioreactor and the secondary membrane aeration biofilm reactor is discharged into the sludge thickening tank.

2. The aquaculture tailwater treatment system based on membrane aeration biofilm reactor according to claim 1, characterized in that: The first-level membrane bioreactor and the second-level membrane aeration biofilm reactor are respectively connected to Roots blowers to provide them with oxygen.

3. The aquaculture tailwater treatment system based on membrane aeration biofilm reactor according to claim 1, characterized in that: The high-efficiency air flotation device is connected to an air compressor.

4. The aquaculture tailwater treatment system based on membrane aeration biofilm reactor according to claim 1, characterized in that: The grit chamber and the clear water chamber are provided with liquid level control devices to monitor and control the water level.

5. The aquaculture tailwater treatment system based on membrane aeration biofilm reactor according to claim 1, characterized in that: The sludge thickening tank is provided with a PAM automatic dosing device.

6. The aquaculture tailwater treatment system based on membrane aeration biofilm reactor according to claim 1, characterized in that: A first lifting pump is provided between the grit chamber and the high-efficiency air flotation device.

7. The aquaculture tailwater treatment system based on membrane aeration biofilm reactor according to claim 1, characterized in that: A second lifting pump is provided between the secondary membrane aeration biofilm reactor and the multi-media filter.

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