A device for treating wastewater containing microplastics and antibiotics

Abstract

A kind of treatment device of wastewater containing microplastics and antibiotics, including air floatation unit, biological treatment unit, depth purification unit arranged in sequence, the air floatation unit includes reaction tank, transition tank, air floatation tank arranged in sequence, stirring machine is provided in the reaction tank, the transition tank is connected with air floatation equipment, for passing into pressurized dissolved air water, the top of air floatation tank is equipped with slag scraper;The biological treatment unit includes anoxic tank and aerobic tank arranged in sequence, diving agitator is provided in the anoxic tank, the bottom of aerobic tank is equipped with aeration device;The depth purification unit includes membrane tank, membrane tank is equipped in the membrane tank, the water outlet is connected with pipeline, water production pump is arranged between the membrane tank and water outlet.The synergistic effect of air floatation pretreatment→biodegradation→membrane interception→activated carbon deep adsorption, the whole process realizes the depth purification to wastewater containing microplastics and antibiotics.

Description

Technical Field

[0001] This utility model relates to wastewater treatment devices, and in particular to a treatment device for wastewater containing microplastics and antibiotics. Background Technology

[0002] Large quantities of primary plastic microspheres and secondary plastic fragments or particles enter the aquatic environment, potentially endangering the health of aquatic organisms and the safety of the ecosystem. Microplastics (size <5mm) are difficult to degrade in the environment and can persist in environmental media such as water and sediment for a long time, accumulating in aquatic organisms and eventually becoming bioaccumulated in humans. They also have certain toxic effects on marine planktonic plants and animals, shellfish, fish, and corals.

[0003] Meanwhile, antibiotics exist in trace amounts (ng / L) in the aquatic environment, exhibiting toxicity to some algae and fish, accumulating upwards, and damaging the ecosystem. Antibiotic use leads to drug resistance in pathogenic microorganisms, causing the effective dose of antibiotics to continuously increase. Furthermore, antibiotics and their derivatives remain in water and food, accumulating over the long term through the food chain, posing potential health risks. For example, long-term accumulation of tetracyclines can inhibit the development and bone growth of young children, and sulfonamides can easily cause allergies in sensitive individuals.

[0004] Design a wastewater treatment device for wastewater containing both microplastics and antibiotics, which can achieve standardized production, shorten project construction time, and broaden application scenarios. Utility Model Content

[0005] In view of this, it is necessary to provide a wastewater treatment device that can efficiently remove microplastics and antibiotics simultaneously.

[0006] A treatment device for wastewater containing microplastics and antibiotics includes a flotation unit, a biological treatment unit, and a deep purification unit arranged in sequence. The flotation unit includes a reaction tank, a transition tank, and a flotation tank arranged in sequence. The reaction tank is equipped with a mixer, and the transition tank is connected to flotation equipment for introducing pressurized dissolved air water. A sludge scraper is installed at the top of the flotation tank. The biological treatment unit includes an anoxic tank and an aerobic tank arranged in sequence. The anoxic tank is equipped with a submersible mixer, and the aerobic tank is equipped with an aeration device at the bottom. The deep purification unit includes a membrane tank, which contains a membrane box. The membrane box is connected to an outlet via a pipeline, and a permeate pump is installed between the membrane box and the outlet.

[0007] This invention utilizes the synergistic effect of air flotation pretreatment → biodegradation → membrane retention. Air flotation achieves a 90% removal rate for microplastics larger than 100μm, while also removing microplastics of 1-5mm, preventing plastic fibers from entangled in the membrane filaments. Then, most antibiotics are degraded using the AO activated sludge method, and finally, a membrane tank is used to filter recalcitrant antibiotics and residual microplastics. The entire process achieves deep purification of wastewater containing microplastics and antibiotics. Attached Figure Description

[0008] Figure 1 This is a structural diagram of the device for treating wastewater containing microplastics and antibiotics according to this utility model.

[0009] Figure 2 This is a schematic diagram of the device for treating wastewater containing microplastics and antibiotics according to this utility model. Detailed Implementation

[0010] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0011] like Figure 1 and Figure 2 As shown, the treatment device for wastewater containing microplastics and antibiotics includes an air flotation unit, a biological treatment unit, and a deep purification unit arranged in sequence. The flow directions of wastewater, clean water, and impurities are indicated by arrows.

[0012] The flotation unit includes a reaction tank 1, a transition tank 2, a contact tank 3, a flotation tank 4, and an effluent tank 5 arranged sequentially. The reaction tank 1 is equipped with a mixer 6; the transition tank 2 is connected to flotation equipment (including a dissolved air pump 7, a dissolved air tank 8, an air compressor 9, etc., all existing technologies, and therefore not described in detail), for introducing pressurized dissolved air water; the top of the flotation tank 4 is equipped with a sludge scraper 10, and an adjacent sludge skimming trough 11 is provided above the flotation tank 4; the bottom of the flotation tank 4 is connected to the effluent tank 5.

[0013] In operation, wastewater first enters reaction tank 1, where a mixer 6 thoroughly mixes the added reagents with the wastewater to enhance the subsequent flotation effect. Subsequently, the wastewater flows into transition tank 2, where pressurized dissolved air is introduced into the flotation equipment, dispersing small bubbles in the wastewater. These bubbles then come into uniform and thorough contact with the microplastics in contact tank 3, where the bubbles (10-40 μm in diameter) generated by the dissolved air release collide with and adsorb the microplastic particles. Afterward, the wastewater flows into flotation tank 4, where suspended solids, including microplastics, are carried to the surface of the flotation tank 4 by the attached small bubbles. The scum is collected by a scraper 10 and removed from the skimming trough 11.

[0014] The effluent tank 5 is connected to an air flotation device for extracting wastewater from the tank 5 to use as a dissolved air source. The wastewater in the effluent tank 5 is injected into the dissolved air tank 8 via the dissolved air pump 7 and then returned to the transition tank 2. This reduces the consumption of fresh water, avoids the introduction of new impurities, and enables the circulating dissolved air pretreatment of the wastewater.

[0015] The reaction tank 1 is also equipped with an online SS monitor 12 and a first level gauge 13, which are used to monitor the dynamic changes of suspended solids (SS) concentration and water level in the reaction tank 1 after the addition of chemicals, to determine the flocculation effect of microplastics, and to adjust the dosage of chemicals.

[0016] The biological treatment unit includes an anoxic tank 14 and an aerobic tank 15 arranged sequentially. A submersible mixer 16 is installed in the anoxic tank 14, and an aeration device 17 is installed at the bottom of the aerobic tank 15. Both the anoxic tank 14 and the aerobic tank 15 contain a large amount of activated sludge. The submersible mixer 16 mixes the wastewater and activated sludge introduced into the anoxic tank 14 while maintaining an anaerobic environment. The aeration device 17, under the action of an aeration blower 33, provides dissolved oxygen to the aerobic tank 15, while simultaneously achieving full-tank mixing through turbulent bubble flow. Through the AO activated sludge degradation method, under the metabolic action of microorganisms, most of the biodegradable organic pollutants in the wastewater, including antibiotics, undergo nitrification, denitrification, oxidation, and adsorption reactions, ultimately being decomposed into carbon dioxide, nitrogen, and water.

[0017] The deep purification unit includes a membrane tank 18, within which a membrane chamber 19 is installed. The bottom of the membrane tank 18 has a sludge discharge port. The membrane chamber 19 is connected to an outlet via a pipeline. A permeate pump 20 and a flow meter 21 are installed between the membrane chamber 19 and the outlet. Under the action of the permeate pump 20, wastewater mixed with activated sludge flows through the membrane chamber 19. The membrane chamber 19 traps residual microplastics and undegraded antibiotics in the wastewater, completing the purification process. The flow meter 21 is used to monitor the outflow rate of the permeate pump 20 in real time. In this embodiment, an activated carbon filter 22 is also connected between the permeate pump 20 and the outlet via parallel pipelines, and valves are installed between each pipeline. By opening and closing the valves, the wastewater filtered by the membrane chamber 19 can be further adsorbed by the activated carbon filter 22 to meet standards before being discharged. Specifically, the membrane chamber 19 is an MBR membrane chamber with a membrane pore size of 0.01~0.03μm and a membrane material of PVDF; the activated carbon filter 22 uses coconut shell-based granular activated carbon (GAC) with an iodine value >1000 and a bulk density of 400~500kg / m³. 3 With a particle size range of 20-40 mesh, it has a good adsorption effect on antibiotics.

[0018] The membrane box 19 is connected to a membrane box flushing fan 23, which is used to blow clean the membrane surface to prevent pollutants such as microplastics and sludge flocs from adhering.

[0019] This invention utilizes the synergistic effect of air flotation pretreatment → biodegradation → membrane retention → activated carbon deep adsorption. Air flotation achieves a 90% removal rate for microplastics larger than 100μm, while also removing microplastics of 1-5mm, preventing plastic fibers from entangled in the MBR membrane fibers. Then, most antibiotics are degraded using the AO activated sludge method. Subsequently, the MBR membrane is used to filter recalcitrant antibiotics and residual microplastics. Finally, activated carbon filter 22 is introduced to further adsorb residual antibiotics before effluent is discharged. The entire process achieves deep purification of wastewater containing microplastics and antibiotics.

[0020] A first sludge return pump 24 is provided between the aerobic tank 15 and the anoxic tank 14; a second sludge return pump 25 is provided between the membrane tank 18 and the aerobic tank 15. By returning the sludge, the microbial biomass in the anoxic tank 14 and the aerobic tank 15 can be maintained, avoiding a decrease in treatment efficiency due to microbial loss. The MBR process has a long SRT (sludge retention time), high sludge concentration (6~15 g / L), and minimal impact of antibiotics on activated sludge, resulting in low activated sludge loss. The aerobic tank 15 is equipped with a second level gauge 26 for real-time monitoring of the liquid level and adjustment of the return pump flow rate based on the water level. In this embodiment, the sludge return ratio from the aerobic tank 15 to the anoxic tank 14 is 300~500%, and the sludge return ratio from the membrane tank 18 to the aerobic tank 15 is 400~600%.

[0021] A vacuum pressure transmitter 27 is installed between the membrane tank 19 and the product water pump 20. A first backwash branch pipe 28 is installed between the vacuum pressure transmitter 27 and the product water pump 20. A backwash water pump 29 is installed on the first backwash branch pipe 28, which is connected to the clean water tank. The equipment is automatically controlled by a PLC cabinet. When the vacuum pressure transmitter 27 detects a vacuum value ≤-40kPa, it indicates membrane pore blockage. The PLC cabinet automatically starts the online backwashing program, and the backwash water pump 29 draws clean water from the clean water tank to flush the membrane tank 19.

[0022] The activated carbon filter 22 is equipped with a second backwash branch pipe 30 and a first electrical contact pressure gauge 31 on its inlet pipe, and a second electrical contact pressure gauge 32 on its outlet pipe. The second backwash branch pipe 30 is connected to the reaction tank 1. When the pressure difference detected by the first electrical contact pressure gauge 31 and the second electrical contact pressure gauge 32 is ≥0.05 MPa, it indicates that the activated carbon filter 22 is clogged. The PLC cabinet starts the backwashing program to clean the activated carbon filter 22, and the backwash water is returned to the reaction tank 1 for further filtration through the second backwash branch pipe 30. In this embodiment, the backwashing intensity is (5~10) L / (s·m²).

Claims

1. A treatment device for wastewater containing microplastics and antibiotics, characterized in that: The system includes a flotation unit, a biological treatment unit, and a deep purification unit arranged in sequence. The flotation unit includes a reaction tank (1), a transition tank (2), and a flotation tank (4) arranged in sequence. The reaction tank (1) is equipped with a mixer (6). The transition tank (2) is connected to flotation equipment for introducing pressurized dissolved air water. The flotation tank (4) is equipped with a sludge scraper (10) at the top. The biological treatment unit includes an anoxic tank (14) and an aerobic tank (15) arranged in sequence. The anoxic tank (14) is equipped with a submersible mixer (16). The aerobic tank (15) is equipped with an aeration device (17) at the bottom. The deep purification unit includes a membrane tank (18). The membrane tank (18) is equipped with a membrane box (19). The membrane box (19) is connected to the outlet through a pipeline. A permeate pump (20) is provided between the membrane box (19) and the outlet.

2. The treatment device for wastewater containing microplastics and antibiotics according to claim 1, characterized in that: The flotation unit includes a reaction tank (1), a transition tank (2), a contact tank (3), a flotation tank (4), and an effluent tank (5) arranged in sequence. A skimming trough (11) is arranged adjacent to the upper part of the flotation tank (4). The bottom of the flotation tank (4) is connected to the effluent tank (5). The effluent tank (5) is connected to flotation equipment for extracting wastewater from the effluent tank (5) as a dissolved air source.

3. The treatment device for wastewater containing microplastics and antibiotics according to claim 1, characterized in that: The deep purification unit also includes an activated carbon filter (22), which is connected between the water pump (20) and the outlet via parallel pipelines, and valves are provided between each pipeline.

4. The treatment device for wastewater containing microplastics and antibiotics according to claim 1, characterized in that: The membrane pore size of the membrane box (19) is 0.01~0.03μm, and the membrane material is PVDF.

5. The treatment device for wastewater containing microplastics and antibiotics according to claim 3, characterized in that: The activated carbon filter (22) uses coconut shell-based granular activated carbon (GAC) with an iodine value >1000 and a bulk density of 400~500 kg / m³. 3 The particle size range is 20~40 mesh.

6. The treatment device for wastewater containing microplastics and antibiotics according to claim 1, characterized in that: A first sludge return pump (24) is provided between the aerobic tank (15) and the anoxic tank (14); a second sludge return pump (25) is provided between the membrane tank (18) and the aerobic tank (15).

7. The treatment device for wastewater containing microplastics and antibiotics according to claim 6, characterized in that: The sludge return ratio from the aerobic tank (15) to the anoxic tank (14) is 300-500%, and the sludge return ratio from the membrane tank (18) to the aerobic tank (15) is 400-600%.

8. The treatment device for wastewater containing microplastics and antibiotics according to claim 1, characterized in that: A vacuum pressure transmitter (27) is provided between the membrane tank (19) and the product water pump (20). A first backwash branch pipe (28) is provided between the vacuum pressure transmitter (27) and the product water pump (20). A backwash water pump (29) is provided on the first backwash branch pipe (28). The first backwash branch pipe (28) is connected to the clean water tank.

9. The treatment device for wastewater containing microplastics and antibiotics according to claim 3, characterized in that: The activated carbon filter (22) is provided with a second backwash branch pipe (30) and a first electrical contact pressure gauge (31) on the inlet pipe, and a second electrical contact pressure gauge (32) on the outlet pipe of the activated carbon filter (22). The second backwash branch pipe (30) is connected to the reaction tank (1).

10. The treatment device for wastewater containing microplastics and antibiotics according to claim 9, characterized in that: The backwashing intensity is (5~10) L / (s·㎡).

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