System and method for promoting degradation of high-salinity wastewater by a rotating biological contactor using water droplet power generation

Abstract

The present application relates to a kind of water drop power generation promotes biological rotating disc degradation high-salinity wastewater system and method, belong to high-salinity industrial wastewater treatment and resource utilization field.The device is composed of two functional modules of water drop power generation system and biological rotating disc processing system, two are connected by wire and pipeline, high-salinity wastewater flows through water drop power generation system under the drive of gravity or lifting pump, utilizes the charge transfer effect generated when liquid drop and polytetrafluoroethylene plate and electrode contact, converts liquid drop kinetic energy into low-voltage direct current, input graphite electrode in biological rotating disc reaction tank through wire, forms low-intensity direct current electric field;Electric field is on the one hand through electrochemical stimulation effect to strengthen the metabolic activity of microorganism under high-salinity environment, on the other hand in-situ generates active oxidant on the electrode surface, synergistically degrades organic pollutants in wastewater;After power generation, water drop enters biological rotating disc reaction tank and completes biological treatment, and the effluent after treatment can be used as discharge water or recycled water source.

Description

Technical Field

[0001] This invention relates to the field of high-salt industrial wastewater treatment and reuse technology, specifically to a system and method for promoting the degradation of high-salt wastewater by a biological rotating disc through water droplet power generation. Background Technology

[0002] Due to energy shortages, unconventional oil and gas resources, represented by shale gas and shale oil, are being rapidly developed globally. my country, as the country with the world's largest shale gas reserves and the third largest shale oil reserves, is currently in a phase of rapid expansion in unconventional oil and gas resource development. The extraction of shale gas and shale oil widely employs horizontal wells and hydraulic fracturing technologies, which, while consuming large amounts of freshwater resources, generate substantial amounts of high-salt flowback wastewater. Hydraulic fracturing flowback fluids have complex compositions, typically containing high concentrations of inorganic salts, organic pollutants, and various recalcitrant components, exhibiting characteristics such as high total dissolved solids (TDS) and high organic content. If not properly treated, the pollutants in the flowback wastewater can adversely affect the safety of surface and groundwater quality and the health of residents. Furthermore, the lack of relevant discharge and reuse standards further increases the difficulty of its treatment.

[0003] High-salt environments significantly inhibit traditional biological treatment processes, leading to decreased microbial activity and poor system stability under such conditions. While rotating biological discs (RBDs), an attachment-growth biological treatment technology, offer advantages such as stable operation and low sludge production, their organic pollutant degradation efficiency still needs further improvement under conditions of high salinity and complex organic matter. Electrochemical technology shows good applicability in high-salt wastewater treatment. Electrochemical enhancement can promote microbial metabolic activity by introducing a low-intensity electric field, while electrochemical oxidation can generate active species with oxidizing capabilities in situ to degrade recalcitrant organic pollutants. However, traditional electrochemical processes typically rely on external power sources, resulting in high energy consumption and limiting their engineering applications.

[0004] Water droplet power generation technology achieves energy conversion based on the contact-separation interface between droplets and solids, primarily used in microelectronics power supply and environmental energy recovery. However, research on its coupling with wastewater treatment processes is lacking, especially its engineering application in high-salinity wastewater treatment systems to achieve in-situ power generation and synergistic pollutant removal. This invention structurally couples the water droplet power generation unit with a biological rotating disk system. Influent droplets fall under gravity and generate low-voltage electricity through a contact-separation process. The generated droplets directly enter the biological rotating disk reaction system to participate in treatment. The generated low-intensity electricity is used to enhance the in-situ electric field and simultaneously perform electrochemical oxidation in the reaction system, thereby improving the removal efficiency of organic pollutants under high-salinity conditions without the need for an external high-energy-consuming power source, and achieving an integrated design of influent potential energy recovery and synergistic pollutant removal. This technology features a simple structure, low energy consumption, and high operational stability, showing promising engineering application prospects. Summary of the Invention

[0005] This invention addresses the core technical problems of existing biological treatment technologies for high-salinity wastewater, such as suppressed microbial activity, unstable removal efficiency of organic pollutants, and reliance on external high-energy-consuming power sources for electrochemical auxiliary treatment. It provides a system and method for promoting the degradation of high-salinity wastewater by using water droplet power generation to drive a biological rotating disc reactor. This invention couples a water droplet power generation unit with a biological rotating disc reactor, utilizing the kinetic energy of droplets generated by the flow of high-salinity wastewater to drive low-voltage power generation. The generated DC power is then used for the electrochemical enhancement of the biological rotating disc and the electrochemical oxidation treatment of the wastewater, achieving highly efficient synergistic removal of organic matter, ammonia nitrogen, and total dissolved solids from high-salinity wastewater without the need for an external high-energy-consuming power source.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: On one hand, this invention provides a system for promoting the degradation of high-salinity wastewater by water droplet power generation, comprising a water droplet power generation unit and a biological rotating disc treatment unit. The water droplet power generation unit is positioned at the front end of the biological rotating disc treatment unit in the fluid pathway, so that the raw water first passes through the water droplet power generation unit before entering the biological rotating disc treatment unit. The water droplet power generation unit is electrically connected to the biological rotating disc treatment unit to transmit the electrical energy generated by the movement of water droplets to the biological rotating disc treatment unit to construct an electric field. This invention, through the combination of the water droplet power generation unit and the rotating disc treatment unit, achieves partially self-powered operation of the treatment system, utilizing the mechanical energy inherent in the high-salinity wastewater and converting it into electrical energy to enhance the performance of the rotating disc treatment unit.

[0007] Preferably, the water droplet power generation unit includes an elevated water tank, a water control valve, and a power generation component. After being lifted into the elevated water tank, the high-salinity wastewater forms water droplets through the water control valve and drips onto the power generation component to generate electricity. This invention, through the configuration of the power generation unit, achieves the technical effect of generating electricity using the gravitational potential energy of high-salinity wastewater, and further enhances the downstream biological rotating disc treatment unit to achieve synergistic and enhanced treatment.

[0008] Preferably, the power generation component includes a dielectric insulating plate, an upper electrode disposed on the upper end of the dielectric insulating plate, and a lower electrode disposed on the lower end; wherein the dielectric insulating plate is a PTFE plate, the upper electrode includes a copper sheet and a platinum wire, and the lower electrode is a copper sheet.

[0009] Preferably, the biological rotating disk treatment unit includes a biological rotating disk reaction tank, a biological rotating disk and a treatment electrode disposed in the reaction tank, and a motor for driving the biological rotating disk to rotate.

[0010] Preferably, the processing electrode is a graphite electrode; the electrical energy generated by the water droplet power generation unit is directly connected to the graphite electrode through a wire to provide a low-voltage DC electric field for the reaction tank.

[0011] Preferably, the biological rotating disc reactor is further equipped with an immersion microfiltration membrane module, and the wastewater is discharged after biological treatment and filtration by the microfiltration membrane.

[0012] Preferably, the biological rotating disk processing unit includes at least one hollow membrane rotating disk assembly covering a microfiltration membrane, which serves both as a biofilm loading and filtration unit.

[0013] On the other hand, the present invention provides an application method for promoting the degradation of high-salt wastewater by a biological rotating disc using water droplet power generation of the aforementioned system, comprising the following steps: S1. High-salt wastewater enters the water droplet power generation unit to form water droplets. The water droplets generate electricity by passing through the power generation components under the action of gravity. S2. After power generation, the high-salt wastewater directly enters the biological rotating disc treatment unit. At the same time, the electrical energy generated in S1 is transmitted to the electrodes in the biological rotating disc treatment unit to carry out electrochemical and biological degradation treatment of the wastewater.

[0014] Preferably, in S1, the flow rate of water droplets entering the power generation component is controlled to be 12 mL / min, and the power generation voltage generated by this process is 0.4 V to 1.5 V.

[0015] Preferably, in step S2, the rotation speed of the biological rotating disc is controlled to be 5 r / min, the proportion of wastewater immersed in the disc is 40%, and the hydraulic retention time of the high-salt wastewater in the biological rotating disc reaction tank is 48 h.

[0016] Compared with the prior art, the present invention has the following significant advantages: 1. This invention is the first to couple water droplet power generation technology with biological rotating disc process. By using the kinetic energy of the wastewater itself to drive electrochemical enhancement, it achieves efficient treatment of high-salinity wastewater without the need for an external high-energy power supply, fundamentally reducing the system's operating energy consumption and ensuring the pollutant removal effect and long-term operational stability of the process.

[0017] 2. The low-voltage DC electric field (0.4–1.5 V) generated by the water droplet power generation unit effectively stimulates the microbial community within the biological rotating disk, promoting the recovery and maintenance of microbial metabolic activity under high-salt conditions, and significantly enhancing the biological rotating disk's ability to process organic pollutants (mainly UV). 254 Characterization) and ammonia nitrogen (NH4) + The degradation and removal efficiency of -N was increased by more than 15.9% and 47.2% respectively compared with the control group.

[0018] 3. The introduction of electrochemical oxidation into the biological rotating disc treatment unit can simultaneously achieve the oxidative decomposition of recalcitrant organic matter during the biodegradation process, reduce the biotoxicity of wastewater, improve biodegradability, and further improve the overall treatment effect. The TDS removal rate is about 6.3% higher than that of the control group.

[0019] 4. This invention can further enhance the effluent quality by integrating an immersion microfiltration membrane module (ERBCM) into the biological rotating disc treatment unit or by replacing one biological rotating disc with a membrane module rotating disc (EMRBC). During a 42-day operating period, UV... 254 NH4 + The mean values ​​of -N and TDS can be reduced to 0.271 cm⁻¹. -1 The optimal treatment effects were observed at concentrations of 1.09 mg / L and 25.49 g / L.

[0020] 5. The device of the present invention has a simple structure, high degree of modularity, convenient operation and maintenance, strong engineering adaptability, and can be flexibly configured according to the processing scale. It is suitable for the treatment and resource utilization of shale gas extraction backflow wastewater and other high-salt industrial wastewater.

[0021] The technical solution of the present invention will be further described in detail below through embodiments. Attached Figure Description

[0022] Figure 1 A schematic diagram of the system for promoting the degradation of high-salt wastewater by a biological rotating disk using water droplet power generation, provided by the present invention; Figure 2 This is a schematic diagram of the water droplet power generation unit in this invention; Figure 3 These are performance diagrams for three specific embodiments of the present invention.

[0023] Figure label: 11. Booster pump; 12. Inlet valve; 13. Biological rotating disc; 14. Outlet pump; 15. Product water valve; 16. Constant speed rotating motor; 17. Rotating shaft; 18. Graphite electrode; 19. Biological rotating disc reaction tank; 2. Water droplet power generation unit; 21. High-level water tank; 22. Valve; 23. Copper sheet electrode; 24. Platinum wire electrode; 25. PTFE plate. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present application, the technical solutions in specific embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by those skilled in the art.

[0025] The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects.

[0026] like Figures 1 to 3 As shown, the device of the present invention includes two functional modules: a biological rotating disk processing unit and a water droplet power generation unit 2. The two are interconnected by pipes and wires and operate in coordination.

[0027] First is the biological rotating disc treatment unit, which consists of the following components: lift pump 11, inlet valve 12, biological rotating disc 13, outlet pump 14, product water valve 15, constant speed rotating motor 16, rotating shaft 17, graphite electrode 18, and biological rotating disc reaction tank 19.

[0028] The biological rotating disc reactor 19 is the core carrier of the entire biological treatment process; its front end is connected to the inlet booster pump 11 and the inlet valve 12 in sequence through pipelines to control the entry of wastewater; its rear end is connected to the outlet pump 14 and the product water valve 15 in sequence to treat the discharge or reuse of the effluent.

[0029] At least three biological rotating discs 13 are installed in the biological rotating disc reactor 19, arranged in series along the length of the reactor. Each disc is driven to rotate synchronously by a constant speed rotating motor 16 through a common rotating shaft 17. The microbial biofilm attached to the surface of the disc is the main functional unit for the biodegradation of organic pollutants. During the rotation, the disc will always be partially submerged in wastewater and partially exposed to air, so that the attached biofilm is alternately in contact with oxygen and in contact with wastewater, ensuring the aerobic metabolism of microorganisms and substrate mass transfer.

[0030] Two graphite electrodes 18 are also installed in the biological rotating reactor 19, serving as the anode and cathode respectively. They are driven by low-voltage DC power provided by the water droplet power generation unit 2, forming a low-intensity DC electric field in the reactor. This field is used to electrochemically enhance the metabolism of microorganisms and degrade difficult-to-treat organic pollutants through electrochemical oxidation.

[0031] The water droplet power generation unit 2 consists of the following components: a high-level water tank 21, a valve 22, a copper sheet electrode 23, a platinum wire electrode 24, and a polytetrafluoroethylene (PTFE) plate, hereinafter collectively referred to as the PTFE plate 25.

[0032] The elevated water tank 21 is located above the biological rotating disc reactor 19. The front end is connected to the lift pump 11 and the inlet valve 12 through a pipeline. It is used to store the lifted high-salt wastewater and provide a stable head for the formation of water droplets with the help of gravity. The bottom of the elevated water tank 21 is connected to the valve 22. By adjusting the valve opening, the dripping rate and flow rate of the water droplets are controlled so that the water droplets fall one by one in a stable rhythm.

[0033] The PTFE plate 25 has excellent hydrophobicity and surface charge accumulation characteristics, making it the core functional material for water droplet power generation. A platinum wire electrode 24 and a copper sheet electrode 23 are attached to the upper end of the PTFE plate 25, and another copper sheet electrode 23 is attached to the lower end.

[0034] The basic principle of water droplet power generation is as follows: Under the action of gravity, the droplet falls from the high-level water tank 21 and contacts the platinum wire electrode 24 at the upper end of the PTFE plate 25 in sequence. The platinum wire acts as an induction electrode to induce the charge distribution inside the droplet. The droplet then slides across the hydrophobic surface of the PTFE plate 25, and during the contact-separation process, the PTFE surface accumulates charge through the triboelectric effect. When the droplet leaves the PTFE plate 25, it contacts the lower copper sheet electrode 23, completing the charge transfer and forming a current loop to generate a low-voltage direct current of 0.4 to 1.5 V. The generated electrical energy is transmitted through wires to the graphite electrode 18 of the biological rotating disc treatment unit to provide electrochemical driving force for the reaction tank. After power generation is completed, the water droplet directly enters the biological rotating disc reaction tank 19 to participate in the subsequent biological treatment process.

[0035] Based on the above basic device, the following two membrane enhancement modules can be selectively integrated to further improve the quality of the effluent: Module 1 is an immersion microfiltration membrane module: a microfiltration membrane module is immersed in the biological rotating disc reactor 19. After the effluent is filtered by the microfiltration membrane, it is pumped out by the effluent pump 14. It can effectively intercept suspended biofilm fragments and residual particulate matter, reduce the turbidity and organic matter concentration of the effluent, and constitute the ERBCM scheme.

[0036] Module 2 is a membrane module turntable: a regular biological turntable 13 in the biological turntable treatment unit is replaced with a membrane module turntable covered with a hollow fiber microfiltration membrane. This membrane module turntable has the dual functions of biomembrane carrier and filtration separation, realizing the integrated coupling of biodegradation and membrane separation, thus forming the EMRBC solution.

[0037] In addition to the device, this invention also provides an application method for degrading high-salinity wastewater using the device, which is performed in the following steps: S1. High-salinity wastewater enters the water droplet power generation device to generate electricity, specifically including: Start the booster pump 11 and open the inlet valve 12 to pump the high-salt wastewater into the high-level water tank 21 to the set level; adjust the opening of valve 22 so that the wastewater drips from the outlet of valve 22 one drop at a time, forming a stable and continuous sequence of water droplets.

[0038] Driven by gravity, the water droplet sequentially follows the following power generation path: First, it contacts the platinum wire electrode 24 at the upper end of the PTFE plate 25. The platinum wire acts as an induction electrode, inducing polarization of the internal charge of the droplet at the moment of contact. Then, the droplet slides downward on the hydrophobic surface of the PTFE plate 25, and contact electrification occurs at the liquid-solid interface. The PTFE surface accumulates negative charges due to friction. When the droplet leaves the PTFE plate 25, it contacts the copper sheet electrode 23 at the lower end, and a directional charge transfer occurs, forming a current loop between the upper and lower electrodes, stably outputting a low-voltage DC current of 0.4 to 1.5 V.

[0039] The generated electrical energy is transmitted via wires to the graphite electrode 18 of the biological rotating disc treatment unit, serving as the driving power for electrochemical enhancement and electrochemical oxidation. The water droplets generated flow from the lower end of the PTFE plate 25 and directly enter the biological rotating disc reaction tank 19.

[0040] S2. High-salinity wastewater undergoes electrochemical-biological synergistic treatment in a biological rotating disc treatment unit, specifically including: After the high-salt wastewater droplets enter the biological rotating disc reactor 19, the constant-speed rotating motor 16 drives the three biological rotating discs 13 to rotate at a uniform speed through the rotating shaft 17, so as to realize the periodic contact between the attached biofilm and the wastewater and the alternating exposure to the air.

[0041] Simultaneously with biological treatment, the graphite electrode 18, driven by the low-voltage DC electric field provided by the water droplet power generation unit 2, applies a low-intensity electrochemical effect to the wastewater, exerting the following two synergistic effects: First, the low-intensity electric field activates the metabolic pathways of halophilic microorganisms through electrostimulation, enhances cell membrane permeability, promotes substrate uptake and enzymatic reactions, enabling microorganisms in the biofilm to maintain high metabolic activity even under the inhibitory environment of high salt osmotic pressure, significantly improving the biological rotating disc's ability to treat organic pollutants (in the form of UV radiation). 254 Characterization) and ammonia nitrogen (NH4) + The degradation efficiency of -N) is improved; secondly, under the condition of being energized, the graphite anode can generate strong oxidizing active species such as hydroxyl radicals (·OH) in situ on the electrode surface, which can oxidize and decompose the recalcitrant organic matter in the wastewater that is difficult to be directly degraded by microorganisms, reduce the toxicity of the wastewater, improve its biodegradability, and further enhance the overall treatment effect.

[0042] The hydraulic retention time (HRT) of the wastewater in the biological rotating disc reactor 19 is 48 hours to ensure sufficient biochemical reactions and electrochemical oxidation processes. After treatment, the effluent is discharged via effluent pump 14 and product water valve 15 as compliant effluent or a source of recycled water. If an immersion microfiltration membrane module (ERBCM) or membrane module rotating disc (EMRBC) solution is integrated, the effluent will undergo membrane filtration before discharge to further remove suspended solids and residual organic matter, thereby improving the effluent quality.

[0043] The beneficial effects of the present invention will then be illustrated through specific embodiments.

[0044] Example 1 This embodiment describes a basic treatment scheme for water droplet power generation coupled with a biological rotating disk (ERBC). Key component parameters: PTFE sheet 25 dimensions: 60 mm × 40 mm × 5 mm; Copper electrode 23 dimensions: 40 mm × 10 mm × 0.06 mm, one at the top and one at the bottom; Platinum wire electrode 24 dimensions: length 10 mm, diameter 0.2 mm, purity ≥99.9%; Graphite electrodes 18: Two, serving as the anode and cathode respectively, are immersed in the biological rotating reactor 19; Biological rotating disc 13: Three discs are connected in series along the direction of water flow. The disc material has good biological adhesion properties.

[0045] Operating parameters: Water flow rate: 12 mL / min, adjustable via valve 22; Generating voltage: 0.4~1.5 V, DC; Biological rotating disk rotation speed: 5 r / min, controlled by constant speed rotating motor 16; Rotary disc immersion ratio: 40%, meaning that 40% of the rotary disc diameter is submerged below the wastewater surface; Hydraulic residence time (HRT): 48 h.

[0046] Work process: Start the booster pump 11 to pump the high-salt wastewater into the high-level water tank 21 to the set level; open valve 22, and the wastewater forms a continuous and stable sequence of water droplets at a flow rate of 12 mL / min. Under the action of gravity, the water droplets pass sequentially through the platinum wire electrode 24, the hydrophobic surface of the PTFE plate 25, and the lower copper sheet electrode 23, generating a low-voltage DC current of 0.4–1.5 V through triboelectric and electrostatic induction coupling mechanisms, which is then transported to the graphite electrode 18 of the biological rotating reactor 19 via wires.

[0047] Water droplets generated from power generation fall into the biological rotating disc reactor 19. A constant-speed rotating motor 16 drives three biological rotating discs 13 to rotate at a uniform speed of 5 r / min, with an immersion ratio of 40%. Under the electrochemical enhancement of a low-voltage electric field, the attached biofilm on the discs reacts with organic pollutants (in the form of UV light) in the wastewater. 254 Characterization) and ammonia nitrogen (NH4) +-N) biodegradation is carried out; at the same time, the graphite electrode 18 generates active oxide species in situ under electrochemical action, which oxidizes and decomposes recalcitrant organic matter, synergistically reducing TDS and organic matter concentration. After the wastewater stays in the reaction tank for 48 hours, the effluent pump 14 is started and the product water valve 15 is opened, and the treated effluent is discharged into the clear water tank or enters the subsequent reuse process.

[0048] Example 2 This embodiment is an integrated immersion microfiltration membrane module (ERBCM) solution. Based on the device and operating parameters of Example 1, this embodiment additionally integrates an immersion microfiltration membrane module into the biological rotating reactor 19. The composition, connection method, and operating parameters of the remaining components are exactly the same as those of Example 1.

[0049] The submersible microfiltration membrane module is fixed to the effluent end of the biological rotating disc reactor 19 in a submerged manner, with the membrane module completely submerged below the wastewater surface. The effluent pump 14 drives the wastewater through the microfiltration membrane by suction negative pressure and discharges it. The biofilm fragments, suspended particles and some residual organic matter trapped on the membrane surface remain in the biological rotating disc reactor 19 and continue to be degraded by microorganisms.

[0050] The influent, power generation, and bioelectrochemical treatment steps in this embodiment are the same as in Example 1. In the effluent stage, the wastewater is not directly discharged through the product water valve 15, but is instead discharged by the effluent pump 14 under suction negative pressure through an immersed microfiltration membrane; the microfiltration membrane filters out suspended solids, biological debris, and some large organic molecules in the wastewater, further reducing UV in the effluent. 254 and NH4 + -N concentration improves the quality of effluent.

[0051] Compared to Example 1 (ERBC), this example showed improved effluent UV levels during a 42-day continuous operation test. 254 It further decreased from 0.369 to 0.302 cm. -1 NH4 + -N decreased from 3.90 to 2.12 mg / L, and TDS decreased from 31.86 to 28.88 g / L, resulting in a significant improvement in effluent quality.

[0052] Example 3 This embodiment is a membrane module turntable integration solution (EMRBC). Based on the device in Example 1, this embodiment replaces an ordinary biological rotating disc 13 in the biological rotating disc processing unit with a membrane module rotating disc covered with a hollow fiber microfiltration membrane, thereby realizing the integrated function of the biofilm carrier and the membrane filtration function; the composition, connection method and operating parameters of the remaining components are exactly the same as in Example 1.

[0053] The membrane module rotating disc is covered with a hollow fiber microfiltration membrane, which has the following dual functions: First, the membrane surface can serve as a carrier for microbial attachment, just like a regular biological rotating disc, to support biofilm and carry out biodegradation; Second, the membrane module rotating disc also acts as a filter element during rotation, and the effluent is discharged through the hollow fiber membrane under the suction negative pressure, performing membrane separation treatment on wastewater and effectively retaining biological debris and suspended organic matter; In addition, the shear hydraulic conditions caused by the rotation of the disc help to slow down the deposition of pollutants on the membrane surface and extend the effective service life of the membrane module.

[0054] The influent, power generation, and bioelectrochemical treatment steps in this embodiment are the same as in Example 1. The membrane module disc rotates synchronously with the other two ordinary biological discs 13. While completing the biodegradation function, the effluent pump 14 draws out water through the hollow fiber membrane module to achieve continuous membrane filtration. The rotational shear force of the membrane module disc effectively inhibits the accumulation of biological fouling on the membrane surface and maintains a stable membrane flux.

[0055] Compared with Example 1 (ERBC) and Example 2 (ERBCM), this example (EMRBC) showed the best treatment efficiency. Results of a 42-day continuous operation test showed that the effluent UV... 254 NH4 + The mean values ​​of -N and TDS decreased to 0.271 cm⁻¹. -1 The concentrations of 1.09 mg / L and 25.49 g / L were the highest, resulting in the best overall removal efficiency and the best effluent quality.

[0056] The specific comparison of the test results of Examples 1, 2 and 3 is shown in the table below.

[0057] Table 1: Comparison of mean effluent water quality indicators for each implementation method after 42 days of continuous operation

[0058] Note: The raw water was wastewater from hydraulic fracturing of a shale gas well in the Sichuan Basin. The above results show that all three embodiments can effectively treat high-salinity wastewater without relying on external high-energy power sources. The coupling of water droplet power generation and biological rotating disk significantly enhances the removal efficiency of organic matter, ammonia nitrogen, and total dissolved solids. Further integration of membrane separation function on this basis can obtain better effluent quality. Among them, the membrane module rotating disk scheme has the best comprehensive treatment efficiency because it achieves triple coupling of biological, electrochemical and membrane separation.

[0059] Finally, it should be noted that the described embodiments are merely some, not all, of the embodiments of the present invention. Those skilled in the art will understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents; that is, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A system for generating electricity from water droplets to promote the degradation of high-salinity wastewater by a biological rotating disc, characterized in that, Includes a water droplet power generation unit and a biological rotating disk processing unit; The water droplet power generation unit is located at the front end of the biological rotating disk treatment unit in the fluid passage, so that the raw water first passes through the water droplet power generation unit and then enters the biological rotating disk treatment unit. The water droplet power generation unit is connected to the biological rotating disk processing unit in the circuit so as to transmit the electrical energy generated by the movement of the raw water droplets to the biological rotating disk processing unit to build an electric field. The water droplet power generation unit includes an elevated water tank, a water control valve, and a power generation component; after high-salt wastewater is lifted into the elevated water tank, it forms water droplets through the water control valve and drips onto the power generation component to generate electricity; The power generation component includes a dielectric insulating plate, an upper electrode disposed at the upper end of the dielectric insulating plate, and a lower electrode disposed at the lower end; wherein the dielectric insulating plate is a polytetrafluoroethylene plate, the upper electrode includes a copper sheet and a platinum wire, and the lower electrode is a copper sheet.

2. The system for promoting the degradation of high-salinity wastewater by a biological rotating disc using water droplet power generation according to claim 1, characterized in that, The biological rotating disk processing unit includes a biological rotating disk reaction tank, a biological rotating disk and processing electrodes disposed in the reaction tank, and a motor for driving the biological rotating disk to rotate.

3. The system for promoting the degradation of high-salinity wastewater by a biological rotating disc using water droplet power generation according to claim 2, characterized in that, The processing electrode is a graphite electrode; the electrical energy generated by the water droplet power generation unit is directly connected to the graphite electrode through a wire to provide a low-voltage DC electric field for the reaction tank.

4. The system for promoting the degradation of high-salinity wastewater by a biological rotating disc using water droplet power generation according to claim 2, characterized in that, The biological rotating disc reactor is also equipped with an immersion microfiltration membrane module, and the wastewater is discharged after biological treatment and filtration by the microfiltration membrane.

5. The system for promoting the degradation of high-salinity wastewater by a biological rotating disc using water droplet power generation according to claim 2, characterized in that, The biological rotating disk processing unit includes at least one hollow membrane rotating disk assembly covered with a microfiltration membrane, which serves both as a biofilm loading and filtration unit.

6. A method for using the water droplet power generation system according to any one of claims 1 to 5 to promote the degradation of high-salinity wastewater by a biological rotating disc, characterized in that, Includes the following steps: S1. High-salt wastewater enters the water droplet power generation unit to form water droplets. The water droplets generate electricity by passing through the power generation components under the action of gravity. S2. After power generation, the high-salt wastewater directly enters the biological rotating disc treatment unit. At the same time, the electrical energy generated in S1 is transmitted to the electrodes in the biological rotating disc treatment unit to carry out electrochemical and biological degradation treatment of the wastewater.

7. The application method according to claim 6, characterized in that, In S1, the flow rate of water droplets entering the power generation component is controlled to be 12 mL / min, and the power generation voltage generated by this process is 0.4 V to 1.5 V.

8. The application method according to claim 6, characterized in that, In step S2, the rotation speed of the biological rotating disc is controlled at 5 r / min, the proportion of wastewater immersed in the disc is 40%, and the hydraulic retention time of the high-salt wastewater in the biological rotating disc reaction tank is 48 h.

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