A high-efficiency oxygen supply and pollutant synergistic degradation system and method based on oxygen-permeable biofilm technology and application thereof

Abstract

This invention discloses a highly efficient oxygen supply and pollutant synergistic enhanced degradation system, method, and application based on oxygen-permeable biological dual-membrane technology. The system includes an oxygen-permeable biological dual-membrane reactor, which comprises a reactor body, an oxygen-permeable biological dual-membrane module, a circulation system, a gas control system, and an inlet / outlet water system. The gas control system includes an air inlet pipe, an intermittent exhaust valve, and an exhaust pipe. One end of the oxygen-permeable biological dual-membrane module is connected to the air inlet pipe, and the other end is connected to the exhaust pipe. The air inlet pipe is used to transport air, and the intermittent exhaust valve is installed at the end furthest from the air inlet pipe and is used to control the exhaust of the oxygen-permeable biological dual-membrane module. The oxygen supply method of this invention combines air supply with intermittent exhaust oxygen supply. Using air as the oxygen source eliminates the safety hazards of pure oxygen, and the intermittent nitrogen discharge through the intermittent exhaust valve overcomes the mass transfer attenuation bottleneck caused by the accumulation of inert components.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a highly efficient oxygen supply and pollutant synergistic enhanced degradation system, method, and application based on oxygen-permeable biological dual-membrane technology. Background Technology

[0002] With increasingly stringent requirements for industrial wastewater treatment and the widespread detection of new pollutants such as surfactants and persistent organic pollutants, traditional wastewater treatment technologies face multiple challenges, including high operating costs and the risk of secondary pollution. [1, 2] Surfactants, due to their excellent emulsifying, dispersing, and wetting properties, are widely used in various industries such as daily chemicals, textiles, electronics manufacturing, and pesticides, leading to their frequent detection in various industrial wastewaters. With the rapid development of the global surfactant market, their environmental emissions have also continued to increase, making them an emerging pollutant that cannot be ignored in wastewater treatment. The presence of surfactants not only exhibits toxic effects on aquatic ecosystems but also inhibits the metabolic activity of microorganisms in activated sludge, affecting the stable operation of wastewater treatment systems. Therefore, exploring efficient removal technologies for surfactants is of significant environmental and engineering importance for ensuring aquatic ecological safety and improving the operational efficiency of wastewater treatment plants.

[0003] Currently, for the treatment of wastewater containing surfactants and recalcitrant organic pollutants, industry and academia have mainly developed the following types of technologies: 1. Activated sludge process: This is currently the most widely used wastewater treatment technology, utilizing microbial metabolism to remove organic matter. Its advantages include relatively low operating costs and ease of operation. However, traditional aerobic biological treatment relies on blower aeration for oxygen supply, resulting in low oxygen transfer efficiency (typically only 10%-30%) and high energy consumption (blowers are the main energy-consuming unit). Especially when treating surfactant-laden wastewater, bubble aeration easily generates large amounts of foam, leading to sludge loss, further reduction in oxygen transfer efficiency, and even system malfunction. Furthermore, traditional aeration, due to uneven oxygen concentration distribution, struggles to create a stable, highly oxidizing environment locally, thus easily leading to insufficient pollutant activation efficiency.

[0004] 2. Chemical treatment method: Chemical methods, such as Fenton oxidation and flocculation, can rapidly oxidize and degrade surfactants and other recalcitrant organic compounds. While highly efficient, these methods generally suffer from drawbacks such as secondary pollution and high operating costs. Therefore, the use of chemical methods in large-scale industrial wastewater treatment still faces the dual challenges of economic viability and environmental friendliness.

[0005] 3. Adsorption method: Adsorption is one of the commonly used physicochemical methods for removing surfactants. It utilizes adsorbents such as activated carbon, zeolite, silica, alumina, and zero-valent iron nanoparticles to remove surfactants through physicochemical action. However, this method suffers from problems such as difficulty in regenerating adsorbent materials and the risk of secondary pollution. Furthermore, traditional adsorption research has largely focused on anionic surfactants, with insufficient attention paid to issues such as the coexistence of multiple types of surfactants or non-anionic surfactants.

[0006] In summary, existing single-technology approaches generally suffer from the following limitations when treating wastewater containing recalcitrant organic pollutants such as surfactants: ① The contradiction between energy consumption and efficiency is prominent: traditional aerated biological treatment has high energy consumption, low oxygen utilization rate, and serious foaming problems; although chemical methods have high removal efficiency, they are expensive to operate. ② Significant risk of secondary pollution: Both chemical and adsorption methods pose a risk of secondary pollution when adding reagents and materials; ③Low system integration: The goals of oxygen supply, pollutant oxidation, anti-foaming, and environmental protection are scattered across different technologies, lacking integrated and collaborative design.

[0007] Therefore, there is an urgent need in this field to develop a novel wastewater treatment technology that combines efficient oxygen supply, micro-interface enhanced oxidation, low energy consumption, and resistance to foam interference, in order to achieve stable, efficient, and low-carbon treatment of surfactants and recalcitrant organic pollutants. While some related technologies can achieve the above effects to a certain extent, they require pure oxygen as an oxygen source, resulting in high costs, significant safety risks, and complex equipment investment and operation and maintenance, which limits their large-scale engineering applications.

[0008] The reference information is as follows: [1]Mohapatra S, Xian JLL, Galvez-Rodriguez A, et al. Photochemicalfate of quaternary ammonium compounds (QACs) and degradation pathwayspredication through computational analysis [J]. Journal of HazardousMaterials, 2024, 465. [2]Primo EN, López-Heras I, Esteve-Núñez A. Electroactive biofilters outperform inert biofilters for treating surfactant-polluted wastewater by means of selecting a low-growth yield microbial community [J]. Journal of Hazardous Materials, 2024, 477. Summary of the Invention

[0009] This invention aims to address at least one of the technical problems existing in the prior art. To this end, this invention proposes a highly efficient oxygen supply and pollutant synergistic degradation system based on oxygen-permeable biological dual-membrane technology. This system not only efficiently and stably degrades pollutants, but also effectively avoids the insufficiency of pure oxygen as an oxygen source.

[0010] This invention also proposes a method for achieving efficient oxygen supply and synergistic enhanced degradation of pollutants using the above system.

[0011] The present invention also proposes applications of the above-described system or method.

[0012] According to one aspect of the present invention, a highly efficient oxygen supply and pollutant synergistic enhanced degradation system based on oxygen-permeable biofilm technology is proposed, comprising an oxygen-permeable biofilm reactor, wherein the oxygen-permeable biofilm reactor comprises a reactor body, an oxygen-permeable biofilm module, a circulation system, a gas control system and an inlet / outlet water system, wherein the oxygen-permeable biofilm module is installed inside the reactor body; The gas control system includes an air intake pipe, an intermittent exhaust valve, and an exhaust pipe. One end of the oxygen-permeable bio-dual membrane module is connected to the air intake pipe, and the other end is connected to the exhaust pipe. The air intake pipe is used to transport air, and the intermittent exhaust valve is installed at the end away from the air intake pipe and is used to control the exhaust of the oxygen-permeable bio-dual membrane module. The circulation system is connected to the inlet and outlet water system, which includes an inlet water system and an outlet water system, and the inlet water system and the outlet water system are respectively connected to the reactor body.

[0013] The degradation system of this invention achieves bubble-free, precise oxygen supply through an oxygen-permeable membrane, forming a stable oxygen gradient and a locally enhanced oxidation environment at the membrane interface. This improves the initial oxidation and activation capacity of recalcitrant pollutants, reduces the energy consumption of traditional aeration, and effectively avoids the foaming problem inherent in high-surface-activity systems. Furthermore, the oxygen supply method combines air supply with intermittent exhaust oxygen supply. Using air as the oxygen source eliminates the safety hazards of pure oxygen, while intermittent nitrogen discharge through an intermittent exhaust valve overcomes the mass transfer attenuation bottleneck caused by the accumulation of inert components (such as nitrogen and water vapor). While avoiding the safety hazards and high costs of pure oxygen, this invention also effectively overcomes multiple shortcomings of traditional aeration processes, such as low oxygen utilization, high energy consumption, insufficient oxidation efficiency, and poor operational stability.

[0014] This invention's system is constructed based on oxygen-permeable biofilm dual-membrane technology. Air is transported through the interior of the oxygen-permeable membrane and diffuses through the membrane wall to the external biofilm region. Replacing traditional bubble aeration with an oxygen-permeable membrane enables a continuous, stable, bubble-free diffused air supply, fundamentally avoiding bubble formation, improving oxygen utilization efficiency, and reducing aeration energy consumption. Furthermore, a stable oxygen gradient is constructed at the membrane interface through the oxygen-permeable membrane, and combined with the biofilm reaction interface, a locally highly oxidatively active region is formed, thereby achieving a synergistic enhancement of pollutant oxidation and subsequent biodegradation. In addition, the system includes a fluid circulation device to maintain fluid shear at the membrane surface, further enhancing the mass transfer process.

[0015] This invention employs an intermittent venting valve installed at the tail end of an oxygen-permeable biofilm module to control the inlet and outlet of gas within the hollow fiber membrane, enabling intermittent venting within the membrane. Based on the membrane aeration principle (gas permeating from the membrane surface into the water), this system generates no air bubbles. Gas is continuously input at the inlet, but the intermittent venting valve is cleverly installed only at the outlet, using the inlet pressure to flush the gas out. This avoids the efficiency reduction issues common in traditional closed-end membrane aeration devices, where oxygen is consumed and inert components like nitrogen remain inside the membrane; it also avoids the gas waste caused by continuously opening the outlet for high-speed flushing in bleeding mode. This solution uses an intermittent valve-opening venting mode: the outlet is closed for a period, then the valve is intermittently and suddenly opened. The inlet pressure quickly pushes the gas trapped inside the membrane out from the outlet, thus refreshing the oxygen content within the membrane. This ingenious on / off valve control effectively solves the problem of reduced air efficiency during membrane aeration.

[0016] According to some embodiments of the present invention, the oxygen-permeable bio-dual membrane assembly includes a hollow fiber membrane, one end of which is connected to an air inlet pipe and the other end of which is connected to an air outlet pipe.

[0017] According to some embodiments of the present invention, the intermittent venting valve is installed at the other end of the hollow fiber membrane. When the present invention uses an air source for oxygen supply, it utilizes intermittent valve opening at the distal end of the membrane to vent air, periodically removing accumulated nitrogen and water vapor from the membrane cavity, restoring oxygen partial pressure and mass transfer flux, and avoiding long-term performance degradation. A control valve is installed at the distal end of the fiber membrane filaments, employing an intermittent venting strategy to continuously introduce air into the membrane cavity while periodically opening the valve, using the pressure difference to quickly remove accumulated nitrogen and water vapor from the membrane cavity, thereby restoring oxygen partial pressure and mass transfer flux.

[0018] According to some embodiments of the present invention, the hollow fiber membrane is made of at least one of polypropylene (PP), polyvinylidene fluoride (PVDF), polyethylene (PE), polyurethane (TPU), or polyethersulfone (PES).

[0019] According to some embodiments of the present invention, the hollow fiber membrane is composed of high-density polyethylene (HDPE) and thermoplastic polyurethane (TPU).

[0020] According to another aspect of the present invention, the present invention also proposes a method for achieving efficient oxygen supply and synergistic enhanced degradation of pollutants using the above-described system, comprising the following steps: Wastewater containing pollutants is introduced into the chamber of the oxygen-permeable biological double membrane module, and air is introduced into the chamber of the module. The intermittent exhaust valve is periodically opened to release air intermittently.

[0021] This invention utilizes an oxygen-permeable membrane to achieve continuous and stable bubble-free oxygen supply, and combines this with the biofilm reaction interface to construct a locally highly oxidatively active region, thereby synergistically enhancing pollutant oxidation and subsequent biodegradation. When air is used as the oxygen source, nitrogen and water vapor in the air gradually accumulate within the membrane cavity, diluting the oxygen partial pressure and reducing mass transfer efficiency. This invention employs an intermittent venting strategy, continuously introducing air into the membrane cavity while periodically opening valves to rapidly remove accumulated nitrogen and water vapor using pressure differential, thus restoring oxygen partial pressure and mass transfer flux. Inert components are discharged by intermittently opening valves at the distal end of the membrane fibers, restoring the oxygen supply mode for mass transfer. Compared to continuous venting, intermittent venting more effectively restores and maintains high oxygen partial pressure, avoiding performance degradation, and is particularly suitable for the biological treatment of surfactant-containing wastewater.

[0022] According to some embodiments of the present invention, the exhaust frequency is 10-20 seconds every 2-60 minutes. This ingenious use of intermittent exhaust avoids the problem of membrane blockage and poor ventilation efficiency caused by directly using air due to its inert components.

[0023] According to some embodiments of the present invention, the exhaust frequency is 15 seconds of exhaust every 2 to 60 minutes.

[0024] According to some embodiments of the present invention, the exhaust frequency is 15 seconds every 2-4 minutes, such as 15 seconds every 3 minutes. By optimizing the exhaust method, frequency, and duration, a stable high oxygen mass transfer efficiency can be maintained during long-term operation. Under optimal exhaust conditions (15 seconds of exhaust every 3 minutes), the oxygen partial pressure within the membrane cavity is sufficient to achieve 100% removal of pollutants, with performance comparable to pure oxygen supply, while significantly reducing supply costs.

[0025] According to some embodiments of the present invention, the degradation process includes at least one of the following process parameters: 1) air supply pressure (i.e., total air pressure): 3-15 psig; 2) hydraulic residence time (HRT): 2-24 h; 3) dissolved oxygen (DO): 0.1-2 mg / L; 4) circulation flow rate: 50-300 mL / min.

[0026] Because air is supplied via membrane diffusion, no bubbles are formed during system operation, thus significantly reducing the risk of foam formation in surfactant systems. The system achieves synergistic optimization of oxygen transfer efficiency and pollutant degradation efficiency by adjusting oxygen supply pressure, hydraulic residence time (HRT), circulation velocity, membrane area loading, and intermittent exhaust frequency.

[0027] According to some embodiments of the present invention, the method further includes inoculating sludge or functional microorganisms to form a biofilm on the surface of the oxygen-permeable biofilm assembly. The present invention creates a locally highly oxidizing environment at the oxygen-permeable membrane-biofilm interface and induces the generation of reactive oxygen species (ROS), achieving synergistic enhancement of initial oxidative activation and subsequent biodegradation of pollutants. The oxygen-permeable membrane interface is used to form a ROS-enhanced oxidation zone for the synergistic degradation of recalcitrant pollutants. According to some embodiments of the present invention, the biofilm formation process further includes pumping in a culture medium containing surfactants simultaneously with the inoculation of sludge or functional microorganisms.

[0028] According to some embodiments of the present invention, the culture medium includes an inorganic salt culture medium in addition to the surfactant component. The surfactant serves as a carbon source. Preferably, the surfactant in the culture medium is the same type as the surfactant in the wastewater to be treated.

[0029] According to some embodiments of the present invention, the pH of the culture medium is 6.8-7.5.

[0030] According to some embodiments of the present invention, the inorganic salt culture medium includes 0.5~1.0 g / L K2HPO4, 0.1~0.5 g / L KH2PO4, 0.1~0.5 g / L MgSO4, 0.1~0.5 g / L KCl, 0.001~0.005 g / L FeSO4, a nitrogen source, and trace elements.

[0031] According to some embodiments of the present invention, the inorganic salt culture medium comprises 0.72 g / L K₂HPO₄, 0.28 g / L KH₂PO₄, 0.25 g / L MgSO₄, 0.25 g / L KCl, 0.002 g / L FeSO₄, and trace elements. 150 mg / L NH₄Cl is used as the nitrogen source, and the pH of the culture medium is adjusted to 6.8-7.5 with 8 mM phosphate buffer.

[0032] According to some embodiments of the present invention, the concentration of the surfactant in the culture medium is 0.5-700 mg / L.

[0033] According to some embodiments of the present invention, the concentration of the surfactant in the culture medium is 1:0.9~1.1 to the concentration of the pollutant in the wastewater to be treated. The concentration of the surfactant in the culture medium is close to or equal to the concentration of the surfactant in the wastewater to be treated; for unknown concentrations, 1 mM can be used as the starting concentration.

[0034] According to some embodiments of the present invention, the biofilm formation process parameters include: 1) gas supply pressure controlled at 1~30 psig; 2) circulation flow rate controlled at 20~500 mL / min; 3) temperature controlled at 10~40℃. Activated sludge or functional microbial communities are inoculated, and the biofilm is cultured under continuous low-load oxygen supply conditions. Under continuous oxygen supply conditions through the oxygen-permeable membrane, a stable oxygen gradient zone forms on the membrane surface, maintaining a high oxygen concentration inside the membrane while the bulk liquid phase maintains a low DO (dissolved oxygen) environment, thereby forming a locally hyperoxidative interface suitable for monooxygenase and dioxygenase reactions.

[0035] According to some embodiments of the present invention, the pollutant includes at least one of cationic surfactants, anionic surfactants, or nonionic surfactants. The present invention is applicable to wastewater containing anionic surfactants, cationic surfactants, amphoteric surfactants, or nonionic surfactants, and is also applicable to wastewater containing multiple surfactants simultaneously.

[0036] According to some embodiments of the present invention, the contaminants include at least one of the following: cathodic hexadecyltrimethylammonium bromide (CTAB), anion-specific sodium dodecyl sulfate (SDS), amphoteric 3-(N,N-dimethyldodecylammonium)propane sulfonate (3-DAPS), and 1,4-dioxane. The present invention is particularly applicable to quaternary ammonium compounds (QACs) and other highly surface-active systems, avoiding foam formation, contaminant stripping, and sludge loss through bubble-free oxygen supply.

[0037] During the continuous oxygen supply process of the oxygen-permeable membrane, oxygen in the air forms a local high oxygen flux region through the membrane interface, and promotes the generation of reactive oxygen species (ROS), including ·OH and ·O2. - H2O2 and1 O2, etc. ROS and the hyperoxia interface jointly promote the initial oxidative activation of pollutants, including long-chain alkyl oxidation, CH bond activation, aromatic ring hydroxylation, ether bond cleavage, and dechlorination of chlorinated organic compounds. Subsequently, intermediate products undergo further mineralization and degradation within the biofilm, achieving deep removal of pollutants.

[0038] According to some embodiments of the present invention, the concentration of pollutants in the wastewater to be treated is 0.5-700 mg / L. The present invention can still operate stably without foaming in the treatment of wastewater containing high concentrations of surfactants.

[0039] According to another aspect of the invention, the invention also proposes the application of the above-described system or method in the degradation of organic matter.

[0040] According to some embodiments of the present invention, the organic material is a foaming organic material.

[0041] According to some embodiments of the present invention, the organic compound is a surfactant.

[0042] Compared with the prior art, the solution of the present invention has the following beneficial effects: 1. High oxygen utilization efficiency and low energy consumption. Because oxygen diffuses directly into the biofilm interface through the membrane, the problem of exhaust gas escape in traditional aeration is avoided, the oxygen utilization rate is significantly improved, and aeration energy consumption can be reduced by 30-70%.

[0043] 2. High safety and low cost. Using air instead of pure oxygen as the oxygen source eliminates the safety risks during the storage and use of pure oxygen from the source, while significantly reducing the cost of gas source procurement and maintenance.

[0044] 3. High oxygen transfer efficiency and stable processing performance. By intermittently opening the valve to discharge the inert gas accumulated in the membrane cavity, the oxygen partial pressure in the membrane cavity is effectively restored, ensuring continuous and efficient oxygen transfer.

[0045] 4. Enhanced initial oxidation of recalcitrant pollutants. By stabilizing the oxygen gradient and ROS generation at the membrane interface, the oxidation activation efficiency of monooxygenase-driven pollutants can be significantly improved, enhancing the degradation capacity of pollutants such as QACs and 1,4-dioxane.

[0046] 5. Prevent foam and pollutant stripping. The system adopts a foam-free oxygen supply method, fundamentally eliminating the foam problem in the surfactant system and reducing the risk of VOCs air stripping.

[0047] 6. High system operational stability. Oxygen-permeable membrane oxygen supply can maintain a stable local DO environment, reducing DO fluctuations and sludge loss problems caused by traditional aeration.

[0048] 7. Applicable to low-carbon wastewater treatment systems. Precise oxygen supply can reduce over-aeration, improve electron utilization efficiency, and provide a new pathway for low-carbon wastewater treatment and synergistic control of new pollutants.

[0049] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0050] Figure 1 The figure shows the parameter test results before and after the treatment of SDS-containing wastewater under different operating conditions using a high-efficiency oxygen supply and pollutant synergistic enhanced degradation system based on oxygen-permeable biological dual-membrane technology according to a specific embodiment of the present invention.

[0051] Figure 2 This is a schematic diagram of the structure of the oxygen-permeable biological double membrane reactor in an embodiment of the present invention.

[0052] Figure 3 This describes the changes in oxygen flux, CTAB concentration, and COD concentration during the operation of the membrane bioreactor under different exhaust cycles (15 s / 60 min, 15 s / 15 min, 15 s / 6 min, and 15 s / 3 min) in Example 4 of this invention. Detailed Implementation

[0053] The following will clearly and completely describe the concept and technical effects of the present invention in conjunction with embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention. Unless otherwise specified, the experimental methods used in the embodiments are conventional methods; the materials and reagents used, unless otherwise specified, are commercially available. Unless otherwise specified, the same parameter value is the same in all embodiments. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0054] In the description of this invention, references to terms such as "some embodiments" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0055] Specifically, a highly efficient oxygen supply and pollutant synergistic enhancement method based on oxygen-permeable biological dual-membrane technology includes the following steps: After constructing the hollow fiber membrane reactor to build an efficient oxygen supply and pollutant synergistic degradation system, activated sludge was inoculated and a culture medium containing 1 mM surfactant (SDS) was pumped in. The oxygen pressure was set at 2.5 psig, the HRT at 12 hours, and the circulation flow rate at 150 mL / min. The system was run continuously for 20-30 days until a stable functional biofilm (with a relative abundance of Pseudomonas spp. >40%) was formed on the membrane surface.

[0056] After successful biofilm cultivation, the culture medium was drained, and wastewater containing SDS (concentration of 1mM-4mM, pH=7.0±0.2) was pumped in via a circulation pump. The oxygen pressure was set to 2.5 psig, the heating time (HRT) to 12 hours, the circulation flow rate to 150 mL / min, and the intermittent venting frequency to vent every 3 minutes for 15 seconds. After 24 hours of reaction, the treated effluent was discharged. The influent and effluent parameters were tested under different operating conditions (SDS influent concentration of 1mM (Stage I), 2mM (Stage II), and 4mM (Stage III)). The results are as follows: Figure 1 As shown. Figure 1 The upper middle section shows the pH values ​​of the influent and effluent; the lower section shows the SDS and COD concentrations. "+" represents the influent pH, and "×" represents the effluent pH. Solid dots indicate the influent SDS concentration, and hollow dots indicate the effluent SDS concentration. Colored areas represent COD concentrations; orange represents the influent, and blue represents the effluent. Under the above conditions, the SDS removal rate can reach over 97% under different operating conditions.

[0057] Example 1

[0058] This example provides a highly efficient oxygen supply and pollutant synergistic enhancement degradation system based on oxygen-permeable biofilm technology, including an oxygen-permeable biofilm reactor, such as... Figure 2As shown, the reactor consists of a main body, an oxygen-permeable biofilm module, a circulation system, a gas control system, and an influent / effluent system. The oxygen-permeable biofilm module is installed inside the main body of the reactor. The gas control system includes an air inlet pipe, an intermittent exhaust valve, and an exhaust pipe. One end of the oxygen-permeable biofilm module is connected to the air inlet pipe, and the other end is connected to the exhaust pipe. The air inlet pipe is used to transport air, and the intermittent exhaust valve is installed at the end furthest from the air inlet pipe and is used to control the exhaust from the exhaust pipe. The influent / effluent system includes an influent system and an effluent system, both of which are connected to the main body of the reactor. The circulation system is connected to the influent / effluent system. The oxygen-permeable biofilm module consists of a hollow fiber membrane and a biofilm attached to the surface of the hollow fiber membrane. The hollow fiber membrane used in this embodiment (Model MHF 200 TL, purchased from Mitsubishi Rayon Co., Ltd.) is a three-layer composite hollow fiber membrane composed of high-density polyethylene (HDPE) and thermoplastic polyurethane (TPU). It consists of several hollow fiber membrane filaments, with the proximal end of the filament connected to the air inlet pipe and the distal end connected to the air outlet pipe. An intermittent exhaust valve is installed at the distal end of the filament.

[0059] The method for efficient oxygen supply and synergistic enhanced degradation of pollutants using the above system comprises the following steps: After constructing the oxygen-permeable biological double-membrane reactor, activated sludge was inoculated onto the surface of the hollow fiber membrane, and a culture medium containing surfactant was pumped in (culture medium composition: the initial concentration of surfactant SDS was set to 1 mM (288 mg / L), (in addition to surfactant, it also contained K2HPO4 0.72 g / L, KH2PO4 0.28 g / L, MgSO4 0.25 g / L, KCl 0.25 g / L, FeSO4 0.002 g / L, 150 mg / L NH4Cl and trace elements (ZnSO4·7H2O 0.10 mg / L, MnCl2·4H2O 0.030 mg / L, H3BO3 0.30 mg / L, CoCl2·6H2O 0.20 mg / L, CuCl2·2H2O 0.010 mg / L, NiCl2·6H2O 0.010 mg / L, Na2MoO4·2H2O)). An inorganic salt culture medium consisting of 0.030 mg / L Na₂SeO₃ and 0.030 mg / L Na₂SeO₃ was prepared, and the pH of the medium was adjusted to approximately 7.0 (6.8 to 7.5 is acceptable) using 8 mM phosphate buffer. Activated sludge was sampled from the aerobic tank section of a municipal wastewater treatment plant. After sampling, the sludge-water mixture was subjected to static sedimentation. The supernatant was discarded, and the concentrated sludge was retained. 30 ml of the concentrated sludge was inoculated per 100 ml reactor volume. The gas supply pressure was set at 2.5 psig, the HRT at 12 hours, and the circulation flow rate at 150 mL / min. The system was run continuously for 30 days. Excess sludge was discharged through continuous flow until a stable functional biofilm formed on the membrane surface.

[0060] After the biofilm was successfully cultured, the culture medium was discharged, and the wastewater to be treated (wastewater containing SDS (290 mg / L, pH=7.0±0.2)) was pumped in through a circulation pump. The oxygen pressure was set to 2.5 psig, the HRT to 12 hours, the circulation flow rate to 150 mL / min, and the intermittent exhaust frequency to exhaust for 15 seconds every 3 minutes. After 24 hours of reaction, the treated effluent was discharged.

[0061] Example 2

[0062] This example provides a highly efficient oxygen supply and pollutant synergistic enhanced degradation system and method based on oxygen-permeable biofilm technology. The difference between this system and Example 1 is that the SDS concentration in the culture medium during biofilm cultivation is 560 mg / L, and the SDS concentration in the wastewater to be treated is also 560 mg / L.

[0063] Example 3

[0064] This example provides a highly efficient oxygen supply and pollutant synergistic enhanced degradation system and method based on oxygen-permeable biofilm technology. The difference between this system and Example 1 is that the concentration of SDS in the culture medium during biofilm cultivation is 1150 mg / L, and the concentration of SDS in the wastewater to be treated is also 1150 mg / L.

[0065] The main parameters, biofilm composition, and influent and effluent SDS measurement results are summarized in Table 1 below.

[0066] Table 1

[0067] As can be seen from the table above, the solution of the present invention can efficiently achieve pollutant degradation.

[0068] In a specific embodiment of this invention, the concentration of sodium dodecyl sulfate (SDS) was determined using high-performance liquid chromatography (HPLC) equipped with an evaporative light scattering detector (ELSD). Chromatographic conditions: Acclaim Surfactant Plus column (3 μm, 3 × 150 mm), mobile phase: acetonitrile:0.1 M ammonium acetate buffer (pH 5) = 70:30 (v / v), flow rate: 1.0 mL / min, detection wavelength: 225 nm, column temperature: 30 °C, injection volume: 20 μL. The sample was filtered through a 0.22 μm filter before injection. The detection limit of this method was 6 mg / L SDS.

[0069] Example 4

[0070] This example provides a highly efficient oxygen supply and pollutant synergistic enhancement system and method based on oxygen-permeable biofilm technology. The difference between this system and Example 1 is that SDS is replaced with an equal concentration of CTAB (1 mM). The degradation effect was tested at different switching frequencies of the intermittent exhaust valve, and the test results are as follows: Figure 3 As shown in the figure, the changes in oxygen flux, CTAB concentration, and COD concentration during the operation of the membrane bioreactor are illustrated under different exhaust cycles (15 s / 60 min, 15 s / 15 min, 15 s / 6 min, and 15 s / 3 min). Figure 3 A shows the oxygen flux at different operating stages. As the aeration frequency increases (i.e., the aeration interval shortens), the oxygen flux gradually increases, from approximately 19 g / m³. 2 ·d increased to approximately 28.5 g / m 2 The oxygen flux was highest under the condition of 15 s / 3 min. Figure 3B represents the changes in CTAB (hexadecyltrimethylammonium bromide) concentration in the influent and effluent. Throughout the operation, the influent CTAB concentration remained relatively stable between 0.8 and 1.1 mM, while the effluent CTAB concentration was consistently much lower than that of the influent, maintaining a range of 0-0.2 mM for most periods, and approaching zero, especially at higher aeration frequencies (15 s / 3 min). This indicates that the system has a high CTAB removal efficiency. Figure 3 C illustrates the changes in COD concentrations in the influent and effluent. The influent COD remained relatively stable (approximately 800-950 mg / L), while the effluent COD remained between 200-400 mg / L. With increasing aeration frequency, the effluent COD generally decreased, stabilizing at approximately 250-300 mg / L during the 15 s / 3 min stage. This indicates that a higher oxygen supply level is beneficial for organic matter removal and improves the system's COD removal efficiency. Overall, increasing the aeration frequency increases the membrane oxygen flux and promotes the removal of CTAB and COD, thus improving reactor performance. The optimal effect was observed at a switching frequency of 15 s / 3 min.

[0071] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A highly efficient oxygen supply and pollutant synergistic enhanced degradation system based on oxygen-permeable biological dual-membrane technology, characterized in that: The system includes an oxygen-permeable biological dual-membrane reactor, which includes a reactor body, an oxygen-permeable biological dual-membrane module, a circulation system, a gas control system, and an inlet and outlet water system, wherein the oxygen-permeable biological dual-membrane module is installed inside the reactor body; The gas control system includes an air intake pipe, an intermittent exhaust valve, and an exhaust pipe. One end of the oxygen-permeable bio-dual membrane module is connected to the air intake pipe, and the other end is connected to the exhaust pipe. The air intake pipe is used to transport air, and the intermittent exhaust valve is installed at the end away from the air intake pipe and is used to control the exhaust of the oxygen-permeable bio-dual membrane module. The circulation system is connected to the inlet and outlet water system, which includes an inlet water system and an outlet water system, and the inlet water system and the outlet water system are respectively connected to the reactor body.

2. The high-efficiency oxygen supply and pollutant synergistic degradation system based on oxygen-permeable biological dual-membrane technology according to claim 1, characterized in that: The oxygen-permeable bio-dual membrane assembly includes a hollow fiber membrane, one end of which is connected to an air inlet pipe and the other end of which is connected to an air outlet pipe. The intermittent exhaust valve is installed at the other end of the hollow fiber membrane.

3. A method for achieving efficient oxygen supply and synergistic enhanced degradation of pollutants using the system as described in claim 1 or 2, characterized in that: Includes the following steps: Wastewater containing pollutants is introduced into the chamber of the oxygen-permeable biological double membrane module, and air is introduced into the chamber of the module. The intermittent exhaust valve is periodically opened to release air intermittently.

4. The method for achieving efficient oxygen supply and synergistic enhanced degradation of pollutants according to claim 3, characterized in that: The exhaust frequency is 15 seconds every 2 to 60 minutes.

5. The method for achieving efficient oxygen supply and synergistic enhanced degradation of pollutants according to claim 3, characterized in that: The degradation process includes at least one of the following process parameters: 1) gas supply pressure: 3-15 psig; 2) hydraulic residence time: 2-24 h; 3) dissolved oxygen: 0.1-2 mg / L; 4) circulation flow rate: 50-300 mL / min.

6. The method for achieving efficient oxygen supply and synergistic enhanced degradation of pollutants according to claim 3, characterized in that: The method further includes inoculating sludge or functional microbial communities to form a biofilm on the surface of the oxygen-permeable biological double membrane component. The biofilm formation process conditions include: 1) the gas supply pressure is controlled at 1~30 psig; 2) the circulation flow rate is controlled at 20~500 mL / min; 3) the temperature is controlled at 10~40℃.

7. The method for achieving efficient oxygen supply and synergistic enhanced degradation of pollutants according to claim 3, characterized in that: The contaminants include at least one of cationic surfactants, anionic surfactants, amphoteric surfactants, or nonionic surfactants.

8. The application of the system according to claim 1 or 2 or the method according to any one of claims 3 to 7 in the degradation of organic matter.

9. The application according to claim 8, characterized in that: The organic matter in question is a foaming organic matter.

10. The application according to claim 8, characterized in that: The organic compound is a surfactant.

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