Mixed gas hollow fiber gas-permeable membrane biological membrane system for industrial waste gas, wastewater and carbon pollution cooperative treatment and treatment method

Abstract

The invention discloses a mixed gas hollow fiber gas-permeable membrane biological membrane system for industrial waste gas, wastewater and carbon pollution cooperative treatment and a treatment method, and relates to industrial waste gas resourceful treatment, wastewater denitrification nitrogen removal and polyhydroxyalkanoate synthesis. The invention relates to a mixed gas hollow fiber gas-permeable membrane biological membrane system for industrial waste gas, wastewater and carbon pollution cooperative treatment. The mixed gas hollow fiber gas-permeable membrane biological membrane system comprises a reactor, a biological membrane system, a water inlet and outlet circulation system, a multi-source industrial mixed gas integrated supply system and a control system, according to the mixed gas hollow fiber gas-permeable membrane biological membrane system for industrial waste gas, waste water and carbon pollution cooperative treatment and the treatment method, efficient treatment of industrial waste gas and waste water is achieved, and meanwhile resource recycling of polyhydroxyalkanoate is achieved. And by designing a multi-source industrial mixed gas integrated supply system, an intelligent control system and a large-scale reactor structure, the problems of poor gas source adaptability, low treatment efficiency, unstable operation and the like in the prior art are solved.

Description

Technical Field

[0001] The invention relates to a biofilm system and a treatment method for industrial waste gas and wastewater treatment. Background Art

[0002] The current industrial system generates large quantities of byproduct gases rich in hydrogen (H2) and carbon dioxide (CO2) during production processes, encompassing core sectors such as coking, ammonia synthesis, biomass gasification, and coal chemical industry. Data shows that the global steel and coking industries emit over 200 billion cubic meters of coke oven gas annually, of which hydrogen accounts for 55%-60%, and the hydrogen content of ammonia synthesis purge gas reaches 50%-70%. These gas resources have long been disposed of through combustion or inefficient recovery, resulting in the dual pressures of hydrogen waste and carbon emissions. At the same time, modern wastewater treatment technologies face bottlenecks such as high carbon source dependence, high operating costs, and low product added value. For example, the denitrification-coupled polyhydroxyalkanoate (PHA) synthesis technology disclosed in patent CN118270916A can achieve synergistic pollutant removal and biomanufacturing, but it still requires the use of NaHCO3 to supplement the dissolved inorganic carbon source, and suffers from pH imbalance and uneven carbon source distribution, hindering its large-scale application.

[0003] In this context, the innovative gas supply model of the hydrogen-based mixed gas permeable membrane bioreactor (H2 / CO2-MBfR) provides a breakthrough in solving the above problems. The hydrogen-based mixed gas permeable membrane bioreactor transmits H2 and CO2 mixed gases simultaneously through the hollow fiber membrane, causing the dissolved CO2 to react with water to produce HCO3 - , not only replaces the addition of exogenous NaHCO3, but also releases H + It can also neutralize the OH produced during denitrification. - , maintaining a stable pH in the reaction system. However, large-scale adoption of this technology urgently requires addressing the core obstacle of high gas supply costs. Using industrial byproduct gas as a source of multi-source industrial mixed gas could significantly reduce the combined costs of wastewater treatment and PHA synthesis, while creating cross-industry circular economy value.

[0004] Taking the coking industry as an example, about 200 m3 of coke oven gas can be recovered after being purified by pressure swing adsorption per ton. 3 If hydrogen is introduced into an MBfR system along with the 2%-5% CO2 it contains, a single unit treating 1,000 tons of wastewater can significantly save on carbon source costs. In the ammonia synthesis sector, CO2 in off-gas can be directly converted into dissolved inorganic carbon required by microorganisms. This gas recovery allows ammonia companies to save millions of yuan annually on reagents and reduce CO2 emissions. Even more promising is biomass gasification syngas, whose natural ratio of H2 (15%-20%) to CO2 (10%-15%) closely matches MBfR requirements and significantly outperforms systems with a single hydrogen source.

[0005] The ability to manipulate the composition of industrial syngas further expands the technology's adaptability. Adjusting the ratios of different gas components in coal-to-chemical syngas through the water-gas shift reaction not only stabilizes the pH of the MBfR system but also potentially increases the proportions of different monomers in PHA materials, enhancing their mechanical properties. Coupling CO2 purification from biogas with green electricity-generated hydrogen production can achieve high-carbon emission reductions, fostering a multi-dimensional synergy between energy, water, and carbon.

[0006] However, the practical application of industrial gas sources still needs to overcome three major technical barriers: first, impurities such as H2S in coke oven gas and CO in synthesis gas may inhibit microbial activity; second, fluctuations in the mixed gas ratio under dynamic conditions affect system stability. Summary of the Invention

[0007] The hollow fiber biofilm system and treatment method for the mixed gas treatment of industrial waste gas, wastewater, and carbon pollution proposed in this paper achieve the coordinated treatment of carbon pollution in industrial waste gas and wastewater, while also enabling the efficient synthesis of polyhydroxyalkanoates (PHAs). By designing a multi-source integrated industrial mixed gas supply system, an intelligent control system, and a large-scale reactor structure, this system overcomes existing issues such as poor gas source compatibility, low treatment efficiency, and unstable operation.

[0008] The mixed gas hollow fiber breathable membrane biofilm system for the coordinated treatment of industrial waste gas, wastewater and carbon pollution of the present invention comprises a reactor (1), a biofilm system, an inlet and outlet water circulation system, a multi-source industrial mixed gas integrated supply system (21) and a control system;

[0009] The biofilm system includes a membrane assembly (5) and an air washing pipeline (20);

[0010] The inlet and outlet water circulation system comprises an inlet peristaltic pump (6) and a circulation peristaltic pump (7); the outlet of the inlet peristaltic pump (6) is connected to a water inlet (4) provided at a lower portion of one side of the reactor (1); the inlet of the circulation peristaltic pump (7) is connected to a circulation water outlet (9) provided at a lower portion of one side of the reactor (1), and the outlet of the circulation peristaltic pump (7) is connected to a circulation water inlet (11) provided at an upper portion of one side of the reactor (1);

[0011] The multi-source industrial mixed gas integrated supply system (21) includes a hydrogen generator (13), a carbon dioxide gas cylinder (15), a first gas concentration sensor (19), a carbon monoxide gas cylinder (22), a methane gas cylinder (23), a multi-source industrial mixed gas cylinder (24), a second gas concentration sensor (25), a gas mass flow meter (26), a secondary mixed pressurized gas cylinder (27), a check valve (28) and a pressurizing pump (29); the hydrogen generator (13), the carbon dioxide gas cylinder (15), the carbon monoxide gas cylinder (22), the methane gas cylinder (23), the multi-source industrial mixed gas cylinder (24), the second gas concentration sensor (25), the gas mass flow meter (26), the secondary mixed pressurized gas cylinder (27), the check valve (28) and the pressurizing pump (29); The gas outlets of the carbon gas cylinder (22), the methane gas cylinder (23) and the multi-source industrial mixed gas cylinder (24) are respectively connected to the gas inlet of the check valve (28), the gas outlet of the check valve (28) is connected to the gas inlet of the pressure pump (29), the gas outlet of the pressure pump (29) is connected to the gas inlet of the secondary mixed pressurized gas cylinder (27), and the gas outlet of the secondary mixed pressurized gas cylinder (27) is respectively connected to the top gas inlet (2) and the bottom gas inlet (3) of the membrane assembly (5); an electronic device is provided on the secondary mixed pressurized gas cylinder (27). A pressure gauge; a mass flow controller (8) is provided on the connecting pipeline between the hydrogen generator (13) and the check valve (28); an electronic pressure reducing valve (14) and a mass flow controller (8) are provided on the connecting pipeline between the carbon dioxide cylinder (15) and the check valve (28), the connecting pipeline between the carbon monoxide cylinder (22) and the check valve (28), and the connecting pipeline between the methane cylinder (23) and the check valve (28), respectively. The mass flow controller (8) is provided on the connecting pipeline between the electronic pressure reducing valve (14). ) on the outlet side; two electronic pressure reducing valves (14), a gas mass flow meter (26) and a second gas concentration sensor (25) are sequentially provided on the connecting pipeline between the multi-source industrial mixed gas cylinder (24) and the check valve (28); the second gas concentration sensor (25) is provided on the inlet side of the check valve (28), the gas mass flow meter (26) is provided on the inlet side of the second gas concentration sensor (25), and the first gas concentration sensor (19) is provided on the outlet side of the secondary mixed pressurized gas cylinder (27);

[0012] The control system comprises an analog / digital converter (12), a PLC controller (17), a heating rod (18), a pressure difference sensor (30), a dissolved oxygen sensor (31) and a pH / temperature sensor (32); the heating rod (18) is arranged in the middle section of the reactor (1); the pressure difference sensor (30) is arranged on the surface of the hollow fiber membrane bundle of the membrane assembly (5); and the dissolved oxygen sensor (31) and the pH / temperature sensor (32) are arranged at the overflow weir at the top of the reactor (1).

[0013] The method for co-treating industrial waste gas, waste water and carbon pollution by using a mixed gas hollow fiber breathable membrane biofilm system for co-treating industrial waste gas, waste water and carbon pollution is carried out in the following steps:

[0014] 1. Start-up of the inlet and outlet water circulation system:

[0015] The water inlet peristaltic pump (6) is turned on to pump the sewage into the reactor (1). The water inlet peristaltic pump (6) is controlled by the PLC controller (17) to maintain the hydraulic retention time in the reactor (1) at 4-24 hours. The sewage enters the reactor (1) and is in full contact with the biofilm, thereby achieving denitrification of the sewage. The effluent of the reactor (1) is discharged from the overflow weir. At the same time, a portion of the sewage in the reactor is circulated from the circulating water outlet (9) to the circulating water inlet (11) through the circulating peristaltic pump (7), so that the sewage is mixed and fully contacts the biofilm. At the same time, a portion of the biofilm that falls off to the bottom sludge hopper under the action of hydraulic shear is reattached to the surface of the membrane assembly (5) along with the circulating sewage to maintain a high active biological content.

[0016] 2. The multi-source industrial mixed gas integrated supply system is put into operation:

[0017] The multi-source industrial mixed gas in the multi-source industrial mixed gas cylinder (24) is decompressed twice in stages to 0.2-0.5 MPa through two electronic pressure reducing valves (14), and then enters the second gas concentration sensor (25) to detect the ratio of each component gas in the multi-source industrial mixed gas cylinder (24). After the gas mass flow meter (26) reaches the target flow rate by adjusting the electronic pressure reducing valve (14) at the gas outlet end of the multi-source industrial mixed gas cylinder (24), the original phase gas in the multi-source industrial mixed gas cylinder (24) is sent to the secondary mixed pressurized gas cylinder (27); the hydrogen generator (13), the carbon dioxide cylinder (15), the carbon monoxide cylinder (22), and the methane cylinder (23) respectively provide hydrogen, carbon dioxide, carbon monoxide and methane as raw gas The PLC controller (17) uses the raw gas to adjust the proportion of the original phase gas entering the secondary mixed pressurized gas cylinder (27) according to the result displayed by the second gas concentration sensor (25), and the flow rates of hydrogen, carbon dioxide, carbon monoxide and methane are adjusted by the gas mass flow controller (8). At the same time, the PLC controller (17) performs a secondary verification ratio on the outlet gas of the secondary mixed pressurized gas cylinder (27) according to the first gas concentration sensor (19). If the partial pressure ratio of the outlet hydrogen and carbon monoxide of the secondary mixed pressurized gas cylinder (27) deviates from the set value, the PLC controller (17) controls the multiple gas mass flow controllers (8) to adjust the raw gas to ensure that the proportion of each component of the mixed gas entering the membrane module (5) remains stable.

[0018] The pressure of the mixed gas in the secondary mixed pressurized gas cylinder (27) is controlled to be 1.5-5 MPa, and the partial pressure ratio of hydrogen to carbon compound in the mixed gas in the secondary mixed pressurized gas cylinder (27) is maintained at (5-9):1; according to the optimal flux requirement of the membrane assembly (5), the pressure of the mixed gas output from the secondary mixed pressurized gas cylinder (27) is adjusted to 5-20 psig through the electronic pressure reducing valve (14) at the gas outlet end of the secondary mixed pressurized gas cylinder (27) and then fed into the membrane assembly (5); the optimal flux of the membrane assembly (5) is 15-30 mL / min;

[0019] 3. Operation of the reactor:

[0020] (1) Reactor (1) startup phase:

[0021] While the mixed gas in the secondary mixed pressurized gas cylinder (27) is passed into the membrane assembly (5), hydrogen autotrophic denitrification sludge is inoculated in the reactor, and the sludge inoculation amount is 8-10 g / L. The membrane assembly (5) is subjected to biofilm formation for 10-20 days, during which the influent nitrate load is 2-5 gN / d. After the biofilm formation is completed, the influent nitrate load is increased to 10-15 gN / d, and the reactor (1) enters the steady-state operation stage. The nitrate concentration of the effluent of the reactor (1) is less than 5 mgN / L.

[0022] (II) Reactor (1) Steady-state operation stage:

[0023] ①, pH adjustment: control the pH of the sewage inside the reactor (1) to 6.0-8.0;

[0024] ② Temperature control: The temperature in the reactor (1) is controlled at 15-25°C by controlling the heating rod (18) through the PLC controller (17);

[0025] ③. Inlet and outlet water circulation: The PLC controller (17) controls the circulating peristaltic pump (7) so that the sewage circulation time in the reactor (1) reaches one cycle of 1-2 hours;

[0026] ④. Gas supply pressure regulation: When the biofilm thickness increases and the membrane flux of the membrane assembly (5) decreases by more than 15%, the gas supply pressure of the electronic pressure reducing valve (14) at the outlet of the secondary mixed pressurized gas cylinder (27) is increased through the PLC controller (17). When the membrane flux of the membrane assembly (5) recovers to 15-30 mL / min, the pressure is stabilized;

[0027] ⑤. Membrane pollution control: When the dissolved oxygen concentration in the sewage monitored by the dissolved oxygen sensor (31) exceeds 1.2 mg / L, the membrane flux change rate is calculated. When the membrane flux change rate reaches or is less than -3 mL / min 2When the membrane is cleaned, compressed nitrogen is injected into the membrane assembly (5) through the air washing pipeline (20) for pulse cleaning to remove the surface biofilm of the membrane assembly (5) until the dissolved oxygen concentration in the sewage does not exceed 1.2 mg / L; if the membrane flux change rate further decreases, 5 g / m 3 Denitrifying bacteria enhance biofilm degradation;

[0028] ⑥. Biofilm collection: When the biofilm accumulation on the membrane assembly (5) exceeds ≥2 mm, the biofilm is collected. Compressed nitrogen is injected into the membrane assembly (5) through the air washing pipeline (20) to form a 0.5-1.5N / m 2 The hydraulic shear force is used to peel off the aged biofilm on the surface while retaining the active biofilm on the bottom. The peeled biofilm is collected in the mud hopper (10). The biofilm sediment in the mud hopper (10) is rich in PHA.

[0029] ⑦. PHA purification.

[0030] The beneficial effects of the present invention are:

[0031] 1. The present invention uses a gas concentration sensor to detect multi-source mixed gas components such as H2, CO2, CO, CH4, etc. in real time, and combines it with raw gas pure H2, CO2, etc. to make supplementary adjustments to ensure that the mixed gas ratio accurately matches the reaction requirements, and the H2 / CO2 ratio reaches the optimal ratio, thereby realizing dynamic adaptation of each component.

[0032] 2. This invention utilizes secondary mixing and pressurization technology to homogenize and pressurize the blended gas, addressing the uneven composition of industrial waste gas (e.g., coke oven gas contains 55%-60% H2 but low CO2), and controlling the partial pressure fluctuation of the mixed gas to within ±3%. Furthermore, the remaining waste gases in the industrial waste gas, such as H2S and CO, can also be utilized as electron donors by autotrophic organisms.

[0033] 3. The present invention is flexibly compatible with a variety of gas sources and is suitable for industrial gas production such as synthesis gas (H2 / CO), coke oven gas (H2 / CH4), and biomass gas (H2 / CO2 / CH4). The ratio is dynamically adjusted through the PLC controller to reduce the cost of carbon sources.

[0034] 4. This system leverages a multi-parameter feedback-dynamic decision-making-execution linkage mechanism built on a PLC, achieving millisecond-level precision control of environmental parameters and gas supply. By real-time monitoring of pH, temperature, DO, and biofilm thickness, the automatic control module dynamically adjusts gas flux and pulse cleaning intensity. This minimizes fluctuations in operating parameters, reduces failure rates, and extends maintenance cycles, significantly improving the reliability of continuous industrial operation.

[0035] 5. The device of the present invention is equipped with a biofilm system, an inlet and outlet water circulation system, a multi-source industrial mixed gas integrated supply system and an automatic control system on the reactor body, which improves the operational stability. The control system adjusts the multi-channel gas flow, mixed gas pressure and flux, pH, temperature, dissolved oxygen and other operating conditions, thereby improving the waste gas and wastewater treatment efficiency and the production efficiency of polyhydroxyalkanoates. It is suitable for large-scale waste gas and sewage treatment and PHA synthesis, and has the advantages of stable operation, strong treatment capacity and easy maintenance.

[0036] 6. This invention utilizes industrial gas as an inorganic carbon source. By regulating the partial pressure ratio of hydrogen and one-carbon compounds in the feed and utilizing hollow fiber membrane modules as a carrier, it achieves synergistic improvements in nitrate removal and PHA accumulation. During stable operation, nearly all nitrate in the wastewater is converted, completely removing the nitrogen load from the wastewater while maintaining the system's efficient denitrification capacity. Simultaneously, the microbial community can complete high-level PHA synthesis within the same cycle, significantly increasing the content and purity of the biopolymer product. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a schematic structural diagram of the mixed gas hollow fiber breathable membrane biofilm system for the coordinated treatment of industrial waste gas, wastewater and carbon pollution in Example 1;

[0038] Figure 2 This is a schematic structural diagram of the multi-source industrial mixed gas integrated supply system (21) of Example 1;

[0039] Figure 3 Schematic diagram of the structure of the biofilm system in Example 1. DETAILED DESCRIPTION

[0040] The technical solution of the present invention is not limited to the specific implementation methods listed below, but also includes any reasonable combination of the specific implementation methods.

[0041] Specific embodiment 1: The mixed gas hollow fiber breathable membrane biofilm system for the coordinated treatment of industrial waste gas, wastewater and carbon pollution in this embodiment includes a reactor (1), a biofilm system, an inlet and outlet water circulation system, a multi-source industrial mixed gas integrated supply system (21) and a control system;

[0042] The biofilm system includes a membrane assembly (5) and an air washing pipeline (20);

[0043] The inlet and outlet water circulation system comprises an inlet peristaltic pump (6) and a circulation peristaltic pump (7); the outlet of the inlet peristaltic pump (6) is connected to a water inlet (4) provided at a lower portion of one side of the reactor (1); the inlet of the circulation peristaltic pump (7) is connected to a circulation water outlet (9) provided at a lower portion of one side of the reactor (1), and the outlet of the circulation peristaltic pump (7) is connected to a circulation water inlet (11) provided at an upper portion of one side of the reactor (1);

[0044] The multi-source industrial mixed gas integrated supply system (21) includes a hydrogen generator (13), a carbon dioxide gas cylinder (15), a first gas concentration sensor (19), a carbon monoxide gas cylinder (22), a methane gas cylinder (23), a multi-source industrial mixed gas cylinder (24), a second gas concentration sensor (25), a gas mass flow meter (26), a secondary mixed pressurized gas cylinder (27), a check valve (28) and a pressurizing pump (29); the hydrogen generator (13), the carbon dioxide gas cylinder (15), the carbon monoxide gas cylinder (22), the methane gas cylinder (23), the multi-source industrial mixed gas cylinder (24), the second gas concentration sensor (25), the gas mass flow meter (26), the secondary mixed pressurized gas cylinder (27), the check valve (28) and the pressurizing pump (29); The gas outlets of the carbon gas cylinder (22), the methane gas cylinder (23) and the multi-source industrial mixed gas cylinder (24) are respectively connected to the gas inlet of the check valve (28), the gas outlet of the check valve (28) is connected to the gas inlet of the pressure pump (29), the gas outlet of the pressure pump (29) is connected to the gas inlet of the secondary mixed pressurized gas cylinder (27), and the gas outlet of the secondary mixed pressurized gas cylinder (27) is respectively connected to the top gas inlet (2) and the bottom gas inlet (3) of the membrane assembly (5); an electronic device is provided on the secondary mixed pressurized gas cylinder (27). A pressure gauge; a mass flow controller (8) is provided on the connecting pipeline between the hydrogen generator (13) and the check valve (28); an electronic pressure reducing valve (14) and a mass flow controller (8) are provided on the connecting pipeline between the carbon dioxide cylinder (15) and the check valve (28), the connecting pipeline between the carbon monoxide cylinder (22) and the check valve (28), and the connecting pipeline between the methane cylinder (23) and the check valve (28), respectively. The mass flow controller (8) is provided on the connecting pipeline between the electronic pressure reducing valve (14). ) on the outlet side; two electronic pressure reducing valves (14), a gas mass flow meter (26) and a second gas concentration sensor (25) are sequentially provided on the connecting pipeline between the multi-source industrial mixed gas cylinder (24) and the check valve (28); the second gas concentration sensor (25) is provided on the inlet side of the check valve (28), the gas mass flow meter (26) is provided on the inlet side of the second gas concentration sensor (25), and the first gas concentration sensor (19) is provided on the outlet side of the secondary mixed pressurized gas cylinder (27);

[0045] The control system comprises an analog / digital converter (12), a PLC controller (17), a heating rod (18), a pressure difference sensor (30), a dissolved oxygen sensor (31) and a pH / temperature sensor (32); the heating rod (18) is arranged in the middle section of the reactor (1); the pressure difference sensor (30) is arranged on the surface of the hollow fiber membrane bundle of the membrane assembly (5); the dissolved oxygen sensor (31) and the pH / temperature sensor (32) are arranged at the overflow weir at the top of the reactor (1).

[0046] This embodiment has the following beneficial effects:

[0047] 1. This embodiment uses a gas concentration sensor to detect multi-source mixed gas components such as H2, CO2, CO, CH4, etc. in real time, combined with supplementary adjustments such as pure H2 and CO2 from raw gas, to ensure that the mixed gas ratio accurately matches the reaction requirements, and the partial pressure ratio of hydrogen to one carbon compound reaches the optimal ratio, thereby achieving dynamic adaptation of each component.

[0048] 2. This implementation utilizes secondary mixing and pressurization technology to homogenize and pressurize the blended gas, addressing the uneven composition of industrial waste gas (e.g., coke oven gas, which contains 55%-60% H2 but low levels of CO2). This allows the partial pressure ratio of the mixed gas to fluctuate within ±3%. Furthermore, the remaining waste gases in the industrial waste gas, such as H2S and CO, can also be utilized as electron donors by autotrophic organisms.

[0049] 3. This implementation method is flexibly compatible with a variety of gas sources and is suitable for industrial production gases such as synthesis gas (H2 / CO), coke oven gas (H2 / CH4), and biomass gas (H2 / CO2 / CH4). The ratio is dynamically adjusted by the PLC controller to reduce carbon source costs.

[0050] 4. This implementation utilizes a PLC-based multi-parameter feedback-dynamic decision-making-execution linkage mechanism, enabling millisecond-level precision control of environmental parameters and gas supply. By monitoring changes in pH, temperature, DO, and biofilm thickness in real time, the automatic control module dynamically adjusts gas flux and pulse cleaning intensity. This minimizes fluctuations in operating parameters, reduces failure rates, and extends maintenance cycles, significantly improving the reliability of continuous industrial operation.

[0051] 5. The device of this embodiment is equipped with a biofilm system, an inlet and outlet water circulation system, a multi-source industrial mixed gas integrated supply system and an automatic control system on the reactor body, which improves the operational stability. The control system adjusts the multi-channel gas flow, mixed gas pressure and flux, pH, temperature, dissolved oxygen and other operating conditions to improve the waste gas and wastewater treatment efficiency and the production efficiency of polyhydroxyalkanoates. It is suitable for large-scale waste gas and sewage treatment and PHA synthesis, and has the advantages of stable operation, strong treatment capacity and easy maintenance.

[0052] 6. This implementation utilizes industrial gas as an inorganic carbon source. By regulating the partial pressure ratio of hydrogen and one-carbon compounds in the feed and utilizing hollow fiber membrane modules as a carrier, it achieves synergistic improvements in nitrate removal and PHA accumulation. During stable operation, nearly all nitrate in the wastewater is converted, completely removing the nitrogen load from the wastewater while maintaining the system's efficient denitrification capacity. Simultaneously, the microbial community can achieve high levels of PHA synthesis within the same cycle, significantly increasing the content and purity of the biopolymer product.

[0053] Specific embodiment 2: This embodiment differs from specific embodiment 1 in that an overflow weir is provided at the top of the reactor (1), and a mud discharge hopper (10) is provided at the bottom of the reactor (1).

[0054] Specific embodiment three: This embodiment differs from specific embodiments one or two in that: the membrane assembly (5) is arranged in the middle section of the reactor (1), a hollow support shaft (33) is provided inside the membrane assembly (5), an air inlet and a plurality of air exhaust holes are provided on the support shaft, the air outlet end of the air washing pipeline (20) is connected to the air inlet of the support shaft, and the air inlet end of the air washing pipeline (20) is connected to an external nitrogen gas source.

[0055] Specific embodiment 4: This embodiment differs from any one of specific embodiments 1 to 3 in that the water inlet peristaltic pump (6) and the circulation peristaltic pump (7) are respectively connected to the PLC controller (17) via electrical signals.

[0056] Specific embodiment 5: This embodiment differs from any one of specific embodiments 1 to 4 in that: the second gas concentration sensor (25), the gas mass flow meter (26), the secondary mixed pressurized gas cylinder (27), the pressure pump (29), a plurality of mass flow controllers (8), a plurality of electronic pressure reducing valves (14), the first gas concentration sensor (19), and the pressure gauge provided on the secondary mixed pressurized gas cylinder (27) are respectively connected to the PLC controller (17) via electrical signals.

[0057] Specific embodiment six: This embodiment differs from any one of specific embodiments one to five in that: the differential pressure sensor (30), the dissolved oxygen sensor (31) and the pH / temperature sensor (32) are respectively connected to the analog / digital converter (12) via electrical signals; the analog / digital converter (12) is connected to the PLC controller (17) via electrical signals, and the heating rod (18) is connected to the PLC controller (17) via electrical signals.

[0058] Specific embodiment seven: This embodiment uses a mixed gas hollow fiber breathable membrane biofilm system for the coordinated treatment of industrial waste gas, wastewater and carbon pollution to treat sewage in accordance with the following steps:

[0059] 1. Start-up of the inlet and outlet water circulation system:

[0060] The water inlet peristaltic pump (6) is turned on to pump the sewage into the reactor (1). The water inlet peristaltic pump (6) is controlled by the PLC controller (17) to maintain the hydraulic retention time in the reactor (1) at 4-24 hours. The sewage enters the reactor (1) and is in full contact with the biofilm, thereby achieving denitrification of the sewage. The effluent of the reactor (1) is discharged from the overflow weir. At the same time, a portion of the sewage in the reactor is circulated from the circulating water outlet (9) to the circulating water inlet (11) through the circulating peristaltic pump (7), so that the sewage is mixed and fully contacts the biofilm. At the same time, a portion of the biofilm that falls off to the bottom sludge hopper under the action of hydraulic shear is reattached to the surface of the membrane assembly (5) along with the circulating sewage to maintain a high active biological content.

[0061] 2. The multi-source industrial mixed gas integrated supply system is put into operation:

[0062] The multi-source industrial mixed gas in the multi-source industrial mixed gas cylinder (24) is decompressed twice in stages to 0.2-0.5 MPa through two electronic pressure reducing valves (14), and then enters the second gas concentration sensor (25) to detect the ratio of each component gas in the multi-source industrial mixed gas cylinder (24). After the gas mass flow meter (26) reaches the target flow rate by adjusting the electronic pressure reducing valve (14) at the gas outlet end of the multi-source industrial mixed gas cylinder (24), the original phase gas in the multi-source industrial mixed gas cylinder (24) is sent to the secondary mixed pressurized gas cylinder (27); the hydrogen generator (13), the carbon dioxide cylinder (15), the carbon monoxide cylinder (22), and the methane cylinder (23) respectively provide hydrogen, carbon dioxide, carbon monoxide and methane as raw gas; PL The C controller (17) uses the raw gas to adjust the proportion of the original phase gas entering the secondary mixed pressurized gas cylinder (27) according to the result displayed by the second gas concentration sensor (25), and the flow rates of hydrogen, carbon dioxide, carbon monoxide and methane are adjusted by the gas mass flow controller (8). At the same time, the PLC controller (17) performs a secondary verification ratio on the outlet gas of the secondary mixed pressurized gas cylinder (27) according to the first gas concentration sensor (19). If the partial pressure ratio (H / C) of the hydrogen gas to the carbon monoxide compound of the outlet gas of the secondary mixed pressurized gas cylinder (27) deviates from the set value, the PLC controller (17) controls the multiple gas mass flow controllers (8) to adjust the raw gas to ensure that the proportion of each component of the mixed gas entering the membrane module (5) remains stable;

[0063] The pressure of the mixed gas in the secondary mixed pressurized gas cylinder (27) is controlled to be 1.5-2.2 MPa, and the partial pressure ratio (H / C) of the mixed gas in the secondary mixed pressurized gas cylinder (27) is maintained at (5-9):1; according to the optimal flux requirement of the membrane assembly (5), the pressure of the mixed gas output from the secondary mixed pressurized gas cylinder (27) is adjusted to 5-20 psig through the electronic pressure reducing valve (14) at the gas outlet end of the secondary mixed pressurized gas cylinder (27) and then fed into the membrane assembly (5); the optimal flux of the membrane assembly (5) is 15-30 mL / min;

[0064] 3. Operation of the reactor:

[0065] (1) Reactor (1) startup phase:

[0066] While the mixed gas in the secondary mixed pressurized gas cylinder (27) is passed into the membrane assembly (5), hydrogen autotrophic denitrification sludge is inoculated in the reactor, and the sludge inoculation amount is 8-10 g / L. The membrane assembly (5) is subjected to biofilm formation for 10-20 days, during which the influent nitrate load is 2-5 gN / d. After the biofilm formation is completed, the influent nitrate load is increased to 10-15 gN / d, and the reactor (1) enters the steady-state operation stage. The nitrate concentration of the effluent of the reactor (1) is less than 5 mgN / L.

[0067] (II) Reactor (1) Steady-state operation stage:

[0068] ①, pH adjustment: control the pH of the sewage inside the reactor (1) to 6.0-8.0;

[0069] ② Temperature control: The temperature in the reactor (1) is controlled at 15-25°C by controlling the heating rod (18) through the PLC controller (17);

[0070] ③. Inlet and outlet water circulation: The PLC controller (17) controls the circulating peristaltic pump (7) so that the sewage circulation time in the reactor (1) reaches one cycle of 1-2 hours;

[0071] ④. Gas supply pressure regulation: When the biofilm thickness increases and the membrane flux of the membrane assembly (5) decreases by more than 15%, the gas supply pressure of the electronic pressure reducing valve (14) at the outlet of the secondary mixed pressurized gas cylinder (27) is increased through the PLC controller (17). When the membrane flux of the membrane assembly (5) recovers to 15-30 mL / min, the pressure is stabilized;

[0072] ⑤. Membrane pollution control: When the dissolved oxygen concentration in the sewage monitored by the dissolved oxygen sensor (31) exceeds 1.2 mg / L, the membrane flux change rate is calculated. When the membrane flux change rate reaches or is less than -3 mL / min 2When the membrane is cleaned, compressed nitrogen is injected into the membrane assembly (5) through the air washing pipeline (20) for pulse cleaning to remove the surface biofilm of the membrane assembly (5) until the dissolved oxygen concentration in the sewage does not exceed 1.2 mg / L; if the membrane flux change rate further decreases, 5 g / m 3 Denitrifying bacteria enhance biofilm degradation;

[0073] ⑥. Biofilm collection: When the biofilm accumulation on the membrane assembly (5) exceeds ≥2 mm, the biofilm is collected. Compressed nitrogen is injected into the membrane assembly (5) through the air washing pipeline (20) to form a 0.8-1.2N / m 2 The hydraulic shear force is applied to peel off 65%-70% of the aged biofilm on the surface, while retaining the active biofilm of 0.5-0.8 mm on the bottom. The peeled biofilm is collected in the mud hopper (10). The biofilm sediment in the mud hopper (10) is rich in PHA.

[0074] ⑦. PHA purification.

[0075] 1. This embodiment uses a gas concentration sensor to detect multi-source mixed gas components such as H2, CO2, CO and CH4 in real time, and combines it with feed gas pure H2, CO2 and other supplementary adjustments to ensure that the mixed gas ratio accurately matches the reaction requirements, and the partial pressure ratio of hydrogen to carbon compounds (H / C) reaches the optimal ratio, achieving dynamic adaptation of each component.

[0076] 2. This implementation utilizes secondary mixing and pressurization technology to homogenize and pressurize the blended gas, addressing the uneven composition of industrial waste gas (e.g., coke oven gas, which contains 55%-60% H2 but low levels of CO2). This allows the partial pressure ratio of the mixed gas to fluctuate within ±3%. Furthermore, the remaining waste gases in the industrial waste gas, such as H2S and CO, can also be utilized as electron donors by autotrophic organisms.

[0077] 3. This implementation method is flexibly compatible with a variety of gas sources and is suitable for industrial production gases such as synthesis gas (H2 / CO), coke oven gas (H2 / CH4), and biomass gas (H2 / CO2 / CH4). The ratio is dynamically adjusted by the PLC controller to reduce carbon source costs.

[0078] 4. This implementation utilizes a PLC-based multi-parameter feedback-dynamic decision-making-execution linkage mechanism, enabling millisecond-level precision control of environmental parameters and gas supply. By monitoring changes in pH, temperature, DO, and biofilm thickness in real time, the automatic control module dynamically adjusts gas flux and pulse cleaning intensity. This minimizes fluctuations in operating parameters, reduces failure rates, and extends maintenance cycles, significantly improving the reliability of continuous industrial operation.

[0079] 5. The device of this embodiment is equipped with a biofilm system, an inlet and outlet water circulation system, a multi-source industrial mixed gas integrated supply system and an automatic control system on the reactor body, which improves the operational stability. The control system adjusts the multi-channel gas flow, mixed gas pressure and flux, pH, temperature, dissolved oxygen and other operating conditions to improve the waste gas and wastewater treatment efficiency and the production efficiency of polyhydroxyalkanoates. It is suitable for large-scale waste gas and sewage treatment and PHA synthesis, and has the advantages of stable operation, strong treatment capacity and easy maintenance.

[0080] 6. This implementation utilizes industrial gas as an inorganic carbon source. By regulating the partial pressure ratio of hydrogen and one-carbon compounds in the feed and utilizing hollow fiber membrane modules as a carrier, it achieves synergistic improvements in nitrate removal and PHA accumulation. During stable operation, nearly all nitrate in the wastewater is converted, completely removing the nitrogen load from the wastewater while maintaining the system's efficient denitrification capacity. Simultaneously, the microbial community can achieve high levels of PHA synthesis within the same cycle, significantly increasing the content and purity of the biopolymer product.

[0081] Specific embodiment eight: This embodiment differs from any one of specific embodiments one to seven in that the sources of the multi-source industrial mixed gas include fossil fuel gasification, blast furnace gas, converter gas and coke oven gas, etc., which are mixed gases produced by industrial production containing hydrogen and one carbon compound such as carbon monoxide, carbon dioxide, methane, etc.

[0082] Specific embodiment nine: This embodiment differs from any one of specific embodiments one to eight in that: in step (two) ①, when pH>8.0, the CO2 content in the mixed gas input from the secondary mixed pressurized gas cylinder (27) is increased to reduce the alkalinity of the solution; when pH<6.0, the CO2 flow rate in the mixed gas is reduced to prevent excessive acidification.

[0083] Specific embodiment ten: This embodiment differs from any one of specific embodiments one to nine in that the PHA purification process is as follows: first, the stripped biofilm is quickly frozen at -80°C, then placed in a freeze dryer and freeze-dried at -60°C for 24 hours to reduce the moisture content to below 5%; then, extraction is performed with a chloroform-ethanol mixed solvent at 50°C for 4 hours, and the extract is separated by centrifugation to obtain PHA particles with a purity of >98%.

[0084] Example 1

[0085] The mixed gas hollow fiber breathable membrane biofilm system for the coordinated treatment of industrial waste gas, wastewater and carbon pollution in this embodiment includes a reactor (1), a biofilm system, an inlet and outlet water circulation system, a multi-source industrial mixed gas integrated supply system (21) and a control system;

[0086] The top of the reactor (1) is provided with an overflow weir, and the bottom of the reactor (1) is provided with a mud hopper (10); the overflow weir allows the water flow to be discharged stably to the outside of the reactor (1), preventing microorganisms from flowing out directly from the outlet with the water flow, reducing the loss of microorganisms, and the overflow weir design ensures a constant liquid level; in this embodiment, the reactor (1) adopts an acrylic cylindrical structure with a diameter of 320 mm, a height of 1100 mm, and a total volume of 30 L; the membrane assembly (5) is a non-porous hollow fiber membrane assembly with a membrane area of ​​15 m 2 The surface is loaded with hydrogen autotrophic denitrifying biofilm, forming a gas-liquid-membrane three-phase contact interface.

[0087] The biofilm system includes a membrane assembly (5) and an air washing pipeline (20); the membrane assembly (5) is arranged in the middle section of the reactor (1); a hollow support shaft (33) is provided inside the membrane assembly (5); an air inlet and a plurality of air exhaust holes are provided on the support shaft; the air outlet end of the air washing pipeline (20) is connected to the air inlet of the support shaft; the air inlet end of the air washing pipeline (20) is connected to an external nitrogen gas source; the external nitrogen gas source regularly performs pulse aeration and flushing on the membrane assembly (5) through the air washing pipeline (20) to remove the decaying biofilm, maintain the proportion of active microorganisms on the membrane surface of the membrane assembly (5), and the biofilm has hydrogen autotrophic denitrifying bacteria as the dominant functional bacterial group, and simultaneously uses H2 as an electron donor and CO2 as an inorganic carbon source to achieve efficient nitrate reduction;

[0088] The inlet and outlet water circulation system comprises an inlet peristaltic pump (6) and a circulation peristaltic pump (7), wherein the outlet of the inlet peristaltic pump (6) is connected to the water inlet (4) provided at the lower part of one side of the reactor (1); the inlet of the circulation peristaltic pump (7) is connected to the circulation water outlet (9) provided at the lower part of one side of the reactor (1), and the outlet of the circulation peristaltic pump (7) is connected to the circulation water inlet (11) provided at the upper part of one side of the reactor (1); the inlet peristaltic pump (6) and the circulation peristaltic pump (7) are respectively connected to the PLC controller (17) for electrical signals; the inlet and outlet water circulation system realizes the transportation of wastewater into the reactor (1) and the uniform mixing inside the reactor (1) so as to fully contact the biofilm on the membrane surface; the wastewater to be treated is injected into the reactor (1) through the inlet peristaltic pump (6), and a closed loop of circulation flow is formed through the circulation peristaltic pump (7), and the treated water flows upward and is discharged from the water outlet through the overflow weir. By controlling the flow rate of the inlet peristaltic pump (7) to adjust the required optimal hydraulic retention time, efficient denitrification can meet the treatment effect while shortening the treatment time and improving the treatment efficiency. At the same time, by controlling the flow rate of the circulating peristaltic pump, while ensuring that the water flow is in full contact with the biofilm, it can avoid excessive shedding of the biofilm, maintain high biological activity, and improve mass transfer efficiency and treatment efficiency. At the same time, the biofilm that falls off under the action of hydraulic shear will also reattach to the surface of the membrane component through the circulation system to maintain a high active biological content.

[0089] The multi-source industrial mixed gas integrated supply system (21) includes a hydrogen generator (13), a carbon dioxide gas cylinder (15), a first gas concentration sensor (19), a carbon monoxide gas cylinder (22), a methane gas cylinder (23), a multi-source industrial mixed gas cylinder (24), a second gas concentration sensor (25), a gas mass flow meter (26), a secondary mixed pressurized gas cylinder (27), a check valve (28) and a pressurizing pump (29); the hydrogen generator (13), the carbon dioxide gas cylinder (15), the carbon monoxide gas cylinder (22), the methane gas cylinder (23) and the multi-source industrial mixed gas cylinder (24) The gas outlet ends are respectively connected to the gas inlet ends of the check valve (28), the gas outlet end of the check valve (28) is connected to the gas inlet end of the pressure pump (29), the gas outlet end of the pressure pump (29) is connected to the gas inlet end of the secondary mixed pressurized gas cylinder (27), and the gas outlet end of the secondary mixed pressurized gas cylinder (27) is respectively connected to the top gas inlet (2) and the bottom gas inlet (3) of the membrane assembly (5); an electronic pressure gauge is provided on the secondary mixed pressurized gas cylinder (27); a mass flow controller (8) is provided on the connecting pipeline between the hydrogen generator (13) and the check valve (28); a mass flow controller (8) is provided on the connecting pipeline between the carbon dioxide gas cylinder (15) and the check valve (28); The connecting pipelines between the multi-source industrial mixed gas cylinder (24) and the check valve (28), and the connecting pipelines between the carbon monoxide cylinder (22) and the check valve (28), and the connecting pipelines between the methane cylinder (23) and the check valve (28) are respectively provided with an electronic pressure reducing valve (14) and a mass flow controller (8), and the mass flow controller (8) is provided on the gas outlet side of the electronic pressure reducing valve (14); the connecting pipelines between the multi-source industrial mixed gas cylinder (24) and the check valve (28) are provided with two electronic pressure reducing valves (14), a gas mass flow meter (26) and a second gas concentration sensor (25) in sequence, and the second gas concentration sensor (25) is provided On the air inlet side of the check valve (28), a gas mass flow meter (26) is arranged on the air inlet side of the second gas concentration sensor (25), and the first gas concentration sensor (19) is arranged on the air outlet side of the secondary mixed pressurized gas cylinder (27); the second gas concentration sensor (25), the gas mass flow meter (26), the secondary mixed pressurized gas cylinder (27), the pressure pump (29), a plurality of mass flow controllers (8), a plurality of electronic pressure reducing valves (14), the first gas concentration sensor (19), and the pressure gauges arranged on the secondary mixed pressurized gas cylinder (27) are respectively connected to the PLC controller (17) for electrical signals;

[0090] The control system comprises an analog / digital converter (12), a PLC controller (17), a heating rod (18), a pressure difference sensor (30), a dissolved oxygen sensor (31) and a pH / temperature sensor (32); the heating rod (18) is arranged in the middle section of the reactor (1) and is electrically connected to the PLC controller (17); the pressure difference sensor (30) is arranged on the surface of the hollow fiber membrane bundle of the membrane assembly (5); the dissolved oxygen sensor (31) and the pH / temperature sensor (32) are arranged at the overflow weir at the top of the reactor (1); the analog / digital converter (12) is electrically connected to the PLC controller (17); the pressure difference sensor (30), the dissolved oxygen sensor (31) and the pH / temperature sensor (32) are respectively connected to the analog / digital converter (1 2) Electrical signal connection; the pressure difference sensor (30), dissolved oxygen sensor (31) and pH / temperature sensor (32) in the control system are used for monitoring the pH value, dissolved oxygen (DO), temperature and pressure difference between the inside and outside of the biofilm in the reactor (1); the analog / digital converter (12) performs analog and digital conversion, and the PLC controller (17) processes data on the pH value, dissolved oxygen, temperature, pressure difference between the inside and outside of the biofilm, pressure of the secondary mixed pressurized gas cylinder (27), gas composition obtained by the gas concentration sensor (19) and gas composition obtained by the second gas concentration sensor (25), and controls the water inlet peristaltic pump (6), the circulation peristaltic pump (7), multiple mass flow controllers (8), multiple electronic pressure reducing valves (14), the heating rod (18) and the pressure pump (29);

[0091] The method for co-treating industrial waste gas, waste water and carbon pollution by using a mixed gas hollow fiber breathable membrane biofilm system for co-treating industrial waste gas, waste water and carbon pollution is carried out in the following steps:

[0092] 1. Start-up of the inlet and outlet water circulation system:

[0093] The water inlet peristaltic pump (6) is turned on to pump the sewage into the reactor (1). The water inlet peristaltic pump (6) is controlled by the PLC controller (17) to maintain the hydraulic retention time inside the reactor (1) at 6 hours. The water inlet peristaltic pump (6) is adjusted in time to obtain the optimal flow rate to meet the treatment effect while improving the treatment efficiency. The sewage enters the reactor (1) and fully contacts with the biofilm, achieving efficient denitrification of the sewage. The effluent of the reactor (1) is discharged from the overflow weir. At the same time, a portion of the sewage inside the reactor is circulated from the circulating water outlet (9) to the circulating water inlet (11) through the circulating peristaltic pump (7), so that the sewage is mixed and fully contacts with the biofilm. At the same time, a portion of the biofilm that falls off to the bottom of the reactor under the action of hydraulic shear is also reattached to the surface of the membrane assembly (5) along with the circulating sewage to maintain a high active biological content.

[0094] 2. The multi-source industrial mixed gas integrated supply system is put into operation:

[0095] The multi-source industrial mixed gas in the multi-source industrial mixed gas cylinder (24) is decompressed twice step by step to 0.5 MPa through two electronic pressure reducing valves (14), and then enters the second gas concentration sensor (25) to detect the ratio of each component gas in the multi-source industrial mixed gas cylinder (24). After the gas mass flow meter (26) reaches the target flow rate by adjusting the electronic pressure reducing valve (14) at the gas outlet end of the multi-source industrial mixed gas cylinder (24), the original phase gas in the multi-source industrial mixed gas cylinder (24) is sent to the secondary mixed pressurized gas cylinder (27); the hydrogen generator (13), the carbon dioxide cylinder (15), the carbon monoxide cylinder (22), and the methane cylinder (23) respectively provide hydrogen, carbon dioxide, carbon monoxide and methane as raw gas; P The LC controller (17) uses the raw gas to adjust the ratio of the original phase gas entering the secondary mixed pressurized gas cylinder (27) according to the result displayed by the second gas concentration sensor (25), and the flow rates of hydrogen, carbon dioxide, carbon monoxide and methane are adjusted by the gas mass flow controller (8). At the same time, the PLC controller (17) performs a secondary verification ratio on the outlet gas of the secondary mixed pressurized gas cylinder (27) according to the first gas concentration sensor (19). If the partial pressure ratio of hydrogen and carbon monoxide in the outlet gas of the secondary mixed pressurized gas cylinder (27) deviates from the set value, the PLC controller (17) controls multiple gas mass flow controllers (8) to adjust the raw gas to ensure that the ratio of each component of the mixed gas entering the membrane module (5) remains stable;

[0096] The pressure of the mixed gas in the secondary mixed pressurized gas cylinder (27) is controlled to be 1.5 MPa, and the partial pressure ratio (H / C) of the mixed gas in the secondary mixed pressurized gas cylinder (27) is maintained at 7:1; according to the optimal flux requirement of the membrane assembly (5), the pressure of the mixed gas output from the secondary mixed pressurized gas cylinder (27) is adjusted to 10 psig through the electronic pressure reducing valve (14) at the gas outlet end of the secondary mixed pressurized gas cylinder (27) and then fed into the membrane assembly (5); the optimal flux of the membrane assembly (5) is 15-30 mL / min;

[0097] Multi-source industrial mixed gas is a mixed gas of carbon monoxide and hydrogen, containing other components such as carbon dioxide and methane; the carbon monoxide and hydrogen can serve as electron donors for autotrophic microorganisms and are key parts of reactor operation; the sources of multi-source industrial mixed gas include fossil fuel gasification, blast furnace gas, converter gas and coke oven gas and other biomass conversion and industrial by-products, chemical synthesis, cement manufacturing, oil and natural gas mining and processing, power generation, thermal energy industry, waste incineration, etc.; multi-source industrial mixed gas is often considered to be one of the main sources of greenhouse gases in industrial production, and controlling and recycling these waste gases is an important direction for carbon emission reduction and resource utilization. In the multi-source industrial mixed gas cylinder (24) of this embodiment, coke oven gas (H2 content of 55%, CH2 content of 25%, CO2 content of 5%) is used as the main gas source, supplemented by synthetic ammonia purge gas (H2 content of 65%, CO2 content of 20%) to form a multi-source industrial mixed gas, and carbon and nitrogen coordinated treatment is achieved through dynamic allocation.

[0098] 3. Operation of the reactor:

[0099] (1) Reactor (1) startup phase:

[0100] While the mixed gas in the secondary mixed pressurized gas cylinder (27) is passed into the membrane module (5), hydrogen autotrophic denitrification sludge is inoculated in the reactor, and the sludge inoculation amount is 9 g / L. The membrane module (5) is subjected to biofilm formation for 15 days, during which the influent nitrate load is 5 gN / d. After the biofilm formation is completed, the influent nitrate load is increased to 15 gN / d, and the reactor (1) enters the steady-state operation stage. The nitrate concentration of the effluent of the reactor (1) is less than 5 mgN / L.

[0101] (II) Reactor (1) Steady-state operation stage:

[0102] ① pH adjustment: The pH of the wastewater inside the reactor (1) is controlled at 6.0-8.0. When the pH is greater than 8.0, the CO2 content in the mixed gas input from the secondary mixed pressurized gas cylinder (27) is increased to reduce the alkalinity of the solution. When the pH is less than 6.0, the CO2 flow rate in the mixed gas is reduced to prevent excessive acidification.

[0103] ② Temperature control: The temperature in the reactor (1) is controlled at 15-25°C by controlling the heating rod (18) through the PLC controller (17);

[0104] ③. Inlet and outlet water circulation: The PLC controller (17) controls the circulating peristaltic pump (7) so that the sewage circulation time in the reactor (1) reaches one cycle every 2 hours;

[0105] ④. Gas supply pressure regulation: When the biofilm thickness increases and the membrane flux of the membrane assembly (5) decreases by more than 15%, the gas supply pressure of the electronic pressure reducing valve (14) at the outlet of the secondary mixed pressurized gas cylinder (27) is increased through the PLC controller (17). When the membrane flux of the membrane assembly (5) recovers to 15-30 mL / min, the pressure is stabilized;

[0106] ⑤. Membrane pollution control: When the dissolved oxygen concentration in the sewage monitored by the dissolved oxygen sensor (31) exceeds 1.2 mg / L, the membrane flux change rate is calculated. When the membrane flux change rate reaches or is less than -3 mL / min 2 When the membrane is cleaned, compressed nitrogen is injected into the membrane assembly (5) through the air washing pipeline (20) for pulse cleaning to remove the surface biofilm of the membrane assembly (5) until the dissolved oxygen concentration in the sewage does not exceed 1.2 mg / L; if the membrane flux change rate further decreases, 5 g / m 3 Denitrifying bacteria enhance biofilm degradation;

[0107] ⑥. Biofilm collection: When the biofilm accumulation on the membrane assembly (5) exceeds ≥2 mm, the biofilm is collected. Compressed nitrogen is injected into the membrane assembly (5) through the air washing pipeline (20) to form a 0.5-1.5N / m 2 The hydraulic shear force is used to peel off the aged biofilm on the surface while retaining the active biofilm on the bottom. The peeled biofilm is collected in the mud hopper (10). The biofilm sediment in the mud hopper (10) is rich in PHA.

[0108] ⑦. PHA purification: First, the stripped biofilm was freeze-dried at -60°C for 24 hours to reduce the moisture content to below 5%. Then, it was extracted with a chloroform-ethanol mixed solvent at 50°C for 4 hours. The extract was separated by centrifugation to obtain PHA particles with a purity of >98%. According to the PHA actual conversion rate calculation formula, the actual PHA conversion rate reached 57.2%, which is 40%-45% higher than the traditional activated sludge method.

[0109] .

Claims

1. A mixed gas hollow fiber breathable membrane biofilm system for the coordinated treatment of industrial waste gas, wastewater and carbon pollution, characterized by: The mixed gas hollow fiber breathable membrane biofilm system for the coordinated treatment of industrial waste gas, wastewater and carbon pollution comprises a reactor (1), a biofilm system, an inlet and outlet water circulation system, a multi-source industrial mixed gas integrated supply system (21) and a control system; The biofilm system includes a membrane assembly (5) and an air washing pipeline (20); The inlet and outlet water circulation system comprises an inlet peristaltic pump (6) and a circulation peristaltic pump (7); the outlet of the inlet peristaltic pump (6) is connected to a water inlet (4) provided at a lower portion of one side of the reactor (1); the inlet of the circulation peristaltic pump (7) is connected to a circulation water outlet (9) provided at a lower portion of one side of the reactor (1), and the outlet of the circulation peristaltic pump (7) is connected to a circulation water inlet (11) provided at an upper portion of one side of the reactor (1); The multi-source industrial mixed gas integrated supply system (21) includes a hydrogen generator (13), a carbon dioxide gas cylinder (15), a first gas concentration sensor (19), a carbon monoxide gas cylinder (22), a methane gas cylinder (23), a multi-source industrial mixed gas cylinder (24), a second gas concentration sensor (25), a gas mass flow meter (26), a secondary mixed pressurized gas cylinder (27), a check valve (28) and a pressurizing pump (29); the hydrogen generator (13), the carbon dioxide gas cylinder (15), the carbon monoxide gas cylinder (22), the methane gas cylinder (23), the multi-source industrial mixed gas cylinder (24), the second gas concentration sensor (25), the gas mass flow meter (26), the secondary mixed pressurized gas cylinder (27), the check valve (28) and the pressurizing pump (29); The gas outlets of the carbon gas cylinder (22), the methane gas cylinder (23) and the multi-source industrial mixed gas cylinder (24) are respectively connected to the gas inlet of the check valve (28), the gas outlet of the check valve (28) is connected to the gas inlet of the pressure pump (29), the gas outlet of the pressure pump (29) is connected to the gas inlet of the secondary mixed pressurized gas cylinder (27), and the gas outlet of the secondary mixed pressurized gas cylinder (27) is respectively connected to the top gas inlet (2) and the bottom gas inlet (3) of the membrane assembly (5); an electronic device is provided on the secondary mixed pressurized gas cylinder (27). A pressure gauge; a mass flow controller (8) is provided on the connecting pipeline between the hydrogen generator (13) and the check valve (28); an electronic pressure reducing valve (14) and a mass flow controller (8) are provided on the connecting pipeline between the carbon dioxide cylinder (15) and the check valve (28), the connecting pipeline between the carbon monoxide cylinder (22) and the check valve (28), and the connecting pipeline between the methane cylinder (23) and the check valve (28), respectively. The mass flow controller (8) is provided on the connecting pipeline between the electronic pressure reducing valve (14). ) on the outlet side; two electronic pressure reducing valves (14), a gas mass flow meter (26) and a second gas concentration sensor (25) are sequentially provided on the connecting pipeline between the multi-source industrial mixed gas cylinder (24) and the check valve (28); the second gas concentration sensor (25) is provided on the inlet side of the check valve (28), the gas mass flow meter (26) is provided on the inlet side of the second gas concentration sensor (25), and the first gas concentration sensor (19) is provided on the outlet side of the secondary mixed pressurized gas cylinder (27); The control system comprises an analog / digital converter (12), a PLC controller (17), a heating rod (18), a pressure difference sensor (30), a dissolved oxygen sensor (31) and a pH / temperature sensor (32); the heating rod (18) is arranged in the middle section of the reactor (1); the pressure difference sensor (30) is arranged on the surface of the hollow fiber membrane bundle of the membrane assembly (5); and the dissolved oxygen sensor (31) and the pH / temperature sensor (32) are arranged at the overflow weir at the top of the reactor (1).

2. The mixed gas hollow fiber breathable membrane biofilm system for the coordinated treatment of industrial waste gas, wastewater and carbon pollution according to claim 1 is characterized by: An overflow weir is provided at the top of the reactor (1), and a mud discharge hopper (10) is provided at the bottom of the reactor (1).

3. The mixed gas hollow fiber breathable membrane biofilm system for the coordinated treatment of industrial waste gas, wastewater and carbon pollution according to claim 1 is characterized by: The membrane assembly (5) is arranged in the middle section of the reactor (1), and a hollow support shaft (33) is arranged inside the membrane assembly (5). The support shaft is provided with an air inlet hole and a plurality of air outlet holes. The air outlet end of the air washing pipeline (20) is connected to the air inlet hole of the support shaft, and the air inlet end of the air washing pipeline (20) is connected to an external nitrogen gas source.

4. The mixed gas hollow fiber breathable membrane biofilm system for the coordinated treatment of industrial waste gas, wastewater and carbon pollution according to claim 1 is characterized by: The water inlet peristaltic pump (6) and the circulation peristaltic pump (7) are respectively connected to the PLC controller (17) via electrical signals.

5. The mixed gas hollow fiber breathable membrane biofilm system for the coordinated treatment of industrial waste gas, wastewater and carbon pollution according to claim 1 is characterized by: The second gas concentration sensor (25), the gas mass flow meter (26), the secondary mixed pressurized gas cylinder (27), the pressure pump (29), the plurality of mass flow controllers (8), the plurality of electronic pressure reducing valves (14), the first gas concentration sensor (19), and the pressure gauge provided on the secondary mixed pressurized gas cylinder (27) are respectively connected to the PLC controller (17) via electrical signals.

6. The mixed gas hollow fiber breathable membrane biofilm system for the coordinated treatment of industrial waste gas, wastewater and carbon pollution according to claim 1 is characterized by: The differential pressure sensor (30), the dissolved oxygen sensor (31), and the pH / temperature sensor (32) are respectively connected to the analog / digital converter (12) via electrical signals; the analog / digital converter (12) is connected to the PLC controller (17) via electrical signals, and the heating rod (18) is connected to the PLC controller (17) via electrical signals.

7. A method for treating wastewater using the mixed gas hollow fiber breathable membrane biofilm system for coordinated treatment of industrial waste gas, wastewater and carbon pollution as claimed in claim 1, characterized in that: The method proceeds as follows:

1. Start-up of the inlet and outlet water circulation system: The water inlet peristaltic pump (6) is turned on to pump the sewage into the reactor (1). The water inlet peristaltic pump (6) is controlled by the PLC controller (17) to maintain the hydraulic retention time in the reactor (1) at 4-24 hours. The sewage enters the reactor (1) and is in full contact with the biofilm, thereby achieving denitrification of the sewage. The effluent of the reactor (1) is discharged from the overflow weir. At the same time, a portion of the sewage in the reactor is circulated from the circulating water outlet (9) to the circulating water inlet (11) through the circulating peristaltic pump (7), so that the sewage is mixed and fully contacts the biofilm. At the same time, a portion of the biofilm that falls off to the bottom sludge hopper under the action of hydraulic shear is reattached to the surface of the membrane assembly (5) along with the circulating sewage to maintain a high active biological content.

2. The multi-source industrial mixed gas integrated supply system is put into operation: The multi-source industrial mixed gas in the multi-source industrial mixed gas cylinder (24) is decompressed twice in stages to 0.2-0.5 MPa through two electronic pressure reducing valves (14), and then enters the second gas concentration sensor (25) to detect the ratio of each component gas in the multi-source industrial mixed gas cylinder (24). After the gas mass flow meter (26) reaches the target flow rate by adjusting the electronic pressure reducing valve (14) at the gas outlet end of the multi-source industrial mixed gas cylinder (24), the original phase gas in the multi-source industrial mixed gas cylinder (24) is sent to the secondary mixed pressurized gas cylinder (27); the hydrogen generator (13), the carbon dioxide cylinder (15), the carbon monoxide cylinder (22), and the methane cylinder (23) respectively provide hydrogen, carbon dioxide, carbon monoxide and methane as raw gas The PLC controller (17) uses the raw gas to adjust the proportion of the original phase gas entering the secondary mixed pressurized gas cylinder (27) according to the result displayed by the second gas concentration sensor (25), and the flow rates of hydrogen, carbon dioxide, carbon monoxide and methane are adjusted by the gas mass flow controller (8). At the same time, the PLC controller (17) performs a secondary verification ratio on the outlet gas of the secondary mixed pressurized gas cylinder (27) according to the first gas concentration sensor (19). If the partial pressure ratio of hydrogen and carbon monoxide in the outlet gas of the secondary mixed pressurized gas cylinder (27) deviates from the set value, the PLC controller (17) controls multiple gas mass flow controllers (8) to adjust the raw gas to ensure that the proportion of each component of the mixed gas entering the membrane module (5) remains stable. The pressure of the mixed gas in the secondary mixed pressurized gas cylinder (27) is controlled to be 1.5-2.2 MPa, and the partial pressure ratio of hydrogen to carbon compound in the mixed gas in the secondary mixed pressurized gas cylinder (27) is maintained at (5-9):1; according to the optimal flux requirement of the membrane assembly (5), the pressure of the mixed gas output from the secondary mixed pressurized gas cylinder (27) is adjusted to 5-20 psig through the electronic pressure reducing valve (14) at the gas outlet end of the secondary mixed pressurized gas cylinder (27) and then fed into the membrane assembly (5); the optimal flux of the membrane assembly (5) is 15-30 mL / min; 3. Operation of the reactor: (1) Reactor (1) startup phase: While the mixed gas in the secondary mixed pressurized gas cylinder (27) is passed into the membrane assembly (5), hydrogen autotrophic denitrification sludge is inoculated in the reactor, and the sludge inoculation amount is 8-10 g / L. The membrane assembly (5) is subjected to biofilm formation for 10-20 days, during which the influent nitrate load is 2-5 gN / d. After the biofilm formation is completed, the influent nitrate load is increased to 10-15 gN / d, and the reactor (1) enters the steady-state operation stage. The nitrate concentration of the effluent of the reactor (1) is less than 5 mgN / L. (II) Reactor (1) Steady-state operation stage: ①, pH adjustment: control the pH of the sewage inside the reactor (1) to 6.0-8.0; ② Temperature control: The temperature in the reactor (1) is controlled at 15-25°C by controlling the heating rod (18) through the PLC controller (17); ③. Inlet and outlet water circulation: The PLC controller (17) controls the circulating peristaltic pump (7) so that the sewage circulation time in the reactor (1) reaches one cycle of 1-2 hours; ④. Gas supply pressure regulation: When the biofilm thickness increases and the membrane flux of the membrane assembly (5) decreases by more than 15%, the gas supply pressure of the electronic pressure reducing valve (14) at the outlet of the secondary mixed pressurized gas cylinder (27) is increased through the PLC controller (17). When the membrane flux of the membrane assembly (5) recovers to 15-30 mL / min, the pressure is stabilized; ⑤. Membrane pollution control: When the dissolved oxygen concentration in the sewage monitored by the dissolved oxygen sensor (31) exceeds 1.2 mg / L, the membrane flux change rate is calculated. When the membrane flux change rate reaches or is less than -3 mL / min 2 When the membrane is cleaned, compressed nitrogen is injected into the membrane assembly (5) through the air washing pipeline (20) for pulse cleaning to remove the surface biofilm of the membrane assembly (5) until the dissolved oxygen concentration in the sewage does not exceed 1.2 mg / L; if the membrane flux change rate further decreases, 5 g / m 3 Denitrifying bacteria enhance biofilm degradation; ⑥. Biofilm collection: When the biofilm accumulation on the membrane assembly (5) exceeds ≥2 mm, the biofilm is collected. Compressed nitrogen is injected into the membrane assembly (5) through the air washing pipeline (20) to form a 0.5-1.5N / m 2 The hydraulic shear force is used to peel off the aged biofilm on the surface while retaining the active biofilm on the bottom. The peeled biofilm is collected in the mud hopper (10). The biofilm sediment in the mud hopper (10) is rich in PHA. ⑦. PHA purification.

8. The method for treating sewage using a mixed gas hollow fiber breathable membrane biofilm system for coordinated treatment of industrial waste gas, wastewater, and carbon pollution according to claim 7, characterized in that: The sources of multi-source industrial mixed gas include fossil fuel gasification, blast furnace gas, converter gas or coke oven gas.

9. The method for treating wastewater by utilizing a mixed gas hollow fiber breathable membrane biofilm system for coordinated treatment of industrial waste gas, wastewater, and carbon pollution according to claim 7, characterized in that: In step (ii) ①, when pH>8.0, the CO2 content in the mixed gas input from the secondary mixed pressurized gas cylinder (27) is increased to reduce the alkalinity of the solution; when pH<6.0, the CO2 flow rate in the mixed gas is reduced to prevent excessive acidification.

10. The method for treating wastewater by utilizing a mixed gas hollow fiber breathable membrane biofilm system for coordinated treatment of industrial waste gas, wastewater, and carbon pollution according to claim 7, characterized in that: The PHA purification process is as follows: first, the stripped biofilm is quickly frozen at -80°C, then placed in a freeze dryer and freeze-dried at -60°C for 24 hours to reduce the moisture content to below 5%; then, it is extracted with a chloroform-ethanol mixed solvent at 50°C for 4 hours, and the extract is separated by centrifugation to obtain PHA particles with a purity of >98%.

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