Sewage treatment process of bioreactor with variable mixed functional areas

Abstract

The invention relates to the technical field of sewage treatment, in particular to a mixed functional area variable bioreactor sewage treatment process which comprises the following steps: sewage to be treated is introduced into a monomer reactor with an adjustable aerobic area, an adjustable anoxic area and an adjustable anaerobic area; detecting inlet water quality parameters in real time through online monitoring equipment, wherein the parameters at least comprise COD (Chemical Oxygen Demand), ammonia nitrogen, total nitrogen and total phosphorus concentration; based on inlet water quality parameters, the volume ratio of the aerobic zone to the anoxic zone to the anaerobic zone is automatically adjusted by a central control system, and the volume ratio is adjusted through a movable partition plate; adjusting the aeration intensity and the internal reflux ratio according to the dissolved oxygen, the oxidation-reduction potential and the pH value monitored in real time in each functional area; nitration reaction is carried out in the aerobic zone, and ammonia nitrogen is converted into nitrate nitrogen; a denitrification reaction is carried out in the anoxic zone, and nitrate nitrogen is converted into nitrogen; the enhanced biological phosphorus removal is realized through the alternate action of the anaerobic zone and the aerobic zone; and discharging the treated sewage out of the system.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, in particular to a sewage treatment process using a bioreactor with a variable mixing functional area. Background Art

[0002] With the acceleration of urbanization, urban wastewater treatment faces the challenge of significant fluctuations in water quality and quantity. Traditional activated sludge processes struggle to maintain stable treatment results when influent quality fluctuates significantly, especially for the removal of nutrients like nitrogen and phosphorus. This often requires adding treatment units or increasing the dosage of chemicals, leading to increased operating costs and reduced treatment efficiency.

[0003] At present, the mainstream technologies for urban sewage treatment mainly include membrane bioreactor (MBR) technology, A 2 / O process, oxidation ditch process, etc.

[0004] Chinese patent CN203683229U discloses a facultative membrane bioreactor wastewater treatment device, which includes an enhanced anaerobic reaction zone and a composite facultative fluidized bed (MBR) reaction zone. This device improves treatment efficiency by organically combining enhanced anaerobic hydrolysis with the membrane bioreactor. However, the volume ratios of the functional zones in this device are fixed, making it unable to adaptively adjust to changes in influent water quality. This results in unstable treatment results when the influent water quality fluctuates significantly.

[0005] Chinese patent CN102249415A discloses an airlift internal circulation bioreactor for denitrification and phosphorus removal. By rationally designing the internal configuration of the airlift internal circulation bioreactor and controlling the aeration intensity, the wastewater circulation rate and dissolved oxygen concentration within the reactor are adjusted to maintain an aerobic state in the peripheral upflow pipes and an anaerobic state in the central downflow pipes. While this technology can achieve simultaneous denitrification and phosphorus removal in wastewater, the volume ratio of its functional areas cannot be flexibly adjusted according to changes in influent water quality.

[0006] U.S. Patent No. 9862628B2 discloses an aeration device with adjustable bubble size for membrane bioreactors. By adjusting the aerator's tilt angle, bubbles of varying sizes can be generated simultaneously, achieving oxygen transfer and membrane surface cleaning during wastewater treatment. While this technology can adjust the aeration effect, it does not involve adjusting the volume of the functional zone.

[0007] The article "Simultaneous effective carbon and nitrogen removals and phosphorus recovery in an intermittently aerated membrane bioreactor integrated system," published in the journal Scientific Reports, describes an intermittently aerated membrane bioreactor system that achieves simultaneous carbon, nitrogen, and phosphorus removal by controlling aerated and non-aerated cycles. While this system achieves functional switching through temporal control, it lacks flexible spatial adjustment capabilities.

[0008] The article "Simultaneous removal of concentrated organics, nitrogen, and phosphorus nutrients by an oxygen-limited membrane bioreactor" published in the Journal of Environmental Management describes an oxygen-limited membrane bioreactor that achieves simultaneous removal of organic matter, nitrogen, and phosphorus by precisely controlling the dissolved oxygen concentration (approximately 0.2 mg / L). This technology uses a fixed reactor structure, making it impossible to adjust the proportions of different functional zones based on influent characteristics.

[0009] While all of the aforementioned existing technologies address wastewater denitrification and phosphorus removal, they share a common drawback: an inability to automatically adjust the volume ratios of different functional zones based on changes in influent water quality. This results in either unstable treatment results or the need for extensive human intervention to adjust operating parameters when faced with fluctuating water quality, increasing operating costs and operational complexity. This is particularly true for municipal wastewater treatment, where water quality fluctuates significantly, where existing technologies struggle to simultaneously maintain stable denitrification and phosphorus removal results and low operating costs.

[0010] Therefore, there is an urgent need for a bioreactor wastewater treatment process that can automatically adapt to changes in influent water quality and flexibly adjust the volume ratio of functional areas to improve treatment efficiency, reduce operating costs, and have higher process flexibility. Summary of the Invention

[0011] In response to the shortcomings of the existing technology, the present invention provides a mixed functional zone variable bioreactor sewage treatment process, which can automatically adjust the volume ratio of the aerobic zone, the anoxic zone and the anaerobic zone according to the changes in the influent water quality, and accurately adjust the dissolved oxygen and the reflow ratio through the intelligent control system, so as to adapt to the fluctuations in water quality and water quantity, maintain a stable denitrification and phosphorus removal effect, and has the characteristics of low operating cost and high process flexibility. It is particularly suitable for urban sewage treatment with large fluctuations in influent water quality.

[0012] To achieve the above object, the present invention provides a wastewater treatment process using a bioreactor with a variable mixing functional area, comprising the following steps:

[0013] The sewage to be treated is introduced into a monomer reactor having adjustable aerobic, anoxic and anaerobic zones; the influent water quality parameters are detected in real time by online monitoring equipment, and the parameters include at least COD, ammonia nitrogen, total nitrogen and total phosphorus concentrations; based on the influent water quality parameters, the central control system automatically adjusts the volume ratio of the aerobic, anoxic and anaerobic zones, and the volume ratio adjustment is achieved by movable baffles; the aeration intensity and the internal recirculation ratio are adjusted according to the dissolved oxygen, redox potential and pH value monitored in real time in each functional zone; nitrification reaction is carried out in the aerobic zone to convert ammonia nitrogen into nitrate nitrogen; denitrification reaction is carried out in the anoxic zone to convert nitrate nitrogen into nitrogen gas; enhanced biological phosphorus removal is achieved by alternating the anaerobic and aerobic zones; and the treated sewage is discharged from the system.

[0014] In a preferred embodiment of the present invention, the movable partition is position-adjusted by a precision drive system, which includes: a brushless DC motor with a rated power of 0.25-1.0 kW; a planetary reducer with a reduction ratio of 50:1 to 100:1; a stainless steel lead screw with a pitch of 5 to 10 mm; and a ceramic-coated aluminum linear guide with a load capacity of 50 to 200 kg. The drive system has a positioning accuracy of ±5 mm and a moving speed of 5 to 20 mm / min.

[0015] Furthermore, the online monitoring equipment includes: a dissolved oxygen sensor using an optical luminescence method, with a measuring range of 0-20 mg / L and an accuracy of ±0.1 mg / L; an ammonia nitrogen sensor using an ion selective electrode, with a measuring range of 0-100 mg / L and an accuracy of ±3%; a nitrate nitrogen sensor using an ultraviolet absorption method, with a measuring range of 0-100 mg / L and an accuracy of ±5%; a phosphate sensor using a colorimetric method, with a measuring range of 0-20 mg / L and an accuracy of ±2%; a glass electrode pH sensor, with a measuring range of pH 4-10 and an accuracy of ±0.1 unit; a platinum electrode redox potential sensor, with a measuring range of -500 to +500 mV and an accuracy of ±5 mV; and a mixed liquor suspended solids concentration sensor using a near-infrared absorption method, with a measuring range of 0-15 g / L and an accuracy of ±5%.

[0016] In another preferred embodiment of the present invention, the central control system adopts a multi-stage control strategy, including: a basic control loop for maintaining the dissolved oxygen concentration in the aerobic zone at 1.5-3.5 mg / L, the mixing intensity at 5-15 W / m3, and the recirculation ratio at 100% to 400% of the inlet flow rate; regional volume optimization control for dynamically adjusting the regional volume based on nitrogen removal demand, with a response time of 15 to 60 minutes; predictive control for using a machine learning algorithm to make adjustments and predictions based on historical performance data and inlet pattern recognition, with a prediction and adjustment time of 1 to 12 hours; the control system uses a fuzzy logic controller for regional volume adjustment, and determines the optimal regional configuration based on inlet and outlet water quality parameters.

[0017] Preferably, the aeration system of the aerobic zone includes: a membrane-type microporous aerator made of EPDM material with a bubble size of 1 to 3 mm; a PVC frame with a maximum pressure bearing capacity of 100 kPa; an ABS distribution pipe with a gas flow rate of 2 to 12 standard cubic meters per hour per square meter; the oxygen transfer efficiency of the aeration system under standard conditions (20°C, clean water) is 3.0 to 4.5 kg of oxygen per kilowatt-hour, and the aerator density is 10% to 15% of the bottom area.

[0018] Furthermore, the anoxic zone uses a medium bubble mixing system, including: an HDPE aerator with a bubble size of 5 to 8 mm; a PVC 80 grade distribution pipe with a gas flow rate of 0.5 to 2.0 standard cubic meters per hour per square meter; the mixing system provides gentle mixing without excessive oxygen transfer, so that the dissolved oxygen level in the anoxic zone is maintained at 0.1 to 0.5 mg / L.

[0019] In one embodiment of the present invention, the anaerobic zone uses a hydraulic mixing system, including: a 316L stainless steel submersible agitator with a motor power of 0.25-1.0 kilowatts; a glass fiber reinforced polypropylene impeller with a diameter of 200-400 mm; and a rotation speed of 50-150 rpm. The mixing system provides a power input of 5-10 watts per cubic meter, preventing the introduction of oxygen while ensuring uniform distribution of biomass.

[0020] In one embodiment of the present invention, the process parameters of each functional zone are as follows: aerobic zone: dissolved oxygen 1.5-3.5 mg / L, redox potential +100 to +300 mV, pH 6.8-7.8, hydraulic retention time 4 to 12 hours, and mixed liquor suspended solids concentration 3.0 to 5.0 g / L; anoxic zone: dissolved oxygen 0.1-0.5 mg / L, redox potential -50 to +50 mV, pH 6.8-7.8, hydraulic retention time 2 to 6 hours, and mixed liquor suspended solids concentration 3.0 to 5.0 g / L; anaerobic zone: dissolved oxygen less than 0.1 mg / L, redox potential -100 to -250 mV, pH 6.5-7.5, hydraulic retention time 1 to 3 hours, and mixed liquor suspended solids concentration 3.0 to 5.0 g / L.

[0021] Preferably, the overall system parameters of the process include: a total hydraulic retention time of 8 to 24 hours; a solid retention time of 10 to 30 days; an F / M ratio of 0.05 to 0.15 kg BOD / kg MLVSS·day; an internal reflow ratio of 100% to 400% of the influent flow rate; a return activated sludge ratio of 50% to 100% of the influent flow rate; and a residual sludge discharge rate of 3% to 10% of the system volume / day.

[0022] More preferably, the process also includes an optional biofilm carrier medium strengthening system, wherein the biofilm carrier medium is made of HDPE material, has a specific surface area of ​​500-1000 square meters / cubic meter, a density of 0.95-0.98 grams / cubic centimeter, a size of 10-25 mm, a filling ratio of 15% to 40% of the regional volume, and a biofilm thickness of 0.1-2.0 mm; the carrier medium provides an attachment surface for the immobilized professional microbial community, enhancing nitrification in the aerobic zone and denitrification in the anoxic zone.

[0023] The sewage treatment process of the bioreactor with variable mixing functional area provided by the present invention has the following beneficial effects:

[0024] (1) Strong adaptability: The volume ratio of the aerobic zone, anoxic zone and anaerobic zone can be adjusted in real time through movable partitions. The treatment process can be automatically adjusted according to the changes in the influent water quality, adapt to water quality fluctuations, and maintain stable effluent water quality.

[0025] (2) Stable treatment effect: Even when the concentrations of influent COD, ammonia nitrogen, total nitrogen and total phosphorus fluctuate greatly, the stable treatment effect of total nitrogen removal rate of 75% to 90% and total phosphorus removal rate of 80% to 95% can be maintained.

[0026] (3) Low energy consumption: The aeration intensity, mixing intensity and reflux ratio are precisely adjusted through the intelligent control system to avoid energy waste. The energy consumption per unit of treated water is 0.3-0.8 kWh / m3, which is 20% to 30% lower than that of traditional processes.

[0027] (4) Easy to operate: It adopts a fully automatic control system to reduce manual intervention, lower operation and maintenance costs and operational difficulty.

[0028] (5) Small footprint: The multifunctional area can be configured in a single reactor, which reduces the footprint by 30% to 50% compared to traditional multi-tank systems.

[0029] (6) Wide adaptability: It is suitable for urban sewage treatment with large fluctuations in water quality and quantity, and can also be used for industrial wastewater pretreatment and small decentralized treatment facilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of the bioreactor with variable mixing functional area of ​​the present invention.

[0031] Figure 2 It is a schematic diagram of the movable partition driving system of the bioreactor with variable mixing functional area of ​​the present invention.

[0032] Figure 3 It is a framework diagram of the control system of the bioreactor with variable mixing functional area of ​​the present invention.

[0033] Figure 4 This is a flow chart of the sewage treatment process of the bioreactor with variable mixing functional area according to the present invention.

[0034] Figure 5 3 is a comparison chart of the total nitrogen removal rates of Examples 1-3 of the present invention.

[0035] Figure 6 3 is a comparison chart of the total phosphorus removal rates of Examples 4-6 of the present invention.

[0036] Figure 7 It is a comparison chart of the treatment stability of the embodiment of the present invention and the comparative example under the condition of fluctuating influent water quality. DETAILED DESCRIPTION

[0037] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0038] like Figure 1As shown, the bioreactor with variable mixing functional area of ​​the present invention is mainly composed of a reactor body, a movable baffle system, an aeration and mixing system, a sensor system and a control system.

[0039] The reactor body is made of fiberglass-reinforced plastic (FRP) in accordance with ASTM D-4097. The reactor wall utilizes an isophthalic polyester resin (25% to 35% by weight) as the matrix, E-glass fiber (60% to 70% by weight) as the reinforcement, a vinyl ester resin (3% to 7% by weight) as the anti-corrosion layer, a hindered amine light stabilizer (0.5% to 1.5% by weight) as the UV stabilizer, and methyl ethyl ketone peroxide (0.5% to 1.5% by weight) as the catalyst. The reactor wall thickness is 8 to 12 mm, with a tensile strength of 100-150 MPa and a flexural modulus of 5-7 GPa. It maintains chemical stability within a pH range of 5.0-9.0 and a temperature range of 5-45°C.

[0040] The movable partition system is the core innovation of this invention. Figure 2 As shown in Figure 1, the system consists of a bulkhead panel, a sealing system, and a drive system. The bulkhead panel is made of polyvinylidene fluoride (PVDF), accounting for 70% to 80% by weight; the sealing gasket is made of EPDM rubber, accounting for 5% to 10% by weight; the drive shaft is made of 316L stainless steel (UNS S31603), accounting for 10% to 15% by weight; and the bearings are made of silicon nitride ceramic, accounting for 2% to 5% by weight. The bulkhead moves on a precision track system with a positioning accuracy of ±5 mm, allowing the volume of each functional zone to be adjusted to 10% to 70% of the total reactor volume.

[0041] The present invention designs a dedicated aeration and mixing system according to the requirements of different functional areas.

[0042] The aerobic zone utilizes a fine bubble aeration system, comprising EPDM membrane-type microporous aerators producing bubbles of 1 to 3 mm; a PVC frame with a maximum pressure tolerance of 100 kPa; and ABS distribution pipes. The system achieves a gas flow rate range of 2 to 12 standard cubic meters per hour per square meter. Under standard conditions (20°C, clean water), the aeration system achieves an oxygen transfer efficiency of 3.0 to 4.5 kg of oxygen per kilowatt-hour. The aerator density is approximately 10 to 15% of the reactor base area.

[0043] The anoxic zone utilizes a medium-bubble mixing system, consisting of HDPE aerators producing 5-8 mm bubbles and PVC Grade 80 distribution piping with a gas flow rate of 0.5-2.0 Nm³ / h·m². This system is designed to provide sufficient mixing intensity while maintaining a low oxygen transfer rate, keeping dissolved oxygen concentrations in the anoxic zone within the ideal range of 0.1-0.5 mg / L.

[0044] The anaerobic zone utilizes a hydraulic mixing system consisting of a 316L stainless steel submersible agitator with a 0.25-1.0 kW motor, a glass fiber reinforced polypropylene impeller with a diameter of 200-400 mm, and an operating speed of 50-150 rpm. This mixing system provides a power input of 5-10 watts per cubic meter, ensuring uniform biomass distribution while preventing the introduction of oxygen into the anaerobic environment.

[0045] like Figure 3 As shown, the present invention uses a comprehensive online monitoring sensor network, including: a dissolved oxygen sensor using optical luminescence (measuring range 0-20 mg / L, accuracy ±0.1 mg / L); an ammonia nitrogen sensor using an ion-selective electrode (measuring range 0-100 mg / L, accuracy ±3%); a nitrate nitrogen sensor using ultraviolet absorption (measuring range 0-100 mg / L, accuracy ±5%); a phosphate sensor using colorimetry (measuring range 0-20 mg / L, accuracy ±2%); a glass electrode pH sensor (measuring range pH 4-10, accuracy ±0.1 unit); a platinum electrode redox potential sensor (measuring range -500 to +500 mV, accuracy ±5 mV); and a mixed liquor suspended solids concentration sensor using near-infrared absorption (measuring range 0-15 g / L, accuracy ±5%). All sensors are certified for continuous operation in wastewater environments, equipped with self-cleaning mechanisms, and have a calibration interval of 7 to 30 days.

[0046] The control system hardware includes an industrial-grade programmable logic controller (PLC) with a scan time of 10-20 milliseconds; a touchscreen human-machine interface (HMI) with a 10-15-inch display, IP65 protection, and a NEMA 4X protective enclosure; Industrial Ethernet and Modbus TCP / IP communication networks with communication speeds of 10 / 100 Mbit / s; and a 24V DC uninterruptible power supply system with a backup time of 1 to 4 hours.

[0047] The control system adopts a three-level hierarchical control strategy: the first level is the basic control loop, which maintains the dissolved oxygen concentration in the aerobic zone at 1.5-3.5 mg / L, the mixing intensity at 5-15 W / m3, and the reflux ratio at 100% to 400% of the inlet flow rate; the second level is regional volume optimization control, which dynamically adjusts the regional volume based on nitrogen removal demand, with a response time of 15 to 60 minutes; the third level is predictive control, which uses a machine learning algorithm to make adjustments and predictions based on historical performance data and inlet pattern recognition, with a prediction and adjustment time of 1 to 12 hours.

[0048] The zone volume adjustment is based on a fuzzy logic controller. Input variables include influent ammonia nitrogen concentration (classified as low, medium, and high, corresponding to 0-20, 15-40, and >35 mg / L, respectively), influent phosphate concentration (classified as low, medium, and high, corresponding to 0-3, 2-6, and >5 mg / L, respectively), and effluent ammonia nitrogen, effluent nitrate, and effluent phosphate concentrations. The output variable is the volume percentage of each functional zone (20%-70% for the aerobic zone, 20%-60% for the anoxic zone, and 10%-40% for the anaerobic zone). Example control rules: If the influent ammonia nitrogen concentration is high and the effluent ammonia nitrogen concentration is medium or high, increase the aerobic zone volume; if the effluent nitrate concentration is high and the influent COD concentration is medium or high, increase the anoxic zone volume; if the influent phosphate concentration is high and the effluent phosphate concentration is medium or high, increase the anaerobic zone volume.

[0049] The sewage treatment process of the present invention is based on a mature biological denitrification and phosphorus removal mechanism and optimizes the treatment effect through variable regional configuration.

[0050] The nitrogen conversion process mainly includes nitrification in the aerobic zone and denitrification in the anoxic zone. In the aerobic zone, ammonia nitrogen is oxidized to nitrite by ammonia-oxidizing bacteria (such as Nitromonas), and then further oxidized to nitrate by nitrite-oxidizing bacteria (such as Nitrobacter and Nitrospira). The reaction formula of this process is: NH4 + +1.5O2→NO2 - +2H + +H2O and NO2 - +0.5O2→NO3 - The rate of nitrification is affected by dissolved oxygen (>1.5 mg / L), temperature (optimum 25-30°C) and pH (optimum 7.2-8.0).

[0051] In the anoxic zone, nitrate is reduced to nitrogen gas by denitrifying bacteria (such as Pseudomonas, Paracoccus, and Eugene) using organic carbon sources as electron donors. The reaction formula can be expressed as: NO3 - +1.08CH3OH+0.24H2CO3→0.056C5H7NO2+0.47N2+1.68H2O+HCO3 - The rate of the denitrification process is mainly affected by carbon source availability (COD / N ratio of 4-6), temperature and dissolved oxygen concentration.

[0052] Phosphorus removal is primarily achieved through the metabolic activity of phosphate-accumulating organisms (PAOs) under alternating anaerobic and aerobic conditions. Under anaerobic conditions, PAOs release phosphate while simultaneously absorbing volatile fatty acids (VFAs) and storing them as polyhydroxyalkanoates (PHAs). Energy is derived from the hydrolysis of polyphosphates. Under subsequent aerobic conditions, PAOs oxidize stored PHAs for energy, absorbing phosphate and storing it as polyphosphates. Net phosphorus removal from the system is achieved through the discharge of polyphosphate-rich sludge.

[0053] The innovation of the present invention lies in that by adjusting the volume ratio of each functional area in real time and optimizing the above-mentioned biological reaction process, the system can automatically adjust the most suitable treatment configuration according to the influent characteristics, thereby maximizing energy utilization efficiency while ensuring the water quality of the effluent.

[0054] The present invention is further described below by means of specific examples, but these examples should not be construed as limiting the present invention.

[0055] Example 1: Treatment of medium-concentration municipal sewage

[0056] This embodiment uses a variable mixing functional area bioreactor with a working volume of 100 cubic meters to treat medium-concentration urban sewage. The reactor body is made of glass fiber reinforced plastic with a wall thickness of 10 mm, a tensile strength of 125 MPa, and a bending modulus of 6 GPa. The movable partition system uses PVDF material partitions (accounting for 75% by weight), EPDM rubber sealing gaskets (accounting for 7.5% by weight), 316L stainless steel drive shafts (accounting for 12.5% ​​by weight) and silicon nitride ceramic bearings (accounting for 5% by weight). The drive system uses a 0.5 kW DC brushless motor, a planetary reducer with a reduction ratio of 75:1, a stainless steel lead screw pitch of 7.5 mm, and a ceramic-coated aluminum linear guide with a load capacity of 100 kg.

[0057] The influent water quality parameters to be treated are: COD 300-400 mg / L, BOD 150-200 mg / L, NH4 + -N 30-40 mg / L, TP 4-6 mg / L, water temperature 15-25℃.

[0058] The system initially sets the functional zone volume ratio as: 40% for the aerobic zone, 35% for the anoxic zone, and 25% for the anaerobic zone. As the system operates, the control system automatically adjusts the volume ratio of each zone based on real-time monitored water quality parameters, generally maintaining it between 35% and 45% for the aerobic zone, 30% and 40% for the anoxic zone, and 20% and 30% for the anaerobic zone.

[0059] The online monitoring system configuration includes: dissolved oxygen sensor (measuring range 0-20 mg / L, accuracy ±0.1 mg / L), ammonia nitrogen sensor (measuring range 0-100 mg / L, accuracy ±3%), nitrate nitrogen sensor (measuring range 0-100 mg / L, accuracy ±5%), phosphate sensor (measuring range 0-20 mg / L, accuracy ±2%), pH sensor (measuring range pH 4-10, accuracy ±0.1 unit), ORP sensor (measuring range -500 to +500 mV, accuracy ±5 mV), and MLSS sensor (measuring range 0-15 g / L, accuracy ±5%).

[0060] The aerobic zone uses EPDM membrane-type microporous aerators with bubble sizes of 1 to 3 mm, a PVC frame with a maximum pressure resistance of 100 kPa, ABS distribution pipes, and a gas flow rate of 8 Nm³ / h·m². The anoxic zone uses HDPE aerators with bubble sizes of 5 to 8 mm, PVC grade 80 distribution pipes, and a gas flow rate of 1.0 Nm³ / h·m². The anaerobic zone uses a 316L stainless steel submersible agitator with a 0.5 kW motor, a 300 mm diameter glass fiber reinforced polypropylene impeller, and a rotational speed of 100 rpm.

[0061] The operating parameters were set as follows: dissolved oxygen 2.5 mg / L in the aerobic zone, redox potential +200 mV, pH 7.3, hydraulic retention time 8 hours, and MLSS concentration 4.0 g / L; dissolved oxygen 0.3 mg / L in the anoxic zone, redox potential 0 mV, pH 7.3, hydraulic retention time 4 hours, and MLSS concentration 4.0 g / L; dissolved oxygen <0.1 mg / L in the anaerobic zone, redox potential -175 mV, pH 7.0, hydraulic retention time 2 hours, and MLSS concentration 4.0 g / L.

[0062] The total hydraulic retention time of the system is 14 hours, the solid retention time is 20 days, the F / M ratio is 0.1 kg BOD / kg MLVSS·day, the internal reflow ratio is 200% of the inlet flow rate, the return activated sludge ratio is 75% of the inlet flow rate, and the excess sludge discharge rate is 5% of the system volume / day.

[0063] After 30 days of operation, the system reached a stable state, and the effluent water quality indicators were: COD 35 mg / L, BOD 8 mg / L, NH4 + -N 0.8 mg / L, TN 8 mg / L, TP 0.5 mg / L. Wastewater treatment efficiency: COD removal rate 91%, BOD removal rate 96%, TN removal rate 85%, TP removal rate 90%. System energy consumption is 0.5 kWh / m3.

[0064] Example 2: Treatment of high-nitrogen, low-carbon wastewater

[0065] This embodiment uses a bioreactor with a variable mixing zone and a working volume of 50 cubic meters to treat industrial mixed wastewater with a high nitrogen and low carbon ratio. The reactor structure and materials are the same as those in Example 1, but the size is correspondingly reduced.

[0066] The influent water quality parameters to be treated are: COD 200-250 mg / L, BOD 80-120 mg / L, NH4 + -N 50-60 mg / L, TP 3-4 mg / L, water temperature 20-30°C. The inlet C / N ratio is relatively low, about 4:1.

[0067] The system initially sets the functional zone volume ratio as: 50% aerobic zone, 40% anoxic zone, and 10% anaerobic zone. As the system operates, the control system automatically adjusts the volume ratio of each zone based on real-time monitored water quality parameters, generally maintaining it between 45% and 55% aerobic zone, 35% and 45% anoxic zone, and 5% and 15% anaerobic zone.

[0068] In this embodiment, in order to enhance the denitrification effect under low C / N ratio conditions, a biofilm carrier medium was added to the anoxic zone. The material was HDPE, with a specific surface area of ​​800 square meters / cubic meter, a density of 0.96 g / cubic centimeter, a size of 15 mm, and a filling ratio of 30% of the area volume.

[0069] The aeration system in the aerobic zone uses EPDM membrane microporous aerators with a bubble size of 1 to 3 mm and a gas flow rate of 10 standard cubic meters per hour per square meter. The mixing system in the anoxic zone uses HDPE aerators with a bubble size of 6 to 8 mm and a gas flow rate of 0.8 standard cubic meters per hour per square meter. The anaerobic zone uses a 316L stainless steel submersible agitator with a 0.4 kW motor, a glass fiber reinforced polypropylene impeller with a diameter of 250 mm and a rotation speed of 120 rpm.

[0070] The operating parameters were set as follows: dissolved oxygen 3.0 mg / L in the aerobic zone, redox potential +250 mV, pH 7.5, hydraulic retention time 9 hours, and MLSS concentration 4.5 g / L; dissolved oxygen 0.2 mg / L in the anoxic zone, redox potential -25 mV, pH 7.4, hydraulic retention time 5 hours, and MLSS concentration 4.5 g / L; dissolved oxygen <0.1 mg / L in the anaerobic zone, redox potential -200 mV, pH 7.0, hydraulic retention time 1 hour, and MLSS concentration 4.5 g / L.

[0071] The total hydraulic retention time of the system is 15 hours, the solid retention time is 25 days, the internal reflow ratio is 300% of the inlet flow, the return activated sludge ratio is 80% of the inlet flow, and the excess sludge discharge rate is 4% of the system volume / day.

[0072] After 30 days of operation, the system reached a stable state, and the effluent water quality indicators were: COD 30 mg / L, BOD 6 mg / L, NH4 + -N 1.0 mg / L, TN 10 mg / L, TP 0.6 mg / L. Wastewater treatment efficiency: COD removal rate 88%, BOD removal rate 95%, TN removal rate 82%, TP removal rate 85%. System energy consumption is 0.6 kWh / m³.

[0073] Example 3: Treatment of high-phosphorus industrial wastewater

[0074] This example uses a bioreactor with a variable mixing zone and a working volume of 200 cubic meters to treat high-phosphorus food processing wastewater. The reactor structure and materials are the same as in Example 1, but the size is enlarged accordingly.

[0075] The influent water quality parameters to be treated are: COD 500-600 mg / L, BOD 300-350 mg / L, NH4 + -N 30-40 mg / L, TP 10-15 mg / L, water temperature 15-25℃.

[0076] The system initially sets the functional zone volume ratio as: 35% for the aerobic zone, 25% for the anoxic zone, and 40% for the anaerobic zone. As the system operates, the control system automatically adjusts the volume ratio of each zone based on real-time monitored water quality parameters, generally maintaining it between 30% and 40% for the aerobic zone, 20% and 30% for the anoxic zone, and 35% and 45% for the anaerobic zone.

[0077] In this embodiment, to enhance biological phosphorus removal, an extended hydraulic retention time in the anaerobic zone and enhanced aerobic-anaerobic alternating cycles are employed. The aerobic zone aeration system utilizes EPDM membrane microporous aerators with a bubble size of 1-2 mm and a gas flow rate of 12 Nm³ / h / m². The anoxic zone mixing system utilizes HDPE aerators with a bubble size of 5-6 mm and a gas flow rate of 1.5 Nm³ / h / m². The anaerobic zone utilizes a 316L stainless steel submersible agitator with a 0.75 kW motor, a 350 mm diameter glass fiber reinforced polypropylene impeller, and an 80 rpm rotational speed.

[0078] The operating parameters were set as follows: dissolved oxygen in the aerobic zone was 3.5 mg / L, redox potential was +300 mV, pH was 7.6, hydraulic retention time was 6 hours, and MLSS concentration was 5.0 g / L; dissolved oxygen in the anoxic zone was 0.2 mg / L, redox potential was -25 mV, pH was 7.4, hydraulic retention time was 3 hours, and MLSS concentration was 5.0 g / L; dissolved oxygen in the anaerobic zone was <0.1 mg / L, redox potential was -230 mV, pH was 6.8, hydraulic retention time was 3 hours, and MLSS concentration was 5.0 g / L.

[0079] The total hydraulic retention time of the system is 12 hours, the solid retention time is 15 days, the internal reflow ratio is 350% of the inlet flow, the return activated sludge ratio is 90% of the inlet flow, and the excess sludge discharge rate is 7% of the system volume / day.

[0080] After 30 days of operation, the system reached a stable state, and the effluent water quality indicators were: COD 40 mg / L, BOD 10 mg / L, NH4 + -N 1.5 mg / L, TN 12 mg / L, TP 0.6 mg / L. Wastewater treatment efficiency: COD removal rate 93%, BOD removal rate 97%, TN removal rate 68%, TP removal rate 95%. System energy consumption is 0.7 kWh / m³.

[0081] Example 4: Treatment of urban sewage in low temperature season

[0082] This embodiment uses a bioreactor with a variable mixing zone and a working volume of 150 cubic meters to treat urban sewage under low winter temperatures. The reactor structure and materials are the same as those in Example 1, but with an additional insulation layer on the outer wall of the reactor.

[0083] The influent water quality parameters to be treated are: COD 250-350 mg / L, BOD 120-180 mg / L, NH4 + -N 25-35 mg / L, TP 3-5 mg / L, water temperature 5-10℃.

[0084] The system initially sets the functional zone volume ratio as: 55% aerobic zone, 30% anoxic zone, and 15% anaerobic zone. As the system operates, the control system automatically adjusts the volume ratio of each zone based on real-time monitored water quality parameters, generally maintaining it between 50% and 60% aerobic zone, 25% and 35% anoxic zone, and 10% and 20% anaerobic zone.

[0085] In this embodiment, in order to address the problem of reduced biological activity under low temperature conditions, the proportion of aerobic zones was increased, and biofilm carrier media were added to both the aerobic and anoxic zones. The media were made of HDPE, had a specific surface area of ​​1000 square meters / cubic meter, a density of 0.97 grams / cubic centimeter, and a size of 20 mm. The filling ratios were 40% and 30% of the regional volume, respectively.

[0086] The aeration system in the aerobic zone uses EPDM membrane microporous aerators with a bubble size of 1-2 mm and a gas flow rate of 10 Nm³ / h·m². The mixing system in the anoxic zone uses HDPE aerators with a bubble size of 5-6 mm and a gas flow rate of 1.2 Nm³ / h·m². The anaerobic zone uses a 316L stainless steel submersible agitator with a 0.6 kW motor, a 300 mm diameter glass fiber reinforced polypropylene impeller, and a rotational speed of 100 rpm.

[0087] The operating parameters were set as follows: dissolved oxygen in the aerobic zone was 3.0 mg / L, redox potential was +250 mV, pH was 7.2, hydraulic retention time was 12 hours, and MLSS concentration was 4.0 g / L; dissolved oxygen in the anoxic zone was 0.3 mg / L, redox potential was -30 mV, pH was 7.2, hydraulic retention time was 6 hours, and MLSS concentration was 4.0 g / L; dissolved oxygen in the anaerobic zone was <0.1 mg / L, redox potential was -150 mV, pH was 7.0, hydraulic retention time was 2 hours, and MLSS concentration was 4.0 g / L.

[0088] The total hydraulic retention time of the system is 20 hours, the solid retention time is 28 days, the internal reflow ratio is 250% of the inlet flow, the return activated sludge ratio is 70% of the inlet flow, and the excess sludge discharge rate is 3.5% of the system volume / day.

[0089] After 45 days of operation, the system reached a stable state, and the effluent water quality indicators were: COD 45 mg / L, BOD 12 mg / L, NH4 + -N 2.0 mg / L, TN 15 mg / L, TP 0.8 mg / L. Wastewater treatment efficiency: COD removal rate 85%, BOD removal rate 93%, TN removal rate 57%, TP removal rate 80%. System energy consumption is 0.8 kWh / m³.

[0090] Example 5: Treatment of high hydraulic load municipal sewage

[0091] This example uses a 300 cubic meter mixed functional area variable bioreactor to treat urban sewage under high hydraulic load conditions during the rainy season. The reactor structure and materials are the same as in Example 1, but the size is enlarged accordingly.

[0092] The influent water quality parameters to be treated are: COD 150-200 mg / L, BOD 70-100 mg / L, NH4 + -N 15-20 mg / L, TP 2-3 mg / L, water temperature 20-25℃, hydraulic load is 50% higher than conventional design.

[0093] The system initially sets the functional zone volume ratio as: 45% aerobic zone, 35% anoxic zone, and 20% anaerobic zone. As the system operates, the control system automatically adjusts the volume ratio of each zone based on real-time monitored water quality parameters, generally maintaining it between 40% and 50% aerobic zone, 30% and 40% anoxic zone, and 15% and 25% anaerobic zone.

[0094] To cope with high hydraulic load conditions, this embodiment utilizes a high-density aeration system in the aerobic zone, with an aerator density reaching 15% of the bottom area. Mixing intensity is also increased in the anoxic and anaerobic zones. The aeration system in the aerobic zone utilizes EPDM membrane-type microporous aerators with a bubble size of 1 to 2 mm and a gas flow rate of 12 standard cubic meters per hour per square meter. The mixing system in the anoxic zone utilizes HDPE aerators with a bubble size of 6 to 8 mm and a gas flow rate of 1.8 standard cubic meters per hour per square meter. The anaerobic zone utilizes a 316L stainless steel submersible agitator with a 1.0 kW motor, a 400 mm diameter glass fiber reinforced polypropylene impeller, and a rotational speed of 120 rpm.

[0095] The operating parameters were set as follows: dissolved oxygen 2.0 mg / L in the aerobic zone, redox potential +180 mV, pH 7.4, hydraulic retention time 5 hours, and MLSS concentration 4.5 g / L; dissolved oxygen 0.3 mg / L in the anoxic zone, redox potential -20 mV, pH 7.3, hydraulic retention time 3 hours, and MLSS concentration 4.5 g / L; dissolved oxygen <0.1 mg / L in the anaerobic zone, redox potential -180 mV, pH 7.0, hydraulic retention time 1.5 hours, and MLSS concentration 4.5 g / L.

[0096] The total hydraulic retention time of the system is 9.5 hours, the solid retention time is 12 days, the internal reflow ratio is 300% of the inlet flow, the return activated sludge ratio is 85% of the inlet flow, and the excess sludge discharge rate is 8% of the system volume / day.

[0097] After 30 days of operation, the system reached a stable state, and the effluent water quality indicators were: COD 40 mg / L, BOD 10 mg / L, NH4 + -N 1.5 mg / L, TN 10 mg / L, TP 0.7 mg / L. Wastewater treatment efficiency: COD removal rate 78%, BOD removal rate 89%, TN removal rate 77%, TP removal rate 75%. System energy consumption is 0.65 kWh / m3.

[0098] Example 6: Treatment of mixed sewage with large fluctuations in water quality

[0099] This embodiment uses a bioreactor with a variable mixing function zone and a working volume of 120 cubic meters to treat mixed urban and industrial sewage with large fluctuations in water quality. The reactor structure and materials are the same as those in Example 1.

[0100] The influent water quality parameters fluctuate widely: COD 200-700 mg / L, BOD 100-400 mg / L, NH4 + -N 20-70 mg / L, TP 3-12 mg / L, water temperature 15-30℃.

[0101] This embodiment gives full play to the advantages of variable functional zones. The control system dynamically adjusts the volume ratio of each zone according to the real-time monitoring of the influent water quality. The aerobic zone varies within the range of 20% to 60%, the anoxic zone within the range of 20% to 50%, and the anaerobic zone within the range of 10% to 40%.

[0102] To enhance the adaptability of the system, this embodiment added biofilm carrier media to the three functional areas. The media were made of HDPE, with a specific surface area of ​​800 square meters / cubic meter, a density of 0.96 grams / cubic centimeter, a size of 15 mm, and a filling ratio of 35%, 25%, and 20% of the regional volume, respectively.

[0103] The aeration system in the aerobic zone utilizes EPDM membrane microporous aerators with bubble sizes ranging from 1 to 3 mm and a gas flow rate of 2 to 12 Nm³ / h / m², automatically adjusted by the control system based on dissolved oxygen demand. The mixing system in the anoxic zone utilizes HDPE aerators with bubble sizes ranging from 5 to 8 mm and a gas flow rate of 0.5 to 2.0 Nm³ / h / m². The anaerobic zone utilizes a 316L stainless steel submersible agitator with a 0.5 kW motor, a 300 mm diameter glass fiber reinforced polypropylene impeller, and a speed of 50 to 150 rpm, automatically adjusted by the control system based on mixing requirements.

[0104] The operating parameters are set as follows: dissolved oxygen in the aerobic zone is 1.5-3.5 mg / L, redox potential is +100 to +300 mV, pH is 6.8-7.8, hydraulic retention time is 4 to 12 hours, and MLSS concentration is 3.0 to 5.0 g / L; dissolved oxygen in the anoxic zone is 0.1-0.5 mg / L, redox potential is -50 to +50 mV, pH is 6.8-7.8, hydraulic retention time is 2 to 6 hours, and MLSS concentration is 3.0 to 5.0 g / L; dissolved oxygen in the anaerobic zone is <0.1 mg / L, redox potential is -100 to -250 mV, pH is 6.5-7.5, hydraulic retention time is 1 to 3 hours, and MLSS concentration is 3.0 to 5.0 g / L.

[0105] The total hydraulic retention time of the system is 8 to 24 hours, the solid retention time is 10 to 30 days, the internal reflow ratio is 100% to 400% of the inlet flow rate, the return activated sludge ratio is 50% to 100% of the inlet flow rate, and the residual sludge discharge rate is 3% to 10% of the system volume / day.

[0106] After 60 days of operation, despite the significant fluctuations in the influent water quality, the system maintained a stable treatment effect, with the average effluent water quality indicators being: COD 45 mg / L, BOD 12 mg / L, NH4 + -N 1.8 mg / L, TN 12 mg / L, TP 0.9 mg / L. Wastewater treatment efficiency: COD removal rate 88%, BOD removal rate 94%, TN removal rate 80%, TP removal rate 85%. Average system energy consumption is 0.55 kWh / m³.

[0107] In order to verify the innovation and superiority of the present invention, the following comparative examples were designed:

[0108] Comparative Example 1: Traditional A with fixed area ratio 2 I / O Process

[0109] This comparative example uses the same volume of A as in Example 1 2 / O process treatment system, but the volume ratio of each functional zone is fixed, namely: anaerobic zone 15%, anoxic zone 25%, aerobic zone 60%. The remaining equipment and materials are basically the same as those in Example 1, but without the function of automatically adjusting the volume ratio of the functional zones.

[0110] Under the same influent conditions (COD 300-400 mg / L, BOD 150-200 mg / L, NH4 + The system achieved comparable treatment performance to Example 1 when the inlet water quality was stable (NH3-N 30-40 mg / L, TP 4-6 mg / L, and water temperature 15-25°C). However, when the inlet water quality fluctuated, particularly when the ammonia nitrogen concentration rose to 50 mg / L, the aerobic zone volume could not be increased, causing the system effluent ammonia nitrogen concentration to rise to 4.5 mg / L, and the total nitrogen removal rate to drop to 70%. Simultaneously, the system's energy consumption rose to 0.65 kWh / m3, approximately 30% higher than that of Example 1.

[0111] Comparative Example 2: Variable Area Bioreactor without Intelligent Control System

[0112] This comparative example employed the same movable baffle system as Example 6, but without the intelligent control system. Functional area volume adjustments required manual adjustments based on laboratory water quality analysis results. Adjustments were limited to once daily, and adjustments relied on operator experience.

[0113] Treating mixed sewage with large fluctuations in water quality (COD 200-700 mg / L, BOD 100-400 mg / L, NH4 +-N 20-70 mg / L, TP 3-12 mg / L, water temperature 15-30℃), the average treatment effect of the system during 60 days of operation is: COD removal rate 82%, BOD removal rate 90%, TN removal rate 72%, TP removal rate 78%. The average water quality indicators of the effluent are: COD 65 mg / L, BOD 20 mg / L, NH4 + -N 4.5 mg / L, TN 18 mg / L, TP 1.6 mg / L. The average energy consumption of the system is 0.7 kWh / m3.

[0114] Compared with Example 6, Comparative Example 2 performed poorly in terms of treatment efficiency and energy consumption. The main reason was that manual adjustment could not respond to changes in water quality in a timely manner, and the accuracy of adjustment decisions was limited by the operator's experience.

[0115] Comparative Example 3: Membrane Bioreactor (MBR) System

[0116] This comparative example uses a conventional membrane bioreactor system with the same working volume as Example 1, but adopts a fixed functional zone design to improve the biomass concentration and effluent water quality through a membrane separation device.

[0117] Under the same influent conditions (COD 300-400 mg / L, BOD 150-200 mg / L, NH4 + -N 30-40 mg / L, TP 4-6 mg / L, water temperature 15-25℃), the system's effluent quality indicators are: COD 25 mg / L, BOD 5 mg / L, NH4 + -N 0.5 mg / L, TN 9 mg / L, TP 0.8 mg / L. Sewage treatment efficiency: COD removal rate 93%, BOD removal rate 97%, TN removal rate 80%, TP removal rate 85%.

[0118] Although the effluent quality of the MBR system was slightly better than that of Example 1, its energy consumption was as high as 1.2 kWh / m³, 2.4 times that of Example 1. Furthermore, the initial investment cost of the MBR system was approximately 40% higher than that of Example 1, and the membrane modules required regular replacement, resulting in high operating and maintenance costs.

[0119] Comparative Example 4: Low-temperature operation system without biofilm carrier

[0120] This comparative example has the same configuration as Example 4, but without the addition of biofilm carrier medium. After 45 days of operation under low temperature conditions (water temperature 5-10°C), the treatment effect of the system is: COD removal rate 75%, BOD removal rate 85%, TN removal rate 45%, TP removal rate 70%. The effluent water quality indicators are: COD 70 mg / L, BOD 22 mg / L, NH4 +-N 8.0 mg / L, TN 20 mg / L, TP 1.2 mg / L.

[0121] Compared with Example 4 in which biofilm carriers were added, the treatment effect was significantly reduced, especially the removal efficiency of ammonia nitrogen, indicating that biofilm carriers play an important role in maintaining the activity of nitrifying bacteria under low temperature conditions.

[0122] In order to comprehensively evaluate the performance of the sewage treatment process of the present invention using a bioreactor with a variable mixing functional area, a systematic performance test was conducted on the above-mentioned examples and comparative examples. The test methods and indicators are as follows:

[0123] Standard water quality analysis methods were used to determine the concentrations of ammonia nitrogen, nitrate nitrogen, nitrite nitrogen, and total nitrogen in the inlet and outlet water. The total nitrogen removal rate was calculated using the following formula: TN removal rate (%) = 100 × (TN inlet - TN outlet) / TN inlet. The ammonia nitrogen removal rate was calculated using the following formula: NH4 + -N removal rate (%) = 100 × (NH4 + -N inlet water-NH4 + -N outflow) / NH4 + -N water inlet.

[0124] Figure 5 The results show a comparison of the total nitrogen removal rates of Examples 1-3 and Comparative Examples 1 and 2 under fluctuating influent water quality conditions. The results demonstrate that the variable-zone bioreactor of the present invention maintains a high and stable total nitrogen removal rate (75% to 85%) despite fluctuating influent ammonia nitrogen concentrations, while the total nitrogen removal rate of Comparative Example 1, which uses a fixed zone ratio, drops significantly to below 70% when the influent ammonia nitrogen concentration increases. Comparative Example 2, which lacks intelligent control, despite having adjustable zones, experiences significant fluctuations in its total nitrogen removal rate (65% to 80%) due to untimely adjustments.

[0125] Standard water quality analysis methods were used to determine the concentrations of orthophosphate and total phosphorus in the inlet and outlet water. The total phosphorus removal rate was calculated using the following formula: TP removal rate (%) = 100 × (TP inlet - TP outlet) / TP inlet.

[0126] Figure 6 The total phosphorus removal rates of Examples 4-6 and Comparative Examples 3 and 4 under conditions of fluctuating total phosphorus concentration in the influent are compared. The results show that the system of the present invention can maintain a total phosphorus removal rate of 80% to 95% by automatically adjusting the volume ratio of the anaerobic zone when the total phosphorus concentration in the influent changes. Although the MBR system (Comparative Example 3) has a higher solid retention capacity, its phosphorus removal efficiency drops to about 75% when the total phosphorus concentration in the influent increases significantly. Under low temperature conditions, the phosphorus removal rate of Comparative Example 4 further drops to 70% due to the lack of support from the biofilm carrier.

[0127] In order to test the stability of the system under conditions of large fluctuations in influent water quality, Example 6 and Comparative Example 2 were subjected to a 60-day continuous operation test, during which multiple influent water quality shock loads were artificially created.

[0128] Figure 7 The results show the changes in effluent quality for both systems when faced with a sudden 50% increase in influent COD, ammonia nitrogen, and total phosphorus concentrations. The results demonstrate that the intelligent control system of the present invention rapidly responds to changes in influent quality, automatically adjusting the functional area volume ratios and operating parameters, allowing effluent quality to stabilize within 12 hours after the load shock. In contrast, in Comparative Example 2, which lacks intelligent control, effluent quality took over 48 hours to stabilize and experienced greater fluctuations.

[0129] Energy consumption of each system was monitored, including aeration, agitation, pumping, and control system energy consumption. The results showed that the average energy consumption of the embodiment of the present invention was 0.5-0.8 kWh / m³, saving 20%-30% compared to the traditional A2 / O process (Comparative Example 1) and 40%-60% compared to the MBR system (Comparative Example 3).

[0130] The main sources of energy savings are: (1) optimizing the biological treatment process and reducing unnecessary energy consumption by precisely controlling the volume ratio of functional areas; (2) using refined aeration control to adjust the aeration volume according to actual oxygen demand; and (3) dynamically adjusting the internal recirculation ratio according to treatment needs to avoid over-pumping.

[0131] A comprehensive evaluation of the treatment effects, energy efficiency, and adaptability of each example revealed that Example 6 demonstrated the best overall performance, making it particularly suitable for treating mixed wastewater with significant fluctuations in water quality. This example fully demonstrates the core innovation of this invention—adaptive functional zone volume adjustment and the advantages of an intelligent control system. While ensuring effluent quality, it achieves low energy consumption and high system stability.

[0132] The core working mechanism of the sewage treatment process of the variable mixing functional zone bioreactor of the present invention is:

[0133] (1) Dynamic space allocation: Through the movable baffle system, the volume ratio of the aerobic zone, anoxic zone, and anaerobic zone can be adjusted in real time, so that the space resources of the reactor can be optimally allocated according to the treatment requirements. For example, when the ammonia nitrogen load of the influent increases, the system will automatically increase the volume ratio of the aerobic zone to improve the nitrification capacity; when the total phosphorus concentration of the influent increases, the system will increase the volume ratio of the anaerobic zone to enhance the biological phosphorus removal effect.

[0134] (2) Precise environmental control: Through a multi-point online monitoring system and multi-level control strategy, ideal environmental parameters such as dissolved oxygen, redox potential, and pH are precisely maintained in each functional zone, creating optimal conditions for the growth and metabolic activities of specific microbial communities. This precise control enables nitrification, denitrification, and biological phosphorus removal to proceed simultaneously and efficiently.

[0135] (3) Predictive adjustment: The predictive control function based on machine learning algorithms can predict the trend of influent water quality changes based on historical data and influent pattern recognition, adjust the system configuration in advance, and avoid fluctuations in treatment effects caused by delayed response.

[0136] (4) Multi-stage bioaugmentation: Through the optional biofilm carrier system, specific functional microorganisms that grow attached to the fixed biomass are added to improve the biological treatment capacity of the system, especially under low temperature or high load conditions, effectively compensating for the problem of insufficient plankton activity.

[0137] The synergistic effect of these mechanisms enables the present invention to effectively adapt to fluctuations in influent water quality while maintaining a high treatment efficiency, thereby achieving intelligent, efficient and low-energy sewage treatment.

[0138] The mixed functional area variable bioreactor sewage treatment process provided by the present invention realizes automatic adjustment of the functional area volume ratio through an innovative movable baffle system, a precision sensor network and an intelligent control algorithm. It can effectively cope with fluctuations in influent water quality and maintain stable nitrogen and phosphorus removal effects, while reducing energy consumption, reducing floor space and improving the overall efficiency of the system.

[0139] Compared with traditional fixed-structure bioreactors, the present invention exhibits obvious advantages in treating sewage with large fluctuations in influent water quality, and is particularly suitable for urban sewage treatment and industrial wastewater treatment with significant seasonal changes.

Claims

1. A mixed functional area variable bioreactor sewage treatment process, characterized in that: The following steps are involved: The sewage to be treated is introduced into a monomer reactor having adjustable aerobic zone, anoxic zone and anaerobic zone; Real-time detection of influent water quality parameters using online monitoring equipment, the parameters including at least COD, ammonia nitrogen, total nitrogen and total phosphorus concentrations; Based on the influent water quality parameters, the central control system automatically adjusts the volume ratio of the aerobic zone, the anoxic zone and the anaerobic zone, and the volume ratio adjustment is achieved through a movable partition; Adjust aeration intensity and internal recirculation ratio according to the real-time monitoring of dissolved oxygen, redox potential and pH value in each functional area; nitrification reaction is carried out in the aerobic zone to convert ammonia nitrogen into nitrate nitrogen; The anoxic zone performs a denitrification reaction to convert nitrate nitrogen into nitrogen gas; Enhanced biological phosphorus removal is achieved through the alternating action of the anaerobic zone and the aerobic zone; Discharge the treated sewage out of the system.

2. The sewage treatment process according to claim 1, characterized in that: The movable partition is position-adjusted by a precision drive system, which includes: Brushless DC motor with a rated power of 0.25-1.0 kW; Planetary reduction gearbox with a reduction ratio of 50:1 to 100:1; Stainless steel screw, pitch 5-10 mm; Ceramic-coated aluminum linear guides with a load capacity of 50-200 kg; The positioning accuracy of the driving system is ±5 mm, and the moving speed is 5 to 20 mm / min.

3. The sewage treatment process according to claim 1, characterized in that: The online monitoring equipment includes: The dissolved oxygen sensor adopts optical luminescence method, with a measurement range of 0-20 mg / L and an accuracy of ±0.1 mg / L; Ammonia nitrogen sensor using ion-selective electrode, with a measurement range of 0-100 mg / L and an accuracy of ±3%; Nitrate nitrogen sensor using UV absorption method, with a measurement range of 0-100 mg / L and an accuracy of ±5%; A phosphate sensor using colorimetry has a measurement range of 0-20 mg / L and an accuracy of ±2%; Glass electrode pH sensor with a measuring range of pH 4-10 and an accuracy of ±0.1 unit; Platinum electrode redox potential sensor with a measurement range of -500 to +500 mV and an accuracy of ±5 mV; The mixed liquid suspended solid concentration sensor adopts near infrared absorption method, with a measurement range of 0-15 g / L and an accuracy of ±5%.

4. The sewage treatment process according to claim 1, characterized in that: The central control system adopts a multi-level control strategy, including: The basic control loop is used to maintain the dissolved oxygen concentration in the aerobic zone at 1.5-3.5 mg / L, the mixing intensity at 5-15 W / m3, and the reflux ratio at 100%-400% of the inlet water flow rate; Zone volume optimization control, dynamically adjusting zone volume based on nitrogen removal demand, with a response time of 15 to 60 minutes; Predictive control uses machine learning algorithms to make adjustments based on historical performance data and water inflow pattern recognition, with a prediction adjustment time of 1 to 12 hours; The control system uses a fuzzy logic controller to adjust the zone volume and determine the optimal zone configuration based on inlet and outlet water quality parameters.

5. The sewage treatment process according to claim 1, characterized in that: The aeration system of the aerobic zone includes: Membrane type microporous aerator, made of EPDM material, bubble size is 1 to 3 mm; PVC frame, maximum pressure bearing capacity 100 kPa; ABS material distribution pipe, gas flow rate is 2-12 standard cubic meters / hour·square meter; The oxygen transfer efficiency of the aeration system under standard conditions (20° C., clean water) is 3.0-4.5 kg oxygen / kWh, and the aerator density is 10%-15% of the bottom area.

6. The sewage treatment process according to claim 1, characterized in that: The anoxic zone adopts a medium bubble mixing system, including: The aerator is made of HDPE material, and the bubble size is 5 to 8 mm; PVC grade 80 distribution pipe, gas flow rate 0.5-2.0 Nm3 / h·m2; The mixing system provides gentle mixing without excessive oxygen transfer, maintaining dissolved oxygen levels in the anoxic zone at 0.1-0.5 mg / L.

7. The sewage treatment process according to claim 1, characterized in that: The anaerobic zone adopts a hydraulic mixing system, including: 316L stainless steel submersible agitator, motor power 0.25-1.0 kW; Glass fiber reinforced polypropylene impeller, diameter 200-400 mm; The speed is 50-150 rpm; The mixing system provides a power input of 5 to 10 watts per cubic meter, preventing the introduction of oxygen while ensuring uniform distribution of biomass.

8. The sewage treatment process according to claim 1, characterized in that: The process parameters of each functional area are as follows: Aerobic zone: dissolved oxygen 1.5-3.5 mg / L, redox potential +100 to +300 mV, pH 6.8-7.8, hydraulic retention time 4 to 12 hours, mixed liquor suspended solids concentration 3.0 to 5.0 g / L; Anoxic zone: dissolved oxygen 0.1-0.5 mg / L, redox potential -50 to +50 mV, pH 6.8-7.8, hydraulic retention time 2 to 6 hours, mixed liquor suspended solids concentration 3.0 to 5.0 g / L; Anaerobic zone: dissolved oxygen less than 0.1 mg / L, redox potential -100 to -250 mV, pH 6.5-7.5, hydraulic retention time 1 to 3 hours, mixed liquor suspended solids concentration 3.0 to 5.0 g / L.

9. The sewage treatment process according to claim 1, characterized in that: The overall system parameters of the process include: The total hydraulic retention time is 8 to 24 hours; Solid residence time is 10 to 30 days; F / M ratio is 0.05-0.15 kg BOD / kg MLVSS·day; The internal reflux ratio is 100% to 400% of the inlet water flow rate; The ratio of returned activated sludge is 50% to 100% of the influent flow rate; The residual sludge discharge rate is 3% to 10% of the system volume per day.

10. The sewage treatment process according to claim 1, characterized in that: It also includes an optional biofilm carrier medium reinforcement system. The biofilm carrier medium is made of HDPE material, has a specific surface area of ​​500-1000 square meters / cubic meter, a density of 0.95-0.98 grams / cubic centimeter, a size of 10-25 mm, a filling ratio of 15% to 40% of the regional volume, and a biofilm thickness of 0.1-2.0 mm; the carrier medium provides an attachment surface for the immobilized professional microbial community, enhancing nitrification in the aerobic zone and denitrification in the anoxic zone.

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