A wastewater treatment system and method based on ultrasonic micro-electrolysis combined with catalytic oxidation

Abstract

This invention discloses a wastewater treatment system and method based on ultrasonic micro-electrolysis combined with catalytic oxidation, belonging to the field of environmental protection technology. The method includes: wastewater undergoing ultrasonic-enhanced micro-electrolysis to generate active free radicals for pretreatment, followed by deep mineralization in a catalytic oxidation unit with ozone; dynamic adjustment of ultrasonic power, ozone dosage, and reflux ratio through fluid circulation and an intelligent control unit; and online monitoring to ensure compliance with standards for effluent. The system integrates ultrasonic micro-electrolysis, catalytic oxidation, intelligent control, and automatic backwashing modules to achieve closed-loop optimized operation. This invention solves the problems of low efficiency, strong reagent dependence, equipment vulnerability, and poor adaptability in existing technologies for treating recalcitrant organic matter. It significantly improves COD removal rate to over 95%, reduces energy consumption by 20%, requires no external reagents, and is suitable for treating challenging wastewater from dyeing, printing, and pharmaceutical industries, possessing advantages of high efficiency, stability, low consumption, and engineering feasibility.

Description

Technical Field

[0001] This invention relates to the field of environmental protection technology, and in particular to a wastewater treatment system and method based on ultrasonic micro-electrolysis combined with catalytic oxidation. Background Technology

[0002] With increasingly stringent industrial wastewater discharge standards and increasingly complex pollutant compositions, the demand for efficient, low-consumption, and sustainable advanced treatment technologies in the wastewater treatment field continues to rise. Current mainstream treatment processes largely rely on physical sedimentation, chemical reagent addition, or single advanced oxidation methods, their core principles based on static pollutant degradation models. However, organic pollutants in wastewater, especially recalcitrant macromolecular organic matter and emerging trace pollutants, have stable chemical structures, high biotoxicity, and strong environmental residues, making them difficult to completely mineralize under conventional treatment conditions. While physical filtration and mechanical cleaning can remove suspended solids and some sedimentary sludge, they cannot destroy the molecular structure of dissolved organic matter; chemical reagents, although capable of partial oxidation or flocculation, easily cause secondary pollution, increase operating costs, and have poor adaptability to water quality fluctuations. Existing technologies generally lack multi-process synergistic enhancement mechanisms, resulting in low reaction efficiency, high energy consumption, and equipment redundancy, making it difficult to meet the comprehensive requirements of modern wastewater treatment for "high-efficiency degradation, compact structure, stable operation, and green low-carbon" practices.

[0003] Among them, ultrasonic cavitation, micro-electrolysis galvanic cell reaction and catalytic oxidation technologies are regarded as cutting-edge directions for the deep treatment of recalcitrant organic wastewater due to their unique advantages in free radical generation, enhanced interfacial mass transfer and pollutant bond breaking. Ultrasonic waves can generate local high temperature and high pressure through cavitation effect, which promotes free radical generation and enhances mass transfer. Micro-electrolysis uses electrode materials such as iron and carbon to construct a galvanic cell system, and achieves pollutant conversion through oxidation-reduction, adsorption flocculation and electrodeposition. Catalytic oxidation uses catalysts to activate oxidants and directionally generate strong oxidizing free radicals to achieve deep mineralization of organic matter.

[0004] However, existing technical solutions often deploy the above processes in isolation or simply in series, lacking reaction interface coupling design and energy synergistic regulation mechanisms. This results in low free radical utilization, redundant reaction paths, and poor equipment integration, making it difficult to leverage the advantages of technological synergy. Structural defects still exist in achieving systematic integration of ultrasonic micro-electrolysis combined with catalytic oxidation: uneven ultrasonic field distribution leads to insufficient local cavitation intensity, weakening the activation effect on the micro-electrolysis interface; micro-electrolysis packing is prone to caking and passivation, lacking an in-situ regeneration mechanism, resulting in continuous decay of reaction activity; the catalytic oxidation unit is disconnected from the upstream process, with oxidant addition and free radical generation being asynchronous, causing oxidant waste and byproduct accumulation; the system as a whole lacks intelligent feedback control, unable to dynamically adjust ultrasonic power, electrolysis current, and catalyst dosage according to water quality fluctuations, leading to rigid operating parameters and artificially high energy consumption. Summary of the Invention

[0005] To address the above problems, this invention provides a wastewater treatment system and method based on ultrasonic micro-electrolysis combined with catalytic oxidation, which solves the problems of low efficiency, insufficient equipment integration, poor operational stability, strong dependence on external chemical agents, easy wear of mechanical structures, high maintenance costs, and weak adaptability under complex water quality conditions in the treatment of recalcitrant organic pollutants.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] A wastewater treatment system based on ultrasonic micro-electrolysis combined with catalytic oxidation includes:

[0008] The ultrasonic micro-electrolysis reaction unit is used to activate the micro-electrolysis reaction through an iron-carbon packed bed and an ultrasonic transducer array to generate atomic hydrogen and hydroxyl radicals, thereby destroying the molecular structure of organic pollutants.

[0009] A catalytic oxidation reaction unit is used to synergistically oxidize residual organic matter with a supported heterogeneous catalyst and an ozone gas distributor.

[0010] The fluid distribution and circulation unit is used to achieve uniform water distribution and partial water return through multi-channel distribution pipelines and a return pump.

[0011] The intelligent control unit is used to collect water quality and operating parameters through a sensor array and dynamically adjust the ultrasonic power, ozone dosage, reflux ratio and inlet flow rate.

[0012] The tailwater monitoring and feedback unit is used to continuously monitor the quality of the final effluent and trigger alarms and emergency procedures when the quality exceeds the standard.

[0013] The packing bed in the ultrasonic micro-electrolysis reaction unit adopts a stepped layered structure, with a coarse particle layer on top and a fine particle layer on the bottom, and porous partitions between the layers; the ultrasonic transducer array adopts a phased array arrangement to support sound field focusing and scanning; the catalyst in the catalytic oxidation reaction unit has a honeycomb integral structure, divided into upper and lower reaction zones; the ozone gas distributor has a microporous titanium plate structure, with a gas pressure stabilizing chamber and a guide plate below; the intelligent control unit adopts a fuzzy adaptive control algorithm; the tailwater monitoring and feedback unit is equipped with multi-parameter integrated sensors and a 3-level alarm mechanism.

[0014] A wastewater treatment method based on ultrasonic microelectrolysis combined with catalytic oxidation includes:

[0015] Step S1: The wastewater to be treated is pumped to the inlet of the ultrasonic micro-electrolysis reaction unit. The ultrasonic micro-electrolysis reaction unit is equipped with a packing bed composed of iron-carbon composite particles with a particle size ranging from 3 mm to 8 mm. The packing bed stacking height is 60% to 80% of the effective volume of the reactor. In the ultrasonic micro-electrolysis reaction unit, an ultrasonic field with a frequency of 20 kHz to 40 kHz and a power density of 0.5 W / cm³ to 1.5 W / cm³ is applied through an ultrasonic transducer array set on the upper and lower sides. The ultrasonic wave propagation direction is perpendicular to the wastewater flow direction, which activates the iron-carbon micro-electrolysis reaction to generate atomic hydrogen and hydroxyl radicals, destroying the molecular structure of organic pollutants and improving their biodegradability.

[0016] In step S2, the effluent pretreated by ultrasonic micro-electrolysis is introduced into a catalytic oxidation reaction unit. The catalytic oxidation reaction unit is filled with a heterogeneous catalyst with titanium dioxide as a carrier and nano-sized copper oxide and manganese oxide composite active components loaded on the surface. The loading amount is 5% to 15% of the carrier mass. In the catalytic oxidation reaction unit, ozone is added through a microporous titanium plate ozone gas distributor set at the bottom. The ozone addition amount is 0.1 g to 0.5 g per liter of wastewater, and the gas flow rate is controlled at 0.5 liters to 2 liters per minute, so that the dissolved ozone comes into contact with the active sites on the catalyst surface and synergistically oxidizes the residual organic matter into carbon dioxide and water.

[0017] Step S3: The ultrasonic micro-electrolysis pretreatment effluent is evenly distributed to multiple parallel reaction channels of the catalytic oxidation reaction unit through a multi-channel distribution pipeline. Each channel is equipped with an independent flow meter and regulating valve to ensure hydraulic load balance. A portion of the effluent from the catalytic oxidation reaction unit is returned to the inlet of the ultrasonic micro-electrolysis reaction unit at a ratio of 10% to 30% by a reflux pump to form an internal circulation enhanced reaction system.

[0018] Step S4: The intelligent control unit collects real-time data from the conductivity sensor and redox potential sensor installed at the inlet of the ultrasonic micro-electrolysis reaction unit, the chemical oxygen demand online monitoring instrument and dissolved ozone concentration sensor installed at the outlet of the catalytic oxidation reaction unit, and the total organic carbon analyzer installed at the tailwater discharge outlet, and dynamically adjusts the ultrasonic transducer power, ozone dosage, reflux ratio and influent flow rate.

[0019] Step S5: The chemical oxygen demand, biochemical oxygen demand, total organic carbon, suspended solids concentration and heavy metal ion residue of the final effluent are continuously monitored by the tailwater monitoring and feedback unit. The sampling frequency is once every 10 minutes. When the monitoring index exceeds the preset threshold, an alarm is triggered and the emergency handling procedure is started.

[0020] The iron-carbon packing bed in the ultrasonic micro-electrolysis reaction unit adopts a stepped layered arrangement structure. The upper layer is a coarse particle layer with a particle size of 6 mm to 8 mm, and the lower layer is a fine particle layer with a particle size of 3 mm to 5 mm. Porous partitions with a pore size of 1 / 2 to 2 / 3 of the packing particle size are set between the layers. The partitions are 5 mm thick and have a porosity of 30% to 50%. The surface is coated with a polytetrafluoroethylene anti-stick coating.

[0021] The ultrasonic transducer array adopts a phased array arrangement, consisting of 16 piezoelectric ceramic transducers arranged in a 4×4 matrix with a spacing of 10 cm between adjacent transducers. Each transducer is equipped with an independent phase controller with a phase adjustment accuracy of 0.1 degrees and a frequency adjustment step of 10 Hz. The sound field scanning mode adopts a spiral trajectory scanning with a scanning cycle of 10 seconds.

[0022] The catalyst in the catalytic oxidation reaction unit adopts a honeycomb integral structure with a specific surface area greater than 300 square meters per gram, a porosity of 40% to 60%, a pore diameter of 1 mm to 3 mm, and a water flow resistance of less than 5000 Pa. The catalyst module has a total height of 1.2 meters and is divided into two reaction zones, with the upper zone filled with a catalyst loaded with copper oxide and the lower zone filled with a catalyst loaded with manganese oxide.

[0023] The ozone gas distributor is made of a 3 mm thick microporous titanium plate with an opening rate of 25%, a pore size distribution of 10 micrometers to 50 micrometers, and a pore density of 2000 per square centimeter. A gas pressure stabilizing chamber with a height of 10 cm is set below the distributor, and a guide plate with an inclination angle of 45 degrees and a spacing of 5 cm is installed in the chamber.

[0024] The central processing unit in the intelligent control unit adopts a fuzzy adaptive control algorithm. The input variables include oxidation-reduction potential, chemical oxygen demand change rate, dissolved ozone concentration deviation and conductivity fluctuation amplitude. The output variables are ultrasonic power adjustment coefficient, ozone flow correction value, reflux ratio adjustment amount and inlet valve opening. The control cycle is 5 seconds, and the adjustment amplitude of each adjustment does not exceed 10% of the previous value.

[0025] The water quality comprehensive analysis module in the tailwater monitoring and feedback unit uses a multi-parameter integrated sensor to simultaneously detect chemical oxygen demand, ammonia nitrogen, total phosphorus, turbidity, and pH value, with a detection accuracy of ±2% of full scale. The alarm system has three threshold levels: Level 1 triggers a yellow indicator light and a low-frequency buzzer; Level 2 triggers a red indicator light, a high-frequency buzzer, and sends an SMS message; and Level 3 triggers system shutdown and initiates an emergency flushing procedure.

[0026] Pretreatment steps: filtration through a 5 mm pore size screen, sedimentation with a 30-minute retention time, and adjustment of the influent pH to 5.5 to 7.5 using sodium hydroxide or sulfuric acid solution; and posttreatment steps: adsorption with coconut shell-based granular activated carbon with an iodine value greater than 1000 mg / g for 20 minutes, followed by ultraviolet disinfection with an irradiation dose of 40 mJ / cm².

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] This invention significantly improves the efficiency of generating active species in the iron-carbon system by constructing an ultrasonic field-enhanced micro-electrolysis reaction mechanism, shortening the reaction time by more than 30%; it achieves deep mineralization of organic pollutants by coupling a supported heterogeneous catalytic oxidation unit, with a chemical oxygen demand removal rate of over 95%; and it ensures the hydraulic balance and stability of the reaction system through fluid distribution and circulation design, reducing the risk of local blockage.

[0029] This invention achieves multi-parameter closed-loop regulation through an intelligent control unit, enhancing the system's adaptability and operational efficiency; through a tailwater monitoring and feedback mechanism, it ensures that the effluent quality consistently meets standards and supports continuous system performance optimization; through automatic backwashing and energy consumption optimization modules, it extends equipment lifespan and reduces operating costs by more than 20%; the overall system has a compact structure and high integration, requires no external chemical additives, is environmentally friendly, and is suitable for the efficient treatment of various complex water qualities such as high-concentration organic wastewater, dyeing and printing wastewater, pharmaceutical wastewater, and chemical wastewater. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. The following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the overall technical architecture of a wastewater treatment system and method based on ultrasonic micro-electrolysis combined with catalytic oxidation proposed in this invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but is merely a selection of embodiments of the present invention.

[0033] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the overall technical architecture of a wastewater treatment system and method based on ultrasonic micro-electrolysis combined with catalytic oxidation, provided by an embodiment of the present invention.

[0034] A wastewater treatment method based on ultrasonic microelectrolysis combined with catalytic oxidation includes:

[0035] Step S1 involves filtering the water through a 5 mm pore size screen, allowing it to settle for 30 minutes, and adjusting the pH of the influent to the range of 5.5 to 7.5 using sodium hydroxide or sulfuric acid solution to match the optimal operating range for the subsequent ultrasonic micro-electrolysis reaction.

[0036] The bar screen system uses a rotary mechanical bar screen with a bar spacing of 5 mm, a bar thickness of 10 mm, and is made of 304 stainless steel. It is equipped with an automatic slag removal device with a slag removal cycle of once every 30 minutes.

[0037] The sedimentation tank is a horizontal flow type, with a length of 5 meters, a width of 2 meters, a depth of 1.5 meters, and a bottom slope of 5%. It is equipped with a sand scraper with a travel speed of 0.5 meters per minute.

[0038] The pH adjustment system adopts a dual-tank parallel structure, with one tank working and the other on standby. Each tank has a volume of 0.5 cubic meters and is equipped with a stirrer with a speed of 100 revolutions per minute and a blade diameter of one-third of the tank diameter. The online pH monitor has a measurement range of 0 to 14, a resolution of 0.01, a response time of 5 seconds, and a control accuracy of ±0.1.

[0039] Wastewater to be treated is transported to the inlet of the ultrasonic micro-electrolysis reactor unit via an inlet pump with a flow rate ranging from 1 to 10 cubic meters per hour. The ultrasonic micro-electrolysis reactor unit is equipped with a packing bed composed of iron-carbon composite particles with a particle size ranging from 3 mm to 8 mm. The packing bed is stacked to a height of 60% to 80% of the effective volume of the reactor.

[0040] The iron-carbon packed bed structure adopts a stepped layered arrangement, with the upper layer consisting of coarse particles with a particle size of 6 mm to 8 mm and the lower layer consisting of fine particles with a particle size of 3 mm to 5 mm.

[0041] Porous partitions with pore sizes ranging from 1 / 2 to 2 / 3 of the filler particle size are installed between the layers. The partitions are 5 mm thick, with pore sizes ranging from 2 mm to 4 mm and porosity ranging from 30% to 50%.

[0042] The surface of the partition is coated with a polytetrafluoroethylene (PTFE) anti-stick coating to prevent iron and carbon particles from adhering to the pores and causing blockage due to oxidation products during long-term operation.

[0043] The ultrasonic transducer array system employs a phased array arrangement, consisting of 16 independently controlled piezoelectric ceramic transducers arranged in a 4×4 matrix, with a spacing of 10 cm between adjacent transducers.

[0044] Each transducer is equipped with an independent phase controller, with a phase adjustment accuracy of 0.1 degrees and a frequency adjustment step of 10 Hz.

[0045] The acoustic field scanning mode uses a spiral trajectory scanning method with a scanning cycle of 10 seconds, covering the entire cross-section of the packing bed to ensure no blind spots.

[0046] The operating frequency is from 20 kHz to 40 kHz, and the power density is from 0.5 W / cm³ to 1.5 W / cm³.

[0047] The ultrasonic waves are arranged perpendicular to the direction of wastewater flow to maximize the cavitation effect and shear force's destructive effect on the pollutant molecular chains.

[0048] Reaction Mechanism: Under the action of an ultrasonic field, the iron-carbon micro-electrolysis reaction is activated, generating atomic hydrogen with strong reducing properties and hydroxyl radicals with strong oxidizing properties, which simultaneously destroy the molecular structure of organic pollutants and improve their biodegradability. The ultrasonic field enhances the micro-electrolysis reaction, increasing the rate of active species generation in the iron-carbon system by more than 40%, and shortening the reaction time to two-thirds of that in traditional micro-electrolysis.

[0049] Step S2: The effluent pretreated by ultrasonic micro-electrolysis is introduced into the catalytic oxidation reaction unit. The catalytic oxidation reaction unit is filled with a heterogeneous catalyst with titanium dioxide as a support and nano-sized copper oxide and manganese oxide composite active components loaded on the surface. The loading amount is 5% to 15% of the support mass.

[0050] The catalyst is designed with a honeycomb-like monolithic structure, with a specific surface area greater than 300 square meters per gram, a porosity of 40% to 60%, and a pore diameter of 1 to 3 millimeters.

[0051] The water flow resistance is less than 5000 Pa, ensuring good fluid flow performance.

[0052] The catalyst module has a total height of 1.2 meters and is divided into two reaction zones: the upper zone is filled with a catalyst supported on copper oxide, and the lower zone is filled with a catalyst supported on manganese oxide.

[0053] The upper zone supported copper oxide catalyst is mainly responsible for the ring-opening reaction of aromatic compounds, while the lower zone supported manganese oxide catalyst is mainly responsible for the deep mineralization of short-chain organic compounds.

[0054] The ozone gas distribution system consists of an ozone gas distributor made of a 3 mm thick microporous titanium plate with a porosity of 25%, a pore size distribution of 10 to 50 micrometers, and a pore density of 2000 pores per square centimeter.

[0055] A gas pressure stabilizing chamber with a height of 10 cm is installed below the distributor. Inside the chamber, there are guide vanes with an inclination angle of 45 degrees and a spacing of 5 cm to ensure uniform distribution of ozone gas.

[0056] The ozone dosage is 0.1 to 0.5 grams per liter of wastewater, and the gas flow rate is controlled at 0.5 to 2 liters per minute.

[0057] This allows dissolved ozone to fully contact the active sites on the catalyst surface, synergistically oxidizing residual organic matter into carbon dioxide and water.

[0058] The reactor's structural parameters are as follows: diameter 1.5 meters, total height 3 meters, and effective volume 4 cubic meters.

[0059] The reactor is equipped with a gas-liquid separation device to prevent ozone gas from entering subsequent treatment units with the water flow.

[0060] The reactor is equipped with a tail gas treatment device at the top, which treats ozone-containing tail gas through activated carbon adsorption.

[0061] Step S3: The ultrasonic micro-electrolysis pretreatment effluent is evenly distributed to multiple parallel reaction channels of the catalytic oxidation reaction unit through a multi-channel distribution pipeline. Each channel is equipped with an independent flow meter and regulating valve to ensure hydraulic load balance. A portion of the effluent from the catalytic oxidation reaction unit is returned to the inlet of the ultrasonic micro-electrolysis reaction unit at a ratio of 10% to 30% by a reflux pump to form an internal circulation enhanced reaction system.

[0062] Multi-channel distribution system: The distribution pipeline adopts a 4-way parallel design, each equipped with an electromagnetic flowmeter with a measurement accuracy of ±0.5%; the regulating valve is a pneumatic diaphragm regulating valve with a regulation ratio of 50:1 and a leakage class of VI; the main pipe diameter of the distributor is 200 mm, the branch pipe diameter is 100 mm, and the pipe material is 316L stainless steel; the distributor is equipped with a flow equalization plate to ensure that the flow distribution deviation of each parallel channel is less than 5%.

[0063] Internal circulation reflux system: The reflux pump is centrifugal, with a flow rate ranging from 0.5 cubic meters to 3 cubic meters per hour and a head of 15 meters; the reflux pipeline diameter is 80 mm, equipped with an electric regulating valve to control the reflux ratio; the reflux ratio can be continuously adjusted within the range of 10% to 30%, with a response time of less than 30 seconds; the reflux point is located before the inlet of the ultrasonic micro-electrolysis reaction unit, and the water is fully mixed with the raw water before entering the reactor.

[0064] Hydraulic retention time control: The hydraulic retention time of the ultrasonic micro-electrolysis reaction unit is 30 to 60 minutes; the hydraulic retention time of the catalytic oxidation reaction unit is 20 to 40 minutes; the retention time is precisely controlled by flow rate adjustment to adapt to different water quality conditions.

[0065] Step S4: The intelligent control unit collects real-time data from the conductivity sensor and redox potential sensor installed at the inlet of the ultrasonic micro-electrolysis reaction unit, the chemical oxygen demand online monitoring instrument and dissolved ozone concentration sensor installed at the outlet of the catalytic oxidation reaction unit, and the total organic carbon analyzer installed at the tailwater discharge outlet, and dynamically adjusts the ultrasonic transducer power, ozone dosage, reflux ratio and influent flow rate.

[0066] Sensor array configuration:

[0067] Conductivity sensor, measurement range 0 to 20,000 microSiemens per centimeter, accuracy ±2%, response time 5 seconds; Redox potential sensor, measurement range -1,000 to 1,000 millivolts, accuracy ±5 millivolts, response time 10 seconds; Chemical oxygen demand online monitor, measurement range 0 to 1,000 milligrams per liter, accuracy ±5%, detection cycle 15 minutes; Dissolved ozone concentration sensor, measurement range 0 to 50 milligrams per liter, accuracy ±3%, response time 30 seconds; Total organic carbon analyzer, measurement range 0 to 200 milligrams per liter, accuracy ±3%, detection cycle 10 minutes.

[0068] Fuzzy adaptive control algorithm: The central processing unit adopts a 32-bit ARM architecture, with a main frequency of 1GHz, 512MB of memory, and 8GB of storage space.

[0069] Input variables include: redox potential, rate of change of chemical oxygen demand, deviation of dissolved ozone concentration, and amplitude of conductivity fluctuation.

[0070] The output variables are: ultrasonic power adjustment coefficient, ozone flow correction value, reflux ratio adjustment amount, and inlet valve opening.

[0071] The control cycle is 5 seconds, and each adjustment does not exceed 10% of the previous set value to ensure stable system operation.

[0072] It adopts a three-layer fuzzy inference structure, contains 27 control rules, and covers various working condition combinations.

[0073] Human-machine interface: 10-inch color touch screen with a resolution of 1024×768 pixels; real-time display of sensor data, equipment operating status, and alarm information; supports historical data query, trend analysis, and report generation functions; equipped with a remote monitoring interface and supports 4G / WiFi wireless communication.

[0074] Step S5: The chemical oxygen demand, biochemical oxygen demand, total organic carbon, suspended solids concentration and heavy metal ion residue of the final effluent are continuously monitored by the tailwater monitoring and feedback unit. The sampling frequency is once every 10 minutes. When the monitoring index exceeds the preset threshold, an alarm is triggered and the emergency handling procedure is started.

[0075] Water quality comprehensive analysis module: It adopts a multi-parameter integrated sensor to simultaneously detect chemical oxygen demand, ammonia nitrogen, total phosphorus, turbidity and pH value; the detection accuracy is ±2% of full scale and the response time is less than 2 minutes; the sensor adopts the spectral analysis method, the light source is a xenon lamp, and the wavelength range is 200 to 800 nanometers; it is equipped with an automatic cleaning device, the cleaning cycle is once every 8 hours, and the cleaning medium is deionized water.

[0076] Level 3 alarm system:

[0077] Level 1 alarm: Triggers a yellow indicator light and a low-frequency buzzer; the threshold is set to 80% of the emission standard.

[0078] Level 2 alarm: Triggers a red indicator light, a high-frequency buzzer, and sends an SMS message; the threshold is set to 95% of the emission standard.

[0079] Level 3 alarm: Triggers system shutdown and initiates emergency flushing procedure, with the threshold set at 100% of the emission standard;

[0080] Emergency response procedures: Automatically close the inlet valve to stop sewage from entering the system; start the emergency flushing pump to flush each reaction unit with clean water; switch to the standby treatment system; notify operation and management personnel via SMS, email, telephone, etc.

[0081] The effluent is adsorbed for 20 minutes using coconut shell-based granular activated carbon with an iodine value greater than 1000 mg / g, and then disinfected with ultraviolet light at a dose of 40 mJ / cm² to ensure that the effluent meets discharge standards or reuse requirements.

[0082] Activated carbon adsorption system: The adsorption tower has a diameter of 1 meter, a height of 2 meters, and is filled with 1.5 cubic meters of activated carbon; the activated carbon particle size is 8 to 30 mesh, and the specific surface area is greater than 1000 square meters per gram; it adopts a top-in, bottom-out flow pattern, and the empty bed contact time is 20 minutes; it is equipped with a backwashing device, and the backwashing cycle is once every 72 hours.

[0083] Ultraviolet disinfection system: It adopts low-pressure high-intensity ultraviolet lamps with a wavelength of 254 nanometers and a single lamp power of 150 watts; the disinfection unit has a diameter of 200 mm and a length of 1.5 meters, with 6 built-in ultraviolet lamps; the irradiation dose is 40 millijoules per square centimeter, and the sterilization efficiency reaches 99.99%; it is equipped with an ultraviolet intensity monitor, which automatically alarms when the intensity is lower than the set value.

[0084] A wastewater treatment system based on ultrasonic micro-electrolysis combined with catalytic oxidation includes:

[0085] The ultrasonic micro-electrolysis reactor unit employs a stepped, layered structure for its iron-carbon packing bed. The upper layer consists of coarse particles with larger diameters, while the lower layer comprises fine particles with smaller diameters. Porous baffles, with pore sizes ranging from one-half to two-thirds the packing particle size, are installed between the layers to prevent packing mixing and promote uniform water flow distribution. The ultrasonic transducer array utilizes a phased array arrangement. By adjusting the phase difference between each transducer, sound field focusing and scanning are achieved, enhancing local cavitation intensity and avoiding blind spots in the sound field. The ultrasonic transducers operate at frequencies from 20 kHz to 40 kHz, with power densities ranging from 0.5 W / cm³ to 1.5 W / cm³. The ultrasonic waves are arranged perpendicular to the wastewater flow direction to maximize the cavitation effect and shear force's destructive effect on pollutant molecular chains.

[0086] The catalytic oxidation reaction unit utilizes a honeycomb-shaped monolithic catalyst with a specific surface area greater than 300 square meters per gram, a porosity of 40% to 60%, and pore diameters of 1 to 3 millimeters, ensuring a water flow resistance of less than 5000 Pa. An ozone gas distributor is positioned at the bottom of the catalyst bed, creating a counter-current contact with the downward-flowing wastewater during the gas's ascent, thus improving gas-liquid mass transfer efficiency. The reaction temperature is controlled within the range of 20°C to 40°C and maintained at a constant temperature through a jacketed heat exchanger. The catalyst uses titanium dioxide as a carrier, with nano-sized copper oxide and manganese oxide composite active components loaded on its surface, at a loading rate of 5% to 15% of the carrier mass. The ozone dosage is 0.1 to 0.5 grams per liter of wastewater, and the gas flow rate is controlled within the range of 0.5 to 2 liters per minute, ensuring that the ozone is fully dissolved in the liquid phase and contacts the active sites on the catalyst surface.

[0087] The intelligent control unit employs a fuzzy adaptive control algorithm in its central processing unit. Input variables include oxidation-reduction potential, chemical oxygen demand (COD) change rate, dissolved ozone concentration deviation, and conductivity fluctuation amplitude. Output variables include ultrasonic power adjustment coefficient, ozone flow correction value, reflux ratio adjustment, and inlet valve opening. The control cycle is five seconds, with each adjustment not exceeding 10% of the previous value to prevent system oscillation. The sensor array includes conductivity and oxidation-reduction potential sensors at the inlet of the ultrasonic micro-electrolysis reaction unit, an online COD monitor and dissolved ozone concentration sensor at the outlet of the catalytic oxidation reaction unit, and a total organic carbon analyzer at the effluent discharge outlet. Based on real-time data collected by the sensors, the central processing unit dynamically adjusts the ultrasonic transducer power, ozone dosage, reflux ratio, and inlet flow rate to achieve closed-loop optimization control of reaction parameters. The actuator drive module controls the operation of the ultrasonic generator, ozone generator, reflux pump, and regulating valve, with a response time of less than 0.5 seconds.

[0088] The effluent monitoring and feedback unit and water quality comprehensive analysis module employ multi-parameter integrated sensors to simultaneously detect chemical oxygen demand (COD), ammonia nitrogen, total phosphorus, turbidity, and pH value, with a detection accuracy of ±2% of full scale. The data storage module uses a solid-state drive array with a storage capacity of at least 1 terabyte, supporting data compression and encrypted transmission. Alarm thresholds are set according to national wastewater discharge standards and can be manually adjusted by operators through a human-machine interface. When monitored indicators exceed preset thresholds, the system automatically triggers an alarm signal and initiates emergency response procedures, including increasing ozone dosage, increasing ultrasonic power, or suspending influent flow and initiating a flushing procedure.

[0089] The fluid distribution and circulation unit includes an inlet pump, a flow regulating valve, a multi-channel distribution pipeline, a return pump, and a return proportional controller. The inlet pump delivers the wastewater to be treated to the inlet of the ultrasonic micro-electrolysis reaction unit at a flow rate ranging from 1 to 10 cubic meters per hour. The multi-channel distribution pipeline evenly distributes the effluent pretreated by ultrasonic micro-electrolysis to multiple parallel reaction channels of the catalytic oxidation reaction unit. Each channel is equipped with an independent flow meter and regulating valve to ensure balanced hydraulic load across channels. The return pump returns a portion of the effluent from the catalytic oxidation reaction unit to the inlet of the ultrasonic micro-electrolysis reaction unit at a ratio of 10% to 30%, forming an internal circulation enhanced reaction system, improving pollutant degradation efficiency and stabilizing the reaction environment.

[0090] An automatic backwashing module is located between the ultrasonic micro-electrolysis reaction unit and the catalytic oxidation reaction unit. The module includes a high-pressure backwashing pump, backwashing pipelines, backwashing nozzles, and a timer controller. The high-pressure backwashing pump operates at a pressure of 0.3 MPa to 0.8 MPa, and is activated every eight hours of operation, with each backwash lasting five minutes. The backwash water flows in the opposite direction to the normal treatment water flow, flushing away deposits on the packing surface and restoring its reactivity.

[0091] The energy consumption optimization module collects real-time power data from the ultrasonic generator, ozone generator, water pump, and fan, calculates the energy consumption per unit of pollutant removal, and compares it with historical best values. When the energy consumption per unit exceeds the optimal value by 15% three times consecutively, the system automatically starts the parameter optimization program to adjust the operating strategy until the energy consumption returns to the normal range.

[0092] The ultrasonic micro-electrolysis reactor unit features a packed bed of iron-carbon composite particles, with a stacking height of 60% to 80% of the reactor's effective volume. The particle size ranges from 3 mm to 8 mm, with the upper layer containing 6 mm to 8 mm particles and the lower layer containing 3 mm to 5 mm particles. Interlayer porous partitions are 5 mm thick, with pore sizes of 2 mm to 4 mm and a porosity of 30% to 50%. The partition surfaces are coated with a PTFE anti-stick coating to prevent pore blockage caused by oxidation products from adhering to the iron-carbon particles during long-term operation. The ultrasonic transducer array consists of 16 independently controlled piezoelectric ceramic transducers arranged in a 4×4 matrix, with a 10 cm spacing between adjacent transducers. Each transducer is equipped with an independent phase controller, with a phase adjustment accuracy of 0.1 degrees and a frequency adjustment step of 10 Hz. The acoustic field scanning mode employs a spiral trajectory scanning pattern with a scanning cycle of 10 seconds, covering the entire cross-section of the packed bed to ensure no blind spots.

[0093] The catalytic oxidation reaction unit consists of a honeycomb catalyst module with 100 independent reaction channels, each with a regular hexagonal cross-section, a side length of 1.5 mm, and a wall thickness of 0.3 mm. The catalyst module has a total height of 1.2 meters and is divided into upper and lower reaction zones. The upper zone is filled with a catalyst loaded with copper oxide, and the lower zone is filled with a catalyst loaded with manganese oxide, achieving gradient degradation of pollutants. The ozone gas distributor is made of microporous titanium plates, 3 mm thick, with a porosity of 25%, a pore size distribution of 10 to 50 micrometers, and a pore density of 2000 pores per square centimeter. A gas pressure stabilizing chamber is located below the gas distributor, with a height of 10 cm and internal guide plates at a 45-degree angle and a plate spacing of 5 cm to ensure uniform distribution of ozone gas. The jacketed heat exchanger adopts a double-layer stainless steel structure, with an outer insulation layer of 5 cm thickness and an inner heat exchange layer, through which circulating water is circulated, with a water temperature control accuracy of ±0.5 degrees Celsius.

[0094] The fluid distribution and circulation unit consists of a multi-channel distribution pipeline comprising a main pipeline and eight branch pipelines. The main pipeline has a diameter of 10050 mm, and the branch pipelines have a diameter of 50 mm. A turbine flow meter is installed at the inlet of each branch pipeline, with a measurement accuracy of 0.5% and a response time of 0.1 seconds. The flow control valve is an electric V-type ball valve with an adjustment accuracy of 0.1% and a full stroke time of 5 seconds. The reflux proportional controller consists of a mass flow meter and a proportional-integral-derivative (PID) controller. The mass flow meter is installed on the reflux pipeline, with a measurement range of 0.1 to 3 cubic meters per hour and a repeatability error of less than 0.2%. The PID controller has a sampling period of 1 second, an integral time constant of 10 seconds, a derivative time constant of 0.5 seconds, and outputs a 4 mA to 20 mA current signal to drive the reflux control valve.

[0095] The intelligent control unit employs an industrial-grade programmable logic controller (PLC) with a 1.2 GHz clock speed and 4 gigabytes of memory, featuring a dual-core redundant structure. In the sensor array, the conductivity sensor measures from 0 to 20,000 micro-Siemens per centimeter with a resolution of 0.1 micro-Siemens per centimeter; the redox potential sensor measures from -1000 mV to +1000 mV with a resolution of 0.1 mV; the online chemical oxygen demand (COD) monitor uses ultraviolet absorption, measuring from 0 to 1000 mg / L with a response time of 30 seconds; the dissolved ozone concentration sensor uses membrane electrode assembly (MEA), measuring from 0 to 20 mg / L with a response time of 10 seconds; and the total organic carbon (TOC) analyzer uses high-temperature catalytic oxidation-non-dispersive infrared detection, measuring from 0 to 500 mg / L with a detection limit of 0.1 mg / L. The actuator drive module consists of a solid-state relay array and a pulse width modulation power amplifier. The solid-state relay switching time is 0.01 milliseconds, the pulse width modulation frequency is 20 kHz, and the output power adjustment range is continuously adjustable from zero to full scale.

[0096] The tailwater monitoring and feedback unit features a multi-parameter integrated sensor system consisting of five independent sensor probes integrated onto a single flange, with a probe spacing of 5 cm and an IP68 protection rating. Chemical oxygen demand (COD) detection employs a dual-wavelength ultraviolet absorption method with wavelengths of 254 nm and 365 nm to eliminate turbidity interference; ammonia nitrogen detection uses an ion-selective electrode method with an amorphous silicon-based composite membrane; total phosphorus detection uses an ammonium molybdate spectrophotometric method with a detection wavelength of 700 nm; turbidity detection uses a 90-degree scattering light method with an infrared LED as the light source; and pH detection uses a glass electrode method with a silver / silver chloride electrode as the reference electrode. The data storage module employs a RAID five-array structure, consisting of four 250 Gigabyte solid-state drives (SSDs) with a total capacity of 1 terabyte, a write speed of 500 terabytes per second, and supports AES 256-bit hardware encryption. The alarm system has three threshold levels: Level 1 is the warning threshold, which triggers a yellow indicator light and a low-frequency buzzer; Level 2 is the intervention threshold, which triggers a red indicator light and a high-frequency buzzer, and automatically sends an SMS notification to the operator; Level 3 is the emergency threshold, which triggers the system to automatically shut down and start an emergency flushing procedure.

[0097] The automatic backwash module uses a plunger-type positive displacement pump with a rated flow rate of 10 liters per minute and a maximum working pressure of 0.8 MPa. It is equipped with a 5-liter pressure buffer tank filled with nitrogen at a pre-charge pressure of 0.4 MPa. The backwashing pipeline is constructed of seamless stainless steel tubing with a diameter of 25 mm. Four rows of backwashing nozzles, eight nozzles per row, are arranged along the height of the reactor, with a nozzle spacing of 20 cm. The nozzles are fan-shaped, with a spray angle of 120 degrees and a nozzle diameter of 1.5 mm, made of silicon carbide ceramic. The timer controller uses a microprocessor and has a built-in real-time clock chip, with a time accuracy of less than 1 second per month. It supports manual forced start and remote start functions.

[0098] The energy consumption optimization module uses high-precision current and voltage transformers for power data acquisition. The current transformer ratio is 100:5, and the voltage transformer ratio is 380:100. The sampling frequency is 1000 Hz, and the accuracy class is 0.2. The formula for calculating the energy consumption per unit of pollutant removal is:

[0099]

[0100] Where E represents the energy consumption per unit of pollutant removal, expressed in kilowatt-hours per kilogram of chemical oxygen demand; The total power of the system is expressed in kilowatts; t is the operating time in hours; and Q is the water volume processed in cubic meters. The influent chemical oxygen demand (COD) concentration is expressed in milligrams per liter. The concentration of chemical oxygen demand (COD) in the effluent is expressed in milligrams per liter.

[0101] Historical best values ​​are stored in non-volatile memory and updated using a sliding window algorithm with a window length of 30 days. The average energy consumption for the day is automatically calculated daily, and the best value is updated accordingly. The parameter optimization program uses a genetic algorithm with a population size of 50, a crossover probability of 0.8, a mutation probability of 0.05, and 100 iterations. The objective function is to minimize unit energy consumption, and the constraint is that the effluent water quality meets the standards.

[0102] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations will be apparent to those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A system for treating wastewater based on combined ultrasonic micro-electrolysis and catalytic oxidation, characterized in that it comprises: include: The ultrasonic micro-electrolysis reaction unit is used to activate the micro-electrolysis reaction through an iron-carbon packed bed and an ultrasonic transducer array to generate atomic hydrogen and hydroxyl radicals, thereby destroying the molecular structure of organic pollutants. A catalytic oxidation reaction unit is used to synergistically oxidize residual organic matter with a supported heterogeneous catalyst and an ozone gas distributor. The fluid distribution and circulation unit is used to achieve uniform water distribution and partial effluent return through multi-channel distribution pipelines and reflux pumps. Among them, the reflux pump returns part of the effluent from the catalytic oxidation reaction unit to the inlet of the ultrasonic micro-electrolysis reaction unit at a ratio of 10% to 30%, forming an internal circulation enhanced reaction system, improving pollutant degradation efficiency and stabilizing the reaction environment. The intelligent control unit is used to collect water quality and operating parameters through a sensor array and dynamically adjust the ultrasonic power, ozone dosage, reflux ratio and inlet flow rate. The tailwater monitoring and feedback unit is used to continuously monitor the quality of the final effluent and trigger alarms and emergency procedures when the quality exceeds the standard. The ultrasonic micro-electrolysis reaction unit employs a stepped, layered packing bed structure, with a coarse-particle layer on top and a fine-particle layer below, separated by porous partitions. The ultrasonic transducer array is arranged in a phased array configuration, supporting sound field focusing and scanning. The catalyst in the catalytic oxidation reaction unit has a honeycomb-shaped integral structure, divided into upper and lower reaction zones. The ozone gas distributor is a microporous titanium plate structure, with a gas pressure stabilizing chamber and a flow guide plate below. The intelligent control unit uses a fuzzy adaptive control algorithm. The tailwater monitoring and feedback unit is equipped with multi-parameter integrated sensors and a three-level alarm mechanism. The iron-carbon packing bed in the ultrasonic micro-electrolysis reaction unit adopts a stepped layered arrangement structure. The upper layer is a coarse particle layer with a particle size of 6 mm to 8 mm, and the lower layer is a fine particle layer with a particle size of 3 mm to 5 mm. A porous partition with a pore size of 1 / 2 to 2 / 3 of the packing particle size is set between the layers. The partition has a thickness of 5 mm, a porosity of 30% to 50%, and a polytetrafluoroethylene anti-stick coating on its surface. The ultrasonic transducer array adopts a phased array arrangement, consisting of 16 piezoelectric ceramic transducers arranged in a 4×4 matrix, with an adjacent transducer spacing of 10 cm. Each transducer is equipped with an independent phase controller, with a phase adjustment accuracy of 0.1 degrees and a frequency adjustment step of 10 Hz. The sound field scanning mode adopts a spiral trajectory scanning with a scanning cycle of 10 seconds. The central processing unit in the intelligent control unit adopts a fuzzy adaptive control algorithm. The input variables include oxidation-reduction potential, chemical oxygen demand change rate, dissolved ozone concentration deviation and conductivity fluctuation amplitude. The output variables are ultrasonic power adjustment coefficient, ozone flow correction value, reflux ratio adjustment amount and inlet valve opening. The control cycle is 5 seconds, and the adjustment amplitude of each adjustment does not exceed 10% of the previous value. The water quality comprehensive analysis module in the tailwater monitoring and feedback unit uses a multi-parameter integrated sensor to simultaneously detect chemical oxygen demand, ammonia nitrogen, total phosphorus, turbidity and pH value, with a detection accuracy of ±2% of full scale. The alarm system has three threshold levels: Level 1 triggers a yellow indicator light and a low-frequency buzzer; Level 2 triggers a red indicator light, a high-frequency buzzer and sends an SMS message; Level 3 triggers system shutdown and starts an emergency flushing procedure. The catalyst in the catalytic oxidation reaction unit adopts a honeycomb integral structure with a specific surface area greater than 300 square meters per gram, a porosity of 40% to 60%, a pore diameter of 1 mm to 3 mm, and a water flow resistance of less than 5000 Pa. The catalyst module has a total height of 1.2 meters and is divided into two reaction zones, with the upper zone filled with a catalyst loaded with copper oxide and the lower zone filled with a catalyst loaded with manganese oxide.

2. The method for treating wastewater by ultrasonic micro-electrolysis combined with catalytic oxidation, applied to the system for treating wastewater by ultrasonic micro-electrolysis combined with catalytic oxidation according to claim 1, characterized in that, include: Step S1: The wastewater to be treated is pumped to the inlet of the ultrasonic micro-electrolysis reaction unit. The ultrasonic micro-electrolysis reaction unit is equipped with a packing bed composed of iron-carbon composite particles with a particle size ranging from 3 mm to 8 mm. The packing bed stacking height is 60% to 80% of the effective volume of the reactor. In the ultrasonic micro-electrolysis reaction unit, an ultrasonic field with a frequency of 20 kHz to 40 kHz and a power density of 0.5 W / cm³ to 1.5 W / cm³ is applied through an ultrasonic transducer array set on the upper and lower sides. The ultrasonic wave propagation direction is perpendicular to the wastewater flow direction, which activates the iron-carbon micro-electrolysis reaction to generate atomic hydrogen and hydroxyl radicals, destroying the molecular structure of organic pollutants and improving their biodegradability. Step S2: The effluent pretreated by ultrasonic micro-electrolysis is introduced into a catalytic oxidation reaction unit. The catalytic oxidation reaction unit is filled with a heterogeneous catalyst with titanium dioxide as a carrier and nano-sized copper oxide and manganese oxide composite active components loaded on the surface. The loading amount is 5% to 15% of the carrier mass. In the catalytic oxidation reaction unit, ozone is added through a microporous titanium plate ozone gas distributor set at the bottom. The ozone addition amount is 0.1 g to 0.5 g per liter of wastewater, and the gas flow rate is controlled at 0.5 liters to 2 liters per minute, so that the dissolved ozone comes into contact with the active sites on the catalyst surface and synergistically oxidizes the residual organic matter into carbon dioxide and water. The ozone gas distributor is made of a microporous titanium plate with a thickness of 3 mm, an opening rate of 25%, a pore size distribution of 10 micrometers to 50 micrometers, and a pore density of 2000 per square centimeter; a gas pressure stabilizing chamber with a height of 10 cm is set below the distributor, and a guide plate with an inclination angle of 45 degrees and a spacing of 5 cm is installed in the chamber. Step S3: The ultrasonic micro-electrolysis pretreatment effluent is evenly distributed to multiple parallel reaction channels of the catalytic oxidation reaction unit through a multi-channel distribution pipeline. Each channel is equipped with an independent flow meter and regulating valve to ensure hydraulic load balance. A portion of the effluent from the catalytic oxidation reaction unit is returned to the inlet of the ultrasonic micro-electrolysis reaction unit at a ratio of 10% to 30% by a reflux pump to form an internal circulation enhanced reaction system. Step S4: The intelligent control unit collects real-time data from the conductivity sensor and redox potential sensor installed at the inlet of the ultrasonic micro-electrolysis reaction unit, the chemical oxygen demand online monitoring instrument and dissolved ozone concentration sensor installed at the outlet of the catalytic oxidation reaction unit, and the total organic carbon analyzer installed at the tailwater discharge outlet, and dynamically adjusts the ultrasonic transducer power, ozone dosage, reflux ratio and influent flow rate. Step S5: The chemical oxygen demand, biochemical oxygen demand, total organic carbon, suspended solids concentration and heavy metal ion residue of the final effluent are continuously monitored by the tailwater monitoring and feedback unit. The sampling frequency is once every 10 minutes. When the monitoring index exceeds the preset threshold, an alarm is triggered and the emergency handling procedure is started.

3. The wastewater treatment method based on ultrasonic micro-electrolysis combined with catalytic oxidation according to claim 2, characterized in that, It also includes a pretreatment step: filtering through a 5 mm pore size grid, sedimentation with a 30-minute retention time, and adjusting the pH of the influent to the range of 5.5 to 7.5 using sodium hydroxide or sulfuric acid solution; and a posttreatment step: adsorption for 20 minutes using coconut shell-based granular activated carbon with an iodine value greater than 1000 mg / g, followed by ultraviolet disinfection with an irradiation dose of 40 mJ / cm².

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