Three-phase catalytic oxidation treatment system for printing and dyeing wastewater

Abstract

The invention discloses a three-phase catalytic oxidation treatment system for printing and dyeing wastewater, belongs to the technical field of sewage treatment, and solves the problems of treatment of wastewater by ozone catalysis, monitoring of missing of trace toxic by-products and metal leaching, poison of effluent and ozone consumption, acidification inactivation circulation and silent collapse of the system. Comprising a pulse electrolysis pretreatment unit used for decomposing pollutants through pulse electrolysis oxidation and adjusting current and duty ratio according to catalyst health degree and bromide ion concentration; the invention discloses a heterogeneous catalytic oxidation main reactor. Bromide ions are reduced through pulse electrolysis, a reaction environment is dynamically regulated and controlled through online metal monitoring to prevent catalyst collapse, and real-time biotoxicity early warning is combined as a final judgment, so that the whole treatment process can sense and break vicious cycles of toxicity generation and catalyst failure in advance, and long-term safety and stability of effluent are ensured.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a three-phase catalytic oxidation treatment system for dyeing and printing wastewater. Background Technology

[0002] Three-phase catalytic oxidation treatment of dyeing and printing wastewater is a highly efficient advanced treatment technology, belonging to the category of Fenton or similar advanced oxidation processes. It constructs a gas-liquid-solid three-phase coexistence reaction environment in a specific reactor, utilizing strong oxidizing free radicals to thoroughly degrade recalcitrant organic matter such as dyes and auxiliaries remaining after biochemical treatment, helping wastewater achieve compliant discharge or reuse. This technology relies heavily on solid catalysts. Compared to the traditional homogeneous Fenton process, the three-phase turbulence formed by aeration within the reactor significantly enhances the contact efficiency between pollutants, oxidants, and catalyst active sites, accelerating the reaction process. It also broadens the applicable pH range, reduces the consumption of reagents for acid-base adjustment and salinity increase, and decreases sludge production, alleviating the difficulty and cost of subsequent sludge treatment and disposal. In engineering applications, it is often set up as an advanced treatment unit after biochemical treatment. A typical process includes pretreatment, biochemical treatment, three-phase catalytic oxidation reaction, neutralization and precipitation, etc. Operating parameters need to be determined experimentally based on actual water quality. Currently, this technology has moved from research to engineering application, with stable treatment effects. It can bring wastewater COD and other indicators up to emission standards. It can also be coupled with membrane separation and other technologies to build a more efficient integrated treatment system that can meet the treatment needs of different dyeing and printing wastewater.

[0003] To meet zero direct discharge standards, large-scale chemical fiber printing and dyeing enterprises in coastal areas have introduced ozone three-phase catalytic oxidation technology to treat high-salt, bromine-containing, and organic amine-containing wastewater. Conventional online monitoring only targets macroscopic indicators such as COD and pH, and cannot identify trace amounts of genotoxic byproducts such as bromoamines and bromonitromethanes generated on the catalyst surface. It is also difficult to detect the slow leaching of catalyst metal ions caused by complexing agents and instantaneous low pH in the early stages. This leads to two interrelated fatal problems in the treatment process: firstly, the active sites of the catalyst unexpectedly become assembly sites that convert harmless halogens into highly toxic organic halides. The platform conceals ecological risks beneath the surface of effluent meeting standards; secondly, trace amounts of leached metal ions trigger uncontrolled homogeneous catalytic reactions in the liquid phase, hijacking and consuming large amounts of ozone. Operators blindly increase ozone dosage to restore efficiency, further lowering the pH and accelerating metal leaching, forming a self-reinforcing vicious cycle of ineffective leaching and acidification. Ultimately, without any effective warning, the system experiences a triple disaster: soaring operating costs, excessive biotoxicity and COD in the effluent, and permanent catalyst deactivation, causing the entire deep treatment unit to completely collapse and resulting in huge economic and environmental losses.

[0004] Therefore, a three-phase catalytic oxidation treatment system for dyeing and printing wastewater is proposed to solve or alleviate the above problems. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a three-phase catalytic oxidation treatment system for dyeing and printing wastewater.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A three-phase catalytic oxidation treatment system for dyeing and printing wastewater includes The pulse electrolysis pretreatment unit is used to decompose pollutants by pulse electrolysis oxidation and to adjust the current and duty cycle according to the catalyst health and bromide ion concentration. A multiphase catalytic oxidation main reactor is used to catalyze the generation of hydroxyl radicals from ozone using a supported catalyst to oxidize pollutants, and to dynamically optimize ozone dosage, pH, and redox potential based on real-time assessments of oxidation efficiency and toxicity risk. The gas-liquid separation and ozone recovery unit is used to separate the gas and liquid of the reaction tail gas and to recover the ozone-containing tail gas after compression and drying to the ozone generator; An online metal ion monitoring and adsorption enrichment unit is used to monitor the concentration of catalyst metal ions leached from the effluent in real time and selectively adsorb and enrich them when the concentration exceeds the standard. The online biotoxicity early warning unit is used to assess the biotoxicity of effluent by utilizing online behavioral monitoring of aquatic organisms as a supplement to traditional chemical indicator monitoring and as the final safety criterion. The central intelligent control unit is used to perform multi-source data fusion, real-time risk calculation, multi-unit collaborative control and safety decision-making and self-learning algorithms, and to coordinate the work of each unit. The pulse electrolysis pretreatment unit, the multiphase catalytic oxidation main reactor, the gas-liquid separation and ozone recovery unit, and the end-of-pipe biotoxicity online early warning unit are connected in sequence through pipelines. The sampling port of the online metal ion monitoring and adsorption enrichment unit is connected in parallel to the effluent pipe of the multiphase catalytic oxidation main reactor. The central intelligent control unit is connected to the other units through a communication bus.

[0007] Preferably, the pulse electrolysis pretreatment unit includes a corrosion-resistant electrolytic cell, a high-frequency pulse power supply, and a digital signal processor. The outlet of the corrosion-resistant electrolytic cell is connected to the inlet of the multiphase catalytic oxidation main reactor via a pipeline. A first electrode plate group and a second electrode plate group are alternately arranged in parallel along the vertical direction within the corrosion-resistant electrolytic cell. The first electrode plate group consists of multiple titanium-based mixed metal oxide coated mesh anode plates connected in series via first titanium-copper composite conductive rods. The second electrode plate group consists of multiple stainless steel perforated cathode plates connected in series via second titanium-copper composite conductive rods. The first and second titanium-copper composite conductive rods are respectively fixed to the sidewall of the corrosion-resistant electrolytic cell by insulating sealing sleeves and penetrate the sidewall of the corrosion-resistant electrolytic cell. A tubular anion exchange membrane assembly is fixedly connected to the fluid downstream of the second electrode plate group and at a predetermined distance from the second electrode plate group. The DC positive power output terminal of the high-frequency pulse power supply is connected to the extension end of the first titanium-copper composite conductive rod outside the tank through a first power cable, and its DC negative power output terminal is connected to the extension end of the second titanium-copper composite conductive rod outside the anti-corrosion electrolytic tank through a second power cable. The drive signal input pins of the insulated gate bipolar transistor drive board inside the high-frequency pulse power supply are connected to the corresponding enhanced pulse width modulation signal output pins on the digital signal processor through ribbon cables. The digital signal processor is connected to the network of the central intelligent control unit through its onboard serial communication interface transmit and receive pins via an RS-485 transceiver.

[0008] Preferably, the multiphase catalytic oxidation main reactor includes a pressure-bearing reaction tower, an ozone dosing and mixing subsystem, a catalyst bed, and a safety monitoring and control subsystem. The pressure-bearing reaction tower has a vertical cylindrical structure, with an inlet at the top connected to the outlet of the pulse electrolysis pretreatment unit via a first pipe, and an outlet at the bottom connected to the inlet of the gas-liquid separation and ozone recycling unit via a second pipe. The ozone dosing and mixing subsystem includes an ozone generator and a Venturi jet mixer. The outlet of the ozone generator is connected to the gas intake port of the Venturi jet mixer via an ozone delivery pipe. The Venturi jet mixer is connected to the main inlet pipe of the pressure-bearing reaction tower. The catalyst bed fills the interior of the pressure-bearing reaction tower and includes multiple catalyst modules and alternating layers of inert packing material stacked from top to bottom. The catalyst modules include spherical composite metal... The system is an oxide catalyst. The safety monitoring and control subsystem includes a first probe for monitoring pH, a second probe for monitoring oxidation-reduction potential, a third probe for detecting conductivity, a temperature sensor for monitoring temperature, a pressure sensor for monitoring pressure, a level switch installed on the pressurized reaction tower, and a flow meter installed on the main inlet pipe of the pressurized reaction tower. The first, second, and third probes, the temperature sensor, and the pressure sensor are embedded at different heights on the side wall of the pressurized reaction tower. A cooling water pipe is connected to a coil in the pressurized reaction tower, and a flow switch is connected to the cooling water pipe. The remote control interface and analog power adjustment interface of the ozone generator are connected to the central intelligent control unit. The normally closed contact of the level switch, the low flow alarm contact of the flow meter, and the normally closed contact of the flow switch are connected in series to the coil circuit of the main power contactor of the ozone generator via a control cable.

[0009] Preferably, the gas-liquid separation and ozone reuse unit includes a gas-liquid separator, a gas compression and purification assembly, a reuse control valve group, and an ozone concentration monitor. The gas inlet of the gas-liquid separator is connected to the top tail gas outlet of the multiphase catalytic oxidation main reactor via a third pipe. Its bottom liquid phase outlet outputs treated water via a fourth pipe, and its top gas phase outlet is sequentially connected to the inlet of the gas compression and purification assembly via a fifth pipe. The gas compression and purification assembly, along the airflow direction, sequentially includes a scroll gas compressor, a refrigerated dryer, and a molecular sieve adsorption tank connected by flanges and sealed pipes. The purified gas outlet of the molecular sieve adsorption tank is connected to the multiphase catalytic oxidation main reactor via a sixth pipe. The ozone generator in the main oxidation reactor has a fresh oxygen mixing inlet. The reuse control valve group includes a pneumatic regulating valve installed on the sixth pipe. The control signal input terminal of the valve positioner in the pneumatic regulating valve is connected to the analog output module of the central intelligent control unit through a shielded twisted pair cable. The ozone concentration monitor includes an online ozone analyzer, whose sampling probe is inserted into the sixth pipe. Its analog signal output terminal is connected to the analog input module of the central intelligent control unit through a signal line. The start / stop terminal of the control circuit of the scroll gas compressor is connected to the normally open contact of an intermediate relay driven by the digital output module of the central intelligent control unit through a control cable.

[0010] Preferably, the end-of-pipe biotoxicity online early warning unit includes a biological observation tank, an image acquisition subsystem, and an auxiliary control subsystem. The inlet of the biological observation tank is connected to the outlet of the gas-liquid separation and ozone recovery unit via a pipeline. The biological observation tank is a stepped flow tank made of transparent material, and its interior is divided into at least two interconnected observation chambers by partitions. The bottom of each observation chamber is covered with an inert substrate to accommodate specific types of indicator aquatic organisms. The image acquisition subsystem includes an industrial camera. Each industrial camera is fixed above the observation chamber by an adjustable bracket. The industrial camera is connected to an industrial Ethernet switch in the central intelligent control unit via a network cable. The auxiliary control subsystem includes an LED strobe light source and a synchronization trigger. The LED strobe light source is located on the upper side of the observation chamber. The external trigger input terminal on its driver is connected to the output terminal of the synchronization trigger via a signal line. The input terminal of the synchronization trigger is connected to the high-speed pulse output channel of the central intelligent control unit via a control cable.

[0011] Preferably, the online metal ion monitoring and adsorption enrichment unit includes a monitoring and sampling module, a signal conditioning circuit, and an adsorption switching execution module. The monitoring and sampling module includes a detection cell. The inlet and outlet of the detection cell are connected via three-way valves to a second pipeline between the outlet of the multiphase catalytic oxidation main reactor and the inlet of the gas-liquid separation and ozone recovery unit. An ion-selective electrode and a reference electrode are encapsulated within the detection cell. The signal output line of the ion-selective electrode passes through the detection cell. The signal input interface of the signal conditioning circuit is connected to the output lines of the ion-selective electrode and the reference electrode via a shielded cable. The signal conditioning circuit includes a junction field-effect transistor (JFET) operational amplifier, a precision operational amplifier, an analog-to-digital converter (ADC) chip, and a microcontroller. The output terminal of the JFET operational amplifier... The module connects to the non-inverting input of a precision operational amplifier, whose output is connected to an analog-to-digital converter (ADC) chip. The ADC chip is connected to a microcontroller via a serial peripheral interface. The microcontroller is connected to the network of a central intelligent control unit via a communication bus. The adsorption switching execution module includes two adsorption tanks. The inlets of the two adsorption tanks are connected to an inlet pneumatic three-way valve, and the outlets of the two adsorption tanks are connected to an outlet pneumatic three-way valve. One branch of the inlet pneumatic three-way valve is connected to a second pipeline, and one branch of the outlet pneumatic three-way valve is also connected to the second pipeline. Both the inlet and outlet pneumatic three-way valves are dual-coil solenoid valves. The coils of the dual-coil solenoid valves are connected to intermediate relay contacts controlled by the digital output module in the central intelligent control unit via control lines.

[0012] Preferably, the central intelligent control unit includes a main controller, communication network equipment, and signal input / output modules. The main controller is a programmable logic controller (PLC) connected to the signal input / output modules via a backplane bus. The communication network equipment includes an industrial Ethernet switch. Multiple network ports of the industrial Ethernet switch are connected via Ethernet cables to a digital signal processor in the pulse electrolysis pretreatment unit, an ozone generator in the multiphase catalytic oxidation main reactor, a microcontroller in the online metal ion monitoring and adsorption enrichment unit, and an industrial camera in the end-of-pipe biotoxicity online early warning unit. The signal input / output modules include an analog input module, an analog output module, a digital input module, and a digital output module. Multiple input channels of the analog input module are connected via shielded twisted-pair cables. The analog output module is connected to the standard current signal output terminals of the first probe, second probe, third probe, temperature sensor, pressure sensor, and ozone concentration monitor in the multiphase catalytic oxidation main reactor, respectively. Multiple output channels of the analog output module are connected via shielded twisted-pair cables to the analog setting terminal of the high-frequency pulse power supply in the pulse electrolysis pretreatment unit, the power adjustment terminal of the ozone generator in the multiphase catalytic oxidation main reactor, and the valve positioner control terminal of the pneumatic adjustment in the gas-liquid separation and ozone recovery unit, respectively. Multiple output channels of the digital output module are connected via control cables to the inlet and outlet pneumatic three-way valves in the online metal ion monitoring and adsorption enrichment unit, and the coils of multiple intermediate relays of the scroll gas compressor in the gas-liquid separation and ozone recovery unit, respectively.

[0013] The present invention has the following beneficial effects: This invention reduces bromide ions through pulse electrolysis, dynamically regulates the reaction environment using online metal monitoring to prevent catalyst degradation, and combines real-time biotoxicity early warning as the final decision, enabling the entire treatment process to detect and interrupt the vicious cycle of toxicity generation and catalyst failure in advance, thereby ensuring the long-term safety and stability of the effluent. Attached Figure Description

[0014] 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. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of the present invention.

[0016] The diagram shows: 1. Pulse electrolysis pretreatment unit; 2. Multiphase catalytic oxidation main reactor; 3. Gas-liquid separation and ozone recovery unit; 4. End-of-pipe biotoxicity online early warning unit; 5. Online metal ion monitoring and adsorption enrichment unit; 6. Central intelligent control unit. Detailed Implementation

[0017] 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 some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0018] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0019] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0020] In the description of this invention, it should be understood that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this invention and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0021] Furthermore, the terms "first," "second," and "third" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0022] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0023] A three-phase catalytic oxidation treatment system for dyeing and printing wastewater, such as Figure 1 As shown, the system includes a pulse electrolysis pretreatment unit 1, a multiphase catalytic oxidation main reactor 2, a gas-liquid separation and ozone recovery unit 3, an online end-of-pipe biotoxicity early warning unit 4, an online metal ion monitoring and adsorption enrichment unit 5, and a central intelligent control unit 6. The pulse electrolysis pretreatment unit 1, the multiphase catalytic oxidation main reactor 2, the gas-liquid separation and ozone recovery unit 3, and the online end-of-pipe biotoxicity early warning unit 4 are sequentially connected via pipelines. The sampling port of the online metal ion monitoring and adsorption enrichment unit 5 is connected in parallel to the effluent pipe of the multiphase catalytic oxidation main reactor 2. The central intelligent control unit 6 is connected to the other units via a communication bus.

[0024] The pulse electrolysis pretreatment unit 1 is used to decompose pollutants through pulse electrolysis oxidation and adjust the current and duty cycle according to the catalyst health and bromide ion concentration; the multiphase catalytic oxidation main reactor 2 is used to catalyze ozone to generate hydroxyl radicals to oxidize pollutants using a supported catalyst and dynamically optimize ozone dosage, pH and redox potential based on real-time assessment of oxidation efficiency and toxicity risk; the gas-liquid separation and ozone reuse unit 3 is used to separate the reaction tail gas into gas and liquid and reuse the ozone-containing tail gas after compression and drying to the ozone generator; the online metal ion monitoring and adsorption enrichment unit 5 is used to monitor the concentration of catalyst metal ions leached in the effluent in real time and selectively adsorb and enrich them when the concentration exceeds the standard; the end-of-pipe biotoxicity online early warning unit 4 is used to assess the biotoxicity of the effluent using online behavioral monitoring of aquatic organisms as a supplement to traditional chemical indicator monitoring and the final safety criterion; the central intelligent control unit 6 is used to perform multi-source data fusion, real-time risk calculation, multi-unit collaborative control and safety decision-making and self-learning algorithms, and coordinate the work of each unit.

[0025] The pulse electrolysis pretreatment unit 1 includes a corrosion-resistant electrolytic cell, a high-frequency pulse power supply, and a digital signal processor. The outlet of the corrosion-resistant electrolytic cell is connected to the inlet of the multiphase catalytic oxidation main reactor 2 via a pipeline. A first electrode plate group and a second electrode plate group are arranged alternately and vertically within the corrosion-resistant electrolytic cell. The first electrode plate group consists of multiple titanium-based mixed metal oxide coated mesh anode plates connected in series via a first titanium-copper composite conductive rod. The second electrode plate group consists of multiple stainless steel perforated cathode plates connected in series via a second titanium-copper composite conductive rod. The first and second titanium-copper composite conductive rods are fixed to the sidewall of the corrosion-resistant electrolytic cell via insulating sealing sleeves and penetrate the sidewall. A [missing information - likely a device or component] is fixedly connected within the corrosion-resistant electrolytic cell. The tubular anion exchange membrane assembly is located downstream of the second electrode plate group and at a preset distance from the second electrode plate group. The DC positive power output terminal of the high-frequency pulse power supply is connected to the extension end of the first titanium-copper composite conductive rod outside the tank through the first power cable. Its DC negative power output terminal is connected to the extension end of the second titanium-copper composite conductive rod outside the anti-corrosion electrolytic tank through the second power cable. The drive signal input pins of the insulated gate bipolar transistor drive board inside the high-frequency pulse power supply are connected to the corresponding enhanced pulse width modulation signal output pins on the digital signal processor through ribbon cables. The digital signal processor connects to the network of the central intelligent control unit 6 through its onboard serial communication interface transmit and receive pins via an RS-485 transceiver.

[0026] The multiphase catalytic oxidation main reactor 2 includes a pressure-bearing reaction tower, an ozone dosing and mixing subsystem, a catalyst bed, and a safety monitoring and control subsystem. The pressure-bearing reaction tower has a vertical cylindrical structure. Its top has an inlet connected to the outlet of the pulse electrolysis pretreatment unit 1 via a first pipe. The bottom of the pressure-bearing reaction tower has an outlet connected to the inlet of the gas-liquid separation and ozone recovery unit 3 via a second pipe. The ozone dosing and mixing subsystem includes an ozone generator and a Venturi jet mixer. The outlet of the ozone generator is connected to the gas intake port of the Venturi jet mixer via an ozone delivery pipe. The Venturi jet mixer is connected to the main inlet pipe of the pressure-bearing reaction tower. The catalyst bed fills the interior of the pressure-bearing reaction tower and consists of multiple layers of catalyst modules and alternately stacked inert packing layers from top to bottom. The catalyst modules include spherical composite metal oxides. The catalyst safety monitoring and control subsystem includes a first probe for monitoring pH, a second probe for monitoring redox potential, a third probe for detecting conductivity, a temperature sensor for monitoring temperature, a pressure sensor for monitoring pressure, a level switch installed on the pressurized reaction tower, and a flow meter installed on the main inlet pipe of the pressurized reaction tower. The first, second, and third probes, the temperature sensor, and the pressure sensor are embedded at different heights on the side wall of the pressurized reaction tower. A coil in the pressurized reaction tower is connected to a cooling water pipe, and a flow switch is connected to the cooling water pipe. The remote control interface and analog power adjustment interface of the ozone generator are connected to the central intelligent control unit 6. The normally closed contact of the level switch, the low flow alarm contact of the flow meter, and the normally closed contact of the flow switch are connected in series to the coil circuit of the main power contactor of the ozone generator through a control cable.

[0027] The gas-liquid separation and ozone recovery unit 3 includes a gas-liquid separator, a gas compression and purification assembly, a recovery control valve group, and an ozone concentration monitor. The gas inlet of the gas-liquid separator is connected to the top tail gas outlet of the multiphase catalytic oxidation main reactor 2 via a third pipe. Its bottom liquid phase outlet outputs treated water via a fourth pipe, and its top gas phase outlet is sequentially connected to the gas inlet of the gas compression and purification assembly via a fifth pipe. The gas compression and purification assembly, along the airflow direction, sequentially includes a scroll gas compressor connected by flanges and sealed pipes, a refrigerated dryer, and a molecular sieve adsorption tank. The purified gas outlet of the molecular sieve adsorption tank is connected to the multiphase catalytic oxidation main reactor 2 via a sixth pipe. The fresh oxygen mixing inlet of the ozone generator in reactor 2, the reuse control valve group includes a pneumatic regulating valve installed on the sixth pipe, the control signal input terminal of the valve positioner in the pneumatic regulating valve is connected to the analog output module of the central intelligent control unit 6 through a shielded twisted pair cable, the ozone concentration monitor includes an online ozone analyzer, whose sampling probe is inserted into the sixth pipe, and its analog signal output terminal is connected to the analog input module of the central intelligent control unit 6 through a signal line, the start / stop terminal of the control circuit of the scroll gas compressor is connected to the normally open contact of the intermediate relay driven by the digital output module of the central intelligent control unit 6 through a control cable.

[0028] The end-of-pipe biotoxicity online early warning unit 4 includes a biological observation tank, an image acquisition subsystem, and an auxiliary control subsystem. The inlet of the biological observation tank is connected to the outlet of the gas-liquid separation and ozone recovery unit 3 via a pipeline. The biological observation tank is a stepped flow tank made of transparent material, and its interior is divided into at least two interconnected observation chambers by partitions. The bottom of each observation chamber is covered with an inert substrate to accommodate specific types of indicator aquatic organisms. The image acquisition subsystem includes industrial cameras. Each industrial camera is fixed above the observation chamber by an adjustable bracket. The industrial cameras are connected to the industrial Ethernet switch in the central intelligent control unit 6 via network cables. The auxiliary control subsystem includes an LED strobe light source and a synchronous trigger. The LED strobe light source is located on the upper side of the observation chamber. The external trigger input terminal on its driver is connected to the output terminal of the synchronous trigger via a signal line. The input terminal of the synchronous trigger is connected to the high-speed pulse output channel of the central intelligent control unit 6 via a control cable.

[0029] The online metal ion monitoring and adsorption enrichment unit 5 includes a monitoring and sampling module, a signal conditioning circuit, and an adsorption switching execution module. The monitoring and sampling module includes a detection cell. The inlet and outlet of the detection cell are connected via three-way valves to a second pipeline between the outlet of the multiphase catalytic oxidation main reactor 2 and the inlet of the gas-liquid separation and ozone recovery unit 3. An ion-selective electrode and a reference electrode are encapsulated within the detection cell. The signal output line of the ion-selective electrode passes through the detection cell. The signal input interface of the signal conditioning circuit is connected to the output lines of the ion-selective electrode and the reference electrode via a shielded cable. The signal conditioning circuit includes a junction field-effect transistor (JFET) operational amplifier, a precision operational amplifier, an analog-to-digital converter (ADC) chip, and a microcontroller. The output of the JFET operational amplifier... The terminal is connected to the non-inverting input of a precision operational amplifier, and the output of the precision operational amplifier is connected to an analog-to-digital converter chip. The analog-to-digital converter chip is connected to a microcontroller via a serial peripheral interface. The microcontroller is connected to the network of the central intelligent control unit 6 via a communication bus. The adsorption switching execution module includes two adsorption tanks. The inlets of the two adsorption tanks are connected to an inlet pneumatic three-way valve, and the outlets of the two adsorption tanks are connected to an outlet pneumatic three-way valve. One branch of the inlet pneumatic three-way valve is connected to a second pipeline, and one branch of the outlet pneumatic three-way valve is connected to the second pipeline. Both the inlet and outlet pneumatic three-way valves are double-coil solenoid valves. The coils of the double-coil solenoid valves are connected to the intermediate relay contacts controlled by the digital output module in the central intelligent control unit 6 via control lines.

[0030] The central intelligent control unit 6 includes a main controller, communication network equipment, and signal input / output modules. The main controller is a programmable logic controller (PLC) that connects to the signal input / output modules via a backplane bus. The communication network equipment includes an industrial Ethernet switch. Multiple network ports of the industrial Ethernet switch are connected via Ethernet cables to the digital signal processor in the pulse electrolysis pretreatment unit 1, the ozone generator in the multiphase catalytic oxidation main reactor 2, the microcontroller in the online metal ion monitoring and adsorption enrichment unit 5, and the industrial camera in the end-of-pipe biotoxicity online early warning unit 4. The signal input / output modules include analog input modules, analog output modules, digital input modules, and digital output modules. Multiple input channels of the analog input modules are connected via shielded twisted-pair cables to the multiphase... The first, second, and third probes, temperature sensor, and pressure sensor in the catalytic oxidation main reactor 2, as well as the standard current signal output terminals of the ozone concentration monitor in the gas-liquid separation and ozone recovery unit 3, are connected via shielded twisted-pair cables to the analog setting terminal of the high-frequency pulse power supply in the pulse electrolysis pretreatment unit 1, the power adjustment terminal of the ozone generator in the multiphase catalytic oxidation main reactor 2, and the control terminal of the pneumatically regulated valve positioner in the gas-liquid separation and ozone recovery unit 3. The multiple output channels of the digital output module are connected via control cables to the inlet and outlet pneumatic three-way valves in the online metal ion monitoring and adsorption enrichment unit 5, and the coils of multiple intermediate relays of the scroll gas compressor in the gas-liquid separation and ozone recovery unit 3.

[0031] When the three-phase catalytic oxidation treatment system for dyeing and printing wastewater is in operation, it performs the following steps: S1, Multi-source information sensing and fusion: Simultaneously acquire sensor data from the pulse electrolysis pretreatment unit 1, the multiphase catalytic oxidation main reactor 2, the online metal ion monitoring and adsorption enrichment unit 5, and the end-stage biotoxicity online early warning unit 4, and perform standardization and feature extraction; The central intelligent control unit 6 synchronously reads the current and voltage data of the pulse electrolysis pretreatment unit 1, the pH, redox potential, temperature, pressure and ozone concentration data of the multiphase catalytic oxidation main reactor 2, the specific metal ion concentration data of the online metal ion monitoring and adsorption enrichment unit 5, and the biological behavior data of the end-of-pipe biotoxicity online early warning unit 4; Robust standardization based on the midpoint and interquartile range of the moving time window is performed on each parameter sequence to eliminate the influence of units and outliers; Key derived parameters were calculated, including the real-time ozone consumption rate based on the inlet and outlet gas flow rates and ozone concentrations of the multiphase catalytic oxidation main reactor 2; the bromine conversion factor based on the bromide ion concentrations in the inlet and outlet water of the reactor; and the system buffer capacity decay index based on changes in pH and current in the pulse electrolysis pretreatment unit 1 within the reactor. S2, Core Risk Status Assessment: Based on the data processed in S1, the dynamic advanced oxidation efficiency index reflecting oxidation efficiency, the toxicity generation potential energy index reflecting potential toxicity risk, and the catalyst stability coefficient reflecting catalyst health are calculated in real time. The dynamic advanced oxidation efficiency index is calculated as follows: based on the ratio of the difference between the ultraviolet absorbance and total organic carbon in the influent and effluent per unit time to the total amount of ozone actually consumed in the reactor per unit time, the dynamic advanced oxidation efficiency index is calculated; wherein, the difference in ultraviolet absorbance and the difference in total organic carbon are weighted and summed with preset weights; The toxicity generation potential index is calculated as follows: the bromine conversion factor is multiplied by the product of the first weighting term and the second weighting term, and then by the nitrogen-containing precursor correction factor to obtain the toxicity generation potential index; wherein, the bromine conversion factor is calculated based on the bromide ion concentrations in the influent and effluent; the first weighting term is the product of the redox potential in the reactor and a first coefficient; the second weighting term is the product of the ratio of effluent to influent UV absorbance and a second coefficient; the nitrogen-containing precursor correction factor is the sum of the product of a number and the organic amine concentration and a third coefficient; The catalyst stability coefficient is calculated as follows: a stability denominator is calculated, which is the sum of a number and three instability contribution terms; the catalyst stability coefficient is the ratio of the number to the stability denominator; wherein, the first instability contribution term is the product of the catalyst metal ion concentration and the first instability weight; the second instability contribution term is the product of the relative decay of the dynamic advanced oxidation efficiency index and the second instability weight; and the third instability contribution term is the product of the system buffer capacity decay index and the third instability weight. S3, Multi-unit Coordinated Dynamic Regulation: Based on the three core indices calculated in S2, the electrolysis parameters of the pulse electrolysis pretreatment unit 1, the ozone dosage of the multiphase catalytic oxidation main reactor 2, and the reaction environment parameters are adjusted in a coordinated manner, and the start-up, shutdown, and switching of the online metal ion monitoring and adsorption enrichment unit 5 are controlled; The specific electrolysis parameters of the linkage-adjusted pulse electrolysis pretreatment unit 1 are as follows: Based on the catalyst stability coefficient, the pulse current density setting value of the pulse electrolysis pretreatment unit 1 is dynamically reduced through a smoothing function to reduce the oxidative stress at the front end of the catalyst when its health deteriorates; Based on the influent bromide ion concentration, the pulse duty cycle setting of the pulse electrolysis pretreatment unit 1 is increased year-on-year to enhance the selective electrochemical removal of bromide ions and reduce toxic precursors at the source. The method for dynamically adjusting the current and duty cycle of the pulse electrolysis unit is as follows: the pulse current density is equal to the product of the reference current density and a proportionality factor obtained by mapping the catalyst stability coefficient through a hyperbolic tangent function; the proportionality factor decreases as the catalyst stability coefficient decreases. The pulse duty cycle is equal to the reference duty cycle, plus the product of the ratio of the influent bromide ion concentration to the normalized bromide ion concentration reference value and a duty cycle adjustment coefficient. The specific adjustments to the ozone dosage and reaction environment parameters in the multiphase catalytic oxidation main reactor 2 are as follows: An ozone dosing feedforward model is established, with the output value being the ozone dosing setpoint. The inputs to the ozone dosing feedforward model include: the total organic carbon concentration in the influent multiplied by a first model coefficient, the bromide ion concentration in the influent multiplied by a second model coefficient, the toxicity generation potential index multiplied by a third model coefficient, and the difference between a number and the catalyst stability coefficient multiplied by a fourth model coefficient. The third model coefficient is negative, used to actively suppress ozone dosing when the toxicity generation potential increases; the fourth model coefficient is negative, used to actively reduce the oxidation load when the catalyst stability decreases. The target pH setting value within the multiphase catalytic oxidation main reactor 2 increases linearly as the catalyst stability coefficient decreases, in order to create an alkaline microenvironment that inhibits metal leaching. The method for dynamically adjusting the pH and redox potential setting values ​​within the reactor is as follows: the target pH setting value is equal to the optimal pH of the catalyst, plus the difference between the catalyst stability reference value and the current catalyst stability coefficient, multiplied by a pH adjustment gain; the target redox potential setting value is equal to the reference redox potential, minus the current toxicity generation potential index, multiplied by a redox potential adjustment gain. The target redox potential setpoint in the multiphase catalytic oxidation main reactor 2 decreases linearly with the increase of the toxicity generation potential index, so as to suppress the generation pathway of toxic byproducts under strong oxidation conditions; The specific steps for controlling the start-up, shutdown, and switching of the online metal ion monitoring and adsorption enrichment unit 5 are as follows: When the catalyst stability coefficient is lower than the first threshold, the central intelligent control unit 6 instructs the online metal ion monitoring and adsorption enrichment unit 5 to start the adsorption cycle and capture the leached metal ions in the effluent; When the catalyst stability coefficient falls below a lower second threshold, the system is instructed to switch to the standby adsorption tank and initiate an adsorbent regeneration cycle. S4, System Safety Decision-Making and Self-Learning: Based on the two-dimensional risk matrix formed by the core indices of S2, it directs the pulse electrolysis pretreatment unit 1, the multiphase catalytic oxidation main reactor 2, and the online metal ion monitoring and adsorption enrichment unit 5 to implement the graded safety plan; simultaneously, based on the system operation data stream, it updates the control model parameters in S3 online. The specific implementation of the graded safety emergency plan is as follows: The two-dimensional plane formed by the toxicity generation potential index and the catalyst stability coefficient is divided into at least four risk level regions; When the system enters a high-risk zone, the central intelligent control unit 6 sends load reduction or soft shutdown commands to the pulse electrolysis pretreatment unit 1 and the multiphase catalytic oxidation main reactor 2, and sends an enhanced adsorption command to the online metal ion monitoring and adsorption enrichment unit 5. When the end-of-line biotoxicity online early warning unit 4 issues a clear alarm indicating excessive toxicity, it triggers the hard-wired emergency shutdown logic across units, directly cutting off the main power supply to the pulse electrolysis pretreatment unit 1 and the multiphase catalytic oxidation main reactor 2; More specifically, the method for activating the graded response plan is as follows: based on the numerical range of the toxicity generation potential index and the catalyst stability coefficient, the system state is divided into at least four risk level zones; when the system enters the first risk level zone, conventional optimization control is executed; when the system enters the second risk level zone, the recirculation mode of the leaching metal adsorption unit is activated, and the toxicity inhibition coefficient in the ozone dosing feedforward model is increased; when the system enters the third risk level zone, the in-situ chemical cleaning procedure for the catalyst is initiated, and part of the influent is switched to a bypass to reduce the treatment load; when the system enters the fourth risk level zone or the effluent biotoxicity exceeds the standard, an emergency hardware shutdown procedure is triggered. The online update of control model parameters is specifically as follows: a recursive least squares estimation algorithm with a forgetting factor is used to identify and update the coefficients of the multi-factor feedforward model used to determine the ozone dosage in S3 online; the toxicity generation potential energy index and the catalyst stability coefficient of the previous cycle are combined with the total organic carbon concentration and bromide ion concentration of the influent in the current cycle to form a feature vector; the difference between the actual measured ozone consumption and the feature vector multiplied by the predicted value of the current model coefficient vector is used as the basis for parameter update, and the model coefficient vector and parameter estimation error covariance matrix are adjusted by calculating the Kalman gain matrix.

[0032] This system aims to address the consequences of a vicious cycle of hidden toxic substances and catalyst metal ion leaching and acidification, ultimately leading to unit collapse, caused by the failure of conventional monitoring methods during the deep treatment of high-salt, bromine-containing, and organic amine-containing wastewater from dyeing and printing enterprises.

[0033] Before the wastewater enters the main oxidation reactor, the pulse electrolysis pretreatment unit 1 reduces the basic substances that will subsequently generate toxic byproducts at the source. Using a current of specific waveform and intensity, the wastewater undergoes an electrochemical transformation near the anode, preferentially converting bromide ions into gaseous elemental bromine, which is easily separated from water by physical methods. This reduces the total amount of bromide ions flowing to subsequent processes. Simultaneously, some structurally simple organic amines are also electrolytically destroyed in this process. This step essentially establishes a preferential purification channel for substances sensitive to oxidation reactions and prone to generating toxic byproducts, reducing the conversion burden and risk in the main reactor. The operating intensity of this unit is not fixed but dynamically adjusted by a central intelligent control unit 6 based on the real-time composition of the wastewater and the overall health status of the system.

[0034] The pretreated wastewater enters the multiphase catalytic oxidation main reactor 2, the primary site for the deep transformation of pollutants. The reactor is filled with a solid catalyst loaded with specific metal oxides, and ozone gas is injected and thoroughly mixed with the wastewater. The active sites on the catalyst surface promote the conversion of ozone into more potent free radicals, thereby completely decomposing stubborn pollutants such as dye macromolecules in the wastewater into carbon dioxide and water. To prevent the catalyst itself from becoming a source of risk, the system closely monitors the reactor environment. Multiple sensors are directly inserted into the reaction liquid to continuously measure the liquid's pH, redox potential, conductivity, temperature, and pressure. These measurements are transmitted in real time to the central intelligent control unit 6. The central intelligent control unit 6, based on its internal logic, comprehensively analyzes this data to determine the catalyst's activity level and whether its operating status is normal. If a downward trend is detected in indicators reflecting catalyst efficiency, accompanied by signals indicating metal ion dissolution, the central intelligent control unit 6 immediately adjusts the ozone supply and the pH within the reactor. The adjustment logic is two-way: on the one hand, the oxidation intensity is appropriately reduced to minimize excessive impact on the catalyst surface; on the other hand, the pH is slightly increased to create a chemical environment unfavorable to the dissolution and detachment of metals from the catalyst framework. This directly interrupts the self-reinforcing process of metal dissolution, ineffective ozone consumption, and system acidification, pulling the reactor back from the brink of runaway to a stable region.

[0035] To provide early and direct evidence of the above process, a small stream of water flowing from the main reactor is continuously guided to the detection cell in the online metal ion monitoring and adsorption enrichment unit 5. Electrodes in the cell can sensitively capture trace amounts of target metal ions in the water, such as copper or manganese ions contained in the catalyst. This detection signal is amplified and converted to form an accurate concentration reading. This reading is considered a thermometer for the integrity of the catalyst structure. Once the reading exceeds a set warning threshold, the central intelligent control unit 6 determines that abnormal dissolution of the catalyst has begun. At this point, the system not only sends the aforementioned adjustment command to the main reactor but also immediately activates the adsorption function of this unit. The water flow is switched to a container filled with special adsorption material, which acts like a magnet to capture and fix the trace metal ions dissolved in the water. This process has two advantages: first, it prevents the dissolved metal ions from continuing to cause unnecessary side reactions in subsequent pipelines; second, it enriches and recovers these metals as resources, reducing material loss.

[0036] Before entering the final discharge channel, the oxidized water must pass the final judgment of the end-of-pipe biotoxicity online early warning unit 4. This unit contains a biological observation tank simulating a natural water flow environment, in which small aquatic organisms sensitive to toxicity, such as specific water fleas or fish fry, are raised. Industrial cameras continuously monitor the activity status of these organisms, such as swimming ability, respiratory rate, or group distribution. The images are transmitted to the central intelligent control unit 6 for analysis. By comparing the biological behavior patterns under normal conditions, an index reflecting the overall toxicity of the water is calculated. This index compensates for the deficiencies of chemical analysis instruments, because regardless of whether the toxic substance is brominated amine or other unknown compounds, if it is harmful to organisms, it will cause abnormal biological behavior. The judgment of this unit has the highest priority. When the biotoxicity index exceeds the standard, it indicates that although the previous chemical indicators may have been normal, the effluent has already posed a threat to the ecological environment. At this time, the central intelligent control unit 6 will bypass the regular adjustment procedures and directly command a reduction in the treatment load or even initiate a temporary shutdown of some processes to ensure that the unqualified water is never discharged.

[0037] The operation of all the aforementioned units, including the intensity of pulse electrolysis, the amount of ozone added, the timing of acid-base adjustment, and the start-up and shutdown of the adsorption unit, is controlled by the central intelligent control unit 6. Sensor data from various units, including pulse electrolysis, the main reactor, metal monitoring, and biotoxicity monitoring, are continuously collected. The oxidation efficiency index, toxicity generation potential index, and catalyst stability index describe the real-time status of the system from the three dimensions of efficiency, safety, and health, respectively.

[0038] Based on the values ​​and trends of these indices, the central intelligent control unit 6 generates a set of coordinated control commands and sends them to each unit, enabling them to take corresponding actions. For example, when the toxicity generation potential index increases, it commands the main reactor to slightly reduce the oxidation intensity while simultaneously commanding the pretreatment unit to strengthen the removal of bromide ions. This command logic can also slowly self-correct internal parameters based on accumulated historical data as the system operates, thereby making the operation of the entire system increasingly adaptable to specific water quality conditions and the life cycle of the catalyst.

[0039] The gas-liquid separation and ozone recycling unit 3 is responsible for processing the remaining tail gas discharged from the main reactor. This unit separates the water mist in the tail gas through a physical cyclone method, then pressurizes and purifies the dry gas containing unreacted ozone, and sends it back to the inlet of the ozone generator. This approach directly improves the utilization rate of expensive ozone gas and reduces the operating cost consumption caused by ineffective decomposition.

[0040] In summary, this system can detect the early signs of hidden toxicity formation and catalyst dissolution even when routine chemical monitoring indicators are still normal. It can then proactively and gently eliminate these signs in their nascent stage through internal adjustments, thereby avoiding multiple disasters such as soaring operating costs, excessive effluent toxicity, and permanent catalyst failure caused by the accumulation of problems. This ensures the long-term stability and reliability of the advanced treatment process for highly challenging wastewater.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., 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 three-phase catalytic oxidation treatment system for dyeing and printing wastewater, characterized in that... ,include A pulse electrolysis pretreatment unit (1) is used to decompose pollutants by pulse electrolysis oxidation and to adjust the current and duty cycle according to the catalyst health and bromide ion concentration; A multiphase catalytic oxidation main reactor (2) is used to catalyze the generation of hydroxyl radicals from ozone using a supported catalyst to oxidize pollutants and dynamically optimize the ozone dosage, pH and redox potential based on real-time assessment of oxidation efficiency and toxicity risk; The gas-liquid separation and ozone recycling unit (3) is used to separate the gas and liquid of the reaction tail gas and to recycle the ozone-containing tail gas to the ozone generator after compression and drying. The online metal ion monitoring and adsorption enrichment unit (5) is used to monitor the concentration of catalyst metal ions leached from the effluent in real time and selectively adsorb and enrich them when the concentration exceeds the standard. The online early warning unit for end-of-pipe biotoxicity (4) is used to assess the biotoxicity of effluent using online behavioral monitoring of aquatic organisms as a supplement to traditional chemical indicator monitoring and as the final safety criterion; The central intelligent control unit (6) is used to perform multi-source data fusion, real-time risk calculation, multi-unit collaborative control and safety decision-making and self-learning algorithms, and to coordinate the work of each unit. Among them, the pulse electrolysis pretreatment unit (1), the multiphase catalytic oxidation main reactor (2), the gas-liquid separation and ozone recycling unit (3), and the end-of-pipe biotoxicity online early warning unit (4) are connected in sequence through pipelines. The sampling port of the online metal ion monitoring and adsorption enrichment unit (5) is connected in parallel to the water outlet pipe of the multiphase catalytic oxidation main reactor (2). The central intelligent control unit (6) is connected to the other units through a communication bus.

2. The three-phase catalytic oxidation treatment system for dyeing and printing wastewater according to claim 1, characterized in that... The pulse electrolysis pretreatment unit (1) includes an anti-corrosion electrolytic cell, a high-frequency pulse power supply, and a digital signal processor. The outlet of the anti-corrosion electrolytic cell is connected to the inlet of the multiphase catalytic oxidation main reactor (2) via a pipeline. A first electrode plate group and a second electrode plate group are arranged alternately in parallel along the vertical direction in the anti-corrosion electrolytic cell. The first electrode plate group is composed of multiple titanium-based mixed metal oxide coated mesh anode plates connected in series by a first titanium-copper composite conductive rod. The second electrode plate group is composed of multiple stainless steel perforated cathode plates connected in series by a second titanium-copper composite conductive rod. The first titanium-copper composite conductive rod and the second titanium-copper composite conductive rod are respectively fixed to the side wall of the anti-corrosion electrolytic cell by an insulating sealing sleeve and are arranged through the side wall of the anti-corrosion electrolytic cell. The anti-corrosion electrolytic cell is solidified in the middle. A tubular anion exchange membrane assembly is fixedly connected to the fluid downstream of the second electrode plate group and at a preset distance from the second electrode plate group. The DC positive power output terminal of the high-frequency pulse power supply is connected to the extension end of the first titanium-copper composite conductive rod outside the tank through the first power cable, and its DC negative power output terminal is connected to the extension end of the second titanium-copper composite conductive rod outside the anti-corrosion electrolytic tank through the second power cable. The drive signal input pins of the insulated gate bipolar transistor drive board inside the high-frequency pulse power supply are connected to the corresponding enhanced pulse width modulation signal output pins on the digital signal processor through ribbon cables. The digital signal processor is connected to the network of the central intelligent control unit (6) through its onboard serial communication interface transmit pin and receive pin via an RS-485 transceiver.

3. The three-phase catalytic oxidation treatment system for dyeing and printing wastewater according to claim 1, characterized in that... The multiphase catalytic oxidation main reactor (2) includes a pressure-bearing reaction tower, an ozone dosing and mixing subsystem, a catalyst bed, and a safety monitoring and control subsystem. The pressure-bearing reaction tower has a vertical cylindrical structure. Its top is provided with an inlet that is connected to the outlet of the pulse electrolysis pretreatment unit (1) through a first pipe. The bottom of the pressure-bearing reaction tower is provided with an outlet that is connected to the inlet of the gas-liquid separation and ozone recycling unit (3) through a second pipe. The ozone dosing and mixing subsystem includes an ozone generator and a Venturi jet mixer. The outlet of the ozone generator is connected to the gas intake port of the Venturi jet mixer through an ozone delivery pipe. The Venturi jet mixer is connected to the main water inlet pipe of the pressure-bearing reaction tower. The catalyst bed is filled inside the pressure-bearing reaction tower. The catalyst bed includes multiple catalyst modules and alternating layers of inert packing material stacked from top to bottom. The catalyst module includes spherical composite... The safety monitoring and control subsystem for the composite metal oxide catalyst includes a first probe for monitoring pH, a second probe for monitoring redox potential, a third probe for detecting conductivity, a temperature sensor for monitoring temperature, a pressure sensor for monitoring pressure, a level switch installed on the pressure-bearing reaction tower, and a flow meter installed on the main inlet pipe of the pressure-bearing reaction tower. The first probe, second probe, third probe, temperature sensor, and pressure sensor are embedded at different heights on the side wall of the pressure-bearing reaction tower. The pressure-bearing reaction tower has a coil connected to a cooling water pipe, and a flow switch is connected to the cooling water pipe. The remote control interface and analog power adjustment interface of the ozone generator are connected to the central intelligent control unit (6). The normally closed contact of the level switch, the low flow alarm contact of the flow meter, and the normally closed contact of the flow switch are connected in series to the coil circuit of the main power contactor of the ozone generator through a control cable.

4. The three-phase catalytic oxidation treatment system for dyeing and printing wastewater according to claim 1, characterized in that... The gas-liquid separation and ozone reuse unit (3) includes a gas-liquid separator, a gas compression and purification assembly, a reuse control valve group, and an ozone concentration monitor. The gas inlet of the gas-liquid separator is connected to the top tail gas outlet of the multiphase catalytic oxidation main reactor (2) through a third pipe. Its bottom liquid phase outlet outputs treated water through a fourth pipe. Its top gas phase outlet is sequentially connected to the gas inlet of the gas compression and purification assembly through a fifth pipe. The gas compression and purification assembly includes, in sequence along the airflow direction, a vortex gas compressor, a refrigerated dryer, and a molecular sieve adsorption tank connected by flanges and sealed pipes. The purified gas outlet of the molecular sieve adsorption tank is connected to the multiphase catalytic oxidation main reactor through a sixth pipe. The ozone generator in the device (2) has a fresh oxygen mixing inlet. The reuse control valve group includes a pneumatic regulating valve installed on the sixth pipeline. The control signal input terminal of the valve positioner in the pneumatic regulating valve is connected to the analog output module of the central intelligent control unit (6) through a shielded twisted pair cable. The ozone concentration monitor includes an online ozone analyzer. Its sampling probe is inserted into the sixth pipeline. Its analog signal output terminal is connected to the analog input module of the central intelligent control unit (6) through a signal line. The start / stop terminal of the control circuit of the scroll gas compressor is connected to the normally open contact of the intermediate relay driven by the digital output module in the central intelligent control unit (6) through a control cable.

5. The three-phase catalytic oxidation treatment system for dyeing and printing wastewater according to claim 1, characterized in that... The terminal biological toxicity online early warning unit (4) includes a biological observation tank, an image acquisition subsystem, and an auxiliary control subsystem. The inlet of the biological observation tank is connected to the outlet of the gas-liquid separation and ozone recovery unit (3) through a pipeline. The biological observation tank is a stepped water tank made of transparent material. Its interior is divided into at least two interconnected observation chambers by a partition. The bottom of each observation chamber is covered with an inert substrate to accommodate specific types of indicator aquatic organisms. The image acquisition subsystem includes an industrial camera. Each industrial camera is fixed above the observation chamber by an adjustable bracket. The industrial camera is connected to the industrial Ethernet switch in the central intelligent control unit (6) through a network cable. The auxiliary control subsystem includes an LED strobe light source and a synchronous trigger. The LED strobe light source is located on the upper side of the observation chamber. The external trigger input terminal on its driver is connected to the output terminal of the synchronous trigger through a signal line. The input terminal of the synchronous trigger is connected to the high-speed pulse output channel of the central intelligent control unit (6) through a control cable.

6. The three-phase catalytic oxidation treatment system for dyeing and printing wastewater according to claim 1, characterized in that... The online metal ion monitoring and adsorption enrichment unit (5) includes a monitoring sampling module, a signal conditioning circuit, and an adsorption switching execution module. The monitoring sampling module includes a detection cell. The inlet and outlet of the detection cell are connected to a second pipeline between the outlet of the multiphase catalytic oxidation main reactor (2) and the inlet of the gas-liquid separation and ozone recovery unit (3) via a three-way valve. An ion-selective electrode and a reference electrode are encapsulated in the detection cell. The signal output line of the ion-selective electrode passes through the detection cell. The signal input interface of the signal conditioning circuit is connected to the output lines of the ion-selective electrode and the reference electrode via a shielded cable. The signal conditioning circuit includes a junction field-effect transistor operational amplifier, a precision operational amplifier, an analog-to-digital converter chip, and a microcontroller. The output terminal of the junction field-effect transistor operational amplifier... The non-inverting input terminal of the precision operational amplifier is connected, and the output terminal of the precision operational amplifier is connected to the analog-to-digital converter chip. The analog-to-digital converter chip is connected to the microcontroller through a serial peripheral interface. The microcontroller is connected to the network of the central intelligent control unit (6) through a communication bus. The adsorption switching execution module includes two adsorption tanks. The inlets of the two adsorption tanks are connected to an inlet pneumatic three-way valve, and the outlets of the two adsorption tanks are connected to an outlet pneumatic three-way valve. One of the ports of the inlet pneumatic three-way valve is connected to a second pipeline, and one of the ports of the outlet pneumatic three-way valve is connected to the second pipeline. The inlet pneumatic three-way valve and the outlet pneumatic three-way valve are both double-coil solenoid valves. The coil of the double-coil solenoid valve is connected to the intermediate relay contact controlled by the digital output module in the central intelligent control unit (6) through a control line.

7. The three-phase catalytic oxidation treatment system for dyeing and printing wastewater according to claim 1, characterized in that... The central intelligent control unit (6) includes a main controller, communication network equipment, and signal input / output modules. The main controller is a programmable logic controller, which is connected to the signal input / output modules via a backplane bus. The communication network equipment includes an industrial Ethernet switch. Multiple network ports of the industrial Ethernet switch are connected via Ethernet cables to the digital signal processor in the pulse electrolysis pretreatment unit (1), the ozone generator in the multiphase catalytic oxidation main reactor (2), the microcontroller in the online metal ion monitoring and adsorption enrichment unit (5), and the industrial camera in the end-of-pipe biotoxicity online early warning unit (4). The signal input / output modules include an analog input module, an analog output module, a digital input module, and a digital output module. Multiple input channels of the analog input module are connected via shielded twisted-pair cables. The first probe, second probe, third probe, temperature sensor, pressure sensor, and ozone concentration monitor in the multiphase catalytic oxidation main reactor (2) and the standard current signal output terminal of the ozone concentration monitor in the gas-liquid separation and ozone recovery unit (3) are connected to the analog setting terminal of the high-frequency pulse power supply in the pulse electrolysis pretreatment unit (1), the power adjustment terminal of the ozone generator in the multiphase catalytic oxidation main reactor (2), and the valve positioner control terminal of the pneumatic adjustment in the gas-liquid separation and ozone recovery unit (3) respectively through shielded twisted pair cables. The multiple output channels of the digital output module are connected to the inlet pneumatic three-way valve and the outlet pneumatic three-way valve in the online metal ion monitoring and adsorption enrichment unit (5) and the coils of multiple intermediate relays of the scroll gas compressor in the gas-liquid separation and ozone recovery unit (3) respectively through control cables.

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