Ozone nanobubble purification environment-friendly treatment system and method

Abstract

The invention discloses an ozone nanobubble purification environment-friendly treatment system and method, and relates to the technical field of wastewater treatment and resource recovery, the system is composed of a pretreatment unit, a multi-field collaborative advanced oxidation reaction unit, an intelligent control center and a post-treatment and resource recovery unit, the pretreatment unit realizes water quality homogenization and acid-base adjustment through a grating well, an adjusting tank and a pH adjusting tank; the multi-field collaborative advanced oxidation reaction unit realizes efficient generation of hydroxyl radicals through a layered coupling architecture and a dynamic optimization algorithm; the intelligent control center optimizes the vacuum ultraviolet light intensity, the ozone adding rate and the nano bubble particle size in real time; the post-treatment and resource recovery unit adopts an ultrafiltration membrane and ion exchange adsorption technology to realize catalyst interception, bromine and iodide ion recovery and small molecular organic acid recycling, and the treatment efficiency of the refractory organic wastewater and the by-product control capability are remarkably improved through three-field synergistic interaction and intelligent dynamic regulation and control.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wastewater treatment and resource recovery, in particular to an ozone nano-bubble purification and environmentally-friendly treatment system and method. BACKGROUND

[0002] As a key branch of advanced oxidation process system, ozone nano-bubble treatment technology has attracted widespread attention in the field of environmental protection such as industrial organic wastewater degradation, drinking water deep purification and removal of refractory pollutants, due to its unique gas-liquid mass transfer advantage. The core principle is to disperse ozone gas into nano-bubbles with a particle size usually in the range of 50 nm-50 μm, significantly improve the solubility and utilization rate of ozone by increasing the gas-liquid contact area and prolonging the residence time of bubbles in water; at the same time, the local high temperature and pressure environment generated during the collapse of nano-bubbles in water can promote the generation of hydroxyl radicals (·OH), thereby enhancing the oxidative degradation capacity of organic pollutants. Compared with traditional ozone aeration technology, the existing ozone nano-bubble technology can improve the ozone utilization rate from 30%-50% to more than 75%, and reduce the energy consumption by 25%-35%, but in the complex water quality treatment scene, the technology still faces the problems of insufficient synergistic efficiency and difficulty in controlling by-products, which restricts its application in higher standard environmental protection.

[0003] Currently, the actual application of ozone nano-bubble technology mostly adopts a two-by-two coupled process form, common schemes including ozone-nano-bubble coupling, ozone-catalytic oxidation-nano-bubble coupling, ultraviolet-ozone-nano-bubble coupling, etc. Among them, the ozone-catalytic oxidation-nano-bubble scheme can promote the decomposition of ozone into ·OH by introducing a supported metal oxide catalyst in the reaction system, and improve the removal efficiency of COD; the ultraviolet-ozone-nano-bubble scheme uses ultraviolet light (such as 254 nm wavelength) to assist ozone photolysis, further increasing the amount of free radicals. The above schemes can achieve certain treatment effect under certain water quality conditions (such as low-concentration organic wastewater, water without bromide ions), for example, the COD removal rate of dyeing wastewater can reach 65%-80%, but all have essential limitations: first, all schemes do not realize the synergistic integration of vacuum ultraviolet (VUV), ozone catalytic oxidation and nano-bubbles, and only generate free radicals through two-by-two action, which limits the efficiency of ·OH generation; second, the process operating parameters (such as ozone dosage, bubble particle size, ultraviolet light intensity) mostly use preset fixed values, which cannot be dynamically adjusted according to the fluctuation of influent water quality (such as COD, bromide ion concentration); third, for the treatment of wastewater containing bromine, the existing coupling mode is difficult to effectively inhibit the generation of bromate, and is prone to the risk of by-product exceeding standard.

[0004] The problem to be solved by the present application is: how to break through the limitations of the traditional two-by-two coupling mode, maximize the yield of free radicals and fundamentally inhibit harmful by-products through the efficient synergy of vacuum ultraviolet (VUV), ozone catalytic oxidation and nanobubble technology. From the technical essence, the traditional two-by-two coupling scheme cannot realize the synergy of energy field (VUV), catalytic reaction (ozone decomposition) and mass transfer enhancement (nanobubbles) - VUV can efficiently photolyze ozone and water molecules to generate ·OH, but lacks the efficient mass transfer support of nanobubbles for ozone and the promotion of catalysts for ozone decomposition, resulting in limited photolysis efficiency; if ozone catalytic oxidation is separated from the auxiliary excitation of VUV and the mass transfer enhancement of nanobubbles, it can only rely on the activity of the catalyst itself to promote the decomposition of ozone, and the amount of ·OH generated is limited; and if nanobubbles are only used as a mass transfer carrier without being combined with VUV and catalytic reaction, they cannot fully exert the energy release advantage of the collapse process. This limitation directly leads to the fact that the existing technology cannot generate enough ·OH when treating high-concentration organic wastewater, and the pollutant removal rate is difficult to improve. When treating wastewater containing bromine, due to the imbalance between the efficiency of ·OH generation and the residence time of ozone, the inhibition rate of bromate can only reach 60%, which cannot meet the strict requirements of the “Drinking Water Health Standards” (GB5749-2022) or industrial wastewater discharge standards for bromate.

[0005] In summary, the existing ozone nanobubble treatment technology is limited by the two-by-two coupling process framework and cannot realize the synergy of VUV, ozone catalytic oxidation and nanobubbles, resulting in the difficulty of balancing free radical yield and harmful by-product control, and cannot meet the current environmental protection field's demand for efficient, low by-product and stable operation of the treatment technology. Therefore, developing a technology scheme that can realize the efficient synergy of the three, and solving the above problems in a targeted manner, is of great significance for promoting the application of ozone nanobubble technology in higher standard environmental protection scenarios, and is also a technical bottleneck that needs to be broken through by technical personnel in the field. SUMMARY

[0006] The purpose of the present application is to overcome the shortcomings of the prior art and provide an ozone nanobubble purification and environmental treatment system and method. By constructing a three-field synergy framework of vacuum ultraviolet light field, ozone catalytic reaction and nanobubble mass transfer / collapse effect, and combining the dynamic optimization algorithm of the intelligent control center, the efficient generation of hydroxyl radicals and the accurate inhibition of by-products are realized.

[0007] To solve the above technical problems, the present application provides the following technical scheme: on the one hand, an ozone nanobubble purification and environmental treatment system, the composition of the system includes: a pretreatment unit, a multi-field synergistic advanced oxidation reaction unit, an intelligent control center and a post-treatment and resource recovery unit;

[0008] The pretreatment unit comprises a grid well, an adjusting pool and a pH adjusting pool connected in sequence, for preliminary physical separation of raw wastewater, water quality and quantity uniformity and pH adjustment, to meet the water requirements of subsequent units;

[0009] The multi-field synergistic advanced oxidation reaction unit comprises a closed cylindrical reactor shell, a water distribution device and a nano-bubble releasing device are arranged at the top of the shell, a water collector is arranged at the bottom of the shell, and the inside of the shell is divided into a photocatalysis zone, an ozone catalysis zone and a nano-bubble collapse zone from top to bottom;

[0010] The photocatalysis zone is located at the upper part of the reactor, a liftable vacuum ultraviolet lamp group is arranged on the central axis, and the inner wall of the photocatalysis zone is lined with an aluminum-based reflection layer with high reflectivity;

[0011] The ozone catalysis zone is located at the middle part of the reactor, is filled with a supported composite metal oxide catalyst, and is stacked on a fixed sieve plate;

[0012] The nano-bubble collapse zone is located at the lower part of the reactor, is connected with an external ozone generator through a Venturi jet device, the air suction port of the Venturi jet device is connected with an ozone conveying pipeline, the water inlet is connected with a water outlet pipeline of the pretreatment unit, and the water outlet is connected with the nano-bubble releasing device; the nano-bubble releasing device adopts a sintered titanium metal microporous filter element with a nominal pore size of 0.5 microns;

[0013] The intelligent control center comprises an industrial control computer, which is connected with a multi-parameter water quality sensor array, a bubble particle size monitor, an ozone concentration sensor, an ultraviolet light intensity sensor and a plurality of flow and pressure transmitters; the industrial control computer is internally provided with a dynamic optimization algorithm based on machine learning, and can output control instructions to an ozone generator, a vacuum ultraviolet lamp group power supply, a nano-bubble generating system circulating pump frequency driver and a pH adjusting pool dosing pump;

[0014] The post-treatment and resource recovery unit comprises a membrane separation device and an ion exchange adsorption device; the water inlet of the membrane separation device is connected with the water outlet collector at the bottom of the reactor, and the ion exchange adsorption device is arranged after the membrane separation device and is filled with selective adsorption resin.

[0015] Further, the dynamic optimization algorithm based on machine learning is internally arranged in the intelligent control center, and the vacuum ultraviolet light intensity, the ozone addition rate and the target particle size of the nano-bubbles are synergistically regulated in real time through the following mathematical formula:

[0016] ;

[0017] wherein, 、 、 respectively represent the set value of the vacuum ultraviolet light intensity, the set value of the ozone addition rate and the set value of the target particle size of the nano-bubbles at the next moment, represents a long short-term memory network model with parameters , , , , , , These represent the real-time monitored parameters: influent chemical oxygen demand (COD), ultraviolet absorbance, bromide ion concentration, temperature, influent flow rate, and pH value. , , , , Representing historical periods arrive The vacuum ultraviolet light intensity, ozone injection acceleration rate, average particle size of nanobubbles, internal system pressure, and instantaneous ozone utilization rate are measured.

[0018] Furthermore, the photocatalytic region, ozone catalytic region, and nanobubble collapse region in the multi-field synergistic advanced oxidation reaction unit achieve a nonlinear enhancement relationship among the three through a synergistic effect coefficient model:

[0019] ;

[0020] in, The synergy coefficient is a dimensionless number. , , , These are the model parameters calibrated through experiments. for The intensity of ultraviolet light in a vacuum at any given moment. This is a reference value for ultraviolet light intensity. for The ozone concentration on the surface of the nanobubbles at any given time. This is a reference value for the ozone concentration in the water body. This serves as a reference value for bubble size. for The average particle size of nanobubbles at time t, This refers to the reaction time.

[0021] Furthermore, the particle size of the bubbles generated by the nanobubble emitter is precisely controlled by a closed-loop control system, which adjusts the pressure of the inlet water of the Venturi jet and the flow rate of ozone gas. The closed-loop control system uses the actual particle size value fed back by the bubble size monitor. With the target particle size setpoint issued by the intelligent control center deviation As input, the control quantity is calculated using an incremental PID control algorithm:

[0022] ;

[0023] in, For the increment of the control variable, , , respectively the proportional, integral, and differential coefficients, , , respectively the proportional, integral, and differential coefficients, , , the particle size deviation at the moment, the control variable is finally converted into a speed control signal for the circulating pump frequency driver and an opening control signal for the ozone pipeline proportional valve.

[0024] Further, the arrangement of the vacuum ultraviolet lamp group and its control strategy are:

[0025] The vacuum ultraviolet lamp group is composed of multiple 185nm wavelength vacuum ultraviolet lamp tubes arranged radially around a central support column, with high-transmittance quartz sheath pipes as lamp tube covers. The vacuum ultraviolet lamp group is installed on the sealed flange at the top of the reactor through a lifting mechanism driven by a servo motor, which can realize stepless adjustment of the height of the lamp group in the reactor.

[0026] The intelligent control center dynamically adjusts the immersion depth and output power of the lamp group according to the real-time monitoring value of the inlet water ultraviolet absorbance , and its control logic is defined by the following function relationship:

[0027] ;

[0028] ;

[0029] wherein, is the immersion depth of the vacuum ultraviolet lamp group, is the maximum allowed immersion depth of the lamp group, is the immersion depth adjustment coefficient, is the real-time monitoring of the inlet water ultraviolet absorbance, indicating that the immersion depth of the lamp group decreases as the inlet water ultraviolet absorbance increases, is the output power of the vacuum ultraviolet lamp group, is the maximum rated power of the ultraviolet lamp group, is the reference value of ultraviolet absorbance, is the real-time inlet flow rate, is the reference value of the inlet flow rate.

[0030] Further, the filling method of the supported composite metal oxide catalyst and its regeneration method are:

[0031] The supported composite metal oxide catalyst uses γ-alumina as the carrier, and the active components include manganese dioxide, magnesium oxide and cerium oxide, with a mass ratio of 5:3:2, and the catalyst is in the form of porous spherical particles with a particle size of 3-5 mm;

[0032] The catalyst is layered and filled in the ozone catalytic zone, and each layer of catalyst is separated by an inert ceramic sieve plate to form multiple independent catalytic bed layers, and each catalytic bed layer is provided with a microporous aeration disc at the bottom, which is connected to the main ozone conveying pipeline through a branch pipe for individually distributing and supplying ozone to each catalytic bed layer;

[0033] The intelligent control center determines whether catalyst blockage or deactivation occurs according to the differential pressure sensor data of the upper and lower openings of each catalytic bed layer When the set threshold is exceeded, the system automatically starts a backwashing program to use high-pressure clean water to backwash the specific bed layer, and when the activity of the catalyst decreases, the system starts an in-situ chemical regeneration program to inject a dilute citric acid solution into the specific bed layer for cleaning and regeneration.

[0034] Further, the system has a special control strategy for bromate inhibition, which is:

[0035] The intelligent control center monitors the bromide ion concentration in the influent in real time When the preset threshold is exceeded, the control strategy automatically switches to the bromate inhibition mode, in which the dynamic optimization algorithm uses the potential generation of bromate as an additional constraint condition for optimization calculation, and preferentially adjusts the combination of the vacuum ultraviolet light intensity and the ozone dosage rate to ensure that the ratio is maintained within an empirical safety interval that can inhibit the generation of bromate, while moderately increasing the target particle size of the nano-bubbles to shorten the residence time of ozone in water.

[0036] Further, the ion exchange adsorption device in the post-treatment and resource recovery unit operates in the following manner:

[0037] The device is filled with two specific adsorption resins, one is a quaternary amine type strong alkaline anion exchange resin for selective adsorption of bromide ions and iodide ions, and the other is a macroporous aromatic adsorption resin for adsorption of small molecule organic acid intermediates in water;

[0038] The adsorption device adopts a mode of multiple columns in parallel and rotation switching, when a group of adsorption columns is saturated, the system automatically switches to standby adsorption columns to continue working, and the saturated columns are regenerated off-line, and the desorption liquid is sent into different recovery tanks, the desorption liquid enriched with bromine and iodine ions is sent into a bromine and iodine recovery tank, and the desorption liquid enriched with organic acids is sent into an organic acid recovery tank.

[0039] In another aspect, an ozone nanobubble purification environmental protection treatment method, the specific steps of the method are:

[0040] S100, water quality sensing and parameter initialization: the system is started, the intelligent control center reads the initial data of each water quality sensor, loads the corresponding wastewater treatment model, and initializes the system operation parameters;

[0041] S200, intelligent decision and parameter setting: the built-in dynamic optimization algorithm based on machine learning calculates and outputs the optimal control parameter combination according to the real-time water quality data and historical operation data obtained in step one, including the vacuum ultraviolet light intensity setting value , ozone addition rate setting value , nanobubble target particle size setting value and catalyst bed backwashing flag;

[0042] S300, multi-field synergistic advanced oxidation reaction: the pretreated wastewater enters the multi-field synergistic advanced oxidation reaction unit, under the instruction of the intelligent control center, the vacuum ultraviolet lamp group, the ozone addition system and the nanobubble generation system work synergistically according to the set parameters, generate high-concentration hydroxyl radicals, and oxidize and degrade organic pollutants in the wastewater. At the same time, the system monitors the bromide ion concentration in real time and dynamically activates the bromate inhibition mode;

[0043] S400, by-product resourceization recovery: the effluent after oxidation treatment enters the post-treatment and resource recovery unit, passes through the membrane separation device and the ion exchange adsorption device in turn, realizes clear water discharge, catalyst particle interception and recovery of bromine, iodine ions and organic acid resources;

[0044] S500, closed-loop feedback and dynamic optimization: the intelligent control center continuously compares the deviation of the final effluent quality from the preset target, and uses it as a feedback signal to dynamically adjust the optimization algorithm model parameters in step S200, realizing self-learning and continuous optimization of the system.

[0045] Further, the specific process of the dynamic optimization algorithm in step S200 for intelligent decision-making includes:

[0046] Standardizing the real-time influent water quality data for pretreatment, eliminating the influence of dimension;

[0047] The normalized data is input into the trained LSTM neural network model together with a recent historical operation data sequence,

[0048] The output layer of the LSTM model includes three main control targets: predicted pollutant removal rate , predicted ozone utilization rate , and predicted bromate formation potential ;

[0049] An optimization algorithm is used to maximize the pollutant removal rate and ozone utilization rate while minimizing the bromate formation potential, and a set of optimal combinations of operating variables is solved in a multi-objective optimization framework , and the combination is issued to the corresponding actuator.

[0050] Compared with the prior art, the ozone nanobubble purification environmental treatment system and method have the following beneficial effects:

[0051] First, the present application aims to solve the problem of insufficient synergistic efficiency of vacuum ultraviolet, ozone catalytic oxidation and nanobubble in existing ozone nanobubble technology. Through structural innovation and process integration, the three fields are synergistically enhanced. Specifically, the system constructs a layered coupling architecture of photocatalytic zone, ozone catalytic zone and nanobubble collapse zone in the multi-field synergistic advanced oxidation reaction unit: the photocatalytic zone uses a liftable vacuum ultraviolet lamp group to generate hydroxyl radicals by exciting ozone and water molecules with 185nm ultraviolet light; the ozone catalytic zone is filled with a supported composite metal oxide catalyst to promote the decomposition of ozone into ·OH and strengthen the reaction with organic matter; the nanobubble collapse zone generates high specific surface area nanobubbles through a Venturi jet to improve ozone utilization rate by taking advantage of its mass transfer, and further promotes the generation of ·OH through the local high temperature and high pressure generated by bubble collapse. The three are synergized by the dynamic optimization algorithm of the intelligent control center, greatly improving the efficiency of ·OH generation and significantly improving the oxidation degradation ability of refractory organic matter.

[0052] Secondly, the ozone adding rate, the nano bubble particle size and the vacuum ultraviolet light intensity are dynamically and coordinately controlled by the intelligent control center, the problems of fixed operation parameters and the incapability of adapting to water quality fluctuation are solved, specifically, a dynamic optimization algorithm is constructed based on the LSTM neural network, parameters such as influent COD, ultraviolet absorbance and bromide ion concentration are taken as inputs, the optimal control parameter combination is calculated and output in real time, including the vacuum ultraviolet light intensity set value, the ozone adding rate set value and the nano bubble target particle size set value, meanwhile, the Venturi jet pressure and the ozone proportional valve opening are accurately adjusted through the closed loop control system, so that the nano bubble particle size is stably kept in the target range, the vacuum ultraviolet lamp group immersion depth and the output power are dynamically adjusted according to the influent water quality, the mechanism can effectively stabilize the pollutant removal rate when the influent COD fluctuates ±20%, and effectively inhibit the generation of bromate, and meet the complex water quality change requirements of the chemical industry, printing and dyeing and other industries.

[0053] Other advantages, objects, and features of the application will be set forth in part in the following specification taken in conjunction with the accompanying drawings, and in part will become apparent to those skilled in the art from a consideration of the following specification and drawings, or can be learned from the practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0054] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description only constitute some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0055] Figure 1 The operation flowchart of the present application;

[0056] Figure 2 The system structure composition diagram of the present application;

[0057] Figure 3 The intelligent control center closed loop control principle diagram of the present application. DETAILED DESCRIPTION

[0058] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined application purpose, the specific embodiments, structures, features and effects according to the present application will be described in detail below in combination with the drawings and preferred embodiments.

[0059] Embodiment one

[0060] As Figure 2 And Figure 3As shown, the present embodiment is aimed at the treatment needs of typical refractory organic wastewater in the chemical industry (containing bromide ions, high COD concentration, and complex composition), and uses the ozone nano-bubble purification and environmental treatment system and method to achieve efficient purification of wastewater and resource recovery of by-products. The present embodiment elaborates on the composition, connection relationship and working principle of each unit of the system, focuses on the water quality adjustment mechanism of the pretreatment unit, the three-field synergistic process of the multi-field synergistic advanced oxidation reaction unit, the dynamic optimization and closed-loop control logic of the intelligent control center, and the resource recovery path of the post-treatment and resource recovery unit; through the synergistic effect of 185 nm vacuum ultraviolet light, supported composite metal oxide catalyst and nano-bubbles, combined with the dynamic optimization algorithm based on LSTM neural network and the bromate special inhibition strategy, the problems of low synergistic efficiency and difficult by-product control of traditional ozone nano-bubble technology are solved.

[0061] Implementation scenario and overall system architecture:

[0062] The present embodiment is applied to a refractory organic wastewater treatment project discharged by a chemical enterprise. The wastewater mainly contains benzene derivatives, ester compounds and trace bromide ions (derived from bromine-containing components in raw materials). The influent COD concentration fluctuates in the range of 800-1500 mg / L, the UV254 value is 0.6-1.2 cm-1, the bromide ion concentration is 0.08-0.3 mg / L, the water temperature is 15-35℃, and the pH value fluctuates in the range of 4.5-9.0. If directly discharged, it will seriously pollute the water environment, and the traditional biochemical treatment process has insufficient degradation efficiency for this type of wastewater, which cannot meet the discharge requirements.

[0063] To solve the above problems, the ozone nano-bubble purification and environmental treatment system adopted by the present embodiment is composed of a pretreatment unit, a multi-field synergistic advanced oxidation reaction unit, an intelligent control center and a post-treatment and resource recovery unit. Each unit is connected in sequence through corrosion-resistant pipes (made of 316L stainless steel, suitable for ozone and acidic environment). Electric regulating valves and flow transmitters are provided on the pipes to realize stable water flow delivery and flow monitoring between units. The overall process flow of the system is as follows: the raw wastewater first enters the pretreatment unit for physical separation and water quality adjustment, and then enters the multi-field synergistic advanced oxidation reaction unit after reaching the standard. Under the synergistic effect of vacuum ultraviolet light, ozone catalyst and nano-bubbles, deep oxidation and degradation of organic pollutants are realized, and bromate generation is inhibited. The effluent after reaction enters the post-treatment and resource recovery unit to complete water separation, catalyst interception and recovery of bromide and iodide ions and organic acids. The intelligent control center collects the operating parameters and water quality data of each unit throughout the process, outputs control instructions through a dynamic optimization algorithm, and realizes adaptive adjustment and stable operation of the system.

[0064] Implementation process of the pretreatment unit:

[0065] The pretreatment unit is the front-end processing link of the system, and its core function is to remove large suspended particles in raw wastewater, to equalize water quality and quantity fluctuations, and to adjust the pH value, so as to provide stable water conditions for the subsequent multi-field collaborative advanced oxidation reaction unit, and to avoid impurities from blocking the equipment or affecting the reaction efficiency due to water quality fluctuations. This unit is composed of a grid well, a regulating tank and a pH adjusting tank in sequence, and the design and operation logic of each structure is as follows:

[0066] Grid well:

[0067] The grid well adopts an underground reinforced concrete structure, and the effective volume is designed according to the hourly treatment capacity of the wastewater and the grid interception efficiency. A mechanical rotary grid is arranged inside, and the grid bar spacing is 5 mm. The raw wastewater enters the grid well by gravity flow, and when the water flows through the grid, the suspended impurities (such as fibers, plastic particles, and silt) in the water are intercepted by the grid bars to prevent the subsequent pipelines, pumps and nano bubble release devices from being blocked. The grid is equipped with an automatic slag cleaning device, and the slag cleaning period is controlled by the intelligent control center according to the liquid level difference signal before and after the grid - when the liquid level difference exceeds 50 mm, the slag cleaning device is automatically started, and the intercepted impurities are scraped into the slag hopper, and after being pressed and dewatered, they are transported out for disposal. After the grid treatment, the suspended solids content in the wastewater can be reduced to below 50 mg / L, meeting the requirements of the subsequent unit for the suspended solids in the influent.

[0068] Regulating tank:

[0069] The regulating tank also adopts a reinforced concrete structure, and the effective residence time is designed to be 8-12 h to adapt to the fluctuation period of wastewater quality and quantity. A submersible mixer (mixing rate of 60-80 r / min) is arranged in the tank to mix the wastewater in the tank thoroughly to avoid the settlement of pollutants and to equalize the water quality (such as COD, pH, and bromide concentration); at the same time, the regulating tank monitors the liquid level in the tank in real time through a liquid level sensor, and when the liquid level is lower than the set lower limit (30% of the tank capacity), the intelligent control center controls the water inlet valve to increase the opening to supplement the wastewater; when the liquid level is higher than the set upper limit (80% of the tank capacity), the water inlet valve opening is reduced to ensure that the water quantity in the tank is always stable, avoiding abnormal operation of the subsequent unit due to water interruption or overload. After the regulating tank treatment, the COD fluctuation range of the wastewater can be reduced to within ±10%, and the water temperature fluctuation is controlled within ±2℃, providing a stable water quality basis for the subsequent reaction.

[0070] pH adjusting tank:

[0071] The pH adjustment tank is an aboveground steel and concrete structure, which is internally provided with a pH sensor (measurement accuracy of ±0.1 pH) and a mechanical stirring device, and is externally provided with a medicament storage tank (storing 30% sulfuric acid solution and 20% sodium hydroxide solution respectively) and a metering dosing pump (flow regulation range of 0-50 L / h), and the control signal of the dosing pump is output by the intelligent control center. Since the supported composite metal oxide catalyst in the multi-field synergistic advanced oxidation reaction unit has the highest activity in the pH range of 6.0-8.0, and this pH range can reduce the self-decomposition loss of ozone, the core objective of the pH adjustment tank is to stably control the pH value of the wastewater in this interval.

[0072] The specific operation process is as follows: the wastewater after equalization in the adjustment tank enters the pH adjustment tank, the pH sensor collects the pH value of the wastewater in real time and transmits it to the intelligent control center; if the pH value is lower than 6.0, the intelligent control center controls the sodium hydroxide solution dosing pump to start, adjusts the flow of the dosing pump according to the pH deviation, and adjusts the flow until the pH value rises to the target range; if the pH value is higher than 8.0, the sulfuric acid solution dosing pump is started, and the pH value is adjusted in the same way; the stirring device operates throughout the process to ensure that the medicament and wastewater are fully mixed and to avoid local pH deviation. After the treatment of the pH adjustment tank, the pH value of the wastewater is stably controlled between 6.5 and 7.5, meeting the requirements of the multi-field synergistic advanced oxidation reaction unit.

[0073] The pipes between the structures of the pretreatment unit are used for gravity transportation, and manual maintenance valves and electric regulating valves are arranged on the pipes, and the electric regulating valves are controlled by the intelligent control center according to the liquid level signals of the tank bodies to ensure that the water flows through the grid well, the adjustment tank and the pH adjustment tank in sequence, and the pretreated effluent is sent to the multi-field synergistic advanced oxidation reaction unit by a lifting pump (made of fluoroplastic, strong corrosion resistance), and the frequency of the lifting pump is adjusted by the inflow flow signal fed back by the flow transmitter to ensure the stability of the inflow flow.

[0074] Implementation process of the multi-field synergistic advanced oxidation reaction unit:

[0075] The multi-field synergistic advanced oxidation reaction unit is the core reaction link of the system, which realizes the efficient generation of hydroxyl radicals ·OH by integrating vacuum ultraviolet light field, ozone catalytic reaction and nano-bubble mass transfer / collapse effect, and then deeply oxidizes and degrades organic pollutants in wastewater, while inhibiting the generation of bromate byproduct by special design. The core components of this unit include a closed cylindrical reactor shell, a water inlet distributor, a nano-bubble release device, a water outlet collector, and a light catalytic zone, an ozone catalytic zone and a nano-bubble collapse zone in the reactor from top to bottom, and the implementation details and synergistic working principles of each part are as follows:

[0076] Reactor shell and water inlet and outlet assembly:

[0077] The reactor shell adopts a vertical closed cylindrical structure, the material is 316L stainless steel, the inner wall is polished to reduce water flow resistance, the height to diameter ratio of the shell is 3:1 (the effective volume is 20 m³), a sealing flange is arranged at the top (for installing the vacuum ultraviolet lamp group and the water distributor), and the bottom is a conical structure (for easy water collection and reducing dead water area). The water inlet distributor at the top of the shell is a multi-hole disc structure (hole diameter is 10 mm, hole spacing is 50 mm), the pretreated wastewater enters the water inlet distributor through the pipeline, is uniformly sprayed to the photocatalytic area through the water distribution holes, to avoid local water flow too fast causing insufficient reaction; a nano bubble release device is installed below the water inlet distributor, the release device uses a sintered titanium metal microporous filter with a nominal pore size of 0.5 μm (inventive parameter, the pore size can stably generate 50-200 nm nano bubbles, taking into account mass transfer efficiency and bubble stability), the release device is connected with the external Venturi jet through a pipeline, to realize mixing of ozone and water and generation of nano bubbles.

[0078] The water outlet collector at the bottom of the reactor is a conical structure, seamlessly connected with the bottom of the shell, the collector is provided with a water outlet pipeline at the bottom, a flow transmitter and an electric regulating valve are installed on the pipeline, to control the water outlet flow of the reactor, to ensure that the residence time of the wastewater in the reactor (design value is 1.5-2.0 h) meets the reaction requirements; a pressure transmitter is arranged on the side wall of the shell, to monitor the internal pressure of the reactor in real time (control range is 0.12-0.15 MPa), to avoid equipment damage caused by too high pressure or affecting the stability of nano bubbles caused by too low pressure.

[0079] Implementation of the photocatalytic area:

[0080] The photocatalytic area is located at the upper part of the reactor, occupying 1 / 3 of the total height of the reactor, and the core function is to generate ·OH by exciting ozone and water molecules with 185 nm vacuum ultraviolet light, and to improve light utilization by a reflective layer. The core components of the photocatalytic area include a liftable vacuum ultraviolet lamp group and a high reflectivity aluminum-based reflective layer, and the specific implementation details are as follows:

[0081] The vacuum ultraviolet lamp group is composed of 6 vacuum ultraviolet lamp tubes with a wavelength of 185 nm (inventive parameter, 185 nm vacuum ultraviolet light can directly photolyze H2O to generate ·OH, and;

[0082] The photolysis of O3 generates O2 and ·O, and ·O further reacts with H2O to generate ·OH. Compared with traditional 254 nm ultraviolet light, the generation efficiency of ·OH is increased by more than 40%). The lamp tubes are arranged radially around the central support column, and the spacing between adjacent lamp tubes is 150 mm, which ensures that the light radiation range covers the entire photocatalytic area. Each lamp tube is externally sleeved with a high-transmittance quartz sheath tube (transmittance ≥ 90%), and the two ends of the sheath tube are connected to the sealing flange at the top of the reactor through sealing joints to prevent ozone and water from seeping into the lamp tube and causing damage. The lamp group is installed on the sealing flange through a lifting mechanism (precision is 1 mm) driven by a servo motor, and the control signal of the lifting mechanism is output by the intelligent control center, which can realize stepless adjustment of the immersion depth of the lamp group in the reactor.

[0083] The inner wall of the photocatalytic area is lined with a high-reflectivity aluminum-based reflective layer (reflectivity ≥ 95%), and the surface of the reflective layer is subjected to anodizing treatment to improve ozone oxidation resistance and surface flatness. The reflective layer reflects the ultraviolet light emitted by the lamp tube into the water body, reduces the loss of ultraviolet light absorbed by the wall, improves the light utilization efficiency, and avoids incomplete reaction of local water body due to insufficient illumination.

[0084] The operation control logic of the photocatalytic area is dynamically adjusted by the intelligent control center according to the influent UV254 value: the UV254 value reflects the concentration of organic matter and the content of aromatic compounds in the water. The higher the UV254 value, the more organic matter needs to be degraded in the water. At this time, the intelligent control center lowers the immersion depth of the lamp group (i.e. the lamp group is closer to the water surface) through the lifting mechanism, reduces the attenuation of ultraviolet light in the water, and ensures that the high-concentration organic matter on the surface layer obtains sufficient light. At the same time, the output power of the lamp group is adjusted according to the UV254 value and the influent flow rate - the higher the UV254 value and the greater the influent flow rate, the higher the power of the lamp group (not more than the rated power), to ensure that sufficient photon energy is obtained in unit volume of wastewater. The specific control relationship follows the following function:

[0085] 1. Lamp group immersion depth control function:

[0086] ;

[0087] Wherein, is the immersion depth of the vacuum ultraviolet lamp group, is the maximum allowed immersion depth of the lamp group (set according to the height of the reactor), is the immersion depth adjustment coefficient (calibrated by experiment), which indicates that the immersion depth of the lamp group decreases as the influent value increases;

[0088] 2. Lamp group output power control function:

[0089] ;

[0090] Wherein, is the output power of the vacuum ultraviolet lamp group, is the maximum rated power of the ultraviolet lamp group, is the ultraviolet absorbance reference value, is the real-time water inflow, is the water inflow reference value, which ensures that the lamp group power matches the organic matter load and water flow load, avoiding energy waste caused by excessive power or insufficient degradation caused by insufficient power.

[0091] Implementation of the ozone catalysis zone:

[0092] The ozone catalysis zone is located in the middle of the reactor, occupying 1 / 3 of the total height of the reactor. Its core function is to promote the decomposition of ozone through a supported composite metal oxide catalyst to generate more ·OH, while extending the residence time of ozone in the water body and strengthening the reaction with organic matter. The core components of this region include a supported composite metal oxide catalyst, a fixed sieve plate, an inert ceramic sieve plate, and a microporous aeration disc. The specific implementation details are as follows:

[0093] The supported composite metal oxide catalyst uses γ-alumina as the carrier (the selection basis is that γ-alumina has a large specific surface area, a reasonable pore size distribution, and strong bonding force with active components). The active components are manganese dioxide, magnesium oxide, and cerium oxide, with a mass ratio of 5:3:2 (creative parameter, manganese dioxide is the main active component, which can efficiently catalyze the decomposition of ozone to generate ·OH; magnesium oxide can adjust the acid sites on the catalyst surface, improving the adsorption capacity for organic matter; cerium oxide can enhance the stability of the catalyst, inhibit the loss of active components, and improve the anti-poisoning ability of the catalyst). The catalyst is made into a porous spherical structure with a particle size of 3-5 mm (this particle size can ensure that the water flow and ozone pass through the catalyst bed smoothly, avoid clogging, and increase the specific surface area to improve the catalytic activity), and the bulk density is 0.8-1.0 g / cm³.

[0094] The catalyst is filled in layers, with a stacking height of 300 mm for each layer. Inert ceramic sieve plates (made of corundum, resistant to acid, alkali, and ozone corrosion) are placed between the layers. The sieve plate has a pore size of 2 mm, which can support the upper layer of catalyst and allow the water flow and ozone to pass through uniformly. A microporous aeration disc (with a pore size of 10-20 μm) is placed at the bottom of each catalyst bed. The aeration disc is connected to the main ozone delivery pipeline through a branch pipe, and an electric proportional valve is installed on the branch pipe to achieve individual control of the ozone supply amount for each catalyst bed. The intelligent control center adjusts the opening degree of the branch pipe proportional valve based on the ozone concentration sensor data at the upper and lower openings of each bed to ensure uniform ozone concentration in each bed and avoid local excess or deficiency of ozone.

[0095] During the operation of the ozone catalysis zone, the intelligent control center monitors the pressure difference between the upper and lower openings of each catalyst bed Judge catalyst state (collected by differential pressure sensor): normal operation, Stable at 5-10 kPa; if more than 15 kPa, indicating that the catalyst surface may be attached to impurities or clogging, the system automatically starts the backwashing program - close the water and ozone supply of the bed, open the high-pressure water pump (pressure is 0.3 MPa), through the microporous aeration plate to inject clean water in the opposite direction, wash the impurities on the surface of the catalyst, and the washing wastewater is discharged through the blowdown valve; if the activity of the catalyst decreases (manifested as the COD removal rate decreases by more than 10% under the same ozone dosage), the system starts the in-situ chemical regeneration program - 5% citric acid solution is injected into the bed through the dosing pump, soaked for 2h, then washed with clean water to restore the active sites of the catalyst, and the regenerated citric acid solution is discharged after neutralization treatment.

[0096] Implementation of nanobubble collapse zone:

[0097] The nanobubble collapse zone is located in the lower part of the reactor, occupying 1 / 3 of the total height of the reactor. Its core function is to generate nanobubbles through a Venturi jet, use the high specific surface area of nanobubbles to improve the mass transfer efficiency of ozone, and at the same time, generate local high temperature and high pressure (up to 1000K, 100MPa) through bubble collapse to promote the generation of ·OH, and strengthen the synergistic effect with catalyst and ultraviolet light. The core components of this area include a Venturi jet, an ozone generator, and a nanobubble particle size closed-loop control system. The specific implementation details are as follows:

[0098] The Venturi jet is made of stainless steel, and its structure includes a contraction section, a throat section, and a diffusion section. The contraction section has a cone angle of 20°, the throat section has a diameter of 20mm, and the diffusion section has a cone angle of 10° (this structure parameter can generate stable negative pressure to ensure efficient ozone suction). The water inlet of the jet is connected to the outlet pipe of the pretreatment unit through a pipeline, the air inlet is connected to the ozone generator through a pipeline, and the water outlet is connected to the nanobubble release device at the top of the reactor through a pipeline. The ozone generator is a medium-frequency surface discharge type generator, with ozone production concentration of 80-120mg / L and gas production adjustment range of 0-5m³ / h. Its operating state is controlled by the intelligent control center according to the ozone concentration sensor data.

[0099] The generation process of nanobubbles is as follows: Pretreated wastewater (pressure 0.2-0.3 MPa) enters the contraction section of the Venturi jet injector, where the flow velocity gradually increases, reaching its maximum in the throat section, generating negative pressure. Ozone generated by the ozone generator is drawn into the throat section under this negative pressure, mixing thoroughly with the water to form a gas-liquid mixture. After entering the diffusion section, the flow velocity gradually decreases, and the pressure rises. The ozone is sheared and broken into tiny bubbles, which are further refined by the nanobubble releaser (0.5 μm pore size) to form nano-sized bubbles (particle size 50-200 nm) that enter the reactor. During their ascent, the nanobubbles significantly improve ozone dissolution efficiency (by more than 60% compared to traditional aeration) due to their large specific surface area (up to 1000 m² / m³ or more). Furthermore, some nanobubbles collapse upon reaching the ozone catalytic and photocatalytic zones, releasing energy to promote ·OH generation and simultaneously disturbing the water flow, enhancing the contact between pollutants, ·OH, and the catalyst.

[0100] To ensure that the nanobubble size remains stable within the target range (set by the intelligent control center based on water quality data), this embodiment employs a closed-loop control system for precise control of the bubble size. This system uses a bubble size monitor (employing laser scattering method, measuring range 10-1000 nm, accuracy ±5 nm) to provide feedback on the actual bubble size. With the target particle size setpoint issued by the intelligent control center deviation As input, an incremental PID control algorithm is used to calculate the control increment. The specific formula is as follows:

[0101] ;

[0102] in, for Constantly control the increase in quantity. This is a proportionality coefficient, its function is to quickly respond to particle size deviation and reduce the deviation amplitude; This is the integral coefficient, and its function is to eliminate static deviations and ensure that the particle size remains stable at the target value. These are the differential coefficients, used to predict the trend of deviation changes, adjust in advance, and avoid overshoot; , , They are respectively , , Particle size deviation at any given time.

[0103] Control increment After conversion by the intelligent control center, the output consists of two control signals: one is the speed control signal for the frequency driver of the circulating pump in the nanobubble generation system—if the actual particle size... Larger than the target particle size If the circulating pump speed is increased, the inlet pressure of the ejector will be increased, further refining the bubbles; if Less than If the speed of the circulating pump is reduced, then the opening control signal of the proportional valve in the ozone pipeline is adjusted; secondly, the opening control signal of the proportional valve in the ozone pipeline is adjusted. Greater than Increase the ozone flow rate appropriately to utilize the shearing effect of ozone gas to help refine the bubbles; if Less than This reduces the ozone flow rate. Through the above closed-loop control, the control precision of the nanobubble particle size can reach ±10nm, ensuring the stability of mass transfer efficiency and collapse effect.

[0104] The realization of the three-field synergistic effect:

[0105] The synergistic effect of the photocatalytic region, the ozone catalytic region, and the nanobubble collapse region is the core innovation of this unit. These three are not simply superimposed, but rather enhance the ·OH generation efficiency through a nonlinear enhancement effect. This synergistic effect is quantified using a synergistic effect coefficient model, with the following formula:

[0106] ;

[0107] in, The synergistic effect coefficient (dimensionless) This indicates the existence of a synergistic enhancement effect, as shown in this embodiment. Stable between 1.5 and 2.0); , , , These are the model parameters calibrated through experiments (adjusted according to wastewater characteristics and reaction conditions). for The intensity of vacuum ultraviolet light at any given moment; This serves as a reference value for ultraviolet light intensity. for Ozone concentration on the surface of nanobubbles at any given time; This is a reference value for the ozone concentration in the water body. This serves as a reference value for bubble particle size. for Average particle size of nanobubbles at time; This refers to the reaction time.

[0108] The physical meaning of this model is: the greater the intensity of vacuum ultraviolet light ( The higher the ratio, the greater the initial amount of ·OH generated; the higher the ratio of ozone concentration on the surface of nanobubbles to the concentration in the bulk, the greater the amount of ozone generated. The larger the nanobubble size, the higher the mass transfer efficiency, and the more efficiently ozone can participate in the reaction; the smaller the nanobubble particle size (…), the higher the mass transfer efficiency, and the more efficiently ozone can participate in the reaction; the smaller the nanobubble particle size (…), the higher the mass transfer efficiency, and the more efficient the .... The higher the ratio, the stronger the collapse effect and the more sufficient the energy release. The item reflects the decay trend of the synergistic effect with reaction time, avoiding energy waste due to the decrease of pollutant concentration in the later stage of the reaction. Through this model, the intelligent control center can monitor the synergistic effect of the three fields in real time. If the ratio is lower than 1.5, it indicates that the synergistic effect is weakening, and the light intensity, ozone dosage rate, or bubble particle size will be adjusted to restore the ratio to the target range, ensuring stable efficiency of OH generation.

[0109] Implementation process of the intelligent control center:

[0110] The intelligent control center is responsible for collecting the operation data and water quality parameters of each unit, and outputs control instructions through a dynamic optimization algorithm based on machine learning, achieving adaptive adjustment, bromate inhibition, and dynamic optimization of operation parameters of the system, ensuring efficient and stable operation of the system under different water quality conditions. The center is composed of a hardware system and a software system, with the following specific implementation details:

[0111] Hardware system composition:

[0112] The hardware core of the intelligent control center is an industrial control computer (using a PLC controller with high stability and anti-interference ability). The computer establishes communication connection with the sensors and actuators of each unit through industrial Ethernet, realizing data collection and instruction issuance. The sensors and actuators included in the hardware system are as follows:

[0113] Multi-parameter water quality sensor array: installed at the outlet of the pretreatment unit, the inlet and outlet of the multi-field synergistic reactor, and the outlet of the post-treatment unit, it can collect water quality parameters such as COD, UV254, bromide ion concentration, pH value, water temperature, etc. in real time, with measurement accuracy of: COD ± 5%, UV254 ± 0.01 cm-¹, bromide ion concentration ± 0.01 mg / L, pH ± 0.1, water temperature ± 0.5℃;

[0114] Bubble particle size monitor: installed below the nano-bubble release device of the multi-field synergistic reactor, it collects real-time data of the average particle size of nano-bubbles;

[0115] Ozone concentration sensor: installed at the outlet of the ozone generator, inside the multi-field synergistic reactor (photocatalytic zone and ozone catalytic zone), and the inlet of the tail gas treatment device, it monitors the ozone concentration to avoid ozone leakage;

[0116] Ultraviolet light intensity sensor: installed on the inner wall of the photocatalytic zone, it collects real-time data of the vacuum ultraviolet light intensity;

[0117] Flow and pressure transmitters: installed on the pipelines of each unit, they collect parameters such as inlet water flow, reactor internal pressure, and pressure difference of each catalytic bed; ​

[0118] Executors: including ozone generator, vacuum ultraviolet lamp group power supply, nanobubble generating system circulating pump frequency driver, pH adjustment tank dosing pump, catalytic bed backwash pump, ion exchange adsorption device switching valve, etc., all receiving control instructions of industrial control computer.

[0119] The hardware system is also equipped with a data storage module (with a capacity of 1 TB, which can store running data for more than 1 year) and a human-computer interaction interface (touch screen, which can display system running state, water quality data and alarm information in real time, support manual operation and parameter setting), and an alarm module is also set, when a parameter exceeds the safety range (such as ozone concentration exceeding the standard, reactor pressure being too high), the alarm module automatically sends out sound and light alarm, and triggers the emergency handling program (such as closing the ozone generator, opening the pressure relief valve).

[0120] Dynamic optimization algorithm based on LSTM:

[0121] The software core of the intelligent control center is a dynamic optimization algorithm based on long short-term memory network (LSTM), which learns historical running data and real-time water quality data to output the optimal control parameter combination at the next moment, including vacuum ultraviolet light intensity set value , ozone dosage rate set value and nanobubble target particle size set value , to ensure the optimal balance between pollutant removal rate, ozone utilization rate and bromate control. The mathematical model of the algorithm is:

[0122] ;

[0123] Among them, is the LSTM neural network model with parameters ; is the weight and bias of the model, which is obtained by training historical data); is the real-time monitored influent COD concentration; is the real-time monitored influent bromide ion concentration; is the real-time water temperature; is the real-time influent flow rate; , , , , , is the vacuum ultraviolet light intensity, ozone dosage rate, nanobubble average particle size, system internal pressure and ozone instantaneous utilization rate data in the historical period to is the length of the historical data window, which is in this embodiment.

[0124] ​The algorithm implementation process consists of three steps:

[0125] 1. Data preprocessing: processing the real-time collected water quality data ( , , The data is standardized by mapping it to the [0,1] interval to eliminate the influence of dimensional differences (e.g., COD is in mg / L, pH is dimensionless) on the model. The standardization formula is as follows: ,in The original data, , These are the historical minimum and maximum values ​​of the parameter, respectively.

[0126] 2. Model Prediction: Standardized real-time data and historical data sequences are input into the trained LSTM model. The model output layer contains predicted values ​​for three control targets, namely the predicted pollutant removal rate. Predicted ozone utilization rate and predicted bromate formation potential (The bromate formation potential reflects the potential amount of bromate to be formed; the lower the value, the better the bromate control effect.)

[0127] 3. Multi-objective optimization: The algorithm aims to "maximize" and , minimize To optimize the objective, a weighted summation method is used to transform the multi-objective function into a single-objective function (the objective function is...). ,in , , (The weighting coefficients are set according to emission standards and operating costs). The objective function is maximized using a particle swarm optimization algorithm, and the corresponding combination of manipulated variables is the optimal combination of control parameters. And send it to the corresponding actuator.

[0128] Bromate-specific inhibition strategy:

[0129] To address the issue of bromide ions in wastewater being easily oxidized to form bromate (a harmful byproduct), the intelligent control center has implemented a bromate suppression mode. This mode is activated when the influent bromide ion concentration is monitored in real-time. When the concentration exceeds a preset threshold (0.1 mg / L in this embodiment), the system automatically switches to this mode and suppresses bromate formation by adjusting the control parameters.

[0130] The core control logic of this mode is: to increase the bromate formation potential. As an additional constraint condition for dynamic optimization algorithms (i.e.) The preset safety value (8 μg / L in this embodiment) prioritizes adjusting the vacuum ultraviolet light intensity. The ratio of the ozone addition rate to the bromide ion concentration is maintained within the empirical safety interval (in this embodiment ). The control principle of the ratio is as follows: When the ratio is too high , the amount of ·OH generated is too much, which is easy to cause excessive oxidation of bromide ions to generate bromate; When the ratio is too low , the residence time of ozone in the water body is too long, which also promotes the generation of bromate; maintaining the ratio within the safety interval can ensure that ·OH preferentially reacts with organic matter, while reducing the contact time of ozone with bromide ions.

[0131] In addition, in the bromate inhibition mode, the intelligent control center moderately increases the target particle size of the nano bubbles (by 20%-30% compared to the normal mode), shortens the residence time of ozone in the water body by increasing the bubble particle size (the larger the particle size, the faster the bubble rising speed, and the shorter the residence time), and further reduces the reaction opportunity of ozone with bromide ions. Through the above strategies, the amount of bromate generated in this embodiment can be stably controlled below 10 μg / L, meeting the requirements of relevant emission standards.

[0132] Implementation process of post-treatment and resource recovery unit:

[0133] The core function of the post-treatment and resource recovery unit is to perform deep treatment on the effluent of the multi-field synergistic advanced oxidation reaction unit, achieve clean water discharge, intercept catalyst particles, and recover bromide and iodide ions and small-molecule organic acids in wastewater, achieving the environmental protection goal of "treatment + resource recovery". This unit is composed of a membrane separation device and an ion exchange adsorption device, and the implementation details and operation logic of each device are as follows:

[0134] Membrane separation device:

[0135] The membrane separation device uses an ultrafiltration membrane system (made of polyvinylidene fluoride, resistant to ozone and acid and alkali corrosion), the membrane assembly is a hollow fiber type, the pore size is 0.01 μm, the operating pressure is 0.1-0.15 MPa, and the membrane flux is 15-20 L / (m²·h). The inlet of the device is connected to the effluent collector at the bottom of the multi-field synergistic reactor through a pipeline, and the core function is to intercept catalyst particles (part of the catalyst falls into the effluent due to wear or flushing) and incompletely degraded macromolecular organic matter in the reaction effluent, to avoid waste caused by catalyst loss or clogging of the subsequent adsorption device.

[0136] The operation process of the membrane separation device is as follows: after the reaction effluent enters the membrane module, under the action of operating pressure, water and small molecules (such as bromide ions, iodide ions and small molecule organic acids) pass through the membrane pores to form a permeate and enter the subsequent ion exchange adsorption device; catalyst particles and macromolecular organic matter are intercepted on the membrane surface to form a concentrated solution. The system is set in a cross-flow filtration mode, and part of the concentrated solution is returned to the multi-field synergistic reactor (the return ratio is 1:5) to improve the utilization rate of the catalyst; when the pressure difference between the inlet and outlet of the membrane module exceeds 0.05 MPa, it indicates that the membrane surface pollution is aggravated, and the intelligent control center starts the chemical cleaning program: first, backwash with clean water for 10 minutes, then circulate cleaning with 0.5% sodium hypochlorite solution for 30 minutes, and finally rinse with clean water until the effluent meets the standard to restore the membrane flux. After the treatment of the membrane separation device, the suspended solids content of the effluent is reduced to below 5 mg / L, and the catalyst interception rate is above 99%.

[0137] Ion exchange adsorption device:

[0138] The ion exchange adsorption device adopts a multi-column parallel structure (4 adsorption columns in this embodiment, 2 columns in operation and 2 columns in standby), the column material is glass fiber reinforced plastic (corrosion resistant and light weight), the effective volume of each column is 5 m³, the inside is filled with two kinds of special adsorption resins, from top to bottom, they are quaternary amine type strong basic anion exchange resin and macroporous aromatic adsorption resin, and the filling height ratio is 1:1.

[0139] The functional positioning of the two kinds of resins is as follows: the quaternary amine type strong basic anion exchange resin has strong hydrophilicity and high exchange capacity, and can selectively adsorb bromide ions and iodide ions in water (exchange capacity is 1.2-1.5 mmol / g), the action mechanism is that the quaternary amine group (-N(CH3)3+) in the resin and halide ions (Br-, I-) undergo ion exchange reaction; the macroporous aromatic adsorption resin has a hydrophobic skeleton and a porous structure, and has strong adsorption capacity (adsorption capacity is 0.8-1.0 g / g) for small molecule organic acids (such as acetic acid, propionic acid, etc., which are derived from organic matter oxidation degradation intermediates), the action mechanism is hydrophobic interaction and van der Waals force adsorption.

[0140] The device adopts a "rotating switching and offline regeneration" operation mode, and the specific process is as follows: the permeate of the membrane separation device first enters the adsorption column in operation, and passes through the quaternary amine type strong basic anion exchange resin and the macroporous aromatic adsorption resin in turn to complete the adsorption of bromide ions and iodide ions and organic acids; a water quality sensor is arranged at the outlet of the adsorption column to monitor the bromide ion concentration and the COD value (reflecting the content of organic acids) in real time, when the outlet bromide ion concentration exceeds 0.01 mg / L or the COD value exceeds 50 mg / L, it indicates that the adsorption column has been saturated, the intelligent control center automatically closes the water inlet and outlet valves of the column, switches to the standby adsorption column for continuous operation, and ensures the continuous treatment of the system.

[0141] The regeneration process of the saturated adsorption column is divided into two steps of off-line desorption and cleaning: for the quaternary amine type strong basic anion exchange resin, 8%-10% sodium chloride solution is used as the desorption agent, the desorption agent passes through the resin layer at a flow rate of 5 m³ / h, the desorption time is 2 h, the bromine and iodine ion concentration in the desorption solution can be enriched to 50-100 mg / L, and is sent to the bromine and iodine recovery tank, and then sodium bromide and sodium iodide products can be extracted by evaporation crystallization; for the macroporous aromatic adsorption resin, 5%-8% sodium hydroxide solution is used as the desorption agent, the desorption flow rate and time are the same as before, and the organic acid concentration in the desorption solution can be enriched to 500-800 mg / L, and is sent to the organic acid recovery tank, and after neutralization and rectification, it can be reused as an industrial raw material. After desorption, the resin is washed with water until the pH value of the effluent is neutral, and is ready for use in the next operation.

[0142] The effluent treated by the post-treatment and resource recovery unit has a COD concentration of less than 50 mg / L, a bromine ion concentration of less than 0.01 mg / L, and a pH value of 6.5-7.5, which meets the first level A standard of the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918-2002) and can be directly discharged or reused in enterprise production (such as cooling water supplement water); at the same time, the recovery rate of organic acid is greatly improved, achieving the collaborative goal of wastewater treatment and resource recovery.

[0143] In summary, the embodiment aims at the treatment of difficult-to-degrade organic wastewater (containing bromine ions) in the chemical industry. The practical application of the ozone nanobubble purification environmental protection treatment system and method verifies the feasibility and superiority of the technical scheme. In the implementation process, the pretreatment unit effectively removes suspended solids and homogenizes the water quality, providing stable conditions for subsequent reactions; the multi-field collaborative advanced oxidation reaction unit greatly improves the efficiency of hydroxyl radical generation through the synergistic effect of 185 nm vacuum ultraviolet light, supported composite metal oxide catalyst and nanobubbles; the intelligent control center realizes adaptive adjustment of system parameters based on the LSTM dynamic optimization algorithm and the bromate special inhibition strategy, and controls the bromate generation to be less than 10 μg / L; the post-treatment and resource recovery unit realizes standard discharge of clean water and resource recovery of bromine and iodine ions and organic acids through membrane separation and ion exchange technology, and the recovery rate is greatly improved.

[0144] The practice of the embodiment shows that the system effectively solves the technical bottlenecks of low synergistic efficiency and difficult byproduct control of traditional ozone nanobubble technology, has the dual advantages of efficient purification and resource recovery, runs stably and has strong adaptability, can be widely applied to difficult-to-degrade organic wastewater treatment projects in the chemical, dyeing and pharmaceutical industries, provides reliable technical support for "pollution reduction and carbon reduction" and resource recycling in the environmental protection field, and has significant economic and environmental benefits.

[0145] Embodiment Two

[0146] AsFigure 1 Based on the first embodiment, this embodiment details the specific steps of the ozone nanobubble purification environmental treatment system and method when working, which are as follows:

[0147] 1. Water quality sensing and parameter initialization (S100):

[0148] When the system starts, the intelligent control center reads the real-time water quality data from the effluent end of the pretreatment unit, including chemical oxygen demand (COD), ultraviolet absorbance (UV254), bromide ion concentration, temperature, pH value, and influent flow rate.

[0149] Based on the initial data, load the pre-defined wastewater treatment model (selected according to wastewater type), and initialize the operating parameters such as vacuum ultraviolet light intensity reference value, ozone dosage rate reference value, and nanobubble target particle size reference value. The actuators (such as the pH adjustment tank dosing pump) perform preliminary operations according to the initialized parameters.

[0150] 2. Intelligent decision-making and parameter setting (S200):

[0151] The intelligent control center combines real-time water quality data and historical operation sequences (such as light intensity, ozone utilization rate, and bubble particle size data for the past 1 hour) to calculate the optimal control parameters through a dynamic optimization algorithm.

[0152] The output parameters include vacuum ultraviolet light intensity set value, ozone dosage rate set value, nanobubble target particle size set value, and catalyst bed backwashing flag (based on pressure difference data). These parameters are sent to the ozone generator, vacuum ultraviolet lamp group lifting mechanism, nanobubble circulating pump, and other actuators.

[0153] 3. Multi-field synergistic advanced oxidation reaction (S300):

[0154] The pretreated wastewater enters the multi-field synergistic advanced oxidation reaction unit:

[0155] In the photocatalytic zone, the vacuum ultraviolet lamp group irradiates the wastewater according to the set light intensity to generate hydroxyl radicals from ozone and water molecules.

[0156] In the ozone catalytic zone, the supported catalyst promotes ozone decomposition and enhances free radical generation.

[0157] In the nanobubble collapse zone, the Venturi jet generates nanobubbles of a set particle size, enhancing ozone mass transfer and collapse effect.

[0158] At the same time, the intelligent control center monitors the bromide ion concentration in real time. If the concentration exceeds the threshold value (0.1 mg / L), the system switches to the bromate inhibition mode, adjusts the light intensity to ozone dosage rate ratio, and moderately increases the bubble particle size to shorten the ozone residence time.

[0159] 4. By-product resource recycling (S400):

[0160] After the reaction, the effluent enters the post-treatment unit:

[0161] The membrane separation device traps catalyst particles and macromolecular organic matter, and the permeate enters the ion exchange adsorption device.

[0162] In the adsorption device, quaternary amine type resin selectively adsorbs bromine and iodine ions, and macroporous aromatic resin adsorbs small molecular organic acids.

[0163] When the adsorption column is saturated (judged based on outlet water quality data), the system automatically switches to the standby column, and the saturated column is regenerated by off-line desorption, and bromine and iodine compounds and organic acids are recovered to the special recovery tank.

[0164] 5. Closed-loop feedback and dynamic optimization (S500):

[0165] The intelligent control center compares the deviation of the final effluent water quality (such as COD, bromine ion concentration) from the preset target (such as COD < 50 mg / L, bromate < 10 μg / L).

[0166] Based on the deviation data, the weight parameters of the dynamic optimization algorithm are dynamically adjusted to realize model self-learning and operation parameter optimization, ensuring that the system adapts to water quality fluctuations and maintains stable performance.

[0167] The workflow realizes efficient wastewater purification and resource recovery, while inhibiting harmful by-products, in line with environmental emission standards, by integrating real-time monitoring, multi-site collaborative reaction and intelligent feedback.

[0168] The above is only a preferred embodiment of the present application, and is not intended to limit the present application in any form. Although the present application has been disclosed as above with a preferred embodiment, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content to make equivalent embodiments with equivalent changes, without departing from the technical solution of the present application. Any modification, equivalent change and modification of the above embodiments based on the technical essence of the present application are still within the scope of the present application.

Claims

1. An ozone nanobubble purification and environmental-friendly treatment system, characterized by, The system comprises a pretreatment unit, a multi-field synergistic advanced oxidation reaction unit, an intelligent control center, and a post-treatment and resource recovery unit. The pretreatment unit comprises a grid well, an adjusting pool and a pH adjusting pool connected in sequence, for preliminary physical separation, water quality and quantity adjustment and pH adjustment of raw wastewater. The multi-field synergistic advanced oxidation reaction unit comprises a closed cylindrical reactor shell, a water distribution device and a nano-bubble releasing device arranged at the top of the shell, and a water collector arranged at the bottom of the shell, and the inside of the shell is divided into a photocatalysis zone, an ozone catalysis zone and a nano-bubble collapse zone from top to bottom. The photocatalysis zone is located at the upper part of the reactor, and a liftable vacuum ultraviolet lamp group is arranged on the central axis of the photocatalysis zone, and the inner wall of the photocatalysis zone is lined with an aluminum-based high-reflectivity reflective layer. The ozone catalysis zone is located at the middle part of the reactor, and is filled with a supported composite metal oxide catalyst, which is stacked on a fixed sieve plate. The nano-bubble collapse zone is located at the lower part of the reactor, and is connected with an external ozone generator through a Venturi jet device, the air suction port of the Venturi jet device is connected with an ozone conveying pipeline, the water inlet is connected with a water outlet pipeline of the pretreatment unit, and the water outlet is connected with the nano-bubble releasing device. The intelligent control center comprises an industrial control computer, which is connected with a multi-parameter water quality sensor array, a bubble particle size monitor, an ozone concentration sensor, an ultraviolet light intensity sensor, and a plurality of flow and pressure transmitters, and the industrial control computer is provided with a dynamic optimization algorithm based on machine learning, and can output control instructions to an ozone generator, a vacuum ultraviolet lamp group power supply, a nano-bubble generating system circulating pump frequency driver and a pH adjusting pool dosing pump. The post-treatment and resource recovery unit comprises a membrane separation device and an ion exchange adsorption device, and the water inlet of the membrane separation device is connected with the water collector at the bottom of the reactor, and the ion exchange adsorption device is arranged after the membrane separation device.

2. The ozone nanobubble purification and environmentally-friendly treatment system according to claim 1, characterized in that, The dynamic optimization algorithm based on machine learning is built in the intelligent control center, and the vacuum ultraviolet light intensity, the ozone addition rate and the target particle size of the nano-bubbles are synergistically and dynamically regulated in real time according to the following mathematical formula: ； wherein, , , respectively represent the set value of the next time instant vacuum ultraviolet light intensity, the set value of the ozone dosage rate and the set value of the nano bubble target particle size, represents a long short-term memory network model with parameters , , , , , , respectively represent the real-time monitored chemical oxygen demand of influent, ultraviolet absorbance, bromide ion concentration, temperature, influent flow and pH value, , , , , respectively represent the vacuum ultraviolet light intensity, the ozone dosage rate, the nano bubble average particle size, the system internal pressure and the ozone instantaneous utilization rate in the historical period to .

3. The ozone nanobubble purification and environmentally-friendly treatment system according to claim 1, characterized in that, The photocatalysis zone, the ozone catalysis zone and the nano-bubble collapse zone in the multi-field synergistic advanced oxidation reaction unit realize the nonlinear enhancement relationship among them through a synergistic effect coefficient model: ； in, The synergy coefficient is a dimensionless number. , , , These are the model parameters calibrated through experiments. for The intensity of ultraviolet light in a vacuum at any given moment. This is a reference value for ultraviolet light intensity. for The ozone concentration on the surface of the nanobubbles at any given time. This is a reference value for the ozone concentration in the water body. This serves as a reference value for bubble size. for The average particle size of nanobubbles at time t, This refers to the reaction time.

4. The ozone nanobubble purification and environmentally-friendly treatment system according to claim 1, characterized in that, The bubble particle size generated by the nanobubble releaser is precisely regulated by a closed loop control system, which is realized by adjusting the water pressure at the inlet of the Venturi jet and the flow of ozone gas; the closed loop control system uses the actual particle size value fed back by the bubble particle size monitor as the deviation of the target particle size set value issued by the intelligent control center As input, the incremental PID control algorithm is used to calculate the control amount:​ ； wherein is an increment of the control variable at the moment, , , Kp, Ki, Kd are proportional, integral, and derivative coefficients, respectively, , , are , , a particle size deviation at the moment, a control variable is finally converted into a rotational speed control signal for a circulating pump frequency driver and an opening control signal for an ozone pipeline proportional valve.

5. The ozone nanobubble purification and environmentally-friendly treatment system according to claim 1, characterized in that, The arrangement mode and control strategy of the vacuum ultraviolet lamp group are as follows: The vacuum ultraviolet lamp group is composed of a plurality of 185nm wavelength vacuum ultraviolet lamp tubes arranged radially around a central support column, and the lamp tube cover is a high-transmittance quartz sheath pipe, and the vacuum ultraviolet lamp group is installed on a sealed flange at the top of the reactor through a lifting mechanism driven by a servo motor, so that the height of the lamp group in the reactor can be adjusted steplessly. The intelligent control center dynamically adjusts the immersion depth and output power of the lamp group according to the real-time monitoring value of the water inlet ultraviolet absorbance The control logic is defined by the following function relationship: The control logic is defined by the following function relationship: The control logic is defined by the following function relationship: ； ； wherein, is the immersion depth of the vacuum ultraviolet lamp set, is the maximum allowed immersion depth of the lamp set, is the immersion depth adjustment coefficient, is the real-time monitored water inlet ultraviolet absorbance, indicating that the immersion depth of the lamp set decreases as the water inlet ultraviolet absorbance increases, is the output power of the vacuum ultraviolet lamp set, is the maximum rated power of the ultraviolet lamp set, is the ultraviolet absorbance reference value, is the real-time water inlet flow rate, is the water inlet flow rate reference value.

6. The ozone nanobubble purification and environmentally-friendly treatment system according to claim 1, characterized in that, The filling mode and regeneration method of the supported composite metal oxide catalyst are as follows: The supported composite metal oxide catalyst takes γ-alumina as a carrier, and the active components include manganese dioxide, magnesium oxide and cerium oxide, and the mass ratio of the three is 5:3:2, and the catalyst is a porous spherical shape with a particle size of 3-5mm; The catalyst is layered and filled in the ozone catalysis zone, and each layer of catalyst is separated by an inert ceramic sieve plate to form a plurality of independent catalyst bed layers, and a microporous aerator is arranged at the bottom of each catalyst bed layer, and the microporous aerator is connected with the main ozone conveying pipeline through a branch pipe to separately distribute and supply ozone to each catalyst bed layer. The intelligent control center determines whether catalyst blockage occurs according to the differential pressure sensor data of the upper and lower ports of each catalytic bed When the differential pressure exceeds a set threshold, the system automatically starts a backwashing program to perform reverse flushing on the specific bed with high-pressure clean water When the catalyst activity decreases, the system starts an in-situ chemical regeneration program to inject a dilute citric acid solution into the specific bed for cleaning and regeneration 7. The ozone nanobubble purification and environmentally-friendly treatment system according to claim 1, characterized in that, The special control strategy of the system for bromate inhibition is: The intelligent control center monitors the bromide ion concentration in the water in real time When the preset threshold is exceeded, the control strategy automatically switches to a bromate inhibition mode, in which the dynamic optimization algorithm adjusts the bromate potential as an additional constraint condition for optimization calculation, and preferentially adjusts the vacuum ultraviolet light intensity and the ozone dosage rate to ensure that the ratio is maintained within an empirical safe range that can inhibit the generation of bromate, while moderately increasing the target particle size of the nano-bubbles to shorten the residence time of ozone in the water.

8. The ozone nanobubble purification and environmentally-friendly treatment system according to claim 1, characterized in that, The operation mode of the ion exchange adsorption device in the post-treatment and resource recovery unit is: The device is filled with two specific adsorption resins, one is a quaternary amine type strong basic anion exchange resin for selectively adsorbing bromide ions and iodide ions, and the other is a macroporous aromatic adsorption resin for adsorbing small molecular organic acid intermediates in water; The adsorption device adopts a multi-column parallel and rotating switching operation mode, when a group of adsorption columns is saturated, the system automatically switches to the standby adsorption column for continuous work, and the saturated column is regenerated by off-line desorption, and the desorption liquid is sent into different recovery tanks, the desorption liquid enriched with bromine and iodine ions is sent into a bromine and iodine recovery tank, and the desorption liquid enriched with organic acids is sent into an organic acid recovery tank.

9. An ozone nanobubble purification and environmental treatment method, suitable for use in an ozone nanobubble purification and environmental treatment system according to any one of claims 1 to 8, characterized in that, The specific steps of the method are: S100, water quality sensing and parameter initialization: the system is started, the intelligent control center reads the initial data of each water quality sensor, loads the corresponding wastewater treatment model, and initializes the system operation parameters; S200, intelligent decision and parameter setting: built-in dynamic optimization algorithm based on machine learning calculates and outputs the optimal control parameter combination according to the real-time water quality data and historical operation data obtained in step one, including the vacuum ultraviolet light intensity set value , the ozone addition rate set value , the target particle size set value of nano bubbles , and the catalyst bed backwashing flag S300, multi-field synergistic advanced oxidation reaction: the pretreated wastewater enters the multi-field synergistic advanced oxidation reaction unit, under the instruction of the intelligent control center, the vacuum ultraviolet lamp group, the ozone adding system and the nano bubble generating system work synergistically according to the set parameters, generate high concentration of hydroxyl radicals, oxidize and degrade organic pollutants in wastewater, at the same time, the system monitors the bromide ion concentration in real time, and dynamically activates the bromate inhibition mode; S400, by-product resource recovery: the effluent after oxidation treatment enters the post-treatment and resource recovery unit, passes through the membrane separation device and the ion exchange adsorption device in turn, realizes clear water discharge, catalyst particle interception and bromine, iodine ion and organic acid resource recovery; S500, closed loop feedback and dynamic optimization: the intelligent control center continuously compares the deviation of the final effluent quality from the preset target, and takes it as a feedback signal to dynamically adjust the optimization algorithm model parameters in step S200.

10. The ozone nanobubble purification and environmentally friendly treatment method according to claim 9, characterized by, The specific process of intelligent decision-making of the dynamic optimization algorithm in step S200 includes: Standardized pretreatment of real-time influent water quality data to eliminate dimensional influence; The standardized data and recent historical operation data sequence are input into the trained LSTM neural network model, The output layer of the LSTM model contains three main control targets: predicted pollutant removal rate , predicted ozone utilization rate , and predicted bromate formation potential ; The optimization algorithm aims to maximize the pollutant removal efficiency and ozone utilization, while minimizing the bromate formation potential, and a set of optimal operation variable combinations is solved in a multi-objective optimization framework and the combination is issued to the corresponding execution mechanism.

Images