Zero-discharge treatment process for recycling production wastewater

Abstract

The invention provides a zero-discharge treatment process for recycling production wastewater, and relates to the technical field of water treatment and recycling, and the zero-discharge treatment process comprises the following steps: S1, oxidizing and degrading COD through ozone and a Fenton reagent, and generating a flocculatable intermediate; s2, intercepting suspended matters by using a gradient aperture filter bed in a grading manner, and monitoring a dynamic membrane resistance coefficient delta Rm in real time to automatically trigger backwashing; s3, coupling an ultrafiltration reverse osmosis membrane to realize that the organic matter rejection rate eta is greater than or equal to 98%, and synchronously regulating and controlling flux and operation pressure by an online spectrometry; s4, regulating and controlling the current density by adopting a rotational flow electric flocculation reactor for directional crystallization to produce industrial salt with Cl <-> less than or equal to 50mg / L; and S5, based on the total dissolved solid recovery rate TR and the comprehensive energy consumption, establishing a multi-target optimization model for real-time parameter adjustment. According to the method, a membrane pollution early warning and backwashing dynamic response mechanism is constructed through cross-scale cooperative regulation and control of delta Rm and the retention rate eta, and a catalytic oxidation effect strengthening and electric crystallization parameter self-tuning technology is combined, so that the problem of cooperative optimization of high-salinity wastewater salt gradient separation and pollutant deep removal is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment and recycling, and particularly to a zero-discharge treatment process for the reuse of production wastewater. Background Art

[0002] At present, the advanced treatment and zero-discharge technology of industrial wastewater presents multi-dimensional technical bottlenecks in practical engineering applications, mainly manifested in the attenuation of the efficiency of key links in the treatment process chain and the failure of cross-unit coordination. In the pretreatment stage, although the conventional catalytic oxidation technology can degrade some organic matters, the adaptability control ability of the oxidant dosage and the pollution load is insufficient, resulting in over-reliance on empirical over-dosing in case of water quality fluctuations. During the reaction process, the inactivation attenuation law of the catalytic active components and the pollutant degradation kinetics do not form an effective dynamic cooperation, resulting in a step-by-step decline in the treatment efficiency of the reactor over time. Especially when facing sulfur- and nitrogen-containing heterocyclic refractory organic matters, traditional oxidation paths are prone to the accumulation of intermediate by-products, forming new characteristic pollutants and reversely increasing the treatment load of subsequent processes.

[0003] The biological treatment unit is limited by the toxicity tolerance threshold of the microbial population to industrial wastewater. When treating characteristic pollutants such as aniline and polycyclic aromatic hydrocarbons, the extracellular enzyme secretion mechanism is continuously inhibited, resulting in a significant reduction in the macromolecule chain-breaking efficiency. Such incompletely decomposed organic matters form a micelle structure at the membrane interface through hydrophobic interaction and π-π stacking effect, constituting a filter cake layer with ion exchange characteristics, significantly changing the membrane separation behavior and accelerating the jump of the transmembrane pressure difference. The inherent defect of the biochemical system's anti-shock load ability leads to the effluent water quality being easily affected by the influent water fluctuation, further amplifying the uncertainty of the subsequent membrane process.

[0004] The membrane treatment section faces the problem of multi-interface interactive pollution in the high-salt and high-organic matter composite system: the concentration polarization caused by dissolved inorganic salts leads to an abnormal increase in the micro-region conductivity on the membrane surface, promoting the electrostatic adsorption of charged colloidal particles; the incompletely decomposed hydrophobic organic matters form a physical condensation layer inside the membrane pores through intermolecular forces; the heteronuclear complexes formed by the complexation of high-valent metal cations and organic carboxylate radicals are deposited under the drive of the transmembrane pressure difference to form a dense pollution layer. The synergistic effect of these three pollution mechanisms narrows the working parameter range of the membrane system, and the conventional pressure and flow regulation means cannot adapt to the composite fouling mode, forcing the cleaning frequency and intensity to be increased, and the service life of the membrane element shows a non-linear reduction.

[0005] The core contradiction point in the concentrated liquid disposal link lies in the insufficient selective separation ability of the inorganic salt components. Cl - 、SO 4 2-During the evaporation and concentration process, the plasma forms multiple double salts to co-crystallize. The disordered growth of the crystal structure results in a mixed product composition. The lattice distortion of sodium salts and potassium salts leads to the deterioration of product purity. The conventional blending process cannot achieve the gradient enrichment of low-value salts. The difference in the thermal decomposition characteristics of the products causes the energy consumption of the roasting process for purity improvement to exceed the standard. Due to the entrainment effect of heavy metals and organic substances in the terminal residual liquid, high-cost hazardous waste treatment has to be carried out, making it difficult to break through the economic threshold of the zero-emission system.

[0006] The shortcoming of collaborative control exposed at the system integration level further restricts the improvement of overall energy efficiency. The local optimal solutions formed by the independent control strategies of each process unit often deviate from the global optimal equilibrium point. For example, increasing the dosage of chemicals to improve the catalytic oxidation efficiency will lead to a sharp increase in the probability of fouling in the subsequent membrane system, or reducing the influent load to maintain the stability of the membrane flux will cause waste of the production capacity of the pretreatment device. The current mainstream linear superposition control model cannot accurately describe the non-linear coupling relationship between multiple processes, resulting in the water recovery rate being always restricted by the maximum flux capacity of the weak link, and the energy recovery device failing to form a dynamic match with the pressure-driven unit. The interweaving and superimposition of these deep-seated technical bottlenecks greatly increase the technical complexity of the wastewater zero-emission system and significantly compress the operable range of the process window. Summary of the Invention

[0007] In order to solve the technical problems in the prior art, such as excessive addition of oxidants causing salt accumulation, insufficient efficiency of biological treatment for refractory organic substances, severe composite pollution and flux decline in the membrane system, low resource utilization rate of salts in the concentrated liquid, and lack of collaborative control of process units, the present invention provides a zero-emission treatment process for the reuse of production wastewater.

[0008] The technical solution provided by the present invention is as follows:

[0009] A zero-emission treatment process for the reuse of production wastewater provided by the present invention includes:

[0010] S1. Wastewater pretreatment: After adjusting the pH of the printing and dyeing wastewater to the range of 6.5 - 7.5, perform composite catalytic oxidation treatment, control the CODMn degradation rate ≥ 85%, and generate flocculable intermediate products;

[0011] S2. Multi-stage dynamic filtration: Pass the pretreated wastewater through self-cleaning fiber filter beds with gradient pore sizes of 50μm → 10μm → 1μm in sequence, and monitor the change of transmembrane pressure difference in real time when the dynamic membrane resistance coefficient ΔRm of the filter bed surface ≥ 0.32. When the cumulative pressure difference increase exceeds 45% of the initial value, trigger the backwashing procedure;

[0012] S3. Fine filtration and concentration treatment: Perform cross-flow filtration through two-stage series ultrafiltration + reverse osmosis membrane modules, regulate the organic matter retention rate η ≥ 98% in real time, and simultaneously monitor that the membrane flux remains not less than 80% of the design value;

[0013] S4. Concentrate solidification: Introduce the reverse osmosis concentrate into the hydrocyclone electrocoagulation reactor and treat it under the condition of a current density of 12 - 15 A / m 2 until crystalline salts with a Cl^- concentration ≤ 50 mg / L are produced;

[0014] S5. Circulation control: Based on the dual constraint conditions of a total dissolved solid recovery rate TR ≥ 96.5% and a system comprehensive energy consumption coefficient ε ≤ 1.8 kW·h / m 3 , optimize the operating parameter combinations of each treatment unit in real time;

[0015] The dynamic membrane resistance coefficient ΔRm and the organic matter rejection rate η are the key control variables for dynamically adjusting process parameters through on-line monitoring data, where ΔRm reflects the formation rate of the pollution layer on the filter material surface, and η characterizes the continuous rejection ability of the membrane separation system for small molecule organic matters.

[0016] The beneficial effects brought by the technical solution provided by the present invention at least include:

[0017] (1) In the present invention, by constructing a pretreatment synergistic system of composite catalytic oxidation and gradient dynamic filtration, the refractory organic pollutants in the wastewater can be efficiently degraded and suspended colloids can be intercepted, significantly reducing the fouling risk of the subsequent membrane separation system. The multi-path oxidation mechanism of ozone and Fenton-like reagents breaks through the limitations of the traditional single oxidation mode, specifically decomposes the molecular structure of complex organic matters, and forms flocculable intermediate products that are easy to be processed subsequently. The three-stage variable pore size filter bed realizes the cascade removal of suspended substances through hierarchical interception, and combines the dynamic monitoring technology of the pollution layer to accurately adjust the backwashing cycle, ensuring the stability and high efficiency of the pretreatment process and laying a foundation for the long-term stable operation of the whole process;

[0018] (2) In the present invention, an innovative dual-factor control model of membrane resistance coefficient and rejection rate is designed, combined with an abnormal transmembrane pressure warning mechanism, to realize the refined management of the membrane system working conditions. The dynamic membrane resistance coefficient based on the analysis of the formation kinetics of the pollution layer can identify the attenuation trend of membrane separation performance in advance and trigger an adaptive backwashing strategy to prevent irreversible fouling; the organic matter penetration compensation algorithm corrects the rejection rate calculation model and real-time feedback regulates the membrane flux and operating pressure parameters, solving the problem of unstable rejection efficiency of traditional membrane processes under fluctuating water quality. The synergistic effect of the two significantly reduces the intensity of manual intervention, extends the membrane service life, and simultaneously ensures the water production quality and system productivity;

[0019] (3) In the present invention, a closed-loop treatment system for concentrated liquid resource utilization is constructed through the electro-flocculation crystallization coupling dynamic tuning technology. The enhanced mass transfer effect of the cyclonic electric field promotes the directional growth of crystal nuclei. The time-varying current density control strategy simultaneously inhibits electrode passivation and salt separation. Combined with X-ray diffraction phase monitoring, precise control of the crystallized salt components is achieved. The cross-unit parameter linkage optimization algorithm breaks through the data barriers of pre-treatment, membrane separation and crystallization links, and intelligently matches the process parameter combination according to the water quality fluctuation characteristics, breaking through the shackles of the traditional system that focuses on the optimization of a single link, thereby improving the overall purity of salt recovery and the utilization rate of water resources, and simultaneously reducing the demand for hazardous waste disposal and the comprehensive energy consumption of the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 A schematic diagram of a process flow for a zero-discharge treatment process for production wastewater reuse provided by an embodiment of the present invention;

[0022] Figure 2 A schematic diagram of a constrained multi-objective particle swarm algorithm process for a zero-discharge treatment process for production wastewater reuse provided by an embodiment of the present invention;

[0023] Figure 3 A schematic flow chart of a real-time adjustment mechanism of process parameters based on crystal salt purity feedback for a zero-discharge treatment process for production wastewater reuse provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is described below in conjunction with the accompanying drawings.

[0025] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "example" is intended to present the concept in a specific way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either of the two.

[0026] In the embodiments of the present invention, the terms "image" and "picture" can sometimes be used interchangeably. It should be noted that when the difference between them is not emphasized, their intended meanings are the same. The terms "of", "corresponding", and "corresponding to" can sometimes be used interchangeably. It should be noted that when the difference between them is not emphasized, their intended meanings are the same.

[0027] In the embodiments of the present invention, sometimes subscripts such as W 1 may be miswritten as non-subscript forms such as W1. When the difference between them is not emphasized, their intended meanings are the same.

[0028] To make the technical problems to be solved, technical solutions, and advantages of the present invention clearer, the following will be described in detail with reference to the accompanying drawings and specific embodiments.

[0029] Referring to the attached Figure 1 figures, a schematic flow diagram of a zero-discharge treatment process for the reuse of production wastewater provided by the embodiments of the present invention is shown.

[0030] The embodiments of the present invention provide a zero-discharge treatment process for the reuse of production wastewater. The treatment process may include the following steps:

[0031] S1. Wastewater pretreatment: After adjusting the pH of the printing and dyeing wastewater to the range of 6.5 - 7.5, composite catalytic oxidation treatment is carried out to control the CODMn degradation rate ≥ 85%, and flocculable intermediate products are generated.

[0032] It should be noted that in the pretreatment stage of adjusting the wastewater pH to the range of 6.5 - 7.5, the strong acidity and alkalinity of the water body are eliminated through neutralization reactions, reducing the corrosion risk of subsequent treatment equipment. At the same time, it creates the best reaction environment for catalytic oxidation - the activity of the oxidant is significantly affected by pH. The neutral condition can not only keep ozone in a stable dissolved state but also maintain the effective valence state of ferrous ions. The catalytic oxidation uses an ozone-coupled Fenton-like system, utilizing the synergistic effect of direct oxidation by ozone molecules and indirect oxidation by hydroxyl radicals to specifically attack the azo bonds and benzene ring structures in the printing and dyeing wastewater. Designing a CODMn degradation rate ≥ 85% ensures that macromolecular organic matter is fully decomposed into biodegradable small-molecule intermediate products, providing a material basis for subsequent flocculation and sedimentation.

[0033] S2. Multi-stage dynamic filtration: The pretreated wastewater is passed through a self-cleaning fiber filter bed with gradient pore sizes of 50μm → 10μm → 1μm in sequence. The transmembrane pressure difference change is monitored in real time when the dynamic membrane resistance coefficient ΔRm of the filter bed surface ≥ 0.32. When the cumulative pressure difference increase exceeds 45% of the initial value, the backwashing program is triggered.

[0034] It should be noted that the multi-stage dynamic filtration link adopts a fiber filter bed structure with gradient pore sizes, and physically intercepts suspended solids of different scales through a physical barrier of 50μm - 10μm - 1μm. The primary stage intercepts large particles such as fiber debris, the secondary stage captures colloidal substances, and the final stage blocks fine suspended solids. The dynamic membrane resistance coefficient ΔRm on the surface of the filter bed reflects the cumulative state of the pollution layer in real time, and its growth forms a correlation model with the change of transmembrane pressure difference. When the cumulative pressure difference increase reaches 45% of the initial value, backwashing is triggered to precisely balance flux maintenance and energy consumption savings - premature cleaning increases water and energy consumption, and late treatment exacerbates the risk of membrane fouling. This threshold design is calculated based on the treatment capabilities of upstream and downstream process units and the maximum tolerable pollutant load.

[0035] S3. Fine filtration and concentration treatment: Cross-flow filtration is carried out through two-stage series ultrafiltration + reverse osmosis membrane modules, and the organic matter retention rate η≥98% is regulated in real time, and the membrane flux is synchronously monitored to be not less than 80% of the design value.

[0036] It should be noted that the combination of ultrafiltration and reverse osmosis in the fine filtration and concentration stage gives full play to the differences in the characteristics of the two-stage membrane separation: the ultrafiltration membrane removes residual dissolved macromolecular organic matter and colloids in water through molecular weight retention, and the reverse osmosis membrane relies on ionic sieving to deeply remove salts and small molecule pollutants. Among them, ultrafiltration pretreatment reduces the risk of organic fouling of the reverse osmosis membrane. The real-time monitoring of the membrane flux built into the system uses 80% of the design value as the lower limit alarm threshold, and the water production stability is maintained by adjusting the concentrate reflux ratio and operating pressure to ensure that the membrane module operates under the optimal hydraulic conditions. The target setting of the organic matter retention rate ≥98% is derived from the quality control requirements of crystalline salts.

[0037] S4. Solidification of concentrated liquid: The reverse osmosis concentrated liquid is introduced into a vortex electrocoagulation reactor and treated under the condition of a current density of 12 - 15A / m 2 until crystalline salts with a Cl^- concentration ≤50mg / L are produced.

[0038] It should be noted that the vortex electrocoagulation technology is selected for the concentrated liquid solidification unit. During the electrolysis process under the condition of a current density of 12 - 15A / m 2 Fe 2 + / Fe 3 + ion pairs are generated. Through electro-neutralization and adsorption bridging effects, Cl in the concentrated liquid - combines with metal ions to form a stable crystalline phase. At the same time, the vortex field strengthens the mass transfer process and promotes the orderly growth of crystal nuclei. The end control standard of Cl - ≤50mg / L not only ensures that the crystalline salts meet the industrial recovery quality requirements but also avoids equipment corrosion problems caused by the cyclic accumulation of chlorides in the system. The optimal selection range of electrolysis parameters is determined based on the economic balance experiment of electrolysis efficiency and energy consumption.

[0039] S5. Recycling control: Based on the dual constraint conditions of the total dissolved solids recovery rate TR≥96.5% and the system comprehensive energy consumption coefficient ε≤1.8kW·h / m 3 , the operating parameter combinations of each treatment unit are optimized in real time.

[0040] It should be noted that the recycling control system constructs an optimization system with two core constraint conditions: the total dissolved solids recovery rate TR≥96.5% ensures the efficient reuse of water resources, and the system comprehensive energy consumption coefficient ε≤1.8kW·h / m 3 controls the operating cost within an economically feasible range, and the two constitute a Pareto front for multi-objective optimization. The system collects characteristic parameters such as ΔRm and η in real time through an online sensor group, establishes a digital twin of the process operation for dynamic simulation, and an intelligent algorithm automatically generates the best parameter combination to guide the coordinated adjustment of each unit, forming an adaptive control ability for fluctuating water quality. In typical application scenarios, the algorithm iteration optimization interval ≤5 minutes to ensure that the entire system continuously operates in an efficient and economic state.

[0041] The dynamic membrane resistance coefficient ΔRm and the organic matter rejection rate η are the key control variables for dynamically adjusting process parameters through online monitoring data. Among them, ΔRm reflects the formation rate of the pollution layer on the filter material surface, and η characterizes the continuous rejection ability of the membrane separation system for small molecule organic matter.

[0042] It should be noted that the technical choice of taking the dynamic membrane resistance coefficient ΔRm and the organic matter rejection rate η as the core control variables stems from their real-time two-way feedback mechanism on the operating state of the membrane separation system. ΔRm quantifies and characterizes the generation rate of the colloid and particle pollution layer on the filter material surface by monitoring the deviation degree of the transmembrane pressure difference from the initial pressure difference per unit time. Its physical essence reflects the kinetic process of filter pore blockage. Introducing ΔRm instead of a fixed pressure difference threshold as the regulation benchmark can dynamically capture the non-linear characteristics in the membrane pollution process - for example, the high ΔRm growth rate in the initial rapid formation stage of the filter cake layer and the slow change trend of the dense pollution layer in the later stage, so as to adaptively adjust the backwashing cycle. At the same time, the calculation of η integrates the COD difference between the permeate and the feed liquid and the co-variable of membrane flux decay, and reduces the error risk of the traditional single concentration ratio algorithm through the pollutant penetration compensation effect of modifying the reference rejection rate. The combined application of the two forms a three-dimensional control space: when ΔRm and η rise simultaneously, it indicates that the pre-treatment efficiency of the previous stage is insufficient, resulting in excessive deposition of organic matter on the membrane surface, and the catalytic oxidation intensity needs to be strengthened; if ΔRm increases sharply while η drops steeply, it indicates that the membrane structure has suffered irreversible damage, triggering the system to operate under protective load reduction. This two-dimensional monitoring based on the membrane physical pollution process and the retention chemical behavior breaks through the limitations of single pressure or concentration monitoring and realizes the intelligent tracking of the membrane system operating point along the best efficiency curve.

[0043] In a possible implementation manner, the composite catalytic oxidation treatment in S1 specifically includes:

[0044] The composite catalytic oxidation treatment uses the synergistic effect of ozone and Fenton-like reagents, and its oxidation rate Rox (mgCOD / (L·min)) is determined by the following formula:

[0045]

[0046] where k 1 = 2.34×10 -3 (min -1 ·(mg / L) -0.7 ),k 2 = 1.78×10 -2 (L 2.5 / (mg 1.7 ·min)), K i = 0.023L / mg, [O 3 is the ozone concentration (mg / L), and the real-time regulation range is 15 - 45mg / L, [H 2 O 2 is the hydrogen peroxide concentration (mg / L), and the control range is 20 - 80mg / L, (Fe 2+ is the ferrous ion concentration (mg / L), and it is maintained at 5 - 15mg / L, T is the reaction temperature (°C), and the working range is 25 - 40°C, [Cl-] is the chloride ion interference concentration (mg / L).

[0047] It should be noted that the composite catalytic oxidation treatment formula is designed based on the oxidation kinetic characteristics of each reactant. The 0.7th power term of the ozone concentration reflects the non-linear dynamic characteristics of its free radical generation efficiency. The exponential terms of H 2 O 2 and Fe 2+ characterize the synergistic effect of the Fenton reaction. Cl - in the interference term is incorporated into the equation through the competitive inhibition coefficient to accurately quantify its inhibitory effect on the oxidation path. This model can not only adapt to the fluctuations of the concentrations of each reactant (such as a drastic change in the influent COD), but also automatically correct the reaction activity through the cube root compensation term of the temperature to ensure the stable treatment efficiency of the system in the wide temperature range of 25 - 40°C. Through the multi-parameter coupling calculation in the formula, the automatic matching of the oxidant dosage and reaction conditions can be realized in practical engineering, avoiding the waste of chemicals or incomplete reactions.

[0048] In a possible implementation, the organic matter retention rate η further includes:

[0049] The calculation formula for the organic matter retention rate η is:

[0050]

[0051] where is the reference rejection rate, C p is the COD value of the permeate (mg / L), collected every 5 minutes by an on-line UV-Vis spectrometer, C f is the COD value of the feed liquid (mg / L), with a preset initial value of 420 - 650 mg / L, J is the actual membrane flux (L / (m 2 ·h)), J 0 is the initial designed membrane flux (L / (m 2 ·h)), α = 2.37 is the empirical correction coefficient, β = 1.89 is the dynamic compensation coefficient, COD Mn is the total organic load (mg / L) measured by the permanganate index method.

[0052] It should be noted that the compensation calculation of the organic matter rejection rate innovatively introduces a membrane flux attenuation term and an organic load correction term. The logarithmic term amplifies the alarm sensitivity of the abnormal decline of the flux, and pre-emptively avoids the risk of membrane pore blockage; the exponential correction term of chemical oxygen demand (the non-linear weight of COD 1200 ) establishes a dynamic compensation mechanism for the organic matter migration model according to the characteristics of printing and dyeing wastewater. By converting the deviation between the actual working condition and the ideal condition through the double compensation coefficient, the system can still maintain the reliability of the rejection performance index when the membrane pollution develops and there is a sudden high-load impact - for example, when the COD suddenly increases in a certain period, resulting in a falsely high reference rejection rate, the compensation term will break through the traditional calculation mode and output the true surplus treatment capacity value.

[0053] In a possible implementation manner, the dynamic membrane resistance coefficient further includes:

[0054] The calculation method of the dynamic membrane resistance coefficient ΔRm is:

[0055]

[0056] Among them, ΔP t is the transmembrane pressure difference after running for t hours, with the unit of kPa, ΔP 0 is the initial transmembrane pressure difference, with the unit of kPa, μ is the hydrodynamic viscosity, with the unit of Pa·s, measured in real time by an on-line viscometer, Q t is the permeation flow rate at time t, with the unit of m 3 / h, A is the effective membrane area, with the unit of m 2 , the ultrafiltration unit is 3.2 m 2 , the reverse osmosis unit is 6.5 m 2 , is the concentration-time coupling factor.

[0057] It should be noted that the measurement framework of the dynamic membrane resistance coefficient ΔRm integrates the dual mechanisms of hydrodynamics and pollution deposition. The pressure difference increment in the molecular term (ΔPt - ΔP 0) It is directly related to the permeability loss of the filter bed. The denominator combines viscosity μ, flow rate Q, and membrane area A to achieve dimensionless normalization under different operating conditions, ensuring the comparability across process units. The coupling factor Γ(TDS,t) dynamically corrects the model through the synergistic effect of total dissolved solids and time. For example, when treating high-salt water quality such as taffeta dyeing wastewater, the increase in TDS will exponentially amplify the sensitivity of the membrane resistance change rate. This parameterized model enables the backwashing decision to no longer rely on a fixed time period but precisely match the physical process of filter media fouling development.

[0058] As Figure 2 shown, in a possible implementation, the optimization process of step S5 further includes:

[0059] The optimization process uses the constrained multi-objective particle swarm optimization algorithm CMOPSO, and the specific steps are as follows:

[0060] S501. Construct a six-dimensional decision space: ozone dosage concentration 15 - 45 mg / L, reverse osmosis operating pressure O RO : 3.5 - 5.2 MPa, electrocoagulation current density I: 12 - 15 A / m 2 , ultrafiltration backwash cycle t back : 20 - 45 min, concentrate recycle ratio γ: 8% - 15%, oxidation reaction temperature T: 25 - 40 °C;

[0061] S502. Dual objective functions:

[0062]

[0063] Among them, is the rejection rate term, is the energy consumption term, η is obtained in real time through on-line spectroscopic analysis, and ∈ is calculated based on the electricity meter data;

[0064] S503. Dynamic constraint processing:

[0065] S5031. Membrane flux adaptive constraint: When is activated, the compensation term:

[0066] S5032. Salt crystallization constraint: If [Cl - > 50 mg / L, then trigger I ← I + 1.5tanh([Cl - -50);

[0067] S504. Synergistic optimization mechanism: velocity update equation

[0068]

[0069] Among them, is the velocity of particle i in the d-th dimension at the k-th iteration, ω = 0.72 is the inertia weight, which controls the influence of the historical velocity, and c 1 = c 2 = 1.49 are the cognitive and social learning factors, r 1 , r 2 ∈U(0,1) are uniformly distributed random numbers, which ensure the search diversity. λ = 0.15 is the energy consumption compensation coefficient, which takes effect when the system energy consumption P total > 1.8 kW·h / m 3 ;

[0070] S505. Particle position update:

[0071]

[0072] When the particle crosses the boundary, execute:

[0073]

[0074] Among them, x d,mid and x d,max correspond to the upper and lower limits of each parameter in S501 respectively;

[0075] S506. Optimization termination condition: Terminate if any of the following conditions is met:

[0076] A. The number of iterations k ≥ 200;

[0077] B. The change range of the global optimal solution is < 0.1% for 15 consecutive generations;

[0078] C. [Cl - ≤ 50 mg / L and η ≥ 98% are maintained for 30 minutes.

[0079] It should be noted that the constrained multi-objective optimization algorithm establishes a dynamic mapping between the six-dimensional decision space and the three key indicators. The chaotic perturbation term in the particle size update equation solves the problem of premature convergence of the particle swarm, and the energy consumption constraint term (sgn function structure, λ coefficient) integrates the electricity cost into the optimization trajectory in real time for the first time. The weight allocation in the normalized objective function breaks through the traditional fixed ratio, and the asymmetric coefficient (dominant rejection rate) highlights the priority of water quality guarantee. The membrane flux constraint activation logic in the algorithm is directly related to the threshold condition in right 3, forming a protective layer to avoid overloading of the ultrafiltration unit - for example, when the influent suspended solids suddenly increase, the system automatically limits the increase in the concentrate reflux ratio to prevent the membrane pressure from exceeding the limit.

[0080] In a possible implementation manner, it further includes a transmembrane pressure difference abnormal warning method:

[0081] When it is detected that ΔRm > 0.32 and satisfies When, execute the gradient backwashing strategy:

[0082] Water flushing in stage A: Flush with demineralized water at 45°C at a flow rate of 3.2 m / s for 120 seconds to remove surface suspended solids;

[0083] Pickling in stage B: Circulate and inject for treatment at pH 40°C for 20 minutes;

[0084] Alkaline washing in stage C: Switch to a NaOH / EDTA mixed solution with pH = 11.5, molar ratio 3:1, and treat for 15 minutes under turbulent flow conditions.

[0085] It should be noted that the gradient backwashing strategy is hierarchically designed for the removal requirements of complex pollutants. Warm water pulses disperse physically adsorbed suspended particles; pickling dissolves carbonate and metal oxide scaling (the dissolution rate of citric acid for iron oxide reaches 93%); alkaline washing degrades biological fouling and chelates heavy metal ions (the binding constant of EDTA with Ca 2+ is logK = 10.7). The exponential growth threshold of the anti-trigger condition (0.08·e^(0.015COD)) innovatively correlates the pollution deterioration rate with the COD load, enabling earlier initiation of defensive cleaning during high-concentration wastewater treatment and avoiding a collapse in treatment performance.

[0086] In a possible implementation, the dynamic adjustment formula for the concentrate recycle ratio γ is:

[0087]

[0088] where TDS is the total dissolved solids content of the reverse osmosis concentrate, in g / L. When γ exceeds 15%, automatically shorten the ultrafiltration backwash cycle to 25 minutes and trigger backwashing.

[0089] It should be noted that the dynamic adjustment model of the concentrate recycle ratio takes into account both the membrane system load and the acceptance capacity of the crystallization unit. The hyperbolic tangent function flexibly responds to the non-linear characteristics of TDS changes - when TDS exceeds 800 g / L, the mutation section of the Γ function curve automatically suppresses the fluctuation of the recycle ratio to prevent the crystallizer from overloading; the ΔRm feedback term ensures the economic balance between membrane fouling and resource recovery. The interlocking control of the recycle ratio and the ultrafiltration backwash cycle forms a resource scheduling mechanism across treatment levels. For example, actively reduce the recycle ratio during the backwashing stage to maintain the stability of system output.

[0090] In a possible implementation, the composite catalytic oxidation treatment further includes:

[0091] Ozone dosage correction method for composite catalytic oxidation treatment:

[0092] S801. When it is detected that COD Mn > 380 mg / L, according to the formula:

[0093]

[0094] Dynamically adjust the ozone concentration;

[0095] S802. If [Cl - > 200 mg / L, then add 2.5 mg / L of potassium ferrocyanide K 4 [Fe(CN) 6 as a radical quenching inhibitor.

[0096] It should be noted that the S-shaped adjustment curve of ozone concentration (based on the logistic function) realizes the surge buffer of the dosing amount in the COD sensitive area (350 - 400 mg / L), avoiding over-dosing in the low-load area and maintaining sufficient radical supply after the critical COD value. When Cl - exceeds 200 mg / L, K 4 Fe(CN) 6 The dosing strategy creates a new radical quenching control system - its C≡N group preferentially captures excess ·OH, redirecting the reaction focus back to the direct oxidation path of ozone molecules, solving the problem of excessive iron sludge generation caused by over-reliance on the Fenton reaction under high-chlorine conditions in traditional processes.

[0097] In a possible implementation, the control of crystal salt purity specifically includes:

[0098] Perform primary crystallization at a current density I = 13 A / m 2 to generate a particle size and where is the X-ray diffraction peak shift angle.

[0099] It should be noted that the dual-criterion system for crystal salt purity combines chemical analysis and phase characterization. The setting of the dominant index of the Cl - mass fraction ensures the basic chemical purity of the salt product, while the strict limitation of the average XRD peak shift (<0.15°) avoids subsequent application problems (such as abnormal heat of dissolution) caused by crystal form defects. The current decay function selects the natural exponential form and cooperates with polarity switching to obtain a complete crystal structure by gradually reducing the electrolysis intensity. At the same time, the periodically reversed electric field forces the passivation layer to peel off (the peeling thickness per cycle is about 0.2 μm), maintaining the salt production efficiency not less than 90% of the initial value.

[0100] As Figure 3 shown, in a possible implementation, S5 also includes a real-time adjustment mechanism for process parameters based on the feedback of crystal salt purity:

[0101] S5a. Parameter coupling equation: Establish a correlation model between the dynamic membrane resistance coefficient ΔRm and the crystal salt concentration Cl - :

[0102]

[0103] When detected use ΔRm adj to replace the original ΔR for the optimization calculation;

[0104] S5b. Adaptive adjustment threshold: If the current purity then immediately execute:

[0105] S5b1. Increase the reverse osmosis pressure to min(1.08P RO , 5.2 MPa);

[0106] S5b2. Correct the electrocoagulation current density to:

[0107]

[0108] where t run ≥0, with the unit of minute;

[0109] S5c. Continuous optimization trigger: When the above adjustments have not reached the standard for 45 minutes, forcefully return to S1 to restart the pretreatment program.

[0110] It should be noted that the parameter co - adjustment mechanism based on the purity of crystal salt breaks through the limitation of the isolated operation of each unit in the traditional wastewater treatment process. The logarithmic amplification term in the ΔRm correction model finely compensates for the hidden harm of excessive Cl - concentration to the membrane system - such as the aggravation of concentration polarization caused by the increase of ionic strength. When the purity drops below the threshold, a three - level response of RO pressure jump combined with S - type regulation of electrolysis intensity is adopted. Among them, the time parameter ε - introduces the operation duration into the control equation to prevent membrane damage caused by long - term high - pressure operation. This cross - stage closed - loop control enables the pretreatment and post - treatment parameters to form a dynamic cooperation. For example, when the membrane section boosts pressure to assist the electrocoagulation unit to improve efficiency, the system will automatically reduce the consumption of catalytic oxidation agents to balance the total energy consumption.

[0111] When implementing this process, the wastewater first enters the adjustment tank to balance the water quality. An acid addition device in the pH adjustment unit is used to monitor the pH value through a sensor array installed on the side wall of the reaction tank, and inject a 10% dilute sulfuric acid solution through closed - loop feedback control to adjust the pH value of the wastewater to the neutral range. The adjusted waste liquid enters the catalytic reaction zone through a deflector. The reaction zone is equipped with a tubular injector for ozone gas dispersion. The Venturi structure at the throat of the injector generates negative pressure to entrain ozone. After gas - liquid mixing, it enters the reaction chamber filled with a honeycomb - structured catalyst. The catalyst module contains a titanium - based carrier and an active component of transition metal oxide, arranged in a hexagonal pore structure, and the inner wall of the pore is loaded with a nanoscale manganese dioxide coating.

[0112] The chemical dosing system in the catalytic oxidation stage includes three metering pumps, which are respectively connected to a hydrogen peroxide storage tank, a ferrous salt solution tank, and a pH buffer container. The aeration discs are distributed in the lower diversion layer, and the pore density on their surfaces changes in a radial gradient. The pore diameter in the central area is 3 mm, which is reduced to 1.5 mm in the edge area. An ultraviolet lamp group is set at the top of the reaction chamber, and the lamp spacing is designed according to the light intensity attenuation model to ensure that the radiation dose of the reaction liquid layer is evenly distributed within the range of 50 - 75 mJ / cm 2 After the reaction, the effluent enters the flocculation tank through the overflow weir, and the height of the weir plate can be adjusted electrically to control the residence time.

[0113] When the fluid enters the multi-stage filtration system, it first passes through a three-stage filter bed unit with decreasing pore diameters. The first-stage filter medium is composed of hydrophobic polypropylene fibers woven together, with a filament diameter of 50 microns, and the weaving angle is set at 45 degrees to form a three-dimensional filtration network; the second-stage filter bed uses pollution-resistant modified PVDF hollow fibers, and the surface is grafted with carboxylic acid groups through plasma treatment; the third stage is equipped with a dynamic membrane module, whose support layer is a stainless steel sintered mesh, and a diatomaceous earth filter aid is pre-coated on the surface to form a renewable filter cake layer. Each filter bed unit is integrated with a differential pressure transmitter. When the detected transmembrane pressure difference increment exceeds 45% of the initial value, the controller activates the backwashing program. The backwashing pipeline is arranged in parallel with the main process pipeline, and adopts a gas-water mixed pulse mode. The pressure of the compressed air storage tank is maintained within an adjustable range of 0.6 - 0.8 MPa, and the backwashing water flow is controlled by a proportional valve within the range of 120% - 150% of the designed flow rate.

[0114] The ultrafiltration unit in the membrane separation section operates in two parallel groups, and the PLC control is used to alternately perform water production and maintenance operations. A transparent viewing window is set on the outer shell of the membrane module to observe the fouling state of the membrane filaments, and an acoustic wave emitter is installed inside to generate a swept-frequency vibration of 20 - 100 kHz. The reverse osmosis unit is equipped with a pressure exchange type energy recovery device, whose rotor assembly is linked with the high-pressure pump and can transfer more than 85% of the pressure energy of the concentrated water to the inlet side. A thermocouple array is wound around the outside of the membrane shell to monitor the axial temperature distribution gradient in real time. When the local temperature difference exceeds 3°C, a protective pressure reduction operation is triggered.

[0115] The electrode assembly of the electrocoagulation crystallization reactor adopts a combined design, which is composed of rotatable anode plates and porous cathode nets arranged alternately. The anode surface is treated by micro-arc oxidation to form a porous ceramic layer. The power supply controller has a bidirectional pulse output function, and the forward current density is set at 12 - 15 A / m 2 The reverse pulse width duty cycle is adjustable. A diversion cone is installed at the bottom of the reactor, and the cone angle is designed to be 60 degrees to form a forced swirling flow field. A foam collection cover is set at the top and connected to a vacuum suction device. A multi-stage diversion baffle is set in the crystallization tank, and the distance between adjacent baffles decreases along the flow direction. An ultrasonic transducer is attached to the surface of the last-stage baffle for crystal nucleus dispersion.

[0116] The control system is configured with an HMI operation terminal, and the display screen is divided into a process flow chart area, a real-time curve area, and an alarm event list area. The data acquisition module records 16 key process parameters per second and uploads them to the cloud database through the OPC protocol. Operators can adjust the dosing ratio coefficient of the medicament in the catalytic oxidation stage through a sliding control, and the modified parameters are written into the controller after secondary confirmation. The system has a three-layer access permission mechanism, and the equipment maintenance mode needs to insert a physical key and enter a dynamic verification code to activate.

[0117] In terms of operation and maintenance management, a standard process including preventive maintenance and emergency fault handling is established. When performing the integrity detection of the membrane system daily, the pressure decay method is adopted: after closing the product water pipeline, 0.2 MPa of compressed air is injected, and if the pressure drop does not exceed 5% within 10 minutes, it is judged as qualified. The catalytic reactor is cleaned in place every week, injecting an alkaline cleaning agent and circulating for 2 hours, soaking in an acidic solution for 1 hour, and finally passing ozone water for sterilization. The mechanical scraper of the electrode assembly automatically performs surface cleaning every 72 hours of operation, and the collected sediment is sampled for XRD phase analysis after drying.

[0118] The pipeline system of the whole set of equipment is connected by quick-installing clamps, and transparent visible sections are set in key pipe sections to observe the medium state. The cable tray and the process pipeline are arranged in layers, and the strong electrical circuit is equipped with a current harmonic filter. The equipment foundation is designed as a modular steel structure frame, and each functional unit is fixed on an independent anti-seismic base, with a 20-mm expansion joint reserved between the bases. A circular drainage ditch is set around the device, the ground is paved with an acid-alkali resistant epoxy coating, and the height of the guardrail meets the requirements of the GB4053.3 standard.

[0119] The beneficial effects brought by the technical solution provided by the embodiment of the present invention at least include:

[0120] (1) In the present invention, by constructing a pretreatment collaborative system of composite catalytic oxidation and gradient dynamic filtration, the refractory organic pollutants in the wastewater can be efficiently degraded and the suspended colloids can be intercepted, significantly reducing the fouling risk of the subsequent membrane separation system. The multi-path oxidation mechanism of ozone and the Fenton-like reagent breaks through the limitations of the traditional single oxidation mode, specifically decomposes the molecular structure of complex organic matter, and forms flocculable intermediate products that are easy to treat subsequently. The three-stage variable pore size filter bed realizes the step-by-step removal of suspended matter through hierarchical interception, and combines the dynamic monitoring technology of the pollution layer to accurately adjust the backwashing cycle, ensuring the stability and high efficiency of the pretreatment process, and laying a foundation for the long-term stable operation of the whole process;

[0121] (2) In the present invention, an innovative dual-factor control model of membrane resistance coefficient and interception rate is designed, combined with an abnormal early warning mechanism of transmembrane pressure difference, to achieve refined management of membrane system working conditions. The dynamic membrane resistance coefficient based on the kinetic analysis of fouling layer formation can identify the attenuation trend of membrane separation performance in advance, triggering an adaptive backwashing strategy to prevent irreversible fouling; the organic matter penetration compensation algorithm corrects the interception rate calculation model, and real-time feedback controls the membrane flux and operating pressure parameters to solve the stubborn problem of instability of interception efficiency in traditional membrane processes under fluctuating water quality. The synergistic effect of the two significantly reduces the intensity of manual intervention, prolongs the service life of the membrane, and simultaneously ensures the quality of produced water and the system yield;

[0122] (3) In the present invention, a closed-loop treatment system for concentrated liquid resource utilization is constructed through the electro-flocculation crystallization coupling dynamic tuning technology. The enhanced mass transfer effect of the cyclonic electric field promotes the directional growth of crystal nuclei. The time-varying current density control strategy simultaneously inhibits electrode passivation and salt separation. Combined with X-ray diffraction phase monitoring, precise control of the crystallized salt components is achieved. The cross-unit parameter linkage optimization algorithm breaks through the data barriers of pre-treatment, membrane separation and crystallization links, and intelligently matches the process parameter combination according to the water quality fluctuation characteristics, breaking through the shackles of the traditional system that focuses on the optimization of a single link, thereby improving the overall purity of salt recovery and the utilization rate of water resources, and simultaneously reducing the demand for hazardous waste disposal and the comprehensive energy consumption of the process.

[0123] The above contents are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

[0124] There are a few points to note:

[0125] (1) The drawings of the embodiments of the present invention only relate to the structures related to the embodiments of the present invention, and other structures may refer to the general design.

[0126] (2) For the sake of clarity, in the drawings used to describe the embodiments of the present invention, the thickness of the layers or regions is exaggerated or reduced, that is, these drawings are not drawn according to the actual scale. It is understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "under" another element, the element may be "directly" "on" or "under" the other element or there may be intermediate elements.

[0127] (3) In the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other to obtain new embodiments.

[0128] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A zero-discharge treatment process for production wastewater reuse, characterized in that: include: S1. Wastewater pretreatment: After adjusting the pH of the printing and dyeing wastewater to the range of 6.5-7.5, composite catalytic oxidation treatment is used to control the CODMn degradation rate to ≥85% and generate flocculating intermediate products; S2, multi-stage dynamic filtration: the pretreated wastewater is sequentially passed through a self-cleaning fiber filter bed with a gradient pore size of 50μm→10μm→1μm, and the transmembrane pressure difference change when the dynamic membrane resistance coefficient ΔRm ≥ 0.32 on the filter bed surface is monitored in real time. When the cumulative pressure difference increase exceeds 45% of the initial value, the backwashing procedure is triggered; S3, fine filtration and concentration treatment: cross-flow filtration is performed through two-stage series ultrafiltration + reverse osmosis membrane components, and the organic matter retention rate η≥98% is adjusted in real time, and the membrane flux is simultaneously monitored to maintain no less than 80% of the design value; S4, concentrated liquid solidification: the reverse osmosis concentrated liquid is introduced into the cyclonic electroflocculation reactor at a current density of 12-15A / m 2 The treatment is carried out under the following conditions until a crystalline salt having a Cl^- concentration of ≤50 mg / L is produced; S5. Circulation control: Based on the total dissolved solid recovery rate TR ≥ 96.5% and the system comprehensive energy consumption coefficient ε ≤ 1.8kW·h / m 3 The dual constraints of the system can be used to optimize the operating parameter combination of each processing unit in real time; The dynamic membrane resistance coefficient ΔRm and the organic matter retention rate η are key control variables for dynamically adjusting process parameters through online monitoring data, wherein ΔRm reflects the formation rate of the contamination layer on the filter material surface, and η characterizes the continuous retention capacity of the membrane separation system for small molecular organic matter.

2. A zero-discharge treatment process for production wastewater reuse according to claim 1, characterized in that: The composite catalytic oxidation treatment in S1 specifically includes: The composite catalytic oxidation treatment uses the synergistic effect of ozone and Fenton-like reagent, and its oxidation rate Rox (mgCOD / (L·min)) is determined by the following formula: Where k1 = 2.34 × 10 -3 (min -1 (mg / L) -0.7 ), k2=1.78×10 -2 (L 2.5 / (mg 1.7 ·min)), K i =0.023L / mg, [O3] is the ozone concentration (mg / L), the real-time control range is 15-45mg / L, [H2O2] is the hydrogen peroxide concentration (mg / L), the control range is 20-80mg / L, [Fe 2+ ] is the ferrous ion concentration (mg / L), maintained at 5-15 mg / L, T is the reaction temperature (℃), the working range is 25-40℃, and [Cl-] is the chloride ion interference concentration (mg / L).

3. A zero-discharge treatment process for production wastewater reuse according to claim 2, characterized in that: The organic matter interception rate η further includes: The calculation formula of the organic matter interception rate η is: in, is the base retention rate, C p is the COD value of the permeate (mg / L), collected every 5 min by an online UV-Vis spectrometer, C f is the feed liquid COD value (mg / L), the preset initial value is 420-650mg / L, J is the actual membrane flux (L / (m 2 ·h)), J0 is the initial design membrane flux (L / (m 2 h), α = 2.37 is the empirical correction coefficient, β = 1.89 is the dynamic compensation coefficient, COD Mn It is the total organic load (mg / L) measured by the permanganate index method.

4. A zero-discharge treatment process for production wastewater reuse according to claim 3, characterized in that: The dynamic film resistance coefficient further includes: The calculation method of the dynamic film resistance coefficient ΔRm is: Among them, ΔP t is the transmembrane pressure difference after t hours of operation, in kPa, ΔP0 is the initial transmembrane pressure difference, in kPa, μ is the fluid dynamic viscosity, in Pa·s, measured in real time by an online viscometer, Q t is the infiltration flow at time t, in m 3 / h, A is the effective membrane area, unit is m 2 , ultrafiltration unit 3.2m 2 , reverse osmosis unit 6.5m 2 , is the concentration-time coupling factor.

5. A zero-discharge treatment process for production wastewater reuse according to claim 4, characterized in that: The optimization process of step S5 further includes: The optimization process adopts the constrained multi-objective particle swarm algorithm CMOPSO, and the specific steps are as follows: S501. Constructing a six-dimensional decision space: ozone concentration 15~45mg / L, reverse osmosis operating pressure O RO :3.5~5.2MPa, electrocoagulation current density I:12~15A / m 2 , UF backwash cycle t back : 20~45min, concentrated liquid circulation ratio γ: 8%~15%, oxidation reaction temperature T: 25~40℃; S502, dual objective function: in, is the interception rate term, is the energy consumption item, η is obtained in real time through online spectral analysis, and ∈ is calculated based on the meter data; S503, dynamic constraint processing: S5031, membrane flux adaptive constraint: when Activate compensation when: S5032, Salt crystallization constraints: If [Cl - ]>50mg / L triggers I←I+1.5tanh([Cl - ]-50); S504, Collaborative Optimization Mechanism: Speed ​​Update Equation in, is the velocity of particle i in the dth dimension in the kth iteration, ω = 0.72 is the inertia weight, which controls the influence of the historical velocity, c1 = c2 = 1.49 is the cognitive and social learning factor, r1, r2∈U(0,1) are uniform random numbers to ensure search diversity, λ = 0.15 is the energy consumption compensation coefficient, when the system energy consumption P total >1.8kW·h / m 3 effective when; S505, particle position update: When a particle crosses the boundary, execute: Among them, x d,min and x d,max respectively correspond to the upper limit and lower limit of each parameter in S501; S506, optimization termination condition: the optimization terminates if any of the following conditions is met: A. The number of iterations k ≥ 200; B. The global optimal solution changes by less than 0.1% for 15 consecutive generations; C. [Cl - ]≤50mg / L and η≥98% for 30 minutes.

6. A zero-discharge treatment process for production wastewater reuse according to claim 5, characterized in that: It also includes abnormal warning methods for transmembrane pressure difference: When ΔRm>0.32 is detected and meets When , the gradient backwash strategy is executed: Phase A: Use 45℃ deionized water at a flow rate of 3.2m / s for 120 seconds to remove suspended matter on the surface; B stage pickling: circulating injection pH40℃ treatment for 20 minutes; Stage C alkaline washing: switch to NaOH / EDTA mixed solution with pH = 11.5, molar ratio 3:1, and process for 15 minutes under turbulent state.

7. A zero-discharge treatment process for production wastewater reuse according to claim 6, characterized in that: include: The dynamic adjustment formula of the concentrated liquid circulation ratio γ is: Wherein, TDS is the total dissolved solid content of the reverse osmosis concentrate, in g / L. When γ exceeds 15%, the ultrafiltration backwashing cycle is automatically shortened to 25 minutes and the backwashing is triggered.

8. A zero-discharge treatment process for production wastewater reuse according to claim 2, characterized in that: The composite catalytic oxidation treatment further comprises: The ozone dosage correction method for the composite catalytic oxidation treatment is as follows: S801, when COD is detected Mn When >380mg / L, according to the formula: Dynamically adjust ozone concentration; S802, if [Cl - ]>200mg / L, add 2.5mg / L potassium ferrocyanide K4[Fe(CN)6] as a free radical quenching inhibitor.

9. A zero-discharge treatment process for production wastewater reuse according to claim 1, characterized in that: The crystal salt purity control specifically includes: At current density I = 13A / m 2 Primary crystallization is carried out under and Where is the X-ray diffraction peak shift angle.

10. A zero-discharge treatment process for production wastewater reuse according to claim 9, characterized in that: The S5 also includes a real-time adjustment mechanism for process parameters based on crystallized salt purity feedback: S5a, parameter coupling equation: establish the dynamic membrane resistance coefficient ΔRm and the crystallization salt concentration Cl - The association model: When detected When ΔRm adj Replace the original ΔRm to participate in the optimization calculation; S5b, adaptive adjustment threshold: if the current purity Then execute immediately: S5b1, reverse osmosis pressure increased to min (1.08P RO ,5.2MPa); S5b2, electrocoagulation current density correction is: Among them, t run ≥0, in minutes; S5c, continuous optimization trigger: When the above adjustment fails to meet the standard for 45 minutes, it is forced to return to S1 to restart the preprocessing program.

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