A method and system for treating high-salinity wastewater

Abstract

This invention belongs to the field of industrial wastewater treatment technology, specifically relating to a method and system for treating wastewater with high salinity (>20 g / L) and high hardness (Ca²⁺>500 mg / L). The invention involves passing wastewater into a bioreactor filled with functionalized microbial capsules. The capsules are prepared by: inoculating halophilic bacteria into a culture medium containing NaCl and trehalose; mixing the resulting bacterial solution with sodium alginate and then adding it dropwise into a CaCl₂ solution; immersing the capsules in a mixture containing polyaspartic acid and magnesium aluminum hydrotalcite to form anti-scaling microspheres; adding carboxylated carbon nanotubes to aniline phosphate buffer, then adding ammonium persulfate, and depositing a polyaniline-carbon nanotube composite conductive layer on the outer periphery of the anti-scaling microspheres; finally, solidifying the microspheres in a copolymer prepolymer solution to form a responsive outer shell. This invention achieves full-process optimization from strain domestication to stable operation by combining functionalized microbial capsules with staged salinity-electric field synergistic regulation, enabling long-term stable treatment of high-salinity and high-hardness wastewater.

Description

Technical Field

[0001] This invention relates to the field of industrial wastewater treatment technology, specifically a method and system for treating high-salinity wastewater. Background Technology

[0002] With the rapid development of industries such as oil extraction, chemical and pharmaceutical manufacturing, the discharge of high-salt and high-hardness wastewater is increasing year by year. Due to its special physicochemical properties, traditional treatment methods are difficult to achieve the desired treatment effect.

[0003] Currently, the treatment of high-salinity and high-hardness wastewater mainly employs physicochemical methods, biological methods, and combined processes. Physicochemical methods, such as reverse osmosis, while having a certain desalination effect, suffer from high energy consumption and severe membrane fouling. Chemical precipitation, although effective in removing hardness ions, requires large amounts of reagents and generates substantial sludge. Traditional biological treatment technologies generally have low treatment efficiency due to the limited activity of microorganisms in high-salinity environments.

[0004] The existing technologies mainly face the following technical challenges: First, high-salt environments lead to an imbalance in the osmotic pressure within microbial cells. In conventional activated sludge processes, the microbial degradation efficiency decreases by more than 60% when the salinity exceeds 30 g / L. Second, high concentrations of hardness ions such as Ca²⁺ and Mg²⁺ easily form inorganic scale layers in the reaction system, which not only clog equipment pipelines but also cover the surface of microorganisms, severely affecting mass transfer efficiency. Third, existing anti-scaling technologies, such as ultrasonic anti-scaling, suffer from problems such as poor frequency stability and high energy consumption, while chemical softening methods can generate secondary pollution.

[0005] To address the shortcomings of existing technologies, this invention aims to provide an efficient and stable solution for treating high-salt and high-hardness wastewater. By constructing functionalized microbial capsules and combining them with staged salinity-electric field synergistic regulation, a complete high-salt and high-hardness wastewater treatment system is established, achieving long-term stable treatment of high-salt and high-hardness wastewater. Summary of the Invention

[0006] To address the shortcomings of existing technologies, one of the objectives of this invention is to provide a method and system for treating high-salinity wastewater by combining functionalized microbial capsules with staged salinity-electric field synergistic regulation, thereby optimizing the entire process from strain domestication to stable operation and achieving long-term stable treatment of high-salinity and high-hardness wastewater.

[0007] Technical solution

[0008] To address the aforementioned technical problems, this invention provides a method and system for treating high-salinity wastewater, which achieves stable and efficient treatment of high-salinity wastewater by combining functionalized microbial capsules with a phased control strategy.

[0009] To address the problem of inhibited microbial activity under high-salt environments, the core of this invention lies in constructing functionalized microbial capsules with specific structures and employing a staged electrolysis enhancement strategy.

[0010] Firstly, this invention provides a method for treating high-salinity wastewater, in which pretreated wastewater is passed into a bioreactor filled with functionalized microbial capsules. The preparation of these functionalized microbial capsules is one of the core steps of this method. Specifically, the preparation method of the functionalized microbial capsules includes the following steps:

[0011] (1) Preparation of salt-tolerant bacterial core: Salt-tolerant bacteria were inoculated into a culture medium containing 125-150 g / L NaCl and 6.8-8.5 g / L trehalose and cultured. The bacterial solution was mixed with 3-5 wt% sodium alginate and then added dropwise to 1-3 wt% CaCl2 solution. Core microspheres were prepared by electrostatic molding. A sodium alginate concentration below 3% would result in insufficient mechanical strength, while a concentration above 5% would hinder substrate diffusion. The curing temperature was controlled at 20-30℃ to balance the cross-linking rate and bacterial survival rate. Experiments showed that the bacterial survival rate could reach 92-95% when cured in this range.

[0012] (2) Construction of anti-scaling layer: The core is immersed in a mixture containing 2-5 wt% polyaspartic acid and 0.5-1.5 wt% magnesium aluminum hydrotalcite, and treated at 38-45℃ for 25-35 min to form anti-scaling microspheres. Treating at 38-45℃ for 25-35 min allows polyaspartic acid to coordinate with the aluminum oxide octahedra of hydrotalcite through carboxyl groups, forming a stable composite anti-scaling layer.

[0013] (3) Formation of conductive layer: 0.1-0.2 wt% carboxylated carbon nanotubes are added to aniline phosphate buffer solution at pH 4.0-4.8. After the above anti-scaling microspheres are immersed, 0.4-0.6 wt% ammonium persulfate is added dropwise, and a polyaniline-carbon nanotube composite conductive layer is deposited on the periphery of the anti-scaling microspheres by electrodeposition.

[0014] Of particular note is that a conductive layer with a volume resistivity ≤10 Ω·cm can be obtained by optimizing the deposition parameters. Aniline monomers exist in a cationic form within a pH range of 4.0–4.8 and are co-deposited with negatively charged carboxylated carbon nanotubes. During ammonium persulfate-initiated polymerization, the carbon nanotubes can intercalate between the polyaniline chains to form a three-dimensional conductive network, reducing the volume resistivity to 8–10 Ω·cm.

[0015] (4) Responsive shell coating: After the above capsule preform is placed in the copolymer prepolymer liquid and cured under ultraviolet light for a period of time, a responsive shell with a thickness of 80-100μm is formed, and functional microbial capsules are obtained. The shell has a swelling degree of 150-200% when pH>8.5, and releases nano-montmorillonite at the same time. These nanosheets can be adsorbed on the surface of the bacteria to form a protective layer and alleviate the salinity shock.

[0016] A copolymer prepolymer solution was prepared by mixing three monomers—N-isopropylacrylamide (NIPAM), methacrylic acid (MAA), and hydroxyethylacrylamide (HEA)—in a molar ratio of (80-88):(8-12):(4-6) with 0.4-0.6 wt% nano-montmorillonite and adding a photoinitiator. The introduction of HEA enhanced the interfacial bonding between the shell and the conductive layer, with peel strength tests showing a result of 15-18 N / cm².

[0017] Furthermore, to improve the salt tolerance acclimatization efficiency of the microbial community, a three-stage gradual control strategy was adopted for the operation of the bioreactor. This design takes into account the microbial adaptation needs to changes in environmental conditions. During the acclimatization period, the salinity of the salt-tolerant bacterial culture medium was gradually increased to 23-27 g / L daily at a gradient of 0.8-1.2 g / L under dissolved oxygen conditions of 2.0-2.5 mg / L, for 4-7 days, allowing the microorganisms to gradually adapt to the salinity changes. This rate is much faster than traditional methods (usually only 0.2-0.5 g / L / d), but combined with the sustained-release protection mechanism of the functionalized capsules, the microbial community can enter a highly active state without a long adaptation period. At the same time, the dissolved oxygen was controlled at 2.0-2.5 mg / L, a level that meets the needs of most aerobic bacteria without causing excessive carbon source consumption. Crucially, when the turbidity fluctuation of the bacterial culture was monitored to be <5-8% and the intracellular Na⁺ / K⁺ ratio was ≤0.2-0.4, the system transitioned to the enhancement phase.

[0018] During the enhancement phase, based on a salinity of 23-27 g / L, a combination of a 0.4-0.6 V / cm DC electric field and a 0.8-1.2 V / cm pulsed electric field is applied to further increase the salinity to 30-35 g / L. Particularly preferred is that the frequency of the pulsed electric field is controlled at 0.8-1.2 Hz, with a duty cycle of 1:4-1:6, which enhances electron transfer while avoiding damage to the bacterial cells. The DC electric field stably maintains the membrane potential of the bacterial community, while the intermittent pulsed mode prevents local pH imbalances caused by electrode polarization. Simultaneously, due to the presence of the conductive layer on the microbial capsule, the energy utilization rate of the applied electric field is significantly improved, reducing desalination energy consumption by more than 30%.

[0019] A more comprehensive approach involves a daily "backwash-ultrasound-seed crystal addition" cyclical maintenance strategy during the stabilization period at a salinity of 30-35 g / L. Specifically: first, backwash at a flow rate of 10-20 cm / s for 20-40 seconds to effectively remove surface deposits without damaging the biofilm structure; then, ultrasonic treatment for 8-12 minutes to prevent the accumulation of hardness ions on the carrier surface; finally, add 80-120 mg / L of aragonite seed crystals. It is noteworthy that controlling the backwash flow rate at 10-20 cm / s effectively removes dead bacteria. Combined with 35-45 kHz ultrasonic treatment and the addition of 80-120 mg / L aragonite, the unique lattice structure of aragonite preferentially induces the precipitation of Ca²⁺ and Mg²⁺ in a non-adhesive crystal form. This, combined with the 35-45 kHz ultrasonic treatment, reduces scale buildup in the reactor by 60-65%, allowing the system to operate stably for extended periods under high salinity conditions of 30-35 g / L.

[0020] The trehalose is added at a concentration of 6-8 g / L during the cell culture stage and maintained at a final concentration of 3-5% by mass during the solidification stage. During the cell culture stage, trehalose primarily enhances the short-term high-salt adaptability of microorganisms by regulating osmotic pressure and activating salt-tolerant genes, increasing the cell survival rate from 30-40% to ≥90%. During the solidification stage, it interacts with sodium alginate-Ca... 2+ A stable three-dimensional gel network is formed, optimizing the mechanical properties of the microspheres and their long-term sustained-release protective effect, enabling the capsules to retain more than 85% of the bacterial cell activity after 90 days of operation.

[0021] In the first aspect, the interlayer spacing of the magnesium aluminum hydrotalcite in the anti-scaling layer is 0.75~0.78 nm, with a Ca²⁺ retention rate ≥90% and a Na⁺ permeability ≥85%. The magnesium aluminum hydrotalcite interlayer spacing is designed to be 0.75-0.78 nm (XRD measurement), a size that selectively retains >90% of Ca²⁺ while allowing Na⁺ to pass freely, preventing calcium carbonate scale from clogging the capsule pores.

[0022] In the first feasible approach, the high-salt, high-hardness wastewater to be treated undergoes a pretreatment stage for purification. Wastewater pretreatment includes the following steps:

[0023] Wastewater is passed through a vortex flocculant with a controlled linear velocity of 1.2 ± 0.1 m / s. This ensures the kinetic conditions for sufficient floc collision and growth without causing floc breakage due to excessive flow velocity. Simultaneous addition of 45-55 mg / L polyacrylamide allows the flocculant to effectively adsorb tiny particles in the water and form a stable floc structure.

[0024] After flocculation, the wastewater enters a filter screen for solid-liquid separation. The filter screen traps suspended solids and adjusts the pH to 7.5-8.0. Preferably, the filter screen surface is modified with perfluorooctyltriethoxysilane, resulting in a static contact angle greater than 120°, which significantly improves the filter screen's anti-fouling ability and ensures that the flux decay rate is less than 5% per week.

[0025] When the online monitoring shows a Ca²⁺ concentration > 800 mg / L, 8-12 mg / L of polyaspartic acid with a molecular weight of 3000-5000 is automatically added. This polymer preferentially forms a soluble complex with Ca²⁺, thereby effectively suppressing the risk of scaling in subsequent treatment units.

[0026] The first aspect of the achievable method also includes a crystallization control stage, in which 25-35 kHz ultrasound with a density of 0.4-0.6 W / cm³ is used in conjunction with a hydrocyclone separator to dynamically remove Ca²⁺ deposits, thereby achieving dynamic descaling. By adjusting the centrifugal force field of the hydrocyclone separator, crystals with a particle size ≥10 μm are efficiently separated. The recovered seed crystals can be repeatedly added after cleaning, resulting in a seed crystal recycling rate >90%.

[0027] Secondly, this invention provides a high-salinity wastewater treatment system, offering dedicated equipment support for implementing the aforementioned method. The system mainly includes a pretreatment unit, a bioreactor, and a crystallization control unit. The bioreactor is filled with functionalized microbial capsules at a volume ratio of 40-50%.

[0028] The microbial capsule achieves efficient desalination through a four-layer synergistic structure: the innermost layer is a sodium alginate gel core encapsulating salt-tolerant bacteria. By adding trehalose and optimizing the CaCl2 crosslinking concentration, the bacteria can maintain intracellular osmotic balance under high osmotic pressure. The selection of sodium alginate concentration (3-5 wt%) ensures that the mechanical strength and mass transfer rate of the microspheres are at the optimal balance point. The middle anti-scaling layer is modified with polyaspartic acid and magnesium aluminum hydrotalcite. The special layered structure of hydrotalcite (0.75-0.78 nm interlayer spacing) can selectively adsorb Ca²⁺ without hindering Na⁺ diffusion, thus avoiding the scaling and clogging problems common in traditional biological carriers. The outer conductive layer is composed of polyaniline-carbon nanotubes. The selective modification of carboxylated carbon nanotubes (0.1-0.2 wt%) can significantly reduce electron transfer resistance, making the volume resistivity of the conductive layer less than 10 Ω·cm, thereby efficiently promoting the electron transfer efficiency of the bacterial community when an electric field is subsequently applied. Furthermore, to enhance the system's adaptability, the outermost layer of the capsule is coated with a pH-responsive polymer composed of a copolymer of N-isopropylacrylamide, methacrylic acid, and hydroxyethylacrylamide. When a sudden change in salinity causes the environmental pH to exceed 8.5, the swelling degree of the outer shell can increase by 150-200%, releasing nano-montmorillonite. These mineral particles can instantaneously bind free Na⁺, providing a buffer period for the bacterial community to activate the expression of salt-tolerant genes.

[0029] In the second possible implementation, the system also includes:

[0030] The pretreatment unit includes a vortex flocculator, wherein the vortex flocculator has a built-in metal filter screen with a pore size of 45~55μm, and the linear velocity of the vortex flocculator is controlled at 1.0~1.5m / s.

[0031] The crystallization control unit integrates a 28~40kHz ultrasonic generator and a hydrocyclone separator, with a seed crystal recovery rate of ≥90%. The underflow port of the hydrocyclone separator is connected to an automatic sludge discharge valve. When the sludge level sensor detects a height >30cm, it triggers sludge discharge, and the single sludge discharge volume is <5% of the hydrocyclone separator volume, which ensures timely removal of sediments without causing biomass loss.

[0032] In a second possible implementation, the surface of the metal filter is coated with a hydrophobic coating of polytetrafluoroethylene at a mass fraction of 0.1-0.3%, which can optimize the solid-liquid separation effect, reduce the risk of clogging, and extend the filter life.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] (1) This invention achieves multiple breakthroughs in the treatment of high-salt and high-hardness wastewater by constructing a four-layer structure of functionalized microbial capsules. The salt-tolerant bacteria core uses sodium alginate as a matrix to encapsulate salt-tolerant bacteria. Trehalose is added to regulate osmotic pressure and activate salt-tolerant genes, increasing the bacterial survival rate from 30%-40% to ≥90% in high-salt environments. During the solidification stage, it forms a stable gel network with sodium alginate-Ca²⁺, ensuring that over 85% of the bacteria remain active after 90 days of operation. The anti-scaling layer uses a composite of polyaspartic acid and magnesium aluminum hydrotalcite. The hydrotalcite, with a 0.75-0.78 nm interlayer spacing, selectively retains ≥90% of Ca²⁺ while allowing ≥85% of Na⁺ to pass through, effectively preventing calcium carbonate scale from clogging the capsule pores and solving the mass transfer obstruction problem caused by scaling in high-hardness wastewater. The conductive layer forms a three-dimensional conductive network through a polyaniline-carbon nanotube composite, with a volume resistivity as low as ≤10 Ω・cm. Under an applied electric field, it significantly improves electron transfer efficiency, reducing desalination energy consumption by over 30%. The responsive outer shell operates at pH > 8.5. With a swelling degree of 150%-200%, it releases 50-80nm nano-montmorillonite that adsorbs onto the surface of the bacteria to form a protective layer, mitigating the impact of sudden changes in salinity. The four-layer structure works synergistically to provide microorganisms with multiple protections, including salt resistance, scale resistance, conductivity, and environmental responsiveness.

[0035] (2) The present invention adopts a phased salinity-electric field synergistic regulation strategy to greatly improve the efficiency and stability of bacterial community treatment. During the adaptation period, a daily salinity gradient of 0.8-1.2 g / L (4 times faster than traditional methods) combined with dissolved oxygen control and the sustained-release protection mechanism of functionalized capsules allows the bacteria to enter a highly active state without a long adaptation period, with a bacterial growth rate ≥0.08-0.15 h⁻¹. When the salinity reaches 23-27 g / L, the turbidity fluctuation of the bacterial solution is <5%-8%, and the intracellular Na⁺ / K⁺ ratio is ≤0.2-0.4, ensuring microbial osmotic pressure balance. During the enhancement period, a DC electric field of 0.4-0.6 V / cm and a pulsed electric field of 0.8-1.2 V / cm are applied. The former stabilizes the bacterial membrane potential, while the latter prevents local pH imbalance caused by electrode polarization. As the salinity continues to increase to 30-35 g / L, the COD removal rate can be stabilized at over 85%. During the stabilization period, a daily "backwash-ultrasound-seed crystal addition" process is performed. The system maintains circulation, backwashes to remove surface deposits, uses ultrasonic treatment to break up scale particles, and induces Ca²⁺ and Mg²⁺ to precipitate in a non-adhesive crystalline form using aragonite seed crystals, thereby reducing the amount of scale deposited in the reactor by 60%-65% and achieving long-term stable operation under high-salt conditions.

[0036] (3) In this invention, the pretreatment and crystallization control unit form a highly efficient auxiliary treatment system to ensure the stable operation of the main treatment unit. Wastewater pretreatment controls the linear velocity to 1.2±0.1m / s through a vortex flocculant and adds 45-55mg / L of polyacrylamide to polymerize suspended solids into flocs ≥500μm. After being intercepted by a metal filter, the removal rate reaches 95%. At the same time, when the Ca²⁺ concentration is >800mg / L, 8-12mg / L of polyaspartic acid is automatically added to complex free Ca²⁺, inhibit scaling, and reduce the treatment load of the anti-scaling layer. In the crystallization control stage, an ultrasonic-assisted cyclone separator is used to destroy the growth of CaCO3 crystal nuclei and efficiently separate crystals with a particle size ≥10μm. The seed crystal recycling rate is >90%, dynamically removing Ca²⁺ deposits and forming a dual anti-scaling mechanism of "internal barrier + external removal" with the anti-scaling layer to avoid equipment blockage and secondary pollution and extend the system operation cycle.

[0037] (4) In this invention, the synergistic effect of the conductive layer of the microbial capsule and the applied electric field is used to achieve efficient energy utilization and enhanced microbial metabolism. In the aniline phosphate buffer solution with pH 4.0-4.8, a polyaniline-carbon nanotube composite conductive layer is formed on the periphery of the anti-fouling microspheres by electrodeposition. The carboxylated carbon nanotubes are interspersed between the polyaniline chains to form a three-dimensional conductive network, which reduces the volume resistivity to 8-10 Ω·cm and significantly reduces the electron transfer resistance. Under the action of the DC electric field and pulsed electric field applied during the enhancement period, the conductive layer efficiently conducts electrical energy, stably maintains the membrane potential of the bacterial community and promotes electron transfer, and enhances the metabolic activity of microorganisms. Compared with the traditional method, the desalination energy consumption is reduced by more than 30%, and the intermittent action of the pulsed electric field avoids electrode polarization and bacterial damage, ensuring that the bacterial community continuously and efficiently degrades pollutants in a high-salt environment. The COD removal rate is increased by 30% compared with the traditional activated sludge method, reaching more than 85%.

[0038] (5) This invention breaks through the bottleneck of traditional high-salt and high-hardness wastewater treatment and achieves efficient and synergistic treatment throughout the entire process. Through the deep coupling of the four-layer structure of functionalized microbial capsules and the phased control strategy, it solves the problems of microbial osmotic pressure imbalance (bacterial survival rate ≥90%), high-hardness ion scaling and clogging, and high energy consumption and low efficiency of traditional methods under high-salt conditions. The salinity can be treated up to 30-35 g / L, the COD removal rate is stable at 85%, and the energy consumption is reduced to 0.9 kWh / m³. The pretreatment and crystallization control unit accurately removes suspended solids and dynamically controls scaling, so that the bacterial activity is maintained at 90% after 90 days of system operation, and the sludge production is only 0.1 kg / m³. Frequent shutdowns for cleaning are not required. A complete system from water pretreatment, microbial enhancement to scaling control is constructed, providing a new solution for the long-term stable treatment of industrial high-salt and high-hardness wastewater.

[0039] The present invention will be explained in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0040] Figure 1 Line graphs showing the COD removal rate in wastewater treatment of Examples 1-3 and Comparative Examples 1-5 of this invention;

[0041] Figure 2 Line graphs showing the cell survival rate of bacteria in wastewater treatment in Examples 1-3 and Comparative Examples 1-5 of the present invention.

[0042] Figure 3 This is a bar chart showing the amount of scaling in the wastewater systems of Examples 1-3 and Comparative Examples 1-5 of the present invention. Detailed Implementation

[0043] To facilitate understanding of the present invention, a more comprehensive description of the present invention will be given below with reference to the accompanying drawings, which illustrate several embodiments of the present invention. However, the present invention can be implemented in different forms and is not limited to the embodiments described in the text. Rather, these embodiments are provided to make the disclosure of the present invention more thorough and complete.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly associated with those skilled in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0045] Example 1: This embodiment of the invention provides a method for treating high-salinity wastewater, comprising the following steps:

[0046] I. Wastewater Pretreatment: Wastewater is passed through a vortex flocculant with a controlled linear velocity of 1.2 m / s, and 50 mg / L polyacrylamide (molecular weight 8 million) is added simultaneously, polymerizing suspended solids from ≤50 μm to ≥500 μm flocs; then, suspended solids are retained by a metal filter, and the pH is adjusted to 7.8, achieving a suspended solids removal rate of 95%; when the online monitoring shows a Ca²⁺ concentration >800 mg / L, 10 mg / L polyaspartic acid (molecular weight 4000) is automatically added, achieving a Ca²⁺ complexation rate of 88%.

[0047] II. Preparation of functionalized microbial capsules, wherein the preparation method of the functionalized microbial capsules includes the following steps:

[0048] (1) Preparation of the core of halophilic bacteria: Halophilic bacteria were inoculated into a culture medium containing 135 g / L NaCl and 7.5 g / L trehalose and cultured. The resulting bacterial solution was mixed with 4 wt% sodium alginate and then added dropwise to a 2 wt% CaCl2 solution. Core microspheres were prepared by electrostatic molding and solidified at 25°C for 2 h. The final concentration of trehalose during the solidification stage was 4%. The bacterial cell density inside the obtained core microspheres was 1.2 × 10⁻⁶. 9 The bacterial cell count was 94% and the diameter of the core microspheres was (200±20) μm.

[0049] (2) Construction of anti-scaling layer: The core was immersed in a mixture containing 3 wt% polyaspartic acid and 1.0 wt% magnesium aluminum hydrotalcite with an interlayer spacing of 0.76 nm. After treatment at 40 °C for 30 min, a 40 μm thick anti-scaling layer was formed, and anti-scaling microspheres were obtained. The Ca²⁺ rejection rate of the anti-scaling microspheres was 92%, and the Na⁺ permeability was 88%.

[0050] (3) Formation of conductive layer: In aniline phosphate buffer at pH 4.5, 0.15 wt% carboxylated carbon nanotubes are added, and after immersing the above anti-scaling microspheres, 0.5 wt% ammonium persulfate is added dropwise. A polyaniline-carbon nanotube composite conductive layer with a volume resistivity of 9 Ω·cm is formed on the outer periphery of the anti-scaling microspheres by electrodeposition.

[0051] (4) Responsive shell coating: After placing the above capsule preform in the copolymer prepolymer liquid and curing it under ultraviolet light for 30 min, a 90 μm thick responsive shell is formed, and functionalized microbial capsules are obtained; the responsive shell has a swelling degree of 150~200% when pH>8.5, and the released nano-montmorillonite particles have a size of 50~80 nm.

[0052] A copolymer prepolymer solution was prepared by mixing three monomers, N-isopropylacrylamide (NIPAM), methacrylic acid (MAA), and hydroxyethylacrylamide (HEA), in a molar ratio of 85:10:5 with 0.5 wt% nano-montmorillonite and adding a photoinitiator.

[0053] III. Phased Operation of the Bioreactor: The functionalized microbial capsules are added to the bioreactor, and the pretreated wastewater is introduced into the bioreactor for phased treatment:

[0054] Adaptation period (4 days): The salinity of the salt-tolerant bacteria culture medium was gradually increased from the initial salinity of 18 g / L to 25 g / L in a daily gradient of 1.0 g / L under dissolved oxygen conditions of 2.3 mg / L. The bacterial cell density and survival rate were monitored to ensure that the bacterial growth rate was ≥0.12 h⁻¹. The adaptation period ended when the salinity reached 25 g / L and the turbidity fluctuation of the bacterial culture was <5% and the intracellular Na⁺ / K⁺ ratio was ≤0.3.

[0055] Enhancement period (7 days): Based on a salinity of 25 g / L, a DC electric field of 0.5 V / cm is applied in conjunction with a pulsed electric field of 1.0 V / cm. The frequency of the pulsed electric field is 1.0 Hz and the duty cycle is 1:5. At the same time, the salinity is increased to 32 g / L at a rate of 1.0 g / L per day, and the COD removal rate is increased to 85%.

[0056] Stabilization period: Under salinity of 32 g / L, a maintenance cycle of backwashing-ultrasound-seedling addition is performed daily. Specifically: first backwash for 30 seconds at a flow rate of 15 cm / s, then sonicate for 10 minutes, and then add 100 mg / L of aragonite seed crystals.

[0057] IV. Crystallization control stage: Using 28kHz ultrasound, with a density of 0.5W / cm³, and in conjunction with a cyclone separator, Ca²⁺ deposits are dynamically removed, and the seed crystal circulation rate is >90%.

[0058] Ultrasonic: 28kHz, power density 0.5W / cm³, synergistic cyclone separator (automatic sludge discharge at the bottom outlet, triggered when sludge level >30cm, single sludge discharge volume 4% of volume), Ca²⁺ sediment removal rate 85%.

[0059] Furthermore, embodiments of the present invention also provide a high-salinity wastewater treatment system, including a bioreactor filled with functionalized microbial capsules at a volume ratio of 45%, wherein the functionalized microbial capsules, from the inside out, are as follows:

[0060] Salt-tolerant bacterial core: A sodium alginate matrix cross-linked with trehalose and calcium, with a bacterial cell density of 1.2 × 10⁻⁶. 9 CFU / mL;

[0061] Anti-fouling layer: composed of polyaspartic acid and magnesium aluminum hydrotalcite, with a thickness of 40μm;

[0062] Conductive layer: A three-dimensional network formed by in-situ polymerization of aniline and loading of carbon nanotubes, with a volume resistivity ≤10Ω·cm;

[0063] Responsive shell: composed of N-isopropylacrylamide, methacrylic acid and hydroxyethylacrylamide copolymer.

[0064] The bioreactor has a processing capacity of 20 m³ / d, maintains 94% bacterial activity after 90 days of operation, consumes 0.9 kWh / m³, and produces 0.1 kg / m³ of sludge.

[0065] Preferably, the high-salinity wastewater treatment system in this embodiment further includes:

[0066] The pretreatment unit includes a vortex flocculator, which has a built-in metal filter screen with a pore size of 50 μm. The surface of the metal filter screen is coated with a 0.2% by mass hydrophobic coating of polytetrafluoroethylene, and the linear velocity of the vortex flocculator is controlled at 1.0~1.5 m / s.

[0067] The crystallization control unit integrates a 28~40kHz ultrasonic generator and a hydrocyclone separator, with a seed crystal recovery rate of ≥90%. The underflow port of the hydrocyclone separator is connected to an automatic sludge discharge valve. When the sludge level sensor detects a height >30cm, it triggers sludge discharge, and the single sludge discharge volume is <5% of the hydrocyclone separator volume.

[0068] Example 2: The high-salinity wastewater treatment method in this example is basically the same as that in Example 1, except that:

[0069] I. Wastewater Pretreatment: Wastewater is passed through a vortex flocculant with a controlled linear velocity of 1.3 m / s, and 55 mg / L of polyacrylamide (molecular weight 8 million) is added simultaneously, causing suspended solids to aggregate into flocs. The wastewater is then filtered through a metal screen to remove suspended solids, and the pH is adjusted to 7.5, achieving a suspended solids removal rate of 95%. When the online monitoring shows a Ca²⁺ concentration > 800 mg / L, 8 mg / L of polyaspartic acid (molecular weight 4000) is automatically added, resulting in a Ca²⁺ complexation rate of 88%.

[0070] II. Preparation of functionalized microbial capsules, wherein the preparation method of the functionalized microbial capsules includes the following steps:

[0071] (1) Preparation of the core of salt-tolerant bacteria: Salt-tolerant bacteria were inoculated into a culture medium containing 125 g / L NaCl and 6 g / L trehalose and cultured. The resulting bacterial solution was mixed with 3 wt% sodium alginate and then added dropwise to 1 wt% CaCl2 solution. Core microspheres were prepared by electrostatic molding and solidified at 25℃ for 2 h. The final concentration of trehalose during the solidification stage was 3%. The bacterial cell density inside the obtained core microspheres was 1.0 × 10⁻⁶. 9 The bacterial cell count was 93% and the diameter of the core microspheres was (200±20) μm.

[0072] (2) Construction of anti-scaling layer: The core was immersed in a mixture containing 2 wt% polyaspartic acid and 0.5 wt% magnesium aluminum hydrotalcite with an interlayer spacing of 0.75 nm. After treatment at 38 °C for 25 min, a 30 μm thick anti-scaling layer was formed, and anti-scaling microspheres were obtained. The Ca²⁺ rejection rate of the anti-scaling microspheres was 91%, and the Na⁺ permeability was 87%.

[0073] (3) Formation of conductive layer: In aniline phosphate buffer at pH 4.0, 0.1 wt% carboxylated carbon nanotubes are added, and after the above anti-scaling microspheres are immersed, 0.4 wt% ammonium persulfate is added dropwise. A polyaniline-carbon nanotube composite conductive layer with a volume resistivity of 10 Ω·cm is formed on the outer periphery of the anti-scaling microspheres by electrodeposition.

[0074] (4) Responsive shell coating: After placing the above capsule preform in the copolymer prepolymer liquid and curing it under ultraviolet light for 25 minutes, a responsive shell with a thickness of 80 μm is formed, and functionalized microbial capsules are obtained; the responsive shell has a swelling degree of 150~200% when pH>8.5, and the released nano-montmorillonite particles have a size of 50~80 nm.

[0075] A copolymer prepolymer solution was prepared by mixing three monomers, N-isopropylacrylamide (NIPAM), methacrylic acid (MAA), and hydroxyethylacrylamide (HEA), in a molar ratio of 80:8:4 with 0.4 wt% nano-montmorillonite and adding a photoinitiator.

[0076] III. Phased Operation of the Bioreactor: The functionalized microbial capsules are added to the bioreactor, and the pretreated wastewater is introduced into the bioreactor for phased treatment:

[0077] Adaptation period: The salinity of the salt-tolerant bacteria culture medium was gradually increased from the initial salinity of 15 g / L to 23 g / L at a daily gradient of 0.8 g / L under dissolved oxygen conditions of 2.0 mg / L. The bacterial cell density and survival rate were monitored to ensure that the bacterial growth rate was ≥0.15 h⁻¹. The adaptation period ended when the salinity reached 23 g / L and the turbidity fluctuation of the bacterial culture was <6% and the intracellular Na⁺ / K⁺ ratio was ≤0.2.

[0078] Enhancement period: Based on a salinity of 23 g / L, a DC electric field of 0.4 V / cm is applied in conjunction with a pulsed electric field of 0.8 V / cm. The frequency of the pulsed electric field is 0.8 Hz and the duty cycle is 1:4. At the same time, the salinity is increased to 30 g / L at a rate of 0.8 g / L per day. The COD removal rate is increased to 83% and the scaling amount is 1.0 g / m²・d.

[0079] Stabilization period: Under salinity of 30 g / L, a maintenance cycle of backwashing-ultrasound-seedling addition is performed daily. Specifically: first backwash for 20 seconds at a flow rate of 10 cm / s, then sonicate for 8 minutes, and then add 80 mg / L of aragonite seed crystals.

[0080] IV. Crystallization control stage: using 28kHz ultrasound, with a density of 0.4W / cm³, and in conjunction with a cyclone separator, Ca²⁺ deposits are dynamically removed, and the seed crystal circulation rate is >90%.

[0081] Example 3: The high-salinity wastewater treatment method in this example is basically the same as that in Example 1, except that:

[0082] I. Wastewater Pretreatment: Wastewater is passed through a vortex flocculant with a controlled linear velocity of 1.1 m / s, and 45 mg / L of polyacrylamide (molecular weight 8 million) is added simultaneously, causing suspended solids to aggregate into flocs. The wastewater is then filtered through a metal screen to remove suspended solids, and the pH is adjusted to 8.0, achieving a suspended solids removal rate of 95%. When the online monitoring shows a Ca²⁺ concentration > 800 mg / L, 8 mg / L of polyaspartic acid (molecular weight 4000) is automatically added, achieving a Ca²⁺ complexation rate of 90%.

[0083] II. Preparation of functionalized microbial capsules, wherein the preparation method of the functionalized microbial capsules includes the following steps:

[0084] (1) Preparation of the core of salt-tolerant bacteria: Salt-tolerant bacteria were inoculated into a culture medium containing 150 g / L NaCl and 8 g / L trehalose and cultured. The resulting bacterial solution was mixed with 5 wt% sodium alginate and then added dropwise to a 3 wt% CaCl2 solution. Core microspheres were prepared by electrostatic molding and solidified at 30℃ for 2 h. The final concentration of trehalose during the solidification stage was 5%. The bacterial cell density inside the obtained core microspheres was 1.1 × 10⁻⁶. 9 The bacterial cell viability was 93% and the diameter of the core microspheres was (200±20) μm.

[0085] (2) Construction of anti-scaling layer: The core was immersed in a mixture containing 2 wt% polyaspartic acid and 0.5 wt% magnesium aluminum hydrotalcite with an interlayer spacing of 0.75 nm. After treatment at 38 °C for 25 min, a 30 μm thick anti-scaling layer was formed, and anti-scaling microspheres were obtained. The Ca²⁺ rejection rate of the anti-scaling microspheres was 91%, and the Na⁺ permeability was 87%.

[0086] (3) Formation of conductive layer: 0.2 wt% carboxylated carbon nanotubes were added to aniline phosphate buffer at pH 4.8. After the anti-scaling microspheres were immersed, 0.6 wt% ammonium persulfate was added dropwise, and a polyaniline-carbon nanotube composite conductive layer with a volume resistivity of 9.5 Ω·cm was formed on the outer periphery of the anti-scaling microspheres by electrodeposition.

[0087] (4) Responsive shell coating: After placing the above capsule preform in the copolymer prepolymer liquid and curing it under ultraviolet light for 30 min, a 120 μm thick responsive shell is formed, and functionalized microbial capsules are obtained; the responsive shell has a swelling degree of 150~200% when pH>8.5, and the released nano-montmorillonite particles have a size of 50~80 nm.

[0088] A copolymer prepolymer solution was prepared by mixing three monomers, N-isopropylacrylamide (NIPAM), methacrylic acid (MAA), and hydroxyethylacrylamide (HEA), in a molar ratio of 88:12:6 with 0.6 wt% nano-montmorillonite and adding a photoinitiator.

[0089] III. Phased Operation of the Bioreactor: The functionalized microbial capsules are added to the bioreactor, and the pretreated wastewater is introduced into the bioreactor for phased treatment:

[0090] Adaptation period: The salinity of the salt-tolerant bacterial culture medium was gradually increased from an initial salinity of 20 g / L to 27 g / L in a daily gradient of 1.2 g / L under dissolved oxygen conditions of 2.5 mg / L. The bacterial cell density and survival rate were monitored to ensure that the bacterial growth rate was ≥0.15 h⁻¹. The adaptation period ended when the salinity reached 27 g / L and the turbidity fluctuation of the bacterial culture was <8% and the intracellular Na⁺ / K⁺ ratio was ≤0.4.

[0091] Enhancement period: Based on a salinity of 27 g / L, a DC electric field of 0.6 V / cm is applied in conjunction with a pulsed electric field of 1.2 V / cm. The frequency of the pulsed electric field is 1.2 Hz and the duty cycle is 1:6. At the same time, the salinity is increased to 35 g / L at a rate of 1.2 g / L per day, the COD removal rate is increased to 85%, and the scaling amount is 1.1 g / m²・d.

[0092] Stabilization period: Under salinity of 35 g / L, a maintenance cycle of backwashing-ultrasound-seedling is performed daily. Specifically: first backwash at a flow rate of 20 cm / s for 40 seconds, then sonicate for 12 minutes, and then add 120 mg / L of aragonite seed crystals.

[0093] IV. Crystallization control stage: using 35kHz ultrasound, with a density of 0.6W / cm³, and in conjunction with a cyclone separator, Ca²⁺ deposits are dynamically removed, and the seed crystal circulation rate is >90%.

[0094] Comparative Example 1: This comparative example uses a traditional treatment method (no biocapsule + no staged control), specifically including the following steps:

[0095] The conventional activated sludge process was used, without capsule protection, with a salinity gradient of 0.2 g / L / d (traditional method), no electric field synergy, and pretreatment only adjusting pH.

[0096] When the salinity reaches 20 g / L, the bacterial survival rate is 30%, the COD removal rate is 55%, the scaling amount is 4.0 g / m²·d, it cannot treat high-salinity wastewater >25 g / L, and the energy consumption is 1.5 kWh / m³ (66.7% higher than Example 1).

[0097] Comparative Example 2: This comparative example uses a single-layer core structure biocapsule. The capsule contains only a salt-tolerant bacterial core (sodium alginate matrix, without anti-fouling layer, conductive layer, or responsive shell). The pretreatment and crystallization control are the same as in Example 1.

[0098] Performance defects: Ca²⁺ directly enters the core, and within 2 weeks, the capsule pores are blocked by CaCO3 (blockage rate 60%). The bacteria die due to impaired mass transfer, the survival rate drops to 45%, the COD removal rate drops sharply to 50%, and the scale buildup is 5.5 g / m²・d.

[0099] Comparative Example 3: This comparative example uses a four-layer biocapsule structure, but the relevant parameters exceed the limits: sodium alginate concentration 2wt% (<3wt%, insufficient mechanical strength), hydrotalcite interlayer spacing 0.85nm (>0.78nm, Ca²⁺ retention rate drops to 70%), and no staged control (salinity directly increases to 35g / L).

[0100] Performance defects: 30% core microsphere breakage rate, failure of anti-scaling layer, scale accumulation of 3.0 g / m²·d, bacterial survival rate of 50% (90 days), and COD removal rate of 70% (15% lower than Example 1).

[0101] Comparative Example 4: This comparative example is basically the same as Comparative Example 3, except that the bioreactor adopts a staged control strategy and the relevant parameters are consistent with those in Example 1.

[0102] Salinity adaptation rate increased to 1.0 g / L / d, and bacterial survival rate increased to 60%. However, due to capsule structure defects, scale buildup still reached 2.5 g / m²・d, and COD removal rate was 75%.

[0103] Comparative Example 5: This comparative example does not use functionalized microbial capsules, but adopts the relevant pretreatment and phased control steps and parameters as described in Example 1.

[0104] This comparative example uses free salt-tolerant bacteria (without encapsulation), and features pretreatment and staged salinity-electric field control. Other conditions are the same as in Example 1.

[0105] Because free bacteria are easily destroyed by high-salt environments, the survival rate is only 45% (90 days), the COD removal rate is 65%, the scaling amount is 2.0 g / m²・d, and the energy consumption is 1.2 kWh / m³.

[0106] Table 1 is a comparison table of relevant parameters for Examples 1-3 and Comparative Examples 1-5.

[0107] Group Salinity treatment range (g / L) COD removal rate (%) Bacterial survival rate (90 days) Scaling amount (g / m²・d) Example 1 32 (Stable Period) 85 94% 1.0 Example 2 30 (Stable Period) 83 93% 1.0 Example 3 35 (Stable Period) 85 93% 1.1 Comparative Example 1 ≤20 55 30% 4.0 Comparative Example 2 ≤25 50 45% 5.5 Comparative Example 3 ≤30 70 50% 3.0 Comparative Example 4 ≤30 75 60% 2.5 Comparative Example 5 ≤30 65 45% 2.0

[0108] As can be seen from Table 1 above:

[0109] (1) In Examples 1-3, the cell survival rate reached 93%-94% at a salinity of 30-35 g / L, and the activity remained ≥90% after 90 days of operation, which was significantly better than Comparative Example 1 (<30%), Comparative Example 2 (45%) and Comparative Example 5 (45%). This is because the trehalose protection mechanism of the salt-tolerant bacteria's core (regulating osmotic pressure + activating salt-tolerant genes) and the nano-montmorillonite release function of the responsive shell synergistically improve the survival rate of microorganisms in high-salt environments, breaking through the bottleneck of the efficiency drop when the salinity is >20 g / L in traditional methods.

[0110] (2) The scale amount in Examples 1-3 was only 1.0-1.1 g / m²·d, which was 72.5%-75% lower than that in Comparative Example 1 (4.0 g / m²·d) and 80%-81.8% lower than that in Comparative Example 2 (5.5 g / m²·d).

[0111] Key technological contribution: The magnesium aluminum hydrotalcite (0.75-0.78nm interlayer spacing) of the anti-scaling layer selectively retains Ca²⁺ (retention rate ≥90%), combined with the "ultrasound + seed crystal addition" maintenance cycle during the stabilization period (reducing scale by 60%-65%), forming a dual anti-scaling system of "internal barrier + external removal", which solves the scaling and clogging problem of high hardness wastewater.

[0112] (3) The COD removal rate in Examples 1-3 reached 83%-85%, which was significantly higher than that in Comparative Example 1 (55%), Comparative Example 2 (50%) and Comparative Example 5 (65%); and it operated stably for a long time at a salinity of 30-35 g / L, while Comparative Example 1 could not handle salinity >25 g / L.

[0113] In this embodiment of the invention, a phased regulation strategy (rapid domestication during the adaptation period + electric field synergy during the reinforcement period + maintenance cycle during the stabilization period) is coupled with a conductive layer (polyaniline-carbon nanotubes, volume resistivity ≤10Ω・cm) to improve electron transfer efficiency and keep the metabolic activity of microorganisms stable in a high-salt environment.

[0114] This invention achieves efficient and stable treatment of high-salt (30-35 g / L) and high-hardness (Ca²⁺ > 500 mg / L) wastewater by deeply coupling a functionalized microbial capsule four-layer structure (salt resistance protection + scale resistance + conductivity + responsiveness) with a staged salinity-electric field synergistic regulation strategy, supplemented by pretreatment and crystallization control units. It comprehensively outperforms the comparative group of traditional methods in key indicators such as salt resistance, scale resistance, treatment efficiency, and energy consumption control.

[0115] Any numerical values ​​cited herein include all values ​​ranging from a lower limit to an upper limit, increasing by one unit, with at least two units between any lower and any higher value. For example, if the quantity of a component or the value of a process variable (e.g., temperature, pressure, time, etc.) is described as being from 1 to 90, preferably from 20 to 80, more preferably from 30 to 70, the purpose is to illustrate that values ​​such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 are also explicitly listed in this specification. For values ​​less than 1, a unit is appropriately considered to be 0.0001, 0.001, 0.01, 0.1, etc. These are merely examples intended for explicit expression, and it can be assumed that all possible combinations of values ​​listed between the minimum and maximum values ​​are similarly explicitly stated in this specification.

[0116] Unless otherwise stated, all ranges include the endpoints and all numbers between them. The terms "approximately" or "about" used with ranges apply to both endpoints of the range. Thus, "approximately 20 to 30" is intended to cover "approximately 20 to approximately 30," including at least the specified endpoints.

[0117] It should be understood that the above description is for illustrative purposes and not for limitation. Many embodiments and applications beyond the provided examples will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of this teaching should not be determined by reference to the above description, but rather by reference to the appended claims and the full scope of their equivalents. For purposes of completeness, all articles and references, including patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the preceding claims is not intended as a waiver of that subject matter, nor should it be construed as an indication that the inventors have not considered that subject matter as part of the disclosed inventive subject matter.

[0118] The present invention has been described by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvement made by adopting the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, shall be within the protection scope of the present invention.

Claims

1. A method for treating high-salinity wastewater, characterized in that, The pretreated wastewater is passed into a bioreactor filled with functionalized microbial capsules. The preparation method of the functionalized microbial capsules includes the following steps: (1) Preparation of salt-tolerant bacteria core: Salt-tolerant bacteria are inoculated into a culture medium containing NaCl and trehalose and cultured. The bacterial solution is mixed with 3-5 wt% sodium alginate and then dripped into 1-3 wt% CaCl2 solution. Core microspheres are obtained by electrostatic molding and solidified at 20-30℃ for a period of time. (2) Anti-scaling layer construction: The core is immersed in a mixture containing 2-5 wt% polyaspartic acid and 0.5-1.5 wt% magnesium aluminum hydrotalcite, and treated at 38-45℃ for 25-35 min to form anti-scaling microspheres; (3) Formation of conductive layer: 0.1-0.2 wt% carboxylated carbon nanotubes are added to aniline phosphate buffer solution at pH 4.0-4.

8. After the above anti-scaling microspheres are immersed, 0.4-0.6 wt% ammonium persulfate is added dropwise, and a polyaniline-carbon nanotube composite conductive layer is deposited on the periphery of the anti-scaling microspheres by electrodeposition. (4) Responsive shell coating: After placing the above capsule preform in the copolymer prepolymer liquid for a period of time and curing it under ultraviolet light, a responsive shell with a thickness of 80-100 μm is formed, and functionalized microbial capsules are obtained; A copolymer prepolymer solution was prepared by mixing three monomers, N-isopropylacrylamide, methacrylic acid and hydroxyethylacrylamide, in a molar ratio of (80~88):(8~12):(4~6) with 0.4~0.6wt% of nano-montmorillonite and adding a photoinitiator. The functionalized microbial capsules are added to a bioreactor, and the pretreated wastewater is then introduced into the bioreactor for staged treatment. Adaptation period: Under dissolved oxygen conditions of 2.0-2.5 mg / L, the salinity of the salt-tolerant bacterial culture medium was gradually increased from an initial salinity of 15-20 g / L to 23-27 g / L in a daily gradient of 0.8-1.2 g / L for 4-7 days. The growth rate was ensured to be ≥0.08-0.15 h⁻¹ by monitoring the cell density and survival rate. The adaptation period ended when the salinity reached 23-27 g / L and the turbidity fluctuation of the bacterial culture was <5-8% and the intracellular Na⁺ / K⁺ ratio was ≤0.2-0.

4. Enhancement period: Based on a salinity of 23~27 g / L, apply a DC electric field of 0.4~0.6 V / cm in conjunction with a pulsed electric field of 0.8~1.2 V / cm. The frequency of the pulsed electric field is 0.8~1.2 Hz and the duty cycle is 1:4~1:

6. At the same time, increase the salinity to 30~35 g / L at a rate of 0.8~1.2 g / L per day. Stabilization period: Under salinity conditions of 30~35g / L, a maintenance cycle of backwashing-ultrasound-seedling addition is performed daily. Specifically: first backwash at a flow rate of 10~20cm / s for 20~40 seconds, then sonicate for 8~12 minutes, and then add 80~120mg / L of aragonite seed crystals.

2. The method for treating high-salinity wastewater according to claim 1, characterized in that, The trehalose is added at a concentration of 6-8 g / L during the cell culture stage and maintained at a final concentration of 3-5% by mass during the solidification stage. And / or, the NaCl is added at a concentration of 125~150 g / L during the cell culture stage.

3. The method for treating high-salinity wastewater according to claim 1, characterized in that, The anti-fouling layer has an interlayer spacing of 0.75~0.78 nm for magnesium aluminum hydrotalcite, a Ca²⁺ retention rate ≥90%, and a Na⁺ permeability ≥85%.

4. The method for treating high-salinity wastewater according to claim 1, characterized in that, The responsive shell swells to 150-200% at pH > 8.5, simultaneously releasing nano-montmorillonite.

5. The method for treating high-salinity wastewater according to any one of claims 1-4, characterized in that, Wastewater pretreatment includes the following steps: Wastewater is passed through a vortex flocculant with a controlled linear velocity of 1.2±0.1m / s, and 45~55mg / L of polyacrylamide is added simultaneously, causing suspended solids to aggregate into flocs; The suspended solids are then removed by a metal filter, and the pH is adjusted to 7.5-8.

0. When the online monitoring shows that the Ca²⁺ concentration is >800 mg / L, 8~12 mg / L of polyaspartic acid is automatically added.

6. The method for treating high-salinity wastewater according to claim 1, characterized in that, It also includes a crystallization control stage, in which 25-35kHz ultrasound is used to dynamically remove Ca²⁺ deposits with a density of 0.4-0.6W / cm³, in conjunction with a cyclone separator, and the seed crystal recycling rate is >90%.

7. A system for implementing the high-salinity wastewater treatment method according to any one of claims 1-6, characterized in that, The system includes a bioreactor filled with functionalized microbial capsules at a volume ratio of 40-50%, wherein the functionalized microbial capsules, from the inside out, are: Salt-tolerant bacteria core: a sodium alginate matrix cross-linked with trehalose and calcium, wherein the bacterial cell density is ≥10. 9 CFU / mL; Anti-fouling layer: composed of polyaspartic acid and magnesium aluminum hydrotalcite, with a thickness of 30~50μm; Conductive layer: A three-dimensional network formed by in-situ polymerization of aniline and loading of carbon nanotubes, with a volume resistivity ≤10Ω·cm; Responsive shell: composed of N-isopropylacrylamide, methacrylic acid and hydroxyethylacrylamide copolymer.

8. The system of the high-salinity wastewater treatment method according to claim 7, characterized in that, Also includes: The pretreatment unit includes a vortex flocculant with a built-in metal filter screen with a pore size of 45~55μm and the linear velocity of the vortex flocculant is controlled at 1.0~1.5m / s. The crystallization control unit integrates a 28~40kHz ultrasonic generator and a hydrocyclone separator, with a seed crystal recovery rate of ≥90%. The underflow port of the hydrocyclone separator is connected to an automatic sludge discharge valve. When the sludge level sensor detects a height >30cm, it triggers sludge discharge, and the single sludge discharge volume is <5% of the hydrocyclone separator volume.

9. The system of the high-salinity wastewater treatment method according to claim 8, characterized in that, The surface of the metal filter screen is coated with a hydrophobic coating of polytetrafluoroethylene with a mass fraction of 0.1-0.3%.

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