Water treatment method based on online peeling and reconstruction of active sacrificial interface and application

Abstract

The application discloses a water treatment method based on an active sacrifice interface of online stripping and reconstruction and application, and belongs to the technical field of membrane separation treatment of water, waste water and sewage. The application solves the problems of performance decline of a membrane function layer, poor pollution control effect and high cost caused by a ceramic membrane pollution control mode. The application contacts a layered activation liquid containing polynuclear hydroxyl metal active species with a ceramic membrane filtration interface, forms a renewable active sacrifice interface, and makes pollutants preferentially combine with the active sacrifice interface. When a membrane specific flux, a transmembrane pressure difference or a ratio of a water outlet concentration to a water inlet concentration reaches a set condition, a stripping liquid is passed to make the interface desorb and carry away the loaded pollutants, and the activation liquid is passed again to reconstruct a new active sacrifice interface online without disassembling the ceramic membrane assembly. The application transfers the membrane pollution from the ceramic membrane body to the renewable interface through the circulation of interface construction, pollution loading, stripping triggering and online reconstruction, reduces irreversible membrane pollution, and improves long-term operation stability.

Description

Technical Field

[0001] This invention belongs to the field of membrane separation and treatment technology for water, wastewater and sewage, and relates to a water treatment method and application based on an active sacrificial interface with online stripping and reconstruction. Background Technology

[0002] Membrane separation technology is widely used in drinking water purification, eutrophic water treatment, reclaimed water reuse, and advanced industrial wastewater treatment due to its advantages such as high separation efficiency and stable effluent quality. Ceramic membranes, in particular, play a crucial role in these fields due to their high mechanical strength, resistance to acid and alkali corrosion, oxidation resistance, and long service life. However, in actual treatment of polluted water containing algae and natural organic matter, as well as complex industrial wastewater, algal cells, proteins, polysaccharides, humic substances, and colloidal particles easily deposit on the membrane surface and at the membrane pore inlet, leading to decreased membrane flux, increased transmembrane pressure differential, and irreversible fouling accumulation, severely restricting the long-term stable operation of ceramic membranes. Current methods for controlling ceramic membrane fouling mainly include pretreatment, coagulation, oxidation, backwashing, and chemical cleaning. Traditional cleaning methods primarily rely on acids, alkalis, or oxidants to directly remove contaminants adhering to the ceramic membrane surface. However, this method easily leads to high reagent consumption and downtime costs during long-term operation, and frequent chemical cleaning may cause a decline in the performance of active sites or functional layers on the membrane surface. Therefore, there is an urgent need to establish a circulating membrane filtration method based on reversible stratification chemistry. This would transform the traditional passive fouling control model, which involves directly cleaning the ceramic membrane surface after fouling has formed, into an active control model that pre-constructs a renewable fouling interface and actively removes fouling. Summary of the Invention

[0003] In order to solve the above-mentioned problems in the prior art, the present invention provides a water treatment method and application based on online stripping and reconstruction of active sacrificial interfaces.

[0004] The technical solution of the present invention is as follows: One objective of this invention is to provide a water treatment method based on online stripping and remodeling of an active sacrificial interface, the method comprising the following steps: Step 1: Construction of the polynuclear hydroxyl metal-active sacrificial interface A layered activation solution containing polynuclear hydroxyl metal active species was prepared. The layered activation solution was used as the liquid to be filtered. The ceramic membrane was brought into contact with the layered activation solution through filtration to form a polynuclear hydroxyl metal active sacrificial interface. Step 2: Wastewater filtration, pollution state triggering, and active sacrificial interface stripping. The pollutants in the wastewater are filtered. When the preset pollution conditions are reached, the filtration is stopped, and a stripping liquid is introduced into the ceramic membrane filtration unit to strip the polynuclear hydroxyl metal active sacrificial interface. Step 3: Online Reconstruction of the Active Sacrifice Interface After the active sacrificial interface is peeled off, there is no need to disassemble the ceramic membrane assembly. The layered activation solution containing polynuclear hydroxyl metal active species is introduced into the ceramic membrane filtration unit again to re-form the polynuclear hydroxyl metal active sacrificial interface, and then the filtration operation is resumed. Step 4: Repeat steps 2 to 3 1-10 times to complete the water treatment process based on ceramic membrane fouling control and online regeneration of the active sacrificial interface.

[0005] Further specifying, the concentration of the polynuclear hydroxyl metal active species component in the layering activation solution of step one is 2-30 mg / L.

[0006] Further specifying, the ceramic membrane composition in step one includes at least one of alumina, zirconium oxide, yttrium-doped zirconium oxide, titanium oxide, manganese oxide, and silicon carbide; the ceramic membrane configuration is planar, tubular, hollow fiber, or multi-channel; and the pore size of the ceramic membrane is 2nm-10μm.

[0007] Further specifying, in step one, the ceramic membrane surface and / or the membrane pore inlet region have binding sites capable of interacting with polynuclear hydroxyl metal active species; the binding sites include at least one of surface hydroxyl groups, defect sites, oxygen vacancies, metal centers, or other active sites that coordinate, condense, electrostatically interact, hydrogen bond, or multi-point bridging with polynuclear hydroxyl metal active species; the binding sites can be provided by the ceramic membrane substrate itself, or can be constructed through doping, surface modification, particle loading, coating, or in-situ growth; the ceramic membrane composition is yttrium-doped zirconium oxide, whose surface hydroxyl groups, oxygen vacancies, and metal centers can coordinate, electrostatically adsorb, and multi-point bridge with polynuclear hydroxyl iron active species, thereby promoting the enrichment and layering of polynuclear hydroxyl iron active species on the membrane surface; the ceramic membrane can also be a composite ceramic membrane containing manganese oxide, whose surface oxygen-containing functional groups and metal active centers can promote the interfacial nucleation and anchoring of polynuclear hydroxyl zirconium active species.

[0008] Further specifying, in step one, the polynuclear hydroxyl metal active species is a hydrolyzed polymer species, metal oxygen hydroxyl cluster, and polymerization precursor formed by two or more metal centers connected by hydroxyl bridges, oxygen bridges, or hydroxyl-oxygen mixed bridges; the polynuclear hydroxyl metal active species includes at least one of polynuclear hydroxyl iron species, polynuclear hydroxyl zirconium species, polynuclear hydroxyl titanium species, and manganese oxygen hydroxyl polymer species; the preparation method of the layered activation solution containing polynuclear hydroxyl metal active species is as follows: add the metal salt to water, adjust the pH to 2-9, and OH... - A layered activation solution containing polynuclear hydroxyl metal active species with a total metal concentration of 2-30 mg / L was obtained by using a molar ratio of 0.5-2.5 and a maturation time of 5-60 min. M represents Al. 3+ or Fe 3+ .

[0009] To further specify, the metal salt is at least one of ferric chloride, ferric sulfate, polyferric sulfate, polyferric chloride, and polyaluminum chloride.

[0010] Further specifying, the contact time in step one is 5-120 minutes.

[0011] Furthermore, the contact time is limited to 10-60 minutes.

[0012] Further defining the active sacrificial interface formed in step one as a continuous thin layer, a discontinuous island layer, a particle bridging layer, or a locally enriched layer at the membrane pore inlet; the active sacrificial interface carries pollutants through at least one of the following mechanisms: charge neutralization, electrostatic interaction, adsorption bridging, coordination, ligand exchange, hydrogen bonding, or interfacial hydration, in order to reduce direct contact between pollutants and the ceramic membrane surface and / or the membrane pore inlet region and to prevent deep pore blockage.

[0013] Further specifying, in step two, the water to be treated is at least one of the following: raw drinking water, eutrophic surface water, algae-containing water, reclaimed water, effluent from advanced domestic sewage treatment, and industrial wastewater; the pollutants are at least one of the following: algal cells, algal-derived organic matter, natural organic matter, proteins, polysaccharides, humic substances, colloidal particles, microplastics, phosphates, arsenates, fluoride ions, and other pollutants capable of electrostatic interactions, adsorption bridging, coordination, or ligand exchange with polynuclear hydroxyl metal active species; algal cells and algal-derived organic matter are only present in algae-containing water; during membrane filtration, the active sacrificial interface preferentially carries pollutants through at least one of the following mechanisms: charge neutralization, adsorption bridging, electrostatic interactions, coordination, ligand exchange, and interfacial hydration.

[0014] Further specifying, during the filtration process in step two, pollutants in the water to be treated preferentially undergo adsorption, binding, coordination, bridging, and / or deposition with the active sacrificial interface.

[0015] Further, the pre-set fouling conditions in step two are that the membrane specific flux (J / J0) is less than 0.55, the transmembrane pressure difference (TMP) is greater than 80 kPa, or the ratio of effluent DOC concentration to influent DOC concentration (C / C0) is greater than 0.8, where C is the effluent DOC concentration and C0 is the influent DOC concentration.

[0016] To further define this, the stripping in step two mainly targets the active sacrificial interface and the filter contaminants attached to it.

[0017] Further specifying, the stripping solution in step two includes a competing ligand, a pH adjuster, a soluble inorganic salt, and water; the concentration of the competing ligand in the stripping solution is 0.5-20 mmol / L, the concentration of the soluble inorganic salt is 10-200 mmol / L, and the pH of the stripping solution is adjusted to 2.0-6.5 by the pH adjuster; the competing ligand is at least one of citrate, tartrate, oxalate, gluconate, and lactate, the soluble inorganic salt is at least one of sodium chloride, sodium sulfate, sodium nitrate, and potassium chloride, and the pH adjuster is at least one of hydrochloric acid, sulfuric acid, nitric acid, sodium hydroxide, and potassium hydroxide.

[0018] Further specifying, the peeling time in step two is 5-120 minutes.

[0019] Furthermore, the stripping process in step two can be combined with at least one of low-pressure backwashing, pulsed flow rinsing, or air-water scrubbing to improve the efficiency of removing contaminated material from the active sacrificial interface.

[0020] Further specifying that in step two, the active sacrificial interface remains stable under normal membrane filtration conditions. After the addition of the stripping solution, the internal interaction of the active sacrificial interface and its interaction with the ceramic membrane surface and / or the membrane pore inlet region are weakened, causing partial or complete stripping of the active sacrificial interface. Moreover, the addition of the stripping solution reduces the layered metal loading of the active sacrificial interface.

[0021] Further specifying, in step two, at least one of the following is adjusted: pH of the stripping solution, ion concentration, and concentration of competing ligands, to cause decoordination, depolymerization, dissolution, and / or desorption at the active sacrificial interface.

[0022] A second objective of this invention is to provide an application of the above-mentioned water treatment method in the treatment of drinking water raw water, algae-containing eutrophic water bodies, surface water, reclaimed water, and industrial wastewater.

[0023] The beneficial effects of this invention are as follows: (1) This invention transforms the traditional passive pollution control mode of directly cleaning the ceramic membrane surface after pollution has formed into an active regulation mode of pre-constructing a renewable pollution interface and actively removing pollution. By constructing an active sacrificial interface in situ on the ceramic membrane surface and / or the membrane pore inlet area, the active sacrificial interface can alleviate the densification of the pollution layer through charge regulation, adsorption bridging, coordination exchange and interfacial hydration, and serve as a renewable buffer interface between pollutants and the ceramic membrane, so that pollutants preferentially accumulate, combine and deposit on the active sacrificial interface, reducing the direct contact between pollutants and the ceramic membrane substrate and the blockage of deep pores; after the preset pollution conditions are reached, without disassembling the membrane module, a stripping solution is introduced, and the active sacrificial interface and its carried pollutants are removed simultaneously through decoordination, depolymerization, dissolution, valence state regulation and / or hydraulic flushing, and a new active sacrificial interface is reconstructed online without disassembling the ceramic membrane unit, thus realizing a closed-loop operation of interface construction-pollution carrying-triggered stripping-online reconstruction.

[0024] (2) This invention constructs a temporary contaminant-bearing interface formed by polynuclear hydroxyl metal active species at the ceramic membrane filtration interface, so that contaminants preferentially bind to or deposit on this interface. After the preset contamination conditions are reached, the interface and contaminants are controllably stripped away by adjusting the pH of the stripping solution, introducing competitive ligands, adjusting the ionic strength, changing the redox state and / or applying hydraulic action. Then, a new active sacrificial interface is reconstructed by replenishing the layering activation solution online, thereby realizing the periodic renewal of the contaminant interface. By cyclically carrying out the interface construction-contaminant bearing-triggered stripping-online reconstruction process, the main membrane contaminants are transferred from the ceramic membrane body to the renewable active sacrificial interface, reducing irreversible membrane contamination, reducing the frequency of deep cleaning and the damage to the ceramic membrane structure and surface active sites during the cleaning process, and extending the stable operation cycle of the ceramic membrane.

[0025] (3) Some metal salts, such as aluminum or iron salts, can form polynuclear hydroxyl metal active species during hydrolysis and aging, which are connected by multiple metal centers through hydroxyl bridges and / or oxygen bridges. Compared with mononuclear ions or large-sized precipitate particles, the polynuclear hydroxyl metal active species of the present invention have higher local charge density, abundant hydroxyl coordination sites and multi-point bridging ability. They can coordinate, condense, electrostatically adsorb or multi-point bridge with hydroxyl groups, defect sites and metal centers on the ceramic membrane surface, and can further form a low-crystallinity metal oxygen hydroxyl polymer interface. Existing water treatment technologies mainly use metal salt hydrolysis products for aqueous phase coagulation, adsorption or formation of fixed functional coatings, and pay less attention to using polynuclear hydroxyl metal active species to form active sacrificial interfaces and perform online interface stripping and regeneration without disassembling the ceramic membrane filter components. This is suitable for membrane treatment of drinking water raw water, algae-containing eutrophic water bodies, surface water, reclaimed water and industrial wastewater.

[0026] (4) After the active sacrificial interface is stripped, the present invention can collect the layered metal components in the stripping solution. Through pH adjustment, solid-liquid separation, membrane concentration, ion exchange, adsorption separation, redox adjustment, or re-hydrolysis and polymerization treatment, a new layered activation solution containing polynuclear hydroxyl metal active species is prepared and reused for subsequent active sacrificial interface reconstruction, thereby reducing the consumption of layering agents and the discharge of metal residues. In addition, the present invention achieves process control of filtration-stripping-reloading by automatically switching triggered by transmembrane pressure difference, membrane flux, or effluent water quality. Attached Figure Description

[0027] Figure 1 Structural diagrams of mononuclear metal species and polynuclear hydroxyl metal active species of the present invention; Figure 2 The effects of ceramic membranes without an active sacrificial interface and polynuclear aluminum hydroxyl active sacrificial interface in Example 1 on membrane specific flux and membrane fouling resistance are shown in (a) specific flux and (b) membrane fouling resistance. Figure 3 The effect of ceramic membranes without an active sacrificial interface and polynuclear aluminum hydroxyl active sacrificial interface in Example 1 on DOC removal rate; Figure 4 This is a graph showing the change in the loading of polynuclear aluminum hydroxyl active species during the reconstruction of the active sacrificial interface in Example 1; Figure 5 This is a graph showing the membrane flux changes over four cycles in Example 1; Figure 6 The effects of ceramic membranes without active sacrificial interfaces and polynuclear hydroxyl iron active sacrificial interfaces in Example 2 on transmembrane pressure difference and membrane fouling resistance are shown in (a) and (b) respectively. Figure 7 This is a graph showing the change in the loading of polynuclear hydroxyl iron active species during the reconstruction of the active sacrificial interface in Example 2; Figure 8 This is a graph showing the change in transmembrane pressure difference over four cycles in Example 2. Detailed Implementation

[0028] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0029] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0030] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0031] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials, reagents, methods, and instruments used are all conventional materials, reagents, methods, and instruments in the art, and can be obtained commercially by those skilled in the art.

[0032] Example 1 Step 1: Construction of the polynuclear aluminum hydroxyl active sacrificial interface A ceramic membrane containing zirconium oxide and alumina components was used as the membrane substrate; polyaluminum chloride was added to water, and the pH was adjusted to 6, OH... - / Al 3+ A layered activation solution containing polynuclear aluminum hydroxyl active species was prepared with a molar ratio of 1.8 and a curing time of 30 min. The total aluminum concentration in the activation solution was 10 mg / L. The layered activation solution was used as the liquid to be filtered. The ceramic membrane was brought into contact with the layered activation solution for 30 min by filtration. This allowed the polynuclear aluminum hydroxyl active species to accumulate on the surface of the ceramic membrane and in the inlet region of the membrane pores, coordinate with Al, bridge, and further hydrolyze and polymerize, forming a polynuclear aluminum hydroxyl active sacrificial interface. Step 2: Filtration of algae-containing water, triggering of contamination status, and controlled stripping of active sacrificial interfaces. A ceramic membrane with a polynuclear aluminum hydroxyl active sacrificial interface was used for filtration of eutrophic water (containing algae). The membrane specific flux J / J0 was continuously recorded. When the membrane specific flux dropped to a preset threshold of 0.55, the control unit automatically shut off the normal water production path, stopped filtration, and switched to the stripping fluid supply path. Without disassembling the ceramic membrane module, the membrane surface was rinsed with deionized water. Then, the stripping fluid was introduced into the ceramic membrane filtration unit to strip the polynuclear aluminum hydroxyl active sacrificial interface. The stripping treatment time was 15 minutes. During the stripping process, the polynuclear aluminum hydroxyl active sacrificial interface, along with the algal cells, organic matter, colloidal particles, and other pollutants it carried, were simultaneously detached from the ceramic membrane surface. The stripping fluid in this step was prepared with 5 mmol / L sodium citrate, 50 mmol / L sodium chloride, and water, and the pH of the stripping fluid was adjusted to 4.5 with hydrochloric acid. The stripping process in this step can be further combined with at least one of low-pressure backwashing, pulse flow rinsing, or air-water scrubbing to improve the efficiency of removing contaminated surfaces from the active sacrificial interface. Step 3: Online Reconstruction of the Active Sacrifice Interface After the active sacrificial interface is stripped off, the control unit automatically switches to the stratification activation liquid supply channel. Without disassembling the ceramic membrane module, the stratification activation liquid containing polynuclear aluminum hydroxyl active species is reintroduced into the ceramic membrane filtration unit. The polynuclear aluminum hydroxyl active sacrificial interface is formed again according to the method in step one, and then the sewage filtration operation is restored. In this embodiment, four cycles were performed, consisting of filtration-fouling triggering-active sacrificial interface stripping-online reconstruction of the active sacrificial interface. In each cycle, the membrane flux recovery rate, reversible fouling resistance, irreversible fouling resistance, polynuclear aluminum hydroxyl loading on the membrane surface, stripping rate, and reloading recovery rate were tested to evaluate the repeatable construction performance of the active sacrificial interface and the long-term stability of the membrane filtration system.

[0033] Recovery and recycling of aluminum components in the stripping fluid in this embodiment: The stripping fluid from the active sacrificial interface process is collected, and its pH is adjusted to 3.0. Sodium hydroxide solution is added under stirring conditions to allow the OH groups to react. - The / Al molar ratio was adjusted to 1.8 and set to 300s. -1 Rapidly mix at a speed gradient for 2 minutes, then at a speed gradient of 80 seconds. -1 The mixture was slowly mixed at a gradient for 10 minutes. After mixing, the pH of the system was further adjusted to 4.5, and the mixture was allowed to stand for 60 minutes to allow the recovered aluminum components to undergo hydrolysis, hydroxyl bridging, and polymerization again, forming a regenerated layer activation solution containing polynuclear hydroxyl aluminum active species. The aluminum speciation of the obtained regenerated layer activation solution was analyzed by Ferron time-wise complexometric colorimetry, and the total aluminum concentration was determined by ICP-OES. After adjusting the total aluminum concentration to the set level with deionized water as needed, the solution was used again for the construction of active sacrificial interfaces on the ceramic membrane surface.

[0034] Figure 2 This section describes the impact of a ceramic membrane without an active sacrificial interface on membrane specific flux and membrane fouling resistance during step two of the filtration process in this embodiment. During filtration, the polynuclear aluminum hydroxyl active species, with their high local positive charge density, abundant hydroxyl coordination sites, and multi-point bridging ability, preferentially enrich, adsorb, coordinate, and deposit pollutants such as algal cells, algal-derived organic matter, colloidal particles, and phosphates at the active sacrificial interface. This reduces direct contact between pollutants and the ceramic membrane filtration interface, as well as their migration into the membrane pores, thus reducing deep pore clogging and irreversible fouling. Figure 2As shown in (a), compared to the ceramic membrane without a polynuclear aluminum hydroxyl active sacrificial interface, the rate of decrease in membrane specific flux during the filtration process is significantly slowed after constructing the active sacrificial interface. Compared to the specific flux of 0.17 for direct filtration without an active sacrificial interface, the specific flux of Example 1 with an active sacrificial interface is increased to 0.56. This indicates that the constructed active sacrificial interface can preferentially carry pollutants such as algal cells, algal-derived organic matter, and colloidal particles, reducing direct contact between pollutants and the ceramic membrane surface and the membrane pore inlet area, thereby mitigating membrane pore clogging and fouling layer compaction. Figure 2 As shown in (b), compared with ceramic membranes without a polynuclear aluminum hydroxyl active sacrificial interface, the total fouling resistance of the membrane was reduced by more than 44% after constructing the active sacrificial interface, with reversible fouling resistance and irreversible fouling resistance reduced by more than 46% and 19%, respectively. Figure 3 As can be seen, after constructing the polynuclear hydroxyaluminum active sacrificial interface in Example 1, the DOC removal rate was increased by more than 74% compared with the control group ceramic membrane without the active aluminum sacrificial layer. These results indicate that the polynuclear hydroxyaluminum active sacrificial interface can effectively improve the pollutant carrying behavior during the ceramic membrane filtration process, reduce membrane fouling resistance, and simultaneously enhance the removal capacity of dissolved organic matter.

[0035] Figure 4 This diagram shows the change in polynuclear aluminum hydroxyl loading during the first reconstruction of the active sacrificial interface in this embodiment. It can be seen that the initial aluminum loading on the ceramic membrane surface is low. After the polynuclear aluminum hydroxyl active species layering treatment, the polynuclear aluminum hydroxyl loading on the membrane surface increases significantly, indicating that the active sacrificial interface can be effectively constructed on the ceramic membrane surface. The construction amount at this point is used as a baseline of 1.0. After the peeling treatment, the polynuclear aluminum hydroxyl loading on the membrane surface decreases significantly to 0.18, indicating that the constructed polynuclear aluminum hydroxyl active sacrificial interface can be selectively removed from the membrane surface. Subsequently, after re-introducing the layering activation solution containing polynuclear aluminum hydroxyl active species for online reconstruction, the polynuclear aluminum hydroxyl loading on the membrane surface increases to 0.91, recovering to a level close to that after the initial construction, indicating that the active sacrificial interface has good peelability and online reconstruction capability. These results further demonstrate that polynuclear aluminum hydroxyl active species can achieve a reversible cycle of construction-peeling-reconstruction at the ceramic membrane filtration interface, providing a foundation for subsequent multi-cycle online regeneration operation.

[0036] Figure 5This diagram shows the membrane flux changes over four filtration cycles in this embodiment. It can be seen that the specific flux gradually decreases with increasing filtration time in each filtration cycle, indicating that pollutants continuously accumulate and deposit on the active sacrificial interface. When the specific flux drops to a preset trigger threshold of 0.55, the system stops normal filtration and sequentially performs active sacrificial interface stripping and online reconstruction. After regeneration, the specific flux significantly recovers to a high level, and then proceeds to the next filtration cycle. With increasing cycle count, the initial specific flux after regeneration in each cycle shows a slight decrease (0.9 in cycle 4), but overall it maintains good recovery capability, indicating that the polynuclear aluminum hydroxyl active sacrificial interface can repeatedly function during multiple contaminant loading-stripping-reconstruction processes. The membrane flux change trend shows good repeatability across four consecutive cycles, indicating that the active sacrificial interface has good repeatable construction capability and online regeneration stability, and can mitigate the continuous accumulation of irreversible membrane fouling during long-term operation.

[0037] Example 2 The difference between this embodiment and Embodiment 1 is that: in step one, a ceramic film containing manganese oxide and aluminum oxide on its surface is used as the film substrate; the activation solution is prepared using polyferric chloride; and the pH is adjusted to 4. - / Fe 3+ The molar ratio was adjusted to 1.5, and the maturation time was 60 min to obtain a layered activation solution containing polynuclear hydroxy iron active species with a total Fe concentration of 10 mg / L. This allowed the polynuclear hydroxy iron active species to accumulate, coordinate, bridge, and further hydrolyze and polymerize on the ceramic membrane surface and inlet region of the membrane pores. A polynuclear hydroxy iron active sacrificial interface was formed through Fe-O-Mn bonds, hydroxyl bridging, electrostatic interactions, and multi-point coordination. This interface was used to treat organic wastewater in step two, and the transmembrane pressure difference was continuously recorded. The signal for the active sacrificial interface stripping in step three was when the transmembrane pressure difference increased to 80 kPa. The remaining process operations and parameter settings were the same as in Example 1.

[0038] Figure 6 The influence of the ceramic membrane without an active sacrificial interface on membrane flux and membrane fouling resistance during step two of the filtration process in this embodiment. For example... Figure 6 As shown in (a), under the same filtration conditions, the transmembrane pressure difference of both groups of membranes gradually increased with the extension of filtration time. However, after constructing the polynuclear hydroxyl iron active sacrificial interface, the rate of increase of the transmembrane pressure difference slowed down significantly. The transmembrane pressure difference of the control group increased rapidly, reaching 80.0 kPa after 40 min of filtration, while the experimental group with the polynuclear hydroxyl iron active sacrificial interface only increased to 48.3 kPa, which was about 39.6% lower than the control group. The results indicate that the polynuclear hydroxyl iron active sacrificial interface can effectively slow down the formation and compaction of the fouling layer during filtration, and reduce the increase in filtration resistance caused by the deposition of organic matter, colloids, and sulfonamide pollutants. Figure 6As shown in (b), the reversible fouling resistance was reduced by 41% and the irreversible fouling resistance by approximately 31% after constructing the polynuclear hydroxyl iron active sacrificial interface. The total fouling resistance was reduced by 40%. This indicates that the polynuclear hydroxyl iron active sacrificial interface can not only reduce the accumulation of pollutants on the ceramic membrane surface, but also reduce the migration of pollutants to the membrane pore inlet and the interior of the membrane pores, thereby simultaneously mitigating both reversible and irreversible fouling.

[0039] Figure 7 This diagram shows the change in the loading of polynuclear hydroxyl iron (PHI) active species during the first reconstruction of the active sacrificial interface in this embodiment. It can be seen that the initial relative iron content on the ceramic membrane surface was low, only 0.12. After the stratification treatment with PHI active species, the relative loading of PHI on the membrane surface increased significantly, normalizing the initial loading to 1.00. This indicates that PHI active species can effectively accumulate on the surface of the manganese oxide ceramic membrane and / or inlet region of the membrane pores, forming an active sacrificial interface. After the stripping treatment, the relative loading of PHI on the membrane surface decreased to 0.25, a 75% reduction compared to the initial state, indicating that the constructed PHI active sacrificial interface can effectively detach from the ceramic membrane filtration interface under preset regeneration conditions. Subsequently, after re-introducing the stratification activation solution containing PHI active species for online reconstruction, the relative loading of PHI on the membrane surface recovered to 0.88, reaching 88% of the initial state. This indicates that after undergoing one contamination loading and stripping process, PHI active species can still re-accumulate on the surface of the manganese oxide ceramic membrane and form a new active sacrificial interface.

[0040] Figure 8This diagram shows the transmembrane pressure difference changes over four filtration cycles in this embodiment. It can be seen that within each filtration cycle, as organic pollutants and colloidal particles gradually accumulate and deposit on the polynuclear hydroxyl iron active sacrificial interface, the transmembrane pressure difference gradually increases with the extension of filtration time. Our designed trigger threshold is 80 kPa for the transmembrane pressure difference or 40 min for the filtration time. Clearly, in the initial few cycles, the transmembrane pressure difference is consistently less than 80 kPa. Therefore, after reaching the 40 min filtration time, the system stops normal filtration and sequentially performs active sacrificial interface stripping and online reconstruction. After regeneration, the transmembrane pressure difference significantly decreases and recovers to near its initial level at the start of the next filtration cycle, indicating that the stripping and reconstruction process effectively releases the membrane fouling resistance. From the four consecutive cycles, it can be seen that the transmembrane pressure difference in each cycle exhibits a relatively consistent pattern of gradual increase – triggering regeneration – significant decrease – and then increase again, indicating that the polynuclear hydroxyl iron active sacrificial interface can repeatedly play a role in multiple fouling loading, stripping, and reconstruction processes. As the number of cycles increases, the transmembrane pressure difference at the end of subsequent cycles increases to some extent, but the overall periodic recovery characteristics are still good, indicating that the active sacrificial interface has good repeatable construction ability and online regeneration stability, and can slow down the continuous accumulation of irreversible fouling on the surface of manganese oxide ceramic membrane.

[0041] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A water treatment method based on online stripping and reconstruction of active sacrificial interfaces, characterized in that, The method includes the following steps: Step 1: Prepare a layered activation solution containing polynuclear hydroxyl metal active species. Use the layered activation solution as the liquid to be filtered. Filter the ceramic membrane to contact the layered activation solution to form a polynuclear hydroxyl metal active sacrificial interface. Step 2: Wastewater filtration, contamination state triggering, and active sacrificial interface stripping: The pollutants in the wastewater are filtered. When the preset pollution conditions are reached, the filtration is stopped, and a stripping liquid is introduced into the ceramic membrane filtration unit to strip the polynuclear hydroxyl metal active sacrificial interface. Step 3: Online reconstruction of the active sacrifice interface: After the active sacrificial interface is peeled off, there is no need to disassemble the ceramic membrane assembly. The layered activation solution containing polynuclear hydroxyl metal active species is introduced into the ceramic membrane filtration unit again to re-form the polynuclear hydroxyl metal active sacrificial interface, and then the filtration operation is resumed. Step 4: Repeat steps 2 to 3 1-10 times to complete the water treatment process based on ceramic membrane fouling control and online regeneration of the active sacrificial interface.

2. The water treatment method according to claim 1, characterized in that, In step one, the ceramic membrane composition includes at least one of alumina, zirconium oxide, yttrium-doped zirconium oxide, titanium oxide, manganese oxide, and silicon carbide. The ceramic membrane configuration is planar, tubular, hollow fiber, or multi-channel. The pore size of the ceramic membrane is 2nm-10μm, and the contact time is 5-120min.

3. The water treatment method according to claim 1, characterized in that, In step one, the polynuclear hydroxyl metal active species are formed by two or more metal centers connected by hydroxyl bridges, oxygen bridges or hydroxyl-oxygen mixed bridges.

4. The water treatment method according to claim 1, characterized in that, The preparation method of the layering activation solution containing polynuclear hydroxyl metal active species is as follows: add metal salt to water, adjust the pH to 2-9, and add OH... - A layered activation solution containing polynuclear hydroxyl metal active species with a total metal concentration of 2-30 mg / L was obtained by using a molar ratio of 0.5-2.5 and a maturation time of 5-60 min. M represents Al. 3+ or Fe 3+ .

5. The water treatment method according to claim 4, characterized in that, The metal salt is at least one of ferric chloride, ferric sulfate, polyferric sulfate, polyferric chloride, and polyaluminum chloride.

6. The water treatment method according to claim 1, characterized in that, In step two, the water to be treated is at least one of the following: raw drinking water, eutrophic surface water, algae-containing water, reclaimed water, effluent from deep treatment of domestic sewage, and industrial wastewater.

7. The water treatment method according to claim 1, characterized in that, In step two, the preset fouling conditions are: membrane flux ratio below 0.55, transmembrane pressure difference greater than 80 kPa, or the ratio of effluent DOC concentration to influent DOC concentration greater than 0.8, and the stripping time is 5-120 min.

8. The water treatment method according to claim 1, characterized in that, In step two, the stripping solution includes competitive ligands, pH adjusters, soluble inorganic salts, and water. The concentration of competitive ligands in the stripping solution is 0.5-20 mmol / L, the concentration of soluble inorganic salts is 10-200 mmol / L, and the pH of the stripping solution is 2.0-6.

5.

9. The water treatment method according to claim 8, characterized in that, The competing ligand is at least one of citrate, tartrate, oxalate, gluconate, and lactate; the soluble inorganic salt is at least one of sodium chloride, sodium sulfate, sodium nitrate, and potassium chloride; and the pH adjuster is at least one of hydrochloric acid, sulfuric acid, nitric acid, sodium hydroxide, and potassium hydroxide.

10. The application of the water treatment method according to any one of claims 1-9 in the treatment of drinking water raw water, algae-containing eutrophic water bodies, surface water, reclaimed water and industrial wastewater.

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