Hydrodynamic and pollutant dual response type nanoremediation material and application thereof

Abstract

The application discloses a kind of water power and pollutant dual response type nano repair materials and its application;Nano repair material has core-shell-outer layer structure, core provides repair function;Inner shell layer can perceive and respond target pollutant concentration, regulate active release;Outer shell layer can respond groundwater flow rate (shear force), regulate particle migration behavior.Nano repair material of the application can realize "low pollution area stable migration, high pollution area efficient activation", solve the problem of short migration distance of traditional nano repair material, non-target consumption fast, especially suitable for repairing complex groundwater flow affected organic pollution plume.The simultaneously provided repair method and repair system realize the controllability and intelligentization of repair process.

Description

Technical Field

[0001] This invention relates to the field of environmental pollution remediation technology, specifically to a hydrodynamic and pollutant-responsive nanomaterial for remediation and its applications. Background Technology

[0002] Remediation of organic contamination in groundwater is a global challenge. Traditional remediation technologies, such as extraction treatment and permeable reactive barriers (PRBs), have significant limitations: extraction treatment is costly and prone to tailing; stationary PRBs are unable to capture the entire contamination plume, and are prone to failure, especially when the contamination source and groundwater flow direction change.

[0003] In recent years, injectable nano-zero valent iron (nZVI) and other migratory remediation materials have attracted attention. However, the migration distance of existing nanomaterials in actual aquifers is limited, mainly due to: aggregation and deposition: nanoparticles are easily deactivated rapidly in porous media due to aggregation and filtration; non-targeted consumption: materials are non-selectively consumed by background substances (such as dissolved oxygen and natural organic matter) along the migration path, and their activity is greatly reduced by the time they reach the core pollution area; mismatch between behavior and demand: the migration and release behavior of materials is pre-set and passive, and cannot dynamically respond to changes in groundwater flow rate and the spatial heterogeneity of pollutant distribution.

[0004] Therefore, there is an urgent need to develop a nanomaterial and its delivery system that can intelligently sense the environment, adaptively regulate its own state, and thus achieve long-distance migration and targeted release of active substances in groundwater. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides a method that can alter the surface properties and reactivity of remediation materials based on groundwater flow dynamics (velocity) and pollutant signals (concentration). This allows the materials to remain stable in low-pollution / low-velocity areas to facilitate migration, while being efficiently activated in high-pollution areas to enhance remediation, thereby significantly improving remediation efficiency and material utilization.

[0006] In a first aspect, the present invention provides a hydrodynamic and pollutant-responsive nano-remediation material, wherein the nano-remediation material has a three-layer structure consisting of a core, an inner shell, and an outer shell arranged from the inside out. The core material is a remediation material used to degrade or fix pollutants in water. The inner shell is a pollutant concentration-responsive polymer layer that undergoes conformational changes by specifically binding with target pollutants in polluted water, and the conformational changes are used to change the degree of core exposure. The outer shell is a hydrodynamically responsive polymer layer composed of an amphiphilic block copolymer, the conformation or bulk density of which reversibly changes with the magnitude of the fluid shear force in the polluted water body.

[0007] The core has a particle size of 50-200nm, the inner shell has a thickness of 5-20nm, and the outer shell has a thickness of 5-50nm.

[0008] Explanation: The remediation material with the above-described structure can simultaneously respond to two environmental signals: hydrodynamic conditions and pollutant concentration. This allows it to intelligently regulate its behavior and function. The hydrodynamic response characteristics of the outer shell enable the material to adaptively adjust its migration and diffusion based on conditions such as formation water flow velocity, ensuring efficient transport to the contaminated area. The pollutant concentration response characteristics of the inner shell only expose the core through conformational changes when pollutant concentrations exceed standards, achieving precise and on-demand remediation. This dual-response mechanism works synergistically, fundamentally solving the problems of poor targeting, low utilization, and easy secondary migration of traditional remediation materials in complex underground environments, significantly improving the efficiency, economy, and environmental friendliness of the remediation process.

[0009] Furthermore, the repair material is a reduction reaction material, an oxidation reaction material, or an adsorption reaction material; The reduction reaction material is zero-valent iron or bimetallic particles; the oxidation reaction material is metal oxide of activated persulfate; and the adsorption reaction material is biochar or activated carbon.

[0010] Note: The diverse selection of core materials in the above method enables this nano-remediation platform to flexibly adapt to pollutants of different properties (such as chlorinated hydrocarbons, aromatic hydrocarbons, heavy metals, etc.), ensuring the reliability and practicality of the material in real complex aquatic environments.

[0011] Furthermore, the pollutant concentration-responsive polymer layer is a polymer having functional groups that interact with the target pollutant. The polymer is selected from one of temperature-sensitive polymers, pH-sensitive polymers, and redox-sensitive polymers. The functional groups include at least one of long-chain alkyl groups, halogen recognition groups, or π-π interaction groups.

[0012] Explanation: The above method uses temperature-sensitive, pH-sensitive, or redox-sensitive polymers as the inner shell matrix, enabling the material to keenly sense changes in key physicochemical parameters (temperature, pH, or redox potential) of polluted water. This allows for the initial identification of the environmental characteristics of pollution. By grafting functional groups (such as long-chain alkyl groups, halogen recognition groups, or π-π interaction groups) specifically binding to the target pollutants onto the polymer chain, conformational changes in the inner shell are precisely triggered only under real pollution scenarios. This avoids ineffective exposure and loss in clean or non-target polluted areas, significantly improving the targeting, selectivity, and material utilization efficiency of remediation efforts. By introducing specific functional groups such as long-chain alkyl groups, halogen recognition groups, and π-π interaction groups, the nanomaterials are endowed with precise molecular-level recognition and selective response capabilities. These groups can efficiently and specifically capture corresponding target pollutants (such as nonpolar organic pollutants, halogenated organics, or aromatic compounds) in the water through intermolecular forces such as hydrophobic interactions, halogen bonds, or aromatic stacking, improving the targeting of the remediation process and reducing ineffective losses and secondary impacts.

[0013] Furthermore, the amphiphilic block copolymer is at least one of Pluronic series copolymers, polyethylene glycol-polyacrylic acid block copolymers, or polyacrylamide derivatives.

[0014] Explanation: The above-mentioned method utilizes amphiphilic block copolymers with specific rheological responses (such as the Pluronic series and PEG-PAA). The molecular chain structure of these copolymers allows them to sense changes in external fluid shear forces. In low-shear-force regions (such as the edge of a contamination plume or low-permeability areas), their molecular chains remain extended or orderly packed, increasing material volume and friction, promoting retention and enrichment in the target area. In high-shear-force regions (such as mainstream channels), their conformation undergoes reversible changes (such as hydrophobic segment curling and changes in packing density), significantly reducing fluid resistance and enabling rapid, deep transport of the material with the water flow. This intelligent rheological response characteristic of "moving smoothly with fast flow and stopping when encountering slow flow" resolves the contradiction between "effective migration" and "target area retention" that traditional nanomaterials struggle to achieve in groundwater remediation, thus ensuring that the remediation agent can efficiently cover and act on various areas of heterogeneous contaminated sites.

[0015] Furthermore, the pollutant concentration-responsive polymer layer is a thermosensitive polymer; the amphiphilic block copolymer is Pluronic F127.

[0016] Secondly, the present invention also provides a method for preparing a hydrodynamic and pollutant-responsive nano-remediation material, comprising the following steps: S1. Prepare the core; select one of the following as the core: nano zero-valent iron, Fe / Pd bimetallic particles, cobalt ferrite nanoparticles, or biochar. S2. Preparation of the inner shell layer: A temperature-sensitive polymer is grafted onto the core surface using atom transfer radical polymerization. The temperature-sensitive polymer is obtained by copolymerizing N-isopropylacrylamide and a target pollutant recognition monomer at a temperature of 60-80°C. The target pollutant recognition monomer includes acrylamide derivatives containing long-chain alkyl or halogen recognition groups for chlorinated hydrocarbon pollutants, or pH-responsive or redox-responsive monomers containing π-π interaction groups for aromatic hydrocarbon pollutants. The molar ratio of N-isopropylacrylamide to the target pollutant recognition monomer ranges from 1 to 10:1. S3. Preparation of the outer shell layer: Immerse the product obtained in S2 in 1-5 wt% Pluronic F127 solution, stir at 25-40℃ for 2-4 hours, and after centrifugation and washing, obtain the nano-repair material.

[0017] Explanation: The above method utilizes a precise surface grafting technique—atom transfer radical polymerization—to firmly construct an inner shell layer with controllable thickness and composition on the core. The specific molar ratio (1~10:1) of N-isopropylacrylamide to the recognition monomer directly modulates the material's response threshold to pollutant concentrations. Simultaneously, the outer shell layer is formed through a gentle self-assembly process using Pluronic F127 solution, ensuring reliable hydrodynamic response. This preparation method guarantees a tight bond and structural integrity among the core, inner shell, and outer shell layers, and also provides the material with reproducible stability, thus laying a solid foundation for large-scale production and practical engineering applications.

[0018] Furthermore, the core is an Fe / Pd bimetallic particle; the preparation method of the Fe / Pd bimetallic particle includes: In an inert atmosphere, ferrous sulfate is reduced with sodium borohydride to generate nano-zero valent iron. Then, chloropalladium acid is loaded onto the surface of the nano-zero valent iron by displacement at a loading of 0.5-5 wt%, to obtain Fe / Pd bimetallic particles.

[0019] Note: The above method prepares nano-zero-valent iron by reduction with sodium borohydride under an inert atmosphere, effectively ensuring the high reactivity of the core. Subsequently, by precisely controlling the palladium loading, highly efficient catalytic sites are constructed on the iron surface, which not only significantly improves the reduction and dechlorination efficiency and selectivity for pollutants such as chlorinated hydrocarbons, but also maximizes catalytic activity with minimal precious metal usage. This method is mature and has well-defined parameters, providing a reliable and economical technical solution for preparing high-performance, scalable core materials.

[0020] Furthermore, the molar ratio of N-isopropylacrylamide to the pollutant identification monomer is adjusted according to the target pollutant threshold. When the concentration of the target pollutant in the polluted water exceeds the target pollutant threshold, the target pollutant undergoes a hydrophilic-hydrophobic transition with the temperature-sensitive polymer chain, and the inner shell changes from a dense state to a swollen and porous state, exposing the core.

[0021] Explanation: The above method, by adjusting the molar ratio of N-isopropylacrylamide to the recognition monomer, can directly set the pollutant concentration threshold at which the inner shell undergoes a hydrophilic-hydrophobic transition. This allows the material to be configured according to the actual needs of different pollution scenarios (such as lightly polluted areas or heavily polluted hotspots), ensuring that its remediation function is activated only above the preset critical pollution concentration, thereby transforming the inner shell from a dense state to a swollen porous state, exposing the core. This method not only avoids unnecessary material consumption and potential side effects in low-concentration environments but also achieves on-demand and precise release of remediation resources, significantly improving the economy, safety, and environmental adaptability of the remediation process.

[0022] Thirdly, the application of a hydrodynamic and pollutant-responsive nano-remediation material is carried out through a nano-remediation material-based remediation system; the remediation system includes: an injection module, an in-situ monitoring module, and an intelligent control module. The injection module is used to inject the nanocomposite material into groundwater; The in-situ monitoring module is used to monitor the hydrodynamic parameters of groundwater, pollutant concentration, and the distribution and state of the nanocomposite material in real time. The intelligent control module, based on the monitoring data from the in-situ monitoring module, dynamically optimizes the injection rate, pulse frequency, and concentration of the nanocomposite material by coupling the groundwater flow model and the pollutant migration and response model.

[0023] The repair method includes: Identify the target pollutants in the contaminated area to be remediated; Based on the target pollutant, the material of the inner shell is determined and the nano-repair material is prepared; The nano-remediation material is injected into the groundwater of the contaminated area through the remediation system until the remediation is completed.

[0024] Description: The remediation system described above deeply integrates remediation materials with real-time monitoring and dynamic control, achieving a leap from extensive application to precise dynamic control in groundwater remediation. Through the in-situ monitoring module, changes in the groundwater flow field and contaminant plume are fed back in real time, while the intelligent control module dynamically optimizes the injection strategy of nanomaterials, maximizing the dual hydrodynamic and contaminant response characteristics of the materials. This method not only significantly improves the targeting, efficiency, and material utilization of remediation but also achieves adaptive optimization and visualized management of the remediation process, providing a complete integrated solution for the efficient and economical remediation of complex, heterogeneous sites.

[0025] The beneficial effects of this invention are: This invention, through the combination of a core-shell-outer layer triple structure design and an intelligent response system, produces multiple significant beneficial effects. The outer shell senses and responds to changes in groundwater flow velocity, intelligently adjusting its conformation to allow the material to accumulate and remain in low-shear regions (such as the edge of a pollution plume) and migrate smoothly in high-shear channels, thus solving the problems of short migration distances and uneven distribution of traditional nanomaterials in strata. Secondly, the inner shell can accurately identify the concentration of target pollutants, triggering conformational changes and exposing the remediation core only in pollution hotspots, achieving "on-demand remediation" and avoiding ineffective consumption and secondary risks in clean areas. Finally, the accompanying remediation system, through real-time monitoring and dynamic control, forms a closed loop of perception-decision-response, optimizing the material's dual-response characteristics. This synergistic innovation ultimately achieves highly efficient targeted remediation, precise and controllable release, and long-term stable effects on organic pollution plumes in complex heterogeneous aquifers, significantly improving remediation efficiency, material utilization, and environmental safety. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the "core-shell-outer layer" structure and mechanism of the dual-response nano-repair material according to an embodiment of the present invention; Figure 2 This is an overall architecture diagram of the intelligent targeted delivery and repair system according to an embodiment of the present invention; Figure 3 This is a schematic diagram illustrating the behavior of the nano-repair material in low-pollution and high-pollution areas according to an embodiment of the present invention; Figure 4 This is a graph comparing the repair effects of Embodiment 1 of the present invention with those of traditional nZVI. Detailed Implementation

[0027] To further illustrate the methods and effects of this invention, the technical solution of this invention will be clearly and completely described below in conjunction with experiments.

[0028] Example 1: A hydrodynamic and pollutant-responsive nanoremediation material, wherein the nanoremediation material has a three-layer structure from the inside out: core-inner shell-outer shell, as shown in the figure. Figure 1 As shown; The core material is a remediation material used to degrade or fix pollutants in water. The inner shell is a pollutant concentration-responsive polymer layer that undergoes conformational changes by specifically binding with target pollutants in polluted water, and the conformational changes are used to change the degree of core exposure. The outer shell is a hydrodynamically responsive polymer layer composed of an amphiphilic block copolymer, the conformation or bulk density of which reversibly changes with the magnitude of the fluid shear force of the polluted water body.

[0029] Specifically, the repair material is a reduction reaction material, an oxidation reaction material, or an adsorption reaction material; the reduction reaction material is zero-valent iron or bimetallic particles; the oxidation reaction material is a metal oxide of activated persulfate; the adsorption reaction material is biochar or activated carbon; the particle size of the core is 50-200 nm, the thickness of the inner shell is 5-20 nm, and the thickness of the outer shell is 5-50 nm.

[0030] The pollutant concentration-responsive polymer layer is a polymer having functional groups that interact with the target pollutant. The polymer is selected from thermosensitive polymers, pH-sensitive polymers, and redox-sensitive polymers. The functional groups include at least one of long-chain alkyl groups, halogen recognition groups, or π-π interacting groups. For example, the thermosensitive polymer can be a copolymer of a thermosensitive N-isopropylacrylamide monomer and a target pollutant recognition monomer ("p-chlorophenylacrylamide," which has specific recognition capabilities for chlorinated hydrocarbons); or a copolymer of a pH-sensitive methacrylic acid monomer and a target pollutant recognition monomer ("pyrene methacrylate," which has specific recognition capabilities for aromatic hydrocarbons); or a copolymer of a redox-sensitive bis(2-methacryloyloxyethyl) disulfide monomer and a target pollutant recognition monomer ("p-chlorophenylacrylamide," which has specific recognition capabilities for chlorinated hydrocarbons).

[0031] Specifically, for the target pollutant chlorinated hydrocarbons, thermosensitive polymers containing long-chain alkyl groups and halogen recognition groups (such as poly(N-isopropylacrylamide-co-octylphenylacrylamide)) are used. The pollutants can enter the polymer network through hydrophobic interactions and specific binding, changing its local microenvironment and triggering polymer conformational changes. For the target pollutant aromatic hydrocarbons, pH / redox responsive polymers containing π-π interaction groups are used.

[0032] The amphiphilic block copolymer is at least one of Pluronic series copolymers, polyethylene glycol-polyacrylic acid block copolymers, or polyacrylamide derivatives. For example, a block copolymer of polyethylene glycol (PEG) and polyacrylic acid (PAA) has a response mechanism where hydrophobic anchoring groups are attached to its ends: at low groundwater flow rates, the outer polymer layer exhibits an extended conformation, providing steric hindrance and hydrophilicity, inhibiting interparticle aggregation and adsorption on the medium surface, and promoting migration. When the groundwater flow rate increases (e.g., near injection wells, in high-permeability channels), the fluid shear force increases, forcing the outer polymer chain to deform and temporarily compress, exposing some hydrophobic regions in the inner layer, making it easier for it to be captured and come into contact with contaminants at specific locations (e.g., low-flow-rate contaminant retention zones).

[0033] In this embodiment of the invention, the pollutant concentration-responsive polymer layer is a temperature-sensitive polymer; the amphiphilic block copolymer is Pluronic F127 from the Pluronic series of copolymers; This invention also provides a method for preparing the above-mentioned hydrodynamic and pollutant-responsive nano-remediation material, including the following steps S1 to S3; The molecular formula of Pluronic F127 is: HO(CH2CH2O) 100 -(CH(CH3)CH2O) 65 -(CH2CH2O )100 H; S1. Prepare the core; select Fe / Pd bimetallic particles as the core; In this embodiment of the invention, the method for preparing the above-mentioned Fe / Pd bimetallic particles includes: In an inert atmosphere (nitrogen), ferrous sulfate was reduced with sodium borohydride to generate nano-zero valent iron. Then, chloropalladic acid was loaded onto the surface of the nano-zero valent iron by displacement at a loading of 2 wt% to obtain Fe / Pd bimetallic particles. For example, an aqueous solution of ferrous sulfate is prepared in a reaction vessel. Under a nitrogen-protected environment, a sodium borohydride solution is slowly added dropwise using a peristaltic pump. High-speed mechanical stirring (approximately 800 rpm) is used to prevent particle agglomeration until a black suspension appears in the solution, which is nano-zero-valent iron (nZVI). The chemical reaction equation (for nZVI formation) is: Alternatively, in some embodiments, commercially available nano-zero-valent iron products can be directly selected; Fe 0The / Pd bimetallic particles (i.e., the Fe / Pd bimetallic particles mentioned in the text) were prepared by liquid-phase reduction to prepare nano-zero-valent iron (nZVI), followed by a substitution reaction to support a palladium (Pd) catalyst. The specific steps were: under nitrogen protection, sodium borohydride (… The solution was added dropwise to ferrous sulfate ( In the solution, stir vigorously; Palladium treatment: After nZVI is generated, chloropalladium acid is added ( ) solution, using The reducing properties are deposited on the particle surface. The chemical reaction equation (Pd loading) is as follows: Ultimately, a Fe / Pd bimetallic core with a particle size of approximately 100 nm is formed; Palladium catalyst support: After iron nuclei are generated, a measured amount of chloropalladic acid solution is added to the reactor. Utilizing the reducing property of iron, palladium ions are reduced and deposited on the surface of the iron particles, forming "spotted" palladium catalytic islands. Final form: After magnetic separation and washing with oxygen-free water, a Fe / Pd bimetallic particle slurry with an average particle size of about 100 nm was obtained.

[0034] S2. Prepare the inner shell layer; graft a temperature-sensitive polymer onto the core surface using atom transfer radical polymerization, wherein the temperature-sensitive polymer is obtained by copolymerizing N-isopropylacrylamide and a target pollutant recognition monomer at a temperature of 60-80°C. The target pollutant recognition monomers include acrylamide derivatives containing long-chain alkyl or halogen recognition groups for chlorinated pollutants, or pH-responsive or redox-responsive monomers containing π-π interaction groups for aromatic pollutants. The molar ratio of N-isopropylacrylamide to the target pollutant identification monomer ranges from 1 to 10:1. Specifically, for chlorinated hydrocarbon pollutants, a molar ratio of 5:1 is more suitable; for aromatic hydrocarbon pollutants, a molar ratio of 10:1 is more suitable; in this embodiment, it is specifically 5:1. The molar ratio of N-isopropylacrylamide and pollutant identification monomer is adjusted according to the target pollutant threshold. When the concentration of the target pollutant in the polluted water exceeds the target pollutant threshold (e.g., vinyl chloride concentration of 1 mg / L), the target pollutant undergoes a hydrophilic-hydrophobic transition with the temperature-sensitive polymer chain, and the inner shell changes from a dense state to a swollen and porous state, exposing the core.

[0035] For example, the monomers selected are thermosensitive "N-isopropylacrylamide" and "p-chlorophenylacrylamide" which have specific recognition ability for chlorinated hydrocarbons as comonomers; graft polymerization: the above polymer chains are chemically grafted onto the surface of Fe / Pd particles using atom transfer radical polymerization (ATRP) process. The schematic formula for the polymerization reaction is as follows: Response mechanism: When the concentration of vinyl chloride in the environment... At this time, vinyl chloride molecules penetrate into the polymer network through hydrophobic interactions, disrupting the hydrogen bonds between polymer chains, causing the polymer chains to curl and collapse, thereby exposing the internal Fe / Pd core.

[0036] Response settings: By adjusting the ratio of the two monomers, the trigger threshold of the "switch" is set to a vinyl chloride concentration of 1 mg / L. That is, when the surrounding vinyl chloride concentration is higher than this value, the polymer layer will shrink (volume collapse) due to enhanced hydrophobicity, exposing the internal Fe / Pd active sites.

[0037] S3. Preparation of the outer shell layer: The product obtained in S2 is immersed in a 2 wt% Pluronic F127 solution, stirred at 30°C for 3 hours, and then centrifuged and washed to obtain the nano-repair material.

[0038] The amphiphilic block copolymer Pluronic F127 was modified onto the outermost layer of the particles using physical adsorption. Molecular formula structure: Among them, the hydrophilic PEO segment provides steric hindrance, while the hydrophobic PPO segment provides anchoring. Shear force response mechanism: Let the fluid shear rate be... The polymer brush thickness is .when At lower levels (far from the injection well). (The polymer chain is long), which manifests as long-range steric hindrance, preventing aggregation; when At higher levels (near the injection point), shear forces cause the polymer chains to tilt and compress. The reduction exposes the inner hydrophobic region, which is beneficial for migration control in heterogeneous media.

[0039] Physical modification: The prepared core-shell particles are immersed in a Pluronic F127 solution. Through electrostatic adsorption and hydrophobic anchoring, the Pluronic F127 molecular chains coat the outermost layer of the particles like "tentacles." Rheological properties: In the high-velocity (high-shear-force) environment near the injection well, these "tentacles" will bend and compress along the water flow direction, reducing resistance; in the low-velocity environment at the far end, the "tentacles" naturally extend, increasing the opportunity for contact with the soil medium.

[0040] In summary, the hydrodynamic and pollutant-responsive nanomaterials and their intelligent delivery system provided by this invention achieve multi-dimensional innovation from material design to remediation strategy. By responding to hydrodynamic conditions through the outer shell, the nanomaterials intelligently adjust their conformation, enabling them to accumulate and reside in low-shear regions and migrate smoothly in high-velocity regions, overcoming the bottlenecks of traditional nanomaterials' short migration distances and uneven distribution in complex strata. Secondly, the inner shell achieves precise targeted remediation by specifically identifying pollutant concentrations, triggering core exposure and activation only in polluted hotspots, significantly improving the accuracy of remediation and material utilization, while reducing ineffective consumption and secondary environmental risks. Furthermore, the selected highly efficient reduction, oxidation, or adsorption cores (such as Fe / Pd bimetallic materials, activated persulfate systems, etc.) can be fully activated in the target area, thereby significantly improving remediation efficiency and thoroughness.

[0041] This invention also provides an application of a hydrodynamic and pollutant-responsive nano-remediation material, which is used for remediation through a nano-remediation material-based remediation system; such as... Figure 2 As shown, the repair system includes: an injection module, an in-situ monitoring module, and an intelligent control module; The injection module is used to receive instructions (the instructions are received through a standardized industrial control and communication interface) and inject the nanocomposite material into the groundwater; Specifically, it includes: a high-pressure injection pump and a dispersion device (ultrasonic or mechanical stirring) for injecting material slurry (concentration 1-10 g / L) into an injection well at a predetermined depth.

[0042] The in-situ monitoring module is used to monitor the hydrodynamic parameters of groundwater, pollutant concentration, and the distribution and state of the nanocomposite material in real time. Specifically, this includes: Groundwater dynamic sensors: real-time monitoring of water level, flow velocity, and flow direction; Online pollutant sensors: monitoring the concentration of target organic matter and degradation intermediates; and Material tracer and state monitoring units: incorporating trace amounts of non-interfering fluorescent and magnetic tracers (such as quantum dots and superparamagnetic iron oxide) into materials to determine the distribution and retention state of the materials in the aquifer using downhole monitoring equipment.

[0043] The intelligent control module, based on the monitoring data from the in-situ monitoring module, dynamically optimizes the injection rate, pulse frequency, and concentration of the nanocomposite material by coupling a groundwater flow model and a pollutant migration and reaction model. Specifically, the intelligent control module incorporates a control algorithm coupled with the groundwater flow and reaction migration model (implemented through secondary development or customized interfaces of open-source groundwater simulation platforms such as MODFLOW / MT3DMS and FEFLOW). This algorithm can dynamically optimize based on the real-time flow field and pollutant plume morphology (using optimization algorithms such as genetic algorithms and particle swarm optimization for forward simulation to quickly evaluate the future remediation effect under different injection strategies such as rate, frequency, and concentration, thereby searching for and recommending the current optimal injection scheme). Injection strategies include injection rate, pulse frequency, and material concentration, designed to match groundwater flow velocity and create a favorable migration path. It also includes activator-assisted injection strategies: when a large amount of material has reached the contaminated area but the degradation rate is insufficient, decisions are made regarding whether to inject slow-release persulfate, electron donors, etc., to "awaken" and enhance the material's activity.

[0044] For example, injection wells: Three injection wells are deployed at the upstream edge of the contamination plume, spaced 5-10 meters apart, to create an injection cross-section covering the entire width of the contamination. Monitoring wells: Nine monitoring wells are deployed downstream in a "fan-shaped" pattern along the groundwater flow direction, divided into near-, mid-, and far-field monitoring zones, to comprehensively capture the migration path of the material and the remediation effect. Injection module: Equipped with a high-pressure injection pump and an ultrasonic disperser, ensuring that the material enters the ground in a uniform slurry form (concentration 5 g / L) without pipe blockage. Sensing module: Multi-parameter sensors are installed in the monitoring wells to transmit water level (flow field data), ORP / pH (reaction environment data), and fluorescence signals (used to track the location of nanomaterials labeled with fluorescent tracers) in real time.

[0045] The repair method using the above-described repair system in this embodiment of the invention includes: 1) Obtain the target pollutants in the contaminated area to be remediated; 2) Based on the target pollutant, determine the material of the inner shell and prepare the nano-repair material; 3) The nano-remediation material is injected into the groundwater of the contaminated area through the remediation system until the remediation is completed.

[0046] The specific implementation steps include the following ①~⑤: ① Site survey and model building: An initial groundwater flow and pollutant migration model is established through investigation, and the locations of injection wells and monitoring wells are determined.

[0047] ② Material preparation and injection: Custom-synthesize dual-response nanomaterials according to the characteristics of the target pollutant (hydrophobicity, degradation mechanism); inject them into the aquifer according to the optimized strategy.

[0048] ③ Intelligent migration and targeted repair; like Figure 3 As shown, the material migrates first under the influence of injection-driven and natural water flow. In clean and low-contamination areas, the outer responsive layer maintains the material's dispersed migration; the inner responsive layer remains dense, protecting the core activity.

[0049] Secondly, when the material enters a highly polluted area, pollutant molecules trigger the swelling / dissociation of the inner response layer, exposing the core active material and initiating efficient degradation and adsorption of pollutants. Simultaneously, the heterogeneity of the pollutant medium in this area often leads to localized flow velocity variations, and the synergistic effect of the outer response layer helps the material to remain appropriately retained in this region.

[0050] ④ Monitoring Feedback and Adaptive Control: The monitoring network tracks the remediation process in real time. The intelligent control module analyzes the data and, if it finds that the material migration is too fast and insufficient reaction has occurred, causing the remediation of the contaminated core area to stagnate, it adjusts the subsequent injection parameters (such as reducing the flow rate to promote retention and injecting an activator).

[0051] ⑤ Long-term repair and ecological restoration: Some materials can be designed as slow-release materials (such as slow dissolution of core-shell structures) to provide long-term repair capabilities.

[0052] Specifically, the operation process and principle of the above-mentioned repair method include the following stages one through four; Phase 1: High-speed advance (targeted delivery); Operation: The repair system controls the injection pump to inject nano-repair materials at a high flow rate (approximately twice the flow rate of natural groundwater).

[0053] Principle: The high shear force generated by high flow velocity forces the F127 (Pluronic F127) polymer chains on the outer layer of the nano-remediation material to compress. At this point, the material is in a "stealthy / low-resistance" state, enabling it to penetrate the pores of uncontaminated soil and avoid being adsorbed by the soil and consumed by non-target substances before reaching the contaminated core area. Reactive solute transport control equations are used to predict material transport patterns. ) and pollutants ( Spatiotemporal distribution in aquifers: in, Concentration vector (including material concentration) and pollutant concentration ); Let be the hydrodynamic dispersion coefficient tensor; This is the groundwater flow velocity vector (corrected in real time by a hydrodynamic sensor). This is a reaction term, and in this invention, it is a nonlinear dynamic term.

[0054] Phase Two: Deceleration Lock (Activated in Place); Triggering conditions: When the downstream monitoring well reports "enhanced fluorescence signal" (remediation material has arrived) and "vinyl chloride concentration is high" (reaching the core of the contamination).

[0055] Intelligent control: The system automatically issues commands to reduce the pressure and flow rate of the injection pump.

[0056] The microscopic changes at this time are (1) ~ (2): (1) Physical locking: The flow rate decreases, the outer polymer chains stretch, and the remediation material is more easily trapped by the soil in the contaminated area and no longer drifts downstream.

[0057] (2) Chemical activation: Due to the high concentration of vinyl chloride in this area (>1 mg / L), the inner polymer senses the target pollutant signal and automatically shrinks, exposing the iron / palladium core, which then begins a highly efficient dechlorination reaction of vinyl chloride. When the material reaches the highly polluted area and is activated, the Fe / Pd system in the core catalytically hydrogenates and dechlorinates vinyl chloride (VC). The anodic reaction is (iron corrosion provides electrons): ; The cathode reaction is (hydrolysis to produce adsorbed hydrogen): ; The main dechlorination reaction is (ethylene chloride reduced to ethylene): ; Overall reaction equation: This process converts highly toxic vinyl chloride into non-toxic ethylene and chloride ions.

[0058] Phase 3: Synergistic Enhancement (Activity Awakening); Monitoring and Judgment: If the system detects that the remediation material has accumulated in the contaminated area, but the degradation rate of pollutants begins to slow down (it may be due to the formation of an oxide layer on the iron surface leading to passivation). Intervention procedure: The system automatically switches the injection mode and injects a low concentration of citric acid solution in a pulsed manner.

[0059] Function: Citric acid, as a mild activator, can wash away the oxide "rust layer" on the surface of iron particles, reawakening the material's reactivity without the need for additional expensive nanomaterials.

[0060] Phase Four: Long-Term Final Steps; Procedure: After the main pollutant plume has been removed, inject a small amount of slow-release persulfate material into the site.

[0061] Objective: To utilize the slow oxidation capacity of persulfate to treat residual trace pollutants and degradation intermediates in soil micropores, ensuring long-term site compliance.

[0062] This invention constructs a systematic and intelligent remediation scheme integrating materials, monitoring, and control. Through in-situ monitoring and dynamic feedback control, it achieves observability, optimization, and controllability of the remediation process, making it particularly suitable for groundwater sites with complex and variable hydrological and pollution conditions. Furthermore, the material system can utilize environmentally friendly polymer monomers, possessing good environmental compatibility and contributing to the development of green remediation technologies. Overall, this invention represents a leap from "passive application" to "intelligent response" of remediation materials and from "experience-driven" to "data-driven" remediation processes, providing an innovative solution for efficient, precise, and sustainable groundwater remediation.

[0063] The implementation results of this embodiment are shown in Figure 4. Compared with traditional technologies, this embodiment, with the same amount of material, achieves improvements in specific technical indicators (migration distance and repair effect) through the aforementioned "fast-forward, slow-stop, on-demand activation" strategy. The effective migration distance is extended by 3 times, solving the problem that traditional nano-iron cannot penetrate or travel far. The repair speed target time is shortened by 50% because the material is concentrated in the core pollution area to generate activity, rather than being wasted during the repair process. No obvious material agglomeration and blockage were found in the monitoring well, proving that the outer hydrodynamic response design has operational stability.

[0064] Example 2: The difference from Example 1 is that in this example, nano-zero-valent iron is used as the core, the target pollutant is a pH-responsive or redox-responsive monomer containing π-π interaction groups targeting the aromatic hydrocarbon pollutant, such as 4-vinylbenzoic acid or a copolymer derivative of 2-(diethylamino)ethyl acrylate and styrene, and the outer shell is poly(acrylamide-co-acrylic acid). The preparation parameters are also different: in S2, the molar ratio of N-isopropylacrylamide to the pollutant recognition monomer is 1:1; the copolymerization temperature is 60-80℃; in S3, the product obtained in S2 is immersed in a 1 wt% poly(acrylamide-co-acrylic acid) solution, stirred at 25℃ for 4 hours, and after centrifugation and washing, the nano-repair material is obtained.

[0065] Example 3: The difference from Example 1 is that in this example, cobalt ferrite nanoparticles are used as the core, the target pollutant is a redox-responsive monomer containing π-π interaction groups targeting the aromatic hydrocarbon pollutant, such as vinyl ferrocene, and the outer shell is poly(acrylamide-co-acrylic acid). The preparation parameters are also different: in S2, the molar ratio of N-isopropylacrylamide to the pollutant recognition monomer is 10:1; the copolymerization temperature is 60-80℃; in S3, the product obtained in S2 is immersed in a 5 wt% poly(acrylamide-co-acrylic acid) solution, stirred at 40℃ for 2 hours, and after centrifugation and washing, the nano-repair material is obtained.

[0066] Example 4: The difference from Example 1 is that biochar is used as the core in this example.

Claims

1. A hydrodynamic and pollutant-responsive nanomaterial for remediation, characterized in that, The nano-repair material has a three-layer structure consisting of a core, an inner shell, and an outer shell arranged from the inside out. The core material is a remediation material used to degrade or fix pollutants in water. The inner shell is a pollutant concentration-responsive polymer layer that undergoes conformational changes by specifically binding with target pollutants in polluted water, and the conformational changes are used to change the degree of core exposure. The outer shell is a hydrodynamically responsive polymer layer composed of an amphiphilic block copolymer, wherein the conformation or bulk density of the hydrodynamically responsive polymer layer changes reversibly with the magnitude of the fluid shear force of the polluted water body. The core has a particle size of 50-200nm, the inner shell has a thickness of 5-20nm, and the outer shell has a thickness of 5-50nm.

2. The hydrodynamic and pollutant-responsive nanoremediation material as described in claim 1, characterized in that, The repair material is a reduction reaction material, an oxidation reaction material, or an adsorption reaction material; The reduction reaction material is zero-valent iron or bimetallic particles; the oxidation reaction material is metal oxide of activated persulfate; and the adsorption reaction material is biochar or activated carbon.

3. The hydrodynamic and pollutant-responsive nano-remediation material as described in claim 2, characterized in that, The pollutant concentration-responsive polymer layer is a polymer having functional groups that interact with the target pollutant. The polymer is selected from one of temperature-sensitive polymers, pH-sensitive polymers, and redox-sensitive polymers. The functional groups include at least one of long-chain alkyl groups, halogen recognition groups, or π-π interaction groups.

4. The hydrodynamic and pollutant-responsive nano-remediation material as described in claim 3, characterized in that, The amphiphilic block copolymer is at least one of Pluronic series copolymers, polyethylene glycol-polyacrylic acid block copolymers, or polyacrylamide derivatives.

5. The hydrodynamic and pollutant-responsive nanoremediation material as described in claim 4, characterized in that, The pollutant concentration-responsive polymer layer is a thermosensitive polymer; the amphiphilic block copolymer is Pluronic F127.

6. The preparation method of a hydrodynamic and pollutant-responsive nano-remediation material as described in claim 5, characterized in that, Includes the following steps: S1. Prepare the core; select one of the following as the core: nano zero-valent iron, Fe / Pd bimetallic particles, cobalt ferrite nanoparticles, or biochar. S2. Preparation of the inner shell layer: A temperature-sensitive polymer is grafted onto the core surface using atom transfer radical polymerization. The temperature-sensitive polymer is obtained by copolymerizing N-isopropylacrylamide and a target pollutant recognition monomer at a temperature of 60-80°C. The target pollutant recognition monomer includes acrylamide derivatives containing long-chain alkyl or halogen recognition groups for chlorinated hydrocarbon pollutants, or pH-responsive or redox-responsive monomers containing π-π interaction groups for aromatic hydrocarbon pollutants. The molar ratio of N-isopropylacrylamide to the target pollutant recognition monomer ranges from 1 to 10:

1. S3. Preparation of the outer shell layer: Immerse the product obtained in S2 in 1-5 wt% Pluronic F127 solution, stir at 25-40℃ for 2-4 hours, and after centrifugation and washing, obtain the nano-repair material.

7. The preparation method of a hydrodynamic and pollutant-responsive nano-remediation material as described in claim 6, characterized in that, The core is an Fe / Pd bimetallic particle; the preparation method of the Fe / Pd bimetallic particle includes: In an inert atmosphere, ferrous sulfate is reduced with sodium borohydride to generate nano-zero valent iron. Then, chloropalladium acid is loaded onto the surface of the nano-zero valent iron by displacement at a loading of 0.5-5 wt%, to obtain Fe / Pd bimetallic particles.

8. The preparation method of a hydrodynamic and pollutant-responsive nano-remediation material as described in claim 6, characterized in that, The molar ratio of N-isopropylacrylamide to the pollutant identification monomer is adjusted according to the target pollutant threshold. When the concentration of the target pollutant in the polluted water exceeds the target pollutant threshold, the target pollutant undergoes a hydrophilic-hydrophobic transition with the temperature-sensitive polymer chain, and the inner shell changes from a dense state to a swollen and porous state, exposing the core.

9. The application of the hydrodynamic and pollutant-responsive nano-remediation material as described in claim 1, characterized in that, Repair is performed using a repair system based on nano-repair materials; the repair system includes: an injection module, an in-situ monitoring module, and an intelligent control module; The injection module is used to inject the nanocomposite material into groundwater; The in-situ monitoring module is used to monitor the hydrodynamic parameters of groundwater, pollutant concentration, and the distribution and state of the nanocomposite material in real time. The intelligent control module, based on the monitoring data from the in-situ monitoring module, dynamically optimizes the injection rate, pulse frequency, and concentration of the nanocomposite material by coupling the groundwater flow model and the pollutant migration and response model.

10. The application as described in claim 9, characterized in that, The repair method includes: Identify the target pollutants in the contaminated area to be remediated; Based on the target pollutant, the material of the inner shell is determined and the nano-repair material is prepared; The nano-remediation material is injected into the groundwater of the contaminated area through the remediation system until the remediation is completed.

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