Bottom mud targeted recycling system and intelligent regulation and control method

Abstract

The invention discloses a bottom mud targeted recycling system and an intelligent regulation and control method. An anode chamber of a bioelectrochemical pretreatment unit of the system is filled with bottom mud slurry, and an anode is a modified carbon felt electrode; the cathode chamber is filled with an acidic solution containing iron ions, and the cathode is a Fe-Mn co-doped biochar electrode; the top of the ultrasonic-microwave gradient mineralization unit is provided with a high-frequency microwave transmitter, an ultrasonic transmitter and an automatic jet device with a built-in charcoal catalyst, and the bottom of the ultrasonic-microwave gradient mineralization unit is provided with a cyclone separator for separating bottom mud and solid residues and discharging the bottom mud and the solid residues; the intelligent decision center predicts the product performance and energy consumption of a conversion path, formulates a network by adopting a quality classification strategy, formulates the quality classification strategy in combination with real-time economic indexes, and shunts the bottom mud and the solid residues to different conversion subsystems according to density and magnetic difference to execute conversion; and the feedback control unit feeds back the heavy metal content and the CO2 concentration fluctuation to the intelligent decision center. According to the invention, bottom mud pollution treatment, directional conversion and high-added-value product co-production are realized.

Description

Technical Field

[0001] This invention relates to the fields of environmental engineering and resource recycling, and in particular to a targeted resource utilization system for sediment and an intelligent control method. Background Technology

[0002] With the acceleration of industrialization and urbanization, the problem of water body sediment pollution is becoming increasingly serious. As the main accumulation carrier of pollutants in water bodies, sediment contains a large amount of heavy metals (such as chromium, copper, lead, arsenic, and cadmium), persistent organic matter (such as polycyclic aromatic hydrocarbons and benzo(a)pyrene), pathogenic microorganisms, and sulfides, among other complex components. Untreated sediment not only causes continuous harm to the aquatic ecosystem through pollutant resuspension and release, but may also threaten human health through bioaccumulation in the food chain, and even lead to soil and groundwater pollution. Therefore, the harmless treatment and resource utilization of sediment has become an important issue for environmental governance and sustainable development.

[0003] Currently, sediment treatment mainly adopts a linear process of dewatering-solidification-building material utilization, but existing technologies have significant limitations: (1) Single treatment methods are difficult to achieve efficient removal and high-value transformation of pollutants simultaneously. For example, conventional biological treatment technology can degrade some organic matter, but its stabilization effect on heavy metals is limited, and the residual heavy metals still pose a risk of leaching under long-term environmental changes; although chemical solidification technology can fix pollutants with agents, the agent residue may cause secondary pollution, and the mechanical properties of the solidified body are insufficient, making it difficult to meet the needs of high-end building materials.

[0004] (2) Traditional processes are fragmented, such as dehydration, solidification and resource recovery, which lead to energy consumption (e.g., high energy consumption of mechanical dehydration and additional heating required for solidification) and secondary pollution risks (e.g., iron sludge pollution after the use of Fenton reagent).

[0005] (3) Resource-based products are mostly limited to low-value-added building materials (such as roadbed fill or low-strength bricks), whose market value is difficult to cover the processing cost, resulting in insufficient economic benefits and seriously restricting the large-scale application of the technology.

[0006] (4) Existing technologies lack the ability to dynamically perceive and intelligently regulate the composition of sediment, and cannot optimize the treatment path according to the type, concentration and occurrence of pollutants, resulting in low resource recovery efficiency, high carbon emissions, and difficulty in dealing with complex and variable sediment components.

[0007] The aforementioned problems highlight the shortcomings of existing technologies in terms of systemicity, economy, and sustainability. Overcoming the technological bottlenecks in the synergistic process of "harmlessness-resource utilization," constructing a low-energy-consumption, multi-product, and intelligent sediment treatment system, and achieving targeted conversion of pollutants and co-production of high-value-added products have become key challenges urgently needing to be addressed in the field of environmental engineering. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention proposes a targeted resource utilization system and intelligent regulation method for sediment. Through bioelectrochemical enhancement, gradient mineralization, and intelligent regulation technologies, it achieves sediment pollution control and high-value resource utilization, breaking through the traditional single treatment mode and forming a closed-loop system for directional transformation of pollutants and multi-product co-production.

[0009] The specific technical solution is as follows: A sediment-targeted resource recovery system includes: a bioelectrochemical pretreatment unit, an ultrasonic-microwave gradient mineralization unit, and an intelligent fractional conversion module; the bioelectrochemical pretreatment unit includes a dual-chamber microbial fuel cell, wherein the anode chamber and the cathode chamber are separated by a proton exchange membrane, the anode chamber is filled with sediment slurry, and a modified carbon felt electrode is used as the anode; the cathode chamber is filled with an acidic solution containing iron ions, and an Fe-Mn co-doped biochar electrode is used as the cathode; The ultrasonic-microwave gradient mineralization unit includes a hollow container that does not react with the bottom mud slurry. Its internal cavity is a multi-frequency coupled reaction chamber, with a mud inlet at the top connected to the bottom mud slurry outlet of the anode chamber. A high-frequency microwave transmitter is arranged at the center of the top of the hollow container, and multiple ultrasonic transmitters are arranged symmetrically in a ring around its outer periphery. An automatic spraying device is arranged at the top of the inner wall for spraying Fe3O4@biochar catalyst. A cyclone separator is installed at the bottom outlet of the hollow container to separate the gases, bottom mud, and solid residues generated during mineralization, which are then discharged through different outlets. A cooling device is installed around the outer periphery of the multi-frequency coupled reaction chamber. The intelligent fractional conversion module includes: an online detection unit, an intelligent decision-making center, multiple conversion subsystems, and a feedback control unit. The online detection unit collects the chemical composition, physical properties, and process parameters of the sediment output from the ultrasonic-microwave gradient mineralization unit, generates a high-dimensional feature matrix, and inputs it into the intelligent decision-making center. The intelligent decision-making center predicts the product performance and energy consumption of the conversion path based on a digital twin model, and formulates a fractional strategy using a fractional strategy combined with real-time economic indicators. Based on the fractional strategy, the sediment and solid residue are diverted to different conversion subsystems according to their density and magnetic differences, correspondingly converting them into high-value-added products. The feedback control unit detects whether the heavy metal content exceeds the standard. If so, it feeds back to the intelligent decision-making center, which, based on the type of heavy metal exceeding the standard, adds corresponding solidification raw materials to the multi-frequency coupled reaction chamber to generate stable minerals. The feedback control unit also adjusts the mineralization pressure of the ultrasonic-microwave gradient mineralization unit according to CO2 concentration fluctuations, ensuring that the standard deviation of the cementitious material strength is less than a specified threshold, and that the remaining sediment is treated according to the optimal economic path.

[0010] Furthermore, the anode surface is treated with nitric acid oxidation and polyaniline coating, and the charge transfer resistance is reduced by embedding nano-zero-valent iron particles; the cathode is made of Fe3O4-MnO2 heterojunction supported by high-temperature calcination of rice husk biochar, which has both catalytic activity and heavy metal adsorption capacity. A peristaltic pump is arranged in the anode chamber to promote the circulation of bottom mud slurry within the anode chamber.

[0011] Furthermore, the sensing data of the dual-chamber microbial fuel cell includes: pH value, redox potential and voltage of the anode chamber; the parameters of the bioelectrochemical pretreatment unit are adjusted accordingly, including: sediment slurry concentration, pH value of the anode chamber, iron ion concentration in the cathode chamber solution, and hydraulic retention time. The sensing data of the multi-frequency coupled reaction chamber includes: hydroxyl radical concentration, chamber temperature, and chamber pressure; based on the sensing data of the multi-frequency coupled reaction chamber and the feedback information of the feedback control unit, the parameters of the ultrasonic-microwave gradient mineralization unit are adjusted, including: microwave power of the high-frequency microwave transmitter, ultrasonic power density of the ultrasonic transmitter, cooling water flow rate, and biochar catalyst dosage.

[0012] Furthermore, the inner wall of the hollow container is provided with a polytetrafluoroethylene anti-corrosion layer; the cooling device includes a hollow partition opened inside the outer wall of the hollow container; cooling water enters from the bottom of the hollow partition and exits from the top; the flow rate of the cooling water is controlled by a control terminal.

[0013] Furthermore, the intelligent decision-making center includes a perception layer, a decision layer, and an execution layer; the perception layer is used to receive the high-dimensional feature matrix output by the online monitoring unit. The decision-making layer is equipped with a quality-based strategy formulation network, which is based on the synergistic effect of convolutional neural networks and reinforcement learning. The convolutional neural network is used to extract spectral spatial features and generate feature vectors f that characterize the occurrence form and resource utilization potential of pollutants through dimensionality reduction by pooling layers. The reinforcement learning is used to dynamically optimize resource allocation weights. It uses the feature vector f as the state space, combines real-time economic indicators to construct a dynamic decision-making model, and outputs policy instructions. The action space of the reinforcement learning includes branch path selection and process parameter adjustment. The dynamic decision-making model designs a reward function with the goal of improving economic efficiency and reducing carbon emissions, and reinforcement learning maximizes the cumulative reward through a proximal policy optimization algorithm.

[0014] Furthermore, the intelligent fractional conversion module employs pneumatic and electromagnetic separation as its diversion methods, and dynamically adjusts the resource allocation weight coefficient based on real-time carbon prices to optimize the objective functions of economic benefits and carbon emissions.

[0015] Furthermore, the conversion subsystem includes: a carbonate mineralization subsystem, a lithium iron phosphate precursor synthesis subsystem, and a supercritical water gasification hydrogen production subsystem; The carbonate mineralization subsystem is used to convert high-silicon aluminum components into carbonate mineralized cementitious materials, the lithium iron phosphate precursor synthesis subsystem is used to convert phosphorus-rich components into lithium iron phosphate precursors, and the supercritical water gasification hydrogen production subsystem is used to convert organic residues into hydrogen.

[0016] A smart control method for a sediment-targeted resource recovery system, implemented based on the aforementioned sediment-targeted resource recovery system, includes the following steps: S1: The sediment slurry to be treated enters the bioelectrochemical pretreatment unit, where electrical energy is generated and heavy metal passivation is achieved, reducing the heavy metal content in the sediment. S2: The pretreated sediment enters the ultrasonic-microwave gradient mineralization unit, producing gas and mineralization residue; the control end adjusts the microwave power and frequency of the high-frequency microwave transmitter and the ultrasonic power and frequency of the ultrasonic transmitter according to the feedback of hydroxyl radical concentration to achieve gradient mineralization in stages. S3: The sediment and mineralized residue treated by the ultrasonic-microwave gradient mineralization unit enter the intelligent fractionation and conversion module together. They are divided according to density and magnetic properties and input into different subsystems to be converted into different high-value-added products.

[0017] Furthermore, in S1, in the bioelectrochemical pretreatment unit, the anode decomposes organic matter in the sediment through microbial catalysis, releasing electrons and protons to form an open-circuit voltage and generate electrical energy; After electrons are transferred to the cathode through the external circuit, they drive the reduction reaction between iron ions and heavy metals. The reduced heavy metals are adsorbed by the cathode and react with sediment sulfides to form stable minerals, thereby achieving heavy metal passivation and reducing the heavy metal content in the sediment.

[0018] Furthermore, in S2, gradient mineralization is achieved in the following three stages: Phase 1: Ultrasonic-driven, used to break up colloidal agglomerates in bottom sediment; the power of the ultrasonic transmitter is 75-85% of its rated power, and the frequency is 20kHz; the duration of this phase is 8-12 minutes. Phase Two: Microwave-driven, high-frequency microwaves are used to target and excite the Fe-O bonds in Fe3O4@biochar, inducing local plasma resonance and driving a Fenton-like reaction to achieve deep oxidation of organic matter and deep solidification of heavy metal minerals; the power of the high-frequency microwave transmitter is 65-75% of its rated power, and the frequency is 5.8 GHz; the duration of this phase is 18-22 minutes. Phase 3: Maintain the power of the high-frequency microwave transmitter at 65%~75% of its rated power, reduce the frequency to 2.45GHz, and gradually heat the bottom mud slurry to the set temperature range to promote the formation of aluminosilicate framework and ensure mineral phase stability; this phase lasts for 8~12 minutes.

[0019] The beneficial effects of this invention are: (1) Bio-electrochemical simultaneous treatment technology: The dual-chamber microbial fuel cell coupled modified anode and Fe-Mn co-doped cathode realizes simultaneous degradation of organic matter and power generation, while stabilizing heavy metals, thus achieving pollution control and energy recovery.

[0020] (2) Gradient mineralization in stages: The multi-frequency coupled reaction chamber of the ultrasonic-microwave gradient mineralization unit mineralizes in three stages, breaking up colloids, driving Fenton-like reactions and reconstructing the mineral skeleton, which reduces energy consumption and solid waste.

[0021] (3) Intelligent separation and resource conversion: Based on the separation strategy, a network and multimodal sensing are formulated to dynamically optimize the separation path of sediment, and the different components in the sediment are accurately converted into high value-added products, which greatly improves economic benefits.

[0022] (4) Adaptive intelligent control: The intelligent decision-making center works with the feedback control unit to adjust process parameters (such as catalyst dosage) in real time, reducing carbon emissions during resource utilization and realizing a closed loop of directional conversion of pollutants and co-production of resources. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the sediment-targeted resource recovery system in an embodiment of the present invention.

[0024] Figure 2 This is a schematic diagram of the intelligent fractional conversion module in an embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram of the structure of the ultrasonic-microwave gradient mineralization unit in an embodiment of the present invention.

[0026] Figure 4 This is a flowchart of the intelligent control method for the sediment-targeted resource utilization system in this embodiment of the invention.

[0027] Figure 5 This is a flowchart of the ultrasonic-microwave gradient mineralization unit in an embodiment of the present invention.

[0028] Figure 6 This is a flowchart of the intelligent fractional conversion module in an embodiment of the present invention.

[0029] In the diagram, the components are: bioelectrochemical pretreatment unit 1, anode chamber 1-1, cathode chamber 1-2, proton exchange membrane 1-3, anode 1-4, cathode 1-5, peristaltic pump 1-6; ultrasonic-microwave gradient mineralization unit 2, hollow container 2-1, ultrasonic transmitter 2-2, high-frequency microwave transmitter 2-3, automatic spraying device 2-4, cyclone separator 2-5, hollow partition 2-6, electron paramagnetic resonance (EPR) probe 2-7; and intelligent fractionation conversion module 3. Detailed Implementation

[0030] The present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. The objectives and effects of the present invention will become clearer as a result. The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0031] like Figure 1 As shown, a sediment-targeted resource utilization system includes: a bioelectrochemical pretreatment unit 1, an ultrasonic-microwave gradient mineralization unit 2, and an intelligent fractional conversion module 3.

[0032] The bioelectrochemical pretreatment unit 1 is based on a dual-chamber microbial fuel cell (MFC). The dual-chamber MFC includes: anode chamber 1-1, cathode chamber 1-2, anode 1-4, cathode 1-5, peristaltic pump 1-6, and online monitoring module. The anode chamber 1-1 and cathode chamber 1-2 are separated by a proton exchange membrane (PEM) 1-3.

[0033] The anode chamber 1-1 is filled with bottom mud slurry (hereinafter referred to as mud) with a high water content (85%-90%). A modified carbon felt electrode is used as the anode 1-4. The surface of this electrode is treated with nitric acid oxidation and polyaniline coating, and has a specific surface area ≥1500 m². 2 / g, and by embedding nano-zero valent iron (nZVI) particles (particle size 50-100nm), the charge transfer resistance is reduced by 70%. Further, the slurry is fed into the anode chamber 1-1 through a feed pump from the slurry inlet at the top, and after bioelectrochemical pretreatment, it is pumped out from the slurry outlet at the bottom of the anode chamber 1-1. During stable operation of the pretreatment unit, the average residence time of the bottom slurry in the reactor (i.e., anode chamber 1-1), i.e., the hydraulic residence time (HRT), is adjusted by controlling the feed pump, thereby controlling the treatment efficiency. Further, a spare first dosing port is also provided on the upper side wall of the anode chamber 1-1, and the required chemical solution can be fed into the anode chamber 1-1 through the first dosing port via a dosing pump.

[0034] Peristaltic pump 1-6 is arranged in anode chamber 1-1. Under the action of peristaltic pump 1-6, the slurry is promoted to circulate in anode chamber 1-1 (flow rate 0.5-1.0L / min), which avoids solid deposition and enhances the mass transfer process.

[0035] Fe-containing materials are injected into cathode chambers 1-2 3+ An acidic solution (pH=3.0-3.5) was prepared, and a Fe-Mn co-doped biochar electrode was used as the cathode 1-5. This electrode was made by high-temperature calcination of rice husk biochar and loading it with a Fe3O4-MnO2 heterojunction, which has both catalytic activity and heavy metal adsorption capacity (Cr(VI) adsorption capacity 180mg / g, Cu(II) 220mg / g). Furthermore, a second dosing port was provided at the upper end of the side wall of the cathode chamber 1-2, and the required chemical solution could be introduced into the cathode chamber 1-2 through the second dosing port by a dosing pump.

[0036] The online monitoring module integrates a pH sensor, an oxidation-reduction potential (ORP) sensor, and a voltage sensor, all electrically connected to the control terminal for real-time data transmission and control. pH and ORP sensors are installed in the liquids of both the anode and cathode chambers to monitor the independent chemical environments within each chamber. The voltage sensor is mounted on the external circuitry to measure the overall power generation performance of the battery system. All sensor data is aggregated at the control terminal, enabling intelligent control of key parameters such as bottom mud slurry concentration, anode chamber pH, cathode chamber iron ion concentration, and hydraulic retention time.

[0037] A pH sensor located in the anode chamber is used to directly monitor the pH of the bottom sediment slurry. Optimal activity of electrogenic microorganisms (such as Geobacter) typically requires a near-neutral pH environment (approximately 6.5-7.5). Monitoring the anode pH ensures microbial activity and prevents pH degradation due to organic acid accumulation, which could inhibit the reaction. A pH sensor located in the cathode chamber is used to monitor the pH of the iron-containing acidic solution. Fenton-like reactions and heavy metal reduction reactions in the cathode chamber are more efficient under acidic conditions (pH = 3.0-3.5), and real-time monitoring is essential to ensure the pH remains stable within the optimal range.

[0038] An ORP sensor, positioned in the anode chamber, monitors the redox state of the sediment. The ORP value reflects the metabolic activity of microorganisms in the sediment and its anaerobic or aerobic state. A sufficiently low ORP (negative value) typically indicates a strong reducing environment, which is conducive to anaerobic microbial electricity generation and the reduction and fixation of certain heavy metals. An ORP sensor, positioned in the cathode chamber, monitors the redox potential of the catholyte. The ORP value directly reflects the iron ion cycle (Fe) within the cathode chamber. 3+ or Fe 2 +The progress and intensity of the reduction reaction of heavy metals (such as Cr(VI)) are key indicators for judging the efficiency of the cathode reaction.

[0039] A voltage sensor is connected to the external circuit between the anode and cathode to measure the output voltage or closed-circuit voltage generated by the microbial fuel cell. Voltage is the most direct indicator for assessing the operating status of the entire bioelectrochemical system. The stability and magnitude of the voltage reflect the degradation rate of organic matter, electron transfer efficiency, and the internal resistance of the system. A drop in voltage may indicate electrode contamination, reduced microbial activity, or insufficient substrate.

[0040] Based on this, the control unit formulates intelligent control strategies and corresponding actuators, as shown in Table 1 below.

[0041] Table 1. Judgment of Abnormalities, Cause Analysis, and Corresponding Control Strategies and Implementing Agencies for Different Monitoring Parameters In terms of the reaction mechanism, microorganisms (such as Geobacter) form a biofilm on the anode surface, fixing themselves in place. Anodes 1-4 decompose organic matter such as humic acid and polysaccharides in the sediment through microbial catalysis, releasing electrons and protons (organic matter → CO2 + H2). + +e - This results in an open-circuit voltage of 0.5-0.8V and a power density of 4-6W / m². 3 Electrons are transferred to cathodes 1-5 via the external circuit, driving Fe... 3+ The reduction reaction with heavy metals specifically includes two pathways: ① Direct electron reduction (dominant pathway) ② Indirect electron reduction (an important enhancement pathway), Fe 3+ Reduced to Fe 2+ Then, it reduces Cr(VI), and is itself oxidized back to Fe. 3+ This Fe 3+ Electrons can be received again at cathodes 1-5, achieving cyclic regeneration. This allows a small amount of iron salt to drive a large amount of heavy metal reduction reactions, greatly improving efficiency and reducing chemical consumption.

[0042] Reduced heavy metals (Cr) obtained through the above two pathways 3+ Cu 0The Cr(VI) is further adsorbed by the Fe-Mn co-doped biochar electrode and reacts with sediment sulfides to form stable minerals (such as Cr(OH)3 and CuS), thus achieving heavy metal passivation. The cathode catalytic efficiency is shown to be Cr(VI) reduction rate > 95% and reaction rate constant k = 0.25 min. -1 .

[0043] Key control parameters for this unit include: bottom mud slurry concentration (15-20% TS, where TS is total solids), pH of anode chamber 1-1 (6.5-7.5), and Fe content of the solution in cathode chamber 1-2. 3+ Concentration (0.1-0.3 mol / L) and hydraulic retention time (HRT) (5-7 days). Operating modes include continuous flow (current density 0.8-1.2 mA / cm³). 2 The system employs both pulse enhancement mode and pulse enhancement mode, which improves mass transfer efficiency through periodic short-term high voltage (1.2-1.5V) to achieve sediment colloid destabilization.

[0044] The bioelectrochemical pretreatment unit 1 uses waste materials (rice husks, waste iron salts) to prepare electrode materials, transforming traditional pollution treatment into a resource and energy recovery process. This unit is powered by the organic matter in the sediment itself, and can simultaneously complete the degradation of organic matter to generate electricity, the stabilization of heavy metals and the breakdown of sediment colloids without the need for an external carbon source.

[0045] The ultrasonic-microwave gradient mineralization unit 2, with a multi-frequency coupled reaction chamber as its core, includes: a hollow container 2-1, an ultrasonic transmitter 2-2, a high-frequency microwave transmitter 2-3, an automatic injection device 2-4, a cyclone separator 2-5, a cooling device, and a hydroxyl radical (•OH) concentration detection device. In this embodiment, the hollow container 2-1 is a cylindrical stainless steel cavity (pressure resistant ≥1.5MPa), and its internal cavity serves as the reaction site, i.e., the multi-frequency coupled reaction chamber. The inner wall of the hollow container 2-1 is provided with a polytetrafluoroethylene anti-corrosion layer. A mud inlet is opened at the upper end of the hollow container 2-1, which is connected to the mud outlet of the anode chamber 1-1 through a pipeline. A pump is installed in this pipeline to introduce pretreated mud into the cavity. An ultrasonic transmitter 2-2 and a high-frequency microwave transmitter 2-3 are arranged on the top of the hollow container 2-1. The high-frequency microwave transmitter 2-3 is located in the center and is used to transmit microwaves with a frequency of 5.8 GHz into the cavity. The power is adjustable in the range of 0-10 kW. The ultrasonic transmitter 2-2 is a 20 kHz low-frequency ultrasonic transducer array (power density 50 W / L), which is uniformly arranged in a ring around the high-frequency microwave transmitter 2-3 and is used to transmit ultrasonic waves into the cavity.

[0046] An automatic injection device 2-4 is installed at the upper end of the hollow container 2-1 to add Fe3O4@biochar catalyst (particle size 50-100μm) into the cavity at 1%-3% of the dry weight of the bottom sediment. The support for the Fe3O4@biochar catalyst is KOH-activated rice husk biochar (specific surface area 1200m²). 2 Fe3O4 nanoparticles (particle size 10-20 nm, magnetic saturation strength 45 emu / g) were loaded by co-precipitation and modified with citric acid to enhance their complexation ability for As and Cd (adsorption capacity increased by 60%).

[0047] A hydrocyclone separator 2-5 is installed at the bottom of the hollow container 2-1 to separate the gases (CO2, H2O), bottom mud and solid residues generated during mineralization in real time, and discharge them through different outlets; as another embodiment, the hydrocyclone separator 2-5 is arranged outside the hollow container 2-1 and connected to the bottom of the hollow container 2-1.

[0048] The cooling device includes hollow partitions 2-6 inside the outer wall of the hollow container. Cooling water enters from the bottom of the hollow partitions 2-6 and exits from the top, used to maintain the reaction temperature of the unit. The cooling device is electrically connected to the control terminal, which dynamically adjusts the microwave power of the high-frequency microwave transmitter and the cooling water flow rate through a PID algorithm to maintain the reaction temperature at 80-120℃ and the pressure at 0.3-0.8MPa.

[0049] The hydroxyl radical concentration detection device includes EPR probes 2-7, arranged inside a hollow container and electrically connected to a control terminal. It is used to monitor the concentration of hydroxyl radicals (•OH) in the mud in real time (≥2 mmol / L). Based on this, the control terminal optimizes the ultrasonic parameters of the low-frequency ultrasonic transducer array and the microwave parameters of the high-frequency microwave transmitter to achieve staged gradient mineralization. Hydroxyl radicals are highly reactive groups with strong oxidizing power and are key to the deep degradation of organic matter and the solidification of heavy metals. In this embodiment, real-time monitoring results show that the concentration of hydroxyl radicals in the mud is ≥2 mmol / L, meeting the efficiency threshold. This indicates that, under the synergistic effect of ultrasound and microwave, the system is continuously generating a sufficiently high concentration of hydroxyl radicals, proving the effectiveness of the technical solution.

[0050] Key control parameters for staged gradient mineralization include ultrasonic power density (40-60 W / L), microwave frequency (main frequency 5.8 GHz, auxiliary frequency 2.45 GHz), reaction temperature (80-120℃), and catalyst dosage (1%-3%). This process reduces energy efficiency by 42% compared to single technologies (power consumption ≤120 kWh for treating 1 ton of sediment), and increases the Fenton-like reaction rate by 3.8 times (k=0.18→0.68 min). -1 ).

[0051] The intelligent graded conversion module 3 is based on an integrated "perception-decision-execution" architecture. Through a graded strategy formulation network, it realizes dynamic optimization and multi-objective decision-making of sediment resource utilization path. The intelligent graded conversion module 3 includes: an online detection unit, an intelligent decision-making center, multiple conversion subsystems, and a feedback control unit.

[0052] The online detection unit uses multimodal sensors to collect real-time data on the chemical composition (heavy metals, organic matter, silicon, aluminum, and phosphorus content), physical morphology (particle distribution, density), and process parameters (temperature, pressure, energy consumption) of the sediment output from the ultrasonic-microwave gradient mineralization unit 2 (i.e., the sediment output after stage three). This data is then used to generate a high-dimensional feature matrix. Specifically, the multimodal sensors integrate X-ray fluorescence spectroscopy (XRF), near-infrared spectroscopy (NIR), and a laser particle size analyzer. XRF is used to analyze the content of heavy metals (As, Pb, Cd, etc.) and key elements (Si, Al, P, Fe). NIR is used for rapid detection of organic matter content and pollutant occurrence morphology. The laser particle size analyzer is used to monitor particle size distribution (0.1 μm-10 mm). The multi-source data is integrated into a ≥50-dimensional feature matrix by a fusion terminal and transmitted to the intelligent decision-making center.

[0053] The intelligent decision-making center relies on the digital twin model to predict the product performance and energy consumption of the transformation path, and adopts a quality-based strategy to formulate the network. It combines real-time economic indicators (material market price, energy consumption cost) to formulate the quality-based strategy. The quality-based strategy formulation network is based on the synergistic effect of convolutional neural network (CNN) and reinforcement learning (RL). CNN is used to extract spectral spatial features, and RL is used to dynamically optimize resource allocation weights.

[0054] The intelligent decision-making center comprises a perception layer, a decision layer, and an execution layer. The perception layer receives the high-dimensional feature matrix output by the online monitoring unit.

[0055] The decision-making layer includes a differential strategy formulation network. A CNN extracts spatial-spectral joint features from spectral data, such as capturing characteristic peaks of heavy metals (e.g., Cr(VI)) using one-dimensional convolutional kernels, or modeling the spatial distribution patterns of pollutants (e.g., As aggregation regions) using two-dimensional convolutional kernels. Specifically, the input to the CNN is a three-dimensional tensor. (Width W, Height H, Number of Spectral Channels C), local features are extracted through convolution operations: In the formula, W is the convolution kernel weight, and b is the bias term.

[0056] Output feature map F conv Furthermore, dimensionality reduction is achieved through pooling layers to generate feature vectors characterizing the occurrence forms and resource utilization potential of pollutants. .

[0057] Based on this, the RL module uses the feature vector f extracted by the CNN as the state space, combined with real-time economic indicators (such as carbon price p). c Lithium iron phosphate market price p LFP ), constructing a dynamic decision-making model. The action space of RL includes the selection of different pathways (such as "lithium iron phosphate synthesis" or "emergency mineralization") and the adjustment of process parameters throughout the entire process (such as catalyst dosage). Table 2 shows examples of adjusting the process parameters of different units.

[0058] Table 2 Examples of Process Parameter Adjustment Throughout the Entire Process The dynamic decision-making model is based on a dual-objective optimization function of economic benefits and carbon emissions, with the goal of maximizing the reward function F for regulation and optimization. The reward function is designed as a multi-objective optimization: In the formula, F represents the reward function, Profit is the total economic benefit of the process, Profit = ∑(product unit price × output - energy consumption cost), α is the weighting coefficient of the total economic benefit of the process; Carbon_Emission represents the total carbon emissions of the process, Carbon_Emission = ∑(carbon emission factor of each link × processing volume), β is the weighting coefficient of the total carbon emissions of the process; α and β are dynamically adjusted with carbon price (e.g., when carbon price > 100 yuan / ton, β increases by 30%) to strengthen the priority of low-carbon pathways.

[0059] RL maximizes cumulative reward through the Proximity Policy Optimization (PPO) algorithm: In the formula, γ is the discount factor, and π θ For policy network parameters, In terms of strategy π θ The expected value of F under the following conditions t This represents the immediate reward obtained at time step t.

[0060] The execution layer controls the pneumatic sorting channel (high-pressure airflow 0.5-1.0MPa) and the electromagnetic separator (magnetic field strength 0.8-1.5T) according to the strategy instructions output by the decision layer to separate the bottom sediment and solid residue into different conversion subsystems based on their density and magnetic differences, thereby achieving precise conversion.

[0061] In this embodiment, the conversion subsystem includes: a carbonate mineralization subsystem, a lithium iron phosphate precursor synthesis subsystem, and a supercritical water gasification hydrogen production subsystem. The carbonate mineralization subsystem is used to convert high-silica-alumina components into carbonate mineralized cementitious materials, the lithium iron phosphate precursor synthesis subsystem is used to convert phosphorus-rich components into lithium iron phosphate precursors, and the supercritical water gasification hydrogen production subsystem is used to convert organic residues into hydrogen.

[0062] The feedback control unit is used to detect whether the heavy metal content exceeds the standard during the process of diverting to different conversion subsystems. If so, it feeds back to the intelligent decision center, and RL triggers the emergency strategy, automatically switching to the emergency solidification channel to carry out emergency solidification treatment. That is, according to the type of heavy metal exceeding the standard, the corresponding solidification raw material (pre-set) is added to the multi-frequency coupling reaction chamber to generate stable minerals and further remove heavy metals from the sediment.

[0063] The feedback control unit is also used to detect whether the CO2 concentration fluctuates. Based on the CO2 concentration fluctuation (±5%), the mineralization pressure (2.8-3.2MPa) of the ultrasonic-microwave gradient mineralization unit 2 is dynamically adjusted to ensure that the standard deviation of the cementitious material strength is <5%; the remaining sediment is treated according to the optimal economic path.

[0064] This module transforms bottom sediment into new energy materials and negative carbon building materials through intelligent separation, increasing the benefits by 5-10 times compared to traditional brick making, and also has the ability to intercept pollution in emergencies and adaptive regulation.

[0065] Based on the aforementioned sediment-targeted resource recovery system, this invention also proposes an intelligent control method for the sediment-targeted resource recovery system, such as... Figure 3 As shown, the specific steps include: S1: The sediment slurry to be treated enters the bioelectrochemical pretreatment unit, generating electrical energy during this process. Specifically, anodes 1-4 decompose organic matter in the sediment through microbial catalysis, releasing electrons and protons to form an open-circuit voltage of 0.5-0.8V; electrons are then transferred to cathodes 1-5 via an external circuit, driving Fe... 3+ The reduction reaction with heavy metals: The reduced heavy metals are adsorbed by cathode 1-5 and react with sediment sulfides to form stable minerals, thereby achieving heavy metal passivation and reducing the heavy metal content in the sediment.

[0066] In this embodiment, taking the treatment of riverbed sediment (COD=3500mg / L, Cr(VI)=120mg / kg) as an example, the COD removal rate reached 87% (reduced to 450mg / L), the Cr(VI) leaching concentration decreased from 2.1mg / L to 0.05mg / L, and the cumulative output of electrical energy was 0.8kWh / m³. 3 Microscopic characterization revealed a 10 μm thick Cr(OH)3 deposition layer on the surface of cathodes 1-5, and Fe in anode chamber 1-1. 2+ or Fe3+ The proportion increased from 0.3 to 1.2, verifying the sustained electron release capability of nZVI.

[0067] S2: The pretreated sediment enters the ultrasonic-microwave gradient mineralization unit, producing gas and mineralization residue.

[0068] like Figure 4 As shown, the control unit has a built-in PID algorithm adjustment system that adjusts the microwave power and frequency based on the hydroxyl radical concentration monitored by EPR probes 2-7. In this embodiment, the ultrasonic-microwave gradient mineralization unit 2 achieves gradient mineralization in three stages through a synergistic effect: Phase 1 (0-10 min) is dominated by ultrasound (power is 75%~85% of the rated power of the ultrasonic transmitter 2-2, preferably 80%). The micron-sized cavitation bubbles generated by the ultrasonic waves at a frequency of 20kHz collapse, releasing shock waves of over 100MPa, breaking up the colloidal aggregates of the sediment, releasing the encapsulated organic matter and heavy metals, and at the same time enhancing mass transfer. The rated power of the ultrasonic transmitter 2-2 is determined according to the reaction chamber volume, sediment properties and treatment objectives, and is usually set in the range of 10-25kW.

[0069] Phase Two (10-30 min) is microwave-dominated (power is 65%~75% of the rated power of the high-frequency microwave transmitter 2-3, preferably 70%). 5.8 GHz high-frequency microwaves target and excite the Fe-O bonds in Fe3O4@biochar, initiating localized plasma resonance (high-temperature hotspot > 500℃), driving a Fenton-like reaction. This achieves deep oxidation of organic matter (COD removal rate > 90%) and deep solidification of heavy metal minerals (such as Pb to PbFe(AsO4)(OH)); the rated power of the high-frequency microwave transmitter 2-3 is determined according to the reaction chamber volume, the properties of the sediment and the treatment target, and is usually set in the range of 5-10kW.

[0070] In Phase Three (30-40 min), the power of the high-frequency microwave transmitter is kept constant at 65%~75% of its rated power, while the frequency is reduced to 2.45 GHz. The slurry is gently heated to the set temperature range to promote the formation of the aluminosilicate framework and ensure mineral phase stability. The catalyst is recovered by magnetic separation (efficiency > 98%), and every 10 batches are regenerated by microwave under N2 atmosphere (800 W, 5 min), with activity recovery > 95%.

[0071] In this embodiment, taking the treatment of lake sediment (TP=1.8%, benzo(a)pyrene=12mg / kg) as an example, the benzo(a)pyrene removal rate reached 99.2%, COD decreased from 2800mg / L to 150mg / L, total phosphorus (TP) leaching rate was 92% (of which 80% was converted into struvite with a purity ≥98%), As leaching concentration decreased from 1.2mg / L to 0.02mg / L, and Escherichia coli inactivation rate was >99.99%. The mineralized residue mainly consisted of quartz and magnetite (XRD characterization) and could be directly used as roadbed filler. This technology replaces traditional Fenton reagents through synergistic physical-chemical action, avoids iron sludge pollution, reduces carbon emissions by 55%, and reduces solid waste by 70% throughout the process, achieving both pollutant degradation and resource activation benefits.

[0072] S3: As Figure 5 As shown, the intelligent fractional conversion module formulates a fractional strategy based on data collected by multimodal sensors. Based on this, the sediment and mineralized residue processed by the ultrasonic-microwave gradient mineralization unit are separated according to density and magnetism, and input into different subsystems, where they are precisely converted into carbonate mineralized cementitious materials, lithium iron phosphate precursors, and hydrogen. This demonstrates the key steps of the sediment-targeted resource utilization system from raw material input to the production of multiple high-value-added products. The fractional conversion path specifically includes: (1) The high-silica-alumina component is diverted to the carbonate mineralization subsystem and converted into carbonate mineralized cementitious material: The carbonate mineralization subsystem includes a high-pressure reactor, in which silica-alumina-rich bottom sludge and industrial CO2 waste gas (concentration ≥12%) are reacted in the high-pressure reactor (3.0MPa, 60℃): Adding 0.1%-0.3% polycarboxylate ether crystal directing agent to a high-pressure reactor generates calcite-type CaCO3 with a compressive strength ≥45MPa, which can replace 30%-50% of cement and reduce carbon emissions by 65%.

[0073] (2) The phosphorus-rich component is diverted to the lithium iron phosphate precursor synthesis subsystem and converted into lithium iron phosphate precursor: phosphatase pretreatment (pH=4.0, 50℃) releases closed-state phosphorus (leaching rate>90%), and reacts with LiOH and FeSO4 at a molar ratio of Li:Fe:P=1:1:1 in a hydrothermal reaction at 180℃ for 12h to synthesize LiFePO4 / C precursor, ensuring a specific capacity>155mAh / g (0.1C) and a capacity retention rate>92% after 1000 cycles.

[0074] (3) Organic residue is diverted to the supercritical water gasification hydrogen production subsystem and converted into hydrogen: Ni-Al2O3 catalyst (50nm particle size) is added to the supercritical reactor (temperature ≥374℃, pressure ≥22.1MPa) to trigger the reaction: The hydrogen yield reached 15-18 L / kg of sediment, and the H2 purity was purified to >99.99% by pressure swing adsorption (PSA).

[0075] This diversion process is controlled in real time by a feedback control unit. First, it detects whether the heavy metal content exceeds the standard during the diversion to different conversion subsystems. If so, for example, when arsenic (As) exceeds the standard (e.g., CAs > 50 mg / kg), the RL triggers an emergency strategy, automatically switching to the emergency solidification channel and adding Ca(OH)2 to generate stable calcium arsenate minerals (Ca3(AsO4)2). The reaction equation is as follows: On the other hand, CO2 concentration fluctuations are detected, and the mineralization pressure (2.8-3.2MPa) is dynamically adjusted based on CO2 concentration fluctuations (±5%) to ensure that the standard deviation of the cementitious material strength is <5%. The remaining sediment is treated according to the optimal economic path, such as the synthesis of lithium iron phosphate precursor (LiFePO4 / C). The optimal economic path is: hydrothermal reaction conditions of T=180℃, t=12h, and product specific capacity >155mAh / g.

[0076] This invention breaks through the traditional single-mode sediment treatment by deeply integrating bioelectrochemical enhancement, gradient mineralization, and intelligent regulation technologies. The bioelectrochemical pretreatment unit 1 simultaneously achieves organic matter-to-electricity generation (COD removal rate 87%, power density 4-6 W / m³). 3 The system combines efficient stabilization of heavy metals (Cr(VI) removal rate > 95%) with a two-stage ultrasonic-microwave gradient mineralization unit to drive deep degradation of pollutants (benzo(a)pyrene removal rate 99.2%) and mineral framework reconstruction (compressive strength ≥ 45 MPa), reducing energy consumption and solid waste (by 70%). The intelligent fractionation and conversion module relies on multimodal sensing and fractionation strategy algorithms to dynamically optimize the sediment fractionation path, accurately converting sediment into high-value-added products, including lithium iron phosphate precursors (specific capacity > 155 mAh / g), 99.99% pure hydrogen, and carbon-negative building materials. The entire process reduces carbon emissions by 55%-65%, energy consumption by ≤ 120 kWh / ton (a 42% reduction), and simultaneously recovers 0.8 kWh / m³ of electricity. 3 This invention combines the advantages of targeted pollutant conversion, resource co-production, and intelligent regulation, resulting in economic benefits that are 5-10 times higher than traditional technologies, and achieving a closed-loop coupling of pollution control and resource recycling.

[0077] It will be understood by those skilled in the art that the above descriptions are merely preferred examples of the invention and are not intended to limit the invention. Although the invention has been described in detail with reference to the foregoing examples, those skilled in the art can still modify the technical solutions described in the foregoing examples or make equivalent substitutions for some of the technical features. All modifications and equivalent substitutions made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A sediment targeting resource recovery system, characterized in that, The application relates to a biological-electrochemical pretreatment unit, an ultrasonic-microwave gradient mineralization unit and an intelligent quality separation and conversion module. The biological-electrochemical pretreatment unit comprises a double-chamber microbial fuel cell, the anode chamber and the cathode chamber of which are separated by a proton exchange membrane, the anode chamber is filled with sludge slurry, and a modified carbon felt electrode is used as the anode; the cathode chamber is filled with an acid solution containing iron ions, and a Fe-Mn co-doped biochar electrode is used as the cathode. The ultrasonic-microwave gradient mineralization unit comprises a hollow container which does not react with the sludge slurry, the internal cavity of the container is a multi-frequency coupling reaction cavity, a slurry inlet is arranged at the upper end of the container and is communicated with the sludge slurry outlet of the anode chamber; a high-frequency microwave emitter is arranged at the top center of the hollow container, a plurality of ultrasonic emitters are arranged in a ring-shaped and symmetrical manner at the outer periphery of the container, and an automatic spraying device is arranged at the top end of the inner wall of the container and is used for spraying Fe3O4@ biochar catalyst; a cyclone separator is arranged at the bottom outlet of the hollow container and is used for separating the gas, sludge and solid residues generated in the mineralization and discharging the gas, sludge and solid residues through different outlets. A cooling device is arranged at the outer periphery of the multi-frequency coupling reaction cavity. The intelligent quality separation and conversion module comprises an online detection unit, an intelligent decision-making center, a plurality of conversion subsystems and a feedback control unit; the online detection unit is used for collecting the chemical composition, physical state and process parameters of the sludge output by the ultrasonic-microwave gradient mineralization unit, inputting a high-dimensional feature matrix into the intelligent decision-making center; the intelligent decision-making center predicts the product performance and energy consumption of the conversion path based on a digital twin model, formulates a network by adopting a quality separation strategy, formulates the quality separation strategy in combination with real-time economic indexes, and separates the sludge and solid residues into different conversion subsystems according to the density and magnetic difference and converts the sludge and solid residues into high-value-added products; the feedback control unit is used for detecting whether the heavy metal content exceeds the standard, if yes, feeding back to the intelligent decision-making center, adding corresponding solidification raw materials into the multi-frequency coupling reaction cavity according to the type of the heavy metal exceeding the standard, and generating stable minerals; the feedback control unit is also used for adjusting the mineralization pressure of the ultrasonic-microwave gradient mineralization unit according to the CO2 concentration fluctuation, ensuring that the standard deviation of the cementing material strength is less than a specified threshold, and processing the remaining sludge according to the optimal economic path.

2. The sediment targeting resource recovery system of claim 1, wherein, The anode surface is treated by nitric acid oxidation and polyaniline coating, and the charge transfer resistance is reduced by embedding nano zero-valent iron particles; the cathode is made of Fe3O4-MnO2 heterojunction loaded on rice husk biochar by high-temperature calcination, and has catalytic activity and heavy metal adsorption capacity; A peristaltic pump is arranged in the anode chamber and is used for promoting the circulation flow of the sludge slurry in the anode chamber.

3. The sediment targeting resource recovery system of claim 1, wherein, The sensing data of the double-chamber microbial fuel cell includes the pH value, the redox point and the voltage of the anode chamber; the parameters of the biological-electrochemical pretreatment unit are adjusted according to the sensing data, including the sludge slurry concentration, the pH value of the anode chamber, the iron ion concentration in the solution in the cathode chamber and the hydraulic retention time. The sensing data of the multi-frequency coupled reaction cavity includes: hydroxyl radical concentration, cavity temperature, and cavity pressure; and the parameters of the ultrasonic-microwave gradient mineralization unit are adjusted according to the sensing data of the multi-frequency coupled reaction cavity and feedback information of a feedback control unit, including: microwave power of the high-frequency microwave emitter, ultrasonic power density of the ultrasonic emitter, cooling water flow, and biological carbon catalyst dosage.

4. The sediment targeting resource recovery system of claim 1, wherein, The inner wall of the hollow container is provided with a polytetrafluoroethylene anticorrosive layer; the cooling device comprises a hollow partition layer opened in the inner wall of the outer wall of the hollow container; cooling water enters from the bottom of the hollow partition layer and exits from the top; and the flow of the cooling water is controlled by the control end.

5. The sediment targeting resource recovery system of claim 1, wherein, The intelligent decision-making center comprises a perception layer, a decision-making layer, and an execution layer; the perception layer is used for receiving a high-dimensional feature matrix output by an online monitoring unit; A quality-based strategy development network is arranged in the decision-making layer, which is based on the synergistic effect of a convolutional neural network and reinforcement learning; the convolutional neural network is used for extracting spectral spatial features, reducing dimensions through a pooling layer, and generating a feature vector f representing the occurrence form of pollutants and resourceization potential; The reinforcement learning is used for dynamically optimizing resource allocation weights, taking the feature vector f as a state space, combining real-time economic indicators, constructing a dynamic decision-making model, and outputting a strategy instruction; and the action space of the reinforcement learning comprises branch path selection and process parameter adjustment; The dynamic decision-making model designs a reward function aiming at improving economic benefits and reducing carbon emissions; and the reinforcement learning maximizes cumulative rewards through a proximal policy optimization algorithm.

6. The sediment targeting resource recovery system of claim 5, wherein, The intelligent quality-based conversion module comprises pneumatic separation and electromagnetic separation, and dynamically adjusts resource allocation weight coefficients according to real-time carbon prices to optimize economic benefit and carbon emission target functions.

7. The sediment targeting resource recovery system of claim 1, wherein, The conversion subsystem comprises: a carbonate mineralization subsystem, a lithium iron phosphate precursor synthesis subsystem, and a supercritical water gasification hydrogen production subsystem; The carbonate mineralization subsystem is used for converting high-silicon aluminum components into carbonate mineralization cementitious materials, the lithium iron phosphate precursor synthesis subsystem is used for converting phosphorus-rich components into lithium iron phosphate precursors, and the supercritical water gasification hydrogen production subsystem is used for converting organic matter residues into hydrogen.

8. An intelligent control method of a sediment targeting resource system, implemented based on the sediment targeting resource system of any one of claims 1-7, characterized in that, The method comprises the following steps: S1: The slurry of the treated bottom mud enters a bioelectrochemical pretreatment unit, in which electric energy is generated and heavy metals are passivated, so as to reduce the content of heavy metals in the bottom mud; S2: The pretreated bottom mud enters an ultrasonic-microwave gradient mineralization unit to produce gas and mineralized residues; the control end adjusts the microwave power and frequency of the high-frequency microwave emitter and the ultrasonic power and frequency of the ultrasonic emitter according to the feedback of the hydroxyl radical concentration, and realizes gradient mineralization in stages; S3: The bottom mud and the mineralized residues treated by the ultrasonic-microwave gradient mineralization unit enter an intelligent quality-based conversion module together, are separated according to density and magnetism, and are respectively input into different subsystems to be converted into different high-value-added products.

9. The intelligent control method of the bottom sediment targeting resource recovery system according to claim 8, characterized in that, In S1, in the bioelectrochemical pretreatment unit, the anode decomposes organic matter in the bottom mud through microbial catalysis to release electrons and protons, form an open circuit voltage, and generate electric energy; After the electrons are transmitted to the cathode through an external circuit, the reduction reaction of iron ions and heavy metals is driven. The heavy metals in the reduced state are adsorbed by the cathode and react with the sulfide of the sediment to form stable minerals, thereby passivating the heavy metals and reducing the content of heavy metals in the sediment.

10. The intelligent control method of the bottom sediment targeting resource recovery system according to claim 8, wherein, In the S2, gradient mineralization is achieved in the following three stages: Stage one: ultrasonic waves are used to break the colloidal aggregates in the sediment; the power of the ultrasonic wave emitter is 75-85% of its rated power, and the frequency is 20 kHz; the duration of this stage is 8-12 minutes; Stage two: high-frequency microwaves are used to target excite the Fe-O bond in the Fe3O4@biochar, induce local plasma resonance, drive the Fenton-like reaction, and realize deep oxidation of organic matter and deep solidification of heavy metal minerals; the power of the high-frequency microwave emitter is 65-75% of its rated power, and the frequency is 5.8 GHz; the duration of this stage is 18-22 minutes; Stage three: the power of the high-frequency microwave emitter is kept at 65-75% of its rated power, the frequency is reduced to 2.45 GHz, and the temperature of the sediment slurry is gradually heated to a set temperature range, so as to promote the formation of silicate-aluminate framework and ensure the stability of the mineral phase; the duration of this stage is 8-12 minutes.

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