A continuous treatment method for environmentally friendly dredging, solidification, and disposal of polluted river and lake sediment

Abstract

This invention discloses a continuous treatment method for environmentally friendly dredging and solidification of polluted river and lake sediment, belonging to the field of environmental engineering technology. The method includes the following components: S100 ecological dredging control range and depth, S200 sediment transportation and dewatering, S300 solidification and resource utilization, and S400 residual water treatment and reuse. By accurately determining the control range and depth of ecological dredging and using a hydrodynamic model to simulate the influence of flow velocity and direction on the migration and transformation of pollutants in sediment, this method effectively avoids large-scale release of pollutants during dredging. At the same time, in the sediment transportation and dewatering stage, efficient transportation equipment and optimized filtration devices are used to reduce disturbance and release of sediment during transportation and dewatering, further reducing the risk of secondary pollution.

Description

Technical Field

[0001] This invention relates to the field of environmental engineering technology, specifically to a continuous treatment method for environmentally friendly dredging and solidification of polluted river and lake sediment. Background Technology

[0002] The treatment of polluted sediment in rivers and lakes has always been an important topic in the field of environmental engineering technology. With the rapid development of industrialization and urbanization, a large number of pollutants enter water bodies through various pathways and gradually accumulate in the sediment. These pollutants not only seriously damage aquatic ecosystems, but also threaten human drinking water safety and health.

[0003] Traditional ecological dredging techniques have significant shortcomings. Due to the lack of scientific and precise simulation and assessment methods, traditional methods often fail to accurately define the scope and depth of dredging, leading to dredging activities being too haphazard and unable to effectively remove polluted bottom sediment. At the same time, they may also cause unnecessary damage to the aquatic environment. Traditional dredging processes lack effective pollutant migration and transformation control mechanisms, which can easily trigger the secondary release of pollutants during the dredging process, further aggravating water pollution.

[0004] In summary, traditional methods for treating polluted river and lake sediments have many shortcomings in terms of the scope and depth of ecological dredging control, and cannot meet the urgent needs of the current environmental protection situation. Therefore, it is particularly important to develop a continuous treatment method for environmentally friendly dredging, solidification and disposal of polluted river and lake sediments. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and to provide a continuous treatment method for environmentally friendly dredging and solidification of polluted river and lake sediments. This method effectively avoids the large-scale release of pollutants during the dredging process and effectively controls secondary pollution by accurately determining the control range and depth of ecological dredging and using a hydrodynamic model to simulate the influence of flow velocity and direction on the migration and transformation of pollutants in the sediment.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a continuous treatment method for environmentally friendly dredging and solidification of polluted river and lake sediment, characterized in that the specific steps of the method are as follows;

[0007] S100, Ecological Dredging Control Scope and Depth: By simulating flow velocity and direction parameters using hydrodynamic models, the impact on the migration and transformation of pollutants in bottom sediment is assessed. Water samples are collected from the overlying water body to measure dissolved oxygen and temperature parameters, analyze the impact of overlying water conditions on the release of pollutants from bottom sediment, and analyze the absorption and release characteristics of pollutants in the polluted bottom sediment layer. The risk of secondary pollution that may occur during the dredging process is assessed to determine the dredging scope, with particular attention to the impact of flow velocity changes on sediment suspension and deposition. Combined with the dissolved oxygen and temperature conditions of the overlying water body, priority areas and depths for dredging are determined, with a focus on the absorption and release characteristics of the polluted bottom sediment layer to reduce secondary pollution during the dredging process.

[0008] S200, Sediment Conveying and Dewatering: It adopts sediment conveying equipment, and at the same time, optimizes the conveying path to reduce the disturbance and release of sediment during the conveying process. It uses a filter device with fixed rings and moving rings stacked on each other, and achieves rapid concentration and continuous dewatering of sediment by driving the screw shaft.

[0009] S300, Solidification and Resource Utilization: For dewatered sediment, an environmentally friendly solidifying agent is used for mixing and stirring, causing the solidifying agent to undergo a hydration reaction with water, reducing the moisture content of the sediment and increasing its strength. The solidified sediment can be used as building material, backfill soil, and for various other purposes, realizing resource utilization. Depending on the properties and strength of the solidified soil, in the treatment of urban black and odorous rivers, the solidified sediment can be reused in the river ecological restoration area to build a new ecological balance.

[0010] S400, Wastewater Treatment and Reuse: Wastewater generated during sediment transport and dewatering is centrally treated through a dedicated collection system. Biological treatment and chemical precipitation processes are used to remove suspended solids, nutrients, and pollutants from the wastewater, ensuring it meets discharge standards and reuse water quality requirements. The treated wastewater is then reused for river replenishment, landscape applications, and industrial cooling water, achieving water resource recycling. Simultaneously, combined with ecological measures such as phytoremediation and microbial remediation, the self-purification capacity of the water body is further enhanced.

[0011] Furthermore, the specific steps of S100 are as follows:

[0012] S101 collects detailed hydrological data of rivers and lakes, including but not limited to multi-dimensional information on flow velocity and direction at different depths and locations. This data is combined with water temperature and density parameters, which can be obtained through on-site sensors or periodic sampling measurements, to ensure the comprehensiveness and accuracy of the hydrodynamic model input data. A high-precision hydrodynamic model is used, with the following formula: Where u is the velocity vector, p is the pressure, ρ is the density, ν is the kinematic viscosity, g is the gravitational acceleration, and F is the velocity vector. T It is the temperature effect term, F DIt is the density effect term, F S It is a sediment impact factor. It not only inputs conventional hydrological data, but also combines water temperature and density parameters to conduct refined simulation analysis, evaluate the migration and transformation laws of sediment pollutants under different flow velocities, flow directions and temperature and density changes, and pay special attention to the impact area of ​​small flow velocity changes on sediment suspension and deposition. Through algorithms and models, it accurately identifies risk areas that may lead to large-scale release of pollutants due to dredging activities. Its risk area identification accuracy can reach the square meter level.

[0013] S102. Water samples were collected from the overlying water body. In addition to measuring dissolved oxygen and temperature parameters, the pH and conductivity of the water were also analyzed. The pH and conductivity were measured using professional water quality monitoring instruments. Multiple sampling and measurements were conducted at different time points and locations to obtain comprehensive water condition data. By establishing a multi-factor correlation model, the parameters of dissolved oxygen, temperature, pH, and conductivity were correlated with the threshold and rate of pollutant release from the sediment. Through this correlation model, the pattern of pollutant release under different combinations of water conditions can be clarified, thereby more accurately assessing the risk of secondary pollution that may occur during the dredging process.

[0014] S103. Layered sampling of the contaminated sediment layer is conducted. The number of sampling layers is determined based on the sediment thickness and degree of contamination, ranging from 3 to 5 layers. Sampling equipment is used to ensure the representativeness of each layer sample, and spectral analysis technology is employed. Where R represents the secondary pollution risk index, n represents the number of types of pollutants, and w i C is the weighting coefficient for the i-th pollutant. i M is the content of the i-th pollutant in the sediment. i S is the migration parameter of the i-th pollutant. i It is a bioavailability parameter of the i-th pollutant. It measures the existence form and content distribution of different pollutants in the sediment. Through spectral analysis, it can quickly and accurately obtain information on multiple pollutants in the sediment and assess the risk of secondary pollution that may occur during the dredging process.

[0015] Furthermore, the specific steps of the hydrodynamic model of S100 also include:

[0016] S104, combining hydrodynamic simulation results, sediment pollution status, and overlying water conditions, initially delineated the dredging area boundaries. Considering multiple factors such as river and lake morphology, water flow conditions, and surrounding ecological environment, the dredging area was iteratively adjusted multiple times. After the initial delineation, water flow and pollutant diffusion under different dredging areas were simulated again. Based on the simulation results, the dredging area was optimized. At the same time, combined with field investigation and monitoring data, the effectiveness and safety of dredging activities were ensured. Sediment samples were collected to determine the content of multiple major pollutants such as nitrogen and phosphorus, as well as heavy metals, to identify highly polluted areas. Combining the overlying water conditions and the distribution characteristics of sediment pollutants, priority dredging areas were determined. Based on the vertical distribution of pollutants in the sediment, the dredging depth in different areas was determined. Through stratified sampling and analysis, the enrichment layers of pollutants in the sediment were identified, ensuring that the dredging depth could effectively remove the polluted layer while avoiding excessive dredging that would lead to resource waste and ecological damage. This method of accurately determining the dredging area, priority areas, and depth can minimize the risk of secondary pollution during the dredging process, improve the dredging effect, and protect the river and lake ecosystem.

[0017] Furthermore, the specific steps of S200 are as follows:

[0018] S201. Based on the underwater topography characteristics and dredging needs of rivers and lakes, select bottom sediment transport equipment, including but not limited to cutter suction dredgers, to ensure that the selected equipment has the ability to transport bottom sediment efficiently and continuously, and consider its adaptability to the environment. Analyze the underwater topography and plan a reasonable bottom sediment transport path to reduce disturbance and release during the transport process. Consider the water flow direction and velocity factors to ensure the stability and safety of the transport path.

[0019] S202, uses cutter suction dredger equipment for the dredging and transportation of bottom mud;

[0020] Power: Equipped with a high-power power system, the main unit power can reach 1000-5000 kilowatts to ensure sufficient digging and conveying capacity.

[0021] Excavation depth: It should be able to adapt to the water depth requirements of different rivers and lakes, with an excavation depth range of 5-30 meters to ensure that the polluted bottom sediment layer can be reached;

[0022] Sludge discharge distance: It has a long sludge discharge distance capability, usually reaching 1000-5000 meters, so as to transport the bottom sludge to the designated location;

[0023] During the transport process, avoid areas with complex terrain, consider the direction and velocity of water flow, and try to transport in the direction of the flow. For long-distance transport, set up pump station auxiliary facilities in a reasonable manner to ensure that the bottom sediment can be transported smoothly to the destination, while maintaining the stable operation of the equipment and avoiding leakage and diffusion of the bottom sediment. At the end point and appropriate location of the bottom sediment transport, set up a filter device, install a fixed ring, and stack a floating ring on the fixed ring to ensure that the filter device has sufficient filtration area and strength to withstand the pressure and flow of the bottom sediment.

[0024] Furthermore, the specific steps of S200 also include:

[0025] S203, start the filtration device. Driven by the screw shaft, the bottom sediment is rapidly concentrated and continuously dewatered in the filtration device. Monitor the dewatering process to ensure that the moisture content of the bottom sediment drops to the predetermined standard. At the same time, observe and record the dewatering efficiency. Collect the dewatered bottom sediment and prepare it for subsequent solidification treatment. Clean the filtration device to ensure that it is in good working condition so that the next round of bottom sediment dewatering operation can be carried out.

[0026] S204 optimizes and adjusts the parameters in the sediment conveying and dewatering process based on actual operating conditions, focusing on the stability of the conveying path, the dewatering efficiency of the filtration device, as well as the floor space and transportation cost factors, to ensure the environmental friendliness and economy of the entire process.

[0027] Furthermore, the specific steps of S300 are as follows:

[0028] S301. Based on the properties of the dehydrated sediment, including but not limited to particle size, porosity, contaminant composition, and the content of organic and inorganic matter, a cement-based environmentally friendly curing agent is selected. This type of curing agent has good adaptability and can undergo an effective hydration reaction with the water in the sediment. When the curing agent reacts with water, it generates a gel-like substance that fills the pores between the sediment particles, thereby reducing the moisture content of the sediment. At the same time, this reaction will form chemical bonds between the sediment particles, significantly increasing the strength of the sediment. During the hydration process, the tricalcium silicate and dicalcium silicate components in the cement will gradually form ettringite and calcium hydroxide products. These products intertwine with each other, tightly wrapping and binding the sediment particles together. In this way, the cured sediment not only has a reduced volume and weight, making it easier for subsequent processing and transportation, but also has better physical and mechanical properties, enabling it to withstand certain external loads and meet the basic requirements as a building material or backfill soil.

[0029] S302 uses professional mixing equipment, such as a forced mixer or a twin-shaft mixer, to add the selected curing agent and dehydrated sediment in a certain ratio. The ratio is determined experimentally based on the properties of the sediment and the expected curing effect. The dry weight ratio of the curing agent to the sediment may be between 1:5 and 1:20. The mixing time is calculated using the formula t = k × V / P, where t is the mixing time, V is the sediment volume, P is the mixing power, and k is an empirical coefficient. The mixing speed should be moderate, controlled at 20-60 rpm, to ensure that the curing agent is evenly distributed in the sediment and achieves the best curing effect. If the mixing time is too short or the speed is too fast, the curing agent may not be fully mixed with the sediment, affecting the curing effect. If the mixing time is too long or the speed is too slow, it will increase energy consumption and processing time, and reduce processing efficiency.

[0030] S303 involves testing the solidified sediment to assess whether its properties and strength meet the requirements of building materials and backfill soil. If adjustments are needed, the type and dosage of the solidifying agent can be optimized based on the test results. The applicable scenarios and uses can be determined based on the properties and strength of the solidified soil. In the treatment of urban black and odorous rivers, special attention is paid to the application of solidified sediment in river ecological restoration areas. The solidified sediment is reused in river ecological restoration areas to build a new ecological balance and promote the ecological restoration of the river.

[0031] Furthermore, the specific steps of S400 are as follows:

[0032] S401, during the sediment transport and dewatering process, a dedicated collection system is set up to collect the generated residual water in a centralized manner. The collection system is guaranteed to have sufficient capacity and efficiency to avoid leakage and diffusion of residual water. The collected residual water is pretreated, such as by screen filtration, to remove large suspended particles. The pretreated residual water enters the subsequent treatment unit.

[0033] S402 introduces the pretreated wastewater into the biological treatment unit, where microorganisms degrade the wastewater to remove organic pollutants and some nutrients. In the chemical precipitation unit, an appropriate amount of chemical agents are added to the wastewater to further remove suspended solids and nutrient pollutants through chemical precipitation.

[0034] Furthermore, the specific steps of S400 also include:

[0035] S403 conducts water quality testing on the treated wastewater to ensure that it meets discharge standards and reuse water quality requirements. If the water quality does not meet the standards, the process parameters of biological treatment and chemical precipitation can be adjusted according to the test results. The treated wastewater can be reused for river replenishment, landscape water and industrial cooling water scenarios to ensure that the reuse water quality meets relevant standards and avoid adverse effects on the environment and human health.

[0036] S404, while treating and reusing wastewater, incorporates ecological measures such as phytoremediation and microbial remediation to further enhance the self-purification capacity of water bodies, promote the restoration and balance of aquatic ecosystems, and conduct long-term monitoring of the wastewater treatment and reuse system to ensure its stable operation and that the effluent quality meets standards. If any potential problems are found, maintenance measures will be taken in a timely manner to ensure the long-term effective operation of the system.

[0037] Furthermore, the specific steps of S400 also include:

[0038] S405, the formula for calculating the residual water flow rate is: Q=A×V, where Q is the flow rate, A is the cross-sectional area of ​​the collection pipe, and V is the water flow velocity. Design and install residual water collection pipes and storage facilities to ensure that the residual water generated during the sediment transport and dewatering process is collected centrally through the collection system. The formula for the biological reaction rate is: r=k×[C]^n, where r is the reaction rate, k is the reaction rate constant, [C] is the pollutant concentration, and n is the reaction order. Construct a biological treatment tank, introduce a microbial community, control the temperature, dissolved oxygen, and pH conditions, and utilize the decomposition and transformation of microorganisms to remove organic matter and some nutrients from the residual water.

[0039] Compared with existing technologies, a continuous treatment method for environmentally friendly dredging and solidification of polluted river and lake sediment has the following advantages:

[0040] First, this method accurately determines the control range and depth of ecological dredging and uses a hydrodynamic model to simulate the impact of flow velocity and direction on the migration and transformation of pollutants in the sediment, effectively avoiding large-scale release of pollutants during the dredging process. At the same time, in the sediment transportation and dewatering stage, efficient transportation equipment and optimized filtration devices are used to reduce the disturbance and release of sediment during transportation and dewatering, further reducing the risk of secondary pollution.

[0041] Second, this method successfully transforms the solidified sediment into various uses such as building materials and backfill soil, realizing the resource utilization of sediment. Especially in the treatment of urban black and odorous rivers, the solidified sediment can be reused in the river ecological restoration area to build a new ecological balance and promote the restoration of the aquatic ecosystem. In addition, the residual water generated during sediment transportation and dewatering can be used for river replenishment, landscape water and industrial cooling water after being treated and purified by a special collection system, realizing the recycling of water resources. This process not only reduces wastewater discharge, but also saves water resources, which is of great significance for improving environmental quality and promoting sustainable development. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0043] Figure 1 A flowchart of a continuous treatment method for environmentally friendly dredging, solidification, and disposal of polluted river and lake sediment;

[0044] Figure 2 A flowchart illustrating the operation of sediment conveying and dewatering equipment;

[0045] Figure 3 Flowchart of the sediment solidification treatment stage;

[0046] Figure 4 A flowchart of the preliminary assessment and planning process for polluted river and lake sediments before environmental dredging. Detailed Implementation

[0047] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0048] Example 1

[0049] Collect hydrological data from rivers and lakes, including flow velocity and direction, and utilize hydrodynamic models. Where u is the velocity vector, p is the pressure, ρ is the density, ν is the kinematic viscosity, g is the gravitational acceleration, and F is the velocity vector. T It is the temperature effect term, F D It is the density effect term, F SThis involves analyzing the impact of sediment on sediment. Simulations are conducted to study the migration and transformation of pollutants in sediment under different flow velocities and directions, with a particular focus on the effects of flow velocity changes on sediment suspension and deposition. This identifies risk areas where large-scale pollutant release due to dredging activities may occur. Based on hydrodynamic simulation results and sediment pollution status, the dredging area boundaries are preliminarily delineated. Simultaneously, considering river and lake morphology and flow conditions, the dredging area is appropriately adjusted to ensure the effectiveness and safety of the dredging activities. Sediment samples are collected to analyze the content and spatial distribution characteristics of major pollutants such as nitrogen and phosphorus, identifying highly polluted areas. Water samples from the overlying water body are also collected to measure dissolved oxygen and temperature parameters, analyzing the impact of overlying water conditions on sediment pollutant release. Based on this comprehensive information, priority areas and depths for dredging are determined, with a focus on the absorption and release characteristics of the polluted sediment layer to reduce secondary pollution during the dredging process.

[0050] Based on the underwater topography and dredging requirements of rivers and lakes, a high-efficiency cutter suction dredger was selected as the sediment transport equipment. The underwater topography was analyzed, and a reasonable sediment transport path was planned to reduce disturbance and release during transport. Simultaneously, the direction and velocity of the water flow were considered to ensure the stability and safety of the transport path. The cutter suction dredger was used for sediment excavation and transport, maintaining stable equipment operation and preventing sediment leakage and diffusion. At the end point and appropriate locations of sediment transport, a filter device with stacked fixed and floating rings was installed. Driven by the helical shaft, rapid concentration and continuous dewatering of the sediment were achieved. This process not only improved dewatering efficiency but also significantly reduced the land area and transportation costs.

[0051] An environmentally friendly curing agent is mixed with dehydrated sediment. The curing agent reacts with water to effectively reduce the moisture content of the sediment and significantly increase its strength. This curing treatment not only reduces the volume and weight of the sediment but also gives it better physical and mechanical properties. The cured sediment can be used as a high-quality building material. Depending on the properties and strength of the cured soil, it can be applied to various fields of urban greening and municipal construction, including park walkway paving, retaining wall backfilling, road and embankment construction. In particular, in the treatment of urban black and odorous rivers, the cured sediment can be reused in river ecological restoration areas to build a new ecological balance and achieve a win-win situation for ecology and economy.

[0052] The wastewater generated during sediment transport and dewatering is centrally treated through a specialized collection system. Suspended solids and nutrient pollutants are removed from the wastewater using biological treatment and chemical precipitation processes to meet discharge standards and reuse water quality requirements. The treated wastewater is then reused for urban landscape water use, greening irrigation, and industrial cooling water applications, achieving effective recycling of water resources. At the same time, combined with ecological measures such as phytoremediation and microbial remediation technologies, the self-purification capacity of the water body is further enhanced, consolidating the treatment results.

[0053] Example 2

[0054] By utilizing a high-precision hydrodynamic model and inputting real-time flow velocity and direction data of the lake, the suspension and deposition behavior of bottom sediment under different scenarios is simulated to scientifically assess its impact on pollutant migration and transformation. This allows for the precise delineation of a reasonable dredging area. Combining the spatial distribution characteristics of nitrogen and phosphorus, the main pollutants in the bottom sediment, with the dissolved oxygen and temperature conditions of the overlying water, the most polluted areas are identified as priority targets for dredging. At the same time, attention is paid to areas sensitive to the effects of flow velocity changes on sediment suspension and deposition to avoid secondary release of pollutants during the dredging process. Based on the above analysis, a detailed dredging plan is developed, clearly defining the scope, depth, and timeline of the dredging to ensure that the dredging activities are both efficient and environmentally friendly.

[0055] Based on the complexity of the lake's underwater topography and dredging needs, efficient and environmentally friendly sediment transport equipment is selected, including but not limited to sludge pumps and cutter suction dredgers, to ensure that the sediment can be transported to the treatment area efficiently and continuously. The sediment transport path is optimized to reduce disturbance and sediment leakage during transport, thereby reducing the impact on the aquatic environment. A high-efficiency filtration device is installed at the transport endpoint, and a screw shaft is used to achieve rapid concentration and continuous dewatering of the sediment. This process not only improves dewatering efficiency but also reduces the land area and subsequent transportation costs.

[0056] An environmentally friendly curing agent was selected and thoroughly mixed with the dehydrated sediment to allow the curing agent to undergo a hydration reaction with water, reducing the moisture content of the sediment and significantly improving its strength and stability. The cured sediment has multiple uses, including as building material and backfill soil. In this project, the cured soil was used for the construction of the lake ecological restoration area, including the construction of artificial wetlands and ecological islands, providing a good base for the restoration of aquatic plants and microbial communities.

[0057] The wastewater generated during sediment transport and dewatering is centrally treated through a specialized collection system. A combination of biological treatment technology and chemical precipitation effectively removes suspended solids, nutrients, and pollutants from the wastewater. The treated wastewater is then reused to replenish the lake, which not only saves water resources but also further improves the overall water quality of the lake by replenishing clean water. At the same time, by combining phytoremediation and microbial remediation technologies, the self-purification capacity of the water body is enhanced, creating a healthier and more stable lake ecosystem.

[0058] Example 3

[0059] An emergency response team composed of environmental experts, hydrodynamicists, and engineers was immediately dispatched to the site. Using drones and remote sensing technology, combined with on-site investigation, the team quickly assessed the scope and extent of the pollution. Within a limited timeframe, a simplified hydrodynamic model was used to conduct preliminary simulations of flow velocity and direction, and the areas requiring immediate dredging were delineated as quickly as possible. The team focused on the migration direction and speed of pollutants to ensure that the dredging area could effectively control the spread of pollutants. Based on the pollution assessment results, the team prioritized the most severely polluted areas and depths, adopting the principle of "urgent matters first, less urgent matters second" to maximize the effectiveness of the emergency response.

[0060] Quickly contact and deploy mobile dredgers and pump trucks to transport sludge to the contaminated site, ensuring that the number of equipment meets the emergency treatment needs. Optimize the equipment layout and transport route based on the site topography and pollution distribution to reduce disturbance and pollution release during transport. Use simple but efficient filtration devices to perform preliminary dewatering treatment on the excavated sludge to reduce its moisture content, facilitating subsequent transportation and solidification.

[0061] Given the urgency of the emergency response, readily available, cost-effective, and environmentally friendly temporary solidification materials were selected. These materials can mix with the dewatered sediment quickly to form a stable solidified body. Thorough mixing of the temporary solidification material with the dewatered sediment is crucial to ensure effective solidification. During the solidification process, the mixing time and ratio must be controlled to achieve the best results.

[0062] The solidified sediment will be temporarily stored in a safe area that has undergone seepage prevention treatment to prevent rainwater infiltration and pollution spread. At the same time, warning signs and barriers will be set up to ensure personnel safety. A plan for subsequent resource utilization and safe disposal will be formulated. After the emergency situation is relieved, the solidified sediment will be further processed and utilized according to the actual situation.

[0063] A temporary collection system should be quickly established to collect residual water generated during sediment transportation and dewatering. This system must have sufficient capacity and leak-proof capabilities to prevent overflow and secondary pollution. An emergency chemical precipitation process should be employed to remove the main pollutants from the residual water. Strict control of reagent dosage and reaction time is necessary during treatment to ensure the treatment meets standards.

[0064] The treated wastewater will be temporarily stored in a safe water tank to avoid direct discharge. Depending on the improvement of river water quality and the surrounding water demand, the treated wastewater will be gradually reused for river replenishment and transferred to a sewage treatment plant for further treatment. During the reuse process, water quality monitoring should be strengthened to ensure that the reused water quality meets relevant standards.

[0065] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A continuous treatment method for environmentally friendly dredging, solidification, and disposal of polluted river and lake sediment, characterized in that, The specific steps of this method are as follows: S100, Ecological Dredging Control Scope and Depth: By simulating flow velocity and direction parameters using hydrodynamic models, the impact on the migration and transformation of pollutants in bottom sediment is assessed. Water samples are collected from the overlying water body to measure dissolved oxygen and temperature parameters, analyze the impact of overlying water conditions on the release of pollutants from bottom sediment, and analyze the absorption and release characteristics of pollutants in the polluted bottom sediment layer. The risk of secondary pollution that may occur during the dredging process is assessed to determine the dredging scope, with particular attention to the impact of flow velocity changes on sediment suspension and deposition. Combined with the dissolved oxygen and temperature conditions of the overlying water body, priority areas and depths for dredging are determined, with a focus on the absorption and release characteristics of the polluted bottom sediment layer to reduce secondary pollution during the dredging process. S200, Sediment Conveying and Dewatering: It adopts sediment conveying equipment, and at the same time, optimizes the conveying path to reduce the disturbance and release of sediment during the conveying process. It uses a filter device with fixed rings and moving rings stacked on each other, and achieves rapid concentration and continuous dewatering of sediment by driving the screw shaft. S300, Solidification and Resource Utilization: For dewatered sediment, an environmentally friendly solidifying agent is used for mixing and stirring, causing the solidifying agent to undergo a hydration reaction with water, reducing the moisture content of the sediment and increasing its strength. The solidified sediment can be used as building material, backfill soil, and for various other purposes, realizing resource utilization. Depending on the properties and strength of the solidified soil, in the treatment of urban black and odorous rivers, the solidified sediment can be reused in the river ecological restoration area to build a new ecological balance. S400, Wastewater Treatment and Reuse: Wastewater generated during sediment transport and dewatering is centrally treated through a dedicated collection system. Biological treatment and chemical precipitation processes are used to remove suspended solids, nutrients, and pollutants from the wastewater, ensuring it meets discharge standards and reuse water quality requirements. The treated wastewater is then reused for river replenishment, landscape applications, and industrial cooling water, achieving water resource recycling. Simultaneously, combined with ecological measures such as phytoremediation and microbial remediation, the self-purification capacity of the water body is further enhanced.

2. The continuous treatment method for environmentally friendly dredging, solidification, and disposal of polluted river and lake sediment according to claim 1, characterized in that, The specific steps of S100 are as follows: S101 collects detailed hydrological data of rivers and lakes, including but not limited to multi-dimensional information on flow velocity and direction at different depths and locations. This data is combined with water temperature and density parameters, which can be obtained through on-site sensors or periodic sampling measurements, to ensure the comprehensiveness and accuracy of the hydrodynamic model input data. A high-precision hydrodynamic model is used, with the following formula: Where u is the velocity vector, p is the pressure, ρ is the density, ν is the kinematic viscosity, g is the gravitational acceleration, and F is the velocity vector. T It is the temperature effect term, F D It is the density effect term, F S It is a sediment impact factor. It not only inputs conventional hydrological data, but also combines water temperature and density parameters to conduct refined simulation analysis, evaluate the migration and transformation laws of sediment pollutants under different flow velocities, flow directions and temperature and density changes, and pay special attention to the impact area of ​​small flow velocity changes on sediment suspension and deposition. Through algorithms and models, it accurately identifies risk areas that may lead to large-scale release of pollutants due to dredging activities. Its risk area identification accuracy can reach the square meter level. S102. Water samples were collected from the overlying water body. In addition to measuring dissolved oxygen and temperature parameters, the pH and conductivity of the water were also analyzed. The pH and conductivity were measured using professional water quality monitoring instruments. Multiple sampling and measurements were conducted at different time points and locations to obtain comprehensive water condition data. By establishing a multi-factor correlation model, the parameters of dissolved oxygen, temperature, pH, and conductivity were correlated with the threshold and rate of pollutant release from the sediment. Through this correlation model, the pattern of pollutant release under different combinations of water conditions can be clarified, thereby more accurately assessing the risk of secondary pollution that may occur during the dredging process. S103. Layered sampling of the contaminated sediment layer is conducted. The number of sampling layers is determined based on the sediment thickness and degree of contamination, ranging from 3 to 5 layers. Sampling equipment is used to ensure the representativeness of each layer sample, and spectral analysis technology is employed. Where R represents the secondary pollution risk index, n represents the number of types of pollutants, and w i C is the weighting coefficient for the i-th pollutant. i M is the content of the i-th pollutant in the sediment. i S is the migration parameter of the i-th pollutant. i It is a bioavailability parameter of the i-th pollutant. It measures the existence form and content distribution of different pollutants in the sediment. Through spectral analysis, it can quickly and accurately obtain information on multiple pollutants in the sediment and assess the risk of secondary pollution that may occur during the dredging process.

3. The continuous treatment method for environmentally friendly dredging, solidification, and disposal of polluted river and lake sediment according to claim 2, characterized in that, The specific steps of the hydrodynamic model of S100 also include: S104. Based on hydrodynamic simulation results, sediment pollution status, and overlying water conditions, the dredging area boundaries were initially delineated. Considering river and lake morphology, flow conditions, and surrounding ecological environment, the dredging area was iteratively adjusted multiple times. After the initial delineation, the flow and pollutant diffusion under different dredging areas were simulated again. The dredging area was optimized based on the simulation results. At the same time, combined with field investigation and monitoring data, the effectiveness and safety of the dredging activities were ensured. Sediment samples were collected to determine the content of nitrogen, phosphorus, and other major pollutants, as well as heavy metals, to identify highly polluted areas. Based on the overlying water conditions and the distribution characteristics of sediment pollutants, priority dredging areas were determined. The dredging depth in different areas was determined according to the vertical distribution of pollutants in the sediment. Through stratified sampling and analysis, the enrichment layers of pollutants in the sediment were identified to ensure that the dredging depth could effectively remove the polluted layer while avoiding excessive dredging that would lead to resource waste and ecological damage.

4. The continuous treatment method for environmentally friendly dredging, solidification, and disposal of polluted river and lake sediment according to claim 1, characterized in that, The specific steps of S200 are as follows: S201. Based on the underwater topography characteristics and dredging needs of rivers and lakes, select bottom sediment transport equipment, including but not limited to cutter suction dredgers, to ensure that the selected equipment has the ability to transport bottom sediment efficiently and continuously, and consider its adaptability to the environment. Analyze the underwater topography and plan a reasonable bottom sediment transport path to reduce disturbance and release during the transport process. Consider the water flow direction and velocity factors to ensure the stability and safety of the transport path. S202, uses cutter suction dredger equipment for the dredging and transportation of bottom mud; Power: Equipped with a high-power power system, the main unit power can reach 1000-5000 kilowatts to ensure sufficient digging and conveying capacity. Excavation depth: It should be able to adapt to the water depth requirements of different rivers and lakes, with an excavation depth range of 5-30 meters to ensure that the polluted bottom sediment layer can be reached; Sludge discharge distance: It has a long sludge discharge distance capability, usually reaching 1000-5000 meters, so as to transport the bottom sludge to the designated location; During the transport process, avoid areas with complex terrain, consider the direction and velocity of water flow, and try to transport in the direction of the flow. For long-distance transport, set up pump station auxiliary facilities in a reasonable manner to ensure that the bottom sediment can be transported smoothly to the destination, while maintaining the stable operation of the equipment and avoiding leakage and diffusion of the bottom sediment. At the end point and appropriate location of the bottom sediment transport, set up a filter device, install a fixed ring, and stack a floating ring on the fixed ring to ensure that the filter device has sufficient filtration area and strength to withstand the pressure and flow of the bottom sediment.

5. The continuous treatment method for environmentally friendly dredging, solidification, and disposal of polluted river and lake sediment according to claim 4, characterized in that, The specific steps of S200 also include: S203, start the filtration device. Driven by the screw shaft, the bottom sediment is rapidly concentrated and continuously dewatered in the filtration device. Monitor the dewatering process to ensure that the moisture content of the bottom sediment drops to the predetermined standard. At the same time, observe and record the dewatering efficiency. Collect the dewatered bottom sediment and prepare it for subsequent solidification treatment. Clean the filtration device to ensure that it is in good working condition so that the next round of bottom sediment dewatering operation can be carried out. S204 optimizes and adjusts the parameters in the sediment conveying and dewatering process based on actual operating conditions, focusing on the stability of the conveying path, the dewatering efficiency of the filtration device, as well as the floor space and transportation cost factors, to ensure the environmental friendliness and economy of the entire process.

6. The continuous treatment method for environmentally friendly dredging, solidification, and disposal of polluted river and lake sediment according to claim 1, characterized in that, The specific steps of S300 are as follows: S301. Based on the properties of the dehydrated sediment, including but not limited to particle size, porosity, contaminant composition, and the content of organic and inorganic matter, a cement-based environmentally friendly curing agent is selected. This type of curing agent has good adaptability and can undergo an effective hydration reaction with the water in the sediment. When the curing agent reacts with water, it generates a gel-like substance that fills the pores between the sediment particles, thereby reducing the moisture content of the sediment. At the same time, this reaction will form chemical bonds between the sediment particles, significantly increasing the strength of the sediment. During the hydration process, the tricalcium silicate and dicalcium silicate components in the cement will gradually form ettringite and calcium hydroxide products. These products intertwine with each other, tightly wrapping and binding the sediment particles together. In this way, the cured sediment not only has a reduced volume and weight, making it easier for subsequent processing and transportation, but also has better physical and mechanical properties, enabling it to withstand certain external loads and meet the basic requirements as a building material or backfill soil. S302 uses professional mixing equipment, such as a forced mixer or a twin-shaft mixer, to add the selected curing agent and dehydrated sediment in a certain ratio. The ratio is determined experimentally based on the properties of the sediment and the expected curing effect. The dry weight ratio of the curing agent to the sediment may be between 1:5 and 1:

20. The mixing time is calculated using the formula t = k × V / P, where t is the mixing time, V is the sediment volume, P is the mixing power, and k is an empirical coefficient. The mixing speed should be moderate, controlled at 20-60 rpm, to ensure that the curing agent is evenly distributed in the sediment and achieves the best curing effect. If the mixing time is too short or the speed is too fast, the curing agent may not be fully mixed with the sediment, affecting the curing effect. If the mixing time is too long or the speed is too slow, it will increase energy consumption and processing time, and reduce processing efficiency. S303 involves testing the solidified sediment to assess whether its properties and strength meet the requirements of building materials and backfill soil. If adjustments are needed, the type and dosage of the solidifying agent can be optimized based on the test results. The applicable scenarios and uses can be determined based on the properties and strength of the solidified soil. In the treatment of urban black and odorous rivers, special attention is paid to the application of solidified sediment in river ecological restoration areas. The solidified sediment is reused in river ecological restoration areas to build a new ecological balance and promote the ecological restoration of the river.

7. The continuous treatment method for environmentally friendly dredging, solidification, and disposal of polluted river and lake sediment according to claim 1, characterized in that, The specific steps of S400 are as follows: S401, during the sediment transport and dewatering process, a dedicated collection system is set up to collect the generated residual water in a centralized manner. The collection system is guaranteed to have sufficient capacity and efficiency to avoid leakage and diffusion of residual water. The collected residual water is pretreated, such as by screen filtration, to remove large suspended particles. The pretreated residual water enters the subsequent treatment unit. S402 introduces the pretreated wastewater into the biological treatment unit, where microorganisms degrade the wastewater to remove organic pollutants and some nutrients. In the chemical precipitation unit, an appropriate amount of chemical agents are added to the wastewater to further remove suspended solids and nutrient pollutants through chemical precipitation.

8. The continuous treatment method for environmentally friendly dredging and solidification of polluted river and lake sediment according to claim 7, characterized in that, The specific steps of S400 also include: S403 conducts water quality testing on the treated wastewater to ensure that it meets discharge standards and reuse water quality requirements. If the water quality does not meet the standards, the process parameters of biological treatment and chemical precipitation can be adjusted according to the test results. The treated wastewater can be reused for river replenishment, landscape water and industrial cooling water scenarios to ensure that the reuse water quality meets relevant standards and avoid adverse effects on the environment and human health. S404, while treating and reusing wastewater, incorporates ecological measures such as phytoremediation and microbial remediation to further enhance the self-purification capacity of water bodies, promote the restoration and balance of aquatic ecosystems, and conduct long-term monitoring of the wastewater treatment and reuse system to ensure its stable operation and that the effluent quality meets standards. If any potential problems are found, maintenance measures will be taken in a timely manner to ensure the long-term effective operation of the system.

9. The continuous treatment method for environmentally friendly dredging, solidification, and disposal of polluted river and lake sediment according to claim 8, characterized in that, The specific steps of S400 also include: S405, the formula for calculating the residual water flow rate is: Q=A×V, where Q is the flow rate, A is the cross-sectional area of ​​the collection pipe, and V is the water flow velocity. Design and install residual water collection pipes and storage facilities to ensure that the residual water generated during the sediment transport and dewatering process is collected centrally through the collection system. The formula for the biological reaction rate is: r=k×[C]^n, where r is the reaction rate, k is the reaction rate constant, [C] is the pollutant concentration, and n is the reaction order. Construct a biological treatment tank, introduce a microbial community, control the temperature, dissolved oxygen, and pH conditions, and utilize the decomposition and transformation of microorganisms to remove organic matter and some nutrients from the residual water.

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