A method for remediating heavily polluted land

Abstract

The present application discloses a method for remediating heavily polluted land. The method divides the land area and makes reasonable design adjustments when injecting the remediation agent according to the divided sub-areas. The remediation agent is injected into the land to be remediated along the horizontal dividing line and the vertical dividing line, and differentiated stirring control is performed in combination with the divided sub-areas, so that the remediation agent can effectively act on the heavily polluted land remediation process, thereby improving the remediation efficiency of the heavily polluted land and reducing the amount of remediation agent used.

Description

Technical Field

[0001] The present application relates to the technical field of contaminated land remediation and treatment, and in particular to a method for remediating heavily contaminated land. Background Art

[0002] Heavily polluted land can cause serious damage to the soil ecosystem. The structure of the microbial community in the soil will change, and the survival of many beneficial microorganisms will be threatened. For example, in soil contaminated by heavy metals, the activity of microorganisms such as nitrogen-fixing bacteria will decrease, affecting the soil fertility formation process. Restoring contaminated land can restore the structure and function of the soil ecosystem, allowing microorganisms, plants and animals to survive and reproduce in a healthy soil environment. Secondly, heavily polluted land may cause harm to human health through the transmission of the food chain. For example, heavy metals in the soil (such as cadmium, lead, mercury, etc.) may be absorbed by plants and then enriched in the plants. When these contaminated plants are eaten, heavy metals will accumulate in the human body, leading to various diseases. Cadmium poisoning may cause kidney damage, and lead poisoning will affect the development of the nervous system.

[0003] Currently, the remediation methods for heavily polluted land usually include: (1) the imported soil method is to cover the surface of the contaminated soil with a layer of clean, uncontaminated soil. This method can effectively isolate pollutants and prevent them from spreading to the outside; (2) thermal desorption is a method of volatilizing or decomposing pollutants by heating the contaminated soil. It is generally divided into low-temperature thermal desorption (temperature range is usually 100-300℃) and high-temperature thermal desorption (temperature exceeds 300℃); (3) according to the type and content of heavy metals in the soil, select appropriate chemical stabilization agents. For example, for heavy metal pollution such as cadmium and lead, commonly used agents include lime, phosphate, etc. The optimal ratio of agents is determined through laboratory tests and field pilot tests. However, at present, when using chemical remediation agents to repair contaminated land, the chemical agents are only injected into the repaired land, and then the land is stirred to mix the chemical remediation agents and the land, thereby achieving the repair of the contaminated land. However, this method fails to efficiently achieve the treatment of land repair, and will cause a large amount of loss of chemical remediation agents. It fails to effectively consider the overall situation of land repair and adjust the design of the repair method. Summary of the Invention

[0004] In an exemplary embodiment of the present application, a method for remediating heavily polluted land is provided. By dividing the land area and making reasonable design adjustments when injecting the remediation agent according to the divided sub-areas, the remediation agent can effectively act on the heavily polluted land remediation process, thereby improving the remediation efficiency of heavily polluted land and reducing the use of remediation agents.

[0005] The present application provides a method for remediating heavily contaminated land, which comprises:

[0006] Determining a horizontal dividing line and a vertical dividing line to divide the land area to be restored into a plurality of sub-areas, the plurality of sub-areas including area A1, area A2, area A3, area B1, area B2, area B3, area C1, area C2, and area C3, the areas A1, A2, and A3 being arranged sequentially along the horizontal direction of the land area to be restored, the areas B1, B2, and B3 being arranged sequentially along the horizontal direction of the land area to be restored, the areas C1, C2, and C3 being arranged sequentially along the horizontal direction of the land area to be restored, the areas A1, A2, and A3 being located above the areas B1, B2, and B3 in the vertical direction of the land area to be restored, and the areas B1, B2, and B3 being located above the areas C1, C2, and C3 in the vertical direction of the land area to be restored;

[0007] The repair agent is injected into the land area to be repaired along the horizontal dividing line and the vertical dividing line. After the injection of the repair agent is completed, a preset time is waited, and then the land in the area A2, the area B1, the area B3, the area C2, and the area B2 is stirred.

[0008] Furthermore, the land in the areas A2, B1, B3 and C2 is stirred at a first stirring speed, and the land in the area B2 is stirred at a second stirring speed, which is greater than the first stirring speed.

[0009] Furthermore, the shapes of the regions A1, A2, A3, B1, B2, B3, C1, C2, and C3 are all rectangular.

[0010] Furthermore, the area of ​​the region A2 is larger than the area of ​​the region A1 and the area of ​​the region A3, the area of ​​the region B2 is larger than the area of ​​the region B1 and the area of ​​the region B3, and the area of ​​the region C2 is larger than the area of ​​the region C1 and the area of ​​the region C3.

[0011] Furthermore, the area of ​​the region A1 is equal to the area of ​​the region B1 and the area of ​​the region C1, the area of ​​the region A2 is equal to the area of ​​the region B2 and the area of ​​the region C2, and the area of ​​the region A3 is equal to the area of ​​the region B3 and the area of ​​the region C3.

[0012] Furthermore, the land in the areas A2, B1, B3 and C2 is stirred at a first stirring depth, and the land in the area B2 is stirred at a second stirring depth, which is greater than the first stirring depth.

[0013] Furthermore, after the injection of the repair agent is completed, wait for a first preset time and then stir the land in the area A2, the area B1, the area B3, and the area C2. After the injection of the repair agent is completed, wait for a second preset time and then stir the land in the area B2. The length of the second preset time is greater than the length of the first preset time.

[0014] The embodiments of the present application have the following beneficial effects: by dividing the land area and making reasonable design adjustments when injecting the remediation agent according to the divided sub-areas, the remediation agent is injected into the land to be remediated along the horizontal dividing line and the vertical dividing line, and differentiated stirring control is performed in combination with the divided sub-areas, so that the remediation agent can effectively act on the heavily polluted land remediation process, thereby improving the remediation efficiency of heavily polluted land and reducing the use of remediation agent. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0016] Figure 1 The following is a flow chart showing a method for remediating heavily contaminated land according to an embodiment of the present application;

[0017] Figure 2 The schematic diagram of dividing the land area to be restored into multiple sub-areas provided in an embodiment of the present application is exemplarily shown. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0019] To further illustrate the technical solutions provided by the embodiments of the present application, the following is a detailed description of the technical solutions in conjunction with the accompanying drawings and specific implementation methods. Although the embodiments of the present application provide the method operation steps as shown in the following embodiments or drawings, more or fewer operation steps may be included in the method based on routine or no creative work. In steps where there is no necessary causal relationship logically, the execution order of these steps is not limited to the execution order provided in the embodiments of the present application.

[0020] refer to Figure 1 and 2 As shown, the present application provides a method for remediating heavily contaminated land, which includes: determining a horizontal dividing line L1 and a vertical dividing line L2 to divide the land area to be remediated into multiple sub-areas, the multiple sub-areas including area A1, area A2, area A3, area B1, area B2, area B3, area C1, area C2, and area C3, area A1, area A2, and area A3 are arranged in sequence along the horizontal direction of the land area to be remediated, area B1, area B2, and area B3 are arranged in sequence along the horizontal direction of the land area to be remediated, area C1, area C2, and area C3 are arranged in sequence along the horizontal direction of the land area to be remediated, area A1, area A2, and area A3 are located above area B1, area B2, and area B3 in the vertical direction of the land area to be remediated, and area B1, area B2, and area B3 are located above area C1, area C2, and area C3 in the vertical direction of the land area to be remediated.

[0021] Furthermore, the shapes of region A1, region A2, region A3, region B1, region B2, region B3, region C1, region C2, and region C3 are all rectangular.

[0022] Furthermore, the area of ​​region A2 is larger than the area of ​​region A1 and the area of ​​region A3, the area of ​​region B2 is larger than the area of ​​region B1 and the area of ​​region B3, and the area of ​​region C2 is larger than the area of ​​region C1 and the area of ​​region C3.

[0023] The area of ​​region A1 is equal to the area of ​​region B1 and the area of ​​region C1, the area of ​​region A2 is equal to the area of ​​region B2 and the area of ​​region C2, and the area of ​​region A3 is equal to the area of ​​region B3 and the area of ​​region C3.

[0024] Inject the repair agent into the land area to be repaired along the horizontal dividing line and the vertical dividing line. After the injection of the repair agent is completed, wait for the preset time and then stir the land in area A2, area B1, area B3, area C2, and area B2.

[0025] The repair agent may be an organic acid (such as citric acid, oxalic acid, etc.), a surfactant (such as sodium dodecylbenzenesulfonate, etc.), or a phosphate agent (such as calcium dihydrogen phosphate, etc.).

[0026] When treating contaminated land with remediation chemicals, dividing the land into multiple sub-areas allows for better control over the placement and distribution of the chemicals. Contamination levels may vary from area to area, and by dividing the areas, remediation chemicals can be precisely distributed based on the severity of the contamination in each sub-area.

[0027] After the sub-areas are divided, construction workers can carry out remediation work in an orderly manner according to the area. In the remediation of large-scale contaminated land, such division can make the construction process more organized and clear.

[0028] Specifically, the land in areas A2, B1, B3, and C2 is stirred at a first stirring speed, and the land in area B2 is stirred at a second stirring speed, which is greater than the first stirring speed.

[0029] In areas A2, B1, B3, and C2, which are located on the periphery of the overall land area, if the stirring speed is too fast, the repair agent will easily spread to the surrounding unrepaired areas. This is because these peripheral areas do not have other repaired areas as barriers and are directly adjacent to the unrepaired land. For example, just like pouring water to the edge of a container full of water, if the water is poured too quickly (analogous to the fast stirring speed causing the agent to spread), the water will easily overflow from the container. Area B2 is located in the central part and is surrounded by other areas to be repaired, so the range of the agent diffusion is relatively easy to control.

[0030] By controlling the stirring speed, unnecessary loss of the repair agent can be avoided, ensuring that the agent can fully play its role in the target repair area, reducing the impact on the surrounding unrepaired land, and thus improving the utilization efficiency of the agent.

[0031] It's possible that the contamination level in the peripheral areas is relatively low, while the contamination level in the central area B2 is higher. If this is the case, the peripheral areas with lower contamination levels don't require the same rapid stirring required in the heavily contaminated central areas to ensure sufficient contact between the reagent and the contaminants. This is because the reagent reacts well with the contaminants even at lower stirring speeds in the less contaminated areas.

[0032] The soil structure in peripheral areas, due to their proximity to land boundaries, may be relatively fragile or differ from that in the central area. Rapid mixing may cause greater damage to the soil structure in these peripheral areas. For example, the soil in these peripheral areas may have a relatively unstable aggregate structure due to long-term exposure to external environmental factors (such as rain erosion and wind).

[0033] By using a slower stirring speed, we can maximize the protection of the soil structure in the peripheral areas while ensuring a certain degree of contact and reaction between the remediation agent and the contaminants. In the central area, B2, where the soil structure is relatively less susceptible to external influences, the stirring speed can be appropriately increased when more thorough stirring is required to treat high levels of contamination.

[0034] Specifically, the soil in areas A2, B1, B3, and C2 is stirred at a first stirring depth, and the soil in area B2 is stirred at a second stirring depth, which is greater than the first stirring depth.

[0035] Areas A2, B1, B3, and C2 are located on the periphery of the overall land area, and outside of them are unremediated land or other environmental media (such as water bodies, vegetation, etc.). If the mixing depth is too great, contaminated soil particles and remediation agents may spread to surrounding unremediated areas or other environmental media. For example, when the mixing depth is too deep, deep soil containing high concentrations of pollutants may mix with shallow, uncontaminated soil, thereby contaminating previously cleaner areas; or agents may penetrate into groundwater and pollute it.

[0036] In contrast, area B2 is located in the central part of the land and is surrounded by other areas to be repaired. Even if the stirring depth is large, the diffusion of pollutants and chemicals is mainly within the designated area to be repaired, and the diffusion risk is relatively low.

[0037] Control the spread of pollutants and remediation agents, reducing potential harm to unremediated areas and the surrounding environment. By limiting the mixing depth in the peripheral area, the impact of remediation activities can be controlled within a reasonable range, ensuring the safety and effectiveness of the remediation process.

[0038] It's possible that the central area (B2) of the land is more polluted than the peripheral areas (A2, B1, B3, and C2). This could be because the pollution source is located near the center of the land, or because the pollutants migrate through the land, accumulating more pollutants in the central area. For example, in some lands contaminated by atmospheric deposition or liquid infiltration, pollutants may accumulate in the central part of the land.

[0039] A deeper stirring depth is necessary for the highly contaminated area B2, so that the remediation agent can fully contact the deep-seated contaminants and achieve better remediation results. However, for the peripheral areas with relatively low contamination levels, a shallower stirring depth may be sufficient to allow the agent and contaminants to fully react.

[0040] According to the degree of contamination in different areas, the mixing depth is reasonably adjusted to optimize the allocation of remediation resources. Excessive mixing in the peripheral areas with less contamination is avoided, reducing unnecessary remediation costs and workload, while ensuring that the central areas with serious contamination are thoroughly remediated.

[0041] The soil properties in the central area B2 may be more conducive to withstanding deeper mixing operations. For example, the soil may have a better aggregate structure, which can maintain a certain stability after deeper mixing. In addition, this deep mixing can better activate remediation factors such as microorganisms within the soil and promote the reaction between the agent and the pollutant. The shallower mixing depth is used in the peripheral areas to protect the natural structure and function of the soil and maintain the stability of the soil ecosystem. For the central area B2, by appropriately increasing the mixing depth, the properties of the soil itself can be fully utilized, the reaction effect between the remediation agent and the pollutant can be enhanced, and the remediation quality can be improved.

[0042] Specifically, after the injection of the repair agent is completed, wait for the first preset time and then stir the land in area A2, area B1, area B3, and area C2. After the injection of the repair agent is completed, wait for the second preset time and then stir the land in area B2. The length of the second preset time is greater than the length of the first preset time.

[0043] Because area B2 is located in the center of the land, it's likely to be more contaminated and complex. Setting a longer second preset time allows the remediation agent more time to fully interact with and react with the contaminants in this area. In contrast, the outer areas (A2, B1, B3, and C2) are likely less contaminated, so the agent won't need as much time to react.

[0044] For complex and potentially higher concentrations of pollutants within Area B2, sufficient reaction time allows the agent to better perform its remediation function. For example, for some stubborn organic pollutants, such as polychlorinated biphenyls (PCBs), time is needed for the active ingredients in the remediation agent (such as microbial agents or chemical oxidants) to fully contact the PCB molecules, breaking them down into harmless small molecules through redox reactions or microbial degradation. A longer waiting time can increase the agent's efficiency in breaking down these stubborn pollutants, thereby enhancing the remediation effect.

[0045] During this waiting time, the remediation agent gradually penetrates and diffuses through the soil pores. For the peripheral areas (A2, B1, B3, and C2), a shorter first preset time allows for stirring before the agent diffuses excessively into unrepaired areas, concentrating the agent within the target remediation area. For area B2, a longer waiting time allows for the agent to fully diffuse and penetrate the interior, taking advantage of the surrounding area being remediated, while minimizing loss to the peripheral unremediated areas.

[0046] This allows for better control of the distribution of the agent and improves its utilization efficiency. For example, if the agent excessively spreads to untreated areas during the mixing process, it will not only waste agent resources but may also cause unnecessary pollution to surrounding untreated areas. By properly setting different waiting times, the agent can be ensured to be effective within the appropriate range in each area, reducing potential risks to the surrounding environment.

[0047] In the technical solution of the present application, the land area is divided and reasonable design adjustments are made when injecting the remediation agent according to the divided sub-areas. The remediation agent is injected into the land to be remediated along the horizontal dividing line and the vertical dividing line, and differentiated stirring control is performed in combination with the divided sub-areas, so that the remediation agent can effectively act on the heavily polluted land remediation process, thereby improving the remediation efficiency of heavily polluted land and reducing the use of remediation agent.

[0048] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0049] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0050] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0051] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0052] Obviously, those skilled in the art may make various changes and modifications to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include these modifications and variations.

Claims

1. A method for remediating heavily polluted land, characterized in that: It includes: Determining a horizontal dividing line and a vertical dividing line to divide the land area to be restored into a plurality of sub-areas, the plurality of sub-areas including area A1, area A2, area A3, area B1, area B2, area B3, area C1, area C2, and area C3, the areas A1, A2, and A3 being arranged sequentially along the horizontal direction of the land area to be restored, the areas B1, B2, and B3 being arranged sequentially along the horizontal direction of the land area to be restored, the areas C1, C2, and C3 being arranged sequentially along the horizontal direction of the land area to be restored, the areas A1, A2, and A3 being located above the areas B1, B2, and B3 in the vertical direction of the land area to be restored, and the areas B1, B2, and B3 being located above the areas C1, C2, and C3 in the vertical direction of the land area to be restored; Injecting a repair agent into the area of ​​the land to be repaired along the horizontal dividing line and the vertical dividing line, waiting for a preset time after completing the injection of the repair agent, and then stirring the land in the area A2, the area B1, the area B3, the area C2, and the area B2; stirring the soil in the areas A2, B1, B3, and C2 at a first stirring speed, and stirring the soil in the area B2 at a second stirring speed, wherein the second stirring speed is greater than the first stirring speed; The soil in the areas A2, B1, B3, and C2 is stirred at a first stirring depth, and the soil in the area B2 is stirred at a second stirring depth, wherein the second stirring depth is greater than the first stirring depth; After the injection of the repair agent is completed, wait for a first preset time and then stir the land in the area A2, the area B1, the area B3, and the area C2. After the injection of the repair agent is completed, wait for a second preset time and then stir the land in the area B2. The length of the second preset time is greater than the length of the first preset time.

2. The method for remediating heavily polluted land according to claim 1, characterized in that: The shapes of the regions A1, A2, A3, B1, B2, B3, C1, C2 and C3 are all rectangular.

3. The method for remediating heavily polluted land according to claim 2, characterized in that: The area of ​​the region A2 is larger than the area of ​​the region A1 and the area of ​​the region A3, the area of ​​the region B2 is larger than the area of ​​the region B1 and the area of ​​the region B3, and the area of ​​the region C2 is larger than the area of ​​the region C1 and the area of ​​the region C3.

4. The method for remediating heavily polluted land according to claim 3, characterized in that: The area of ​​the region A1 is equal to the area of ​​the region B1 and the area of ​​the region C1, the area of ​​the region A2 is equal to the area of ​​the region B2 and the area of ​​the region C2, and the area of ​​the region A3 is equal to the area of ​​the region B3 and the area of ​​the region C3.

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