Remediation method for heavily-polluted land

Abstract

The invention discloses a heavily-polluted land remediation method, which comprises the following steps of: dividing a land area, performing reasonable design and adjustment when a remediation agent is injected according to the divided sub-areas, and injecting the remediation agent into a to-be-remedied land along a transverse boundary and a longitudinal boundary. Differentiated stirring control is performed in combination with the divided partial sub-regions, so that the remediation agent can efficiently act on the remediation process of the heavily-polluted land, the remediation efficiency of the heavily-polluted land is improved, and the use amount of the remediation agent is reduced.

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 accumulate in the human body, leading to various diseases. Cadmium poisoning may cause kidney damage, and lead poisoning may affect the development of the nervous system, etc.

[0003] At present, the remediation methods for heavily polluted land usually include: (1) The imported soil method is to cover the surface of the polluted soil with a layer of uncontaminated clean soil. This method can effectively isolate pollutants and prevent them from spreading to the outside; (2) Thermal desorption is a method of heating the contaminated soil to volatilize or decompose pollutants. 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 are lime, phosphate, etc. The optimal ratio of agents is determined through laboratory tests and on-site pilot tests. However, at present, when chemical remediation agents are used to remediate contaminated land, the chemical agents are only injected into the remediation land, and then the land is stirred to mix the chemical remediation agents with the land, thereby achieving remediation of the contaminated land. However, this method fails to efficiently achieve the treatment of land remediation, and will cause a large amount of loss of chemical remediation agents. It fails to effectively consider the overall situation of land remediation and adjust the design of the remediation method. Summary of the invention

[0004] A method for remediating heavily polluted land is provided in an exemplary embodiment of the present application. 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 amount of remediation agent used.

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

[0006] Determine a transverse dividing line and a longitudinal dividing line to divide the land area to be restored into a plurality of sub-areas, wherein the plurality of sub-areas include area A1, area A2, area A3, area B1, area B2, area B3, area C1, area C2, and area C3, wherein the areas A1, area A2, and area A3 are sequentially arranged along the transverse direction of the land area to be restored, the areas B1, area B2, and area B3 are sequentially arranged along the transverse direction of the land area to be restored, the areas C1, area C2, and area C3 are sequentially arranged along the transverse direction of the land area to be restored, the areas A1, area A2, and area A3 are located above the areas B1, area B2, and area B3 in the longitudinal direction of the land area to be restored, and the areas B1, area B2, and area B3 are located above the areas C1, area C2, and area C3 in the longitudinal 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 area A2, the area B1, the area B3, and the area C2 is stirred at a first stirring speed, and the land in the area B2 is stirred at a second stirring speed, and the second stirring speed is greater than the first stirring speed.

[0009] Furthermore, the shapes of the region A1, region A2, region A3, region B1, region B2, region B3, region C1, region C2, and region 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 area A2, the area B1, the area B3, and the area C2 is stirred at a first stirring depth, and the land in the area B2 is stirred at a second stirring depth, and the second stirring depth 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 the heavily polluted land and reducing the amount of remediation agent used. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. 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 creative labor.

[0016] Figure 1 A schematic diagram of a process for remediating heavily polluted land provided in an embodiment of the present application is exemplarily shown;

[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 solution provided by the embodiment of the present application, this is described in detail below in conjunction with the accompanying drawings and specific implementation methods. Although the embodiment of the present application provides the method operation steps shown in the following embodiments or drawings, more or fewer operation steps may be included in the method based on routine or no creative labor. In the 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 embodiment of the present application.

[0020] refer to Figure 1 and 2 As shown, the present application provides a method for remediating heavily polluted 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 include 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 the regions A1, A2, A3, B1, B2, B3, C1, C2, and C3 are all rectangles.

[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 area of ​​land to be repaired along the horizontal dividing line and the vertical dividing line. After the repair agent is injected, wait for a 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 dodecylbenzene sulfonate, etc.), or a phosphate agent (such as calcium dihydrogen phosphate, etc.).

[0026] When using remediation agents to treat contaminated land, dividing the area into multiple sub-areas can better control the placement and distribution of the agent. The degree of contamination in different areas may vary. By dividing the area, the remediation agent can be accurately placed according to the contamination status of each sub-area.

[0027] After dividing the sub-areas, construction workers can carry out restoration work in an orderly manner according to the areas. In the restoration of large areas of contaminated land, such division can make the construction process more organized.

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

[0029] In areas A2, B1, B3, and C2 located outside the overall land area, if the stirring speed is too fast, the repair agent will easily spread to the unrepaired surrounding areas. Because these peripheral areas have no other repaired areas as barriers and are directly adjacent to the unrepaired land. For example, just like pouring water at the edge of a container full of water, if the water filling speed is too fast (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 agent diffusion is relatively easy to control.

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

[0031] It is possible that the pollution level in the peripheral area is relatively low, while the pollution level in the central area B2 is high. If this is the case, for the peripheral area with low pollution level, it is not necessary to stir the reagents and pollutants fully by rapid stirring as in the central area with serious pollution. This is because in the area with less pollution, the reagents can react with the pollutants better at a lower stirring speed.

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

[0033] By adopting a lower stirring speed, the soil structure of the peripheral area can be protected to the greatest extent while ensuring that the remediation agent has a certain contact reaction with the pollutant. As for the central area B2, since its soil structure is relatively less affected by the outside world, the stirring speed can be appropriately increased when more sufficient stirring is needed to deal with a high degree of pollution.

[0034] Specifically, the land in regions A2, B1, B3, and C2 is stirred at a first stirring depth, and the land in region 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 outside 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 large, contaminated soil particles and remediation agents may spread to the 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 the originally cleaner areas; or the agents may penetrate into the groundwater and pollute the groundwater.

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

[0037] Control the diffusion range of pollutants and remediation agents to reduce 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 is possible that the pollution level in the central area B2 of the land is more serious than that in the peripheral areas (A2, B1, B3, C2). This may be because the pollution source is located near the center of the land, or the central area accumulates more pollutants during the migration of pollutants within the land. For example, for some lands polluted 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 area B2 with a high degree of pollution, so that the repair agent can fully contact the deep pollutants to achieve a better repair effect. For the peripheral area with a relatively low degree of pollution, a shallower stirring depth may be sufficient to allow the agent and the pollutants to fully react.

[0040] According to the pollution degree of different areas, the mixing depth is reasonably adjusted to optimize the allocation of remediation resources. Avoid excessive mixing in the peripheral areas with less pollution, reduce unnecessary remediation costs and workload, and ensure that the central areas with serious pollution are thoroughly remediated.

[0041] The soil properties in the central area B2 may be more conducive to withstand deeper mixing operations. For example, the soil may have a better aggregate structure and can maintain a certain stability after deeper mixing. This deep mixing can better activate the microorganisms and other remediation factors inside the soil and promote the reaction between the agent and the pollutants. The shallower mixing depth is used in the peripheral area 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 a 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 a 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] Since area B2 is located in the central part of the land, it may be contaminated to a higher degree and complexity. Setting a longer second preset time allows the remediation agent to have more time to fully contact and react with the pollutants in this area. In contrast, the pollution level in the peripheral areas (A2, B1, B3, C2) may be relatively light, and the agent does not need such a long time to react with the pollutants.

[0044] For complex and potentially higher-content pollutants in region B2, sufficient reaction time allows the agent to better perform its repair function. For example, for some stubborn organic pollutants, such as polychlorinated biphenyls (PCBs), time is needed for the active ingredients in the repair agent (such as microbial agents or chemical oxidants) to fully contact the PCBs molecules and decompose them into harmless small molecules through redox reactions or microbial degradation. A longer waiting time can improve the efficiency of the agent in decomposing these stubborn pollutants, thereby improving the repair effect.

[0045] During the waiting time, the repair agent will gradually penetrate and diffuse in the soil pores. For the peripheral areas (A2, B1, B3, C2), the shorter first preset time can be used to stir the agent before it diffuses excessively to the unrepaired area, so that the agent can be concentrated in the target repair area to work. For area B2, the longer waiting time can take advantage of the fact that it is surrounded by areas to be repaired, allowing the agent to fully diffuse and penetrate inside, while reducing the loss to the peripheral unrepaired areas.

[0046] This can better control the distribution range of the agent and improve the utilization efficiency of the agent. For example, during the stirring process, if the agent has spread excessively to the unrepaired area, it will not only waste agent resources, but also cause unnecessary pollution to the surrounding unrepaired areas. By reasonably setting different waiting times, it can ensure that the agent can play a role in each area within the appropriate range, 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. This allows the remediation agent to effectively act on the heavily polluted land remediation process, thereby improving the remediation efficiency of heavily polluted land and reducing the amount of remediation agent used.

[0048] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may 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 may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include 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 box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes 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 capable of directing a computer or other programmable data processing device to operate 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 A 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 operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions 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 can 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 also intended to include these modifications and variations.

Claims

1. A method for remediating heavily polluted land, characterized in that: It includes: Determine a transverse dividing line and a longitudinal dividing line to divide the land area to be restored into a plurality of sub-areas, wherein the plurality of sub-areas include area A1, area A2, area A3, area B1, area B2, area B3, area C1, area C2, and area C3, wherein the areas A1, area A2, and area A3 are sequentially arranged along the transverse direction of the land area to be restored, the areas B1, area B2, and area B3 are sequentially arranged along the transverse direction of the land area to be restored, the areas C1, area C2, and area C3 are sequentially arranged along the transverse direction of the land area to be restored, the areas A1, area A2, and area A3 are located above the areas B1, area B2, and area B3 in the longitudinal direction of the land area to be restored, and the areas B1, area B2, and area B3 are located above the areas C1, area C2, and area C3 in the longitudinal direction of the land area to be restored; 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.

2. The method for remediating heavily polluted land according to claim 1, characterized in that: The land in the area A2, the area B1, the area B3 and the area C2 is stirred at a first stirring speed, and the land in the area B2 is stirred at a second stirring speed, wherein the second stirring speed is greater than the first stirring speed.

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

4. The method for remediating heavily polluted land according to claim 3, 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.

5. The method for remediating heavily polluted land according to claim 4, 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.

6. The method for remediating heavily polluted land according to claim 2, characterized in that: The land in the area A2, the area B1, the area B3, and the area C2 is stirred at a first stirring depth, and the land in the area B2 is stirred at a second stirring depth, wherein the second stirring depth is greater than the first stirring depth.

7. The method for remediating heavily polluted land according to claim 6, characterized in that: After the repair agent is injected, 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 repair agent is injected, 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.

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