In-situ thermal desorption soil remediation system and method

Abstract

The invention relates to an in-situ thermal desorption soil remediation system and method, and belongs to the technical field of soil remediation. S2, technology selection and scheme design; s3, system installation and debugging; s4, heating and extracting; and S5, tail gas treatment and emission. S6, monitoring and evaluating; and S7, performing final-period management and maintenance. According to the in-situ thermal desorption soil remediation system and method, pollutants are volatilized from the soil by heating the soil, and are collected and treated through the extraction system, so that organic pollutants in the soil can be quickly and effectively removed; according to the soil remediation method, heating treatment is directly conducted on a polluted site, and dust raising and soil structure damage possibly generated in the soil excavation process are avoided; organic pollutants generated in the thermal desorption process can be recycled and reused, so that resource saving and environment protection are realized, and the method has the advantages of efficiently removing pollutants, reducing site damage and secondary pollution and saving resources.

Description

Technical Field

[0001] The present invention relates to the technical field of soil remediation, and in particular to an in-situ thermal desorption soil remediation system and method. Background Art

[0002] In-situ thermal desorption technology has been used in the remediation of contaminated land since the 1970s. As an important means of in-situ remediation technology for volatile and semi-volatile organic polluted soil, its application in developed countries abroad has been relatively mature. This technology increases the temperature of the contaminated area by heating, changes the physical and chemical properties of the pollutants, increases the concentration of pollutants in the gas phase or liquid phase, and thus improves the removal rate of pollutants.

[0003] The basic principle of the in-situ thermal desorption soil remediation system is to heat the contaminated soil to above the boiling point of the target pollutant, and selectively promote the gasification, volatilization or cracking of the pollutants by controlling the system temperature and material residence time, so that the target pollutants are separated and removed from the soil particles. When the pollutants are converted into gas, their fluidity will be greatly improved, and the volatilized gaseous products will be collected and captured for purification.

[0004] As the nature of soil pollution and the contaminated areas continue to become more complex, the application of a single in-situ thermal desorption remediation technology can no longer meet the remediation needs of all contaminated soils. Therefore, the use of a combination of multiple technologies is an inevitable trend for the treatment and remediation of contaminated soils in my country in the future. At the same time, in order to improve the remediation efficiency and economy of in-situ thermal desorption technology, it is necessary to strengthen the research and development of related equipment and technologies, and continuously improve technical specifications.

[0005] In summary, as an advanced soil remediation technology, the in-situ thermal desorption soil remediation system and method have broad application prospects and important practical value in the field of contaminated soil treatment. By continuously optimizing and improving this technology, soil pollution problems can be more effectively solved, and the ecological environment and human health can be protected. Therefore, an in-situ thermal desorption soil remediation system and method are proposed to solve the above-mentioned problems. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention provides an in-situ thermal desorption soil remediation system and method, which has the advantages of efficient removal of pollutants, reduction of site damage and secondary pollution, strong adaptability, wide application range, environmental friendliness, resource conservation and significant economic benefits. It solves the problem that the existing soil remediation methods have low efficiency in removing pollutants, strong destructiveness, and easily cause secondary damage and waste of resources.

[0007] To achieve the above object, the present invention provides the following technical solution: an in-situ thermal desorption soil remediation method, comprising the following steps:

[0008] S1. Site investigation and assessment: Conduct detailed investigation of the contaminated site to understand the type, concentration, distribution and soil characteristics of the pollutants; assess the geological conditions, groundwater level and permeability coefficient of the contaminated site to determine the applicable type of in-situ thermal desorption technology;

[0009] S2. Technology selection and solution design: Select appropriate in-situ thermal desorption technology based on the survey results;

[0010] S3. System installation and commissioning: Install the heating system, configure the extraction system, install the exhaust gas treatment system at the contaminated site, and commission the entire system to ensure that all components operate normally and achieve the expected results;

[0011] S4, heating and extraction: Start the heating system to heat the contaminated soil to above the boiling point of the target pollutants; selectively promote the gasification, volatilization or cracking of pollutants by controlling the system temperature and material residence time, and use the extraction system to collect the volatilized gaseous pollutants and purify them;

[0012] S5. Exhaust gas treatment and emission: The collected exhaust gas is condensed, incinerated and dusted to remove pollutants and ensure that the exhaust gas emissions after treatment meet local environmental protection standards;

[0013] S6. Monitoring and evaluation: During the remediation process, regularly monitor the concentration changes of pollutants in the soil and groundwater; evaluate the remediation effect to ensure that pollutants are effectively removed;

[0014] S7. Post-management and maintenance: After the restoration is completed, the site will be managed to prevent the emergence of new pollution sources; the restoration system will be regularly inspected and maintained to ensure its long-term stable operation.

[0015] Furthermore, the in-situ thermal desorption technology in S2 includes resistance thermal desorption, thermal conduction thermal desorption and steam thermal desorption.

[0016] Furthermore, the heating system in S3 is any one of an electrode array, a heating well or a heat treatment blanket.

[0017] Furthermore, the extraction system in S3 is any one of a negative pressure extraction well and a gas phase extraction device.

[0018] Furthermore, the tail gas treatment system in S3 includes a condenser, an incinerator and a dust collector.

[0019] Another technical problem to be solved by the present invention is to provide an in-situ thermal desorption soil remediation system, comprising an energy supply system module, a heating system module, an extraction system module, a wastewater tail gas treatment module and a monitoring system module; the energy supply system module is bidirectionally electrically connected to the heating system module, the heating system module is bidirectionally electrically connected to the extraction system module, the extraction system module is bidirectionally electrically connected to the wastewater tail gas treatment module, and the wastewater tail gas treatment module is bidirectionally electrically connected to the monitoring system module;

[0020] The energy supply system module is used to provide the required energy for the entire repair system;

[0021] The heating system module is used to heat the contaminated soil to a target temperature;

[0022] The extraction system module is used to collect the volatilized pollutants and transport them to the subsequent treatment system;

[0023] The wastewater and tail gas treatment module is used to treat tail gas and wastewater containing pollutants to ensure that the discharge meets the standards;

[0024] The monitoring system module is used to monitor the operating status and repair effect of the system in real time to ensure the normal operation and repair effect of the system.

[0025] Furthermore, the energy in the energy supply system module is either electric energy or gas.

[0026] Furthermore, the heating method in the heating system module is any one of resistance heating, heat conduction heating or steam heating.

[0027] Compared with the prior art, the present invention provides an in-situ thermal desorption soil remediation system and method, which has the following beneficial effects:

[0028] 1. The in-situ thermal desorption soil remediation system and method heats the soil to volatilize pollutants from the soil, and collects and processes them through an extraction system, so as to quickly and effectively remove organic pollutants in the soil. The soil remediation method directly performs heating treatment at the pollution site, avoiding dust and soil structure damage that may be generated during soil excavation. The organic pollutants generated during the thermal desorption process can be recycled and reused to achieve resource conservation and environmental protection. It has the advantages of efficient removal of pollutants, reduction of site damage and secondary pollution, strong adaptability, wide application range, environmental friendliness, resource conservation and significant economic benefits.

[0029] 2. The in-situ thermal desorption soil remediation system and method can effectively remove volatile and semi-volatile organic pollutants from the soil by precisely controlling the heating temperature and duration through the heating system module; by recycling and reusing the organic pollutants generated during the thermal desorption process, the recycling of resources is achieved, further improving the environmental performance of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a process flow diagram of an in-situ thermal desorption soil remediation system and method proposed by the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Embodiment 1:

[0033] See also Figure 1 In this embodiment, an in-situ thermal desorption soil remediation method comprises the following steps:

[0034] S1. Site investigation and assessment: Conduct detailed investigation of the contaminated site to understand the type, concentration, distribution and soil characteristics of the pollutants; assess the geological conditions, groundwater level and permeability coefficient of the contaminated site to determine the applicable type of in-situ thermal desorption technology;

[0035] S2. Technology selection and solution design: Select appropriate in-situ thermal desorption technology based on the survey results;

[0036] S3. System installation and commissioning: Install the heating system, configure the extraction system, install the exhaust gas treatment system at the contaminated site, and commission the entire system to ensure that all components operate normally and achieve the expected results;

[0037] S4, heating and extraction: Start the heating system to heat the contaminated soil to above the boiling point of the target pollutants; selectively promote the gasification, volatilization or cracking of pollutants by controlling the system temperature and material residence time, and use the extraction system to collect the volatilized gaseous pollutants and purify them;

[0038] S5. Exhaust gas treatment and emission: The collected exhaust gas is condensed, incinerated and dusted to remove pollutants and ensure that the exhaust gas emissions after treatment meet local environmental protection standards;

[0039] S6. Monitoring and evaluation: During the remediation process, regularly monitor the concentration changes of pollutants in the soil and groundwater; evaluate the remediation effect to ensure that pollutants are effectively removed;

[0040] S7. Post-management and maintenance: After the restoration is completed, the site will be managed to prevent the emergence of new pollution sources; the restoration system will be regularly inspected and maintained to ensure its long-term stable operation.

[0041] In this embodiment, the pollutants are volatilized from the soil by heating the soil, and are collected and processed by an extraction system, so that organic pollutants in the soil can be removed quickly and effectively; the soil remediation method directly performs heating treatment at the pollution site, avoiding dust and soil structure damage that may be generated during soil excavation; the organic pollutants generated during the thermal desorption process can be recycled and reused to achieve resource conservation and environmental protection, and has the advantages of efficient removal of pollutants, reduction of site damage and secondary pollution, strong adaptability, wide application range, environmental friendliness, resource conservation and significant economic benefits.

[0042] Specifically, the in-situ thermal desorption techniques in S2 include resistive thermal desorption, thermal conduction thermal desorption and steam thermal desorption.

[0043] Specifically, the tail gas treatment system in S3 includes a condenser, an incinerator and a dust collector.

[0044] It should be noted that the heating system in S3 is any one of an electrode array, a heating well or a heat treatment blanket.

[0045] It should be noted that the extraction system in S3 is any one of a negative pressure extraction well and a gas phase extraction device.

[0046] The working principle of the above embodiment is:

[0047] By heating the soil, pollutants are volatilized from the soil, and then collected and processed through an extraction system, organic pollutants in the soil can be removed quickly and effectively. This soil remediation method directly performs heating treatment at the pollution site, avoiding dust and soil structure damage that may be generated during soil excavation. Organic pollutants generated during thermal desorption can be recycled and reused to achieve resource conservation and environmental protection.

[0048] Embodiment 2:

[0049] An in-situ thermal desorption soil remediation system in this embodiment includes an energy supply system module, a heating system module, an extraction system module, a wastewater exhaust gas treatment module and a monitoring system module; the energy supply system module is bidirectionally electrically connected to the heating system module, the heating system module is bidirectionally electrically connected to the extraction system module, the extraction system module is bidirectionally electrically connected to the wastewater exhaust gas treatment module, and the wastewater exhaust gas treatment module is bidirectionally electrically connected to the monitoring system module.

[0050] In this embodiment, the energy supply system module is used to provide the required energy for the entire remediation system; the heating system module is used to heat the contaminated soil to the target temperature; the extraction system module is used to collect volatilized pollutants and transport them to the subsequent treatment system; the wastewater and tail gas treatment module is used to treat the tail gas and wastewater containing pollutants to ensure that the emissions meet the standards; the monitoring system module is used to monitor the operating status and remediation effect of the system in real time to ensure the normal operation and remediation effect of the system.

[0051] In this embodiment, the heating system module accurately controls the heating temperature and duration, so that volatile and semi-volatile organic pollutants in the soil can be efficiently removed. By recycling and reusing the organic pollutants generated during the thermal desorption process, resource recycling is achieved, further improving the environmental performance of the system.

[0052] It should be noted that the energy in the energy supply system module is either electricity or gas.

[0053] It should be noted that the heating method in the heating system module is any one of resistance heating, heat conduction heating or steam heating.

[0054] The working principle of the above embodiment is:

[0055] By precisely controlling the heating temperature and duration through the heating system module, volatile and semi-volatile organic pollutants in the soil can be efficiently removed; by recycling and reusing the organic pollutants generated during the thermal desorption process, resource recycling is achieved, further improving the environmental performance of the system.

[0056] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0057] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An in-situ thermal desorption soil remediation method, characterized in that: The following steps are involved: S1. Site investigation and assessment: Conduct detailed investigation of the contaminated site to understand the type, concentration, distribution and soil characteristics of the pollutants; assess the geological conditions, groundwater level and permeability coefficient of the contaminated site to determine the applicable type of in-situ thermal desorption technology; S2. Technology selection and solution design: Select appropriate in-situ thermal desorption technology based on the survey results; S3. System installation and commissioning: Install the heating system, configure the extraction system, install the exhaust gas treatment system at the contaminated site, and commission the entire system to ensure that all components operate normally and achieve the expected results; S4, heating and extraction: Start the heating system to heat the contaminated soil to above the boiling point of the target pollutants; selectively promote the gasification, volatilization or cracking of pollutants by controlling the system temperature and material residence time, and use the extraction system to collect the volatilized gaseous pollutants and purify them; S5. Exhaust gas treatment and emission: The collected exhaust gas is condensed, incinerated and dusted to remove pollutants and ensure that the exhaust gas emissions after treatment meet local environmental protection standards; S6. Monitoring and evaluation: During the remediation process, regularly monitor the concentration changes of pollutants in the soil and groundwater; evaluate the remediation effect to ensure that pollutants are effectively removed; S7. Post-management and maintenance: After the restoration is completed, the site will be managed to prevent the emergence of new pollution sources; the restoration system will be regularly inspected and maintained to ensure its long-term stable operation.

2. The in-situ thermal desorption soil remediation method according to claim 1, characterized in that: The in-situ thermal desorption technology in S2 includes resistance thermal desorption, thermal conduction thermal desorption and steam thermal desorption.

3. The in-situ thermal desorption soil remediation method according to claim 1, characterized in that: The heating system in S3 is any one of an electrode array, a heating well or a heat treatment blanket.

4. The in-situ thermal desorption soil remediation method according to claim 1, characterized in that: The extraction system in S3 is any one of a negative pressure extraction well and a gas phase extraction device.

5. The in-situ thermal desorption soil remediation method according to claim 1, characterized in that: The tail gas treatment system in S3 includes a condenser, an incinerator and a dust collector.

6. An in-situ thermal desorption soil remediation system, using the in-situ thermal desorption soil remediation method according to any one of claims 1 to 5, characterized in that: It includes an energy supply system module, a heating system module, an extraction system module, a wastewater tail gas treatment module and a monitoring system module; the energy supply system module is bidirectionally electrically connected to the heating system module, the heating system module is bidirectionally electrically connected to the extraction system module, the extraction system module is bidirectionally electrically connected to the wastewater tail gas treatment module, and the wastewater tail gas treatment module is bidirectionally electrically connected to the monitoring system module; The energy supply system module is used to provide the required energy for the entire repair system; The heating system module is used to heat the contaminated soil to a target temperature; The extraction system module is used to collect the volatilized pollutants and transport them to the subsequent treatment system; The wastewater and tail gas treatment module is used to treat tail gas and wastewater containing pollutants to ensure that the discharge meets the standards; The monitoring system module is used to monitor the operating status and repair effect of the system in real time to ensure the normal operation and repair effect of the system.

7. The in-situ thermal desorption soil remediation system according to claim 6, characterized in that: The energy in the energy supply system module is any one of electric energy or gas.

8. The in-situ thermal desorption soil remediation system according to claim 6, characterized in that: The heating method in the heating system module is any one of resistance heating, heat conduction heating or steam heating.

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