System for assessing the sustainability of in-situ thermal processing coupled with chemical remediation of organic contaminated sites

Abstract

The application discloses a kind of in-situ heat treatment coupling chemical method repair organic pollution site sustainability evaluation model, using LCA-BMPs comprehensive model, the total score of the sustainability of in-situ repair scheme of organic pollution site is calculated, and the sustainability is judged according to total score;The application quantitatively evaluates the sustainability of the environment, economy and society of three indicators of in-situ heat treatment coupling repair organic pollution site in a comprehensive manner, quantitatively evaluates the environmental sustainability and carbon emission in the repair process, and obtains the total quantitative sustainable result through LCA-BMPs comprehensive model, breaks the barrier that pollution site repair technology economy and social evaluation is strong in subjectivity, environmental, economic and social three aspects of sustainable evaluation coupling is weak, provides feasible method basis for the quantitative sustainable evaluation and comprehensive evaluation of pollution site repair technology environment, economy and society.

Description

Technical Field

[0001] This invention relates to the field of contaminated site remediation assessment technology, specifically to a sustainability assessment system for in-situ thermal treatment coupled with chemical methods for remediating organically contaminated sites. Background Technology

[0002] In recent years, with the advancement of industrialization and urbanization, the situation of organic pollution in soil and groundwater in my country has become increasingly severe. Studies have shown that organic pollutants were detected in at least 48.42% of 791 groundwater samples from 69 cities in 31 provinces across the country; and complex organic pollution is significant, mainly including chloroform, 1,2-dichloroethane, 1,1,2-trichloroethane, and 1,1,2,2-tetrachloroethane. Currently, key chemical sites in some cities such as Beijing, Nanjing, and Shanghai, as well as soil and groundwater in the Yangtze River Delta and Pearl River Delta regions, exhibit varying degrees of chlorinated hydrocarbon pollution, necessitating urgent remediation and risk management of organically contaminated sites. Remediation technologies for organically contaminated sites include physical remediation (such as thermal desorption and vapor phase extraction), chemical remediation (such as chemical oxidation / reduction), and bioremediation. Different remediation technologies can be applied in situ or ex-situ. In-situ thermal treatment technology is widely used because it is less sensitive to underground heterogeneity, can treat multiple organic pollutants simultaneously, requires less remediation time, and has high remediation efficiency.

[0003] However, in-situ thermal treatment technology has low heat utilization efficiency during high-temperature remediation processes (e.g., 300℃~550℃), with up to 80% of the heat energy lost during the heating of soil and groundwater. Therefore, the cost and energy consumption of in-situ thermal treatment technology are usually much higher than other remediation technologies. Furthermore, minerals and organic matter in soil and groundwater are decomposed and destroyed under high-temperature remediation, leading to a decline in soil reusability. Thus, high energy consumption and the environmental side effects of high temperatures have become bottlenecks in the development and application of in-situ thermal treatment technology. Studies have shown that the combined physical and chemical remediation of organic pollutants is significantly superior to single physical remediation methods. For example, in-situ thermal treatment coupled with in-situ chemical oxidation technology can activate oxidants (such as persulfate) at relatively low temperatures (55℃) and remove organic pollutants in a short time, avoiding irreversible damage to the soil caused by high temperatures, while also significantly reducing energy consumption caused by high-temperature heating. Currently, the main heating methods for in-situ thermal treatment include heat conduction heating, resistance heating, and steam-enhanced extraction.

[0004] Meanwhile, against the backdrop of global carbon emission reduction, sustainable remediation has become an inevitable trend in the development of organic contaminated site remediation in my country. Sustainable assessment, from a life-cycle perspective, comprehensively considers the environmental, economic, and social impacts of remediation activities, focusing on reducing secondary environmental pollution and energy and resource consumption during the remediation process, thereby minimizing the environmental footprint. This is a crucial strategy for achieving green and sustainable development. In-situ thermal treatment technology is considered ungreen and unsustainable due to its high energy consumption, high carbon emissions, and the potential for soil degradation that hinders land reuse. However, in-situ thermal treatment coupled with chemical remediation technology can achieve synergistic remediation of organic contaminated sites in both time and space. Studies have shown that the heating temperature required by this coupled remediation technology is only half or even lower than that of single thermal treatment remediation technologies, and the energy consumption is only one-third of that of single thermal treatment, thus significantly reducing environmental impacts such as carbon emissions and remediation costs. However, current research on in-situ thermal treatment coupled with chemical methods for the remediation of organically contaminated sites is mostly based on laboratory scale. Quantitative sustainability assessment models have not yet been established, and these methods have not been applied to actual organically contaminated site remediation. This results in the uncertainty of the potential environmental "net benefits" and socio-economic benefits of in-situ thermal treatment coupled with chemical methods for the remediation of large-scale organically contaminated sites. This hinders the sustainable development of in-situ thermal treatment coupled technology. There is an urgent need to establish a sustainability assessment system for in-situ thermal treatment coupled with chemical methods, and to conduct sustainability assessments of actual remediation projects. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides a sustainability assessment system for in-situ thermal treatment coupled with chemical methods to remediate organically contaminated sites.

[0006] The technical solution of this invention is: a sustainability assessment system for in-situ thermal treatment coupled with chemical methods for remediating organically contaminated sites. The system structure is as follows: S 总 = (1) In the formula, S 总 S represents the overall sustainability score of the in-situ thermal treatment coupled with / in-situ chemical remediation scheme. 总 The range is 0~100, where IV represents the environmental indicator score obtained by the LCA quantitative assessment method, the social indicator score obtained by the BMPs quantitative assessment method, and the economic indicator score; IVmax represents the maximum score among the environmental, social, and economic indicators; and W is the weight of each indicator. Sustainability Total Score 总 A higher value indicates a higher sustainability of the in-situ remediation plan for organically contaminated sites; the total sustainability score S... 总 The smaller the value, the lower the sustainability of the in-situ remediation plan for organically contaminated sites.

[0007] The environmental index score is obtained by evaluating the in-situ thermal treatment coupled remediation scheme of organic contaminated site through the LCA quantitative assessment method, obtaining the LCA assessment result of in-situ remediation of organic contaminated site, and then calculating it based on the LCA assessment result. The social and economic indicators scores are obtained by evaluating the in-situ thermal treatment coupled remediation scheme for organic contaminated sites using the BMPs quantitative assessment method. The BMPs assessment results for in-situ remediation of organic contaminated sites are then calculated based on the BMPs assessment results.

[0008] Note: The above model is constructed by combining environmental, economic, and social sustainability factors and employing the Life Cycle Assessment (LCA) coupled with Best Management Practices (BMPs) method. It can systematically and comprehensively quantitatively assess the environmental, economic, and social sustainability of TCH-ISCO remediation technology, providing theoretical guidance and data support for the research, development, upgrading, and application of TCH-ISCO remediation technology. The LCA-BMPs integrated model assesses the degree to which a technology meets defined standards. It integrates different types of environmental, economic, and social quantitative data into a comprehensive evaluation, quantifies and normalizes it, and achieves the goal of assessing the sustainability of different remediation schemes. Its ability to integrate different types of data perfectly matches the integration of environmental, economic, and social outcomes in sustainability assessment.

[0009] Furthermore, the in-situ heat treatment coupled repair scheme includes, but is not limited to, heat conduction heating and resistance heating repair schemes; the in-situ chemical repair scheme includes, but is not limited to, in-situ chemical oxidation.

[0010] Furthermore, the environmental indicators include: sub-indicators of human health, ecosystem, and resource consumption; the social indicators include: sub-indicators of worker injury, health risk, community participation, community satisfaction, transparency, and smog; and the economic indicators include: sub-indicators of direct economic expenditure, project risk and restoration duration, land value-added, and employment.

[0011] Explanation: The reasons for selecting the above sub-indicators are as follows: The sub-indicators of human health, ecosystem, and resource consumption are quantitatively calculated using the life cycle assessment endpoint method; worker injury and health risks are important factors in social indicators, aiming to minimize health damage caused by the remediation process; community participation and community satisfaction can increase community participation in the project; the transparency sub-indicator ensures the transparency of the remediation project to the public, allowing them to understand the project's progress and potential harms at all times; smoke and dust describe the physical impact of the remediation process on the community; direct economic expenditure describes the quantifiable direct costs of the remediation project and is a core element of the economic indicators; project risk describes the possibility of project failure, leading to long-term additional costs; the duration of the remediation action is also required; the appreciation potential of the remediated land is also a core element in assessing economic indicators; employment is a quantitative indicator for the re-employment of community residents and may increase the employment rate of people around the remediation area; the above sub-indicators can systematically and comprehensively quantitatively assess the environmental, economic, and social sustainability of TCH-ISCO remediation technology and identify the key processes and core elements affecting the sustainability of TCH-ISCO remediation technology.

[0012] Furthermore, the quantitative assessment method for LCA is as follows: First, the functional units are defined, the system boundaries are delineated, and life cycle inventory data is collected. Then, SimaPro 9.0 software is used to select the feature model ReCiPe2016, select the impact category corresponding to the sub-indicator in the LCA environmental indicator to be obtained, and classify the life cycle inventory data into the selected impact category. The calculation and sensitivity analysis are started to obtain the midpoint and endpoint values ​​and determine the key sustainability influencing factors. The ReCiPe endpoint score was normalized to obtain the endpoint value of the LCA assessment result. The unit of the endpoint value result is kpt. The higher the kpt value, the smaller the environmental impact of the in-situ remediation plan for the organic contaminated site. The lower the kpt value, the greater the environmental impact of the in-situ remediation plan for the organic contaminated site. The method for calculating environmental indicator scores based on LCA assessment results is as follows: If the scores of the environmental impact endpoint index in two different in-situ thermal treatment coupled chemical remediation schemes are a and b, respectively, and the unit is kPt, The endpoint score of the repair scheme with the smaller kPt value is selected and assigned a value of 100. The endpoint score of the other repair scheme is reduced by the same factor, i.e., a / b times, and its score is 100*a / b. The three endpoint results of the two different in-situ thermal treatment coupled chemical repair schemes are obtained by the same method.

[0013] Finally, with each endpoint indicator weighted at 0.33, the weighted average of the three endpoint indicators is calculated, and the weighted averages are summed to obtain the final environmental indicator score, which differs from the in-situ thermal treatment coupled with chemical remediation scheme.

[0014] Note: By defining functional units, system boundaries, and specific remediation processes, the assessment of remediation schemes becomes more targeted; the LCA quantitative assessment method can quantitatively calculate the environmental impact of the entire process of contaminated site remediation from a life-cycle perspective, making it a powerful tool for assessing the environmental sustainability of contaminated sites both domestically and internationally.

[0015] Furthermore, the LCA assessment results include: midpoint value results, endpoint value results, carbon emission results, and sensitivity analysis results; the data for the LCA quantitative assessment method comes from the Ecoinvent database; the collection principles for the life cycle inventory data include: collecting quantitative data within the system boundary, and collecting quantitative data through measurement, calculation, or estimation; life cycle data includes: data on raw material acquisition, site construction, operation, and project completion.

[0016] Note: The ReCiPe2016 feature model in SimaPro 9.0 software is applicable to the calculation of carbon emission factors in soil remediation in Asia. By selecting the feature model and dividing the data, the results of quantitative assessment of LCA can be calculated more scientifically.

[0017] Furthermore, the impact categories are divided into three parts: environmental impact, economic impact, and social impact, each corresponding to a sub-indicator within the environmental, economic, and social indicators. Environmental impact includes three categories: resource consumption, ecosystem impact, and human health impact. Sub-indicators for resource consumption include mineral resource consumption and primary energy consumption; sub-indicators for ecosystem impact include greenhouse gas emissions, terrestrial ecotoxicity, and marine ecotoxicity; and sub-indicators for human health include carcinogenic and non-carcinogenic toxicity. Economic impact includes five categories: direct economic input, project risk, remediation time, land value appreciation, and employment impact. Social impact includes six categories: worker injury, health risks, smog and dust, community participation, community satisfaction, and transparency.

[0018] Note: By setting the corresponding values ​​of the above-mentioned impact categories and their indicators, the corresponding values ​​of each sub-indicator can be calculated one by one.

[0019] Furthermore, the method for evaluating the in-situ thermal treatment coupled remediation scheme of organic contaminated sites using the BMPs quantitative assessment method is as follows: determine the functional units and system boundaries, then screen and collect BMPs data for model calculation, obtain the total score of each indicator, and then use the following formula (2) to obtain the final sub-indicator score S: S= (2) Where S1 is the total score of all indicators, i.e. the evaluation result of BMPs, with a value of 5; S is the final sub-indicator score, with a value of 1 to 5; Ma is the number of BMPs; M is the number of BMPs actually executed during the repair process; The method for calculating the social and emergency indicator scores from the BMPs assessment results is as follows: Among social indicators, For the worker safety sub-indicator and the smoke and dust sub-indicator, based on the size of the BMPs results in the two schemes, the sub-indicator with the larger result value is assigned a score of 100, and the sub-indicator of the other scheme is reduced by the same factor year-on-year; for other indicators in the social indicators, the corresponding scores are obtained according to the full score of 5 points, corresponding to the percentage ratio. Then, the weights of each sub-indicator are set and a weighted average is calculated to obtain the social indicator score. Among economic indicators, For the direct cost sub-indicator and the project risk sub-indicator, based on the size of the BMPs results in the two scenarios, the sub-indicator with the larger result value is assigned a score of 100, and the sub-indicator of the other scenario is reduced by the same factor year-on-year; for other economic indicators, the corresponding scores are obtained according to a 5-point full score system, corresponding to a percentage system. Then, the weights of each sub-indicator are set and a weighted average is calculated to obtain the final economic indicator score.

[0020] Note: BMPs can reduce the environmental, economic and social impacts of contaminated soil and groundwater remediation by regulating remediation behavior; by reducing the uncertainty of social and economic sustainability indicators in previous studies and reducing the influence of subjective human factors, there are not many comprehensive combinations of BMPs that can be applied to environmental, economic and social assessments. Existing studies have mostly focused on the assessment of individual environmental impact factors.

[0021] Furthermore, the method for screening and collecting BMPs data is as follows: First, screen the BMPs common to SuRF-UK, USEPA and ASTM, and exclude the BMPs that are the same as those in the three, as well as the BMPs other than TCH and ISCO; then combine TCH and ISCO, and remove the same BMPs to obtain the BMPs data.

[0022] SuRF-UK is the UK Sustainable Remediation Forum: This study compares SuRF-UK's 2021 white paper, "Sustainable Management Practices for Management of Land Contamination"; ASTM is the American Society for Testing and Materials; USEPA is the US Environmental Protection Agency; This study compares ASTM's 2014 "Standard Guide for Integrating Sustainable Objectives into Cleanup" program. Note: By using the above method for screening, since the common parts among the existing technologies are more important and recognized, the common methods are selected, while all duplicates and BMPs outside the scope are excluded, making the obtained data more scientific and practical.

[0023] Furthermore, the functional unit is: repairing 1000m 3 Sustainability impacts of contaminated soil and groundwater below control limits; system boundaries are defined as the period from the start of the remediation project to its completion, including four phases: raw material acquisition, site construction, operation, and remediation completion.

[0024] The application of a sustainability assessment model for in-situ thermal treatment coupled with chemical methods to remediate organically contaminated sites was demonstrated, which was used to evaluate the optimal remediation scheme among multiple in-situ remediation options for organically contaminated sites.

[0025] Furthermore, it was used to evaluate the most suitable sites for the TCH-ISCO remediation scheme.

[0026] Furthermore, it can be used to optimize in-situ remediation schemes for organically contaminated sites. The optimization method is as follows: based on the sensitivity analysis results in the LCA assessment, the key sustainability influencing factors of the in-situ remediation scheme for organic contaminated sites are determined, and measures to improve the in-situ remediation scheme for organic contaminated sites are proposed using the key sustainability influencing factors; the key sustainability influencing factors include raw material consumption, electricity consumption, transportation consumption, and oxidant consumption.

[0027] The beneficial effects of this invention are: (1) This invention combines environmental, economic and social sustainability factors and uses the life cycle assessment method (LCA) coupled with the best management practices (BMPs) to construct a sustainable quantitative assessment method for TCH-ISCO remediation technology. It includes three major items and 14 minor items of sustainable quantitative assessment indicators, including environmental, economic and social sustainability. It systematically and comprehensively quantitatively assesses the sustainability of the three major indicators of TCH-ISCO remediation technology, and identifies the key processes and core elements that affect the sustainability of TCH-ISCO remediation technology. It provides theoretical guidance and data support for the research, development, upgrading and promotion of TCH-ISCO remediation technology.

[0028] (2) This invention quantitatively assessed the environmental sustainability and carbon emissions of TCH-ISCO remediation technology, demonstrating the carbon reduction benefits of TCH-ISCO remediation technology; it established a quantitative assessment method of BMPs to evaluate the economic and social sustainability of TCH-ISCO remediation technology during the remediation process, and obtained the overall quantitative sustainability results of TCH-ISCO remediation technology through LCA-BMPs, breaking the barrier of strong subjectivity in the economic and social assessment of contaminated site remediation technology in recent years, and providing a feasible methodological basis for the future quantitative economic and social sustainability assessment of contaminated site remediation technology.

[0029] (3) This invention takes a TCH-ISCO remediation demonstration project of an organic contaminated site in Tianjin as an application case and a TCH technology application case as a control. By calculating the overall sustainability scores of TCH-ISCO remediation technology and TCH remediation technology, the final sustainability score of TCH-ISCO remediation technology is 89.6 points and the final sustainability score of TCH remediation technology is 61.9 points, which confirms the superiority and sustainability of TCH-ISCO remediation technology. At the same time, it identifies the key factors affecting its environmental sustainability and carbon emissions as well as the key indicators affecting economic and social sustainability. Attached Figure Description

[0030] Figure 1 This is a graph showing the environmental impact percentage of each LCA in this invention, where a represents TCH-ISCO and b represents TCH. Figure 2 This is a graph showing the impact of point values ​​in the environment caused during the repair process of this invention. Figure 3 This is a graph showing the impact of point values ​​in the environment caused during the repair process of this invention. Figure 4 This is a graph of the endpoint results of this invention, where a represents the total impact and b represents the impact of the three endpoint indicators. Figure 5 The carbon emission flow data between the LCA stages of this invention is shown in Figure a, which represents the TCH-ISCO remediation technology, and Figure b represents TCH. Figure 6 This is a sensitivity analysis diagram of the LCA results of the TCH-ISCO and TCH repair technologies of this invention; Figure 7 This is a sensitivity analysis diagram of carbon emission results for the TCH-ISCO and TCH remediation technologies of this invention; Figure 8 This is a schematic diagram illustrating the quantitative sustainable economic and social outcomes of this invention, where a represents the economic outcome and b represents the social outcome. Figure 9 This is a schematic diagram of the overall sustainability assessment results of this invention. a represents the environmental, economic and social assessment results; b represents the overall quantitative sustainability assessment results. Detailed Implementation

[0031] The present invention will now be described in more detail with reference to specific embodiments, so as to better demonstrate the advantages of the present invention.

[0032] Example 1: A TCH-ISCO remediation was carried out at a chlorinated hydrocarbon contaminated site in a chemical reagent factory in Tianjin, China. The implementation process is as follows: A sustainability assessment system for in-situ thermal treatment coupled with chemical methods for the remediation of organically contaminated sites, with the following system structure: S 总 = (1) In the formula, S 总 S represents the overall sustainability score of the in-situ thermal treatment coupled with / in-situ chemical remediation scheme. 总 The range is 0~100, where IV represents the environmental indicator score obtained by the LCA quantitative assessment method, the social indicator score obtained by the BMPs quantitative assessment method, and the economic indicator score; IVmax represents the maximum score among the environmental, social, and economic indicators; and W is the weight of each indicator. Sustainability Total Score 总 A higher value indicates a higher sustainability of the in-situ remediation plan for organically contaminated sites; the total sustainability score S... 总 The smaller the value, the lower the sustainability of the in-situ remediation plan for organically contaminated sites.

[0033] The environmental index score is obtained by evaluating the in-situ thermal treatment coupled remediation scheme of organic contaminated site through the LCA quantitative assessment method, obtaining the LCA assessment result of in-situ remediation of organic contaminated site, and then calculating it based on the LCA assessment result. The social and economic indicators scores are obtained by using the BMPs quantitative assessment method to evaluate the in-situ thermal treatment coupled remediation scheme for organic contaminated sites, and then calculating the scores based on the BMPs assessment results. The environmental indicators include: sub-indicators of human health, ecosystem, and resource consumption; the social indicators include: sub-indicators of worker injury, health risk, community participation, community satisfaction, transparency, and smog; the economic indicators include: sub-indicators of direct economic expenditure, project risk and restoration duration, land value-added, and employment. The quantitative assessment method for LCA is as follows: First, the functional units are defined, the system boundaries are delineated, and life cycle inventory data is collected. Then, SimaPro 9.0 software is used to select the feature model ReCiPe2016, select the impact category corresponding to the sub-indicator in the LCA environmental indicator to be obtained, and classify the life cycle inventory data into the selected impact category. The calculation and sensitivity analysis are started to obtain the midpoint and endpoint values ​​and determine the key sustainability influencing factors. The in-situ heat treatment coupled repair scheme includes, but is not limited to, heat conduction heating and resistance heating repair schemes; the in-situ chemical repair scheme includes, but is not limited to, in-situ chemical oxidation; The ReCiPe endpoint score was normalized to obtain the endpoint value of the LCA assessment result. The unit of the endpoint value result is kpt. The higher the kpt value, the smaller the environmental impact of the in-situ remediation plan for the organic contaminated site. The lower the kpt value, the greater the environmental impact of the in-situ remediation plan for the organic contaminated site. The method for calculating environmental indicator scores based on LCA assessment results is as follows: If the scores of the environmental impact endpoint index in two different in-situ thermal treatment coupled chemical remediation schemes are a and b, respectively, and the unit is kPt, The endpoint score of the repair scheme with the smaller kPt value is selected and assigned a value of 100. The endpoint score of the other repair scheme is reduced by the same factor, i.e., a / b times, and its score is 100*a / b. The three endpoint results of the two different in-situ thermal treatment coupled chemical repair schemes are obtained by the same method.

[0034] Finally, with each endpoint indicator weighted at 0.33, the weighted average of the three endpoint indicators is calculated, and the weighted averages are summed to obtain the final environmental indicator score, which is different from the in-situ thermal treatment coupled chemical remediation scheme. The LCA assessment results include: midpoint results, endpoint results, carbon emission results, and sensitivity analysis results; the data for the LCA quantitative assessment method comes from the Ecoinvent database; the collection principles for the life cycle inventory data include: collecting quantitative data within the system boundary, and collecting quantitative data through measurement, calculation, or estimation; life cycle data includes: data on raw material acquisition, site construction, operation, and project completion; The lifecycle inventory data includes data on raw material acquisition, site construction, operation, and project completion. These four phases are further divided into raw materials, energy, resources, transportation, and emissions. The raw material acquisition phase includes various well-building materials such as quartz sand and bentonite, general equipment such as electrical control boxes, and chemicals. The site construction phase includes the construction of heating wells, injection wells, and temperature monitoring wells, as well as materials such as insulating bricks, concrete, and cables consumed during site leveling. The operation phase includes the power consumption of heating wells, injection wells, and temperature monitoring wells. The project completion phase includes landfilling of various wells and waste transportation. Detailed system boundary definitions for TCH-ISCO remediation technology and TCH remediation technology (comparison) can be found in [link to documentation]. Figure 5 The key environmental impact indicators in this assessment included greenhouse gas emissions, so data on electricity and fuel consumption throughout the process were included, but the manufacturing of machinery and vehicles used on-site and the removal of such machinery were excluded. The time frame was 100 years to facilitate long-term monitoring of the dynamic changes at the remediation site; the results are shown in Table 1. The impact categories are divided into three parts: environmental impact, economic impact, and social impact. Environmental impact includes three categories: resource consumption, ecosystem impact, and human health impact. Sub-indicators for resource consumption include mineral resource consumption and primary energy consumption; sub-indicators for ecosystem impact include greenhouse gas emissions, terrestrial ecotoxicity, and marine ecotoxicity; sub-indicators for human health impact include carcinogenic and non-carcinogenic toxicity. Economic impact includes five categories: direct economic input, project risk, remediation time, land value appreciation, and employment impact. Social impact includes six categories: worker injury, health risks, smog and dust, community participation, community satisfaction, and transparency. The method for evaluating the in-situ thermal treatment coupled remediation scheme of organic contaminated site by quantitative assessment using BMPs is as follows: determine the functional units and system boundaries, then screen and collect BMPs data for model calculation, obtain the total score of each index, and then use the following formula (2) to obtain the final sub-index score S: S= (2) Where S1 is the total score of all indicators, i.e. the evaluation result of BMPs, with a value of 5; S is the final sub-indicator score, with a value of 1 to 5; Ma is the number of BMPs; M is the number of BMPs actually executed during the repair process; The method for calculating the social and emergency indicator scores from the BMPs assessment results is as follows: Among social indicators, For the worker safety sub-indicator and the smoke and dust sub-indicator, based on the size of the BMPs results in the two schemes, the sub-indicator with the larger result value is assigned a score of 100, and the sub-indicator of the other scheme is reduced by the same factor year-on-year; for other indicators in the social indicators, the corresponding scores are obtained according to the full score of 5 points, corresponding to the percentage ratio. Then, a weighted average is calculated based on the sub-indicators of worker injury (weight 0.2), health risk (weight 0.2), and all other sub-indicators (weight 0.15) to obtain the social index score. Among economic indicators, For the direct cost sub-indicator and the project risk sub-indicator, based on the size of the BMPs results in the two scenarios, the sub-indicator with the larger result value is assigned a score of 100, and the sub-indicator of the other scenario is reduced by the same factor year-on-year; for other economic indicators, the corresponding scores are obtained according to a 5-point full score system, corresponding to a percentage system. Then, based on the weights of the direct economic expenditure sub-indicator (0.2), project risk (0.3), repair duration (0.2), land value-added (0.2), and employment (0.1), a weighted average is calculated to obtain the economic indicator score. Because the health risks in the social sustainability indicators and the project risks in the economic sustainability indicators differ depending on the remediation technologies used, and because the inherent risks of the project itself vary, even if the implemented Biosafety Management Platforms (BMPs) are the same, an immature remediation technology will inevitably pose a greater project risk than a mature one. Therefore, expert ratings have been incorporated into these two indicators, with the expert ratings weighted at 50%, and the remaining results determined by the BMPs. The calculation formula is as follows: S3= )+ (3) Where S1 is the total score of all indicators, with a value of 5; S2 is the expert recommendation score, with a value of 1 to 5; S3 is the final sub-indicator score, with a value of 1 to 5; Ma is the number of BMPs; M is the number of BMPs actually executed during the repair process; The method for screening and collecting BMPs data is as follows: First, screen the BMPs common to SuRF-UK, USEPA and ASTM, and exclude the BMPs that are the same as those in the three, as well as the BMPs other than TCH and ISCO; then combine TCH and ISCO, and remove the same BMPs to obtain the BMPs data; finally, a total of 50 BMPs for TCH and 55 BMPs for TCH-ISCO repair technology are obtained. The sustainability assessment model for in-situ thermal treatment coupled with chemical methods for the remediation of organically contaminated sites was applied to evaluate the optimal remediation scheme among multiple in-situ remediation options for organically contaminated sites. This model was then used to optimize the in-situ remediation schemes for organically contaminated sites. The optimization method involved identifying key sustainability influencing factors based on the sensitivity analysis results of the LCA assessment, and then proposing measures to improve the in-situ remediation schemes using these key sustainability influencing factors. These key sustainability influencing factors included raw material consumption, electricity consumption, transportation consumption, and oxidant consumption.

[0035] Example 2 The difference between this embodiment and Embodiment 1 is that TCH remediation was carried out at a chlorinated hydrocarbon contaminated site in a chemical reagent factory in Tianjin, China.

[0036] Experimental Example I. Quantitative Assessment Results of LCA 1. Midpoint value results: like Figure 1 , 2 As shown in Figure 3, quantitative calculations using LCA show that the environmental impact of the TCH-ISCO remediation technology is lower than that of the TCH remediation technology in all aspects. Specifically, the power consumption of the heating well operation in the TCH-ISCO remediation technology (40,698 kWh) accounts for 68.8% of the total carbon emissions (50,700 kg CO2 eq), 60.8% of the fossil resource consumption (9,740 kg oil eq), 60.2% of PM2.5 emissions (73 kg PM2.5 eq), and 59.4% of SO2 emissions (160 kg SO2 eq). The contribution of oxidant use to carbon emissions is minimal (8.1%, 5,980 kg CO2 eq). Similarly, the environmental impact of the power consumption during the TCH remediation process (286,858 kWh) is higher than that of the power consumption during the TCH-ISCO operation. Under the same functional units and remediation scenarios, throughout the entire life cycle of TCH remediation technology, the power consumption of heating wells accounts for 94.1% of total carbon emissions (358,000 kg CO2 eq), and has a significantly increased impact on fine particulate matter formation (92.9%, 520 kg PM2.5 eq) and fossil resource consumption (92.1%, 68,800 kg oil eq).

[0037] 2. Endpoint Value Results like Figure 4As shown, the LCA endpoint results for TCH-ISCO remediation technology and TCH are based on the ReCiPe endpoint index normalized score, mainly including three categories: human health, ecosystem, and resources. Kilopoints (kpt) are the unit of measurement for the endpoint results and are a standardized indicator that reveals the overall environmental impact; the higher the kpt value, the smaller the environmental impact. The endpoint result for TCH is 3.4 kpt, while the endpoint result for TCH-ISCO remediation technology is 13.7 kpt. The environmental impact of TCH remediation technology is four times that of TCH-ISCO remediation technology, and it has a greater impact on human health, ecosystem, and resources. Specifically, the human health result for TCH-ISCO remediation technology is 3.41 kPt, while the human health result for TCH remediation technology is 13.62 kPt. This indicates that human health is the primary source of environmental impact for both remediation technologies. Both remediation technologies had relatively small impacts on resources and ecosystems. The TCH-ISCO remediation technology had an ecosystem impact of 0.09 kPt and a resource impact of 0.02 kPt, while the TCH remediation technology had an ecosystem impact of 0.42 kPt and a resource impact of 0.06 kPt.

[0038] 3. Carbon Emission Results like Figure 5 The data quantitatively calculates the carbon emissions and emission paths of TCH-ISCO remediation technology and TCH at different stages and sub-stages. The carbon emission proportions of TCH-ISCO remediation technology in the four stages of raw material production, site construction, operation, and project completion are 11%, 12%, 76%, and 1%, respectively; while the carbon emission proportions of TCH remediation technology in the four stages are 2%, 3%, 94%, and 1%, respectively. This shows that the carbon emissions during the operation of TCH remediation technology are higher and constitute the main carbon emission process. Furthermore, the main sub-stage activity for carbon emissions in both technologies is the electricity consumption of heating wells. In TCH remediation technology, the carbon emissions from electricity consumption of various wells account for 93% of the total carbon emissions, while in TCH-ISCO remediation technology, the carbon emissions from electricity consumption of various wells account for 68%. Except for heating wells, the carbon emissions from all activities within the TCH remediation technology demonstration area are less than 5%. However, the reduced carbon emissions from TCH-ISCO remediation technology, which consumes less electricity compared to TCH remediation technology, increase the proportion of carbon emissions from well construction materials (7%, 5,589 kg), site construction (6%, 4,584 kg), and transportation (11%, 6,369 kg).

[0039] 4. Sensitivity Analysis Results like Figure 6 , 7As shown in the sensitivity analysis results, power consumption is the biggest factor causing the environmental impact of TCH-ISCO remediation technology and TCH remediation technology. When power consumption is halved, the environmental impact of TCH-ISCO remediation technology and TCH remediation technology decreases by 25.4% and 44.6%, respectively; when power consumption is doubled, the carbon emissions of TCH-ISCO remediation technology and TCH remediation technology increase by approximately 68.8% and 94.3%, respectively.

[0040] 5. Environmental impact reduction measures Sensitivity analysis results also show that reducing electricity consumption by half reduced the overall environmental impact of TCH-ISCO remediation technology and TCH by 25.4% and 44.6%, respectively. Therefore, reducing electricity consumption and modifying the power structure are effective potential pathways to mitigate environmental burden. During on-site remediation, the following can be used to reduce electricity consumption: First, improving thermal efficiency and reducing heat loss by optimizing the distance and depth between heating rods; second, selecting appropriate oxidizing agents and their corresponding optimal activation temperatures is an important way to reduce energy consumption; third, adopting more advanced and efficient heating technologies, such as microwave and ultrasonic heating, is important; in addition, switching the power source to alternative green energy can reduce costs and carbon footprint. Modifying the power structure will be one of the effective methods for optimizing TCH-ISCO and TCH remediation technologies in the future.

[0041] II. Quantitative Assessment Results of Economic and Social Sustainability As shown in Tables 2, 3, and 4, the quantitative evaluation results of BMPs for the TCH-ISCO repair technology are shown in Table 2; the quantitative evaluation results of BMPs for the TCH repair technology are shown in Table 3; and the overall evaluation results of BMPs are shown in Table 4. like Figure 8 As shown, quantitative calculations were performed using BMPs. In terms of social sustainability, TCH remediation technology performed better than TCH-ISCO remediation technology in terms of worker injury and health risks, with consistent results in community participation, community satisfaction, and transparency. TCH-ISCO remediation technology performed better in reducing noise and smoke. Regarding economic sustainability, the results showed that, on average, every 1m² of remediation... 3 For organically contaminated soil and groundwater, the direct expenditure of TCH remediation technology is three times that of TCH-ISCO remediation technology.

[0042] In terms of economic sustainability, TCH-ISCO remediation technology is less expensive under the same remediation scenario, costing approximately one-third that of TCH, thus offering higher economic benefits. However, due to its less frequent on-site use, TCH-ISCO carries greater potential risks. Regarding social sustainability, TCH-ISCO poses greater health risks due to higher exposure risks during oxidant production and use. TCH remediation also generates higher levels of smoke and dust due to the involvement of pollutant extraction and post-treatment processes. However, TCH-ISCO achieves a higher overall sustainability score than TCH, indicating better sustainability and development potential. Environmental sustainability is the area with the largest difference between the two remediation technologies, while the differences in economic and social sustainability outcomes are not significant.

[0043] The conclusions of both parties are as follows: Quantitative assessments show that for both TCH-ISCO and TCH remediation technologies, the supply of electricity accounts for the largest share of environmental sustainability impact, at 68% and 93%, respectively. Under the same remediation scenarios, TCH-ISCO remediation technology has 80% lower carbon emissions than TCH remediation technology, demonstrating significant carbon reduction benefits. Furthermore, the overall environmental impact of TCH-ISCO remediation technology is only 25% of that of TCH remediation technology, making it more environmentally friendly than TCH remediation alone. In addition, the direct cost of TCH-ISCO remediation technology is 70% lower than that of TCH remediation technology, demonstrating significant economic benefits. Regarding social sustainability, TCH remediation technology is slightly superior to TCH-ISCO remediation technology, primarily due to the greater health risks posed by the chemical application in TCH-ISCO remediation technology.

[0044] III. Calculation Results of the LCA-BMPs Integrated Model As shown in Table 5, Weight1 represents the weights of the environmental, economic, and social sub-indicators, and the sum of the weights of all indicators is 1. Among environmental indicators, If the scores of the environmental impact endpoint index in two different in-situ thermal treatment coupled chemical remediation schemes are a and b, respectively, and the unit is kPt, The endpoint score of the remediation scheme with the smaller kPt value is selected and assigned a value of 100. The endpoint score of the other remediation scheme is reduced by the same factor, i.e., a / b times, and its score is 100*a / b. The three endpoint results of the two different in-situ thermal treatment coupled chemical remediation schemes are obtained by the same method. Finally, with each endpoint indicator weighted at 0.33, the weighted average of the three endpoint indicators is calculated, and the weighted averages are summed to obtain the final environmental indicator score, which is different from the in-situ thermal treatment coupled chemical remediation scheme. Among social indicators, For worker safety sub-indicators and smoke and dust sub-indicators, based on the size of the BMPs results in the two schemes, the sub-indicator with the larger result value is assigned a score of 100, and the sub-indicator of the other scheme is reduced by the same factor year-on-year. For other indicators in the social indicators, the corresponding scores are obtained according to a 5-point scale, which corresponds to a percentage scale. Among economic indicators, For the direct cost sub-indicator and the project risk sub-indicator, based on the size of the BMPs results in the two scenarios, the sub-indicator with the larger result value is assigned a score of 100, and the sub-indicator of the other scenario is reduced by the same factor year-on-year. For other economic indicators, a score is obtained based on a 5-point scale, corresponding to a percentage scale. In the environmental sustainability assessment, the three indicators of human health, resource consumption, and ecosystems are considered to be at the same level, with each having a weight of 0.33. In the social sustainability assessment, worker injury and health risks have a higher weight of 0.2, while the others have a weight of 0.15. In the economic sustainability assessment, project risk is considered to be the highest-weighted indicator because remediation would require higher economic input. The three categories of environment, economy, and society in Weight2 each have a weight of 0.33, with a total weight of 1.

[0045] like Figure 9 As shown, the TCH-ISCO remediation technology demonstrates better environmental and economic sustainability, with a significant difference in environmental sustainability scores, while the social sustainability scores are similar. The final quantitative sustainability assessment score for TCH-ISCO is 89.6, while that for TCH is 61.9. TCH-ISCO is more sustainable than TCH because it generates less waste, produces lower emissions, and is more cost-effective. In fact, according to the final calculations, under the same functional unit, TCH-ISCO reduces the total cost by 70% and achieves an 80% carbon reduction compared to TCH, demonstrating significant development potential.

[0046] The quantitative sustainability assessment results of this study indicate that TCH-ISCO remediation technology is more sustainable than TCH remediation technology and has better development prospects. Overall, this study established a quantitative sustainability assessment method for TCH-ISCO remediation technology, providing a basis for the quantitative assessment of green and sustainable remediation technologies in the field of soil and groundwater remediation.

[0047] Table 1 Lifecycle Inventory Data

[0048] Table 2. Social and economic indicators of TCH-ISCO remediation technology: Quantitative assessment results of BMPs

[0049] Table 3. Social and economic indicators of TCH remediation technology and quantitative assessment results of BMPs.

[0050] Table 4. Quantitative assessment results of the economic and social sustainability of TCH-ISCO and TCH remediation technologies.

[0051] Table 5. Calculation process and results of the LCA-BMPs integrated model.

[0052] Note: * indicates execution; / indicates not executed.

Claims

1. A sustainability assessment system for in-situ thermal treatment coupled with chemical methods for the remediation of organically contaminated sites, characterized in that, The system structure is as follows: S 总 = （1） In the formula, S 总 S represents the overall sustainability score of the in-situ thermal treatment coupled with / in-situ chemical remediation scheme. 总 The range is 0~100, where IV represents the environmental indicator score obtained by the LCA quantitative assessment method, the social indicator score obtained by the BMPs quantitative assessment method, and the economic indicator score; IVmax represents the maximum score among the environmental, social, and economic indicators; and W is the weight of each indicator. Sustainability Total Score 总 A higher value indicates a higher sustainability of the in-situ remediation plan for organically contaminated sites; the total sustainability score S... 总 The smaller the value, the lower the sustainability of the in-situ remediation plan for organically contaminated sites; The environmental index score is obtained by evaluating the in-situ thermal treatment coupled remediation scheme of organic contaminated site through the LCA quantitative assessment method, obtaining the LCA assessment result of in-situ remediation of organic contaminated site, and then calculating it based on the LCA assessment result. The social and economic indicators scores are obtained by using the BMPs quantitative assessment method to evaluate the in-situ thermal treatment coupled remediation scheme for organic contaminated sites, and then calculating the scores based on the BMPs assessment results. The quantitative assessment method for LCA is as follows: First, the functional units were defined, the system boundaries were delineated, and lifecycle inventory data was collected. Then, SimaPro 9.0 software was used to select the feature model ReCiPe2016, select the impact category corresponding to the sub-indicator in the LCA environmental indicator to be obtained, and classify the lifecycle inventory data into the selected impact category. The calculation and sensitivity analysis were started to obtain the midpoint and endpoint values ​​and determine the key sustainability influencing factors. The ReCiPe endpoint score was normalized to obtain the endpoint value of the LCA assessment result. The unit of the endpoint value result is kpt. The higher the kpt value, the smaller the environmental impact of the in-situ remediation plan for the organic contaminated site. The lower the kpt value, the greater the environmental impact of the in-situ remediation plan for the organic contaminated site. The method for calculating environmental indicator scores based on LCA assessment results is as follows: If the scores of the environmental impact endpoint index in two different in-situ thermal treatment coupled chemical remediation schemes are a and b, respectively, and the unit is kPt, The endpoint score of the remediation scheme with the smaller kPt value is selected and assigned a value of 100. The endpoint score of the other remediation scheme is reduced by the same factor, i.e., a / b times, and its score is 100*a / b. The three endpoint results of the two different in-situ thermal treatment coupled chemical remediation schemes are obtained by the same method. Finally, with each endpoint indicator weighted at 0.33, the weighted average of the three endpoint indicators is calculated, and the weighted averages are summed to obtain the final environmental indicator score, which differs from the in-situ thermal treatment coupled with chemical remediation scheme.

2. The sustainability assessment system for in-situ thermal treatment coupled with chemical remediation of organically contaminated sites as described in claim 1, characterized in that, The in-situ thermal treatment coupled repair scheme includes, but is not limited to, thermal conduction heating and resistance heating repair schemes; the in-situ chemical repair scheme includes, but is not limited to, in-situ chemical oxidation repair schemes.

3. The sustainability assessment system for in-situ thermal treatment coupled with chemical remediation of organically contaminated sites as described in claim 1, characterized in that, The environmental indicators include: sub-indicators of human health, ecosystem, and resource consumption; the social indicators include: sub-indicators of worker injury, health risk, community participation, community satisfaction, transparency, and smog; the economic indicators include: sub-indicators of direct economic expenditure, project risk and restoration duration, land value-added, and employment.

4. The sustainability assessment system for in-situ thermal treatment coupled with chemical remediation of organically contaminated sites as described in claim 1, characterized in that, The LCA assessment results include: midpoint value results, endpoint value results, carbon emission results, and sensitivity analysis results; the data for the LCA quantitative assessment method comes from the Ecoinvent database; the collection principles for the life cycle inventory data include: collecting quantitative data within the system boundary, and collecting quantitative data through measurement, calculation, or estimation; life cycle data includes: data on raw material acquisition, site construction, operation, and project completion.

5. The sustainability assessment system for in-situ thermal treatment coupled with chemical remediation of organically contaminated sites as described in claim 1, characterized in that, The method for evaluating the in-situ thermal treatment coupled remediation scheme of organic contaminated site by quantitative assessment using BMPs is as follows: determine the functional units and system boundaries, then screen and collect BMPs data for model calculation, obtain the total score of each index, and then use the following formula (2) to obtain the final sub-index score S: S= （2） Where S1 is the total score of all indicators, i.e. the evaluation result of BMPs, with a value of 5; S is the final sub-indicator score, with a value of 1 to 5; Ma is the number of BMPs; M is the number of BMPs actually executed during the repair process; The method for calculating the social and emergency indicator scores from the BMPs assessment results is as follows: Among social indicators, For the worker safety sub-indicator and the smoke and dust sub-indicator, based on the size of the BMPs results in the two schemes, the sub-indicator with the larger result value is assigned a score of 100, and the sub-indicator of the other scheme is reduced by the same factor year-on-year; for other indicators in the social indicators, the corresponding scores are obtained according to the full score of 5 points, corresponding to the percentage ratio. Then, the weights of each sub-indicator are set and a weighted average is calculated to obtain the social indicator score. Among economic indicators, For the direct cost sub-indicator and the project risk sub-indicator, based on the size of the BMPs results in the two scenarios, the sub-indicator with the larger result value is assigned a score of 100, and the sub-indicator of the other scenario is reduced by the same factor year-on-year; for other economic indicators, the corresponding scores are obtained according to a 5-point full score system, corresponding to a percentage system. Then, the weights of each sub-indicator are set and a weighted average is calculated to obtain the final economic indicator score.

6. The sustainability assessment system for in-situ thermal treatment coupled with chemical remediation of organically contaminated sites as described in claim 5, characterized in that, The method for screening and collecting BMPs data is as follows: First, screen the BMPs common to in-situ thermal treatment and in-situ chemical remediation of organic contaminated sites published by UK SuRF-UK, USUSEPA and USASTM. Then, exclude BMPs that are duplicates of the same type among the three, as well as BMPs that are not related to in-situ thermal treatment and in-situ chemical remediation. Then, the BMPs from in-situ heat treatment and in-situ chemical remediation are combined, and finally, the duplicate BMPs after combination are removed to obtain all the BMPs data of in-situ heat treatment coupled with chemical remediation.

7. The sustainability assessment system for in-situ thermal treatment coupled with chemical remediation of organically contaminated sites as described in claim 5, characterized in that, The functional unit is: Repair 1000m 3 Sustainability impacts of contaminated soil and groundwater below control levels.

8. The application of the sustainability assessment system for in-situ thermal treatment coupled with chemical remediation of organically contaminated sites as described in claim 1, characterized in that, It was used to evaluate the optimal remediation plan among multiple in-situ remediation options for organically contaminated sites; the evaluation criterion was: total sustainability score S. 总 The largest value indicates the highest sustainability of the in-situ remediation scheme for organically contaminated sites, further demonstrating that the in-situ remediation scheme for organically contaminated sites is optimal. This method is used to evaluate the most suitable sites for in-situ thermal treatment coupled remediation schemes for organically contaminated sites; the evaluation criterion is: total sustainability score S. 总 The largest value indicates the highest sustainability of the in-situ remediation scheme for organically contaminated sites, further demonstrating that this in-situ remediation scheme is optimal.

9. The application of the sustainability assessment system for in-situ thermal treatment coupled with chemical remediation of organically contaminated sites as described in claim 1, characterized in that, It can be used to optimize in-situ remediation solutions for organically contaminated sites. The optimization method is as follows: Based on the sensitivity analysis results in the LCA assessment, the key sustainability influencing factors of the in-situ remediation scheme for organic contaminated sites are identified. Using the key sustainability influencing factors, measures to optimize the in-situ remediation scheme for organic contaminated sites are proposed to reduce its impact. The key sustainability influencing factors include raw material consumption, electricity consumption, transportation consumption, and oxidant consumption.

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