A method for decision-making of contaminated soil leaching remediation based on carbon emission intensity

Abstract

This invention discloses a decision-making method for contaminated soil leaching remediation based on carbon emission intensity, comprising six steps: project basic information analysis, construction of a carbon emission intensity assessment model, establishment of a basic dataset for leaching remediation, removal rate response surface fitting, carbon emission intensity response surface fitting, and recommendation of ex-situ leaching remediation schemes. The carbon emission intensity refers to the carbon emission value corresponding to a unit amount of pollutant removed. Compared to traditional carbon emission assessment indicators based on remediation volume, the carbon emission intensity indicator can take into account both decontamination and carbon reduction assessment needs. Based on the calculation and fitting prediction of carbon emission intensity values, this method selects and determines the optimal combination of low-carbon remediation process parameters for construction parties according to the principles of achieving the removal rate target and minimizing the carbon emission intensity value, providing strong support for carbon emission reduction decisions in soil pollution remediation and possessing good potential for widespread application.

Description

Technical Field

[0001] This invention belongs to the field of soil pollution remediation, specifically relating to a decision-making method for leaching remediation of contaminated soil based on carbon emission intensity. Background Technology

[0002] With the rapid industrialization and modernization of human society, soil pollution incidents are becoming increasingly frequent. Leaching remediation technology removes pollutants from soil through water or chemical solutions, reducing the risks of soil pollution to ecosystems and human health. It is one of the main engineering technologies for the remediation of contaminated sites. In recent years, the number of soil leaching remediation projects in my country has increased, and the technological level of leaching remediation processes has significantly improved. However, there is still considerable room for improvement in terms of remediation energy consumption, material consumption, environmental impact, and carbon emissions.

[0003] The Party and the State have called for accelerating the comprehensive green transformation of economic and social development, and all sectors are actively promoting the greening and low-carbon upgrading of production processes. In December 2023, the General Office of the Ministry of Ecology and Environment issued the "Guiding Opinions on Promoting Soil Pollution Risk Management and Green and Low-Carbon Remediation," making carbon emission reduction in soil pollution remediation a new focus for management departments and companies in the industry. However, for a long time, research on soil pollution remediation has mainly focused on improving the effectiveness of pollution control, while the environmental impact and carbon emission control mechanisms of remediation activities have lacked in-depth exploration. The pollutant removal rate remains the main, and even the only, indicator for decision-making in remediation projects, which makes the decision-making results unable to meet the requirements of simultaneous pollution reduction and carbon reduction. For example, in leaching remediation projects, construction companies generally use the pollutant leaching rate in small-scale tests as the basis for selecting leaching agents and optimizing leaching process parameters, while the impact of process condition adjustments on remediation carbon emissions lacks data support, and the implementation of the decision-making plan may increase the environmental load. On the other hand, there is a lack of research on the carbon footprint of soil pollution leaching remediation technology, the correlation between leaching remediation carbon emissions and pollutant removal effects is unclear, and the carbon emission reduction suggestions put forward by scholars based on carbon emission assessment results lack practical guiding significance. In summary, existing research findings and engineering experience cannot provide effective support for designing efficient and low-carbon soil leaching remediation schemes. There is a need to develop a decision-making method for soil pollution leaching remediation that takes into account both decontamination and carbon emission reduction, so as to help develop green and low-carbon remediation models for polluted soil. Summary of the Invention

[0004] To address the aforementioned issues, this patent proposes a decision-making method for contaminated soil leaching remediation based on carbon emission intensity. By introducing carbon emission intensity calculation and fitting prediction into the technical solution, it takes into account both pollution control and carbon emission reduction decision-making needs, providing a new methodological tool for screening and determining the optimal low-carbon leaching remediation process.

[0005] The specific technical solution is as follows:

[0006] A decision-making method for contaminated soil leaching remediation based on carbon emission intensity includes the following steps:

[0007] Step 1: Project Basic Information Analysis. Collect basic data on the target site, identify target pollutants in the soil, and select the intended leaching agent and trapping agent types; collect information on ex-situ leaching remediation equipment, analyze the remediation process flow, and determine process parameter indicators;

[0008] Step 2: Construction of a carbon emission intensity assessment model. This involves analyzing the sources of carbon emissions from the leaching remediation process, collecting carbon emission factor data, establishing a formula for calculating the carbon emissions from the remediation process, and constructing a carbon emission intensity assessment model.

[0009] Step 3: Establishment of the basic dataset for leaching remediation. Single-factor experiments and response surface methodology experiments were designed to obtain the pollutant elution effects corresponding to different combinations of process parameters, thus constructing the basic dataset.

[0010] Step 4: Removal rate response surface fitting. Based on the leaching remediation dataset from Step 3, a removal rate response surface fitting is performed. The significance of the fitting results is tested, the validity of the experimental data is determined, and a formula for predicting pollutant removal rates is constructed.

[0011] Step 5: Carbon emission intensity response surface fitting. Based on the basic dataset of leaching remediation from Step 3, calculate the corresponding carbon emission intensity values; perform carbon emission intensity response surface fitting prediction and verify the significance of the fitting results; generate alternative low-carbon remediation process parameter combinations by randomly fitting the data under the condition that the carbon emission intensity tends to decrease.

[0012] Step Six: Recommendation of Ex-situ Leaching Remediation Scheme. Based on the pollutant removal rate prediction formula in Step Four, calculate the pollutant removal rate data corresponding to each alternative low-carbon remediation process parameter combination; using the remediation target value as a benchmark, and based on the principles of achieving the removal rate target and minimizing the carbon emission intensity value, select the optimal combination from the alternative low-carbon remediation process parameter combinations to form a recommended scheme for ex-situ low-carbon leaching remediation of contaminated soil.

[0013] The target pollutant in step one is a heavy metal or an organic pollutant, and the number of pollutants is one or more; the target pollutant may also be a combination of heavy metals and organic pollutants.

[0014] The remediation process in step one includes, but is not limited to, pulping and leaching, vibrating screening, solid-liquid separation, and wastewater purification; the process parameters include the concentration of the leaching agent (Conc). 淋洗剂 ), rinse time (Time) 淋洗 Liquid-to-solid ratio 液固比 ), and can also be added, removed or replaced according to actual needs.

[0015] The carbon emission intensity in step two is based on the amount of pollutant removed per unit, meaning the carbon emission intensity equals the carbon emission corresponding to the amount of pollutant removed per unit during the remediation activity. Its value is the ratio of carbon emissions to pollutant removal during the remediation activity. The carbon emission intensity assessment model is as follows: Carbon Emission Intensity T 碳排放 =TE 总碳排放 / TS 总去除量 =E 碳排放 / S 去除量 , of which TE 总碳排放 and TS 总去除量 E represents the total carbon emissions and total pollutant removal of the remediation project, respectively. 碳排放 and S 去除量 These represent the carbon emissions and pollutant removal per unit of soil remediation, respectively; T 碳排放 The unit is kg CO2eq / kg pollutant The unit can also be adjusted according to needs.

[0016] The scope of the total carbon emissions calculation includes all direct and indirect carbon emissions generated from the consumption of chemicals, electricity, and diesel fuel. The sources of the total carbon emissions include, but are not limited to, the production and transportation of leaching agents and wastewater treatment agents, the electricity input for the operation of off-site leaching and repair equipment, and the diesel input for the operation of machinery and vehicles.

[0017] The basic dataset for step three includes the pollutant elution effects from single-factor experiments and response surface methodology (RSM) experiments. The RSM experiments employ the Box-Behnken Designs method to design the experimental schemes; the RSM experiments include at least five center point treatment groups.

[0018] The elution effect of the pollutants is the removal rate of one target pollutant or the average removal rate of multiple target pollutants in the response surface methodology experiment. The removal rate of one target pollutant is calculated using the formula: Removal rate R = TS 总去除量 / TS 初始 ×100%=(TS) 初始 -TS 修复后 ) / TS 初始 ×100%=(C 初始 -C 修复后 ) / C 初始 ×100%, of which TS 总去除量 TS represents the total amount of soil pollutants removed during the remediation project. 初始 and TS 修复后 These represent the initial total amount and the total amount of soil pollutants after remediation, respectively, C 初始 and C 修复后 These represent the initial and post-remediation concentrations of pollutants in the soil, respectively. The formula for calculating the average removal rate of multiple target pollutants is: Removal Rate R ave=(∑R i ) / n, R i Let be the removal rate of the i-th pollutant, and n be the number of pollutant types under investigation.

[0019] The formula for predicting the pollutant removal rate in step four is a multivariate quadratic equation based on process parameter indicators.

[0020] The significance test of the removal rate fitting results in step four includes a model fit significance test and a lack-of-fit term significance test. The significance test result P for the model fit is... 拟合度1 The significance test result P for the lack-of-fit term should be less than 0.05. 失拟项1 It should be greater than 0.05. When P 拟合度1 and P 失拟项1 If the values ​​do not meet the requirements, step three should be repeated to optimize the experimental gradient of the key process parameters and collect data again.

[0021] The carbon emission intensity response surface fitting result in step five is a multivariate quadratic equation based on process parameter indices, with a fitting degree R. 2 Greater than 0.9.

[0022] The significance test of the carbon emission intensity fitting results in step five includes a model fit significance test and a lack-of-fit term significance test. The significance test result P for the model fit is... 拟合度2 The significance test result P for the lack-of-fit term should be less than 0.05. 失拟项2 It should be greater than 0.05. When P 拟合度2 and P 失拟项2 If the values ​​do not meet the requirements, steps three and four should be repeated, the response surface experimental scheme should be optimized, the experimental gradient of process parameters should be adjusted, and the basic data should be collected again.

[0023] The number of alternative low-carbon remediation process parameter combinations in step five is 10 to 100, preferably 30, and can be adjusted according to actual needs.

[0024] The beneficial effects of this invention are as follows:

[0025] (1) Compared with traditional remediation scheme decision-making methods that only consider the effect of pollutant removal, this invention introduces the concept of carbon emission intensity based on the ratio of carbon emissions to removal rate, and selects and determines the combination of process parameters according to the principle of achieving the removal rate target and the lowest carbon emission intensity value. This technical solution can take into account the decision-making needs of pollution control and carbon emission reduction, and provides a new method and tool for construction units to quickly select the optimal low-carbon remediation process scheme, which has good application potential.

[0026] (2) This method collects basic data on contaminated soil leaching and remediation through single-factor experiments and response surface methodology (RSM) experiments. Then, it employs RSM fitting to construct a multivariate quadratic equation for the removal rate based on process parameters, enabling rapid fitting and prediction of pollutant removal rates and reducing the workload of data collection. Furthermore, this technical solution extends the RSM fitting method used for removal rate prediction to carbon emission intensity fitting and prediction. Compared to traditional multivariate linear regression, this fitting method considers the interaction between process parameters and carbon emission intensity, better reflecting the nonlinear correlation between carbon emission intensity and process parameters, resulting in higher fitting accuracy for carbon emission intensity and providing more accurate data support for screening low-carbon process parameter combinations.

[0027] (3) The decision-making method proposed in this invention is applicable to ex-situ leaching remediation technology for contaminated soil. It can be used for decision-making activities in single or combined soil heavy metal / organic pollution remediation projects, demonstrating strong applicability and a wide range of applications. By adjusting process parameters, this method can also be used for process decision-making activities in other types of contaminated soil or groundwater remediation technologies, providing scientific and technological support for the remediation of contaminated sites in my country and contributing to the construction of a green, low-carbon, and circular economy system. Attached Figure Description

[0028] Figure 1 Flowchart for implementing the decision-making methodology;

[0029] Figure 2 This is a response surface fitting diagram of the lead removal rate in the examples;

[0030] Figure 3 The image shows the response surface fitting plot of carbon emission intensity in the example. 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

[0033] For a soil lead contamination remediation project at an abandoned site, the ex-situ leaching remediation process was determined using the technical solution proposed in this invention. The specific implementation process is as follows:

[0034] (1) Project basic information analysis

[0035] The target pollutant in the soil of this site is lead (Pb), and the lead content exceeds the national standard "Soil Environmental Quality Standard for Construction Land Soil Pollution Risk Control (Trial)" (GB 36600-2018).

[0036] The proposed remediation process for this site is ex-situ leaching remediation. The specific remediation process is as follows:

[0037] a. Excavating contaminated soil and manually removing large stones;

[0038] b. The contaminated soil is fed into the leaching remediation equipment, mixed with the leaching agent, and slurry is prepared for leaching.

[0039] c. Vibrating sieve, solid-liquid separation, solid samples are sent to the inspection area, and after passing the inspection, they are sent out of the work area. Liquid samples are sent to the sewage treatment equipment.

[0040] d. Add a precipitating agent to the sewage treatment equipment to precipitate heavy metals, purify the water, and reuse or discharge it from the site after passing the inspection.

[0041] In this case, the key evaluation indicators that the construction company intends to determine through the decision-making process include the concentration of the rinsing agent (Conc). 淋洗剂 ), rinse time (Time) 淋洗 Liquid-to-solid ratio 液固比 ).

[0042] Based on the decision-making requirements, basic information on the technical equipment of the construction team was collected. The proposed leaching agent is EDTA, and the capture agents are PAC, PAM, and Na2S. The proposed ex-situ leaching remediation equipment mainly includes slurry-making leaching equipment, vibrating screening equipment, solid-liquid separation equipment, and wastewater treatment equipment. The power and reagent information for each piece of equipment are as follows: The operating power of the slurry-making leaching equipment is P... 造浆淋洗 = 31.6kW; Operating power P of vibrating screening equipment 振动筛分 =71

[0043] kW; Operating power P of solid-liquid separation equipment 固液分离 = 93.5kW; Wastewater treatment operating power P 废水处理 =28.2

[0044] kW, Time per run 废水处理 =0.03h / m 3 The dosage of capture agents PAC, PAM, and Na2S (Conc) w1 =1.90

[0045] kg / m 3 soil, Conc w2 =0.19kg / m 3 soil, Conc w3 =0.19kg / m 3 Soil; distance L for purchasing leaching agent 淋洗剂 =50km, procurement distance L of the capture agent w1 =L w2 =L w3 =50km; fuel consumption per 100km for transport vehicles N 运输

[0046] =35L / 100km, single transport volume is W=60t.

[0047] (2) Construction of carbon emission intensity assessment model

[0048] Since excavation of contaminated soil does not affect the determination of leaching process parameters, this embodiment does not include the excavation stage in the carbon emission accounting boundary. Therefore, the carbon emission accounting boundary includes the slurry preparation and leaching stage, the solid-liquid separation stage, and the wastewater treatment stage. Analysis of the carbon emission sources of the contaminated soil leaching remediation process shows that the carbon emissions of the contaminated soil leaching remediation process mainly come from indirect carbon emissions during the production of leaching agents, water, and capture agents; direct and indirect carbon emissions from diesel combustion of machinery vehicles during agent transportation; and indirect carbon emissions from electricity consumption during the operation of the leaching remediation equipment.

[0049] The collected carbon emission factor data are summarized as follows: The indirect carbon emission factor of the rinsing agent production process is F. f = 4.3859kg CO2eq / kg, the carbon emission factor of water is F w =0.21kg CO2 eq / m 3 The indirect carbon emission factors of the production processes of capture agents PAC, PAM, and Na2S are respectively F b1 =1.6879kg CO2eq / kg, F b2 = 3.2546 kg CO2eq / kg, F b3 =2.9396kg CO2eq / kg, the indirect carbon emission factor of electricity is F e =0.5703kg CO2 eq / kWh; the total carbon emission factor of diesel is F g = 3.7659kg CO2eq / kg, the total carbon emission factor is the sum of the direct carbon emission factor and the indirect carbon emission factor.

[0050] Establish a formula for calculating carbon emissions from remediation: Carbon emissions E 碳排放 = Carbon emissions E from rinsing agents 淋洗剂 + Carbon emissions from water resource inputs E 水 + Carbon emissions from the capture agent input E 捕获剂 + Carbon emissions from pharmaceutical transportation E 药剂运输 + Carbon emissions from pulp washing equipment operation E 造浆淋洗 + Carbon emissions from vibrating screening equipment operation E 振动筛分 + Carbon emissions from solid-liquid separation equipment operation E 固液分离 +Carbon emissions from wastewater treatment equipment operation E废水处理

[0051] Specifically, the formulas for each sub-item are as follows:

[0052] E 淋洗剂 =Conc 淋洗剂 ×Ratio 液固比 ×K×F f In the formula, K represents the amount of soil remediation, which is assigned a value of 1.

[0053] E 水 =Ratio 液固比 ×K×F w ;

[0054] E 捕获剂 =Ratio 液固比 ×K×(Conc w1 ×F b1 +Conc w2 ×F b2 +Conc w3 ×F b3 );

[0055] E 药剂运输 =N 运输 ×(L 淋洗剂 ×((Conc 淋洗剂 ×(Ratio 液固比 ×K)) / W)+((Ratio 液固比 ×K)×(L w1 ×C w1 +

[0056] L w2 ×Conc w2 +L w3 ×Conc w3 )) / W))×F g ;

[0057] E 造浆淋洗 =Time 淋洗 ×P 造浆淋洗 ×F e ;

[0058] E 振动筛分 =Time 淋洗 ×P 振动筛分 ×F e ;

[0059] E 固液分离 =Time 淋洗 ×P 固液分离 ×F e ;

[0060] E 废水处理 =Time废水处理 ×P 废水处理 ×Ratio 液固比 ×K×F e .

[0061] After aggregation, carbon emissions E 碳排放 =Conc 淋洗剂 ×Ratio 液固比 ×K×F f +Ratio 液固比 ×K×F w +Ratio 液固比 ×K×(Conc w1 ×F b1 +Conc w2 ×F b2 +Conc w3 ×F b3 )+N 运输 ×(L 淋洗剂 ×((Conc 淋洗剂 ×(Ratio 液固比 ×K)) / W)+((Ratio 液固比 ×K)×(L w1 ×C w1 +L w2 ×Conc w2 +L w3 ×Conc w3 )) / W))×F g +Time 淋洗 ×P 造浆淋洗 ×F e +Time 淋洗 ×P 振动筛分 ×F e +Time 淋洗 ×P 固液分离 ×F e +Time 废水处理 ×P 废水处理 ×Ratio 液固比 ×K×F e

[0062] Substituting the data from the above case, the formula for calculating the carbon emissions from the remediation in this case is: E 碳排放 =7.84×10 3 ×Conc rinsing agent + 0.20 × Ratio (liquid-solid ratio) + 0.003 × Time rinsing - 1.17 × 10 3 E carbon emissions are measured in kg. eqCO2 / tsoil.

[0063] Furthermore, by constructing the carbon emission intensity assessment model for this case, we can obtain:

[0064] Carbon emission intensity T 碳排放 =TE 总碳排放 / TS 总去除量 =E 碳排放 / S 去除量 =E 碳排放 / (C 初始 -C 修复后 )

[0065] Among them, TE 总碳排放 and TS 总去除量 These represent the total carbon emissions and total Pb removal of the remediation project, respectively, in kg. CO2eq and g; E 碳排放 and S 去除量 These represent the carbon emissions and Pb removal per unit of soil remediation, respectively, in kg. CO2eq / t and g / t; C 初始 and C 修复后 The values ​​represent Pb concentration before and after soil remediation, both in g / t; T carbon emissions are in kg. CO2eq / kg Pb.

[0066] Substituting into the above formula for calculating carbon emissions from remediation, we can obtain the carbon emission intensity T. 碳排放 = (7.84 × 10 3 ×Conc 淋洗剂 +0.20×Ratio 液固比 +0.003×Time 淋洗 -1.17×10 3 ) / (C 初始 -C 修复后 ).

[0067] (3) Establishment of basic dataset for rinsing remediation

[0068] Single-factor experiments and response surface methodology were designed to obtain the pollutant elution effects corresponding to different combinations of process parameters, and a basic dataset was constructed. The specific implementation process is as follows:

[0069] a single-factor trial

[0070] Based on data acquisition requirements, experiments were designed to investigate rinsing time, rinsing agent concentration, and liquid-to-solid ratio. In the rinsing time experiment, the experimental gradients were 30, 60, 120, 180, and 240 min, with the rinsing agent concentration and liquid-to-solid ratio fixed at 0.01 mol / L and 8 mL / g, respectively. In the rinsing agent concentration experiment, the experimental gradients were 0.01, 0.05, 0.10, 0.15, and 0.20 mol / L, with the rinsing time and liquid-to-solid ratio fixed at 4 h and 8 mL / g, respectively. In the liquid-to-solid ratio experiment, the experimental gradients were 2, 3, 4, 5, and 8 mL / g, with the rinsing agent concentration and rinsing time fixed at 0.01 mol / L and 4 h, respectively.

[0071] Further, according to the experimental protocol, different doses of contaminated soil and leaching agent were weighed into reaction vessels and shaken in the dark at 25°C and 180 rpm to elute Pb from the soil. After the required leaching time was reached, the samples were removed, and solid-liquid separation was performed. The Pb content in the liquid was tested using AAS, and the pollutant removal rate was calculated. The formula for the removal rate is R = (C... 初始 -C 修复后 ) / C 初始 ×100%, where C 初始 and C 修复后 The values ​​represent the initial and post-remediation concentrations of Pb in the soil, respectively.

[0072] b Response Surface Experiment

[0073] Based on the inflection point data of the removal rate change curves in the single-factor experiments, the experimental gradient for the response surface methodology was selected, with rinsing times of 60, 150, and 240 min, rinsing agent concentrations of 0.10, 0.15, and 0.20 mol / L, and liquid-to-solid ratios of 4, 6, and 8 mL / g. Using Design-Expert 13, a three-factor, three-level experiment was designed using the Box-Behnken Design (BBD) method, incorporating EDTA-2Na concentration, rinsing time, and liquid-to-solid ratio. Five center points were set, resulting in a total of 17 small-scale experiments. Furthermore, using an experimental procedure similar to that of the single-factor experiments, the pollutant concentration changes were obtained, and the removal rate was calculated.

[0074] c Basic Dataset Construction

[0075] The results of single-factor experiments and response surface methodology experiments are summarized to form a basic dataset.

[0076] Table 1. Datasets for single-factor and response surface experiments

[0077]

[0078]

[0079] (4) Removal rate response surface fitting

[0080] Based on the basic dataset from step three, the pollutant removal rate equation based on process parameter indicators was obtained by fitting the response surface method in Design Expert software. This equation is a ternary quadratic equation:

[0081] R = 72.57 - 204.65 × Conc 淋洗剂 +0.19×Time 淋洗剂 -3.68Ratio 液固比 -0.31×Conc 淋洗剂 ×Time 淋洗剂 -16.16×Conc 淋洗剂 ×Ratio 液固比 -0.013×Time 淋洗剂 ×Ratio 液固比 +1460×(Conc 淋洗剂 ) 2 -0.000037×

[0082] (Time 淋洗剂 ) 2 +0.70×(Ratio 液固比 ) 2

[0083] Model fitting R 2 It is 0.970.

[0084] A significance test was conducted on the removal rate fitting results, including the significance test result P for the model fit. 拟合度1 The value is 0.0002, and the significance test result P for the lack-of-fit term is... 失拟项1 The value is 0.5019, and the fitting result meets the requirements of the response surface methodology (P). 拟合度2 The value should be less than 0.05, and the significance test result P for the lack-of-fit term should be... 失拟项2 It should be greater than 0.05).

[0085] The surface fitting results of the removal rate response curve are as follows Figure 2 As shown.

[0086] (5) Carbon emission intensity response surface fitting

[0087] carbon emission intensity fitting

[0088] Based on the basic dataset in (3), the carbon emission intensity assessment model in (2) (carbon emission intensity T) is used. 碳排放 =

[0089] (7.84×10 3 ×Conc 淋洗剂 +0.20×Ratio 液固比+0.003×Time 淋洗 -1.17×10 3 ) / (C 初始 -C 修复后 The carbon emission intensity value corresponding to each combination of process parameters is calculated.

[0090] Furthermore, the carbon emission intensity equation based on process parameters was obtained by fitting the response surface method in Design Expert software, which is a ternary quadratic equation:

[0091] T 碳排放 =5.00 + 75.2 × Conc 淋洗剂 +5.98×Ratio 液固比 -0.025×Time 淋洗 -401×(Conc 淋洗剂 ) 2 -0.40×(Ratio 液固比 ) 2 +129×(Time 淋洗剂 ) 2 +129×Conc 淋洗剂 ×Ratio 液固比 -0.36×Conc 淋洗剂 ×Time 淋洗 -0.006×Time 淋洗 ×Ratio 液固比

[0092] Model fitting R 2 It is 0.990.

[0093] A significance test was conducted on the carbon emission intensity fitting results, including a model fit significance test and a lack-of-fit term significance test. The significance test result P of the model fit was... 拟合度2 If the value is less than 0.001, the significance test result P for the lack-of-fit term is... 失拟项2 The value is 0.6916, and the fitting result meets the requirements of the response surface methodology (P). 拟合度2 The value should be less than 0.05, and the significance test result P for the lack-of-fit term should be... 失拟项2 It should be greater than 0.05).

[0094] The carbon emission intensity response surface fitting results are as follows: Figure 3 As shown.

[0095] To compare the accuracy of different fitting methods, this embodiment also uses a multiple linear regression model to fit the carbon emission intensity value, obtaining equation T. 碳排放 =792×Conc 淋洗剂 +15.3×Ratio 液固比 -0.08×Time淋洗 -70.7, R 2 The R-value is 0.951. 2 R below the response surface fitting method 2 The value is due to the interaction between process parameters and carbon emission intensity. The multiple linear regression model cannot reflect the interaction between parameters, while the response surface fitting method based on the ternary quadratic equation provides a better fit for the carbon emission intensity value.

[0096] Fitting of alternative carbon remediation process parameter combinations

[0097] Based on the above equations, the combination of remediation process parameters was generated by random fitting using Design Expert software. With the condition of decreasing carbon emission intensity, the top 30 combinations of remediation process parameters were selected as candidate low-carbon remediation process parameter combinations.

[0098] Table 2 Alternative Low-Carbon Remediation Process Parameter Combinations

[0099]

[0100]

[0101] (6) Recommended treatment plan for ectopic rinsing

[0102] The pollutant removal rate prediction formula based on step four (R = 72.57 - 204.65 × Conc) 淋洗剂 +0.19×Time 淋洗剂 -3.68Ratio 液固比 -0.31×Conc 淋洗剂 ×Time 淋洗剂 -16.16×Conc 淋洗剂 ×Ratio 液固比 -0.013×Time 淋洗剂 ×Ratio (liquid-solid ratio) + 1460 × (Conc (rinsing agent)) 2 -0.000037 × (Time rinse agent) 2 +0.70×(Ratio - liquid-to-solid ratio) 2 ), calculate the pollutant removal rate data corresponding to the 30 sets of alternative low-carbon remediation process parameter combinations in step five.

[0103] Using the 80% removal rate limit provided by the construction contractor as the critical point, the alternative low-carbon remediation process parameter combinations that meet the remediation requirements are ranked according to their carbon emission intensity values. The Test 1 treatment group with the lowest carbon emission intensity value is selected as the optimal remediation process parameter combination. The specific process parameters and their removal rate and carbon emission intensity values ​​are as follows: Conc 淋洗剂 =0.10mol / L, Time 淋洗=239.38min, Ratio 液固比 =4.01, R=80.63%, T 碳排放 = 52.57kg CO2eq / kg Pb. This result was submitted to the construction team as a recommended solution for ex-situ low-carbon leaching remediation of contaminated soil.

[0104] The above embodiments should be understood as being used only to illustrate the present invention more clearly, and not to limit the scope of the present invention. After reading the present invention, any modifications of the present invention by those skilled in the art in various equivalent forms fall within the scope defined by the appended claims.

Claims

1. A decision-making method for contaminated soil leaching remediation based on carbon emission intensity, characterized in that: Includes the following steps: Step 1: Project Basic Information Analysis. Collect basic data on the site, identify target pollutants, and select the intended type of leaching agent and capture agent; Information on ex-situ rinsing repair equipment was collected, the repair process flow was analyzed, and process parameters were determined; these process parameters included rinsing agent concentration (Conc). 淋洗剂 ), rinse time (Time) 淋洗 ) and liquid-solid ratio (Ratio) 液固比 ); Step 2: Construction of a carbon emission intensity assessment model. This involves analyzing the carbon emission sources of the leaching remediation process, collecting carbon emission factor data, establishing a formula for calculating remediation carbon emissions, and constructing a carbon emission intensity assessment model. The carbon emission intensity is based on the amount of pollutant removed per unit of remediation activity and is the ratio of carbon emissions to pollutant removal. The carbon emission intensity assessment model is defined as carbon emission intensity T. 碳排放 =TE 总碳排放 / TS 总去除量 =E 碳排放 / S 去除量 , of which TE 总碳排放 and TS 总去除量 E represents the total carbon emissions and total pollutant removal of the remediation project, respectively. 碳排放 and S 去除量 These represent the carbon emissions and pollutant removal amounts corresponding to a unit of soil remediation volume, respectively. Step 3: Establishment of the basic dataset for leaching remediation. Design single-factor experiments and response surface methodology experiments to obtain the pollutant elution effects corresponding to different combinations of process parameters, and construct the basic dataset for leaching remediation. Step 4, Removal rate response surface fitting. Based on the basic dataset of leaching remediation, removal rate response surface fitting is carried out, the significance of the fitting results is tested, the validity of the experimental data is judged, and a pollutant removal rate prediction formula is constructed. Step 5: Carbon emission intensity response surface fitting. Based on the basic dataset of rinsing remediation, calculate the carbon emission intensity values ​​corresponding to different combinations of process parameters; Carbon emission intensity response surface fitting prediction was carried out, and the significance of the fitting results was tested; Under the condition of decreasing carbon emission intensity, a combination of parameters for alternative low-carbon remediation processes is generated through fitting. Step Six: Recommendation of Ex-situ Lavage Remediation Scheme. Based on the pollutant removal rate prediction formula in Step Four, calculate the pollutant removal rate data corresponding to the alternative low-carbon remediation process parameter combinations; Based on the principles of achieving the removal rate target and minimizing carbon emission intensity, the optimal combination of low-carbon remediation process parameters was selected and determined, forming a recommended scheme for low-carbon rinsing remediation process.

2. The decision-making method for contaminated soil leaching remediation based on carbon emission intensity according to claim 1, characterized in that: The pollutant elution effect in step three is the removal rate of one target pollutant or the average removal rate of multiple target pollutants in the response surface methodology experiment. The pollutant can be a heavy metal or an organic pollutant, or a combination of heavy metals and organic pollutants. The removal rate of one target pollutant is calculated using the formula: Removal rate R = TS 总去除量 / TS 初始 ×100%=(TS) 初始 -TS 修 (Cinitial - Cpost-remediation) / Cinitial × 100% = (Cinitial - Cpost-remediation) / Cinitial × 100%, where the total TS removal is the total amount of soil pollutants removed during the remediation project, TS 初始 and TS 修复后 These represent the initial total amount and the total amount of soil pollutants after remediation, respectively, C 初始 and C 修复后 These represent the initial and post-remediation concentrations of pollutants in the soil, respectively; the formula for calculating the average removal rate of the various target pollutants is: Removal Rate R ave =(∑R i ) / n, R i Let be the removal rate of the i-th pollutant, and n be the number of pollutant types under investigation.

3. The decision-making method for contaminated soil leaching remediation based on carbon emission intensity according to claim 1, characterized in that: The pollutant removal rate prediction formula in step four is a multivariate quadratic equation based on process parameter indicators; the significance test of the removal rate fitting results includes a model fit significance test and a lack-of-fit term significance test, and the model fit significance test result P... 拟合度1 The significance test result P for the lack-of-fit term should be less than 0.

05. 失拟项1 It should be greater than 0.

05.

4. The decision-making method for contaminated soil leaching remediation based on carbon emission intensity according to claim 1, characterized in that: The carbon emission intensity response surface fitting result in step five is a multivariate quadratic equation based on process parameter indices, with a fitting degree R. 2 It should be greater than 0.9; the significance test of the fitting results of carbon emission intensity includes the significance test of model fit and the significance test of the lack of fit term; The significance test result of the model fit P 拟合度2 The significance test result P for the lack-of-fit term should be less than 0.

05. 失拟项2 It should be greater than 0.05.

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