Heavy non-aqueous phase liquid pollution remediation precursor solution, preparation method and remediation method
By synergistically preparing microemulsion precursor solutions with surfactants and co-surfactants, the problems of long DNAPL repair cycles and low residual phase removal rates were solved, achieving efficient, low-cost, and environmentally friendly pollution remediation effects.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-17
- Publication Date
- 2026-03-27
AI Technical Summary
In existing groundwater remediation technologies, the remediation cycle for heavy non-aqueous liquid pollutants (DNAPLs) is long and the residual phase removal rate is low, making it difficult to meet the efficiency requirements of engineering remediation.
Microemulsion precursors were prepared by synergistic compounding of surfactants and co-surfactants. In-situ microemulsions were formed by utilizing the residual DNAPLs in the aqueous layer. The surface tension of the aqueous phase was reduced by synergistic compounding of polyoxyethylene nonionic surfactants and polyol nonionic surfactants, and the surface activity was enhanced by adding Gemini surfactants, thus forming a stable O/W emulsion system.
It achieves efficient removal of DNAPLs, reduces remediation costs, is stable and environmentally friendly, and has a low risk of secondary pollution, which is significantly better than traditional methods.
Smart Images
Figure BDA0005745146780000061 
Figure BDA0005745146780000091 
Figure BDA0005745146780000101
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of heavy non-aqueous phase liquid pollution remediation, in particular to a heavy non-aqueous phase liquid pollution remediation precursor liquid, a preparation method of the precursor liquid and a heavy non-aqueous phase liquid pollution remediation method. BACKGROUND
[0002] Dense Non-Aqueous Phase Liquids (DNAPLs) are a class of organic pollutants with high density and low solubility in water, including polychlorinated biphenyls, chlorinated hydrocarbons, chlorinated aromatic hydrocarbons, etc. Due to their high density, high volatility and strong adsorption to environmental media, once they enter the underground environment, they often infiltrate along the stratum fissure, pore or discontinuous zone of stratum structure and accumulate in the deeper aquifer or bedrock fissure, forming a highly stable and complex pollution source area. After long-term contact with groundwater, DNAPLs can continuously release dissolved pollutants to the surrounding water body, forming persistent groundwater pollution for several years or even decades, which poses a significant threat to ecological safety and human health.
[0003] In the existing groundwater remediation technology system, extraction-treatment is used to treat DNAPLs pollution, but due to the limitations of the phase stability of DNAPLs and the adsorption effect of soil, the existing technology has the problems and shortcomings of long remediation period, high operation cost and low residual phase removal rate, which is difficult to meet the efficiency requirements of engineering remediation. SUMMARY
[0004] The purpose of the present application is to provide a heavy non-aqueous phase liquid pollution remediation precursor liquid and a remediation method, and the technical problems to be solved are the long remediation period of the existing groundwater remediation technology system and the low residual phase removal rate of DNAPLs.
[0005] The first aspect of the present application provides a heavy non-aqueous phase liquid pollution remediation precursor liquid, which comprises 5-10 parts by volume of a surfactant, 1-5 parts by volume of a co-surfactant and 80-90 parts by volume of water; the surfactant is composed of 10-20 parts by volume of an oleophilic non-ionic surfactant, 10-20 parts by volume of an oleophilic hydrophilic non-ionic surfactant and 50-75 parts by volume of a gemini surfactant; the co-surfactant is one or a combination of the other of an alkenylene benzene sulfonate and thiourea.
[0006] The heavy non-aqueous phase liquid pollution remediation precursor liquid of the present application as described above, preferably, the gemini surfactant is synthesized from fatty acid polyoxyethylene ester, glutaraldehyde, diethylene triamine and sodium bisulfite.
[0007] The precursor solution for remediation of heavy non-aqueous liquid pollution of the present invention, as described above, preferably includes the following steps for synthesizing the gemini surfactant: Step 1, using N,N-dimethylformamide as a solvent, glutaraldehyde and diethylenetriamine are added at a molar ratio of 1:2, and the mixture is stirred at 100°C for 2 hours; Step 2, fatty acid polyoxyethylene ester is added to the mixture from Step 1 at a molar ratio of glutaraldehyde to fatty acid polyoxyethylene ester of 1:1, the temperature is raised to 150°C, and the mixture is reacted for 3 hours; Step 3, sodium bisulfite is added at a molar ratio of glutaraldehyde to sodium bisulfite of 1:1, the mixture is stirred at 100°C for 12 hours, washed with alcohol, and rotary evaporated to obtain the gemini surfactant.
[0008] The precursor solution for remediation of heavy non-aqueous liquid contamination as described above, preferably, is a combination of one or two of fatty acid glycerides and sucrose fatty acid esters.
[0009] The precursor solution for remediation of heavy non-aqueous liquid contamination as described above, preferably, comprises one or a combination of two of the following: fatty alcohol polyoxyethylene ether with HLB = 10-12 and alkylphenol polyoxyethylene ether with HLB = 12.8.
[0010] The precursor solution for remediation of heavy non-aqueous liquid contamination as described above preferably comprises: 8 parts by volume of surfactant, 3 parts by volume of co-surfactant, and 80-86 parts by volume of water; wherein the surfactant is composed of 6 parts by volume of lipophilic nonionic surfactant, 15 parts by volume of lipophilic and hydrophilic nonionic surfactant, and 60 parts by volume of gemini surfactant.
[0011] The second aspect of the present invention provides a method for preparing a precursor liquid, wherein the precursor liquid is a heavy non-aqueous phase liquid pollution remediation precursor liquid as described in any of the above claims, comprising the following steps: adding a surfactant to water, placing the mixture under a constant temperature condition of 20°C in a water bath, shaking and stirring on a shaker for 2 hours to dissolve until there is no foam on the surface, and finally adding a co-surfactant.
[0012] Another aspect of the present invention provides a method for remediating sites contaminated by heavy non-aqueous liquids, using a precursor solution for remediation of heavy non-aqueous liquid contamination as described in any of the above claims. Preferably, the remediation includes the following steps: injecting the precursor solution into the contaminated site containing the heavy non-aqueous liquid; after the heavy non-aqueous liquid in the contaminated site and the precursor solution form a microemulsion in situ, extracting the microemulsion from the contaminated site.
[0013] The beneficial effects of this invention are:
[0014] 1. The precursor solution of this invention is prepared by synergistic compounding of surfactant and co-surfactant to form a microemulsion precursor solution. After being injected into the underground environment, the residual DNAPLs in the aquifer are used as the oil phase to form an in-situ microemulsion, thereby achieving the purpose of efficient removal of DNAPLs.
[0015] 2. The precursor liquid of this invention significantly reduces the surface tension of the aqueous phase and constructs a stable O / W emulsion system through the synergistic compounding of polyoxyethylene nonionic surfactant and polyol nonionic surfactant. The addition of Gemini surfactant further greatly enhances the surface activity. No additional salts or alcohols are required. The solvent concentration used is low, the economic benefits are high, and it has good prospects for industrial application.
[0016] 3. In the precursor solution of the present invention, the co-surfactant is at least one of imide benzene sulfonate and thiourea. The co-surfactant can be inserted between the hydrophobic chains of the surfactant, and enhance the mechanical strength of the interfacial film and reduce the interfacial tension through hydrophobic-hydrophobic interactions and hydrogen bonding. Moreover, its synergistic use with Gemini-type surfactants can significantly improve the solubilization ability of chlorinated hydrocarbon DNAPLs.
[0017] 4. The precursor solution of this invention is oil-free, has a simple composition, is stable, environmentally friendly, and poses a low risk of secondary pollution. This invention demonstrates significantly better removal efficiency from DNAPL-contaminated sites than traditional surfactants, effectively reducing remediation costs. Detailed Implementation
[0018] The embodiments described herein are specific implementations of the present invention, used to illustrate the concept of the invention, and are illustrative and exemplary, and should not be construed as limiting the implementation or scope of the invention. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein.
[0019] The following embodiments of the present invention include two types: the first type is the gemini surfactant of the present invention, and the other is a commercially available gemini surfactant. The gemini surfactant of the present invention is synthesized from fatty acid polyoxyethylene ester, glutaraldehyde, diethylenetriamine, and sodium bisulfite. The synthesis steps of the gemini surfactant are as follows: Step 1, using N,N-dimethylformamide as a solvent, glutaraldehyde and diethylenetriamine are added at a molar ratio of 1:2, and the mixture is stirred at 100°C for 2 hours; Step 2, fatty acid polyoxyethylene ester is added to the mixture from Step 1 at a molar ratio of glutaraldehyde to fatty acid polyoxyethylene ester of 1:1, the temperature is raised to 150°C, and the mixture is reacted for 3 hours; Step 3, sodium bisulfite is added at a molar ratio of glutaraldehyde to sodium bisulfite of 1:1, the mixture is stirred at 100°C for 12 hours, washed with alcohol, and rotary evaporated to obtain the gemini surfactant. The commercially available gemini surfactant is sodium alkyl diphenyl ether disulfonate. The twin surfactant of this invention selects sulfonate groups with salt resistance and resistance to media adsorption as anionic hydrophilic groups, polyoxyethylene groups with low temperature resistance and a degree of polymerization of 3 or higher as nonionic hydrophilic groups, straight alkyl carbon chains with good biodegradability as hydrophobic chains, and diethylenetriamine that can promote micelle formation as a crosslinking agent.
[0020] In the efficacy verification of this invention, a one-dimensional simulated column of trichloroethylene was used. The simulated column had a diameter of 2.5 cm and a height of 30 cm, and was made of acrylic glass. Inlet and outlet ports were located at the top and bottom of the simulated column, respectively. River sand with a particle size of 0.1-0.2 mm was used as the packing medium. 10 mL of 3 mol / L trichloroethylene was mixed with the river sand and then packed into the one-dimensional simulated column. The trichloroethylene pollution removal effect was measured as follows: the precursor solution prepared in the example was continuously injected from bottom to top into the one-dimensional simulated column containing a certain concentration of trichloroethylene at a flow rate of 0.5 mL / min. First, 1 PV (PV is unit pore volume) of precursor solution was injected, followed by rinsing with deionized water. The trichloroethylene content in the eluted water sample was continuously measured, and the pollutant removal rate was calculated. A total of 4 PV of aqueous solution was injected before elution was completed, and the tail liquid was extracted.
[0021] This invention provides a method for remediating sites contaminated with heavy non-aqueous liquids, using a precursor solution prepared according to this invention. The remediation process includes the following steps: injecting the precursor solution into the contaminated site containing the heavy non-aqueous liquid; after the heavy non-aqueous liquid and the precursor solution form a microemulsion in situ, the microemulsion is extracted from the contaminated site. In one specific remediation method, the precursor solution is injected into the contaminated site through an injection well, and then extracted through an extraction well to remove the microemulsion formed in situ by the heavy non-aqueous liquid and the precursor solution.
[0022] Example 1
[0023] The precursor solution for remediation of heavy non-aqueous liquid contamination in this embodiment includes: 5 parts by volume of surfactant, 5 parts by volume of co-surfactant (sodium α-olefin sulfonate), and 90 parts by volume of water; the surfactant is composed of 20 parts by volume of lipophilic nonionic surfactant (fatty acid glyceride), 10 parts by volume of lipophilic and hydrophilic nonionic surfactant (fatty alcohol polyoxyethylene ether), and 75 parts by volume of gemini surfactant (the gemini surfactant of this invention).
[0024] The preparation method of the above-mentioned precursor solution includes the following steps: adding surfactants (lipophilic nonionic surfactants, lipophilic hydrophilic nonionic surfactants and gemini surfactants) to water, placing the mixture in a 20°C water bath at a constant temperature, shaking and stirring on a shaker for 2 hours to dissolve until there is no foam on the surface, and finally adding co-surfactants to obtain the precursor solution for the remediation of heavy non-aqueous liquid pollution.
[0025] The elution and remediation effect of the prepared precursor solution was determined using a one-dimensional trichloroethylene simulated column. The precursor solution prepared in the example was continuously injected from bottom to top into a one-dimensional simulated column containing a certain concentration of trichloroethylene at a flow rate of 0.5 mL / min. First, 1 PV of precursor solution was injected, followed by rinsing with deionized water. The trichloroethylene content in the eluted water sample was continuously measured, and the pollutant removal rate was calculated. A total of 4 PV of aqueous solution was injected before elution was completed, and the tailings were extracted.
[0026]
[0027] In the formula: the total amount of contaminants is the product of the concentration and volume of trichloroethylene added to the one-dimensional simulation column; the amount of contaminants removed is the product of the concentration and volume of trichloroethylene in the eluent.
[0028] Example 2
[0029] The precursor solution for remediation of heavy non-aqueous liquid contamination in this embodiment comprises: 10 parts by volume of surfactant, 1 part by volume of co-surfactant (thiourea), and 80 parts by volume of water; the surfactant consists of 10 parts by volume of lipophilic nonionic surfactant (fatty acid glyceride), 20 parts by volume of lipophilic-hydrophilic nonionic surfactant (alkylphenol polyoxyethylene ether), and 50 parts by volume of gemini surfactant (the gemini surfactant of this invention). The preparation method of the precursor solution and the determination of the elution remediation effect are the same as in Example 1.
[0030] Example 3
[0031] The precursor solution for remediation of heavy non-aqueous liquid contamination in this embodiment comprises: 8 parts by volume of surfactant, 3 parts by volume of co-surfactant (thiourea), and 82 parts by volume of water; the surfactant consists of 16 parts by volume of lipophilic nonionic surfactant (sucrose fatty acid ester), 15 parts by volume of lipophilic-hydrophilic nonionic surfactant (fatty alcohol polyoxyethylene ether), and 60 parts by volume of gemini surfactant (the gemini surfactant of this invention). The preparation method of the precursor solution and the determination of the elution remediation effect are the same as in Example 1.
[0032] Example 4
[0033] The precursor solution for remediation of heavy non-aqueous liquid contamination in this embodiment comprises: 8 parts by volume of surfactant, 2 parts by volume of co-surfactant (thiourea), and 86 parts by volume of water; the surfactant consists of 20 parts by volume of lipophilic nonionic surfactant (fatty acid glyceride), 16 parts by volume of lipophilic-hydrophilic nonionic surfactant (alkylphenol polyoxyethylene ether), and 65 parts by volume of gemini surfactant (the gemini surfactant of this invention). The preparation method of the precursor solution and the determination of the elution remediation effect are the same as in Example 1.
[0034] Example 5
[0035] The precursor solution for remediation of heavy non-aqueous liquid contamination in this embodiment comprises: 9 parts by volume of surfactant, 3 parts by volume of co-surfactant (sodium α-olefin sulfonate), and 87 parts by volume of water; the surfactant consists of 15 parts by volume of lipophilic nonionic surfactant (sucrose fatty acid ester), 20 parts by volume of lipophilic-hydrophilic nonionic surfactant (fatty alcohol polyoxyethylene ether), and 75 parts by volume of gemini surfactant (the gemini surfactant of this invention). The preparation method of the precursor solution and the determination of the elution remediation effect are the same as in Example 1.
[0036] Example 6
[0037] The precursor solution for remediation of heavy non-aqueous liquid contamination in this embodiment comprises: 8 parts by volume of surfactant, 3 parts by volume of co-surfactant (thiourea), and 86 parts by volume of water; the surfactant consists of 16 parts by volume of lipophilic nonionic surfactant (sucrose fatty acid ester), 15 parts by volume of lipophilic-hydrophilic nonionic surfactant (fatty alcohol polyoxyethylene ether), and 60 parts by volume of gemini surfactant (commercially available gemini surfactant). The preparation method and elution remediation effect determination of the above precursor solution are the same as in Example 1.
[0038] Example 7
[0039] The precursor solution for remediation of heavy non-aqueous liquid contamination in this embodiment comprises: 8 parts by volume of surfactant, 3 parts by volume of co-surfactant (thiourea), and 86 parts by volume of water; the surfactant consists of 15 parts by volume of an oleophilic-hydrophilic nonionic surfactant (fatty alcohol polyoxyethylene ether) and 60 parts by volume of a gemini surfactant (the gemini surfactant of this invention). The preparation method and elution remediation effect determination of the above precursor solution are the same as in Example 1. The only difference is the addition of surfactants to the water: an oleophilic-hydrophilic nonionic surfactant and a gemini surfactant.
[0040] Example 8
[0041] The precursor solution for remediation of heavy non-aqueous liquid contamination in this embodiment comprises: 8 parts by volume of surfactant, 3 parts by volume of co-surfactant (thiourea), and 86 parts by volume of water; the surfactant consists of 16 parts by volume of lipophilic nonionic surfactant (sucrose fatty acid ester) and 60 parts by volume of gemini surfactant (the gemini surfactant of this invention). The preparation method and elution remediation effect determination of the above precursor solution are the same as in Example 1. The only difference is the addition of surfactants to the water: lipophilic nonionic surfactant and gemini surfactant.
[0042] Example 9
[0043] The precursor solution for remediation of heavy non-aqueous liquid contamination in this embodiment comprises: 8 parts by volume of surfactant, 3 parts by volume of co-surfactant (thiourea), and 86 parts by volume of water; the surfactant consists of 16 parts by volume of lipophilic nonionic surfactant (sucrose fatty acid ester) and 15 parts by volume of lipophilic-hydrophilic nonionic surfactant (fatty alcohol polyoxyethylene ether). The preparation method and elution remediation effect determination of the above precursor solution are the same as in Example 1. The only difference is the addition of surfactants to the water: lipophilic nonionic surfactant and lipophilic-hydrophilic nonionic surfactant.
[0044] Example 10
[0045] The precursor solution for remediation of heavy non-aqueous liquid contamination in this embodiment comprises: 8 parts by volume of surfactant, 0.8 parts by volume of co-surfactant (thiourea), and 86 parts by volume of water; the surfactant consists of 16 parts by volume of lipophilic nonionic surfactant (sucrose fatty acid ester), 15 parts by volume of lipophilic-hydrophilic nonionic surfactant (fatty alcohol polyoxyethylene ether), and 60 parts by volume of gemini surfactant (the gemini surfactant of this invention). The preparation method of the precursor solution and the determination of the elution remediation effect are the same as in Example 1.
[0046] Table 1 shows the elution and repair experiment results of Examples 1 to 10.
[0047] Table 1 Results of the elution and retrieval experiment
[0048]
[0049]
[0050] Comparing the experimental results of Example 3 and Example 6, the removal rate of chlorinated hydrocarbons was significantly reduced when using commercially available gemini surfactants, indicating that the self-made gemini surfactants are significantly superior to commercially available products in terms of interfacial activity, solubilization ability, and synergistic effect with other components in the system.
[0051] Comparing the experimental results of Examples 3 and 7, 8, and 9, the removal rate of chlorinated hydrocarbons decreased significantly without the addition of a lipophilic nonionic surfactant, indicating that it plays a key role in enhancing the affinity between the system and the chlorinated hydrocarbon organic phase. The removal rate of chlorinated hydrocarbons also decreased significantly without the addition of a lipophilic and hydrophilic nonionic surfactant, demonstrating its indispensability in constructing stable O / W emulsions and maintaining interfacial activity. The removal rate of chlorinated hydrocarbons decreased significantly without the addition of the gemini surfactant of this invention, confirming that this component is the core for achieving efficient solubilization and improving the repair effect.
[0052] Comparing the experimental results of Example 3 and Example 10, when the amount of co-surfactant added is less than the range of the present invention, the mechanical strength of the interfacial film is insufficient, resulting in a decrease in the removal rate of chlorinated hydrocarbons as the amount added decreases, and the ideal repair effect cannot be achieved.
[0053] In summary, the precursor solution and application method for remediation of heavy non-aqueous liquid contamination of the present invention have the following technical advantages:
[0054] 1. The precursor solution of this invention is prepared by synergistic compounding of surfactant and co-surfactant to form a microemulsion precursor solution. After being injected into the underground environment, the residual DNAPLs in the aquifer are used as the oil phase to form an in-situ microemulsion, thereby achieving the purpose of efficient removal of DNAPLs.
[0055] 2. The precursor liquid of this invention significantly reduces the surface tension of the aqueous phase and constructs a stable O / W emulsion system through the synergistic compounding of polyoxyethylene nonionic surfactant and polyol nonionic surfactant. The addition of Gemini surfactant further greatly enhances the surface activity. No additional salts or alcohols are required. The solvent concentration used is low, the economic benefits are high, and it has good prospects for industrial application.
[0056] 3. In the precursor solution of the present invention, the co-surfactant is at least one of imide benzene sulfonate and thiourea. The co-surfactant can be inserted between the hydrophobic chains of the surfactant, and enhance the mechanical strength of the interfacial film and reduce the interfacial tension through hydrophobic-hydrophobic interactions and hydrogen bonding. Moreover, its synergistic use with Gemini-type surfactants can significantly improve the solubilization ability of chlorinated hydrocarbon DNAPLs.
[0057] 4. The precursor solution of this invention is oil-free, has a simple composition, is stable, environmentally friendly, and poses a low risk of secondary pollution. This invention demonstrates significantly better removal efficiency from DNAPL-contaminated sites than traditional surfactants, effectively reducing remediation costs.
[0058] The technical features disclosed above are not limited to the combinations of the disclosed features with other features. Those skilled in the art can also make other combinations of the technical features according to the purpose of the invention to achieve the purpose of the invention.
Claims
1. A precursor solution for the remediation of heavy non-aqueous liquid contamination, characterized in that, include: The surfactant comprises 5-10 parts by volume of a surfactant, 1-5 parts by volume of a co-surfactant, and 80-90 parts by volume of water; the surfactant comprises 10-20 parts by volume of a lipophilic nonionic surfactant, 10-20 parts by volume of a lipophilic-hydrophilic nonionic surfactant, and 50-75 parts by volume of a gemini surfactant; the co-surfactant is one or a combination of two of imidene benzenesulfonate and thiourea.
2. The precursor solution for remediation of heavy non-aqueous liquid contamination according to claim 1, characterized in that, The twin-type surfactant is synthesized from fatty acid polyoxyethylene ester, glutaraldehyde, diethylenetriamine, and sodium bisulfite.
3. The precursor solution for remediation of heavy non-aqueous liquid contamination according to claim 2, characterized in that, The synthesis steps of the Gemini surfactant are as follows: Step 1, using N,N-dimethylformamide as solvent, glutaraldehyde and diethylenetriamine are added at a molar ratio of 1:2, and the mixture is stirred at 100°C for 2 hours; Step 2, fatty acid polyoxyethylene ester is added to the mixture from Step 1 at a molar ratio of glutaraldehyde to fatty acid polyoxyethylene ester of 1:1, the temperature is raised to 150°C, and the mixture is reacted for 3 hours; Step 3, sodium bisulfite is added at a molar ratio of glutaraldehyde to sodium bisulfite of 1:1, the mixture is stirred at 100°C for 12 hours, washed with alcohol, and rotary evaporated to obtain the Gemini surfactant.
4. The precursor solution for remediation of heavy non-aqueous liquid contamination according to claim 1, characterized in that, The lipophilic nonionic surfactant is one or a combination of two of the following: fatty acid glycerides and sucrose fatty acid esters.
5. The precursor solution for remediation of heavy non-aqueous liquid contamination according to claim 1, characterized in that, The lipophilic and hydrophilic nonionic surfactant is one or a combination of two of the following: fatty alcohol polyoxyethylene ether with HLB=10-12 and alkylphenol polyoxyethylene ether with HLB=12.
8.
6. The precursor solution for remediation of heavy non-aqueous liquid contamination according to claim 1, characterized in that, include: 8 parts by volume of surfactant, 3 parts by volume of co-surfactant, and 80-86 parts by volume of water; The surfactant is composed of 6 parts by volume of a lipophilic nonionic surfactant, 15 parts by volume of a lipophilic-hydrophilic nonionic surfactant, and 60 parts by volume of a gemini surfactant.
7. A method for preparing a precursor solution, characterized in that, The precursor solution is the heavy non-aqueous liquid pollution remediation precursor solution according to any one of claims 1 to 6, comprising the following steps: adding a surfactant to water, placing the mixture under a constant temperature condition of 20°C in a water bath, shaking and stirring on a shaker for 2 hours to dissolve until there is no foam on the surface, and finally adding a co-surfactant.
8. A method for remediating sites contaminated with heavily non-aqueous liquids, characterized in that, The remediation of sites contaminated with heavy non-aqueous liquids is carried out using the precursor solution for remediation of heavy non-aqueous liquid contamination as described in any one of claims 1 to 6.
9. The method for remediating heavily contaminated sites by non-aqueous liquids according to claim 8, characterized in that, The repair includes the following steps: The precursor liquid is injected into a contaminated site containing heavy non-aqueous liquid. After the heavy non-aqueous liquid in the contaminated site and the precursor liquid form a microemulsion in situ, the microemulsion is extracted from the contaminated site.