Selective adsorption sponge and soil leaching wastewater recycling device containing same

Abstract

The invention provides a selective adsorption sponge and a soil leaching wastewater recycling device containing the same. The preparation method of the selective adsorption sponge comprises the following steps: reacting a surfactant, an alkaline compound, carboxylic acid and sulfydryl-containing silane, drying to obtain an initial sponge, reacting the initial sponge with an alkenyl perfluorinated compound under the action of an initiator, and drying to obtain the selective adsorption sponge. The soil leaching wastewater recycling device mainly comprises a screening and intercepting device, a precision filtering device and a selective adsorption tower filled with the selective adsorption sponge, and further comprises a surfactant replenishing tank.

Description

Technical Field

[0001] The invention belongs to the technical field of environmental protection soil treatment, and in particular relates to a selective adsorption sponge and a soil leaching wastewater recycling device containing the sponge. Background Art

[0002] With the increasing demand for petroleum products in modern society and the rapid development of petrochemicals, environmental pollution incidents caused by oil are emerging one after another. After entering the environment, oil products will cause serious damage to the atmosphere, water bodies and soil, especially soil. Petroleum pollutants will destroy the composition and structure of soil organic matter, reduce soil permeability, damage soil microecology, cause nutrient loss, and make the soil no longer suitable for plant growth. In recent years, my country has experienced many oil leakage accidents in oil mining areas, long-distance pipelines, refineries and storage tank areas, causing large-scale and long-term soil pollution. How to repair contaminated soil is a difficult problem facing environmental protection workers.

[0003] At present, there are two main methods for soil remediation: biological methods and physical and chemical methods. The biological method requires a long remediation cycle and is mainly aimed at low-concentration pollution areas, which is more limited in actual use. The physical and chemical methods mainly include soil gas extraction, thermal desorption, chemical oxidation and soil leaching. Gas extraction is mainly aimed at oil products with good volatility, and it has almost no effect on soil contaminated by crude oil; thermal desorption has high requirements on soil type, high energy consumption, and high remediation costs; chemical oxidation mineralizes all pollution into carbon dioxide and water, with a large amount of reagents and no effective resource recovery. Soil leaching is a better in situ / ex situ remediation method, which often uses a surfactant-containing eluent to elute the contaminated soil, and has the characteristics of thorough remediation and short remediation time. However, the biggest problem limiting its use is the secondary pollution of surfactants (such as sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, Tween series) and the treatment of wastewater containing surfactants.

[0004] In recent years, with the rapid development of bioengineering, biosurfactants have gradually come into people's attention. Biosurfactants are amphiphilic substances with hydrophobic groups and hydrophilic groups produced by microbial metabolism. They can significantly reduce surface and interfacial tension. Compared with chemical surfactants, biosurfactants have the advantages of low toxicity, good biocompatibility, and degradability. In the field of soil remediation, biosurfactants have gradually replaced chemical surfactants as the main force in soil leaching and remediation processes because of their biodegradability, but this also brings about the problem of repeated use of biosurfactants. This is because the production cost of biosurfactants is more expensive than that of chemical surfactants, so it is necessary to reuse the biosurfactants in the leaching solution. The reuse process involves the removal of particulate matter, the recovery of oil products, and the reuse of biosurfactants in the leaching solution.

[0005] Similar to chemical surfactants, biological surfactants can elute oil products by solubilizing and emulsifying, that is, the hydrophilic groups of biological surfactants face water, and the lipophilic and hydrophobic groups face oil droplets, but this will form a large number of water-in-oil structures, making it difficult to selectively separate oil products and biological surfactants. However, unlike ionic chemical surfactants, biological surfactants are often glycolipids and lipopeptides, which are somewhat similar to non-ionic chemical surfactants. Glycolipid biological surfactants are complexes composed of sugars and long-chain fatty acids or hydroxylated fatty acids. The main biological surfactants of glycolipids are trehalose lipids, rhamnolipids, sophorolipids, and mannosyl erythritol esters; lipopeptides are a class of amphiphilic substances composed of fatty acids and peptides. For the above-mentioned biological surfactants, due to their lack of easily ionized groups, conventional ion exchange / electrochemical methods are difficult to separate oil products and biological surfactants. If membrane separation is used to separate biosurfactants and oil products, the membrane must not only be resistant to pressure, oil and pollution, but also have extremely high requirements on the separation properties of the membrane.

[0006] Currently, there is no mature method for reusing wastewater generated by leaching oil-containing soil with biosurfactants. Summary of the invention

[0007] The purpose of the present invention is to provide a method for recycling oil-containing soil leaching wastewater containing biosurfactant.

[0008] To achieve the above object, the present invention provides a method for preparing a selective adsorption sponge in a first aspect:

[0009] 1) mixing a surfactant, an alkaline compound, a carboxylic acid and a first solvent to obtain a first reaction solution;

[0010] 2) allowing the mercapto-containing silane to react with the first reaction solution, and drying to obtain an initial sponge;

[0011] 3) mixing the alkenyl perfluoro compound, the initiator and the second solvent to obtain a second reaction solution;

[0012] 4) immersing the initial sponge in the second reaction solution, performing a second reaction, and drying to obtain the selective adsorption sponge.

[0013] According to a specific embodiment of the present invention, the first reaction solution comprises 0.8 to 1.2 parts by mass of the surfactant, 3 to 6 parts by mass of the alkaline compound, 0.2 to 0.4 parts by mass of the carboxylic acid and 12 to 20 parts by mass of the first solvent; and / or

[0014] In step 2), the mass ratio of the mercapto-containing silane to the first reaction solution is (4 to 6):(20 to 25);

[0015] and / or

[0016] In step 3), the second reaction solution comprises 0.8 to 1.2 parts by mass of the alkenyl perfluoro compound, 0.002 to 0.004 parts by mass of the initiator and 4 to 6 parts by mass of the second solvent; and / or

[0017] In step 4), the volume ratio of the initial sponge to the second reaction liquid is 1:(2 to 3);

[0018] Preferably, the first reaction solution comprises 0.8 to 1.2 parts by mass of the surfactant, 4 to 5 parts by mass of the alkaline compound, 0.24 to 0.36 parts by mass of the carboxylic acid and 14 to 18 parts by mass of the first solvent; and / or

[0019] In step 2), the mass ratio of the mercapto-containing silane to the first reaction solution is (4 to 5.5):(20 to 23);

[0020] and / or

[0021] In step 3), the second reaction solution includes 1 part by mass of the alkenyl perfluoro compound, 0.002 to 0.004 parts by mass of the initiator, and 4 to 5 parts by mass of the second solvent.

[0022] According to a specific embodiment of the present invention, the surfactant is C 10 To C 18 Long chain alkyl trimethyl ammonium halide; and / or

[0023] The alkaline compound is at least one of urea, ethylenediamine and triethylamine; and / or

[0024] The carboxylic acid is at least one of formic acid, acetic acid and oxalic acid; and / or

[0025] The mercapto-containing silane is mercaptopropyl alkoxy silane; and / or

[0026] The alkenyl perfluoro compound is at least one of allyl pentafluorobenzene, allyl perfluoropentanoate, 1H,1H,2H-perfluoro-1-hexene, 1H,1H,7H-perfluorohept-1-ene, 1H,1H,2H-heptafluoropent-1-ene, 1H,1H,2H-perfluoro-1-dodecene, allyl heptafluoroisopropyl ether and allyl 2,2,3,3,4,4,5,5-octafluoropentyl ether;

[0027] Preferably, the surfactant is selected from at least one of cetyltrimethylammonium chloride, cetyltrimethylammonium bromide, octadecyltrimethylammonium chloride, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, octadecyltrimethylammonium bromide, tetradecyltrimethylammonium bromide and dodecyltrimethylammonium bromide; and / or

[0028] The carboxylic acid is formic acid and / or acetic acid; and / or

[0029] The mercapto-containing silane is at least one of mercaptopropylmethyldimethoxysilane, mercaptopropylmethyldiethoxysilane, mercaptopropyltrimethoxysilane and mercaptopropyltriethoxysilane;

[0030] Preferably, the surfactant is at least one of hexadecyltrimethylammonium chloride, dodecyltrimethylammonium chloride and octadecyltrimethylammonium chloride; and / or

[0031] The mercapto-containing silane is at least one of mercaptopropylmethyldimethoxysilane, mercaptopropylmethyldiethoxysilane and mercaptopropyltrimethoxysilane; and / or

[0032] The alkenyl perfluoro compound is at least one of 1H,1H,2H-heptafluoropent-1-ene, allyl pentafluorobenzene and 1H,1H,2H-perfluoro-1-hexene;

[0033] Preferably, the first solvent is water; and / or

[0034] The second solvent is a lower alcohol; and / or

[0035] The initiator is azobisisobutyronitrile and / or dibenzoyl peroxide.

[0036] According to a specific embodiment of the present invention, the first reaction is carried out under closed conditions; and / or the temperature of the first reaction is 70° C. to 90° C.; and / or

[0037] The temperature of the second reaction is 50°C to 70°C; and / or

[0038] The duration of the first reaction and the second reaction is independently 8h to 12h;

[0039] Preferably, the temperature of the first reaction is 80°C; and / or

[0040] The temperature of the second reaction is 60°C; and / or

[0041] The duration of the first reaction and the second reaction is independently 10 hours;

[0042] Preferably, the drying conditions in step 2) and step 4) are independently drying at 60 to 70° C. for 4 to 6 hours; and / or

[0043] Purifying and drying the reaction product obtained from the first reaction; and / or

[0044] purifying and drying the reaction product obtained from the second reaction;

[0045] Preferably, the conditions for purifying the reaction product obtained by the first reaction and the reaction product obtained by the second reaction are independently washing with ethanol and / or methanol.

[0046] The second aspect of the present invention provides a selective adsorption sponge prepared by the method described in the first aspect of the present invention.

[0047] According to a specific embodiment of the present invention, the bulk density of the selective adsorption sponge is 20 kg / m 3 Up to 30kg / m 3 .

[0048] The third aspect of the present invention provides a soil leaching wastewater reuse device, which comprises a screening and interception device 1, a precision filtering device 2 and a selective adsorption tower 3 connected in sequence;

[0049] The screening and interception device 1 is used to intercept particulate matter in the soil leaching wastewater;

[0050] The precision filtering device 2 is used for secondary interception of particulate matter in soil leaching wastewater;

[0051] The selective adsorption tower 3 is filled with a selective adsorption sponge for selectively adsorbing oil substances in the soil leaching wastewater;

[0052] The selective adsorption sponge is the selective adsorption sponge prepared by the method described in the first aspect of the present invention or the selective adsorption sponge described in the second aspect of the present invention.

[0053] According to a specific embodiment of the present invention, the filling amount of the selective adsorption sponge in the selective adsorption tower 3 is 2 to 3 times the bulk density of the selective adsorption sponge; and / or

[0054] The height-to-diameter ratio of the selective adsorption tower 3 is (3 to 5): 1; and / or the empty bed velocity is 8 to 20 m / h; and / or the apparent residence time is 5 min to 20 min; and / or

[0055] The screening and interception device 1 is selected from a flat grid, a fixed curved grid or a rotary drum grid; and / or

[0056] The filter element in the precision filtering device 2 is selected from at least one of polytetraethylene, polysulfone, nylon, polypropylene and acetate fiber;

[0057] Preferably, the screening and interception device 1 is a rotary drum screen; and / or the spacing between the screen bars is 0.2 mm to 5 mm; and / or the rotary drum screen is at an angle of 30° to 40° to the flow direction of the soil leaching wastewater;

[0058] Preferably, the initial pressure drop of the filter element in the precision filtration device 2 is 0.01 MPa to 0.02 MPa; and / or the pore size is 10 μm to 50 μm;

[0059] Preferably, the rotary drum screen is provided with a flushing device and has a self-cleaning function.

[0060] According to a specific embodiment of the present invention, the device further comprises a surfactant replenishing tank 4;

[0061] Preferably, the surfactant replenishing tank 4 is connected to the selective adsorption tower 3 .

[0062] In the device provided by the present invention, a plurality of selective adsorption towers 3 are connected in parallel after the precision filtering device 2 according to actual application needs.

[0063] The primary interception mentioned in the present invention refers to the interception of large particles with a particle size of more than 1 mm; the secondary interception refers to the interception of suspended soil particles.

[0064] A fourth aspect of the present invention provides a method for reusing wastewater from oil-containing soil washing containing biosurfactants, which comprises the following steps:

[0065] Provide a soil washing wastewater recycling device according to the third aspect of the present invention;

[0066] A. passing the oil-containing soil washing wastewater containing biosurfactant through the screening and interception device 1 to perform the primary interception to obtain a first treated liquid;

[0067] B. passing the first treatment liquid through the precision filtration device 2 to perform the secondary interception to obtain a second treatment liquid;

[0068] C. allowing the second treatment liquid to enter the selective adsorption tower 3 to selectively adsorb oil substances to obtain a third treatment liquid;

[0069] Preferably, the third treatment liquid is discharged into the surfactant replenishing tank 4, and a fourth treatment liquid is obtained after adding a biological surfactant.

[0070] According to a specific embodiment of the present invention, when the working pressure of the precision filter device 2 is greater than 4 times its initial pressure drop, the precision filter device 2 is backwashed; and / or

[0071] The content of the biosurfactant in the fourth treatment liquid is 8 g / L to 10 g / L; and / or

[0072] The residence time of the third treatment liquid in the surfactant replenishment tank 4 is 2 to 5 minutes;

[0073] Preferably, the biosurfactant is a glycolipid biosurfactant and / or a lipopeptide biosurfactant;

[0074] Preferably, the glycolipid biosurfactant is at least one of trehalolipids, rhamnolipids, sophorolipids and mannitol erythritol esters.

[0075] The glycolipid biosurfactant referred to in the present invention is a complex composed of sugar and long-chain fatty acid or hydroxylated fatty acid.

[0076] The lipopeptide biosurfactant referred to in the present invention is an amphiphilic substance composed of fatty acids and peptides.

[0077] Beneficial effects of the present invention:

[0078] In view of the problem that it is difficult to reuse the biosurfactant in the oily soil leaching wastewater containing biosurfactant in the prior art, the present invention provides a selective adsorption sponge and a soil leaching wastewater recycling device containing the same. The selective adsorption sponge is prepared by the following method: first, a surfactant, an alkaline compound, a carboxylic acid and a thiol-containing silane are reacted, and an initial sponge is obtained after drying, and then the initial sponge and an olefin perfluoro compound are reacted under the action of an initiator, and the selective adsorption sponge is obtained after drying. The selective adsorption sponge is lipophilic and hydrophobic, and the surface is a rough nanostructure, showing a double hydrophobic property of hydrophobicity and oleophobicity, which can selectively adsorb oil substances and almost does not adsorb biosurfactants, thereby realizing the separation of biosurfactants and oil substances. Specifically: the selective adsorption sponge has a selective adsorption value S of 264 to 291 for diesel and rhamnolipid at room temperature, which is above 200, and can achieve efficient selective adsorption of diesel, thereby realizing the separation of diesel and rhamnolipid. The soil leaching wastewater recycling device mainly includes a screening and interception device 1, a precision filtering device 2 and a selective adsorption tower 3 filled with the selective adsorption sponge, and secondly includes a surfactant replenishing tank 4. The soil leaching wastewater recycling device provided by the present invention is used to reuse the oil-containing soil leaching wastewater containing biosurfactants: firstly, primary interception and secondary interception are performed to remove particulate matter in the wastewater, and then the selective adsorption tower is used to selectively adsorb oil substances in the wastewater and retain the biosurfactants in the wastewater, and then the biosurfactants are added to the treated wastewater containing biosurfactants (i.e., the fourth treatment liquid) in the surfactant replenishing tank for leaching and reuse. In the process of recycling soil leaching wastewater containing biosurfactant (specifically rhamnolipid or sophorolipid or lipopeptide), oil substances (specifically diesel oil pollution or gasoline oil pollution or crude oil pollution) and particulate matter by using the soil leaching wastewater recycling device provided by the present invention: compared with the initial content of various components in the wastewater, the content of particulate matter is reduced by 92.4% to 94.5% after treatment by the screening and interception device and the precision filtration device, and the adsorption rate of oil substances reaches 98.4% to 99.9% and the biosurfactant maintenance rate reaches 88.9% to 98.4% after further treatment by the selective adsorption tower; finally, after the biosurfactant is added in the surfactant replenishing tank, the content of the biosurfactant in the fourth treatment liquid reaches 8.0 to 9.5 g / L, and the fourth treatment liquid can be reused for leaching of oil-containing soil. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Figure 1 This is a scanning electron microscope image of the selective adsorption sponge prepared in Example 1;

[0080] Figure 2 This is an image of the water contact angle of the selective adsorption sponge prepared in Example 1, wherein the water contact angle of the selective adsorption sponge is 150°;

[0081] Figure 3 The oil contact angle image of the selective adsorption sponge prepared in Example 1, wherein the oil contact angle of the selective adsorption sponge is 136°;

[0082] Figure 4 This is a diagram of a soil leaching wastewater reuse device provided by the present invention, wherein 1-screening and interception device; 2-precision filtration device; 3-selective adsorption tower; 4-surfactant addition tank; the arrow indicates the flow direction of soil leaching wastewater. DETAILED DESCRIPTION

[0083] The present invention will be further described below in conjunction with examples, but the examples of the present invention are only exemplary descriptions, and the implementation manner does not constitute a limitation of the present invention under any circumstances.

[0084] Example 1

[0085] Preparation of selective adsorption sponge

[0086] 1) Weigh 12 g of hexadecyltrimethylammonium chloride, 48 g of urea, 3.6 g of acetic acid and 168 g of water, mix well, and obtain 231.6 g of a first reaction solution;

[0087] 2) 52.64 g of mercaptopropylmethyldimethoxysilane and 231.6 g of the first reaction solution obtained in step 1) were mixed, and the mixture was reacted at 80° C. for 10 h under a sealed condition. The obtained reaction product was washed with methanol for 6 times to remove the remaining unreacted substances, and then dried at 65° C. for 5 h to obtain an initial sponge;

[0088] 3) mixing 1H,1H,2H-perfluoro-1-hexene, azobisisobutyronitrile and propanol to obtain a second reaction solution having a mass ratio of 1H,1H,2H-perfluoro-1-hexene:azobisisobutyronitrile:propanol of 1:0.003:5;

[0089] 4) Then, the initial sponge prepared in step 2) is immersed in the second reaction solution of step 3), the volume of the second reaction solution is 2.5 times the volume of the initial sponge, and then reacted at 60°C for 10 hours. The obtained reaction product is washed with methanol 6 times to remove the remaining unreacted product, and then dried at 65°C for 5 hours to obtain a selective adsorption sponge with a bulk density of 22.3 kg / m 3 .

[0090] Example 2

[0091] Preparation of selective adsorption sponge

[0092] 1) Weigh 8 g of dodecyltrimethylammonium chloride, 40 g of ethylenediamine, 2.4 g of formic acid and 160 g of water, mix well, and obtain 210.4 g of a first reaction solution;

[0093] 2) 42.08 g of mercaptopropylmethyldiethoxysilane and 210.4 g of the first reaction solution obtained in step 1) were mixed, and the mixture was reacted at 80° C. for 10 h under a sealed condition. The obtained reaction product was washed with methanol for 6 times to remove the remaining unreacted matter, and then dried at 65° C. for 5 h to obtain an initial sponge;

[0094] 3) mixing allyl pentafluorobenzene, azobisisobutyronitrile and ethanol to obtain a second reaction solution having a mass ratio of allyl pentafluorobenzene: azobisisobutyronitrile: ethanol of 1:0.002:4;

[0095] 4) Then, the initial sponge prepared in step 2) is immersed in the second reaction solution of step 3), the volume of the second reaction solution is 3 times the volume of the initial sponge, and then reacted at 60°C for 10 hours. The obtained reaction product is washed with methanol 6 times to remove the remaining unreacted product, and then dried at 65°C for 5 hours to obtain a selective adsorption sponge with a bulk density of 25.4 kg / m 3 .

[0096] Example 3

[0097] Preparation of selective adsorption sponge

[0098] 1) Weigh 10 g of octadecyltrimethylammonium chloride, 50 g of triethylamine, 3 g of formic acid and 140 g of water, mix well to obtain 203 g of the first reaction solution;

[0099] 2) 40.6 g of mercaptopropyltrimethoxysilane and 203 g of the first reaction solution obtained in step 1) were mixed, and the mixture was reacted at 80° C. for 10 h under a sealed condition. The obtained reaction product was washed with methanol for 6 times to remove the remaining unreacted matter, and then dried at 65° C. for 5 h to obtain an initial sponge;

[0100] 3) mixing 1H,1H,2H-heptafluoropent-1-ene, dibenzoyl peroxide and ethanol to obtain a second reaction solution having a mass ratio of 1H,1H,2H-heptafluoropent-1-ene:dibenzoyl peroxide:ethanol of 1:0.004:5;

[0101] 4) Then the initial sponge prepared in step 2) is immersed in the second reaction solution of step 3), the volume of the second reaction solution is twice the volume of the initial sponge, and then reacted at 60°C for 10 hours, the obtained reaction product is washed with methanol 6 times to remove the remaining unreacted products, and then dried at 65°C for 5 hours to obtain a selective adsorption sponge with a bulk density of 24.5 kg / m 3 .

[0102] Test Example 1

[0103] 1. Observation of the morphology of selective adsorption sponge

[0104] The surface morphologies of the selective adsorption sponges prepared in Examples 1 to 3 were observed by scanning electron microscopy, and the selective adsorption sponge prepared in Example 1 was taken as an example for description.

[0105] Figure 1 This is a scanning electron microscope image with a magnification of 1000 times of the surface of the selective adsorption sponge prepared in Example 1. It can be observed from the figure that the surface of the selective adsorption sponge has a nano-rough structure composed of dense spherical particles.

[0106] The surface of the selective adsorption sponge prepared in Example 2 and Example 3 can be observed under a scanning electron microscope. Figure 1 Similar nano-rough structures.

[0107] 2. Determination of hydrophobicity and oleophobicity of the selective adsorption sponge surface

[0108] The water contact angle and oil contact angle of the selective adsorption sponge surface prepared in Examples 1 to 3 were measured by using a German KRUSS optical contact angle measuring instrument DSA100.

[0109] Figure 2 , Figure 3 The water contact angle and oil contact angle of the selective sponge surface prepared in Example 1 are respectively reflected. The water contact angle of the selective adsorption sponge surface prepared in Example 1 is 150°, and the oil contact angle is 136°, which has the dual hydrophobic and oleophobic properties.

[0110] The water contact angle of the surface of the selective adsorption sponge prepared in Example 2 is 152°, and the oil contact angle is 132°; the water contact angle of the surface of the selective adsorption sponge prepared in Example 3 is 148°, and the oil contact angle is 131°, and the surface also has hydrophobic and oleophobic properties.

[0111] The selective adsorption sponges prepared in Examples 1 to 3 are lipophilic and hydrophobic, and their surfaces have a nano-rough structure and amphiphilic properties, which help them to selectively adsorb oil substances during contact and collision with emulsified oil (water-in-oil structure in the presence of biosurfactants), reduce their adsorption of biosurfactants, and achieve separation of biosurfactants and oil substances.

[0112] 3. Determination of the selective adsorption value S of diesel and rhamnolipid by the selective adsorption sponge:

[0113] At room temperature (25°C), diesel, rhamnolipid and water were mixed evenly to prepare a diesel-rhamnolipid aqueous solution with a diesel content of 5 g / L and a rhamnolipid content of 5 g / L; then 5 cm 3The selective adsorption sponge prepared in any one of Examples 1 to 3 was immersed in 1000 mL of diesel-rhamnolipid aqueous solution for selective adsorption, and adsorption equilibrium was reached after 1 hour; the diesel content (X1) and rhamnolipid content (X2) in the selective adsorption sponge after adsorption equilibrium, and the diesel content (Y1) and rhamnolipid content (Y2) in the diesel-rhamnolipid aqueous solution after adsorption equilibrium were respectively measured, and the selective adsorption value S of the selective adsorption sponge for diesel and rhamnolipid was calculated according to formula (1).

[0114] S=(X1 / X2)(Y2 / Y1) Formula (1)

[0115] According to the above method, the selective adsorption values ​​S of the selective adsorption sponges prepared in Examples 1 to 3 for diesel and rhamnolipid were measured respectively.

[0116] Among them, the rhamnolipid content was determined by using Agilent Technologies 1290-6460 liquid chromatography-triple quadrupole mass spectrometry (LC-QQQ), a C18 chromatographic column was used as the separation column, acetonitrile and ammonium acetate aqueous solution were used as the mobile phase, an electrospray ionization source negative ion mode (ESI negative) was used, and the ion collection range was 200 to 1000 m / z.

[0117] The diesel content was determined using a 7890B gas chromatograph from Agilent Technologies, USA. An HP-5 chromatographic column was used for separation and a hydrogen flame ionization detector was used for quantification. The specific results are shown in Table 1.

[0118] Table 1. Selective adsorption values ​​S of the selective adsorption sponge for diesel and rhamnolipid

[0119] Serial number Selective adsorption value S Example 1 285 Example 2 264 Example 3 291

[0120] The data in Table 1 show that the selective adsorption values ​​S of the selective adsorption sponges prepared in Examples 1 to 3 for diesel and rhamnolipid are 264 to 291, all above 200, which proves that the selective adsorption sponges prepared in Examples 1 to 3 can achieve efficient selective adsorption of diesel and separation of diesel and rhamnolipid.

[0121] Example 4

[0122] Soil washing wastewater reuse device

[0123] The soil washing wastewater recycling device provided in this embodiment is as follows: Figure 4As shown. Among them, 1 is a screening and interception device, specifically a rotary drum grille, the spacing between its bars is 0.4mm, it is at an angle of 35° to the flow direction of the soil leaching wastewater, and it is equipped with a flushing device and has a self-cleaning function; 2 connected to it is a precision filtration device, which uses polysulfone as a filter element, has a pore size of 20μm, an initial pressure drop of 0.15MPa, and backwashing is performed when the working pressure exceeds its initial pressure drop by 4 times; 3 connected to 2 is a selective adsorption tower (here specifically 3 parallel selective adsorption towers a1, b1, c1, their height-to-diameter ratios are all 4:1, the empty bed flow rate is all 12m / h, the apparent residence time is all 10min, and the selective adsorption towers prepared in Examples 1 to 3 are filled in turn inside Adsorption sponge, the filling amount is 2.5 times of the bulk density of the selective adsorption sponge prepared in Examples 1 to 3 respectively), the selective adsorption towers a1, b1, c1 are all equipped with spare adsorption towers a2, b2, c2, the selective adsorption tower can be switched to the spare selective adsorption tower after saturation, and the selective adsorption sponge filled in the selective adsorption tower after saturation is squeezed, cleaned and regenerated, for example, the selective adsorption sponge filled in the selective adsorption tower a1 is switched to the spare selective adsorption tower a2 after saturation; 4 connected to 3 is a surfactant replenishing tank, which is used to add surfactant to the third treatment liquid after treatment by the selective adsorption tower to obtain a fourth treatment liquid for reuse.

[0124] The soil leaching wastewater recycling device provided in Example 4 is used to treat the oil-containing soil leaching wastewater containing biosurfactants

[0125] Generally, the biosurfactant content in the oily soil leaching wastewater containing biosurfactants is 2 to 10 g / L, the waste oil content is 4 to 20 g / L, and the particulate matter content is 50 to 500 mg / L. The following three groups of oily soil leaching wastewater containing biosurfactants are selected and treated using the soil leaching wastewater recycling device provided in Example 4 and the method provided by the present invention.

[0126] For the convenience of the experiment, the following adjustments were made to the soil leaching wastewater reuse device in Example 4: the surfactant replenishing tank in the soil leaching wastewater reuse device was adjusted to 3 surfactant replenishing tanks of the same specifications, so that the outlets of the selective adsorption towers a1, b1, and c1 in the soil leaching wastewater reuse device are respectively connected to a surfactant replenishing tank, and the surfactant replenishing tanks connected to the outlets of the selective adsorption towers a1, b1, and c1 are numbered as surfactant replenishing tanks A, B, and C respectively.

[0127] (1) Determination of biosurfactant, oil and particulate matter content in wastewater:

[0128] 1) Liquid chromatography-mass spectrometry to determine the content of biosurfactants and gas chromatography to determine the content of oil pollution

[0129] Specifically, the content of biosurfactant was determined using Agilent Technologies Inc. 1290-6460 liquid chromatography-triple quadrupole mass spectrometry (LC-QQQ), a C18 chromatographic column was used as the separation column, acetonitrile and ammonium acetate aqueous solution were used as the mobile phase, an electrospray ionization source negative ion mode (ESI negative) was used, and the ion collection range was 200 to 1000 m / z.

[0130] The oil content was determined by Agilent Technologies 7890B gas chromatograph, separated by HP-5 chromatographic column, and quantified by hydrogen flame ionization detector.

[0131] 2) Gravimetric method for determination of particulate matter content in wastewater:

[0132] Weigh the initial volume of the wastewater and record it as V, and weigh the weight of the dry filter paper m 1 Then the wastewater was filtered, the filter residue was collected, washed three times with pure water, and then dried at 105°C. After cooling to room temperature, the obtained filter paper and filter residue were weighed. 2 , the content of particulate matter in the wastewater is calculated to be (m 2 -m 1 ) / V.

[0133] (2) Components and contents of the three wastewaters

[0134] Wastewater 1: contains rhamnolipid, diesel oil and particulate matter; the content of rhamnolipid, the content of diesel oil and the content of particulate matter in the wastewater 1 before treatment are respectively determined by the method described in (1);

[0135] The results were as follows: before treatment, the rhamnolipid content in wastewater 1 was 6.3 g / L, the diesel oil content was 5.8 g / L, and the particulate matter content was 325 mg / L;

[0136] Wastewater 2: contains sophorolipids, gasoline oil and particulate matter; the content of sophorolipids, the content of gasoline oil and the content of particulate matter in wastewater 2 before treatment are respectively determined by the method described in (1);

[0137] The results were as follows: before treatment, the sophorolipid content in wastewater 2 was 7.8 g / L, the gasoline oil content was 11.3 g / L, and the particulate matter content was 236 mg / L;

[0138] Wastewater 3: contains lipopeptides, crude oil pollution and particulate matter; the content of lipopeptides, the content of crude oil pollution and the content of particulate matter in wastewater 3 before treatment are respectively determined by the method described in (1);

[0139] The results of the measurements were as follows: before treatment, the lipopeptide content in wastewater 3 was 8.3 g / L, the crude oil content was 7.3 g / L, and the particulate matter content was 223 mg / L.

[0140] Example 5

[0141] A. The wastewater 1 is first discharged into the screening and interception device 1 (i.e., a rotary drum screen with a bar spacing of 0.4 mm and an angle of 35° with the flow direction of the soil leaching wastewater) to intercept large particles and obtain the first treated liquid ①;

[0142] B. allowing the obtained first treated liquid ① to enter a precision filtration device 2 with a polysulfone filter element (pore size of 20 μm, initial pressure drop of 0.15 MPa), so that the soil particulate matter suspended in the first treated liquid ① is retained by the filter element, thereby obtaining a second treated liquid (1);

[0143] C. The obtained second treatment liquid (1) is divided into three paths and respectively discharged into three parallel selective adsorption towers 3 (specifically, selective adsorption towers a1, b1, and c1, each of which has a height-to-diameter ratio of 4:1, an empty bed velocity of 12 m / h, an apparent residence time of 10 min, and is filled with the selective adsorption sponges prepared in Examples 1 to 3 in sequence, and the filling amount is 2.5 times the bulk density of the selective adsorption sponges prepared in Examples 1 to 3 in sequence), the selective adsorption sponges filled in the selective adsorption towers a1, b1, and c1 selectively adsorb the diesel oil in the second treatment liquid (1), but hardly adsorb the rhamnolipid therein, and the third treatment liquids I, II, and III retaining rhamnolipid are obtained in sequence respectively;

[0144] D. The obtained third treatment liquids Ⅰ, Ⅱ and Ⅲ are discharged into the surfactant replenishment tanks A, B and C respectively and stay there for 3 minutes. During this period, rhamnolipid is added to the third treatment liquids Ⅰ, Ⅱ and Ⅲ to obtain the fourth treatment liquids Ⅰ, Ⅱ and Ⅲ respectively. After the replenishment, the three groups of fourth treatment liquids can be reused to re-leach the oil-containing soil.

[0145] Test Example 2

[0146] During the treatment process of Example 5, the second treatment liquid (1) is sampled at the outlet of the precision filtration device 2 to obtain sample 1, the third treatment liquids I, II and III are sampled at the outlets of the selective adsorption towers a1, b1 and c1 in sequence to obtain samples 2-1, 2-2 and 2-3, and the fourth treatment liquids i, ii and iii are sampled at the outlets of the surfactant addition tanks A, B and C in sequence to obtain samples 3-1, 3-2 and 3-3; the rhamnolipid content and diesel oil content in samples 1, 2-1, 2-2, 2-3, 3-1, 3-2 and 3-3 are determined by liquid chromatography-mass spectrometry and gas chromatography, and the content of particulate matter is determined by weight method. The specific results are shown in Table 2.

[0147] Table 2. Rhamnolipids, diesel oil and particulate matter content during the treatment of wastewater 1

[0148]

[0149] It can be seen from Table 2 that the content of particulate matter in sample 1 obtained from the outlet of the precision filtration device is 21 mg / L, which is 93.5% lower than the initial content of particulate matter in wastewater 1, indicating that the screening interception device and the precision filtration device have removed most of the particulate matter in wastewater 1; in samples 2-1 to 2-3 obtained from the outlet of the selective adsorption tower, the content of diesel oil is 0.07 g / L, 0.09 g / L, and 0.12 g / L, respectively, and the content of rhamnolipid is 5.6 g / L, 5.9 g / L, and 6.2 g / L, respectively, which is lower than the initial content of particulate matter in wastewater 1. Compared with the initial content of rhamnolipid and diesel oil in water 1, the content maintenance rate of rhamnolipid in samples 2-1 to 2-3 is 88.9%, 93.7%, and 98.4%, respectively, and the adsorption rate of diesel oil is 98.8%, 98.4%, and 98.4%, respectively. It can be seen that the selective adsorption sponge prepared by Examples 1 to 3 filled in the selective adsorption tower can selectively adsorb diesel oil efficiently, while the adsorption amount of rhamnolipid is very small, which can effectively reduce the loss of rhamnolipid during the treatment process and achieve the separation of diesel oil and rhamnolipid. In addition, it can be seen that the content of particulate matter in samples 2-1 to 2-3 obtained at the outlet of the selective adsorption tower is slightly lower than that in sample 1 obtained at the outlet of the precision filtration device, indicating that the selective adsorption tower can not only selectively adsorb diesel oil, but also supplement the adsorption of particulate matter to a certain extent, thereby maximizing the removal rate of particulate matter during the treatment process. Secondly, it can be seen that the rhamnolipid contents in samples 3-1 to 3-3 obtained from the outlet of the surfactant replenishment tank are 8.2 g / L, 8.0 g / L, and 8.1 g / L, respectively, which are significantly increased compared with the initial rhamnolipid content in wastewater 1. This is because rhamnolipid is added in the surfactant replenishment tank, so that the treated wastewater 1 (i.e., the fourth treatment liquid i, ii, iii) can be reused for leaching operations of oil-containing soil.

[0150] Example 6

[0151] A. Firstly, the wastewater 2 is discharged into the screening and interception device 1 (i.e., a rotary drum screen with a bar spacing of 0.4 mm and an angle of 35° with the flow direction of the soil washing wastewater), so that large particles are intercepted to obtain the first treated liquid ②;

[0152] B. allowing the obtained first treated liquid ② to enter a precision filtration device 2 with a polysulfone filter element (pore size of 20 μm, initial pressure drop of 0.15 MPa), so that the soil particulate matter suspended in the first treated liquid ② is retained by the filter element, thereby obtaining a second treated liquid (2);

[0153] C. The obtained second treatment liquid (2) is discharged into three parallel selective adsorption towers 3 (specifically, selective adsorption towers a1, b1, and c1, each of which has a height-to-diameter ratio of 4:1, an empty bed flow rate of 12 m / h, an apparent residence time of 10 min, and is filled with the selective adsorption sponges prepared in Examples 1 to 3 in sequence, and the filling amount is 2.5 times the bulk density of the selective adsorption sponges prepared in Examples 1 to 3 in sequence), and the selective adsorption sponges filled in the selective adsorption towers a1, b1, and c1 selectively adsorb the gasoline oil in the second treatment liquid (2), but hardly adsorb the sophorolipid therein, and obtain the third treatment liquids IV, V, and VI respectively, which retain the sophorolipid;

[0154] D. The obtained third treatment liquids IV, V, and VI are discharged into the surfactant addition tanks A, B, and C respectively and stay there for 3 minutes. During this period, sophora biosurfactant is added to the third treatment liquids IV, V, and VI to obtain fourth treatment liquids iv, v, and vi in ​​turn. After the addition, the three groups of fourth treatment liquids can be reused to re-eluting the oil-containing soil.

[0155] Test Example 3

[0156] In the treatment process of Example 6, the second treatment liquid (2) was sampled at the outlet of the precision filtration device 2 to obtain sample 4, the third treatment liquids IV, V, and VI were sampled at the outlets of the selective adsorption towers a1, b1, and c1 to obtain samples 5-1, 5-2, and 5-3, and the fourth treatment liquids iv, v, and vi were sampled at the outlets of the surfactant addition tanks A, B, and C to obtain samples 6-1, 6-2, and 6-3; the sophorolipid content and gasoline oil content in samples 4, 5-1, 5-2, 5-3, 6-1, 6-2, and 6-3 were determined by liquid chromatography-mass spectrometry and gas chromatography, and the content of particulate matter was determined by weight method. The specific results are shown in Table 3.

[0157] Table 3. Contents of sophorolipids, gasoline oil and particulate matter during the treatment of wastewater 2

[0158]

[0159] As can be seen from Table 3, the content of particulate matter in sample 4 obtained from the outlet of the precision filtration device is 13 mg / L, which is 94.5% lower than the initial content of particulate matter in wastewater 2, indicating that the screening interception device and the precision filtration device have removed most of the particulate matter in wastewater 2; in samples 5-1 to 5-3 obtained from the outlet of the selective adsorption tower, the content of gasoline oil pollution is 0.02 g / L, 0.04 g / L, and 0.05 g / L, respectively, and the content of sophorolipids is 7.2 g / L, 7.3 g / L, and 7. 0g / L, compared with the initial content of sophorolipids and gasoline oil in wastewater 2, the content maintenance rate of sophorolipids reached 92.3%, 93.6%, and 89.7%, respectively, and the adsorption rate of gasoline oil reached 99.8%, 99.6%, and 99.6%, respectively. It can be seen that the selective adsorption sponge prepared by Examples 1 to 3 filled in the selective adsorption tower can selectively adsorb gasoline oil efficiently, while the adsorption amount of sophorolipids is very small, which can effectively reduce the loss of sophorolipids during the treatment process and realize the separation of gasoline oil and sophorolipids. In addition, it can be seen that the content of particulate matter in samples 5-1 to 5-3 obtained at the outlet of the selective adsorption tower is also slightly lower than that in sample 4 obtained at the outlet of the precision filtration device, indicating that the selective adsorption tower can not only selectively adsorb gasoline oil, but also supplement the adsorption of particulate matter to a certain extent, thereby maximizing the removal rate of particulate matter during the treatment process. Secondly, it can be seen that the sophorolipid contents in samples 6-1 to 6-3 obtained from the outlet of the surfactant replenishment tank are 9.5 g / L, 9.2 g / L, and 9.2 g / L, respectively, which are significantly increased compared with the initial content of sophorolipids in wastewater 2. This is because sophorolipids are added in the surfactant replenishment tank, so that the treated wastewater 2 (i.e., the fourth treatment liquids ⅳ, ⅴ, and ⅵ) can be reused for leaching operations of oil-containing soils.

[0160] Example 7

[0161] A. The wastewater 3 is first discharged into the screening and interception device 1 (i.e., a rotary drum screen with a bar spacing of 0.4 mm and an angle of 35° with the flow direction of the soil washing wastewater) to intercept large particles and obtain the first treated liquid ③;

[0162] B. allowing the obtained first treated liquid ③ to enter a precision filtration device 2 with a polysulfone filter element (pore size of 20 μm, initial pressure drop of 0.15 MPa), so that the soil particles suspended in the first treated liquid ③ are retained by the filter element, thereby obtaining a second treated liquid (3);

[0163] C. The obtained second treatment liquid (3) is discharged into three parallel selective adsorption towers 3 (specifically, selective adsorption towers a1, b1, and c1, each of which has a height-to-diameter ratio of 4:1, an empty bed velocity of 12 m / h, an apparent residence time of 10 min, and is filled with the selective adsorption sponges prepared in Examples 1 to 3 in sequence, and the filling amount is 2.5 times the bulk density of the selective adsorption sponges prepared in Examples 1 to 3 in sequence), and the selective adsorption sponges filled in the selective adsorption towers a1, b1, and c1 selectively adsorb the crude oil in the second treatment liquid (3), but hardly adsorb the lipopeptides therein, thereby obtaining third treatment liquids VII, VIII, and IX retaining the lipopeptides;

[0164] D. The obtained third treatment liquids VII, VIII and IX are discharged into the surfactant replenishment tanks A, B and C respectively and stay there for 3 minutes. During this period, lipopeptides are added to the third treatment liquids VII, VIII and IX to obtain the fourth treatment liquids ⅶ, ⅷ and ⅸ respectively. After the replenishment, the three groups of fourth treatment liquids can be reused to re-leach the oil-containing soil.

[0165] Test Example 4

[0166] During the treatment process of Example 7, the second treatment liquid (3) was sampled at the outlet of the precision filtration device 2 to obtain sample 7, the third treatment liquids VII, VIII, and IX were sampled at the outlets of the selective adsorption towers a1, b1, and c1 to obtain samples 8-1, 8-2, and 8-3, and the fourth treatment liquids ⅶ, ⅷ, and ⅸ were sampled at the outlets of the surfactant addition tanks A, B, and C to obtain samples 9-1, 9-2, and 9-3; the lipopeptide content and crude oil content in samples 7, 8-1, 8-2, 8-3, 9-1, 9-2, and 9-3 were determined by liquid chromatography-mass spectrometry and gas chromatography, and the content of particulate matter was determined by weight method. The specific results are shown in Table 4.

[0167] Table 4. Lipopeptide, crude oil and particulate matter content during the treatment of wastewater 3

[0168]

[0169] It can be seen from Table 4 that the content of particulate matter in sample 7 obtained from the outlet of the precision filtration device is 17 mg / L, which is 92.4% lower than the initial content of particulate matter in wastewater 3, indicating that the screening interception device and the precision filtration device have removed most of the particulate matter in wastewater 3; in samples 8-1 to 8-3 obtained from the outlet of the selective adsorption tower, the content of crude oil pollution is 0.01 g / L, 0.03 g / L, and 0.04 g / L, respectively, and the content of lipopeptide is 7.4 g / L, 7.6 g / L, and 7.7 g / L, respectively. 7.5g / L, compared with the initial contents of lipopeptides and crude oil pollution in wastewater 3, the content maintenance rate of lipopeptides reached 89.2%, 91.6%, and 90.4%, respectively, and the adsorption rate of crude oil pollution reached 99.9%, 99.6%, and 99.6%, respectively. It can be seen that the selective adsorption sponge prepared by Examples 1 to 3 filled in the selective adsorption tower can selectively adsorb crude oil pollution efficiently, while the adsorption amount of lipopeptides is very small, which can effectively reduce the loss of lipopeptides during the treatment process and realize the separation of crude oil pollution and lipopeptides. In addition, it can be seen that the content of particulate matter in samples 8-1 to 8-3 obtained at the outlet of the selective adsorption tower is also slightly lower than that in sample 7 obtained at the outlet of the precision filtration device, indicating that in addition to selectively adsorbing crude oil pollution, the selective adsorption tower can also supplement the adsorption of particulate matter to a certain extent, thereby maximizing the removal rate of particulate matter during the treatment process. Secondly, it can be seen that the lipopeptide contents in samples 9-1 to 9-3 obtained from the outlet of the surfactant replenishment tank are 8.9 g / L, 8.4 g / L, and 8.6 g / L, respectively, which are significantly increased compared with the initial lipopeptide content in wastewater 3. This is because lipopeptides are added in the surfactant replenishment tank, so that the treated wastewater 3 (i.e., the fourth treatment liquid ⅶ, ⅷ, ⅸ) can be reused for leaching operations of oil-containing soil.

[0170] Although the present invention has been described with reference to specific embodiments, it will be appreciated by those skilled in the art that various changes may be made without departing from the true spirit and scope of the present invention. In addition, the subject matter, spirit and scope of the present invention may be varied to accommodate specific situations, materials, material combinations and methods. All of these changes are included within the scope of the claims of the present invention.

Claims

1. A method for preparing a selective adsorption sponge: 1) mixing a surfactant, an alkaline compound, a carboxylic acid and a first solvent to obtain a first reaction solution; 2) allowing the mercapto-containing silane to react with the first reaction solution, and drying to obtain an initial sponge; 3) mixing the alkenyl perfluoro compound, the initiator and the second solvent to obtain a second reaction solution; 4) immersing the initial sponge in the second reaction solution, performing a second reaction, and drying to obtain the selective adsorption sponge.

2. The method according to claim 1, characterized in that In step 1), the first reaction solution comprises 0.8 to 1.2 parts by mass of the surfactant, 3 to 6 parts by mass of the alkaline compound, 0.2 to 0.4 parts by mass of the carboxylic acid and 12 to 20 parts by mass of the first solvent; and / or In step 2), the mass ratio of the mercapto-containing silane to the first reaction solution is (4 to 6):(20 to 25); and / or In step 3), the second reaction solution comprises 0.8 to 1.2 parts by mass of the alkenyl perfluoro compound, 0.002 to 0.004 parts by mass of the initiator and 4 to 6 parts by mass of the second solvent; and / or In step 4), the volume ratio of the initial sponge to the second reaction liquid is 1:(2 to 3).

3. The method according to claim 1 or 2, characterized in that: The surfactant is C 10 To C 18 Long chain alkyl trimethyl ammonium halide; and / or The alkaline compound is at least one of urea, ethylenediamine and triethylamine; and / or The carboxylic acid is at least one of formic acid, acetic acid and oxalic acid; and / or The mercapto-containing silane is mercaptopropyl alkoxy silane; and / or The alkenyl perfluoro compound is at least one of allyl pentafluorobenzene, allyl perfluoropentanoate, 1H,1H,2H-perfluoro-1-hexene, 1H,1H,7H-perfluorohept-1-ene, 1H,1H,2H-heptafluoropent-1-ene, 1H,1H,2H-perfluoro-1-dodecene, allyl heptafluoroisopropyl ether and allyl 2,2,3,3,4,4,5,5-octafluoropentyl ether; Preferably, the surfactant is selected from at least one of cetyltrimethylammonium chloride, cetyltrimethylammonium bromide, octadecyltrimethylammonium chloride, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, octadecyltrimethylammonium bromide, tetradecyltrimethylammonium bromide and dodecyltrimethylammonium bromide; and / or The mercapto-containing silane is at least one of mercaptopropylmethyldimethoxysilane, mercaptopropylmethyldiethoxysilane, mercaptopropyltrimethoxysilane and mercaptopropyltriethoxysilane; Preferably, the first solvent is water; and / or The second solvent is a lower alcohol; and / or The initiator is azobisisobutyronitrile and / or dibenzoyl peroxide.

4. The method according to any one of claims 1 to 3, characterized in that The first reaction is carried out under closed conditions; and / or the temperature of the first reaction is 70° C. to 90° C.; and / or The temperature of the second reaction is 50°C to 70°C; and / or The duration of the first reaction and the second reaction is independently 8h to 12h; Preferably, the drying conditions in step 2) and step 4) are independently drying at 60° C. to 70° C. for 4 h to 6 h.

5. A selective adsorption sponge prepared by the method according to any one of claims 1 to 4.

6. A soil leaching wastewater recycling device, comprising a screening and interception device (1), a precision filtering device (2) and a selective adsorption tower (3) connected in sequence; The screening and interception device (1) is used to intercept particulate matter in the soil leaching wastewater. The precision filtering device (2) is used for secondary interception of particulate matter in soil leaching wastewater; The selective adsorption tower (3) is filled with a selective adsorption sponge for selectively adsorbing oil substances in soil leaching wastewater; The selective adsorption sponge is the selective adsorption sponge prepared by the method according to any one of claims 1 to 4 or the selective adsorption sponge according to claim 5.

7. The device according to claim 6, characterized in that The filling amount of the selective adsorption sponge in the selective adsorption tower (3) is 2 to 3 times the bulk density of the selective adsorption sponge; and / or The screening and interception device (1) is selected from a flat grid, a fixed curved grid or a rotary drum grid; and / or The filter element in the precision filtering device (2) is selected from at least one of polytetraethylene, polysulfone, nylon, polypropylene and acetate fiber.

8. The device according to claim 6 or 7, characterized in that The device also includes a surfactant replenishment tank (4); Preferably, the surfactant replenishment tank (4) is connected to the selective adsorption tower (3).

9. A method for recycling wastewater from oily soil washing containing biosurfactants, comprising the following steps: Providing a soil leaching wastewater recycling device according to any one of claims 6 to 8; A. passing the oily soil washing wastewater containing the biosurfactant through the screening and interception device (1) to perform the primary interception to obtain a first treated liquid; B. passing the first treatment liquid through the precision filtration device (2) to perform the secondary interception to obtain a second treatment liquid; C. allowing the second treatment liquid to enter the selective adsorption tower (3) to selectively adsorb oil substances to obtain a third treatment liquid; Preferably, the third treatment liquid is discharged into a surfactant replenishing tank (4), and a fourth treatment liquid is obtained after adding a biosurfactant.

10. The method according to claim 9, characterized in that The content of the biosurfactant in the fourth treatment liquid is 8 g / L to 10 g / L; and / or The residence time of the third treatment liquid in the surfactant replenishment tank (4) is 2 minutes to 5 minutes; Preferably, the biosurfactant is a glycolipid biosurfactant and / or a lipopeptide biosurfactant.

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