CN108655168B - Method for repairing polycyclic aromatic hydrocarbon contaminated soil by using g-C3N4/Fe3O4 composite material - Google Patents
Method for repairing polycyclic aromatic hydrocarbon contaminated soil by using g-C3N4/Fe3O4 composite material Download PDFInfo
- Publication number
- CN108655168B CN108655168B CN201810332509.4A CN201810332509A CN108655168B CN 108655168 B CN108655168 B CN 108655168B CN 201810332509 A CN201810332509 A CN 201810332509A CN 108655168 B CN108655168 B CN 108655168B
- Authority
- CN
- China
- Prior art keywords
- soil
- polycyclic aromatic
- aromatic hydrocarbon
- composite material
- polluted
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
- B09C—RECLAMATION OF CONTAMINATED SOIL
- B09C1/00—Reclamation of contaminated soil
- B09C1/08—Reclamation of contaminated soil chemically
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K17/00—Soil-conditioning materials or soil-stabilising materials
- C09K17/02—Soil-conditioning materials or soil-stabilising materials containing inorganic compounds only
- C09K17/04—Soil-conditioning materials or soil-stabilising materials containing inorganic compounds only applied in a physical form other than a solution or a grout, e.g. as granules or gases
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Soil Sciences (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Inorganic Chemistry (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Processing Of Solid Wastes (AREA)
Abstract
The invention belongs to the technical field of soil remediation, and particularly relates to a soil remediation methodg‑C3N4/Fe3O4The application of the composite material in remediation of polycyclic aromatic hydrocarbon-polluted soil. In the present invention, by mixing Fe3O4Nanoparticles with g-C3N4The visible light absorption performance of the material is improved, and the recombination of photoproduction electrons and holes is effectively inhibited, so that the photocatalysis performance of the material is improved. G to C3N4The steps for repairing polycyclic aromatic hydrocarbon contaminated soil comprise detection of contaminated soil, crushing and sieving of contaminated soil, and g-C3N4/Fe3O4The composite material is mixed with the polluted soil, the polycyclic aromatic hydrocarbon in the soil can be removed through illumination after the mixed soil is flattened, and the pH value of the soil does not need to be adjusted in the whole soil remediation process. The remediation method can greatly reduce the phytotoxicity of pollutants in the soil, and the growth coefficients of the plants planted on the remediated soil and the plants planted on the uncontaminated soil are not obviously different.
Description
Technical Field
The invention relates to a method for repairing polycyclic aromatic hydrocarbon contaminated soil by using a g-C3N4/Fe3O4 composite material, and belongs to the technical field of soil repair.
Background
Soil is an important resource for human survival and development, and once the soil is polluted, the pollutants in the soil can cause secondary pollution to surface water and underground water. Contaminants in the soil can enter the human body through drinking water or the soil-plant system via the food chain, directly endangering human health. For a long time, due to extensive economic development modes, unreasonable industrial structure and layout and high pollutant emission total amount in China, soil pollution in partial areas is serious, and related pollution events are frequent. Polycyclic Aromatic Hydrocarbons (PAHs) refer to hydrocarbons in which two or more benzene rings are combined in a linear, angular, or cluster shape. Polycyclic aromatic hydrocarbons mainly come from incomplete combustion of organic pollutants such as petroleum and coal and widely exist in air, soil and water environment. Polycyclic aromatic hydrocarbons have extremely high hydrophobicity and high stability, so that they are easily accumulated in soil. Polycyclic aromatic hydrocarbons are typical Persistent Organic Pollutants (POPs) with carcinogenicity, teratogenicity and mutagenicity, so that polycyclic aromatic hydrocarbon-polluted soil poses great threat to human health and needs to be repaired.
Photocatalytic technology has long been overlooked in the field of soil remediation. There are two main reasons why the photocatalytic technology is not regarded in the soil remediation field: (1) typical photocatalysts are e.g. TiO2ZnO and the like only have catalytic capability under ultraviolet light, can only have less than 5 percent of ultraviolet light in sunlight, and have insufficient utilization rate of the sunlight; (2) the photocatalyst is mainly composed of metal-based oxides, sulfides or salts, and the heavy metals once enter the soil, so that the risk of secondary pollution exists. g-C3N4The photocatalyst is a nonmetal photocatalyst which responds under visible light, has the forbidden band width of 2.7eV, and has excellent chemical stability and thermal stability. Pure g-C3N4Has the defects of poor conductivity and high recombination rate of photo-generated electrons and holes, so that the photo-catalytic activity of the material is not ideal. Fe3O4Has excellent conductivity of 1.9 × 106And (5) S/m. By virtue of its excellent conductivity with g-C3N4Form g-C by complexation3N4/Fe3O4The composite material can inhibit the recombination of photo-generated electrons and holes, expand the visible light absorption range of the catalyst and improve the visible light catalytic activity of the catalyst. In addition, relative to othersMetal oxide, Fe3O4Has extremely low toxicity and price. To sum up, g-C3N4/Fe3O4The composite material can be used as a soil remediation material which is environment-friendly and has low cost. However, no relevant applications are reported at present.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a method for repairing polycyclic aromatic hydrocarbon polluted soil by using a g-C3N4/Fe3O4 composite material.
The technical problem of the invention can be achieved by adopting the following measures:
mono, g-C3N4Preparation of (1) and Fe3O4Characteristics of the nanoparticles
The melamine was placed in a covered crucible and calcined at 550 ℃ for 3 hours. Ultrasonically oscillating the roasted product in a mixed solution (volume ratio is 1: 2) of ethanol and water for 2 hours, separating solid from liquid, and drying to obtain g-C3N4；
Fe3O4The nano-particles are purchased from the market, and the particle size of the nano-particles is between 10 and 20 nanometers.
II, based on g-C3N4/Fe3O4The method for repairing the polycyclic aromatic hydrocarbon polluted soil of the composite material comprises the following steps:
(1) determining the types and the contents of the polycyclic aromatic hydrocarbons in the polycyclic aromatic hydrocarbon polluted soil;
(2) pretreating polycyclic aromatic hydrocarbon contaminated soil: firstly, naturally drying a proper amount of polycyclic aromatic hydrocarbon contaminated soil, then grinding and crushing the soil, and finally, selecting soil sieves with different meshes according to the detection result of the step (1) to sieve the crushed soil to obtain soil particles;
(3) according to the detection result of the step (1), Fe3O4Nanoparticles with g-C3N4Ultrasonic oscillating and mixing in mixed solution of ethanol and water according to a certain proportion, separating solid from liquid, and drying to obtain g-C3N4/Fe3O4A composite material;
(4) will be provided withg-C obtained in step (3)3N4/Fe3O4Uniformly stirring the composite material and the polycyclic aromatic hydrocarbon polluted soil according to a certain proportion, and flattening to form a soil layer with a certain thickness;
(5) and (3) placing the flattened soil layer under a light source for irradiation, spraying water during the irradiation to keep the soil at a certain water content, and removing the polycyclic aromatic hydrocarbon in the soil after the soil is irradiated for a certain time.
In the step (2), the mesh number of the soil sieve is determined according to the detection result of the step (1) on the type and content of the polycyclic aromatic hydrocarbon in the polluted soil, and when the total content of the polycyclic aromatic hydrocarbon is lower than 1000mg of polycyclic aromatic hydrocarbon/kg of soil, the soil is sieved by a 60-mesh soil sieve; and when the total content of the polycyclic aromatic hydrocarbon is higher than 1000mg of polycyclic aromatic hydrocarbon/kg of soil, screening the soil by using a 120-mesh soil screen.
In step (3), g-C3N4/Fe3O4Fe in composite materials3O4Nanoparticles with g-C3N4The mass ratio is determined according to the detection result of the step (1) on the types and the contents of the polycyclic aromatic hydrocarbons in the polluted soil. g-C when the total content of polycyclic aromatic hydrocarbons is less than 1000mg polycyclic aromatic hydrocarbons/kg soil3N4/Fe3O4Fe in composite materials3O4Nanoparticles with g-C3N4The mass ratio is controlled to be 1: 100-5: 100 or more; g-C when the total content of polycyclic aromatic hydrocarbons is higher than 1000mg polycyclic aromatic hydrocarbons/kg soil3N4/Fe3O4Fe in composite materials3O4Nanoparticles with g-C3N4The mass ratio is controlled to be 5: 100-50: 100, respectively.
In the step (3), in the mixed solution of ethanol and water, the volume ratio of ethanol to water is 1: 2; the time for mixing by ultrasonic oscillation is 2 h.
In the step (4), according to the detection result of the type and the content of the polycyclic aromatic hydrocarbon in the polycyclic aromatic hydrocarbon polluted soil in the step (1), determining to add g-C into the polluted soil3N4/Fe3O4Optimum addition amount of the composite material. When the total content of polycyclic aromatic hydrocarbong-C below 1000mg polycyclic aromatic hydrocarbons/kg soil3N4/Fe3O4The mass percentage of the composite material and the polluted soil is controlled to be between 0.5 and 3 percent; g-C when the total content of polycyclic aromatic hydrocarbons is higher than 1000mg polycyclic aromatic hydrocarbons/kg soil3N4/Fe3O4The mass percentage of the composite material and the polluted soil is controlled to be between 3 and 10 percent.
In step (4), g-C3N4/Fe3O4The composite material and the polycyclic aromatic hydrocarbon polluted soil are uniformly stirred, and the thickness of a soil layer formed after the composite material and the polycyclic aromatic hydrocarbon polluted soil are flattened is not more than 1 cm.
In the step (5), the soil is kept with a certain water content of 30-90%.
In the step (5), the light source can be an ultraviolet light source, and can also be a visible light source or sunlight.
Evaluation of phytotoxicity of the soil polluted by the polycyclic aromatic hydrocarbon after restoration:
phytotoxicity evaluations were performed by planting experiments on lettuce in different soils. Lettuce seeds were planted in unpolluted soil, polycyclic aromatic hydrocarbon-contaminated soil and restored polycyclic aromatic hydrocarbon-contaminated soil, respectively, and four sets of parallel planting experiments were performed per soil. The growth coefficients (germination rate, root length, leaf length and fresh weight) of lettuce planted in each soil were examined to evaluate the phytotoxicity of the soil.
5 lettuce plants were planted in one flowerpot filled with soil, four pots were planted per soil, that is, 20 lettuce seeds were planted per soil. And (3) placing the flowerpot filled with the lettuce seeds into a plant incubator, wherein the illumination time and the dark time of a fluorescent lamp in the incubator are respectively 16 hours and 8 hours, and the corresponding temperatures are 22 ℃ and 16 ℃. During the culture process, the water content of the soil is controlled to be 60 percent, so that the water needs to be supplemented periodically. After the lettuce seeds were cultured in soil for 5 days, the germination rates of the seeds in the three soils were counted. After the germination rate is counted, two lettuce seedlings are left in each flowerpot for growth experiments. After two weeks of continued culture, lettuce was harvested and the roots, leaf length and fresh weight of lettuce grown in three soils were counted. The growth coefficients (germination percentage, root length, leaf length and fresh weight) of the lettuce obtained in the three soils are sorted and analyzed by software (SPSS software, version22.0), so as to compare the phytotoxicity of the soil polluted by the polycyclic aromatic hydrocarbon after remediation.
The invention has the advantages that:
(1)g-C3N4/Fe3O4the composite material has a specific pure g-C3N4More excellent visible light absorption performance
(2)g-C3N4/Fe3O4The composite material can generate superoxide radical with strong oxidizing property under the irradiation of visible light.
(3)g-C3N4/Fe3O4The composite material does not need to adjust the pH value of the soil in the whole process of degrading the polycyclic aromatic hydrocarbon in the soil. The soil remediation material can degrade polycyclic aromatic hydrocarbons in soil whether the soil is acidic soil, neutral soil or alkaline soil.
(4)g-C3N4/Fe3O4The composite material does not need to be added with any other medicament in the whole process of degrading the polycyclic aromatic hydrocarbon in the soil.
(5) Based on g-C3N4/Fe3O4The soil remediation method of the composite material can greatly reduce the toxicity of the polycyclic aromatic hydrocarbon-polluted soil, so that the remediated soil does not have adverse effect on the growth of plants. There was no significant difference in the growth coefficients (germination percentage, root length, leaf length, fresh weight) of plants grown on the remediated soil compared to plants grown on uncontaminated soil.
Drawings
FIG. 1 shows g-C3N4，Fe3O4And g-C3N4/Fe3O4XRD spectrum of the composite material;
FIG. 2 shows g-C3N4/Fe3O4TEM images of the composite;
FIG. 3 is g-C3N4And g-C3N4/Fe3O4Solid ultraviolet absorption spectrum of the composite material;
FIG. 4 shows g-C3N4And g-C3N4/Fe3O4The solid fluorescence spectrum of the composite material has an excitation wavelength of 325 nm;
FIG. 5 is g-C3N4And g-C3N4/Fe3O4Photocurrent response graph of the composite material;
FIG. 6 shows g-C3N4/Fe3O4ESR spectrum of the composite material;
FIG. 7 is g-C3N4/Fe3O4The degradation rate curve of the composite material to phenanthrene in the polluted soil under visible light or no light.
FIG. 8 shows lettuce planted in unpolluted soil g-C3N4/Fe3O4And comparing the growth conditions of the phenanthrene-polluted soil and the phenanthrene-polluted soil repaired by the composite material.
FIG. 9 planting in uncontaminated soil, g-C3N4/Fe3O4The growth coefficient of the lettuce in the phenanthrene-polluted soil and the phenanthrene-polluted soil which are repaired by the composite material, (a) the germination rate; (b) root length; (c) leaf length; (d) fresh weight.
FIG. 10 shows g-C3N4/Fe3O4The degradation rate curve of the composite material to high-concentration phenanthrene in the polluted soil under visible light or no light.
FIG. 11 shows g-C3N4/Fe3O4The degradation rate curve of the composite material to high-concentration phenanthrene in the polluted soil under the illumination of ultraviolet light;
FIG. 12 shows g-C3N4/Fe3O4The degradation rate of naphthalene, anthracene, phenanthrene and pyrene compound contaminated soil of the composite material under the sunlight illumination;
FIG. 13 shows g-C3N4/Fe3O4The degradation rate of the composite material in the polluted soil is controlled by the degradation rate of phenanthrene, naphthalene, acenaphthene, anthracene, benzopyrene and pyrene.
Detailed Description
The invention will be further described with reference to the following figures and specific examples, but the scope of the invention is not limited thereto.
Example 1:
g-C under visible light3N4/Fe3O4Composite material for restoring phenanthrene-polluted soil
g-C3N4/Fe3O4Method for restoring phenanthrene-polluted soil by using composite material
(1) The phenanthrene-contaminated soil obtained by sampling the contaminated land is detected to have a phenanthrene content of 300 mg/kg soil.
(2) And naturally drying the appropriate amount of polycyclic aromatic hydrocarbon polluted soil for about one week. Subsequently, the soil is crushed. Sieving the crushed soil by using a 60-mesh soil sieve to obtain soil particles;
(3) mixing Fe3O4Nanoparticles with g-C3N4According to the mass ratio of 1: 100, ultrasonic vibration mixing in mixed solution of ethanol and water (volume ratio 1: 2) for 2 hours, solid-liquid separation, drying to obtain g-C3N4/Fe3O4A composite material.
FIG. 1 shows g-C3N4，Fe3O4And g-C3N4/Fe3O4XRD spectrum of the composite material. The XRD spectrograms of the three materials are compared, so that the g-C can be prepared by the method3N4/Fe3O4A composite material.
FIG. 2 shows g-C3N4/Fe3O4TEM images of the composite. As can be seen from the figure, a large amount of nano Fe3O4Particles adhering to flake g-C3N4Thereby forming g-C3N4/Fe3O4A composite material.
FIG. 3 is g-C3N4And g-C3N4/Fe3O4Solid ultraviolet absorption spectrum of the composite material. By comparing the ultraviolet absorption spectra of the two substances, it can be seen that Fe is absorbed by3O4And g-C3N4The composite material can greatly improve the absorption performance of the material in a visible light region.
FIG. 4 shows g-C3N4And g-C3N4/Fe3O4Solid fluorescence spectrum of the composite material. g-C by comparison of the solid fluorescence spectra of the two substances3N4/Fe3O4The composite material has a ratio g-C3N4Low fluorescence intensity, thus demonstrating the effect of passing Fe3O4And g-C3N4Recombination can effectively inhibit the recombination of photogenerated electrons and holes.
FIG. 5 is g-C3N4And g-C3N4/Fe3O4Photocurrent response graph of the composite material. As can be seen, g-C is observed under visible light3N4/Fe3O4The photo-generated current ratio g-C generated by the composite material3N4The generated photo-generated current is strong, thus proving that Fe is generated by mixing Fe3O4And g-C3N4The recombination can effectively inhibit the recombination rate of the photo-generated electrons and the holes and generate more photo-generated electrons.
FIG. 6 shows g-C3N4/Fe3O4ESR spectrum of the composite material. As can be seen from the figure, g-C3N4/Fe3O4The composite material can generate superoxide radical under visible light.
(4) g-C obtained in step (3)3N4/Fe3O4The mass percentage of the composite material to the contaminated soil is 0.5 percent, and g-C is added3N4/Fe3O4The composite material and the polycyclic aromatic hydrocarbon polluted soil are uniformly stirred. After the mixture is uniformly stirred, the soil is flattened, and the thickness of the soil layer is controlled within 0.5 cm.
(5) The phenanthrene-contaminated soil is irradiated for 2 hours under visible light (the wavelength is more than 420nm, the average light intensity is about 8100Lux), the water content is controlled at 60% during the irradiation period, and the degradation rate of phenanthrene is about 92.3% (figure 7).
Evaluation of phytotoxicity after restoration of phenanthrene-contaminated soil
And respectively planting the lettuce in the unpolluted soil, the restored phenanthrene-polluted soil and the phenanthrene-polluted soil. As can be seen from FIG. 8, after 19 days of cultivation, the phenanthrene-contaminated soil had a greater toxicity to lettuce, and the growth of lettuce was completely inhibited. g-C of phenanthrene-polluted soil3N4/Fe3O4After the composite material is repaired, the toxicity is greatly reduced, and the lettuce planted on the composite material has no obvious difference from the lettuce planted on uncontaminated soil.
Fig. 9 shows the germination rate, root length, leaf length and fresh weight of lettuce in unpolluted soil, in restored phenanthrene-contaminated soil and in phenanthrene-contaminated soil, respectively, and the corresponding data are shown in table 1 below. It can be seen that phenanthrene in the soil has no obvious influence on the germination rate of lettuce seeds, but has obvious inhibition effect on root length, leaf length and fresh weight. g-C of phenanthrene-polluted soil3N4/Fe3O4After the composite material is repaired, the grown lettuce has no obvious difference in root length, leaf length and fresh weight from the lettuce grown in the uncontaminated soil, and the g-C-based lettuce is proved3N4/Fe3O4The soil remediation method of the composite material is an environment-friendly material and a method thereof.
TABLE 1 lettuce germination, root length, leaf length and fresh weight in different soils
Example 2:
in sunlight, g-C3N4/Fe3O4Application of composite material in repairing high-concentration phenanthrene-polluted soil
(1) The content of phenanthrene in the phenanthrene-polluted soil obtained by sampling the polluted land is up to 2150mg phenanthrene/kg soil through detection.
(2) And naturally drying the appropriate amount of polycyclic aromatic hydrocarbon polluted soil for about one week. Subsequently, the soil is crushed. Sieving the crushed soil by using a 120-mesh soil sieve to obtain soil particles;
(3) mixing Fe3O4Nanoparticles with g-C3N4According to the mass ratio of 30: 100, ultrasonic vibration mixing in mixed solution of ethanol and water (volume ratio 1: 2) for 2 hours, solid-liquid separation, drying to obtain g-C3N4/Fe3O4A composite material.
(4) g-C obtained in step (3)3N4/Fe3O4The mass percentage of the composite material to the contaminated soil is 6 percent, and g-C is added3N4/Fe3O4The composite material and the polycyclic aromatic hydrocarbon polluted soil are uniformly stirred. After the mixture is uniformly stirred, the soil is flattened, and the thickness of the soil layer is controlled within 0.2 cm.
(5) The phenanthrene-contaminated soil was irradiated under sunlight (average light intensity of about 2610Lux) for 2 hours, the water content during the irradiation period was controlled at 80%, and the degradation rate of phenanthrene was about 93.5% (FIG. 10).
Evaluation of phytotoxicity after restoration of phenanthrene-contaminated soil
Lettuce was planted in unpolluted soil, restored phenanthrene-contaminated soil and phenanthrene-contaminated soil, respectively, and cultured for 19 days with growth coefficients as shown in table 2 below. Unlike soil contaminated with low concentrations of phenanthrene, in soil with high concentrations of phenanthrene, the germination rate of lettuce seeds is significantly inhibited, but the soil is subject to g-C3N4/Fe3O4After the composite material is repaired, the germination rate is not obviously different from that of the uncontaminated soil. Root length, leaf length and fresh weight also did not differ significantly from lettuce grown in uncontaminated soil.
TABLE 2 lettuce germination, root length, leaf length and fresh weight in different soils
| Percentage of germination (%) | Root length (centimeter) | Leaf length (centimeter) | Fresh weight (gram) | |
| Unpolluted soil | 93.3 | 4.02 | 2.62 | 0.044 |
| Soil after restoration | 90.5 | 3.98 | 2.62 | 0.041 |
| High concentration phenanthrene polluted soil | 63.1 | 0.51 | 0.61 | 0.031 |
Example 3:
under a UV light source, g-C3N4/Fe3O4Composite material for repairing high-concentration phenanthrene-polluted soil
(1) The content of phenanthrene in the phenanthrene-polluted soil obtained by sampling the polluted land is up to 2150mg phenanthrene/kg soil through detection.
(2) And naturally drying the appropriate amount of polycyclic aromatic hydrocarbon polluted soil for about one week. Subsequently, the soil is crushed. Sieving the crushed soil by using a 120-mesh soil sieve to obtain soil particles;
(3) mixing Fe3O4Nanoparticles with g-C3N4According to the mass ratio of 30: 100, ultrasonic vibration mixing in mixed solution of ethanol and water (volume ratio 1: 2) for 2 hours, solid-liquid separation, drying to obtain g-C3N4/Fe3O4A composite material.
(4) g-C obtained in step (3)3N4/Fe3O4The mass percentage of the composite material to the contaminated soil is 6 percent, and g-C is added3N4/Fe3O4The composite material and the polycyclic aromatic hydrocarbon polluted soil are uniformly stirred. And after uniformly stirring, flattening the soil, and controlling the thickness of the soil layer within 1 cm.
(5) The phenanthrene-contaminated soil was irradiated under ultraviolet light (average light intensity of about 4500Lux) for 2 hours, the water content during the irradiation period was controlled at 20%, and the degradation rate of phenanthrene was about 97% (fig. 11).
Evaluation of phytotoxicity after restoration of phenanthrene-contaminated soil
Lettuce was planted in unpolluted soil, restored phenanthrene-contaminated soil and phenanthrene-contaminated soil, respectively, and cultured for 19 days with growth coefficients as shown in table 3 below. Unlike soil contaminated with low concentrations of phenanthrene, in soil with high concentrations of phenanthrene, the germination rate of lettuce seeds is significantly inhibited, but the soil is subject to g-C3N4/Fe3O4After the composite material is repaired, the germination rate is not obviously different from that of the uncontaminated soil. Root length, leaf length and fresh weight also did not differ significantly from lettuce grown in uncontaminated soil.
TABLE 3 germination rate, root length, leaf length and fresh weight of lettuce in the remediated soil
| Percentage of germination (%) | Root length (centimeter) | Leaf length (centimeter) | Fresh weight (gram) | |
| Unpolluted soil | 93.3 | 4.02 | 2.62 | 0.044 |
| Soil after restoration | 90.9 | 4.01 | 2.63 | 0.043 |
| High concentration phenanthrene polluted soil | 63.1 | 0.51 | 0.61 | 0.031 |
Example 4:
in sunlight, g-C3N4/Fe3O4Application of composite material in remediation of composite polycyclic aromatic hydrocarbon contaminated soil
(1) Polycyclic aromatic hydrocarbon contaminated soil is obtained by sampling from a contaminated land, and the polycyclic aromatic hydrocarbon contaminated soil contains naphthalene, anthracene, phenanthrene and pyrene in concentrations of 350mg of naphthalene/kg of soil, 1350mg of anthracene/kg of soil, 531mg of phenanthrene/kg of soil and 768mg of pyrene/kg of soil through detection.
(2) And naturally drying the appropriate amount of polycyclic aromatic hydrocarbon polluted soil for about one week. Subsequently, the soil is crushed. Sieving the crushed soil by using a 120-mesh soil sieve to obtain soil particles;
(3) mixing Fe3O4Nanoparticles with g-C3N4According to the mass ratio of 40: 100, ultrasonic vibration mixing in mixed solution of ethanol and water (volume ratio 1: 2) for 2 hours, solid-liquid separation, drying to obtain g-C3N4/Fe3O4A composite material.
(4) g-C obtained in step (3)3N4/Fe3O4The mass percentage of the composite material to the contaminated soil is 8 percent, and g-C is added3N4/Fe3O4The composite material and the polycyclic aromatic hydrocarbon polluted soil are uniformly stirred. After the mixture is uniformly stirred, the soil is flattened, and the thickness of the soil layer is controlled within 0.3 cm.
(5) The contaminated soil was irradiated under sunlight (average light intensity of about 2280Lux) for 6 hours, the water content during the irradiation period was controlled at 80%, and the degradation rates of naphthalene, anthracene, phenanthrene, and pyrene in the soil were 96%, 91%, 87%, and 92%, respectively (FIG. 12).
Evaluation of phytotoxicity after remediation of polycyclic aromatic hydrocarbon-contaminated soil
Lettuce was planted in unpolluted soil, restored polycyclic aromatic hydrocarbon-contaminated soil and composite polycyclic aromatic hydrocarbon-contaminated soil, respectively, and cultured for 19 days with growth coefficients as shown in table 4 below. The toxicity of the soil polluted by the composite polycyclic aromatic hydrocarbon is obviously higher than that of single polycyclic aromatic hydrocarbon phenanthrene, and the lettuce cannot germinate and grow in the soil polluted by the composite polycyclic aromatic hydrocarbon. However, the g-C of the composite polycyclic aromatic hydrocarbon contaminated soil3N4/Fe3O4After the composite material is repaired, the grown lettuce has no obvious difference in root length, leaf length and fresh weight from lettuce grown in uncontaminated soil, and the toxicity of soil polluted by polycyclic aromatic hydrocarbon is greatly reduced.
TABLE 4 germination, root length, leaf length and fresh weight of lettuce in the remediated soil
| Percentage of germination (%) | Root length (centimeter) | Leaf length (centimeter) | Fresh weight (gram) | |
| Unpolluted soil | 93.3 | 4.02 | 2.62 | 0.044 |
| Soil after restoration | 91.8 | 3.99 | 2.60 | 0.042 |
Example 5:
g-C under visible light3N4/Fe3O4Composite material for repairing composite polycyclic aromatic hydrocarbon polluted soil
(1) Polycyclic aromatic hydrocarbon contaminated soil is obtained by sampling from a contaminated land, and the polycyclic aromatic hydrocarbon contaminated soil is detected to contain phenanthrene, naphthalene, acenaphthene, anthracene, benzopyrene and pyrene, wherein the concentrations of the phenanthrene, the naphthalene, the acenaphthene, the anthracene, the benzopyrene and the pyrene are 230 mg/kg of soil, 750mg of soil, 150mg of acenaphthene/kg of soil, 530mg of anthracene/kg of soil, 830mg of benzopyrene/kg of soil and 731mg of pyrene/kg of soil respectively.
(2) And naturally drying the appropriate amount of polycyclic aromatic hydrocarbon polluted soil for about one week. Subsequently, the soil is crushed. Sieving the crushed soil by using a 120-mesh soil sieve to obtain soil particles;
(3) mixing Fe3O4Nanoparticles with g-C3N4According to the mass ratio of 50: 100, ultrasonic vibration mixing in mixed solution of ethanol and water (volume ratio 1: 2) for 2 hours, solid-liquid separation, drying to obtain g-C3N4/Fe3O4A composite material.
(4) g-C obtained in step (3)3N4/Fe3O4The mass percentage of the composite material to the contaminated soil is 10 percent, and g-C is added3N4/Fe3O4The composite material and the polycyclic aromatic hydrocarbon polluted soil are uniformly stirred. After the mixture is uniformly stirred, the soil is flattened, and the thickness of the soil layer is controlled within 0.2 cm.
(5) The polluted soil is irradiated for 10 hours under visible light (the wavelength lambda is more than 420nm, the average light intensity is about 2380Lux), the water content is controlled at 70% during the irradiation, and the degradation rates of phenanthrene, naphthalene, acenaphthene, anthracene, benzopyrene and pyrene in the soil are 87%, 91%, 93%, 88%, 87% and 93% respectively (figure 13).
Evaluation of phytotoxicity after remediation of polycyclic aromatic hydrocarbon-contaminated soil
Lettuce was planted in unpolluted soil, restored polycyclic aromatic hydrocarbon-contaminated soil and composite polycyclic aromatic hydrocarbon-contaminated soil, respectively, and cultured for 19 days with growth coefficients as shown in table 5 below. The toxicity of the soil polluted by the composite polycyclic aromatic hydrocarbon is obviously higher than that of single polycyclic aromatic hydrocarbon phenanthrene, and the lettuce cannot germinate and grow in the soil polluted by the composite polycyclic aromatic hydrocarbon. However, the g-C of the composite polycyclic aromatic hydrocarbon contaminated soil3N4/Fe3O4After the composite material is repaired, the grown lettuce has no obvious difference in root length, leaf length and fresh weight from the lettuce grown in the soil without being polluted, and proves that the toxicity of the soil polluted by the polycyclic aromatic hydrocarbon is greatly reduced based on g-C3N4/Fe3O4The soil remediation method of the composite material is an environment-friendly material and a method thereof.
TABLE 5 germination rate, root length, leaf length and fresh weight of lettuce in the remediated soil
| Percentage of germination (%) | Root length (centimeter) | Leaf length (centimeter) | Fresh weight (gram) | |
| Unpolluted soil | 93.3 | 4.02 | 2.62 | 0.044 |
| Soil after restoration | 88.9 | 3.99 | 2.58 | 0.042 |
Claims (9)
1. Application of g-C3N4/Fe3O4The method for repairing the polycyclic aromatic hydrocarbon polluted soil by the composite material is characterized by comprising the following steps:
(1) determining the types and the contents of the polycyclic aromatic hydrocarbons in the polycyclic aromatic hydrocarbon polluted soil;
(2) pretreating polycyclic aromatic hydrocarbon contaminated soil: firstly, naturally drying a proper amount of polycyclic aromatic hydrocarbon contaminated soil, then grinding and crushing the soil, and finally, selecting soil sieves with different meshes according to the detection result of the step (1) to sieve the crushed soil to obtain soil particles;
(3) according to the detection result of the step (1), Fe3O4Nanoparticles with g-C3N4Ultrasonic oscillating and mixing in mixed solution of ethanol and water according to a certain proportion, separating solid from liquid, and drying to obtain g-C3N4/Fe3O4A composite material;
(4) g-C obtained in step (3)3N4/Fe3O4Uniformly stirring the composite material and the polycyclic aromatic hydrocarbon polluted soil according to a certain proportion, and flattening to form a soil layer with a certain thickness;
(5) and (3) placing the flattened soil layer under a light source for irradiation, spraying water during the irradiation to keep the soil at a certain water content, and removing the polycyclic aromatic hydrocarbon in the soil after the soil is irradiated for a certain time.
2. The method according to claim 1, wherein in the step (2), the mesh number of the soil sieve is determined according to the detection result of the step (1) on the types and the contents of the polycyclic aromatic hydrocarbons in the polluted soil, and when the total content of the polycyclic aromatic hydrocarbons is lower than 1000mg of polycyclic aromatic hydrocarbons per kg of soil, the soil is sieved by using a 60-mesh soil sieve; and when the total content of the polycyclic aromatic hydrocarbon is higher than 1000mg of polycyclic aromatic hydrocarbon/kg of soil, screening the soil by using a 120-mesh soil screen.
3. The method according to claim 1, wherein in step (3), g-C3N4/Fe3O4Fe in composite materials3O4Nanoparticles with g-C3N4The mass ratio is determined according to the detection result of the step (1) on the types and the contents of the polycyclic aromatic hydrocarbons in the polluted soil: g-C when the total content of polycyclic aromatic hydrocarbons is less than 1000mg polycyclic aromatic hydrocarbons/kg soil3N4/Fe3O4Fe in composite materials3O4Nanoparticles with g-C3N4The mass ratio is controlled to be 1: 100-5: 100 or more; g-C when the total content of polycyclic aromatic hydrocarbons is higher than 1000mg polycyclic aromatic hydrocarbons/kg soil3N4/Fe3O4Fe in composite materials3O4Nanoparticles with g-C3N4The mass ratio is controlled to be 5: 100-50: 100, respectively.
4. The method according to claim 1, wherein in the step (3), the volume ratio of the ethanol to the water in the mixed solution of the ethanol and the water is 1: 2; the time for mixing by ultrasonic oscillation is 2 h.
5. The method according to claim 1, wherein in the step (4), the addition of g-C to the polluted soil is determined according to the detection result of the type and content of the polycyclic aromatic hydrocarbon in the polycyclic aromatic hydrocarbon polluted soil in the step (1)3N4/Fe3O4The optimal addition amount of the composite material; g-C when the total content of polycyclic aromatic hydrocarbons is less than 1000mg polycyclic aromatic hydrocarbons/kg soil3N4/Fe3O4The mass percentage of the composite material and the polluted soil is controlled to be between 0.5 and 3 percent; g-C when the total content of polycyclic aromatic hydrocarbons is higher than 1000mg polycyclic aromatic hydrocarbons/kg soil3N4/Fe3O4The mass percentage of the composite material and the polluted soil is controlled to be between 3 and 10 percent.
6. The method according to claim 1, wherein in step (4), g-C3N4/Fe3O4The composite material and the polycyclic aromatic hydrocarbon polluted soil are uniformly stirred, and the thickness of a soil layer formed after the composite material and the polycyclic aromatic hydrocarbon polluted soil are flattened is not more than 1 cm.
7. The method of claim 1, wherein in step (5), the soil is maintained at a moisture content of between 30% and 90%.
8. The method of claim 1, wherein in step (5), the light source is sunlight.
9. The method of claim 1, wherein in step (5), the light source is an ultraviolet light source or a visible light source.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810332509.4A CN108655168B (en) | 2018-04-13 | 2018-04-13 | Method for repairing polycyclic aromatic hydrocarbon contaminated soil by using g-C3N4/Fe3O4 composite material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810332509.4A CN108655168B (en) | 2018-04-13 | 2018-04-13 | Method for repairing polycyclic aromatic hydrocarbon contaminated soil by using g-C3N4/Fe3O4 composite material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108655168A CN108655168A (en) | 2018-10-16 |
| CN108655168B true CN108655168B (en) | 2020-03-06 |
Family
ID=63783315
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810332509.4A Active CN108655168B (en) | 2018-04-13 | 2018-04-13 | Method for repairing polycyclic aromatic hydrocarbon contaminated soil by using g-C3N4/Fe3O4 composite material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108655168B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109233838B (en) * | 2018-11-02 | 2020-06-30 | 扬州工业职业技术学院 | Eu (Eu)3+Se codoped with Fe3O4/g-C3N4Material and application thereof in environmental remediation |
| CN109317088A (en) * | 2018-11-14 | 2019-02-12 | 南昌工程学院 | A kind of g-C3N4 magnetic material separates the application method of catechol in water |
| CN110201994A (en) * | 2019-06-12 | 2019-09-06 | 江苏大学 | A kind of restorative procedure of the polycyclic aromatic hydrocarbon pollution based on vinegar grain and titanium powder plant waste sulfate ferrous iron |
| CN111687194A (en) * | 2020-05-21 | 2020-09-22 | 国网河北省电力有限公司电力科学研究院 | g-C3N4/TiO2Method for repairing polycyclic aromatic hydrocarbon polluted soil by composite material |
| CN113856729A (en) * | 2021-11-04 | 2021-12-31 | 齐鲁工业大学 | Photodegradation catalyst, preparation method thereof and application thereof in degrading antibiotics |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL9400226A (en) * | 1994-02-14 | 1995-09-01 | Univ Twente | Method and device for cleaning contaminated soil. |
| CN101176879A (en) * | 2006-11-08 | 2008-05-14 | 中国科学院沈阳应用生态研究所 | Photocatalysis method for removing PAHs in soil |
| CN102433126A (en) * | 2011-09-06 | 2012-05-02 | 浙江大学 | Natural eluting agent and method for repairing polycyclic aromatic hydrocarbon (PAH)-polluted soil |
| CN102941223A (en) * | 2012-11-25 | 2013-02-27 | 西安费斯达自动化工程有限公司 | Ultraviolet ozone processing method for residual pesticide in rice field soil |
| CN103736514B (en) * | 2014-01-08 | 2015-07-08 | 阜阳师范学院 | Preparation method and application of novel C3N4/ZnO/Fe2O3 composite photocatalyst |
| CN106824246B (en) * | 2014-11-06 | 2019-08-27 | 江苏理工学院 | TiO 22/g-C3N4Preparation method of composite visible light catalyst |
-
2018
- 2018-04-13 CN CN201810332509.4A patent/CN108655168B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN108655168A (en) | 2018-10-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108655168B (en) | Method for repairing polycyclic aromatic hydrocarbon contaminated soil by using g-C3N4/Fe3O4 composite material | |
| Tang et al. | All-solid-state Z-scheme WO3 nanorod/ZnIn2S4 composite photocatalysts for the effective degradation of nitenpyram under visible light irradiation | |
| Korake et al. | Highly active lanthanum doped ZnO nanorods for photodegradation of metasystox | |
| Liang et al. | A novel vacancy-strengthened Z-scheme g-C3N4/Bp/MoS2 composite for super-efficient visible-light photocatalytic degradation of ciprofloxacin | |
| Wang et al. | Remediation of phenanthrene contaminated soil by g-C3N4/Fe3O4 composites and its phytotoxicity evaluation | |
| Zhang et al. | Carbon quantum dots sensitized ZnSn (OH) 6 for visible light-driven photocatalytic water purification | |
| Roza et al. | ZnO nanorods decorated with carbon nanodots and its metal doping as efficient photocatalyst for degradation of methyl blue solution | |
| Vakili et al. | Synthesis of immobilized cerium doped ZnO nanoparticles through the mild hydrothermal approach and their application in the photodegradation of synthetic wastewater | |
| Sankeetha et al. | A novel Ni doped BaTiO3/h-BN nanocomposite for visible light assisted enhanced photocatalytic degradation of textile effluent and phytotoxicity evaluation | |
| She et al. | Effects of nano bamboo charcoal on PAHs-degrading strain Sphingomonas sp. GY2B | |
| Liu et al. | A facile strategy for photocatalytic degradation of seven neonicotinoids over sulfur and oxygen co-doped carbon nitride | |
| CN111389356B (en) | Preparation method of graphene oxide and magnetic sludge biochar composite material applied to removal of low-concentration imidacloprid in water | |
| Wang et al. | Effectiveness evaluation of environmentally friendly stabilizers on remediation of Cd and Pb in agricultural soils by multi-scale experiments | |
| An et al. | Bi-functional biochar-g-C3N4-MgO composites for simultaneously minimizing pollution: Photocatalytic degradation of pesticide and phosphorus recovery as slow-release fertilizer | |
| Suvathi et al. | Improved photocatalytic dye degradation and seed germination through enzyme-coupled titanium oxide nanopowder-A cost-effective approach | |
| Liu et al. | Photocatalytic degradation of dinotefuran by layered phosphorus-doped carbon nitride and its mechanism | |
| Kumar et al. | Novel green photo-catalyst ‘turmeric roots’ for pesticides degradation: preparation and characterizations | |
| CN110201994A (en) | A kind of restorative procedure of the polycyclic aromatic hydrocarbon pollution based on vinegar grain and titanium powder plant waste sulfate ferrous iron | |
| Dhanapal et al. | Nanotechnology approaches for the remediation of agricultural polluted soils | |
| Venkatesh et al. | Solar light-driven photocatalysis by Co doped SnS nanoparticles towards degradation of noxious organic pollutant: Mechanism and toxicity assessment | |
| Hangan et al. | Preliminary study regarding the use of medicinal and decorative plants in the concept of peri-urban gardens with role on environmental protection. | |
| Nivetha et al. | Heavy metal contamination in groundwater and impact on plant and human | |
| Singh et al. | Biogenic synthesis of Allium cepa derived magnetic carbon dots for enhanced photocatalytic degradation of methylene blue and rhodamine B dyes | |
| CN112958034B (en) | Natural mineral material and application thereof in adsorption and decomposition of formaldehyde and air purification | |
| Rani et al. | Green fabrication and photoactivity of novel heteroatom modified metal heaxcyanocobaltate nanocomposites for efficient removal of organic pollutants from wastewater |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |