CN111360059A - In-situ remediation method for organic matter contaminated soil - Google Patents

In-situ remediation method for organic matter contaminated soil Download PDF

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CN111360059A
CN111360059A CN202010269149.5A CN202010269149A CN111360059A CN 111360059 A CN111360059 A CN 111360059A CN 202010269149 A CN202010269149 A CN 202010269149A CN 111360059 A CN111360059 A CN 111360059A
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bentonite
tio
cds
soil
magnetic
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吉永明
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Henan Yuqian Technology Transfer Center Co Ltd
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Henan Yuqian Technology Transfer Center Co Ltd
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    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
    • B09C—RECLAMATION OF CONTAMINATED SOIL
    • B09C2101/00—In situ

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  • Life Sciences & Earth Sciences (AREA)
  • Soil Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Processing Of Solid Wastes (AREA)
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Abstract

The invention discloses an in-situ remediation method of organic contaminated soil, which comprises the steps of firstly simply pretreating the organic contaminated soil, and then adding a solubilizer/TiO2Spraying CdS bentonite magnetic hydrogel microspheres on the surface layer of soil, and photocatalytic degrading organic pollutants under the irradiation of sunlight by using solubilizer/TiO2The CdS bentonite magnetic hydrogel microspheres are simple to prepare, can be separated and recovered under the action of an external magnetic field, can be repeatedly carried out according to the pollution degree of organic matters in soil, greatly reduce the soil remediation difficulty and save labor and equipment. The method carries out in-situ remediation on the soil surface, has the advantages of high photocatalytic reaction speed, no selectivity on pollutants, short remediation time, repeated implementation, suitability for soil remediation of different pollution degrees, no need of subsequent treatment, no use of chemical reagents, no secondary pollution, direct seeding after remediation and good economic benefit.

Description

In-situ remediation method for organic matter contaminated soil
Technical Field
The invention relates to the technical field of soil pollution remediation, in particular to an in-situ remediation method for organic matter polluted soil.
Background
With the rapid development of industry and agriculture, the environmental pollution problem is becoming more serious. Soil problems are becoming more and more serious as chemical, coke, oil refining, agriculture and transportation industries are rapidly developing. Organic pollutants in soil often include petroleum hydrocarbons, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and some pesticides that are difficult to degrade. Organic pollutants are easy to accumulate in the food chain due to the potential toxicity, carcinogenicity and weak biological effectiveness of the organic pollutants, and recently, the organic pollution in soil becomes a focus of environmental governance. The diversity of the types and the wide application of the synthetic organic matters lead the sources of organic pollution to be wide, such as the production and the preservation of food, the industrial manufacture, and the medical care of human beings and animals to generate a large amount of organic pollutants, which forces researchers to do a great deal of work on the soil organic pollution remediation.
The currently common organic matter contaminated soil remediation methods include a physical chemical remediation method, a chemical oxidation method, a photocatalytic degradation method, an electrodynamic remediation method, a microbial remediation method, a phytoremediation method, a pyrolysis method and the like. The physical and chemical remediation method is generally solvent cleaning or soil leaching, needs a large amount of organic reagents and organic solvents, and is easy to cause secondary pollution to soil; although the chemical oxidation method has good degradation effect on pollutants, byproducts with extremely high toxicity are generated in the process, and the organic matter types are likely to increase; the photocatalytic degradation method can only degrade organic pollutants in surface soil; the electrokinetic repair needs to provide a dissolving agent, consumes a large amount of electric energy and is easy to remain; the microorganism repairing method has the defects of few effective strains, poor strain viability and difficulty in obtaining long-term treatment effect; phytoremediation methods generally take a long time, perhaps several decades; pyrolysis requires complete removal of water from the soil, consumes a large amount of heat energy, and the remediation process has to add lime or other chemicals while producing HCl, SOx、NOxCausing air pollution.
Compared with other repair methods, photocatalytic degradation has many advantages: the method is applicable to various pollutants, can be simultaneously applied to saturated and unsaturated, viscous and semi-viscous soil, and has quite high economic benefit; can be used together with other technologies; the damage to the property and structure of the soil is small, and secondary pollution is not easy to form; is more suitable for comprehensively treating dense soil with low permeability coefficient and the like. Patent No. CN 103056155 discloses a reactor and its processing method for low temperature plasma cooperating with photocatalysis to treat polluted soil, the polluted soil is first discharge reacted in low temperature plasma reaction section for once degradation, the residual organic matters volatilized from the soil are introduced into the photocatalysis reaction section for photocatalysis reaction, the degradation time of organic pollutants in the soil is shortened, the degradation effect is improved, but the defects of complicated pretreatment, high equipment cost and excessive power consumption of ex-situ remediation soil exist.
Disclosure of Invention
In view of the defects of the organic matter contaminated soil remediation method, the invention aims to provide the organic matter contaminated soil in-situ remediation method which is low in operation difficulty, high in organic matter removal rate, short in remediation time, free of secondary pollution and low in energy consumption. The specific technical scheme is as follows:
an in-situ remediation method for organic contaminated soil, which comprises the following steps:
loosening and crushing organic matter contaminated soil, removing impurities, detecting the content of organic pollutants in the soil, and irrigating by injecting water to keep the humidity of the soil at 25-35%;
step two, adding solubilizer/TiO according to the mass ratio of 1:1002Spraying magnetic hydrogel microspheres of CdS bentonite on the surface layer of target soil, and adding solubilizer/TiO2The surface-loaded solubilizer of the CdS bentonite magnetic hydrogel microspheres can promote the dissolution of organic matters in soil, the organic pollutants are subjected to photocatalytic degradation by irradiating sunlight or simulated sunlight for more than 4 hours, and then TiO is separated by using a magnetic field2Washing/drying CdS bentonite magnetic hydrogel microspheres for 10-20 s by using water, and irradiating by using an ultraviolet lamp for later use;
and step three, turning, loosening and crushing soil to maintain the soil humidity at 25-35%, and repeating the step two until the content detection value of the organic pollutants in the soil reaches the standard.
Furthermore, the bentonite used in the invention is modified bentonite, and the modification method comprises the following steps: crushing and sieving calcium-based bentonite, and adding 2-5 kg of modifier into every 100 kg of calcium-based bentonite, wherein the modifier is dodecyl polyglycoside quaternary ammonium salt and AlCl3•H2And adding water into the O, uniformly mixing, placing the bentonite and the modifier in a 15000W microwave oven for irradiation for 10-20 min, drying and grinding to obtain the modified bentonite.
Further, the solubilizer is one or more of an anionic surfactant, a cationic surfactant, a zwitterionic surfactant and a nonionic surfactant.
Further, the solubilizer/TiO2TiO in CdS bentonite magnetic hydrogel microspheres2Nanoparticles and CdS nanoparticles in Fe2O3The nano particles/bentonite are uniformly distributed, and the average particle size is 5-10 nm.
Further, the solubilizer/TiO2The preparation method of the CdS bentonite magnetic hydrogel microspheres comprises the following steps:
（1）Fe3O4preparation of nanoparticles/bentonite: dispersing modified bentonite into deionized water, stirring at normal temperature, heating to 80 deg.C, adding FeSO under nitrogen protection4•7H2O and FeCl3•6H2O（Fe2+：Fe3+=3: 4), stirring to mix thoroughly, adding NaOH rapidly until the pH of the solution is 10, stirring continuously, cooling naturally, separating out magnetic substance under an external magnetic field, washing with water and ethanol for several times, vacuum drying at 60 deg.C for 12 h to obtain Fe3O4Nano-particles/bentonite;
（2）TiO2preparation of CdS nanoparticles: adding cadmium acetate and thiourea into deionized water, and adding TiO with a certain mass after completely dissolving2Nano particles, transferring the solution into a polytetrafluoroethylene reaction kettle, placing the reaction kettle in a constant-temperature oven at 130 ℃, standing for 12 hours, and naturally cooling; separating out the product, respectively washing with deionized water and anhydrous ethanol for several times, vacuum drying at 80 deg.C for 12 hr to obtain TiO2A CdS nanoparticle;
（3）Fe3O4nano particle/bentonite loaded TiO2[ CdS nanoparticles: mixing Fe3O4Dispersing the nano particles/bentonite into deionized water, stirring at normal temperature, heating to 80 ℃, adding TiO2the/CdS nano-particles are fully mixed while being stirred, the magnetic substance is separated out under the external magnetic field after natural cooling, the mixture is washed for a plurality of times and dried for 12 hours in vacuum at the temperature of 60 ℃, and the loaded TiO is obtained2Fe of CdS nanoparticles3O4Nano-particles/bentonite;
（4）TiO2preparation of CdS bentonite magnetic hydrogel microspheres: adding supported TiO into carboxymethyl cellulose aqueous solution2Fe of CdS nanoparticles3O4Mixing nano particle and bentonite homogeneously to obtain viscous suspension, and cross-linking to obtain TiO2/CdS bentoniteMagnetic hydrogel microspheres;
(5) solubilizer/TiO2Preparation of CdS bentonite magnetic hydrogel microspheres: adding TiO into the mixture2Soaking the magnetic CdS bentonite hydrogel microspheres in aqueous solution of surfactant micelle, taking out, washing with distilled water, and drying at 40 deg.C to obtain TiO2The magnetic hydrogel microsphere of CdS bentonite.
The surfactant loaded on the surface layer of the bentonite magnetic hydrogel microsphere continuously desorbs the organic pollutants combined with soil particles, and the desorbed organic pollutants enter the pore channel of the hydrogel microsphere and are quickly adsorbed by the modified bentonite in the hydrogel microsphere, so that TiO loaded on the bentonite is adsorbed2The CdS composite photocatalyst is always in high reaction substrate concentration, so that the photocatalytic reaction rate is greatly improved, and the rapid degradation of organic pollutants is promoted.
The invention combines a plurality of photocatalysts, and the catalytic activity is single TiO2The catalytic activity of the nano particles is more than 10 times that of the nano particles, and the TiO is prepared by a hydrothermal method2The average particle diameter of the nano particles and CdS nano particles is 5-10 nm, and Fe3O4Residual trace Fe in nano particle/bentonite preparation process3+CdS nanoparticles with TiO2All can effectively reduce TiO by contacting2The forbidden band width of the semiconductor can not only strengthen the photocatalysis of the semiconductor, but also expand the absorption wavelength range of the semiconductor to a visible light region, directly utilize the energy of sunlight, avoid an additional ultraviolet light source, avoid the harm of ultraviolet ray escaping to a human body, greatly save energy and reduce the processing cost.
The invention prepares the solubilizer/TiO2Magnetic hydrogel microsphere of CdS bentonite, Fe loaded by bentonite3O4The nano particles have paramagnetism, so that the hydrogel microspheres are easy to separate and recover under an external magnetic field, the photocatalyst nano particles are uniformly dispersed and firmly adsorbed by the modified bentonite, the agglomeration and inactivation of the catalyst are avoided, volatile organic pollutants in the soil are quickly adsorbed by the bentonite hydrogel, the organic pollutants combined with the soil are adsorbed by the bentonite hydrogel through a dissolution-adsorption mechanism, and the adsorption sitesThe organic pollutants at the adsorption sites are degraded and mineralized thoroughly by the bentonite-loaded photocatalyst under the action of sunlight, and meanwhile, the adsorption sites are released, adsorbed and degraded again, so that the degradation rate of the organic pollutants is greatly improved.
Compared with the prior art, the in-situ remediation method for the organic matter contaminated soil has the following beneficial effects:
1. the in-situ remediation method of the organic matter contaminated soil provided by the invention only needs to mix the solubilizer/TiO2The CdS bentonite magnetic hydrogel microspheres are sprayed on the surface layer of soil, and the degradation of organic pollutants in the soil can be completed under the irradiation of sunlight, and the used solubilizer/TiO2The CdS bentonite magnetic hydrogel microspheres are simple to prepare, can be separated and recovered under the action of an external magnetic field, greatly reduce the difficulty of soil remediation and save manpower and equipment;
2. compared with the existing organic matter contaminated soil remediation technology, the method has the advantages that the in-situ remediation is carried out on the soil surface, the photocatalytic reaction speed is high, the selectivity to pollutants is avoided, the remediation time is short, the method can be repeatedly carried out, the method is suitable for the remediation of the soil with different pollution degrees, the subsequent treatment is not needed, no chemical reagent is used, the secondary pollution is generated, the direct seeding can be carried out after the remediation, and the economic benefit is good.
Detailed Description
To further illustrate the technical means adopted by the present invention and the effects thereof, the following detailed description is given with reference to the preferred embodiments of the present invention.
Example 1
An in-situ remediation method for organic contaminated soil, which comprises the following steps:
loosening and crushing organic matter contaminated soil, removing impurities, detecting the type and content of organic pollutants in the soil, and irrigating by injecting water to keep the humidity of the soil at 25%;
step two, adding the solubilizer/TiO according to the mass ratio of 1:802Spraying CdS bentonite magnetic hydrogel microspheres on the surface layer of target soil, and allowing sunlight or simulated sunlightIrradiating for 4 hours to carry out photocatalytic degradation on organic pollutants, and then separating solubilizer/TiO by utilizing a magnetic field2Washing, drying and irradiating by an ultraviolet lamp for 10 s for later use;
and step three, turning, loosening and crushing the soil to maintain the soil humidity at 25%, repeating the operation of the step two for six times, and detecting the content of various organic pollutants in the soil.
Furthermore, the bentonite used in the invention is modified bentonite, and the modification method comprises the following steps: crushing and sieving calcium-based bentonite, and adding 2-5 kg of modifier into every 100 kg of calcium-based bentonite, wherein the modifier is dodecyl polyglycoside quaternary ammonium salt and AlCl3•H2And adding water into the O, uniformly mixing, placing the bentonite and the modifier in a 15000W microwave oven for irradiation for 10-20 min, drying and grinding to obtain the modified bentonite.
Further, the solubilizer is one or more of an anionic surfactant, a cationic surfactant, a zwitterionic surfactant and a nonionic surfactant.
Further, the solubilizer/TiO2TiO in CdS bentonite magnetic hydrogel microspheres2Nanoparticles and CdS nanoparticles in Fe2O3The nano particles/bentonite are uniformly distributed, and the average particle size is 5-10 nm.
Further, the solubilizer/TiO2The preparation method of the CdS bentonite magnetic hydrogel microspheres comprises the following steps:
（1）Fe3O4preparation of nanoparticles/bentonite: dispersing modified bentonite into deionized water, stirring at normal temperature, heating to 80 deg.C, adding FeSO under nitrogen protection4•7H2O and FeCl3•6H2O（Fe2+：Fe3+=3: 4), stirring to mix thoroughly, adding NaOH rapidly until the pH of the solution is 10, stirring continuously, cooling naturally, separating out magnetic substance under an external magnetic field, washing with water and ethanol for several times, vacuum drying at 60 deg.C for 12 h to obtain Fe3O4Nano-particles/bentonite;
（2）TiO2preparation of CdS nanoparticles: taking cadmium acetateAdding thiourea into deionized water, and adding TiO with a certain mass after the thiourea is completely dissolved2Nano particles, transferring the solution into a polytetrafluoroethylene reaction kettle, placing the reaction kettle in a constant-temperature oven at 130 ℃, standing for 12 hours, and naturally cooling; separating out the product, respectively washing with deionized water and anhydrous ethanol for several times, vacuum drying at 80 deg.C for 12 hr to obtain TiO2A CdS nanoparticle;
（3）Fe3O4nano particle/bentonite loaded TiO2[ CdS nanoparticles: mixing Fe3O4Dispersing the nano particles/bentonite into deionized water, stirring at normal temperature, heating to 80 ℃, adding TiO2the/CdS nano-particles are fully mixed while being stirred, the magnetic substance is separated out under the external magnetic field after natural cooling, the mixture is washed for a plurality of times and dried for 12 hours in vacuum at the temperature of 60 ℃, and the loaded TiO is obtained2Fe of CdS nanoparticles3O4Nano-particles/bentonite;
（4）TiO2preparation of CdS bentonite magnetic hydrogel microspheres: adding supported TiO into carboxymethyl cellulose aqueous solution2Fe of CdS nanoparticles3O4Mixing nano particle and bentonite homogeneously to obtain viscous suspension, and cross-linking to obtain TiO2Magnetic hydrogel microspheres of CdS bentonite;
(5) solubilizer/TiO2Preparation of CdS bentonite magnetic hydrogel microspheres: adding TiO into the mixture2Soaking the magnetic CdS bentonite hydrogel microspheres in aqueous solution of surfactant micelle, taking out, washing with distilled water, and drying at 40 deg.C to obtain TiO2The magnetic hydrogel microsphere of CdS bentonite.
Example 2
An in-situ remediation method for organic contaminated soil, which comprises the following steps:
loosening and crushing organic matter contaminated soil, removing impurities, detecting the type and content of organic pollutants in the soil, and irrigating by injecting water to keep the soil humidity at 30%;
step two, adding solubilizer/TiO according to the mass ratio of 1:1002Spraying CdS bentonite magnetic hydrogel microspheres on the surface layer of target soil, and irradiating with sunlight or simulated sunlightCarrying out photocatalytic degradation on organic pollutants for 5 hours, and then separating solubilizer/TiO by using a magnetic field2Washing/drying CdS bentonite magnetic hydrogel microspheres with water, and irradiating with ultraviolet light for 15 s;
and step three, turning, loosening and crushing the soil to maintain the soil humidity at 30%, repeating the operation of the step two for five times, and detecting the content of various organic pollutants in the soil.
Furthermore, the bentonite used in the invention is modified bentonite, and the modification method comprises the following steps: crushing and sieving calcium-based bentonite, and adding 2-5 kg of modifier into every 100 kg of calcium-based bentonite, wherein the modifier is dodecyl polyglycoside quaternary ammonium salt and AlCl3•H2And adding water into the O, uniformly mixing, placing the bentonite and the modifier in a 15000W microwave oven for irradiation for 10-20 min, drying and grinding to obtain the modified bentonite.
Further, the solubilizer is one or more of an anionic surfactant, a cationic surfactant, a zwitterionic surfactant and a nonionic surfactant.
Further, the solubilizer/TiO2TiO in CdS bentonite magnetic hydrogel microspheres2Nanoparticles and CdS nanoparticles in Fe2O3The nano particles/bentonite are uniformly distributed, and the average particle size is 5-10 nm.
Further, the solubilizer/TiO2The preparation method of the CdS bentonite magnetic hydrogel microspheres comprises the following steps:
（1）Fe3O4preparation of nanoparticles/bentonite: dispersing modified bentonite into deionized water, stirring at normal temperature, heating to 80 deg.C, adding FeSO under nitrogen protection4•7H2O and FeCl3•6H2O（Fe2+：Fe3+=3: 4), stirring to mix thoroughly, adding NaOH rapidly until the pH of the solution is 10, stirring continuously, cooling naturally, separating out magnetic substance under an external magnetic field, washing with water and ethanol for several times, vacuum drying at 60 deg.C for 12 h to obtain Fe3O4Nano-particles/bentonite;
（2）TiO2preparation of CdS nanoparticles: taking cadmium acetate and sulfurAdding urea into deionized water, and adding TiO with a certain mass after the urea is completely dissolved2Nano particles, transferring the solution into a polytetrafluoroethylene reaction kettle, placing the reaction kettle in a constant-temperature oven at 130 ℃, standing for 12 hours, and naturally cooling; separating out the product, respectively washing with deionized water and anhydrous ethanol for several times, vacuum drying at 80 deg.C for 12 hr to obtain TiO2A CdS nanoparticle;
（3）Fe3O4nano particle/bentonite loaded TiO2[ CdS nanoparticles: mixing Fe3O4Dispersing the nano particles/bentonite into deionized water, stirring at normal temperature, heating to 80 ℃, adding TiO2the/CdS nano-particles are fully mixed while being stirred, the magnetic substance is separated out under the external magnetic field after natural cooling, the mixture is washed for a plurality of times and dried for 12 hours in vacuum at the temperature of 60 ℃, and the loaded TiO is obtained2Fe of CdS nanoparticles3O4Nano-particles/bentonite;
（4）TiO2preparation of CdS bentonite magnetic hydrogel microspheres: adding supported TiO into carboxymethyl cellulose aqueous solution2Fe of CdS nanoparticles3O4Mixing nano particle and bentonite homogeneously to obtain viscous suspension, and cross-linking to obtain TiO2Magnetic hydrogel microspheres of CdS bentonite;
(5) solubilizer/TiO2Preparation of CdS bentonite magnetic hydrogel microspheres: adding TiO into the mixture2Soaking the magnetic CdS bentonite hydrogel microspheres in aqueous solution of surfactant micelle, taking out, washing with distilled water, and drying at 40 deg.C to obtain TiO2The magnetic hydrogel microsphere of CdS bentonite.
Example 3
An in-situ remediation method for organic contaminated soil, which comprises the following steps:
loosening and crushing organic matter contaminated soil, removing impurities, detecting the type and content of organic pollutants in the soil, and irrigating by injecting water to keep the soil humidity at 35%;
step two, adding solubilizer/TiO according to the mass ratio of 1:1102The CdS bentonite magnetic hydrogel microspheres are sprayed on the surface layer of target soil and irradiated by 6 hours of sunlight or simulated sunlightOf TiO 22The organic pollutants are degraded by photocatalysis through CdS, and then the solubilizer/TiO is separated by utilizing a magnetic field2Washing/drying CdS bentonite magnetic hydrogel microspheres for 20 s under ultraviolet irradiation;
and step three, turning, loosening and crushing the soil to maintain the soil humidity at 35%, repeating the operation of the step two for four times, and detecting the content of various organic pollutants in the soil.
Furthermore, the bentonite used in the invention is modified bentonite, and the modification method comprises the following steps: crushing and sieving calcium-based bentonite, and adding 2-5 kg of modifier into every 100 kg of calcium-based bentonite, wherein the modifier is dodecyl polyglycoside quaternary ammonium salt and AlCl3•H2And adding water into the O, uniformly mixing, placing the bentonite and the modifier in a 15000W microwave oven for irradiation for 10-20 min, drying and grinding to obtain the modified bentonite.
Further, the solubilizer is one or more of an anionic surfactant, a cationic surfactant, a zwitterionic surfactant and a nonionic surfactant.
Further, the solubilizer/TiO2TiO in CdS bentonite magnetic hydrogel microspheres2Nanoparticles and CdS nanoparticles in Fe2O3The nano particles/bentonite are uniformly distributed, and the average particle size is 5-10 nm.
Further, the solubilizer/TiO2The preparation method of the CdS bentonite magnetic hydrogel microspheres comprises the following steps:
（1）Fe3O4preparation of nanoparticles/bentonite: dispersing modified bentonite into deionized water, stirring at normal temperature, heating to 80 deg.C, adding FeSO under nitrogen protection4•7H2O and FeCl3•6H2O（Fe2+：Fe3+=3: 4), stirring to mix thoroughly, adding NaOH rapidly until the pH of the solution is 10, stirring continuously, cooling naturally, separating out magnetic substance under an external magnetic field, washing with water and ethanol for several times, vacuum drying at 60 deg.C for 12 h to obtain Fe3O4Nano-particles/bentonite;
（2）TiO2preparation of CdS nanoparticles: vinegar taking deviceAdding cadmium oxide and thiourea into deionized water, and adding TiO with a certain mass after the cadmium oxide and the thiourea are completely dissolved2Nano particles, transferring the solution into a polytetrafluoroethylene reaction kettle, placing the reaction kettle in a constant-temperature oven at 130 ℃, standing for 12 hours, and naturally cooling; separating out the product, respectively washing with deionized water and anhydrous ethanol for several times, vacuum drying at 80 deg.C for 12 hr to obtain TiO2A CdS nanoparticle;
（3）Fe3O4nano particle/bentonite loaded TiO2[ CdS nanoparticles: mixing Fe3O4Dispersing the nano particles/bentonite into deionized water, stirring at normal temperature, heating to 80 ℃, adding TiO2the/CdS nano-particles are fully mixed while being stirred, the magnetic substance is separated out under the external magnetic field after natural cooling, the mixture is washed for a plurality of times and dried for 12 hours in vacuum at the temperature of 60 ℃, and the loaded TiO is obtained2Fe of CdS nanoparticles3O4Nano-particles/bentonite;
（4）TiO2preparation of CdS bentonite magnetic hydrogel microspheres: adding supported TiO into carboxymethyl cellulose aqueous solution2Fe of CdS nanoparticles3O4Mixing nano particle and bentonite homogeneously to obtain viscous suspension, and cross-linking to obtain TiO2Magnetic hydrogel microspheres of CdS bentonite;
(5) solubilizer/TiO2Preparation of CdS bentonite magnetic hydrogel microspheres: adding TiO into the mixture2Soaking the magnetic CdS bentonite hydrogel microspheres in aqueous solution of surfactant micelle, taking out, washing with distilled water, and drying at 40 deg.C to obtain TiO2The magnetic hydrogel microsphere of CdS bentonite.
Comparative example 1
The same as example 3 except that CdS nanoparticles were not included.
Comparative example 2
The procedure is as in example 3 except that the bentonite used is an unmodified bentonite.
Repair test
Rectangular organic pollution soil blocks of a chemical plant in Henan are selected as treatment objects, and the organic pollutants in the soil are detected to be 21, wherein aniline, chlorobenzene, nitrobenzene, phthalic acid ester and polycyclic aromatic hydrocarbon account for more than 75% of the pollutants. The rectangular soil block was divided vertically by 5 equal parts and treated by the remediation methods corresponding to examples 1 to 3 and comparative examples 1 to 2, respectively.
Analysis of results
According to the detection results of the contents of various main organic pollutants in the soil before and after remediation, the removal rates of the organic pollutants in the soil before and after remediation in examples 1-3 and comparative examples 1-2 are respectively calculated, and the obtained results are shown in table 1:
TABLE 1 organic contaminant content before and after soil remediation in examples 1 to 3 and comparative examples 1 to 2
Figure DEST_PATH_IMAGE001
As can be seen from the data in Table 1, the repair methods in embodiments 1 to 3 of the present invention have removal rates of aniline, chlorobenzene, nitrobenzene, phthalate, and polycyclic aromatic hydrocarbons of greater than 90%, which indicates that the in-situ repair method for organic contaminated soil provided by the present invention has a good repair effect. The comparative example 1 has obviously reduced removal rate of various organic pollutants because of no CdS nano-particles, because CdS nano-particles can react with Fe3+、TiO2The nanometer particles are used for concerted catalysis, so that the TiO content is greatly improved2The catalytic activity of the nano particles is greatly improved, the utilization rate of visible light is also greatly improved, so that the CdS nano particles are not contained, the processing operation is the same as that of the embodiment 3, and finally the removal rate of organic pollutants is greatly reduced; the bentonite used in comparative example 2 is non-modified bentonite, and the removal rate of organic pollutants is also obviously reduced, because the crude oil residue in the modified bentonite can promote the dissolution of the organic pollutants in the soil, the modified bentonite has larger specific surface area, can quickly adsorb volatile and dissolved organic pollutants in the soil, provides high reaction substrate concentration in the photocatalysis process, and keeps high photocatalysis efficiency.
The above description is only for the specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto, and other modifications or equivalent substitutions made by the technical solution of the present invention by the ordinary skilled in the art should be covered within the scope of the claims of the present invention without departing from the spirit and scope of the technical solution of the present invention.

Claims (5)

1. An in-situ remediation method for organic contaminated soil is characterized by comprising the following steps:
loosening and crushing organic matter contaminated soil, removing impurities, detecting the content of organic pollutants in the soil, and irrigating by injecting water to keep the humidity of the soil at 25-35%;
step two, adding solubilizer/TiO according to the mass ratio of 1:1002Spraying magnetic hydrogel microspheres of CdS bentonite on the surface layer of target soil, and adding solubilizer/TiO2The surface-loaded solubilizer of the CdS bentonite magnetic hydrogel microspheres can promote the dissolution of organic matters in soil, the organic pollutants are subjected to photocatalytic degradation by irradiating sunlight or simulated sunlight for more than 4 hours, and then TiO is separated by using a magnetic field2Washing/drying CdS bentonite magnetic hydrogel microspheres for 10-20 s by using water, and irradiating by using an ultraviolet lamp for later use;
and step three, turning, loosening and crushing soil to maintain the soil humidity at 25-35%, and repeating the step two until the content detection value of the organic pollutants in the soil reaches the standard.
2. The in-situ remediation method for organic-contaminated soil according to claim 1, wherein the bentonite is modified bentonite, and the modification method comprises: crushing and sieving calcium-based bentonite, and adding 2-5 kg of modifier into every 100 kg of calcium-based bentonite, wherein the modifier is dodecyl polyglycoside quaternary ammonium salt and AlCl3•H2And adding water into the O, uniformly mixing, placing the bentonite and the modifier in a 15000W microwave oven for irradiation for 10-20 min, drying and grinding to obtain the modified bentonite.
3. The method of claim 1, wherein the solubilizing agent/TiO is selected from the group consisting of sodium chloride, potassium chloride, sodium chloride2The solubilizer in the CdS bentonite magnetic hydrogel microsphere is one or more of anionic surfactant, cationic surfactant, zwitterionic surfactant and nonionic surfactantAnd (4) seed preparation.
4. solubilizer/TiO for the in-situ remediation method of organic-contaminated soil according to claim 12The CdS bentonite magnetic hydrogel microsphere is characterized by comprising the following steps of:
（1）Fe3O4preparation of nanoparticles/bentonite: dispersing modified bentonite into deionized water, stirring at normal temperature, heating to 80 deg.C, adding FeSO under nitrogen protection4•7H2O and FeCl3•6H2O（Fe2+：Fe3+=3: 4), stirring to mix thoroughly, adding NaOH rapidly until the pH of the solution is 10, stirring continuously, cooling naturally, separating out magnetic substance under an external magnetic field, washing with water and ethanol for several times, vacuum drying at 60 deg.C for 12 h to obtain Fe3O4Nano-particles/bentonite;
（2）TiO2preparation of CdS nanoparticles: adding cadmium acetate and thiourea into deionized water, and adding TiO with a certain mass after completely dissolving2Nano particles, transferring the solution into a polytetrafluoroethylene reaction kettle, placing the reaction kettle in a constant-temperature oven at 130 ℃, standing for 12 hours, and naturally cooling; separating out the product, respectively washing with deionized water and anhydrous ethanol for several times, vacuum drying at 80 deg.C for 12 hr to obtain TiO2A CdS nanoparticle;
（3）Fe3O4nano particle/bentonite loaded TiO2[ CdS nanoparticles: mixing Fe3O4Dispersing the nano particles/bentonite into deionized water, stirring at normal temperature, heating to 80 ℃, adding TiO2the/CdS nano-particles are fully mixed while being stirred, the magnetic substance is separated out under the external magnetic field after natural cooling, the mixture is washed for a plurality of times and dried for 12 hours in vacuum at the temperature of 60 ℃, and the loaded TiO is obtained2Fe of CdS nanoparticles3O4Nano-particles/bentonite;
（4）TiO2preparation of CdS bentonite magnetic hydrogel microspheres: adding supported TiO into carboxymethyl cellulose aqueous solution2Fe of CdS nanoparticles3O4Mixing nano particles with bentonite to obtain thick suspension, and cross-linkingReacting to obtain TiO2Magnetic hydrogel microspheres of CdS bentonite;
(5) solubilizer/TiO2Preparation of CdS bentonite magnetic hydrogel microspheres: adding TiO into the mixture2Soaking the magnetic CdS bentonite hydrogel microspheres in aqueous solution of surfactant micelle, taking out, washing with distilled water, and drying at 40 deg.C to obtain TiO2The magnetic hydrogel microsphere of CdS bentonite.
5. A solubilizing agent/TiO according to claim 42The magnetic hydrogel microsphere of CdS bentonite is characterized in that TiO2Nanoparticles and CdS nanoparticles in Fe2O3The nano particles/bentonite are uniformly distributed, and the average particle size is 5-10 nm.
CN202010269149.5A 2020-04-08 2020-04-08 In-situ remediation method for organic matter contaminated soil Withdrawn CN111360059A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112154906A (en) * 2020-10-29 2021-01-01 黄河水利委员会黄河水利科学研究院 Root-dividing region drip irrigation system for agricultural non-point source sewage purification and application thereof
CN114577663A (en) * 2022-03-08 2022-06-03 四川大学 Method for separating and quantitatively analyzing bioavailable organic debris in river beach soil

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112154906A (en) * 2020-10-29 2021-01-01 黄河水利委员会黄河水利科学研究院 Root-dividing region drip irrigation system for agricultural non-point source sewage purification and application thereof
CN114577663A (en) * 2022-03-08 2022-06-03 四川大学 Method for separating and quantitatively analyzing bioavailable organic debris in river beach soil
CN114577663B (en) * 2022-03-08 2023-05-05 四川大学 Method for separating and quantitatively analyzing bioavailable organic scraps in river beach soil

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