CN111229817A - Modified SDS nano zero-valent iron and application thereof - Google Patents

Modified SDS nano zero-valent iron and application thereof Download PDF

Info

Publication number
CN111229817A
CN111229817A CN202010112875.6A CN202010112875A CN111229817A CN 111229817 A CN111229817 A CN 111229817A CN 202010112875 A CN202010112875 A CN 202010112875A CN 111229817 A CN111229817 A CN 111229817A
Authority
CN
China
Prior art keywords
valent iron
sds
zero
liquid
nano zero
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.)
Granted
Application number
CN202010112875.6A
Other languages
Chinese (zh)
Other versions
CN111229817B (en
Inventor
应蓉蓉
夏冰
孔令雅
张斌
张晓雨
赵彩衣
芦园园
尹爱经
冯艳红
张亚
单艳红
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ANHUI PROVINCIAL ACADEMY OF ENVIRONMENTAL SCIENCE
Nanjing Institute of Environmental Sciences MEE
Original Assignee
ANHUI PROVINCIAL ACADEMY OF ENVIRONMENTAL SCIENCE
Nanjing Institute of Environmental Sciences MEE
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by ANHUI PROVINCIAL ACADEMY OF ENVIRONMENTAL SCIENCE, Nanjing Institute of Environmental Sciences MEE filed Critical ANHUI PROVINCIAL ACADEMY OF ENVIRONMENTAL SCIENCE
Priority to CN202010112875.6A priority Critical patent/CN111229817B/en
Publication of CN111229817A publication Critical patent/CN111229817A/en
Application granted granted Critical
Publication of CN111229817B publication Critical patent/CN111229817B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
    • B09C—RECLAMATION OF CONTAMINATED SOIL
    • B09C1/00—Reclamation of contaminated soil
    • B09C1/10—Reclamation of contaminated soil microbiologically, biologically or by using enzymes
    • 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
    • C09K17/40—Soil-conditioning materials or soil-stabilising materials containing mixtures of inorganic and organic compounds
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
    • C12P3/00—Preparation of elements or inorganic compounds except carbon dioxide
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
    • C12P39/00—Processes involving microorganisms of different genera in the same process, simultaneously

Landscapes

  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Organic Chemistry (AREA)
  • Wood Science & Technology (AREA)
  • Zoology (AREA)
  • Biotechnology (AREA)
  • Soil Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Microbiology (AREA)
  • Health & Medical Sciences (AREA)
  • Bioinformatics & Cheminformatics (AREA)
  • Biochemistry (AREA)
  • General Engineering & Computer Science (AREA)
  • General Chemical & Material Sciences (AREA)
  • Genetics & Genomics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Environmental & Geological Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Materials Engineering (AREA)
  • Biomedical Technology (AREA)
  • Molecular Biology (AREA)
  • Mycology (AREA)
  • Processing Of Solid Wastes (AREA)

Abstract

The invention belongs to the field of heavy metal pollution remediation in polluted environment, and discloses modified SDS (sodium dodecyl sulfate) nano zero-valent iron which is prepared by the following process: 1) respectively culturing pseudomonas aeruginosa and aspergillus niger into pseudomonas aeruginosa liquid and aspergillus niger liquid with certain concentrations, and then mixing to obtain composite bacterial liquid; 2) spraying compound bacteria solution on SDS nanometer zero-valent iron, stirring uniformly, and storing at 4 ℃. The SDS nano zero-valent iron is modified, so that the leaching toxicity of heavy metals can be obviously reduced.

Description

Modified SDS nano zero-valent iron and application thereof
Technical Field
The invention belongs to the field of heavy metal pollution remediation in polluted environments, and relates to modified SDS (sodium dodecyl sulfate) nano zero-valent iron and application thereof.
Background
The nanoscale zero-valent iron has reduction and adsorption capacity incomparable with that of ordinary millimeter-scale or micron-scale zero-valent iron, can efficiently convert environmental pollutants such as chlorine-containing organic matters, toxic metals and inorganic compounds into low-toxicity or inert substances, and is more and more concerned by scientific researchers. As shown in the results of field experiments on groundwater in 40 TCE/DNAPL contaminated sites by using nano-iron technology, the U.S. environmental protection agency has reached a pollutant removal rate of more than 98% in a relatively short time, as since 2003. Besides being widely applied to the remediation of organic pollutants, the nanoscale zero-valent iron is beginning to be applied to the treatment of heavy metal pollution in water, such As Cd, As, Cr, Zn, Ni, Ag, Pb and the like. Research shows that a certain amount of nano zero-valent iron can completely remove As (V) in underground water, the reaction rate of the nano zero-valent iron to Cr (VI) and Pb (II) in a water body is 30 times that of common iron powder, the removal amount of the nano zero-valent iron to Cr (VI) after reaction for two months is 4.8 times that of the common iron powder, and the outstanding reaction activity of the nano zero-valent iron is shown.
In view of the superiority of the nano zero-valent iron in heavy metal pollution treatment compared with the traditional zero-valent iron, researchers begin to try to treat the soil polluted by single heavy metals such As As, Cr (VI), Hg and the like by using the modified nano zero-valent iron As a soil stabilizer, so that the nano zero-valent iron has a good stabilizing effect. Researches find that sodium dodecyl sulfate modified nano zero-valent iron (SDS-nZVI) has a stabilizing effect on arsenic, so that the content of As extracted by a leaching toxicity method (TCLP) in arsenic tailings is reduced by 52.25%. For the soil polluted by multiple metals, the current research is relatively lack. The mechanism research on the heavy metal pollution remediation by nano zero-valent iron mainly focuses on the mechanism of removing heavy metal by nano zero-valent iron in water at present, and comprises the following steps: (1) in relation to the standard redox potential of heavy metals, theoretically provided that the standard redox potential is higher than Fe2+Fe (-0.41V), namely Fe can be reduced; (2) the nano zero-valent iron has small particle size and large specific surface area, so the surface energy is high, the adsorption capacity is strong, and part of heavy metal ions in water can be removed through adsorption; (3) fe to H2Conversion of O to H2And OH-Some metal ions in solution with OH-The nano zero-valent iron particles are matched with each other on the surface to generate coprecipitation of the slightly soluble substance. There are generally multiple mechanisms for one element. High resolution X-ray photoelectron spectroscopy (HR-XPS) results show Zn in solution2+And Cd2+Is not reduced, and Hg2+、Ag+Is reduced into simple substance Hg and Ag. Research finds that part of Pb in the solution2+OH on the surface of nano-iron-Form Pb (OH)2And PbO2And another part of the adsorbed Pb2+Then reduced to zero-valent lead. It is found by research using XPS, X-ray near-edge spectroscopy (XANES) and X-ray fine structure spectroscopy (EXAFS) that Cr (VI) in the solution is totally reduced to Cr (III) and Cr (OH) is coated on the surface of nano zero-valent iron particles3Precipitation and CrxFe1-
x(OH)3The form exists. In polluted soil, the existing research mainly focuses on the stabilizing effect of nano zero-valent iron and modification thereof on soil heavy metalThe mechanism of stabilization of heavy metals is not clear. Because the soil is a heterogeneous body consisting of various components and particles with different sizes, the physical and chemical properties of the components with different particle sizes are different, and the adsorption capacity of heavy metal elements is also greatly different. Research shows that the arsenic content in soil particles is in positive correlation with the proportion of the clay particles, and the arsenic content in soil fine particles is higher. Also in the soil, the content of Cd and Zn gradually increases as the soil particle size decreases. This brings difficulty to the research on the mechanism of stabilizing heavy metals with stabilizers. The conventional heavy metal stabilizer/modifier, such as limestone, fly ash, clay mineral material and the like, mainly stabilizes heavy metals in soil by the following mechanism:
(1) ion exchange or coordination adsorption of heavy metal ions on the surface of the stabilizer/modifier; (2) inorganic salts with low solubility are generated by dissolution-precipitation with heavy metals; (3) firstly, inorganic salt precipitation phase is generated on the surface, and heavy metal ions are diffused into crystal lattices of the minerals. Then, whether the stabilizing mechanism of the modified nano zero-valent iron on heavy metals in soil is similar to the mechanism for removing heavy metals in water or not is not determined, and the heavy metals such As Cd, Cu, As, Pb and the like in soil are stabilized through the processes of reduction, adsorption, matching/coprecipitation, or the stabilizing mechanism is consistent with the mechanism of the traditional soil stabilizer; and whether there is competitive adsorption or synergy in the presence of multiple metals, such as in Fe (OH)3The phenomenon that Zn/Cd/Pb and As on the surface can jointly form composite precipitation and the like cannot be expected.
There are many methods for preparing nano zero-valent iron, and the preparation process can be roughly divided into: solid phase method, gas phase method, liquid phase method, synthetic method, etc. The liquid phase reduction method in the liquid phase preparation method is widely applied to the preparation of the nano iron particles, and researches are made on the adoption of the liquid phase reduction method to prepare the nano zero-valent iron to adsorb humic acid and reduce trivalent arsenic in surface water; the research also adopts a liquid phase reduction method to prepare the nano zero-valent iron to treat the waste water containing the chloronitrobenzene. The method has the advantages of simple operation, mild condition and easy control, and the prepared nano iron powder has high purity and uniform particle size, and is the most common method for preparing nano zero-valent iron in laboratories and industries at present.
Due to factors such as reaction conditions and economic cost, the efficiency of restoring heavy metal composite contaminated soil by nano zero-valent iron is not high, and the combined treatment of the nano zero-valent iron and aerobic microorganism degradation becomes a research hotspot. Many researchers have tried to use nanoscale zero-valent iron in combination with microorganisms for environmental remediation of pollutants, but nanoscale zero-valent iron often has adverse effects on microbial cells, probably because nanoscale zero-valent iron with smaller particle size can attach inside and outside microbial cell membranes, causing destruction of cell membrane structures and extravasation of cell contents. Therefore, the chemical activity and the influence on the microbial cell membrane of the nano zero-valent iron are considered. The research on the types of microorganisms which can coexist with the nano zero-valent iron and can synergistically repair the heavy metal contaminated soil is a technical problem to be overcome.
Disclosure of Invention
In order to solve the technical problems, the invention aims to provide modified SDS nano zero-valent iron and application thereof in repairing heavy metal contaminated soil.
In order to achieve the technical purpose, the invention adopts the following technical scheme:
a modified SDS nanometer zero-valent iron is prepared by the following processes:
1) respectively culturing pseudomonas aeruginosa and aspergillus niger into pseudomonas aeruginosa liquid and aspergillus niger liquid with certain concentrations, and then mixing to obtain composite bacterial liquid;
2) spraying compound bacteria solution on SDS nanometer zero-valent iron, stirring uniformly, and storing at 4 ℃.
Preferably, the concentration of the pseudomonas aeruginosa liquid and the concentration of the aspergillus niger liquid are both (0.5-5) multiplied by 109cfu/ml。
Preferably, the volume ratio of the pseudomonas aeruginosa liquid to the aspergillus niger liquid is 1-3: 1-3.
Preferably, the ratio of the composite bacterial liquid to the SDS nano zero-valent iron is 1L: 2-6 kg.
More preferably, the preparation method of the SDS nano zero-valent iron comprises the following steps:
at the room temperature, the reaction kettle is used for heating,under the condition of nitrogen, 0.026M NaBH in the volume ratio of 1:14And 0.012M FeSO4·7H2Mixing and continuously stirring until no bubbles are generated; after the reaction is finished, adding 0.0082M SDS solution into the mixed solution with the same volume, and stirring for at least 5 min; and after the reaction is finished, drying the obtained solid under a vacuum condition to obtain the catalyst.
As another aspect of the invention, the invention also claims the application of the modified SDS nano zero-valent iron in repairing heavy metal contaminated soil.
Further, the heavy metal is any one or a combination of any two or more of Zn, Cr and Pb.
Note that the strains of the present invention belong to conventional strains, and can be purchased from commercial sources. The scale-up culture of the strains of the present invention is a routine culture method in the art, is not an innovative point of the present invention, and is not described in detail herein.
Compared with the prior art, the beneficial effects of the invention mainly include but are not limited to the following aspects:
SDS (sodium dodecyl sulfate) serving as a modifier can be adsorbed on the surface of the nano-iron particle to modify the surface characteristics of the nano-iron particle, and the nano-iron particle is prevented from colliding and gathering through an electrostatic stabilization effect, a steric hindrance effect and an electrostatic steric hindrance effect, so that the stable dispersing capacity of the nano-iron particle is improved; and the SDS has certain foaming function, can increase the sweep efficiency of the nano-iron in the solution, thus strengthen the movement of the nano-zero-valent iron particles in the horizontal direction, and make the particles disperse comparatively. The modifier SDS is added in the preparation process, so that the agglomeration of the nano zero-valent iron particles can be effectively inhibited, and the high specific surface area and the reaction activity of the particles are maintained; besides weakening the physical interaction, the modifier can be adsorbed on the surface of the nano iron particle, so that the reaction of high-activity sites on the surface of the particle with surrounding media is prevented, and the nano iron particle is not easy to oxidize. And the particle size of the modified nano zero-valent iron particles is greatly reduced, the specific surface area is increased, and the adsorption capacity is improved.
According to the invention, strains suitable for being combined with SDS nanometer zero-valent iron are screened through various strains, and different strains are adopted for modification, so that the leaching toxicity difference is large, wherein the combination of pseudomonas aeruginosa and aspergillus niger is adopted, the synergistic performance is good, the Zn leaching effect is optimal, 81% and 67% of the Zn leaching effect are respectively reduced compared with the zero-valent iron and the SDS nanometer zero-valent iron (the Fe concentration is 0.25g/L), and the effect in an experimental group with the Fe concentration of 0.50g/L also has a similar trend; no matter in the low-dose or high-dose group, leaching of heavy metals Cr and Pb can not be detected, the detection limit is lower, and the effect is obviously better than that of other combination modes. Compared with the method for repairing the heavy metal contaminated soil by using the single nano zero-valent iron, the method can obviously reduce the adding amount of the nano zero-valent iron material and avoid the damage of the adding excessive nano zero-valent iron to the soil structure.
Drawings
FIG. 1: influence on leaching toxicity of heavy metal Zn after stabilization of different nano zero-valent iron;
FIG. 2: influence on leaching toxicity of heavy metal Cr after stabilization of different nano zero-valent iron;
FIG. 3: influence on leaching toxicity of heavy metal Pb after stabilization of different nano zero-valent iron.
Detailed Description
Those skilled in the art can modify the process parameters appropriately to achieve the desired results with reference to the disclosure herein. It is expressly intended that all such similar substitutes and modifications which would be obvious to one skilled in the art are deemed to be included in the invention. While the products and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations and modifications, or appropriate alterations and combinations, of the products and methods described herein may be made and utilized without departing from the spirit, scope, and spirit of the invention. For a further understanding of the present invention, reference will now be made in detail to the following examples.
The biological material is selected from Pseudomonas putida ATCC23483, Saccharomyces cerevisiae ATCC 9763, Acinetobacter baumannii ATCC19606, Pseudomonas aeruginosa ATCC9027 and Aspergillus niger ATCC 16404.
Example 1
TABLE 1 Main reagents List
Figure BDA0002390614400000051
Preparation of mono-and zero-valent iron
FeSO with the concentration of 0.07mol/L is added into a 500mL three-neck flask at room temperature4·7H2O solution (30% absolute ethanol + 70% ultrapure water), then in BH4 -/Fe2+At a molar ratio of 2.0, 2d · s is added to the solution-1At a rate of adding NaBH dropwise4The solution is rapidly stirred by a mechanical stirrer, and the whole process is carried out in N2Under the protection condition.
The basic principle of the reaction is as follows:
Fe2++2BH4 -+6H2O→Fe0↓+2B(OH)3+7H2↑
wait for NaBH4After all the solution is added, stirring is continued for 20min until no bubbles are generated in the solution. After the reaction is finished, performing centrifugal separation on the solution for multiple times, removing supernatant, washing the obtained black solid with ethanol for multiple times, performing vacuum drying, and placing the black solid in a container filled with N2And ground and stored in a glove box.
Preparation of Sodium Dodecyl Sulfate (SDS) nano zero-valent iron
At room temperature, under the condition of nitrogen, 0.026M NaBH in 1:1 volume ratio4And 0.012M FeSO4·7H2Mixing and continuously stirring until no bubbles are generated; after the reaction is finished, adding 0.0082M SDS into the mixed solution with the same volume, and stirring for at least 5 min; and after the reaction is finished, putting the obtained solid in a vacuum oven for drying, and storing the solid in a glove box for later use.
The specific surface areas of the zero-valent iron and the SDS nanometer zero-valent iron are respectively measured by a specific surface and pore analyzer. The results showed that the specific surface areas were 19m, respectively2G and 27m2The specific surface area of the nano iron is increased after the surface modification.
SDS as a modifier can be adsorbed on the surface of the nano-iron particle to modify the surface characteristics of the nano-iron particle, and the nano-iron particle is prevented from colliding and gathering through electrostatic stabilization effect, steric hindrance effect and electrostatic steric hindrance effect, so that the stable dispersing ability of the nano-iron particle is improved. And the SDS has certain foaming function, can increase the sweep efficiency of the nano-iron in the solution, thus strengthen the movement of the nano-zero-valent iron particles in the horizontal direction, and make the particles disperse comparatively. The modifier SDS is added in the preparation process, so that the agglomeration of the nano zero-valent iron particles can be effectively inhibited, and the high specific surface area and the reaction activity of the particles are maintained; besides weakening the physical interaction, the modifier can be adsorbed on the surface of the nano iron particle, so that the reaction of high-activity sites on the surface of the particle with surrounding media is prevented, and the nano iron particle is not easy to oxidize. And the particle size of the modified nano zero-valent iron particles is greatly reduced, the specific surface area is increased, and the adsorption capacity is improved.
Example 2
Preparation of modified SDS nano zero-valent iron
Group 1, Pseudomonas aeruginosa was cultured to a concentration of 1X 10 according to the conventional method9cfu/ml bacterial liquid;
spraying a bacterium solution on the SDS nano zero-valent iron, wherein the ratio of the bacterium solution to the SDS nano zero-valent iron is 1L: 4kg, stirring evenly, and storing at 4 ℃.
Group 2 Aspergillus niger was cultured to a concentration of 1X 10 according to the conventional method9cfu/ml bacterial liquid;
spraying a bacterium solution on the SDS nano zero-valent iron, wherein the ratio of the bacterium solution to the SDS nano zero-valent iron is 1L: 4kg, stirring evenly, and storing at 4 ℃.
Group 3, Acinetobacter baumannii was cultured to a concentration of 1X 10 according to a conventional method9cfu/ml bacterial liquid;
spraying a bacterium solution on the SDS nano zero-valent iron, wherein the ratio of the bacterium solution to the SDS nano zero-valent iron is 1L: 4kg, stirring evenly, and storing at 4 ℃.
Group 4 Saccharomyces cerevisiae was cultured to a concentration of 1X 10 according to a conventional method9cfu/ml bacterial liquid;
spraying a bacterium solution on the SDS nano zero-valent iron, wherein the ratio of the bacterium solution to the SDS nano zero-valent iron is 1L: 4kg, stirring evenly, and storing at 4 ℃.
Group 5 Pseudomonas putida was cultured to a concentration of 1X 10 according to a conventional method9cfu/ml bacterial liquid;
spraying a bacterium solution on the SDS nano zero-valent iron, wherein the ratio of the bacterium solution to the SDS nano zero-valent iron is 1L: 4kg, stirring evenly, and storing at 4 ℃.
Group 6, Pseudomonas aeruginosa and Pseudomonas putida were cultured to a concentration of 1X 10, respectively, according to a conventional method9Mixing cfu/ml bacterial liquid according to a volume ratio of 1:1 to obtain composite bacterial liquid;
spraying a compound bacterial solution to the SDS nano zero-valent iron, wherein the ratio of the compound bacterial solution to the SDS nano zero-valent iron is 1L: 4kg, stirring evenly, and storing at 4 ℃.
Group 7, Pseudomonas aeruginosa and Aspergillus niger were cultured to a concentration of 1X 10, respectively, according to conventional methods9Mixing cfu/ml bacterial liquid according to a volume ratio of 1:1 to obtain composite bacterial liquid;
spraying a compound bacterial solution to the SDS nano zero-valent iron, wherein the ratio of the compound bacterial solution to the SDS nano zero-valent iron is 1L: 4kg, stirring evenly, and storing at 4 ℃.
Group 8 Aspergillus niger and Pseudomonas putida were cultured to a concentration of 1X 10, respectively, according to a conventional method9Mixing cfu/ml bacterial liquid according to a volume ratio of 1:1 to obtain composite bacterial liquid;
spraying a compound bacterial solution to the SDS nano zero-valent iron, wherein the ratio of the compound bacterial solution to the SDS nano zero-valent iron is 1L: 4kg, stirring evenly, and storing at 4 ℃.
Example 3
And (3) researching leaching toxicity of the heavy metal after stabilization of different nano zero-valent iron.
In practical application, the stability of the material in soil has a determining effect on the repairing effect, so that only the material with good stability in the soil environment can be put into practical application; according to the research, representative actual polluted soil is selected as a research object, and the stability of the nano zero-valent iron is verified.
TABLE 2 physicochemical Properties and heavy Metal content of the soil to be tested
Figure BDA0002390614400000081
Design of experiments
100g of contaminated air-dried soil passing through a 2mm sieve is weighed in 11 beakers respectively, the zero-valent iron, the SDS zero-valent iron, the solutions of the groups 1 to 8 and the water (blank control CK group) with the same volume are added respectively until the mixture is wetted, and the mixture is horizontally shaken for 12 hours after being sealed. Equilibrating at room temperature for 14 days, drying at 40 deg.C for 12 hr, grinding, and sealing for storage. The Fe concentrations were 0.25 and 0.50g/L, respectively.
The TCLP method detects the leaching toxicity of heavy metals and expresses the leaching coefficient as follows:
Figure BDA0002390614400000082
as can be seen from Table 2, the heavy metal content in the soil exceeds the international limit value standard, and therefore the soil has ecological risks. After the stabilization treatment, the leaching contents of Zn, Cr and Pb in the blank pair photograph (CK) group were 150.6, 21.1 and 19.8mg/kg, respectively; as shown in fig. 1, after stabilization treatment, the leaching toxicity of heavy metal Zn in soil is significantly reduced, and compared with a blank control, each group is significantly reduced; compared with zero-valent iron, the leaching toxicity is greatly reduced after the SDS modification; after different bacterial strains are adopted for modification, the leaching toxicity difference is large, the groups 1,6 and 7 reduce the leaching toxicity, other groups do not change obviously, in the groups 1,6 and 7, the group 7 adopts the combination of pseudomonas aeruginosa and aspergillus niger, the effect is best, the effect is reduced by 81 percent and 67 percent (the concentration of Fe is 0.25g/L) compared with that of zero-valent iron and SDS nanometer zero-valent iron respectively, and the effect in an experimental group with the concentration of Fe of 0.50g/L also has a similar trend.
As shown in fig. 2-3, after stabilization, the leaching toxicity of heavy metals of Cr and Pb in the soil is significantly reduced, and compared with the blank control, each group is significantly reduced; compared with zero-valent iron, the leaching toxicity is greatly reduced after the SDS modification; different bacterial strains are adopted to modify the nano zero-valent iron, so that the effect difference caused by the nano zero-valent iron is large, in a single bacterial strain, the pseudomonas aeruginosa is beneficial to reducing the leaching toxicity, the aspergillus niger and the pseudomonas putida also have certain influence, but the effect is not obvious, and the other two bacterial strains have no influence on the leaching toxicity; pseudomonas aeruginosa, aspergillus niger and pseudomonas putida are combined to verify whether synergistic effect exists, as shown in fig. 2-3, the combination of pseudomonas aeruginosa and aspergillus niger is adopted in the group 7, the effect is best, leaching of heavy metals Cr and Pb cannot be detected no matter in a low-dose group or a high-dose group, the leaching is lower than the lower limit of detection, and the effect is obviously superior to other combination modes.
In the description of the specification, reference is made to the terms "one embodiment," some embodiments, "" an example, "" an implementation, "" the implementation, "
The description of "a particular example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims (7)

1. A modified SDS nanometer zero-valent iron is prepared by the following processes:
1) respectively culturing pseudomonas aeruginosa and aspergillus niger into pseudomonas aeruginosa liquid and aspergillus niger liquid with certain concentrations, and then mixing to obtain composite bacterial liquid;
2) spraying compound bacteria solution on SDS nanometer zero-valent iron, stirring uniformly, and storing at 4 ℃.
2. The modified SDS nanoscale zero-valent iron according to claim 1, wherein the concentrations of the Pseudomonas aeruginosa liquid and the Aspergillus niger liquid are both (0.5-5) x 109cfu/ml。
3. The modified SDS nanoscale zero-valent iron according to claim 1, wherein the volume ratio of the Pseudomonas aeruginosa liquid to the Aspergillus niger liquid is 1-3: 3-1.
4. The modified SDS nanoscale zero-valent iron according to claim 1, wherein the ratio of the composite bacterial liquid to the SDS nanoscale zero-valent iron is 1L: 2-6 kg.
5. The modified SDS nanoscale zero-valent iron according to claim 4, wherein the preparation method of the SDS nanoscale zero-valent iron comprises the following steps:
at room temperature, under the condition of nitrogen, 0.026M NaBH in 1:1 volume ratio4And 0.012M FeSO4·7H2Mixing and continuously stirring until no bubbles are generated; after the reaction is finished, adding 0.0082M SDS solution into the mixed solution with the same volume, and stirring for at least 5 min; and after the reaction is finished, drying the obtained solid under a vacuum condition to obtain the catalyst.
6. Use of a modified SDS nano zero valent iron according to any one of claims 1 to 5 for remediation of heavy metal contaminated soil.
7. The use according to claim 6, wherein the heavy metal is any one or a combination of any two or more of Zn, Cr and Pb.
CN202010112875.6A 2020-02-24 2020-02-24 Modified SDS nano zero-valent iron and application thereof Active CN111229817B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010112875.6A CN111229817B (en) 2020-02-24 2020-02-24 Modified SDS nano zero-valent iron and application thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010112875.6A CN111229817B (en) 2020-02-24 2020-02-24 Modified SDS nano zero-valent iron and application thereof

Publications (2)

Publication Number Publication Date
CN111229817A true CN111229817A (en) 2020-06-05
CN111229817B CN111229817B (en) 2021-02-09

Family

ID=70879995

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010112875.6A Active CN111229817B (en) 2020-02-24 2020-02-24 Modified SDS nano zero-valent iron and application thereof

Country Status (1)

Country Link
CN (1) CN111229817B (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104310726A (en) * 2014-09-30 2015-01-28 湖南大学 Method for removing heavy metal chromium in bottom mud by using modified nano zero-valent iron
CN106590685A (en) * 2015-10-19 2017-04-26 粮华生物科技（北京）有限公司 In-situ bioremediation preparation and remediation method for heavy metal contaminated soil
CN110157445A (en) * 2019-05-09 2019-08-23 海盐县凌特生物科技有限公司 A kind of microorganism renovation agent and preparation method thereof

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104310726A (en) * 2014-09-30 2015-01-28 湖南大学 Method for removing heavy metal chromium in bottom mud by using modified nano zero-valent iron
CN106590685A (en) * 2015-10-19 2017-04-26 粮华生物科技（北京）有限公司 In-situ bioremediation preparation and remediation method for heavy metal contaminated soil
CN110157445A (en) * 2019-05-09 2019-08-23 海盐县凌特生物科技有限公司 A kind of microorganism renovation agent and preparation method thereof

Also Published As

Publication number Publication date
CN111229817B (en) 2021-02-09

Similar Documents

Publication Publication Date Title
Kumar et al. A review on accessible techniques for removal of hexavalent Chromium and divalent Nickel from industrial wastewater: Recent research and future outlook
Teng et al. Enhanced passivation of lead with immobilized phosphate solubilizing bacteria beads loaded with biochar/nanoscale zero valent iron composite
Fourest et al. Heavy metal biosorption by fungal mycelial by-products: mechanisms and influence of pH
Akhtar et al. Remediation of heavy metals (Cr, Zn) using physical, chemical and biological methods: a novel approach
Bingol et al. Removal of chromate anions from aqueous stream by a cationic surfactant-modified yeast
Li et al. Stabilization of biosolids with nanoscale zero-valent iron (nZVI)
US11738380B2 (en) Method of in-situ remediation of arsenic-contaminated soil
CN111229812B (en) Modified nano zero-valent iron and application thereof in remediation of heavy metal contaminated soil
CN113368811B (en) Biological type iron-manganese composite material, preparation method and application
CN110451597A (en) A kind of nano zero valence iron@molecular sieves compound material and preparation method thereof and purposes
Tasharrofi et al. Environmentally friendly stabilized nZVI-composite for removal of heavy metals
US5443729A (en) Method for removing manganese from water
CN114405492A (en) Activated carbon-zero-valent iron composite gel particles, preparation method thereof and application thereof in removing heavy metal ions
CN113292130A (en) Preparation method and application of nano iron sulfide modified composite material based on heavy metal polluted wastewater remediation
Lodi et al. Chromium (III) removal by Spirulina platensis biomass
Dave et al. Copper remediation by Eichhornia spp. and sulphate-reducing bacteria
CN107790099B (en) Adsorbing material for phosphorus and heavy metal polluted water and preparation method thereof
CN111235059B (en) Process for preparing modified SDS nano zero-valent iron
CN111229817B (en) Modified SDS nano zero-valent iron and application thereof
Modak et al. Biosorption of copper and zinc using waste Aspergillus niger biomass
CN105330092A (en) Technology for processing transformer oil stains
CN112427019A (en) Anaerobic granular sludge loaded vulcanized nano zero-valent iron adsorbing material and preparation method and application thereof
Kang et al. Metal removal from wastewater by bacterial sorption: Kinetics and competition studies
CN115011352B (en) Iron-carbon-based restoration material for organic matter-heavy metal composite contaminated soil, and preparation method and application method thereof
CN111250052A (en) Multi-group chelating magnetic hypha water purifying agent and preparation method and application thereof

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