A nanocomposite preparation, a preparation method and application thereof

Abstract

The present application belongs to the technical field of environmental pollution remediation, and particularly relates to a nano-composite preparation, a preparation method thereof and application. The nano-composite preparation provided by the present application comprises a nano material and an extracellular polymer solution of microorganisms, wherein the nano material is graphene oxide or a multi-walled carbon nanotube; and the microorganism is Amycolatopsis amylolytica HPD-2, which is preserved by the China General Microbiological Culture Collection Center with a preservation number of CGMCC No. 2568. Compared with a single system, the nano material and the extracellular polymer system can improve the bioavailability of PAHs in soil, thereby improving the degradation of PAHs. The present application makes full use of the high surface activity of the nano material and the degradation characteristics of the extracellular polymer of the degrading bacteria, and the synergistic effect between the two significantly improves the degradation removal rate of PAHs in soil and water, thereby greatly shortening the remediation period of PAHs contaminated soil and water.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of environmental pollution remediation, and particularly relates to a nano-composite preparation and a preparation method and application thereof. BACKGROUND

[0002] Polycyclic aromatic hydrocarbons (PAHs) are a kind of persistent organic pollutants which are two or more than two benzene rings fused together in linear, angular or cluster. PAHs are mainly derived from incomplete combustion of fossil fuels and biomass, and leakage and emission in the process of oil exploitation, transportation, production and use. Due to the stable physicochemical properties, strong hydrophobicity and “three effects” of PAHs, it is difficult to be degraded after polluting soil and water, and gradually becomes a global environmental problem.

[0003] At present, the removal methods of PAHs mainly include adsorption method, chemical oxidation method and biodegradation method. For example, Chinese patent CN109748350A discloses an adsorbent for removing heavy metals and PAHs in water body and a remediation method; Chinese patent CN109650522A discloses a method for removing PAHs in water body by using iron-manganese bimetallic oxide modified biochar photo-Fenton composite material. Although the removal efficiency of adsorption method and chemical oxidation method is high, there are still problems of incomplete removal, secondary pollution caused by large amount of chemical materials, and relatively high remediation cost.

[0004] Microbial remediation has the advantages of simple operation, low cost and no secondary pollution, and some PAHs degrading microorganisms have been screened at present. For example, Chinese patent CN101348773A reports that Paracoccus aminovorans HPD-2 can degrade high molecular weight PAHs (benzo[a]pyrene, pyrene or fluoranthene), and the bacteria have a wide substrate spectrum and good degradation ability for PAHs in the environment. However, in actual remediation engineering, due to the restriction of indigenous microorganisms competition and environmental conditions, exogenous microorganisms are often difficult to play a stable role in situ soil environment and water environment, so as to fail to achieve ideal remediation effect. Moreover, microbial remediation usually has problems of low remediation efficiency and long remediation period. SUMMARY

[0005] Therefore, the present application aims to provide a nano-composite preparation and a preparation method and application thereof. The nano-composite preparation provided by the present application can effectively degrade PAHs in contaminated soil and water, and shorten the remediation period.

[0006] In order to achieve the above-mentioned purpose, the present application provides the following technical solutions.

[0007] The application provides a kind of nanocomposite preparation, including nanomaterial and microbial extracellular polymer solution, the nanomaterial is graphene oxide or multi-walled carbon nanotube;The microorganism is Amycolatopsis amnioniphila HPD-2, which is preserved by China General Microbiological Culture Collection Center, and the preservation number is CGMCC No.2568.

[0008] Preferably, the concentration of extracellular polymers in the extracellular polymer solution is 2-16 g / L.

[0009] Preferably, the ratio of the mass of nanomaterial to the volume of microbial extracellular polymer solution is 2-20 g:1 L.

[0010] The application also provides a preparation method of the nanocomposite preparation described in the above technical solution, comprising the following steps:

[0011] Amycolatopsis amnioniphila HPD-2 is inoculated in a culture medium for cultivation, and the obtained culture system is separated to obtain microbial bodies;

[0012] The microbial bodies are washed and resuspended to obtain a microbial broth;

[0013] The microbial broth is sequentially subjected to ultrasonication, centrifugation and filtration to obtain a microbial extracellular polymer solution;

[0014] The nanomaterial is dispersed in the microbial extracellular polymer solution to obtain a nanocomposite preparation.

[0015] Preferably, the OD600 value of the microbial broth is 0.6-1.2.

[0016] Preferably, the filtration is performed using a 0.22 μm filter membrane.

[0017] Preferably, the ultrasonication temperature is room temperature, the ultrasonication time is 10 min, and the ultrasonication power is 240 W.

[0018] The application also provides the application of the nanocomposite preparation described in the above technical solution or the nanocomposite preparation prepared by the preparation method described in the above technical solution in repairing polycyclic aromatic hydrocarbon contaminated water and / or polycyclic aromatic hydrocarbon contaminated soil.

[0019] Preferably, the volume of the nanocomposite preparation is 2.5% of the volume of the polycyclic aromatic hydrocarbon contaminated water.

[0020] Preferably, the mass of the nanocomposite preparation is 10% of the dry weight of the polycyclic aromatic hydrocarbon contaminated soil.

[0021] The application provides a kind of nanocomposite preparation, including nanomaterial and microbial extracellular polymer solution, the nanomaterial is graphene oxide or multi-walled carbon nanotube;The microorganism is Amycolatopsis amnioniphila HPD-2, which is preserved by China General Microbiological Culture Collection Center, and the preservation number is CGMCC No.2568.

[0022] The nanocomposite preparation provided by the application can provide a carrier for the mutual contact of extracellular polymers and PAHs, enrich PAHs and extracellular polymers, accelerate the interaction between extracellular polymers and PAHs, and accelerate the electron transfer process in the degradation process of extracellular polymers to PAHs. In addition, compared with a single system, the nanomaterial and extracellular polymer system can improve the bioavailability of PAHs in soil, thereby accelerating and improving the degradation of PAHs. The application makes full use of the high surface activity of nanomaterials and the degradation characteristics of extracellular polymers of degrading bacteria, and the synergistic effect between the two significantly accelerates and improves the degradation and removal of PAHs in soil and water, improves the degradation and removal rate of PAHs, and thus greatly shortens the repair period of PAHs contaminated soil and water.

[0023] In addition, the preparation method of the nanocomposite preparation is simple in operation, low in cost and good in effect, has the prospect of large-scale industrial production, is suitable for in-situ repair of PAHs contaminated soil and water and does not cause secondary pollution. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The figure is the removal rate of BaP in the soil after the culture of application examples 1-2 and comparative application examples 1-4 of the application;

[0025] Figure 2 The figure is the removal rate of BaP in the mixed aqueous solution of application examples 3-4 and comparative application example 5 of the application;

[0026] Figure 3 The figure is the removal rate of BaP in the mixed aqueous solution added with the nanocomposite preparation containing different concentrations of graphene oxide in application example 5 of the application;

[0027] Figure 4 The figure is the removal rate of BaP in the mixed aqueous solution added with the nanocomposite preparation containing different concentrations of extracellular polymer solution of Amycolatopsis amnioniphila in application example 6 of the application. DETAILED DESCRIPTION

[0028] The application provides a kind of nanocomposite preparation, including nanomaterial and microbial extracellular polymer solution, the nanomaterial is graphene oxide or multi-walled carbon nanotube;The microorganism is Amycolatopsis amnioniphila HPD-2, which is preserved by China General Microbiological Culture Collection Center, and the preservation number is CGMCC No.2568.

[0029] Unless otherwise specified, the source of the raw materials used in the present application is not particularly limited, and commercially available products known to those skilled in the art can be used.

[0030] The nanocomposite preparation provided by the present application comprises a nanomaterial; the nanomaterial is graphene oxide or a multi-walled carbon nanotube, preferably graphene oxide.

[0031] The nanocomposite preparation provided by the present application comprises an extracellular polymer solution of microorganisms; the microorganism is Paracoccus aminovorans HPD-2, which is preserved by the China General Microbiological Culture Collection Center with a preservation number of CGMCC No. 2568.

[0032] In the present application, the concentration of the extracellular polymer in the extracellular polymer solution of the microorganism is preferably 2-16 g / L, and more preferably 16 g / L; the ratio of the mass of the nanomaterial to the volume of the extracellular polymer solution of the microorganism is preferably 2-20 g: 1 L, and more preferably 8 g / L.

[0033] The nanomaterial in the nanocomposite preparation provided by the present application can provide a carrier for the mutual contact of the extracellular polymer and PAHs, and enrich the PAHs and the extracellular polymer at the same time, thereby accelerating the interaction between the extracellular polymer and the PAHs, and can accelerate the electron transfer process in the degradation process of the extracellular polymer to the PAHs. In addition, compared with a single system, the nanomaterial and the extracellular polymer system can further improve the bioavailability of the PAHs in the soil, thereby accelerating and improving the degradation of the PAHs. The present application makes full use of the high surface activity of the nanomaterial and the degradation characteristics of the extracellular polymer of the degrading bacteria, and the synergistic effect between the two significantly accelerates and improves the degradation and removal of the PAHs in the soil and water, improves the degradation and removal rate of the PAHs, and thus greatly shortens the repair period of the PAHs contaminated soil and water.

[0034] The present application also provides a preparation method of the nanocomposite preparation described in the above technical solution, comprising the following steps:

[0035] Paracoccus aminovorans HPD-2 is inoculated into a culture medium for culture, and the obtained culture system is separated to obtain microbial cells;

[0036] The microbial cells are washed and resuspended to obtain a microbial bacterial solution;

[0037] The microbial bacterial solution is sequentially subjected to ultrasonic treatment, centrifugation and filtration to obtain an extracellular polymer solution of microorganisms;

[0038] The nanomaterial is dispersed in the extracellular polymer solution of the microorganisms to obtain a nanocomposite preparation.

[0039] The present application inoculates the Paracoccus aminophilus HPD-2 into a culture medium for culture, and separates the obtained culture system to obtain a culture solution.

[0040] In the present application, the culture medium is preferably a liquid LB culture medium. The present application does not have special limitation on the process of inoculation and culture, and the inoculation and culture process known in the art can be adopted.

[0041] In the embodiments of the present application, the liquid LB culture medium is specifically: yeast extract 5.0 g / L, proteose peptone 10.0 g / L, NaCl 10.0 g / L, the rest is deionized water, the pH value is adjusted to 7.0, and sterilization is performed at 0.12 MPa and 121℃ for 20 min for standby.

[0042] In the present application, the inoculation rate of inoculating the Paracoccus aminophilus HPD-2 into the culture medium is preferably 1%.

[0043] In the embodiments of the present application, the culture is specifically: the Paracoccus aminophilus HPD-2 bacteria solution stored at -80℃ is taken out, 100 μL of the Paracoccus aminophilus HPD-2 bacteria solution is inoculated into 10 mL of the liquid LB culture medium for rejuvenation culture, and then the culture is continued for 16 h after being inoculated into the liquid LB culture medium at a volume ratio of 10% under the condition of 30℃ and 150 r / min.

[0044] After obtaining the culture solution, the present application separates the culture solution to obtain a microbial bacteria body.

[0045] In the present application, the separation is preferably centrifugation; the rotation speed of the centrifugation is preferably 5000-8000 rpm, and more preferably 6000-7000 rpm; and the centrifugation time is preferably 5-15 min, and more preferably 5-10 min.

[0046] After obtaining the microbial bacteria body, the present application preferably washes and resuspends the microbial bacteria body to obtain a microbial bacteria solution.

[0047] In the present application, the reagent used for the washing and resuspension is independently preferably a phosphate buffer. In the present application, the concentration of the phosphate buffer is preferably 0.2 mol / L, and the pH value is preferably 7.4.

[0048] In the present application, the number of washing is preferably 2 times.

[0049] The present application does not have special limitation on the process of resuspension, and the resuspension process known in the art can be adopted to make the microbial bacteria solution meet the requirements.

[0050] In the present application, the OD600 value of the microbial bacteria solution is preferably 0.6-1.2, and more preferably 0.8-1.0.

[0051] After obtaining the microbial solution, the microbial solution is subjected to ultrasonic treatment in the present application.

[0052] In the present application, the temperature of the ultrasonic treatment is preferably room temperature; the time of the ultrasonic treatment is preferably 10 min; and the power of the ultrasonic treatment is preferably 240 W.

[0053] After the ultrasonic treatment, the microbial solution after the ultrasonic treatment is subjected to centrifugal treatment in the present application.

[0054] In the present application, the speed of the centrifugal treatment is preferably 5000-8000 rpm, more preferably 5000 rpm; and the time of the centrifugal treatment is preferably 10-15 min, more preferably 10 min.

[0055] After the centrifugal treatment, the supernatant of the microbial solution obtained by the centrifugal treatment is subjected to filtration to obtain an extracellular polymer solution of microorganisms.

[0056] In the present application, the filtration is preferably performed using a 0.22 μm filter membrane.

[0057] After obtaining the extracellular polymer solution of microorganisms, a nanomaterial is dispersed in the extracellular polymer solution of microorganisms to obtain a nanocomposite preparation.

[0058] The dispersion process is not particularly limited in the present application, and a process well known in the art can be used.

[0059] The preparation method of the nanocomposite preparation provided by the present application is simple in operation, low in cost, and good in effect, and has the prospect of large-scale industrial production, and is suitable for in-situ remediation of PAHs contaminated soil and water bodies without secondary pollution.

[0060] The present application also provides the nanocomposite preparation of the above technical solution or the nanocomposite preparation prepared by the preparation method of the above technical solution for remediation of polycyclic aromatic hydrocarbon contaminated water bodies and polycyclic aromatic hydrocarbon contaminated soil.

[0061] In the present application, the volume of the nanocomposite preparation is preferably 2.5% of the volume of the polycyclic aromatic hydrocarbon contaminated water body.

[0062] In the present application, the mass of the nanocomposite preparation is preferably 10% of the dry weight of the polycyclic aromatic hydrocarbon contaminated soil.

[0063] In the present application, the kind of the polycyclic aromatic hydrocarbon preferably comprises one or more of phenanthrene, pyrene and benzo[a]pyrene, and more preferably benzo[a]pyrene; the content of the polycyclic aromatic hydrocarbon in the polycyclic aromatic hydrocarbon-contaminated soil is preferably 1-50 mg / kg, and more preferably 5-20 mg / kg; and the content of the polycyclic aromatic hydrocarbon in the polycyclic aromatic hydrocarbon-contaminated water body is preferably 1-50 mg / L, and more preferably 5-20 mg / L.

[0064] In the embodiment of the present application, the application mode of the nanocomposite preparation in repairing the polycyclic aromatic hydrocarbon-contaminated soil is specifically adding the nanocomposite preparation into the polycyclic aromatic hydrocarbon-contaminated soil, mixing, adjusting the water content of the soil to 60% of the field water-holding capacity, and then standing for culture; the culture temperature is preferably 30℃; and the culture time is preferably 15 d.

[0065] In the embodiment of the present application, the application mode of the nanocomposite preparation in repairing the polycyclic aromatic hydrocarbon-contaminated water body is specifically adding the nanocomposite preparation into the polycyclic aromatic hydrocarbon-contaminated water body, and then performing culture repair. In the present application, the culture mode is preferably oscillation culture, the oscillation temperature is preferably 30℃; and the oscillation time is preferably ≥12 h, and more preferably 24 h.

[0066] The technical solutions in the present application will be described clearly and completely in combination with the embodiments in the present application, but they should not be understood as limitations to the protection scope of the present application.

[0067] Example 1

[0068] LB medium was prepared, and the ingredients and amounts were as follows: yeast extract 5.0 g / L, protein peptone 10.0 g / L, NaCl 10.0 g / L, the rest was deionized water, and the pH value was adjusted to 7.0. The medium was sterilized at 0.12 MPa and 121℃ for 20 min. Paracoccus aminovorans bacteria liquid stored at -80℃ was taken out, and 100 μL of Paracoccus aminovorans HPD-2 bacteria liquid was inoculated into 10 mL of liquid LB medium for recovery culture. After being cultured at 30℃ and 150 rpm for 8 h, 10% of the volume was inoculated into liquid LB medium for further culture for 16 h. After centrifugation at 6000 rpm for 5 min, the bacteria suspension was washed twice with phosphate buffer (concentration of 0.2 mol / L, pH value of 7.4) and resuspended. The OD600 value of the bacteria suspension was adjusted to 1.0 to obtain Paracoccus aminovorans HPD-2 bacteria liquid. After ultrasonic treatment (power of 240 W) of the bacteria liquid at room temperature for 10 min, centrifugation was performed at 5000 rpm for 10 min. The supernatant was filtered with a 0.22 μm filter membrane. The filtered liquid was an extracellular polymer solution, and the concentration of the extracellular polymer in the solution was 2 g / L. Graphene oxide was uniformly dispersed in the Paracoccus aminovorans extracellular polymer solution, and the concentration was 2 g / L to obtain a nanocomposite preparation (EPS+GO).

[0069] Example 2

[0070] The difference from Example 1 is that graphene oxide is replaced by multi-walled carbon nanotubes to obtain a nanocomposite preparation (EPS+CNT), and the rest is the same as Example 1.

[0071] Example 3

[0072] LB medium was prepared, and the ingredients and amounts contained were as follows: yeast extract 5.0 g / L, proteose peptone 10.0 g / L, NaCl 10.0 g / L, and the rest was deionized water, and the pH was adjusted to 7.0, sterilized at 0.12 MPa and 121 ℃ for 20 min for standby. Paracoccus aminovorans bacteria liquid stored at -80 ℃ was taken out, 100 μL of Paracoccus aminovorans HPD-2 bacteria liquid was inoculated into 10 mL of liquid LB medium for resuscitation culture, and then cultured at 30 ℃ and 150 r / min for 8 h, and then inoculated into liquid LB medium at a volume ratio of 10% for continuous culture for 16 h. After centrifugation at 5000 rpm for 10 min, the logarithmic growth phase cells of the above-mentioned bacteria were obtained; after washing twice with phosphate buffer (concentration of 0.2 mol / L, pH value of 7.4) and resuspension, the OD600 value of the bacterial suspension was adjusted to 1.0 to obtain Paracoccus aminovorans HPD-2 bacteria liquid. After ultrasonic treatment (power of 240 W) of the above-mentioned bacteria liquid at room temperature for 10 min, centrifugation was performed at 5000 rpm for 10 min, and the supernatant was filtered with a 0.22 μm filter membrane. The filtered liquid was an extracellular polymer solution, and the concentration of the extracellular polymer in the extracellular polymer solution was 2 g / L. Graphene oxide was uniformly dispersed in the Paracoccus aminovorans extracellular polymer solution, and the concentration of the added graphene oxide was 4 g / L to obtain a nanocomposite preparation (EPS+GO).

[0073] Example 4

[0074] The difference from Example 3 is that the graphene oxide is replaced by multi-walled carbon nanotubes to obtain a nanocomposite preparation (EPS+CNT), and the rest is the same as Example 3.

[0075] Example 5

[0076] The difference from Example 3 is that the concentration of graphene oxide added is set to 0.004 g / L, 0.04 g / L, 0.4 g / L, 1 g / L, 2 g / L, 8 g / L, and 20 g / L, respectively, and the rest is the same as Example 3.

[0077] Example 6

[0078] The difference from Example 3 is that the concentration of extracellular polymer (EPS) added when preparing the nanocomposite preparation is set to 0.5 g / L, 1 g / L, 4 g / L, 8 g / L, and 16 g / L, respectively, and the rest is the same as Example 3.

[0079] Comparative Example 1

[0080] The difference from Example 1 is that only Paracoccus aminovorans extracellular polymer solution (EPS) is used without adding nanomaterials, and the rest is the same as Example 1.

[0081] Comparative Example 2

[0082] The difference from Example 1 is that only graphene oxide (GO) is added, and the rest is consistent with Example 1.

[0083] Comparative Example 3

[0084] The difference from Example 2 is that only multi-walled carbon nanotubes (CNT) are added, and the rest is consistent with Example 2.

[0085] Application Example 1

[0086] The soil collected from the Fencheng is used as the test soil, and benzo[a]pyrene (BaP) is used as a representative PAHs to prepare BaP contaminated soil, and the BaP content in the soil is 23 mg / kg. The nanocomposite preparation (EPS+GO) prepared in Example 1 is added to the soil according to the addition ratio of 10 wt.% of the dry weight of the soil, and is mixed and placed in a incubator at 30°C for 15d.

[0087] Application Example 2

[0088] The difference from Application Example 1 is that the nanocomposite preparation prepared in Example 1 is replaced by the nanocomposite preparation (EPS+CNT) prepared in Example 2, and the rest is consistent with Application Example 1.

[0089] Application Example 3

[0090] The solution with a concentration of 5 mg / L of benzo[a]pyrene (BaP) is used as the test water body, and the nanocomposite preparation (EPS+GO) prepared in Example 3 is added to the test water body according to the ratio of 2.5% (v / v), and the test water body is placed in a shaker at 30°C and 150 r / min for 24h.

[0091] Application Example 4

[0092] The difference from Application Example 3 is that the nanocomposite preparation prepared in Example 3 is replaced by the nanocomposite preparation (EPS+CNT) prepared in Example 4, and the rest is consistent with Application Example 3.

[0093] Application Example 5

[0094] The difference from Application Example 3 is that the nanocomposite preparation prepared in Example 3 is replaced by the nanocomposite preparation (EPS+GO) containing different concentrations of graphene oxide prepared in Example 5, and the rest is consistent with Application Example 3.

[0095] Application Example 6

[0096] The difference from Application Example 3 is that the nanocomposite preparation prepared in Example 3 is replaced by the nanocomposite preparation containing different concentrations of extracellular polymers (EPS+GO) prepared in Example 6, and the rest is consistent with Application Example 3.

[0097] Comparative Application Example 1

[0098] The difference from Application Example 1 is that the nanocomposite preparation prepared in Example 1 is replaced by the extracellular polymers solution of Amycolatopsis sp. (EPS) prepared in Comparative Example 1, and the rest is consistent with Application Example 1.

[0099] Comparative Application Example 2

[0100] The difference from Application Example 1 is that the nanocomposite preparation prepared in Example 1 is replaced by graphene oxide (GO) of Comparative Example 2, and the rest is consistent with Application Example 1.

[0101] Comparative Application Example 3

[0102] The difference from Application Example 1 is that the nanocomposite preparation prepared in Example 1 is replaced by multi-walled carbon nanotubes (CNT) of Comparative Example 3, and the rest is consistent with Application Example 1.

[0103] Comparative Application Example 4

[0104] The difference from Application Example 1 is that contaminated soil (CK) is used as a control, and no remediation aid is added, and the rest is consistent with Application Example 1.

[0105] Comparative Application Example 5

[0106] The extracellular polymer solution of Comparative Example 4 is added to the test water body at a ratio of 2.5% (v / v) to the solution of benzo[a]pyrene (BaP) with a concentration of 5 mg / L, and the mixed solution is placed in a shaking bed at 30°C and 150 rpm for 24 h.

[0107] Performance test

[0108] (1) The content of BaP in the soil after culture of Application Examples 1-2 and Comparative Examples 1-4 was determined, and the removal rate was calculated, and the results are shown in Table 1. Figure 1

[0109] Figure 1 ​​It can be seen that after 15 days of repair, the removal rate of BaP in the soil prepared by the nanocomposite preparation (EPS+GO) of Example 1 is 68.37%, which is increased by 59.72% compared with the control (CK) without adding any repair, obviously promoting the removal of BaP in the soil, and the removal effect of BaP in the soil is also obviously improved compared with the treatment of adding only graphene oxide (GO) or adding only microbial extracellular polymer (EPS), which is increased by 39.42% and 42.53% respectively.

[0110] By Figure 1 It can be seen that after 15 days of repair, the removal rate of BaP in the soil prepared by the nanocomposite preparation (EPS+CNT) of Example 2 is 47.58%, which is increased by 38.93% compared with the control (CK) without adding any repair, obviously promoting the removal of BaP in the soil, and the removal effect of BaP in the soil is also obviously improved compared with the treatment of adding only multi-walled carbon nanotubes (CNT) or adding only microbial extracellular polymer (EPS), which is increased by 26.2% and 18.63% respectively.

[0111] By Figure 1 It can be seen that after 15 days of repair, the removal rate of BaP in the soil of the control (CK) without adding any repair is only 8.65%.

[0112] By Figure 1 It can be seen that after 15 days of repair, the removal rate of BaP in the soil prepared by adding only microbial extracellular polymer (EPS) is 28.95%, which is obviously improved compared with the control (CK) without adding any repair agent, and is increased by 20.3%.

[0113] By Figure 1 It can be seen that after 15 days of repair, the removal rate of BaP in the soil prepared by adding only graphene oxide (GO) is 25.84%, which is obviously improved compared with the control (CK) without adding any repair agent, and is increased by 17.2%.

[0114] By Figure 1 It can be seen that after 15 days of repair, the removal rate of BaP in the soil prepared by adding only multi-walled carbon nanotubes (CNT) is 21.38%, which is obviously improved compared with the control (CK) without adding any repair agent, and is increased by 12.73%.

[0115] (2) The residual concentration of BaP in the mixed aqueous solution of Application Examples 3-4 and Comparative Application Example 5 was determined at a certain time, and the removal rate of BaP in the aqueous solution was calculated, and the results are shown in Figure 2 .

[0116] By Figure 2As can be seen, after 12 hours of cultivation, the nanocomposite formulation (EPS+GO) prepared in Example 3 achieved a BaP removal rate of 77.6% in the test water, while the treatment in Comparative Application Example 5, which only added extracellular polymeric substances (EPS), did not have a degradation effect on BaP in the aqueous solution. When the cultivation time was further extended to 24 hours, the BaP degradation removal rate of the nanocomposite formulation (EPS+GO) prepared in Example 3 slightly increased to 80.1% in the test water.

[0117] Depend on Figure 2 As can be seen, after 12 hours of cultivation, the nanocomposite formulation (EPS+CNT) prepared in Example 4 achieved a BaP degradation and removal rate of 69.5% in the test water, while the treatment in Application Example 5, which only added extracellular polymeric substances (EPS), did not have a degradation effect on BaP in the solution. When the cultivation time was further extended to 24 hours, the BaP degradation and removal rate of the nanocomposite formulation (EPS+CNT) prepared in Example 4 continued to increase, reaching 77.2%.

[0118] Depend on Figure 2 It is evident that within 24 hours of cultivation, the treatment of adding only extracellular polymeric substances (EPS) did not have a degradation effect on BaP in the solution.

[0119] (3) Samples were taken and the residual concentration of BaP in the mixed aqueous solution containing different concentrations of graphene oxide nanocomposite formulations as described in Example 5 were determined, and the removal rate of BaP in the aqueous solution was calculated. The results are as follows: Figure 3 As shown.

[0120] Depend on Figure 3 It is evident that after 24 hours of cultivation, when the graphene oxide addition amount was 0.004–1 g / L, the degradation effect of the nanocomposite formulation prepared from graphene oxide and extracellular polymer solution on BaP in water was relatively limited, only 2.8–6.9%. When the graphene oxide addition amount was 2 g / L, the degradation rate of BaP in water by the nanocomposite formulation prepared from graphene oxide and extracellular polymer solution was 38.1%. With the continuous increase of the graphene oxide addition amount, the degradation rate of BaP in water by the nanocomposite formulation significantly improved. When the graphene oxide addition amount was 4–20 g / L, the degradation rate of BaP in water by the nanocomposite formulation prepared from graphene oxide and extracellular polymer solution reached 83.9–92.0%.

[0121] (4) Samples were taken and the residual concentration of BaP in the mixed aqueous solution containing different concentrations of *Paragonimus ammoniac* extracellular polymeric solution as described in Example 6 were determined, and the removal rate of BaP in the aqueous solution was calculated. The results are as follows: Figure 4 As shown.

[0122] Depend on Figure 4It can be seen that the removal rate of BaP in water by the nanocomposite prepared from graphene oxide and EPS solution is continuously improved with the increase of the amount of EPS added. When the amount of EPS added is 0.5 g / L and 1 g / L, the removal rate of BaP in water by the nanocomposite is 76.3% and 78.1%, respectively. When the amount of EPS added is more than 2 g / L, the removal rate of BaP in water by the composite system is more than 85%. When the amount of EPS added is 16 g / L, the removal rate of BaP in water by the composite system can reach 92%.

[0123] Although the above embodiments have made a detailed description of the present application, it is only a part of the embodiments of the present application but not all the embodiments. Other embodiments can be obtained according to the above embodiments without creativity, which are all within the protection scope of the present application.

Claims

1. The application of nanocomposite formulations in the remediation of polycyclic aromatic hydrocarbon (PAH) contaminated water bodies and / or PAH contaminated soil, characterized in that, The nanocomposite formulation consists of an extracellular polymeric solution of nanomaterials and microorganisms. The nanomaterials are graphene oxide or multi-walled carbon nanotubes. The microorganisms are Paracoccus ammoniaphala HPD-2, which is deposited by the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 2568. The concentration of the extracellular polymer in the extracellular polymer solution is 2~16 g / L; The mass ratio of the graphene oxide to the volume of the extracellular polymer solution of the microorganism is 4-20 g: 1 L; the mass ratio of the multi-walled carbon nanotubes to the volume of the extracellular polymer solution of the microorganism is 2-4 g: 1 L. The volume of the nanocomposite preparation is 2.5% of the volume of the polycyclic aromatic hydrocarbon-contaminated water body; The mass of the nanocomposite preparation is 10% of the dry weight of the polycyclic aromatic hydrocarbon contaminated soil; The polycyclic aromatic hydrocarbon is benzo[a]pyrene.

2. The application according to claim 1, characterized in that, The preparation method of the nanocomposite formulation includes the following steps: HPD-2 paraammophilic cocci were inoculated into a culture medium and cultured. The resulting culture system was then isolated to obtain the microbial cells. The microbial cells were washed and resuspended to obtain a microbial culture solution; The microbial culture was subjected to sonication, centrifugation, and filtration in sequence to obtain an extracellular polymeric solution of the microorganisms. The nanomaterials were dispersed in an extracellular polymer solution of the microorganisms to obtain a nanocomposite formulation.

3. The application according to claim 2, characterized in that, The OD600 value of the microbial culture solution is 0.6~1.

2.

4. The application according to claim 2, characterized in that, The filtration is performed using a 0.22μm filter membrane.

5. The application according to claim 2, characterized in that, The ultrasound was performed at room temperature; the ultrasound duration was 10 minutes; and the ultrasound power was 240W.

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