Trehalose lipid modified charcoal as well as preparation method and application thereof

Abstract

The invention discloses trehalose lipid modified biochar and a preparation method and application thereof.The preparation method of the trehalose lipid modified biochar comprises the steps that trehalose lipid and water are mixed to be uniform, and a trehalose lipid solution is obtained; the preparation method comprises the following steps: uniformly mixing a trehalose lipid solution and biochar, standing, drying, cooling to room temperature to obtain a black solid, cleaning the black solid to be neutral, drying, and sieving for the first time to obtain the trehalose lipid modified biochar. The trehalose lipid modified biochar is added into the petroleum-contaminated soil, and the petroleum-contaminated soil is repaired by strengthening microorganisms. The addition of the trehalose lipid modified biochar can obviously improve the physicochemical properties of the petroleum-contaminated soil, provide a good growth environment for microorganisms, increase the bioavailability of petroleum hydrocarbon in the soil, reduce the stress effect of petroleum pollutants on the microorganisms, and significantly improve the biodegradation rate of petroleum hydrocarbon in the petroleum-contaminated soil.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of contaminated soil remediation, and particularly relates to trehalose lipid modified biochar as well as a preparation method and application thereof. BACKGROUND

[0002] Oil spills and emissions are common at various stages of crude oil and petroleum product exploration, processing and transportation, which causes significant damage to the colloidal structure of soil and its ecological functions. Oil is an important energy and chemical raw material, which is composed of more than 17,000 identified chemical components, including highly toxic polycyclic aromatic hydrocarbons (PAHs), aromatics, naphthenes and alkanes. In particular, polycyclic aromatic hydrocarbons, which are known for their carcinogenic properties, have been designated as priority pollutants by the United States Environmental Protection Agency. With the continuous development of industrial society, organic matter and oil pollutants in the soil accumulate year by year and have a tendency to get worse, which has a far-reaching impact on the soil ecosystem, leading to a decrease in microbial biomass and a decrease in soil microbial diversity. In addition to the impact on the soil, these complex pollutants also pose serious health risks to humans and animals. In recent years, the use of low-cost and environmentally friendly biochar remediation technology and phytoremediation technology to treat oil-contaminated soil has been widely recognized by researchers at home and abroad.

[0003] Biochar is a pyrolysis product of waste biomass, which has high carbon stability and adsorption capacity for various pollutants. It is known for its porous, large specific surface area and rich surface functional groups with adsorption activity. These characteristics make it an effective carrier for adsorbing petroleum hydrocarbon pollutants in soil. In addition, biochar can reduce the toxicological effects of petroleum hydrocarbons on soil microorganisms, providing favorable environmental conditions for the survival of microorganisms, thereby improving the microbial remediation effect of oil-contaminated soil.

[0004] However, some high molecular weight polycyclic aromatic hydrocarbons, such as benzopyrene, have low bioavailability in soil, which limits the remediation effect of biochar. Studies have shown that the addition of surfactants can help to dissolve and elute organic pollutants such as petroleum hydrocarbons in soil, and also help to improve the bioavailability of petroleum hydrocarbons in soil, thereby improving the effect of microbial remediation of oil-contaminated soil. However, conventional chemical surfactants, such as sodium alkyl benzene sulfonate (LAS) and alkyl phenol polyoxyethylene ether (APEO), have high energy consumption in the preparation process and can cause secondary pollution, which limits the production and widespread application of surfactants. How to efficiently remediate oil-contaminated soil without increasing energy consumption and causing secondary pollution is a problem that needs to be solved. SUMMARY

[0005] In view of the deficiencies of the prior art, the purpose of the present application is to provide a trehalose lipid modified biochar.

[0006] Another object of the present application is to provide a preparation method of the above-mentioned trehalose lipid modified biochar.

[0007] Another object of the present application is to provide an application of the above-mentioned trehalose lipid modified biochar in enhancing microbial remediation of petroleum contaminated soil. The trehalose lipid modified biochar is used to improve the soil microenvironment and increase the bioavailability of petroleum hydrocarbons in soil, solve the problems of low bioavailability of organic pollutants in soil and low microbial degradation rate, and achieve the purpose of enhancing microbial remediation of petroleum contaminated soil by adding the trehalose lipid modified biochar into the petroleum contaminated soil.

[0008] The object of the present application is achieved by the following technical solutions.

[0009] A preparation method of a trehalose lipid modified biochar, comprising the following steps:

[0010] Step 1, mixing trehalose lipid and water until uniform to obtain a trehalose lipid solution, wherein the mass fraction of the trehalose lipid and the volume fraction of the water are in a ratio of 10: (500-1500), the unit of the mass fraction is g, and the unit of the volume fraction is mL.

[0011] In step 1, the trehalose lipid and water are mixed and ultrasonicated at room temperature until uniform to obtain the trehalose lipid solution. The ultrasonication time is 1-4 h, preferably 2 h.

[0012] Step 2, mixing the trehalose lipid solution and biochar until uniform, standing for 6-12 h, drying, cooling to room temperature to obtain a black solid, washing the black solid to neutral, drying, and first sieving to obtain the trehalose lipid modified biochar, wherein the mass fraction of the biochar and the volume fraction of the trehalose lipid solution are in a ratio of 1: (10-15), the unit of the mass fraction is g, and the unit of the volume fraction is mL.

[0013] In step 2, the trehalose lipid solution and biochar are mixed and stirred at room temperature until uniform. The stirring speed is 180-230 rpm, preferably 180-200 rpm, and the stirring time is 24-48 h.

[0014] In step 2, the drying temperature is 60-120 ℃, and the drying time is 12-18 h.

[0015] In step 2, the drying temperature is 60-120 ℃, and the drying time is 12-18 h.

[0016] In step 2, the first sieving has a mesh size of 100-300 mesh, preferably 200 mesh.

[0017] In the technical scheme, the method for obtaining the biochar comprises: secondly screening the dry and powdered biomass raw material, pyrolyzing the biomass raw material in a limited oxygen environment at 300-700 DEG C for 2-3 hours, thirdly screening the biomass raw material, cleaning the biomass raw material to neutral, drying the biomass raw material, and obtaining the biochar.

[0018] In the method for obtaining the biochar, the biomass raw material is carbon-rich biomass, and the carbon-rich biomass is corn straw or wheat straw.

[0019] In the method for obtaining the biochar, the second screening is performed at a mesh number of 100-200, and the third screening is performed at a mesh number of 50-100.

[0020] The biochar modified by trehalose lipids obtained by the preparation method.

[0021] The application of the biochar modified by trehalose lipids in the remediation of oil-contaminated soil by microorganisms.

[0022] In the technical scheme, the microorganism is an actinobacteria, a proteobacteria, an acidobacteria, a chlorobi or a gemmatimonadetes.

[0023] In the technical scheme, the method for remediation of oil-contaminated soil by microorganisms with the biochar modified by trehalose lipids comprises the following steps:

[0024] S1, adding the biochar modified by trehalose lipids to the oil-contaminated soil;

[0025] In S1, the biochar modified by trehalose lipids accounts for 1-4 wt% of the oil-contaminated soil.

[0026] S2, maintaining the field water capacity of the oil-contaminated soil added with the biochar modified by trehalose lipids at 40-60%.

[0027] Compared with the prior art, the application has the following beneficial effects:

[0028] 1. The biochar modified by trehalose lipids is added to the oil-contaminated soil to remediate the oil-contaminated soil by microorganisms. The addition of the biochar modified by trehalose lipids can significantly improve the physicochemical properties of the oil-contaminated soil, provide a good growth environment for microorganisms and increase the bioavailability of petroleum hydrocarbons in the soil, reduce the stress effect of the petroleum pollutants on the microorganisms, thereby promoting the growth and development of the microorganisms and significantly improving the biodegradation rate of the petroleum hydrocarbons in the oil-contaminated soil.

[0029] 2. The preparation method is low in cost, wide in application range, free of secondary pollution, helpful to improving the soil structure and beautifying the environment. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1Scanning electron microscope image (SEM) of the biochar produced for Example 1 at 10.0 kx;

[0031] Figure 2 Scanning electron microscope image (SEM) of the biochar produced for Example 1 at 2.0 kx;

[0032] Figure 3 Scanning electron microscope image (SEM) of the trehalulose lipid modified biochar produced for Example 2 at 10.0 kx;

[0033] Figure 4 Scanning electron microscope image (SEM) of the trehalulose lipid modified biochar produced for Example 2 at 2.0 kx;

[0034] Figure 5 Scanning electron microscope image (SEM) of the sophorolipid modified biochar produced for Comparative Example 1 at 10.0 kx;

[0035] Figure 6 Scanning electron microscope image (SEM) of the sophorolipid modified biochar produced for Comparative Example 1 at 2.0 kx;

[0036] Figure 7 Fourier transform infrared scan (FTIR) of the biochar produced for Example 1, the trehalulose lipid modified biochar produced for Example 2 and the sophorolipid modified biochar produced for Comparative Example 1;

[0037] Figure 8 Pore size distribution of the biochar produced for Example 1, the trehalulose lipid modified biochar produced for Example 2 and the sophorolipid modified biochar produced for Comparative Example 1;

[0038] Figure 9 Trend graph of total petroleum hydrocarbon content in soil degraded for different days for Examples 3~7, Comparative Example 2 and the control group;

[0039] Figure 10 Trend graph of total petroleum hydrocarbon degradation rate in soil degraded for different days for Examples 3~7, Comparative Example 2 and the control group;

[0040] Figure 11 Abundance graph of microbial community at the level of door in soil degraded for different days for Examples 3~7;

[0041] Figure 12 Abundance graph of microbial community at the level of door in soil degraded for different days for Comparative Example 2 and the control group. DETAILED DESCRIPTION

[0042] The technical solutions of the present application will be further illustrated below in combination with specific embodiments. The technical solutions of the present application will be further illustrated below in combination with specific embodiments.

[0043] The following examples and the manufacturers and purities of the drugs involved in the tests are as follows:

[0044] The following examples and the information of the instruments used in the tests are as follows:

[0045] In the following examples, the biomass raw material is corn stalk (agricultural waste), which is taken from Lianyungang City, Jiangsu Province.

[0046] In the following examples, the calculation formula of the total petroleum hydrocarbon degradation rate is as follows:

[0047] ,

[0048] X = 10, 30 and 60.

[0049] In the following examples, the water is deionized water.

[0050] Example 1

[0051] A method for preparing a biochar, comprising: washing a biomass raw material with deionized water to remove surface dust, drying in an oven at 60 ℃ for 12 h, crushing the dried biomass raw material into a powder and sieving through a 200 mesh sieve (second sieving), placing in a ceramic crucible (full), removing air with N2, immediately covering the lid of the ceramic crucible and sealing with tin foil, placing in a ceramic fiber muffle furnace at 500 ℃ for limited oxygen pyrolysis for 3 h, sieving through a 50 mesh sieve (third sieving), washing with deionized water until the pH is 7.0, drying in an oven at 80 ℃ for 12 h, to obtain a biochar (500BC).

[0052] Example 2

[0053] A method for preparing a trehalose lipid modified biochar, comprising the following steps:

[0054] Step 1, mix 10 g of trehalose lipid with 1 L of water, ultrasonic at room temperature at a frequency of 40 kHz for 2 h to be uniform, to obtain a trehalose lipid solution;

[0055] Step 2, the biochar prepared in Example 1 and the trehalose lipid solution were mixed in a beaker, stirred at room temperature with a magnetic stirrer at a speed of 180 rpm for 24 h until uniform, and then left to stand at room temperature for 9 h. The solid-liquid separation (filtration) was performed by a vacuum filtration device, and then dried in a constant temperature drying box at 80 ℃ for 12 h. After cooling to room temperature, the black solid was obtained. The black solid was washed with deionized water until the pH was 7.0, and then dried at 80 ℃ for 12 h until the weight was constant. The 200 mesh first screening was performed to obtain the trehalose lipid modified biochar (500BC-Tre), wherein the mass fraction of the biochar and the volume fraction of the trehalose lipid solution were 1:10, the unit of the mass fraction was g, and the unit of the volume fraction was mL.

[0056] Comparative Example 1

[0057] A preparation method of a sophorolipid modified biochar, comprising the following steps:

[0058] Step 1, obtaining biochar, the step of obtaining biochar was the same as the step of preparing biochar in Example 1;

[0059] Step 2, the biochar and the sophorolipid solution were mixed in a beaker, stirred at room temperature with a magnetic stirrer at a speed of 180 rpm for 24 h until uniform, and then left to stand at room temperature for 8 h. The solid-liquid separation (filtration) was performed by a vacuum filtration device, and then dried in a constant temperature drying box at 80 ℃ for 12 h. After cooling to room temperature, the sophorolipid modified biochar (500BC-SLs) was obtained by washing with deionized water until the pH was 7.0, drying at 80 ℃ for 12 h until the weight was constant, and screening at 200 mesh. In the sophorolipid modified biochar (500BC-SLs), the mass fraction of the biochar and the volume fraction of the sophorolipid solution were 1:10, the unit of the mass fraction was g, and the unit of the volume fraction was mL. The sophorolipid solution was a mixture of deionized water and sophorolipid, which was obtained by mixing 10 g of sophorolipid and 1 L of deionized water, and then uniformly dispersing by ultrasonic at a frequency of 40 kHz for 2 h at room temperature.

[0060] The total specific surface area, total pore volume and pore size of the biochar (500BC) prepared in Example 1, the trehalose lipid modified biochar (500BC-Tre) prepared in Example 2, and the sophorolipid modified biochar prepared in Comparative Example 1 were shown in Table 1.

[0061] Table 1

[0062] As shown in Table 1, the total specific surface area of the biochar (500BC) and the trehalose lipid modified biochar (500BC-Tre) was 101.470 m 2 / g and 13.460 m 2 / g. The total specific surface area of ​​trehalose-modified biochar was reduced by 86% compared to that of regular biochar, while the pore size of trehalose-modified biochar was increased. This phenomenon is due to the binding of trehalose with biochar, which fills some of the micropores in the biochar, leaving larger pores, thus increasing the pore size of 500BC-Tre.

[0063] SEM analysis was performed on the biochar (500BC) prepared in Example 1, the trehalose-modified biochar (500BC-Tre) prepared in Example 2, and the sophorose-modified biochar (500BC-SLs) prepared in Comparative Example 1. The results are as follows: Figures 1-6 As shown, Figure 1 and Figure 2 SEM image of the biochar (500 BC) prepared in Example 1. Figure 3 and Figure 4 SEM image of the trehalose-modified biochar (500BC-Tre) prepared in Example 2. Figure 5 and Figure 6 SEM image of the sophorolipid-modified biochar (500 BC-SLs) prepared in Comparative Example 1. Figures 1-6 It can be seen that the surface of 500BC exhibits a honeycomb-like porous structure. After trehalose lipid modification, the surface of 500BC-Tre changed significantly, with a large number of irregular spherical structures appearing, scattered between the surface and pores, forming a rough granular structure. 500BC-SLs also showed a similar structure to 500BC-Tre, with the pores of 500BC-SLs filled with a large number of irregular spherical structures, resulting in increased surface roughness.

[0064] Fourier transform infrared (FTIR) spectroscopy was performed on the biochar prepared in Example 1 (500BC), the trehalose-modified biochar prepared in Example 2 (500BC-Tre), and the sophorose-modified biochar prepared in Comparative Example 1 (500BC-SLs). The test results are as follows: Figure 7 As shown. By Figure 7 It can be seen that after modification with sophorolipids, the peak intensities of -OH, COC, and Si-O-Si in 500BC-SLs were increased, indicating that the functional groups of sophorolipids combined with biochar after modification, and the sophorolipid molecules were loaded onto 500BC. Furthermore, after modification with trehalose, the peak intensities of -OH, C=O, COC, and Si-O-Si in 500BC-Tre were all enhanced compared to 500BC and 500BC-SLs. 500BC-Tre showed an increased peak intensity at 1080 cm⁻¹. -1There is a strong peak of C-O-C containing oxygen functional groups. This is due to the presence of a large number of C-O-C groups in trehalose lipids, and the stretching vibration peak of C-O-C in 500BC overlaps with that of trehalose lipids. The trehalose lipids are complexed on the surface of 500BC through intermolecular hydrogen bonds and van der Waals forces, increasing the oxygen-containing functional groups on the surface of 500BC. These conclusions show that trehalose lipids have been successfully loaded onto the biochar.

[0065] The pore size of the biochar (500BC) prepared in Example 1, the trehalose lipid modified biochar (500BC-Tre) prepared in Example 2, and the sophorose lipid modified biochar (500BC-SLs) prepared in Comparative Example 1 was tested, and the pore size distribution diagram is shown in Figure 8 As shown in Figure 8 The pore size of the trehalose lipid modified biochar increased to varying degrees compared to the pore size of the biochar.

[0066] Example 3, Examples 5-7, and Comparative Example 2

[0067] The total petroleum hydrocarbon content in the soil was determined:

[0068] Experimental group: Collect clean soil around Tianjin Dagang oilfield, collect 8.0 cm deep into the soil surface. The collected soil is air-dried at room temperature, and sieved through a 2 mm sieve to obtain clean soil. Mix the clean soil with petroleum to make the total petroleum hydrocarbon concentration in the soil reach 40 g / kg, then pour water 350 ml at a time at room temperature, and stand to balance for two weeks (the water in the soil will evaporate and lose to the air, and after two weeks of balance, the water in the soil and the water in the air reach balance). The petroleum contaminated soil is obtained. The degradation material is applied to repair the petroleum contaminated soil, and the specific method includes the following steps:

[0069] S1, add the degradation material to the petroleum contaminated soil and mix well, the mass of the degradation material is Xwt% of the petroleum contaminated soil (X value see Table 2), and the degradation material is one of 500BC (biochar prepared in Example 1), 500BC-Tre (trehalose lipid modified biochar prepared in Example 2), and the sophorose lipid modified biochar prepared in Comparative Example 1;

[0070] S2, according to the requirement of 250g per bottle, the petroleum contaminated soil added with the degradation material is placed in a glass culture bottle with a permeable cover (volume is 360mL), and water is poured to keep the petroleum contaminated soil added with the degradation material at 50% of the field water capacity (water is poured once a day), and the weighing method is used to maintain the water content.

[0071] Control group: basically the same as the "experimental group", the difference is only that no degradation material is added.

[0072] The soil was collected at day 0, 10, 30 and 60 respectively to determine the total petroleum hydrocarbon content in the soil: 5.0 g of soil was weighed (the way to obtain 5.0 g of soil was to sample at three soil depths (0-5 cm, 5-10 cm and 10-15 cm) and mix evenly), the soil was wrapped with filter paper and fixed with staples. The wrapped soil sample was placed in a glass soxhlet extraction tube, 75 mL of n-hexane and 75 mL of dichloromethane were added for extraction, the glass soxhlet extraction tube was connected and assembled with a round bottom flask, and extracted in a fat extractor at 60 °C for 12 h. After the extraction was completed, the extract was cooled, and the n-hexane and dichloromethane were concentrated to dryness at 38 °C with a rotary evaporator, and then rediluted to 1 mL with n-hexane for determination of total petroleum hydrocarbon content. The total petroleum hydrocarbon content was determined according to the Petroleum Hydrocarbons (C 10 -C 40 ) determination standard, and was determined by gas chromatography (GC), specifically using an Agilent 7890 gas chromatograph (Agilent, CA, USA). The operating parameters were as follows: the carrier gas was high-purity nitrogen, the flow rate of high-purity nitrogen was 1.1 mL / min; the air flow rate was 300 ml / min; the hydrogen flow rate was 40 ml / min; the tail gas flow rate was 30 ml / min; the chromatographic column was HP-5 (30 m x 0.32 mm, 0.25 μm); no split mode; the injection volume was 1 μl; the injection port temperature was 300 °C, and the detector temperature was 325 °C. The temperature program was as follows: the initial temperature was 45 °C, maintained for 3 min, then increased to 210 °C at a rate of 15 °C / min, maintained for 0 min, and finally increased to 300 °C at a rate of 30 °C / min, maintained for 8 min.

[0073] The degradation material used in Example 3, Examples 5-7 and Comparative Example 2 and the value of X are shown in Table 2.

[0074] Table 2

[0075] Example 4

[0076] Basically the same as Example 3, the only difference is that the degradation material is a mixture of the biochar (500BC) prepared in Example 1 and the trehalose lipid solution, the mass fraction of the biochar and the volume fraction of the trehalose lipid solution are in a ratio of 1:10, the unit of mass fraction is g, and the unit of volume fraction is ml. The degradation material is added in the order of adding the biochar (500BC) first and then adding the trehalose lipid solution. In Example 4, the mass of the degradation material is 2 wt% of the petroleum contaminated soil.

[0077] In Examples 3-7, Comparative Example 2 and the control group, the total petroleum hydrocarbon content in the soil was determined on days 0, 10, 30 and 60, as shown in Table 3.

[0078] Table 3

[0079] The total petroleum hydrocarbon degradation rates in Examples 3-7, Comparative Example 2 and the control group are shown in Table 4.

[0080] Table 4

[0081] Compared with the control group, the addition of biochar, sophorolipid-modified biochar and trehalose lipid-modified biochar had a significant remediation effect on the petroleum-contaminated soil, and the amount of added degradation material had a significant effect on the change in total petroleum hydrocarbon content. As shown in Tables 3, 4, Figure 9 and Figure 10 the total petroleum hydrocarbon content and total petroleum hydrocarbon degradation rate changed more significantly in Examples 5-7 and Comparative Example 2 on day 60. On day 60, the total petroleum hydrocarbon degradation rates of Examples 5, 6 and 7 were 52.2%, 57.1% and 48.3% respectively (i.e. the total petroleum hydrocarbon concentrations in Examples 5, 6 and 7 were reduced by 52.2%, 57.1% and 48.3% respectively).

[0082] The total petroleum hydrocarbon degradation rate of Example 7 (trehalose lipid-modified biochar addition amount of 4 wt%) was lower than that of Example 6 (trehalose lipid-modified biochar addition amount of 2 wt%), and increasing the addition amount of trehalose lipid-modified biochar did not further improve the total petroleum hydrocarbon degradation rate. This may be because trehalose lipid increases the solubility of petroleum hydrocarbons, the petroleum content in the soil increases and the stress on the microorganisms in the soil increases, inhibiting the growth of petroleum-degrading bacteria.

[0083] At day 60, the concentrations of total petroleum hydrocarbons in Examples 3 and 4 were reduced by 31.1% and 38.9%, respectively, both of which were lower than that in Example 6. The degradation material used in Example 6 was 500BC-Tre, which has more oxygen-containing functional groups on the surface. These oxygen-containing functional groups act as electron acceptors during soil remediation, regulating the process of electron transfer of microorganisms, thereby promoting the degradation of petroleum hydrocarbons by microorganisms. Compared with Example 3, Example 6 not only added biochar to improve the permeability of the soil and provide a carbon source for microorganisms, thereby promoting the growth rate and degradation capacity of microorganisms, but also introduced trehalose lipids to enhance the degradation of petroleum hydrocarbons by microorganisms (mainly by its solubilization and emulsification of petroleum hydrocarbons to improve the availability of petroleum hydrocarbons to microorganisms). The degradation material in Example 4 was a mixture of biochar (500BC) and a trehalose lipid solution, which were only physically mixed and added to the petroleum-contaminated soil, which easily led to the degradation or adsorption inactivation of trehalose lipids. Compared with Example 4, the degradation material (500BC-Tre) used in Example 6 was trehalose lipid-modified biochar, which made the trehalose lipids more stable and could maintain the solubilization effect for a long time, adapting to the long-term needs of petroleum hydrocarbon degradation. Therefore, 500BC-Tre had better remediation performance.

[0084] At day 60, the concentration of total petroleum hydrocarbons in Comparative Example 2 was reduced by 52.9%, which was higher than that in Examples 4 and 3 and lower than that in Example 6. This indicates that the trehalose lipid-modified biochar showed better performance in enhancing the microbial degradation of petroleum hydrocarbons under the condition of adding the same mass fraction of degradation material. This is because the critical micelle concentration (CMC) of trehalose lipids is usually 0.1-10 mg / L, which is lower than that of sophorolipids (the CMC of sophorolipids is usually 20-40 mg / L), so trehalose lipids can form micelles at a lower concentration of petroleum hydrocarbons and disperse petroleum hydrocarbons more efficiently. In addition, the polar groups (such as hydroxyl, carboxyl) of trehalose lipids bind more tightly with the oxygen-containing functional groups (-COOH, -OH) on the surface of biochar through hydrogen bonding or electrostatic interaction, and are less likely to desorb in the soil.

[0085] The soil samples after degradation of Examples 3-7, Comparative Example 2, and the control group at day 0, day 10, day 30, and day 60, respectively, were subjected to species and functional composition analysis to obtain the community abundance of different dominant microorganisms. Referring to the paper “Research on the Synthesis Mechanism of Coccoid Pigment in Activated Sludge and Its Carbon Source Regulation” by Zou Kui et al., the genomic DNA in the soil samples was extracted and the abundance was calculated to obtain the trend graphs shown in FIGS. 1-4. Figure 11 and Figure 12 The sequence data generated by high-throughput sequencing has been submitted to the NCBI database with the accession number PRJNA1166985.

[0086] The phyla of Actinobacteria and Proteobacteria are well known for their high petroleum-degrading ability in microbial communities, according to Figure 11 The community abundance of the phyla of Actinobacteria and Proteobacteria was analyzed. In Figure 11 the examples, “Example 3 (0)” represents the microbial community corresponding to Example 3 on the 0th day of degradation, “Example 3 (10)” represents the microbial community corresponding to Example 3 on the 10th day of degradation, “Example 3 (30)” represents the microbial community corresponding to Example 3 on the 30th day of degradation, “Example 3 (60)” represents the microbial community corresponding to Example 3 on the 60th day of degradation. As shown in Figure 11 and Figure 12 shown, on the 60th day, the sum of the community abundance of the phyla of Actinobacteria and Proteobacteria corresponding to Example 3, Example 4, Example 5, Example 6, Example 7 and Comparative Example 2 was 59.3%, 60.4%, 62.7%, 63.9%, 62.1% and 63.1%, respectively. The sum of the community abundance of the phyla of Actinobacteria and Proteobacteria corresponding to the control group was only 57.3%, indicating that the addition of biochar improved the community abundance of the dominant microorganisms for degrading petroleum hydrocarbons in the soil. The sum of the community abundance of the phyla of Actinobacteria and Proteobacteria corresponding to Example 6 was the largest on the 60th day, indicating that the addition of 2 wt% trehalose lipid-modified biochar was superior to other degradation materials in promoting the metabolic activity of petroleum-degrading bacteria.

[0087] During the entire soil experiment, the community abundance of the phylum of Proteobacteria increased significantly with the increase of degradation time, and eventually exceeded the phylum of Actinobacteria to become the main petroleum-degrading microorganism. After 60 days of experiment, the community abundance of the phylum of Proteobacteria corresponding to Example 6, Example 3, Example 4, Example 5 and Example 7 was 38.5%, 34.2%, 35.6%, 36.1% and 35.2%, respectively. The community abundance of the phylum of Proteobacteria corresponding to the control group was 35.8%, and the community abundance of the phylum of Proteobacteria corresponding to Comparative Example 2 was 36.2%. The community abundance of the phylum of Proteobacteria corresponding to Example 6 was the highest. In addition, compared with the 10th day, the community abundance of the phylum of Proteobacteria corresponding to Example 6 increased by 26.3% on the 30th day, the community abundance of the phylum of Proteobacteria corresponding to Example 3 increased by 20.1%, the community abundance of the phylum of Proteobacteria corresponding to Example 4 increased by 22.7%, the community abundance of the phylum of Proteobacteria corresponding to Example 5 increased by 24.3%, the community abundance of the phylum of Proteobacteria corresponding to Example 7 increased by 23.4%, the community abundance of the phylum of Proteobacteria corresponding to the control group increased by 19.8%, and the community abundance of the phylum of Proteobacteria corresponding to Comparative Example 2 increased by 25.3%. The community abundance of the phylum of Proteobacteria corresponding to Example 6 increased the most. As a degradation material, trehalose lipid-modified biochar effectively promoted the enrichment of the phylum of Proteobacteria when its mass was 2 wt% of the petroleum-contaminated soil.

[0088] Notably, Gemmatimonadetes is also the dominant phylum of petroleum hydrocarbon degrading bacteria, combined with Figure 11 and Figure 12 were analyzed. On the 60th day, the community abundance of Gemmatimonadetes corresponding to Example 6 was 6.8%, and that of Comparative Example 2 was 5.4%. This is because sophorolipids may have growth inhibition on Gemmatimonadetes, while trehalose lipids have better biocompatibility and less negative impact on microbial communities.

[0089] In addition, the sugar moiety of trehalose lipids is more easily metabolized by Pseudomonas in Proteobacteria as a secondary carbon source, thereby promoting its growth, while the sophorose structure of sophorolipids may require a specific enzymatic pathway, with lower utilization.

[0090] In summary, the community abundance of petroleum hydrocarbon degrading microorganisms corresponding to Example 6 is greater than that of Comparative Example 2, and trehalose lipid modified biochar shows more excellent effect of enhancing microbial remediation of petroleum contaminated soil than sophorolipid modification.

[0091] The application of trehalose lipid modified biochar to remediate petroleum contaminated soil is not only a promising carbon reduction strategy, but also a sustainable method of controlling agricultural waste resources. It helps to improve the problems of soil degradation and productivity decline caused by petroleum pollution, and to increase the community abundance of petroleum hydrocarbon degrading dominant bacteria in soil.

[0092] The above has exemplarily described the present application, it should be explained that, without departing from the core of the present application, any simple modification, modification or other equivalent replacement which can not cost creative labor of those skilled in the art falls into the protection scope of the present application.

Claims

1. A method for preparing trehalose-modified biochar, characterized in that, Includes the following steps: Step 1: Mix trehalose lipids and water until homogeneous to obtain a trehalose lipid solution, wherein the mass fraction of trehalose lipids to the volume fraction of water is 10:(500~1500), the mass fraction is in g and the volume fraction is in mL; Step 2: Mix the trehalose lipid solution and biochar until homogeneous, let stand, dry, and cool to room temperature to obtain a black solid. Wash the black solid until neutral, dry it, and sieve it for the first time to obtain trehalose lipid modified biochar. The ratio of the mass fraction of the biochar to the volume fraction of the trehalose lipid solution is 1:(10-15), where the mass fraction is in g and the volume fraction is in mL.

2. The preparation method according to claim 1, characterized in that, In step 1, trehalose lipids are mixed with water and sonicated at room temperature until homogeneous to obtain a trehalose lipid solution.

3. The preparation method according to claim 1, characterized in that, In step 2, the trehalose lipid solution and biochar are mixed and stirred at room temperature until homogeneous.

4. The preparation method according to claim 1, characterized in that, The method for obtaining the biochar includes: sieving the dried, powdered biomass raw material a second time, then pyrolyzing it at 300-700 °C under limited oxygen for 2-3 h, sieving it a third time, washing it until neutral, and drying it to obtain biochar.

5. The preparation method according to claim 4, characterized in that, The biomass raw material is corn stalks or wheat stalks.

6. Trehalose-modified biochar obtained by any one of the preparation methods of claims 1 to 5.

7. The application of the phycolipid-modified biochar as described in claim 6 in enhancing microbial remediation of petroleum-contaminated soil.

8. The application according to claim 7, characterized in that, The microorganisms belong to the phyla Actinobacteria, Proteobacteria, Acidobacteria, Chlorella, and Bacillus.

9. The application according to claim 7, characterized in that, Methods for enhancing microbial remediation of petroleum-contaminated soils with trehalose-modified biochar include: adding trehalose-modified biochar to petroleum-contaminated soils while maintaining 40-60% field capacity.

10. The application according to claim 9, characterized in that, The phycolipid-modified biochar is 1-4 wt% of petroleum-contaminated soil by weight.

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