Preparation method and application of an oil spill remediation agent for treating marine oil spills

Abstract

The application discloses a preparation method and application of an oil spill remediation agent for treating marine oil spills, and the preparation method comprises the following steps: (1) mixing pine sawdust powder and an iron salt solution under oxygen limitation, pyrolyzing at 500-600 DEG C, and drying to obtain magnetic pine sawdust biochar; the mass-volume ratio (g:mL) of the pine sawdust powder and the iron salt solution is 1:10-20; the iron salt is composed of FeCl3 and FeSO4, and the molar ratio of FeCl3 to FeSO4 is 1:1-3; (2) mixing the magnetic pine sawdust biochar obtained in step (1), myristic acid and 10% (v / v) methanol aqueous solution, stirring, washing and drying to obtain the oil spill remediation agent; the oil spill remediation agent has higher adsorption capacity and suspension reuse performance, is beneficial to the removal of marine oil, reduces the treatment and recovery difficulty of traditional adsorption materials, and finally achieves the purpose of energy saving and environmental protection.

Description

Technical Field

[0001] This invention relates to the field of marine environmental protection technology, and in particular to a method for preparing and applying an oil spill remediation agent for treating marine oil spills. Background Technology

[0002] Numerous studies have been conducted on the treatment of marine oil spills. For example, invention patent CN 116535614 A relates to a polyurethane foam based on HDI trimer curing agent, its preparation method, and its application. This material exhibits excellent hydrophobicity, making it promising for oil-water separation and a highly likely candidate for future marine oil spill treatment. Invention patent CN112058290 A relates to the application of photocatalytically modified materials in the removal of marine oil spills. Its photocatalytically modified material is a g-C3N4 / bentonite composite material, which possesses excellent adsorption properties and photocatalytic degradation effects, showing promising application prospects in marine oil spill cleanup. Invention patent CN 116574310 A relates to biomass-based nanofiber aerogels, which exhibit excellent oil absorption and compressive elastic properties.

[0003] Once oil spills into the ocean, it forms an oil film on the surface, and its diffusion is influenced by various factors. Adsorption is a highly efficient, selective, simple, environmentally friendly, regenerable, and adaptable method for oil spill treatment that reduces secondary pollution. After a marine oil spill, large quantities of oil spill remediation agents need to be added for adsorption, requiring inexpensive and widely available raw materials and a simple manufacturing process. After absorbing oil, the remediation agent should be able to remain suspended in the aquatic environment for a considerable period and be promptly separated and recovered, exhibiting reusability and achieving energy conservation and environmental protection. This is the key challenge in preparing oil spill remediation agents. None of the aforementioned patents mention recyclability. Summary of the Invention

[0004] The technical problem this invention aims to solve is to address the shortcomings of existing technologies. This invention provides a method for preparing and applying an oil spill remediation agent for treating marine oil spills. The oil spill remediation agent prepared by this method uses widely available and inexpensive raw materials, and possesses characteristics such as large specific surface area, high porosity, few oxygen-containing functional groups on the surface, strong oleophilic and hydrophobic properties, good magnetic properties, and good buoyancy after oil absorption. It exhibits good removal effects in simulated oil absorption. The remediation agent demonstrates good buoyancy, magnetic recovery effect, and reuse performance after oil absorption.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution.

[0006] A method for preparing an oil spill remediation agent for treating marine oil spills includes the following steps:

[0007] (1) Under limited oxygen conditions, pine sawdust powder, iron salt and water are mixed and pyrolyzed at 500-600℃, and dried to obtain magnetic pine sawdust biochar; the mass-volume ratio (g:mL) of the pine sawdust powder to the iron salt solution is 1:10~20; the iron salt is composed of FeCl3 and FeSO4, and the molar ratio of FeCl3 to FeSO4 is 1:1-3;

[0008] (2) The magnetic pine wood chips biochar, myristic acid and 10% (v / v) methanol aqueous solution obtained in step (1) are mixed, stirred, washed and dried to obtain an oil spill repair agent; the mass-volume ratio (g:g:mL) of the magnetic biochar, myristic acid and 10% (v / v) methanol aqueous solution is 2:0.5~3.0:100.

[0009] In the preparation method of the oil spill repair agent, in step (1), the pyrolysis time is 2-3h and the heating rate is 15℃ / min.

[0010] The preparation method of the oil spill repair agent, in step (1), the specific preparation process of the pine wood chip powder is as follows: after crushing the pine wood, it is sieved to maintain a uniform particle size, and then washed and dried to obtain pine wood chip powder; the washing is carried out with deionized water, and the drying temperature is 60℃.

[0011] In the preparation method of the oil spill repair agent, in step (1), the iron salt is FeCl3 and FeSO4. 1.8g of FeCl3 and 3.66g of FeSO4 are dissolved in 195mL of water. The reaction is carried out under stirring conditions and the pH value of the solution is monitored. The pH value is adjusted by 1mol / L NaOH solution. The time for monitoring the pH value of the solution to be 10.0±0.2 is 1h.

[0012] In the preparation method of the oil spill repair agent, in step (1), the concentration of the iron salt solution is 0.1 mol / L.

[0013] In the preparation method of the oil spill repair agent, in step (1), after stirring, the agent is wrapped in plastic wrap and stored, then washed. The storage time is 24 hours, the number of washings is 5 to 8, the drying temperature is 60°C, and the drying time is 24 hours.

[0014] In the preparation method of the oil spill repair agent, in step (2), the stirring is carried out at a constant temperature of 60-80℃ for 5-7 hours.

[0015] In the preparation method of the oil spill repair agent, in step (2), the washing is performed three times with hexane, and the drying temperature is 60°C.

[0016] An oil spill repair agent prepared by any of the methods described above.

[0017] The application of the aforementioned oil spill remediation agent in the treatment of marine oil spills includes the following steps: mixing the oil spill remediation agent, seawater, and light crude oil to achieve adsorption equilibrium; after adsorption, the oil spill remediation agent is suspended in the upper layer and separated and recovered using a magnet; the separated oil spill remediation agent can be desorbed by adding hydrochloric acid and then adsorbed again, and the oil spill remediation agent can be recycled to achieve the removal of oil from the ocean.

[0018] In the aforementioned application, the mass ratio of light crude oil to oil spill remediation agent is 4:1, the salinity of the seawater is 20%~40%, the mixing time is 2 hours, the shaking speed is 120~200 r / min, and the reaction temperature is 0~25℃.

[0019] (1) This invention provides a method for treating marine oil spills, using an oil spill remediation agent to adsorb petroleum from seawater. The oil spill remediation agent uses inexpensive pine sawdust as a biomass raw material. During high-temperature pyrolysis, the organic matter such as cellulose, hemicellulose, and lignin in the pine sawdust volatilizes and decomposes, and the branched carbon structure also breaks down, forming many micropores. The raw material, iron salt, and water are mixed, and after being magnetized by impregnation, they are pyrolyzed to form magnetic biochar. The magnetic biochar, myristic acid, and methanol aqueous solution are then mixed, stirred, washed, and dried to obtain the oil spill remediation agent. Loading metallic iron ions onto the biochar serves two purposes: firstly, the surface of the magnetic biochar is modified, typically having a larger specific surface area and more active sites, thus improving the adsorption capacity of the oil spill remediation agent; secondly, due to its magnetism, it can be quickly and easily separated from the aquatic environment by an external magnetic field, reducing the complexity of subsequent treatment. Acid modification of magnetic biochar is necessary because previous studies typically used strong acids such as hydrochloric acid or sulfuric acid, which presents problems such as high cost and safety hazards in the preparation process. Therefore, this invention uses myristic acid for modification. Firstly, as the acid concentration increases, the oxidizing power is enhanced, and the internal pore structure of the magnetic biochar is corroded, creating more adsorption sites. Secondly, myristic acid is a fatty acid with a long-chain hydrocarbon structure. Its introduction may form hydrophobic functional groups on the surface of the magnetic biochar, promoting the formation of a non-polar layer and enhancing hydrophobicity, enabling it to float for extended periods without sinking. The hydrophobic tail hydrocarbon chain also provides more contact area and sites for oil adsorption. The oil spill remediation agent of this invention has characteristics such as large specific surface area, high porosity, fewer oxygen-containing functional groups on the surface, strong oleophilic and hydrophobic properties, good magnetism, and good buoyancy after oil absorption, thus effectively treating marine oil spills. Through magnetization and the introduction of myristic acid, it exhibits better adsorption performance when treating oil spills. The raw material for oil spill remediation agents, biochar, is made from organic waste. After modification with myristic acid, it retains its renewability and environmental friendliness, making it suitable for sustainable development and green technologies.

[0020] (2) This invention also provides the application of oil spill remediation agents in the treatment of marine oil spills. The oil spill remediation agent, artificial seawater, and light crude oil are mixed and placed on a shaker for adsorption reaction. After adsorption equilibrium is reached, the oil spill remediation agent is suspended in the upper layer and separated and recovered using a magnet. The separated oil spill remediation agent can be desorbed by adding a low concentration of hydrochloric acid and then adsorbed again. The oil spill remediation agent can be recycled, effectively treating marine oil spills. It features low price, simple operation, good adsorption effect, and environmental friendliness, making it suitable for actual marine environments. Compared with existing oil spill treatment agents, the oil spill remediation agent of this invention has higher adsorption capacity and suspension reuse performance, which is beneficial for the removal of oil from the ocean, reduces the difficulty of processing and recycling traditional adsorption materials, and ultimately achieves an energy-saving and environmentally friendly goal. Attached Figure Description

[0021] Figure 1 SEM images of the oil spill repair agent (OSRA) prepared in Embodiment 1 of the present invention and the oil spill treatment agent 1 (OSTA-I) prepared in Comparative Example 1.

[0022] Figure 2 The infrared spectra of oil spill treatment agent 1 (OSTA-I) prepared in Comparative Example 1, oil spill treatment agent 2 (OSTA-II) prepared in Comparative Example 2, and oil spill repair agent (OSRA) prepared in Example 1 are shown.

[0023] Figure 3 The contact angle diagrams are of oil spill treatment agent 1 (OSTA-I) prepared in Comparative Example 1, oil spill treatment agent 2 (OSTA-II) prepared in Comparative Example 2, and oil spill repair agent (OSRA) prepared in Example 1.

[0024] Figure 4 The change in oil absorption capacity of oil spill treatment agent 1 (OSTA-I), oil spill treatment agent 2 (OSTA-II), and oil spill repair agent (OSRA) over time in Example 4 of the present invention.

[0025] Figure 5 These are top and front views of the aggregation and suspension states of oil spill treatment agent 1 (OSTA-I) and oil spill remediation agent (OSRA) after adsorbing oil in seawater in Embodiment 5 of the present invention.

[0026] Figure 6 This refers to the change in the suspended volume ratio of oil spill treatment agent 1 (OSTA-I), oil spill treatment agent 2 (OSTA-II), and oil spill repair agent (OSRA) in a simulated seawater solution over time in Example 5 of this invention.

[0027] Figure 7 This is the separation and recovery effect of the oil spill remediation agent (OSRA) in Example 6 of the present invention after adsorbing oil in a simulated seawater environment.

[0028] Figure 8 This invention demonstrates the recyclability of the oil spill remediation agent (OSRA) in a simulated seawater environment in Example 6 of this invention, which adsorbs petroleum. Detailed Implementation

[0029] The present invention will be described in detail below with reference to specific embodiments.

[0030] Example 1:

[0031] A method for treating marine oil spills according to the present invention, and a method for preparing an oil spill remediation agent, comprising the following steps:

[0032] Pine wood chips, agricultural and forestry waste, are crushed, sieved to maintain a uniform particle size, washed with deionized water, and dried in a 60℃ oven for 12 hours to obtain pretreated pine wood chips.

[0033] Dissolve 1.8 g of FeCl3 and 3.66 g of FeSO4 in 195 mL of water, and thoroughly mix the pretreated pine sawdust powder with the iron salt solution at a mass-volume ratio of 1:10 (g:mL).

[0034] Add 1 mol / L NaOH solution dropwise, stirring continuously, and monitor the time it takes for the solution pH to reach 10.0 ± 0.2 for 1 hour.

[0035] After storing the material wrapped in plastic wrap for 24 hours, wash it 5-8 times until the pH of the supernatant is neutral. Dry the treated raw material in a 60℃ oven for 24 hours.

[0036] After being magnetized, the raw materials were placed in a crucible, compacted, and then wrapped with tin foil. Under limited oxygen conditions, the materials were placed in a box-type muffle furnace and heated to 500°C for 2 hours to obtain magnetic biochar.

[0037] Dissolve 1.0 g of myristic acid in 100 mL of 10% (v / v) methanol aqueous solution, add 2 g of magnetic biochar, and stir at 70 °C for 6 hours.

[0038] It was then washed three times with hexane and dried in an oven at 60°C to obtain an oil spill repair agent, denoted as OSRA.

[0039] Example 2: An oil spill repair agent 2 (OSRA-II) is prepared in a manner basically the same as that of the oil spill repair agent (OSRA) in Example 1, except that in step (6), 0.5g of myristic acid is dissolved in 100mL of 10% (v / v) methanol aqueous solution, 2g of magnetic biochar is added, and the mixture is stirred at 70°C for 6 hours. The resulting oil spill repair agent 2 is designated as OSRA-II.

[0040] Example 3: An oil spill repair agent 3 (OSRA-III) was prepared in a manner basically the same as that of the oil spill repair agent (OSRA) in Example 1, except that in step (6), 3.0 g of myristic acid was dissolved in 100 mL of 10% (v / v) methanol aqueous solution, 2 g of magnetic biochar was added, and the mixture was stirred at 70 °C for 6 hours. The resulting oil spill repair agent 3 was designated as OSRA-III.

[0041] Comparative Example 1: A method for preparing an unmodified oil spill treatment agent 1, comprising the following steps:

[0042] Pine wood chips, agricultural and forestry waste, are crushed, sieved to maintain a uniform particle size, washed with deionized water, and dried in a 60℃ oven for 12 hours to obtain pretreated pine wood chips.

[0043] (2) Dissolve 1.8g of FeCl3 and 3.66g of FeSO4 in 195mL of water, and mix the pretreated pine wood chips and iron salt solution thoroughly at a mass-volume ratio of 1:10;

[0044] (3) Add 1 mol / L NaOH solution dropwise, stir continuously and monitor the time when the pH value of the solution is 10.0±0.2 for 1 hour.

[0045] (4) After storing the material in plastic wrap for 24 hours, wash the material 5-8 times until the pH of the supernatant is neutral. Dry the treated raw material in an oven at 60°C for 24 hours.

[0046] (5) After the magnetically treated raw material is placed in a crucible and compacted, it is wrapped with tin foil and placed in a box-type muffle furnace under limited oxygen conditions. The temperature is increased to 500℃ for 2 hours at a heating rate of 15℃ / min to obtain oil spill treatment agent 1, denoted as OSTA-I.

[0047] Comparative Example 2:

[0048] An oil spill treatment agent 2 (OSTA-II) is prepared in a manner that is basically the same as that of the oil spill repair agent (OSRA) in Example 1, except that: in step (6), lauric acid is used instead of myristic acid; the oil spill treatment agent 2 obtained therefrom is denoted as (OSTA-II).

[0049] Example 4:

[0050] This embodiment tests the adsorption performance of oil spill remediation agents on oil in seawater, including the following steps:

[0051] Take 0.05 g (±0.005 g) each of the oil spill remediation agent (OSRA) from Example 1, oil spill treatment agent 1 (OSTA-I) from Comparative Example 1, and oil spill treatment agent 2 (OSTA-II) from Comparative Example 2, and add them to several conical flasks. Then add 100 mL of artificial seawater and 0.2 g of light crude oil to each flask, seal them, and place them on a shaker at a speed of 180 r / min for 2 h to conduct an adsorption experiment. All the above experiments were performed in triplicate, and the oil content of the remaining solution was determined using an infrared oil analyzer.

[0052] Example 5:

[0053] This embodiment tests the suspension performance of the oil spill repair agent before and after oil absorption, including the following steps:

[0054] Oil spill remediation agent (OSRA) from Example 1, oil spill treatment agent 1 (OSTA-I) from Comparative Example 1, and oil spill treatment agent 2 (OSTA-II) from Comparative Example 2 were added to equal volumes of artificial seawater, and their settling was observed and recorded at regular intervals. Three beakers were filled with equal volumes of artificial seawater and petroleum. The results of petroleum adsorption after adding oil spill remediation agent (without any agent), adding oil spill treatment agent 1 (OSTA-I) from Comparative Example 1, and adding oil spill remediation agent (OSRA) from Example 1 were compared, and photographs were taken and recorded.

[0055] Example 6: This example tests the recyclability of the oil spill remediation agent, including the following steps:

[0056] 100 mL of artificial seawater, 0.2 g of petroleum, and 0.05 g of the oil spill remediation agent (OSRA) from Example 1 were added to a conical flask. The flask was then placed on a shaker at 180 r / min for adsorption. After adsorption, the oil spill remediation agent was separated and recovered using an external magnet. It was then desorbed with a low concentration of hydrochloric acid. After 2 hours, the oil spill remediation agent was washed and dried, and the adsorption experiment was repeated. This adsorption-desorption process was repeated 5 times, and the petroleum removal rate was measured after each adsorption.

[0057] Figure 1 SEM images of the oil spill repair agent (OSRA) prepared in Embodiment 1 of the present invention and the oil spill treatment agent 1 (OSTA-I) prepared in Comparative Example 1. Figure 1 In Figure (a), SEM images of oil spill treatment agent 1 (OSTA-I) prepared in Comparative Example 1 are shown. It can be observed that OSTA-I forms a well-developed porous structure, mostly exhibiting a wrinkled tubular pore structure with a uniform distribution. This is due to the volatilization and decomposition of organic matter such as cellulose (decomposes at 305-375℃), hemicellulose (decomposes at 200-350℃), and lignin (decomposes at 250-500℃) in pine sawdust during high-temperature pyrolysis, which also causes the branched carbon structure to break, resulting in numerous micropores. The increased surface roughness and more porous structure of OSTA-I are beneficial for improving adsorption performance. The presence of numerous fine particles on the surface of OSTA-I may be due to the adhesion of Fe3O4 particles during magnetization. Figure 1 In the diagram, (b), (c), and (d) are SEM images of the oil spill repair agent prepared in step 1. It can be seen that the OSRA exhibits uneven pore size distribution and a rough, wrinkled surface. This is likely due to the corrosive nature of myristic acid during the modification process, which damages or alters the carbon structure of the OSRA, resulting in an uneven surface. The rough, wrinkled surface and complex pore structure of the OSRA also contribute to its improved oil absorption capacity.

[0058] Table 1 shows the BET analysis of the oil spill repair agent (OSRA) prepared in Embodiment 1 of the present invention and the oil spill treatment agent 1 (OSTA-I) prepared in Comparative Example 1. Figure 1 It can be seen that the specific surface area of ​​OSTA-I increased to 195.41 m² after modification with myristic acid. 2 / g. Based on the data of specific surface area, total pore volume, and average pore size of OSTA-I and OSRA, it can be seen that myristic acid modification has an impact on specific surface area. The reason for the increase in specific surface area after myristic acid modification may be due to its oxidation effect, which leads to the corrosion of the internal pores of the oil spill repair agent, changes in the carbon structure, and an increase in the number of micropores.

[0059] Table 1

[0060] sample <![CDATA[Specific surface area (m 2 / g)]]> <![CDATA[Total pore volume (cm 3 / g)]]> Average pore radius (nm) OSTA-I 152.36 0.0523 2.17 OSRA 195.41 0.1509 2.06

[0061] Figure 2 The images show the infrared spectra of oil spill treatment agent 1 (OSTA-I) prepared in Comparative Example 1, oil spill treatment agent 2 (OSTA-II) prepared in Comparative Example 2, and oil spill repair agent (OSRA) prepared in Example 1. Figure 2 It can be seen that the absorption peak positions of the three oil spill treatment agents are roughly the same, indicating that the oil spill treatment agents before and after acid modification have similar types of functional groups. The absorption peaks of -OH and C=O functional groups are weakened, and the reduction of oxygen-containing functional groups is beneficial to enhancing the hydrophobicity of OSTA-II and OSRA, thereby improving their oil absorption effect. The acid-modified oil spill repair agent has an absorption peak at 611 cm⁻¹. -1 The absorption peak of Fe-O in the nearby Fe3O4 is still present.

[0062] Figure 3 This diagram shows the contact angles of oil spill treatment agent 1 (OSTA-I) prepared in Comparative Example 1, oil spill treatment agent 2 (OSTA-II) prepared in Comparative Example 2, and oil spill remediation agent (OSRA) prepared in Example 1. The diagram shows that the water contact angle of OSTA-I is 144.0°, that of OSTA-II is 155.8°, and that of OSRA is 169.0°. This indicates that the modification with myristic acid improves the hydrophobicity of the oil spill remediation agent, allowing OSRA to remain suspended on the water surface for a longer period, thus facilitating the recovery of oil from the water body after adsorption.

[0063] Figure 4The figure shows the change in oil absorption capacity over time for oil spill treatment agent 1 (OSTA-I), oil spill treatment agent 2 (OSTA-II), and oil spill repair agent (OSRA) in Example 4 of this invention. As can be seen from the figure, the oil absorption capacity of OSTA-I, OSTA-II, and OSRA all increases with time. It was found that acid modification has a significant impact on their oil absorption capacity. The oil absorption capacity of acid-modified OSTA-II and OSTA is higher than that of unmodified OSTA-I. Overall, the adsorption performance of oil in seawater is ranked as follows: OSRA > OSTA-II > OSTA-I, with OSRA modified with myristic acid showing the best oil absorption performance.

[0064] Figure 5 The figures show a top view (first row) and a front view (second row) of the aggregation and suspension states of oil spill treatment agent 1 (OSTA-I) and oil spill remediation agent (OSRA) after adsorbing oil from seawater in Example 5 of this invention: a. Simple oil film; b. Oil + OSTA-I; c. Oil + OSRA. As can be seen from the figures, when the oil spill treatment agent finishes adsorbing oil, the unmodified OSTA-I, after absorbing oil, is in an agglomerated state, agglomerating into irregular spheres, which quickly settle with shaking. The acid-modified OSRA, after absorbing oil, exhibits a sheet-like aggregation distribution and can remain suspended well for about one week. The pores of OSTA-I adsorb seawater along with oil; therefore, after contact with simulated oil-contaminated seawater for a period of time, the increased water adsorbed in the pores leads to a higher particle density, causing it to settle quickly. Water occupying the pores of OSTA-I also affects its oil absorption effect. After modification with myristic acid, the carboxylic acid groups carried by myristic acid are introduced into the oxidized functional groups on the surface of the oil spill remediation agent, effectively preventing water from penetrating into the small and medium pores of the agent. This allows OSRA to adsorb more oil and also improves its suspension performance, significantly extending its suspension time on the water surface and expanding the time window for further recycling.

[0065] Figure 6This figure shows the change in the suspended volume ratio of oil spill treatment agent 1 (OSTA-I), oil spill treatment agent 2 (OSTA-II), and oil spill remediation agent (OSRA) in a simulated seawater solution over time in Example 5 of this invention. As can be seen from the figure, approximately 20% of the unmodified OSTA-I settled directly after being added to the water surface, with a semi-precipitation time of about 2 days, and complete precipitation by the 8th day. The modified OSTA-II and OSRA, modified with lauric acid and myristic acid, did not settle within the first three days after being added to the simulated seawater solution, with the semi-precipitation time increasing to about 10 days, and complete precipitation occurring after about 20 days. It can be inferred that lauric acid and myristic acid effectively prevent seawater from penetrating the macropores, mesopores, and micropores of the oil spill remediation agent. By preventing water from filling most of the internal pores of the oil spill remediation agent, the overall particle density is prevented from exceeding the density of the aqueous phase, facilitating the recovery of the oil spill remediation agent from the sea surface after oil absorption.

[0066] Figure 7 This figure shows the separation and recovery effect of the oil spill remediation agent in Example 6 of the present invention after adsorbing oil in a simulated seawater environment. As can be seen from the figure, the OSRA adsorbed with oil can be successfully adsorbed by a magnet and successfully separated from the simulated marine environment.

[0067] Figure 8 This figure illustrates the recyclability of the oil spill remediation agent in Example 6 of this invention in a simulated seawater environment. As shown in the figure, OSRA can be reused to adsorb oil after multiple adsorption-desorption processes. During the five adsorption-regeneration cycles, the oil removal efficiencies of OSRA were 94.3%, 91.2%, 87.8%, 82.4%, and 75.3%, respectively. With increasing adsorption-regeneration cycles, the adsorption performance of OSRA for oil decreased, but after five regeneration cycles, its oil adsorption capacity remained around 75%. The decrease in oil removal efficiency during adsorption-regeneration may be due to negative changes in the physicochemical properties of the OSRA surface during regeneration; oil droplets and some intermediate products adhering to the interior and surface of the OSRA, occupying adsorption sites; and the leaching of magnetic substances during regeneration. These factors all contribute to a decrease in oil absorption efficiency. The results of adsorption recovery and reuse demonstrate that OSRA is a recyclable oil spill remediation agent.

[0068] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for preparing an oil spill remediation agent for treating marine oil spills, characterized by, Comprising the following steps: (1) mixing pine sawdust powder and iron salt solution to react, the reaction is carried out under stirring, and the pH value of the solution is adjusted, the pH value is adjusted by 1 mol / L NaOH solution; the pH value of the solution is monitored for 1h when the pH value is 10.0±0.2; after the obtained material is stored after being coated with preservative film, it is washed until the pH value of the supernatant is neutral, and the treated raw material is dried in an oven; the storage time is 24h, the drying temperature is 60℃, and the drying time is 24h; after the magnetically treated raw material is compacted and coated with tin paper, it is pyrolyzed at 500-600℃ under oxygen limitation, dried, and the magnetic pine sawdust biochar is obtained; the mass-volume ratio (g:mL) of the pine sawdust powder to the iron salt solution is 1:10-20; the iron salt is composed of FeCl3 and FeSO4, and the molar ratio of FeCl3 to FeSO4 is 1:1-3; (2) reacting the magnetic pine sawdust biochar obtained in step (1), myristic acid and 10% (v / v) methanol aqueous solution, stirring, washing and drying to obtain an oil spill remediation agent; the mass-volume ratio (g:g:mL) of the magnetic pine sawdust biochar, myristic acid and 10% (v / v) methanol aqueous solution is 2:0.5-3.0:

100.

2. The method of preparing an oil spill remediation agent according to claim 1, wherein, In step (1), the pyrolysis time is 2-3h, and the heating rate is 15℃ / min.

3. The method of preparing an oil spill remediation agent according to claim 1, wherein, In step (1), the specific preparation process of the pine sawdust powder is as follows: the pine wood is crushed, sieved to maintain a uniform particle size, then washed and dried to obtain the pine sawdust powder; the washing is carried out with deionized water, and the drying temperature is 60℃.

4. The method of preparing an oil spill remediation agent according to claim 1, wherein In step (2), the stirring is carried out at a constant temperature of 60-80℃, and the stirring time is 5-7h.

5. The method of preparing an oil spill remediation agent according to claim 1, wherein In step (2), the washing is carried out with hexane for 3 times, and the drying temperature is 60℃.

6. An oil spill remediation agent prepared by the method of any one of claims 1-5.

7. Use of the oil spill remediation agent according to claim 6 for treating marine oil spills, characterized in that, Comprising the following steps: Mixing the oil spill remediation agent, seawater and light crude oil to reach adsorption equilibrium; after adsorption is completed, the oil spill remediation agent is suspended in the upper layer, and is separated and recovered by a magnet; the separated oil spill remediation agent can be desorbed by adding hydrochloric acid and then adsorbed again, so that the oil spill remediation agent can be recycled to remove oil in the sea.

8. Use according to claim 7, characterized in that, The mass ratio of the light crude oil to the oil spill remediation agent is 4:1, and the salinity of the seawater is 20%-40%.

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