Preparation method and application of oil spill repairing agent for treating marine oil spill

Abstract

The invention discloses a preparation method and application of an oil spill repairing agent for treating marine oil spill, and the preparation method of the oil spill repairing agent for treating marine oil spill comprises the following steps: (1) under the condition of limited oxygen, mixing pine sawdust powder and an iron salt solution, 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 to the ferric salt solution is 1: (10-20); the ferric 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 charcoal obtained in the step (1), myristic acid and a 10% (v / v) methanol aqueous solution, stirring, washing and drying to obtain an oil spill repairing agent; the oil spill repairing agent disclosed by the invention has higher adsorption capacity and suspension recycling performance, is beneficial to removal of petroleum in the ocean, reduces the treatment and recovery difficulty of a traditional adsorption material, and finally achieves the purposes of energy conservation and environmental protection.

Description

Technical Field

[0001] The invention relates to the technical field of marine environmental protection, and in particular to a preparation method and application of an oil spill repair agent for treating marine oil spills. Background Art

[0002] With the rapid development of industries such as petroleum and shipping, oil spills occur frequently, posing a serious threat to my country's marine ecological security and social and economic development. There have been many studies on the treatment of marine oil spills. For example, invention patent CN 116535614A relates to a polyurethane foam based on HDI trimer curing agent and its preparation method and application. The material has good hydrophobicity, which makes it have broad prospects in the field of oil-water separation and is the most potential material for treating marine oil spills in the future. Invention patent CN 112058290 A relates to the application of photocatalytic modified materials in removing marine oil spills. Its photocatalytic modified material is a g-C3N4 / bentonite composite material, which has good adsorption performance and photocatalytic degradation effect, and has good application prospects in the field of clearing marine oil spills. Invention patent CN 116574310A relates to biomass-based nanofiber aerogel, which has good oil absorption performance and compressive elastic properties.

[0003] Once oil leaks into the ocean, the oil will form an oil film on the water surface, and the diffusion process is affected by many factors. The adsorption method is an oil spill treatment method that is highly efficient, highly selective, easy to operate, environmentally friendly, regenerative, widely adaptable, and reduces secondary pollution. After a marine oil spill accident occurs, a large amount of oil spill repair agent needs to be added for adsorption, which requires that the raw materials for its preparation are cheap, widely available, and the process for preparing the oil spill repair agent is simple. After the oil spill repair agent absorbs the oil, the repair agent can be suspended in the water environment for a long time and separated and recovered in time, with reuse performance, achieving the purpose of energy saving and environmental protection. This is the difficulty in preparing the oil spill repair agent. None of the above invention patents mention recycling and reuse performance. Summary of the invention

[0004] The technical problem to be solved by the present invention is to address the deficiencies of the prior art. The present invention provides a preparation method and application of an oil spill repair agent for treating marine oil spills; the oil spill repair agent prepared by the preparation method has a wide range of raw materials and is inexpensive, has large specific surface area, high porosity, fewer surface oxygen-containing functional groups, strong lipophilic and hydrophobic properties, good magnetism, and good floating performance after oil absorption, and has good removal effect on simulated oil absorption. The repair agent has good floating performance, magnetic recovery effect and reuse performance after oil absorption.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions.

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

[0007] (1) Under oxygen-limited conditions, pine sawdust powder, iron salt and water are mixed, pyrolyzed at 500-600° C., 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 sawdust 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 remediation 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 remediation agent, in step (1), the pyrolysis time is 2-3 hours and the heating rate is 15°C / min.

[0010] The preparation method of the oil spill remediation agent, in step (1), the specific preparation process of the pine sawdust powder is: pine wood is crushed and sieved to maintain a uniform particle size, and then washed and dried to obtain pine sawdust powder; the washing is carried out with deionized water, and the drying temperature is 60°C.

[0011] The preparation method of the oil spill remediation 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 and adjusted under stirring conditions, and the pH value of the solution is monitored. The pH value is adjusted using 1mol / LNaOH solution, and the pH value of the monitored solution is 10.0±0.2 for 1h.

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

[0013] The preparation method of the oil spill repair agent, in step (1), after the stirring, the mixture is wrapped with a plastic wrap and stored, and then washed. The storage time is 24 hours, the washing times are 5 to 8 times, 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 performed at a constant temperature of 60-80° C., and the stirring time is 5-7 hours.

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

[0016] An oil spill remediation agent prepared by any of the above methods for preparing an oil spill remediation agent.

[0017] An application of the oil spill repair agent in treating marine oil spills comprises the following steps: mixing the oil spill repair agent, seawater and light crude oil to achieve adsorption equilibrium; after the adsorption is completed, the oil spill repair agent is suspended in the upper layer and is separated and recovered by a magnet; the separated oil spill repair agent is desorbed by adding hydrochloric acid, and can be adsorbed again, and the oil spill repair agent can be recycled to achieve the removal of oil in the ocean.

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

[0019] Compared with the prior art, the advantages of the present invention are:

[0020] (1) The present invention provides a method for treating marine oil spills, using an oil spill remediation agent to adsorb oil in seawater. The oil spill remediation agent uses low-cost pine sawdust as biomass raw material. During the high-temperature pyrolysis process, organic matter such as cellulose, hemicellulose and lignin in the pine sawdust is volatilized and cracked, and the branched carbon structure is also broken, forming many micropores. The raw materials, iron salts and water are mixed, and after magnetization by an impregnation method, pyrolysis is performed to form magnetic biochar. The magnetic biochar, myristic acid and methanol aqueous solution are then mixed, stirred, washed and dried to obtain an oil spill remediation agent. The metal iron ions are loaded on the biochar. On the one hand, the surface of the magnetic biochar is modified, usually with a larger specific surface area and more active sites, which improves the adsorption capacity of the oil spill remediation agent. On the other hand, due to its magnetism, it can be quickly and conveniently separated from the water environment by an external magnetic field, reducing the complexity of subsequent treatment. Magnetic biochar is acid-modified, because previous studies usually use strong acids such as hydrochloric acid or sulfuric acid during acid modification, there are problems such as high cost and potential safety hazards in the preparation process, so the present invention uses myristic acid for modification. On the one hand, when the concentration of the acid increases, the oxidizability will increase, the pore structure inside the magnetic biochar is corroded, and more adsorption sites can be created. On the other hand, myristic acid is a fatty acid with a long-chain hydrocarbon structure, and its introduction may form hydrophobic functional groups on the surface of the magnetic biochar, prompting the surface of the magnetic biochar to form a non-polar layer, enhancing hydrophobicity, so that it can keep floating for a long time without sinking, and the hydrocarbon chain at the hydrophobic tail also provides more contact area and position for oil adsorption. The oil spill repair agent of the present invention has the characteristics of large specific surface area, high porosity, less surface oxygen-containing functional groups, strong lipophilic hydrophobicity, better magnetism, and better floating performance after oil absorption, so that marine oil spill accidents can be effectively handled. By introducing magnetization and myristic acid, it is made to show better adsorption performance when treating oil pollution. The raw material of oil spill remediation agent, biochar, is made from organic waste. After modification with myristic acid, it still maintains its renewability and environmental friendliness, making it suitable for sustainable development and green technology.

[0021] (2) The present invention also provides the use of an oil spill repair agent in treating marine oil spills. The oil spill repair agent, artificial seawater and light crude oil are mixed and placed on a shaking table for adsorption reaction. After adsorption equilibrium, the oil spill repair agent is suspended in the upper layer and separated and recovered by a magnet. The separated oil spill repair agent can be adsorbed again after adding low-concentration hydrochloric acid to desorb it. The oil spill repair agent can be recycled to effectively treat marine oil spills. It has the characteristics of low price, simple operation, good adsorption effect, green environmental protection, etc., and is suitable for the actual marine environment. Compared with the existing oil spill treatment agent, the oil spill repair agent of the present invention has higher adsorption capacity and suspension reuse performance, which is beneficial to the removal of petroleum in the ocean, reduces the difficulty of processing and recycling traditional adsorption materials, and finally achieves the purpose of energy saving and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 SEM images of the oil spill remediation agent (OSRA) prepared in Example 1 of the present invention and the oil spill treatment agent 1 (OSTA-I) prepared in Comparative Example 1.

[0023] Figure 2 The infrared spectra of the oil spill treatment agent 1 (OSTA-I) prepared in comparative example 1 of the present invention, the oil spill treatment agent 2 (OSTA-II) prepared in comparative example 2, and the oil spill remediation agent (OSRA) prepared in example 1 are shown.

[0024] Figure 3 The contact angle diagrams are of the oil spill treatment agent 1 (OSTA-I) prepared in comparative example 1 of the present invention, the oil spill treatment agent 2 (OSTA-II) prepared in comparative example 2, and the oil spill remediation agent (OSRA) prepared in example 1.

[0025] Figure 4 The oil absorption of oil spill treatment agent 1 (OSTA-I), oil spill treatment agent 2 (OSTA-II) and oil spill remediation agent (OSRA) in Example 4 of the present invention changes over time.

[0026] Figure 5 The top view and front view show the aggregation and suspension states of the oil spill treatment agent 1 (OSTA-I) and the oil spill remediation agent (OSRA) in Example 5 of the present invention after adsorbing oil in seawater.

[0027] Figure 6 It is the change of 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 simulated seawater solution over time in Example 5 of the present invention.

[0028] 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.

[0029] Figure 8 The oil spill remediation agent (OSRA) in Example 6 of the present invention has a recycling performance in adsorbing oil in a simulated seawater environment. DETAILED DESCRIPTION

[0030] The present invention is described in detail below in conjunction with specific embodiments.

[0031] Embodiment 1:

[0032] A method for treating marine oil spills and a method for preparing an oil spill repair agent of the present invention comprises the following steps:

[0033] (1) Pine sawdust from agricultural and forestry waste was crushed and sieved to maintain a uniform particle size, washed with deionized water, and then dried in an oven at 60°C for 12 hours to obtain pretreated pine sawdust.

[0034] (2) 1.8 g of FeCl3 and 3.66 g of FeSO4 were dissolved in 195 mL of water, and the pretreated pine sawdust powder and the iron salt solution were fully mixed at a mass volume ratio of 1:10 (g:mL);

[0035] (3) Add 1 mol / L NaOH solution dropwise, continue stirring and monitor the pH value of the solution until it reaches 10.0±0.2 for 1 h.

[0036] (4) After wrapping with plastic wrap and storing for 24 hours, wash the material 5 to 8 times until the pH value of the supernatant is neutral. Dry the treated raw material in an oven at 60°C for 24 hours.

[0037] (5) The raw materials after magnetic treatment were placed in a crucible, compacted, and then wrapped with tin foil. Under oxygen-limited conditions, the raw materials were placed in a box-type muffle furnace and heated to 500°C at a heating rate of 15°C / min for pyrolysis for 2 h to obtain magnetic biochar.

[0038] (6) 1.0 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 h.

[0039] (7) The product was then washed three times with hexane and dried in an oven at 60 °C to obtain an oil spill remediation agent, which was designated as OSRA.

[0040] Example 2: An oil spill remediation agent 2 (OSRA-II) is prepared in the same manner as the oil spill remediation agent (OSRA) in Example 1, except that in step (6), 0.5 g of myristic acid is dissolved in 100 mL of 10% (v / v) methanol aqueous solution, 2 g of magnetic biochar is added, and the mixture is stirred at 70° C. for 6 hours. The obtained oil spill remediation agent 2 is referred to as OSRA-II.

[0041] Example 3: An oil spill remediation agent 3 (OSRA-III) is prepared in the same manner as the oil spill remediation agent (OSRA) in Example 1, except that in step (6), 3.0 g of myristic acid is dissolved in 100 mL of 10% (v / v) methanol aqueous solution, 2 g of magnetic biochar is added, and the mixture is stirred at 70° C. for 6 hours. The obtained oil spill remediation agent 3 is referred to as OSRA-III.

[0042] Comparative Example 1: A method for preparing an oil spill treatment agent 1 which has not been acid-modified, comprising the following steps:

[0043] (1) Pine sawdust from agricultural and forestry waste was crushed and sieved to maintain a uniform particle size, washed with deionized water, and then dried in an oven at 60°C for 12 hours to obtain pretreated pine sawdust.

[0044] (2) Dissolve 1.8 g of FeCl3 and 3.66 g of FeSO4 in 195 mL of water, and mix the pretreated pine sawdust and the iron salt solution in a mass-to-volume ratio of 1:10;

[0045] (3) Add 1 mol / L NaOH solution dropwise, continue stirring and monitor the pH value of the solution until it reaches 10.0±0.2 for 1 h.

[0046] (4) After wrapping with plastic wrap and storing for 24 hours, wash the material 5 to 8 times until the pH value of the supernatant is neutral. Dry the treated raw material in an oven at 60°C for 24 hours.

[0047] (5) The raw material after magnetic treatment was placed in a crucible, compacted, and then wrapped with tin foil. It was placed in a box-type muffle furnace under oxygen-limited conditions and heated to 500°C at a heating rate of 15°C / min for pyrolysis for 2 h to obtain oil spill treatment agent 1, denoted as OSTA-I

[0048] Comparative Example 2:

[0049] An oil spill treatment agent 2 (OSTA-II) is prepared in substantially the same manner as the oil spill remediation agent (OSRA) in Example 1, except that in step (6), lauric acid is used instead of myristic acid; the prepared oil spill treatment agent 2 is recorded as (OSTA-II).

[0050] Embodiment 4:

[0051] This embodiment tests the adsorption performance of the oil spill remediation agent on petroleum in seawater, comprising the following steps:

[0052] Take 0.05 g (± 0.005 g) of each of the oil spill remediation agent (OSRA) in Example 1, the oil spill treatment agent 1 (OSTA-I) in Comparative Example 1, and the oil spill treatment agent 2 (OSTA-II) in Comparative Example 2, add them to several conical bottles, add 100 mL of artificial seawater and 0.2 g of light crude oil, seal them, and place them on a shaker for 2 hours for adsorption experiments. The shaker speed is 180 r / min. The above experiments were conducted three times in parallel, and the oil content of the remaining solution was determined using an infrared oil meter.

[0053] Embodiment 5:

[0054] This embodiment tests the suspension performance of the oil spill remediation agent before and after oil absorption, including the following steps:

[0055] The oil spill remediation agent (OSRA) in Example 1, the oil spill treatment agent 1 (OSTA-I) in Comparative Example 1, and the oil spill treatment agent 2 (OSTA-II) in Comparative Example 2 were added to equal amounts of artificial seawater, and their sedimentation was observed and recorded regularly. Three beakers were added with equal amounts of artificial seawater and oil, and the oil spill remediation agent (OSRA) in Example 1 was added, and the oil spill adsorption was compared without any oil spill remediation agent, with the oil spill treatment agent 1 (OSTA-I) in Comparative Example 1, and with the oil spill remediation agent (OSRA) in Example 1. The results were recorded by taking photos.

[0056] Example 6: This example tests the recyclability of the oil spill remediation agent, including the following steps:

[0057] 100 mL of artificial seawater, 0.2 g of petroleum, and 0.05 g of the oil spill remediation agent (OSRA) in Example 1 were added to a conical flask, and placed on a 180 r / min shaker for adsorption experiments. After the adsorption was completed, the oil spill remediation agent was separated and recovered by an external magnet. Then it was desorbed with low-concentration hydrochloric acid. After 2 hours, the oil spill remediation agent was washed and dried, and the adsorption experiment was carried out again. The adsorption-desorption process was repeated 5 times, and the removal rate of oil was measured after each adsorption.

[0058] Figure 1 SEM images of the oil spill remediation agent (OSRA) prepared in Example 1 of the present invention and the oil spill treatment agent 1 (OSTA-I) prepared in Comparative Example 1. Figure 1 In the figure, (a) is the SEM image of the oil spill treatment agent 1 (OSTA-I) prepared in Example 1. It can be observed that OSTA-I has formed a well-developed pore structure, and the morphology mostly presents a wrinkled tubular pore structure, and the pore structure is evenly distributed. The reason is that during the high-temperature pyrolysis process, the organic matter such as cellulose (decomposed at 305-375℃), hemicellulose (decomposed at 200-350℃) and lignin (decomposed at 250-500℃) in the pine sawdust are volatilized and cracked, and the branched carbon structure will also break, forming many micropores. The surface roughness of OSTA-I increases, and the structure is more fluffy, which is conducive to improving the adsorption performance. There are a large number of fine particles on the surface of OSTA-I, which may be the reason for the Fe3O4 particles attached to the surface during the magnetization process. Figure 1 In the figure, (b), (c), and (d) are SEM images of the oil spill remediation agent obtained in Example 1. It can be seen that the pore size distribution of OSRA is uneven, the surface is uneven, and it presents a rough and wrinkled shape. This may be because the carbon structure of OSRA is destroyed or changed due to the corrosiveness of myristic acid during the modification process, forming an uneven surface. The surface of OSRA is rough and wrinkled, and the pore structure is complex, which is also conducive to improving its oil absorption effect.

[0059] Table 1 shows the BET analysis of the oil spill remediation agent (OSRA) prepared in Example 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 m after modification with myristic acid. 2 / g. According to 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 effect on specific surface area. The reason for the increase in specific surface area after myristic acid modification may be due to its oxidation, which causes the internal pores of the oil spill remediation agent to be corroded and the carbon structure to change, thereby increasing the number of micropores.

[0060] Table 1

[0061]

[0062] Figure 2 The infrared spectra of the oil spill treatment agent 1 (OSTA-I) prepared in comparative example 1 of the present invention, the oil spill treatment agent 2 (OSTA-II) prepared in comparative example 2 and the oil spill remediation agent (OSRA) prepared in Example 1 are shown in FIG. 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 functional group types. The absorption peaks of -OH and C=O functional groups are weakened. The reduction of oxygen-containing functional groups is conducive to enhancing the hydrophobicity of OSTA-II and OSRA and improving the oil absorption effect of the two. The oil spill remediation agent after acid modification has a peak at 611cm -1 The absorption peak of Fe-O in Fe3O4 that appears nearby still exists.

[0063] Figure 3 The contact angle diagrams of the oil spill treatment agent 1 (OSTA-I) prepared in comparative example 1 of the present invention, the oil spill treatment agent 2 (OSTA-II) prepared in comparative example 2, and the oil spill remediation agent (OSRA) prepared in Example 1 are shown in the figure. It can be seen from the figure that the water contact angle of OSTA-I is 144.0°, the water contact angle of OSTA-II is 155.8°, and the water contact angle of OSRA is 169.0°. It is shown that the modification of myristic acid makes the hydrophobicity of the oil spill remediation agent better, which makes OSRA suspended on the water surface for a longer time, thereby facilitating the recovery of oil from the water body after adsorption.

[0064] Figure 4The figure shows the change of oil absorption over time of oil spill treatment agent 1 (OSTA-I), oil spill treatment agent 2 (OSTA-II) and oil spill remediation agent (OSRA) in Example 4 of the present invention. It can be seen from the figure that the adsorption of oil by OSTA-I, OSTA-II and OSRA increases with time. It is found that acid modification has a greater impact on their oil absorption capacity. The adsorption of oil by acid-modified OSTA-II and OSTA is improved compared with that of unmodified OSTA-I. Overall, the adsorption performance of oil in seawater is ranked as follows: OSRA>OSTA-II>OSTA-I, and the best oil absorption performance is OSRA modified with myristic acid.

[0065] Figure 5 The top view (first row) and front view (second row) of the aggregation and suspension state of the oil spill treatment agent 1 (OSTA-I) and the oil spill remediation agent (OSRA) in Example 5 of the present invention after absorbing oil in seawater, a. Simple oil film; b. Oil + OSTA-I; c. Oil + OSRA. It can be seen from the figure that when the oil spill treatment agent finishes adsorbing oil to oil, the OSTA-I that has not been acid-modified is in a state of agglomeration after absorbing oil, aggregated into irregular spheres, and quickly settles with the shaking of the shaking table. The acid-modified OSRA is distributed in flakes after absorbing oil, and can be well suspended for about 1 week. The pores of OSTA-I absorb seawater while absorbing oil. Therefore, after a period of contact with simulated oil-contaminated seawater, the pores absorb more water, resulting in a larger particle density and will sink quickly, and water occupying the pores of OSTA-I will also affect its oil absorption effect. After modification with myristic acid, the carboxylic acid groups carried by myristic acid are introduced into the oxidative functional groups on the surface of the oil spill remediation agent, which can effectively prevent water from penetrating into the small and medium pores of the oil spill remediation agent. This not only enables OSRA to absorb more oil, but also improves the suspension performance of OSRA, significantly prolonging its suspension time on the water surface and expanding the time window for subsequent further recycling.

[0066] Figure 6It is the change of the suspension volume ratio of oil spill treatment agent 1 (OSTA-I), oil spill treatment agent 2 (OSTA-II) and oil spill remediation agent (OSRA) in simulated seawater solution over time in Example 5 of the present invention. It can be seen from the figure that about 20% of the unmodified OSTA-I directly settles after being added to the water surface, and the semi-precipitation time is about 2 days, and it is completely precipitated on the 8th day. OSTA-II and OSRA modified with lauric acid and myristic acid did not settle within three days after being added to the simulated seawater solution. The semi-precipitation time increased to about 10 days and completely settled in about 20 days. It can be inferred that lauric acid and myristic acid can effectively prevent seawater from penetrating into the macropores, mesopores and pores of the oil spill remediation agent. By preventing water from filling most of the internal pores of the oil spill remediation agent, the overall density of the particles can be prevented from exceeding the density of the water phase, which facilitates the recovery of the oil spill remediation agent from the sea surface after absorbing oil.

[0067] Figure 7 This is the separation and recovery effect of the oil spill remediation agent after adsorbing oil in a simulated seawater environment in Example 6 of the present invention. As can be seen from the figure, the OSRA adsorbed with oil can be successfully adsorbed by the magnet and successfully separated from the simulated marine environment.

[0068] Figure 8 The recycling performance of the oil spill repair agent in Example 6 of the present invention in the simulated seawater environment for adsorbing oil. As can be seen from the figure, OSRA can be reused to adsorb oil after multiple adsorption-desorption processes. In the 5 cycles of adsorption regeneration, the oil removal efficiency of OSRA was 94.3%, 91.2%, 87.8%, 82.4%, and 75.3%, respectively. With the increase in the number of adsorption regenerations, the adsorption performance of OSRA for oil decreased, but after 5 regenerations, its adsorption amount for oil was still around 75%. The reason for the decrease in the oil removal efficiency of OSRA during the adsorption regeneration process may be that the physical and chemical properties of the surface of OSRA undergo negative changes during the regeneration process; oil droplets and some intermediate products adhere to the inside and surface of OSRA, and the adsorption sites are occupied; magnetic substances will also be leached during the regeneration process, and these reasons will lead to a decrease in the oil absorption effect. The results of adsorption recovery and reuse show that OSRA is a recyclable oil spill repair agent.

[0069] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A method for preparing an oil spill remediation agent for treating marine oil spills, characterized in that: The following steps are involved: (1) Under oxygen-limited conditions, pine sawdust powder and an iron salt solution are mixed, pyrolyzed at 500-600° C., 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; (2) The magnetic pine sawdust biochar, myristic acid and 10% (v / v) methanol aqueous solution obtained in step (1) are reacted, stirred, washed and dried to obtain an oil spill remediation 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.

2. The method for preparing the oil spill repair agent according to claim 1, characterized in that: In step (1), the pyrolysis time is 2-3 hours and the heating rate is 15°C / min.

3. The method for preparing the oil spill repair agent according to claim 1, characterized in that: In step (1), the specific preparation process of the pine sawdust powder is: pine wood is crushed and sieved to maintain a uniform particle size, and then washed and dried to obtain pine sawdust powder; the washing is carried out with deionized water, and the drying temperature is 60°C.

4. The method for preparing the oil spill repair agent according to claim 1, characterized in that: In step (1), the iron salts are FeCl3 and FeSO4, and 1.8 g of FeCl3 and 3.66 g of FeSO4 are dissolved in 195 mL of water. The reaction is carried out and adjusted under stirring conditions, and the pH value of the solution is monitored. The pH value is adjusted using 1 mol / L NaOH solution, and the pH value of the monitored solution is 10.0±0.2 for 1 hour.

5. The method for preparing the oil spill repair agent according to claim 1, characterized in that: In step (1), the reaction is stored by wrapping with plastic wrap and then washed. The storage time is 24 hours, the washing times are 5 to 8 times, the drying temperature is 60° C., and the drying time is 24 hours.

6. The method for preparing the oil spill repair agent according to claim 1, characterized in that: In step (2), the stirring is performed at a constant temperature of 60-80° C., and the stirring time is 5-7 hours.

7. The method for preparing the oil spill repair agent according to claim 1, characterized in that: In step (2), the washing is performed three times with hexane, and the drying temperature is 60°C.

8. An oil spill repair agent prepared by the preparation method of the oil spill repair agent according to any one of claims 1 to 7.

9. Use of the oil spill remediation agent as claimed in claim 8 in treating marine oil spills, characterized in that: The following steps are involved: The oil spill repair agent, seawater and light crude oil are mixed to reach adsorption equilibrium; after the adsorption, the oil spill repair agent is suspended in the upper layer and is separated and recovered with a magnet; the separated oil spill repair agent is desorbed by adding hydrochloric acid and can be adsorbed again. The oil spill repair agent can be recycled to achieve the removal of oil in the ocean.

10. The use according to claim 9, characterized in that: The mass ratio of the light crude oil to the oil spill repair agent is 4:1, and the salinity of the seawater is 20% to 40%.

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