Modified polystyrene resin as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of waste liquid treatment, and particularly relates to modified polystyrene resin as well as a preparation method and application thereof, the preparation method comprises the following steps: (1) mixing hydroxyl methyl polystyrene resin with a sulfonating agent for sulfonation reaction to obtain sulfonated resin; (2) mixing the sulfonated resin prepared in the step (1) with a swelling agent, after swelling, adding a catalyst, acid liquor and an amino compound for reaction, and filtering to obtain amine salinized resin; and (3) mixing the amine salinized resin prepared in the step (2) with an organic solvent, adding a silane treating agent, reacting, adding water to hydrolyze silane groups in the mixture, filtering to obtain silanized surface modified resin, and washing to obtain the modified polystyrene resin.

Description

Technical Field

[0001] The present invention belongs to the technical field of waste liquid treatment, and particularly relates to a modified polystyrene resin, a preparation method thereof and an application thereof. Background Art

[0002] In the current non-ferrous metal smelting and lithium battery front-end production industries, organic solvents such as P204 and P507 are generally dissolved in 260# solvent oil as extractants, and are used for countercurrent extraction with feed liquid or stripping acid to produce raffinate or stripping liquid. The oil in the solution mainly includes dispersed oil, dissolved oil and emulsified oil. The difficulty in removing oil lies in dissolved oil and emulsified oil. Due to the existence of emulsified oil, dissolved oil and dispersed oil, the oil content in the raffinate or stripping liquid is greater than 200 ppm. In the raffinate and stripping liquid during the production process of nickel salts, copper salts and cobalt salts, strict requirements are imposed on the oil concentration, otherwise it will cause blistering, holes and unevenness on the surfaces of electrodeposited nickel, cobalt and copper products, affecting the surface quality of the products.

[0003] Currently, the commonly used oil removal processes in the industry are ultrasonic air flotation oil removal and activated carbon oil removal, but they can only reduce the oil content in the raffinate or stripping liquid to about 50 ppm, and the oil removal effect is poor. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the related art. For this purpose, the present invention provides a modified polystyrene resin, a preparation method thereof and an application thereof. The modified polystyrene resin can effectively remove oil substances in waste liquids such as raffinate or stripping liquid, so that the waste liquid can be recycled.

[0005] The above technical object of the present invention is achieved by the following technical solutions:

[0006] A preparation method of a modified polystyrene resin, comprising the following steps:

[0007] (1) Mixing a hydroxymethyl polystyrene resin with a sulfonating agent for a sulfonation reaction to obtain a sulfonated resin;

[0008] (2) Mixing the sulfonated resin obtained in step (1) with a swelling agent, adding a catalyst, an acid solution and an amino compound for reaction after swelling, and filtering to obtain an amine saltified resin;

[0009] (3) Mixing the amine saltified resin obtained in step (2) with an organic solvent, adding a silane treating agent for reaction, then adding water to hydrolyze the silane groups therein, filtering to obtain a silanized surface-modified resin, and washing to obtain the modified polystyrene resin.

[0010] In one embodiment, in step (1), the sulfonating agent is at least one of sulfuryl fluoride, chlorosulfonic acid, trifluoromethylsulfinyl chloride and chlorocarbonylsulfinyl chloride.

[0011] In one embodiment, in step (1), the sulfonating agent is obtained by dissolving sulfuryl fluoride in dichloromethane. The concentration of sulfuryl fluoride in the sulfonating agent is 2 mol / L, and the solid-liquid ratio of the hydroxymethyl polystyrene resin to the sulfonating agent is (5 - 8):(10 - 15) g / mL.

[0012] In one embodiment, in step (1), the sulfonating agent is at least one of chlorosulfonic acid, trifluoromethylsulfinyl chloride, and chlorocarbonylsulfinyl chloride, and the solid-liquid ratio of the hydroxymethyl polystyrene resin to the sulfonating agent is (5 - 8):(10 - 15) g / mL.

[0013] In one embodiment, in step (1), the mixing means adding the sulfonating agent dropwise to the hydroxymethyl polystyrene resin after ice-bathing for mixing.

[0014] In one embodiment, in step (1), the temperature of the sulfonation reaction is 40 - 50 °C, and the time of the sulfonation reaction is 6 - 10 h.

[0015] In one embodiment, in step (1), after the sulfonation reaction is completed, nitrogen is introduced to remove the remaining sulfonating agent.

[0016] In one embodiment, in step (2), the swelling agent is at least one of acetone, tetrahydrofuran, ethylene glycol, and glycerol.

[0017] In one embodiment, the solid-liquid ratio of the hydroxymethyl polystyrene resin to the swelling agent is (5 - 8):(40 - 60) g / mL.

[0018] In one embodiment, in step (2), the catalyst is at least one of copper(I) iodide, copper(I) chloride, copper(I) bromide, and aluminum chloride.

[0019] In one embodiment, in step (2), the solid-liquid ratio of the catalyst to the swelling agent is (2 - 8):(100 - 500) g / mL.

[0020] In one embodiment, in step (2), the solid-liquid ratio of the catalyst to the swelling agent is (3 - 5):(200 - 300) g / mL.

[0021] In one embodiment, in step (2), the acid solution is concentrated sulfuric acid with a concentration ≥ 90 wt%.

[0022] In one embodiment, in step (2), the volume ratio of the acid solution to the swelling agent is (3 - 5):(200 - 300).

[0023] In one embodiment, in step (2), the amino compound is at least one of propylamine, isopropylamine, ethylenediamine, and propylenediamine.

[0024] In one embodiment, in step (2), the volume ratio of the amino compound to the swelling agent is (5 - 8) : (200 - 300).

[0025] In one embodiment, in step (2), the temperature of the reaction is 60 - 80 °C, and the reaction time is 10 - 15 h.

[0026] In one embodiment, in step (3), the organic solvent is at least one of tetrahydrofuran, diethyl ether, ethyl acetate, and acetone.

[0027] In one embodiment, the solid-liquid ratio of the hydroxymethyl polystyrene resin to the organic solvent is (5 - 8) : (40 - 60) g / mL.

[0028] In one embodiment, in step (3), the silane treating agent is at least one of methacryloxypropyltris(trimethylsiloxy)silane, allyltrimethoxysilane, allyl(dichloro)methylsilane, (2-methylallyl)trimethylsilane, allyloxytrimethylsilane, and allyloxy-tert-butyldimethylsilane.

[0029] In one embodiment, the solid-liquid ratio of the hydroxymethyl polystyrene resin to the silane treating agent is (5 - 8) : (2 - 3) g / mL.

[0030] In one embodiment, in step (3), the temperature of the reaction is 40 - 60 °C, and the reaction time is 3 - 5 h.

[0031] In one embodiment, in step (3), the washing means first soaking the silylated surface-modified resin in absolute ethanol, then soaking it in a sodium hydroxide solution, and finally washing it with water until neutral.

[0032] A modified polystyrene resin is prepared by the preparation method described above.

[0033] Application of the modified polystyrene resin described above in the oil removal treatment of oily waste liquid.

[0034] A method for detecting the oil content of an oily waste liquid, comprising the following steps: adding the modified polystyrene resin described above to the oily waste liquid, adjusting the pH to acidic and then performing adsorption, separating the solid and liquid, taking out the modified polystyrene resin, soaking it in an alkali solution and then eluting it with an eluent to obtain an eluate, and then detecting the oil content of the eluate under a spectrophotometer.

[0035] In one embodiment, the solid-liquid ratio of the modified polystyrene resin to the oily waste liquid is (1 - 2) : (5 - 20) g / mL.

[0036] In one embodiment, the oil content in the oily waste liquid is 100 - 5000 mg / L.

[0037] In one embodiment, adjusting the pH to acidic means adjusting the pH to 3 - 4.5.

[0038] In one embodiment, the adsorption temperature is 20 - 80 °C, and the adsorption time is 0.5 - 3 h.

[0039] In one embodiment, the modified polystyrene resin after elution can be recycled for the adsorption of oily waste liquid.

[0040] The beneficial effects of the present invention are as follows:

[0041] (1) The preparation method of the modified polystyrene resin of the present invention obtains a sulfonated amino salt functional group by subjecting hydroxymethyl polystyrene resin to hydroxy sulfonation with a sulfonating agent and then performing an amination reaction with an amino compound under the catalysis of a specific catalyst, which reduces the hydrophilic groups on the resin surface, can achieve lipophilic modification of the resin, and the amine salt resin can also achieve an electrostatic attraction effect on the oil in the raffinate, strengthening the adsorption operation of the resin on the oil. The resistance of the grafted sulfonated amino salt functional group can strengthen the directional silanization modification of the resin;

[0042] (2) The preparation method of the modified polystyrene resin of the present invention uses a specific silane treatment agent to perform directional silanization modification on the resin, so that the modified polystyrene resin can adjust the size of the gel resin pores of the Si - H2O - Si structure through acid - base regulation during the process of adsorbing oil substances, shortening the equilibrium time of resin oil adsorption and oil desorption, and can realize the adsorption and desorption of oil in the solution system by regulating the pH of the adsorption system;

[0043] (3) The modified polystyrene resin of the present invention is conducive to the detection of the oil content in oily waste liquid. Only by cooperating with 20 - 30 mL of eluent can it be used to test the oil content of 50 - 100 mL of oily waste liquid with an oil content of 100 - 5000 mg / L, reducing the consumption of a large amount of perchloroethylene solvent in the traditional perchloroethylene extraction oil content detection, and the modified polystyrene resin can be reused to further reduce the consumption of perchloroethylene solvent. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic flow chart of Embodiment 1 of the present invention;

[0045] Figure 2 It is an SEM image of the hydroxymethyl polystyrene resin before modification in Embodiment 1 of the present invention;

[0046] Figure 3 It is an SEM image of the modified polystyrene resin prepared in Embodiment 1 of the present invention;

[0047] Figure 4 It is the infrared spectrum of the resin before and after modification in Example 1 of the present invention;

[0048] Figure 5 It is the SEM image of the modified polystyrene resin prepared in Comparative Example 1;

[0049] Figure 6 It is the SEM image of the modified polystyrene resin prepared in Comparative Example 2. Detailed implementation manners

[0050] The present invention will be further described below in conjunction with specific embodiments.

[0051] Example 1:

[0052] A preparation method of a modified polystyrene resin, as Figure 1 shown, includes the following steps:

[0053] (1) Sulfuryl fluoride is dissolved in dichloromethane to obtain a sulfuryl fluoride sulfonating agent solution with a sulfuryl fluoride concentration of 2 mol / L. 50 mL of the sulfuryl fluoride sulfonating agent solution is added dropwise to 25 g of hydroxymethyl polystyrene resin after ice bath, and the temperature is raised to 40 °C for reaction for 6 h. After the reaction is completed, nitrogen is introduced to remove the remaining sulfuryl fluoride to obtain sulfonated resin. The SEM image of the hydroxymethyl polystyrene resin is as Figure 2 shown;

[0054] (2) 200 mL of acetone solution is added in step (1) to fully swell the resin. 3 g of cuprous iodide is added as a catalyst, 3 mL of concentrated sulfuric acid with a concentration of 98 wt% is added, and then 5 mL of propylamine solution is added. After heating to 60 °C for reaction for 10 h, the amine salt resin is obtained by filtration;

[0055] (3) The amine salt resin in step (2) is placed in 200 mL of tetrahydrofuran solution, and 10 mL of methacryloxypropyltris(trimethylsiloxy)silane is used for silanization modification of the resin at 40 °C for 3 h; then 20 mL of deionized water is added to hydrolyze the silane groups in the solution to obtain silanized surface-modified resin;

[0056] (4) The resin filtered in step (3) is successively soaked in 50 mL of absolute ethanol and 50 mL of 2 wt% sodium hydroxide solution for 2 h, and washed with distilled water until neutral to obtain the modified polystyrene resin. The SEM image of the prepared modified polystyrene resin is as Figure 3 shown. Compared with Figure 2 the unmodified resin, it has larger pores, Figure 3 in the pores of the modified resin in Figure 4 there are more lipophilic alkylated silane particles attached, having a certain lipophilicity, and thus can adsorb and enrich the oil in the solution; the infrared spectra of the resin before and after modification are asFigure 4 It can be seen that the characteristic absorption peak positions of the modified resin at 3290.5 cm -1 and 3132.3 cm -1 correspond to the peak position of -NH-. The new peak that appears in the modified resin at 1100 - 1300 cm -1 corresponds to the peak position of Si-O, indicating that the Si-O and -NH- structures are grafted onto the surface of the modified resin.

[0057] A method for detecting the oil content of oily waste liquid, comprising the following steps:

[0058] (1) Add 5 g of the modified polystyrene resin as described above to 50 mL of oily waste water with an oil content of 100 mg / L, which is prepared by mixing a 25 wt% P204 sulfonated kerosene organic solution and distilled water. After adjusting the pH to 4.5 with concentrated sulfuric acid, circulate and adsorb at 20 °C for 0.5 h, and then perform solid-liquid separation;

[0059] (2) Immerse and wash the adsorbed oil-containing resin obtained in step (1) in 5 mL of 5 wt% sodium hydroxide solution for 5 min, then desorb it with 20 mL of chloroform at 50 °C, and the regenerated resin can be used for the adsorption of oily waste water;

[0060] (3) Detect the oil content of the eluate in step (2) under a spectrophotometer.

[0061] Example 2:

[0062] A preparation method of a modified polystyrene resin, comprising the following steps:

[0063] (1) Dissolve sulfuryl fluoride in dichloromethane to obtain a sulfuryl fluoride sulfonating agent solution with a sulfuryl fluoride concentration of 2 mol / L. After ice-bathing 65 mL of the sulfuryl fluoride sulfonating agent solution, drop it into 30 g of hydroxymethyl polystyrene resin, raise the temperature to 45 °C and react for 8 h. After the reaction, pass nitrogen to remove the remaining sulfuryl fluoride to obtain a sulfonated resin;

[0064] (2) Add 250 mL of acetone solution to the resin in step (1) to fully swell the resin. Add 4 g of cuprous iodide as a catalyst, add 4 mL of concentrated sulfuric acid with a concentration of 98 wt% under acidic conditions, and then add 6.5 mL of propylamine solution. Heat to 70 °C and react for 12 h, and then filter to obtain an amine-salted resin;

[0065] (3) Place the amine-salted resin in step (2) in 250 mL of tetrahydrofuran solution, use 12 mL of methacryloxypropyl tris(trimethylsiloxy)silane, react at 50 °C for 4 h to modify the resin by silanization; then add 25 mL of deionized water to hydrolyze the silane groups in the solution to obtain a silanized surface-modified resin;

[0066] (4) The resin obtained by filtering in step (3) is successively soaked in 50 mL of anhydrous ethanol and 50 mL of 2 wt% sodium hydroxide solution for 4 h, and washed with distilled water until neutral to obtain the modified polystyrene resin.

[0067] A method for detecting the oil content of an oily waste liquid, comprising the following steps:

[0068] (1) Add 7.5 g of the modified polystyrene resin as described above to 70 mL of an oily waste water with an oil content of 2000 mg / L, which is prepared by mixing a 25 wt% P204 sulfonated kerosene organic solution and distilled water. After adjusting the pH to 3 with concentrated sulfuric acid, circulate and adsorb at 20 °C for 1 h, and then perform solid-liquid separation;

[0069] (2) Immerse and wash the adsorbed oil-containing resin obtained in step (1) in 7 mL of 5 wt% sodium hydroxide solution for 7 min, then desorb with 25 mL of chloroform at 55 °C, and the regenerated resin can be used for the adsorption of oily waste water;

[0070] (3) Detect the oil content of the eluate in step (2) under a spectrophotometer.

[0071] Example 3:

[0072] A preparation method of a modified polystyrene resin, comprising the following steps:

[0073] (1) Dissolve sulfuryl fluoride in dichloromethane to obtain a sulfuryl fluoride sulfonating agent solution with a sulfuryl fluoride concentration of 2 mol / L. After ice-bathing 80 mL of the sulfuryl fluoride sulfonating agent solution, drop it into 40 g of hydroxymethyl polystyrene resin, raise the temperature to 50 °C and react for 10 h. After the reaction is completed, introduce nitrogen to remove the remaining sulfuryl fluoride to obtain the sulfonated resin;

[0074] (2) Add 300 mL of acetone solution in step (1) to fully swell the resin, add 5 g of copper iodide as a catalyst, add 8 mL of propylamine solution under acidic conditions with 5 mL of concentrated sulfuric acid with a concentration of 98 wt%, heat to 80 °C and react for 15 h, and then filter to obtain the amine salt resin;

[0075] (3) Place the amine salt resin in step (2) in 300 mL of tetrahydrofuran solution, use 15 mL of methacryloxypropyltris(trimethylsiloxy)silane, react at 60 °C for 5 h to perform silanization modification on the resin; then add 30 mL of deionized water to hydrolyze the silyl group in the solution to obtain the silanized surface-modified resin;

[0076] (4) The resin obtained by filtering in step (3) is successively soaked in 50 mL of anhydrous ethanol and 50 mL of 2 wt% sodium hydroxide solution for 3 h, and washed with distilled water until neutral to obtain the modified polystyrene resin.

[0077] A method for detecting the oil content of oily waste liquid, comprising the following steps:

[0078] (1) Add 10 g of the modified polystyrene resin as described above to 100 mL of oily waste water with an oil content of 5000 mg / L, which is prepared by mixing 25 wt% P204 sulfonated kerosene organic solution and distilled water. After adjusting the pH to 3 with concentrated sulfuric acid, circulate and adsorb at 20 °C for 3 h, and then perform solid-liquid separation;

[0079] (2) Immerse and wash the adsorbed oil-containing resin obtained in step (1) in 10 mL of 5 wt% sodium hydroxide solution for 10 min, then desorb with 30 mL of tetrachloromethane at 60 °C, and the regenerated resin can be used for the adsorption of oily waste water;

[0080] (3) Detect the oil content of the eluate in step (2) with a spectrophotometer.

[0081] Comparative Example 1:

[0082] A method for preparing a modified polystyrene resin, which is different from Example 1 only in that the cuprous iodide catalyst in step (2) is replaced with a ferric chloride catalyst, and the remaining steps and parameters are exactly the same as those in Example 1. The SEM diagram of the prepared modified polystyrene resin is as Figure 5 shown. When ferric chloride is used as the catalyst, the sulfonation degree on the surface of the polystyrene resin is low, and methacryloxypropyltris(trimethylsiloxy)silane cannot be effectively grafted onto the resin surface, and the silane undergoes disordered hydrolysis to form Figure 5 the disordered grafted silanized particle powder shown, Figure 3 as shown in which the sulfonation degree on the surface of the polystyrene resin is high under the selected cuprous iodide catalyst. After methacryloxypropyltris(trimethylsiloxy)silane is effectively grafted onto the resin surface, the organosilane substances at the ends of the organic functional groups decompose into siloxane polymers with long-chain alkanes grafted on the surface under the action of water, and thus orderly spherical particles are formed by normal grafting hydrolysis on the surface of the modified resin.

[0083] Comparative Example 2:

[0084] A method for preparing a modified polystyrene resin, which is different from Example 1 only in that methacryloxypropyltris(trimethylsiloxy)silane in step (3) is replaced with tris(trimethylsiloxysilane), and the remaining steps and parameters are exactly the same as those in Example 1. The SEM diagram of the prepared modified polystyrene resin is as Figure 6 shown. When short-chain olefin-free alkylsilane is used instead of methacryloxypropyltris(trimethylsiloxy)silane for hydrolysis, the silane cannot effectively hydrolyze on the surface of the modified resin due to the lack of long-chain olefin functional groups, resulting in Figure 3Instead of spherical particles, a rough surface structure with non-selective hydrolysis is formed.

[0085] Blank control experiment: Replace the modified polystyrene resin in Examples 1-3 with unmodified polystyrene resin. The adsorption and oil removal test methods for the 3 groups of blank resins are the same as those in Examples 1, 2, and 3 respectively.

[0086] Tetrachloroethylene extraction experiment: After extracting the oil in the oily wastewater in Examples 1-3 with tetrachloroethylene, detect the oil content in the tetrachloroethylene. The extraction conditions are as follows: Take 500 ml of oily wastewater, adjust the pH value to ≤2.0 with dilute hydrochloric acid, add 20 g of sodium chloride, shake well, then add 50 ml of tetrachloroethylene to extract the oil in the oily wastewater into the tetrachloroethylene. After stratification, pass the lower layer through a sand core funnel filled with anhydrous sodium sulfate and then measure the oil content with an infrared oil analyzer (if it exceeds the curve range, it needs to be diluted with tetrachloroethylene to within the curve range).

[0087] The test results of the examples and comparative examples are shown in Table 1 below, and the test results of the blank control experiment and the tetrachloroethylene extraction experiment are shown in Table 2 below. It can be seen from Table 1 and Table 2 that the oil content of the oily wastewater used in Example 1 is 100 mg / L, and the result measured by the tetrachloroethylene measurement method is 92 mg / L; the test result after adsorption by the blank polystyrene resin is 63 mg / L; the test result after using the modified polystyrene resin is 96 mg / L; the oil content of the oily wastewater used in Example 2 is 2000 mg / L, and the result measured by the tetrachloroethylene measurement method is 1946 mg / L; the test result after adsorption by the blank polystyrene resin is 1196 mg / L; the test result after using the modified polystyrene resin is 1965 mg / L; the oil content of the oily wastewater used in Example 3 is 5000 mg / L, and the result measured by the tetrachloroethylene measurement method is 4918 mg / L; the test result after adsorption by the blank polystyrene resin is 2315 mg / L; the test result after using the modified polystyrene resin is 4983 mg / L. This shows that the modified polystyrene resin has more excellent adsorption performance for oil substances in oily wastewater compared with the blank polystyrene resin, and is also superior to the conventional adsorption of oil by tetrachloroethylene, and can be used for testing the oil content in oily wastewater.

[0088] After replacing the catalyst in Comparative Example 1 with respect to Example 1, the test result using the modified polystyrene resin decreased from 96 mg / L in Example 1 to 75 mg / L; after replacing the modified grafted silane in Comparative Example 2 with respect to Example 1, the test result using the modified polystyrene resin decreased from 96 mg / L in Example 1 to 81 mg / L.

[0089] Table 1. Test Results

[0090]

[0091] Table 2. Test Results

[0092]

Claims

1. A method for preparing a modified polystyrene resin, characterized in that: It includes the following steps: (1) Mix hydroxymethyl polystyrene resin with a sulfonating agent for a sulfonation reaction to obtain a sulfonated resin; (2) Mix the sulfonated resin obtained in step (1) with a swelling agent. After swelling, add a catalyst, an acid solution and an amino compound for reaction, and filter to obtain an amine saltified resin; (3) Mix the amine saltified resin obtained in step (2) with an organic solvent, add a silane treating agent for reaction, then add water to hydrolyze the silyl group therein, filter to obtain a silanized surface-modified resin, wash to obtain the modified polystyrene resin.

2. The preparation method of a modified polystyrene resin according to claim 1, characterized in that: In step (1), the sulfonating agent is at least one of sulfuryl fluoride, chlorosulfonic acid, trifluoromethylsulfinyl chloride and chlorocarbonylsulfinyl chloride.

3. The preparation method of a modified polystyrene resin according to claim 1, wherein: In step (2), the swelling agent is at least one of acetone, tetrahydrofuran, ethylene glycol and glycerol.

4. The preparation method of a modified polystyrene resin according to claim 1, characterized in that: In step (2), the catalyst is at least one of cuprous iodide, cuprous chloride, cuprous bromide and aluminum chloride.

5. The preparation method of a modified polystyrene resin according to claim 1, characterized in that: In step (2), the amino compound is at least one of propylamine, isopropylamine, ethylenediamine and propanediamine.

6. The preparation method of a modified polystyrene resin according to claim 1, characterized in that: In step (3), the organic solvent is at least one of tetrahydrofuran, ether, ethyl acetate and acetone.

7. The preparation method of a modified polystyrene resin according to claim 1, characterized in that: In step (3), the silane treating agent is at least one of methacryloxypropyl tris(trimethylsiloxy)silane, allyltrimethoxysilane, allyl(dichloro)methylsilane, (2-methylallyl)trimethylsilane, allyloxytrimethylsilane and allyloxy-tert-butyldimethylsilane.

8. A modified polystyrene resin, characterized in that: Prepared by the preparation method according to any one of claims 1-7.

9. Use of the modified polystyrene resin according to claim 8 in the oil removal treatment of oily waste liquid.

10. A method for detecting the oil content of oily waste liquid, characterized in that, It includes the following steps: Add the modified polystyrene resin according to claim 8 to the oily waste liquid, adjust the pH to acidic and then perform adsorption, solid-liquid separation, take out the modified polystyrene resin, soak it in an alkali solution and then elute it with an eluent to obtain an eluate, and then detect the oil content of the eluate under a spectrophotometer.

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