Application of metal-free porous carbon material prepared by microwave carbonization of waste plastics in degradation of organic pollutants

Abstract

The metal-free porous carbon catalytic material is prepared by adopting microwave pyrolysis of waste plastic polyethylene glycol terephthalate (PET) and is applied to efficient activation of peroxymonosulfate (PMS) so as to degrade organic pollutants such as tetracycline (TC) and the like. The preparation method comprises the following steps: uniformly grinding a solid mixture of waste plastic PET, sodium lignin sulfonate and NaOH, and pyrolyzing for 5 minutes at 800 W by adopting a commercial microwave oven to prepare the metal-free porous carbon material catalyst derived from the waste plastic. Defect enrichment, introduction of C = O and increase of the specific surface area are all beneficial to improvement of the catalytic performance. The optimal catalyst P1S2 can realize complete degradation of a target pollutant TC within 20 min, and the rate constant reaches 0.303 min <-1 >. NaOH is used as a microwave absorbent and a pore-forming agent, so that a porous structure is favorably generated in the metal-free carbon material. Compared with a traditional pyrolysis mode, microwave treatment is more beneficial to increase of the specific surface area of a catalytic material and formation and exposure of active sites (defects and C = O) and is also beneficial to PMS catalytic activation, and a non-free radical degradation approach dominated by electron transfer is achieved. In addition, due to introduction of PET, formation of C = O in the catalytic material is facilitated, and degradation of TC in a non-free radical way is enhanced.

Description

Technical Field

[0001] The present invention relates to the application of a metal-free porous carbon material prepared by microwave carbonization of waste plastics in the degradation of organic pollutants Background Art

[0002] Plastic waste management has become a major global issue that needs to be addressed urgently today. Research results at home and abroad have consistently revealed that the widespread use of plastics and their relatively short service life have led to the emergence of a huge amount of waste, and these thousands of tons of plastic waste have further exacerbated environmental challenges. Microplastics generated by the decomposition of waste polymer materials have widely polluted marine and river ecosystems and drinking water sources. At the same time, the treatment process also consumes a large amount of resources. Therefore, solving the problem of "white pollution" has become an urgent task.

[0003] So far, carbon materials have shown great application potential due to their wide availability, eco-friendliness, and simple and direct preparation process. Thanks to their non-metallic composition, excellent stability, and abundant active sites, carbon materials have been widely used as green catalysts in the field of wastewater treatment. The high surface area, excellent porosity, electron conductivity, abundant and adjustable catalytic active sites, and stable performance at high temperatures of carbon materials have made the conversion of waste plastics into high-value-added carbon materials a current research hotspot. However, although a few microwave-assisted methods for degrading waste plastics have been established, these methods are still relatively complex. How to conveniently and efficiently convert waste plastics into carbon material catalysts under microwave action and apply them to processes such as efficient catalysis is still an area that needs to be explored and is full of challenges.

[0004] The widespread use of antibiotics in multiple fields such as animal husbandry, agriculture, and medicine has led to the emergence of antibiotic resistance genes and resistant bacteria in the natural environment. With the increase in drug consumption, incomplete removal, and their potential hazards to human health and the ecosystem, the World Health Organization has regarded them as a major public health threat in the 21st century. Tetracycline (TC), as an antibiotic widely used in medicine and animal husbandry, has strong antibacterial properties, significant ecological toxicity, potential carcinogenicity, and is difficult to biodegrade naturally. Even trace amounts of TC pose a serious threat to humans. However, traditional treatment methods such as adsorption, filtration, biodegradation, or electrochemical oxidation are limited in degrading TC. Currently, advanced oxidation processes (AOPs) involving peroxymonosulfate (PMS) show great potential in treating organic pollutants due to the high oxidation potential of reactive oxygen species (ROS), fast reaction kinetics, and wide pH applicability. Previous studies have shown that the enrichment of defect structures, the formation of oxygen-containing functional groups, the construction of porous structures, and the increase in specific surface area in catalytic materials can significantly promote the activation of PMS. However, most of the materials currently used for catalytic activation of PMS rely on transition metals and their oxides (such as Co, Fe, Cu, and Mn oxides), which inevitably brings the risk of secondary pollution. Therefore, it is particularly urgent to develop an efficient and environmentally friendly strategy to degrade TC and thus reduce related environmental risks.

[0005] In the preparation process of carbon materials, microwave technology has shown significant advantages over traditional pyrolysis methods in terms of energy transfer, increasing the material yield, and achieving instant and precise time control. Sodium hydroxide, etc., are widely used as microwave absorbers due to their low cost, high dielectric loss coefficient, and the ability to absorb high doses of microwaves. However, to date, there has been no reported method for carbonizing waste plastics using microwave treatment without the presence of transition metals. Summary of the Invention

[0006] The present invention uses waste plastic polyethylene terephthalate (PET) as the raw material, sodium hydroxide as the microwave absorber and pore-forming agent, and sodium lignosulfonate as the carbonization assistant. After mixing all the raw materials evenly using a mortar, simple microwave-assisted pyrolysis is carried out for 5 min to prepare a metal-free carbon material catalyst derived from waste plastics with a porous morphology. The preparation method of the catalyst in the present invention is simple, the preparation time is short, the catalyst can effectively activate PMS for the degradation of organic pollutants, and it is easy to recycle.

[0007] The present invention discloses the application of a metal-free porous carbon material prepared by microwave carbonization of waste plastics in the degradation of organic pollutants, which is characterized in that: by using a simple microwave pyrolysis method, with low-cost and easily available waste plastic polyethylene terephthalate (PET) as the raw material, NaOH as the microwave absorber and pore-forming agent, and sodium lignosulfonate as the carbonization assistant, a metal-free carbon material catalyst with a porous morphology capable of efficiently degrading organic pollutants is rapidly synthesized by pyrolysis in a microwave oven with a power of 800 W for 5 min; The preparation steps of the above-mentioned metal-free porous carbon material catalyst are as follows: Weigh 0.5 g of waste PET powder, 1.0 g of sodium lignosulfonate and 0.5 g of NaOH. After grinding the mixture evenly in a ceramic mortar, put it into a 25 mL crucible and pyrolyze it in a commercial microwave oven with a power of 800 W for 5 min. After the material is cooled, wash it with water / ethanol and vacuum dry it at 60 °C for 12 hours to obtain the metal-free carbon catalytic material P1S2; Keep the mass of NaOH at 0.5 g. When the mass ratio of PET powder to sodium lignosulfonate is 1:4, 1:3, 1:2 and 1:1, the prepared materials are named P1S4, P1S3, P1S2 and P1S1 respectively; The reaction of the catalyst activating peroxymonosulfate (PMS) to degrade organic pollutants: Use a thermostatic magnetic stirring water bath to control the temperature, and use 0.1 mol / L sulfuric acid or sodium hydroxide solution to adjust the initial pH. Add the catalyst and PMS to a 50 mL aqueous solution containing 10 mg / L organic pollutants to start the degradation process; Extract 1.5 mL of the reaction solution at a predetermined time interval, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of the organic pollutant with a UV-visible spectrophotometer.

[0008] The above-mentioned application of a metal-free porous carbon material prepared by microwave carbonization of waste plastics in the degradation of organic pollutants is characterized in that: the preparation process of the catalyst is simple, the preparation time is short, and the prepared catalyst exhibits obvious porous structure characteristics; Compared with the traditional pyrolysis method, microwave treatment is not only beneficial to the expansion of specific surface area and the formation of defects, but also beneficial to the generation of C=O in the carbon material.

[0009] The above-mentioned application of a metal-free porous carbon material prepared by microwave carbonization of waste plastics in the degradation of organic pollutants is characterized in that: the prepared metal-free porous carbon material P1S2 has a high degradation efficiency for organic pollutants, and the removal rate of tetracycline can reach 100% within 20 min, and the rate constant can reach 0.303 min −1; The removal rates of oxytetracycline, sulfamethoxazole, norfloxacin, trichlorophenol, and carbamazepine pollutants were 100%, 89.4%, 88.4%, 100%, and 74.2%, respectively, which confirmed the good applicability of the P1S2 / PMS catalytic system for the degradation of different organic pollutants.

[0010] The application of the metal-free porous carbon material prepared by microwave carbonization of waste plastics as described above in the degradation of organic pollutants is characterized in that: in the P1S2 / PMS catalytic system, the degradation of TC is a non-free radical-involved pathway dominated by direct electron transfer, and the singlet oxygen 1 O2 generated by the activation of PMS is a minor active species.

[0011] Description of the drawings Figure 1 (a) is the scanning electron microscope (SEM) image of the catalyst P1S2, Figure 1 (b) is the transmission electron microscope (TEM) image of P1S2.

[0012] Figure 2 (a) is the X-ray diffraction (XRD) pattern of the catalysts P1S1, P1S2, P1S3, P1S4, C, P1S2-600; Figure 2 (b) is the XRD pattern of the original waste plastic powder PET; Figure 2 (c) is the Raman spectrum comparison of P1S1, P1S2, P1S3, P1S4, C and P1S2-600; Figure 2 (d) is the N2 adsorption / desorption isotherm curve of P1S2 and P1S2-600.

[0013] Figure 3 is the X-ray photoelectron spectroscopy (XPS) of the catalysts P1S2, P1S2-600 and C. (a) Full spectrum, (b) C 1s, (c) O 1s, (d) S 2p.

[0014] Figure 4 is the electron paramagnetic resonance spectroscopy (EPR) image of the catalyst P1S2. Detailed implementation manners

[0015] The present invention will be described in detail below in combination with specific implementation cases.

[0016] Implementation case 1: The specific preparation steps of the porous carbon catalyst are as follows: Weigh 0.5 g of waste PET powder, 1.0 g of sodium lignosulfonate and 0.5 g of NaOH. After uniformly mixing them in a ceramic mortar, place the mixture in a 25 mL crucible and put it into a commercial microwave oven for pyrolysis at a power of 800 W for 5 min. After the material cools down, wash it with water / ethanol and dry it under vacuum at 60 °C for 12 hours to obtain the metal-free porous carbon catalytic material P1S2. Keeping the mass of sodium hydroxide at 0.5 g and the total mass of PET powder and sodium lignosulfonate at 1.5 g, when the mass ratio of PET powder to sodium lignosulfonate is 1:4, 1:3, 1:2 and 1:1, the prepared materials are named P1S4, P1S3, P1S2 and P1S1 respectively. For comparison, a catalyst C without waste plastic is prepared by microwave pyrolysis of a mixture of 1.5 g of sodium lignosulfonate and 0.5 g of NaOH at 800 W for 5 min. Different from the preparation process of P1S2, the P1S2-600 material is prepared by pyrolysis in a tubular furnace at 600 °C for 2 hours in a flowing N2 atmosphere. The specific surface areas of the prepared catalysts P1S2, P1S2-600 and C are 91.83 m 2 / g, 34.64 m 2 / g, 130.84 m 2 / g.

[0017] Figure 1 (a) is the SEM image of P1S2, Figure 1 (b) is the TEM image of P1S2. The morphology and structure of the catalyst were characterized by SEM, and it was found that the P1S2 catalytic material exhibited obvious porous structure characteristics. It can also be seen from Figure 1 (b) that the P1S2 catalytic material presented a porous structure.

[0018] Figure 2 (a) is the characterization of the crystal structure of the prepared catalytic material by XRD. No diffraction peaks of waste plastic PET were detected in all catalysts ( Figure 2 b), indicating that the plastic was successfully carbonized. Two broad signals were observed near 23.1 - 24.0° and 44.1° for all the prepared catalysts, which were attributed to the (002) and (100) crystal planes of amorphous carbon and crystalline carbon. Compared with C without added plastic, after adding PET, the (002) diffraction peak of amorphous carbon became broader and shifted from 23.1° to 24.0°. The broadening and displacement of the (002) diffraction peak indicated the presence of defects and amorphous carbon structure in the catalytic material. In addition, compared with P1S2-600 prepared by the traditional pyrolysis method, the (002) diffraction peak of the carbon material prepared by microwave was significantly broadened, which meant that microwave treatment also contributed to the generation of defects and amorphous structures. Figure 2(c) Raman spectroscopy tests were carried out to analyze the effects of the ratio of PET to sodium lignosulfonate and the pyrolysis method on the fine carbon structure in the metal-free carbon catalytic material samples. In Raman spectroscopy, the D band near 1350 cm -1 and the G band near 1580 cm -1 represent disordered carbon and graphitized carbon, and the intensity ratio of the D band to the G band (I D / I G ) represents the degree of disorder and defects in the carbon material. With the increase in the content of PET plastic, the defects of C, P1S4, P1S3, and P1S2 gradually increase, and the I D / I G value of P1S2 reaches 1.446. The formation of a porous structure in P1S2 may be the reason for the increase in the degree of defects. With the further increase in PET, the I D / I G value of P1S1 decreases, which may be due to the fact that excessive PET is not conducive to the formation of defects. The I D / I G value of P1S2-600 is 1.248, which is less than the I D / I G value of the microwave carbonized material P1S2, indicating that microwave is more conducive to the formation of defective carbon than the traditional pyrolysis method.

[0019] The specific surface area and pore characteristics of P1S2, P1S2-600, and C catalytic materials were tested by BET nitrogen adsorption-desorption isotherms ( Figure 2 d). The isotherm of the catalyst is consistent with the type-IV isotherm, indicating the presence of mesoporous structures. Compared with C (130.84 m 2 / g) without waste plastic, the specific surface area of P1S2 slightly decreases to 91.83 m 2 / g. However, when using the traditional pyrolysis method, the specific surface area of P1S2-600 decreases to 34.64 m 2 / g, indicating that the microwave treatment carbonization method is more conducive to the increase in the specific surface area during the construction of catalytic materials.

[0020] Figure 3 The components and valence states of the catalyst were determined by XPS. In the full spectrum of Figure 3 (a), the characteristic peaks of C, O, and S elements in the P1S2, P1S2-600, and C composite materials can be clearly seen. To study the valence states of C, O, and S, high-resolution XPS was used to detect the carbon material catalyst. In Figure 3The peaks at 284.8, 286.2, 288.4, and 290.8 eV in the C 1s of (b) are C=C, C-OH, C=O, and π-π*. It can be observed from the spectrum that the content of C=O is P1S2 > P1S2-600 > C, indicating that the introduction of PET and microwave treatment are both beneficial to the formation of C=O. The C=O in the catalytic material will be conducive to the activation of PMS to generate 1 O2, thus accelerating the degradation of pollutants. The C=O peak of P1S2-600 prepared by traditional pyrolysis is lower than that of P1S2 prepared by microwave-assisted pyrolysis, indicating that traditional pyrolysis is not conducive to the generation of C=O active sites. The peaks near 531.7, 533.2, and 535.4 eV in the O 1s are C-OH, C=O, and adsorbed oxygen ( Figure 3 c). Similarly, the characteristic peak of C=O in P1S2 is significantly higher than that in P1S2-600 and C, which corresponds to the phenomenon observed in the C 1s spectrum. Compared with C, some C=O groups in P1S2 should mainly come from waste plastic PET. For the S 2p spectrum in the catalytic material ( Figure 3 d), the signals near 164.0 and 165.0 eV are attributed to thiophene S 2p3 / 2 and 2p1 / 2. At the same time, 168.5 and 169.7 eV are attributed to surface-bound sulfite and sulfate. The S 2p spectrum indicates that various states of sulfur exist in all three materials.

[0021] Figure 4 is the EPR image of the catalyst P1S2, further clarifying the defects of P1S2. The g value of 2.003 confirms the existence of vacancy defects. Vacancy defects will lead to asymmetric charge distribution, changes in the local density of π electrons, and an increase in chemical activity in carbon materials, thereby further promoting the degradation of pollutants by enhancing substrate adsorption and promoting PMS activation. After PMS binds to P1S2 to form the PMS-carbon complex (C-S2O8 2- ), electron-rich pollutants tend to transfer electrons to C-S2O8 2- to promote PMS decomposition and pollutant removal. In this process, vacancy defects act as electron shuttle channels to promote the transfer of electrons from pollutants to PMS.

[0022] Example 2 (The reaction is shown in Table 1, entry 1, degradation of tetracycline (TC) by PMS) Set the temperature of the constant-temperature magnetic stirring water bath to 25 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TC (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it using a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It was found that the degradation rate of TC by PMS within 20 minutes was 17.4%, and the rate constant was 0.018 min -1 。 Example 3 (For the degradation of TC by the P1S2 catalyst, see Table 1, entry 2, reaction) Set the temperature of the constant-temperature magnetic stirring water bath to 25 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of the P1S2 catalyst and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TC (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it using a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It was found that the degradation rate of TC by the P1S2 catalyst within 20 minutes was 100%, and the rate constant was 0.303 min -1 。 Example 4 (For the degradation of TC by the C catalyst, see Table 1, entry 3, reaction) Set the temperature of the constant-temperature magnetic stirring water bath to 25 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of the C catalyst and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TC (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it using a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It was found that the degradation rate of TC by the C catalyst within 20 minutes was 64.8%, and the rate constant was 0.098 min -1 。 Example 5 (For the degradation of TC by the P1S2-600 catalyst, see Table 1, entry 4, reaction) Set the temperature of the constant-temperature magnetic stirring water bath to 25 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of P1S2-600 catalyst and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TC (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it using a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It was found that the degradation rate of TC by the P1S2-600 catalyst within 20 minutes was 72.2%, and the rate constant was 0.114 min -1 。

[0023]

[0024] Example 6 (The reaction is shown in Table 2, entry 1, degradation of TC by P1S4 catalyst) Set the temperature of the constant-temperature magnetic stirring water bath to 25 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of P1S4 catalyst and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TC (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it using a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It was found that the degradation rate of TC by the P1S4 catalyst within 20 minutes was 78.4%, and the rate constant was 0.125 min -1 。 Example 7 (The reaction is shown in Table 2, entry 2, degradation of TC by P1S3 catalyst) Set the temperature of the constant-temperature magnetic stirring water bath to 25 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of P1S3 catalyst and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TC (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it using a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It was found that the degradation rate of TC by the P1S3 catalyst within 20 minutes was 79.0%, and the rate constant was 0.139 min -1 。 Example 8 (The reaction is shown in Table 2, entry 4, degradation of TC by P1S1 catalyst) Set the temperature of the constant-temperature magnetic stirring water bath to 25 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of the P1S1 catalyst and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TC (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It was found that the degradation rate of TC by the P1S1 catalyst within 20 minutes was 82.4%, and the rate constant was 0.159 min -1 。

[0025]

[0026] Example 9 (The reaction is shown in Table 3, entry 1, degradation of TC by 0.06 g / L of the P1S2 catalyst) Set the temperature of the constant-temperature magnetic stirring water bath to 25 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.06 g / L of the P1S2 catalyst and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TC (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It was found that the degradation rate of TC by the P1S2 catalyst within 20 minutes was 86.0%, and the rate constant was 0.152 min -1 。 Example 10 (The reaction is shown in Table 3, entry 2, degradation of TC by 0.08 g / L of the P1S2 catalyst) Set the temperature of the constant-temperature magnetic stirring water bath to 25 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.08 g / L of the P1S2 catalyst and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TC (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It was found that the degradation rate of TC by the P1S2 catalyst within 20 minutes was 90.7%, and the rate constant was 0.187 min -1 。 Implementation Case 11 (Reaction see Table 3, Entry 4, Degradation of TC by P1S2 catalyst at 0.12 g / L) Set the temperature of the thermostatic magnetic stirring water bath to 25 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.12 g / L of P1S2 catalyst and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TC (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It was found that the degradation rate of TC by the P1S2 catalyst was 100% within 20 minutes, and the rate constant was 0.259 min -1 .

[0027]

[0028] Implementation Case 12 (Reaction see Table 4, Entry 1, Effect of 0.4 g / L of PMS on TC degradation) Set the temperature of the thermostatic magnetic stirring water bath to 25 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of P1S2 catalyst and 0.4 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TC (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It was found that the degradation rate of TC by the P1S2 catalyst was 66.7% within 20 minutes, and the rate constant was 0.109 min -1 . Implementation Case 13 (Reaction see Table 4, Entry 2, Effect of 0.5 g / L of PMS on TC degradation) Set the temperature of the thermostatic magnetic stirring water bath to 25 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of P1S2 catalyst and 0.5 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TC (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It was found that the degradation rate of TC by the P1S2 catalyst was 82.4% within 20 minutes, and the rate constant was 0.158 min-1 。 Implementation Case 14 (For the reaction, see Table 4, Entry 4, Effect of 0.7 g / L PMS on TC degradation) Set the temperature of the thermostatic magnetic stirring water bath to 25 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of the P1S2 catalyst and 0.7 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of an aqueous TC (10 mg / L) solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It was found that the degradation rate of TC by the P1S2 catalyst was 100% within 20 minutes, and the rate constant was 0.264 min -1 。

[0029]

[0030] Implementation Case 15 (For the reaction, see Table 5, Entry 1, Degradation of a 5 mg / L TC solution by the P1S2 catalyst.) Set the temperature of the thermostatic magnetic stirring water bath to 25 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of the P1S2 catalyst and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of an aqueous TC (5 mg / L) solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It was found that the degradation rate of TC by the P1S2 catalyst was 100% within 20 minutes, and the rate constant was 0.332 min -1 。 Implementation Case 16 (For the reaction, see Table 5, Entry 3, Degradation of a 15 mg / L TC solution by the P1S2 catalyst.) Set the temperature of the thermostatic magnetic stirring water bath to 25 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of P1S2 catalyst and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TC (15 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It is found that the degradation rate of TC by the P1S2 catalyst within 20 minutes is 93.7%, and the rate constant is 0.167 min -1 . Example 17 (For the reaction, see Table 5, entry 4, degradation of 20 mg / L TC solution by P1S2 catalyst.) Set the temperature of the thermostatic magnetic stirring water bath to 25 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of P1S2 catalyst and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TC (20 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It is found that the degradation rate of TC by the P1S2 catalyst within 20 minutes is 75.0%, and the rate constant is 0.091 min -1 .

[0031]

[0032] Example 18 (For the reaction, see Table 6, entry 1, degradation of TC by P1S2 catalyst at pH 2.6) Set the temperature of the thermostatic magnetic stirring water bath to 25 °C, and adjust the initial pH to 2.6 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of P1S2 catalyst and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TC (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It is found that the degradation rate of TC by the P1S2 catalyst within 20 minutes is 92.3%, and the rate constant is 0.173 min -1 . Implementation Case 19 (Reaction see Table 6, Entry 2, Degradation of TC by P1S2 Catalyst at pH 5.2) Set the temperature of the constant-temperature magnetic stirring water bath to 25 °C, and adjust the initial pH to 5.2 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of P1S2 catalyst and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TC (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It was found that the degradation rate of TC by the P1S2 catalyst within 20 minutes was 91.8%, and the rate constant was 0.160 min -1 . Implementation Case 20 (Reaction see Table 6, Entry 4, Degradation of TC by P1S2 Catalyst at pH 8.6) Set the temperature of the constant-temperature magnetic stirring water bath to 25 °C, and adjust the initial pH to 8.6 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of P1S2 catalyst and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TC (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It was found that the degradation rate of TC by the P1S2 catalyst within 20 minutes was 94.9%, and the rate constant was 0.197 min -1 . Implementation Case 21 (Reaction see Table 6, Entry 5, Degradation of TC by P1S2 Catalyst at pH 10.8) Set the temperature of the constant-temperature magnetic stirring water bath to 25 °C, and adjust the initial pH to 10.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of P1S2 catalyst and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TC (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It was found that the degradation rate of TC by the P1S2 catalyst within 20 minutes was 89.8%, and the rate constant was 0.129 min -1 .

[0033]

[0034] Example 22 (Reaction see Table 7, entry 1, degradation of TC by P1S2 catalyst at 15 °C) Set the temperature of the constant-temperature magnetic stirring water bath to 15 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of P1S2 catalyst and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TC (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It was found that the degradation rate of TC by the P1S2 catalyst within 20 minutes was 79.3%, and the rate constant was 0.142 min -1 。 Example 23 (Reaction see Table 7, entry 2, degradation of TC by P1S2 catalyst at 20 °C) Set the temperature of the constant-temperature magnetic stirring water bath to 20 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of P1S2 catalyst and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TC (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It was found that the degradation rate of TC by the P1S2 catalyst within 20 minutes was 89.8%, and the rate constant was 0.207 min -1 。 Example 24 (Reaction see Table 7, entry 4, degradation of TC by P1S2 catalyst at 30 °C) Set the temperature of the constant-temperature magnetic stirring water bath to 30 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of P1S2 catalyst and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TC (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It was found that the degradation rate of TC by the P1S2 catalyst within 20 minutes was 100%, and the rate constant was 0.332 min -1 。

[0035]

[0036] Example 25 (Reaction see Table 8, entry 1, degradation of TC by P1S2 catalyst in the presence of H2PO4 − ) Set the temperature of the constant-temperature magnetic stirring water bath to 25 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of P1S2 catalyst, 10 mmol / L of H2PO4 − solution and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TC (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It was found that the degradation rate of TC by the P1S2 catalyst was 95.3% within 20 minutes. Example 26 (Reaction see Table 8, entry 2, degradation of TC by P1S2 catalyst in the presence of SO4 − ) Set the temperature of the constant-temperature magnetic stirring water bath to 25 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of P1S2 catalyst, 10 mmol / L of SO4 − solution and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TC (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TC with a UV-visible spectrophotometer (357 nm). It was found that the degradation rate of TC by the P1S2 catalyst was 91.3% within 20 minutes. Example 27 (Reaction see Table 8, entry 3, degradation of TC by P1S2 catalyst in the presence of Cl − ) Set the temperature of the constant-temperature magnetic stirring water bath to 25 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of P1S2 catalyst, 10 mmol / L of Cl −The degradation reaction was initiated with a solution and 0.6 g / L of PMS. At predetermined time intervals, 1.5 mL of the reaction solution was withdrawn, filtered through a 0.22 µm microporous membrane, and the filtrate was injected into a centrifuge tube containing 1 mL of methanol. The concentration of TC was measured using a UV-visible spectrophotometer (357 nm), and it was found that the degradation rate of TC by the P1S2 catalyst was 91.9% within 20 minutes. Example 28 (Reaction see Table 8, entry 4, NO3 − Degradation of TC by the P1S2 catalyst in the presence of The temperature of the thermostatic magnetic stirring water bath was set at 25 °C, and the initial pH was adjusted to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. In a 100 mL round-bottom flask containing 50 mL of an aqueous TC (10 mg / L) solution, 0.10 g / L of the P1S2 catalyst, 10 mmol / L of NO3 − solution and 0.6 g / L of PMS were added to initiate the degradation reaction. At predetermined time intervals, 1.5 mL of the reaction solution was withdrawn, filtered through a 0.22 µm microporous membrane, and the filtrate was injected into a centrifuge tube containing 1 mL of methanol. The concentration of TC was measured using a UV-visible spectrophotometer (357 nm), and it was found that the degradation rate of TC by the P1S2 catalyst was 89.4% within 20 minutes. Example 29 (Reaction see Table 8, entry 5, effect of humic acid (HA) on the degradation of TC by the P1S2 catalyst) The temperature of the thermostatic magnetic stirring water bath was set at 25 °C, and the initial pH was adjusted to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. In a 100 mL round-bottom flask containing 50 mL of an aqueous TC (10 mg / L) solution, 0.10 g / L of the P1S2 catalyst, 0.2 g / L of humic acid solution, and 0.6 g / L of PMS were added to initiate the degradation reaction. At predetermined time intervals, 1.5 mL of the reaction solution was withdrawn, filtered through a 0.22 µm microporous membrane, and the filtrate was injected into a centrifuge tube containing 1 mL of methanol. The concentration of TC was measured using a UV-visible spectrophotometer (357 nm), and it was found that the degradation rate of TC by the P1S2 catalyst was 81.4% within 20 minutes.

[0037]

[0038] Example 30 (Reaction see Table 9, entries 1 - 5) To evaluate the stability of the P1S2 catalyst, 5 cyclic experiments were conducted. After each run, the obtained samples were collected by filtration, washing, and vacuum drying overnight. The resulting solid was used for the next cycle. The temperature of the thermostatic magnetic stirring water bath was set at 25 °C, and the initial pH was adjusted to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. 0.10 g / L of P1S2 catalyst and 0.6 g / L of PMS were added to initiate the degradation reaction in a 100 mL round-bottom flask containing 50 mL of TC (10 mg / L) aqueous solution. At predetermined time intervals, 1.5 mL of the reaction solution was extracted, filtered through a 0.22 µm microporous membrane, and the filtrate was injected into a centrifuge tube containing 1 mL of methanol. The concentration of TC was measured using a UV-visible spectrophotometer (357 nm). It was found that the degradation rate of TC by the P1S2 catalyst remained above 80% in the first four cyclic experiments and was 75.4% in the fifth cycle.

[0039]

[0040] Example 31 (The reaction is shown in Table 10, entry 1, degradation of oxytetracycline hydrochloride (OTC) by the P1S2 catalyst) The temperature of the thermostatic magnetic stirring water bath was set at 25 °C, and the initial pH was adjusted to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. 0.10 g / L of P1S2 catalyst and 0.6 g / L of PMS were added to initiate the degradation reaction in a 100 mL round-bottom flask containing 50 mL of OTC (10 mg / L) aqueous solution. At predetermined time intervals, 1.5 mL of the reaction solution was extracted, filtered through a 0.22 µm microporous membrane, and the filtrate was injected into a centrifuge tube containing 1 mL of methanol. The concentration of OTC was measured using a UV-visible spectrophotometer (352 nm). It was found that the degradation rate of OTC by the P1S2 catalyst was 89.4% within 20 minutes, and the rate constant was 0.244 min -1 。 Example 32 (The reaction is shown in Table 10, entry 2, degradation of sulfamethoxazole (SMX) by the P1S2 catalyst) Set the temperature of the constant-temperature magnetic stirring water bath to 25 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of P1S2 catalyst and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of SMX (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of SMX with a UV-visible spectrophotometer (267 nm). It was found that the degradation rate of SMX by the P1S2 catalyst within 20 minutes was 88.4%, and the rate constant was 0.203 min -1 .

[0041] Example 33 (For the reaction, see Table 10, entry 3, degradation of norfloxacin (NOR) by P1S2 catalyst) Set the temperature of the constant-temperature magnetic stirring water bath to 25 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of P1S2 catalyst and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of NOR (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of NOR with a UV-visible spectrophotometer (278 nm). It was found that the degradation rate of NOR by the P1S2 catalyst within 20 minutes was 100%, and the rate constant was 0.156 min -1 . Example 34 (For the reaction, see Table 10, entry 4, degradation of trichlorophenol (TCP) by P1S2 catalyst) Set the temperature of the constant-temperature magnetic stirring water bath to 25 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of P1S2 catalyst and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of TCP (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of TCP with a UV-visible spectrophotometer (281 nm). It was found that the degradation rate of TCP by the P1S2 catalyst within 20 minutes was 74.2%, and the rate constant was 0.430 min -1 . Example 35 (For the reaction, see Table 10, entry 5, degradation of carbamazepine (CBZ) by P1S2 catalyst) Set the temperature of the thermostatic magnetic stirring water bath to 25 °C, and adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of P1S2 catalyst and 0.6 g / L of PMS to a 100 mL round-bottom flask containing 50 mL of CBZ (10 mg / L) aqueous solution to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, inject the filtrate into a centrifuge tube containing 1 mL of methanol, and measure the concentration of CBZ with a UV-visible spectrophotometer (286 nm). It was found that the degradation rate of CBZ by the P1S2 catalyst was 83.2% within 20 minutes, and the rate constant was 0.116 min -1 .

[0042]

[0043] Example 36 (For the reaction, see Table 11, the effect of different quenchers on the degradation of TC) Methanol (MeOH) and tert-butanol (TBA) are commonly used as radical quenchers. MeOH can quench SO4 •‒ and • OH, TBA can quench • OH, p-benzoquinone (BQ) can quench O2 ·- , while curcumin (Cur) and potassium dichromate (K2Cr2O7) can quench singlet oxygen ( 1 O2) and electrons (e - ), respectively. Set the temperature of the thermostatic magnetic stirring water bath to 25 °C, adjust the initial pH to 6.8 with 0.1 mol / L sulfuric acid or sodium hydroxide solution. Add 0.10 g / L of P1S2 catalyst and an excess of quencher to a 100 mL flask containing 50 mL of TC aqueous solution (10 mg / L), and then add 0.6 g / L of PMS to the reactor to start the degradation reaction. Extract 1.5 mL of the reaction solution at predetermined time intervals, filter it through a 0.22 µm microporous membrane, and inject the filtrate into a centrifuge tube containing 1 mL of methanol. Then, detect the concentration of the TC solution with a UV-visible spectrophotometer at 357 nm. It was found that under the quenching effects of MeOH, TBA, BQ, Cur, and K2Cr2O7, the degradation rates of the P1S2 catalyst for TC were 89.5%, 93.1%, 89.4%, 88.8%, and 27.3% within 20 minutes, respectively. The quenching results show that the radical quenchers have little inhibitory effect on the degradation of TC by the P1S2 / PMS system, indicating that the metal-free catalytic material P1S2 prepared by microwave pyrolysis of waste plastics generates SO4 •‒ , • OH, O2 ·-The amount is very small, and the degradation of TC hardly depends on these three free radicals. After adding Cur, the inhibitory effect on TC degradation is very limited, and the degradation efficiency is 88.8%. This may be related to 1 the low oxidation ability and poor stability of O2. After adding the e - scavenger K2Cr2O7, the TC degradation efficiency decreased to 27.3%, indicating that electron transfer has the most obvious contribution in the P1S2 / PMS system. Generally speaking, in the P1S2 / PMS catalytic system, the degradation of TC is a non-free radical-involved pathway dominated by direct electron transfer, and the singlet oxygen 1 O2 generated by the catalytic activation of PMS plays a secondary role in the degradation of TC.

[0044]

Claims

1. Application of metal-free porous carbon material prepared by microwave carbonization of waste plastics in the degradation of organic pollutants, characterized in that: A simple microwave pyrolysis method was used to quickly synthesize a metal-free carbon material catalyst with porous morphology that can be used for efficient degradation of organic pollutants by pyrolyzing the low-cost and easily available waste plastic polyethylene terephthalate (PET) as raw material, NaOH as microwave absorber and pore-forming agent, and sodium lignin sulfonate as carbonization auxiliary agent in a microwave oven at 800 W for 5 min. The preparation steps of the metal-free porous carbon material catalyst are as follows: weigh 0.5 g of waste PET powder, 1.0 g of sodium lignin sulfonate and 0.5 g of NaOH, grind the mixture evenly in a ceramic mortar and put it into a 25 mL crucible, pyrolyze it in a commercial microwave oven with a power of 800 W for 5 min, and after the material is cooled, wash it with water / ethanol and vacuum dry it at 60°C for 12 hours to obtain the metal-free porous carbon catalytic material P1S2; keep the mass of NaOH at 0.5 g, when the mass ratio of PET powder to sodium lignin sulfonate is 1:4, 1:3, 1:2 and 1:1, the prepared materials are named P1S4, P1S3, P1S2 and P1S1 respectively; The degradation reaction of organic pollutants by catalyst-activated peroxymonosulfate (PMS) was as follows: the temperature was controlled by a constant temperature magnetic stirring water bath, the initial pH was adjusted by 0.1 mol / L sulfuric acid or sodium hydroxide solution, and the catalyst and PMS were added to 50 mL of aqueous solution containing 10 mg / L of organic pollutants to start the degradation process; 1.5 mL of the reaction solution was extracted at predetermined time intervals, filtered using a 0.22 µm microporous membrane, and the filtrate was injected into a centrifuge tube containing 1 mL of methanol, and the concentration of organic pollutants was determined by a UV-visible spectrophotometer.

2. The use of a metal-free porous carbon material prepared by microwave carbonization of waste plastics in the degradation of organic pollutants according to claim 1, characterized in that: The preparation process of the catalyst is simple and the preparation time is short. The prepared catalyst exhibits obvious porous structure characteristics. Compared with the traditional pyrolysis method, microwave treatment is not only beneficial to the expansion of specific surface area and the formation of defects, but also beneficial to the production of C=O in carbon materials.

3. The use of a metal-free porous carbon material prepared by microwave carbonization of waste plastics in the degradation of organic pollutants according to claim 1, characterized in that: The prepared metal-free porous carbon material P1S2 has high degradation efficiency for organic pollutants. The removal rate of tetracycline can reach 100% within 20 minutes, and the rate constant can reach 0.303 min −1 The removal rates of oxytetracycline, sulfamethoxazole, norfloxacin, trichlorophenol and carbamazepine were 100%, 89.4%, 88.4%, 100% and 74.2%, respectively, which confirmed that the P1S2 / PMS catalytic system has good applicability for the degradation of different organic pollutants.

4. The use of a metal-free porous carbon material prepared by microwave carbonization of waste plastics in the degradation of organic pollutants according to claim 1, characterized in that: In the P1S2 / PMS catalytic system, the degradation of TC is a non-radical pathway dominated by direct electron transfer. The singlet oxygen generated by PMS is activated. 1 O2 is the secondary active species.

Images