CN114570368A

CN114570368A - Preparation of cobalt-phosphorus-based catalyst and application of cobalt-phosphorus-based catalyst in activation of persulfate to degradation of antibiotics in wastewater

Info

Publication number: CN114570368A
Application number: CN202210183806.3A
Authority: CN
Inventors: 杨春平; 傅鑫涛; 吴少华; 林燕; 王岳; 李翔; 邬鑫; 邹俊聪
Original assignee: Hunan University
Current assignee: Hunan University
Priority date: 2022-02-28
Filing date: 2022-02-28
Publication date: 2022-06-03

Abstract

The invention discloses a preparation method of a cobalt-based phosphorus catalyst and application of the cobalt-based phosphorus catalyst in degrading antibiotics in wastewater by activating persulfate. According to the method, the activity of the cobalt phosphorus catalyst limited by porous carbon is adjusted to improve the persulfate activation efficiency, so that various antibiotic wastewater is degraded, the process has the advantages of simplicity in operation, no byproduct generation, high reaction rate, good degradation effect, economy, environmental friendliness and the like, the antibiotics can be rapidly degraded in complex water quality, the antibiotics in wastewater containing high-concentration salt and complex practical water can be completely removed, and meanwhile, the catalyst shows excellent stress resistance, so that the method has a good prospect in industrial wastewater and practical application.

Description

Preparation of cobalt-phosphorus-based catalyst and application of cobalt-phosphorus-based catalyst in activation of persulfate to degradation of antibiotics in wastewater

Technical Field

The invention belongs to the field of water treatment, and particularly relates to a preparation method of a cobalt-phosphorus based catalyst and application of the cobalt-phosphorus based catalyst in degradation of antibiotics in wastewater by activating persulfate.

Background

With the increasing production and use of various antibiotics, a large amount of antibiotic wastewater is generated, and the content of the antibiotics in natural water is correspondingly increased, so that serious environmental and health risks are brought. Taking sulfamethoxazole pharmaceutical wastewater as an example, the concentration of pollutants is high, the COD value can reach tens of thousands or hundreds of thousands of milligrams per liter, and meanwhile, a large amount of salt substances exist in the wastewater, so that the traditional biological treatment method is greatly inhibited. In recent years, the persulfate-based advanced oxidation process has good practical performance in treating high-concentration organic wastewater, and compared with the defects of limited oxidation capacity of hydroxyl free radical generated in the traditional Fenton process, generation of a large amount of iron mud and the like, the persulfate-based advanced oxidation process can realize efficient removal of organic matters in wastewater without generation of other products. However, the persulfate process is mainly limited by the activation efficiency, the traditional ultrasonic, heating and ultraviolet irradiation cannot promote the high activation of the persulfate, the transition metal catalyst can realize the high-efficiency activation of the persulfate, but the persulfate is easy to leach out and brings harm to the aquatic environment, and therefore the construction of the high-efficiency and stable transition metal catalyst is the key point of the persulfate activation technology.

Meanwhile, the transition metal phosphide formed after the phosphorization can further improve the catalytic performance. In recent years, phosphorus cobaltate has been attracting much attention because of its high catalytic performance, but is limited by the leaching of metal ions and the influence of each component of wastewater, and the like, making it difficult to be put into practical use. Therefore, the synthesis of stable phosphorus cobaltate capable of maintaining good catalytic performance under high salt condition and high organic matter condition is a necessary measure for improving the application of the phosphorus cobaltate.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide the preparation of a cobalt-based phosphorus catalyst which is environment-friendly, high in treatment efficiency, good in removal effect and high in salt resistance and the application of the cobalt-based phosphorus catalyst in activating persulfate to degrade antibiotics in wastewater.

In order to solve the technical problems, the invention adopts the technical scheme that:

a process for preparing the cobalt-phosphorus based catalyst used to activate persulfate for degrading the antibiotics in sewage includes in-situ doping zeolite imidazole ester skeleton precursor, high-temp calcining

The carbonization is carried out, then the low-temperature oxidation is carried out, finally the phosphorus doping is carried out under the low-temperature condition, thereby forming the carbonization-oxidation-phosphorization flow pattern, and the method comprises the following steps:

s1, synthesizing the stable cobaltosic oxide and carbon material composite precursor through primary calcination, secondary calcination and acid washing.

S2, synthesizing the porous carbon matrix-limited cobalt phosphorus catalyst under low-temperature conditions by doping with different amounts of phosphorus sources.

In a further improvement of the above method, in step S1, the method comprises the steps of:

(1) 2.87 g of cobalt nitrate is dissolved in 80-100 ml of methanol solution, which is called 1 solution. 6.52g of 2-methylimidazole is dissolved in 200-220 ml of methanol solution, which is called 2 solution. Then the solution 1 is poured into the solution 2 quickly, and stirred vigorously at room temperature of 20-30 ℃. And after 12-14 h, carrying out high-speed centrifugation to collect a purple product, washing the purple product with ultrapure water and methanol for more than three times, putting the washed purple product into a vacuum drying oven, and drying the purple product for 8-10 h at the temperature of 60-80 ℃ to obtain a blocky purple product.

(2) Grinding the blocky purple product in the step (1) into powder, then placing the powder into a tube furnace, and carrying out primary calcination under an argon atmosphere to obtain a black powder product. The argon atmosphere is a mixed atmosphere containing argon and air; the volume fraction of argon in the argon atmosphere is 5%; the heating rate in the primary calcination process is 2-5 ℃/min; the calcining temperature is 800-1000 ℃; the calcining time is 3-5 h;

(3) washing the black powder product in the step (2) by 0.5mol/L to remove unstable cobalt on the surface of the material, then washing the material for multiple times until the solution is neutral, and then putting the material into a vacuum drying oven to dry the material for 12-16 h at the temperature of 60-80 ℃. The ratio of sulfuric acid to black powder products in the acid washing process is 100ml to 1 g; the temperature in the acid washing process is 70-80 ℃; the pickling time is 12-14 h;

(4) placing the product obtained in the step (3) in a tube furnace, and carrying out secondary calcination in air atmosphere to obtain carbon material-coated cobaltosic oxide nanoparticles, namely Co₃O₄and/NC. The temperature rise rate in the secondary calcination process is 2-5 ℃/min; the calcining temperature is 350-400 ℃; the calcining time is 4-6 h;

in a further improvement of the above process, in step S2, the process includes a synthetic carbon matrix-defined cobalt-phosphorous catalyst comprising: placing a phosphorus source upstream of the quartz boat, Co₃O₄Placing the quartz boat at the downstream of the NC, then placing the quartz boat in a tube furnace, and carrying out reaction under argon atmosphere to obtain CoP/NC. Co₃O₄The mass ratio of NC to sodium hypophosphite is 1: 1-100; the phosphorus source is sodium hypophosphite monohydrate and other medicines capable of generating gaseous phosphine; the argon atmosphere is a mixed atmosphere containing argon and air; the above-mentionedThe volume fraction of argon in the argon atmosphere is 5 percent; the heating rate in the reaction process is 2-5 ℃/min; the reaction temperature is 300-350 ℃; the reaction time is 2-4 h;

the method is further improved, adopts the preparation of the cobalt-based phosphorus catalyst and the application thereof in activating persulfate to degrade antibiotics in wastewater, and comprises the following steps: mixing the CoP/NC catalyst with the antibiotic wastewater, and performing degradation reaction at 20-50 ℃ to realize the degradation of the antibiotic in the wastewater; the addition amount of the CoP/NC catalyst is 10-100 mg of the CoP/NC catalyst added in each liter of antibiotic wastewater; the antibiotic wastewater is antibiotic wastewater containing various high-concentration salts or surface water containing antibiotics from different sources; the initial concentration of the antibiotics in the antibiotic wastewater is 1-100 mg/L, and the initial concentration of various salts in the wastewater is 0.05-0.6 mM; the persulfate is one or two of peroxymonosulfate or peroxydisulfate; the concentration of the persulfate is 0.01-3.0 mM; the pH value of the reaction system is 3-11; the antibiotic in the antibiotic wastewater is at least one of sulfamethoxazole, sulfamethazine, tetracycline, terramycin, penicillin and bisphenol.

The principle of the invention is as follows: ZIF-67 generated by the reaction of cobalt nitrate and a zeolite imidazole ester framework is taken as a precursor, and different CoP/NC catalysts are obtained by modifying and regulating the proportion of phosphorus in the material. Therefore, the invention obtains the CoP/NC with high catalytic performance by regulating and controlling the content of phosphorus in the catalyst. The high catalytic performance of CoP is utilized to activate persulfate so as to promote the generation of sulfate radicals and singlet oxygen, thereby treating the antibiotics in the wastewater.

Compared with the prior art, the invention has the advantages that:

(1) the invention provides a preparation method of a cobalt-phosphorus-based catalyst and application of the cobalt-phosphorus-based catalyst in degradation of antibiotics in wastewater by activating persulfate. The synthesized CoP/NC has high catalytic performance, the activity of the synthesized CoP/NC can be adjusted by adjusting the content of phosphorus, the synthesized CoP/NC can be in contact with persulfate to realize the degradation of antibiotics in a short time, and meanwhile, the synthesized CoP/NC is a green and friendly catalyst, and the leaching amount of metal ions is little, so that the synthesized CoP/NC is harmless to the environment.

(2) The process adopted in the invention has no byproduct generation and does not need to be carried out twice, thereby providing an economic, energy-saving and environment-friendly process. The process realizes the degradation of antibiotics under the conditions of high salt and high concentration of organic matters. Meanwhile, the process has small influence on the pH, and the antibiotic can be degraded in a large range.

(3) The catalyst synthesis method has the advantages of safety, simplicity, easy operation, low requirements on preparation conditions and preparation equipment, low cost, high yield, greenness, no pollution and the like, can form chain production, and is easy for large-scale production.

(4) According to the invention, the catalyst can tolerate the interference of natural organic substances in the water body, and has high efficiency in removing antibiotics in the actual natural water body, so that the catalyst has practical application potential.

Drawings

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention.

FIG. 1 is a graph showing the degradation effect of the porous carbon-defined cobalt phosphorus catalyst with different phosphorus content control on sulfamethoxazole under different time conditions in example 1.

FIG. 2 is a graph showing the degradation effect of the porous carbon-defined cobalt phosphorus catalyst on sulfamethoxazole under different concentrations of chloride salt in example 2.

FIG. 3 is a graph of the free chlorine yield of the porous carbon-defined phosphorus cobalt catalyst of example 2 at various concentrations of chloride salt.

FIG. 4 is a graph showing the degradation effect of the porous carbon-defined cobalt phosphorus catalyst on sulfamethoxazole under different concentrations of sulfate in example 2.

FIG. 5 is a graph showing the degradation effect of the porous carbon-limited cobalt phosphorus catalyst on sulfamethoxazole under different time conditions at different temperatures in example 3.

FIG. 6 is a graph showing the degradation effect of the porous carbon-limited cobalt phosphorus catalyst on sulfamethoxazole in an actual water body under different time conditions in example 4.

Detailed Description

The invention is further described below with reference to the drawings and specific preferred embodiments of the description, without thereby limiting the scope of protection of the invention.

Example 1

The preparation method of the cobalt-phosphorus based catalyst and the application of the cobalt-phosphorus based catalyst in activating persulfate to degrade sulfamethoxazole in wastewater specifically comprises the following steps of treating sulfamethoxazole wastewater by using a porous carbon-limited cobalt-phosphorus catalyst:

weighing porous carbon limited cobalt phosphorus catalyst (CoP/NC-1, CoP/NC-5, CoP/NC-10, CoP/NC-30, CoP/NC-50), carbon material and cobaltosic oxide composite catalyst (Co/NC-1, CoP/NC-5, CoP/NC-50)₃O₄/NC), 4mg of each was added to 100ml of sulfamethoxazole solution (0.1mM of peroxomonosulfate was added to the solution simultaneously with the catalyst) at a concentration of 5mg/L, and the reaction was started by starting the water bath shaker. All the above reactions were carried out in 250ml Erlenmeyer flasks; the pH of the solution is 7.5; the shaker speed was 150 rmp. The temperature of the water bath shaking table is 30 ℃;

blank group: no catalyst was added, and the other conditions were the same.

During the reaction, 1.0mL of sample was collected and immediately mixed with an excessive amount of sodium thiosulfate solution at 1, 2, 3, 4, 5 and 7min, respectively, the concentration of the remaining sulfamethoxazole was measured by high performance liquid chromatography, and the degradation of sulfamethoxazole by activated peroxymonosulfate with the porous carbon-limited cobalt-based phosphorus catalyst at different times was calculated, and the results are shown in FIG. 1.

FIG. 1 is a graph showing the degradation effect of the porous carbon-defined cobalt phosphorus catalyst with different phosphorus content control on sulfamethoxazole under different time conditions in example 1. As can be seen from FIG. 1, in the absence of a catalyst, degradation of sulfamethoxazole is hardly achieved by the unactivated salt of monopersulfate. When catalyzed, the sulfamethoxazole group can achieve substantially complete degradation. It can be observed that the degradation effect of CoP/NC-1, CoP/NC-5 and CoP/NC-10 on sulfamethoxazole is better than that of the precursor Co3O4/NC, while the degradation effect of CoP/NC-30 and CoP/NC-50 on sulfamethoxazole is worse than that of Co3O 4/NC. This result reflects the control of catalyst activity by doping with different amounts of phosphorus. Meanwhile, as can be seen from FIG. 1, CoP/NC-5 shows the optimal catalytic activity to almost achieve 100% removal of sulfamethoxazole within 1min, while other catalysts can achieve removal within 7 min.

In this embodiment, the preparation method of a porous carbon-limited cobalt-phosphorus catalyst (CoP/NC-5) includes the following steps:

(1) 2.87 grams of cobalt nitrate was dissolved in 80ml of methanol solution, referred to as 1 solution. 6.52g of 2-methylimidazole are dissolved in 200ml of methanol solution, referred to as 2 solution. The solution 1 was then poured rapidly into the solution 2 and stirred vigorously at room temperature at 25 ℃. And after 12h, carrying out high-speed centrifugation to collect a purple product, washing the purple product for more than three times by using ultrapure water and methanol, putting the washed purple product into a vacuum drying oven, and drying the purple product for 8h at the temperature of 60 ℃ to obtain a blocky purple product.

(2) Grinding the blocky purple product in the step (1) into powder, then placing the powder into a tube furnace, and carrying out primary calcination under an argon atmosphere to obtain a black powder product. The argon atmosphere is a mixed atmosphere containing argon and air; the volume fraction of argon in the argon atmosphere is 5%; the heating rate in the primary calcination process is 2 ℃/min; the calcining temperature is 900 ℃; the calcining time is 3 hours;

(3) washing the black powder product in the step (2) with 0.5mol/L to remove unstable cobalt on the surface of the material, then washing the material for multiple times until the solution is neutral, and then putting the material into a vacuum drying oven to dry the material for 12 hours at 60 ℃. The proportion of sulfuric acid to black powder products in the acid washing process is 100ml:1 g; the temperature in the acid washing process is 80 ℃; the pickling time is 12 hours;

(4) putting the product obtained in the step (3) into a tube furnace, and carrying out secondary calcination in air atmosphere to obtain carbon material-coated cobaltosic oxide nanoparticles called Co₃O₄and/NC. The heating rate in the secondary calcination process is 2 ℃/min; the describedThe calcining temperature is 350 ℃; the calcining time is 4 h;

(5) in step (4), the method comprises the following steps: placing sodium hypophosphite at the upstream of the quartz boat, Co₃O₄Placing the quartz boat at the downstream of the NC, then placing the quartz boat in a tube furnace, and carrying out reaction under argon atmosphere to obtain CoP/NC-5₃O₄The ratio of NC to sodium hypophosphite is 1: 5; the argon atmosphere is a mixed atmosphere containing argon and air; the volume fraction of argon in the argon atmosphere is 5%; the heating rate in the reaction process is 2 ℃/min; the temperature of the reaction is 300 ℃; the reaction time was 2 h.

Example 2

The preparation method of the cobalt phosphorus-based catalyst and the application method of the cobalt phosphorus-based catalyst in activating persulfate to degrade sulfamethoxazole in high-salt wastewater are basically the same as those in example 1, and the differences are only that: the sulfamethoxazole wastewater solution of example 2 was added with different concentrations of chloride and sulfate, respectively, at concentrations of 0, 50, 100, and 600 mM. The catalyst in example 2 was selected from CoP/NC-5 in example 1.

FIG. 2 is a graph showing the degradation effect of the porous carbon-limited cobalt-phosphorus catalyst on sulfamethoxazole under different concentrations of chloride salt in example 2 of the present invention. As can be seen from FIG. 2, in the chlorine salt system, the degradation rate of sulfamethoxazole is obviously accelerated, and the higher the concentration is, the faster the degradation rate is, which reflects that sulfamethoxazole can be efficiently degraded in high-chlorine wastewater. Subsequently, by analyzing the active species in the high-chlorine system, it can be seen from FIG. 3 that the degradation of sulfamethoxazole is promoted by the free chlorine generated in the reaction, and when the system does not have a CoP/NC-5 catalyst, the chloride ions react with persulfate to generate free chlorine and the yield of free chlorine increases as the concentration of chloride ions increases. When the system is added with the CoP/NC-5 catalyst, the yield of free chlorine is further improved, and part of the free chlorine participates in the degradation of sulfamethoxazole.

FIG. 4 is a graph showing the degradation effect of the porous carbon-limited cobalt-phosphorous catalyst on sulfamethoxazole under different concentrations of sulfate in example 2 of the present invention. As can be seen from FIG. 4, in the high sulfate system, the degradation of sulfamethoxazole is inhibited to a certain extent, and the stronger the inhibition effect is with the increase of concentration, 50mM of sulfate ion shows a slight inhibition effect and 300 and 600mM of sulfate ion have stronger inhibition effect, but the degradation rate of sulfamethoxazole is inhibited by high concentration of sulfate and the degradation effect is not inhibited, and the degradation effect can reach 100% within 7 min.

Example 3

4 groups of the CoP/NC-5 catalyst of example 1, 4mg each, were weighed out and added to 100ml of 5mg/L sulfamethoxazole solution (0.1mM of peroxomonosulfate was added to the solution together with the catalyst), and then the reaction was started on a water bath shaker, and the temperature was controlled using a water bath shaker, and the reaction temperature of each of the four groups was 20 ℃, 30 ℃, 40 ℃ and 50 ℃. All the reactions described above were carried out in 250ml Erlenmeyer flasks; the pH of the solution is 7.5; the shaker speed was 150 rmp.

During the reaction, 1.0mL of sample was collected and immediately mixed with an excessive amount of sodium thiosulfate solution at 0.5, 1, 2, 3, 4, 5 and 7min, respectively, the concentration of the remaining sulfamethoxazole was measured by high performance liquid chromatography, and the degradation of sulfamethoxazole by the porous carbon-limited cobalt-activated phosphonium catalyst activated peroxymonosulfate at different times was calculated, and the results are shown in FIG. 5.

FIG. 5 is a graph showing the degradation effect of the porous carbon-limited cobalt phosphorus catalyst on sulfamethoxazole under different time conditions at different temperatures in example 3. As can be seen from the figure, the temperature has obvious influence on the degradation of sulfamethoxazole, when the reaction temperature is 20 ℃, the reaction rate is obviously slower than that of other groups, the activation rate of the peroxymonosulfate is slower at the temperature, but the low temperature only influences the reaction process, but the final degradation efficiency can still reach 100%. Although the temperatures of other three groups are greatly different, the difference is small, the reaction rate is faster along with the temperature rise within 1min, and the degradation efficiency of sulfamethoxazole can reach 100% within 1min in three groups of experiments at different temperatures.

Example 4

The preparation method of the cobalt-phosphorus based catalyst and the application of the cobalt-phosphorus based catalyst in activating persulfate to degrade sulfamethoxazole in practical water bodies specifically comprise the following steps of treating sulfamethoxazole wastewater by using the cobalt-phosphorus based catalyst limited by porous carbon:

4 groups of the CoP/NC-5 catalyst of example 1, 4mg each, were weighed out and added to 100ml of a 1mg/L sulfamethoxazole real water sample (0.1mM of peroxomonosulfate was added to the solution simultaneously with the catalyst), followed by initiation of the reaction by shaking in a water bath. All the above reactions were carried out in 250ml Erlenmeyer flasks; the pH of the solution is 7.5; the shaker speed was 150 rmp. The temperature of the water bath shaker is 30 ℃. The actual water samples are Hunan river water samples and post lake water samples.

During the reaction, at 1, 2, 3, 4, 5 and 7min, 1.0mL of sample was collected and immediately mixed with an excess of sodium thiosulfate solution, the concentration of the remaining sulfamethoxazole was measured by high performance liquid chromatography, and the degradation of sulfamethoxazole by activated peroxymonosulfate with the porous carbon-limited cobalt-based phosphorus catalyst at different times was calculated, and the results are shown in FIG. 6.

FIG. 6 is a graph showing the degradation effect of the porous carbon-limited cobalt phosphorus catalyst on sulfamethoxazole in an actual water body under different time conditions in example 4. As can be seen from FIG. 6, in two practical water bodies, the degradation rate of the methyl oxazole of sulfamethoxazole is lower than that of the ultrapure water system in example 1, which is attributed to the fact that a large amount of free organic substances exist in the practical water body and a part of the organic substances consume active substances generated by the reaction, although the reaction rate is inhibited to a certain extent in the practical water body, the final removal effect of sulfamethoxazole can still reach 100% within 3min, which indicates that the cobalt-phosphorus catalyst defined by porous carbon has practical application prospects in removing antibiotics in the practical water body by activating persulfate.

Claims

1. The preparation method of the cobalt-based phosphorus catalyst and the application of the cobalt-based phosphorus catalyst in activated persulfate degradation wastewater are characterized in that the activity of the porous carbon-limited cobalt-based phosphorus catalyst is controlled by regulating phosphorus content to carry out oxidation treatment on the antibiotics in the wastewater, the porous carbon-limited cobalt-based phosphorus catalyst comprises a graphitized carbon matrix, and the graphitized carbon matrix is internally wrapped with cobalt-based phosphorus nanoparticles.

2. The method according to claim 1, wherein the content of CoP in the nano-particles of phosphorus cobaltate encapsulated in the graphitized carbon matrix is 2% to 8%, and the percentage content of phosphorus atoms in the nano-particles of phosphorus cobaltate encapsulated in the graphitized carbon matrix is 2% to 20%.

3. The method according to claim 2, wherein the method of preparing the porous carbon-defined phosphorus cobaltate catalyst with activity controlled by regulating phosphorus content comprises the steps of:

S2, synthesizing the porous carbon-limited cobalt phosphorus catalyst by doping with different amounts of phosphorus sources under low temperature conditions.

4. The method according to claim 3, wherein in step S1, the method cobalt and carbon material composite precursor comprises the steps of:

(1) 2.87 g of cobalt nitrate was dissolved in 80 to 100ml of a methanol solution, which was referred to as a 1 solution. 6.52g of 2-methylimidazole is dissolved in 200-220 ml of methanol solution, which is called 2 solution. Then the solution 1 is poured into the solution 2 quickly, and stirred vigorously at room temperature of 20-30 ℃. And after 12-14 h, carrying out high-speed centrifugation to collect a purple product, washing the purple product with ultrapure water and methanol for more than three times, putting the washed purple product into a vacuum drying oven, and drying the purple product for 8-10 h at the temperature of 60-80 ℃ to obtain a blocky purple product.

(3) washing the black powder product in the step (2) by 0.5mol/L to remove unstable cobalt on the surface of the material, then washing the material for multiple times until the solution is neutral, and then putting the material into a vacuum drying oven to dry the material for 12-16 h at the temperature of 60-80 ℃. The proportion of sulfuric acid to black powder products in the acid washing process is 100ml:1 g; the temperature in the acid washing process is 70-80 ℃; the pickling time is 12-14 h;

in a further improvement of the above process, in step S2, the process includes a synthetic carbon matrix-defined cobalt-phosphorous catalyst comprising: placing a phosphorus source upstream of the quartz boat, Co₃O₄Placing the quartz boat at the downstream of the NC, then placing the quartz boat in a tube furnace, and carrying out reaction under argon atmosphere to obtain CoP/NC. Co₃O₄The mass ratio of NC to sodium hypophosphite is 1: 1-100; the phosphorus source is sodium hypophosphite monohydrate and other medicines capable of generating gaseous phosphine; the argon atmosphere is a mixed atmosphere containing argon and air; the volume fraction of argon in the argon atmosphere is 5%; the heating rate in the reaction process is 2-5 ℃/min; the reaction temperature is 300-350 ℃; the reaction time is 2-4 h.

5. The method according to claim 4, wherein the tricobalt tetroxide and carbon material composite precursor is Co₃O₄(ii)/NC, the porous carbon-defined cobalt-phosphorous catalyst being CoP/NC; the Co₃O₄The specific surface area of/NC is 400-500 m²·g^-1The aperture is 2-4 nm, and the particle size is 200-270 nm; the specific surface area of the CoP/NC is 190-250 m²·g^-1The pore diameter is 2.5 to 5nm, and the particle diameter is 210 to 280 nm.

6. The preparation method of the cobalt-phosphorus based catalyst and the application of the cobalt-phosphorus based catalyst in activating persulfate to degrade antibiotics in wastewater according to any one of claims 1 to 5, wherein the oxidation treatment of the antibiotics in the wastewater is performed by adopting the cobalt-phosphorus catalyst limited by porous carbon, and the method comprises the following steps: mixing a phosphorus cobaltate catalyst limited by porous carbon with the antibiotic wastewater, and adding persulfate to perform catalytic oxidation reaction, thereby degrading the antibiotic in the wastewater.

7. The preparation method of the cobalt-phosphorus based catalyst and the application of the cobalt-phosphorus based catalyst in activating persulfate degradation wastewater according to claim 6 are characterized in that the addition amount of the porous carbon-limited cobalt-phosphorus catalyst is 10-100 mg of the porous carbon-limited cobalt-phosphorus catalyst added in each liter of antibiotic wastewater; the antibiotic wastewater is antibiotic wastewater containing various high-concentration salts or surface water containing antibiotics from different sources; the persulfate is one or two of peroxymonosulfate or peroxydisulfate; the pH value of the reaction system is 3-11; the antibiotic in the antibiotic wastewater is at least one of sulfamethoxazole, sulfamethazine, tetracycline, terramycin, penicillin and bisphenol.

8. The preparation method of the cobalt-based phosphorus catalyst and the application of the cobalt-based phosphorus catalyst in activated persulfate degradation wastewater, according to claim 7, wherein the initial concentration of the antibiotics in the antibiotic wastewater is 1-100 mg/L, and the initial concentration of various salts in the wastewater is 50-600 mM; the concentration of the persulfate is 0.01-3.0 mM; the reaction temperature is 20-50 ℃.