A method for removing organic pollutants from water bodies using activated persulfate

Abstract

The application discloses a method for removing organic pollutants in water bodies by activating persulfate, and comprises the following steps: adding a metal precursor into a solvent to obtain a metal precursor solution; adding an organic ligand into the solvent to obtain a ligand solution; adding the ligand solution into the metal precursor solution and adding an additive to react, and after the reaction is completed, post-treatment is performed to obtain a conductive coordination polymer containing metal-nitrogen active sites; and the conductive coordination polymer and the persulfate are put into the water body containing the organic pollutants to complete degradation of the organic pollutants. The conductive coordination polymer containing the metal-nitrogen active sites is used as a catalyst, high-density and active center coordination configuration adjustable metal-nitrogen active sites are used to efficiently activate the persulfate, and the purpose of quickly removing the organic pollutants in the water bodies is achieved.

Description

Technical Field

[0001] This invention belongs to the field of environmental remediation technology, specifically relating to a method for removing organic pollutants from water bodies using activated persulfate. Background Technology

[0002] Organic pollutants are among the most prevalent and harmful pollutants in water bodies. Persulfate-activated advanced oxidation technologies (PS-AOPs) possess high redox potentials (2.5–3.1 V), long half-lives (30–40 μs), and a wide pH range (2–9), making them an economical and efficient means of degrading organic pollutants in water. Persulfate activation typically employs physical and chemical activation methods. Conventional physical activation methods, such as heating, ultraviolet light, and microwaves, suffer from low activation efficiency and high energy consumption. Commonly used chemical activation methods include homogeneous and heterogeneous catalytic activation. Homogeneous catalytic activation may lead to metal ion leaching and deposition, causing secondary pollution. Heterogeneous catalytic activation uses catalysts, such as transition metal oxides, which offer higher stability and reusability, but insufficient exposure of active metal centers results in unsatisfactory catalytic efficiency, a bottleneck hindering the development of PS-AOPs.

[0003] The invention patent (application number: 202010123675.0) discloses a magnetic material for in-situ growth of CNTs using MOFs that can activate persulfate. A MOF precursor is formed by combining dihydroxybenzoic acid and a bimetallic salt, which is then mixed with melamine and calcined at an appropriate temperature to prepare a magnetic material for in-situ growth of carbon nanotubes. This method can achieve the purpose of activating persulfate and degrading organic matter in water.

[0004] The invention patent (application number: 202110299892.X) discloses a MOF-derived FeO / Fe3C@C / N magnetic mesoporous composite material and its preparation method. The MOF precursor (Fe(Hbidc)) is prepared by hydrothermal method using dicarbonylcyclopentadienyl iron dimer as metal source and benzimidazole-5,6-dicarboxylic acid as organic ligand. Then, the magnetic carbonized derivative (FeO / Fe3C@C / N) is obtained by high-temperature calcination and used as a persulfate activated catalyst.

[0005] The invention patent (application number: 202210340856.8) discloses a Co-MOF-derived cobalt carbon-nitrogen hollow polyhedral catalyst and its application in the catalytic activation of persulfate. The inventors believe that this hollow polyhedral catalyst can reduce the dissolution of cobalt metal and can effectively degrade low-concentration pollutants at the ppb level.

[0006] The aforementioned catalyst for activating persulfate was prepared using MOFs as raw materials and through calcination. Although MOFs have a high specific surface area and well-developed pore structure, and are rich in metal active centers, after calcination, metal atoms aggregate to form metal nanoparticles, and the coordination configuration of the metal-nitrogen active sites is unclear, resulting in low catalytic activity and poor selectivity. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for removing organic pollutants from water by activating persulfate. The method uses a conductive coordination polymer containing metal-nitrogen active sites as a catalyst and utilizes high-density metal-nitrogen active sites with tunable coordination configurations to efficiently activate persulfate, thereby achieving the goal of rapidly removing organic pollutants from water.

[0008] This invention provides the following technical solution:

[0009] A method for removing organic pollutants from water using activated persulfate includes the following steps:

[0010] The metal precursor is added to the solvent to obtain a metal precursor solution;

[0011] Organic ligands are added to a solvent to obtain a ligand solution;

[0012] The ligand solution was added to the metal precursor solution, and additives were added to carry out the reaction. After the reaction was completed, post-treatment was performed to obtain a conductive coordination polymer containing metal-nitrogen active sites.

[0013] The conductive coordination polymer and persulfate are added to water containing organic pollutants to complete the degradation of the organic pollutants.

[0014] Furthermore, the metal precursor is one or more combinations of hydrochloride, acetate, sulfate, nitrate, and oxalate of Fe, Co, Ni, Cu, and Mn metals.

[0015] Furthermore, when the metal in the metal precursor is a bimetal, the molar ratio of the two metals is (9:1) to (1:9); when the metal in the metal precursor is a multimetal, the ratio of the molar amount of one metal to the sum of the molar amounts of the other metals is (9:1) to (1:9).

[0016] Furthermore, the organic ligand is an organic compound capable of forming a π-π / π-d conjugated structure with metal ions.

[0017] Furthermore, the organic ligand includes one of 2,3,6,7,10,11-hexamethylenebenzobenzene (HITP), hexamethylenebenzene hydrochloride (HAB), 1,2,4,5-phenyltetramine hydrochloride (BTA), 1,3,5-triamino-2,4,6-trinitrobenzene (TATB), and their derivatives.

[0018] Furthermore, the organic ligand also includes one of tetrahydroxy-p-benzoquinone (THQ), 2,3,6,7,10,11-hexahydroxybenzophenanthrene (HHTP), benzothiophenol (BHT), thiofulvalene benzoic acid (TTF), and their derivatives. This organic ligand can be used in combination with the organic ligand described above in a 1:1 molar ratio.

[0019] Furthermore, the solvent is one or a combination of deionized water, ethanol, methanol, isopropanol, DMSO, DMF, and DMAc.

[0020] Furthermore, the additive is ammonia. The role of ammonia is to provide an alkaline environment, thereby initiating the complexation of organic ligands with metal ions.

[0021] Furthermore, the molar ratio of the organic ligand, metal precursor, and additive is 1:(0.1–10):(0.1–100). Within this ratio range, the metal ions in the reaction system can form well-coordinated active centers with the organic ligand.

[0022] Furthermore, the reaction temperature is 0–120°C, and the reaction time is 1–12 h. By controlling the reaction temperature and reaction time, the crystallinity of the polymer can be adjusted.

[0023] Furthermore, the post-processing includes washing, filtering, and drying the reaction products.

[0024] Furthermore, the mass ratio of the conductive coordination polymer to the persulfate is 1:(1-100).

[0025] Furthermore, the conductive coordination polymer is used in wastewater treatment at a concentration of 1–100 mg / L, depending on the concentration of the pollutants.

[0026] Furthermore, the persulfate used in wastewater treatment is 100-1000 mg / L, depending on the concentration of pollutants.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] This invention uses a conductive coordination polymer containing metal-nitrogen active sites as a catalyst. It utilizes the high density of metal-nitrogen active sites in the conductive coordination polymer to efficiently activate persulfate, rapidly generating strong oxidizing free radicals, and utilizes the high conductivity of the conductive coordination polymer to accelerate the electron transfer process, thereby achieving the purpose of rapidly removing organic pollutants from water. In addition, by using different ligands, the type of active center, coordination configuration and coordination environment can be precisely controlled, realizing the controllable regulation of catalytic activity. Attached Figure Description

[0029] Figure 1 This is a SEM image of the conductive coordination polymer Co-BTA prepared in Example 1 of this invention;

[0030] Figure 2 This is the XPS full spectrum of the conductive coordination polymer Co-BTA prepared in Example 1 of this invention;

[0031] Figure 3 This is the N1s high-resolution XPS spectrum of the conductive coordination polymer Co-BTA prepared in Example 1 of this invention;

[0032] Figure 4 This is a graph showing the degradation performance of TC by the conductive coordination polymer Co-BTA prepared in Example 1 of this invention. Detailed Implementation

[0033] The following embodiments are only used to illustrate the technical solutions of the present invention more clearly, and should not be used to limit the scope of protection of the present invention.

[0034] Example 1:

[0035] S1. Weigh 1.0 mmol of cobalt nitrate and add it to 20 ml of deionized water. Stir and mix thoroughly to form a cobalt nitrate aqueous solution.

[0036] S2. Weigh 1.0 mmol of 1,2,4,5-phenyltetramine hydrochloride (BTA), add it to 20 ml of deionized water, and stir thoroughly to disperse and form a ligand solution.

[0037] S3. Pour the above ligand solution into a cobalt nitrate aqueous solution, add 2 ml of concentrated ammonia, sonicate until homogeneous, react at 25°C for 2 hours, wash, filter, and dry to obtain a conductive coordination polymer (Co-BTA) containing Co-N4 active sites.

[0038] S4. First, tetracycline hydrochloride was selected as a representative pollutant and prepared into an aqueous solution with a concentration of 50 mg / L. Then, 10 mg of the above-mentioned conductive coordination polymer was weighed and used as a catalyst. It was added to 100 mL of wastewater containing tetracycline hydrochloride and stirred thoroughly for 30 min to allow the pollutant molecules to reach adsorption-desorption equilibrium on the catalyst surface. Then, 100 mg of persulfate was added and stirred thoroughly for 15 min. During this period, 3 mL of aqueous solution was taken out every 3 min and filtered through a needle filter with a 0.45 μm microporous membrane. The degradation efficiency of tetracycline hydrochloride in the aqueous solution was detected by a UV-Vis spectrophotometer, and the final tetracycline hydrochloride removal rate was recorded.

[0039] Example 2:

[0040] S1. Weigh 1.0 mmol of ferric oxalate and add it to 30 ml of DMSO. Stir and mix thoroughly to form a ferric oxalate solution.

[0041] S2. Weigh 0.5 mmol of hexaaminobenzene hydrochloride (HAB) and 0.5 mmol of benzene hexathiophenol (BHT), add them to 30 ml of DMSO, stir thoroughly to disperse, and form a ligand solution.

[0042] S3. Pour the above ligand solution into the ferric oxalate solution, add 0.5 ml of concentrated ammonia, sonicate until homogeneous, react at 60 °C for 2 hours, wash, filter, and dry to obtain the conductive coordination polymer (Fe-HAB / BHT) containing Fe-N2S2 active sites.

[0043] S4. First, tetracycline hydrochloride was selected as a representative pollutant and prepared into an aqueous solution with a concentration of 50 mg / L. Then, 10 mg of the above-mentioned conductive coordination polymer was weighed and used as a catalyst. It was added to 100 mL of wastewater containing tetracycline hydrochloride and stirred thoroughly for 30 min to allow the pollutant molecules to reach adsorption-desorption equilibrium on the catalyst surface. Then, 100 mg of persulfate was added and stirred thoroughly for 15 min. During this period, 3 mL of aqueous solution was taken out every 3 min and filtered through a needle filter with a 0.45 μm microporous membrane. The degradation efficiency of tetracycline hydrochloride in the aqueous solution was detected by a UV-Vis spectrophotometer, and the final tetracycline hydrochloride removal rate was recorded.

[0044] Example 3:

[0045] S1. Weigh 1.0 mmol of copper acetate and add it to 30 ml of deionized water. Stir and mix thoroughly to form a copper acetate solution.

[0046] S2. Weigh 0.5 mmol of 1,2,4,5-phenyltetramine hydrochloride (BTA) and 0.5 mmol of 2,3,6,7,10,11-hexahydroxybenzophenanthrene (HHTP), add them to 30 ml of deionized water, and stir thoroughly to disperse and form a ligand solution.

[0047] S3. Pour the above ligand solution into copper acetate solution and add 0.5 ml of concentrated ammonia. After sonication and homogenization, react at 60°C for 2 hours. Wash, filter, and dry to obtain a conductive coordination polymer (Cu-BTA / HHTP) containing Cu-N2O2 active sites.

[0048] S4. First, tetracycline hydrochloride was selected as a representative pollutant and prepared into an aqueous solution with a concentration of 50 mg / L. Then, 10 mg of the above-mentioned conductive coordination polymer was weighed and used as a catalyst. It was added to 100 mL of wastewater containing tetracycline hydrochloride and stirred thoroughly for 30 min to allow the pollutant molecules to reach adsorption-desorption equilibrium on the catalyst surface. Then, 100 mg of persulfate was added and stirred thoroughly for 15 min. During this period, 3 mL of aqueous solution was taken out every 3 min and filtered through a needle filter with a 0.45 μm microporous membrane. The degradation efficiency of tetracycline hydrochloride in the aqueous solution was detected by a UV-Vis spectrophotometer, and the final tetracycline hydrochloride removal rate was recorded.

[0049] Example 4:

[0050] S1. Weigh 1.0 mmol of manganese sulfate and add it to 10 ml of deionized water. Stir and mix thoroughly to form a manganese sulfate solution.

[0051] S2. Weigh 0.5 mmol of 2,3,6,7,10,11-hexaminobenzobenzyl (HITP) and 0.5 mmol of 2,3,6,7,10,11-hexamylbenzophenanthrene (HHTP), add them to 10 ml of deionized water, and stir thoroughly to disperse and form a ligand solution.

[0052] S3. Pour the above ligand solution into manganese sulfate solution, add 3 ml of concentrated ammonia, sonicate until homogeneous, and then perform a hydrothermal reaction at 120°C for 2 hours. After washing, filtering, and drying, a conductive coordination polymer (Mn-HITP / HHTP) containing Mn-N2O2 active sites is obtained.

[0053] S4. First, tetracycline hydrochloride was selected as a representative pollutant and prepared into an aqueous solution with a concentration of 50 mg / L. Then, 10 mg of the above-mentioned conductive coordination polymer was weighed and used as a catalyst. It was added to 100 mL of wastewater containing tetracycline hydrochloride and stirred thoroughly for 30 min to allow the pollutant molecules to reach adsorption-desorption equilibrium on the catalyst surface. Then, 100 mg of persulfate was added and stirred thoroughly for 15 min. During this period, 3 mL of aqueous solution was taken out every 3 min and filtered through a needle filter with a 0.45 μm microporous membrane. The degradation efficiency of tetracycline hydrochloride in the aqueous solution was detected by a UV-Vis spectrophotometer, and the final tetracycline hydrochloride removal rate was recorded.

[0054] Example 5:

[0055] S1. Weigh 2.0 mmol of cobalt nitrate and add it to 50 ml of deionized water. Stir and mix thoroughly to form a cobalt nitrate aqueous solution.

[0056] S2. Weigh 5.0 mmol of 1,2,4,5-phenyltetramine hydrochloride (BTA), add it to 50 ml of deionized water, and stir thoroughly to disperse and form a ligand solution.

[0057] S3. Pour the above ligand solution into a cobalt nitrate aqueous solution, add 10 ml of concentrated ammonia, sonicate until homogeneous, react at 25°C for 2 hours, wash, filter, and dry to obtain a conductive coordination polymer (Co-BTA) containing Co-N4 active sites.

[0058] S4. First, tetracycline hydrochloride was selected as a representative pollutant and prepared into an aqueous solution with a concentration of 50 mg / L. Then, 10 mg of the above-mentioned conductive coordination polymer was weighed and used as a catalyst. It was added to 100 mL of wastewater containing tetracycline hydrochloride and stirred thoroughly for 30 min to allow the pollutant molecules to reach adsorption-desorption equilibrium on the catalyst surface. Then, 100 mg of persulfate was added and stirred thoroughly for 15 min. During this period, 3 mL of aqueous solution was taken out every 3 min and filtered through a needle filter with a 0.45 μm microporous membrane. The degradation efficiency of tetracycline hydrochloride in the aqueous solution was detected by a UV-Vis spectrophotometer, and the final tetracycline hydrochloride removal rate was recorded.

[0059] Example 6:

[0060] S1. Weigh 0.5 mmol of cobalt nitrate and 0.5 mmol of ferric nitrate, add them to 20 ml of deionized water, and stir thoroughly to form a mixed aqueous solution of cobalt nitrate and ferric nitrate.

[0061] S2. Weigh 1.0 mmol of 1,2,4,5-phenyltetramine hydrochloride (BTA), add it to 20 ml of deionized water, and stir thoroughly to disperse and form a ligand solution.

[0062] S3. Pour the above ligand solution into a mixed aqueous solution of cobalt nitrate and ferric nitrate, add 2 ml of concentrated ammonia, sonicate until homogeneous, react at 25°C for 2 hours, wash, filter, and dry to obtain a bimetallic conductive coordination polymer (CoFe-BTA) containing Co-N4 and Fe-N4 active sites.

[0063] S4. First, tetracycline hydrochloride was selected as a representative pollutant and prepared into an aqueous solution with a concentration of 50 mg / L. Then, 10 mg of the above-mentioned bimetallic conductive coordination polymer was weighed and used as a catalyst. It was added to 100 mL of wastewater system containing tetracycline hydrochloride and stirred thoroughly for 30 min to allow the pollutant molecules to reach adsorption-desorption equilibrium on the catalyst surface. Then, 100 mg of persulfate was added and stirred thoroughly for 15 min. During this period, 3 mL of aqueous solution was taken out every 3 min and filtered through a needle filter with a 0.45 μm microporous membrane. The degradation efficiency of tetracycline hydrochloride in the aqueous solution was detected by a UV-Vis spectrophotometer, and the final tetracycline hydrochloride removal rate was recorded.

[0064] Example 7:

[0065] S1. Weigh 0.2 mmol of cobalt nitrate, 0.2 mmol of ferric nitrate, 0.2 mmol of nickel nitrate, 0.2 mmol of copper nitrate, and 0.2 mmol of manganese nitrate, add them to 20 ml of deionized water, and stir thoroughly to form a mixed metal nitrate aqueous solution.

[0066] S2. Weigh 1.0 mmol of 1,2,4,5-phenyltetramine hydrochloride (BTA), add it to 20 ml of deionized water, and stir thoroughly to disperse and form a ligand solution.

[0067] S3. Pour the above ligand solution into a mixed metal nitrate aqueous solution, add 2 ml of concentrated ammonia, sonicate until homogeneous, react at 25°C for 2 hours, wash, filter, and dry to obtain a high-entropy conductive coordination polymer (CoFeNiCuMn-BTA) containing Co-N4, Fe-N4, Ni-N4, Cu-N4, and Mn-N4 active sites.

[0068] S4. First, tetracycline hydrochloride was selected as a representative pollutant and prepared into an aqueous solution with a concentration of 50 mg / L. Then, 10 mg of the high-entropy conductive coordination polymer prepared above was weighed and used as a catalyst. It was added to 100 mL of wastewater system containing tetracycline hydrochloride and stirred thoroughly for 30 min to allow the pollutant molecules to reach adsorption-desorption equilibrium on the catalyst surface. Then, 100 mg of persulfate was added and stirred thoroughly for 15 min. During this period, 3 mL of aqueous solution was taken out every 3 min and filtered through a needle filter with a 0.45 μm microporous membrane. The degradation efficiency of tetracycline hydrochloride in the aqueous solution was detected by a UV-Vis spectrophotometer, and the final tetracycline hydrochloride removal rate was recorded.

[0069] Comparative Example 1:

[0070] S1. Weigh 1.0 mmol of cobalt nitrate and add it to 30 ml of DMSO. Stir and mix thoroughly to form a cobalt nitrate solution.

[0071] S2. Weigh 1.0 mmol of benzene hexathiophenol (BHT) and add it to 30 ml of DMSO. Stir thoroughly to disperse and form a ligand solution.

[0072] S3. Pour the above ligand solution into a cobalt nitrate solution and add 0.5 ml of concentrated ammonia. After sonication and homogenization, react at 60°C for 2 hours. Wash, filter, and dry to obtain a conductive coordination polymer (Co-BHT) containing Co-S4 active sites.

[0073] S4. First, tetracycline hydrochloride was selected as a representative pollutant and prepared into an aqueous solution with a concentration of 50 mg / L. Then, 10 mg of the above-mentioned conductive coordination polymer was weighed and used as a catalyst. It was added to 100 mL of wastewater containing tetracycline hydrochloride and stirred thoroughly for 30 min to allow the pollutant molecules to reach adsorption-desorption equilibrium on the catalyst surface. Then, 100 mg of persulfate was added and stirred thoroughly for 15 min. During this period, 3 mL of aqueous solution was taken out every 3 min and filtered through a needle filter with a 0.45 μm microporous membrane. The degradation efficiency of tetracycline hydrochloride in the aqueous solution was detected by a UV-Vis spectrophotometer, and the final tetracycline hydrochloride removal rate was recorded.

[0074] Comparative Example 2:

[0075] S1. Weigh 1.0 mmol of cobalt nitrate and add it to 30 ml of deionized water. Stir and mix thoroughly to form a cobalt nitrate solution.

[0076] S2. Weigh 1.0 mmol of 2,3,6,7,10,11-hexahydroxybenzophenanthrene (HHTP), add it to 30 ml of deionized water, and stir thoroughly to disperse and form a ligand solution.

[0077] S3. Pour the above ligand solution into a cobalt nitrate solution, add 3 ml of concentrated ammonia, sonicate until homogeneous, react at 60°C for 2 hours, wash, filter, and dry to obtain a conductive coordination polymer (Co-HHTP) containing Co-O4 active sites.

[0078] S4. First, tetracycline hydrochloride was selected as a representative pollutant and prepared into an aqueous solution with a concentration of 50 mg / L. Then, 10 mg of the above-mentioned conductive coordination polymer was weighed and used as a catalyst. It was added to 100 mL of wastewater containing tetracycline hydrochloride and stirred thoroughly for 30 min to allow the pollutant molecules to reach adsorption-desorption equilibrium on the catalyst surface. Then, 100 mg of persulfate was added and stirred thoroughly for 15 min. During this period, 3 mL of aqueous solution was taken out every 3 min and filtered through a needle filter with a 0.45 μm microporous membrane. The degradation efficiency of tetracycline hydrochloride in the aqueous solution was detected by a UV-Vis spectrophotometer, and the final tetracycline hydrochloride removal rate was recorded.

[0079] Comparative Example 3:

[0080] S1. Weigh 1 mmol of cobalt nitrate and add it to 20 ml of deionized water. Stir and mix thoroughly to form a cobalt nitrate aqueous solution.

[0081] S2. Weigh 1 mmol of 1,2,4,5-phenyltetramine hydrochloride, add it to 20 ml of deionized water, and stir thoroughly to disperse and form a ligand solution.

[0082] S3. Pour the above ligand solution into a cobalt nitrate aqueous solution, add 2 ml of concentrated ammonia, sonicate until homogeneous, react at 25°C for 2 hours, wash, filter and dry to obtain a conductive coordination polymer containing Co-N active sites.

[0083] S4. The above conductive coordination polymer is calcined in a nitrogen atmosphere furnace at 800°C for 2 hours to obtain N-doped carbon material containing Co nanoparticles (Co@NC).

[0084] S5. First, tetracycline hydrochloride was selected as a representative pollutant and prepared into an aqueous solution with a concentration of 50 mg / L. Then, 10 mg of the above Co@NC was weighed as a catalyst and added to 100 mL of wastewater containing tetracycline hydrochloride. After stirring thoroughly for 30 min, the pollutant molecules reached adsorption-desorption equilibrium on the catalyst surface. Then, 100 mg of persulfate was added and stirred thoroughly for 15 min. During this period, 3 mL of aqueous solution was taken out every 3 min and filtered through a needle filter with a 0.45 μm microporous membrane. The degradation efficiency of tetracycline hydrochloride in the aqueous solution was detected by a UV-Vis spectrophotometer, and the final tetracycline hydrochloride removal rate was recorded.

[0085] Comparative Example 4:

[0086] S1. Weigh 1 mmol of cobalt nitrate and add it to 10 ml of methanol. Stir and mix thoroughly to form a cobalt nitrate solution.

[0087] S2. Weigh 4 mmol of 2-methylimidazole and add it to 10 ml of methanol. Stir thoroughly to disperse and form a ligand solution.

[0088] S3. Pour the above ligand solution into a cobalt nitrate solution, sonicate until homogeneous, react at 25°C for 12 hours, wash, filter and dry to obtain a Co-containing metal-organic framework material (ZIF-67).

[0089] S4. First, tetracycline hydrochloride was selected as a representative pollutant and prepared into an aqueous solution with a concentration of 50 mg / L. Then, 10 mg of ZIF-67 was weighed as a catalyst and added to 100 mL of wastewater containing tetracycline hydrochloride. After stirring thoroughly for 30 min, the pollutant molecules reached adsorption-desorption equilibrium on the catalyst surface. Then, 100 mg of persulfate was added and stirred thoroughly for 15 min. During this period, 3 mL of aqueous solution was taken out every 3 min and filtered through a needle filter with a 0.45 μm microporous membrane. The concentration of pollutants in the aqueous solution was detected by a UV-Vis spectrophotometer to investigate the degradation efficiency of the conductive coordination polymer on tetracycline hydrochloride and to record the final tetracycline hydrochloride removal rate.

[0090] Performance comparison:

[0091] 1. For example Figure 1 This is a SEM image of the conductive coordination polymer Co-BTA prepared in Example 1. Figure 1 It can be seen that Co-BTA exhibits a blocky morphology formed by the aggregation of small particles.

[0092] 2. For example Figure 2 The XPS full spectrum of the conductive coordination polymer Co-BTA prepared in Example 1 is shown. Figure 2 XPS full spectrum confirmed the presence of N, C and Co in the sample, and no additional Cl was detected. - Anions and NH 4+ The presence of cations to balance the charge indicates that Co-BTA is in an electrically neutral state, with the O1s peak at 530 eV primarily originating from air adsorbed on the surface.

[0093] 3. For example Figure 3 The image shows the N1s high-resolution XPS spectrum of the conductive coordination polymer Co-BTA prepared in Example 1. Figure 3It can be seen that the N 1s high-resolution XPS spectrum can be fitted to two peaks at 398.0 and 399.8 eV, which correspond to CN and Co-N bonds, respectively, indicating that the N atom is coordinated with the Co ion.

[0094] 4. For example Figure 4 Comparison of the degradation performance of tetracycline hydrochloride (TC) aqueous solution, TC aqueous solution without catalyst and with only added persulfate (PMS), and TC aqueous solution with catalyst (the conductive coordination polymer Co-BTA prepared in Example 1) and PMS. Figure 4 It is known that TC hardly undergoes self-decomposition in the absence of catalyst and PMS, so its degradation rate is 0. In the presence of only PMS, PMS may partially decompose, generating a small amount of highly oxidizing free radicals, resulting in the degradation of negligible TC, with a degradation rate of about 10%. However, when Co-BTA and PMS are present simultaneously, TC is completely degraded within 3 minutes, demonstrating that Co-BTA coordination polymers with Co-N4 active sites have excellent PMS activation capabilities, generating a large number of reactive oxygen species, which in turn leads to the decomposition of TC molecules.

[0095] 5. The degradation effects of pollutants in Examples 1-7 and Comparative Examples 1-4 after 15 minutes are shown in Table 1 below.

[0096] Table 1. Degradation effects of pollutants in Examples 1-7 and Comparative Examples 1-4

[0097]

[0098]

[0099] As shown in Table 1, under the same solution conditions, the conductive coordination polymer containing metal-nitrogen (MN) active sites exhibits higher degradation performance for TC, indicating that the MN active sites have stronger catalytic activity for PMS activation. Furthermore, by adjusting the metal center (Co, Fe, Cu, Mn, etc.) and the ligand type, the coordination form of MN can be controlled, and high catalytic performance can be achieved in all cases.

[0100] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for removing organic pollutants from water using activated persulfate, characterized in that, Includes the following steps: The metal precursor is added to the solvent to obtain a metal precursor solution; Organic ligands are added to a solvent to obtain a ligand solution; The ligand solution was added to the metal precursor solution, and additives were added to carry out the reaction. After the reaction was completed, post-treatment was performed to obtain a conductive coordination polymer containing metal-nitrogen active sites. The conductive coordination polymer and persulfate are added to water containing organic pollutants to complete the degradation of organic pollutants; The metal precursor is one or more of the following: hydrochloride, acetate, sulfate, nitrate, and oxalate of Fe, Co, Ni, Cu, and Mn metals; The organic ligands include one of 2,3,6,7,10,11-hexamethylenebenzobenzene, hexamethylenebenzene hydrochloride, 1,2,4,5-phenyltetramine hydrochloride, 1,3,5-triamino-2,4,6-trinitrobenzene and their derivatives. The organic ligands also include one of tetrahydroxy-p-benzoquinone, 2,3,6,7,10,11-hexahydroxybenzophenanthrene, benzenehexathiophenol, thiofulvalene benzoic acid and its derivatives; The molar ratio of the organic ligand, metal precursor, and additive is 1:(0.1~10):(0.1~100).

2. The method for removing organic pollutants from water using activated persulfate according to claim 1, characterized in that, When the metal in the metal precursor is a bimetal, the molar ratio of the two metals is (9:1) to (1:9); when the metal in the metal precursor is a multimetal, the ratio of the molar amount of one metal to the sum of the molar amounts of the other metals is (9:1) to (1:9).

3. The method for removing organic pollutants from water using activated persulfate according to claim 1, characterized in that, The solvent is one or a combination of deionized water, ethanol, methanol, isopropanol, DMSO, DMF, and DMAc.

4. The method for removing organic pollutants from water using activated persulfate according to claim 1, characterized in that, The additive is ammonia.

5. The method for removing organic pollutants from water using activated persulfate according to claim 1, characterized in that, The reaction temperature is 0~120℃, and the reaction time is 1~12h.

6. The method for removing organic pollutants from water using activated persulfate according to claim 1, characterized in that, The mass ratio of the conductive coordination polymer to the persulfate is 1:(1~100).

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