Method for degrading chlorophenol organic pollutants in water by activating persulfate with cobalt-cerium dioxide monatomic catalyst in presence of bicarbonate radical

Abstract

The invention belongs to the field of water pollution treatment, and particularly relates to a method for degrading chlorophenol organic pollutants in water by activating persulfate with a cobalt-cerium dioxide monatomic catalyst in the presence of bicarbonate radicals. According to the invention, cerium nitrate hexahydrate is calcined in a muffle furnace to obtain cerium dioxide. A catalyst precursor is prepared by a traditional isovolumetric impregnation method. The prepared catalyst precursor is annealed at different temperatures to obtain a series of catalysts, the catalytic performance of Co1-CeO2-700 is optimal, and the Co1-CeO2-700 has more excellent catalytic performance in the presence of bicarbonate radicals. The preparation method provided by the invention has the advantages of simple steps, convenience in operation, quick effect of treating chlorophenol, high product yield and low cost, and has good economic value and social benefit. The prepared monatomic catalyst has the advantages of being high in atom utilization rate, good in stability, excellent in catalytic effect and the like, and is expected to become a key technology for solving actual water environment organic pollution.

Description

Technical Field

[0001] The invention belongs to the field of water pollution treatment, and particularly relates to a method and application of activating PMS by a cobalt-cerium dioxide single-atom catalyst in the presence of a certain amount of bicarbonate. Background Art

[0002] Chlorophenols (CPs) are a class of highly stable and refractory organic pollutants, widely present in industrial wastewater (e.g., from oil refining, coking, papermaking, and textiles) and domestic sewage. Due to their broad-spectrum bactericidal properties, CPs are commonly used as raw materials in the pesticide, pharmaceutical, and textile printing and dyeing industries, and are also used to disinfect and preserve products such as wooden furniture, fruits and vegetables, leather, and coatings. Consequently, as typical organic halogenated pollutants in the environment, CPs are often present in incompletely treated industrial wastewater. They are poorly biodegradable and, after long-term accumulation in organisms, can have teratogenic, carcinogenic, and mutagenic effects. Furthermore, CPs are environmentally persistent, recognized as toxic and hazardous pollutants, and have been designated as priority pollutants by multiple countries. Among monochlorophenols, parachlorophenol (4-CP) is the most toxic, and wastewater containing 4-CP must be treated before discharge into the environment. Controlling environmental pollution caused by 4-CP is crucial for protecting the health of both humans and organisms in the environment. However, due to the high stability and difficulty in degradation of 4-CP, conventional treatment methods such as biological methods, physical methods and some chemical methods cannot completely, economically and efficiently remove 4-CP.

[0003] In order to solve this problem, advanced oxidation technology refers to the use of Fenton reaction, Fenton-like reaction, ozone, hydrogen peroxide, photolysis, photocatalysis, sonolysis, electrochemistry and other methods to produce active species with strong oxidizing ability, thereby achieving effective treatment of sewage. It has the characteristics of high efficiency, wide application range and thorough degradation. Due to the unique asymmetric structure of PMS, it is easily activated to produce a large amount of reactive oxygen species (ROS) for the elimination of 4-CP. The advanced oxidation process based on peroxymonosulfate has been accepted as one of the current preferred methods. It mainly produces reactive oxygen species by activating oxidants (such as hydrogen peroxide and persulfate (PMS)) through catalysts to oxidize and degrade organic pollutants. Summary of the Invention

[0004] The object of the present invention is to provide a method for producing a - The present invention discloses a method and application for degrading chlorophenol organic pollutants in water by activating persulfate (PMS) in the presence of cobalt-cerium dioxide single-atom catalyst (Co1-CeO2). The catalyst prepared by the present invention has the characteristics of high atom utilization, can efficiently degrade chlorophenol organic pollutants, and can achieve rapid degradation of chlorophenol organic pollutants within 10 minutes.

[0005] In order to achieve the above-mentioned object, the present invention provides the following technical solution: the carrier cerium dioxide and cobalt nitrate hexahydrate are immersed in water, dried, the dried solids are collected and calcined at different temperatures to obtain a cobalt-cerium dioxide single-atom catalyst, the cobalt-cerium dioxide single-atom catalyst and PMS are added to the contaminated water body to oxidize and remove the aromatic organic pollutants in the water body.

[0006] The cobalt-cerium dioxide single atom catalyst was used in conjunction with potassium peroxymonosulfate PMS system to - The method comprises the following steps:

[0007] (1) impregnating the carrier cerium dioxide and cobalt nitrate hexahydrate in water, drying, collecting the dried solids and calcining them at different temperatures to obtain a cobalt-cerium dioxide single-atom catalyst in an air atmosphere at 500°C-700°C, at a heating rate of 5°C / min, and annealing for 10.0 h;

[0008] (2) Cobalt-cerium dioxide single atom catalyst and potassium peroxymonosulfate PMS are added to the mixture containing bicarbonate HCO3 - In polluted water bodies, the bicarbonate concentration is 0.1mM~1mM, which oxidizes and eliminates chlorophenols in the water.

[0009] Preferably, the calcination temperature in step (1) is 700°C.

[0010] Preferably, the mass ratio of the carrier cerium dioxide to cobalt is 1:0.02; the mass concentration and molar concentration of the cobalt-cerium dioxide single-atom catalyst and PMS are 0.15-0.2 g / L and 0.2-0.6 mM respectively.

[0011] Preferably, the specific preparation method of the cobalt-cerium dioxide single-atom catalyst Co1-CeO2-500 and Co1-CeO2-700 is as follows:

[0012] (1) Place 4 g of Ce(NO3)3·6H2O in a muffle furnace, heat at a rate of 5°C / min, and calcine at 350°C for 2.0 h to obtain CeO2, which is then ground;

[0013] (2) A Co1-CeO2 catalyst precursor was prepared by a conventional equal volume impregnation method. The CeO2 obtained in step (1) was stirred in deionized water to form a slurry, and the required amount of Co(NO3)2 solution was added dropwise. The mixture was impregnated for 2.0 h and dried in a vacuum at 40°C overnight to prepare a Co-CeO2 catalyst precursor with a Co loading of 2.0 wt%;

[0014] (3) The Co1-CeO2 catalyst precursor obtained in step (2) was ground and annealed at 500°C and 700°C in air atmosphere at a heating rate of 5°C / min for 10.0 h. The obtained catalysts were recorded as Co1-CeO2-500 and Co1-CeO2-700, respectively.

[0015] Preferably, the cobalt-cerium dioxide single-atom catalyst has an atomic dispersion effect, and can achieve rapid degradation and removal of chlorophenol within 10 minutes.

[0016] Preferably, the cobalt-cerium dioxide single atom catalyst is added to the water containing chlorophenol, fully mixed and stirred, and then PMS is added. The oxidant is activated by the cobalt-cerium dioxide single atom catalyst to generate a large number of free radicals and non-free radicals, which convert HCO3 - Converted to CO3 ·- , efficiently degrade chlorophenols.

[0017] Preferably, in 1 mM HCO3 - In the presence of Co-CeO2-700 / HCO3 - The / PMS system can completely degrade 5 mg / L of 4-CP within 10 minutes.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] (1) The present invention proposes that in water containing 1mM bicarbonate, the catalyst can efficiently activate 0.2mM PMS and completely degrade 5mg / L of para-chlorophenol (4-CP) within 10 minutes. Experiments show that Co-CeO2-700 / HCO3 - / PMS system, including SO4 ·- 、O2 ·- 、 1 O2 and CO3 ·- Compared with the Co-CeO2-700 / PMS system, the CO3 ·- The production of HCO3 at environmentally relevant concentrations is rarely considered in current research. - The present invention proposes the possible impact of HCO3 - It can efficiently degrade 4-CP and is suitable for the treatment of organic pollutants in industrial wastewater.

[0020] (2) The degradation rate is greatly improved: at 1mM HCO3 - Under the conditions of existence, the Co-CeO2-700 / HCO3 of the present invention -The / PMS system can completely degrade 5 mg / L of 4-CP in just 10 minutes, while traditional heterogeneous catalysts (such as Fe3O4, MnO2, CuO / Al2O3, TiO2, ZnO, zero-valent iron, montmorillonite, and hematite) typically require over 60 minutes to achieve the same effect, demonstrating significant advantages. This system not only requires a low catalyst dosage (only 0.2 g / L, far less than the 0.5-1 g / L of traditional catalysts) but also achieves a faster degradation rate, providing a superior solution for environmental remediation.

[0021] (3) Environmental adaptability breakthrough HCO3 - Inhibitory effect: In traditional advanced oxidation technology, HCO3 - It is usually regarded as a free radical scavenger, which will reduce the degradation efficiency. However, the present invention innovatively converts HCO3 - Converted to CO3 ·- (E 0 =1.78V), turning it from an "inhibitor" into a "promoter".

[0022] (4) Reduced catalyst costs: The metal loading of the cobalt-cerium dioxide single-atom catalyst developed in the present invention is only 2 wt%. Compared with traditional nanocatalysts (such as supported Co3O4, Fe2O3 nanoparticles, Ni / Al2O3, CuO-TiO2 composite materials, etc.), which usually require a metal loading of 10-20 wt%, the metal usage is reduced to 1 / 5-1 / 10, which greatly reduces the metal usage and significantly reduces the catalyst cost.

[0023] (5) Clarify Co-CeO2-700 / HCO3 - The synergistic mechanism of the / PMS ternary system was confirmed by probe experiments. ·- This study plays a key role in the design of environmentally friendly catalysts and provides new ideas for the design of environmentally friendly catalysts.

[0024] These advantages make the present invention significantly competitive in engineering applications, and it is particularly suitable for the deep treatment of difficult-to-degrade organic wastewater in industries such as papermaking and printing and dyeing.

[0025] (6) Figure 5 As shown in the figure, the Co1-CeO2-700 single-atom catalyst prepared in this experiment exhibited excellent catalytic performance in the degradation of 4-CP. In the Co1-CeO2-700 / PMS system, the removal rate of 4-CP was 40% in 20 minutes; while in the Co1-CeO2-700 / HCO3 - / PMS system, 4-CP can be completely degraded in 10 minutes (removal rate 100%). - The introduction of significantly improved the activation efficiency of PMS, which may achieve efficient degradation by promoting the free radical generation oxidation pathway. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 is the XRD pattern of the single-atom catalyst prepared in Example 1 of the present invention;

[0028] Figure 2 is an EPR graph of oxygen vacancies in Co1-CeO2-700 prepared in Example 1 of the present invention;

[0029] Figure 3 This is a diagram showing the effects of a series of catalysts prepared in Example 1 on the degradation of p-chlorophenol (4-CP) by activating PMS;

[0030] Figure 4 This is a diagram showing the adsorption effect of Co1-CeO2-700 prepared in Example 1 on para-chlorophenol (4-CP);

[0031] Figure 5 The best single-atom catalyst prepared in Example 1 is quantitative HCO3 - Figure 3 shows the effect of activated PMS on the degradation of p-chlorophenol (4-CP) in the presence of 4-chlorophenol;

[0032] Figure 6 This is a diagram showing the effect of determining active species in a quenching experiment of Co1-CeO2-700 prepared in Example 1 of the present invention;

[0033] Figure 7 The Co1-CeO2-700 prepared in Example 1 of the present invention is in a certain amount of HCO3 - The effect of quenching experiment in the presence of active species was determined;

[0034] Figure 8 The Co1-CeO2-700 prepared in Example 1 of the present invention is in a certain amount of HCO3 - Graph showing the effects of probe experiments in the presence of activated PMS. DETAILED DESCRIPTION

[0035] The above contents of the present invention are further described in detail below through examples, but this should not be understood as limiting the scope of the above subject matter of the present invention to the following examples. All technologies implemented based on the above contents of the present invention fall within the scope of the present invention.

[0036] Example 1:

[0037] Preparation of Co1-CeO2 single atom catalyst:

[0038] 4g of Ce(NO3)3·6H2O was placed in a muffle furnace and calcined at 350°C for 2.0h at a heating rate of 5°C / min to obtain CeO2. A Co1-CeO2 catalyst precursor was prepared using a traditional equal volume impregnation method. 2g of the obtained CeO2 was stirred into a slurry with a small amount of deionized water, and 2mL of a 0.34M Co(NO3)2 solution was added dropwise. The mixture was impregnated for 2.0h and dried under vacuum at 40°C overnight. This prepared a Co1-CeO2 catalyst precursor with a Co loading of 2.0wt%.

[0039] The obtained Co1-CeO2 catalyst precursor was dried overnight, taken out, ground, and annealed for 10.0 h in an air atmosphere at 300°C, 500°C, 700°C, and 800°C, respectively, with a heating rate of 5°C / min. The obtained catalysts were recorded as Co1-CeO2-300, Co1-CeO2-500, Co1-CeO2-700, and Co1-CeO2-800, respectively.

[0040] The phase analysis of the single atom catalyst prepared in Example 1 was carried out by XRD. Figure 1 As shown, the diffraction peaks of 2θ in the single atom catalyst are 28.55°, 33.08°, 47.48°, 56.34°, 59.09°, 69.42°, 76.70°, and 79.07°, which correspond to the (111), (200), (220), (311), (222), (400), (331), (420), and (422) planes of the standard card of CeO2 numbered No. 00-043-1002, respectively, which confirms the formation of Co1-CeO2 single atom catalyst. Figure 1 The characteristic peaks of the standard card are provided below. Figure 2 As shown in the figure, the best material (Co1-CeO2-700) obtained has obvious oxygen vacancy characteristic signals. The oxygen vacancies (Vo) in cerium dioxide (CeO2) can be clearly characterized by electron paramagnetic resonance (EPR). Its characteristic signals usually appear in the range of g≈1.96–2.01, corresponding to the paramagnetic Ce formed by the oxygen vacancies capturing electrons. 3+ -Vo Defect Center.

[0041] Example 2:

[0042] Optimal material selection:

[0043] Typically, catalytic degradation experiments are performed in 50 mL vials with magnetic stirring at 750 rpm and a water bath temperature of 25°C. The specific steps are as follows:

[0044] 30 mL of a 5 mg / L 4-CP solution was added to a vial. Under magnetic stirring, the PMS stock solution was added sequentially to a concentration of 0.6 mM in the reaction system (a relatively high concentration of 0.6 mM was chosen to efficiently screen the optimal material). The reaction was initiated by adding a single-atom material suspension to a concentration of 0.2 g / L. At designated time points, 1 mL of the reaction solution was collected and quickly mixed with 1 mL of a 10 mM sodium thiosulfate solution to terminate the reaction. The mixture was filtered through a 0.22 μm polytetrafluoroethylene filter into a brown liquid phase vial, and residual contaminants were analyzed by high-performance liquid chromatography (HPLC). All degradation experiments were performed in triplicate, and the results are presented as mean and standard deviation.

[0045] In addition, the materials were added into 4-CP solution alone to evaluate the adsorption performance of single-atom materials on 4-CP, e.g. Figure 4 As shown in the figure, the adsorption effect of the materials themselves is not obvious. All degradation experiments were carried out in triplicate and the results are expressed as mean and standard deviation.

[0046] The results are as follows Figure 3 As shown, the Co1-CeO2 single-atom catalysts prepared in this experiment demonstrated excellent catalytic performance in the degradation of 4-CP. Under the conditions of a PMS concentration of 0.6 mM, a material concentration of 0.2 g / L, and a 4-CP concentration of 5 mg / L, the 4-CP removal rates ranked from high to low as follows: Co1-CeO2-700 > Co1-CeO2-500 > Co1-CeO2-300 > Co-CeO2-800. Among them, Co1-CeO2-700 exhibited the best catalytic performance, completely degrading 5 mg / L of 4-CP in just 30 minutes. This was followed by Co1-CeO2-500, which degraded 92% in 30 minutes; Co1-CeO2-300, which degraded 78% in 30 minutes; and Co-CeO2-800, which degraded 59% in 30 minutes.

[0047] Example 3:

[0048] Co1-CeO2-700 / PMS and Co1-CeO2-700 / HCO3 - / Determination of degradation effect of PMS system:

[0049] The catalytic degradation experiment was conducted in a 50 mL vial. Magnetic stirring was used throughout the experiment at 750 rpm and the water bath temperature was maintained at 25°C. The specific steps are as follows:

[0050] Take 30mL of 5mg / L 4-CP solution and add it to a penicillin bottle. Under magnetic stirring, add PMS mother solution in sequence to make its concentration in the reaction system 0.2mM (the concentration of 0.2mM can produce sufficient free radical production to ensure the complete degradation of pollutants while achieving the best reagent utilization and treatment economy); single-atom material suspension, make its concentration in the reaction system 0.2g / L, Co1-CeO2-700 / HCO3 - / PMS system by adding NaHCO3 mother liquor to make the HCO3 - The reaction was initiated at a concentration of 1 mM. At designated time points, 1 mL of the reaction solution was collected and quickly mixed with 1 mL of a 10 mM sodium thiosulfate solution to terminate the reaction. The mixture was filtered through a 0.22 μm polytetrafluoroethylene filter into a brown liquid phase vial, and residual contaminants were determined by high-performance liquid chromatography (HPLC). All degradation experiments were performed in triplicate, and the results are presented as the mean and standard deviation.

[0051] The results are as follows Figure 5 As shown in the figure, the Co1-CeO2-700 single-atom catalyst prepared in this experiment exhibited excellent catalytic performance in the degradation of 4-CP. In the Co1-CeO2-700 / PMS system, the removal rate of 4-CP was 40% in 20 minutes; while in the Co1-CeO2-700 / HCO3 - / PMS system, 4-CP can be completely degraded in 10 minutes (removal rate 100%). - The introduction of significantly improved the activation efficiency of PMS, which may achieve efficient degradation by promoting the oxidation pathway of free radical generation.

[0052] Example 4:

[0053] Co-CeO2-700 / PMS system and Co-CeO2-700 / HCO3 - Determination of active species generated during the degradation process of / PMS system:

[0054] Typically, catalytic degradation experiments are performed in 50 mL vials with magnetic stirring at 750 rpm and a water bath temperature of 25°C. The specific steps are as follows:

[0055] 30 mL of 5 mg / L 4-CP solution was added to a penicillin bottle. Under magnetic stirring, PMS mother liquor was added in sequence to a concentration of 0.6 mM in the reaction system; a single-atom material suspension was added to a concentration of 0.2 g / L in the reaction system; and the corresponding active species quencher was used to initiate the reaction. At the specified time point, 1 mL of the reaction solution was taken and quickly mixed with 1 mL of 10 mM sodium thiosulfate aqueous solution to terminate the reaction. The above mixture was filtered through a 0.22 μm polytetrafluoroethylene filter membrane into a brown liquid phase vial, and residual contaminants were detected by high-performance liquid chromatography (HPLC).

[0056] In order to analyze the main active species in the degradation of 4-CP by Co1-CeO2-700 / PMS system, methanol (MeOH), tert-butyl alcohol (TBA), 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO), furfuryl alcohol (FFA) and 1,10-phenanthroline (phen) were used as quenchers to carry out active species quenching experiments to clarify the free radical (SO4 ·- 、 · OH, O2 ·- ) and non-free radicals ( 1 The role of O2) in the degradation process.

[0057] All degradation experiments were carried out in parallel for three times, and the results were expressed as mean and standard deviation. Figure 6 As shown in the figure, after adding phen (5 mM) into the system, the degradation rate of 4-CP within 20 min was less than 5%. This is because phen has a strong metal chelating ability and blocks the reaction between the single-atom Co site and PMS, thereby inhibiting the degradation of 4-CP. MeOH (20 mM) was added into the system as SO4 ·- and · OH quencher, the degradation rate of 4-CP within 20 minutes was only 20%; TBA was added to the system as · When OH quencher is used, the removal rate of 4-CP is almost unchanged, indicating that SO4 ·- ,and · OH is not the main active species that causes 4-CP degradation. When TEMPO (5 mM) is added to the system to quench O2 ·- When the degradation efficiency of 4-CP was reduced from 40% to 10%, it was found that the system contained O2 ·- When FFA (5mM) was added to the system, the 1 When O2 is applied, the degradation efficiency of 4-CP decreases from 40% to 2%, indicating that the system contains 1 O2.

[0058] To analyze Co1-CeO2-700 / HCO3 -The main active species in the degradation of 4-CP by the / PMS system were selected. Methanol (MeOH), tert-butyl alcohol (TBA), 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO), furfuryl alcohol (FFA) and 1,10-phenanthroline (phen) were used as quenchers to carry out active species quenching experiments to clarify the free radical (SO4 ·- 、 · OH, O2 ·- ) and non-free radicals ( 1 The role of O2) in the degradation process.

[0059] All degradation experiments were carried out in parallel for three times, and the results were expressed as mean and standard deviation. Figure 7 As shown. After adding phen (5mM) to the system, the degradation rate of 4-CP within 20min was less than 5%. This is because phen has a strong metal chelating ability and blocks the reaction between the single-atom Co site and PMS, thereby inhibiting the degradation of 4-CP. MeOH (20mM) was added to the system as SO4 ·- and · OH quencher, the degradation rate of 4-CP within 20 min was only 50%; TBA was added to the system as · When OH quencher is used, the removal rate of 4-CP is almost unchanged, indicating that SO4 ·- ,and · OH is not the main active species that causes 4-CP degradation. When TEMPO (5 mM) is added to the system to quench O2 ·- When the degradation efficiency of 4-CP was reduced from 100% to 40%, it was found that the system contained O2 ·- When FFA (5mM) was added to the system, the 1 When O2 is used, the degradation efficiency of 4-CP decreases from 100% to 3%, indicating that the system contains 1 O2.

[0060] Therefore, it can be shown that both systems contain SO4 ·- 、O2 ·- and 1 O2.

[0061] Example 5:

[0062] Co1-CeO2-700 / HCO3 - / PMS system probe experiment:

[0063] N,N-dimethylaniline (DMA) is a ·- The high selectivity and reactivity of the ·- concentration.

[0064] Co1-CeO2-700 / HCO3 - The probe experiment of the / PMS system was carried out in a 50mL vial. The experiment was carried out with magnetic stirring at 750 rpm and the water bath temperature was maintained at 25°C. The specific steps are as follows:

[0065] 30 mL of 10 μM DMA solution was added to a vial. Under magnetic stirring, NaHCO3 solution, PMS mother liquor, and single-atom material suspension were added in sequence to initiate the reaction. At the designated time point, 1 mL of the reaction solution was taken and quickly mixed with 1 mL of sodium thiosulfate aqueous solution to terminate the reaction. The above mixture was filtered through a 0.22 μm polytetrafluoroethylene filter membrane into a brown liquid phase vial, and the DMA concentration decay was analyzed by high-performance liquid chromatography (HPLC).

[0066] The results are as follows Figure 8 As shown in the figure, the concentration of DMA dropped to 0 within 5 minutes, indicating that CO3 ·- The production of.

[0067] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity. Equal changes and modifications made within the scope of the patent application of the present invention should all fall within the scope of protection of the present invention.

Claims

1. A method for degrading chlorophenol organic pollutants in water by activating persulfate with a cobalt-cerium dioxide single-atom catalyst in the presence of bicarbonate, characterized in that: The cobalt-cerium dioxide single atom catalyst was used in conjunction with potassium peroxymonosulfate PMS system to - The method comprises the following steps: (1) impregnating the carrier cerium dioxide and cobalt nitrate hexahydrate in water, drying, collecting the dried solids and calcining them at different temperatures to obtain a cobalt-cerium dioxide single-atom catalyst in an air atmosphere at 500°C-700°C, at a heating rate of 5°C / min, and annealing for 10.0 h; (2) Cobalt-cerium dioxide single atom catalyst and potassium peroxymonosulfate PMS are added to the mixture containing bicarbonate HCO3 - In polluted water bodies, the bicarbonate concentration is 0.1mM~1mM, which oxidizes and eliminates chlorophenols in the water.

2. The method for degrading chlorophenol organic pollutants in water by activating persulfate with a cobalt-cerium oxide single-atom catalyst in the presence of bicarbonate according to claim 1, characterized in that: The calcination temperature in step (1) is 700°C.

3. The method for degrading chlorophenol organic pollutants in water by activating persulfate with a cobalt-cerium oxide single-atom catalyst in the presence of bicarbonate according to claim 1, characterized in that: The mass ratio of the carrier cerium dioxide and cobalt is 1:0.02; the mass concentration and molar concentration of the cobalt-cerium dioxide single-atom catalyst and PMS are 0.15-0.2 g / L and 0.2-0.6 mM respectively.

4. The method for degrading chlorophenol organic pollutants in water by activating persulfate with a cobalt-cerium oxide single-atom catalyst in the presence of bicarbonate according to claim 1, wherein: The specific preparation methods of cobalt-cerium dioxide single-atom catalysts Co1-CeO2-500 and Co1-CeO2-700 are as follows: (1) Place 4 g of Ce(NO3)3·6H2O in a muffle furnace, heat at a rate of 5°C / min, and calcine at 350°C for 2.0 h to obtain CeO2, which is then ground; (2) A Co1-CeO2 catalyst precursor was prepared by a conventional equal volume impregnation method. The CeO2 obtained in step (1) was stirred in deionized water to form a slurry, and the required amount of Co(NO3)2 solution was added dropwise. The mixture was impregnated for 2.0 h and dried in a vacuum at 40°C overnight to prepare a Co-CeO2 catalyst precursor with a Co loading of 2.0 wt%; (3) The Co1-CeO2 catalyst precursor obtained in step (2) was ground and heated at 500°C and 700°C respectively. o C in air atmosphere, heating rate was 5℃ / min, annealing was carried out for 10.0h, and the obtained catalysts were recorded as Co1-CeO2-500 and Co1-CeO2-700, respectively.

5. The method for degrading chlorophenol organic pollutants in water by activating persulfate with a cobalt-cerium oxide single-atom catalyst in the presence of bicarbonate according to claim 1, characterized in that: The cobalt-cerium dioxide single-atom catalyst has an atomic dispersion effect and can achieve rapid degradation and removal of chlorophenol within 10 minutes.

6. The method for degrading chlorophenol organic pollutants in water by activating persulfate with a cobalt-cerium oxide single-atom catalyst in the presence of bicarbonate according to claim 1, characterized in that: The cobalt-cerium dioxide single atom catalyst is added to the water containing chlorophenol, fully mixed and stirred, and then PMS is added. The oxidant is activated by the cobalt-cerium dioxide single atom catalyst to produce a large number of free radicals and non-free radicals, which convert HCO3 - Converted to CO3 ·- , efficiently degrade chlorophenols.

7. The method for degrading chlorophenol organic pollutants in water by activating persulfate with a cobalt-cerium oxide single-atom catalyst in the presence of bicarbonate according to claim 4, characterized in that: In 1 mM HCO3 - In the presence of Co-CeO2-700 / HCO3 - The / PMS system can completely degrade 5 mg / L of 4-CP within 10 minutes.

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