Method for treating chloroquine phosphate wastewater by activating PMS with platinum nano-catalyst

Abstract

The invention relates to the technical field of pharmaceutical wastewater treatment, in particular to a method for treating chloroquine phosphate wastewater by activating PMS with a platinum nano-catalyst, which comprises the following steps: S1, preparing the platinum nano-catalyst: dropwise adding an ethylene glycol solution of H2PtCl6 into an ethylene glycol solution of NaOH heated in an oil bath, stirring and cooling to room temperature to obtain the brownish black platinum nano-catalyst, the average particle size of platinum nanoparticles in the platinum nano-catalyst is less than or equal to 3 nm; and S2, activating PMS by the platinum nano-catalyst to carry out chloroquine phosphate degradation reaction, namely adding the platinum nano-catalyst and potassium peroxymonosulfate composite salt into chloroquine phosphate wastewater, and carrying out degradation reaction under irradiation of 222 nm ultraviolet light. In order to improve the reaction activity of peroxymonosulfate and further improve the degradation efficiency of chloroquine phosphate in a water body, a UV / PMS system is optimized by adopting a platinum nano-catalyst, and help can be provided for treating wastewater containing chloroquine phosphate.

Description

Technical Field

[0001] This invention relates to the field of pharmaceutical wastewater treatment technology, specifically to a method for treating chloroquine phosphate wastewater by activating PMS with a platinum nanocatalyst. Background Technology

[0002] In today's medical field, antiviral drugs play a crucial role in disease treatment. However, with their widespread use, a serious environmental problem has gradually emerged. Taking chloroquine phosphate as an example, due to the characteristics of the human digestive system, some patients cannot fully digest and absorb the drug during treatment. These underutilized drugs and their metabolites inevitably enter urban sewage systems through the normal pathway of human excretion. At the same time, the discharge of medical wastewater has become a significant source of antiviral drugs like chloroquine phosphate entering sewage systems.

[0003] Conventional wastewater treatment processes primarily focus on removing common pollutants such as organic matter, nitrogen, and phosphorus. For antiviral drugs with complex structures and unique properties, like chloroquine phosphate, there is a lack of effective removal methods. Traditional wastewater treatment plants struggle to effectively remove antiviral drugs from wastewater, and residual antiviral drugs in the water pose significant risks to aquatic life and ecotoxicological hazards. Therefore, the removal of antiviral drugs from wastewater has become a pressing problem in the field of environmental protection.

[0004] Peroxymonosulfate (PMS) disinfection technology has demonstrated unique advantages in wastewater treatment. PMS exhibits a significantly low tendency to generate disinfection byproducts, greatly reducing the risk of secondary pollution caused by these byproducts compared to traditional disinfection methods. Its long-lasting disinfection duration maintains its inhibitory effect on microorganisms in water for an extended period, ensuring long-term water quality stability. The diverse activation pathways of PMS provide greater possibilities for its application under various environmental conditions. In particular, due to its asymmetric structural characteristics, PMS is readily activated by ultraviolet light, generating highly oxidizing ·OH and reactive sulfate radicals. These radicals can react with trace amounts of organic pollutants in water, degrading them into harmless small molecules through a series of complex oxidation processes. Studies have shown that the UV / PMS system exhibits excellent degradation performance in the treatment of various organic pollutants, demonstrating significant application potential in water treatment.

[0005] Currently, in research on chloroquine phosphate, Chinese invention patent application CN 115180683 A discloses a method for degrading chloroquine phosphate in pharmaceutical wastewater using a UV / PMS system. This method utilizes the synergistic effect of UV and PMS, and under experimental conditions, can achieve a degradation efficiency of over 90% for chloroquine phosphate within 10 minutes. However, this method uses a traditional ultraviolet light source with a wavelength of 254 nm, which poses serious hazards to human skin and eyes. Summary of the Invention

[0006] To address the technical problem that existing PMS (Polymer Sulfate Membrane Suppressant) light sources pose serious hazards to human skin and eyes during chloroquine phosphate treatment, this invention provides a method for treating chloroquine phosphate wastewater using a platinum nanocatalyst-activated PMS. This method enables the degradation of chloroquine phosphate at 222 nm, resulting in lower hazard and significantly improved degradation efficiency.

[0007] The technical solution of this invention is as follows: A method for treating chloroquine phosphate wastewater by activating PMS with a platinum nanocatalyst includes the following steps: S1. Preparation of platinum nanocatalysts: A solution of H2PtCl6 in ethylene glycol was added dropwise to an ethylene glycol solution of NaOH heated in an oil bath. The mixture was stirred and cooled to room temperature to obtain a brownish-black platinum nanocatalyst with an average particle size of platinum nanoparticles ≤3 nm. S2, Platinum nanocatalyst activates PMS for the degradation of chloroquine phosphate: Platinum nanocatalyst and potassium persulfate composite salt were added to chloroquine phosphate wastewater and the degradation reaction was carried out under 222 nm ultraviolet light irradiation. The molar ratio of chloroquine phosphate, platinum nanocatalyst, and potassium persulfate composite salt is 1:100~500:100~2000.

[0008] Furthermore, step S1 specifically includes: S11: Heat a 0.15 mol / L NaOH ethylene glycol solution in an oil bath to 140~200℃, add a stabilizer, and then add a 3~7 mmol / L H2PtCl6 ethylene glycol solution dropwise while stirring. S12: After the addition is complete, continue heating and stirring for 10 minutes, then stop heating and let it cool to room temperature before stopping stirring to obtain a brownish-black platinum nanocatalyst.

[0009] Furthermore, the stabilizer used in step S11 is 1 mol / L sodium citrate.

[0010] Furthermore, in step S11, the volume ratio of the ethylene glycol solution of NaOH to the ethylene glycol solution of H2PtCl6 is 9:1.

[0011] Furthermore, step S2 specifically involves: S21: Add 0.1~2 mmol / L potassium persulfate complex salt and 0.1~0.5 mmol / L platinum nanocatalyst to chloroquine phosphate wastewater with a concentration of 1 μmol / L, and adjust the pH value to 6~9 with PBS buffer solution to form a reaction system; S22: The reaction system was placed in a black box and irradiated with a 222 nm ultraviolet low-pressure mercury lamp to degrade chloroquine phosphate.

[0012] Furthermore, in step S21, the amount of platinum nanocatalyst added is 0.2~0.5 mmol / L. The amount of potassium persulfate complex salt added is 1~2 mmol / L.

[0013] Furthermore, in step S21, the dosage of platinum nanocatalyst is 0.2 mmol / L. The concentration of chloroquine phosphate in the chloroquine phosphate wastewater was 1 μmol / L. The dosage of potassium persulfate compound salt is 0.5 mmol / L.

[0014] Furthermore, the PBS buffer solution used in step S21 is prepared by dissolving NaH2PO4·2H2O and Na2HPO4·12H2O in ultrapure water, with NaH2PO4·2H2O and Na2HPO4·12H2O mixed in different proportions to adjust different pH values.

[0015] Furthermore, the reaction temperature in step S22 is maintained at 25±3℃.

[0016] Furthermore, the chloroquine phosphate wastewater in step S2 was prepared in the laboratory.

[0017] The beneficial effects of this invention are as follows: To improve the reactivity of peroxymonosulfate and further enhance the degradation efficiency of chloroquine phosphate in water, this invention constructs a chloroquine phosphate wastewater treatment system that utilizes platinum nanocatalysts to activate PMS in conjunction with 222 nm ultraviolet light. The ultra-small particle size (average particle size ≤3 nm) of the platinum nanocatalyst endows it with an extremely high specific surface area and abundant surface active sites. These sites can efficiently activate PMS through electron transfer, promoting its decomposition to generate a large number of highly oxidizing sulfate radicals and hydroxyl radicals. At the same time, under irradiation with 222 nm ultraviolet light, the activation effect of PMS can be further enhanced.

[0018] Experimental data show that under optimized conditions (platinum nanocatalyst dosage 0.2 mmol / L, PMS dosage 0.1 mmol / L, pH=7, 222 nm UV irradiation), chloroquine phosphate degradation rate of 99% can be achieved in just 6 minutes, demonstrating the significant advantage of rapid degradation.

[0019] In summary, this invention achieves efficient, rapid, and environmentally friendly treatment of chloroquine phosphate wastewater. Its comprehensive advantages in treatment efficiency, environmental safety, economy, and application scalability not only provide a targeted solution for chloroquine phosphate wastewater treatment, but also have significant implications for promoting the development of water treatment technology towards higher efficiency, greener practices, and lower costs, providing practical technical support for the purification of actual drug-containing wastewater. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a transmission electron microscope image of the platinum nanocatalyst prepared in Example 1.

[0022] Figure 2 This is a comparison chart of the degradation effects of chloroquine phosphate wastewater under ultraviolet light, natural light, and black box conditions without ultraviolet light in Example 1.

[0023] Figure 3 This is a comparison chart of the degradation effect of chloroquine phosphate wastewater under different dosages of platinum nanocatalysts in Example 2.

[0024] Figure 4 This is a comparison chart of the degradation effect of chloroquine phosphate wastewater under different dosages of potassium peroxymonosulfate composite salt in Example 3.

[0025] Figure 5 This is a comparison chart of the degradation effect of chloroquine phosphate wastewater at different pH values ​​in Example 4. Detailed Implementation

[0026] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0027] Unless otherwise specified, the raw materials or reagents used in the specific embodiments of this invention are all commercially available products well known to those skilled in the art.

[0028] In a specific embodiment of the present invention, chloroquine phosphate wastewater with a concentration of 1 μmol / L, prepared in the laboratory, was used to simulate wastewater for application effect testing. The PBS buffer solution was prepared by dissolving NaH2PO4·2H2O and Na2HPO4·12H2O in ultrapure water.

[0029] This invention provides a method for treating chloroquine phosphate wastewater by activating PMS with a nanocatalyst. This method comprehensively improves PMS activity and optimizes chloroquine phosphate degradation efficiency from both catalyst preparation and reaction system regulation perspectives. It is a practical and economical method for treating pharmaceutical wastewater, comprising the following steps: S1. Preparation of platinum nanocatalysts: A solution of H2PtCl6 in ethylene glycol was added dropwise to an ethylene glycol solution of NaOH heated in an oil bath. The mixture was stirred and cooled to room temperature to obtain a brownish-black platinum nanocatalyst with an average particle size of platinum nanoparticles ≤3 nm. S2, Platinum nanocatalyst activates PMS for the degradation of chloroquine phosphate: Platinum nanocatalyst and potassium persulfate composite salt (potassium persulfate monosulfate) were added to chloroquine phosphate wastewater and the degradation reaction was carried out under 222 nm ultraviolet light irradiation. The dosage of platinum nanocatalyst was 0.1~0.5 mmol / L. The concentration of chloroquine phosphate in the chloroquine phosphate wastewater was 1 μmol / L. The dosage of potassium persulfate compound salt is 0.1~2 mmol / L.

[0030] In the preparation stage of platinum nanocatalysts, the concentration of the ethylene glycol solution of NaOH was controlled at 0.15 mol / L, and the concentration of the ethylene glycol solution of H₂PtCl₆ was 3–7 mmol / L, with a volume ratio of 9:1. Simultaneously, a suitable reaction temperature (oil bath heating to 140–200℃) was maintained. This ensured the complete reduction of the H₂PtCl₆ precursor to platinum nanoparticles in the alkaline ethylene glycol system, while temperature control prevented excessive particle growth leading to increased particle size and reduced active sites. Further addition of 1 mol / L sodium citrate as a stabilizer effectively inhibited platinum nanoparticle aggregation, maintained their dispersibility, and further ensured sufficient exposure of active sites, avoiding catalytic activity attenuation caused by aggregation.

[0031] During the degradation reaction stage, the dosage range of platinum nanocatalyst, 0.1–0.5 mmol / L, was precisely considered: Too low a dosage results in insufficient active sites for activating PMS, leading to a slower PMS decomposition rate and reduced generation of active species (such as sulfate radicals), thus limiting the degradation efficiency of chloroquine phosphate. Conversely, a dosage exceeding 0.5 mmol / L not only increases the cost of catalyst preparation and use but also risks catalyst aggregation due to interactions, reducing the activity per unit mass of catalyst. Therefore, this range is crucial for balancing catalytic activity and economic efficiency. Correspondingly, the PMS dosage was designed to be 0.1–2 mmol / L. Insufficient PMS dosage leads to excessively low concentrations of active species, hindering rapid degradation of chloroquine phosphate; excessive PMS dosage may cause side reactions with the generated active species, resulting in their depletion. Furthermore, unreacted PMS residues may have secondary impacts on the water body. Therefore, this range ensures sufficient and efficient utilization of active species.

[0032] This method uses 222 nm ultraviolet light. This wavelength of ultraviolet light can not only excite PMS molecules and promote their decomposition to produce active species, but also enhance the electron transfer ability of platinum nanocatalysts through photocatalysis, further improving the activation efficiency of the catalyst for PMS. This synergistic effect enables the system to achieve efficient degradation of chloroquine phosphate in a short time.

[0033] pH affects the surface charge state of platinum nanocatalysts and the decomposition pathway of PMS. At pH values ​​of 6–9 (especially the optimal pH of 7), the electron transfer efficiency of the catalyst surface active sites is highest, and PMS is more readily decomposed into highly oxidizing sulfate and hydroxyl radicals. The synergistic effect of these radicals significantly enhances the degradation rate of chloroquine phosphate. Simultaneously, the neutral environment of pH 7 is close to the pH range of natural water bodies, avoiding the impact of extreme pH values ​​on subsequent aquatic ecosystems.

[0034] This invention can degrade chloroquine phosphate at room temperature of 25±3℃, with low energy consumption and no need for additional heating or cooling equipment, which is in line with the engineering application scenarios of actual wastewater treatment.

[0035] Example 1 The treatment of chloroquine phosphate wastewater with a concentration of 1.0 μmol / L was carried out under natural light irradiation, black box without ultraviolet light irradiation, or black box with ultraviolet light irradiation, with or without the addition of platinum nanocatalyst. The specific steps are as follows: S1. Preparation of platinum nanocatalysts: S11: Transfer 9 mL of 0.15 mol / L NaOH in ethylene glycol to a 25 mL round-bottom flask equipped with a condenser. Heat in an oil bath to 160 °C. After the temperature stabilizes, add 1 mol / L sodium citrate while stirring vigorously. Then, add 1 mL of 3.0 mmol / L H2PtCl6 in ethylene glycol dropwise to the round-bottom flask.

[0036] S12: After the addition is complete, continue heating and stirring for 10 minutes, then stop heating and let it cool to room temperature before stopping stirring to obtain a brownish-black platinum nanocatalyst. Take one drop of the platinum nanocatalyst and drop it onto a copper mesh coated with a carbon film, then vacuum dry at 50°C for 3 days. Observe the sample using a transmission electron microscope; the results are as follows... Figure 1 As shown in the figure. After magnifying the obtained electron microscope image, approximately 300 particles were randomly measured and statistically analyzed. The longest and shortest diameters of each particle were measured, and the average value was calculated to obtain an average particle size of 2.17 nm for the platinum nanoparticles.

[0037] S2, Removal of chloroquine phosphate: S21: Add 1 mmol / L potassium persulfate complex salt to chloroquine phosphate wastewater, and add or not add 0.2 mmol / L platinum nanocatalyst to form a reaction system. Adjust the pH of the reaction system to 7 with PBS buffer solution. S22: The reaction system was placed under natural light, black box without ultraviolet light, or black box with 222 nm ultraviolet light, respectively. The temperature was controlled at 25±3℃ and the magnetic stirrer was turned on to carry out the degradation of chloroquine phosphate.

[0038] Samples were taken at 1, 2, 3, 4, 6, 9, 12, and 15 mins under six different treatment conditions. The concentration of chloroquine phosphate was determined using ultra-high performance liquid chromatography (UHPLC), and the degradation rate was calculated. It was found that under both natural light irradiation and black-box (no UV irradiation) conditions, the removal efficiency of chloroquine phosphate by adding platinum nano-catalyst to activate PMS was significantly higher than that without platinum nano-catalyst. Under natural light irradiation, the degradation rate of chloroquine phosphate by adding platinum nano-catalyst to activate PMS was 70% (e.g., under natural light irradiation). Figure 2 (As shown in the natural light curve); Under black box conditions without ultraviolet light irradiation, the degradation rate of chloroquine phosphate activated by adding platinum nanocatalyst to PMS was 50% (e.g. Figure 2 (As shown in the PMS curve). The above experimental results indicate that platinum nanocatalysts can enhance the treatment effect of PMS on chloroquine phosphate.

[0039] When irradiated with 222 nm UV light under a black box, the treatment effect of chloroquine phosphate with or without platinum nano-catalyst was superior to that of other treatment groups. After 6 minutes of treatment, the degradation rate of chloroquine phosphate under 222 nm UV light irradiation without platinum nano-catalyst was 80%, while the degradation rate of chloroquine phosphate under 222 nm UV light irradiation with platinum nano-catalyst to activate PMS reached 99% (e.g., ...). Figure 2 (As shown in the UV / PMS curve). The above experimental results indicate that the PMS system under 222 nm UV light and platinum nanocatalyst conditions is significantly activated, and the treatment effect of chloroquine phosphate wastewater is significantly improved.

[0040] Example 2 Based on Example 1, the dosage of platinum nanocatalyst was changed to treat chloroquine phosphate wastewater. The specific steps are as follows: S1. Prepare platinum nanocatalysts according to the same process and conditions as in S1 of Example 1; S2, Removal of chloroquine phosphate: S21: Add 1 mmol / L potassium persulfate compound salt to each of four portions of chloroquine phosphate wastewater with a concentration of 1.0 μmol / L, and then add 0 mmol / L, 0.1 mmol / L, 0.2 mmol / L or 0.5 mmol / L platinum nanocatalysts respectively to form a reaction system. Adjust the pH of the reaction system to 7 with PBS buffer solution. S22: The reaction system was placed in a black box, irradiated with a 222 nm ultraviolet low-pressure mercury lamp, and the temperature was controlled at 25±3℃. A magnetic stirrer was turned on to carry out the degradation of chloroquine phosphate.

[0041] Samples were taken at 0, 1, 2, 3, 4, 6, 9, 12, and 15 min, and the concentration of chloroquine phosphate was determined using ultra-high performance liquid chromatography (UHPLC). The results are as follows: Figure 3 As shown.

[0042] Experimental results showed that the content of chloroquine phosphate in all wastewaters decreased as the reaction progressed, and the rate of decrease was significantly faster in wastewater with catalyst addition than in wastewater without catalyst. After 6 minutes of reaction, the removal rate of chloroquine phosphate in wastewater without catalyst (0 mmol / L) reached 80%. With catalyst additions of 0.1 mmol / L, 0.2 mmol / L, and 0.5 mmol / L, the degradation rates reached 96%, 99%, and 100%, respectively. This indicates that platinum nanocatalysts can effectively accelerate the degradation of chloroquine phosphate and improve wastewater treatment. Considering both cost and effectiveness, 0.2 mmol / L is the optimal dosage, under which good treatment results can be achieved within 6 minutes.

[0043] Example 3 Based on Example 1, the dosage of potassium persulfate complex salt was changed to treat chloroquine phosphate wastewater. The specific steps are as follows: S1. Prepare platinum nanocatalysts according to the same process and conditions as in S1 of Example 1; S2, removal of chloroquine phosphate: S21: Add 0 mmol / L, 0.5 mmol / L, 1 mmol / L, 1.5 mmol / L or 2 mmol / L potassium persulfate complex salt to five portions of chloroquine phosphate wastewater with a concentration of 1.0 μmol / L, respectively. Then add 0.2 mmol / L platinum nanocatalyst to each portion of the wastewater to form a reaction system. Adjust the pH of the reaction system to 7 using PBS buffer solution. S22: The reaction system was placed in a black box, irradiated with a 222 nm ultraviolet low-pressure mercury lamp, and the temperature was controlled at 25±3℃. A magnetic stirrer was turned on to carry out the degradation of chloroquine phosphate.

[0044] Samples were taken at 0, 1, 2, 3, 4, 6, 9, 12, and 15 min, and the concentration of chloroquine phosphate was determined using ultra-high performance liquid chromatography (UHPLC). The results are as follows: Figure 4 As shown.

[0045] Experimental results showed that the content of chloroquine phosphate in all wastewaters decreased as the reaction progressed, and the rate of decrease was significantly faster in wastewater treated with potassium persulfate than in wastewater without it. At 6 min of reaction, the removal rate of chloroquine phosphate in wastewater without potassium persulfate (0 mmol / L) was only 15%. When potassium persulfate was added at concentrations of 0.5 mmol / L, 1 mmol / L, 1.5 mmol / L, or 2 mmol / L, the degradation rates reached 95%, 99%, 100%, and 100%, respectively. Considering both cost and effectiveness, the optimal dosage of potassium persulfate compound salt was determined to be 1 mmol / L.

[0046] Example 4 Based on Example 1, the pH value of the reaction system was changed using PBS buffer solution to treat chloroquine phosphate wastewater. The specific steps are as follows: S1. Prepare platinum nanocatalysts according to the same process and conditions as in S1 of Example 1; S2, Removal of chloroquine phosphate: S21: Add 1 mmol / L potassium persulfate compound salt to each of four portions of chloroquine phosphate wastewater with a concentration of 1.0 μmol / L, and then add 0.2 mmol / L platinum nanocatalyst to each to form a reaction system. Adjust the pH of the reaction system to 6, 7, 8 or 9 respectively using PBS buffer solution. S22: The reaction system was placed in a black box, irradiated with a 222 nm ultraviolet low-pressure mercury lamp, and the temperature was controlled at 25±3℃. A magnetic stirrer was turned on to carry out the degradation of chloroquine phosphate.

[0047] Samples were taken at 0, 1, 2, 3, 4, 6, 9, 12, and 15 min, and the concentration of chloroquine phosphate was determined using ultra-high performance liquid chromatography (UHPLC). The results are as follows: Figure 5 As shown.

[0048] Experimental results showed that the content of chloroquine phosphate in each wastewater decreased as the reaction progressed. When the system pH was 6, the 6-minute degradation rate of the wastewater was 95%; when the pH was increased to 7, the 6-minute degradation rate significantly increased to 99%; when the pH continued to rise to 8, the 6-minute degradation rate remained at a high level of 99%; and when the pH reached 9, the 6-minute degradation rate further increased to 100%. From a practical application perspective, the system with a pH of 7 is closer to the neutral environment of natural water bodies, while maintaining a stable high degradation rate of 99%, meeting the requirements for efficient treatment. Therefore, the optimal pH was chosen as 7.

[0049] Example 5 The treatment of chloroquine phosphate wastewater with a concentration of 1.0 μmol / L includes the following steps: S1. Preparation of platinum nanocatalysts: S11: Transfer 9 mL of 0.15 mol / L NaOH in ethylene glycol to a 25 mL round-bottom flask equipped with a condenser. Heat in an oil bath to 180°C. After the temperature stabilizes, add 1 mol / L sodium citrate while stirring vigorously. Then, add 1 mL of 5.0 mmol / L H2PtCl6 in ethylene glycol dropwise to the round-bottom flask.

[0050] S12: After the addition is complete, continue heating and stirring for 10 minutes, then stop heating and let it cool to room temperature before stopping stirring to obtain a brownish-black platinum nanocatalyst. Take one drop of the platinum nanocatalyst and drop it onto a copper mesh coated with a carbon film, then vacuum dry at 50°C for 3 days. Observe the sample using a transmission electron microscope; the results are as follows... Figure 1 As shown in the figure. After magnifying the obtained electron microscope image, approximately 300 particles were randomly measured and statistically analyzed. The longest and shortest diameters of each particle were measured, and the average value was calculated to obtain an average particle size of 2.36 nm for the platinum nanoparticles.

[0051] S2, Platinum nanocatalyst activates PMS for the degradation of chloroquine phosphate: S21: Add 1 mmol / L potassium persulfate complex salt and 0.2 mmol / L platinum nanocatalyst to chloroquine phosphate wastewater to form a reaction system, and adjust the pH of the reaction system to 7 with PBS buffer solution; S22: Place the reaction system in a black box, irradiate it with a 222 nm ultraviolet low-pressure mercury lamp, control the temperature at 25±3℃ and turn on the magnetic stirrer to carry out the degradation of chloroquine phosphate.

[0052] The results showed that the PMS system was significantly activated under 222 nm ultraviolet light and platinum nanocatalyst conditions, generating a large number of active groups such as hydroxyl radicals and sulfate radicals. 99% of chloroquine phosphate could be removed in 6 min of reaction.

[0053] Example 6 The treatment of chloroquine phosphate wastewater with a concentration of 1.0 μmol / L includes the following steps: S1. Preparation of platinum nanocatalysts: S11: Transfer 9 mL of 0.15 mol / L NaOH in ethylene glycol to a 25 mL round-bottom flask equipped with a condenser. Heat in an oil bath to 200 °C. After the temperature stabilizes, add 1 mol / L sodium citrate while stirring vigorously. Then, add 1 mL of 7.0 mmol / L H2PtCl6 in ethylene glycol dropwise to the round-bottom flask.

[0054] S12: After the addition is complete, continue heating and stirring for 10 minutes, then stop heating and let it cool to room temperature before stopping stirring to obtain a brownish-black platinum nanocatalyst. Take one drop of the platinum nanocatalyst and drop it onto a copper mesh coated with a carbon film, then vacuum dry at 50°C for 3 days. Observe the sample using a transmission electron microscope; the results are as follows... Figure 1 As shown in the figure. After magnifying the obtained electron microscope image, approximately 300 particles were randomly measured and statistically analyzed. The longest and shortest diameters of each particle were measured, and the average value was calculated to obtain an average particle size of 2.48 nm for the platinum nanoparticles.

[0055] S2, Platinum nanocatalyst activates PMS for the degradation of chloroquine phosphate: S21: Add 1 mmol / L potassium persulfate complex salt and 0.2 mmol / L platinum nanocatalyst to chloroquine phosphate wastewater to form a reaction system, and adjust the pH of the reaction system to 7 with PBS buffer solution; S22: Place the reaction system in a black box, irradiate it with a 222 nm ultraviolet low-pressure mercury lamp, control the temperature at 25±3℃ and turn on the magnetic stirrer to carry out the degradation of chloroquine phosphate.

[0056] The results showed that the PMS system was significantly activated under 222 nm ultraviolet light and platinum nanocatalyst conditions, generating a large number of active groups such as hydroxyl radicals and sulfate radicals. 98% of chloroquine phosphate could be removed in 6 min of reaction.

[0057] Although the present invention has been described in detail with reference to the accompanying drawings and preferred embodiments, the present invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the present invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the present invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should also be covered within the protection scope of the present invention.

Claims

1. A method for treating chloroquine phosphate wastewater by activating PMS with a platinum nanocatalyst, characterized in that, Includes the following steps: S1. Preparation of platinum nanocatalysts: A solution of H2PtCl6 in ethylene glycol was added dropwise to an ethylene glycol solution of NaOH heated in an oil bath. The mixture was stirred and cooled to room temperature to obtain a brownish-black platinum nanocatalyst with an average particle size of platinum nanoparticles ≤3 nm. S2, Platinum nanocatalyst activates PMS for the degradation of chloroquine phosphate: Platinum nanocatalyst and potassium persulfate composite salt were added to chloroquine phosphate wastewater and the degradation reaction was carried out under 222 nm ultraviolet light irradiation. The molar ratio of chloroquine phosphate, platinum nanocatalyst, and potassium persulfate composite salt is 1:100~500:100~2000.

2. The method for treating chloroquine phosphate wastewater by activating PMS with platinum nanocatalyst as described in claim 1, characterized in that, Step S1 is as follows: S11: Heat a 0.15 mol / L NaOH ethylene glycol solution in an oil bath to 140~200℃, add a stabilizer, and then add a 3~7 mmol / L H2PtCl6 ethylene glycol solution dropwise while stirring. S12: After the addition is complete, continue heating and stirring for 10 minutes, then stop heating and let it cool to room temperature before stopping stirring to obtain a brownish-black platinum nanocatalyst.

3. The method for treating chloroquine phosphate wastewater by activating PMS with platinum nanocatalyst as described in claim 2, characterized in that, The stabilizer used in step S11 is 1 mol / L sodium citrate.

4. The method for treating chloroquine phosphate wastewater by activating PMS with platinum nanocatalyst as described in claim 2, characterized in that, In step S11, the volume ratio of the ethylene glycol solution of NaOH to the ethylene glycol solution of H2PtCl6 is 9:

1.

5. The method for treating chloroquine phosphate wastewater by activating PMS with platinum nanocatalyst as described in claim 1, characterized in that, Step S2 is as follows: S21: Add 0.1~2 mmol / L potassium persulfate complex salt and 0.1~0.5 mmol / L platinum nanocatalyst to chloroquine phosphate wastewater with a concentration of 1 μmol / L, and adjust the pH value to 6~9 with PBS buffer solution to form a reaction system; S22: The reaction system was placed in a black box and irradiated with a 222 nm ultraviolet low-pressure mercury lamp to degrade chloroquine phosphate.

6. The method for treating chloroquine phosphate wastewater by activating PMS with platinum nanocatalyst as described in claim 5, characterized in that, In step S21, the amount of platinum nanocatalyst added is 0.2~0.5 mmol / L. The amount of potassium persulfate complex salt added is 1~2 mmol / L.

7. The method for treating chloroquine phosphate wastewater by activating PMS with platinum nanocatalyst as described in claim 5, characterized in that, In step S21, the dosage of platinum nanocatalyst is 0.2 mmol / L. The concentration of chloroquine phosphate in the chloroquine phosphate wastewater was 1 μmol / L. The dosage of potassium persulfate compound salt is 0.5 mmol / L.

8. The method for treating chloroquine phosphate wastewater by activating PMS with platinum nanocatalyst as described in claim 5, characterized in that, The PBS buffer solution used in step S21 was prepared by dissolving NaH2PO4·2H2O and Na2HPO4·12H2O in ultrapure water.

9. The method for treating chloroquine phosphate wastewater by activating PMS with platinum nanocatalyst as described in claim 5, characterized in that, The reaction temperature in step S22 is maintained at 25±3℃.

10. The method for treating chloroquine phosphate wastewater by activating PMS with platinum nanocatalyst as described in claim 1, characterized in that, The chloroquine phosphate wastewater in step S2 was prepared in the laboratory.

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