Method for catalytically degrading organic pollutants by inducing metal sulfide at low temperature

Abstract

The invention discloses a method for catalytically degrading organic pollutants by inducing metal sulfide at low temperature. The method comprises the following steps: adding metal sulfide into the organic pollutants, and uniformly dispersing to obtain a reaction solution; and putting the obtained reaction solution in a low-temperature environment, starting a light source, carrying out catalytic degradation reaction, and heating to room temperature after the reaction is finished, thereby obtaining the catalyst. The low-temperature environment is-10 DEG C to-60 DEG C; the mass ratio of the organic pollutants to the metal sulfide in the reaction solution is (1-3): 1. According to the method, solvent water of a system is converted from a liquid phase to a solid phase under a low-temperature condition, reactant molecules are eliminated and concentrated between solid-phase ice crystals, on one hand, the concentration of the metal sulfide photocatalyst is multiplied, and the utilization rate of light energy can be increased; on the other hand, the oxygen utilization rate can be increased through oxygen gathering, and therefore generation of active oxygen species is accelerated to improve the degradation efficiency of pollutants.

Description

Technical Field

[0001] The present invention relates to a method for degrading organic pollutants, in particular to a method for catalytically degrading organic pollutants by inducing metal sulfide at low temperature, and belongs to the field of environmental pollution remediation. Background Art

[0002] With the acceleration of industrialization, the emission of organic pollutants is becoming increasingly severe, posing a significant threat to the environment and ecosystems. Traditional organic pollutant treatment technologies, such as biological treatment and chemical oxidation, face numerous challenges in treating refractory organic matter. These organic matter are complex and highly stable, making them difficult to effectively degrade by microorganisms and traditional chemical oxidants. Furthermore, the treatment process is prone to secondary pollution, resulting in high treatment costs.

[0003] In recent years, photocatalytic oxidation technology has shown great potential in the degradation of organic pollutants due to its high efficiency and sustainability. Metal sulfide photocatalysts, particularly due to their high light absorption capacity and excellent separation of photogenerated electron-hole pairs, have become a research hotspot. However, photocatalytic efficiency is still limited by factors such as the required high catalyst concentration, poor light energy utilization, and oxygen concentration. Therefore, the development of efficient, environmentally friendly, and economical methods for the degradation of organic pollutants is of paramount importance. Summary of the Invention

[0004] To address the challenges of the existing technology, the present invention aims to provide a method for low-temperature induced metal sulfide catalytic degradation of organic pollutants. This method converts the reaction solution into a solid phase at low temperatures, concentrating the catalyst and oxygen in micron-sized intergranular water. This significantly increases the concentration of reactants and effectively enhances the interfacial electron transport capacity, thereby significantly improving the degradation efficiency of organic pollutants in the reaction solution.

[0005] In order to achieve the above technical objectives, the present invention provides a method for low-temperature induced metal sulfide catalytic degradation of organic pollutants, comprising: adding metal sulfide to the organic pollutants and uniformly dispersing them to obtain a reaction solution; placing the obtained reaction solution in a low-temperature environment, activating a light source to carry out a catalytic degradation reaction, and heating the solution to room temperature after the reaction is completed.

[0006] The low temperature environment is -10 to -60°C; the mass ratio of organic pollutants to metal sulfides in the reaction solution is 1 to 3:1.

[0007] The low-temperature degradation method of organic pollutants provided by the present invention mainly converts the solvent water in the system from a liquid phase to a solid phase under low-temperature conditions, while the solute (reactant molecules) are excluded and concentrated between the solid phase ice crystals. On the one hand, the concentration of the metal sulfide photocatalyst itself is multiplied, which can improve the utilization rate of light energy; on the other hand, the accumulation of oxygen can improve its utilization rate of oxygen, thereby accelerating the production of reactive oxygen species to improve the degradation efficiency of pollutants.

[0008] As a preferred solution, the organic pollutant is at least one of CBZ, phenols, tetracyclines, quinolones and sulfonamides.

[0009] As a preferred solution, the metal sulfide is at least one of zinc sulfide, copper sulfide, iron sulfide, manganese sulfide, molybdenum disulfide and tungsten disulfide.

[0010] As a preferred embodiment, the CBZ is carbamazepine.

[0011] As a preferred solution, the phenols are phenol and / or bisphenol A.

[0012] As a preferred solution, the tetracycline is tetracycline; and the quinolone is ofloxacin and / or ciprofloxacin.

[0013] As a preferred solution, the sulfonamide is sulfamethoxazole and / or sulfisoxazole.

[0014] As a preferred solution, the concentration of metal sulfide in the reaction solution is 1-10 mg / L.

[0015] As a preferred solution, the concentration of organic pollutants in the reaction solution is 1-20 mg / L.

[0016] As a preferred solution, the particle size of the metal sulfide is 20-60 nm.

[0017] As a preferred solution, oxygen may be added to the reaction solution to obtain an oxygen-rich solution.

[0018] As a preferred solution, the oxygen filling flow rate is 100-200 mL / min, and the filling time is 5-15 min.

[0019] As a preferred solution, the process of the catalytic degradation reaction is: maintaining the reaction temperature at -15 to -25°C until the reaction solution solidifies, starting the light source to initiate the reaction, and the reaction time is 1 to 6 hours.

[0020] As a preferred solution, the light source is a xenon lamp with a power of 200-300W.

[0021] As a preferred solution, the pH of the reaction solution is neutral.

[0022] As a preferred solution, the heating process after the reaction is completed adopts a warm water bath at a temperature of 30-40°C to completely convert it into a liquid phase.

[0023] As a preferred solution, the process for detecting the content of organic pollutants in the liquid phase obtained by heating is: filtering the obtained liquid phase and then detecting it by high performance liquid chromatography.

[0024] As a preferred solution, the filtration treatment adopts a 0.22 μm needle filter; the mobile phase combination used in the liquid chromatography detection is a mixture of water and methanol or a mixture of acetonitrile and 1‰ formic acid water.

[0025] In the present invention, the method for degrading organic pollutants adopts freezing technology, which can concentrate the catalyst, organic pollutants and oxygen in the micron-scale intercrystalline. Compared with the liquid solution, this method can increase the solute concentration by several orders of magnitude, thereby significantly enhancing the transmission efficiency of interfacial electrons. The oxygen adsorbed on the catalyst surface can be reduced to the greatest extent, generating highly oxidizing reactive oxygen species (ROS), such as hydroxyl radicals (•OH), superoxide radicals (•O2 - ) and singlet oxygen ( 1 O2), these ROS have strong oxidizing properties; at the same time, the contact area between the concentrated organic pollutants and the catalyst is increased, thereby significantly improving their own degradation efficiency.

[0026] Compared with the prior art, the beneficial technical effects of the technical solution provided by the present invention are:

[0027] 1) The method provided by the present invention converts the reaction solution into a solid phase at low temperature, concentrating the catalyst and oxygen in micron-sized intercrystalline water, significantly increasing the concentration of reactants and effectively enhancing the transmission capacity of interfacial electrons, thereby significantly improving the degradation efficiency of organic pollutants in the reaction solution.

[0028] 2) In the technical solution provided by the present invention, metal sulfide is used as the catalyst for the reaction without any modification or purification. Moreover, since the present invention improves the catalytic reaction activity by spatial confinement, the catalytic effect is significantly improved compared to the liquid phase reaction state under any identical reaction conditions.

[0029] 3) In the technical solution provided by the present invention, due to the spatial confinement effect under freezing conditions, a large amount of reactants are enriched on the catalyst surface, effectively increasing the contact area between the catalyst and the reactants, and realizing the efficient generation of hydrogen peroxide by the photocatalyst at low concentrations. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The degradation curves of carbamazepine by zinc sulfide under normal temperature and freezing conditions in Example 1 of the present invention and Comparative Example 1 are shown;

[0031] in Figure 1 (a) is the 1-6h degradation curve of carbamazepine by zinc sulfide under room temperature and freezing conditions in air atmosphere. Figure 1 (b) is the 1-6h degradation curve of carbamazepine by zinc sulfide under normal temperature and freezing conditions in oxygen atmosphere;

[0032] Figure 2 The degradation curves of carbamazepine by copper sulfide under normal temperature and freezing conditions in Example 2 of the present invention and Comparative Example 2 are shown;

[0033] in Figure 2 (a) is the 1-6h degradation curve of carbamazepine by copper sulfide under room temperature and freezing conditions in air atmosphere. Figure 2 (b) is the 1-6h degradation curve of carbamazepine by copper sulfide under oxygen atmosphere at room temperature and freezing conditions;

[0034] Figure 3 This is a graph showing the degradation effect of zinc sulfide on carbamazepine at different freezing temperatures in Example 3 of the present invention;

[0035] Figure 4 The degradation effects of iron sulfide, manganese sulfide, molybdenum disulfide, and tungsten disulfide on carbamazepine under normal temperature and freezing conditions in Examples 4 to 7 of the present invention and Comparative Examples 4 to 7 are shown;

[0036] Figure 5 The degradation effect of zinc sulfide on different organic pollutants under normal temperature and freezing conditions in Example 8 of the present invention and Comparative Example 8 is shown;

[0037] Figure 6 The graph shows the degradation effect of copper sulfide on different organic pollutants under normal temperature and freezing conditions in Example 9 of the present invention and Comparative Example 9. DETAILED DESCRIPTION

[0038] The following will further describe the specific embodiments of the present invention in conjunction with the accompanying drawings and technical solutions. Obviously, the embodiments described are only some of the many possible implementation forms of the present invention, and not all of them. Based on the embodiments disclosed in the present invention, any other embodiments explored by ordinary technicians in this field without involving creative efforts should be deemed to be within the scope of protection claimed by the present invention.

[0039] Furthermore, the technical solutions of the various embodiments of the present invention may, in principle, be combined with one another, but such combination must be capable of successful implementation by a person skilled in the art. If such a combination of technical solutions results in a conflict or is unimplementable, such combination of technical solutions shall be deemed non-existent and shall not fall within the scope of protection claimed by the present invention.

[0040] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or those recommended by the manufacturer. All reagents or instruments used, if the manufacturer is not specified, are commercially available conventional products.

[0041] Unless otherwise defined, all technical and scientific terms used in the present invention are consistent with the prior art knowledge of those skilled in the art and the description of the present invention. The present invention can also be implemented using any methods, equipment and materials in the prior art that are similar or equivalent to the methods, equipment and materials described in the embodiments of the present invention.

[0042] Example 1

[0043] This embodiment provides a method for degrading organic pollutants by using freezing-induced metal sulfides, the process of which is as follows:

[0044] 1. Weigh 10 mg of carbamazepine powder, dissolve it in a small amount of methanol, and dilute to 1000 mL with deionized water to prepare a 10 mg / L carbamazepine stock solution;

[0045] 2. Measure 500 mL of the carbamazepine stock solution from step 1 into a 1000 mL beaker, weigh 5 mg of nano-zinc sulfide and add it thereto, ultrasonicate at a power of 200 W for 10 min to uniformly disperse it to obtain an unoxygenated reaction solution, measure 10 mL of the reaction solution and place it into 6 25 mL quartz test tubes, plug them, label them, and seal them with sealing film for later use.

[0046] 3. Into the unoxygenated reaction solution prepared in step 2, introduce O2 at a flow rate of 150 mL / min for 10 minutes to saturate the reaction solution with O2 to obtain an oxygen-enriched reaction solution. Measure 10 mL of the reaction solution into six 25 mL quartz test tubes, plug them, label them, and seal them with sealing film for later use.

[0047] 3. Adjust the temperature of the low-temperature constant-temperature reaction bath to -20°C, place the 6 / 6 quartz test tubes of the non-oxygenated / oxygen-enriched reaction solutions from steps 2 and 3 into the low-temperature constant-temperature reaction bath, and illuminate with a 250W xenon lamp at the same time. Set this moment as the reaction starting point, and the reaction time is 1 to 6 hours. Take one non-oxygenated and one oxygen-enriched reaction tube every 1 hour.

[0048] 4. Place the removed quartz test tube in a water bath at 35±1°C for thawing. After the solution is completely thawed, immediately filter the thawed / reacted sample through a 0.22 μm needle filter to obtain a test liquid free of zinc sulfide particles. Determine the concentration of carbamazepine using high performance liquid chromatography.

[0049] Comparative Example 1

[0050] This comparative example is exactly the same as Example 1, except that: the temperature of the low-temperature constant-temperature reaction bath is adjusted to 25°C, 10 mL of the unoxygenated / oxygen-enriched reaction solution of steps 2 and 3 are measured and placed in 6 / 6 25 mL quartz test tubes, respectively, stoppered and labeled, and sealed with sealing film. The tubes are placed in a low-temperature constant-temperature reaction bath and illuminated with a 250 W xenon lamp. This moment is designated as the reaction starting point, and the reaction time is 1 to 6 hours.

[0051] The results of Example 1 and Comparative Example 1 are as follows Figure 1 As shown in the figure, in air atmosphere, the 6-h degradation rates of carbamazepine by zinc sulfide at room temperature and frozen conditions were 7.26% and 75.02%, respectively; in oxygen atmosphere, they were 0.12% and 96.16%, respectively. The increased degradation rates of carbamazepine in air and oxygen atmosphere were 67.76% and 96.04%, respectively. It can be seen that zinc sulfide has a higher degradation efficiency for carbamazepine under low-temperature freezing conditions.

[0052] Example 2

[0053] This embodiment is identical to Example 1, except that: 1. 5 mg of nano-copper sulfide was weighed and added to 500 mL of the carbamazepine stock solution prepared in step 1 of Example 1. The solution was then ultrasonically dispersed at a power of 200 W for 10 min to obtain a non-oxygenated reaction solution. 10 mL of the reaction solution was then placed in six 25 mL quartz test tubes, which were stoppered, labeled, and sealed with a sealing film for subsequent use. 2. O was introduced into the non-oxygenated reaction solution prepared in step 1 at a flow rate of 150 mL / min for 10 minutes until the O in the reaction solution reached saturation, thereby obtaining an oxygen-enriched reaction solution. 10 mL of the reaction solution was then placed in six 25 mL quartz test tubes, which were stoppered, labeled, and sealed with a sealing film for subsequent use.

[0054] Comparative Example 2

[0055] This comparative example is exactly the same as Example 2, except that: the temperature of the low-temperature constant-temperature reaction bath is adjusted to 25°C, 10 mL of the unoxygenated / oxygen-enriched reaction solution of steps 1 and 2 of Example 2 are measured and placed in 6 / 6 25 mL quartz test tubes, respectively, stoppered and labeled, and sealed with sealing film. The tubes are placed in a low-temperature constant-temperature reaction bath and illuminated with a 250 W xenon lamp. This moment is defined as the reaction starting point, and the reaction time is 1 to 6 hours.

[0056] The results of Example 2 and Comparative Example 2 are as follows Figure 2 As shown in the figure, in air atmosphere, the 6-hour degradation rates of copper sulfide for carbamazepine at room temperature and frozen conditions were 0.79% and 93.74%, respectively; in oxygen atmosphere, they were 0.19% and 87.75%, respectively. The increased degradation rates of carbamazepine in air and oxygen atmosphere were 92.95% and 87.56%, respectively. It can be seen that copper sulfide has a higher degradation efficiency for carbamazepine under low-temperature freezing conditions.

[0057] Example 3

[0058] This example is identical to Example 1, except that the temperature of the low-temperature constant-temperature reaction bath was adjusted to -50, -40, -30, -20, -10, and 0°C, respectively. 10 mL of the oxygen-enriched reaction solution from step 3 of Example 1 was measured and placed in six 25 mL quartz test tubes, which were stoppered and labeled, sealed with sealing film, and placed in a low-temperature constant-temperature reaction bath. Illumination was performed using a 250 W xenon lamp. This moment was designated as the reaction starting point, and the reaction time was 6 hours.

[0059] The results of Example 3 are as follows Figure 3 As shown in the figure, under oxygen atmosphere, zinc sulfide has the highest degradation rate of carbamazepine at a freezing temperature of -20°C. The freezing rate of solvent water into ice is different at different freezing temperatures, and it will affect the size of the intercrystalline water layer. These factors will lead to differences in the degradation efficiency of carbamazepine at different freezing temperatures.

[0060] Example 4

[0061] This example is identical to Example 1, except that 5 mg of nano-iron sulfide was weighed and added to 500 mL of the carbamazepine stock solution prepared in step 1 of Example 1. The mixture was evenly dispersed by ultrasonication at a power of 200 W for 10 min. O2 was introduced into the solution at a flow rate of 150 mL / min for 10 minutes to saturate the reaction solution with O2 to obtain an oxygen-enriched reaction solution. 10 mL of the reaction solution was placed in a 25 mL quartz test tube, stoppered, labeled, and sealed with sealing film. The tube was placed in a low-temperature constant-temperature reaction bath and illuminated with a 250 W xenon lamp. This moment was designated as the starting point of the reaction, and the reaction time was 6 hours.

[0062] Comparative Example 4

[0063] This comparative example is exactly the same as Example 4, except that the temperature of the low-temperature constant-temperature reaction bath was adjusted to 25°C, 10 mL of the oxygen-enriched reaction solution prepared in Example 4 was measured and placed in a 25 mL quartz test tube, which was stoppered and labeled, sealed with sealing film, and placed in the low-temperature constant-temperature reaction bath for reaction for 6 hours.

[0064] The results of Example 4 and Comparative Example 4 are as follows Figure 4 As shown in the data, the degradation rate of carbamazepine by iron sulfide at a freezing temperature of -20°C is 76.18%, while it is only 3.57% at room temperature. The degradation efficiency of carbamazepine by iron sulfide under freezing conditions is increased by 21.34 times.

[0065] Example 5

[0066] This example is identical to Example 1, except that 5 mg of nano-manganese sulfide was weighed and added to 500 mL of the carbamazepine stock solution prepared in step 1 of Example 1. The mixture was uniformly dispersed by ultrasonication at a power of 200 W for 10 min. O2 was introduced into the solution at a flow rate of 150 mL / min for 10 minutes to saturate the reaction solution with O2 to obtain an oxygen-enriched reaction solution. 10 mL of the reaction solution was added to a 25 mL quartz test tube, which was stoppered, labeled, and sealed with sealing film. The tube was placed in a low-temperature constant-temperature reaction bath and illuminated with a 250 W xenon lamp. This moment was designated as the starting point of the reaction, and the reaction time was 6 hours.

[0067] Comparative Example 5

[0068] This comparative example is exactly the same as Example 5, except that: the temperature of the low-temperature constant-temperature reaction bath is adjusted to 25°C, 10 mL of the oxygen-enriched reaction solution prepared in Example 5 is measured and placed in a 25 mL quartz test tube, the tube is stoppered and labeled, and sealed with sealing film, and placed in the low-temperature constant-temperature reaction bath for reaction for 6 hours.

[0069] The results of Example 5 and Comparative Example 5 are as follows Figure 4 As shown in the data, the degradation rate of carbamazepine by manganese sulfide at a freezing temperature of -20°C was 63.57%, while it was only 1.98% at room temperature. The degradation efficiency of carbamazepine by manganese sulfide under freezing was increased by 32.11 times.

[0070] Example 6

[0071] This example is exactly the same as Example 1, except that 5 mg of nano-molybdenum disulfide was weighed and added to 500 mL of the carbamazepine stock solution prepared in step 1 of Example 1. The mixture was evenly dispersed by ultrasonication at a power of 200 W for 10 min. O2 was introduced into the solution at a flow rate of 150 mL / min for 10 minutes to saturate the reaction solution with O2 to obtain an oxygen-enriched reaction solution. 10 mL of the reaction solution was added to a 25 mL quartz test tube, which was stoppered, labeled, and sealed with sealing film. The tube was placed in a low-temperature constant-temperature reaction bath and illuminated with a 250 W xenon lamp. This moment was designated as the starting point of the reaction, and the reaction time was 6 hours.

[0072] Comparative Example 6

[0073] This comparative example is exactly the same as Example 6, except that: the temperature of the low-temperature constant-temperature reaction bath is adjusted to 25°C, 10 mL of the oxygen-enriched reaction solution prepared in Example 6 is measured and placed in a 25 mL quartz test tube, the tube is stoppered and labeled, and sealed with sealing film, and placed in the low-temperature constant-temperature reaction bath for reaction for 6 hours.

[0074] The results of Example 6 and Comparative Example 6 are as follows Figure 4 As shown in the figure, the degradation rate of carbamazepine by molybdenum disulfide at a freezing temperature of -20°C is 88.20%, while it is only 10.23% at room temperature. The degradation efficiency of carbamazepine by molybdenum disulfide under freezing is increased by 8.62 times.

[0075] Example 7

[0076] This example is identical to Example 1, except that 5 mg of nano-tungsten disulfide was weighed and added to 500 mL of the carbamazepine stock solution prepared in step 1 of Example 1. The mixture was uniformly dispersed by ultrasonication at a power of 200 W for 10 min. O2 was introduced into the solution at a flow rate of 150 mL / min for 10 minutes to saturate the reaction solution with O2 to obtain an oxygen-enriched reaction solution. 10 mL of the reaction solution was placed in a 25 mL quartz test tube, stoppered, labeled, and sealed with sealing film. The tube was placed in a low-temperature constant-temperature reaction bath and illuminated with a 250 W xenon lamp. This moment was designated as the starting point of the reaction, and the reaction time was 6 hours.

[0077] Comparative Example 7

[0078] This comparative example is identical to Example 7, except that the temperature of the low-temperature constant-temperature reaction bath was adjusted to 25°C, 10 mL of the oxygen-enriched reaction solution prepared in Example 7 was measured and placed in a 25 mL quartz test tube, which was stoppered and labeled, sealed with sealing film, and placed in a low-temperature constant-temperature reaction bath for reaction for 6 h.

[0079] The results of Example 7 and Comparative Example 7 are as follows Figure 4 As shown in the figure, the degradation rate of carbamazepine by tungsten disulfide at a freezing temperature of -20°C is 57.19%, while it is only 5.00% at room temperature. The degradation efficiency of carbamazepine by tungsten disulfide under freezing is increased by 11.44 times.

[0080] Example 8

[0081] Weigh 10 mg of phenol, add a small amount of ethanol to dissolve, and dilute to 1000 mL with deionized water to prepare a 10 mg / L phenol stock solution; weigh 10 mg of bisphenol A, add a small amount of ethanol to dissolve, and dilute to 1000 mL with deionized water to prepare a 10 mg / L bisphenol A stock solution; weigh 10 mg of tetracycline, add a small amount of ethanol to dissolve, and dilute to 1000 mL with deionized water to prepare a 10 mg / L tetracycline stock solution; weigh 10 mg ofloxacin, add a small amount of ethanol to dissolve, and dilute to 1000 mL with deionized water to prepare a 10 mg / L ofloxacin stock solution; weigh 10 mg of sulfamethoxazole, add a small amount of methanol to dissolve, and dilute to 1 with deionized water. 000mL, to prepare a 10mg / L sulfamethoxazole stock solution; weigh 5mg of nano zinc sulfide and add it to 500mL of the above five organic pollutant stock solutions respectively. Ultrasonicate at a power of 200W for 10 minutes to uniformly disperse them. O2 is introduced into the solution at a flow rate of 150mL / min for 10 minutes to saturate the reaction solution with O2 to prepare an oxygen-enriched reaction solution. 10mL of the reaction solution is measured in five 25mL quartz test tubes, stoppered, labeled, and sealed with sealing film. The tubes are placed in a low-temperature constant-temperature reaction bath and illuminated with a 250W xenon lamp. This moment is designated as the reaction starting point, and the reaction time is 6 hours. After the reaction is completed, wait until the solution is completely thawed, and the thawed sample is immediately filtered with a 0.22μm syringe filter to obtain a test liquid free of zinc sulfide particles. The concentration of organic pollutants is determined by high-performance liquid chromatography.

[0082] Comparative Example 8

[0083] This comparative example is exactly the same as Example 8, except that: the temperature of the low-temperature constant-temperature reaction bath is adjusted to 25°C, 10 mL of the oxygen-enriched reaction solution prepared in Example 8 is measured and placed in five 25 mL quartz test tubes, stoppered and labeled, and sealed with sealing film, and placed in the low-temperature constant-temperature reaction bath for reaction for 6 hours.

[0084] The results of Example 8 and Comparative Example 8 are as follows Figure 5 As shown in the figure, compared with room temperature, at a freezing temperature of -20°C, zinc sulfide generally has an accelerated degradation effect on organic pollutants with different structures such as phenol, bisphenol A, tetracycline, ofloxacin, and sulfamethoxazole.

[0085] Example 9

[0086] This example is identical to Example 8, except that: 10 mg of ciprofloxacin was weighed, a small amount of ethanol was added to dissolve it, and the volume was adjusted to 1000 mL with deionized water to prepare a 10 mg / L ciprofloxacin stock solution; 10 mg of sulfisoxazole was weighed, a small amount of methanol was added to dissolve it, and the volume was adjusted to 1000 mL with deionized water to prepare a 10 mg / L sulfisoxazole stock solution; 5 mg of nano-copper sulfide was weighed and added to 500 mL of phenol, bisphenol A, tetracycline prepared in Example 8 and ciprofloxacin and sulfisoxazole prepared in this example, respectively. Stock solutions of five organic pollutants were ultrasonically dispersed at 200W for 10 minutes. O₂ was then introduced into the solution at a flow rate of 150mL / min for 10 minutes to saturate the reaction solution with O₂, producing an oxygen-enriched reaction solution. 10mL of this reaction solution was then measured and placed into five 25mL quartz test tubes. These tubes were stoppered, labeled, and sealed with parafilm. The tubes were then placed in a low-temperature, constant-temperature reaction bath and illuminated with a 250W xenon lamp. This moment was designated the reaction starting point, and the reaction time was 6 hours. After the reaction, the solution was completely thawed and the thawed sample was immediately filtered through a 0.22μm syringe filter to obtain a test solution free of copper sulfide particles. The concentration of the organic pollutants was then determined using high-performance liquid chromatography.

[0087] Comparative Example 9

[0088] This comparative example is identical to Example 9, except that the temperature of the low-temperature constant-temperature reaction bath was adjusted to 25°C, 10 mL of the oxygen-enriched reaction solution prepared in Example 9 was measured and placed in five 25 mL quartz test tubes, stoppered and labeled, and sealed with sealing film. The tubes were then placed in the low-temperature constant-temperature reaction bath for reaction for 6 h.

[0089] The results of Example 9 and Comparative Example 9 are as follows Figure 6 As shown in the figure, compared with room temperature, at a freezing temperature of -20°C, copper sulfide generally has an accelerated degradation effect on organic pollutants with different structures such as phenol, bisphenol A, tetracycline, ciprofloxacin, and sulfamethoxazole.

[0090] It can be seen that the method of freezing-induced metal sulfide degradation of organic pollutants can achieve efficient degradation of organic pollutants under the condition of low concentration of metal sulfide photocatalyst; it is simple to operate, low-cost, green and environmentally friendly; safe, reliable and highly applicable.

[0091] In summary, the above technical solutions of the present invention are only preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention's description and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for low-temperature induction of metal sulfide catalytic degradation of organic pollutants, characterized in that: include: Add metal sulfide to the organic pollutant and disperse it evenly to obtain a reaction solution; place the obtained reaction solution in a low-temperature environment, start a light source to carry out a catalytic degradation reaction, and heat it to room temperature after the reaction is completed to obtain; The low temperature environment is -10 to -60°C; the mass ratio of organic pollutants to metal sulfides in the reaction solution is 1 to 3:

1.

2. The method for low-temperature induced metal sulfide catalytic degradation of organic pollutants according to claim 1, characterized in that: The organic pollution is at least one of CBZ, phenols, tetracyclines, quinolones and sulfonamides; the metal sulfide is at least one of zinc sulfide, copper sulfide, iron sulfide, manganese sulfide, molybdenum disulfide and tungsten disulfide.

3. The method for low-temperature induced metal sulfide catalytic degradation of organic pollutants according to claim 2, characterized in that: The CBZ class is carbamazepine; the phenol class is phenol and / or bisphenol A; the tetracycline class is tetracycline; the quinolone class is ofloxacin and / or ciprofloxacin; and the sulfonamide class is sulfamethoxazole and / or sulfisoxazole.

4. The method for low-temperature induced metal sulfide catalytic degradation of organic pollutants according to claim 1, characterized in that: The concentration of the metal sulfide in the reaction solution is 1-10 mg / L; the concentration of the organic pollutants in the reaction solution is 1-20 mg / L; and the particle size of the metal sulfide is 20-60 nm.

5. The method for low-temperature induced metal sulfide catalytic degradation of organic pollutants according to claim 1, characterized in that: The reaction solution may also be charged with oxygen to obtain an oxygen-enriched solution; the oxygen charging flow rate is 100-200 mL / min, and the charging time is 5-15 min.

6. The method of claim 1, wherein: The process of the catalytic degradation reaction is: maintaining the reaction temperature at -15 to -25°C until the reaction solution solidifies, starting the light source to start the reaction, and the reaction time is 1 to 6 hours.

7. The method for low-temperature induced metal sulfide catalytic degradation of organic pollutants according to claim 1 or 5, characterized in that: The light source is a xenon lamp with a power of 200-300W; the pH of the reaction solution is neutral.

8. The method of claim 1, wherein: After the reaction is completed, the temperature is raised to 30-40° C. in a warm water bath to completely convert the reaction into a liquid phase.

9. The method for low-temperature induced metal sulfide catalytic degradation of organic pollutants according to claim 8, characterized in that: The process for detecting the content of organic pollutants in the liquid phase obtained by heating is as follows: filtering the obtained liquid phase and then detecting it by high performance liquid chromatography.

10. The method for low-temperature induced metal sulfide catalytic degradation of organic pollutants according to claim 9, characterized in that: The filtration treatment adopts a 0.22 μm needle filter for filtration; the mobile phase combination used in the liquid chromatography detection is a mixture of water and methanol or a mixture of acetonitrile and 1‰ formic acid water.

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