Method and device for purifying water body containing micro-nano particles

Abstract

The invention provides a method and a device for purifying a water body containing micro-nano particles. The method comprises the following steps: adding graphene oxide into the water body containing the micro-nano particles for dispersion treatment, adjusting the pH value of the water body to be acidic, then standing for settling, and filtering to obtain the water body without the micro-nano particles. The graphene oxide can be combined with the micro-nano particles through common electrons due to the super-large specific surface area and rich oxygen-containing functional groups, a large number of micro-nano particles are efficiently adsorbed, meanwhile, mutual agglomeration of the graphene oxide is promoted in an acid environment, the graphene oxide is rapidly settled, and the adsorption capacity of the graphene oxide is improved. And the micro-nano particles in the water body containing the micro-nano particles can be effectively removed through filtration.

Description

Technical Field

[0001] The present invention relates to the technical field of water purification, and particularly relates to a method and device for purifying water containing micro-nano particles. Background Art

[0002] The pollution problem of micro-nano particles has attracted wide international attention and has been defined as one of the new pollutants. In recent years, scientists have found that micro-nano particles exist extremely widely, including in seawater, human blood, deep in the lungs, drinking water, and even in clouds. These findings indicate that micro-nano particles have been widely distributed in the global environment, have a long environmental half-life, and pose a serious threat to the ecosystem and human health.

[0003] The purification of micro-nano particles in water is one of the key concerns of people. At present, the technologies for physically separating and purifying micro-nano particles in water mainly include the following two methods:

[0004] Method 1: Filtration method. When the solution to be purified passes through a filter (such as filter paper, filter membrane, etc.), the solid remains on the filter, and the solution passes through the filter smoothly, achieving solid-liquid separation and purifying the solution. However, when in use, a microfiltration membrane with a smaller pore size is generally required. The use cost of the microfiltration membrane is relatively high; in addition, since the micro-nano particles are filtered and the size of the filter membrane is microporous, the micropores of the filter membrane are easily blocked during the filtration process, resulting in the filter membrane being unable to be used normally when purifying a small amount of solution.

[0005] Method 2: Centrifugal separation method. Centrifugal separation mainly relies on the action of centrifugal force to make the suspended substances in the water precipitate out easily, so as to achieve solid-liquid separation and purify the solution. However, since the micro-nano particles to be precipitated are involved, a relatively high angular velocity is required to make the centrifugal force much greater than the gravity to separate them. For this, only a high-speed centrifuge can be used. At present, the capacity of high-speed centrifuges is relatively small, and it is difficult to batch process or purify a large amount of solution, with low purification efficiency and high energy consumption.

[0006] Generally speaking, these methods are simple to operate and easy to implement, but the efficiency of removing micro-nano particles is relatively low, and it is difficult to remove nano-scale micro-nano particles. Summary of the Invention

[0007] The technical problem to be solved by the present invention is how to effectively remove micro-nano particles in water.

[0008] The present invention solves the above technical problem by the following technical means:

[0009] In the first aspect of the present invention, a method for purifying water containing micro-nano particles is provided. Graphene oxide is added to the water containing micro-nano particles for dispersion treatment, the pH of the water is adjusted to be acidic, and then it is allowed to stand for sedimentation and filtered to obtain water from which micro-nano particles have been removed.

[0010] Beneficial effects: Through the ultra-large specific surface area and abundant oxygen-containing functional groups of graphene oxide, the present invention can combine with micro-nano particles by sharing electrons, efficiently adsorb a large number of micro-nano particles, and at the same time promote the aggregation of graphene oxide among each other in an acidic environment, causing the graphene oxide to settle rapidly. Then, through filtration, the micro-nano particles in the water body containing micro-nano particles can be effectively removed.

[0011] Preferably, the content of the graphene oxide in the water body containing micro-nano particles is 1-5 g / L.

[0012] Preferably, the method for adjusting the pH of the water body includes the following methods: introducing an acidic gas or adding an acid.

[0013] Beneficial effects: The purpose of introducing an acidic gas or adding an acid in the present invention is to improve the rapid settlement of graphene oxide. At the same time, the acidic gas can be removed by heating the filtered water body, so as to achieve the purpose that the water body does not contain acidic gas; adding an acid can generate a precipitate by adding a corresponding base, or heating the water body with the added acid to volatilize the solute in the acid, thereby achieving the purpose that the water body does not contain acid.

[0014] Preferably, the acidic gas is carbon dioxide or hydrogen chloride.

[0015] Preferably, the acid includes one of sulfuric acid, nitric acid, hydrochloric acid or acetic acid.

[0016] Beneficial effects: Adding sulfuric acid to adjust the pH in the present invention can improve the rapid settlement of graphene oxide. After that, barium hydroxide or calcium hydroxide can be added to remove sulfuric acid, while nitric acid, hydrochloric acid or acetic acid can be volatilized by heating to achieve the removal effect.

[0017] Preferably, the oxygen in the graphene oxide accounts for 25-50% of the total mass.

[0018] Beneficial effects: When removing micro-nano particles by graphene oxide in the present invention, if the oxygen content in the graphene oxide is too low, the graphene oxide cannot be stably dispersed in the water body containing micro-nano particles, and the effect of removing micro-nano particles is not good; if the oxygen content in the graphene oxide is too high, it is difficult for the graphene oxide to settle, which will also result in a poor effect of removing micro-nano particles.

[0019] Preferably, the purity of the graphene oxide is not less than 99.9 wt%.

[0020] Beneficial effects: When removing micro-nano particles by graphene oxide in the present invention, if the purity of the graphene oxide is too low, impurities are easily introduced, and it will also affect the adsorption of micro-nano particles by the graphene oxide, resulting in a poor effect of removing micro-nano particles.

[0021] Preferably, the pH in adjusting the pH of the water body is less than 5.

[0022] Preferably, the micro-nano particles include one or more of polystyrene, polyethylene, polypropylene, polyvinyl chloride, polyester, polyamide, acrylonitrile-butadiene-styrene copolymer, azo dye, triphenylmethane dye, fluorescent dye, sulfur dye or anthraquinone dye.

[0023] In the second aspect of the present invention, a water purification device containing micro-nano particles is provided, which uses the above-mentioned water purification method containing micro-nano particles. The device includes a reaction kettle, which is connected to a separation tank. The reaction kettle is provided with a stirring device and a pH meter, and the separation tank is provided with a filtering device.

[0024] Beneficial effects: The purification device of the present invention removes micro-nano particles with the assistance of graphene oxide, without using a microporous filter membrane, thus avoiding the problem of microporous filter membrane blockage. Graphene oxide has a micron-sized large lamellar structure and will not block the filtering device. It can self-crosslink into a film on the surface of the filtering device and is very easy to clean. Graphene oxide can combine with micro-nano particles by sharing electrons, so graphene oxide can effectively adsorb micro-nano particles. By adjusting the pH value, the sedimentation between graphene oxides is accelerated, so it does not rely on high-speed centrifugation equipment or devices either.

[0025] Preferably, the separation tank is further provided with a heating device, and the aperture of the filtering device is 30-50um.

[0026] Beneficial effects: The present invention adds a heating device to the separation tank to remove acidic gases or solutes in acids from the filtered water body. Description of the Drawings

[0027] Figure 1 is a schematic structural diagram of a water purification device containing micro-nano particles in the embodiment;

[0028] Figure 2 is a microscopic view before and after purification of the water body containing micro-nano particles in the embodiment;

[0029] Figure 3 is a transmission electron microscope photograph of graphene oxide before and after purification in the embodiment;

[0030] In the figure: 1 - air inlet, 2 - exhaust port, 3 - pressure gauge, 4 - ultrasonic stirring rod, 5 - feed port, 6 - discharge port, 7 - filter plate, 8 - separation tank, 9 - heater, 10 - outlet, 11 - pressure relief port, 12 - gas cylinder, 13 - reaction kettle, 14 - pH meter. Specific Embodiments

[0031] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Apparently, the described embodiments are only a part rather than all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0032] The test materials, reagents, etc. used in the following embodiments can be obtained from commercial channels without special instructions.

[0033] For those not specifying specific technologies or conditions in the embodiments, they can all be carried out according to the technologies or conditions described in the literature in this field or according to the product specifications.

[0034] Graphene oxide is an oxide of graphene, with a brownish-yellow color, and its structure spans the typical scales of general chemistry and materials science. After graphene is oxidized, the number of oxygen-containing functional groups on the graphene sheets increases, making it have excellent hydrophilicity. Therefore, graphene oxide has the characteristics of polymers, colloids, thin films, and amphiphilic molecules.

[0035] Graphene oxide has long been regarded as a hydrophilic substance because of its excellent dispersibility in water. However, relevant experimental results show that graphene oxide actually has amphiphilicity, with a hydrophilic to hydrophobic property distribution from the edge to the center of the graphene flakes. Graphene oxide also has an important characteristic: in acidic water bodies, graphene oxide is very easy to aggregate and settle. In addition, graphene oxide inherits the characteristic of the ultra-large specific surface area of graphene and contains abundant oxygen-containing functional groups, and can share electrons with micro-nano particles, thus realizing chemical adsorption.

[0036] The present invention provides a method for purifying water bodies containing micro-nano particles, specifically as follows: The method for purifying water bodies containing micro-nano particles is specifically as follows: Add graphene oxide to the water body containing micro-nano particles for dispersion treatment, adjust the pH of the water body to be acidic, and then perform static settlement and filtration to obtain the water body with micro-nano particles removed.

[0037] The method for purifying water bodies containing micro-nano particles of the present invention can be realized in other ways or through the device for purifying water bodies containing micro-nano particles of the present invention. The present invention is realized through the device for purifying water bodies containing micro-nano particles, and the specific embodiments are as follows.

[0038] The water body containing micro-nano particles used in this embodiment is the waste liquid for preparing organic long-afterglow materials, and the waste liquid contains various micro-nano particles, including one or more of polystyrene, polyethylene, polypropylene, polyvinyl chloride, polyester, polyamide, acrylonitrile-butadiene-styrene copolymer, azo dye, triphenylmethane dye, fluorescent dye, sulfur dye, or anthraquinone dye.

[0039] Example 1

[0040] This example provides a water purification device containing micro-nano particles. As Figure 1 shown, the water purification device containing micro-nano particles includes a reaction kettle 13 and a separation tank 8. The reaction kettle 13 is provided with a feed inlet 5, a discharge outlet 6, an exhaust port 2, an air inlet 1, a pressure gauge 3, a pH meter 14 and a stirring device; the separation tank 8 is provided with a filtering device, a heating device, a pressure relief port 11 and an outlet 10.

[0041] There is no restrictive requirement for the position of the feed inlet 5 as long as materials can be added. In this example, the water containing micro-nano particles and graphene oxide are added through the feed inlet 5, and the feed inlet 5 is arranged on the side of the top of the reaction kettle 13.

[0042] There is no restrictive requirement for the position of the discharge outlet 6 as long as materials can flow out. In this example, the discharge outlet 6 is arranged at the bottom of the reaction kettle 13 to enable the materials to flow out quickly. The discharge outlet 6 of the reaction kettle 13 is communicated with the separation tank 8, and a control valve (not shown in the figure) is provided to control the outflow of the materials.

[0043] The exhaust port 2 is used to discharge the air in the reaction kettle 13. Therefore, the exhaust port 2 is arranged at the top of the reaction kettle 13, which is more conducive to the discharge of air. The exhaust port 2 is provided with a control valve (not shown in the figure) to control the discharge of air.

[0044] The air inlet 1 is used to introduce acidic gas into the reaction kettle 13. The air inlet 1 is arranged at the bottom of the reaction kettle 13 to bubble the acidic gas through the materials in the reaction kettle 13 to promote the dispersion and adsorption of graphene oxide. The air inlet 1 is communicated with a gas tank 12 and is provided with a control valve (not shown in the figure). The gas tank 12 contains acidic gas, and the control valve is used to control the introduction of the acidic gas into the reaction kettle 13. If acid is added to the reaction kettle 13, it can be added through the feed inlet 5, or an additional acid inlet can be set for adding acid.

[0045] The pressure gauge 3 is used to detect the pressure of the reaction kettle 13. Therefore, the pressure gauge 3 is arranged at the top of the reaction kettle 13 to more accurately detect the pressure of the reaction kettle 13 and prevent excessive introduction of acidic gas, thus avoiding potential safety hazards.

[0046] There is no restrictive requirement for the position of the pH meter 14 as long as it can detect the pH of the materials in the reaction kettle 13. The pH meter 14 is arranged in the middle of the reaction kettle 13. By detecting the pH of the liquid in the reaction kettle 13, it can be known whether the materials in the reaction kettle 13 reach acidity, and the materials in the reaction kettle 13 can be allowed to settle statically.

[0047] The stirring device only needs to be able to achieve the stirring function. It includes a stirring rod or an ultrasonic stirring rod 4. In this embodiment, it is an ultrasonic stirring rod 4, which is arranged at the top of the reaction kettle 13 and can disperse the graphene oxide in the reaction kettle 13. Using the ultrasonic stirring rod 4 has a better dispersion effect than the stirring rod.

[0048] The filtering device only needs to be able to achieve solid-liquid separation, and its pore size is 30-50um. The filtering device includes a filter plate 7 or a filter net. In this embodiment, the filter plate 7 is used, and the pore size is 40um. The filter plate 7 is detachable and can be disassembled for replacement and cleaning.

[0049] The heating device only needs to be able to heat the separation tank 8. The purpose is to heat the water body in the separation tank 8. The heating temperature is set according to the vaporization temperature of the acidic gas or the vaporization temperature of the solute in the acid, so as to accelerate the volatilization of the acidic gas or the solute in the acid in the water body, and obtain the water body with micro-nano particles removed, which flows out through the outlet 10. In this embodiment, the heating device is a heating rod 9, and the heating rod 9 is arranged at the bottom of the separation tank 8. The acidic gas in the separation tank 8 flows out through the pressure relief port 11 to prevent the air pressure in the separation tank 8 from being too high and causing potential safety hazards.

[0050] The purification method of the water body purification device containing micro-nano particles is as follows:

[0051] S1 Add the water body containing micro-nano particles and graphene oxide into the reaction kettle 13 through the feed port 5, so that the content of graphene oxide in the water body containing micro-nano particles reaches 1g / L, and then use the ultrasonic stirring rod 5 to disperse the graphene oxide; the oxygen mass in the graphene oxide accounts for 25% of the total mass, and the purity of graphene oxide is 99.98wt%. The micro-nano particles in the water body containing micro-nano particles are mainly polystyrene, specifically as Figure 2 shown on the left in the figure. It can be seen from the figure that there are obvious particles in the water body and the particle size is about 1 nanometer.

[0052] S2 Open the exhaust port 2 and the intake port 1, so that the acidic gas in the gas tank enters the reaction kettle 13, and the air in the reaction kettle 13 flows out through the exhaust port 2. The acidic gas bubbles in the reaction kettle 13 to promote the dispersion of graphene oxide and the adsorption of micro-nano particles; the acidic gas is carbon dioxide, and carbon dioxide can react with water to form carbonic acid. The acidity of carbonic acid makes the water body in the reaction kettle 13 acidic, which is beneficial to the adsorption of micro-nano particles by graphene oxide.

[0053] S3 Close the exhaust port 2, observe the pressure gauge 3, and when the pressure gauge 3 shows 3atm, close the intake port 1 to stop introducing the acidic gas. Then observe the pH meter value. When the pH meter value is less than 4, it means that the graphene oxide attached with micro-nano particles begins to settle.

[0054] Let S4 stand for static sedimentation for 12 h. After sedimentation, open the discharge port 6 at the bottom of the reaction kettle 13. By virtue of the high pressure of the acidic gas in the reaction kettle 13 and the filter plate 7, solid-liquid separation is rapidly achieved, and the filtrate flows into the separation tank 8.

[0055] S5 Use the heater 9 to heat the separation tank 8 at a heating temperature of 80 °C. Heat the filtrate to make the acidic gas in the water body overflow through the pressure relief port 11. Finally, the water body with micro-nano particles removed flows out through the outlet 10. The water body with micro-nano particles removed is as Figure 2 shown on the right. As can be seen from the figure, no obvious micro-nano particles can be found in the water body, indicating that the micro-nano particles have been completely removed.

[0056] The graphene oxide in this embodiment is as Figure 3 shown. Figure 3 The left side is a picture of the graphene oxide before purification. As can be seen from the figure, there are no particles attached to the graphene oxide sheets. Figure 3 The right side is a picture of the graphene oxide after purification. As can be seen from the figure, micro-nano particles are densely attached to the graphene oxide sheets, which Figure 2 mutually corroborates, indicating that after the water body containing micro-nano particles is purified, the micro-nano particles are effectively combined with the graphene oxide, enabling the micro-nano particles to be removed from the water body.

[0057] Example 2

[0058] This embodiment provides a method for purifying a water body containing micro-nano particles, using the water body purification device containing micro-nano particles in Example 1, specifically as follows:

[0059] S1 Add the water body containing micro-nano particles and graphene oxide into the reaction kettle 13 through the feed port 5, so that the content of graphene oxide in the water body containing micro-nano particles reaches 4 g / L, and then use the ultrasonic stirrer 5 to disperse the graphene oxide; 40% of the total mass of the graphene oxide is oxygen, the purity of the graphene oxide is 99.98 wt%, and the micro-nano particles in the water body containing micro-nano particles are mainly polyvinyl chloride.

[0060] S2 Open the exhaust port 2 and the intake port 1, so that the acidic gas in the gas tank enters the reaction kettle 13. The air in the reaction kettle 13 flows out through the exhaust port 2, and the acidic gas bubbles in the reaction kettle 13 to promote the dispersion of graphene oxide and the adsorption of micro-nano particles; the acidic gas is carbon dioxide.

[0061] S3 Close the exhaust port 2, observe the pressure gauge 3, and when the pressure gauge 3 shows 3 atm, close the intake port 1 to stop introducing the acidic gas. Then observe the pH meter value. When the pH meter value is lower than 7, it indicates that the graphene oxide attached with micro-nano particles begins to settle.

[0062] Let it stand and settle for 12 h. After settlement, open the discharge port 6 at the bottom of the reaction kettle 13, and use the high pressure of the acidic gas in the reaction kettle 13 and the filter plate 7 to quickly achieve solid-liquid separation. The filtrate flows into the separation tank 8.

[0063] S5 Use the heater 9 to heat the separation tank 8. The heating temperature is 100 °C. Heat the filtrate to make the acidic gas in the water body overflow through the pressure relief port 11. Finally, the purified water body flows out through the outlet 10.

[0064] Example 3

[0065] This example provides a method for purifying water containing micro-nano particles, using the water purification device containing micro-nano particles in Example 1, specifically as follows:

[0066] S1 Add the water containing micro-nano particles and graphene oxide into the reaction kettle 13 through the feed port 5, so that the content of graphene oxide in the water containing micro-nano particles reaches 5 g / L, and then use the ultrasonic stirrer 5 to disperse the graphene oxide; 50% of the total mass of the graphene oxide is oxygen, and the purity of the graphene oxide is 99.98 wt%. The micro-nano particles in the water containing micro-nano particles are mainly anthraquinone dyes.

[0067] S2 Open the exhaust port 2 and the inlet port 1, so that the acidic gas in the gas tank enters the reaction kettle 13, and the air in the reaction kettle 13 flows out through the exhaust port 2. The acidic gas bubbles in the reaction kettle 13 to promote the dispersion of graphene oxide and the adsorption of micro-nano particles; the acidic gas is carbon dioxide.

[0068] S3 Close the exhaust port 2, observe the pressure gauge 3, when the pressure gauge 3 shows 3 atm, close the inlet port 1 to stop introducing the acidic gas, and then observe the pH meter value. When the pH meter value is lower than 7, it indicates that the graphene oxide attached with micro-nano particles begins to settle.

[0069] S4 Let it stand and settle for 12 h. After settlement, open the discharge port 6 at the bottom of the reaction kettle 13, and use the high pressure of the acidic gas in the reaction kettle 13 and the filter plate 7 to quickly achieve solid-liquid separation. The filtrate flows into the separation tank 8.

[0070] S5 Use the heater 9 to heat the separation tank 8. The heating temperature is 100 °C. Heat the filtrate to make the acidic gas in the water body overflow through the pressure relief port 11. Finally, the purified water body flows out through the outlet 10.

[0071] Example 4

[0072] This example provides a method for purifying water containing micro-nano particles, using the water purification device containing micro-nano particles in Example 1, specifically as follows:

[0073] S1 Add the water containing micro-nano particles and graphene oxide into the reaction kettle 13 through the feed inlet 5. The oxygen mass in the graphene oxide accounts for 25% of the total mass, and the purity of the graphene oxide is 99.98 wt%. Make the content of graphene oxide in the water containing micro-nano particles reach 1 g / L, and then use the ultrasonic stirrer 5 to disperse the graphene oxide.

[0074] S2 Open the exhaust port 2, and add acid, which is hydrochloric acid, into the reaction kettle 13 through the feed inlet 5. The air in the reaction kettle 13 flows out through the exhaust port 2, and the hydrochloric acid is stirred and mixed by the ultrasonic stirrer 5. Observe the value of the pH meter. When the value of the pH meter is lower than 5, it indicates that the graphene oxide attached with micro-nano particles begins to settle.

[0075] S3 Let it stand and settle for 14 h. After settling, open the discharge port 6 at the bottom of the reaction kettle 13, and use the filter plate 7 to achieve solid-liquid separation. The filtrate flows into the separation tank 8.

[0076] S5 Use the heater 9 to heat the separation tank 8, and the heating temperature is 140 °C. Heat the filtrate to vaporize the solute hydrogen chloride in the hydrochloric acid, and the hydrogen chloride gas overflows through the pressure relief port 11. Finally, the water body removing micro-nano particles flows out through the outlet 10.

[0077] Example 5

[0078] This example provides a method for purifying water containing micro-nano particles. Compared with Example 4, the difference is that the acid is sulfuric acid, and then barium hydroxide solution is added to the water body removing micro-nano particles, so that sulfuric acid in the water body reacts with the barium hydroxide solution to generate barium sulfate precipitate, and the sulfuric acid in the water body is removed by filtration.

[0079] Comparative Example 1

[0080] This comparative example provides a method for purifying water containing micro-nano particles. Compared with Example 1, the difference is that the graphene oxide is replaced with porous carbon oxide, and the micro-nano particles in the water body cannot be removed.

[0081] The reason why the purification method of this comparative example cannot remove micro-nano particles: Porous carbon oxide cannot stably suspend in the water body containing micro-nano particles, precipitates at the bottom of the water body containing micro-nano particles, and cannot achieve the effect of adsorbing micro-nano particles.

[0082] Comparative Example 2

[0083] This comparative example provides a method for purifying water containing micro-nano particles. Compared with Example 1, the difference is that the graphene oxide is replaced with carbon black oxide, and the micro-nano particles in the water body cannot be removed.

[0084] Reasons why the purification method of this comparative example cannot remove micro-nano particles: The oxidized carbon black completely floats in the water body containing micro-nano particles and cannot achieve the purpose of sedimentation by adsorbing micro-nano particles. Therefore, micro-nano particles cannot be removed.

[0085] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for purifying water containing micro-nano particles, characterized in that: Graphene oxide is added to water containing micro-nano particles for dispersion treatment, the pH of the water is adjusted to be acidic, and then the water is allowed to stand for sedimentation and filtered to obtain the water from which the micro-nano particles are removed.

2. The method for purifying water containing micro-nano particles according to claim 1, characterized in that: The content of the graphene oxide in the water containing the micro-nano particles is 1-5 g / L.

3. The method for purifying water containing micro-nano particles according to claim 1, characterized in that: The method for adjusting the pH of water body includes the following methods: introducing acidic gas or adding acid.

4. The method for purifying water containing micro-nano particles according to claim 3, characterized in that: The acid gas is carbon dioxide or hydrogen chloride.

5. The method for purifying water containing micro-nano particles according to claim 3, characterized in that: The acid includes one of sulfuric acid, nitric acid, hydrochloric acid or acetic acid.

6. The method for purifying water containing micro-nano particles according to claim 1 or 2, characterized in that: The mass of oxygen in the graphene oxide accounts for 25-50% of the total mass.

7. The method for purifying water containing micro-nano particles according to claim 1 or 2, characterized in that: The purity of the graphene oxide is not less than 99.9wt%.

8. The method for purifying water containing micro-nano particles according to claim 3, characterized in that: Adjust the water pH to less than 5.

9. A water purification device containing micro-nano particles, characterized in that: A method for purifying water containing micro-nano particles according to any one of claims 1 to 8, wherein the device comprises a reaction kettle (13), the reaction kettle (13) is connected to a separation tank (8), the reaction kettle (13) is provided with a stirring device and a pH meter (14), and the separation tank (8) is provided with a filtering device.

10. The water purification device containing micro-nano particles according to claim 9, characterized in that: The separation tank (8) is also provided with a heating device, and the pore size of the filtering device is 30-50 um.

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