A method for simultaneously removing microplastics and antibiotics from sewage

Abstract

The invention discloses a method for synchronously removing microplastics and antibiotics in sewage, comprising the following steps: S1, preparing a pre-composite: taking tetrabutyl titanate, graphene dispersion, glacial acetic acid and ethanol as raw materials, and preparing the raw materials into a pre-composite by a sol-gel method; S2, preparing a sewage treatment agent: taking the pre-composite, copper oxide powder, deionized water and persulfate solution to prepare a sewage treatment agent; S3, sewage treatment: sequentially using the sewage treatment agent and activated carbon to treat sewage; the invention utilizes the pre-composite to form a synergistic effect, improves the adsorption and degradation capabilities of microplastics and antibiotics, and can synchronously and efficiently remove microplastics and antibiotics in sewage.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and in particular to a method for simultaneously removing microplastics and antibiotics from sewage. Background Art

[0002] Microplastics have become a new source of pollution in water bodies due to their difficulties in degradation and easy adsorption of pollutants. The abuse and incomplete metabolism of antibiotics lead to their residues in the environment, causing drug-resistant bacteria problems and ecological risks.

[0003] The simultaneous removal of microplastics and antibiotics from sewage is an important challenge currently faced by the field of environmental protection. There are currently a variety of treatment methods for the removal of microplastics and antibiotics. For microplastics, although physical methods such as screening and filtration are easy to operate, their removal efficiency is limited, especially for nano-level microplastics. Although chemical degradation and biological degradation have potential advantages, the former is costly and may cause secondary pollution, while the latter is limited by the type of microorganisms and degradation efficiency. For antibiotics, traditional sewage treatment processes such as activated sludge and biofilm methods have certain effects, but the removal rate is not high and it is easy to produce drug-resistant bacteria. Although advanced oxidation technology and electrochemical methods have high degradation efficiency, they also face cost and technical difficulties.

[0004] However, there are still many challenges in the simultaneous removal of microplastics and antibiotics from sewage. Microplastics and antibiotics exist in sewage in very different forms and properties. How to achieve simultaneous and efficient removal of the two is a technical challenge. Efficient treatment methods often mean higher cost investment. How to reduce costs while ensuring treatment effects is an urgent problem to be solved. Therefore, there is a need for a sewage treatment agent and treatment method that can treat microplastics and antibiotics together and has better treatment effects, so as to simultaneously treat sewage. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a method for simultaneously removing microplastics and antibiotics from sewage.

[0006] A method for simultaneously removing microplastics and antibiotics from sewage, comprising the following steps:

[0007] S1. Preparing a pre-composite: taking tetrabutyl titanate, graphene dispersion, glacial acetic acid and ethanol as raw materials in a volume ratio of 1-5:1-2:0.5:10, and preparing a pre-composite by a sol-gel method;

[0008] S2. Preparation of sewage treatment agent:

[0009] S2-1, taking a pre-complex, copper oxide powder and deionized water in a ratio of 1-2 g: 0.6-0.9 g: 100 ml; firstly adding the copper oxide powder into the deionized water, ultrasonically treating for 20-30 min to obtain a copper oxide mixed solution, adding the pre-complex into the copper oxide mixed solution, ultrasonically treating for 40-50 min to obtain a B mixed solution;

[0010] S2-2, evaporating and drying the mixed solution B to obtain a solid material, adding the solid material to a peroxymonosulfate solution at a ratio of 1-2 g:100 mL and stirring for 2-3 h to obtain a sewage treatment agent; wherein the concentration of the peroxymonosulfate solution is 1 g / L;

[0011] S3. Wastewater treatment:

[0012] S3-1. First, filter the sewage to be treated, and then use dilute hydrochloric acid or sodium hydroxide to adjust the pH of the sewage to be treated to 7 to obtain pretreated sewage; the sewage to be treated contains microplastics and antibiotics;

[0013] S3-2, adding the sewage treatment agent to the pretreated sewage at a volume ratio of 0.1-0.5:1-2, stirring the reaction for 3-4 hours at a temperature of 20-30°C and a stirring speed of 100-200 rpm to obtain a C mixed solution;

[0014] S3-3, centrifuge the C mixed solution for 25-35 minutes to obtain a filtrate, and use activated carbon to adsorb the filtrate. The amount of activated carbon is 10-15 g / L, and the mixture is stirred for 30-35 minutes and then filtered. The treatment is completed.

[0015] Description: Tetrabutyl titanate in the pre-composite forms a composite material with graphene through the sol-gel method, which enhances the stability and adsorption performance of the material; copper oxide powder is evenly dispersed under ultrasonic treatment and forms a synergistic effect with the pre-composite, which improves the adsorption and degradation capacity of microplastics and antibiotics; after adding permonosulfate solution, permonosulfate produces highly active free radicals (such as sulfate radicals and hydroxyl radicals) under the catalytic action of copper oxide. These free radicals have strong oxidizing properties and can efficiently degrade antibiotics in water; the above treatment method utilizes the synergistic effect of multiple materials and processes, improves the treatment efficiency, and can simultaneously and efficiently remove microplastics and antibiotics in sewage. It should be understood that permonosulfate is an environmentally friendly disinfectant that can decompose organic pollutants without producing harmful byproducts to water bodies.

[0016] Furthermore, the preparation of the pre-composite by the sol-gel method comprises:

[0017] S1-1, firstly add tetrabutyl titanate and glacial acetic acid to ethanol in sequence and stir for 30-40 min to obtain a mixed solution A; then drop the graphene dispersion into the mixed solution A, and continue stirring for 2-3 h while dropping to form a colloidal solution;

[0018] S1-2, heating the colloidal solution at 70-80° C. with stirring for 3-4 hours to obtain a sol;

[0019] S1-3, drying the sol at a temperature of 90-100° C. for 12 h, and then calcining at 400-450° C. for 2-3 h under nitrogen protection to obtain a pre-composite.

[0020] Description: The above method achieves a uniform compound of titanate and graphene, and forms a composite material with a coating structure of titanate as the inner layer and graphene as the outer layer; the overall performance of the material is improved. Graphene has a large specific surface area and hydrophobicity, and can effectively adsorb microplastic particles in water; titanate, graphene and copper oxide form a synergistic effect, which can improve the removal efficiency of microplastics and antibiotics.

[0021] Furthermore, the stirring speeds of both times in S1-1 are 150-180 rpm, the stirring speed of the heating stirring in S1-2 is 80-110 rpm; the stirring speed in S2-2 is 220-240 rpm, and the stirring speed in S3-3 is 220-240 rpm.

[0022] Note: The above parameter range is more preferred. By clarifying the stirring speed in different steps, the uniformity and efficiency of the reaction in each stage are ensured, thereby improving the quality of the pre-complex and the sewage treatment agent.

[0023] Furthermore, the preparation method of the graphene dispersion comprises:

[0024] First, the microcrystalline graphite is ground to a particle size of 5-50 μm; the microcrystalline graphite is mixed with water in a ratio of 1 g: 50-100 mL to obtain a suspension;

[0025] Then, a surfactant accounting for 0.1-0.5% of the volume of the suspension is added to the suspension, and stirred for 25-35 minutes at a stirring speed of 220-240 rpm to obtain an activated suspension;

[0026] The activated suspension is then homogenized by a high-pressure homogenizer, the homogenization time is 15-60s, the homogenization pressure is 50-200MPa, and the process is repeated 8-10 times to obtain a graphene dispersion.

[0027] Note: The above method ensures the uniform dispersion and stability of graphene in water through grinding, adding surfactants and high-pressure homogenization treatment, which can effectively improve the dispersion effect of graphene and avoid agglomeration, thereby improving its performance and efficiency in subsequent applications.

[0028] Furthermore, the graphene dispersion liquid is dripped into the A mixed liquid at a dripping speed of 0.5 ml / s.

[0029] Note: The above setting of the dripping speed is crucial to ensure the uniformity of the reaction and control the reaction process, avoiding excessive local concentration due to too fast a dripping speed or insufficient reaction due to too slow a dripping speed.

[0030] Furthermore, the filtration described in S3-1 uses a sieve with a pore size of 1 mm.

[0031] Note: The sieves with the above pore sizes can help to effectively remove larger suspended solids and particles in sewage, providing cleaner water quality for subsequent treatment steps and ensuring treatment results.

[0032] Furthermore, in S3-3, the centrifugal speed of the centrifugal filtration is 2000~3000 rpm.

[0033] Note: The above centrifugal parameters enable the solid particles and liquid in the C mixed liquid to be effectively separated, thereby improving the separation efficiency and treatment effect.

[0034] Furthermore, in S2-1, the ultrasonic frequency of the ultrasonic treatment is 40~50kHz.

[0035] Note: The above ultrasonic parameters are helpful to optimize the dispersion effect of copper oxide powder in deionized water, thereby improving the mixing uniformity of the pre-composite and the copper oxide mixed solution.

[0036] Furthermore, the method of evaporation and drying treatment described in S2-2 is: placing the mixed solution B on a rotary evaporator, and performing rotary evaporation at a rotation speed of 100~200rpm at a vacuum degree of -0.08~-0.1MPa and a temperature of 40~50°C, until the deionized water in the mixed solution B is completely evaporated to obtain a solid material.

[0037] Note: The above method ensures that the deionized water in the B mixture can evaporate efficiently and evenly by specifying the vacuum degree, temperature and rotation speed, avoiding local overheating and material loss, and ensuring the purity and quality of the solid material.

[0038] The beneficial effects of the present invention are:

[0039] The tetrabutyl titanate in the pre-composite of the method of the present invention forms a composite material with graphene through a sol-gel method, thereby enhancing the stability and adsorption performance of the material; the copper oxide powder is evenly dispersed under ultrasonic treatment and forms a synergistic effect with the pre-composite, thereby improving the adsorption and degradation capabilities of microplastics and antibiotics; after the permonosulfate solution is added, the permonosulfate generates highly active free radicals under the catalysis of copper oxide, and the free radicals have strong oxidizing properties and can efficiently degrade antibiotics in water, thereby efficiently removing microplastics and antibiotics in sewage. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a flowchart of an embodiment of the present invention. DETAILED DESCRIPTION

[0041] Example 1: Figure 1 As shown, a method for simultaneously removing microplastics and antibiotics from sewage comprises the following steps:

[0042] S1. Preparing a pre-composite: taking tetrabutyl titanate, graphene dispersion, glacial acetic acid and ethanol as raw materials in a volume ratio of 2:1.5:0.5:10, and preparing a pre-composite by a sol-gel method;

[0043] The pre-composite prepared by the sol-gel method includes:

[0044] S1-1. Tetrabutyl titanate and glacial acetic acid were first added to ethanol in sequence and stirred for 35 min to obtain a mixed solution A; then the graphene dispersion was dripped into the mixed solution A and stirred for 2.5 h to form a colloidal solution; the graphene dispersion was dripped into the mixed solution A at a rate of 0.5 ml / s; the stirring speeds for both times were 170 rpm;

[0045] The preparation method of the graphene dispersion comprises:

[0046] First, the microcrystalline graphite is ground to a particle size of 5-50 μm; the microcrystalline graphite is mixed with water in a ratio of 1 g: 80 mL to obtain a suspension;

[0047] Then, a surfactant accounting for 0.3% of the volume of the suspension was added to the suspension, and stirred for 30 min at a stirring speed of 230 rpm to obtain an activated suspension;

[0048] The activated suspension was then homogenized by a high-pressure homogenizer, the homogenization time was 30 seconds, the homogenization pressure was 100 MPa, and the process was repeated 9 times to obtain a graphene dispersion.

[0049] S1-2, heating and stirring the colloidal solution at 75°C for 3.5 hours to obtain a sol; the stirring speed of the heating and stirring is 90 rpm;

[0050] S1-3, drying the sol at 95°C for 12 hours, and then calcining at 420°C for 2.5 hours under nitrogen protection to obtain a pre-composite;

[0051] S2. Preparation of sewage treatment agent:

[0052] S2-1, taking the pre-complex, copper oxide powder and deionized water in a ratio of 1.5g:0.8g:100ml; firstly adding the copper oxide powder into the deionized water, ultrasonically treating for 25min to obtain a copper oxide mixed solution, adding the pre-complex into the copper oxide mixed solution, ultrasonically treating for 45min to obtain a B mixed solution; the ultrasonic frequency of the ultrasonic treatment is 45kHz;

[0053] S2-2, evaporating and drying the mixed solution B to obtain a solid material, wherein the evaporation and drying method is as follows: placing the mixed solution B on a rotary evaporator, performing rotary evaporation at a vacuum degree of -0.09 MPa and a temperature of 45° C. at a rotation speed of 150 rpm, until the deionized water in the mixed solution B is completely evaporated to obtain a solid material;

[0054] The solid material was added to the peroxymonosulfate solution at a ratio of 1.5 g:100 mL and stirred for 2.5 h at a stirring speed of 250 rpm to obtain a sewage treatment agent; wherein the mass concentration of the peroxymonosulfate solution was 1 g / L;

[0055] S3. Wastewater treatment:

[0056] S3-1, first filter the untreated sewage with a pH of 8, and then use dilute hydrochloric acid to adjust the pH of the untreated sewage to 7 to obtain pretreated sewage; the untreated sewage contains microplastics and antibiotics; the filtration in S3-1 uses a sieve with a pore size of 1 mm;

[0057] S3-2, adding the sewage treatment agent to the pretreated sewage at a volume ratio of 0.3:1.5, stirring the reaction for 3.5 hours at a temperature of 25°C and a stirring speed of 150 rpm to obtain a C mixed solution;

[0058] S3-3, centrifuge the C mixed solution for 30 minutes to obtain a filtrate, adsorb the filtrate with activated carbon, the amount of activated carbon is 12g / L, stir for 32 minutes and then filter, the stirring speed is 230rpm; the treatment is completed; the centrifugal speed of the centrifugal filtration is 2500 rpm.

[0059] Example 2: This example is different from Example 1 in that the raw material components for preparing the pre-composite are different, and tetrabutyl titanate, graphene dispersion, glacial acetic acid and ethanol are taken as raw materials in a volume ratio of 1:2:0.5:10.

[0060] Example 3: This example is different from Example 1 in that the raw material components for preparing the pre-composite are different, and tetrabutyl titanate, graphene dispersion, glacial acetic acid and ethanol are taken as raw materials in a volume ratio of 5:1:0.5:10.

[0061] Example 4: This example is different from Example 1 in that the parameters for preparing the pre-composite are different. S1-1, tetrabutyl titanate and glacial acetic acid are first added to ethanol in sequence and stirred for 30 minutes to obtain a mixed solution A; then the graphene dispersion is dripped into the mixed solution A, and the stirring is continued for 3 hours to form a colloidal solution; the dripping speed of the graphene dispersion into the mixed solution A is 0.5 ml / s; the stirring speeds for both times are 180 rpm;

[0062] The preparation method of the graphene dispersion comprises:

[0063] Microcrystalline graphite and water were mixed in a ratio of 1 g:50 mL to obtain a suspension;

[0064] Then, a surfactant accounting for 0.1% of the volume of the suspension was added to the suspension, and stirred for 25 min at a stirring speed of 240 rpm to obtain an activated suspension;

[0065] The activated suspension was then homogenized by a high-pressure homogenizer, the homogenization time was 60 s, the homogenization pressure was 50 MPa, and the process was repeated 10 times to obtain a graphene dispersion.

[0066] S1-2, heating and stirring the colloidal solution at 70°C for 3 hours to obtain a sol; the stirring speed of the heating and stirring is 80 rpm;

[0067] S1-3, drying the sol at 90°C for 12 hours, and then calcining at 450°C for 2 hours under nitrogen protection to obtain a pre-composite.

[0068] Example 5: This example is different from Example 1 in that the parameters for preparing the pre-composite are different. S1-1, tetrabutyl titanate and glacial acetic acid are first added to ethanol in sequence and stirred for 40 minutes to obtain a mixed solution A; then the graphene dispersion is dripped into the mixed solution A, and the stirring is continued for 2 hours to form a colloidal solution; the dripping speed of the graphene dispersion into the mixed solution A is 0.5 ml / s; the stirring speeds for both times are 150 rpm;

[0069] The preparation method of the graphene dispersion comprises:

[0070] Mix microcrystalline graphite and water in a ratio of 1 g: 100 mL to obtain a suspension;

[0071] Then, a surfactant accounting for 0.5% of the volume of the suspension was added to the suspension, and stirred for 35 min at a stirring speed of 220 rpm to obtain an activated suspension;

[0072] The activated suspension was then homogenized by a high-pressure homogenizer, the homogenization time was 15 s, the homogenization pressure was 200 MPa, and the process was repeated 8 times to obtain a graphene dispersion.

[0073] S1-2, heating and stirring the colloidal solution at 80°C for 4 hours to obtain a sol; the stirring speed of the heating and stirring is 110 rpm;

[0074] S1-3, drying the sol at 100°C for 12 hours, and then calcining at 400°C for 3 hours under nitrogen protection to obtain a pre-composite.

[0075] Example 6: This example is different from Example 1 in that the raw material components for preparing the sewage treatment agent are different. In S2-1, the pre-complex, copper oxide powder, and deionized water are taken in a ratio of 2g:0.6g:100ml; in S2-2, the solid material is added to the peroxymonosulfate solution in a ratio of 1g:100mL and stirred.

[0076] Example 7: The difference between this example and Example 1 is that the raw material components for preparing the sewage treatment agent are different. In S2-1, the pre-complex, copper oxide powder, and deionized water are taken in a ratio of 1g:0.9g:100ml; in S2-2, the solid material is added to the peroxymonosulfate solution in a ratio of 2g:100mL and stirred.

[0077] Example 8: The difference between this example and Example 1 is that the condition parameters for preparing the sewage treatment agent are different. S2-1, first add copper oxide powder to deionized water, ultrasonically treat for 20 minutes to obtain a copper oxide mixed solution, add the pre-complex to the copper oxide mixed solution, ultrasonically treat for 40 minutes, and obtain a mixed solution B; the ultrasonic frequency is 40kHz; S2-2, place the mixed solution B on a rotary evaporator, and rotary evaporate at a vacuum degree of -0.1MPa and a temperature of 50°C at a rotation speed of 200rpm until the deionized water in the mixed solution B is completely evaporated to obtain a solid material; add the solid material to a persulfate solution and stir for 3 hours at a stirring speed of 240rpm to obtain a sewage treatment agent.

[0078] Example 9: The difference between this example and Example 1 is that the condition parameters for preparing the sewage treatment agent are different. S2-1, first add copper oxide powder to deionized water, ultrasonically treat for 30 minutes, to obtain a copper oxide mixed solution, add the pre-complex to the copper oxide mixed solution, ultrasonically treat for 50 minutes, to obtain a mixed solution B; the ultrasonic frequency is 50kHz; S2-2, place the mixed solution B on a rotary evaporator, and rotary evaporate at a vacuum degree of -0.08MPa and a temperature of 40°C at a rotation speed of 100rpm until the deionized water in the mixed solution B is completely evaporated to obtain a solid material; add the solid material to a persulfate solution and stir for 2 hours at a stirring speed of 220rpm to obtain a sewage treatment agent.

[0079] Example 10: This example is different from Example 1 in that the sewage treatment ratio parameters are different. In S3-2, the sewage treatment agent is added to the pretreated sewage at a volume ratio of 0.1:1, and the amount of activated carbon in S3-3 is 10 g / L.

[0080] Example 11: This example is different from Example 1 in that the sewage treatment ratio parameters are different. In S3-2, the sewage treatment agent is added to the pretreated sewage at a volume ratio of 0.5:2, and the amount of activated carbon in S3-3 is 15 g / L.

[0081] Example 12: This example is different from Example 1 in that the temperature parameters of sewage treatment are different, and the temperature in S3-2 is 20°C.

[0082] Example 13: This example is different from Example 1 in that the temperature parameters of sewage treatment are different, and the temperature in S3-2 is 30°C.

[0083] Example 14: This example is different from Example 1 in that the sewage treatment time parameters are different. In S3-2, the reaction is stirred continuously for 3 hours. In S3-3, the C mixed solution is centrifuged and filtered for 35 minutes to obtain a filtrate. The filtrate is adsorbed with activated carbon, stirred for 35 minutes, and then filtered.

[0084] Example 15: This example is different from Example 1 in that the sewage treatment time parameters are different. In S3-2, the reaction is stirred continuously for 4 hours. In S3-3, the C mixed solution is centrifuged and filtered for 25 minutes to obtain a filtrate. The filtrate is adsorbed with activated carbon, stirred for 30 minutes, and then filtered.

[0085] Example 16: This example is different from Example 1 in that the sewage treatment stirring and filtration parameters are different: the stirring speed in S3-2 is 200 rpm; in S3-3, the stirring speed is 220 rpm; the treatment is completed; the centrifugal speed of centrifugal filtration is 3000 rpm.

[0086] Example 17: This example is different from Example 1 in that the sewage treatment stirring and filtration parameters are different: the stirring speed in S3-2 is 100 rpm; in S3-3, the stirring speed is 240 rpm; the treatment is completed; the centrifugal speed of centrifugal filtration is 2000 rpm.

[0087] Example 18: This example is different from Example 1 in that the pH of the wastewater to be treated is 6, and sodium hydroxide is used for adjustment in S3.

[0088] Experimental Example: The description of this experimental example is based on the recorded schemes in Example 1 to Example 17, and is intended to illustrate the practical application effect of the present invention.

[0089] Plastic and antibiotics were added to pure water to obtain experimental sewage, in which microplastics were polyethylene with a mass concentration of 1 g / L; antibiotics were sulfadiazine antibiotics with a mass concentration of 100 ng / L, and the methods of Examples 1 to 17 and Comparative Examples 1 to 4 were used to treat the experimental sewage, respectively. The comparison results are as follows:

[0090] 1. Explore the effects of different treatment methods on the degradation of wastewater containing microplastics and antibiotics;

[0091] Comparative Example 1: The difference from Example 1 is that a flocculant is used instead of the sewage treatment agent in the embodiment of the present invention to carry out the treatment in step S3;

[0092] Comparative Example 2: The difference from Example 1 is that titanium dioxide is used instead of the pre-composite in the example of the present invention to carry out the treatment of steps S2 and S3;

[0093] Comparative Example 3: The difference from Example 1 is that no graphene dispersion liquid is added to S1-1, and the methods of S1-2 and S1-3 are directly carried out to obtain a pre-composite;

[0094] Comparative Example 4: The difference from Example 1 is that the precomplex is directly added to the sewage at a mass concentration of 3 g / L, and the stirring and filtering treatment in S3-2 is performed;

[0095] Example 1 and Comparative Examples 1 to 4 were compared, as shown in Table 1;

[0096] Table 1 Effects of different treatment methods on the degradation of wastewater containing microplastics and antibiotics

[0097]

[0098] As can be seen from Table 1, by comparing Example 1 with Comparative Example 1, it can be seen that the sewage treatment agent in Example 1 can achieve synchronous and effective removal of microplastics and antibiotics in sewage, and Comparative Example 1 can partially remove microplastics, but the removal efficiency is low, and the removal effect of antibiotics is low. Therefore, for sewage containing both microplastics and antibiotics, the practicality of Comparative Example 1 needs to be improved. The method in Example 1 of the present invention can utilize the synergistic effect of the pre-complex, copper oxide powder and permonosulfate, so that the formed sewage treatment agent is suitable for the removal of microplastics and antibiotics in sewage.

[0099] By comparing Example 1 with Comparative Example 2, it can be seen that compared with the sewage treatment agent obtained by directly using titanium dioxide, copper oxide powder and permonosulfate to react in Comparative Example 2, the pre-composite used in Example 1 has better effect. This may be because the titanate and graphene in Example 1 are uniformly compounded to form a composite material with a coating structure with titanate as the inner layer and graphene as the outer layer; while in Comparative Example 2, this composite material is not formed, and it is difficult to achieve the effect of Example 1, and the corresponding removal efficiency of microplastics and antibiotics needs to be improved.

[0100] By comparing Example 1 with Comparative Example 3, it can be found that the sewage treatment agent obtained after adding the graphene dispersion in Example 1 has a better effect, and the sewage treatment agent obtained in Comparative Example 3 without adding graphene has a lower treatment effect. This may be because graphene has a large specific surface area and hydrophobicity. At the same time, the adsorption effect of graphene can optimize the mixed form of the pre-complex, copper oxide powder and peroxymonosulfate, so that the treatment effect of the obtained sewage treatment agent is better.

[0101] By comparing Example 1 with Comparative Example 4, it can be seen that in Comparative Example 4, directly adding the pre-complex to the sewage also has a good effect, but the overall removal rate is not as good as that of the method in Example 1. This may be because permonosulfate produces highly active free radicals (such as sulfate radicals and hydroxyl radicals) under the catalysis of copper oxide. These free radicals have strong oxidizing properties and can efficiently degrade antibiotics in water.

[0102] 2. Explore the effects of different parameters on the degradation of wastewater containing microplastics and antibiotics;

[0103] Examples 1 to 17 were compared, as shown in Table 2.

[0104] Table 2 Effects of different parameters on the degradation of wastewater containing microplastics and antibiotics

[0105]

[0106] As can be seen from Table 2, by comparing Example 1, Example 2 and Example 3, it can be found that the raw material ratio of the pre-composite in Example 1 is more preferred. The reason may be that under the ratio of Example 1, the composite structure of the material is better, which is conducive to the adsorption of microplastics and the degradation of antibiotics; by comparing Example 1, Example 4 and Example 5, it can be found that the parameters for preparing the pre-composite in Example 1 are more preferred; by comparing Example 1, Example 6 and Example 7, it can be found that the raw material components for preparing the sewage treatment agent in Example 1 are more preferred; by comparing Example 1, Example 8 and Example 9, it can be found that the condition parameters for preparing the sewage treatment agent in Example 1 are more preferred, which can be This may be because the ultrasonic treatment and evaporation conditions in Example 1 are more favorable to the mixed form of copper oxide and the pre-complex; by comparing Example 1, Example 10 and Example 11, it can be found that the sewage treatment ratio parameters in Example 1 are more preferred; by comparing Example 1, Example 14 and Example 15, it can be found that the sewage treatment time parameters in Example 1 are more preferred; by comparing Example 1, Example 16 and Example 17, it can be found that the stirring and filtration parameters in Example 1 are more preferred. This may be because, under these parameter conditions, the sewage treatment agent and sewage can be fully mixed and the components in the sewage treatment agent can effectively act on the microplastics and antibiotics in the sewage.

Claims

1. A method for simultaneously removing microplastics and antibiotics from sewage, characterized in that: The following steps are involved: S1. Preparation of pre-complex: Tetrabutyl titanate, graphene dispersion, glacial acetic acid and ethanol are taken as raw materials in a volume ratio of 1-5:1-2:0.5:10, and the raw materials are prepared by a sol-gel method to obtain a pre-composite; The pre-composite prepared by the sol-gel method comprises: S1-1, firstly add tetrabutyl titanate and glacial acetic acid to ethanol in sequence and stir for 30-40 min to obtain a mixed solution A; then drop the graphene dispersion into the mixed solution A, and continue stirring for 2-3 h while dropping to form a colloidal solution; S1-2, heating the colloidal solution at 70-80° C. with stirring for 3-4 hours to obtain a sol; S1-3, drying the sol at a temperature of 90-100° C. for 12 h, and then calcining at 400-450° C. for 2-3 h under nitrogen protection to obtain a pre-composite; S2. Preparation of sewage treatment agent: S2-1, taking a pre-complex, copper oxide powder and deionized water in a ratio of 1-2 g: 0.6-0.9 g: 100 ml; firstly adding the copper oxide powder into the deionized water, ultrasonically treating for 20-30 min to obtain a copper oxide mixed solution, adding the pre-complex into the copper oxide mixed solution, ultrasonically treating for 40-50 min to obtain a B mixed solution; S2-2, evaporating and drying the mixed solution B to obtain a solid material, adding the solid material to a peroxymonosulfate solution at a ratio of 1-2 g:100 mL and stirring for 2-3 h to obtain a sewage treatment agent; wherein the concentration of the peroxymonosulfate solution is 1 g / L; S3. Wastewater treatment: S3-1. First, filter the sewage to be treated, and then use dilute hydrochloric acid or sodium hydroxide to adjust the pH of the sewage to be treated to 7 to obtain pretreated sewage; the sewage to be treated contains microplastics and antibiotics; S3-2, adding the sewage treatment agent to the pretreated sewage at a volume ratio of 0.1-0.5:1-2, stirring the reaction for 3-4 hours at a temperature of 20-30°C and a stirring speed of 100-200 rpm to obtain a C mixed solution; S3-3, centrifuge the C mixed solution for 25-35 minutes to obtain a filtrate, and use activated carbon to adsorb the filtrate. The amount of activated carbon is 10-15 g / L, and the mixture is stirred for 30-35 minutes and then filtered. The treatment is completed.

2. A method for simultaneously removing microplastics and antibiotics from sewage as claimed in claim 1, characterized in that: The stirring speeds of both times in S1-1 are 150~180 rpm, the stirring speed of heating stirring in S1-2 is 80~110 rpm; the stirring speed in S2-2 is 220~240 rpm, and the stirring speed in S3-3 is 220~240 rpm.

3. A method for simultaneously removing microplastics and antibiotics from sewage as claimed in claim 1, characterized in that: The preparation method of the graphene dispersion comprises: First, the microcrystalline graphite is ground to a particle size of 5-50 μm; the microcrystalline graphite is mixed with water in a ratio of 1 g: 50-100 mL to obtain a suspension; Then, a surfactant accounting for 0.1-0.5% of the volume of the suspension is added to the suspension, and stirred for 25-35 minutes at a stirring speed of 220-240 rpm to obtain an activated suspension; The activated suspension is then homogenized by a high-pressure homogenizer, the homogenization time is 15-60s, the homogenization pressure is 50-200MPa, and the process is repeated 8-10 times to obtain a graphene dispersion.

4. A method for simultaneously removing microplastics and antibiotics from sewage as claimed in claim 1, characterized in that: The graphene dispersion liquid is dripped into the mixed liquid A at a dripping speed of 0.5 ml / s.

5. The method for simultaneously removing microplastics and antibiotics from sewage according to claim 1, characterized in that: The filtration described in S3-1 uses a sieve with a pore size of 1 mm.

6. A method for simultaneously removing microplastics and antibiotics from sewage as claimed in claim 1, characterized in that: In S3-3, the centrifugal speed of the centrifugal filtration is 2000~3000 rpm.

7. The method for simultaneously removing microplastics and antibiotics from sewage according to claim 1, characterized in that: In S2-1, the ultrasonic frequency of the ultrasonic treatment is 40~50kHz.

8. The method for simultaneously removing microplastics and antibiotics from sewage according to claim 1, characterized in that: The method of evaporation and drying treatment described in S2-2 is: placing the B mixed solution on a rotary evaporator, and performing rotary evaporation at a vacuum degree of -0.08~-0.1MPa and a temperature of 40~50°C at a rotation speed of 100~200rpm until the deionized water in the B mixed solution is completely evaporated to obtain a solid material.

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