A method for treating quinolone pharmaceutical wastewater

Abstract

This invention belongs to the field of water treatment technology, specifically relating to a method for treating quinolone pharmaceutical wastewater. The method involves introducing a treatment agent into the quinolone pharmaceutical wastewater and then degrading the antibiotics in the wastewater through stirring. The treatment agent is a mixture of a catalyst and persulfate, wherein the catalyst is CeO2, Fe2O3 / CeO2, or Fe2O3-MO / CeO2, where M = Cu, Co, Ni, or Mn. This invention uses CeO2, Fe2O3 / CeO2, or Fe2O3-MO / CeO2 as a catalyst, which has a good specific surface area and can activate sodium persulfate at room temperature, thereby achieving the degradation of quinolone pharmaceutical wastewater with a degradation rate of over 97%.

Description

Technical Field

[0001] This invention belongs to the field of water treatment technology, specifically relating to a method for treating quinolone pharmaceutical wastewater. Background Technology

[0002] Quinolone antibiotics are a common class of synthetic antibiotics, widely used in aquaculture and the medical industry due to their low cost, stable performance, strong antibacterial activity, and broad spectrum. However, only a small fraction of quinolone antibiotics are effective in organisms, with the majority unabsorbed and released into the environment through excrement. The presence of these broad-spectrum antibiotics in aquatic environments can cause long-term destructive effects on ecosystems and induce antibiotic resistance in bacteria. Even at low concentrations, their toxicity, persistence, and bioaccumulation can seriously harm ecosystems and human health. Therefore, the removal of quinolone antibiotics from aquatic environments has attracted considerable attention from researchers, and there is an urgent need to develop an efficient and environmentally friendly method to address the water pollution caused by quinolone antibiotics. Summary of the Invention

[0003] The purpose of this invention is to provide a method for treating quinolone pharmaceutical wastewater, using CeO2, Fe2O3 / CeO2 or Fe2O3-MO / CeO2 as catalysts. These catalysts have a good specific surface area and can activate sodium persulfate at room temperature, thereby achieving the degradation of quinolone pharmaceutical wastewater with a degradation rate of over 97%.

[0004] The technical solution of this invention:

[0005] The first technical problem to be solved by the present invention is to provide a method for treating quinolone pharmaceutical wastewater. The method involves introducing a treatment agent into the quinolone pharmaceutical wastewater and achieving the degradation of antibiotics in the wastewater through stirring. The treatment agent is a mixture of a catalyst and persulfate, wherein the catalyst is CeO2, Fe2O3 / CeO2 or Fe2O3-MO / CeO2, and M = Cu, Co, Ni or Mn, etc.

[0006] Furthermore, the mass ratio of the catalyst to persulfate is 1 to 4:1 (preferably 4:1).

[0007] Furthermore, the persulfate is sodium persulfate, potassium persulfate, or ammonium persulfate, etc.

[0008] Furthermore, the ratio of the catalyst to the quinolone pharmaceutical wastewater is 0.5 g / L to 1.25 g / L (preferably 1 g / L), that is, 0.5 to 1.25 g of catalyst is added per L of quinolone pharmaceutical wastewater.

[0009] Furthermore, the mass ratio of persulfate to quinolone pharmaceutical wastewater is 0.1 to 0.4:1 (preferably 0.25).

[0010] Furthermore, the Fe2O3 / CeO2 is prepared using the following method:

[0011] 1) Cerium nitrate is calcined at 250–800℃ (preferably 500℃) for 2–5 h (preferably 3 h) to obtain the support CeO2;

[0012] 2) Dissolve ferric nitrate in distilled water, stir until dissolved, add the carrier CeO2 obtained in step 1), let stand, stir and sonicate, then dry; finally calcine at 250-800℃ for 2-5 hours to obtain the product Fe2O3 / CeO2.

[0013] Furthermore, in the Fe2O3 / CeO2, the mass of Fe element accounts for 1 to 30% of the total mass of the catalyst.

[0014] Furthermore, the Fe2O3 / CeO2 catalyst has a pore size of 2–10 nm and exhibits a good mesoporous structure.

[0015] Furthermore, in the Fe2O3 / CeO2, the Fe species are highly dispersed on the CeO2 support.

[0016] The second technical problem to be solved by this invention is to point out the use of CeO2 in the treatment of quinolone pharmaceutical wastewater, which can activate persulfate at room temperature, thereby degrading antibiotics in quinolone pharmaceutical wastewater.

[0017] The third technical problem to be solved by this invention is to point out the use of Fe2O3 / CeO2 or Fe2O3-MO / CeO2 catalysts in the treatment of quinolone pharmaceutical wastewater, which can activate persulfate at room temperature, thereby degrading antibiotics in quinolone pharmaceutical wastewater, wherein M = Cu, Co, Ni or Mn, etc.

[0018] The beneficial effects of this invention are:

[0019] 1) This invention is the first to use CeO2, Fe2O3 / CeO2 or Fe2O3-MO / CeO2 catalysts to treat quinolone pharmaceutical wastewater. Since the catalyst can activate persulfate at room temperature, thereby degrading antibiotics in quinolone pharmaceutical wastewater, no additional energy is required, making it a low-energy method.

[0020] 2) The catalyst Fe2O3 / CeO2 used in this invention is simple to synthesize and is conducive to industrial production; moreover, its components are simple, non-toxic and inexpensive.

[0021] 3) The treatment method of the present invention has a degradation rate of over 97% for several typical quinolone antibiotics. Therefore, it is a simple, efficient and low-energy method. Attached Figure Description

[0022] Figure 1 XRD diffraction patterns of Fe2O3, CeO2, and XFe2O3 / CeO2; by Figure 1 It can be seen that the XFe2O3 / CeO2 catalyst was successfully prepared, and Fe2O3 was highly dispersed on the CeO2 surface.

[0023] Figure 2 The image shows the BET distribution of XFe2O3 / CeO2, where a is the N2 adsorption-desorption isotherm of the catalyst, and b is the pore size distribution of the catalyst. Figure 2 It can be seen that the XFe2O3 / CeO2 catalyst has a good mesoporous structure.

[0024] Figure 3 A comparison of the degradation performance of XFe2O3 / CeO2 and its addition of persulfate on ciprofloxacin; (from...) Figure 3 It can be seen that XFe2O3 / CeO2 activated PMS can degrade ciprofloxacin by up to 97%.

[0025] Figure 4 Comparison of XFe2O3 / CeO2 degradation and activated PMS degradation of norfloxacin; by Figure 4 It can be seen that XFe2O3 / CeO2 activated PMS can degrade norfloxacin by up to 97%.

[0026] Figure 5 A comparison of the degradation performance of CeO2 and its addition of persulfate on ciprofloxacin; (from...) Figure 5 It can be seen that CeO2-activated PMS degrades ciprofloxacin by approximately 89%.

[0027] Figure 6 A comparison chart showing the degradation performance of norfloxacin by CeO2 and its addition of persulfate; (from...) Figure 6 It can be seen that CeO2-activated PMS degrades norfloxacin by approximately 90%.

[0028] Figure 7 A comparison of the degradation performance of norfloxacin by Fe2O3-CuO / CeO2 and by adding persulfate; (from...) Figure 7 It can be seen that Fe2O3-CuO / CeO2 activated persulfate degrades norfloxacin by approximately 81%.

[0029] Figure 8 Comparative diagram of Fe2O3 degradation and its activated persulfate degradation of ciprofloxacin; by Figure 8It can be seen that Fe2O3 activated PMS degrades ciprofloxacin by approximately 64%.

[0030] Figure 9 Comparison of Fe2O3 degradation and activated persulfate degradation of norfloxacin; by Figure 9 It can be seen that Fe2O3 activated PMS degrades norfloxacin by approximately 65%.

[0031] Figure 10 A comparison of the degradation of ciprofloxacin by persulfate activated by different catalysts; by Figure 10 It can be seen that 10Fe2O3 / CeO2 has the highest degradation rate compared with other supported materials. Detailed Implementation

[0032] This invention is the first to point out that CeO2, Fe2O3 / CeO2, or Fe2O3-MO / CeO2 catalysts can be used to treat quinolone pharmaceutical wastewater. These catalysts have a good specific surface area and can activate sodium persulfate at room temperature, thereby achieving the degradation of quinolone pharmaceutical wastewater with a degradation rate of over 97%. No additional energy is required, making it a low-energy-consumption method.

[0033] The specific embodiments of the present invention will be further described below with reference to examples, but the present invention is not limited to the scope of the examples described.

[0034] Example 1

[0035] 1. Preparation of Fe2O3 / CeO2:

[0036] 1) 20g of cerium nitrate was directly calcined in a muffle furnace at 500℃ for 3h to obtain the support CeO2;

[0037] 2) Dissolve 0.0721g, 0.3607g, 0.721g, and 1.443g of ferric nitrate in 10mL of distilled water and stir until dissolved. Then add 0.99g, 0.95g, 0.9g, and 0.8g of the CeO2 support obtained in step 1, respectively. Let stand and stir for 1h and sonicate for 15min. Then transfer the samples to a water bath and evaporate to dryness at 70℃. After evaporation, transfer the samples to an oven at 80℃ and dry for 8-12h. Then calcine them in a muffle furnace at 300℃ for 2h to obtain product X Fe2O3 / CeO2, where X represents the mass fraction (wt.%) of Fe in the total catalyst Fe2O3 / CeO2. X = 1, 5, 10, and 20, which are respectively denoted as 1Fe2O3 / CeO2, 5Fe2O3 / CeO2, 10Fe2O3 / CeO2, and 20Fe2O3 / CeO2.

[0038] 2. Implementation steps for catalyst degradation of ciprofloxacin:

[0039] 1) Prepare a 20 mg / L cyclofloxacin solution, measure the absorbance, and record it as the initial absorbance A0;

[0040] 2) Weigh 80 mg of Fe2O3 / CeO2 material and dissolve it in 80 mL of cyclofloxacin solution. Stir thoroughly, and take samples of the supernatant at 15 min, 30 min, 45 min, 60 min, 75 min, and 90 min to measure the absorbance A. x ;

[0041] 3) Calculate the degradation rate using Formula 1.

[0042] Formula 1: Degradation rate (%) = (A0 - A x ) / A0*100

[0043] 3. Implementation steps for catalyst activation of sodium persulfate to degrade ciprofloxacin:

[0044] 1) Prepare a 20 mg / L cyclofloxacin solution, measure the absorbance, and record it as the initial absorbance A0;

[0045] 2) Weigh 80 mg of Fe2O3 / CeO2 material and dissolve it in 80 mL of cyclofloxacin solution. Add 0.02 g of sodium persulfate and stir thoroughly. Take samples of the supernatant at 15 min, 30 min, 45 min, 60 min, 75 min, and 90 min to measure the absorbance A. x ;

[0046] 3) Calculate the degradation rate using Formula 1.

[0047] Formula 1: Degradation rate (%) = (A0 - A x ) / A0*100

[0048] 4. Performance Results:

[0049] Catalyst performance characterization results:

[0050] The phase composition of the prepared Fe2O3, CeO2, and XFe2O3 / CeO2 catalysts was analyzed by XRD, and the test results are as follows: Figure 1Obvious XRD peaks were observed in CeO2 and XFe2O3 / CeO2 samples at 2θ = 28.5, 33.1, 47.4, 56.3, 59.2, 69.5, 76.8, and 79.1°, respectively, belonging to the CeO2 phase with a cubic fluorite structure (JCPDS: 34-0394). The XRD peaks at 2θ = 28.5, 33.1, 47.4, and 56.3° correspond to the {111}, {200}, {220}, and {311} crystal planes of CeO2, respectively. The pure CeO2 sample exhibited narrow and strong characteristic XRD peaks of the CeO2 crystal phase, indicating that the CeO2 sample possesses a large grain size and high crystallinity. This is mainly attributed to the high-temperature calcination and reduction, which promoted the formation of the highly crystallinity CeO2 phase. The Fe2O3 sample exhibited distinct XRD peaks at 2θ = 24.1, 33.1, 35.6, 40.8, 49.4, 54.0, 57.5, 62.4, 64.0, 71.8, and 75.4°, which are characteristic peaks of Fe2O3 (JCPDS:72-0469) and correspond to the {012}, {104}, {110}, {113}, {024}, {116}, {018}, {214}, {300}, {1010}, and {220} crystal planes of Fe2O3, respectively.

[0051] With the addition of Fe2O3, the characteristic XRD peaks of CeO2 in the XFe2O3 / CeO2 catalyst became weaker and broader. This can be attributed to the high-temperature heat treatment during the preparation of the XFe2O3 / CeO2 catalyst, which promoted the dissolution of Fe species into the CeO2 lattice, forming a large amount of Fe-O-Ce solid solution, resulting in a decrease in the CeO2 lattice parameters. Compared with the Fe2O3 sample, almost no diffraction peaks of Fe species were observed in the XFe2O3 / CeO2 catalyst. This indicates that, on the one hand, even with an addition of 20%, the Fe species content is significantly reduced compared to the 100% relative content of Fe2O3; on the other hand, the interaction between Fe and CeO2 inhibited the growth of Fe species grains, resulting in a high dispersion of Fe species on the CeO2 support surface, leading to a significant reduction in the crystallinity of metallic Fe species.

[0052] The specific surface area and pore structure of the prepared XFe2O3 / CeO2 catalyst were tested using the low-temperature N2 adsorption-desorption (BET) method. The results for specific surface area, pore size, and pore volume are as follows: Figure 2 And Table 1. From Figure 2 (b) It can be seen that the mesopores of XFe2O3 / CeO2 are mainly concentrated in the 2-10 nm range. Table 1 shows that the specific surface area of ​​XFe2O3 / CeO2 increases with increasing Fe species loading, while the pore volume and pore size decrease. The catalyst with 20% Fe loading (20Fe2O3 / CeO2) has the largest specific surface area (62.64 nm).2 / g).

[0053] like Figure 2 (a) As indicated by IUPAC classification, the N2 adsorption-desorption isotherms of the XFe2O3 / CeO2 catalyst show a distinct type IV H3 adsorption-desorption hysteresis loop, suggesting that the prepared catalysts all possess a good mesoporous structure. The formation of the hysteresis loop is attributed to capillary condensation of adsorbed N2 molecules within the mesoporous structure of the XFe2O3 / CeO2 catalyst. Figure 2 (b) The pore size distribution of the XFe2O3 / CeO2 catalyst further confirms the excellent mesoporous structure of the prepared catalyst. As shown in Table 1, the specific surface area of ​​the prepared xFC catalyst increases with increasing Fe loading, while the pore volume and pore size decrease. This is mainly attributed to the fact that the relative density of Fe oxides is all around 5.0 g / cm³. 3 The relative density of Ce oxide is approximately 7.0 g / cm³. 3 The addition of Fe oxides with relatively low density increases the mass and volume of the prepared XFe2O3 / CeO2 catalyst. Generally, for similar materials, a larger volume corresponds to a larger specific surface area. Simultaneously, the introduction of Fe species can form a large amount of Fe-O-Ce solid solution. The Fe species entering the CeO2 lattice alter the regularity of the catalyst, thereby promoting a good synergistic effect between Fe and Ce species. The interaction between Fe and Ce species effectively inhibits the grain growth and agglomeration of single metal species, forming smaller particles and promoting the high dispersion of metallic Fe components on the CeO2 support, thus increasing its specific surface area and reducing grain size. However, with the increase of Fe loading, a large amount of aggregated iron oxides blocks or partially covers the pore structure, leading to a decrease in pore volume and pore size.

[0054] Table 1. BET test data for XFe2O3 / CeO2

[0055]

[0056] The test results of the catalyst obtained in this invention for the degradation of ciprofloxacin are as follows: Figure 3 ,Depend on Figure 3 It can be seen that the degradation of ciprofloxacin by 1Fe2O3 / CeO2, 5Fe2O3 / CeO2, 10Fe2O3 / CeO2, and 20Fe2O3 / CeO2 increases with time, but gradually stabilizes over time, reaching degradation saturation. Compared with the catalyst without sodium persulfate (PMS), the maximum degradation rate of XFe2O3 / CeO2 is about 35%. After adding PMS, the maximum degradation rate of XFe2O3 / CeO2 is as high as 97%, which is much higher than that of the catalyst without PMS.

[0057] Example 2

[0058] The preparation of the catalyst Fe2O3 / CeO2 is the same as in Example 1; the process for treating pharmaceutical wastewater is the same as in Example 1, except that it is used to degrade norfloxacin solution.

[0059] Degradation of norfloxacin test results are as follows Figure 4 ,Depend on Figure 4 It can be seen that the degradation of norfloxacin by 1Fe2O3 / CeO2, 5Fe2O3 / CeO2, 10Fe2O3 / CeO2, and 20Fe2O3 / CeO2 increases with time, but gradually stabilizes over time, reaching degradation saturation. Compared with the catalyst without PMS, the maximum degradation rate of XFe2O3 / CeO2 is about 70%. After adding PMS, the maximum degradation rate of XFe2O3 / CeO2 reaches as high as 97%.

[0060] Example 3

[0061] The specific process is the same as in Example 1, and the catalyst material is CeO2 prepared in Example 1. CeO2 was used to degrade ciprofloxacin, and the test results are as follows. Figure 5 It can be seen that the degradation rate of CeO2 alone is about 51%, but after adding PMS, the degradation rate of ciprofloxacin by CeO2+PMS is about 90%. The test results for CeO2 used to degrade norfloxacin are as follows... Figure 6 The degradation rate of CeO2 alone is about 50%, but with the addition of PMS, the degradation rate of norfloxacin by CeO2+PMS is about 90%.

[0062] Example 4

[0063] The preparation process of the catalyst Fe2O3-CuO / CeO2 is as follows:

[0064] 1) 20g of cerium nitrate was directly calcined in a muffle furnace at 500℃ for 3h to obtain the support CeO2;

[0065] 2) Dissolve 0.721g of ferric nitrate and 0.415g of copper nitrate (to make Fe:Cu = 1:1) in 10mL of distilled water and stir until dissolved. Then add 0.9g of the carrier CeO2 obtained in step 1, let stand and stir for 1h and sonicate for 15min. Then transfer it to a water bath and evaporate to dryness at 70℃. After evaporation, transfer the sample to an oven at 80℃ and dry for 8-12h. Then calcine it in a muffle furnace at 300℃ for 2h to obtain the product 10Fe2O3-CuO / CeO2.

[0066] 10Fe2O3-CuO / CeO2 was used to degrade norfloxacin, and the results were as follows: Figure 7 ,Depend on Figure 7It is known that the degradation rate of Fe2O3-CuO / CeO2 is about 25%, but after adding PMS, the degradation rate of norfloxacin by Fe2O3-CuO / CeO2 is about 80%.

[0067] Comparative Example 1

[0068] 20g of ferric nitrate was directly calcined in a muffle furnace at 500℃ for 3 hours to obtain Fe2O3. Other processes were the same as in Example 1. Ciprofloxacin was degraded using Fe2O3, and the test results are as follows... Figure 8 ,Depend on Figure 8 It can be seen that the degradation rate of Fe2O3 alone is about 15%, but after adding PMS, the degradation rate of ciprofloxacin by Fe2O3+PMS is about 64%. The test results for the degradation of norfloxacin using Fe2O3 are as follows... Figure 9 ,Depend on Figure 9 It is known that the degradation rate of Fe2O3 alone is about 15%, but after adding PMS, the degradation rate of norfloxacin by Fe2O3+PMS is about 65%.

[0069] Comparative Example 2

[0070] This invention also prepared 10Fe2O3 / MnO, 10Fe2O3 / ZrO2, 10Fe2O3 / KIT6, and 10Fe2O3 / MgO catalysts according to the method of Example 1, and tested their performance in degrading ciprofloxacin after introduction into PMS. The results are as follows: Figure 10 As shown, by Figure 10 It was found that the degradation rates of 10Fe₂O₃ / MnO, 10Fe₂O₃ / ZrO₂, 10Fe₂O₃ / KIT₆, 10Fe₂O₃ / MgO, and 10Fe₂O₃ / CeO₂ rapidly increased within 15 min, and then tended to stabilize, with degradation rates of 37.6%, 43.9%, 62.9%, 73.4%, and 95.5%, respectively. Compared with other supported materials, 10Fe₂O₃ / CeO₂ exhibited the highest degradation rate. This is because the support affects the initial dispersion of the active components and the aggregation during the reaction process, thus affecting the catalytic performance. XRD and In-situ XPS showed that the interaction between Fe and CeO₂ inhibited the growth of Fe species grains, resulting in high dispersion of Fe species on the CeO₂ support surface. The abundant oxygen vacancies and numerous weakly basic centers on the Ce surface of the support are conducive to promoting electron transfer. Therefore, compared with other supports, the good synergistic coupling and electronic effects at the Fe and Ce interface are more beneficial to the degradation of ciprofloxacin.

Claims

1. A method for treating quinolone pharmaceutical wastewater, characterized in that, The treatment method is as follows: a treatment agent is introduced into the quinolone pharmaceutical wastewater, and the antibiotics in the quinolone pharmaceutical wastewater are degraded by stirring; wherein, the treatment agent is a mixture of a catalyst and persulfate, and the catalyst is Fe2O3 / CeO2; The Fe2O3 / CeO2 was prepared by the following method: 1) Cerium nitrate was calcined at 250–800 °C for 2–5 h to obtain the support CeO2; 2) Dissolve ferric nitrate in distilled water, stir until dissolved, add the carrier CeO2 obtained in step 1), let stand, stir and sonicate, then transfer to a water bath and evaporate to dryness at 70 ℃. After evaporation, transfer the sample to an 80 ℃ oven and dry for 8-12 h, then place it in a muffle furnace and calcine at 300 ℃ for 2 h to obtain the product Fe2O3 / CeO2.

2. The method for treating quinolone pharmaceutical wastewater according to claim 1, characterized in that, The mass ratio of the catalyst to persulfate is 1 to 4:

1.

3. A method for treating quinolone pharmaceutical wastewater according to claim 1 or 2, characterized in that, The persulfate is sodium persulfate, potassium persulfate, or ammonium persulfate.

4. A method for treating quinolone pharmaceutical wastewater according to claim 1 or 2, characterized in that, The ratio of the catalyst to quinolone pharmaceutical wastewater is 0.5 g / L to 1.25 g / L.

5. A method for treating quinolone pharmaceutical wastewater according to claim 1 or 2, characterized in that, In the Fe2O3 / CeO2, the mass of Fe element accounts for 1 to 30% of the total catalyst mass.

6. The method for treating quinolone pharmaceutical wastewater according to claim 5, characterized in that, In the Fe2O3 / CeO2, the mass of Fe element accounts for 1%, 5%, 10% or 20% of the total catalyst mass.

7. The method for treating quinolone pharmaceutical wastewater according to claim 5, characterized in that, The Fe2O3 / CeO2 catalyst has a pore size of 2–10 nm.

8. The application of Fe2O3 / CeO2 catalyst in the treatment of quinolone pharmaceutical wastewater, characterized in that, The Fe2O3 / CeO2 catalyst can activate persulfate at room temperature, thereby degrading antibiotics in quinolone pharmaceutical wastewater; The Fe2O3 / CeO2 was prepared by the following method: 1) Cerium nitrate was calcined at 250–800 °C for 2–5 h to obtain the support CeO2; 2) Dissolve ferric nitrate in distilled water, stir until dissolved, add the carrier CeO2 obtained in step 1), let stand, stir and sonicate, then transfer to a water bath and evaporate to dryness at 70 ℃. After evaporation, transfer the sample to an 80 ℃ oven and dry for 8-12 h, then place it in a muffle furnace and calcine at 300 ℃ for 2 h to obtain the product Fe2O3 / CeO2.

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