Method for removing chloramphenicol in water by using phosphated micro-iron

Abstract

The present application belongs to the field of water treatment, and relates to a method for removing chloramphenicol in water by using phosphatized micro-iron. The method provided by the present application is characterized in that phosphatized micro-iron is added into water containing chloramphenicol to be treated, and stirring is performed to remove chloramphenicol in the water. The present application provides a novel and efficient method for removing chloramphenicol in water. bm The method can quickly and efficiently remove chloramphenicol, and is suitable for a wide pH range. bm The P-ZVI has good reduction performance and can efficiently remove chloramphenicol in water. bm The preparation method is simple, and the P-ZVI is suitable for industrial production and has a wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of water treatment, specifically relating to a method for removing chloramphenicol from water using phosphorylated micronized iron. Background Technology

[0002] Chloramphenicol (CAP) is a synthetic chloronitro aromatic antibiotic widely used in aquaculture due to its low cost. However, CAP is not completely metabolized in organisms and may be excreted into the environment in feces and enter the human body through the food chain, posing a threat to human health. Therefore, effective water treatment methods are urgently needed to control it.

[0003] Currently, the main methods for removing CAP from water bodies include adsorption, advanced oxidation, and biological methods. Adsorption methods are characterized by their simplicity, low energy consumption, and environmental friendliness. Activated carbon is the most commonly used adsorbent, but it suffers from high cost and regeneration difficulties. Advanced oxidation technologies, including photocatalytic oxidation and ozone oxidation, are highly efficient at degrading CAP, but they are highly pH-dependent and may produce more toxic byproducts. Biological degradation technologies have low operating costs and simple processes, but their application is limited by the large land area required, long treatment time, and the high mortality rate of microorganisms. Therefore, there is still a need to explore a green and simple method for the efficient degradation of chloramphenicol.

[0004] Zero-valent iron (ZVI) has been widely used in water treatment due to its excellent reducing ability. However, ZVI also has some limitations; its surface is easily passivated, resulting in low electron utilization of pollutants. To optimize ZVI performance, various ZVI modification techniques have been proposed. The main modification techniques include doping ZVI with noble metals or other elements, surface modification with surfactants or polymers, embedding ZVI into carriers, and stabilizing ZVI on porous materials. Currently, ball milling technology is gaining increasing attention in the ZVI field, especially in surface activation and modification. Mechanical ball milling can not only reduce the particle size of ZVI but also remove the oxide layer from its surface, thereby enhancing its surface activity. In methods using mechanical ball milling to modify ZVI, researchers often add additives to ball mill with ZVI to regulate the functional group structure of the ZVI surface, thereby enhancing the adsorption / coordination, redox, flocculation / precipitation of pollutants on the ZVI surface and improving the efficiency of ZVI in removing pollutants. Representative additives include sulfides and oxalic acid. Currently, phosphate-modified zero-valent iron (ZVFe) is a novel modification method. The modified material has a smaller particle size, better dispersibility, and more thorough contact with contaminants in solution. Furthermore, its larger specific surface area allows for greater contact with contaminants and the removal of more active sites. In addition, the tight bond between phosphate and ZVFe may have a synergistic effect on the removal of target contaminants, suggesting that phosphorylated ZVFe may be more effective than unmodified ZVFe in removing contaminants. However, there are currently no reports in the field of applying phosphorylated ZVFe to the removal of CAP (capillary phosphate). Summary of the Invention

[0005] The purpose of this invention is to provide a phosphorylated micronized iron (P-ZVI) bm Methods for removing chloramphenicol from water to achieve efficient degradation of chloramphenicol.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] A phosphorylated micron-sized iron (P-ZVI) bm A method for removing chloramphenicol from water, wherein the method involves adding micronized iron phosphate to water containing chloramphenicol and stirring the mixture to remove the chloramphenicol from the water.

[0008] Preferably, the method for preparing the phosphorylated micronized iron includes: ball milling reduced iron powder and potassium dihydrogen phosphate to obtain phosphorylated micronized iron. More preferably, the molar ratio (phosphorus-iron ratio) of potassium dihydrogen phosphate and reduced iron powder is 1:2 to 1:15; more preferably, the ball-to-particle ratio of the ball milling is 4.5:1; more preferably, the grinding balls include 3mm grinding balls and 5mm grinding balls, and the ratio of the number of the two is 2 (3mm balls): 1 (5mm balls); more preferably, the ball milling speed is 300 to 500 rpm, and the ball milling time is 1 to 4 hours. The phosphorylated micronized iron obtained by the above technical solution can be effectively applied to the removal of chloramphenicol in the present invention. Phosphorylated micronized iron may also be obtained under conditions outside the scope of the above technical solution, but the removal effect of chloramphenicol in water applied to the present invention may be poor. More preferably, the particle size of the phosphorylated micronized iron is 100 to 500 mesh.

[0009] More preferably, the phosphorylated micronized iron P-ZVI bm The specific preparation method of the material includes: adding potassium dihydrogen phosphate and reduced iron powder in a molar ratio of 1:10 into a ball mill jar, then adding 60 grinding balls with a diameter of 3 mm and 30 grinding balls with a diameter of 5 mm, with a ball-to-material ratio of 4.5:1, placing the grinding jar in a planetary ball mill and grinding at a speed of 500 rpm, rotating clockwise for 30 minutes and counterclockwise for 30 minutes as one cycle, repeating the cycle 4 times, for a total of 4 hours.

[0010] More preferably, the reduced iron powder is in the micron range with a particle size of 100-500 mesh.

[0011] Preferably, the chloramphenicol CAP concentration in the water to be treated is 100–1500 μg·L⁻¹. -1 More preferably 500 μg·L -1 Within the specified range, basic removal of CAP can be guaranteed within 1 hour.

[0012] Preferably, the amount of phosphorylated micronized iron added is not less than 0.5 g·L. -1 More preferably 0.5–3 g·L -1 More preferably 1–3 g·L -1 .

[0013] Preferably, the pH of the reaction is 3 to 11, within which the CAP removal rate is higher than 99.9% after 40 minutes of reaction; more preferably, it is 3 to 9, which ensures that the CAP removal rate is higher than 99.9% after 20 minutes of reaction.

[0014] Preferably, the reaction temperature is 20°C to 30°C, more preferably 25°C.

[0015] Preferably, the stirring rate of the reaction is 30-60 rpm, more preferably 45 rpm, and the reaction time is not less than 10 min, more preferably 10-60 min, and even more preferably 10-20 min.

[0016] More preferably, the reaction is carried out under anaerobic conditions.

[0017] Preferably, the reaction is carried out in an anaerobic chamber, and the concentration of chloramphenicol in the water to be treated is 500 μg·L⁻¹. -1 The feed amount of phosphorylated micronized iron is 2 g·L. -1 Under conditions of pH 5 and temperature 25℃, a 99.9% removal rate can be achieved by reacting at a stirring rate of 45 rpm for 20 minutes.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides a novel and efficient method for removing chloramphenicol from water, which involves using phosphorylated micron-sized iron P-ZVI. bm P-ZVI is used for the removal of organic pollutants, achieving rapid and efficient removal of chloramphenicol. It is also less sensitive to the pH of the reaction system and can be adapted to a wide pH range. bm It has excellent reducing properties and can efficiently remove chloramphenicol from water. Meanwhile, P-ZVI... bm The preparation method is simple, suitable for industrial production, and has broad application prospects. Attached Figure Description

[0019] Figure 1 It is P-ZVI bm SEM image.

[0020] Figure 2 It's ZVI bm and P-ZVI bm Particle size distribution diagram.

[0021] Figure 3 It is commercial iron powder (ZVI), ball-milled micron iron (ZVI) bm ), phosphorylated micron iron (P-ZVI) bm The comparison chart shows the effect of removing CAP, where [ZVI]0 = 2 g·L -1 [ZVI] bm ]0=2g·L -1 [P-ZVI] bm ]0=2g·L -1 [CAP]0 = 500 μg·L -1 pH = 6.5, rotation speed = 45 rpm, P / Fe = 1:10.

[0022] Figure 4 Is the initial CAP concentration relative to P-ZVI?bm Remove the effects of CAP, where [P-ZVI] bm ]0=2g·L -1 pH = 6.5, rotation speed = 45 rpm, P / Fe = 1:10.

[0023] Figure 5 The effect of initial solution pH on P-ZVI bm Remove the effects of CAP, where [P-ZVI] bm ]0=2g·L -1 [CAP]0 = 500 μg·L -1 Rotational speed = 45 rpm, P / Fe = 1:10.

[0024] Figure 6 It is P-ZVI bm The effect of dosage on CAP removal, where [CAP]0 = 500 μg·L -1 pH = 6.5, rotation speed = 45 rpm, P / Fe = 1:10.

[0025] Figure 7 It is P / Fe against P-ZVI bm Remove the effects of CAP, where [P-ZVI] bm ]0=2g·L -1 [CAP]0 = 500 μg·L -1 pH = 6.5, rotation speed = 45 rpm.

[0026] Figure 8 It is P-ZVI bm Comparison of CAP removal effects with S-ZVI, where [S-ZVI]0 = 2 g·L -1 [CAP]0 = 500 μg·L -1 pH = 6.5, rotation speed = 45 rpm. Detailed Implementation

[0027] To better clarify and understand the objectives, process solutions, and advantages of this invention, the technical solutions and implementation methods of this invention will be further described clearly, completely, and in detail below through specific embodiments and in conjunction with the accompanying drawings. It should be understood that the embodiments described in this invention are implemented under the premise of the technical solutions of this invention, providing detailed implementation methods and specific operating procedures, but are only some embodiments of this invention, not all embodiments. The specific implementation methods described are limited to illustrating and explaining this invention and do not limit this invention. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0028] Unless otherwise specified, the experimental methods and conditions used in the following examples are conventional methods and conditions. The materials, reagents, and instruments used in the examples, unless otherwise specified, can be obtained commercially or prepared by conventional methods. The reaction conditions described in the invention can all achieve the reactions and obtain the desired products. Due to space limitations, some examples are listed below to further illustrate the advantages of the technical solution of the present invention.

[0029] Example 1

[0030] (1) Preparation of P-ZVI bm Material:

[0031] Potassium dihydrogen phosphate and reduced iron powder (99% reduced iron powder purchased from Shanghai Maclean Biochemical Technology Co., Ltd.) were added to a ball mill jar at a molar ratio of 1:10. Then, 60 grinding balls with a diameter of 3 mm and 30 grinding balls with a diameter of 5 mm were added, with a ball-to-material ratio of 4.5:1. The grinding jar was placed in a planetary ball mill and ball milled at a speed of 500 rpm. One cycle consisted of 30 minutes of forward rotation and 30 minutes of reverse rotation. The cycle was repeated 4 times for a total of 4 hours. Figure 1 It is P-ZVI bm SEM image.

[0032] (2) Experimental methods:

[0033] This experiment was conducted in an anaerobic chamber. First, P-ZVI was weighed. bm Add 0.08 g of the material to a 40 mL brown extraction flask, then add 40 mL of anoxic water and an appropriate volume of CAP stock solution to bring the initial CAP concentration in the extraction flask to 500 μg·L⁻¹. -1 After tightening the cap, place the extraction flask on a rotary incubator and react at 45 rpm at room temperature. The initial pH of the solution is 6.5. During the reaction, take 1 mL samples at regular intervals, filter them through a 0.45 μm mixed cellulose membrane, and inject them into the liquid chromatography vial. Finally, analyze the samples by high performance liquid chromatography.

[0034] P-ZVI bm Material replacement with commercial iron powder (ZVI) and ball-milled micron iron (ZVI) bm The removal efficiency of chloramphenicol was tested accordingly. The commercial iron powder used was reduced iron powder (99%) purchased from Shanghai Maclean Biochemical Technology Co., Ltd.; the ball-milled micronized iron ZVI was also tested. bm The preparation method is as follows: First, add 4g of reduced iron powder (commercial iron powder) into a ball mill jar, then add 60 grinding balls with a diameter of 3mm and 30 grinding balls with a diameter of 5mm. Place the ball mill jar into a planetary ball mill and ball mill at a speed of 500rpm. Rotate forward for 30 minutes and reverse for 30 minutes as one cycle. Repeat the cycle 4 times for a total of 4 hours. Figure 2 It's ZVI bm and P-ZVI bm The particle size distribution is shown in Table 1. bm and P-ZVI bm A summary table of specific surface area, pore volume, and average pore size.

[0035] Table 1 ZVI bm and P-ZVI bm Summary table of specific surface area (BET), pore volume and average pore size (BJH)

[0036]

[0037] Test results are available Figure 3 As shown, Figure 3 Commercial iron powder (ZVI), ball-milled micron iron (ZVI) bm ), phosphorylated micron iron (P-ZVI) bm Comparison images showing the effects of removing CAP. It can be seen that ZVI and ZVI... bm P-ZVI bm The dosage is 2g·L -1 The initial CAP concentration was 500 μg·L⁻¹. -1 After 1 hour of reaction, ZVI removed 5.7% of CAP. bm The removal rate of CAP was 5.6%, and P-ZVI... bm The removal rate of CAP reached 99.9% within 20 minutes. This is in comparison with ZVI and ZVI. bm Compared to P-ZVI bm The removal effect on CAP was significantly improved beyond expectations.

[0038] Example 2

[0039] The P-ZVI prepared in Example 1 was used bm Materials. This experiment was conducted in an anaerobic chamber. First, P-ZVI was weighed. bm 0.08 g of the material was added to a 40 mL brown extraction flask, followed by 40 mL of anoxic water and the corresponding volume of CAP solution to achieve initial concentrations of 100, 300, 500, 1000, and 1500 μg·L⁻¹. -1 After tightening the cap, place the extraction bottle on a rotary incubator and react at 45 rpm at room temperature. The initial pH of the solution is 6.5. During the reaction, take samples at regular intervals, 1 mL each time. Filter the sample through a 0.45 μm mixed cellulose membrane and inject it into the liquid chromatography vial. Finally, analyze the sample by high performance liquid chromatography.

[0040] Test results are available Figure 4 As shown, Figure 4Initial CAP concentration versus P-ZVI bm The effect of CAP removal. It can be seen that the removal rate of CAP by the material gradually decreases with increasing initial CAP concentration. However, the removal rate remains relatively high when the initial CAP concentration is between 100 and 1500 μg·L⁻¹. -1 Within the specified range, CAP can be basically removed within 1 hour.

[0041] Example 3

[0042] The P-ZVI prepared in Example 1 was used bm Materials. This experiment was conducted in an anaerobic chamber. First, P-ZVI was weighed. bm Add 0.08 g of the material to a 40 mL brown extraction flask, add 40 mL of deoxygenated water, and use 1 mol·L⁻¹ extractant. -1 Adjust the pH of the solution to 3, 5, 7, 9, or 11 using HCl or NaOH, then add the corresponding volume of CAP solution to bring the initial concentration to 500 μg·L⁻¹. -1 After tightening the cap, place the extraction bottle on a rotary culture device and react at 45 rpm at room temperature. Take samples at regular intervals during the reaction, 1 mL each time. Filter the sample through a 0.45 μm mixed cellulose membrane and inject it into a liquid chromatography vial. Finally, analyze the sample by high performance liquid chromatography.

[0043] Test results are available Figure 5 As shown, Figure 5 The initial pH of the solution versus P-ZVI bm The effect of CAP removal. It can be seen that within the pH range of 3–11, the material achieves a CAP removal rate of 99.9% within 1 hour. As the pH increases, the CAP removal rate decreases. Within the pH range of 3–9, the CAP removal rate can be maintained above 99.9% after 20 minutes of reaction, and within the pH range of 3–11, the CAP removal rate can be maintained above 99.9% after 40 minutes of reaction.

[0044] Example 4

[0045] The P-ZVI prepared in Example 1 was used bm Materials. This experiment was conducted in an anaerobic chamber. P-ZVI was weighed separately. bm 0.02, 0.04, 0.08, and 0.12 g of the materials were added to a 40 mL brown extraction flask, followed by 40 mL of anoxic water and the corresponding volume of CAP solution to achieve an initial concentration of 500 μg·L⁻¹. -1 After tightening the cap, place the extraction flask on a rotary incubator and react at 45 rpm at room temperature. The initial pH of the solution is 6.5. During the reaction, take 1 mL samples at regular intervals, filter them through a 0.45 μm mixed cellulose membrane, and inject them into the liquid chromatography vial. Finally, analyze the samples by high performance liquid chromatography.

[0046] Test results are available Figure 6 As shown, Figure 6 P-ZVI bm Dosage for P-ZVI bm The effect of CAP was removed. It can be seen that at a dosage of 0.5–3 g·L⁻¹, -1 Within the specified range, the removal rate of CAP can be guaranteed to be higher than 90% within 1 hour. As the dosage increases, the removal rate of CAP by the material gradually increases. When the material dosage is 2 g·L⁻¹, the removal rate reaches its maximum. -1 and 3g·L -1 When the reaction time was 20 min, the removal rate of CAP was higher than 99.9%.

[0047] Example 5

[0048] Based on the method for preparing phosphorylated micronized iron in Example 1, phosphorylated micronized iron with phosphorus-to-iron ratios of 1:2, 1:5, 1:15, 1:20, and 1:100 were prepared. This experiment was conducted in an anaerobic chamber. First, P-ZVI with different phosphorus-to-iron ratios was weighed... bm Add 0.08 g of each material to a 40 mL brown extraction flask, then add 40 mL of deoxygenated water and the corresponding volume of CAP stock solution to bring the initial CAP concentration in the extraction flask to 500 μg·L⁻¹. -1 After tightening the cap, place the extraction flask on a rotary incubator and react at 45 rpm at room temperature. The initial pH of the solution is 6.5. During the reaction, take 1 mL samples at regular intervals, filter them through a 0.45 μm mixed cellulose membrane, and inject them into the liquid chromatography vial. Finally, analyze the samples by high performance liquid chromatography.

[0049] Test results are available Figure 7 As shown, Figure 7 The graph shows the removal effect of micronized iron phosphate (P-ZVI) with different P / Fe ratios on CAP. It can be seen that the removal effect of P-ZVI varies with different P / Fe ratios. The P / Fe ratio in the range of 1:2 to 1:15 shows the best removal effect on CAP, with a removal rate exceeding 99.9% within 20 minutes. P-ZVI with P / Fe ratios of 1:20 and 1:100 also shows good results. bm P-ZVI with P / Fe ratios of 1:2 to 1:15 bm In comparison, the removal rate of CAP decreased significantly.

[0050] Comparative Example 1

[0051] Preparation method of micronized zero-valent iron sulfide (S-ZVI): (1) Acid washing: In an anaerobic glove box, deionized water with deoxygenation treatment is used to prepare a solution with a concentration of 50 mmol·L⁻¹. -1(2) Sulfation: Add 20 mL of dilute hydrochloric acid to a 40 mL extraction flask, then add 5.6 g of commercial micron-sized zero-valent iron, shake well, and let stand for 1 h to remove iron oxides from the surface. -1 Na2S solution was used to obtain S-ZVI with sulfur-to-iron ratios of 1:10 and 1:20. After being placed in a rotary culturer and rotated for 12 hours, the mixture was filtered. (3) Drying: The filtered solid was freeze-dried (12 hours) to obtain dried S-ZVI powder with different sulfurization ratios.

[0052] This experiment was conducted in an anaerobic chamber. First, 0.08 g of each of S-ZVI with different sulfur-to-iron ratios was weighed and added to 40 mL brown extraction flasks. Then, 40 mL of anoxic water and the corresponding volume of CAP stock solution were added to bring the initial CAP concentration in the extraction flasks to 500 μg·L⁻¹. -1 After tightening the cap, place the extraction flask on a rotary incubator and react at 45 rpm at room temperature. The initial pH of the solution is 6.5. During the reaction, take 1 mL samples at regular intervals, filter them through a 0.45 μm mixed cellulose membrane, and inject them into the liquid chromatography vial. Finally, analyze the samples by high performance liquid chromatography.

[0053] Test results are available Figure 8 As shown, Figure 8 P-ZVI bm Comparison of CAP removal effects between P-ZVI and S-ZVI. It can be seen that compared to P-ZVI... bm Compared to other systems, S-ZVI showed poorer removal efficiency for CAP. After 20 minutes of reaction, P-ZVI... bm CAP was essentially completely degraded, while S-ZVI with S / Fe ratios of 1:10 and 1:20 showed removal rates of only 45.9% and 70.6% for CAP, respectively. After 60 minutes of reaction, the removal rates of S-ZVI with S / Fe ratios of 1:10 and 1:20 were still only 83.3% and 95.6% for CAP, respectively. This demonstrates the excellent effect of phosphorylated micronized iron on chloramphenicol removal.

[0054] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Other variations and modifications may be made without departing from the technical solutions described in the claims.

Claims

1. A method for removing chloramphenicol from water using phosphorylated micron-sized iron, characterized in that, The method involves adding ferric phosphoric acid micronized powder to water containing chloramphenicol, stirring the reaction to remove chloramphenicol from the water. The preparation method of the ferric phosphoric acid micronized powder includes: ball milling reduced iron powder and potassium dihydrogen phosphate to obtain ferric phosphoric acid micronized powder; the molar ratio of potassium dihydrogen phosphate to reduced iron powder is 1:2 to 1:15; the ball-to-powder ratio is 4.5:1; the grinding balls include 3mm and 5mm grinding balls in a 2:1 ratio; the ball milling speed is 300 to 500 rpm; and the ball milling time is 1 to 4 hours. The pH of the reaction is 3 to 11, and the chloramphenicol CAP concentration in the water to be treated is 100 to 1500 μg·L⁻¹. -1 The amount of phosphorylated micronized iron added is not less than 0.5 g·L. -1 The stirring rate of the reaction is 30-60 rpm, and the reaction time is not less than 10 min.

2. The method for removing chloramphenicol from water using phosphorylated micronized iron according to claim 1, characterized in that, The preparation method of the phosphorylated micronized iron specifically includes: adding potassium dihydrogen phosphate and reduced iron powder in a molar ratio of 1:10 into a ball mill jar, then adding 60 grinding balls with a diameter of 3 mm and 30 grinding balls with a diameter of 5 mm, with a ball-to-material ratio of 4.5:1, placing the grinding jar in a planetary ball mill and ball milling at a speed of 500 rpm, rotating clockwise for 30 minutes and counterclockwise for 30 minutes as one cycle, repeating the cycle 4 times, for a total of 4 hours.

3. The method for removing chloramphenicol from water using phosphorylated micronized iron according to claim 1, characterized in that, The pH of the reaction is 3 to 9.

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