Method for removing sulfadiazine in hydrolyzed urine by using nanoscale zero-valent iron activated periodate

Abstract

The invention belongs to the technical field of advanced oxidation, and relates to a method for removing sulfadiazine in hydrolyzed urine by activating periodate with nanoscale zero-valent iron, which comprises the following steps: firstly preparing the hydrolyzed urine containing sulfadiazine, then adding quantitative nanoscale zero-valent iron, and finally adding periodate to carry out oxidation reaction. The sulfadiazine can be efficiently removed. Starting from antibiotic pollution source treatment, the method has the advantages of simple process, high anti-interference capability and the like, and sulfadiazine in the hydrolyzed urine can be efficiently removed.

Description

Technical Field

[0001] The invention relates to the field of advanced oxidation technology, in particular to a method for removing and hydrolyzing sulfadiazine in urine by activating periodate with nanometer zero-valent iron. Background Art

[0002] Antibiotics are widely distributed in the environment and pose a serious threat to ecosystems and human health. Wastewater treatment plants are often regarded as the outposts of antibiotic management, but traditional treatment technologies, such as sedimentation, filtration and chlorination, cannot target the removal of antibiotics in complex water bodies, such as sulfonamides and tetracyclines. Therefore, source control of antibiotics has become a more effective management strategy. Some studies have reported methods for treating antibiotics in urine, such as the use of ferrate and peracetic acid (PAA) coupling to effectively degrade sulfonamide antibiotics in urine. However, as an explosive liquid oxidant, the large-scale use of PAA may pose a safety hazard. In addition to PAA, periodate (PI) is also widely used to degrade organic pollutants, and its solid form greatly improves safety during transportation and storage. In addition, unlike PAA, the application of PI does not cause acidification of wastewater, which greatly saves treatment costs. Therefore, PI-AOPs have the advantages of safety, greenness, and simple operation.

[0003] Nano-zero-valent iron (nZVI) is widely used to construct Fenton-like oxidation processes, which can generate a variety of active substances (such as hydroxyl radicals (·OH), sulfate radicals (SO4 ·- ), high-valent metals (Fe(IV)), etc.) to degrade and even mineralize different organic pollutants. For example, nZVI activated persulfate can effectively degrade polycyclic aromatic hydrocarbons in soil; nZVI / manganese oxide composites prepared by ball milling can also effectively activate perPI to degrade sulfamethoxazole (SMX). The Fe(IV) generated during the activation process is basically not consumed by inorganic anions, and has excellent stability.

[0004] In summary, it is of great significance to develop a simple and efficient sulfadiazine removal technology to control antibiotic pollution at the source. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method for removing sulfadiazine in hydrolyzed urine by activating periodate with nano-zero-valent iron. The method uses simple and easily available commercially available nano-zero-valent iron as an activator to activate periodate to remove sulfadiazine in hydrolyzed urine, and has a high removal rate.

[0006] In order to solve the above technical problems, a technical solution adopted by the present invention is: to provide a method for removing sulfadiazine in urine by activating periodate with nano-zero-valent iron, comprising the following steps:

[0007] First, hydrolyzed urine containing sulfadiazine is prepared, then a quantitative amount of nano zero-valent iron is added, and finally periodate is added for oxidation reaction to achieve efficient removal of sulfadiazine.

[0008] In a preferred embodiment of the present invention, the inorganic components of the hydrolyzed urine include 0.06M NaCl, 0.015M Na2SO4, 0.04M KCl, 0.25M NH4OH, 0.0136M NaH2PO4, and 0.25M NH4HCO3.

[0009] In a preferred embodiment of the present invention, the pH of the hydrolyzed urine is 9.

[0010] In a preferred embodiment of the present invention, the concentration of sulfadiazine is 10-40 μM.

[0011] In a preferred embodiment of the present invention, the dosage of the nano zero-valent iron is 0.3-0.6 g / L.

[0012] In a preferred embodiment of the present invention, the concentration of the periodate oxidant is 1-10 mM.

[0013] In a preferred embodiment of the present invention, the oxidation reaction is carried out at room temperature, with a stirring rate of 500 rpm and a reaction time of 48 hours.

[0014] In the present invention, nanometer zero-valent iron activates periodate to generate high-valent metals and iodine free radicals to remove and hydrolyze sulfadiazine in urine.

[0015] The beneficial effects of the present invention are:

[0016] (1) The present invention uses commercially available nano zero-valent iron as an activator, which has the characteristics of simple operation, low cost, and easy large-scale use;

[0017] (2) The oxidant selected in the present invention is periodate, which has good chemical stability, is relatively safe in storage and transportation, and has certain operational convenience in practical applications;

[0018] (3) This process can effectively remove sulfadiazine from hydrolyzed urine and control antibiotic pollution at the source, which has great application value and promotion prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a diagram showing the effect of nano-zero-valent iron activating PI on the removal of sulfadiazine in urine by hydrolysis in Example 1;

[0020] Figure 2 This is a diagram showing the effect of different amounts of nano zero-valent iron added in Example 2 on the removal of sulfadiazine in hydrolyzed urine;

[0021] Figure 3 This is a diagram showing the effect of different periodate addition amounts on the removal of sulfadiazine in hydrolyzed urine in Example 3;

[0022] Figure 4 This is a diagram showing the effect of different initial concentrations of sulfadiazine on the removal of sulfadiazine in hydrolyzed urine in Example 4;

[0023] Figure 5 This is a diagram showing the experimental effect of the nZVI / PI system column in Example 5. DETAILED DESCRIPTION

[0024] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0025] In the following comparative examples and embodiments, unless otherwise specified, the raw materials and instruments used are commercially available, conventional equipment is used, and the data obtained are the average values ​​of three repeated experiments.

[0026] Embodiment 1:

[0027] A method for removing sulfadiazine in urine by activating periodate with nano-zero-valent iron comprises the following steps:

[0028] First, 50 mg of nZVI was weighed and added to a beaker containing 100 mL of pre-prepared hydrolyzed urine, in which the concentration of sulfadiazine in the hydrolyzed urine was 20 μM. Subsequently, a certain concentration of PI mother solution was added so that the concentration of PI in the reaction system was 5 mM. The magnetic stirrer was started for the degradation reaction, and the reaction time was 48 hours.

[0029] The inorganic components of the hydrolyzed urine include NaCl (0.06M), Na2SO4 (0.015M), KCl (0.04M), NH4OH (0.25M), NaH2PO4 (0.0136M), and NH4HCO3 (0.25M), and the pH of the hydrolyzed urine is 9.

[0030] During the degradation of sulfadiazine, 1 mL of the sample was taken at 0 hours, 0.5 hours, 1 hour, 2 hours, 4 hours, 8 hours, 20 hours, 30 hours, and 48 hours and filtered through a 0.22 μM water filter. Subsequently, 0.5 mL of 100 mM sodium thiosulfate was added to 0.5 mL of the filtrate to completely terminate the oxidation reaction. The concentration of sulfadiazine was detected by high performance liquid chromatography (HPLC).

[0031] Control experiment:

[0032] nZVI group: no oxidant PI was added, and other conditions were the same.

[0033] PI group: no activator nZVI was added, and other conditions were the same.

[0034] Figure 1 The results are shown in Example 1. The removal effect of PI activated by nano-zero-valent iron on the hydrolysis of sulfadiazine in urine. Figure 1 As shown in Figure 2, the removal effect of sulfadiazine by adding nZVI or PI alone was poor, with the removal rates of sulfadiazine being 7.42% and 39.17%, respectively (the pseudo-first-order apparent kinetic constants kapp were 0.0019 h -1 and 0.0113h -1 In contrast, the nZVI / PI oxidation system could rapidly remove sulfadiazine from urine, with a removal rate and kapp of 92.78% and 0.09 h, respectively. -1 , indicating that nZVI and PI have significant synergistic effects.

[0035] Embodiment 2:

[0036] The effect of different catalyst addition amounts on the removal of sulfadiazine was investigated. Specifically, nano-zero-valent iron was used to activate periodate to remove sulfadiazine in hydrolyzed urine, including the following steps:

[0037] 30, 40, 50, and 60 mg of nZVI were weighed and added to 100 mL of hydrolyzed urine with a sulfadiazine concentration of 20 μM. Then, a certain concentration of PI mother solution was added to make the concentration of PI in the reaction system 5 mM. The magnetic stirrer was started for the degradation reaction, and the reaction time was 48 hours.

[0038] The inorganic components of the hydrolyzed urine include NaCl (0.06M), Na2SO4 (0.015M), KCl (0.04M), NH4OH (0.25M), NaH2PO4 (0.0136M), and NH4HCO3 (0.25M), and the pH of the hydrolyzed urine is 9.

[0039] During the degradation of sulfadiazine, 1 mL of the sample was taken at 0 hours, 0.5 hours, 1 hour, 2 hours, 4 hours, 8 hours, 20 hours, 30 hours, and 48 hours and filtered through a 0.22 μM water filter. Subsequently, 0.5 mL of 100 mM sodium thiosulfate was added to 0.5 mL of the filtrate to completely terminate the oxidation reaction. The concentration of sulfadiazine was detected by high performance liquid chromatography (HPLC).

[0040] Figure 2 The results are shown in Figure 2. The effect of different amounts of nano-zero-valent iron added on the removal of sulfadiazine in hydrolyzed urine. Figure 2As shown, when the nZVI concentration increased from 0.3 g / L to 0.6 g / L, the oxidation rate of sulfadiazine was significantly accelerated.

[0041] Embodiment 3:

[0042] The effects of different periodate addition amounts on the removal of sulfadiazine were investigated. Specifically, periodate was activated by nano-zero-valent iron to remove hydrolyzed urine containing sulfadiazine, including the following steps:

[0043] 50 mg of nZVI was weighed and added to 100 mL of hydrolyzed urine with a sulfadiazine concentration of 20 μM. Then, a certain concentration of PI mother solution was added so that the concentration of PI in the reaction system was 1, 2, 5, and 10 mM, respectively. The magnetic stirrer was started for the degradation reaction, and the reaction time was 48 hours.

[0044] The inorganic components of the hydrolyzed urine include NaCl (0.06M), Na2SO4 (0.015M), KCl (0.04M), NH4OH (0.25M), NaH2PO4 (0.0136M), and NH4HCO3 (0.25M), and the pH of the hydrolyzed urine is 9.

[0045] During the degradation of sulfadiazine, 1 mL of the sample was taken at 0 hours, 0.5 hours, 1 hour, 2 hours, 4 hours, 8 hours, 20 hours, 30 hours, and 48 hours and filtered through a 0.22 μM water filter. Subsequently, 0.5 mL of 100 mM sodium thiosulfate was added to 0.5 mL of the filtrate to completely terminate the oxidation reaction. The concentration of sulfadiazine was detected by high performance liquid chromatography (HPLC).

[0046] Figure 3 The results are shown in Figure 3 for the effect of different periodate addition amounts on the removal of sulfadiazine in hydrolyzed urine. Figure 3 As shown in the figure, as the periodate dosage increases from 1 mM to 10 mM, the removal efficiency of sulfadiazine also increases. This is mainly because a larger PI dosage can effectively increase the concentration of active species in the oxidation system.

[0047] Embodiment 4:

[0048] The effect of different sulfadiazine concentrations on the nZVI / PI system was investigated. Specifically, the hydrolyzed urine containing sulfadiazine was removed by activating periodate with nano-zero-valent iron, including the following steps:

[0049] 50 mg of nZVI was weighed and added to 100 mL of hydrolyzed urine with sulfadiazine concentrations of 10, 20, 30, and 40 μM, respectively. Then, a certain concentration of PI mother solution was added so that the concentration of PI in the reaction system was 5 mM. The magnetic stirrer was started for the degradation reaction, and the reaction time was 48 hours.

[0050] The inorganic components of the hydrolyzed urine include NaCl (0.06M), Na2SO4 (0.015M), KCl (0.04M), NH4OH (0.25M), NaH2PO4 (0.0136M), and NH4HCO3 (0.25M), and the pH of the hydrolyzed urine is 9.

[0051] During the degradation of sulfadiazine, 1 mL of the sample was taken at 0 hours, 0.5 hours, 1 hour, 2 hours, 4 hours, 8 hours, 20 hours, 30 hours, and 48 hours and filtered through a 0.22 μM water filter. Subsequently, 0.5 mL of 100 mM sodium thiosulfate was added to 0.5 mL of the filtrate to completely terminate the oxidation reaction. The concentration of sulfadiazine was detected by high performance liquid chromatography (HPLC).

[0052] Figure 4 The results are shown in Table 4. The initial concentrations of different sulfadiazine in Example 4 affect the removal of sulfadiazine in the hydrolyzed urine. Figure 4 As shown, the initial concentration of sulfadiazine significantly affected its oxidation rate. The oxidation rate of high concentration sulfadiazine (40 μM) decreased significantly, which was due to the rapid consumption of active species.

[0053] Embodiment 5:

[0054] The application potential of the nZVI / PI system was investigated by constructing a fixed bed reactor, including the following steps:

[0055] 2g of nZVI and quartz sand were mixed and pre-loaded in the column, and clean quartz sand was placed at both ends of the column to fix the material. Then, the column experiment was carried out at a flow rate of 0.2mL min-1. The initial concentration of sulfadiazine in the hydrolyzed urine was set to 1μM. The removal effect of sulfadiazine was studied by pumping PI (5mM) and sulfadiazine solution (1μM) into a fixed bed reactor at the same time. The concentration of antibiotics in the influent and effluent was analyzed at specific time intervals to calculate the removal efficiency.

[0056] Figure 5 The figure shows the effect of nZVI / PI system on the removal of sulfadiazine in hydrolyzed urine under column experimental conditions. During the first 16 hours of reaction, the removal rate of sulfadiazine reached 100% (outlet concentration / inlet concentration). However, as the reaction proceeded, sulfadiazine gradually accumulated on the surface of nZVI, the ability of nZVI to activate PI weakened, and the outlet concentration of sulfadiazine gradually increased. After 40 hours, the column was completely inactivated. The results of the column experiment clearly revealed that the nZVI-activated PI system has certain application potential in eliminating antibiotics in hydrolyzed urine.

[0057] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0058] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for removing sulfadiazine from urine by activating periodate with nano-zero-valent iron, characterized in that: The following steps are involved: First, hydrolyzed urine containing sulfadiazine is prepared, then a quantitative amount of nano zero-valent iron is added, and finally periodate is added for oxidation reaction to achieve efficient removal of sulfadiazine.

2. The method for removing sulfadiazine in urine by activating periodate with nano-zero-valent iron according to claim 1, characterized in that: The inorganic components of the hydrolyzed urine include 0.06M NaCl, 0.015M Na2SO4, 0.04M KCl, 0.25M NH4OH, 0.0136M NaH2PO4, and 0.25M NH4HCO3.

3. The method for removing sulfadiazine in urine by activating periodate with nano-zero-valent iron according to claim 1, characterized in that: The pH of the hydrolyzed urine is 9.

4. The method for removing sulfadiazine in urine by activating periodate with nano-zero-valent iron according to claim 1, characterized in that: The concentration of the sulfadiazine is 10-40 μM.

5. The method for removing sulfadiazine in urine by activating periodate with nano-zero-valent iron according to claim 1, characterized in that: The dosage of the nano zero-valent iron is 0.3-0.6 g / L.

6. The method for removing sulfadiazine in urine by activating periodate with nano-zero-valent iron according to claim 1, characterized in that: The periodate oxidant concentration is 1-10 mM.

7. The method for removing sulfadiazine in urine by activating periodate with nano-zero-valent iron according to claim 1, characterized in that: The oxidation reaction was carried out at room temperature, with a stirring rate of 500 rpm and a reaction time of 48 hours.

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