Co-removal method for phenol and norfloxacin

Abstract

The invention belongs to the technical field of water treatment, and particularly discloses a phenol and norfloxacin co-removal method. The method comprises the following steps: mixing a water body containing phenol and norfloxacin with horse radish peroxidase to obtain a mixed solution; then hydrogen peroxide is added to activate horse radish peroxidase for reaction, and co-removal of phenol and norfloxacin in the water body is achieved. Horseradish peroxidase is activated through hydrogen peroxide, then phenol is catalyzed by the catalytic action of the horseradish peroxidase to form polymer precipitates, and norfloxacin in water is further removed through adsorption or nucleophilic addition reaction of the generated polymer and norfloxacin. Therefore, the phenol and the norfloxacin in the water body are efficiently removed.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and particularly to a method for co-removing phenol and norfloxacin. Background Art

[0002] The harm of antibiotic pollution to human health and the ecological environment has attracted wide attention. How to efficiently and greenly remove antibiotics in the environment has become an urgent problem to be solved.

[0003] As a typical fluoroquinolone antibiotic, norfloxacin (NOR) is widely used in the treatment of infections. It has stable properties, is difficult to be degraded and transformed in the natural environment, and has poor biodegradability, which makes it have a long persistence in the environment. At present, NOR residues have been detected in various water bodies, posing potential risks to water bodies and ecosystems.

[0004] Phenol is a toxic chemical widely used in industry and laboratories, with strong toxicity. It can cause poisoning to aquatic animals and endanger human health and the safety of the ecological environment through the food chain.

[0005] Some pharmaceutical wastewater or hospital wastewater contains both phenol and norfloxacin. The concentration of phenol in common pharmaceutical wastewater is generally 0.6 - 2 mmol / L, and the concentration of norfloxacin is 0.003 - 0.03 mg / L; the concentration of phenol in hospital wastewater is generally 0.01 - 0.05 mmol / L, and the concentration of norfloxacin is 0.001 - 0.05 mmol / L. The conventional treatment method is to first use physicochemical methods to remove phenol, and then use physicochemical or biological methods to remove norfloxacin. The process is relatively cumbersome and costly.

[0006] At present, there are few treatment methods for the co-removal of norfloxacin and phenol in water bodies. Therefore, developing an efficient and green treatment technology to simultaneously eliminate the pollution of water bodies containing both phenol and norfloxacin has become an urgent scientific problem to be solved. Summary of the Invention

[0007] In view of this, the present invention provides a method for co-removing phenol and norfloxacin to solve the problem that there are few reports on the method for co-removing norfloxacin and phenol by existing methods.

[0008] To achieve the above object, the present invention adopts the following technical scheme:

[0009] A method for co-removing phenol and norfloxacin, comprising the following steps:

[0010] Mix a water body containing phenol and norfloxacin with horseradish peroxidase to obtain a mixed solution; then add hydrogen peroxide to activate horseradish peroxidase and carry out a reaction to achieve the co-removal of phenol and norfloxacin in the water body.

[0011] Preferably, the pH value of the water body containing phenol and norfloxacin is 7-8.

[0012] Preferably, the molar concentration of phenol in the mixed solution is 0.01-2 mmol / L, the molar concentration of norfloxacin is 0.001-0.05 mmol / L, and the concentration of horseradish peroxidase is 0.5-8 U / mL.

[0013] Preferably, the molar ratio of phenol to norfloxacin in the mixed solution is 10-666:1;

[0014] The dosage ratio of phenol to horseradish peroxidase in the mixed solution is 0.0125-1 mmol / L:1 U / mL.

[0015] Preferably, in the reaction system during the reaction, the dosage ratio of hydrogen peroxide to horseradish peroxidase is 0.25-4 mmol / L:1 U / mL.

[0016] Preferably, the temperature of the reaction is 20-30 °C, and the reaction time ≥ 120 min.

[0017] Preferably, the reaction is carried out under shaking conditions, and the shaking frequency ≥ 150 rpm.

[0018] As can be seen from the above technical solutions, compared with the prior art, the present invention has the following beneficial effects:

[0019] In the present invention, horseradish peroxidase is activated by hydrogen peroxide, and then the catalytic action of horseradish peroxidase is used to catalyze phenol to form a polymer precipitate. The generated polymer further removes norfloxacin in the water by adsorption or nucleophilic addition reaction with norfloxacin, thereby realizing the efficient removal of phenol and norfloxacin in the water body; the present invention uses the polymer formed by enzyme-catalyzed phenol to remove phenol. Since the polymer formed by catalyzing phenol contains phenolic hydroxyl groups, norfloxacin can be further removed by catalytic or adsorption action. Experimental results show that the method provided by this application can remove 99% of phenol and 78% of norfloxacin in the water body, and has a remarkable treatment effect. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0021] Figure 1It is the degradation kinetic diagram of norfloxacin at different concentrations in Example 1 of the present invention (time - time);

[0022] Figure 2 It is the degradation kinetic diagram of phenol under different concentrations of norfloxacin in Example 1 of the present invention (time - time);

[0023] Figure 3 It is the degradation kinetic diagram of norfloxacin under different concentrations of phenol in Example 2 of the present invention (time - time);

[0024] Figure 4 It is the degradation kinetic diagram of phenol at different concentrations in Example 2 of the present invention (time - time);

[0025] Figure 5 It is the degradation kinetic diagram of norfloxacin in different water bodies of the present invention (time - time);

[0026] Figure 6 It is the degradation kinetic diagram of phenol in different water bodies of the present invention (time - time). Detailed implementation manners

[0027] The present invention provides a method for co - removing phenol and norfloxacin, which includes the following steps:

[0028] Mix the water body containing phenol and norfloxacin with horseradish peroxidase to obtain a mixed solution; then add hydrogen peroxide to activate horseradish peroxidase for reaction to achieve the co - removal of phenol and norfloxacin in the water body.

[0029] In the present invention, the pH value of the water body containing phenol and norfloxacin is 7 - 8, specifically it can be 7.2, 7.4, 7.5, 7.6, 7.8.

[0030] In the present invention, the molar concentration of phenol in the mixed solution is 0.01 - 2 mmol / L, specifically it can be 0.05 mmol / L, 0.1 mmol / L, 0.2 mmol / L, 0.4 mmol / L, 0.5 mmol / L, 0.6 mmol / L, 0.8 mmol / L, 1 mmol / L, 1.2 mmol / L, 1.5 mmol / L, 1.8 mmol / L; the molar concentration of norfloxacin is 0.001 - 0.05 mmol / L, specifically it can be 0.005 mmol / L, 0.01 mmol / L, 0.02 mmol / L, 0.03 mmol / L, 0.04 mmol / L; the concentration of horseradish peroxidase is 0.5 - 8 U / mL, specifically it can be 1 U / mL, 2 U / mL, 3 U / mL, 4 U / mL, 5 U / mL, 6 U / mL, 7 U / mL.

[0031] In the present invention, the molar ratio of phenol to norfloxacin in the mixed solution is 10 - 666:1, preferably 50 - 600:1, more preferably 80 - 500:1, still more preferably 100 - 400:1, and most preferably 200:1.

[0032] In the present invention, the dosage ratio of phenol to horseradish peroxidase in the mixed solution is 0.0125 - 1 mmol / L:1 U / mL, preferably 0.05 - 0.8 mmol / L:1 U / mL, more preferably 0.1 - 0.6 mmol / L:1 U / mL, and still more preferably 0.25 mmol / L:1 U / mL.

[0033] In the present invention, when the ratio parameter of phenol to norfloxacin is lower than the lower limit of the present invention, the problem that norfloxacin cannot be removed will occur; only within the range defined by the present invention can the ideal efficiency of co-removing phenol and norfloxacin be achieved simultaneously. When the ratio parameter of phenol to horseradish peroxidase is higher than the upper limit of the present invention, the enzyme activity is insufficient to catalyze the oxidation and removal of phenol, resulting in the problem of insufficient reaction and removal of phenol, and further resulting in the problem of low removal rate of norfloxacin; only within the range defined by the present invention can the ideal efficiency of co-removing phenol and norfloxacin be achieved simultaneously.

[0034] In the present invention, in the reaction system during the reaction, the dosage ratio of hydrogen peroxide to horseradish peroxidase is 0.25 - 4 mmol / L:1 U / mL, preferably 0.5 - 3 mmol / L:1 U / mL, more preferably 1 - 2 mmol / L:1 U / mL, and still more preferably 1 mmol / L:1 U / mL.

[0035] In the present invention, when the ratio parameter of hydrogen peroxide to horseradish peroxidase is lower than the lower limit of the present invention, the concentration of hydrogen peroxide is too low to fully activate the activity of horseradish peroxidase, resulting in insufficient enzyme activity to catalyze the oxidation and removal of phenol, resulting in the problem of insufficient reaction and removal of phenol, and further resulting in the problem of low removal rate of norfloxacin; when the ratio parameter is higher than the upper limit of the present invention, the concentration of hydrogen peroxide is too high to inhibit the enzyme activity and thus the enzyme activity is too low; only within the range defined by the present invention can the ideal efficiency of co-removing phenol and norfloxacin be achieved simultaneously.

[0036] In the present invention, the temperature of the reaction is 20 - 30 °C, specifically it can be 22 °C, 24 °C, 25 °C, 26 °C, 28 °C; the reaction time is ≥120 min, specifically it can be 130 min, 135 min, 140 min, 145 min, 150 min.

[0037] In the present invention, the reaction is carried out under shaking conditions, and the shaking frequency is ≥ 150 rpm, specifically it can be 155 rpm, 160 rpm, 165 rpm, 170 rpm.

[0038] In the present invention, the reaction can also be carried out under stirring conditions.

[0039] In the present invention, it is preferred to add hydrochloric acid to terminate the enzyme reaction at the end of the reaction. The role of hydrochloric acid is to inactivate horseradish peroxidase and prevent further reaction of the enzyme.

[0040] In the present invention, after the reaction is completed, it is preferred to separate phenol and norfloxacin from the water body by solid-liquid separation to achieve the purification treatment of the water body.

[0041] In the present invention, the solid-liquid separation method includes filtration, and the filtration preferably uses a filter membrane with a pore size of 0.22 μm.

[0042] The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0043] Example 1

[0044] Dissolve norfloxacin powder in ultrapure water to prepare a 100 mg / L norfloxacin original stock solution for standby; transfer the phenol solution to ultrapure water to prepare a 25 mmol / L phenol original stock solution for standby; take NaCl, KCl, Na 2 HPO 4 and KH 2 PO 4 Dissolve them in ultrapure water to prepare a PBS buffer solution (the purpose of adding the buffer solution is to prepare a simulated polluted water body to simulate the influence of ions that may exist in the sewage on the scheme); then mix the norfloxacin original stock solution, the phenol original stock solution, the PBS buffer solution and water to obtain a simulated polluted water body (the molar concentration of phenol is 0.5 mmol / L, the mass concentration of norfloxacin is 1, 2, 4, 8, 16 mg / L, and the total molar concentration of the PBS buffer solution is 0.01 mol / L). Adjust the pH of the simulated polluted water body to 7 with 0.1 mol / L HCl and NaOH for standby.

[0045] In a serum bottle, dissolve horseradish peroxidase powder in simulated polluted water (the concentration of horseradish peroxidase is 2 U / mL), then add a hydrogen peroxide solution with a molar concentration of 20 mmol / L for activation (the concentration of hydrogen peroxide after mixing is 2 mmol / L). Place the serum bottle on a constant temperature shaker and shake. After the shaking ends, add hydrochloric acid to terminate the enzyme reaction. Filter and sample through a 0.22 μm filter membrane, and use an ultra-high pressure liquid chromatograph to measure the remaining contents of norfloxacin and phenol.

[0046] In the above process, the temperature of the shaking is 25 °C, the shaking frequency is 150 rpm, and the time is 120 min.

[0047] The degradation kinetic diagrams of norfloxacin at different concentrations are as Figure 1 shown, and the degradation kinetic diagrams of phenol under different concentrations of norfloxacin are as Figure 2 shown. Through Figure 1 and 2 it can be obtained that in the experiment of simulating actual water bodies using PBS buffer solution, when the enzyme and phenol concentrations are constant, the lower the concentration of norfloxacin (NOR), the higher the degradation rate of NOR, and the highest is 77%; the concentration of NOR has no effect on the removal rate of phenol, and the removal rate of phenol is close to 99% in all cases.

[0048] Example 2

[0049] Adjust the mass concentration of norfloxacin in Example 1 to 1 mg / L, and change the molar concentration of phenol to 0.1, 0.5, 1, 2 mmol / L. The degradation kinetic diagrams of norfloxacin under different concentrations of phenol are as Figure 3 shown, and the degradation kinetic diagrams of phenol at different concentrations are as Figure 4 shown. Through Figure 3 and Figure 4 it can be seen that when the enzyme and norfloxacin concentrations are constant, as the concentration of phenol increases, the removal rate of phenol gradually decreases; the effect of the phenol concentration between 0.1 mmol / L and 2 mmol / L on the removal rate of NOR is that the removal rate of NOR first increases and then decreases, and when the phenol concentration is 0.5 mmol / L, the removal rate of NOR is the largest, which is 78%.

[0050] Example 3

[0051] Dissolve norfloxacin powder in ultrapure water to prepare a 100 mg / L norfloxacin original stock solution for standby; transfer the phenol solution to ultrapure water to prepare a 25 mmol / L phenol original stock solution for standby; different from Example 1, the solution in the reaction body is the actual river water taken from the river; then mix the norfloxacin original stock solution, the phenol original stock solution, and the actual river water to obtain the simulated pollutants in the actual water body (the molar concentration of phenol is 0.5 mmol / L, and the mass concentration of norfloxacin is 1 mg / L). Adjust the pH of the simulated polluted water body to 7 with 0.1 mol / L HCl and NaOH for standby.

[0052] In a serum bottle, dissolve horseradish peroxidase powder in the simulated polluted water body (the concentration of horseradish peroxidase is 2 U / mL), then add a hydrogen peroxide solution with a molar concentration of 20 mmol / L for activation (the concentration of hydrogen peroxide after mixing is 2 mmol / L), place the serum bottle on a constant temperature shaker and shake, after the shaking is completed, filter and sample through a 0.22 μm filter membrane, and use an ultra-high pressure liquid chromatograph to measure the remaining contents of norfloxacin and phenol.

[0053] In the above process, the temperature of the shaking is 25 °C, the shaking frequency is 150 rpm, and the time is 120 min.

[0054] The horseradish peroxidase in the present invention is rich in sources and abundant in plants; the horseradish peroxidase provided by the present invention can achieve the highest removal of 99% of phenol and 96% of norfloxacin in the water body.

[0055] Example 4

[0056] The difference between this example and Example 3 is only that lake water is used to replace river water.

[0057] The horseradish peroxidase in the present invention is rich in sources and abundant in plants; the horseradish peroxidase provided by the present invention can achieve the highest removal of 99% of phenol and 96% of norfloxacin in the water body.

[0058] The degradation kinetic diagram of norfloxacin under different water bodies is as Figure 5 shown, and the degradation kinetic diagram of phenol under different water bodies is as Figure 6 shown. Among them, Figure 5 and Figure 6 in, for the scheme with a molar concentration of phenol of 0.5 mmol / L and a mass concentration of norfloxacin of 1 mg / L in Example 1, it is denoted as PBS, Example 3 is denoted as river water, Example 4 is denoted as lake water, and ultrapure water is used to replace the river water in Example 3, denoted as ultrapure water. Through Figure 5 and Figure 6It can be seen that the removal rates of phenol and norfloxacin in this experiment are higher in actual river water and lake water than in ultrapure water and PBS-simulated actual water bodies, indicating that the complexity of the actual water body is more conducive to the progress of this experiment.

[0059] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other.

[0060] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for removing phenol and norfloxacin together, characterized in that: The steps include: The water containing phenol and norfloxacin is mixed with horseradish peroxidase to obtain a mixed solution; then hydrogen peroxide is added to activate the horseradish peroxidase to react, thereby achieving the co-removal of phenol and norfloxacin in the water.

2. A method for removing phenol and norfloxacin together according to claim 1, characterized in that: The pH value of the water containing phenol and norfloxacin is 7-8.

3. A method for removing phenol and norfloxacin together according to claim 2, characterized in that: The molar concentration of phenol in the mixed solution is 0.01-2 mmol / L, the molar concentration of norfloxacin is 0.001-0.05 mmol / L, and the concentration of horseradish peroxidase is 0.5-8 U / mL.

4. A method for removing phenol and norfloxacin together according to claim 3, characterized in that: The molar ratio of phenol to norfloxacin in the mixed solution is 10-666:1; The dosage ratio of phenol to horseradish peroxidase in the mixed solution is 0.0125-1 mmol / L: 1 U / mL.

5. A method for removing phenol and norfloxacin according to any one of claims 1 to 4, characterized in that: In the reaction system during the reaction, the dosage ratio of hydrogen peroxide to horseradish peroxidase is 0.25-4 mmol / L:1 U / mL.

6. A method for removing phenol and norfloxacin together according to claim 5, characterized in that: The reaction temperature is 20-30° C., and the reaction time is ≥120 min.

7. A method for removing phenol and norfloxacin together according to claim 6, characterized in that: The reaction is carried out under shaking conditions, and the shaking frequency is ≥150 rpm.

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