CN107321355B - Preparation method and application of tetracycline polluted water body remediation material - Google Patents

Abstract

The invention discloses a preparation method and application of a tetracycline polluted water body remediation material. A preparation method of nano cerium dioxide comprises the following steps: 1) adding cerium nitrate and a surfactant into water, and mixing and stirring to obtain a mixed solution A; 2) adding the ammonium carbonate solution into the mixed solution A, and stirring to obtain a mixed solution B; 3) and filtering the mixed solution B, washing and drying the obtained precipitate, calcining, and grinding into powder to obtain the nano cerium dioxide. Also discloses the preparation of a nano Fe by using the nano cerium dioxide⁰@CeO₂The method of (1). And a method of using the same⁰@CeO₂The method is applied to the remediation method of tetracycline polluted water. The invention provides a method for preparing Fe⁰@CeO₂Heterogeneous Fenton technology as catalyst to prepare Fe⁰@CeO₂The method is used for repairing tetracycline pollution in water, improves the reaction activity and the mineralization degree of tetracycline, and reduces the risk of secondary pollution.

Description

Preparation method and application of tetracycline polluted water body remediation material

Technical Field

The invention relates to a preparation method and application of a tetracycline polluted water body remediation material.

Background

Drugs and personal care products (PPCPs) now constitute a new class of world pollutants and have attracted considerable attention in recent years, including various antibiotics, synthetic musk, analgesics, hypotensives, contraceptives, hypnotics, weight loss drugs, hair sprays, hair dyes, and antiseptics. Tetracycline antibiotics are a broad spectrum antibiotic that are widely used throughout the world in human and veterinary health, aquaculture, as a feed for growth promoters and to inhibit fungal growth in fruit trees.

The traditional tetracycline removal method mainly comprises physical adsorption and photodegradation, but the physical adsorption can not completely degrade pollutants, other methods are further selected to realize complete mineralization, and the photodegradation is limited by factors such as light scattering and absorption, so that the removal efficiency is low. Recently, advanced oxidation techniques (AOPs) have become one of the most popular techniques for degrading antibacterial substances. In a broad sense, advanced oxidation technology refers to a set of chemical treatment procedures that degrade water and contaminants present in wastewater by oxidation. Heterogeneous Fenton technology is the lowest cost and the best effect technology in advanced oxidation technology, and can be well applied to tetracycline removal due to the characteristics of fast generation of hydroxyl free radicals and the like. Although these studies have achieved good results in heterogeneous fenton degradation of tetracycline, some problems remain. For example, the nano zero-valent iron is easy to agglomerate, and the reduction degradation efficiency of the nano zero-valent iron is reduced to a certain extent. Research finds that the reaction activity can be further improved and the agglomeration problem of the nano particles can be solved to a certain extent by loading another noble metal, such as Cu, Pd, Ni, Pt, Ce and the like, on the surface of the nano zero-valent iron.

Disclosure of Invention

The invention aims to provide a preparation method and application of a tetracycline polluted water body remediation material.

The technical scheme adopted by the invention is as follows:

a preparation method of nano cerium dioxide comprises the following steps:

1) adding cerium nitrate and a surfactant into water, and mixing and stirring to obtain a mixed solution A;

2) adding the ammonium carbonate solution into the mixed solution A, and stirring to obtain a mixed solution B;

3) and filtering the mixed solution B, washing and drying the obtained precipitate, calcining, and grinding into powder to obtain the nano cerium dioxide.

In the step 1) of the preparation method of the nano cerium dioxide, the mass ratio of the cerium nitrate, the surfactant and the water is (30-50): (3-5): 1000.

in the step 2) of the preparation method of the nano cerium dioxide, the molar concentration of the ammonium carbonate solution is 0.05-0.2 mol/L.

In step 3), the calcining conditions are as follows: the heating rate is 15-25 ℃/min, the calcining temperature is 500-800 ℃, and the calcining time is 3-5 h.

In the preparation method of the nano cerium dioxide, the surfactant is polyethylene glycol or polyvinyl alcohol.

Nano Fe⁰@CeO₂The preparation method comprises the following steps:

1) adding nano cerium dioxide, ferric salt and a dispersing agent into an ethanol water solution, and stirring and mixing to obtain a solution a;

2) adding an ethanol water solution b containing a reducing agent into the solution a, stirring for reaction, washing, drying and grinding the separated product in sequence to obtain the nano Fe⁰@CeO₂；

Wherein, the nano cerium dioxide is prepared according to the method.

Nano Fe⁰@CeO₂In the step 1), the mass ratio of the iron salt, the nano cerium dioxide, the dispersing agent, the ethanol and the water is (3-10): (1-2): 1: (30-120): (90-360).

Nano Fe⁰@CeO₂In the solution b in the step 2), the mass ratio of the reducing agent, ethanol and water is 1: (10-30): (30-90).

Nano Fe⁰@CeO₂In the preparation method, the iron salt is ferrous sulfate, the dispersing agent is polyvinylpyrrolidone, and the reducing agent is a metal hydride reducing agent.

A method for restoring tetracycline polluted water body is to use nano Fe⁰@CeO₂Adding into tetracycline polluted water, adding hydrogen peroxide, mixing, and repairing; the nano Fe⁰@CeO₂Prepared according to the method described above.

The invention has the beneficial effects that:

the invention provides a method for preparing Fe⁰@CeO₂Heterogeneous Fenton technology as catalyst to prepare Fe⁰@CeO₂The method is used for repairing tetracycline pollution in water, improves the reaction activity and the mineralization degree of tetracycline, and reduces the risk of secondary pollution.

The method comprises the following specific steps:

(1) nano Fe of the invention⁰@CeO₂The granule can be usedThe tetracycline in the water body is removed, so that the removal efficiency is effectively improved;

(2) the nano Fe prepared by the method of the invention⁰@CeO₂Particle reduction of nano-Fe⁰The agglomeration of the particles can quickly and efficiently catalyze and degrade the tetracycline in the solution, no toxic substances are separated out, and no secondary pollution is generated;

(3) the method has the advantages of short restoration time, simple restoration method and convenient operation, and only needs to directly add the nano Fe into the polluted water body⁰@CeO₂The particles and the hydrogen peroxide are fully mixed in a selected time, other complicated devices and processes are not needed, and the method is easy to popularize and use.

Drawings

FIG. 1 is Fe prepared according to the present invention⁰@CeO₂SEM images of solid particles;

FIG. 2 shows Fe prepared according to the present invention⁰@CeO₂TEM images of solid particles;

FIG. 3 shows different Fe⁰@CeO₂With Fe⁰The adding amount of the tetracycline is a heterogeneous Fenton removal efficiency graph of the tetracycline in the water body under the same adding amount of the hydrogen peroxide;

FIG. 4 shows the same Fe⁰@CeO₂With Fe⁰The adding amount of the tetracycline is shown in a heterogeneous Fenton removal efficiency graph of the tetracycline in the water body under different adding amounts of hydrogen peroxide;

FIG. 5 is the same Fe⁰@CeO₂With Fe⁰The adding amount of the tetracycline is equal to the adding amount of the hydrogen peroxide, and the heterogeneous Fenton removal efficiency graph of the tetracycline in the water body is obtained under different initial pH values;

FIG. 6 is a graph of the efficiency of various reaction systems for the removal of tetracycline from a body of water.

Detailed Description

A preparation method of nano cerium dioxide comprises the following steps:

1) adding cerium nitrate and a surfactant into water, and mixing and stirring to obtain a mixed solution A;

2) adding the ammonium carbonate solution into the mixed solution A, and stirring to obtain a mixed solution B;

3) and filtering the mixed solution B, washing and drying the obtained precipitate, calcining, and grinding into powder to obtain the nano cerium dioxide.

Further, the preparation method of the nano cerium dioxide comprises the following step 3): and filtering and separating the mixed solution B to obtain a white colloid, washing the white colloid with ultrapure water and ethanol for 3 times to obtain a white colloid A, drying the white colloid A to obtain a precipitate, calcining the precipitate in a muffle furnace, and grinding the precipitate into powder to obtain the nano cerium dioxide.

Preferably, in the step 1) of the preparation method of nano-ceria, the mass ratio of cerium nitrate, the surfactant and water is (30-50): (3-5): 1000.

preferably, in the step 2) of the preparation method of nano-ceria, the molar concentration of the ammonium carbonate solution is 0.05-0.2 mol/L.

Preferably, in the step 3) of the preparation method of nano-cerium dioxide, the drying temperature is 80-100 ℃ and the drying time is 8-12 h.

Preferably, in step 3), the calcination conditions are as follows: the heating rate is 15-25 ℃/min, the calcining temperature is 500-800 ℃, and the calcining time is 3-5 h; further preferably, in step 3), the calcination conditions are as follows: the heating rate is 20 ℃/min, the calcining temperature is 500 ℃, and the calcining time is 4 h.

Preferably, in the preparation method of nano-cerium dioxide, the surfactant is polyethylene glycol (PEG) or polyvinyl alcohol (PVA); further preferably, the surfactant is polyethylene glycol.

Nano Fe⁰@CeO₂The preparation method comprises the following steps:

1) adding nano cerium dioxide, ferric salt and a dispersing agent into an ethanol water solution, and stirring and mixing to obtain a solution a;

2) adding an ethanol water solution b containing a reducing agent into the solution a, stirring for reaction, washing, drying and grinding the separated product in sequence to obtain the nano Fe⁰@CeO₂；

Wherein, the nano cerium dioxide is prepared according to the method.

Preferably, in the nanometer rangeFe⁰@CeO₂In the step 1), the mass ratio of the iron salt, the nano cerium dioxide, the dispersing agent, the ethanol and the water is (3-10): (1-2): 1: (30-120): (90-360).

Preferably, nano Fe⁰@CeO₂In the solution b in the step 2), the mass ratio of the reducing agent, ethanol and water is 1: (10-30): (30-90).

Preferably, nano Fe⁰@CeO₂In the preparation method, the ferric salt is ferrous sulfate, the dispersing agent is polyvinylpyrrolidone, and the reducing agent is a metal hydride reducing agent; the reducing agent is further preferably an alkali metal hydride reducing agent; still more preferably, the reducing agent is one of potassium borohydride, sodium borohydride and lithium borohydride.

A method for restoring tetracycline polluted water body is to use nano Fe⁰@CeO₂Adding into tetracycline polluted water, adding hydrogen peroxide, mixing, and repairing; the nano Fe⁰@CeO₂Prepared according to the method described above.

Preferably, in the repair method, tetracycline and nano Fe⁰@CeO₂And H₂O₂The mass ratio of (A) to (B) is 10: (1-20): (68-544).

The present invention will be described in further detail with reference to specific examples.

Preparation example:

a preparation method of nano cerium dioxide particles comprises the following steps:

(1) adding 0.1mol/L cerous nitrate hexahydrate and 4g/L PEG 4000 into 100ml of ultrapure water, and stirring and mixing;

(2) 150ml of 0.1mol/L (NH)₄)₂CO₃Adding the aqueous solution into the solution in the step (1), stirring for 15min at 45 ℃, filtering and washing for several times to obtain white colloidal cerium carbonate;

(3) drying the white colloid in a drying oven at 80 deg.C for 8 h;

(4) and (3) putting the dried white colloid into a muffle furnace, heating to 500 ℃ at the speed of 20 ℃/min, roasting for 4h, taking out the yellow solid after the temperature of the muffle furnace is reduced to room temperature, and grinding into powder to obtain the nano cerium dioxide.

Nano Fe⁰@CeO₂The preparation method of the particles comprises the following steps:

(1) 0.023mol/L of the prepared nano-cerium dioxide, 0.05mol/L of ferrous sulfate hexahydrate and 4g/LPVP are added into 100ml of 30% v/v ethanol water solution; obtaining a solution A;

(2) preparing 50ml of 0.3mol/L sodium borohydride solution by using 30% v/v ethanol water solution, dropwise adding the solution into the solution A under the condition of stirring in a protective atmosphere (nitrogen), continuously stirring at the speed of 400rpm for reaction for 15min, separating by using a magnetic separation method, washing, drying in vacuum at the temperature of 65 ℃ for 12h, and grinding into powder to obtain Fe⁰@CeO₂Solid particles.

FIGS. 1 and 2 are Fe prepared according to the present invention⁰@CeO₂SEM and TEM images of solid particles. From FIGS. 1 and 2, nano Fe can be observed⁰Attached to CeO₂The above.

Application example:

fe obtained in preparation example⁰@CeO₂The solid particles and hydrogen peroxide are added into the tetracycline polluted water body, and the initial concentration of the tetracycline is 100 mg/L. Wherein the repairing material Fe⁰@CeO₂The adding amount of the (B) is 0.01 g/L-0.2 g/L; the adding amount of the hydrogen peroxide is 20mmol/L-160 mmol/L.

Following is Fe prepared according to the invention⁰@CeO₂The repairing material is further tested for effect.

Experiment for removing tetracycline in water body

Preparation of tetracycline solution:

the tetracycline standard stock solution (100mg/L) is prepared by adopting ultrapure water, and is refrigerated and stored in a dark place.

1. Influence of different catalytic material adding amounts on heterogeneous Fenton removal of tetracycline in water body

Adding 50mL of tetracycline solution with initial pH of 5.8 into 150mL of conical flask with plug, respectively adding 0.01g/L, 0.03g/L, 0.05g/L, 0.1g/L and 0.2g/L of catalytic material, adding 100mmol/L of hydrogen peroxide, covering on a constant temperature oscillator (26 ℃), and oscillating at a speed of 100mmol/LThe degree is 250r/min, and the light is avoided. At a preselected time period, 1ml of the solution was passed through a 0.22 μ M microfiltration membrane and 2 drops of t-butanol were added dropwise, tetracycline concentration was analyzed by HPLC, UV-visible detector wavelength was 360nm, mobile phase was 0.1M oxalic acid: b, nitrile: methanol 45:35:20, flow rate 1.0mL/min, sample size 20 uL. The detection results are shown in FIG. 3, and it can be seen from FIG. 3 that Fe⁰@CeO₂When the adding amount is 0.01g/L and 0.03g/L, the reaction is carried out for 60min, the tetracycline removal rate is respectively 42.32 percent and 66.92 percent, when the adding amount is increased to 0.05g/L, the tetracycline removal rate is increased to 87.95 percent, and when the adding amount is Fe⁰@CeO₂When the adding amount is 0.1g/L, the removal rate of the tetracycline is about 90.24 percent; and nano Fe⁰When the addition amount was 0.01g/L, 0.03g/L, 0.05g/L, the reaction was carried out for 60min, the tetracycline removal rates were 33.35%, 36.58%, 47.47%, respectively, and when the addition amount was increased to 0.1g/L, the tetracycline removal rate was increased to 74.16%.

From the results, when Fe⁰@CeO₂When the adding amount is increased from 0.05g/L to 0.1g/L, the tetracycline removal rate is increased by 2.29 percent, which indicates that when the adding amount is 0.05g/L, the degradation is basically balanced; fe⁰When the dosage is increased from 0.1g/L to 0.2g/L, the tetracycline removal rate is increased by 9.94 percent along with the Fe⁰The degradation rate can be gradually enhanced by increasing the adding amount. However, in subsequent experiments, in order to verify the advantages of the composite material, 0.1g/L was selected as the addition amount of the catalyst to be studied subsequently.

2. Influence of different hydrogen peroxide addition amounts on heterogeneous Fenton removal of tetracycline in water body

50mL of tetracycline solution with the initial pH of 5.8 is added into a 150mL conical flask with a plug, 0.1g of catalytic material is added, then 20mmol/L, 40mmol/L, 60mmol/L, 80mmol/L, 100mmol/L, 120mmol/L, 140mmol/L and 160mmol/L of hydrogen peroxide are respectively added, the flask is covered on a constant temperature oscillator (26 ℃), the oscillation speed is 250r/min, and the flask is protected from light. At a preselected time period, 1ml of the solution was passed through a 0.22 μ M microfiltration membrane and 2 drops of t-butanol were added dropwise, tetracycline concentration was analyzed by HPLC, UV-visible detector wavelength was 360nm, mobile phase was 0.1M oxalic acid: b, nitrile: methanol 45:35:20, flow rate 1.0mL/min, sample size 20 uL. Detection ofThe measurement results are shown in FIG. 4. As can be seen from FIG. 4, Fe⁰@CeO₂Under the system, when the dosage of the hydrogen peroxide is 100mmol/L, the reaction is carried out for 60min, the removal rate of the tetracycline is 91.42 percent, when the dosage is increased to 120mmol/L, the removal rate of the tetracycline is reduced to 89.25 percent, which indicates that the dosage of the hydrogen peroxide of 100mmol/L is Fe⁰@CeO₂The optimal adding amount is under the system; and nano Fe⁰When the adding amount of hydrogen peroxide in the system is 60mmol/L, the reaction is carried out for 60min, the removal rate of the tetracycline is 69.60%, when the adding amount is increased to 100mmol/L, the removal rate of the tetracycline is reduced to 65.16%, and the difference is less than 5%. In subsequent experiments, to compare Fe⁰@CeO₂Material and nano Fe⁰The material is selected to be 100mmol/L as the adding amount of hydrogen peroxide for subsequent research.

3. Influence of different initial pH values on tetracycline removal from water body

The initial pH of the various solutions was adjusted by dropwise addition of 0.1M HCl or NaOH. Adding 50mL of tetracycline solution into a 150mL conical flask with a plug, adding 0.1g of catalytic material, adding 100mmol/L hydrogen peroxide, covering on a constant temperature oscillator (26 ℃), and keeping out of the sun at an oscillation speed of 250 r/min. At a preselected time period, 1ml of the solution was passed through a 0.22 μ M microfiltration membrane and 2 drops of t-butanol were added dropwise, tetracycline concentration was analyzed by HPLC, UV-visible detector wavelength was 360nm, mobile phase was 0.1M oxalic acid: b, nitrile: methanol 45:35:20, flow rate 1.0mL/min, sample size 20 uL. The results are shown in FIG. 5. As can be seen from FIG. 5, when the initial pH of the solution was 5.8, at Fe⁰@CeO₂The tetracycline removal rate under the system reaches 92.41 percent, and the rate is higher than that of nano Fe⁰The removal rate of tetracycline under the system reaches 70.75 percent; at pH 3, at Fe⁰@CeO₂The tetracycline removal rate under the system is increased to 95.31 percent, but the rate is increased to Fe⁰@CeO₂The tetracycline removal rate under the system increased to 93.36%. This may be due to the fact that as the pH is lowered, the dissolution of the nano-iron is accelerated, resulting in an increase in ferrous ions that can provide catalysis. The results show that the composite repair material has a wider effective pH range. However, when the pH of the solution is increased to 7, the tetracycline removal rates under two conditions are 65.32% and 66.30%, respectively, which have certain limitsThe magnitude of the drop. When the pH was raised to 9, the degradation rates of the two systems were 83.31% and 88.76%, respectively, which may be due primarily to Fe²⁺And Fe³⁺Forming colloid under alkaline condition, and performing coagulation adsorption on tetracycline.

4. Comparison of efficiency of different reaction systems for removing tetracycline in water

To explore the prepared nano Fe⁰@CeO₂Catalytic material and nano Fe⁰The solid particles remove the influence of the tetracycline in the water, and two materials are respectively selected and added with hydrogen peroxide to remove the tetracycline in the water body. In the experiment, the dosage of the solid material is 0.1g/L, the concentration of hydrogen peroxide is 100mmol/L, the initial pH value of the reaction is 6.8, the reaction kettle is covered on a constant temperature oscillator (26 ℃), the oscillation speed is 250r/min, and the reaction kettle is protected from light. At a preselected time period, 1ml of the solution was passed through a 0.22 μ M microfiltration membrane and 2 drops of t-butanol were added dropwise, tetracycline concentration was analyzed by HPLC, UV-visible detector wavelength was 360nm, mobile phase was 0.1M oxalic acid: b, nitrile: methanol 45:35:20, flow rate 1.0mL/min, sample size 20 uL.

The results of the experiment are shown in FIG. 6. As can be seen from FIG. 6, the tetracycline removal rate tended to increase with reaction time and then to reach equilibrium. At 10min of reaction, H alone₂O₂The tetracycline removal rate is 9.55 percent, and the single nano Fe⁰21.17% of nano Fe alone⁰@CeO₂30.17% of nano Fe⁰+H₂O₂40.97, nano Fe⁰@CeO₂+H₂O₂76.58; reaction for 60min, H alone₂O₂The tetracycline removal rate is 19.82 percent, and the single nano Fe⁰45.23% of individual nano Fe⁰@CeO₂51.82% of nano Fe⁰+H₂O₂67.45% of nano Fe⁰@CeO₂+H₂O₂The content was 89.13%. From the results, Fe⁰@CeO₂+H₂O₂Can rapidly remove tetracycline, and Fe is generated when the reaction is carried out for 10min⁰@CeO₂+H₂O₂The removal rate of the tetracycline is about nano Fe⁰+H₂O₂2 times of the reaction time, the tetracycline removal rate after the reaction for 60min is also larger than that of the nano Fe⁰+H₂O₂Single nano Fe⁰@CeO₂Single nano Fe⁰H alone₂O₂And (4) the tetracycline removal rate. In addition Fe⁰@CeO₂+H₂O₂Reaction rate constant (0.02994 min)^-1) Is about Fe⁰+H₂O₂(0.01585 min)^-1)2 times. Comparing the removal effects of 5 different reaction systems, the nano Fe is obviously seen⁰@CeO₂+H₂O₂The removal effect of the reaction system is optimal. Indicating nano Fe⁰@CeO₂The material gives full play to the nano Fe⁰With nano CeO₂The combined advantages strengthen the effect of the material on removing the tetracycline in the water body.

In summary, the invention of nano Fe⁰@CeO₂With nano Fe⁰Compared with the prior art, the reaction activity and stability of the heterogeneous Fenton catalyst for degrading tetracycline are effectively improved, and the in-situ remediation of water pollution is facilitated; can be used for repairing the water body polluted by tetracycline with higher concentration, and has high repairing efficiency.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims (1)

1. A method for restoring tetracycline polluted water is characterized by comprising the following steps: mixing nano Fe⁰@CeO₂Adding into tetracycline polluted water, adding hydrogen peroxide, mixing, and repairing;

the tetracycline and the nano Fe⁰@CeO₂And H₂O₂The mass ratio of (A) to (B) is 10: (1-20): (68-544);

the nano Fe⁰@CeO₂The preparation method comprises the following steps:

1) adding nano cerium dioxide, ferric salt and a dispersing agent into an ethanol water solution, and stirring and mixing to obtain a solution a;

2) adding an ethanol water solution b containing a reducing agent into the solution a, stirring for reaction, washing, drying and grinding the separated product in sequence to obtain the nano Fe⁰@CeO₂；

The nano Fe⁰@CeO₂In the step 1), the mass ratio of the iron salt, the nano cerium dioxide, the dispersing agent, the ethanol and the water is (3-10): (1-2): 1: (30-120): (90-360);

the nano Fe⁰@CeO₂In the solution b in the step 2), the mass ratio of the reducing agent, ethanol and water is 1: (10-30): (30-90);

the nano Fe⁰@CeO₂In the preparation method of (1), the iron salt is ferrous sulfate; the dispersant is polyvinylpyrrolidone; the reducing agent is a metal hydride reducing agent;

the preparation method of the nano cerium dioxide comprises the following steps:

1) adding cerium nitrate and a surfactant into water, and mixing and stirring to obtain a mixed solution A;

2) adding the ammonium carbonate solution into the mixed solution A, and stirring to obtain a mixed solution B;

3) filtering the mixed solution B, washing and drying the obtained precipitate, calcining, and grinding into powder to obtain nano cerium dioxide;

in the step 1) of the preparation method of the nano cerium dioxide, the mass ratio of the cerium nitrate, the surfactant and the water is (30-50): (3-5): 1000, parts by weight; the surfactant is polyethylene glycol;

in the step 2) of the preparation method of the nano cerium dioxide, the molar concentration of the ammonium carbonate solution is 0.05-0.2 mol/L;

in step 3), the calcining conditions are as follows: the heating rate is 15-25 ℃/min, the calcining temperature is 500-800 ℃, and the calcining time is 3-5 h.

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