Tetracycline degradation method based on Cu-CNv heterogeneous Fenton-like catalyst

Abstract

According to the tetracycline degradation method based on the Cu-CNv heterogeneous Fenton-like catalyst, Cu-CNv serves as the catalyst, antibiotics adsorbed in a water environment can be mineralized and decomposed through a heterogeneous Fenton-like advanced oxidation technology, the degradation rate of a Cu-CNv heterojunction with high catalytic efficiency to 50 mg / L of tetracycline Fenton within 40 min reaches 93.98%, operation is easy, and the tetracycline degradation method based on the Cu-CNv heterogeneous Fenton-like catalyst is suitable for industrial production. The catalyst has good stability, does not produce copper sludge, and solves the problems of narrow PH application range, catalyst recovery incapability, large H2O2 consumption, low catalytic efficiency, low active site and the like in the traditional homogeneous Fenton technology.

Description

Technical Field

[0001] The invention relates to the field of Fenton-like catalysts, and in particular to a tetracycline degradation method based on a Cu-CNv heterogeneous Fenton-like catalyst. Background Art

[0002] Antibiotic water pollution has caused serious harm to humans and ecosystems, and is a difficult and key point in my country's wastewater treatment. Traditional homogeneous Fenton technology can effectively remove refractory pollutants, but Cu 2+ The ratio of concentration to H2O2, pH value, and temperature will affect the reaction rate, and sludge is easily produced, and the catalyst is difficult to recover after the reaction. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a tetracycline degradation method based on a Cu-CNv heterogeneous Fenton-like catalyst in view of the above shortcomings.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] The tetracycline degradation method based on Cu-CNv heterogeneous Fenton-like catalyst comprises the following steps:

[0006] Step 1: preparing a Cu-CNv heterogeneous Fenton-like catalyst, specifically comprising the following steps:

[0007] Step 1.1, calcining urea at high temperature in a crucible to obtain a g-C3N4 sample (named CN);

[0008] Step 1.2, adding the fired CN into deionized water containing NaBH4, and obtaining a CNv suspension after ultrasonic dispersion and stirring;

[0009] Step 1.3, after adding Cu(NO3)3·3H2O solution into CNv suspension, ultrasonically disperse for more than 5 min, and then stir on a magnetic stirrer for 3 h;

[0010] Step 1.4, after the reaction in the previous step is completed, the obtained product is centrifuged and washed multiple times with deionized water and ethanol, and dried to obtain a Cu-CNv heterogeneous Fenton-like catalyst;

[0011] Step 2: Add the Cu-CNv heterogeneous Fenton-like catalyst from the previous step into the tetracycline solution to degrade tetracycline.

[0012] Furthermore, the magnetic stirrer is a multi-station magnetic stirrer.

[0013] Furthermore, in step 1.2, the volume of deionized water containing NaBH4 is 40 mL, and the concentration of NaBH4 is 1 mol / L.

[0014] Furthermore, the mass fraction of CN in the CNv suspension is 0.8%.

[0015] Furthermore, in step 1.3, the concentration of the Cu(NO3)3·3H2O solution is 0.05 mol / L and the volume is 800 μL.

[0016] The beneficial effects of the present invention are:

[0017] The Cu-CNv heterogeneous Fenton-like catalyst obtained by the present invention can mineralize and decompose the antibiotics adsorbed in the water environment, has high catalytic efficiency, and the Cu-CNv heterojunction has a Fenton degradation rate of 93.98% for 50 mg / L tetracycline within 40 minutes. The operation is simple, the catalyst has good stability, and no copper sludge is generated. The traditional homogeneous Fenton technology has a narrow pH range, the catalyst cannot be recycled, the H2O2 dosage is large, the catalytic efficiency is low, and the active sites are low. The problems are solved. Experiments have proved that compared with the monomer CN, the Cu-CNv composite material has strong adsorption performance and significantly improved degradation rate. When the reaction is 40 minutes, the Fenton-like degradation rate is as high as 93.98%.

[0018] The present invention is described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Figure (A) shows the adsorption-degradation tetracycline performance test diagram of Cu-CNv, Cu-CNv / H2O2, CN and CN / H2O2 heterojunctions, and Figure (B) shows the 40-min columnar degradation diagram corresponding to Cu-CNv, Cu-CNv / H2O2, CN and CN / H2O2 heterojunctions;

[0020] Figure 2 Figure (A) is the universal diagram of the Cu-CNv / H2O2 system (target pollutant concentration is 20 mg / L), and Figure (B) is the XRD diagram of the CN and Cu-CNv heterojunction. DETAILED DESCRIPTION

[0021] The following examples are provided for a better understanding of the present invention, but are not intended to limit the present invention. The experimental methods in the following examples are conventional methods unless otherwise specified. The experimental materials used in the following examples are purchased from conventional biochemical reagent stores unless otherwise specified.

[0022] Step 1: preparing a Cu-CNv heterogeneous Fenton-like catalyst, specifically comprising the following steps:

[0023] Step 1.1, 10g urea was placed in a crucible, the initial temperature was 20℃, the heating time was 106min, the heating temperature was 550℃, the constant temperature time was 2h, the constant temperature was 550℃, and the heating rate was 5℃ / min. The g-C3N4 sample (named CN) was collected;

[0024] Step 1.2, take 0.4g CN, add 1M NaBH4 into 40ml deionized water, and disperse by ultrasonic for 5min to obtain CNv suspension;

[0025] Step 1.3, 800 μL of 0.05M Cu(NO3)3·3H2O was added to the CNv suspension obtained in step 2, and then stirred on a magnetic stirrer for 3 hours; after the reaction was completed, the obtained product was washed three times by centrifugation with deionized water and ethanol, and finally dried overnight in vacuum at 60°C (named Cu-CNv).

[0026] Heterogeneous Fenton-like degradation of tetracycline method: Weigh 40 mg of Cu-CNv catalytic material and disperse it in a reactor containing 50 mL of tetracycline solution (50 mg / L TCH). Before the degradation experiment, stir in the dark for 30 minutes to allow the catalytic material to reach adsorption saturation with TCH, then add 100 μL of H2O2 solution to the solution, and use a low-temperature constant temperature circulation system to control the reaction temperature to 25°C. At regular intervals, take out the reaction solution, centrifuge it and filter it with a 0.22 μm filter membrane, and finally measure its absorbance with a spectrophotometer.

[0027] We tested the adsorption-degradation performance of tetracycline by Cu-CNv and CN materials, with 50 mg / L TCH as the target pollutant and 100 μL of H2O2 added. Figure 1 Figures (A) and (B) are the degradation performance diagram and bar graph of the sample after 30 minutes of adsorption and 40 minutes of reaction, respectively. Compared with the monomer CN material, the degradation rate of the Cu-CNv composite material is significantly improved, and the strongest Fenton-like degradation rate is 93.98% at 40 minutes of reaction. Figure 1 As shown in Figure (B), the degradation efficiencies of tetracycline by Cu-CNv / H2O2, Cu-CNv, CN / H2O2 and CN at 40 min were 93.98%, 10.95%, 2.22% and 0.06% respectively.

[0028] Figure 2 Figure (A) is the universal diagram of the Cu-CNv / H2O2 system (target pollutant concentration is 20 mg / L), and Figure (B) is the XRD diagram of the CN and Cu-CNv heterojunction.

[0029] The above is an example of the best implementation of the present invention, and the parts not described in detail are common knowledge of ordinary technicians in the field. The protection scope of the present invention shall be based on the content of the claims, and any equivalent transformation based on the technical enlightenment of the present invention is also within the protection scope of the present invention.

Claims

1. A tetracycline degradation method based on a Cu-CNv heterogeneous Fenton-like catalyst, characterized in that: The following steps are involved: Step 1: preparing a Cu-CNv heterogeneous Fenton-like catalyst, specifically comprising the following steps: Step 1.1, calcining urea at high temperature in a crucible to obtain a g-C3N4 sample named CN; Step 1.2, adding the fired CN into deionized water containing NaBH4, and obtaining a CNv suspension after ultrasonic dispersion and stirring; Step 1.3, after adding Cu(NO3)3·3H2O solution into CNv suspension, ultrasonically disperse for more than 5 min, and then stir on a magnetic stirrer for 3 h; Step 1.4, after the reaction in the previous step is completed, the obtained product is centrifuged and washed multiple times with deionized water and ethanol, and dried to obtain a Cu-CNv heterogeneous Fenton-like catalyst; Step 2: Add the Cu-CNv heterogeneous Fenton-like catalyst from the previous step into the tetracycline solution to degrade tetracycline.

2. The method for tetracycline degradation based on Cu-CNv heterogeneous Fenton-like catalyst according to claim 1, characterized in that: The magnetic stirrer is a multi-station magnetic stirrer.

3. The method for tetracycline degradation based on Cu-CNv heterogeneous Fenton-like catalyst according to claim 1, characterized in that: In the step 1.2, the volume of deionized water containing NaBH4 is 40 mL, and the concentration of NaBH4 is 1 mol / L.

4. The method for tetracycline degradation based on Cu-CNv heterogeneous Fenton-like catalyst according to claim 1, characterized in that: The mass fraction of CN in the CNv suspension is 0.8%.

5. The method for tetracycline degradation based on Cu-CNv heterogeneous Fenton-like catalyst according to claim 1, characterized in that: In step 1.3, the concentration of the Cu(NO3)3·3H2O solution is 0.05 mol / L and the volume is 800 μL.

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