LU501787B1

LU501787B1 - Photoelectric biological fenton system and antibiotic wastewater treatment process thereof

Info

Publication number: LU501787B1
Application number: LU501787A
Authority: LU
Inventors: Hongbo Wang
Original assignee: Univ Yantai
Priority date: 2022-04-04
Filing date: 2022-04-04
Publication date: 2022-10-04

Abstract

The preparation process is as follows: 1. preparation of Ag@Z0F catalyst: 2. preparation of Ag@Z0F cathode: 3. preparation of SnO2 -CTAB particles: 4. preparation of Pb02 /Sn02 anode; 5. Take Ag@Z0F obtained in step 2 as the cathode and Pb02 /Sn02 obtained in step 4 as the anode electrode, put them in a reactor and fix them with wires and connect them to an external power supply, put the iron sheet as the sacrificial anode into the reactor, and put an aeration pump under the cathode electrode to provide oxygen needed in Fenton reaction. The Ag@Z0F catalytic cathode and the Sn02 /Pb02 catalytic anode of the present invention realize the effective removal of tetracycline through rational use of catalysts and optimization of treatment process, so that tetracycline wastewater which is difficult to degrade can be effectively treated and recycled.

Description

DESCRIPTION LU501787

PHOTOELECTRIC BIOLOGICAL FENTON SYSTEM AND ANTIBIOTIC WASTEWATER TREATMENT PROCESS THEREOF

TECHNICAL FIELD The invention relates to a photoelectric biological Fenton system and an antibiotic wastewater treatment process thereof, belonging to the technical field of sewage purification and wastewater resource utilization.

BACKGROUND As an advanced oxidation technology to remove organic matter quickly and effectively, Fenton has become the most promising wastewater treatment method for refractory organic matter, including pesticide wastewater, antibiotic wastewater, pharmaceutical wastewater and so on. Nowadays, more and more drugs such as tetracycline are used, but antibiotic wastewater 1s difficult to degrade, so the degradation of antibiotic wastewater has become an environmental problem that people pay more and more attention to.

The traditional electro-Fenton added Fe 2+ at the beginning of the reaction, and the content of H 2 O 2 produced at the initial stage of the experiment was low. Excessive pre-added Fe 2+ compared with H 2 O 2 will capture the generated hydroxyl radical (OH) and reduce the treatment effect of pollutants.

Although electro-Fenton has made great progress as a promising technology, and its performance has been greatly improved, due to the limitation of structural factors, its shortcomings of low content of hydrogen peroxide and low efficiency of pollution degradation reaction still need to be solved. Although many scholars have optimized Fenton's performance and structure, these problems still severely limit the application of the system. In order to improve the efficiency of pollutant degradation, changing the catalytic performance of cathode and anode has become the best method, but this method has not been publicly reported yet.

SUMMARY The purpose of the present invention is to solve the above-mentioned shortcomings in the prior art and provide an effective reaction device for treating tetracycline wastewater by induction Fenton. The Ag@ZOF catalytic cathode and SnO 2 /PbO 2 catalytic anode of the present invention realize the effective removal of tetracycline by reasonably using catalysts and optimizing the treatment process, so that tetracycline wastewater which is difficult to degradé/501 787 can be effectively treated and recovered.

To achieve the above purpose, the present invention provides the following technical scheme: One of the aims of the present invention is to provide a preparation process of Fenton reactor, which is characterized by comprising the following steps: (1) preparing Ag@ZOF catalyst: adding zinc nitrate and silver sulfate into methanol for ultrasonic treatment to obtain solution A; Magnetic stirring dimethyl imidazole in methanol to obtain solution B; Slowly dropping solution A into solution B, and continuously stirring to obtain Ag@ZOF catalyst; (2) preparing the Ag@ZOF cathode: removing impurities on the surface of the stainless steel mesh to make the catalyst more favorable for attachment, and then immersing the stainless steel mesh in the Ag@ZOF catalyst obtained in step (1) to make the Ag@ZOF adhere to the surface of the stainless steel mesh; (3) preparing SnO 2 -CTAB particles: preparing SnO 2 -CTAB particles by hydrothermal synthesis; (4) Preparation of PbO 2 /SnO 2 anode: adding SnO 2 -CTAB particles and Pb(NO 3) 2 into water and stirring, adding nitric acid and sodium fluoride to prepare electrolyte, and attaching PbO 2 /SnO 2 particles to the surface of titanium mesh by electrodeposition; (5) Take Ag@ZOF obtained in step (2) as the cathode and PbO 2 /SnO 2 obtained in step (4) as the anode electrode, put them in a reactor and fix them and connect them to an external power supply with wires, put the iron sheet as the sacrificial anode into the reactor, and put an aeration pump under the cathode electrode to provide oxygen needed in Fenton reaction.

In the step (1), Smmol of zinc nitrate and Immol of silver sulfate are added into 50mL of methanol for ultrasonic treatment for 8-15min, and when the solution is completely dissolved, solution A is obtained; Magnetically stirring 20mmol2- 2-methylimidazole (C 4 H 6 N 2) in 50mL methanol for 15-25min to obtain solution B; In the step (1), SOmL of solution A is slowly dropped into SOmL of solution B, and stirred at 35-45 °C for 1 hour to obtain Ag@ZOF catalyst when the solution is milky white liquid;

In the step (2), the Ag@ZOF catalyst and stainless steel mesh are placed in a culture dishJ501787 and stood for 24 hours, and the Ag@ZOF white precipitation catalyst is attached to the stainless steel mesh to form an Ag@ZOF cathode; In the step (3), 2mmol cetyltrimethyl ammonium bromide (CTAB) is dissolved in 100mL of water and stirred, after being completely dissolved, 0.45G sncl2.2h20 is added to form milky white suspension, then the solution is transferred to an autoclave lined with polytetrafluoroethylene, the autoclave is heated to 160°C for 6 hours in a vacuum drying oven, then naturally cooled at room temperature, and light yellow precipitate is collected. Washing the light yellow precipitate with water and ethanol to make the generated SnO 2 -CTAB particles purer, and drying the washed light yellow precipitate to obtain SnO 2 -CTAB particles; In the step (4), 0.66 mmol of SnO2-CTAB particles and 1.32 mmol Pb(NO 3) 2 are added into water and stirred, and 1M nitric acid and 0.05mol of sodium fluoride are added to prepare electrolyte, and PbO 2 /SnO 2 particles are attached to the surface of titanium mesh by electrodeposition; In the step (4), the titanium mesh is made of stainless steel mesh as cathode and anode, PbO 2 /SnO 2 particles are attached to the surface of the titanium mesh by electrodeposition, and the PbO 2 /SnO 2 anode 1s prepared.

The second object of the invention is to provide a Fenton reactor prepared by the Fenton reactor preparation process.

The third object of the present invention is to provide an application of Fenton reactor in treating tetracycline wastewater which is difficult to degrade.

The invention has the following beneficial effects:

1. Ag 2SO _ 4 combined with zinc-based organic framework has large specific surface area, many active sites, low cost and easy preparation;

2. PbO 2 /SnO 2 catalytic anode combines the advantages of easy preparation, high chemical stability, low cost and porous structure of SnO 2, and PbO 2/SnO2 anode improves the redox ability of Fenton reaction;

3. Compared with the traditional electro-Fenton experiment, this experiment is improved on this basis. Introduce the sacrificial iron anode into the acidic solution, and the sacrificial anode is not connected to the power supply. In this process, the sacrificial iron anode can dissolve a proper amount of divalent iron ions to participate in Fenton reaction, and at the same time, it cdJ501787 more effectively react with the generated H 2 O 2 to generate hydroxyl radicals to degrade organic matters.

4. The Ag@ZOF cathode and SnO 2 /PbO 2 anode which catalyze the degradation of tetracycline are prepared. The Ag@ZOF cathode can not only adsorb a part of tetracycline, but also significantly improve Fenton's activity of generating hydrogen peroxide and free radical ions.

To sum up, the Fenton reactor effectively improves the degradation efficiency of tetracycline, and effectively recycles tetracycline wastewater.

BRIEF DESCRIPTION OF THE FIGURES Fig. 11s cyclic voltammograms of ZOF and Ag@ZOF cathodes; In the figure, the abscissa represents voltage, unit V, ordinate represents current, unit A, scanning rate 0.01 V/s, cyclic voltammogram scanned in Imol/L Na 2 SO 4, Fig. 2 is the cyclic voltammogram of SnO 2 /PbO 2 anode; In the figure: the abscissa represents voltage, unit V, ordinate represents current, unit A, scanning rate 0.01V/s, scanning cyclic voltammogram in 1mol/L Na 2 SO 4. M1:0.66 mmol SnO 2 -CTAB particles and 1.32 mmol Pb(NO 3) 2 were electrodeposited to form the anode. M2 titanium mesh has no anode attached with catalyst. M3: 0.66 mmol of SnO2-CTAB particles and

0.66 mmol Pb(NO 3) 2 were electrodeposited to form the anode.

Fig. 3 shows the treatment performance of Fenton degradation of tetracycline.

In the figure: the abscissa represents time in min; the left ordinate represents the removal efficiency; the note on the right represents the concentration of tetracycline in wastewater, in mg/L.

DESCRIPTION OF THE INVENTION Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of the present invention.

Example 1 LU501787 Preparation of Ag@ZOF catalytic cathode and SnO 2 /PbO 2 catalytic anode, Fenton reaction device installation steps are as follows: (1) preparation of ag (@ zof cathode: 5 mmol of zinc nitrate and 1 mmol of silver sulfate are added into 50 mL of methanol for ultrasonic treatment for 8-15min to obtain solution a. Subsequently, solution B was obtained by adding 20 mmol 2- 2-methylimidazole (C 4 H 6 N 2) to 50mL of methanol and magnetically stirring for 15-25 minutes. Then, SOmL of solution A was slowly dropped into SOmL of solution B, and the mixture was stirred at 40°C for 1 hour. Get Ag@ZOF catalyst. Stainless steel mesh was pretreated by ultrasonic alternately in acetone, deionized water, 0.5 M hydrochloric acid, deionized water and 0.5 M H 2 SO 4. 20 minutes, then rinse with ultrapure water. Aft that solution containing Ag@ZOF catalyst is stir, the uncooled solution is poured into a culture dish together with the pretreated stainless steel substrate. Then, the culture dish was sealed and stood at room temperature for 24 hours, and finally a white solid with uniform adhesion was obtained. The preparation of Ag@ZOF cathode is completed.

(2) Preparation of SnO2/PbO2 anode: dissolve 2 mmol cetyltrimethyl ammonium bromide (CTAB) in 100 mL ultrapure water and magnetically stir for 30min. After CTAB was completely dissolved, 0.45 g sncl2 2h20 was added with stirring. After 30 minutes, a milky white suspension was formed. Transfer the solution to a 100 mL autoclave lined with polytetrafluoroethylene. Subsequently, the autoclave was heated to 160°C in a vacuum drying oven for 6 hours. The solution after subsequent treatment is naturally cooled at room temperature. Then, the prepared solution was centrifuged to collect light yellow precipitate, and washed with water and ethanol for 10 times. Finally, the washed pale yellow precipitate was dried at 50°C to obtain SnO 2 -CTAB particles. 0.66 mmol SnO 2 -CTAB particles and 1.32 mmol Pb(NO 3) 2 were added into 100mL water and stirred, and 1 M nitric acid and 0.05mol sodium fluoride were added to prepare electrolyte. Electrodeposition experiments were carried out with titanium mesh as cathode and stainless steel mesh as anode. At last, SnO 2 /PbO 2 particles are attached to the anode surface to form SnO 2 /PbO 2 anode.

(3) Installation of the reaction device: the prepared anode and cathode electrodes are fixed and connected to the anode and cathode of the DC power supply with wires respectively. Fix the sacrificial iron anode, and put it under the cathode into the aeration pump device.

Comparative example 1: LU501787 Preparation of ZOF catalytic cathode and SnO 2 /PbO 2 catalytic anode, Fenton reaction device installation steps are as follows: (1) preparation of 1)ZOF catalytic cathode: Smmol of Zn (no 3) 2.6h20 was added into 50 mL of methanol for ultrasonic treatment for 10min to obtain solution C. Subsequently, a solution B was obtained by adding 20 mmol 2- 2-methylimidazole (C 4 H 6 N 2) to 50mL of methanol and magnetically stirring for 20 minutes. Then, slowly drop solution C into solution B, and keep stirring. The mixed solution was stirred at 40°C for 1 hour. Get ZOF catalyst. The stainless steel mesh was treated according to the steps in Example 1. Aft that solution containing ZOF catalyst is stir, the uncooled solution 1s poured into a culture dish together with the pretreated stainless steel substrate. Then, the culture dish was sealed and stood at room temperature for 24 hours, and finally a white solid with uniform adhesion was obtained. The preparation of ZOF catalytic cathode is completed.

(2) preparation of SnO2/PbO2 anode: same as in example 1.

(3) Installation of reaction device: same as Example 1.

Comparative example 2: Preparation of Ag@ZOF catalytic cathode and SnO 2 /PbO 2 catalytic anode, Fenton reaction device installation steps are as follows: (1) preparation of ag @ zof cathode: same as in example 1.

(2) using titanium mesh as anode.

(3) Installation of reaction device: same as Example 1.

Comparative example 3: Preparation of Ag@ZOF catalytic cathode and SnO 2 /PbO 2 catalytic anode, Fenton reaction device installation steps are as follows: (1) preparation of ag @ zof cathode: same as in example 1.

(2) Preparation of SnO2/PbO2 anode: The preparation of SnO 2 -CTAB particles is the same as Example 1. 0.66 mmol SnO 2 -CTAB particles and 0.66 mmol Pb(NO 3) 2 were added into 100mL water and stirred, and 1 M nitric acid and 0.05 mol sodium fluoride were added to prepare electrolyte. Electrodeposition experiments were carried out with titanium mesh as cathode and stainless steel mesh as anode. PbO 2 /SnO 2 particles were attached to the surface 68501787 titanium mesh, and PbO 2 /SnO 2 anode was prepared.

(3) Installation of reaction device: same as Example 1.

Test 1 The catalytic cathodes obtained in Example 1 and Comparative Example 1 were examined for redox.

The oxidation-reduction test of catalytic cathode was carried out by cyclic voltammetry at a scanning speed of 0.01V/s, and the catalytic cathodes containing different catalysts were characterized by cyclic voltammetry in 1 mol/L sodium sulfate solution. The results are shown in Figure 1. As can be seen from Figure 1, the cyclic voltammetric curve of Ag@ZOF catalytic cathode has an obvious redox peak compared with that of ZOF, which indicates that the catalytic Ag@ZOF cathode has an obvious promoting effect on the redox reaction compared with ZOF cathode.

Test 2 The catalytic cathodes obtained in Example 1 and Comparative Examples 2-3 were examined for redox.

Cyclic voltammetry was used to test the oxidation-reduction of catalytic anode at a scanning speed of 0.01 V/s. Anodes with different catalyst ratios were characterized by cyclic voltammetry in 1 mol/L sodium sulfate solution, and the results are shown in Figure 2. As can be seen from Figure 2, compared with M2, the cyclic voltammetric curve of M1 has obvious redox peak, showing higher capacitance. It shows that M1 is more effective than M2 and M3 in promoting redox reaction.

Test 3 The Ag@ZOF catalytic cathode, SnO 2 /PbO 2 catalytic anode and Fenton reaction device prepared in example 1 were tested for the performance of tetracycline wastewater treatment.

The prepared Ag@ZOF cathode and SnO 2 /PbO 2 anode are fixed and connected to the anode and cathode of DC power supply with wires respectively. Fix the sacrificial iron anode, and put it under the cathode into the aeration pump device. With 0.05 M Na 2 SO 4 aqueous solution as supporting electrolyte, tetracycline with different concentrations (10 m/L, 15 m/L, 20 m/L and 25 m/L, respectively) was used as simulated wastewater, and the performance of tetracycline treatment system was tested. The result is shown in Figure 3. It can be seen that th&501787 Fenton reaction device of the invention can effectively remove tetracycline and realize the effective purification of tetracycline wastewater.

Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that many changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

CLAIMS LU501787

1. À preparation process of Fenton reactor, characterized by comprising the following preparation processes: (1) preparing Ag@ZOF catalyst: adding zinc nitrate and silver sulfate into methanol for ultrasonic treatment to obtain solution A; magnetic stirring dimethyl imidazole in methanol to obtain solution B; slowly dropping solution A into solution B, and continuously stirring to obtain Ag@ZOF catalyst; (2) preparing the Ag@ZOF cathode: removing impurities on the surface of the stainless steel mesh to make the catalyst more favorable for attachment, and then immersing the stainless steel mesh in the Ag@ZOF catalyst obtained in step (1) to make the Ag@ZOF adhere to the surface of the stainless steel mesh; (3) preparing SnO 2 -CTAB particles: preparing SnO 2 -CTAB particles by hydrothermal synthesis; (4) preparation of PbO 2 /SnO 2 anode: adding SnO 2 -CTAB particles and Pb(NO 3) 2 into water and stirring, adding nitric acid and sodium fluoride to prepare electrolyte, and attaching PbO 2 /SnO 2 particles to the surface of titanium mesh by electrodeposition; (5) take Ag@ZOF obtained in step (2) as the cathode and PbO 2 /SnO 2 obtained in step (4) as the anode electrode, put them in a reactor and fix them and connect them to an external power supply with wires, put the iron sheet as the sacrificial anode into the reactor, and put an aeration pump under the cathode electrode to provide oxygen needed in Fenton reaction.

2. The preparation process of Fenton reactor according to claim 1, characterized in that in step (1), SmmoL of zinc nitrate and mmol of silver sulfate are added into SOmL of methanol for ultrasonic treatment for 8-15min, and when the solution is completely dissolved, solution A is obtained; 20 mmol 2- 2-methylimidazole (C 4 H 6 N 2) was magnetically stirred in 50mL methanol for 15-25 minutes to obtain solution B.

3. The preparation process of Fenton reactor according to claim 2, characterized in that in step (1), SOmL of solution A is slowly dropped into 50mL of solution B, and stirred at 35-45°Cfor 1 hour, and when the solution is milky white liquid, the Ag@ZOF catalyst is obtained.

4. The preparation process of Fenton reactor according to claim 1, characterized in that 4501787 step (2), the Ag@ZOF catalyst and stainless steel mesh are placed in a culture dish and stood for 24 hours, and the Ag@ZOF white precipitation catalyst is attached to the stainless steel mesh to form the Ag@ZOF cathode.

5. The preparation process of Fenton reactor according to claim 1, characterized in that in the step (3), 2mmol cetyltrimethyl ammonium bromide (CTAB) is dissolved in 100mL water and stirred, after completely dissolved, 0.45 g of SnCI 2 2H 2 O is added to form milky suspension, and then the solution is transferred to an autoclave lined with polytetrafluoroethylene; heating the autoclave to 160°C in a vacuum drying oven for 6 hours, then naturally cooling at room temperature, collecting light yellow precipitate, washing the light yellow precipitate with water and ethanol to make the generated SnO 2 -CTAB particles purer, and drying the washed light yellow precipitate to obtain SnO 2 -CTAB particles.

6. The preparation process of Fenton reactor according to claim 1, characterized in that in step (4), 0.66 mmol of SnO2-CTAB particles and 1.32 mmol Pb(NO 3) 2 are added into water to be stirred, 1M nitric acid and 0.05mol of sodium fluoride are added to prepare electrolyte, and PbO 2 /SnO 2 particles are attached to the surface of titanium mesh by electrodeposition.

7. The preparation process of Fenton reactor according to claim 6, characterized in that in step (4), titanium mesh is used as cathode and stainless steel mesh is used as anode, PbO 2 /SnO 2 particles are attached to the surface of titanium mesh by electrodeposition, and PbO 2 /SnO 2 anode is prepared.

8. The Fenton reactor prepared by the Fenton reactor preparation process according to any one of claims 1 to 7.

9. The application of Fenton reactor according to claim 8 in the treatment of tetracycline wastewater which is difficult to degrade.