Method for treating fluoroquinolone antibiotic-containing wastewater by electrochemical membrane reactor

Abstract

The application provides a method for treating fluorine-containing quinolone antibiotic wastewater by using an electrochemical membrane reactor, and belongs to the technical field of antibiotic wastewater treatment. The fluorine-containing quinolone antibiotic wastewater is introduced into the electrochemical membrane reactor for electrolysis treatment, wherein the electrochemical membrane reactor has an anode membrane and a cathode membrane, and the anode membrane is a titanium-based electrocatalytic membrane loaded with an electrocatalyst. The specific surface area of the anode membrane can be effectively increased by doping boron elements, the stability of the electrode membrane is improved, and then the electrocatalytic activity of the anode membrane is improved, and the degradation rate reaches 100% after electrolysis for 1h.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of antibiotic wastewater treatment, and particularly relates to a method for treating fluorine quinolone antibiotic-containing wastewater by using an electrochemical membrane reactor. BACKGROUND

[0002] Fluorine quinolone drugs are broad-spectrum antibiotics, and have the characteristics of strong antibacterial activity, no cross-resistance with other antibacterial drugs, and small toxic and side effects, and are widely used in poultry, livestock, aquaculture and other breeding industries to prevent and treat animal diseases, and excessive use will lead to residues in the animal body, causing harm to human health. Fluorine quinolone antibiotics have high solubility in water and are often detected in sewage treatment plants, rivers and groundwater. Because fluorine quinolone antibiotics have the characteristics of stable structure and high adsorption affinity, it is difficult to completely degrade them by traditional wastewater treatment technologies.

[0003] At present, the commonly used methods for treating antibiotics include physical methods, biological methods and chemical methods. The physical method mainly uses adsorption and membrane separation methods to separate antibiotics from water bodies. Although the adsorption method has low cost and simple preparation of adsorbents, the adsorbed antibiotics can easily desorb under the influence of the outside world, causing secondary pollution to the environment. The membrane separation method has the advantages of simple operation, strong selectivity and low energy consumption, but it is easy to cause membrane pollution and secondary pollution of concentrated water, which seriously affects the interception of antibiotics. The electrochemical treatment of high-concentration fluorine quinolone antibiotic-containing wastewater has low degradation efficiency: for example, a device for treating fluorine quinolone antibiotic-containing wastewater and a method thereof disclosed in Chinese patent CN109824214B, by electrochemically electrolyzing high-concentration fluorine quinolone antibiotics, the anode plate is titanium-based PbO2, and the cathode plate is a stainless steel sheet. The degradation rate of antibiotics can reach 98% in 4 hours. Therefore, it is of great significance to study a method for treating fluorine quinolone antibiotic-containing wastewater by using an electrochemical membrane reactor to improve the degradation efficiency. SUMMARY

[0004] The present application aims to provide a method for treating fluorine quinolone antibiotic-containing wastewater by using an electrochemical membrane reactor to improve the low degradation efficiency of fluorine quinolone antibiotic-containing wastewater.

[0005] In order to achieve the above-mentioned application purposes, the present application provides the following technical solutions:

[0006] The present application provides a method for treating fluorine quinolone antibiotic-containing wastewater by using an electrochemical membrane reactor, which comprises the following steps: passing the fluorine quinolone antibiotic-containing wastewater into an electrochemical membrane reactor for electrolytic treatment; the electrochemical membrane reactor has an anode membrane and a cathode membrane, wherein the anode membrane is a titanium-based electrocatalytic membrane loaded with an electrocatalyst.

[0007] Preferably, the electrically catalyzed catalyst loaded in the titanium-based electrically catalyzed film is boron-doped lead oxide.

[0008] Preferably, the method for preparing the electrically catalyzed catalyst loaded titanium-based electrically catalyzed film comprises the following steps: preparing a mixed solution of lead nitrate, boric acid and water, and performing electrodeposition on a titanium substrate in the mixed solution to obtain the electrically catalyzed catalyst loaded titanium-based electrically catalyzed film.

[0009] Preferably, the cathode film of the electrochemical membrane reactor is a modified graphite felt.

[0010] Preferably, the method for preparing the modified graphite felt comprises the following steps: immersing the graphite felt in a mixed dispersion liquid, taking out the graphite felt after the immersion is completed, and drying and heat-treating the graphite felt to obtain the modified graphite felt.

[0011] Preferably, the mixed dispersion liquid is prepared from carbon black, polytetrafluoroethylene emulsion and a solvent.

[0012] Preferably, the electrolyte used in the electrolysis treatment is sodium sulfate, sodium chloride or sodium nitrate; the concentration of the electrolyte is 0.03-0.1 mol / L; and the pH value of the fluorine-containing quinolone antibiotic wastewater is 3.0-11.0.

[0013] Preferably, the distance between the anode film and the cathode film is 2-4 cm.

[0014] Preferably, the current density of the electrolysis is 10-20 mA / cm 2 .

[0015] The present application has the following advantages:

[0016] (1) The present application can effectively increase the specific surface area of the anode film by doping boron element, improve the stability of the electrode film, and further improve the electrocatalytic activity of the anode film. The degradation rate of the antibiotic in the wastewater after electrolysis for 1 h reaches 100%.

[0017] (2) The modified graphite felt prepared by loading carbon black and polytetrafluoroethylene on the graphite felt can generate more active substances as the cathode film, and further improve the degradation efficiency of the fluorine-containing quinolone antibiotic. DETAILED DESCRIPTION

[0018] The present application provides a method for treating fluorine-containing quinolone antibiotic wastewater by using an electrochemical membrane reactor, which comprises the following steps: introducing the fluorine-containing quinolone antibiotic wastewater into the electrochemical membrane reactor for electrolysis treatment; and the electrochemical membrane reactor has an anode film and a cathode film, wherein the anode film is a titanium-based electrically catalyzed film loaded with an electrically catalyzed catalyst.

[0019] In the present application, the electrically catalyzed catalyst loaded in the titanium-based electrically catalyzed film is boron-doped lead oxide.

[0020] In the present application, the preparation method of the titanium-based electrocatalytic film loaded with electrocatalyst is as follows: a mixed solution of lead nitrate, boric acid and water is prepared, and a titanium substrate is placed in the mixed solution for electrodeposition to obtain the titanium-based electrocatalytic film loaded with electrocatalyst.

[0021] In the present application, the molar ratio of lead nitrate to boric acid is 20-40:0.5-1.5; and the deposition parameters are as follows: the deposition temperature is 30℃, the current density is 1.5 mA / cm 2 , and the deposition time is 1 h.

[0022] In the present application, the cathode film of the electrochemical membrane reactor is a modified graphite felt.

[0023] In the present application, the preparation method of the modified graphite felt is as follows: the graphite felt is immersed in a mixed dispersion liquid, and after the immersion is completed, the graphite felt is taken out for drying and heat treatment to obtain the modified graphite felt.

[0024] In the present application, the mixed dispersion liquid is prepared from carbon black, polytetrafluoroethylene emulsion and solvent.

[0025] In the present application, in the mixed dispersion liquid, the amount ratio of carbon black, polytetrafluoroethylene emulsion and solvent is 0.5-1.5 g:1.0-2.5 g:20-40 mL; and the mass fraction of the polytetrafluoroethylene emulsion is 60%.

[0026] In the present application, the immersion time is 1 h; and the heat treatment temperature is 200-300℃, and the time is 0.5-1.5 h.

[0027] In the present application, the electrolyte used in the electrolysis treatment is sodium sulfate, sodium chloride or sodium nitrate; the concentration of the electrolyte is 0.03-0.1 mol / L; and the pH value of the fluoroquinolone antibiotic-containing wastewater is 3.0-11.0, preferably 4.0-10.0, and further preferably 7.0.

[0028] In the present application, the distance between the anode film and the cathode film is 2-4 cm, and preferably 3 cm.

[0029] In the present application, the current density of the electrolysis is 10-20 mA / cm 2 , preferably 12-18 mA / cm 2 , and further preferably 15 mA / cm 2 .

[0030] The technical solutions provided by the present application will be described in detail below in combination with examples, but they should not be understood as limiting the scope of protection of the present application.

[0031] The titanium substrate and the graphite felt used in the examples and the comparative examples of the present application are both pretreated titanium substrate and pretreated graphite felt.

[0032] In the present application, the size of the titanium substrate is 50mm*30mm*2mm, and the pretreatment process of the titanium substrate is as follows: the titanium plate is polished by using 200#, 400#, 600#, 800# and 1000# sandpaper in sequence and then washed with deionized water to obtain a smooth titanium substrate. Then the titanium substrate is immersed in an 80℃ NaOH solution (concentration of 40wt%) for alkaline washing for 2h to remove oil, and then immersed in a micro-boiling oxalic acid solution (concentration of 10wt%) for 2h for reflux etching, and then washed with deionized water after being taken out to obtain a titanium substrate with a rough surface.

[0033] In the present application, the size of the graphite felt is 50mm*30mm*2mm, and the pretreatment process of the graphite felt is as follows: the graphite felt is ultrasonically treated in pure water and acetone for 1h respectively, and then dried at 100℃ for standby use.

[0034] Preparation Example 1

[0035] A mixed solution of lead nitrate and boric acid is prepared according to a molar ratio of 30:0.5, and the concentration of lead nitrate is 0.5mol / L. Then the pretreated titanium substrate is placed in the above-mentioned mixed solution for electrodeposition, wherein the deposition temperature is 30℃, the current density is 1.5mA / cm 2 , and the deposition time is 1h to obtain a boron-doped lead oxide-titanium-based anode film, which is recorded as boron-doped lead oxide-titanium-based anode film-1.

[0036] Preparation Example 2

[0037] A mixed solution of lead nitrate and boric acid is prepared according to a molar ratio of 30:1.0, and the concentration of lead nitrate is 0.5mol / L. Then the pretreated titanium substrate is placed in the above-mentioned mixed solution for electrodeposition, wherein the deposition temperature is 30℃, the current density is 1.5mA / cm 2 , and the deposition time is 1h to obtain a boron-doped lead oxide-titanium-based anode film, which is recorded as boron-doped lead oxide-titanium-based anode film-2.

[0038] Preparation Example 3

[0039] A mixed solution of lead nitrate and boric acid is prepared according to a molar ratio of 30:1.5, and the concentration of lead nitrate is 0.5mol / L. Then the pretreated titanium substrate is placed in the above-mentioned mixed solution for electrodeposition, wherein the deposition temperature is 30℃, the current density is 1.5mA / cm 2 , and the deposition time is 1h to obtain a boron-doped lead oxide-titanium-based anode film, which is recorded as boron-doped lead oxide-titanium-based anode film-3.

[0040] Preparation Example 4

[0041] 0.5 g of carbon black and 1.5 g of polytetrafluoroethylene emulsion (mass fraction of 60%) were dispersed in a mixed solvent of deionized water and isopropanol (volume of deionized water of 30 mL and volume of isopropanol of 5 mL) and ultrasonic treatment was performed for 1 h to obtain a mixed dispersion liquid with different carbon black contents. The pretreated graphite felt was immersed in the mixed dispersion liquid and ultrasonic treatment was performed for 1 h. The graphite felt was taken out and dried in a constant temperature drying box at 80°C for 12 h. Finally, the graphite felt was placed in a muffle furnace for heat treatment at a temperature of 250°C for 1 h to prepare a modified graphite felt cathode film, which was recorded as modified graphite felt cathode film-1.

[0042] Preparation Example 5

[0043] 1.0 g of carbon black and 1.5 g of polytetrafluoroethylene emulsion (mass fraction of 60%) were dispersed in a mixed solvent of deionized water and isopropanol (volume of deionized water of 30 mL and volume of isopropanol of 5 mL) and ultrasonic treatment was performed for 1 h to obtain a mixed dispersion liquid with different carbon black contents. The pretreated graphite felt was immersed in the mixed dispersion liquid and ultrasonic treatment was performed for 1 h. The graphite felt was taken out and dried in a constant temperature drying box at 80°C for 12 h. Finally, the graphite felt was placed in a muffle furnace for heat treatment at a temperature of 250°C for 1 h to prepare a modified graphite felt cathode film, which was recorded as modified graphite felt cathode film-2.

[0044] Preparation Example 6

[0045] 1.5 g of carbon black and 1.5 g of polytetrafluoroethylene emulsion (mass fraction of 60%) were dispersed in a mixed solvent of deionized water and isopropanol (volume of deionized water of 30 mL and volume of isopropanol of 5 mL) and ultrasonic treatment was performed for 1 h to obtain a mixed dispersion liquid with different carbon black contents. The pretreated graphite felt was immersed in the mixed dispersion liquid and ultrasonic treatment was performed for 1 h. The graphite felt was taken out and dried in a constant temperature drying box at 80°C for 12 h. Finally, the graphite felt was placed in a muffle furnace for heat treatment at a temperature of 250°C for 1 h to prepare a modified graphite felt cathode film, which was recorded as modified graphite felt cathode film-3.

[0046] The boron-doped lead oxide-titanium-based anode film prepared in Preparation Examples 1 to 3 and the modified graphite felt cathode film prepared in Preparation Examples 4 to 6 were arranged with a certain spacing between the anode film and the cathode film, and were placed in a organic glass reactor (as an electrolytic cell). A direct current stabilized power supply was connected to the organic glass reactor, the positive electrode of the direct current stabilized power supply was connected to the anode film, and the negative electrode was connected to the cathode film. The organic glass reactor was placed on a magnetic stirrer to assemble an electrochemical membrane reactor.

[0047] Application Example 1

[0048] The fluorine-containing quinolone antibiotic-containing wastewater is electrolyzed by using the electrochemical membrane reactor assembled above, the distance between the cathode membrane and the anode membrane is 2 cm, the initial concentration of the antibiotic in the wastewater is 5 mg / L, the initial pH value is 7.0, the fluorine-containing quinolone antibiotic-containing wastewater and sodium sulfate are poured into the organic glass reactor, so that the concentration of the sodium sulfate electrolyte is 0.05 mol / L, the magnetic stirrer is started, and the direct current stabilized power supply is started at the same time, and the current density is adjusted to 20 mA / cm 2 The wastewater is electrolyzed, and the concentration of the antibiotic in the wastewater is detected every 5 min during the electrolysis process, and the detection results are shown in Table 1.

[0049] Table 1: Degradation effect of antibiotics by different anode membranes and cathode membranes

[0050]

[0051]

[0052] It can be seen from Table 1 that the degradation effect of antibiotics is different when the doping amount of boron in the anode membrane is different, and the degradation effect can be significantly improved as the doping amount of boron increases; the addition amount of carbon black in the modified graphite felt cathode membrane also affects the degradation effect of antibiotics, and the degradation effect is optimal when the addition amount of carbon black is 1.0 g.

[0053] Application Example 2

[0054] The fluorine-containing quinolone antibiotic-containing wastewater is electrolyzed by using the boron-doped lead oxide-titanium-based anode membrane-3 and the modified graphite felt cathode membrane-2 as the anode membrane and the cathode membrane, the distance between the cathode membrane and the anode membrane is 3 cm, the initial concentration of the antibiotic in the wastewater is 10 mg / L, 20 mg / L, 30 mg / L, 50 mg / L, 100 mg / L and 150 mg / L, respectively, the initial pH value is 7.0, the fluorine-containing quinolone antibiotic-containing wastewater and sodium sulfate are poured into the organic glass reactor, so that the concentration of the sodium sulfate electrolyte is 0.05 mol / L, the magnetic stirrer is started, and the direct current stabilized power supply is started at the same time, and the current density is adjusted to 20 mA / cm 2 The wastewater is electrolyzed, and the concentration of the antibiotic in the wastewater is detected every 5 min during the electrolysis process, and the detection results are shown in Table 2.

[0055] Table 2: Degradation effect of antibiotics at different initial concentrations

[0056] Antibiotic concentration (mg / L) Degradation rate at 60 min (%) 10 100 20 100 30 100 50 100 100 98.2 150 96.5

[0057] It can be seen from Table 2 that by using the electrochemical double membrane reactor of the application, the degradation rate is as high as 100% when the antibiotic concentration is less than 50 mg / L after 60 min of electrolysis, and good degradation effect can also be achieved for high-concentration antibiotic wastewater.

[0058] From the above examples, the application provides a method for treating fluorine-containing quinolone antibiotic wastewater by using an electrochemical membrane reactor. The fluorine-containing quinolone antibiotic wastewater is introduced into the electrochemical membrane reactor for electrolysis treatment, wherein the electrochemical membrane reactor has an anode membrane and a cathode membrane, and the anode membrane is a titanium-based electrocatalytic membrane loaded with an electrocatalyst. The application can effectively increase the specific surface area of the anode membrane by doping boron elements, improve the stability of the electrode membrane, and further improve the electrocatalytic activity of the anode membrane. The degradation rate reaches 100% after 1h of electrolysis.

[0059] The above only describes the preferred embodiments of the application, and it should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the application, and these improvements and refinements should also be considered within the protection scope of the application.

Claims

1. A method for treating fluoroquinolone antibiotic-containing wastewater by an electrochemical membrane reactor, characterized in that, The method comprises the following steps: The fluorine-containing quinolone antibiotic wastewater is introduced into an electrochemical membrane reactor for electrolysis treatment; the electrochemical membrane reactor has an anode membrane and a cathode membrane, wherein the anode membrane is a titanium-based electrocatalytic membrane loaded with an electrocatalyst; The electrocatalyst loaded in the titanium-based electrocatalytic membrane loaded with an electrocatalyst is boron-doped lead oxide; The preparation method of the titanium-based electrocatalytic membrane loaded with an electrocatalyst is as follows: a mixed solution of lead nitrate, boric acid and water is prepared, and a titanium substrate is placed in the mixed solution for electrodeposition to obtain the titanium-based electrocatalytic membrane loaded with an electrocatalyst; The molar ratio of the lead nitrate to the boric acid is 20-40:0.5-1.5; The cathode membrane of the electrochemical membrane reactor is a modified graphite felt; The preparation method of the modified graphite felt is as follows: the graphite felt is immersed in a mixed dispersion liquid, and after the immersion is completed, the graphite felt is taken out for drying and heat treatment to obtain the modified graphite felt; the mixed dispersion liquid is prepared from carbon black, polytetrafluoroethylene emulsion and a solvent; The electrolyte used in the electrolysis treatment is sodium sulfate, sodium chloride or sodium nitrate; the concentration of the electrolyte is 0.03-0.1 mol / L; and the pH value of the fluorine-containing quinolone antibiotic wastewater is 3.0-11.

0.

2. The method of claim 1, wherein the electrochemical membrane reactor is operated at a temperature of 20 to 40°C, a pH of 2 to 4, and a current density of 10 to 100 mA / cm2. The distance between the anode membrane and the cathode membrane is 2-4 cm.

3. The method of claim 2, wherein the electrochemical membrane reactor is operated at a temperature of 20 to 40 °C, a pH of 2 to 5, and a current density of 10 to 100 mA / cm2. The current density of the electrolysis is 10 to 20 mA / cm 2 .

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