CN113336308B - A method for degrading and recycling antibiotic wastewater - Google Patents

Abstract

The invention discloses a method for degrading and recycling antibiotic wastewater. Nickel source and tin dioxide are weighed, dissolved in ultrapure water, left standing, stirred in a water bath until dry, reduced at high temperature and then cooled in a furnace, and the solid is taken out for grinding; The resulting powder and antibiotic wastewater are added to the reaction kettle, the reaction kettle is tightened, and the oxidation reaction is carried out under stirring to degrade the antibiotics and obtain formic acid; the method can efficiently remove the high-concentration antibiotics contained in the wastewater, and generate formic acid by recycling, thereby realizing pollution. Material resources, turning waste into treasure.

Description

A kind of method for degrading and recycling antibiotic wastewater

technical field

The invention relates to the field of antibiotic wastewater treatment, and relates to a method for degrading and recycling antibiotic wastewater.

Background technique

Because antibiotics have excellent antibacterial properties, they are widely used in medicine, agricultural drugs, aquaculture, animal husbandry and other industries, and 40%-90% enter the environment in the form of parent or metabolite, causing serious environmental hazards. . Researchers have carried out a lot of exploration on antibiotic wastewater treatment, but most of the current treatment technologies only go to the level of COD (chemical oxygen demand) removal, and there is no report on the resource utilization of antibiotics.

Therefore, it is an urgent problem to find a way to recycle the pollution of antibiotic wastewater, reduce the environmental toxicity of antibiotics, and reduce the spread of resistance genes.

Under high temperature and high pressure, the physical and chemical parameters of water are changed, the mass and heat transfer performance is greatly improved, and the reaction process is fast and efficient. Therefore, the sub-supercritical water technology has broad prospects for the treatment of antibiotic wastewater without pre-dehydration treatment. The sub-supercritical water technology is widely used in the recycling of organic matter. Not so easy to implement in react.

SUMMARY OF THE INVENTION

The invention provides a method for treating antibiotic wastewater with convenient preparation, economy and remarkable effect, which specifically comprises the following steps:

(1) Weigh nickel source and tin dioxide, add ultrapure water to dissolve, stir to dryness under water bath after standing, place in tube furnace, cool with furnace after high temperature reduction, take out solid and grind;

(2) adding the ground powder and antibiotic waste water in step (1) to the reaction kettle, tightening the reaction kettle, and carrying out an oxidation reaction under stirring to degrade the antibiotic to obtain formic acid simultaneously.

Step (1) The nickel source is nickel nitrate, nickel chloride or other nickel salts, and the amount ratio of the nickel source to the tin dioxide substance is 1-5:1.

Step (1) the standing time is 12～24h, and the temperature of the water bath is 50～85°C.

Step (1) high temperature reduction is to be heated to 500 to 550 ° C with a heating rate of 5 to 8 ° C/min under the mixed gas of nitrogen and hydrogen, and the reduction time is 1 to 3 h, wherein the volume ratio of nitrogen and hydrogen is 95: 5.

Step (2) The antibiotic concentration in the antibiotic wastewater is 3-12 mg/mL, the antibiotic is enrofloxacin, tetracycline or norfloxacin, and the mass ratio of the antibiotic in the antibiotic wastewater to the ground powder is 5-10:1.

In step (2), hydrogen peroxide is also added, and the substance ratio of the hydrogen peroxide to the antibiotics in the antibiotic wastewater is 5-57:1.

Step (2) The material of the reaction kettle is Hastelloy, the volume is 25mL, the stirring speed is 400-500r/min, the oxidation reaction temperature is 180-330°C, and the reaction time is more than 0.5h.

The beneficial effects of the present invention are:

(1) The use of sub-supercritical water technology can enhance the mass transfer and heat transfer capacity in the reaction, speed up the contact reaction process for antibiotics, and also degrade antibiotics to produce formic acid.

(2) The Ni/SnO ₂ catalyst prepared by the impregnation method forms a NixSny alloy, which greatly improves the catalytic activity, can effectively reduce the reaction conditions, and the catalyst preparation process is simple, the source of materials is wide, and the price is low.

(3) The present invention is simple in operation process, widely available in material sources, can solve the limiting factors such as mass transfer, degrade antibiotic wastewater quickly and efficiently, and can also recycle to produce formic acid, thus realizing comprehensive treatment of wastewater and recycling of waste. use.

Description of drawings

Fig. 1 is the degradation rate figure of norfloxacin in embodiment 1;

Fig. 2 is the formic acid yield figure in the norfloxacin degradation reaction among the embodiment 1;

Fig. 3 is the scanning electron microscope picture of Ni/ _SnO catalyst obtained in embodiment 2;

Fig. 4 is the X-ray diffractogram of the Ni/ _SnO catalyst obtained in Example 2;

Fig. 5 is the H ₂ -TPR curve diagram of the Ni/SnO ₂ catalyst obtained in Example 2;

Fig. 6 is the XPS figure of Ni/ _SnO catalyst obtained in Example 2;

Fig. 7 is a graph of the degradation rate of norfloxacin in Example 2;

Fig. 8 is the formic acid yield figure in the norfloxacin degradation reaction among the embodiment 2;

Fig. 9 is the degradation rate figure of enrofloxacin among the embodiment 3;

Fig. 10 is the formic acid output figure in the enrofloxacin degradation reaction among the embodiment 3;

Figure 11 is a graph of the degradation rate of tetracycline in Example 4;

FIG. 12 is a graph showing the yield of formic acid in the tetracycline degradation reaction in Example 4. FIG.

Detailed ways

The present invention will be described in further detail below through the examples, but the present invention is not limited to the content, and any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention. within.

Example 1

A method for degrading and recycling antibiotic wastewater, the specific steps are as follows:

(1) take by weighing nickel nitrate and tin dioxide, wherein the amount ratio of nickel nitrate and tin dioxide substance is 1:1, add ultrapure water to dissolve, the volume ratio g of nickel nitrate and tin dioxide total mass and ultrapure water :mL is 1:10, after standing for 12 hours, stir to dry in a water bath at 70°C, put it in a tube furnace, pass in a mixed gas of nitrogen and hydrogen, and heat up to 550°C at a heating rate of 7°C/min to reduce 2h, after natural cooling, take out the solid and grind to obtain Ni/SnO ₂ catalyst, wherein the flow ratio of nitrogen and hydrogen is 95:5;

(2) the catalyst and antibiotic waste water obtained in step (1) are added to the reaction kettle, and the reaction kettle is tightened, wherein the antibiotic waste water concentration is 7.7 mg/mL, and the antibiotic is norfloxacin, and the difference between the antibiotic and the catalyst in the antibiotic waste water is 7.7 mg/mL. The mass ratio is 5:1;

(3) Set the temperature in the reaction kettle to 180°C, the magnetic rotational speed to 500r/min, and the reaction for 0.5-6h.

Fig. 1 is a graph of the degradation rate of norfloxacin in this example. After 0.5h of reaction, the degradation rate reaches over 85%, and the reaction time is prolonged, and finally the degradation rate can reach over 99%.

Fig. 2 is a graph of the yield of formic acid in the degradation reaction of norfloxacin in the present embodiment, it can be seen that in the process of the sub-supercritical water catalytic liquefaction reaction, formic acid is generated, and the yield is about 2%.

Example 2

A method for degrading and recycling antibiotic wastewater, the specific steps are as follows:

(1) take by weighing nickel nitrate and tin dioxide, wherein the amount ratio of nickel nitrate and tin dioxide substance is 1:1, add ultrapure water to dissolve, the volume ratio g of nickel nitrate and tin dioxide total mass and ultrapure water :mL is 1:10, after standing for 12 hours, stir to dry in a water bath at 70°C, put it in a tube furnace, pass in a mixed gas of nitrogen and hydrogen, and heat up to 550°C at a heating rate of 7°C/min to reduce 2h, after natural cooling, take out the solid and grind to obtain Ni/SnO ₂ catalyst, wherein the flow ratio of nitrogen and hydrogen is 95:5;

(2) catalyst, antibiotic waste water, hydrogen peroxide obtained in step (1) are added to the reaction kettle, and the reaction kettle is tightened, wherein the antibiotic waste water concentration is 7.7mg/mL, and the antibiotic is norfloxacin, and the antibiotics in the antibiotic waste water and The mass ratio of the catalyst is 5:1, and the amount ratio of the antibiotics in the hydrogen peroxide and the antibiotic wastewater is 19:1;

(3) The temperature of the reaction kettle is set to 180°C, the magnetic rotation speed is 500r/min, and the reaction is carried out for 0.5-6h.

Fig. 3 is a scanning electron microscope image of the Ni/SnO ₂ catalyst prepared in this example, it can be seen that the Ni/SnO ₂ catalyst forms a sheet crystal, and the lattice fringes can be clearly seen.

Figure 4 shows the X-ray diffraction pattern of the Ni/SnO ₂ catalyst prepared in this example, and it can be seen that two new peaks of NiO and NixSny appear in the catalyst.

Figure 5 shows the H ₂ -TPR curve of the Ni/SnO ₂ catalyst prepared in this example. The peak at around 610°C should be Sn. Generally, SnO ₂ has a stable structure and will be reduced only after 700°C. The reduction temperature under the heterozygote decreases, indicating that a synergistic effect occurs between the metals, and the catalyst Ni/ _SnO2 has a good redox ability.

Figure 6 is an XPS diagram of the Ni/ _SnO catalyst prepared in this example, Figure 6 (a), (b), (c) are the XPS diagrams of oxygen element, nickel element, and tin element, respectively, Figure 6 (b) The peak at 852.9 eV belongs to the metallic state of Ni, and the peak around 485 eV in Figure 6(c) belongs to the metallic state of Sn. It can be seen that NixSny alloy is formed in the Ni/SnO ₂ catalyst prepared by the impregnation method, which is the catalyst with high activity. reason.

Fig. 7 is a graph of the degradation rate of norfloxacin in this example. It can be seen that after the reaction of norfloxacin at a low temperature of 180°C for 0.5 h, the degradation rate can reach more than 85%, and the reaction time is prolonged, and finally the degradation can reach more than 99% Rate.

Fig. 8 is a graph of the yield of formic acid in the degradation reaction of norfloxacin in this example, it can be seen that in the process of the sub-supercritical water catalytic liquefaction reaction, formic acid is generated, and the yield is about 3%.

Example 3

A method for degrading and recycling antibiotic wastewater, the specific steps are as follows:

(1) take by weighing nickel nitrate and tin dioxide, wherein the amount ratio of nickel nitrate and tin dioxide substance is 1:3, add ultrapure water to dissolve, the volume ratio g of nickel nitrate and tin dioxide total mass and ultrapure water :mL is 1:20, after standing for 18 hours, stir to dryness in a 50°C water bath, put it in a tube furnace, pass in a mixed gas of nitrogen and hydrogen, and heat up to 500°C at a heating rate of 5°C/min to reduce 3h, after natural cooling, take out the solid and grind to obtain Ni/SnO ₂ catalyst, wherein the flow ratio of nitrogen and hydrogen is 95:5;

(2) catalyst, antibiotic waste water, hydrogen peroxide prepared in step (1) are added in the reaction kettle, and the reaction kettle is tightened, wherein the antibiotic waste water concentration is 12 mg/mL, and the antibiotic is enrofloxacin, and the antibiotic and the catalyst in the antibiotic waste water The mass ratio of hydrogen peroxide and antibiotics in wastewater is 8:1, and the amount ratio of antibiotics in hydrogen peroxide and antibiotic wastewater is 5:1;

(3) The temperature of the reaction kettle is set to 300°C, the rotational speed of the magnetic force is 400r/min, and the reaction is carried out for 0.5-6h.

Fig. 9 is a graph of the degradation rate of enrofloxacin in this example, and it can be found that the degradation rate of enrofloxacin reaches more than 94% in 0.5h.

Figure 10 is a graph of the formic acid yield in the enrofloxacin degradation reaction in this example, it can be seen that in the sub-supercritical water catalytic liquefaction reaction process, formic acid is generated, and the formic acid yield is increased to 20% to 32%.

Example 4

A method for degrading and recycling antibiotic wastewater, the specific steps are as follows:

(1) take by weighing nickel chloride and tin dioxide, wherein the amount ratio of nickel chloride and tin dioxide substance is 1:5, add ultrapure water to dissolve, nickel chloride and tin dioxide total mass and ultrapure water The volume ratio of g:mL is 1:15. After standing for 24 hours, stir in a water bath at 85°C until dry, place it in a tube furnace, pass in a mixed gas of nitrogen and hydrogen, and heat up to 8°C/min. Reduction at 540 °C for 1 h, after natural cooling, the solid was taken out and ground to obtain a Ni/SnO ₂ catalyst, in which the flow ratio of nitrogen and hydrogen was 95:5;

(2) catalyst, antibiotic waste water, hydrogen peroxide obtained in step (1) are added in the reaction kettle, and the reaction kettle is tightened, wherein the antibiotic waste water concentration is 3mg/mL, and the antibiotic is tetracycline, and the mass ratio of the antibiotic in the antibiotic waste water and the catalyst It is 10:1, and the substance ratio of the antibiotics in hydrogen peroxide and antibiotic wastewater is 57:1;

(3) The temperature of the reaction kettle is set to 330°C, the magnetic rotation speed is 450r/min, and the reaction is carried out for 0.5-6h.

Figure 11 is a graph of the degradation rate of tetracycline in this example, and the degradation rate reaches about 96% after 0.5 h.

Figure 12 is a graph of the yield of formic acid in the tetracycline degradation reaction in this example. It can be seen that in the process of the sub-supercritical water catalytic liquefaction reaction, formic acid is generated, and the yield is about 3%.

It can be seen from Examples 1-4 that the degradation reaction is efficient and fast, and the degradation rate can reach more than 85% within 0.5h. The addition of hydrogen peroxide will increase the formic acid production within a certain range. This is because the addition of hydrogen peroxide will During the reaction, free radicals such as hydroxyl groups with strong oxidizing properties are generated, which can attack the chemical bonds of antibiotics and promote the decarboxylation reaction. In sub-supercritical water, water will release hydrogen and combine to form formic acid; another way is to attack by free radicals Chemical bonds, dealkylation, hydroxylation and other effects occur, oxidative degradation of antibiotics into small molecular alcohols and aldehydes, and finally further oxidation to form formic acid, but excessive hydrogen peroxide will cause formic acid to decompose into CO ₂ and H ₂ O.

Claims (4)

1. a method for degrading and recycling antibiotic waste water, is characterized in that, specifically comprises the following steps: (1) Weigh the nickel source and tin dioxide, add ultrapure water to dissolve, leave standing and stir in a water bath until dry, cool down with the furnace after high temperature reduction, take out the solid and grind; the nickel source is nickel nitrate or nickel chloride, and the nickel source and The substance ratio of tin dioxide is 1~5:1; the high temperature reduction is to heat up to 500~550°C at a heating rate of 5~8°C/min under the mixed gas of nitrogen and hydrogen, and reduce it for 1~3h. The volume ratio of nitrogen and hydrogen is 95:5; (2) Add the ground powder and antibiotic waste water in step (1) into the reaction kettle, tighten the reaction kettle, and carry out the oxidation reaction under stirring. When the time is more than 0.5h, formic acid is obtained while degrading the antibiotic. 2 . The method for degrading and recycling antibiotic wastewater according to claim 1 , wherein in step (1), the standing time is 12 to 24 hours, and the temperature of the water bath is 50 to 85° C. 3 . 3. The method for degrading and recycling antibiotic waste water according to claim 1, wherein the antibiotic concentration in the step (2) antibiotic waste water is 3～12 mg/mL, and the antibiotic is enrofloxacin, tetracycline or norfloxacin , the mass ratio of the antibiotics in the antibiotic wastewater to the ground powder is 5~10:1. 4. The method for degrading and recycling antibiotic waste water according to claim 1, characterized in that, in step (2), hydrogen peroxide is also added, and the substance ratio of the hydrogen peroxide to the antibiotics in the antibiotic waste water is 5～57:1.

Images