CN115301276A - Preparation method of N/LC catalyst for purifying antibiotic wastewater - Google Patents

Abstract

The invention discloses a preparation method of an N/LC catalyst for purifying antibiotic wastewater, which comprises the following steps: (1) Weighing lignin, melamine and urea, adding deionized water, carrying out ultrasonic treatment, manually stirring, and uniformly mixing to obtain a reaction precursor; (2) putting the reaction precursor into an oven for drying and grinding; (3) And putting the ground reaction precursor into a tube furnace under the protection of nitrogen gas for twice calcination to obtain the N/LC catalyst. The catalyst prepared by the method provided by the invention has a stable structure, has high capacity of activating persulfate to degrade antibiotics, and has the potential of efficiently purifying antibiotic wastewater. The method has the advantages of simple equipment, low cost of raw materials, simple and environment-friendly process and great industrial production value.

Description

A kind of preparation method of N/LC catalyst for purifying antibiotic waste water

technical field

The invention relates to the technical field of wastewater purification, in particular to a preparation method of an N/LC catalyst used for purifying antibiotic wastewater.

Background technique

With the rapid development of science and technology, there are more and more types of antibiotics used in daily life. Antibiotics are widely used in livestock and poultry farming, water plant farming and pharmaceutical industries. While antibiotics bring convenience to human health, the incomplete absorption and utilization of antibiotics into the water environment also brings risks to the water ecological environment and poses a serious threat to human health and safety. Therefore it is necessary to develop a method for purifying antibiotic waste water.

Among the various methods of purifying antibiotic-based wastewater. The persulfate advanced oxidation method can produce sulfate radicals with stronger oxidation ability than the traditional Fenton method, and has become a research hotspot in recent years. Sulfate radical is a strong free radical with stronger oxidation ability than hydroxyl radical. The standard oxidation potential of sulfate radical is 2.503.1V, while that of hydroxyl radical is 1.902.7V. There are many ways to activate persulfate, which can be activated by external energy such as heat, ultraviolet and ultrasound, and can also be activated by transition metals and heterogeneous catalysts. For example, the Chinese invention patent (CN114570368A) discloses the preparation of a cobalt phosphorus-based catalyst and its application in activating persulfate to degrade antibiotics in waste water. It belongs to the metal heterogeneous carbon-based catalyst, and the ability to activate persulfate is enhanced by introducing metal heteroatoms to change the electron distribution and pore structure inside the carbon material.

But metal heterogeneous catalysts also have disadvantages. The introduced metal heteroatoms may leach out after the reaction and cause secondary pollution, and the pH of the solution may need to be adjusted before and after activation. Therefore, seeking a catalyst that will not cause secondary pollution is of great significance for the efficient degradation of antibiotic wastewater.

Contents of the invention

In view of the metal heterogeneous catalyst metal ion leaching problem in the prior art, the object of the present invention is to provide a preparation method of N/LC catalyst for purifying antibiotic wastewater to solve the above problems.

The object of the present invention adopts following technical scheme to realize:

A simple photocatalyst preparation method for removing antibiotic waste water, comprising the following steps:

(1) Weigh lignin, melamine and urea, add deionized water to ultrasonic and manually stir, and obtain the reaction precursor after uniform mixing;

(2) Put the reaction precursor into an oven to dry and grind;

(3) The ground reaction precursor was placed in a tube furnace under a nitrogen atmosphere for two calcinations to obtain an N/LC catalyst.

Preferably, the molar ratio of lignin, melamine and urea in the step (1) is 1:10-20:30-40.

Preferably, in the step (1), the time for ultrasonication and manual stirring is 30 minutes.

Preferably, the oven drying temperature in the step (2) is 800-100° C., and the drying time is 24048 hours.

Preferably, in the step (3), the process of temperature-programmed treatment during the first calcination is as follows: the initial temperature is 30°C, under the protection of nitrogen, the temperature is raised to 400°C at 5°C/min, and kept for 2 hours.

Preferably, in the step (3), the carbon material obtained by the first calcination is ground, and then the second calcination is performed. The process of temperature programming treatment during the second calcination is as follows: the initial temperature is 30°C, under the protection of nitrogen, the temperature is raised to 900°C at 5°C/min, and kept for 2h.

The beneficial effects of the present invention are:

The nitrogen-doped carbon material catalyst prepared by the method of the invention has a stable structure and can quickly activate persulfate to degrade antibiotics in waste water. The raw materials used in the present invention are stirred and mixed evenly at normal temperature, and then calcined twice after being dried to obtain the N/LC catalyst. The preparation process is simple, the reaction conditions are mild, the raw materials used are cheap and easy to obtain, and the method has application value in large-scale industrial production.

The catalyst prepared by the invention uses lignin as carbon source, and melamine and urea as nitrogen source. On the basis of carbon materials, non-metallic heteroatoms are introduced, which changes the electronic structure of the carbon plane and introduces new active sites. The prepared N/LC catalyst is a non-metallic heterogeneous catalyst, which avoids the problem of metal ion leaching.

Description of drawings

The present invention is further described by using the accompanying drawings, but the embodiments in the accompanying drawings do not constitute any limitation to the present invention. For those of ordinary skill in the art, they can also obtain other according to the following accompanying drawings without creative work. Attached picture.

Fig. 1 is the SEM figure of the N/LC catalyst prepared by embodiment 1;

FIG. 2 is an effect diagram of the N/LC catalyst prepared in Example 1 activating persulfate to purify tetracycline solution.

Detailed ways

The following examples of the present invention are described in detail below. The following examples are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operating procedures are provided, but the protection scope of the present invention is not limited to the following the embodiment.

The present invention is further described in conjunction with the following examples.

Example:

A simple photocatalyst preparation method for removing antibiotic waste water, comprising the following steps:

(1) Weigh lignin, melamine and urea, add deionized water to ultrasonic and manually stir, and obtain the reaction precursor after uniform mixing;

(2) Put the reaction precursor into an oven to dry and grind;

(3) The ground reaction precursor was placed in a tube furnace under a nitrogen atmosphere for two calcinations to obtain an N/LC catalyst.

Specifically, with reference to Figures 1-2, the following examples 1-3 are used for specific description.

Example 1

The simple photocatalyst preparation method for removing antibiotic wastewater provided by the embodiment of the present invention comprises the following steps:

Weigh 3g of lignin, 12g of melamine and 12g of urea into a clean beaker, add 20mL of deionized water and stir ultrasonically for 30 minutes until the liquid in the beaker becomes viscous to obtain a reaction precursor. The molar ratio of lignin:melamine:urea in the reaction precursor is 1:16:34. Then the reaction precursor was dried in an oven at 80°C for 24 hours, and the obtained sample was ground. The ground reaction precursor is calcined for the first time, and the process of temperature programming treatment during the first calcination is as follows: the initial temperature is 30°C, under the protection of nitrogen, the temperature is raised to 400°C at 5°C/min, and kept for 2h . Grinding the carbon material obtained by the first calcination, and then performing the second calcination. The process of temperature programming treatment during the second calcination is as follows: the initial temperature is 30°C, under the protection of nitrogen, the temperature is raised to 900°C at 5°C/min, and kept for 2h. After cooling, grind the obtained carbon material evenly to obtain the N/LC catalyst.

Example 2

The simple photocatalyst preparation method for removing antibiotic wastewater provided by the embodiment of the present invention comprises the following steps:

Weigh 3g of lignin, 7.5g of melamine and 10.6g of urea into a clean beaker, add 20mL of deionized water and stir ultrasonically for 30 minutes until the liquid in the beaker becomes viscous to obtain a reaction precursor. The molar ratio of lignin:melamine:urea in the reaction precursor is 1:10:30. Then the reaction precursor was dried in an oven at 80°C for 24 hours, and the obtained sample was ground. The ground reaction precursor is calcined for the first time, and the process of temperature programming treatment during the first calcination is as follows: the initial temperature is 30°C, under the protection of nitrogen, the temperature is raised to 400°C at 5°C/min, and kept for 2h . Grinding the carbon material obtained by the first calcination, and then performing the second calcination. The process of temperature programming treatment during the second calcination is as follows: the initial temperature is 30°C, under the protection of nitrogen, the temperature is raised to 900°C at 5°C/min, and kept for 2h. After cooling, grind the obtained carbon material evenly to obtain the N/LC catalyst.

Example 3

The simple photocatalyst preparation method for removing antibiotic wastewater provided by the embodiment of the present invention comprises the following steps:

Weigh 3g of lignin, 15g of melamine and 14.1g of urea into a clean beaker, add 20mL of deionized water and stir ultrasonically for 30 minutes until the liquid in the beaker becomes viscous to obtain a reaction precursor. The molar ratio of lignin: melamine: urea in the reaction precursor is 1:20:40. Then the reaction precursor was dried in an oven at 80°C for 24 hours, and the obtained sample was ground. The ground reaction precursor is calcined for the first time, and the process of temperature programming treatment during the first calcination is as follows: the initial temperature is 30°C, under the protection of nitrogen, the temperature is raised to 400°C at 5°C/min, and kept for 2h . Grinding the carbon material obtained by the first calcination, and then performing the second calcination. The process of temperature programming treatment during the second calcination is as follows: the initial temperature is 30°C, under the protection of nitrogen, the temperature is raised to 900°C at 5°C/min, and kept for 2h. After cooling, grind the obtained carbon material evenly to obtain the N/LC catalyst.

Analysis for Figure 1:

Scanning electron micrographs were taken for the N/LC catalyst prepared in Example 1. As shown in Figure 1, it can be seen that the N/LC catalyst has a rich surface structure and many pore structures.

Analysis for Figure 2:

Figure 2 shows the selection of tetracycline hydrochloride solution with an initial concentration of 20mg/L as a typical representative of antibiotic wastewater, and the performance of the prepared N/LC catalyst for degrading tetracycline wastewater by activated persulfate was studied. The experimental conditions were as follows: 100ml of tetracycline hydrochloride solution with an initial concentration of 20mg/L was used as simulated wastewater, the amount of N/LC catalyst was 30mg, the amount of PMS was 0.5mM, and the reaction time was 60min. It can be seen from the figure that the degradation rate is very fast in the first ten minutes of the reaction, and then tends to be stable. After reacting for 60 minutes, the removal rate of tetracycline hydrochloride wastewater reached 90.4%.

The catalyst prepared by the method provided in the above embodiments of the present invention has a stable structure, has a high ability to activate persulfate to degrade antibiotics, and has the potential to efficiently purify antibiotic wastewater. The equipment used in the invention is simple, the raw material is cheap, the process is simple and environment-friendly, and has great industrialized production value.

The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make many modifications and changes according to the concept of the present invention without creative efforts. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art shall be within the scope of protection defined by the claims.

Claims (8)

1. a kind of preparation method for the N/LC catalyst of purifying antibiotics waste water is characterized in that, comprises the following steps: (1) Weigh lignin, melamine and urea and add them to deionized water, ultrasonically stir, and evenly mix to obtain a reaction precursor; (2) Put the reaction precursor into an oven to dry and grind; (3) The ground reaction precursor was placed in a tube furnace under a nitrogen atmosphere for two calcinations to obtain an N/LC catalyst. 2. the N/LC catalyst preparation method that is used to purify antibiotics wastewater as claimed in claim 1, is characterized in that, the mol ratio of lignin, melamine and urea is 1:10～20 in described step (1) :30～40. 3. the N/LC catalyst preparation method that is used to purify antibiotics waste water as above-mentioned claim 1 is characterized in that, the mol ratio of lignin, melamine and urea is 1:16:34 in described step (1) . 4. the N/LC catalyst preparation method that is used to purify antibiotics wastewater as claimed in claim 1, is characterized in that, in described step (1), lignin quality is 3g, and melamine quality is 12g, and urea quality is 12g , the volume of deionized water is 20mL. 5. the N/LC catalyst preparation method that is used to purify antibiotics wastewater as claimed in claim 1, is characterized in that, in described step (1), the time of ultrasonic and manual stirring is 30min. 6. The method for preparing an N/LC catalyst for purifying antibiotic wastewater according to claim 1, wherein the oven drying temperature in the step (2) is 800-100° C., and the drying time is 24048 hours. 7. the N/L catalyst preparation method that is used to purify antibiotics waste water as described in above-mentioned claim 1 is characterized in that, in described step (3), the process of temperature-programmed processing during first calcining is: initial temperature 30°C, under the protection of nitrogen, the temperature was raised to 400°C at 5°C/min, and kept for 2h. 8. the N/LC catalyst preparation method that is used to purify antibiotics wastewater as claimed in claim 1, is characterized in that, in described step (3), the carbon material obtained by calcining for the first time is ground, and then The second calcination: the process of temperature programming treatment during the second calcination is as follows: the initial temperature is 30°C, under the protection of nitrogen, the temperature is raised to 900°C at 5°C/min, and kept for 2h.

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