阅读说明：本技术 一种利用碳纳米管激活过氧碳酸氢盐降解磺酰胺的方法 (Method for degrading sulfonamide by activating peroxybicarbonate through carbon nano tube ) 是由 马原 孙佩哲 郭娜 于 2021-08-31 设计创作，主要内容包括：本发明涉及一种利用单壁碳纳米管激活过氧碳酸氢盐降解磺胺甲恶唑的方法,单壁碳纳米管在其导带中提供连续的电子态,可以从有机共轭分子中收集电子,在过氧化氢与碳酸氢盐的活化体系中快速高效激活过氧碳酸氢盐。本发明方法采用单壁碳纳米管激活过氧碳酸氢盐对磺胺甲恶唑进行处理,能够有效处理磺胺甲恶唑,具有催化性能强、抗干扰能力强、分散性好、稳定性强、易于回收重复利用的优点,在被磺胺甲恶唑污染的水体中具有良好的应用前景。(The invention relates to a method for degrading sulfamethoxazole by activating peroxybicarbonate by using a single-walled carbon nanotube, wherein the single-walled carbon nanotube provides continuous electronic states in a conduction band thereof, can collect electrons from organic conjugated molecules, and quickly and efficiently activates peroxybicarbonate in an activation system of hydrogen peroxide and bicarbonate. The method adopts the single-walled carbon nanotube to activate the peroxydicarbonate to treat the sulfamethoxazole, can effectively treat the sulfamethoxazole, has the advantages of strong catalytic performance, strong anti-interference capability, good dispersibility, strong stability and easy recycling, and has good application prospect in water bodies polluted by the sulfamethoxazole.)

1. Peroxydicarbonates are activated using single-walled carbon nanotubes.

2. The sulfamethoxazole is removed by using a system of activating peroxybicarbonate by using a single-walled carbon nanotube.

3. The method of claim 1, wherein the single-walled carbon nanotube is 1g/L, the hydrogen peroxide is 10mM, the sodium bicarbonate solution is 250mM, the disodium hydrogen phosphate is 10mM, the rotation speed of the system is 200r, and the temperature is 25 ℃.

4. The method of claim 1, wherein the rate of peroxybicarbonate activation is measured by filtering 1mL of the sample rapidly through a membrane filter holder containing a 0.45 μ M membrane, shaking 1mL of 0.5M sulfuric acid, 0.1M titanyl sulfate, and 7.9mL of ultrapure water, and measuring the absorbance at 410nm using an ultraviolet spectrophotometer to obtain the absorbance of hydrogen peroxide.

5. Since hydrogen peroxide and peroxybicarbonate are a relationship between a reactant and a product, the activation rate of peroxybicarbonate is estimated as follows:

activation rate (%) - (1-A)_t/A₀)×100

A (A) of₀Denotes the absorbance value of hydrogen peroxide at 0, A_tThe absorbance of hydrogen peroxide after t hours from the reaction was expressed.

6. In claim 2, the reacted system was added with extract (0.1M NaOH: methanol 1: 1) and the mixture was shaken on a constant temperature shaker at 200rpm for 10 minutes to desorb sulfamethoxazole adsorbed on biochar.

7. The extracted mixture was then filtered into a High Performance Liquid Chromatography (HPLC) vial by rapidly pushing it through a membrane filter holder fitted with a 0.22 μm membrane using a 1mL plastic syringe, and then 0.5mM sodium thiosulfate was added to the vial to quench the oxidation reaction.

8. According to the peak area tested by the high performance liquid chromatography, the degradation rate of sulfamethoxazole is obtained, and the degradation rate is expressed as follows:

percent degradation rate (%) - (1-SMX)_t/SMX₀)×100

The SMX₀Shows the area of the peak of sulfamethoxazole at the time when the reaction had not started, SMX_tThe peak area of sulfamethoxazole after t hours from the reaction was shown.

Technical Field

The invention belongs to the field of advanced oxidation treatment of sulfonamide pollutants, relates to a method for degrading organic matters by activating peroxybicarbonate by using a single-walled carbon nanotube, and particularly relates to a method for degrading sulfamethoxazole by activating peroxybicarbonate by using a single-walled carbon nanotube.

Background

Sulfamethoxazole is a common sulfonamide antibiotic and is generally widely used clinically as a broad-spectrum antibacterial agent. The abuse of antibiotics can cause water body pollution, cause long-term adverse effects on an ecosystem and cause the appearance of antibiotics and anti-pathogenic microorganisms. Sulfamethoxazole has been detected so far in various municipal sewage treatment plants, hospital sewage, surface water and even drinking water systems. Sulfamethoxazole is widely applied and is difficult to degrade in natural water, and the sulfamethoxazole is difficult to effectively remove by a conventional water treatment method. The advanced oxidation process is utilized to degrade sulfamethoxazole in water body, which is a potential strategy at present.

The high-grade oxidation method based on the peroxybicarbonate is a water treatment method with high treatment efficiency, thorough removal, low cost, convenient operation and high pH tolerance. In this system, the percarbonate, acting as an oxidant, is activated under the catalytic action of the catalyst to generate highly reactive oxidizing radicals or intermediate active species, which further attack and degrade the target pollutants. Nowadays, metal-based catalysts are widely used for activating percarbonate because of their high catalytic activity, but their application is limited by problems such as secondary pollution caused by the elution of existing heavy metals. Single-walled carbon nanotubes are another class of green catalyst materials that are under development with potential for use. The structure of the carbon nanotube is completely formed by sp2 hybridized carbon, and has the advantages of excellent electrical property, high mechanical strength, high chemical stability, high aspect ratio and high activation specific surface area. Single-walled carbon nanotubes are seamless nanocylinders rolled from small strips of graphene sheets, most of which have a diameter of about 1nm and a length of up to centimeter level. Single-walled carbon nanotubes exist in bundled form, consisting of up to hundreds of individual tubes, whose oxidation occurs mostly at the ends and a few at the defect sites. Single-walled carbon nanotubes provide a continuum of electronic states in their conduction band that can be collected from organic conjugated molecules. The method has great significance for improving the treatment effect of the bicarbonate advanced oxidation system on organic pollutants, particularly sulfamethoxazole, by utilizing the green single-walled carbon nanotube material with high-efficiency catalytic capability, strong anti-interference capability.

Disclosure of Invention

The technical problem to be solved by the invention is to overcome the defects of the prior art and provide the method for degrading sulfamethoxazole by activating percarbonate through single-walled carbon nanotubes, which has the advantages of simple operation, short period, easy recovery and reuse, high degradation efficiency, good removal effect and strong anti-interference capability.

In order to solve the technical problems, the invention adopts the following technical scheme:

firstly, activating peroxybicarbonate by using single-walled carbon nanotubes;

and secondly, removing sulfamethoxazole by using a system of activating peroxybicarbonate by using the single-walled carbon nanotube.

Wherein, the first step needs 1g/L of single-walled carbon nano-tube, 10mM of hydrogen peroxide, 250mM of sodium bicarbonate solution and 10mM of disodium hydrogen phosphate.

In the first step, 1mL of sample is taken to quickly push through a membrane filter bracket provided with a 0.45-micron membrane for filtration, 1mL of 0.5M sulfuric acid, 0.1M titanyl sulfate and 7.9mL of ultrapure water are added for shaking uniformly, then the absorbance at 410nm is measured by using an ultraviolet spectrophotometer immediately, the absorbance of hydrogen peroxide is obtained, and the activation rate of peroxybicarbonate is calculated due to the relation between the hydrogen peroxide and peroxybicarbonate as a reactant and a product, wherein the activation rate is expressed as:

activation rate (%) - (1-A)_t/A₀)×100

A₀Denotes the absorbance value of hydrogen peroxide at 0, A_tThe absorbance of hydrogen peroxide after t hours from the reaction was expressed.

Wherein the first step is to shake the mixture on a constant temperature (25 ℃) shaker at 200rpm for 24 hours in order to make the distribution of the single-walled carbon nanotubes more uniform.

Wherein the second step is to add 20. mu.M sulfamethoxazole to the activated system of the first step, and the reaction is started and the homogeneous system is maintained by mixing the suspension at 200rpm at room temperature (25. + -. 2 ℃).

Wherein the second step adds the extract (0.1M NaOH: methanol 1: 1) to the reacted system and shakes the mixture on a constant temperature shaker at 200rpm for 10 minutes to desorb sulfamethoxazole adsorbed on the single-walled carbon nanotubes. The extracted mixture was then filtered into a High Performance Liquid Chromatography (HPLC) vial by quickly pushing it through a membrane filter holder fitted with a 0.22 μm membrane using a 1mL plastic syringe. Then, 0.5mM sodium thiosulfate was added to the vial to quench the oxidation reaction, and the degradation rate of sulfamethoxazole was obtained from the peak area measured by high performance liquid chromatography, and the degradation rate was expressed as:

percent degradation rate (%) - (1-SMX)_t/SMX₀)×100

SMX₀Shows the area of the peak of sulfamethoxazole at the time when the reaction had not started, SMX_tThe peak area of sulfamethoxazole after t hours from the reaction was shown.

Advantageous effects

The invention has the beneficial effects that:

(1) the method for degrading organic pollutants by activating peroxydicarbonate by using the single-walled carbon nanotube has the advantages of simple operation, high degradation efficiency, high stability and the like, and has good application prospect in urine wastewater systems and polluted natural water bodies.

(2) The invention provides a method for degrading sulfamethoxazole by using single-walled carbon nanotubes to activate peroxybicarbonate, wherein hydrogen peroxide and bicarbonate generate peroxybicarbonate, and the single-walled carbon nanotubes can activate the peroxybicarbonate (see formula (1) to formula (2)). The single-walled carbon nanotube structure is completely formed by sp2 hybridized carbon, so that the single-walled carbon nanotube has faster and more efficient electron transfer performance.

(3) The single-walled carbon nanotube mainly contains C, H, O and other three elements, does not contain metal elements, and does not have the risks of secondary pollution such as metal dissolution and the like. The single-walled carbon nanotube has the advantages of strong catalytic performance, strong anti-interference capability, good dispersibility, strong stability and easy recycling, and is an environment-friendly catalytic material which has excellent catalytic performance and can be widely applied and is used for activating peroxydicarbonate.

Drawings

FIG. 1 is a graph showing the activation rate of single-walled carbon nanotubes for peroxydicarbonate in example 1 of the present invention and the activation rate of single-walled carbon nanotubes for hydrogen peroxide in comparative example 1.

FIG. 2 is a diagram of sulfamethoxazole degraded by bicarbonate peroxide activated by a single-walled carbon nanotube in example 2, a diagram of sulfamethoxazole degraded by hydrogen peroxide activated by a single-walled carbon nanotube in comparative example 2, and a diagram of sulfamethoxazole adsorbed by a single-walled carbon nanotube in comparative example 3.

Detailed Description

The invention is further described below with reference to the drawings and specific preferred embodiments of the description, without thereby limiting the scope of protection of the invention.

The materials and instruments used in the following examples are commercially available and the starting materials were analytically pure. In the following examples, unless otherwise specified, the data obtained are the average of two or more replicates.

Example 1 activation of peroxydicarbonates by single-walled carbon nanotubes

Soaking the single-wall carbon nanotube in ultrapure water for 24h, adding hydrogen peroxide into the single-wall carbon nanotube of 1g/L and sodium bicarbonate solution of 250mM and disodium hydrogen phosphate of 10 mM. At room temperature (25. + -. 2 ℃ C.), the reaction was started and the homogeneous system was maintained by mixing the suspension at 200 rpm. After 0, 1, 2, 3, 4 and 6 hours from the start of the reaction, 1mL of a sample of the supernatant was quickly filtered through a membrane filter holder equipped with a 0.45 μ M membrane, 1mL of 0.5M sulfuric acid, 0.1M titanyl sulfate and 7.9mL of ultrapure water were added thereto and shaken, immediately thereafter, absorbance at 410nm was measured using an ultraviolet spectrophotometer to obtain absorbance of hydrogen peroxide, and since hydrogen peroxide and peroxybicarbonate are in a relationship between a reactant and a product (see formula (3)), the rate of activation of peroxybicarbonate was estimated and expressed as:

activation rate (%) - (1-A)_t/A₀)×100 (3)

A₀Denotes the absorbance value of hydrogen peroxide at 0, A_tThe absorbance of hydrogen peroxide after t hours from the reaction was expressed.

Comparative example 1 activation of Single-walled carbon nanotubes with Hydrogen peroxide

Soaking the single-wall carbon nanotube in ultrapure water for 24h, and adding hydrogen peroxide into the single-wall carbon nanotube at a concentration of 1g/L and disodium hydrogen phosphate at a concentration of 10 mM. At room temperature (25. + -. 2 ℃ C.), the reaction was started and the homogeneous system was maintained by mixing the suspension at 200 rpm. After 0, 1, 2, 3, 4, and 6 hours from the start of the reaction, 1mL of a sample of the supernatant was quickly filtered by pushing it through a membrane filter holder equipped with a 0.45 μ M membrane, 1mL of 0.5M sulfuric acid, 0.1M titanyl sulfate, and 7.9mL of ultrapure water were added thereto and shaken, and immediately thereafter, the absorbance at 410nm was measured using an ultraviolet spectrophotometer to obtain the absorbance of hydrogen peroxide, whereby the activation rate of hydrogen peroxide was calculated, and the activation rate was expressed by the same method as in formula 3.

FIG. 1 is the activation rate of single-walled carbon nanotubes for peroxydicarbonate in example 1 and the activation rate of single-walled carbon nanotubes for hydrogen peroxide in comparative example 1. It can be seen from fig. 1 that the single-walled carbon nanotubes of the present invention have better activation effect on peroxydicarbonates than hydrogen peroxide. After the reaction time of 2 hours, the activation rate of the single-walled carbon nanotube to the peroxydicarbonate can reach 95%.

Example 2 Single-walled carbon nanotubes activated peroxybicarbonate to remove sulfamethoxazole from water

Soaking the single-walled carbon nanotube in ultrapure water for 24h, adding hydrogen peroxide into the single-walled carbon nanotube of 1g/L and adding sodium bicarbonate solution of 250mM, disodium hydrogen phosphate of 10mM and sulfamethoxazole of 20 μ M. The pH of the reaction system was adjusted to about 9. At room temperature (25. + -. 2 ℃ C.), the reaction was started and the homogeneous system was maintained by mixing the suspension at 200 rpm. After 0, 1, 2, 3, 4, 6 hours from the start of the reaction, 1mL of each supernatant was sampled, and an extract (0.1M NaOH: methanol ═ 1: 1) was added thereto, and the mixture was shaken at 200rpm on a constant temperature shaker for 10 minutes to desorb the SMX adsorbed on the single-walled carbon nanotubes. The extracted mixture was then filtered into a High Performance Liquid Chromatography (HPLC) vial by quickly pushing it through a membrane filter holder fitted with a 0.22 μm membrane using a 1mL plastic syringe. Then, 0.5mL of sodium thiosulfate was added to the vial to quench the oxidation reaction, and the peak area according to the hplc measurement gave the degradation rate of SMX (see formula (4)) expressed as:

percent degradation rate (%) - (1-SMX)_t/SMX₀)×100 (4)

SMX₀Shows the area of the peak of sulfamethoxazole at the time when the reaction had not started, SMX_tThe peak area of sulfamethoxazole after t hours from the reaction was shown.

Comparative example 2 Single-walled carbon nanotube activation of peroxybicarbonate to remove sulfamethoxazole from water

Soaking the single-walled carbon nanotube in ultrapure water for 24h, adding 1g/L of the single-walled carbon nanotube into a sodium bicarbonate solution of 250mM, 10mM of disodium hydrogen phosphate and 20 μ M of sulfamethoxazole. The treatment method was the same as in example 2.

Comparative example 3 Single-walled carbon nanotube for directly removing sulfamethoxazole in water

Soaking the single-wall carbon nanotube in ultrapure water for 24h, and adding 10mM disodium hydrogen phosphate and 20 μ M sulfamethoxazole into 1g/L single-wall carbon nanotube. The treatment method was the same as in example 2.

FIG. 2 shows that the single-walled carbon nanotube in example 2 activates peroxybicarbonate to degrade sulfamethoxazole, the single-walled carbon nanotube in comparative example 2 activates hydrogen peroxide to degrade sulfamethoxazole, and the single-walled carbon nanotube in comparative example 3 itself adsorbs sulfamethoxazole. It can be seen that the single-walled carbon nanotube activated peroxybicarbonate has very good degradation effect on sulfamethoxazole within one hour, and the degradation rate is improved and slowed down after 1-5 hours.

In conclusion, the single-walled carbon nanotube has the advantages of strong catalytic performance, strong anti-interference capability, good dispersibility, strong stability and easy recycling, and when the single-walled carbon nanotube is used for activating peroxybicarbonate to degrade sulfonamide organic pollutants (such as sulfamethoxazole) in a water body, the single-walled carbon nanotube can efficiently remove the sulfonamide organic pollutants (such as sulfamethoxazole) in the water body, so that the single-walled carbon nanotube has high use value and good application prospect.

The foregoing is merely a preferred embodiment of the invention, which is not to be construed as limiting the invention. Many possible variations and modifications of the present invention may be made by one of ordinary skill in the art using the above disclosure. Therefore, any simple modification of the above embodiments according to the technical essence of the present invention is within the protection scope of the technical solution of the present invention.