Method for efficiently removing sulfamethoxazole in water through combination of trichloroisocyanuric acid and ferrate

Abstract

The invention discloses a method for efficiently removing sulfamethoxazole in water by combining trichloroisocyanuric acid and ferrate, and aims to solve the problem that ferrate has a poor degradation effect on antibiotic-containing sewage. The method for removing sulfamethoxazole in water comprises the following steps: 1, dissolving ferrate in a buffer solution with the pH value of 7-9 to obtain a ferrate solution; 2, dissolving trichloroisocyanuric acid in a buffer solution with the pH value of 7-9 to obtain a trichloroisocyanuric acid solution; 3, adding the ferrate solution and the trichloroisocyanuric acid solution into the wastewater containing the sulfamethoxazole; and 4, carrying out a stirring reaction on the wastewater containing sulfamethoxazole at room temperature. The trichloroisocyanuric acid and the ferrate are combined for use, the ferrate can oxidize free chlorine to generate Cl., meanwhile, Cl. Can also oxidize iron ions to generate intermediate products such as Fe (IV), a redox cycle with high reactivity can be formed between the trichloroisocyanuric acid and the ferrate, and the degradation efficiency of sulfamethoxazole is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of water and sewage treatment, and particularly relates to a method for removing sulfamethoxazole in water by combining trichloroisocyanuric acid and ferrate. Background Art

[0002] Sulfamethoxazole is a widely used sulfonamide antibiotic used to treat various bacterial infections, such as urinary tract infections and respiratory tract infections. Due to its widespread use and long half-life, sulfamethoxazole is easily detected in the environment and may have an impact on the ecosystem. Therefore, removing sulfamethoxazole from water has become an important environmental protection issue.

[0003] As a commonly used chlorinated disinfectant, trichloroisocyanuric acid has received more and more attention in the field of sewage treatment in recent years. Trichloroisocyanuric acid has high disinfection and degradation capabilities, and is stable. Compared with traditional chlorinating agents, trichloroisocyanuric acid, as a highly efficient chlorinating agent, has significant advantages in bactericidal effect, stability, ease of use, and environmental friendliness, making it widely used in many fields. Therefore, it has a good prospect for promotion and application in water treatment processes. Summary of the invention

[0004] The present invention aims to solve the problem that ferrate has a poor degradation effect on sewage containing antibiotics, and to provide an environmentally friendly and economical method for removing sulfamethoxazole in water by combining trichloroisocyanuric acid with ferrate.

[0005] The method of the present invention for efficiently removing sulfamethoxazole from water by combining trichloroisocyanuric acid with ferrate is achieved by the following steps:

[0006] 1. dissolving ferrate in a buffer solution of pH=7-9 to obtain a ferrate solution;

[0007] 2. dissolving trichloroisocyanuric acid in a buffer solution with a pH of 7 to 9 to obtain a trichloroisocyanuric acid solution;

[0008] 3. adding ferrate solution and trichloroisocyanuric acid solution into the wastewater containing sulfamethoxazole;

[0009] Fourth, the wastewater containing sulfamethoxazole is stirred and reacted at room temperature, thereby completing the method of efficiently removing sulfamethoxazole from water by combining trichloroisocyanuric acid and ferrate;

[0010] In step 3, the concentration of trichloroisocyanuric acid in the wastewater system containing sulfamethoxazole is controlled to be 2-10 μmol / L, and the concentration of ferrate is controlled to be 10-50 μmol / L.

[0011] The trichloroisocyanuric acid selected by the present invention is a very strong oxidant and chlorinating agent. Compared with traditional chlorinating agents (such as bleaching powder, sodium hypochlorite, etc.), it has the characteristics of being cheap and easy to obtain, easy to store and transport, and having higher effective chlorine content and being non-toxic and harmless. The redox potential of trichloroisocyanuric acid is 4.84V, which has strong oxidizing properties. The trichloroisocyanuric acid in the method of the present invention for efficiently degrading sulfamethoxazole in water by combining trichloroisocyanuric acid and ferrate is dissolved in water to generate a certain amount of free chlorine, and ferrate also has a certain oxidizing ability. The coexistence of the two will synergize the oxidation effect. Ferrate will oxidize free chlorine to generate Cl·, and Cl· will also oxidize iron ions to generate intermediate products with certain oxidizing ability such as Fe(IV), and a highly reactive redox cycle will be formed between the two, enhancing the redox ability of the system, thereby more efficiently degrading sulfamethoxazole.

[0012] The method of efficiently degrading sulfamethoxazole in water by combining trichloroisocyanuric acid and ferrate according to the present invention comprises the following steps:

[0013] Beneficial effects:

[0014] 1. Compared with the oxidation degradation of sulfamethoxazole in water by single ferrate or single trichloroisocyanuric acid, the combination of trichloroisocyanuric acid and ferrate in the present invention can produce active species with oxidation ability, thereby enhancing the degradation efficiency of sulfamethoxazole.

[0015] 2. The process of the present invention is simple and easy to operate, and has a fast reaction and high removal efficiency for antibiotics such as sulfamethoxazole. The removal rate of sulfamethoxazole in water after a reaction of 10 minutes can reach more than 93%.

[0016] 3. The method of the present invention uses trichloroisocyanuric acid and ferrate to efficiently degrade sulfamethoxazole in water. Trichloroisocyanuric acid has a good bactericidal effect, which provides additional advantages for wastewater treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a degradation kinetic curve of sulfamethoxazole by the trichloroisocyanuric acid and ferrate system in Example 1;

[0018] Figure 2 is a degradation kinetic curve of sulfamethoxazole by the ferrate system alone in comparative example 1;

[0019] Figure 3 This is a degradation kinetic curve of sulfamethoxazole by trichloroisocyanuric acid alone system in comparative example 2;

[0020] Figure 4 is a degradation kinetic curve of sulfamethoxazole by the trichloroisocyanuric acid and ferrate system in Example 2;

[0021] Figure 5 This is a graph showing the degradation kinetics of sulfamethoxazole by the trichloroisocyanuric acid and ferrate system in Example 3. DETAILED DESCRIPTION

[0022] Specific implementation method 1: The method of this implementation method for efficiently removing sulfamethoxazole in water by combining trichloroisocyanuric acid and ferrate is implemented according to the following steps:

[0023] 1. dissolving ferrate in a buffer solution of pH=7-9 to obtain a ferrate solution;

[0024] 2. dissolving trichloroisocyanuric acid in a buffer solution with a pH of 7 to 9 to obtain a trichloroisocyanuric acid solution;

[0025] 3. adding ferrate solution and trichloroisocyanuric acid solution into the wastewater containing sulfamethoxazole;

[0026] Fourth, the wastewater containing sulfamethoxazole is stirred and reacted at room temperature, thereby completing the method of efficiently removing sulfamethoxazole from water by combining trichloroisocyanuric acid and ferrate;

[0027] In step 3, the concentration of trichloroisocyanuric acid in the wastewater system containing sulfamethoxazole is controlled to be 2-10 μmol / L, and the concentration of ferrate is controlled to be 10-50 μmol / L.

[0028] In this embodiment, trichloroisocyanuric acid and ferrate are used together to efficiently remove sulfamethoxazole in water. The combination of the two increases the oxidizability and stability of the system to achieve efficient degradation of pollutants.

[0029] Specific implementation method 2: This implementation method is different from specific implementation method 1 in that the ferrate described in step 1 is potassium ferrate, sodium ferrate or barium ferrate.

[0030] Specific implementation method three: This implementation method is different from specific implementation method one or two in that in step one and step two, the pH of the buffer solution is adjusted by perchloric acid or 1 mmol / L sodium hydroxide solution.

[0031] Specific embodiment 4: This embodiment is different from specific embodiments 1 to 3 in that the concentration of trichloroisocyanuric acid in the trichloroisocyanuric acid solution in step 2 is 100 μmol / L.

[0032] Specific embodiment 5: This embodiment is different from specific embodiments 1 to 4 in that the concentration of sulfamethoxazole in the wastewater containing sulfamethoxazole in step 3 is 0.5 to 20 μmol / L.

[0033] Specific embodiment 6: This embodiment is different from specific embodiments 1 to 5 in that in step 3, ferrate solution and trichloroisocyanuric acid solution are added to the wastewater containing sulfamethoxazole, and the molar ratio of ferrate to trichloroisocyanuric acid is controlled to be 2:1.

[0034] This embodiment optimizes the molar ratio of ferrate to trichloroisocyanuric acid to improve the removal rate of sulfamethoxazole in water.

[0035] Specific embodiment seven: This embodiment differs from any one of specific embodiments one to six in that in step three, ferrate solution and trichloroisocyanuric acid solution are added to wastewater containing sulfamethoxazole, and the molar ratio of ferrate to sulfamethoxazole is controlled to be (3-5):1.

[0036] This implementation method optimizes the dosage of ferrate.

[0037] Specific embodiment eight: This embodiment differs from specific embodiments one to seven in that in step three, the concentration of trichloroisocyanuric acid in the wastewater system containing sulfamethoxazole is controlled to be 6-10 μmol / L, and the concentration of ferrate is controlled to be 15-25 μmol / L.

[0038] In this embodiment, the preferred concentration of trichloroisocyanuric acid is 10 μmol / L, and the preferred concentration of ferrate is 20 μmol / L.

[0039] Specific implementation method 9: The difference between this implementation method and any one of specific implementation methods 1 to 8 is that in step 4, the rotation speed of the mechanical stirring is controlled to be 500-800 r / min.

[0040] Specific implementation method ten: This implementation method is different from specific implementation methods one to nine in that the stirring reaction time in step four is 5 to 20 minutes.

[0041] Example 1: The method of this example of using trichloroisocyanuric acid and ferrate to efficiently remove sulfamethoxazole from water is implemented according to the following steps:

[0042] 1. At room temperature, potassium ferrate is dissolved in a borax buffer solution (concentration of 10 mmol / L) at pH = 7 to obtain a ferrate solution. This process can inhibit the self-decomposition of ferrate to prevent the activity of the oxidant from decaying;

[0043] 2. Dissolve trichloroisocyanuric acid in a borax buffer solution at pH = 7 at room temperature to obtain a trichloroisocyanuric acid solution;

[0044] 3. Adding ferrate solution and trichloroisocyanuric acid solution into the wastewater containing sulfamethoxazole at a concentration of 5 μmol / L;

[0045] Fourth, the wastewater containing sulfamethoxazole was stirred at room temperature at a stirring speed of 700r / min, thereby completing the method of efficiently removing sulfamethoxazole from water by combining trichloroisocyanuric acid and ferrate;

[0046] In step 3, the concentration of trichloroisocyanuric acid in the wastewater system containing sulfamethoxazole is controlled to be 5 μmol / L, and the concentration of ferrate is controlled to be 20 μmol / L.

[0047] In this embodiment, at reaction times of 0 min, 0.5 min, 1 min, 2 min, 3 min, 5 min and 10 min, 1.45 ml of the solution of step 4 was filtered through a membrane and added to the solution pre-added with 0.02 ml of Na 2 S 2 O 3 The analysis was performed in HPLC vials containing 0.5 mol / L of 1% ethanol and 0.05 ml of methanol. A total of three experiments were performed.

[0048] The degradation kinetics curve of sulfamethoxazole obtained in this example is as follows: Figure 1 shown.

[0049] In this example, trichloroisocyanuric acid and ferrate were used together to efficiently degrade sulfamethoxazole in water. After stirring for 5 minutes, the removal rate of sulfamethoxazole in water was 61%; after stirring for 10 minutes, the removal rate of sulfamethoxazole in water was 63%.

[0050] Comparative Example 1: This comparative example is to illustrate the difference in the effect of adding trichloroisocyanuric acid on the degradation of sulfamethoxazole in water by ferrate. The difference from Example 1 is that trichloroisocyanuric acid is not added during the degradation of sulfamethoxazole in water in step 4. The other steps and parameters are the same as those in Specific Example 1.

[0051] The degradation kinetic curve of sulfamethoxazole obtained in this comparative example is as follows: Figure 2 shown.

[0052] In this example, ferrate alone was used to degrade sulfamethoxazole in water. After stirring for 10 minutes, the removal rate of sulfamethoxazole in water was 22%.

[0053] Comparative Example 2: This comparative example is to illustrate the difference in the effect of adding ferrate on the degradation of sulfamethoxazole in water by trichloroisocyanuric acid. The difference from Example 1 is that ferrate is not added in the degradation process of sulfamethoxazole in water in step 4. The other steps and parameters are the same as those in Specific Example 1.

[0054] The degradation kinetic curve of sulfamethoxazole obtained in this comparative example is as follows: Figure 3 shown.

[0055] In this example, trichloroisocyanuric acid alone was used to degrade sulfamethoxazole in water. After stirring for 10 minutes, the removal rate of sulfamethoxazole in the water was 17%.

[0056] Example 2: The method of this example of using trichloroisocyanuric acid and ferrate to efficiently remove sulfamethoxazole from water is implemented according to the following steps:

[0057] 1. At room temperature, potassium ferrate is dissolved in a borax buffer solution (concentration of 10 mmol / L) at pH = 7 to obtain a ferrate solution. This process can inhibit the self-decomposition of ferrate to prevent the activity of the oxidant from decaying;

[0058] 2. Dissolve trichloroisocyanuric acid in a borax buffer solution at pH = 7 at room temperature to obtain a trichloroisocyanuric acid solution;

[0059] 3. Adding ferrate solution and trichloroisocyanuric acid solution into the wastewater containing sulfamethoxazole at a concentration of 5 μmol / L;

[0060] Fourth, the wastewater containing sulfamethoxazole was stirred at room temperature at a stirring speed of 700r / min, thereby completing the method of efficiently removing sulfamethoxazole from water by combining trichloroisocyanuric acid and ferrate;

[0061] In step 3, the concentration of trichloroisocyanuric acid in the wastewater system containing sulfamethoxazole is controlled to be 10 μmol / L, and the concentration of ferrate is controlled to be 20 μmol / L.

[0062] In this embodiment, at reaction times of 0 min, 0.5 min, 1 min, 2 min, 3 min, 5 min and 10 min, 1.45 ml of the solution of step 4 was filtered through a membrane and added to the solution pre-added with 0.02 ml of Na 2 S 2 O 3 The analysis was performed in HPLC vials containing 0.5 mol / L (0.5 mol / L) and 0.05 ml of methanol.

[0063] The degradation kinetics curve of sulfamethoxazole obtained in this example is as follows: Figure 4 shown.

[0064] The trichloroisocyanuric acid and ferrate in this embodiment are used to efficiently degrade sulfamethoxazole in water. After stirring for 5 minutes, the removal rate of sulfamethoxazole in water is 91%; after stirring for 10 minutes, the removal rate of sulfamethoxazole in water is 93%. In this embodiment, the excess trichloroisocyanuric acid can ensure that ferrate is thoroughly stimulated to produce intermediate valence iron and more Cl·, etc. The presence of Cl· can convert the low-valent iron in the solution into a high-valent state, thereby forming a valence cycle between iron and producing more intermediate products such as Fe(IV), Fe(V), etc., thereby improving the removal effect of sulfamethoxazole in water.

[0065] Example 3: The method of this example of using trichloroisocyanuric acid and ferrate to efficiently remove sulfamethoxazole from water is implemented according to the following steps:

[0066] 1. At room temperature, potassium ferrate is dissolved in a borax buffer solution (concentration of 10 mmol / L) at pH = 7 to obtain a ferrate solution. This process can inhibit the self-decomposition of ferrate to prevent the activity of the oxidant from decaying;

[0067] 2. Dissolve trichloroisocyanuric acid in a borax buffer solution at pH = 7 at room temperature to obtain a trichloroisocyanuric acid solution;

[0068] 3. Adding ferrate solution and trichloroisocyanuric acid solution into the wastewater containing sulfamethoxazole at a concentration of 5 μmol / L;

[0069] Fourth, the wastewater containing sulfamethoxazole was stirred at room temperature at a stirring speed of 700r / min, thereby completing the method of efficiently removing sulfamethoxazole from water by combining trichloroisocyanuric acid and ferrate;

[0070] In step 3, the concentration of trichloroisocyanuric acid in the wastewater system containing sulfamethoxazole is controlled to be 10 μmol / L, and the concentration of ferrate is controlled to be 50 μmol / L.

[0071] In this embodiment, at reaction times of 0 min, 0.5 min, 1 min, 2 min, 3 min, 5 min and 10 min, 1.45 ml of the solution of step 4 was filtered through a membrane and added to the solution pre-added with 0.02 ml of Na 2 S 2 O 3 The analysis was performed in HPLC vials containing 0.5 mol / L (0.5 mol / L) and 0.05 ml of methanol.

[0072] The degradation kinetics curve of sulfamethoxazole obtained in this example is as follows: Figure 5 shown.

[0073] In this example, trichloroisocyanuric acid and ferrate were used together to efficiently degrade sulfamethoxazole in water. After stirring for 2 minutes, the removal rate of sulfamethoxazole in water was 100%.

Claims

1. A method for efficiently removing sulfamethoxazole from water by combining trichloroisocyanuric acid and ferrate, characterized in that The method for removing sulfamethoxazole from water is achieved by the following steps:

1. dissolving ferrate in a buffer solution of pH=7-9 to obtain a ferrate solution; 2. dissolving trichloroisocyanuric acid in a buffer solution with a pH of 7 to 9 to obtain a trichloroisocyanuric acid solution; 3. adding ferrate solution and trichloroisocyanuric acid solution into the wastewater containing sulfamethoxazole; Fourth, the wastewater containing sulfamethoxazole is stirred and reacted at room temperature, thereby completing the method of efficiently removing sulfamethoxazole from water by combining trichloroisocyanuric acid and ferrate; In step 3, the concentration of trichloroisocyanuric acid in the wastewater system containing sulfamethoxazole is controlled to be 2-10 μmol / L, and the concentration of ferrate is controlled to be 10-50 μmol / L.

2. The method for efficiently removing sulfamethoxazole from water by combining trichloroisocyanuric acid and ferrate according to claim 1, characterized in that The ferrate described in step 1 is potassium ferrate, sodium ferrate or barium ferrate.

3. The method for efficiently removing sulfamethoxazole from water by combining trichloroisocyanuric acid and ferrate according to claim 1, characterized in that In step 1 and step 2, the pH of the buffer solution is adjusted by perchloric acid or 1 mmol / L sodium hydroxide solution.

4. The method for efficiently removing sulfamethoxazole from water by combining trichloroisocyanuric acid and ferrate according to claim 1, characterized in that The concentration of trichloroisocyanuric acid in the trichloroisocyanuric acid solution in step 2 is 100 μmol / L.

5. The method for efficiently removing sulfamethoxazole from water by combining trichloroisocyanuric acid and ferrate according to claim 1, characterized in that The concentration of sulfamethoxazole in the wastewater containing sulfamethoxazole in step 3 is 0.5 to 20 μmol / L.

6. The method for efficiently removing sulfamethoxazole from water by combining trichloroisocyanuric acid and ferrate according to claim 1, characterized in that In step 3, the ferrate solution and the trichloroisocyanuric acid solution are added to the wastewater containing sulfamethoxazole, and the molar ratio of ferrate to trichloroisocyanuric acid is controlled to be 2:

1.

7. The method for efficiently removing sulfamethoxazole from water by combining trichloroisocyanuric acid and ferrate according to claim 1, characterized in that In step 3, the ferrate solution and the trichloroisocyanuric acid solution are added to the wastewater containing sulfamethoxazole, and the molar ratio of ferrate to sulfamethoxazole in the wastewater is controlled to be (3-5):

1.

8. The method for efficiently removing sulfamethoxazole from water by combining trichloroisocyanuric acid and ferrate according to claim 1, characterized in that In step 3, the concentration of trichloroisocyanuric acid in the wastewater system containing sulfamethoxazole is controlled to be 6-10 μmol / L, and the concentration of ferrate is controlled to be 15-25 μmol / L.

9. The method for efficiently removing sulfamethoxazole from water by combining trichloroisocyanuric acid and ferrate according to claim 1, characterized in that In step 4, the rotation speed of the mechanical stirring is controlled to be 500-800 r / min.

10. The method for efficiently removing sulfamethoxazole from water by combining trichloroisocyanuric acid and ferrate according to claim 1, characterized in that The stirring reaction time in step 4 is 5 to 20 minutes.

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