A method for decomposing iohexol and acetochlor by far-ultraviolet light

Abstract

The present invention belongs to the field of water treatment technology and relates to a method for the far-ultraviolet photodegradation of iohexol and acetochlor. The method comprises the following steps: S1, adjusting the pH of a treated aqueous solution containing target pollutants to 4-10; S2, conducting the reaction at an ultraviolet wavelength of 200-230 nm. Compared with existing technologies, the present invention not only efficiently degrades iohexol and acetochlor, but also can treat other new pollutants with different structures in surface water. It has multiple advantages, including no secondary pollution, low cost, simple process, and no risk of mercury leakage, ensuring safe and stable use.

Description

Technical Field

[0001] The invention belongs to the technical field of water treatment, and in particular relates to a method for decomposing iohexol and acetochlor by far-ultraviolet light. Background Art

[0002] Emerging pollutants are toxic and hazardous chemicals that are biotoxic, environmentally persistent, and bioaccumulative. Traditional water treatment technologies are unable to effectively remove and control trace amounts of these pollutants. Furthermore, their complex and variable migration and transformation pathways within the environment can ultimately lead to their infiltration into natural water bodies, posing a potential threat to human health and the ecological environment. This has sparked widespread public concern. Strengthening the control of emerging pollutants is consistent with the concept of sustainable development, an inevitable requirement for ensuring environmental safety, and of great significance for preventing environmental and health risks.

[0003] Emerging pollutants are widely present in the environment, are highly stable, and complex, and may pose risks to human health and aquatic systems. Iohexol and acetochlor, representative emerging pollutants, are widely used in human applications and their usage is increasing. They have been detected in large quantities in various environmental media. Specifically, iohexol concentrations in rivers and municipal wastewater treatment plants range from 20 to 1500 ng / L and 100 to 1000 ng / L, respectively, and concentrations in drinking water plants exceed 10 ng / L. During the disinfection process, iohexol also produces cytotoxic and genotoxic disinfection byproducts, posing a threat to drinking water safety. Acetochlor concentrations in secondary wastewater range from 50 to 16,000 ng / L, and in groundwater exceed the EU drinking water limit of 100 ng / L. Studies have shown that long-term exposure to acetochlor may affect neurological function, and the US Environmental Protection Agency has classified it as a Class B-2 carcinogen. However, traditional treatment processes are unable to effectively control these trace substances, making the development of more efficient treatment methods a hot topic.

[0004] Patent application CN117185405A provides a method for removing the iodinated developer iohexol from water using a combined UV / permonosulfate process. The specific steps are as follows: S1: pretreating a water sample to be treated; S2: adding permonosulfate to the pretreated water sample, adjusting the pH, and then oxidizing and degrading the iodinated developer iohexol in the water using UV light. This method can achieve over 99% iohexol removal efficiency, resulting in relatively thorough degradation, quickly and effectively reducing the concentration of iohexol, a difficult-to-degrade organic pollutant in water, and mitigating the potential risk of generating highly toxic iodinated disinfection byproducts. However, this patent application suffers from the following shortcomings: 1. The complexity of the technical solution. The method proposed in this patent involves multiple steps and requires the additional addition of permonosulfate, which not only increases treatment costs but also operational complexity. 2. It has shortcomings in environmental friendliness and safety. The low-pressure mercury vapor discharge lamp used in this patent carries the risk of mercury contamination, has a long warm-up time, and has relatively low photoelectric conversion efficiency. 3. The treatment scope is limited. This patent application only treats iohexol, a single pollutant. Summary of the Invention

[0005] The purpose of the present invention is to overcome the problems existing in the above-mentioned prior art and provide a method for the far-ultraviolet photodegradation of iohexol and acetochlor. While the method efficiently degrades iohexol and acetochlor, it can also treat other new pollutants with different chemical structures in surface water, such as ibuprofen, sulfamethoxazole and carbamazepine.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] The present invention provides a method for decomposing iohexol and acetochlor by far-ultraviolet light, comprising the following steps:

[0008] S1, adjusting the pH of the aqueous solution to be treated containing the target pollutant to 4-10;

[0009] S2, reacting at an ultraviolet wavelength of 200-230 nm.

[0010] Furthermore, in step S1, the molar concentration of the target pollutant in the aqueous solution to be treated is 5-20 mM.

[0011] Furthermore, in step S1, the target pollutant is selected from at least one of iohexol, acetochlor, carbamazepine, ibuprofen or sulfamethoxazole.

[0012] Furthermore, in step S2, the ultraviolet wavelength is 221-223 nm, and more preferably 222 nm.

[0013] Furthermore, in step S2, the reaction is carried out while stirring.

[0014] Furthermore, the stirring speed is 300-500 rpm.

[0015] Furthermore, in step S2, the reaction is carried out in a far ultraviolet irradiation device.

[0016] Furthermore, in step S2, the reaction is carried out at room temperature in the dark.

[0017] Furthermore, in step S2, the reaction time is 2-60 min.

[0018] The present invention also provides an application of any of the above-mentioned far-ultraviolet photolysis methods for iohexol and acetochlor in water treatment, which can efficiently degrade new pollutants in water, such as iohexol, acetochlor, ibuprofen and sulfamethoxazole, to meet increasingly stringent water quality standards.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) The present invention provides a method for photodegrading iohexol and acetochlor using far-ultraviolet light. No additional oxidant or catalyst is required during the degradation process. The method is a green, safe, and environmentally friendly new pollutant treatment technology that conforms to the development trend of current environmental protection concepts. The method also gives full play to the high energy characteristics of far-ultraviolet light, realizes efficient photocatalytic degradation of difficult-to-degrade new pollutants, and significantly improves the overall water treatment efficiency.

[0021] (2) The present invention provides a method for the far-ultraviolet photolysis of iohexol and acetochlor. The method carries out the reaction at an ultraviolet wavelength of 200-230 nm and adopts a krypton chloride excimer lamp as a far-ultraviolet light source. The method not only eliminates the use of toxic mercury elements, but also exhibits multiple advantages such as a shorter startup stabilization time, a photoelectric conversion efficiency of up to about 10%, lower ozone generation, and higher human safety, providing a strong guarantee for practical application.

[0022] (3) The present invention provides a method for the far-ultraviolet photolysis of iohexol and acetochlor, which can effectively reduce the content of iohexol and acetochlor in surface water, thereby providing a new idea and method for the treatment of these two pollutants. At the same time, it can also treat other new pollutants with different chemical structures in surface water, such as ibuprofen, sulfamethoxazole and carbamazepine, further broadening its scope of application.

[0023] (4) Compared with the shortcomings of patent application CN117185405A, the far-ultraviolet photolysis method adopted in the present invention has simpler steps and does not require the addition of any additional oxidant, so the cost is lower and the treatment process is simpler; the far-ultraviolet photolysis method uses a krypton chloride excimer lamp, which has no risk of mercury leakage, a shorter stabilization time, and a higher photoelectric conversion efficiency, so it performs better in terms of environmental protection and safety; in addition, the far-ultraviolet photolysis method can treat a variety of new pollutants, including iohexol, acetochlor, carbamazepine, ibuprofen, sulfamethoxazole, etc., and has a wider range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a graph showing the degradation performance test of iohexol or acetochlor in Examples 1-2 and Comparative Examples 1-2 of the present invention;

[0025] Figure 2 This is a diagram showing the economic benefit evaluation of iohexol degradation in Example 1 of the present invention and Comparative Example 1;

[0026] Figure 3 This is a diagram for evaluating the economic benefits of acetochlor degradation in Example 2 of the present invention and Comparative Example 2;

[0027] Figure 4 This is a graph showing the degradation performance test of various new pollutants in Examples 1-5 of the present invention;

[0028] Figure 5 This is a schematic structural diagram of the far ultraviolet irradiation device used in the present invention. DETAILED DESCRIPTION

[0029] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0030] Unless otherwise specified, the reagents, methods, instruments and equipment used in the present invention are conventional reagents, methods, instruments and equipment in the art. Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0031] The present invention provides a method for decomposing iohexol and acetochlor by far-ultraviolet light, comprising the following steps:

[0032] S1, adjusting the pH of the aqueous solution to be treated containing the target pollutant to 4-10, wherein the molar concentration of the target pollutant in the aqueous solution to be treated is 5-20 mM, and the target pollutant is selected from at least one of iohexol, acetochlor, carbamazepine, ibuprofen, or sulfamethoxazole;

[0033] S2, the reaction is carried out in a far-ultraviolet irradiation device with stirring at room temperature in the dark under ultraviolet wavelength range of 200-230nm, the stirring speed is 300-500rpm, and the reaction time is 2-60min; the preferred ultraviolet wavelength is 221-223nm, and more preferably 222nm.

[0034] The above-mentioned far-ultraviolet photolysis method of iohexol and acetochlor can be used for water treatment to efficiently degrade new pollutants in water, such as iohexol, acetochlor, ibuprofen and sulfamethoxazole, to meet the increasingly stringent water quality standards.

[0035] The far ultraviolet irradiation device in the following examples and comparative examples is as follows Figure 5 As shown, it includes six parts, namely, an outer light-proof black box, a krypton chloride excimer lamp, a heat sink, a collimator, a magnetic stirrer and a reaction area, wherein the heat sink is arranged on the back of the circuit device.

[0036] Example 1

[0037] This embodiment provides a method for decomposing iohexol by far-ultraviolet light, comprising the following steps:

[0038] (1) Phosphate buffer solution was added to an aqueous solution containing iohexol to a final iohexol concentration of 10 mM, and the pH was adjusted to 7.0 using a 1 M sodium hydroxide solution and a 0.18 M dilute sulfuric acid solution. The pH-adjusted solution to be treated was placed in a culture dish and placed in a far-ultraviolet irradiation device; the culture dish was placed on a magnetic stirrer and stirred at a constant speed of 450 rpm.

[0039] (2) Turn on the far-ultraviolet irradiation device with an ultraviolet wavelength of 222 nm. The solution is protected from light at room temperature for photolysis reaction, and the reaction is stopped after 45 minutes.

[0040] Example 2

[0041] This embodiment provides a method for decomposing acetochlor by far-ultraviolet light, comprising the following steps:

[0042] (1) A phosphate buffer solution is added to an aqueous solution containing acetochlor to a final concentration of 10 mM acetochlor, and the pH is adjusted to 7.0 using a 1 M sodium hydroxide solution and a 0.18 M dilute sulfuric acid solution. The pH-adjusted solution to be treated is placed in a culture dish and placed in a far-ultraviolet irradiation device; the culture dish is placed on a magnetic stirrer and stirred at a constant speed of 450 rpm.

[0043] (2) Turn on the far-ultraviolet irradiation device with an ultraviolet wavelength of 222 nm. The solution is protected from light at room temperature for photolysis reaction, and the reaction is stopped after 45 minutes.

[0044] Example 3

[0045] This embodiment provides a method for the far-ultraviolet photolysis of carbamazepine, comprising the following steps:

[0046] (1) A phosphate buffer solution is added to an aqueous solution containing carbamazepine to a final carbamazepine concentration of 10 mM, and the pH is adjusted to 7.0 using a 1 M sodium hydroxide solution and a 0.18 M dilute sulfuric acid solution. The pH-adjusted solution to be treated is placed in a culture dish and placed in a far-ultraviolet irradiation device; the culture dish is placed on a magnetic stirrer and stirred at a constant speed of 450 rpm.

[0047] (2) Turn on the far-ultraviolet irradiation device with an ultraviolet wavelength of 222 nm. The solution is protected from light at room temperature for photolysis reaction, and the reaction is stopped after 45 minutes.

[0048] Example 4

[0049] This embodiment provides a method for decomposing ibuprofen by far-ultraviolet light, comprising the following steps:

[0050] (1) A phosphate buffer solution is added to an aqueous solution containing ibuprofen to a final ibuprofen concentration of 10 mM, and the pH is adjusted to 7.0 using a 1 M sodium hydroxide solution and a 0.18 M dilute sulfuric acid solution. The pH-adjusted solution to be treated is placed in a culture dish and placed in a far-ultraviolet irradiation device; the culture dish is placed on a magnetic stirrer and stirred at a constant speed of 450 rpm.

[0051] (2) Turn on the far-ultraviolet irradiation device with an ultraviolet wavelength of 222 nm. The solution is protected from light at room temperature for photolysis reaction, and the reaction is stopped after 45 minutes.

[0052] Example 5

[0053] This embodiment provides a method for decomposing sulfamethoxazole by far-ultraviolet light, comprising the following steps:

[0054] (1) Phosphate buffer solution is added to an aqueous solution containing sulfamethoxazole to a final concentration of 10 mM sulfamethoxazole, and the pH is adjusted to 7.0 using a 1 M sodium hydroxide solution and a 0.18 M dilute sulfuric acid solution. The pH-adjusted solution to be treated is placed in a culture dish and placed in a far-ultraviolet irradiation device; the culture dish is placed on a magnetic stirrer and stirred at a constant speed of 450 rpm.

[0055] (2) Turn on the far-ultraviolet irradiation device with an ultraviolet wavelength of 222 nm. The solution is protected from light at room temperature for photolysis reaction, and the reaction is stopped after 45 minutes.

[0056] Example 6

[0057] This embodiment provides a method for decomposing iohexol by far-ultraviolet light, comprising the following steps:

[0058] (1) A phosphate buffer solution is added to an aqueous solution containing iohexol to a final iohexol concentration of 5 mM, and the pH is adjusted to 5.0 using a 1 M sodium hydroxide solution and a 0.18 M dilute sulfuric acid solution. The pH-adjusted solution to be treated is placed in a culture dish and placed in a far-ultraviolet irradiation device; the culture dish is placed on a magnetic stirrer and stirred at a constant speed of 450 rpm.

[0059] (2) Turn on the far-ultraviolet irradiation device with an ultraviolet wavelength of 222 nm. The solution is subjected to photolysis reaction at room temperature in the dark, and the reaction is stopped after 30 minutes.

[0060] Example 7

[0061] This embodiment provides a method for decomposing iohexol by far-ultraviolet light, comprising the following steps:

[0062] (1) A phosphate buffer solution is added to an aqueous solution containing iohexol to a final iohexol concentration of 20 mM, and the pH is adjusted to 9.0 using a 1 M sodium hydroxide solution and a 0.18 M dilute sulfuric acid solution. The pH-adjusted solution to be treated is placed in a culture dish and placed in a far-ultraviolet irradiation device; the culture dish is placed on a magnetic stirrer and stirred at a constant speed of 450 rpm.

[0063] (2) Turn on the far-ultraviolet irradiation device with an ultraviolet wavelength of 222 nm. The solution is protected from light at room temperature for photolysis reaction, and the reaction is stopped after 45 minutes.

[0064] Example 8

[0065] This embodiment provides a method for decomposing acetochlor by far-ultraviolet light, comprising the following steps:

[0066] (1) A phosphate buffer solution is added to an aqueous solution containing acetochlor to a final concentration of 20 mM acetochlor, and the pH is adjusted to 5.0 using a 1 M sodium hydroxide solution and a 0.18 M dilute sulfuric acid solution. The pH-adjusted solution to be treated is placed in a culture dish and placed in a far-ultraviolet irradiation device; the culture dish is placed on a magnetic stirrer and stirred at a constant speed of 450 rpm.

[0067] (2) Turn on the far-ultraviolet irradiation device with an ultraviolet wavelength of 222 nm. The solution is protected from light and subjected to photolysis reaction at room temperature. The reaction is stopped after 15 minutes.

[0068] Example 9

[0069] This embodiment provides a method for decomposing acetochlor by far-ultraviolet light, comprising the following steps:

[0070] (1) A phosphate buffer solution is added to an aqueous solution containing acetochlor to a final concentration of 5 mM acetochlor, and the pH is adjusted to 9.0 using a 1 M sodium hydroxide solution and a 0.18 M dilute sulfuric acid solution. The pH-adjusted solution to be treated is placed in a culture dish and placed in a far-ultraviolet irradiation device; the culture dish is placed on a magnetic stirrer and stirred at a constant speed of 450 rpm.

[0071] (2) Turn on the far-ultraviolet irradiation device with an ultraviolet wavelength of 222 nm. The solution is protected from light at room temperature for photolysis reaction, and the reaction is stopped after 5 minutes.

[0072] Comparative Example 1

[0073] This comparative example provides a method for removing iohexol from water, and the specific steps are as follows:

[0074] (1) Phosphate buffer solution was added to an aqueous solution containing iohexol to a final iohexol concentration of 10 mM, and the pH was adjusted to 7.0 using a 1 M sodium hydroxide solution and a 0.18 M dilute sulfuric acid solution. The pH-adjusted solution to be treated was placed in a culture dish and placed in a conventional mercury lamp irradiation apparatus; the culture dish was placed on a magnetic stirrer and stirred at a constant speed of 450 rpm.

[0075] (2) Turn on the traditional mercury lamp irradiation device, the ultraviolet wavelength is 254nm, the solution is reacted in the dark at room temperature, and the reaction is stopped after the ultraviolet dose is consistent with that in Example 1.

[0076] Comparative Example 2

[0077] This comparative example provides a method for removing acetochlor from water, and the specific steps are as follows:

[0078] (1) A phosphate buffer solution is added to an aqueous solution containing acetochlor to a final concentration of 10 mM acetochlor, and the pH is adjusted to 7.0 using a 1 M sodium hydroxide solution and a 0.18 M dilute sulfuric acid solution. The pH-adjusted solution to be treated is placed in a culture dish and placed in a conventional mercury lamp irradiation apparatus; the culture dish is placed on a magnetic stirrer and stirred at a constant speed of 450 rpm.

[0079] (2) A conventional mercury lamp irradiation device was turned on, and the ultraviolet wavelength was 254 nm. The solution was reacted in the dark at room temperature. The reaction was stopped after the ultraviolet dose was consistent with that in Example 2.

[0080] Comparative Example 3

[0081] This comparative example provides a method for removing iohexol from water, and the specific steps are as follows:

[0082] (1) A phosphate buffer solution is added to an aqueous solution containing iohexol to a final iohexol concentration of 10 mM, and the pH is adjusted to 5.0 using a 1 M sodium hydroxide solution and a 0.18 M dilute sulfuric acid solution. The pH-adjusted solution to be treated is placed in a culture dish and placed in a conventional mercury lamp irradiation apparatus; the culture dish is placed on a magnetic stirrer and stirred at a constant speed of 450 rpm.

[0083] (2) Turn on the traditional mercury lamp irradiation device, the ultraviolet wavelength is 254nm, the solution is reacted in the dark at room temperature, and the reaction is stopped after the ultraviolet dose is consistent with that in Example 1.

[0084] Comparative Example 4

[0085] This comparative example provides a method for removing iohexol from water, and the specific steps are as follows:

[0086] (1) A phosphate buffer solution is added to an aqueous solution containing iohexol to a final iohexol concentration of 10 mM, and the pH is adjusted to 9.0 using a 1 M sodium hydroxide solution and a 0.18 M dilute sulfuric acid solution. The pH-adjusted solution to be treated is placed in a culture dish and placed in a conventional mercury lamp irradiation apparatus; the culture dish is placed on a magnetic stirrer and stirred at a constant speed of 450 rpm.

[0087] (2) Turn on the traditional mercury lamp irradiation device, the ultraviolet wavelength is 254nm, the solution is reacted in the dark at room temperature, and the reaction is stopped after the ultraviolet dose is consistent with that in Example 1.

[0088] Comparative Example 5

[0089] This comparative example provides a method for removing acetochlor from water, and the specific steps are as follows:

[0090] (1) A phosphate buffer solution is added to an aqueous solution containing acetochlor to a final concentration of 10 mM acetochlor, and the pH is adjusted to 5.0 using a 1 M sodium hydroxide solution and a 0.18 M dilute sulfuric acid solution. The pH-adjusted solution to be treated is placed in a culture dish and placed in a conventional mercury lamp irradiation apparatus; the culture dish is placed on a magnetic stirrer and stirred at a constant speed of 450 rpm.

[0091] (2) A conventional mercury lamp irradiation device was turned on, and the ultraviolet wavelength was 254 nm. The solution was reacted in the dark at room temperature. The reaction was stopped after the ultraviolet dose was consistent with that in Example 2.

[0092] Comparative Example 6

[0093] This comparative example provides a method for removing acetochlor from water, and the specific steps are as follows:

[0094] (1) A phosphate buffer solution is added to an aqueous solution containing acetochlor to a final concentration of 10 mM acetochlor, and the pH is adjusted to 9.0 using a 1 M sodium hydroxide solution and a 0.18 M dilute sulfuric acid solution. The pH-adjusted solution to be treated is placed in a culture dish and placed in a conventional mercury lamp irradiation apparatus; the culture dish is placed on a magnetic stirrer and stirred at a constant speed of 450 rpm.

[0095] (2) A conventional mercury lamp irradiation device was turned on, and the ultraviolet wavelength was 254 nm. The solution was reacted in the dark at room temperature. The reaction was stopped after the ultraviolet dose was consistent with that in Example 2.

[0096] The reaction conditions of Examples 1-9 and Comparative Examples 1-6 are shown in Table 1.

[0097] Table 1 Reaction conditions of Examples 1-9 and Comparative Examples 1-6

[0098]

[0099]

[0100] The following photodegradation performance tests were performed on Examples 1-9 and Comparative Examples 1-6.

[0101] Detection instruments: The concentrations of the new pollutants (iohexol, acetochlor, carbamazepine, ibuprofen, and sulfamethoxazole) in this study were detected using an Agilent HPLC1260 Ultra Performance Liquid Chromatography (UPLC) equipped with a UV detector and a Waters, USA MS C18 chromatographic column (250.00 mm×2.10 mm, 3.50 μm).

[0102] Test Method: Before the degradation experiment begins, prepare the required substrate stock solutions, including iohexol solution, acetochlor solution, carbamazepine solution, ibuprofen solution, and sulfamethoxazole solution. Before the experiment, dilute the stock solution to the target concentration (10 μM) and add phosphate buffer solution to a concentration of 10 mM. Adjust the pH to the desired value by adding NaOH and dilute H₂SO₄ solution.

[0103] At the beginning of the experiment, 50mL of reaction solution was placed in a culture dish and a small magnet was placed in the container. In the degradation experiment, the reaction container was placed on a magnetic stirrer and stirred at a uniform speed. For experiments requiring photolysis, a far-ultraviolet device or a traditional mercury lamp device was synchronously turned on for ultraviolet irradiation, and the reaction started timing. The reaction stopped after the experimental required time, wherein the experimental time of Examples 1-5 was 45min, the experimental time of Comparative Example 1, Comparative Example 3, and Comparative Example 4 was the same as that of Example 1 until the ultraviolet dose was the same, and the experimental time of Comparative Example 2, Comparative Example 5, and Comparative Example 6 was the same as that of Example 2 until the ultraviolet dose was the same. Take out 1mL of water sample and inject it into a liquid phase vial, and add a quencher (Na2S2O3) to quench the remaining oxidant, shake well and wait for high performance liquid chromatography detection. Figure 1 China-Israel C t / C0 is the vertical axis, and the UV dose (mJ cm -2 ) is the horizontal axis. Figure 2-3 In the figure, EE / O (KWh / L) is the vertical axis, and the examples or comparative examples are the horizontal axis. Figure 4 China-Israel C t / C0 is the vertical axis, time (min) and UV dose (mJ cm -2 ) is the horizontal axis, where C0 and C t represent the initial concentration and reaction concentration of organic matter, respectively.

[0104] The photodegradation performance test results of Examples 1-9 and Comparative Examples 1-6 are shown in Table 2.

[0105] Table 2 Degradation rates of pollutants in Examples 1-9 and Comparative Examples 1-6

[0106]

[0107]

[0108] Figure 1 This is a graph showing the degradation performance test of iohexol or acetochlor in Examples 1-2 of the present invention and Comparative Examples 1-2. Figure 1 The data show the degradation of iohexol and acetochlor under different UV light sources. It can be clearly seen that different UV light sources will significantly affect the degradation performance of iohexol and acetochlor. 254 Compared with (Comparative Example 1-2), UV 222 (Example 1-2) At pH = 7.0 and the same ultraviolet dose, the degradation efficiency of iohexol and acetochlor was higher, and the removal rates were increased from 72.46% and 19.31% to 100%, respectively.

[0109] Compared with Example 1, the iohexol in Comparative Example 3 of the present invention is 254The degradation rate under the reaction conditions is 68.53%. In Comparative Example 4 of the present invention, iohexol is degraded at pH = 9.0, UV 254 The degradation rate under the reaction conditions was 75.82%; compared with Example 2, in Comparative Example 5 of the present invention, acetochlor was 254 The degradation rate under the reaction conditions is 17.41%. In Comparative Example 6 of the present invention, acetochlor is 17.41% under the reaction conditions of pH = 9.0 and UV 254 The degradation rate under the reaction conditions was 16.54%. Figure 1 The results show that the present invention has a better 254 , UV 222 Under the same ultraviolet dose, the degradation efficiency of iohexol and acetochlor is higher, and the removal rate can reach 100%.

[0110] The present invention further evaluates the EE / O value of different systems, which represents the electrical energy required to degrade one order of magnitude of organic matter in 1L of solution (kWh L -1 ), the lower the value, the lower the energy consumption of the process and the higher the photoelectric conversion efficiency. The EE / O value is an effective method to evaluate the electrical energy consumption during ultraviolet photolysis of pollutants and can reflect the economic benefits of the process. Figure 2 This is a diagram showing the economic benefit evaluation of iohexol degradation in Example 1 and Comparative Example 1. Figure 3 This is a diagram for evaluating the economic benefits of acetochlor degradation in Example 2 and Comparative Example 2.

[0111] Figure 2 and Figure 3 The data shows that UV 222 / UV 254 The EE / O values ​​of photolysis of iohexol and acetochlor were 0.59951KWh / L / 1.27985KWh / L and 0.25443KWh / L / 7.69024KWh / L, respectively. 222 The irradiation process greatly reduces energy consumption and is a new, efficient and economical pollutant removal technology with significantly better economic benefits than UV 254 Irradiation technology is in line with the concept of sustainable development.

[0112] Figure 4 The degradation performance test diagram of various new pollutants in Examples 1-5 is shown in FIG. Figure 4 The data showed that 5 common new pollutants (iohexol, acetochlor, carbamazepine, ibuprofen and sulfamethoxazole) were detected by UV 222 Degradation under irradiation (Examples 1-5). The results show that UV alone 222It can completely degrade iohexol, acetochlor, ibuprofen and sulfamethoxazole within 45 minutes, and even the highly photoresistant carbamazepine has a degradation rate of 32.3%.

[0113] In Example 6 of the present invention, iohexol was added at pH=5.0 and UV 222 The degradation rate under the reaction conditions is 80.45%. In Example 7 of the present invention, iohexol is subjected to the conditions of pH=9.0, UV 222 The degradation rate under the reaction conditions of 85.21% is 85.21%. In Example 8 of the present invention, acetochlor is at pH = 5.0, UV 222 The degradation rate under the reaction conditions of acetochlor was 77.70%. In Example 9 of the present invention, the degradation rate of acetochlor was 77.70% under the reaction conditions of pH = 9.0, UV 222 The degradation rate under the reaction conditions was 46.49%. These results indicate that the far-ultraviolet photolysis method of the present invention has the advantages of strong stability, wide applicability, and high flexibility when the pH value is 5-9 and the ultraviolet wavelength is 200-230 nm.

[0114] The above results fully demonstrate the wide applicability of the far-UV photolysis system, which is expected to become a powerful supplement and alternative to traditional water treatment technology, and open up new paths for the development of the water treatment field.

[0115] The above description of the embodiments is intended to facilitate understanding and use of the invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention, without departing from the scope of the present invention, should be within the scope of protection of the present invention.

Claims

1. A method for decomposing iohexol and acetochlor by far-ultraviolet light, characterized in that: The steps include: S1, adjusting the pH of the aqueous solution to be treated containing the target pollutant to 4-10; S2, the reaction was carried out at a UV wavelength of 200-230 nm.

2. The method for decomposing iohexol and acetochlor by far-ultraviolet light according to claim 1, wherein: In step S1, the molar concentration of the target pollutant in the aqueous solution to be treated is 5-20 mM.

3. The method for decomposing iohexol and acetochlor by far-ultraviolet light according to claim 1, wherein: In step S1, the target pollutant further includes at least one of carbamazepine, ibuprofen or sulfamethoxazole.

4. The method for decomposing iohexol and acetochlor by far-ultraviolet light according to claim 1, wherein: In step S2, the ultraviolet wavelength is 221-223 nm.

5. The method for decomposing iohexol and acetochlor by far-ultraviolet light according to claim 1, wherein: In step S2, the reaction is carried out while stirring.

6. The method for decomposing iohexol and acetochlor by far-ultraviolet light according to claim 5, characterized in that: The stirring speed of the stirring is 300-500 rpm.

7. The method for decomposing iohexol and acetochlor by far-ultraviolet light according to claim 1, wherein: In step S2, the reaction is carried out in a far ultraviolet irradiation device.

8. The method for decomposing iohexol and acetochlor by far-ultraviolet light according to claim 1, wherein: In step S2, the reaction is carried out at room temperature in the dark.

9. The method for decomposing iohexol and acetochlor by far-ultraviolet light according to claim 1, wherein: In step S2, the reaction time is 2-60 min.

10. Use of the method for decomposing iohexol and acetochlor by far-ultraviolet light according to any one of claims 1 to 9 in water treatment.

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