Method for preparing high-concentration chlorine dioxide solution without catalyst

Abstract

The invention discloses a method for preparing a high-concentration chlorine dioxide solution without a catalyst, relates to the technical field of disinfection, and compared with a conventional method, the stability and the purity of the generated chlorine dioxide solution are improved. The method comprises the step of reacting a sodium chlorite solution with potassium persulfate to generate chlorine dioxide. According to the present invention, the prepared sodium chlorite solution and the potassium persulfate are subjected to the light-shielding reaction in the reactor, such that the sufficient reaction of the sodium chlorite solution and the potassium persulfate is definitely ensured, the efficient chlorine dioxide preparation is achieved, no additional buffer agent is added so as to prepare the aqueous phase chlorine dioxide solution, and the long-term stable storage can be achieved.

Description

Technical Field

[0001] This invention relates to the field of disinfection technology, specifically a method for preparing a high-concentration chlorine dioxide solution without a catalyst. Background Technology

[0002] The field of disinfection technology is dedicated to the research and development of chemical reagents for eliminating or inhibiting harmful microorganisms, covering multiple aspects such as formulation design, production processes, quality control, and application evaluation. Common disinfectants include chlorine-based disinfectants, alcohol-based disinfectants, iodine-based disinfectants, and quaternary ammonium salts, which are widely used in healthcare, food processing, water treatment, and public health.

[0003] Among numerous disinfectants, chlorine dioxide (ClO2) is increasingly becoming an important choice in condensate water purification due to its high efficiency and environmental friendliness. Its unique single-electron transfer oxidation mechanism can rapidly kill bacteria, viruses, spores, and protozoa, and it does not readily react with organic precursors in water to form carcinogenic byproducts such as trihalomethanes. The reduction product is mainly harmless chlorite (ClO2). - ) and chloride ions (Cl - Furthermore, chlorine dioxide exists as a dissolved gas in the aqueous phase, does not hydrolyze to produce acid, and is far less corrosive to metals such as stainless steel than chlorine-based disinfectants, which helps extend the service life of equipment.

[0004] Based on the aforementioned advantages, chlorine dioxide shows broad application potential in systems such as cooling tower circulating water, steam condensate recycling, and central air conditioning condensate treatment. However, the preparation cost of chlorine dioxide is generally higher than that of chlorine gas, the reaction process requires precise control, and the yield still needs to be improved. Existing methods often use catalysts to increase the reaction rate, but this may introduce safety risks and process complexity; some formulations use stabilizers, which may also lead to undesirable byproducts.

[0005] To address the above problems, this invention provides a catalyst-free method for preparing high-concentration chlorine dioxide solutions. Summary of the Invention

[0006] The purpose of this invention is to provide a catalyst-free method for preparing high-concentration chlorine dioxide solution, thereby solving the problems raised in the prior art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A catalyst-free method for preparing a high-concentration chlorine dioxide solution includes the following steps: Step 1: Mix sodium chlorite powder with deionized water and stir to obtain sodium chlorite solution; Step 2: Weigh a fixed amount of potassium persulfate to obtain potassium persulfate; Step 3: Mix sodium chlorite solution and potassium persulfate thoroughly to react and obtain a high-concentration chlorine dioxide solution.

[0008] Furthermore, in step 1, the concentration of the sodium chlorite solution is 8 g / L-28 g / L.

[0009] Furthermore, in step 1, the concentration of the sodium chlorite solution is 12 g / L to 24 g / L. Furthermore, in step 1, the concentration of the sodium chlorite solution is 16 g / L–20 g / L.

[0010] Furthermore, in step one, the stirring process is as follows: dissolve sodium chlorite in deionized water, mix, and then magnetically stir at 25°C to 40°C for 20-30 minutes until completely dissolved.

[0011] Furthermore, potassium persulfate has a purity of 50%-100%, while a purity of 90%-99% is required to prepare chlorine dioxide at a concentration of 3000-4000 ppm; and a purity of 70%-89% is required to prepare chlorine dioxide at a concentration of 1000-3000 ppm.

[0012] Furthermore, the potassium persulfate is potassium persulfate powder or potassium persulfate solution, the concentration of the potassium persulfate solution is 14 g / L-44 g / L, and the mass ratio of sodium chlorite to potassium persulfate is 1:(1.2-1.5).

[0013] Furthermore, the ratio of sodium chlorite solution to potassium persulfate powder is 1 mL sodium chlorite solution to 20-28 mg potassium persulfate powder.

[0014] Furthermore, step three is carried out under light-protected conditions to prevent the photodegradation of chlorine dioxide.

[0015] Furthermore, in step three, the reaction time is controlled between 30 and 240 minutes.

[0016] Furthermore, the molar ratio of potassium persulfate to sodium chlorite is 1:(1.9-3.88).

[0017] Furthermore, the potassium persulfate can also be an activated carbon material loaded with S-potassium persulfate. The preparation method is as follows: potassium thiosulfate and ammonium persulfate are dissolved in deionized water and then immersed in activated carbon at room temperature; ammonia water is added to adjust the pH of the solution to 9, and after stirring evenly, the solution is allowed to stand at room temperature to obtain loaded activated carbon; the activated carbon is washed and vacuum dried to obtain modified activated carbon; the modified activated carbon is pyrolyzed under a nitrogen atmosphere to form a sulfur-loaded composite material; atomized potassium persulfate aqueous solution is sprayed onto the surface of the sulfur-loaded composite material, and vacuum dried and cured for 12 hours to obtain the activated carbon material loaded with S-potassium persulfate.

[0018] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention uses sodium chlorite and potassium persulfate as precursors for the preparation of chlorine dioxide. In addition to its application in disinfection, the efficiently prepared chlorine dioxide can also be used as a strong oxidant for air purification and the degradation of harmful substances.

[0019] 2. This invention uses sodium chlorite and potassium persulfate as precursors, and the formulation ratio allows for the production of higher concentrations of chlorine dioxide with fewer byproducts. This invention effectively inhibits the formation of hypochlorite, and chlorine dioxide is generated by the combination of chlorite and persulfate. Since the reaction is carried out in an aqueous system, the generated chlorine dioxide exists in the form of an aqueous solution. In the reaction of chlorite and potassium persulfate, in addition to chlorine dioxide and hypochlorite, sulfate radicals (SO4·), hydroxyl radicals (OH·), and superoxide radicals (O2·) are also formed. - In addition to free radicals, non-free radical singlet oxygen is also formed. The chlorine dioxide prepared using the method of this invention achieves higher yield and concentration compared to traditional preparation methods.

[0020] 3. This invention utilizes the reduction reaction between thiosulfate and ammonium persulfate under alkaline conditions. S is loaded onto activated carbon material via impregnation and then cured by pyrolysis. Simultaneously, a mist of persulfate aqueous solution is sprayed and dried at low temperature to fix the persulfate onto the composite material, thus preparing an activated carbon material loaded with S-potassium persulfate. This significantly accelerates the generation rate of chlorine dioxide, resulting in stronger oxidation and more thorough disinfection. The activated carbon material greatly promotes electron transfer between potassium persulfate and sodium chlorite / sulfur, thereby accelerating the initial reaction. The loaded sulfur or sulfides can act as an activator for potassium persulfate, continuously and controllably activating it into more potent sulfate radicals through an electron transfer mechanism. This is equivalent to providing a free radical source in situ at the reaction site. This composite system promotes the reaction along the dominant pathway of generating chlorine dioxide and free radicals, avoiding excessive oxidation of chlorite to chlorate, thereby increasing the concentration of chlorine dioxide obtained. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments, and all described quantities are by weight. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] The sources and types of substances involved in this invention are not specifically limited. Exemplary examples include the following raw materials: activated carbon: product number: ST8573, which can be purchased from Jiangsu Zhongyuan Activated Carbon Co., Ltd.; sodium chlorite: purity ≥80%, molecular weight: 90.44; sodium hypochlorite: available chlorine ≥5.0%, molecular weight: 74.44; sodium chlorate: purity ≥50%, molecular weight: 106.44; potassium persulfate: purity 50%, molecular weight: 270.3; potassium permonosulfate: analytical grade, molecular weight: 307.38.

[0023] Example 1: Step 1: Preparation of sodium chlorite solution Sodium chlorite was mixed with deionized water and magnetically stirred for 20 minutes until completely dissolved, to prepare a sodium chlorite solution with a concentration of 16 g / L. Step 2: Prepare potassium persulfate powder Weigh out 24 mg of potassium persulfate powder under dry conditions; Step 3: Prepare a high-concentration chlorine dioxide solution In a 5 mL light-proof reactor, add 1 mL of sodium chlorite solution and 24 mg of potassium persulfate powder, shake the mixture thoroughly and react for 90 min to obtain a high-concentration chlorine dioxide solution.

[0024] Example 2: Step 1: Preparation of sodium chlorite solution Sodium chlorite was mixed with deionized water and magnetically stirred for 25 minutes until completely dissolved, to prepare a sodium chlorite solution with a concentration of 12 g / L. Step 2: Prepare potassium persulfate powder Weigh out 24 mg of potassium persulfate powder under dry conditions; Step 3: Prepare a high-concentration chlorine dioxide solution In a 5 mL light-proof reactor, add 1 mL of sodium chlorite solution and 24 mg of potassium persulfate powder, shake the mixture thoroughly and react for 90 min to obtain a high-concentration chlorine dioxide solution.

[0025] Example 3: Step 1: Preparation of sodium chlorite solution Sodium chlorite was mixed with deionized water and magnetically stirred for 30 minutes until completely dissolved, to prepare a sodium chlorite solution with a concentration of 18 g / L. Step 2: Prepare potassium persulfate powder Weigh 20 mg of potassium persulfate powder under dry conditions; Step 3: Prepare a high-concentration chlorine dioxide solution In a 5 mL light-proof reactor, add 1 mL of sodium chlorite solution and 24 mg of potassium persulfate powder, shake the mixture thoroughly and react for 90 min to obtain a high-concentration chlorine dioxide solution.

[0026] Example 4: Step 1: Preparation of sodium chlorite solution Sodium chlorite was mixed with deionized water and magnetically stirred for 30 minutes until completely dissolved, to prepare a sodium chlorite solution with a concentration of 20 g / L. Step 2: Prepare potassium persulfate powder Weigh out 28 mg of potassium persulfate powder under dry conditions; Step 3: Prepare a high-concentration chlorine dioxide solution In a 5 mL light-proof reactor, add 1 mL of sodium chlorite solution and 28 mg of potassium persulfate powder, shake the mixture thoroughly and react for 90 min to obtain a high-concentration chlorine dioxide solution.

[0027] Example 5: Step 1: Preparation of sodium chlorite solution Sodium chlorite was mixed with deionized water and magnetically stirred for 20 minutes until completely dissolved, to prepare a sodium chlorite solution with a concentration of 16 g / L. Step 2: Prepare activated carbon material loaded with S-potassium persulfate Dissolve 0.05 mol potassium thiosulfate and 0.05 mol ammonium persulfate in 100 mL of deionized water. After dissolution, immerse the activated carbon material at room temperature. Add ammonia to adjust the pH of the solution to 9, stir evenly, and let stand at room temperature for 24 h to obtain loaded activated carbon. Remove the supernatant, take out the loaded activated carbon, and wash it repeatedly with distilled water until the pH of the outflowing washing liquid is 7.2. Then, place it in an oven and vacuum dry at 80 °C for 6 h to obtain modified activated carbon. Modified activated carbon was pyrolyzed in a tube furnace at a temperature of 500℃ for 120 min at a heating rate of 10℃ / min under a nitrogen atmosphere to form a sulfur-loaded composite material. 50 mL of a 2.4 g / L potassium persulfate aqueous solution was sprayed onto the surface of the sulfur-loaded composite material and vacuum dried and cured at 20℃ for 12 h to obtain S-potassium persulfate-loaded activated carbon material. Step 3: Prepare a high-concentration chlorine dioxide solution In a 5 mL light-proof reactor, add 1 mL of sodium chlorite solution and 24 mg of activated carbon material loaded with S-potassium persulfate. Shake the mixture thoroughly and react for 90 min. Filter to obtain a high-concentration chlorine dioxide solution.

[0028] Comparative Example 1: The salt sodium chlorite was replaced with sodium chlorate, but the rest was the same as in Example 1; specifically: Step 1: Preparation of sodium chlorate solution Sodium chlorate was mixed with deionized water and magnetically stirred for 20 minutes until completely dissolved, to prepare a sodium chlorate solution with a concentration of 16 g / L. Step 2: Prepare potassium persulfate powder Weigh out 24 mg of potassium persulfate powder under dry conditions; Step 3: Prepare a high-concentration chlorine dioxide solution In a 5 mL light-protected reactor, add 1 mL of sodium chlorate solution and 24 mg of potassium persulfate powder, shake the mixture thoroughly and react for 90 min to obtain a high-concentration chlorine dioxide solution.

[0029] Comparative Example 2: The salt sodium chlorite was replaced with sodium hypochlorite, while the rest was the same as in Example 1; specifically: Step 1: Preparation of sodium hypochlorite solution Sodium hypochlorite was mixed with deionized water and magnetically stirred for 20 minutes until completely dissolved, to prepare a sodium hypochlorite solution with a concentration of 16 g / L. Step 2: Prepare potassium persulfate powder Weigh out 24 mg of potassium persulfate powder under dry conditions; Step 3: Prepare a high-concentration chlorine dioxide solution In a 5 mL light-proof reactor, add 1 mL of sodium hypochlorite solution and 24 mg of potassium persulfate powder, shake the mixture thoroughly and react for 90 min to obtain a high-concentration chlorine dioxide solution.

[0030] Comparative Example 3: The concentration of sodium hypochlorite solution was changed to 25 g / L, and potassium persulfate was changed to potassium permonosulfate; the rest was the same as in Example 1. Specifically: Step 1: Preparation of sodium chlorite solution Sodium chlorite was mixed with deionized water and magnetically stirred for 20 minutes until completely dissolved, to prepare a sodium chlorite solution with a concentration of 25 g / L. Step 2: Prepare potassium persulfate powder Weigh out 24 mg of potassium persulfate powder under dry conditions; Step 3: Prepare a high-concentration chlorine dioxide solution In a 5 mL light-proof reactor, 1 mL of sodium chlorite solution and 24 mg of potassium persulfate powder were added. The mixture was shaken thoroughly and reacted for 90 min to obtain a catalyst-free high-concentration chlorine dioxide solution.

[0031] Comparative Example 4: The concentration of the sodium hypochlorite solution was changed to 42 g / L, and the rest was the same as in Example 1; specifically: Step 1: Preparation of sodium chlorite solution Sodium chlorite was mixed with deionized water and magnetically stirred for 20 minutes until completely dissolved, to prepare a sodium chlorite solution with a concentration of 42 g / L. Step 2: Prepare potassium persulfate powder Weigh out 24 mg of potassium persulfate powder under dry conditions; Step 3: Prepare a high-concentration chlorine dioxide solution In a 5 mL light-proof reactor, 1 mL of sodium chlorite solution and 24 mg of potassium persulfate powder were added. The mixture was shaken thoroughly and reacted for 90 min to obtain a catalyst-free high-concentration chlorine dioxide solution.

[0032] Comparative Example 5: The sodium chlorite solution was removed, and the rest was the same as in Example 1; specifically: In a 5 mL light-protected reactor, 24 mg of potassium persulfate powder was added and reacted for 90 min to obtain the sample.

[0033] Comparative Example 6: The potassium persulfate powder was removed, and the rest was the same as in Example 1; specifically: Step 1: Preparation of sodium chlorite solution Sodium chlorite was mixed with deionized water and magnetically stirred for 20 minutes until completely dissolved, to prepare a sodium chlorite solution with a concentration of 16 g / L. Step 2: Preparation of high-concentration chlorine dioxide solution In a 5 mL light-protected reactor, 1 mL of sodium chlorite solution was added and the reaction was allowed to proceed for 90 min to obtain a high-concentration chlorine dioxide solution.

[0034] Comparative Example 7: The amount of potassium persulfate powder was changed to 50 mg, and the rest was the same as in Example 1; specifically: Step 1: Preparation of sodium chlorite solution Sodium chlorite was mixed with deionized water and magnetically stirred for 20 minutes until completely dissolved, to prepare a sodium chlorite solution with a concentration of 16 g / L. Step 2: Prepare potassium persulfate powder Weigh out 50 mg of potassium persulfate powder under dry conditions; Step 3: Prepare a high-concentration chlorine dioxide solution In a 5 mL light-protected reactor, add 1 mL of sodium chlorite solution and 50 mg of potassium persulfate powder, shake the mixture thoroughly and react for 90 min to obtain a high-concentration chlorine dioxide solution.

[0035] Comparative Example 8: The amount of potassium persulfate powder was changed to 55 mg, and the rest was the same as in Example 1; specifically: Step 1: Preparation of sodium chlorite solution Sodium chlorite was mixed with deionized water and magnetically stirred for 20 minutes until completely dissolved, to prepare a sodium chlorite solution with a concentration of 16 g / L. Step 2: Prepare potassium persulfate powder Weigh out 55 mg of potassium persulfate powder under dry conditions; Step 3: Prepare a high-concentration chlorine dioxide solution In a 5 mL light-proof reactor, add 1 mL of sodium chlorite solution and 55 mg of potassium persulfate powder, shake the mixture thoroughly and react for 90 min to obtain a high-concentration chlorine dioxide solution.

[0036] Comparative Example 9: The amount of potassium persulfate powder was changed to 60 mg, and the rest was the same as in Example 1; specifically: Step 1: Preparation of sodium chlorite solution Sodium chlorite was mixed with deionized water and magnetically stirred for 20 minutes until completely dissolved, to prepare a sodium chlorite solution with a concentration of 16 g / L. Step 2: Prepare potassium persulfate powder Weigh out 60 mg of potassium persulfate powder under dry conditions; Step 3: Prepare a high-concentration chlorine dioxide solution In a 5 mL light-protected reactor, add 1 mL of sodium chlorite solution and 60 mg of potassium persulfate powder, shake the mixture thoroughly and react for 90 min to obtain a high-concentration chlorine dioxide solution.

[0037] Comparative Example 10: The amount of ammonium persulfate was changed to 0.5 mol, and the rest was the same as in Example 5. Specifically: Step 1: Preparation of sodium chlorite solution Sodium chlorite was mixed with deionized water and magnetically stirred for 20 minutes until completely dissolved, to prepare a sodium chlorite solution with a concentration of 16 g / L. Step 2: Prepare activated carbon material loaded with S-potassium persulfate 0.05 mol potassium thiosulfate and 0.5 mol ammonium persulfate were dissolved in 100 mL of deionized water. After dissolution, activated carbon material was immersed in the solution at room temperature. Ammonia water was added to adjust the pH of the solution to 9. After stirring evenly, the solution was allowed to stand at room temperature for 24 h to obtain loaded activated carbon. The supernatant was removed, and the loaded activated carbon was taken out and washed repeatedly with distilled water until the pH of the outflowing washing liquid was 7.2. The carbon was then placed in an oven and vacuum dried at 80 °C for 6 h to obtain modified activated carbon. Modified activated carbon was pyrolyzed in a tube furnace at a temperature of 500℃ for 120 min at a heating rate of 10℃ / min under a nitrogen atmosphere to form a sulfur-loaded composite material. 50 mL of a 2.4 g / L potassium persulfate aqueous solution was sprayed onto the surface of the sulfur-loaded composite material and vacuum dried and cured at 20℃ for 12 h to obtain S-potassium persulfate-loaded activated carbon material. Step 3: Prepare a high-concentration chlorine dioxide solution In a 5 mL light-proof reactor, add 1 mL of sodium chlorite solution and 24 mg of activated carbon material loaded with S-potassium persulfate. Shake the mixture thoroughly and react for 90 min. Filter to obtain a high-concentration chlorine dioxide solution.

[0038] experiment: The chlorine dioxide disinfectant solutions prepared in Examples 1–5 and Comparative Examples 1–10 were tested using a Hach spectrophotometer (DR6000) and the DPD method (powder packet method). 0.01 mL of a catalyst-free high-concentration chlorine dioxide solution was prepared and diluted to 10 mL as a sample. The test values ​​were then read according to the detection procedure. The actual experimental results were calculated based on the dilution factor; therefore, the calculated ClO2 concentration may exceed the water saturation concentration of ClO2 (3 g / L). The specific test procedure is as follows: Determine the chlorine dioxide detection procedure and install the adapter; pour the sample into the cuvette until the liquid surface is aligned, and measure the blank value; take 10 mL of sample into the second cuvette, ensuring the liquid surface is aligned, measure the sample, wipe the first cuvette and place it in the adapter as the blank value; after zeroing the instrument, add four drops of glycine reagent to the second cuvette containing the sample and shake well; add one packet of DPD free chlorine powder to the second cuvette containing the sample, shake well, let the cuvette stand for 30 seconds to allow undissolved powder to settle, and then immediately proceed with the detection procedure; read the chlorine dioxide concentration within 1 minute after adding the DPD powder packet, and express the result as the concentration of ClO2 (g / L); the obtained test results are shown in Table 1 below: Conclusion: As shown in the table, under the same conditions, the concentration of chlorine dioxide prepared in Examples 1–4 is higher than that in Comparative Examples 1–9. Under 90 min light-protected reaction conditions, the yield of chlorine dioxide in Example 1 reached 3.60 g / L to 4.02 g / L. In Comparative Examples 1, 2, 5, and 6, the yield of chlorine dioxide was 0 when 1 mL of sodium chlorite solution was mixed with 24 mg of potassium persulfate. In Comparative Examples 3 and 4, the yields of chlorine dioxide were 2.62 g / L and 3.67 g / L, respectively, when 1 mL of sodium chlorite solution was mixed with potassium persulfate, both lower than that in Example 1 at the same concentration. This indicates that the precursors sodium chlorite and persulfate selected in this invention are the optimal reactants for the formation of chlorine dioxide. In Comparative Examples 7, 8, and 9, the yield did not increase even with a larger amount of potassium persulfate, further demonstrating that the optimal ratio was used in Examples 1–4.

[0039] In Example 3, the reduced amount of potassium persulfate resulted in a lower chlorine dioxide yield after the mixed reaction compared to Example 1. Conversely, in Example 4, the increased amount of potassium persulfate led to a higher chlorine dioxide yield than in Example 1; this indicates that variations in potassium persulfate concentration do indeed affect chlorine dioxide production. However, analysis showed that exceeding 24 g / L reduced cost-effectiveness: each 1 g / L increase improved the yield by ≤0.5%; and each 1 g / L increase led to an 8.3% increase in reagent cost. Therefore, the optimal concentration of potassium persulfate is 24 mg.

[0040] Example 5, which used activated carbon material loaded with S-potassium persulfate, showed superior overall performance because S acts as a reaction initiator, further promoting the reaction. In contrast, increasing the amount of ammonium persulfate in the reactants in the comparative example did not increase the resulting chlorine dioxide concentration, indicating that the current ratio is superior. Overall, the embodiments of this invention demonstrate that a high chlorine dioxide yield was achieved through the mixed reaction of selected precursors, and the optimal reaction ratio was determined. The low cost of sodium hypochlorite solution and potassium persulfate makes this invention more cost-effective than existing chlorine dioxide preparation technologies.

[0041] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A process for the production of high concentration chlorine dioxide solution without catalyst, characterized in that: The method comprises the following steps: Step 1: mixing sodium chlorite powder with deionized water and stirring to obtain a sodium chlorite solution; Step 2: weighing a certain amount of potassium persulfate to obtain potassium persulfate; Step 3: mixing the sodium chlorite solution with the potassium persulfate and reacting to obtain a high-concentration chlorine dioxide solution.

2. The method of claim 1, wherein: In step 1, the concentration of sodium chlorite is 8 g / L-28 g / L.

3. The method of claim 1, wherein: In step 2, the purity of potassium persulfate is 50%-99%.

4. The method of producing a high concentration chlorine dioxide solution without a catalyst according to claim 1, characterized by: The potassium persulfate is potassium persulfate powder or a potassium persulfate solution, and the concentration of the potassium persulfate solution is 14 g / L-44 g / L.

5. The method of claim 4, wherein the method is free of a catalyst. The mass-volume ratio of the potassium persulfate powder to the sodium chlorite solution is (20-28): 1 g / L.

6. The method of producing a high concentration chlorine dioxide solution without a catalyst according to claim 1, characterized by: The step three is reacted under light-proof conditions.

7. The method of producing a high concentration chlorine dioxide solution without a catalyst according to claim 1, characterized by: In step three, the reaction time is controlled to be 30-240 min.

8. The method of producing a high concentration chlorine dioxide solution without a catalyst according to claim 1, characterized by: The molar ratio of potassium persulfate to sodium chlorite is 1: (1.9-3.88).

9. The method of making high concentration chlorine dioxide solutions without a catalyst according to claim 1, characterized in that: The potassium persulfate can also be an activated carbon material loaded with S-potassium persulfate, and the preparation method comprises the following steps: dissolving potassium thiosulfate and ammonium persulfate in deionized water, immersing the activated carbon at room temperature, adding ammonia water to adjust the pH of the solution to 9, stirring uniformly, and then standing at room temperature to obtain a loaded activated carbon; washing, vacuum drying, and obtaining a modified activated carbon; pyrolyzing the modified activated carbon under a nitrogen atmosphere; forming a sulfur-loaded composite material; spraying a misty potassium persulfate aqueous solution onto the surface of the sulfur-loaded composite material, vacuum drying and solidifying for 12 h to obtain an activated carbon material loaded with S-potassium persulfate.

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