Preparation method of solution for treating phosphorus-containing wastewater and sewage treatment method

Abstract

The invention relates to a preparation method of a solution for treating phosphorus-containing wastewater and a sewage treatment method, and the preparation method comprises the following steps: providing raw materials including calcium oxide, sodium sulfate, potassium pyrophosphate, sodium nitrate, sodium cellulose and water; dissolving sodium sulfate, potassium pyrophosphate and sodium cellulose in water to obtain a first semi-finished product solution, and dissolving calcium oxide and sodium nitrate in water to obtain a second semi-finished product solution; aging the first semi-finished product solution and the second semi-finished product solution; mixing the aged first semi-finished product solution with the aged second semi-finished product solution to obtain a third semi-finished product solution; aging the third semi-finished product solution; and diluting the aged third semi-finished product solution to obtain the solution for treating the phosphorus-containing sewage. On the premise that a stirring device is not added, a uniform and stable suspension solution can be formed, the energy consumption and the cost are reduced, the adding amount of lime can be accurately controlled, and the process management difficulty is reduced.

Description

Technical Field

[0001] This application relates to the field of wastewater treatment, and more specifically to a method for preparing a solution for treating phosphorus-containing wastewater and a sewage treatment method. Background Art

[0002] During industrial production, wastewater containing various pollutants will inevitably be generated. Among them, the harm of phosphorus-containing wastewater is relatively serious.

[0003] In the related art, adding lime alone is adopted to treat phosphorus-containing wastewater. However, when using lime, since lime milk is prone to precipitation, it is necessary to increase a stirring device to make the generated calcium hydroxide not precipitate in the form of extremely small particles. However, increasing the stirring device increases energy consumption, equipment maintenance and labor costs, and it is difficult to accurately control the dosage of lime, which brings great difficulties to the process management. Summary of the Invention

[0004] A series of simplified concepts are introduced in the Summary of the Invention section, which will be further elaborated in the Detailed Description section. The Summary of the Invention section of this application does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the protection scope of the claimed technical solution.

[0005] In view of the existing problems, on the one hand, this application provides a method for preparing a solution for treating phosphorus-containing sewage, and the preparation method includes:

[0006] Providing raw materials, the raw materials including calcium oxide, sodium sulfate, potassium pyrophosphate, sodium nitrate, sodium carboxymethyl cellulose and water;

[0007] Dissolving the sodium sulfate, the potassium pyrophosphate and the sodium carboxymethyl cellulose in water to obtain a first semi-finished solution, and dissolving the calcium oxide and the sodium nitrate in water to obtain a second semi-finished solution;

[0008] Aging the first semi-finished solution and the second semi-finished solution;

[0009] Mixing the aged first semi-finished solution and the second semi-finished solution to obtain a third semi-finished solution;

[0010] Aging the third semi-finished solution;

[0011] Diluting the aged third semi-finished solution to obtain the solution for treating phosphorus-containing sewage.

[0012] In some embodiments of the present application, in the raw materials, the mass ratio of calcium oxide, sodium sulfate, potassium pyrophosphate, sodium nitrate, and sodium carboxymethyl cellulose is: 40% - 50%: 10% - 20%: 10% - 20%: 1% - 10%: 1% - 3%.

[0013] In some embodiments of the present application, the raw materials further include calcium chloride, and the calcium chloride is dissolved in the second semi-finished product solution.

[0014] In some embodiments of the present application, in the raw materials, the mass ratio of calcium oxide, sodium sulfate, calcium chloride, potassium pyrophosphate, sodium nitrate, and sodium carboxymethyl cellulose is 40% - 50%: 20% - 40%: 10% - 20%: 1% - 20%: 1% - 5%: 1% - 3%.

[0015] In some embodiments of the present application,

[0016] The aging time of the first semi-finished product solution and the second semi-finished product solution is 12 hours to 48 hours;

[0017] The aging time of the third semi-finished product solution is 20 hours to 36 hours.

[0018] In some embodiments of the present application, when mixing the aged first semi-finished product solution and the second semi-finished product solution, the flow rates of the first semi-finished product solution and the second semi-finished product solution are controlled not to be greater than the set flow rate.

[0019] According to another aspect of the present application, a sewage treatment method is provided, and the sewage treatment method includes:

[0020] Using the solution for treating phosphorus-containing sewage obtained by the preparation method described in any one of the above to perform sewage treatment.

[0021] The preparation method of the solution for treating phosphorus-containing wastewater and the sewage treatment method of the present application can, without adding a stirring device, make the generated calcium hydroxide evenly distributed in the solution in extremely small particles without precipitation, prepare a uniform and stable suspension solution, and the prepared solution can efficiently remove phosphorus and other impurity components in the wastewater. Moreover, the raw materials of the solution are simple and easy to obtain, and the price is low, thereby reducing energy consumption and cost, and can accurately control the dosage of lime, reducing the difficulty of process management. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other objects, features, and advantages of the present application will become more apparent by describing the embodiments of the present application in more detail with reference to the accompanying drawings. The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. They are used together with the embodiments of the present application to explain the present application and do not constitute a limitation to the present application. In the drawings, the same reference numerals generally represent the same components or steps.

[0023] Figure 1 The flowchart of the preparation method of the solution for treating phosphorus-containing sewage in a specific embodiment of the present application is shown.

[0024] Figure 2 The flow block diagram of the preparation method of the solution for treating phosphorus-containing sewage in a specific embodiment of the present application is shown.

[0025] Figure 3 The flow block diagram of the preparation method of the solution for treating phosphorus-containing sewage in another specific embodiment of the present application is shown. Specific Embodiment

[0026] In the following description, a large number of specific details are given to provide a more thorough understanding of the present application. However, it is obvious to those skilled in the art that the present application can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present application, some well-known technical features in the art are not described.

[0027] It should be understood that the present application can be implemented in different forms and should not be construed as limited to the embodiments presented herein. On the contrary, providing these embodiments will make the disclosure thorough and complete and will fully convey the scope of the present application to those skilled in the art. In the drawings, for clarity, the dimensions and relative dimensions of layers and regions may be exaggerated. The same reference numerals represent the same elements throughout.

[0028] In the related art, a method of separately adding lime or adding calcium chloride is adopted to treat phosphorus-containing wastewater.

[0029] Among them, the method of separately adding lime has at least the following deficiencies: Since lime milk is prone to precipitation, a stirring device needs to be added to make the generated calcium hydroxide in extremely small particles without precipitation. However, adding a stirring device increases energy consumption, increases equipment maintenance and labor costs, and it is difficult to accurately control the dosage of lime, bringing great difficulties to the process management;

[0030] The method of adding calcium chloride has at least the following deficiencies: Calcium chloride needs to be used in combination with sodium hydroxide, and the price is relatively high, increasing the cost of wastewater treatment.

[0031] To thoroughly understand this application, detailed steps and structures will be presented in the following description to illustrate the technical solutions proposed in this application. The preferred embodiments of this application are described in detail below. However, in addition to these detailed descriptions, this application may have other implementation manners.

[0032] Embodiment 1

[0033] According to one aspect of this application, a preparation method for a solution for treating phosphorus-containing sewage is provided. As Figures 1 to 3 shown, the preparation method includes the following steps:

[0034] Step S1: Provide raw materials, including calcium oxide, sodium sulfate, potassium pyrophosphate, sodium nitrate, sodium carboxymethyl cellulose, and water;

[0035] Step S2: Dissolve sodium sulfate, potassium pyrophosphate, and sodium carboxymethyl cellulose in water to obtain a first semi-finished product solution, and dissolve calcium oxide and sodium nitrate in water to obtain a second semi-finished product solution;

[0036] Step S3: Age the first semi-finished product solution and the second semi-finished product solution;

[0037] Step S4: Mix the aged first semi-finished product solution and the second semi-finished product solution to obtain a third semi-finished product solution;

[0038] Step S5: Age the third semi-finished product solution;

[0039] Step S6: Dilute the aged third semi-finished product solution to obtain a solution for treating phosphorus-containing sewage.

[0040] Based on this, the preparation method for the solution for treating phosphorus-containing sewage in this embodiment can, without adding a stirring device, make the generated calcium hydroxide evenly distributed in the solution in extremely small particles without precipitation, and obtain a uniform and stable suspension solution. Moreover, the prepared solution can efficiently remove phosphorus and other impurity components in the wastewater, and the raw materials of the solution are simple to obtain and low in price, thereby reducing energy consumption and cost, and can accurately control the dosage of lime, reducing the difficulty of process management.

[0041] Among them, in the raw materials provided in step S1, calcium oxide (i.e., lime) can react with water to generate calcium hydroxide. Calcium hydroxide can not only generate calcium ions to react with phosphate ions in the phosphorus-containing wastewater to form calcium phosphate precipitation, but also increase the pH value of the phosphorus-containing wastewater. A higher pH value can make phosphate ions more likely to combine with calcium ions to form insoluble calcium phosphate precipitation, thereby achieving the removal of phosphorus.

[0042] Sodium cellulose is a high molecular polymer that can not only significantly increase the viscosity of the solution, prevent the calcium hydroxide particles in the solution from settling, and make the calcium hydroxide particles suspended in the solution to form a suspension solution, but also form a hydration layer by adsorbing on the surface of the calcium hydroxide particles, reduce the collision and aggregation between the calcium hydroxide particles, and maintain the dispersion stability of the suspension solution.

[0043] As a strong electrolyte, sodium sulfate can not only increase the ionic strength in the solution, promote the aggregation of calcium hydroxide colloid particles generated by the reaction of calcium oxide and water, form stable suspended particles in the solution, but also adjust the pH value of the solution to make it closer to the appropriate reaction alkalinity range, which is beneficial to the subsequent treatment of phosphorus-containing wastewater. It can also promote the flocculation process by enhancing the ionic strength of the solution, make the calcium phosphate and other precipitates generated in the process of treating phosphorus-containing wastewater easier to aggregate into larger particles, accelerate the precipitation separation, and improve the phosphorus removal efficiency. Moreover, in the process of treating phosphorus-containing wastewater, the sulfate ions ionized from sodium sulfate can react with some metal ion impurities in the wastewater to form insoluble sulfate precipitates, cooperate with the reaction of calcium ions and phosphorus, help remove more impurities in the wastewater, and make the water quality more comprehensively purified.

[0044] Potassium pyrophosphate can inhibit the excessive aggregation of calcium hydroxide particles, make substances such as calcium hydroxide particles better dispersed in the suspension, maintain the uniform dispersion of the suspension, and improve the reaction efficiency in the process of treating wastewater. Moreover, potassium pyrophosphate has a stable pH buffering capacity, can control the pH value of the suspension within a certain range, prevent the pH value from fluctuating greatly due to reactions and other factors during the treatment process, provide a stable alkaline environment for the calcium hydroxide dephosphorization reaction, and ensure the stability of the dephosphorization effect. In addition, potassium pyrophosphate can form stable soluble complexes with polyvalent metal ions (such as Fe 3+ , Al 3+ , Ca 2+ , Mg 2+ etc.) in the wastewater to prevent these metal ions from combining with phosphates prematurely to form insoluble precipitates, thereby optimizing the subsequent precipitation process of phosphates.

[0045] As an oxidant, sodium nitrate can promote the oxidation and decomposition of organic phosphorus compounds (such as pesticides and detergent residues) in the wastewater, convert them into inorganic phosphates (PO4 3- ), which is convenient for subsequent precipitation removal. Moreover, sodium nitrate can inhibit the activity of microorganisms such as sulfate-reducing bacteria, avoid the generation of harmful gases such as hydrogen sulfide in the wastewater. In addition, sodium nitrate can also provide sodium ions to adjust the ionic strength of the suspension, affect the activity of ions in the solution and the balance of chemical reactions, optimize the reaction conditions, and promote the reaction of calcium hydroxide and phosphate ions to proceed in the direction of forming precipitates, thereby improving the phosphorus removal rate.

[0046] In some embodiments, the proportions of calcium oxide, sodium sulfate, potassium pyrophosphate, sodium nitrate, sodium carboxymethyl cellulose and water in the raw materials can be formulated according to the actual situation, and no limitation is imposed thereon. Exemplarily, as Figure 2 shown, in the raw materials, the mass ratio of calcium oxide, sodium sulfate, potassium pyrophosphate, sodium nitrate and sodium carboxymethyl cellulose is: 40% to 50%: 10% to 20%: 10% to 20%: 1% to 10%: 1% to 3%, and water can be added appropriately according to the concentration of the required solution.

[0047] In some embodiments, the raw materials may further include calcium chloride, and the calcium chloride is dissolved in the second semi-finished product solution. Among them, calcium chloride can provide additional calcium ions and promote the precipitation of phosphates when treating phosphorus-containing wastewater. The reason is that although calcium hydroxide generated by calcium oxide and water can produce calcium ions, calcium chloride has high solubility and can quickly release calcium ions, so as to form calcium phosphate precipitation with phosphates and strengthen the phosphorus removal effect. Especially when the pH of the phosphorus-containing wastewater is low, calcium chloride can make up for the slow dissolution of calcium hydroxide.

[0048] In some embodiments, the proportions of calcium oxide, sodium sulfate, calcium chloride, potassium pyrophosphate, sodium nitrate, sodium carboxymethyl cellulose and water in the raw materials can be formulated according to the actual situation, and no limitation is imposed thereon. Exemplarily, as Figure 3 shown, in the raw materials, the mass ratio of calcium oxide, sodium sulfate, calcium chloride, potassium pyrophosphate, sodium nitrate and sodium carboxymethyl cellulose is 40% to 50%: 20% to 40%: 10% to 20%: 1% to 20%: 1% to 5%: 1% to 3%, and water can be added appropriately according to the concentration of the required solution.

[0049] In step S2, instead of dissolving raw materials such as calcium oxide, sodium sulfate, potassium pyrophosphate, sodium nitrate, and sodium carboxymethyl cellulose in water together, sodium sulfate, potassium pyrophosphate, and sodium carboxymethyl cellulose are respectively dissolved in water to obtain a first semi-finished product solution, and calcium oxide and sodium nitrate are dissolved in water to obtain a second semi-finished product solution, and then the first semi-finished product solution and the second semi-finished product solution are mixed in subsequent steps. The advantage of the above method is that the second semi-finished product solution obtained by dissolving calcium oxide and sodium nitrate in water is a concentrated solution with a high calcium ion content, and the first semi-finished product solution obtained by dissolving sodium sulfate, potassium pyrophosphate, and sodium carboxymethyl cellulose in water is used as an auxiliary solution for uniformly dispersing and suspending calcium hydroxide particles in the solution. Separately preparing the first semi-finished product solution and the second semi-finished product solution and then mixing them can obtain a more uniform and stable suspension solution compared with the method of dissolving raw materials such as calcium oxide, sodium sulfate, potassium pyrophosphate, sodium nitrate, and sodium carboxymethyl cellulose in water together.

[0050] It should be noted that before mixing the first semi-finished product solution and the second semi-finished product solution, the first semi-finished product solution and the second semi-finished product solution can be aged in step S3. For the first semi-finished product solution, aging can allow more sufficient time for chemical reactions of sodium sulfate, potassium pyrophosphate, and sodium carboxymethyl cellulose in water, making reactions such as dissolution and hydrolysis more complete and the system reach a more stable chemical equilibrium state. For the second semi-finished product solution, aging can optimize the particle size distribution of calcium hydroxide particles formed by the reaction of calcium oxide with water, making the particle size distribution of calcium hydroxide particles more uniform. Moreover, aging can also promote the crystal form transformation of calcium hydroxide particles, converting the initially unstable-structured or metastable crystal form of calcium hydroxide particles into a more stable and compliant crystal form. Additionally, the aging process also helps to improve the crystal structure, reduce crystal defects, and make the arrangement more regular.

[0051] Among them, the aging time of the first semi-finished product solution and the second semi-finished product solution can be set according to actual situations and is not limited herein. Exemplarily, as Figure 2 or Figure 3 shown, the aging time of the first semi-finished product solution and the second semi-finished product solution is 12 hours to 48 hours. For example, the aging time can be 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, 25 hours, 26 hours, 27 hours, 28 hours, 29 hours, 30 hours, 31 hours, 32 hours, 33 hours, 34 hours, 35 hours, 36 hours, 37 hours, 38 hours, 39 hours, 40 hours, 41 hours, 42 hours, 43 hours, 44 hours, 45 hours, 46 hours, 47 hours, 48 hours, etc.

[0052] After that, in step S4, the aged first semi-finished product solution and the second semi-finished product solution are mixed to obtain a third semi-finished product solution. It should be noted that when mixing the aged first semi-finished product solution and the second semi-finished product solution, to avoid precipitation of calcium hydroxide particles, the flow rates of the first semi-finished product solution and the second semi-finished product solution during the mixing process can be controlled. Exemplarily, the flow rates of the first semi-finished product solution and the second semi-finished product solution are controlled not to exceed the set flow rate to prevent calcium hydroxide particles from precipitating after mixing and improve the dispersion uniformity of calcium hydroxide particles in the obtained third semi-finished product solution.

[0053] Similarly, the third semi-finished product solution can be aged in step S5. Aging helps calcium hydroxide particles disperse more uniformly in the solution, avoiding situations of too high or too low local concentration, thereby improving the quality and stability of the final product.

[0054] Among them, the aging time of the third semi-finished product solution can be set according to actual conditions, and no limitation is imposed thereon. Exemplarily, as Figure 2 or Figure 3 shown, the aging time of the first semi-finished product solution and the second semi-finished product solution is 20 hours to 36 hours. For example, the aging time is 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, 25 hours, 26 hours, 27 hours, 28 hours, 29 hours, 30 hours, 31 hours, 32 hours, 33 hours, 34 hours, 35 hours, 36 hours, etc.

[0055] It should be noted that the above process has essentially completed the preparation process of the solution for treating phosphorus-containing sewage in this embodiment. However, when the solution for treating phosphorus-containing sewage prepared above is actually used to treat phosphorus-containing sewage, different concentrations are required for different treatment situations. Therefore, the third semi-finished product solution can also be diluted with water according to actual usage in step S6 to obtain the actual required concentration to meet the actual on-site treatment situation.

[0056] In some embodiments, the solution for treating phosphorus-containing wastewater in this embodiment can be applied to industries such as steel, electronics, chemical engineering, environmental protection, and semiconductors, and no limitation is imposed thereon. For example, the solution for treating phosphorus-containing wastewater in this embodiment can be used in urban sewage treatment plants, where it can neutralize acidic wastewater in the primary sedimentation tank, promote the solid-liquid separation of sludge, and remove phosphorus. Also, for example, the solution for treating phosphorus-containing wastewater in this embodiment can be applied to industrial wastewater treatment, which is suitable for the treatment processes of organic wastewater, acidic wastewater, and phosphorus-containing wastewater, and can effectively reduce the pollutant content of the wastewater.

[0057] Compared with the phosphorus removal methods in the related art, the solution for treating phosphorus-containing wastewater obtained by the preparation method of this embodiment has at least the following advantages:

[0058] Efficiently neutralize sewage: In sewage treatment, calcium hydroxide in the solution for treating phosphorus-containing wastewater in this embodiment can quickly neutralize acidic wastewater and neutralize it to neutral, thereby reducing environmental pollution;

[0059] Promote the solid-liquid separation of sludge: Calcium hydroxide in the solution for treating phosphorus-containing wastewater in this embodiment can quickly coagulate sludge particles and separate them from the liquid phase, thereby improving the solid-liquid separation efficiency and reducing energy consumption;

[0060] Effectively remove phosphorus: Calcium hydroxide in the solution for treating phosphorus-containing wastewater in this embodiment can react with phosphate to form calcium phosphate precipitate, effectively removing phosphorus in the sewage and reducing phosphorus pollution in the environment;

[0061] The raw materials are simple and easy to obtain, the price is low, the effect is remarkable, and it is easy to promote.

[0062] Example 2

[0063] A solution for treating phosphorus-containing sewage was prepared according to the preparation method in Example 1. The specific preparation process is as follows:

[0064] First, raw materials were provided. The raw materials included calcium oxide, sodium sulfate, potassium pyrophosphate, sodium nitrate, sodium carboxymethyl cellulose, and water. Among them, the mass ratio of calcium oxide, sodium sulfate, potassium pyrophosphate, sodium nitrate, and sodium carboxymethyl cellulose was 50%:20%:20%:7%:3%, and the amount of water used was appropriate according to the actual situation.

[0065] After that, sodium sulfate, potassium pyrophosphate, and sodium carboxymethyl cellulose were dissolved in water to obtain a first semi-finished product solution, and calcium oxide and sodium nitrate were dissolved in water to obtain a second semi-finished product solution.

[0066] After that, the first semi-finished product solution and the second semi-finished product solution were aged for 20 hours.

[0067] After that, the aged first semi-finished product solution and the second semi-finished product solution were mixed to obtain a third semi-finished product solution. Among them, during the mixing process, the flow rates of the first semi-finished product solution and the second semi-finished product solution were controlled not to be greater than the set flow rate, and they were fully stirred and mixed evenly.

[0068] After that, the third semi-finished product solution was aged for 24 hours.

[0069] After that, the aged third semi-finished product solution was diluted with water to a concentration of 50% to obtain a solution for treating phosphorus-containing sewage.

[0070] For the solution for treating phosphorus-containing sewage prepared in this example, after standing for two weeks, the solute in the solution was still in a uniform distribution state, and the solution did not show stratification or any precipitation, having excellent distribution uniformity and stability.

[0071] Example 3

[0072] A solution for treating phosphorus-containing sewage was prepared according to the preparation method in Example 1. The specific preparation process is as follows:

[0073] First, raw materials were provided. The raw materials included calcium oxide, calcium chloride, sodium sulfate, potassium pyrophosphate, sodium nitrate, sodium carboxymethyl cellulose, and water. Among them, the mass ratio of calcium oxide, calcium chloride, sodium sulfate, potassium pyrophosphate, sodium nitrate, and sodium carboxymethyl cellulose was 50%:10%:22%:10%:5%:3%, and the amount of water used was appropriate according to the actual situation.

[0074] After that, sodium sulfate, potassium pyrophosphate, and sodium carboxymethyl cellulose were dissolved in water to obtain a first semi-finished product solution, and calcium oxide and sodium nitrate were dissolved in water to obtain a second semi-finished product solution.

[0075] After that, the first semi-finished product solution and the second semi-finished product solution are aged for 20 hours.

[0076] After that, the aged first semi-finished product solution and the second semi-finished product solution are mixed to obtain a third semi-finished product solution. Among them, during the mixing process, the flow rates of the first semi-finished product solution and the second semi-finished product solution are controlled not to be greater than the set flow rate, and they are fully stirred evenly.

[0077] After that, the third semi-finished product solution is aged for 24 hours.

[0078] After that, the aged third semi-finished product solution is diluted with water to a concentration of 50% to obtain a solution for treating phosphorus-containing sewage.

[0079] For the solution for treating phosphorus-containing sewage prepared in this embodiment, after standing for two weeks, the solute in the solution is still in a uniform distribution state, and the solution does not show stratification and any precipitation, and has excellent distribution uniformity and stability.

[0080] Example 4

[0081] According to another aspect of the present application, a sewage treatment method is provided, including: using the solution for treating phosphorus-containing sewage obtained by the preparation method to treat sewage.

[0082] Among them, the preparation method can be implemented as the preparation method of the solution for treating phosphorus-containing sewage in the above text, and reference can be made to the introduction in the above text, which will not be elaborated here.

[0083] Based on the above description, the preparation method and the sewage treatment method of the solution for treating phosphorus-containing wastewater according to the embodiments of the present application can, without adding a stirring device, make the generated calcium hydroxide evenly distributed in the solution in extremely small particles without generating precipitation, prepare a uniform and stable suspension solution, and the prepared solution can efficiently remove phosphorus and other impurity components in the wastewater, and the raw materials of the solution are simple and easy to obtain and inexpensive, thereby reducing energy consumption and cost, and can accurately control the dosage of lime and reduce the process management difficulty.

[0084] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely exemplary and are not intended to limit the scope of the present application thereto. Those of ordinary skill in the art can make various changes and modifications therein without departing from the scope and spirit of the present application. All such changes and modifications are intended to be included within the scope of the present application as claimed by the appended claims.

[0085] Similarly, it should be understood that, for the purpose of streamlining the present application and assisting in understanding one or more of the various aspects of the application, in the description of the exemplary embodiments of the present application, the various features of the present application are sometimes grouped together into a single embodiment, figure, or description thereof. However, the methods of the present application should not be construed as reflecting an intention that the claimed present application requires more features than are expressly recited in each claim. Rather, as reflected by the corresponding claims, the point of the application is that the corresponding technical problems can be solved with features less than all the features of a single disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into the detailed description, where each claim itself serves as a separate embodiment of the present application.

[0086] In addition, those skilled in the art will appreciate that, although some of the embodiments described herein include certain features included in other embodiments but not others, combinations of features of different embodiments are meant to be within the scope of the present application and form different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.

[0087] It should be noted that the above embodiments illustrate rather than limit the present application, and those skilled in the art can design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The use of the words first, second, and third, etc. does not denote any order. These words can be interpreted as names.

Claims

1. A method for preparing a solution for treating phosphorus-containing sewage, characterized in that, The preparation method includes: providing raw materials, which include calcium oxide, sodium sulfate, potassium pyrophosphate, sodium nitrate, sodium carboxymethyl cellulose, and water; dissolving the sodium sulfate, the potassium pyrophosphate, and the sodium carboxymethyl cellulose in water to obtain a first semi-finished product solution, and dissolving the calcium oxide and the sodium nitrate in water to obtain a second semi-finished product solution; aging the first semi-finished product solution and the second semi-finished product solution; mixing the aged first semi-finished product solution and the second semi-finished product solution to obtain a third semi-finished product solution; aging the third semi-finished product solution; diluting the aged third semi-finished product solution to obtain the solution for treating phosphorus-containing sewage.

2. The preparation method according to claim 1, characterized in that, In the raw materials, the mass ratio of the calcium oxide, sodium sulfate, potassium pyrophosphate, sodium nitrate, and sodium carboxymethyl cellulose is: 40% - 50%: 10% - 20%: 10% - 20%: 1% - 10%: 1% - 3%.

3. The preparation method according to claim 1, characterized in that The raw materials further include calcium chloride, and the calcium chloride is dissolved in the second semi-finished product solution.

4. The preparation method according to claim 3, characterized in that, In the raw materials, the mass ratio of the calcium oxide, sodium sulfate, calcium chloride, potassium pyrophosphate, sodium nitrate, and sodium carboxymethyl cellulose is 40% - 50%: 20% - 40%: 10% - 20%: 1% - 20%: 1% - 5%: 1% - 3%.

5. The preparation method according to claim 1, wherein the aging time for the first semi-finished product solution and the second semi-finished product solution is 12 hours to 48 hours; the aging time for the third semi-finished product solution is 20 hours to 36 hours.

6. The preparation method according to claim 1, characterized in that, When mixing the aged first semi-finished product solution and the second semi-finished product solution, control the flow rates of the first semi-finished product solution and the second semi-finished product solution to be not greater than the set flow rate.

7. A sewage treatment method, characterized in that, The sewage treatment method includes: using the solution for treating phosphorus-containing sewage obtained by the preparation method according to any one of claims 1 - 6 to conduct sewage treatment.

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